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2D geometric morphometric analysis casts doubt on the validity of large tanged points as cultural markers in the European Final Palaeolithic
DEFF Research Database (Denmark)
Serwatka, Kamil; Riede, Felix
directeurs, especially in northern Europe. The vast majority of these finds are from the surface or derive from less-than-secure contexts. Several recent papers have cast doubt on the validity of this artefact class as a taxonomically sensitive marker. Here, we further investigate this issue using 2D...
Can snag creation benefit a primary cavity nester: response to an experimental pulse in snag abundance
John Kilgo; Mark Vukovich
Thresholds in response by cavity-nesting bird populations to variations in the snag resource are poorly understood. In addition, limited information exists on the value of artificially created snags for cavity-nesting birds. Therefore, uncertainty exists in whether artificially created snags can yield a positive population response among snag-dependent birds. We used...
Snags - Spears and Didion Ranches [ds317
California Department of Resources — These data are the characteristics of the individual snags (standing dead trees) found at 15 sample points with three 0.05-ha circular plot habitat samples taken in...
DEFF Research Database (Denmark)
Bubandt, Nils Ole
Response to Hau Symposium on Bubandt, Nils. 2014. The empty seashell: Witchcraft and doubt on an Indonesian island. Ithaca, NY: Cornell University Press.......Response to Hau Symposium on Bubandt, Nils. 2014. The empty seashell: Witchcraft and doubt on an Indonesian island. Ithaca, NY: Cornell University Press....
A comparison of selected parametric and imputation methods for estimating snag density and snag quality attributes
Eskelson, Bianca N.I.; Hagar, Joan; Temesgen, Hailemariam
Snags (standing dead trees) are an essential structural component of forests. Because wildlife use of snags depends on size and decay stage, snag density estimation without any information about snag quality attributes is of little value for wildlife management decision makers. Little work has been done to develop models that allow multivariate estimation of snag density by snag quality class. Using climate, topography, Landsat TM data, stand age and forest type collected for 2356 forested Forest Inventory and Analysis plots in western Washington and western Oregon, we evaluated two multivariate techniques for their abilities to estimate density of snags by three decay classes. The density of live trees and snags in three decay classes (D1: recently dead, little decay; D2: decay, without top, some branches and bark missing; D3: extensive decay, missing bark and most branches) with diameter at breast height (DBH) ≥ 12.7 cm was estimated using a nonparametric random forest nearest neighbor imputation technique (RF) and a parametric two-stage model (QPORD), for which the number of trees per hectare was estimated with a Quasipoisson model in the first stage and the probability of belonging to a tree status class (live, D1, D2, D3) was estimated with an ordinal regression model in the second stage. The presence of large snags with DBH ≥ 50 cm was predicted using a logistic regression and RF imputation. Because of the more homogenous conditions on private forest lands, snag density by decay class was predicted with higher accuracies on private forest lands than on public lands, while presence of large snags was more accurately predicted on public lands, owing to the higher prevalence of large snags on public lands. RF outperformed the QPORD model in terms of percent accurate predictions, while QPORD provided smaller root mean square errors in predicting snag density by decay class. The logistic regression model achieved more accurate presence/absence classification
Woodpecker Excavation and Use of Cavities in Polystyrene Snags
Richard N. Conner; Daniel Saenz
We examined woodpecker excavation and use of artificial polystyrene snags in four forest types in eastern Texas for five years. Twenty-three of 47 artificial snags were used by Downy Woodpeckers (Picoides pubescens) for cavity excavation and subsequent nocturnal roosting; they did not use the artificial snags for nesting. Although six ather species of woodpeckers...
Segregation during cleavage in the mammalian embryo? A critical comparison of whole-mount/CLSM and section immunohistochemistry casts doubts on segregation of axis-relevant leptin domains in the rabbit.
Littwin, T; Denker, H-W
Segregation of certain cytoplasmic molecules during cleavage and blastocyst formation that was previously reported to occur in the human and the mouse (Antczak and Van Blerkom Mol Hum Reprod 3:1067-1086, 1997; Antczak and Van Blerkom Hum Reprod 14:429-447, 1999) has been reinvestigated in the rabbit model. Additional methodology was used and two approaches were compared: (1) whole-mount immunohistochemistry followed by confocal laser scanning microscopy (WM-IHC/CLSM) versus (2) IHC performed on histological sections of resin-embedded material (S-IHC). This study concentrates on leptin and cytoskeletal proteins (actin and cytokeratins). With S-IHC, leptin was localized predominantly on the surface of blastomeres which is facing the perivitelline space, and in the extracellular embryonic coats, without any polar asymmetry being detectable along (presumptive) embryonic axes. A polar distribution of leptin with a pattern that could be interpreted as predictive of the prospective embryonic-abembryonic axis was seen only with WM-IHC/CLSM, not with S-IHC, although the latter gave excellent resolution. With both techniques, no differences between blastomeres were detected with respect to actin and cytokeratin patterns, an increased expression of cytokeratin in trophoblast cells occurring no earlier than at blastocyst formation. Artifacts that can occur with the two methodological approaches are critically discussed, as is the possible significance of the findings for theories on the differentiation of trophoblast versus embryoblast and on axis formation in early mammalian development. It is concluded that these data call for cautioning when studying distribution patterns of diffusible molecules with WM-IHC/CLSM technology, whereas patterns obtained with S-IHC are more reliable. Specifically these data cast doubts on previous claims that leptin IHC would allow to monitor cytoplasmic domain segregation occurring during cleavage as an element of early embryonic pattern
Modeling snag dynamics in northern Arizona mixed-conifer and ponderosa pine forests
Joseph L. Ganey; Scott C. Vojta
Snags (standing dead trees) are important components of forested habitats that contribute to ecological decay and recycling processes as well as providing habitat for many life forms. As such, snags are of special interest to land managers, but information on dynamics of snag populations is lacking. We modeled trends in snag populations in mixed-conifer and ponderosa...
Snag characteristics and dynamics following natural and artificially induced mortality in a managed loblolly pine forest
Energy Technology Data Exchange (ETDEWEB)
Zarnoch, Stanley J.; Vukovich, Mark A.; Kilgo, John C.; Blake, John I.
A 14-year study of snag characteristics was established in 41- to 44-year old loblolly pine (Pinus taeda L.) stands in southeastern USA. During the initial 5.5 years, no stand manipulation or unusually high-mortality events occurred. Afterwards, three treatments were applied consisting of trees thinned and removed, trees felled and not removed, and artificial creation of snags produced by girdling and herbicide injection. The thinned treatments were designed to maintain the same live canopy density as the snag-created treatment, disregarding snags that remained standing.We monitored snag height, diameter, density, volume, and bark percentage; the number of cavities was monitored in natural snags only. During the first 5.5 years, recruitment and loss rates were stable, resulting in a stable snag population. Large snags (≥25 cm diameter) were common, but subcanopy small snags (10 to <25 cm diameter) dominated numerically. Large natural snags survived (90% quantile) significantly longer (6.0–9.4 years) than smaller snags (4.4–6.9 years). Large artificial snags persisted the longest (11.8 years). Cavities in natural snags developed within 3 years following tree death. The mean number of cavities per snag was five times greater in large versus small snags and large snags were more likely to have multiple cavities, emphasizing the importance of mature pine stands for cavity-dependent wildlife species.
Long-term dynamics and characteristics of snags created for wildlife habitat
Barry, Amy M.; Hagar, Joan; Rivers, James W.
Snags provide essential habitat for numerous organisms and are therefore critical to the long-term maintenance of forest biodiversity. Resource managers often use snag creation to mitigate the purposeful removal of snags at the time of harvest, but information regarding how created snags change over long timescales (>20 y) is absent from the literature. In this study, we evaluated the extent to which characteristics of large (>30 cm diameter at breast height [DBH]) Douglas-fir (Pseudotsuga menziesii) snags created by topping had changed after 25–27 y. We also tested whether different harvest treatments and snag configurations influenced present-day snag characteristics. Of 690 snags created in 1989–1991, 91% remained standing during contemporary surveys and 65% remained unbroken along the bole. Although most snags were standing, we detected increased bark loss and breaking along the bole relative to prior surveys conducted on the same pool of snags. Although snag characteristics were not strongly influenced by snag configuration, we found that snags in one harvest treatment (group selection) experienced less bark loss and had lower evidence of use by cavity-nesting birds (as measured by total cavity cover) relative to snags created with clearcut and two-story harvest treatments. Our results indicate that Douglas-fir snags created by topping can remain standing for long time-periods (≥25 y) in managed forests, and that the influence of harvest treatment on decay patterns and subsequent use by wildlife is an important consideration when intentionally creating snags for wildlife habitat.
Snag distributions in relation to human access in ponderosa pine forests
Jeff P. Hollenbeck; Lisa J. Bate; Victoria A. Saab; John F. Lehmkuhl
Ponderosa pine (Pinus ponderosa) forests in western North America provide habitat for numerous cavity-using wildlife species that often select large-diameter snags for nesting and roosting. Yet large snags are often removed for their commercial and firewood values. Consequently we evaluated effects of human access on snag densities and diameter-class distributions at...
Changes in snag populations on National Forest System lands in Arizona, 1990s to 2000s
Joseph L. Ganey; Christopher Witt
Snags receive special management attention as important components of forest systems. We used data from the US Department of Agriculture (USDA) Forest Service Forest Inventory and Analysis Program, collected during two recent time periods (1995 to 1999 and 2001 to 2010), to evaluate trends in snag populations in two forest types in Arizona. Densities of snags â¥4 in....
Snag densities in old-growth stands on the Gasquet Ranger District, Six Rivers National Forest, California
Thomas M. Jimerson
Baseline levels for densities of snags (standing dead trees) wered etermined in undisturbed old-growth stands on the Gasquet Ranger District. Six Riven National Forest, California. Snag species, number, diameter at breast height (d.b.h.), height, cavity type, cavity use, decay class, and snag origin were recorded on 317 plots over a 2-year period. The 2121 snags...
Collecting a whitebark snag for visitor center display
Jane Kapler Smith
An educational display entitled "Whitebark pine forests-High country tapestry of life" is being assembled at the Montana Natural History Center (MNHC) in Missoula. It will include a whitebark pine snag and several animal specimens (two grizzly bears, a Clark's nutcracker, and a red squirrel), arrayed in front of a large photo of whitebark pine habitat....
Properties of Sn-Ag proximity effect bridges
Energy Technology Data Exchange (ETDEWEB)
Fan Hongchang; Yu Zheng
We have measured the I-V characteristics, I/sub c/(t) and T/sub c/ of Sn-Ag proximity effect bridges, obtaining some interesting results. We have also analyzed and tried to explain the results in terms of phenomenological theories, believing that microbridge theories of Skocpol, Beasley and Tinkham (SBT) also apply to our proximity effect bridges.
Microstructure evolution of eutectic Sn-Ag solder joints
Yang, Wenge; Messler, Robert W.; Felton, Lawrence E.
Laser and infrared reflow soldering methods were used to make Sn-Ag eutectic solder joints for surface-mount components on printed wiring boards. The microstructures of the joints were evaluated and related to process parameters. Aging tests were conducted on these joints for times up to 300 days and at temperature up to 190°C. The evolution of microstructure during aging was examined. The results showed that Sn-Ag solder microstructure is unstable at high temperature, and microstructural evolution can cause solder joint failure. Cu-Sn intermetallics in the solder and at copper-solder interfaces played an important role in both the microstructure evolution and failure of solder joints. Void and crack formation in the aged joints was also observed.
Snag densities in relation to human access and associated management factors in forests of Northeastern Oregon, USA
Lisa J. Bate; Michael J. Wisdom; Barbara C. Wales
A key element of forest management is the maintenance of sufficient densities of snags (standing dead trees) to support associated wildlife. Management factors that influence snag densities, however, are numerous and complex. Consequently, accurate methods to estimate and model snag densities are needed. Using data collected in 2002 and Current Vegetation Survey (CVS)...
Implementing the expanded prescribed fire program on the Gila National Forest, New Mexico: implications for snag management
Paul F. Boucher; William M. Block; Gary V. Benavidez; L. E. Wiebe
Efforts to return natural fire to the Gila National Forest, New Mexico, have resulted in controversy regarding management of snags (standing dead trees). The importance of snags for wildlife, especially cavity-dependent birds, is well documented. Although general uses of snags by birds are known (nesting, roosting, perching, and foraging), we know little about the...
Cavity trees, snags, and selection cutting: a northern hardwood case study
Laura S. Kenefic; Ralph D. Nyland
Although traditional application of the selection system includes a focus on high-value trees that may reduce cavities and snags, few studies have quantified those habitat features in managed uneven-aged stands. We examined the effects of single-tree selection cutting on cavity trees and snags in a northern hardwood stand immediately prior to the second cutting....
Selection of fire-created snags at two spatial scales by cavity-nesting birds
Victoria A. Saab; Ree Brannon; Jonathan Dudley; Larry Donohoo; Dave Vanderzanden; Vicky Johnson; Henry Lachowski
We examined the use of snag stands by seven species of cavity-nesting birds from 1994-1998. Selection of snags was studied in logged and unlogged burned forests at two spatial scales: microhabitat (local vegetation characteristics) and landscape (composition and patterning of surrounding vegetation types). We modeled nest occurrence at the landscape scale by using...
Snag recruitment and mortality in a bottomland hardwood forest following partial harvesting: second-year results
Brian Roy Lockhart; Philip A. Tappe; David G. Peitz; Christopher A. Watt
Snags are defined simply as standing dead trees. They function as an important component of wildlife habitat. Unfortunately, little information has been gathered regarding snags in bottomland forest ecosystems. We initiated a study to determine the effects of harvesting on the flora and fauna of a bottomland hardwood ecosystem adjacent the Mississippi River in...
Modeling respiration from snags and coarse woody debris before and after an invasive gypsy moth disturbance
Heidi J. Renninger; Nicholas Carlo; Kenneth L. Clark; Karina V.R. Schäfer
Although snags and coarse woody debris are a small component of ecosystem respiration, disturbances can significantly increase the mass and respiration from these carbon (C) pools. The objectives of this study were to (1) measure respiration rates of snags and coarse woody debris throughout the year in a forest previously defoliated by gypsy moths, (2) develop models...
Wright, Michael D.; And Others
Three articles discuss (1) casting technology as it relates to industry, with comparisons of shell casting, shell molding, and die casting; (2) evaporative pattern casting for metals; and (3) high technological casting with silicone rubber. (JOW)
Religiousness, religious doubt, and death anxiety.
Henrie, James; Patrick, Julie Hicks
Terror Management Theory (TMT) (Greenberg, Pyszczynski, & Solomon, 1986) suggests that culturally-provided worldviews (e.g., religion) may protect individuals from experiencing death anxiety, and several studies have supported this position. However, if one's worldview can offer protection, doubts concerning one's worldview could undermine this protection. The current study investigated whether age, gender, religiousness, and religious doubt were associated with death anxiety. Using data from 635 younger, middle-aged, and older adults, a structural equation model with age, gender, religiousness, and religious doubt predicting death anxiety was tested. The model had a good fit (chi2 (76) = 193.467, p death anxiety. Results were consistent with TMT, as religiousness was inversely associated with death anxiety, while religious doubt was positively associated with death anxiety.
Characteristics of religious doubts in young
Directory of Open Access Journals (Sweden)
Dušanić Srđan
Full Text Available At the time of general popularity of religion it is certainly interesting to examine the degree of religious skepticism in young and the role of certain personality traits and family. The assumption was that religious doubt is higher in people with higher self-efficacy, liberalism, intellectualism and the experience of family trauma, and less pronounced dogmatism. The assumptions are set based on the results of certain international research (for example, Hunsberger and Altemeyer and hence theoretical goal of the research is to check international findings in our region. The survey was conducted in the Republic of Srpska. The total sample comprised 352 respondents, 67% of whom were girls and 33% boys. The average age was 18. The most important scale, the scale of religious skepticism, had high reliability (Cronbach alpha 0.92. There were several open questions about the reasons and motives for religious doubts, and content analysis of these responses was performed. The results show that religious skepticism is not so high among the young and the average mean on a five-degree scale is M = 1.98. Greater values than the average were obtained for reasons relating to: disbelief in life after death, illnesses and traumas, suspicions because of conflicts between religious communities, imposing religion, death of close relatives, the position of women in religion, the rules that deny pleasure etc. About 37% of respondents said they had episodes of religious doubts. The results indicate possible simultaneous existence of religious attitudes and religious doubts. Significant predictors of religious doubts may be religious socialization, family trauma, gender. Content analysis of responses to open-ended questions indicated that death or illness figure as the most common causes of religious skepticism. The results are discussed and compared with the international ones. It is obvious that there is a need for further research of religious doubts. .
Doubt and Certainty in ESL Textbooks.
Holmes, Janet
Considers previous research and data regarding the relative frequencies of a wide variety of lexical items expressing doubt and certainty in written and spoken corpuses and uses the data to evaluate the adequacy of some well-known English as a second language textbooks. (Author/CB)
No doubt about it: when doubtful role models undermine men's and women's math performance under threat.
Marx, David M; Monroe, Allyce H; Cole, Chris E; Gilbert, Patricia N
Past work has shown that female role models are effective buffers against stereotype threat. The present research examines the boundary conditions of this role model effect. Specifically, we argue that female role models should avoid expressing doubt about their math abilities; otherwise they may cease to buffer women from stereotype threat. For men, a non-doubtful male role model should be seen as threatening, thus harming performance. A doubtful male role model, however, should be seen as non-threatening, thus allowing men to perform up to their ability in math. To test this reasoning, men and women were exposed to either an outgroup or ingroup role model who either expressed doubt or did not. Participants then took a math exam under stereotype threat conditions. As expected, doubtful ingroup role models hurt women, but helped men's performance. Outgroup role models' expressed doubt had no differential effect on performance. We also show that expressions of doubt take on a different meaning when expressed by a female rather than a male role model.
I doubt, therefore African philosophy exists | Ramose | South African ...
African Journals Online (AJOL)
In this essay the question whether or not African philosophy exists is considered through an examination of the meaning of doubt. In St. Augustine and Descartes the basic presupposition with regard to doubt is the indubitable certainty that the doubting subject must exist before there can be any doubt at all. By parity of ...
Created snag characteristics and cavity-nesting bird associations in the CFIRP stands, McDonald-Dunn Research Forest, Corvallis, OR, USA, 2016
U.S. Geological Survey, Department of the Interior — Snags provide critical habitat for nearly one-third of wildlife species in forests of the Pacific Northwest, so historic declines in snags are thought to have had a...
MULLIGAN SELF MOBILIZATION VERSUS MULLIGAN SNAGs ON CERVICAL POSITION SENSE
Directory of Open Access Journals (Sweden)
Shereen M. Said
Full Text Available Background: Neck pain is very common. It can negatively affect the patient's life and may result in disability.This study conducted to compare the effect of different Mulligan techniques which is more effective(Mulligan self-mobilizationorMulligan SNAGson cervical position sense, pain and function. Methods: 87subjects with chronic mechanical neck pain, three groups were randomly assignedtoGroup(129 subjects received Mulligan self-mobilization and traditional treatment.Group(229 subjects received Mulligan SNAGs and traditional treatment. Group(329subjects received traditional treatment only.Position sense measured by Joint reposition error, pain measured by visual analog scale and function by Functional Neck disability index.Measurements were taken pre and post the intervention period. Results: MANOVA test revealed thatthere was significant improvement in valuesof the post-treatmentin allGroupscompared with pre-treatment of JPE (pre:P=0.725, post:P<0.001, VAS (pre=0.984, post:P<0.001 and NDI (pre=0.903,post:P<0.001. Conclusion: It can be reasoned that both Mulligan self-mobilization and Mulligan SNAGstechniques have a similar effect in JPE, VAS and NDI favoring traditional in chronic mechanical neck pain patients.
Effect of Mulligan Concept Lumbar SNAG on Chronic Nonspecific Low Back Pain.
Hussien, Hisham Mohamed; Abdel-Raoof, Neveen Abdellatif; Kattabei, Omaima Mohamed; Ahmed, Hassan Hussien
The purpose of this study was to investigate the outcomes of adding lumbar sustained natural apophyseal glide (SNAG) to a conventional therapy program for chronic nonspecific low back pain (LBP). Forty-two participants with chronic nonspecific LBP were randomly divided into 2 groups. The study group (aged 27.1 ± 8.3, 20 men, 3 women) received a conventional physical therapy program consisted of stretching and strengthening exercises plus SNAG (based on the Mulligan concept) on the affected lumbar levels, and the control group (aged 28.9 ± 7.7, 13 men, 6 women) received the same conventional program without SNAG 3 times per week for 1 month. Outcome measures were repositioning error (the primary outcome), pain, and function measured by an isokinetic dynamometer, visual analog scale, and the Oswestry Disability Index. Measurements were recorded before and after the end of the treatment period. The comparison between pretreatment and posttreatment test scores indicated that both study and control groups had significant improvement in all dependent variables (P > .001). However, adding SNAG to the conventional program resulted in higher improvement in terms of repositioning error, pain, and function (P = .02, .002, .008) respectively. This preliminary study indicated improvement in both groups. Adding SNAG to conventional programs in the treatment of chronic nonspecific LBP may result in greater improvement of repositioning error, pain reduction, and improved function.
... the urine; Fatty casts; Red blood cell casts; White blood cell casts Images ... Clinical Nephrology . 5th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 4. Gerber GS, Brendler CB. Evaluation ...
Storage and flux of carbon in live trees, snags, and logs in the Chugach and Tongass national forests
Tara Barrett
Carbon storage and flux estimates for the two national forests in Alaska are provided using inventory data from permanent plots established in 1995â2003 and remeasured in 2004â2010. Estimates of change are reported separately for growth, sapling recruitment, harvest, mortality, snag recruitment, salvage, snag falldown, and decay. Although overall aboveground carbon...
DecAID advisor: a tool for managing snags, down wood and wood decay in PNW forests.
Bruce G. Marcot; Grant Gunderson; Kim Mellen; Janet L. Ohmann
Past tools for modeling and setting guidelines for snag and down wood management have been based on theory, professional judgment, models of wildlife species use as habitat and empirical data. However, recent studies reveal that guidelines for amounts of snags and down wood on national forests of Washington and Oregon may have been lower than the new field data on use...
Thinning and prescribed fire effects on snag abundance and spatial pattern in an eastern Cascade Range dry forest, Washington, USA
Paul F. Hessburg; Nicholas A. Povak; R. Brion. Salter
Mechanical thinning and prescribed burning practices are commonly used to address tree stocking, spacing, composition, and canopy and surface fuel conditions in western US mixed conifer forests. We examined the effects of these fuel treatments alone and combined on snag abundance and spatial pattern across 12 10-ha treatment units in central Washington State. A snag...
Taboo thoughts and doubt/checking
Pinto, Anthony; Eisen, Jane L.; Mancebo, Maria C.; Greenberg, Benjamin D.; Stout, Robert L.; Rasmussen, Steven A.
The purpose of this report was to improve upon earlier factor analyses of obsessive-compulsive disorder (OCD) symptom categories by minimizing the heterogeneity in the aggressive obsessions category. An exploratory factor analysis was conducted on data from 293 adults with primary OCD. The resulting five factors (Symmetry/Ordering, Hoarding, Doubt/Checking, Contamination/Cleaning, and Taboo Thoughts) are phenomenologically more homogeneous than prior category-based factors and are consistent with those derived in previous item-level analyses. PMID:17368563
Self-Doubt: One Moral of the Story
Verducci, Susan
This essay focuses on the value of self-doubt in moral inquiry and in moral education. Using John Patrick Shanley's play, "Doubt: A parable," as illustration, it shows how self-doubt initiates and extends moral inquiry, highlights one's epistemic fallibility and connects the inquirer to the virtue of humility. The essay draws…
Integrating motion-detection cameras and hair snags for wolverine identification
Audrey J. Magoun; Clinton D. Long; Michael K. Schwartz; Kristine L. Pilgrim; Richard E. Lowell; Patrick Valkenburg
We developed an integrated system for photographing a wolverine's (Gulo gulo) ventral pattern while concurrently collecting hair for microsatellite DNA genotyping. Our objectives were to 1) test the system on a wild population of wolverines using an array of camera and hair-snag (C&H) stations in forested habitat where wolverines were known to occur, 2)...
Thinning effects on tree mortality and snag recruitment in western Oregon
Erich Kyle Dodson; Klaus J. Puettmann; Adrian. Ares
Tree mortality shapes forest structural development and the resulting dead wood provides habitat for many species. However, the eff ects of thinning on mortality and large snag recruitment have been variable and remain poorly understood. We examined thinning eff ects on tree mortality at eleven Density Management Study (DMS) sites in western Oregon. Th inning reduced...
Influence of Bank Afforestation and Snag Angle-of-fall on Riparian Large Woody Debris Recruitment
Don C. Bragg; Jeffrey L. Kershner
A riparian large woody debris (LWD) recruitment simulator (Coarse Woody Debris [CWD]) was used to test the impact of bank afforestation and snag fall direction on delivery trends. Combining all cumulative LWD recruitment across bank afforestation levels averaged 77.1 cubic meters per 100 meter reach (both banks forested) compared to 49.3 cubic meters per 100 meter...
The effects of thinning intensity on snag and cavity tree abundance in an Appalachian hardwood stand
Aaron T. Graves; Mary Ann Fajvan; Gary W. Miller
Traditional silvicultural practices focus on manipulating forest vegetation structure for commodity production. Structural features important to wildlife, such as snags, trees with decay, and cavity trees are also affected by forest management, but these effects are often not quantified. This study measured the effects of different thinning intensities (45, 60, and 75...
Snags and Down Wood on Upland Oak Sites in the Missouri Ozark Forest Ecosystem Project
Stephen R. Shifley; Brian L. Brookshire; David R. Larsen; Laura A. Herbeck; Randy G. Jensen
We analyzed volume, surface area, and percent cover of down wood to determine if there were pre-treatment differences among the sites in the Missouri Ozark Forest Ecosystem Project. We also compared pre-treatment values for the number and basal area of snags. We observed no statistically significant differences (P > 0.05) among treatment classes for these...
Mountain pine beetle-killed trees as snags in Black Hills ponderosa pine stands
J. M. Schmid; S. A. Mata; W. C. Schaupp
Mountain pine beetle-killed ponderosa pine trees in three stands of different stocking levels near Bear Mountain in the Black Hills National Forest were surveyed over a 5-year period to determine how long they persisted as unbroken snags. Rate of breakage varied during the first 5 years after MPB infestation: only one tree broke during the first 2 years in the three...
Psychoemotional Features of a Doubtful Disorder: Functional Dyspepsia
Dragos, D; Ionescu, O; Micut, R; Ojog, DG; Tanasescu, MD
Objective. To delineate the psychological profile of individuals prone to FD-like symptoms (FDLS). Method. A triple questionnaire of 614 items (including psychological and medical ones) was given to 10192 respondents, the results were analyzed by means of Cronbach alpha, and Chi square test, together with an ad-hoc designed method that implied ranking and outliers detecting. Results and conclusions. FDLS appears to be an accompanying feature of many (if not most) human emotions and are more frequent in anxious, timid, pessimistic, discontent, irascible, tense, success-doubting, unexpected-dreading individuals, bothered by persistent thoughts and tormented by the professional requirements and the lack of time. A higher degree of specificity might have: chiefly fear of failure, susceptibility, and tension, secondarily emotivity, fear of unpredictable events, sense of insufficient time, preoccupation with authority factors, and tendency to endure unacceptable situations, and also faulty patience and lack of punctuality. Rumination appears to be the psychological tendency most strongly associated with FD. Nocturnal epigastric pain seems to indicate a submissive nature but a rather responsibilities-free childhood, while early satiety is associated with inclination to work and responsibility and preoccupation with self-image. The superposition of FD symptoms with biliary and esophageal symptoms cast a doubt over the distinctness and even the materiality of the various functional digestive disorders. Abbreviations: ChiSq = chi-square; CrA = Cronbach alpha; OdRa = odds ratio; OdRaCL = OdRa confidence limits; E = exponential (for the sake of legibility we have used the exponential notation throughout this article; i.e. 4E-28 = 4×10-28); ErrProb = probability of error; SS = statistically significant; SD = standard deviation; a / m = the calculations were done by taking into account the average/ maximal score; P / M = psychological / medical category; PaMm / PmMa / PmMm / Pa
Dead wood in managed forests: how much and how much is enough?: development of a snag-quantification method by remote sensing & GIS and snag targets based on Three-toed woodpeckers' habitat requirements
Bütler Sauvain, Rita; Schlaepfer, Rodolphe
The aims of this research were twofold: to develop an efficient method for the quantification of large spruce snags (standing dying and dead trees), and to establish snag target values for sustainable forest management. We answer the two basic questions: how much dead wood is currently available in managed forests? And how much dead wood is enough for biodiversity conservation? It is widely accepted that modern forest management has to be sustainable. One generally recognised criterion of sus...
An investigation of doubt in obsessive-compulsive disorder.
Samuels, Jack; Bienvenu, O Joseph; Krasnow, Janice; Wang, Ying; Grados, Marco A; Cullen, Bernadette; Goes, Fernando S; Maher, Brion; Greenberg, Benjamin D; McLaughlin, Nicole C; Rasmussen, Steven A; Fyer, Abby J; Knowles, James A; Nestadt, Paul; McCracken, James T; Piacentini, John; Geller, Dan; Pauls, David L; Stewart, S Evelyn; Murphy, Dennis L; Shugart, Yin-Yao; Kamath, Vidya; Bakker, Arnold; Riddle, Mark A; Nestadt, Gerald
Clinicians have long considered doubt to be a fundamental characteristic of obsessive-compulsive disorder (OCD). However, the clinical relevance of doubt in OCD has not been addressed. Participants included 1182 adults with OCD who had participated in family and genetic studies of OCD. We used a clinical measure of the severity of doubt, categorized as none, mild, moderate, severe, or extreme. We evaluated the relationship between doubt and OCD clinical features, Axis I disorders, personality and personality disorder dimensions, impairment, and treatment response. The severity of doubt was inversely related to the age at onset of OCD symptoms. Doubt was strongly related to the number of checking symptoms and, to a lesser extent, to the numbers of contamination/cleaning and hoarding symptoms. Doubt also was related to the lifetime prevalence of recurrent major depression and generalized anxiety disorder; to the numbers of avoidant, dependent, and obsessive-compulsive personality disorder traits; and to neuroticism and introversion. Moreover, doubt was strongly associated with global impairment and poor response to cognitive behavioral treatment (CBT), even adjusting for OCD severity and other correlates of doubt. Doubt is associated with important clinical features of OCD, including impairment and cognitive-behavioral treatment response. Copyright © 2017 Elsevier Inc. All rights reserved.
Incremental Beliefs About Ability Ameliorate Self-Doubt Effects
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Qin Zhao
Full Text Available Past research has typically shown negative effects of self-doubt on performance and psychological well-being. We suggest that these self-doubt effects largely may be due to an underlying assumption that ability is innate and fixed. The present research investigated the main hypothesis that incremental beliefs about ability might ameliorate negative effects of self-doubt. We examined our hypotheses using two lab tasks: verbal reasoning and anagram tasks. Participants' self-doubt was measured and beliefs about ability were measured after participants read articles advocating either for incremental or entity theories of ability. American College Testing (ACT scores were obtained to index actual ability level. Consistent with our hypothesis, for participants who believed ability was relatively fixed, higher self-doubt was associated with increased negative affect and lower task performance and engagement. In contrast, for participants who believed that ability was malleable, negative self-doubt effects were ameliorated; self-doubt was even associated with better task performance. These effects were further moderated by participants' academic ability. These findings suggest that mind-sets about ability moderate self-doubt effects. Self-doubt may have negative effects only when it is interpreted as signaling that ability is immutably low.
High density of tree-cavities and snags in tropical dry forest of western Mexico raises questions for a latitudinal gradient.
Directory of Open Access Journals (Sweden)
Leopoldo Vázquez
Full Text Available It has been suggested that a latitudinal gradient exists of a low density of snags and high density of naturally-formed tree-cavities in tropical vs. temperate forests, though few cavities may have characteristics suitable for nesting by birds. We determined snag and cavity density, characteristics, and suitability for birds in a tropical dry forest biome of western Mexico, and evaluated whether our data fits the trend of snag and cavity density typically found in tropical moist and wet forests. We established five 0.25-ha transects to survey and measure tree-cavities and snags in each of three vegetation types of deciduous, semi-deciduous, and mono-dominant Piranhea mexicana forest, comprising a total of 3.75 ha. We found a high density of 77 cavities/ha, with 37 cavities suitable for birds/ha, where density, and characteristics of cavities varied significantly among vegetation types. Lowest abundance of cavities occurred in deciduous forest, and these were in smaller trees, at a lower height, and with a narrower entrance diameter. Only 8.6% of cavities were excavated by woodpeckers, and only 11% of cavities were occupied, mainly by arthropods, though 52% of all cavities were unsuitable for birds. We also found a high density of 56 snags/ha, with greatest density in deciduous forest (70 snags/ha, though these were of significantly smaller diameter, and snags of larger diameter were more likely to contain cavities. The Chamela-Cuixmala tropical dry forest had the highest density of snags recorded for any tropical or temperate forest, and while snag density was significantly correlated with mean snag dbh, neither latitude nor mean dbh predicted snag density in ten forest sites. The high spatial aggregation of snag and cavity resources in tropical dry forest may limit their availability, particularly for large-bodied cavity adopters, and highlights the importance of habitat heterogeneity in providing resources for primary and secondary cavity-nesters.
High density of tree-cavities and snags in tropical dry forest of western Mexico raises questions for a latitudinal gradient.
Vázquez, Leopoldo; Renton, Katherine
It has been suggested that a latitudinal gradient exists of a low density of snags and high density of naturally-formed tree-cavities in tropical vs. temperate forests, though few cavities may have characteristics suitable for nesting by birds. We determined snag and cavity density, characteristics, and suitability for birds in a tropical dry forest biome of western Mexico, and evaluated whether our data fits the trend of snag and cavity density typically found in tropical moist and wet forests. We established five 0.25-ha transects to survey and measure tree-cavities and snags in each of three vegetation types of deciduous, semi-deciduous, and mono-dominant Piranhea mexicana forest, comprising a total of 3.75 ha. We found a high density of 77 cavities/ha, with 37 cavities suitable for birds/ha, where density, and characteristics of cavities varied significantly among vegetation types. Lowest abundance of cavities occurred in deciduous forest, and these were in smaller trees, at a lower height, and with a narrower entrance diameter. Only 8.6% of cavities were excavated by woodpeckers, and only 11% of cavities were occupied, mainly by arthropods, though 52% of all cavities were unsuitable for birds. We also found a high density of 56 snags/ha, with greatest density in deciduous forest (70 snags/ha), though these were of significantly smaller diameter, and snags of larger diameter were more likely to contain cavities. The Chamela-Cuixmala tropical dry forest had the highest density of snags recorded for any tropical or temperate forest, and while snag density was significantly correlated with mean snag dbh, neither latitude nor mean dbh predicted snag density in ten forest sites. The high spatial aggregation of snag and cavity resources in tropical dry forest may limit their availability, particularly for large-bodied cavity adopters, and highlights the importance of habitat heterogeneity in providing resources for primary and secondary cavity-nesters.
47 CFR 32.1171 - Allowance for doubtful accounts.
... 47 Telecommunication 2 2010-10-01 2010-10-01 false Allowance for doubtful accounts. 32.1171....1171 Allowance for doubtful accounts. (a) This account shall be credited with amounts charged to... amounts covered thereby which have been found to be impracticable of collection. (b) If no such allowance...
Academic Resourcefulness, Coping Strategies and Doubting in University Undergraduates
Xuereb, Sharon
This study hypothesised that academic resourcefulness and coping strategies would predict doubting amongst university undergraduates. Doubting refers to the serious consideration of prematurely withdrawing from university. It was predicted that mature students would report higher levels of academic resourcefulness and adaptive coping strategies,…
coulec ci de meitre en cause i continuation de lutilisation d'un facteur de fonderie . a-i sssiiin fiiiale at Servi I e fiirum pour lcs tettants des...PAR LA REGLEMENTATION FRANCAISE POUR LES PIECES DE FONDERIE UTILISEES DANS LES AVIONS MILITAIRES par M.Robert 2 CASTING AIRWORTHINESS: JOINT EIROPEAN...FROM THEORY TO PRACTICAL APPLICATION by R.Genoux 5 EVALUATION OF TITANIUM CASTINGS FOR AEROSPACE COMPONENTS by G.Arsento 6 LE FACTEUR DE FONDERIE EN
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Sweta S Parmar
Full Text Available Hair casts or pseudonits are circumferential concretions,which cover the hair shaft in such a way that, it could be easily removed. They are thin, cylindrical, and elongated in length. We present an unusual case of an 8-year-old girl presenting with hair casts. Occurrence of these is unusual, and they may have varied associations. This patient was suffering from developmental delay. It is commonly misdiagnosed as and very important to differentiate from pediculosis capitis.
Casting doubt on the value of assessing the cardiac index in pregnancy.
Ram, Maya; Lavie, Anat; Lev, Shaul; Blecher, Yair; Amikam, Uri; Shulman, Yael; Avnon, Tomer; Weiner, Eran; Many, Ariel
The objective of this study is to assess the reliability of the cardiac index (CI) in healthy pregnant women at term by investigating the correlation between the cardiac output (CO) and the body surface area (BSA) using a novel non-invasive cardiography technique (NICaS™). Sixty-one healthy, normotensive women with a singleton pregnancy at term (≥37 gestational weeks) participated in this prospective observational study between 1/2015 and 6/2015 L. Each woman was assessed for CO by the NICaS™, an impedance device that non-invasively measures the CO and its derivatives. The NICaS™ demonstrated a very good correlation with the gold standard Swan-Ganz catheter. BSA was determined by the Dubois nomogram. The mean ± standard deviation maternal age was 34.2 ± 5.3 years, mean height 166 ± 6 cm, and mean body mass index 23.9 ± 4.9 kg/m2. The mean gestational age was 38.8 ± 0.7 weeks. The correlation between the CO and the BSA was poor (Pearson r = 0.254, p < .005). The current study demonstrated poor correlation between the CO and the BSA in pregnant women, therefore, making the CI a non-reliable variable for assessing CO in pregnant women. We, therefore, suggest that the CO rather than the CI is the preferred parameter for hemodynamic measurements in this population.
Can mesophotic reefs replenish shallow reefs? Reduced coral reproductive performance casts a doubt.
Shlesinger, Tom; Grinblat, Mila; Rapuano, Hanna; Amit, Tal; Loya, Yossi
Mesophotic coral ecosystems (i.e. deep coral reefs at 30-120 m depth) appear to be thriving while many shallow reefs in the world are declining. Amidst efforts to understand and manage their decline, it was suggested that mesophotic reefs might serve as natural refuges and a possible source of propagules for the shallow reefs. However, our knowledge of how reproductive performance of corals alters with depth is sparse. Here, we present a comprehensive study of the reproductive phenology, fecundity and abundance of seven reef-building conspecific corals in shallow and mesophotic habitats. Significant differences were found in the synchrony and timing of gametogenesis and spawning between shallow and mesophotic coral populations. Thus, mesophotic populations exhibited delayed or protracted spawning events, which led to spawning of the mesophotic colonies in large proportions at times where the shallow ones had long been depleted of reproductive material. All species investigated demonstrated a substantial reduction in fecundity and/or oocyte sizes at mesophotic depths (40-60 m). Two species (Seriatopora hystrix and Galaxea fascicularis) displayed a reduction in both fecundity and oocyte size at mesophotic depths. Turbinaria reniformis had only reduced fecundity and Acropora squarrosa and Acropora valida only reduced oocyte size. In Montipora verrucosa, reduced fecundity was found during one annual reproductive season while in the following year only reduced oocyte size was found. In contrast, reduced oocyte size in mesophotic populations of Acropora squarrosa was consistent along three studied years. One species, Acropora pharaonis, was found to be infertile at mesophotic depths along two studied years. The above indicate that reproductive performance decreases with depth; and that although some species are capable of reproducing at mesophotic depths, their contribution to the replenishment of shallow reefs may be inconsequential. Reduced reproductive performance with depth, combined with the possible narrower tolerance to environmental factors further suggests that mesophotic corals may in fact be more vulnerable than previously conceived. Furthermore, we posit that the observed temporal segregation in reproduction could lead to assortative mating, and this, in turn, may facilitate adaptive divergence across depth. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Cantor, Brian
INDUSTRIAL PERSPECTIVEDirect chillcasting of aluminium alloysContinuous casting of aluminium alloysContinuous casting of steelsCastings in the automotive industryCast aluminium-silicon piston alloysMODELLING AND SIMULATIONModelling direct chill castingMold filling simulation of die castingThe ten casting rulesGrain selection in single crystal superalloy castingsDefects in aluminium shape castingPattern formation during solidificationPeritectic solidificationSTRUCTURE AND DEFECTSHetergeneous nucleation in aluminium alloysCo
Arts practices in unreasonable doubt? Reflections on understandings of arts practices in healthcare contexts
Broderick, Sheelagh
This article suggests that the discourse on arts and health encompass contemporary arts practices as an active and engaged analytical activity. Distinctions between arts therapy and arts practice are made to suggest that clinical evidence-based evaluation, while appropriate for arts therapy, is not appropriate for arts practice and in effect cast them in unreasonable doubt. Themes in current discourse on "arts" and "health" are broadly sketched to provide a context for discussion of arts practices. Approaches to knowledge validation in relation to each domain are discussed. These discourses are applied to the Irish healthcare context, offering a reading of three different art projects; it suggests a multiplicity of analyses beyond causal positive health gains. It is suggested that the social turn in medicine and the social turn in arts practices share some similar pre-occupations that warrant further attention. PMID:22675403
Are Brain Dead Individuals Dead? Grounds for Reasonable Doubt
Brugger, E. Christian
According to the biological definition of death, a human body that has not lost the capacity to holistically organize itself is the body of a living human individual. Reasonable doubt against the conclusion that it has lost the capacity exists when the body appears to express it and no evidence to the contrary is sufficient to rule out reasonable doubt against the conclusion that the apparent expression is a true expression (i.e., when the conclusion that what appears to be holistic organizat...
Ruppel, R.H.; Winters, C.E.
A device is described for casting uranium which comprises a crucible, a rotatable table holding a plurality of molds, and a shell around both the crucible and the table. The bottom of the crucible has an eccentrically arranged pouring hole aligned with one of the molds at a time. The shell can be connected with a vacuum.
Identity of Hitherto doubtful specific names in European Nepticulidae (Lepidoptera)
Nieukerken, van E.J.; Johansson, R.
The identity of hitherto doubtful specific names in Nepticulidae has been established on the basis of type material where possible, or after a critical reexamination of the original descriptions. In addition a few previously synonymized names have been reevaluated. The identity of 17 names could be
Nodular cast iron and casting monitoring
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S. Pietrowski
Full Text Available In this paper quality monitoring of nodular cast iron and casting made of it is presented. A control system of initial liquid cast iron to spheroidization, after spheroidization and inoculation with using of TDA method was shown. An application of an ultrasonic method to assessment of the graphite form and the metal matrix microstructure of castings was investigated.
Marsden, Kenneth C.; Meyer, Mitchell K.; Grover, Blair K.; Fielding, Randall S.; Wolfensberger, Billy W.
A casting device includes a covered crucible having a top opening and a bottom orifice, a lid covering the top opening, a stopper rod sealing the bottom orifice, and a reusable mold having at least one chamber, a top end of the chamber being open to and positioned below the bottom orifice and a vacuum tap into the chamber being below the top end of the chamber. A casting method includes charging a crucible with a solid material and covering the crucible, heating the crucible, melting the material, evacuating a chamber of a mold to less than 1 atm absolute through a vacuum tap into the chamber, draining the melted material into the evacuated chamber, solidifying the material in the chamber, and removing the solidified material from the chamber without damaging the chamber.
Gray, C.F.; Thompson, R.H.
An apparatus is described for casting small quantities of uranlum. It consists of a crucible having a hole in the bottom with a mold positioned below. A vertical rcd passes through the hole in the crucible and has at its upper end a piercing head adapted to break the oxide skin encasing a molten uranium body. An air tight cylinder surrounds the crucible and mold, and is arranged to be evacuated.
Love Yourself as a Person, Doubt Yourself as a Therapist?
Nissen-Lie, Helene A; Rønnestad, Michael Helge; Høglend, Per A; Havik, Odd E; Solbakken, Ole Andrè; Stiles, Tore C; Monsen, Jon T
There are reasons to suggest that the therapist effect lies at the intersection between psychotherapists' professional and personal functioning. The current study investigated if and how the interplay between therapists' (n = 70) professional self-reports (e.g., of their difficulties in practice in the form of 'professional self-doubt' and coping strategies when faced with difficulties) and presumably more global, personal self-concepts, not restricted to the professional treatment setting (i.e., the level of self-affiliation measured by the Structural Analysis of Social Behaviour (SASB) Intrex, Benjamin, ), relate to patient (n = 255) outcome in public outpatient care. Multilevel growth curve analyses were performed on patient interpersonal and symptomatic distress rated at pre-, post- and three times during follow-up to examine whether change in patient outcome was influenced by the interaction between their therapists' level of 'professional self-doubt' and self-affiliation as well as between their therapists' use of coping when faced with difficulties, and the interaction between type of coping strategies and self-affiliation. A significant interaction between therapist 'professional self-doubt' (PSD) and self-affiliation on change in interpersonal distress was observed. Therapists who reported higher PSD seemed to evoke more change if they also had a self-affiliative introject. Therapists' use of coping strategies also affected therapeutic outcome, but therapists' self-affiliation was not a moderator in the interplay between therapist coping and patient outcome. A tentative take-home message from this study could be: 'Love yourself as a person, doubt yourself as a therapist'. Copyright © 2015 John Wiley & Sons, Ltd. The findings of this study suggest that the nature of therapists' self-concepts as a person and as a therapist influences their patients' change in psychotherapy. These self-concept states are presumably communicated through the therapists
Chaudhry, Anil R [Xenia, OH; Dzugan, Robert [Cincinnati, OH; Harrington, Richard M [Cincinnati, OH; Neece, Faurice D [Lyndurst, OH; Singh, Nipendra P [Pepper Pike, OH
A foam material comprises a liquid polymer and a liquid isocyanate which is mixed to make a solution that is poured, injected or otherwise deposited into a corresponding mold. A reaction from the mixture of the liquid polymer and liquid isocyanate inside the mold forms a thermally collapsible foam structure having a shape that corresponds to the inside surface configuration of the mold and a skin that is continuous and unbroken. Once the reaction is complete, the foam pattern is removed from the mold and may be used as a pattern in any number of conventional casting processes.
Doubt and Denial: Epistemic Responsibility Meets Climate Change Scepticism
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Lorraine Code
Full Text Available The analysis in this essay is indebted to the analysis of climate change scepticism developed in Naomi Oreskes's and Eric Conway's Merchants of Doubt where they expose the vested interests that produce a degree of doubt with respect to climate change science. The argument addresses the appeal to an inflated conception of human freedom – Liberty – that is allegedly threatened by injunctions to control pollution in the interests of ecologically conscious behaviour across a range of human practices of consumption. The essay draws on and advocates rethinking issues about epistemic responsibility and testimonial injustice in working toward developing ecologically informed climate change advocacy. El análisis de este ensayo está influenciado por el análisis sobre escepticismo ante el cambio climático desarrollado por Naomi Oreskes y Eric Conway en Merchants of Doubt, donde exponen los intereses creados, que producen un grado de duda en relación a la ciencia del cambio climático. El argumento se refiere a la apelación a una concepción exagerada de la libertad humana - la Libertad - , presuntamente amenazada por medidas cautelares para controlar la contaminación en los intereses de la conducta ecológicamente consciente a través de toda una gama de prácticas humanas de consumo. El ensayo se basa en, y aboga por repensar las cuestiones acerca de la responsabilidad epistémica y defiende replantear las cuestiones acerca de la responsabilidad epistémica e injusticia testimonial en el trabajo hacia el desarrollo ecológicamente informado de la defensa del cambio climático.
The role of fire-return interval and season of burn in snag dynamics in a south Florida slash pine forest
Lloyd, John D.; Slater, Gary L.; Snyder, James R.
Standing dead trees, or snags, are an important habitat element for many animal species. In many ecosystems, fire is a primary driver of snag population dynamics because it can both create and consume snags. The objective of this study was to examine how variation in two key components of the fire regime—fire-return interval and season of burn—affected population dynamics of snags. Using a factorial design, we exposed 1 ha plots, located within larger burn units in a south Florida slash pine (Pinus elliottii var. densa Little and Dorman) forest, to prescribed fire applied at two intervals (approximately 3-year intervals vs. approximately 6-year intervals) and during two seasons (wet season vs. dry season) over a 12- to 13-year period. We found no consistent effect of fire season or frequency on the density of lightly to moderately decayed or heavily decayed snags, suggesting that variation in these elements of the fire regime at the scale we considered is relatively unimportant in the dynamics of snag populations. However, our confidence in these findings is limited by small sample sizes, potentially confounding effects of unmeasured variation in fire behavior and effects (e.g., intensity, severity, synergy with drought cycles) and wide variation in responses within a treatment level. The generalizing of our findings is also limited by the narrow range of treatment levels considered. Future experiments incorporating a wider range of fire regimes and directly quantifying fire intensity would prove useful in identifying more clearly the role of fire in shaping the dynamics of snag populations.
Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...
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Zivojin Spasic
Full Text Available Urinary tract and renal abnormalities represent 20% of all congenital malformations.Prenatal fetal ultrasonography revealed data of echostructure of renal parenchyma, dilatation of urinary sistem and visualisation of the fetal bladder after 16 weeks of gestation.Pyelic dilatation is considered when the anteroposterior diameter exceeds 4 mm before and 7 mm after 33 th week of gestation.All the children with antenatal doubt of urinary malformation should be examined. In the last 2 years we examined 25 newborns with antenatal doubt about urinary abnormalities. Multicystic dysplastic kidney was identified in 20%, posterior urethral valves in 12%, ureterocela in 8%, vesicoureteric junction anomaly in 24%, and high grade VUR in 32%. In the secound group of newborns, which was at the same time controlled due to the postnatally revealed hydronephrosis, our annual follow-up showed that there was spontaneous reduction of changes in 50% of cases, while in 25% of cases we revealed the reflux and vesicouretheric junction anomaly in 25%.Prenatally diagnosed hydronephrosis is more severe than hydronephrosis of the same degree revealed postnatally. Hydronephrosis in the first postnatal days in sterile urine conditions has spontaneous regression in one third of examined children.
When in doubt follow your nose – a wayfinding strategy
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Tobias eMeilinger
Full Text Available Route selection is governed by various strategies which often allow minimizing the required memory capacity. Previous research showed that navigators primarily remember information at route decision points and at route turns, rather than at intersections which required straight walking. However, when actually navigating the route or indicating directional decisions, navigators make fewer errors when they are required to walk straight. This tradeoff between location memory and route decisions accuracy was interpreted as a when in doubt follow your nose strategy which allows navigators to only memorize turns and walk straight by default, thus considerably reducing the number of intersections to memorize. These findings were based on newly learned routes. In the present study we show that such an asymmetry in route memory also prevails for planning routes within highly familiar environments. Participants planned route sequences between locations in their city of residency by pressing arrow keys on a keyboard. They tended to ignore straight walking intersections, but they ignored turns much less so. However, for reported intersections participants were quicker at indicating straight walking than turning. Together with results described in the literature, these findings suggest that a when in doubt follow your nose strategy is applied also within highly familiar spaces and might originate from limited working memory capacity during planning a route.
The ancient Chinese casting techniques
Tan Derui; Lian Haiping
In the course of Chinese civilization, which lasted more than 5,000 years, casting production has made a huge contribution. In this paper, some representative metal castings were presented. According to their forming techniques, they can be grouped into stone mould casting, clay mould casting, ablation casting, lost wax casting, stack casting, permanent mould casting, sand casting, etc. According to their materials, they can be categorized into tin bronze, bimetallic bronze, malleable cast ir...
Doubt, Despair and Hope in Western Thought: Unamuno and the Promise of Education
Roberts, Peter
This article examines the importance of doubt in Western philosophy, with particular attention to the work of Søren Kierkegaard and Miguel de Unamuno. Kierkegaard's pseudonymous author Johannes Climacus ventures down the pathway of doubt, finds it perplexing and difficult and discovers that he is unable to return to his pre-doubting self. In…
Energy Technology Data Exchange (ETDEWEB)
J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka
Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.
The certainty that engendered doubt: paternity and DNA
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Claudia Fonseca
Full Text Available There has been a surge in the use of DNA paternity tests in Brazil in both private and government laboratories. This raises interesting questions about the influence of the medical and legal spheres on gender and kinship relations in contemporary society. To analyze this phenomenon, we conducted research and observations in various government agencies in Porto Alegre (the Public Defender's office, Mediation Hearings, Family Court and the Court's Medical Service of people involved in legal disputes over paternal identification. We also studied how recent changes in the laws concerning paternal recognition are applied by the different personalities on the scene. Based on this data, we present the hypothesis that far from inspiring greater tranquility, the simple existence of the test instigates doubt. This has profound repercussions on our form of "knowing" who is the father. The situation described in this paper raises new challenges for an anthropology of knowledge, which focuses on an analysis of Western beliefs - including scientific ones.
Reply to 'Climate of doubt: a re-evaluation of Büntgen and Di Cosmo's environmental hypothesis for the Mongol withdrawal from Hungary, 1242 CE'.
Büntgen, Ulf; Cosmo, Nicola Di
In our 2016 article in Scientific Reports, we advanced a new hypothesis for the Mongol withdrawal from Hungary in 1242 CE, based on a joint analysis of climatic, environmental, and historical data. The re-evaluation now offered by Pinke et al. casts doubt on this hypothesis. However, their arguments are based on a level of generality that fails to appreciate the specific conditions of the Mongol invasion, do not offer new or different climatic data, and are supported by anachronistic production data and environmental information, which cannot be related to the period in question. While we acknowledge the importance of an open debate, we stand by our conclusions.
Indian Academy of Sciences (India)
equiaxed transition ..... solute in a cast product, important ones being: size of casting, rate of solidification, mode of heat extraction ..... the segregated region. A principal breakthrough in quantitative evaluation of segregation distribution has come.
Plastic casting resin poisoning
Epoxy poisoning; Resin poisoning ... Epoxy and resin can be poisonous if they are swallowed or their fumes are breathed in. ... Plastic casting resins are found in various plastic casting resin products.
Prophecy and Doubt in Just Above My Head
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Christopher Z. Hobson
Full Text Available Written in the aftermath of the civil rights era's expansive hopes, James Baldwin's last novel, Just Above My Head (1979, examines a fundamental issue, the choice between hope and skepticism, or prophecy and doubt. Baldwin approaches this issue by questioning two cornerstone ideas of his fiction, the need for prophetic art and this art's focus on anticipating a renovated society, often pictured in terms adapted from apocalyptic biblical texts and Gospel music lyrics. Just Above My Head is Baldwin's fullest presentation of this kind of art and its linkage to apocalyptic hopes. He dramatizes these ideas in the art of his Gospel singer protagonist, particularly in a climactic scene of artistic dedication whose Gospel lyric envisions "tearing down the kingdom of this world." Yet Baldwin also unsparingly questions these same ideas through plot and the blues-inflected skeptical-tragic consciousness of his narrator. Responding to a 1970s moment when hopes for transcendent justice seemed passé, Just Above My Head's unique contribution is not to try to resolve the ideas it counterposes, but to face both the possible falseness of prophetic hope and our continuing need for it, and to present the necessity for choice in a final dream that holds the key to the novel's meaning. In presenting this issue through a sustained double-voiced narrative that reexamines its author's artistic practice and raises fundamental choices in outlook and conduct, Just Above My Head evidences the continuing artistic vitality of Baldwin's late fiction.
A COMPARATIVE STUDY ON THE EFFECT OF SELF SNAGs VERSUS DYNAMIC ISOMETRIC EXERCISES IN DESK JOB PEOPLE WITH CHRONIC NECK PAIN
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Ningombam Geetanjali Devi
Full Text Available Background: Neck pain is a common global problem, an important source of disability Bad posture of neck with respect to chest is one of the commonest causes of chronic neck pain. This is common to the job related (e.g. computer professionals, clerks, bank employees where the neck is kept in a flexed position for long periods of time. The objectives of the study is to compare the effectiveness of self SNAGs with dynamic isometric exercise in chronic neck pain. Methods: It is a comparative experimental study. This study includes (N=40 desk job people with chronic neck pain subjects with age group of 25-45 years. They were randomly assigned into 2 groups (Group A and B. Group A had 20 (N=20 subjects who are treated with self SNAGs, Group B had 20 (N=20 who are treated with dynamic isometric exercise using resistance band. The subjects were given intervention once a day for 6 weeks. Results: At the end of 6 weeks, both neck pain and disability decreased in both groups, range of motion had also improved statistically significantly in both groups, but the results showed that the pain scores are significantly improved in group A( t = -2.707 which is significant at 5% level of significance (p = 0.01. It has been inferred that VAS decreases more when self SNAGs was applied and the difference of means of NDI, t = -4.468 which is highly significant (p = 0.00 implying that NDI decrease more when self SNAGs was applied as compared to dynamic isometric exercise. Conclusion: From the above study it is concluded that, self SNAGs is an effective way of decreasing pain and increasing functional ability when compared to dynamic isometric exercise using resistance band.
Multiple possible inaccuracies cast doubt on a recent report suggesting selective serotonin reuptake inhibitors to be toxic and ineffective.
Hieronymus, Fredrik; Lisinski, Alexander; Näslund, Jakob; Eriksson, Elias
According to a systematic review on the use of selective serotonin reuptake inhibitors (SSRIs) in adult depression that was recently published in BMC Psychiatry, the results of which have been widely disseminated in lay media, these drugs increase the risk for serious adverse events (SAEs) while exerting poor antidepressant efficacy. A cursory analysis, however, suggests the analysis of SAEs conducted by the authors to be marred by both methodological inaccuracies and blatant errors. After having corrected for these apparent mistakes, we conducted a sensitivity analysis in which we also accounted for a possible moderating effect of age; while this suggests SSRIs to be safe drugs in the non-elderly, they do confirm what is already known, that is, that they may enhance the risk for SAEs in the old. Given the loose definition of SAE, including also innocuous phenomena, the possible clinical significance of the latter observation, however, remains unclear until the nature and actual impact of the SAEs in question have been clarified. Moreover, with respect to efficacy, we find the paper in BMC Psychiatry misleading: first, the authors seem unaware of the well-established shortcomings associated with the conventional efficacy parameter on which their analysis is based, second, they have included suboptimal SSRI doses and third, they have missed some pivotal trials. Unless there are explanations for the many peculiarities in this paper that have escaped us, and which may be satisfactorily clarified by the authors, it seems important that the conclusions presented in this paper be publicly rectified.
Study Casts Doubt on Strength of Charter Managers: Author Says Final Text Eased Negative Findings on CMOs
Viadero, Debra
A report from Education Sector raises questions about the ability of charter schools and charter-management organizations (CMOs) to scale up as dramatically as their supporters might hope. "The extraordinary demands of educating disadvantaged students to higher standards, the challenges of attracting the talent required to do that work, the burden…
Time of flight MR angiography assessment casts doubt on the association between transient global amnesia and intracranial jugular venous reflux
Energy Technology Data Exchange (ETDEWEB)
Kang, Yeonah; Kim, Eunhee; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheolkyu; Bae, Yun Jung; Lee, Kyung Mi [Seoul National University College of Medicine, Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Lee, Dong Hoon [Seoul Medical Center, Department of Radiology, Seoul (Korea, Republic of)
Evidence of intracranial venous reflux flow due to jugular venous reflux (JVR) on time of flight (TOF) MR angiography (MRA) is thought to be highly associated with transient global amnesia (TGA) - evidence that supports the venous congestion theory of TGA pathophysiology. However, recent studies indicate that intracranial JVR on TOF MRA is occasionally observed in normal elderly. Therefore, the purpose of this study was to compare the prevalence of intracranial JVR on TOF MRA in patients with TGA and two control groups. Three age- and sex-matched groups of subjects that received MRI and MRA were enrolled. The groups comprised 167 patients with TGA, 167 visitors to the emergency room (ER) and 167 visitors to a health promotion centre (HPC). Intracranial JVR was defined as abnormal venous signals in the inferior petrosal, sigmoid and/or transverse sinuses on TOF MRA. The prevalence of intracranial JVR was assessed across the three groups. Intracranial JVR was seen in seven (4.2 %) TGA patients, eight (4.8 %) ER visitors and three (1.8 %) HPC visitors, respectively. No statistically significant differences were observed among the three groups. TGA patients showed a low prevalence of intracranial JVR on TOF MRA, and no statistical differences were found in comparison with control groups. (orig.)
Testing the Toxicofera: comparative transcriptomics casts doubt on the single, early evolution of the reptile venom system.
Hargreaves, Adam D; Swain, Martin T; Logan, Darren W; Mulley, John F
The identification of apparently conserved gene complements in the venom and salivary glands of a diverse set of reptiles led to the development of the Toxicofera hypothesis - the single, early evolution of the venom system in reptiles. However, this hypothesis is based largely on relatively small scale EST-based studies of only venom or salivary glands and toxic effects have been assigned to only some putative Toxicoferan toxins in some species. We set out to examine the distribution of these proposed venom toxin transcripts in order to investigate to what extent conservation of gene complements may reflect a bias in previous sampling efforts. Our quantitative transcriptomic analyses of venom and salivary glands and other body tissues in five species of reptile, together with the use of available RNA-Seq datasets for additional species, shows that the majority of genes used to support the establishment and expansion of the Toxicofera are in fact expressed in multiple body tissues and most likely represent general maintenance or "housekeeping" genes. The apparent conservation of gene complements across the Toxicofera therefore reflects an artefact of incomplete tissue sampling. We therefore conclude that venom has evolved multiple times in reptiles. Copyright © 2014 Elsevier Ltd. All rights reserved.
Undiagnosed Disease, Especially Diabetes, Casts Doubt on some of Reported Health 'Advantage' of Recent Mexican Immigrants
Barcellos, Silvia Helena; Goldman, Dana P.; Smith, James P.
Newly arrived Mexican immigrants generally report better health in the United States than do native-born Americans, but this health advantage erodes over time. At issue is whether this advantage is illusory – or a product of disease that goes undiagnosed in Mexico but is discovered after immigration. Using the National Health and Nutrition Survey we compare clinical to self-reported diagnosed disease prevalence. We find that diagnosed prevalence is 47 percent lower among recent Mexican immigrants than among natives for both diabetes and hypertension, and that undiagnosed disease explains one third of this recent immigrant advantage for diabetes and one fifth for hypertension. The remaining health advantage might be explained by immigrant selectivity (how migrants differ from those in Mexico who stayed) or assimilation (the process of integration into the U.S.). Since undiagnosed disease can have adverse health consequences, medical practice should emphasize disease detection among new arrivals as part of routine doctor or hospital visits. PMID:23213157
Direct Dating and Physico-Chemical Analyses Cast Doubts on the Coexistence of Humans and Dwarf Hippos in Cyprus
Zazzo, Antoine; Lebon, Matthieu; Quiles, Anita; Reiche, Ina; Vigne, Jean-Denis
In the Mediterranean, the island dwarf megafaunas became extinct around the end of the Pleistocene, during a period of rapid and global climate change. In Cyprus, this coincided with the first human presence on the island, as attested by the rock shelter of Akrotiri-Aetokremnos where an Epipaleolithic anthropogenic layer (stratum 2) was found overlying a massive accumulation of pygmy hippopotamus (Phanourios minor (Desmarest, 1822)) [Boekschoten and Sondaar, 1972] bones (stratum 4). The relationship between the two layers is highly controversial and the role played by humans in hippo extinction remains fiercely debated. Here, we provide new, direct radiocarbon and physico-chemical analyses on calcined bones which elucidates the complex depositional history of the assemblage. Bone turquoise was identified using micro-PIXE analysis and depth-profiling together with Vis spectroscopy, demonstrating that these bones were not freshly burned. Bayesian modeling of the radiocarbon dates indicates that stratum 4 accumulated during the first half of the 13th mill cal BP and that calcination occurred several hundred years later. We conclude that accumulation occurred naturally during the beginning of the Younger Dryas and that Epipalaeolithic visitors subsequently used the bones as fuel, starting from the mid-13th mill cal BP. At that time, dwarf hippos were probably already extinct or at least highly endangered. Our results shed new light on the possible causes of hippo extinction, on the subsequent introduction of the wild boar and on the earliest occupation of the island by humans. PMID:26284623
Direct Dating and Physico-Chemical Analyses Cast Doubts on the Coexistence of Humans and Dwarf Hippos in Cyprus.
Directory of Open Access Journals (Sweden)
Antoine Zazzo
Full Text Available In the Mediterranean, the island dwarf megafaunas became extinct around the end of the Pleistocene, during a period of rapid and global climate change. In Cyprus, this coincided with the first human presence on the island, as attested by the rock shelter of Akrotiri-Aetokremnos where an Epipaleolithic anthropogenic layer (stratum 2 was found overlying a massive accumulation of pygmy hippopotamus (Phanourios minor (Desmarest, 1822 [Boekschoten and Sondaar, 1972] bones (stratum 4. The relationship between the two layers is highly controversial and the role played by humans in hippo extinction remains fiercely debated. Here, we provide new, direct radiocarbon and physico-chemical analyses on calcined bones which elucidates the complex depositional history of the assemblage. Bone turquoise was identified using micro-PIXE analysis and depth-profiling together with Vis spectroscopy, demonstrating that these bones were not freshly burned. Bayesian modeling of the radiocarbon dates indicates that stratum 4 accumulated during the first half of the 13th mill cal BP and that calcination occurred several hundred years later. We conclude that accumulation occurred naturally during the beginning of the Younger Dryas and that Epipalaeolithic visitors subsequently used the bones as fuel, starting from the mid-13th mill cal BP. At that time, dwarf hippos were probably already extinct or at least highly endangered. Our results shed new light on the possible causes of hippo extinction, on the subsequent introduction of the wild boar and on the earliest occupation of the island by humans.
Glovebox Advanced Casting System Casting Optimization
Energy Technology Data Exchange (ETDEWEB)
Fielding, Randall Sidney [Idaho National Lab. (INL), Idaho Falls, ID (United States)
Casting optimization in the GACS included three broad areas; casting of U-10Zr pins, incorporation of an integral FCCI barrier, and development of a permanent crucible coating. U-10Zr casting was improved over last year's results by modifying the crucible design to minimize contact with the colder mold. Through these modifications casting of a three pin batch was successful. Incorporation of an integral FCCI barrier also was optimized through furnace chamber pressure changes during the casting cycle to reduce gas pressures in the mold cavities which led to three full length pins being cast which incorporated FCCI barriers of three different thicknesses. Permanent crucible coatings were tested against a base case; 1500°C for 10 minutes in a U-20Pu-10Zr molten alloy. None of the candidate coating materials showed evidence of failure upon initial visual examination. In all areas of work a large amount of characterization will be needed to fully determine the effects of the optimization activities. The characterization activities and future work will occur next year.
Thickness measurement of Sn-Ag hot dip coatings on Large Hadron Collider Superconducting strands by coulometry
Arnau-Izquierdo, G; Oberli, L R; Scheuerlein, C; Taborelli, M; 10.1149/1.1715094
Amperostatic coulometry is applied for the thickness measurement of Sn-Ag hot dip coatings, which comprise an extended Sn-Cu interdiffusion layer. Complementary measurements, notably weight loss, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence (XRF) and dynamic secondary ion mass spectroscopy (DSIMS) have been performed in order to obtain a better interpretation of the coulometry results. Based on the experimental results presented in this article the three potential changes that are observed during coulometry measurements are ascribed to (1) the entire dissolution of pure Sn, (2) the formation of a CuCl salt layer and (3) the surface passivation. The measurement of the pure Sn mass is well reproducible despite of strong coating thickness variations that are detected by XRF. Several experimental problems, in particular a coating undercutting, hamper the determination of the Sn mass in the intermetallic Sn-Cu layer.
Effect of Casting Material on the Cast Pressure After Sequential Cast Splitting.
Roberts, Aaron; Shaw, K Aaron; Boomsma, Shawn E; Cameron, Craig D
Circumferential casting is a vital component of nonoperative fracture management. These casts are commonly valved to release pressure and decrease the risk of complications from swelling. However, little information exists regarding the effect of different casting supplies on the pressure within the cast. Seventy-five long-arm casts were performed on human volunteers, divided between 5 experimental groups with 15 casts in each groups. Testing groups consisted of 2 groups with a plaster short-arm cast overwrapped with fiberglass to a long arm with either cotton or synthetic cast padding. The 3 remaining groups included fiberglass long-arm casts with cotton, synthetic, or waterproof cast padding. A pediatric blood pressure cuff bladder was placed within the cast and inflated to 100 mm Hg. After inflation, the cast was sequentially released with pressure reading preformed after each stage. Order of release consisted of cast bivalve, cast padding release, and cotton stockinet release. After release, the cast was overwrapped with a loose elastic bandage. Difference in pressure readings were compared based upon the cast material. Pressures within the cast were found to decrease with sequential release of cast. The cast type had no effect of change in pressure. Post hoc testing demonstrated that the type of cast padding significantly affected the cast pressures with waterproof padding demonstrating the highest pressure readings at all time-points in the study, followed by synthetic padding. Cotton padding had the lowest pressure readings at all time-points. Type of cast padding significantly influences the amount of pressure within a long-arm cast, even after bivalving the cast and cutting the cast padding. Cotton cast padding allows for the greatest change in pressure. Cotton padding demonstrates the greatest change in pressure within a long-arm cast after undergoing bivalve. Synthetic and waterproof cast padding should not be used in the setting of an acute fracture to
High integrity automotive castings
Energy Technology Data Exchange (ETDEWEB)
Weiss, D. [Eck Industries Inc., St. Manitowoc, WI (United States)
This paper described the High Integrity Magnesium Automotive Casting (HI-MAC) program, which was developed to ensure the widespread adoption of magnesium in structural castings. The program will encourage the use of low pressure permanent molds, squeeze casting, and electromagnetic pumping of magnesium into dies. The HI-MAC program is currently investigating new heat treatment methods, and is in the process of creating improved fluid flow and solidification modelling to produce high volume automotive components. In order to address key technology barriers, the program has been divided into 8 tasks: (1) squeeze casting process development; (2) low pressure casting technology; (3) thermal treatment; (4) microstructure control; (5) computer modelling and properties; (6) controlled molten metal transfer and filling; (7) emerging casting technologies; and (8) technology transfer throughout the automotive value chain. Technical challenges were outlined for each of the tasks. 1 ref., 3 tabs., 5 figs.
Allison, A.G.
S>A process is described for preparing a magnesium oxide slip casting slurry which when used in conjunction with standard casting techniques results in a very strong "green" slip casting and a fired piece of very close dimensional tolerance. The process involves aging an aqueous magnestum oxide slurry, having a basic pH value, until it attains a specified critical viscosity at which time a deflocculating agent is added without upsetting the basic pH value.
DeCarlo, Mark; Malone, Kathy; Darmelio, John; Rettig, Arthur
Attempts by sports medicine professionals to return high school athletes with hand and wrist injuries to competition quickly and safely have been the source of confusion and debate on many playing fields around the country. In addition to the differing views regarding the appropriateness of playing cast usage in high school football, a debate exists among sports medicine professionals as to which material is best suited for playing cast construction. Materials used in playing cast constructio...
DEFF Research Database (Denmark)
Roy, Dayabati
This paper explores the institution of caste and its operation in a micro-level village setting of West Bengal, an Indian state, where state politics at grass roots level is vibrant with functioning local self-government and entrenched political parties. This ethnographic study reveals that caste...
"Am I cut out for this?" Understanding the experience of doubt among first-year medical students.
Liu, Rhianon; Carrese, Joseph; Colbert-Getz, Jorie; Geller, Gail; Shochet, Robert
Existing research shows that medical students experience high levels of distress. The purpose of this study was to understand how medical students experience doubt, and how doubt relates to distress. A mixed-methods study was conducted among first-year students at the Johns Hopkins University School of Medicine in June 2012. Students answered survey questions and participated in focus groups about doubt and other forms of distress. Ninety-four percent (112) of students responded to the survey, with 49% reporting a moderate or high degree of doubt. Compared to those reporting no or low doubt, students with moderate/high doubt were significantly more likely to question their purpose and identity, struggle to cope with doubt, and experience depression and emotional hardening. Twenty-eight percent of students (34/112) participated in focus groups to explore their doubt, and three themes emerged: types of doubt, ways of coping with doubt, and impact of doubt. Doubt is highly prevalent among first-year medical students, affects their identity and purpose, and has positive and negative consequences. Doubt among medical students merits awareness and further study, as it may be an important mediator of students' emerging identity and sense of well-being.
Directory of Open Access Journals (Sweden)
J. Szajnar
Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.
eEF1A Mediates the Nuclear Export of SNAG-Containing Proteins via the Exportin5-Aminoacyl-tRNA Complex
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José Manuel Mingot
Full Text Available Exportin5 mediates the nuclear export of double-stranded RNAs, including pre-microRNAs, adenoviral RNAs, and tRNAs. When tRNAs are aminoacylated, the Exportin5-aminoacyl (aa-tRNA complex recruits and coexports the translation elongation factor eEF1A. Here, we show that eEF1A binds to Snail transcription factors when bound to their main target, the E-cadherin promoter, facilitating their export to the cytoplasm in association with the aa-tRNA-Exportin5 complex. Snail binds to eEF1A through the SNAG domain, a protein nuclear export signal present in several transcription factor families, and this binding is regulated by phosphorylation. Thus, we describe a nuclear role for eEF1A and provide a mechanism for protein nuclear export that attenuates the activity of SNAG-containing transcription factors.
The ancient Chinese casting techniques
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Tan Derui
Full Text Available In the course of Chinese civilization, which lasted more than 5,000 years, casting production has made a huge contribution. In this paper, some representative metal castings were presented. According to their forming techniques, they can be grouped into stone mould casting, clay mould casting, ablation casting, lost wax casting, stack casting, permanent mould casting, sand casting, etc. According to their materials, they can be categorized into tin bronze, bimetallic bronze, malleable cast iron, ductile cast iron, brass, cupronickel alloy (Packtong, etc. According to their surface decorative techniques they can be devided into gem inlay, gilding, gold and silver inlay, copper inlay, engraved decoration, surface tin-enrichment, mother-of-pearl inlay, burnished works with gold or silver inlay, surface coloring and cloisonné enamel, etc.
Decarlo, M; Malone, K; Darmelio, J; Rettig, A
Attempts by sports medicine professionals to return high school athletes with hand and wrist injuries to competition quickly and safely have been the source of confusion and debate on many playing fields around the country. In addition to the differing views regarding the appropriateness of playing cast usage in high school football, a debate exists among sports medicine professionals as to which material is best suited for playing cast construction. Materials used in playing cast construction should be hard enough to provide sufficient stabilization to the injured area and include adequate padding to absorb blunt impact forces. The purpose of the biomechanical portion of this investigation was to attempt to determine the most appropriate materials for use in constructing playing casts for the hand and wrist by assessing different materials for: 1) hardness using a Shore durometer, and 2) ability to absorb impact using a force platform. Results revealed that RTV11 and Scotchcast were the "least hard" of the underlying casting materials and that Temper Stick foam greatly increased the ability of RTV11 to absorb impact. Assessment of the mechanical properties of playing cast materials and review of current developments in high school football rules are used to aid practitioners in choosing the most appropriate materials for playing cast construction.
Energy Technology Data Exchange (ETDEWEB)
Makhlouf M. Makhlouf; Diran Apelian
The objective of this project is to develop a technology for clean metal processing that is capable of consistently providing a metal cleanliness level that is fit for a given application. The program has five tasks: Development of melt cleanliness assessment technology, development of melt contamination avoidance technology, development of high temperature phase separation technology, establishment of a correlation between the level of melt cleanliness and as cast mechanical properties, and transfer of technology to the industrial sector. Within the context of the first task, WPI has developed a standardized Reduced Pressure Test that has been endorsed by AFS as a recommended practice. In addition, within the context of task1, WPI has developed a melt cleanliness sensor based on the principles of electromagnetic separation. An industrial partner is commercializing the sensor. Within the context of the second task, WPI has developed environmentally friendly fluxes that do not contain fluorine. Within the context of the third task, WPI modeled the process of rotary degassing and verified the model predictions with experimental data. This model may be used to optimize the performance of industrial rotary degassers. Within the context of the fourth task, WPI has correlated the level of melt cleanliness at various foundries, including a sand casting foundry, a permanent mold casting foundry, and a die casting foundry, to the casting process and the resultant mechanical properties. This is useful in tailoring the melt cleansing operations at foundries to the particular casting process and the desired properties of cast components.
LENUS (Irish Health Repository)
Keohane, John
Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.
Bainite obtaining in cast iron with carbides castings
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S. Pietrowski
Full Text Available In these paper the possibility of upper and lower bainite obtaining in cast iron with carbides castings are presented. Conditions, when in cast iron with carbides castings during continuous free air cooling austenite transformation to upper bainite or its mixture with lower bainte proceeds, have been given. A mechanism of this transformation has been given, Si, Ni, Mn and Mo distribution in the eutectic cell has been tested and hardness of tested castings has been determined.
Adhesion Casting In Low Gravity
Noever, David A.; Cronise, Raymond J.
Adhesion casting in low gravity proposed as technique for making new and improved materials. Advantages of low-gravity adhesion casting, in comparison with adhesion casting in normal Earth gravity, comes from better control over, and greater uniformity of, thicknesses of liquid films that form on and adhere to solid surfaces during casting.
Energy Technology Data Exchange (ETDEWEB)
Imhoff, Seth D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gibbs, Paul Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Solis, Eunice Martinez [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Process exploration for fuel production for the High Flux Isotope Reactor (HFIR) using cast LEU-10wt.%Mo as an initial processing step has just begun. This project represents the first trials concerned with casting design and quality. The studies carried out over the course of this year and information contained in this report address the initial mold development to be used as a starting point for future operations. In broad terms, the final billet design is that of a solid rolling blank with an irregular octagonal cross section. The work covered here is a comprehensive view of the initial attempts to produce a sound casting. This report covers the efforts to simulate, predict, cast, inspect, and revise the initial mold design.
... you can get a special waterproof sleeve to cover it. Depending on where your cast or splint is on your body, you may find it easier to take a sponge bath. This means that instead of getting all ...
Poco, John F.
The invention describes a method for making monolithic castings of transparent silica aerogel with densities in the range from 0.001 g/cm.sup.3 to 0.6 g/cm.sup.3. Various shapes of aerogels are cast in flexible polymer molds which facilitate removal and eliminate irregular surfaces. Mold dimensions are preselected to account for shrinkage of alcogel which occurs during the drying step of supercritical extraction of solvent.
Anderson, J.W.; Miley, F.; Pritchard, W.C.
A coated mold for casting plutonium comprises a mold base portion of a material which remains solid and stable at temperatures as high as the pouring temperature of the metal to be cast and having a thin coating of the order of 0.005 inch thick on the interior thereof. The coating is composed of finely divided calcium fluoride having a particle size of about 149 microns. (AEC)
Silman, G. I.; Makarenko, K. V.
An analytical review of data on general-purpose grayed cast iron with different forms of graphite (lamellar, vermicular, globular, flaked) is presented. Grades of cast iron, their compositions, special features of structure of the graphite, and properties of gray, high-strength and malleable irons are described. The data on the kinds of iron considered are compared with those stipulated in international and some national standards.
The role and impact of 3D printing technologies in casting
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Jin-wu Kang
Full Text Available 3D printing is such a magical technology that it extends into almost every sector relating to manufacturing, not to mention casting production. In this paper, the past, present and future of 3D printing in the foundry sector are profoundly reviewed. 3D printing has the potential to supplement or partially replace the casting method. Today, some castings can be directly printed by metal powders, for example, titanium alloys, nickel alloys and steel parts. Meanwhile, 3D printing has found an unique position in other casting aspects as well, such as printing the wax pattern, ceramic shell, sand core, sand mould, etc. Most importantly, 3D printing is not just a manufacturing method, it will also revolutionize the design of products, assemblies and parts, such as castings, patterns, cores, moulds and shells in casting production. The solid structure of castings and moulds will be redesigned in future into truss or spatially open and skeleton structures. This kind of revolution is just sprouting, but it will bring unimaginable impact on manufacturing including casting production. Nobody doubts the potential of 3D printing technologies in manufacturing, but they do have limitations and drawbacks.
Comparison of marginal accuracy of castings fabricated by conventional casting technique and accelerated casting technique: an in vitro study.
Reddy, S Srikanth; Revathi, Kakkirala; Reddy, S Kranthikumar
Conventional casting technique is time consuming when compared to accelerated casting technique. In this study, marginal accuracy of castings fabricated using accelerated and conventional casting technique was compared. 20 wax patterns were fabricated and the marginal discrepancy between the die and patterns were measured using Optical stereomicroscope. Ten wax patterns were used for Conventional casting and the rest for Accelerated casting. A Nickel-Chromium alloy was used for the casting. The castings were measured for marginal discrepancies and compared. Castings fabricated using Conventional casting technique showed less vertical marginal discrepancy than the castings fabricated by Accelerated casting technique. The values were statistically highly significant. Conventional casting technique produced better marginal accuracy when compared to Accelerated casting. The vertical marginal discrepancy produced by the Accelerated casting technique was well within the maximum clinical tolerance limits. Accelerated casting technique can be used to save lab time to fabricate clinical crowns with acceptable vertical marginal discrepancy.
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Stanisław Cudziło
Full Text Available [b]Abstract[/b]. This paper reviews the current state and future developments of melt-cast high explosives. First the compositions, properties and methods of preparation of trinitrotoluene based (TNT conventional mixtures with aluminum, hexogen (RDX or octogen (HMX are described. In the newer, less sensitive explosive formulations, TNT is replaced with dinitroanisole (DNANDNANDNAN and nitrotriazolone (NTONTONTO, nitroguanidine (NG or ammonium perchlorate (AP are the replacement for RDRDX and HMX. Plasticized wax or polymer-based binder systems for melt castable explosives are also included. Hydroxyl terminated polybutadiene (HPTB is the binder of choice, but polyethylene glycol, and polycaprolactone with energetic plasticizers are also used. The most advanced melt-cast explosives are compositions containing energetic thermoplastic elastomers and novel highly energetic compounds (including nitrogen rich molecules in whose particles are nanosized and practically defect-less.[b]Keywords[/b]: melt-cast explosives, detonation parameters
The effects of the Mulligan Sustained Natural Apophyseal Glide (SNAG mobilisation in the lumbar flexion range of asymptomatic subjects as measured by the Zebris CMS20 3-D motion analysis system
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Strimpakos Nikolaos
Full Text Available Abstract Background Mulligan's mobilisation techniques are thought to increase the range of movement (ROM in patients with low back pain. The primary aim of this study was to investigate the application of the Mulligan's Sustained Natural Apophyseal Glide (SNAG technique on lumbar flexion ROM. The secondary aim was to measure the intra- and inter-day reliability of lumbar ROM employing the same procedure. Methods 49 asymptomatic volunteers participated in this double-blinded study. Subjects were randomly assigned to receive either SNAG mobilisation (n = 25, or a sham mobilisation (n = 24. The SNAG technique was applied at the L3and L4 spinal levels with active flexion in sitting by an experienced manual therapist. Three sets of 10 repetitions at each of the two spinal levels were performed. The sham mobilisation was similar to the SNAG but did not apply the appropriate direction or force. Lumbar ROM was measured by a three dimensional electronic goniometer (Zebris CMS20, before and after each technique. For the reliability, five measurements in two different days (one week apart were performed in 20 healthy subjects. Results When both interventions were compared, independent t tests yielded no statistically significant results in ROM between groups (p = 0.673. Furthermore no significant within group differences were observed: SNAG (p = 0.842, sham (p = 0.169. Intra- and inter-day reliability of flexion measurements was high (ICC1,1 > 0.82, SEM Conclusion While the Zebris proved to be a reliable device for measuring lumbar flexion ROM, SNAG mobilisation did not demonstrate significant differences in flexion ROM when compared to sham mobilisation. Trial registration Current Controlled Trials NCT00678093.
Casting Characteristics of Aluminum Die Casting Alloys
Energy Technology Data Exchange (ETDEWEB)
Makhlouf M. Makhlouf; Diran Apelian
The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.
Do Parents Blame or Doubt Their Child More when Sexually Abused by Adolescents versus Adults?
Walsh, Wendy A.; Cross, Theodore P.; Jones, Lisa M.
Although the importance of parental support for child sexual abuse victims is well documented, the nature of parental support for victims sexually abused by adolescents is less understood. In this exploratory study, we examine whether parents differ in their levels of blame or doubt for their child when sexually abused by adolescents versus…
The doubt-certainty continuum in psychopathology, lay thinking, and science.
Ron, Omri; Oren, Ela; Dar, Reuven
This paper presents a theoretical model suggesting that doubt and certainty are two extremes of a continuum. Different people can be located in different locations on this continuum, according to how much they tend to seek refutation vs. confirmation. In both ends of the continuum lay mental disorders, which can be seen as extreme deviations from the usual relatively stable equilibrium between the two thinking processes. One end is defined by excessive skepticism and manifested as obsessive compulsive disorder (OCD), a disorder characterized by incessant doubt. The other end is defined by excessive certainty and lack of doubt, manifested as delusional disorders. Throughout this article, we demonstrate that the differences between normative thoughts and delusional thoughts are relatively vague, and that in general, the human default tendency is to prefer certainty over doubt. This preference is reflected in the confirmation bias as well as in other cognitive constructs such as overconfidence and stereotypes. Recent perspectives on these biases suggest that the human preference for confirmation can be explained in evolutionary terms as adaptive and rational. A parallel view of the scientific enterprise suggests that it also requires a certain equilibrium between skepticism and confirmation. We conclude by discussing the importance of the dialectic relationship between confirmation and refutation in both lay thinking and scientific thought. Copyright © 2015 Elsevier Ltd. All rights reserved.
Doubts about actions and flanker incongruity-related potentials and performance
Tops, Mattie; Wijers, Albertus A.
The brain networks that are involved in flanker incongruity and error processing are also consistently implicated in mental disorders such as obsessive compulsive disorder (OCD) that feature increased "Doubts about Actions" (DaA) scores. In the present study we investigated whether DaA scores,
Carel, R S; Salman, H; Bar-Ziv, J
A case of silicosis in a 47-year-old worker who was employed for many years in a small souvenir casting shop is described. This work site demonstrates many unfavorable characteristics of small industries, such as lack of awareness of the need for safety measures, exposure control, protection of workers, and lack of compliance with environmental and medical-legal standards.
70° ~ Does injured extremity maintain good color , temp, and cap refill ~ Were thermal injuries avoided by ensuring water was not hot and cast was...immediate assistance if: )- Numbness (pins and needles) of fingers > Excessive swelling of fmgers > Blueness or whiteness of fingers > Severe pain
Effect of pressure applied during casting on temperatures beneath casts.
Deignan, Brian J; Iaquinto, Joseph M; Eskildsen, Scott M; Woodcock, Cassandra A; Owen, John R; Wayne, Jennifer S; Kuester, Victoria G
Burns and pressure sores are common injuries during cast application. Various factors such as water temperature, padding, and cast material layers may play a role in these injuries; however, the effect of cast molding on temperatures and pressures has not been investigated. This raises the following questions, does the application of molding during cast application: (1) alter skin level temperatures in a variety of cast materials? and (2) risk inducing either thermal injury or pressure necrosis? An upper extremity model was created to measure pressure and temperature underneath casting materials. Cast padding, water bath temperature, and cast thickness were standardized. A 3-point mold was simulated using 3 casting materials-Fiberglass only, Plaster Only splint, and Plaster splint overwrapped with Fiberglass-while pressure and temperature were recorded. : Pressure application led to a statistically significant (PFiberglass combination reached an average peak temperature of 47.9°C, which was maintained for up to 6 minutes. Neither Fiberglass nor Plaster Only reached peak temperatures of this magnitude (average of 42.7 and 43.6°C, respectively). Peak (369 mm Hg) and highest residual (21 mm Hg) pressures were below harmful levels. Pressure application during casting is a risk factor for burn injuries. Care should be taken when molding a plaster splint overwrapped in fiberglass by waiting until the plaster has fully cooled. Combined with other known risk factors, the pressure from molding a cast could increase the likelihood of causing cutaneous burns.
The casting of western sculpture during the XIXth century: sand casting versus lost wax casting
Beentjes, T.P.C.
This paper will discuss research into bronze casting techniques as practiced during the XIXth and early XXth century. Both natural sand casting (fonte au sable naturel) and lost wax casting (fonte à la cire perdue) were employed during this period and sometimes rivalled for commissions. Before the
Cast iron - a predictable material
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Jorg C. Sturm
Full Text Available High strength compacted graphite iron (CGI or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven
Melting and casting of FeAl-based cast alloy
Energy Technology Data Exchange (ETDEWEB)
Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)
The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.
Fighting the Whole System: Dissociative Identity Disorder, Labeling Theory, and Iatrogenic Doubting.
Floris, Jessica; McPherson, Susan
This research examines how individuals diagnosed with dissociative identity disorder construe their experiences of being labeled with a contested diagnosis. Semistructured interviews were conducted in the United Kingdom with 5 women and 2 men diagnosed with dissociative identity disorder. A framework analysis was conducted. The analysis identified 2 overarching themes: diagnosis cross-examined and navigating care systems. The diagnosis appeared to be continually assessed by participants for its fit with symptoms, and the doubt among professionals seemed to be unhelpfully reflected in participants' attempts to understand and come to terms with their experiences. The findings are considered in light of labeling theory, the iatrogenic effects of professional doubt, and current debates concerning the reliability and validity of psychiatric diagnostic systems that have been reinvigorated by the publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
Dialogues of The Doubt: Dostoevsky's The Eternal Husband and Machado de Assis's Dom Casmurro
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Andréa de Barros
Full Text Available This article establishes a dialogic analysis of Dostoevski's The Eternal Husband (1870 and Machado de Assis's Dom Casmurro(1899, focusing on the treatment of the doubt as an aesthetic cathegory by both authors. This dialog opens room to questions related to the specificities of their prose in the context of Realism and to the signs of dialogism on the writing of the authors.
foot is adequate. A refractory , open sand should be used. Melting and Casting: The alloys are successfully produced from electro-nickel and copper...desirable if the charge is not chiefly Monel Metal scrap. About 0.1% magnesium should be ;ell stirred into the melt in the ladle before pouring. The addition...such as is used for the more refractory valve trim alloys. Carboloy tools probably can be used to advantage for the high silicon Monel Metal alloys
Casting larger polycrystalline silicon ingots
Energy Technology Data Exchange (ETDEWEB)
Wohlgemuth, J.; Tomlinson, T.; Cliber, J.; Shea, S.; Narayanan, M.
Solarex has developed and patented a directional solidification casting process specifically designed for photovoltaics. In this process, silicon feedstock is melted in a ceramic crucible and solidified into a large grained semicrystalline silicon ingot. In-house manufacture of low cost, high purity ceramics is a key to the low cost fabrication of Solarex polycrystalline wafers. The casting process is performed in Solarex designed casting stations. The casting operation is computer controlled. There are no moving parts (except for the loading and unloading) so the growth process proceeds with virtually no operator intervention Today Solarex casting stations are used to produce ingots from which 4 bricks, each 11.4 cm by 11.4 cm in cross section, are cut. The stations themselves are physically capable of holding larger ingots, that would yield either: 4 bricks, 15 cm by 15 an; or 9 bricks, 11.4 cm by 11.4 an in cross-section. One of the tasks in the Solarex Cast Polycrystalline Silicon PVMaT Program is to design and modify one of the castings stations to cast these larger ingots. If successful, this effort will increase the production capacity of Solarex`s casting stations by 73% and reduce the labor content for casting by an equivalent percentage.
Motivated Doubts: A Comment on Walton'S Theory of Criticism
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Laar Jan Albert van
Full Text Available In his theory of criticism, D. N. Walton presupposes that an opponent either critically questions an argument, without supplementing this questioning with any reasoning of her own, or that she puts forward a critical question and supplements it with a counterargument, that is, with reasoning in defense of an opposite position of her own. In this paper, I show that there is a kind of in-between critical option for the opponent that needs to be taken into account in any classification of types of criticism, and that should not be overlooked in a system of dialogue norms, nor in a procedure for developing a strategically expedient critique. In this third option, an opponent questions and overtly doubts a statement of the proponent and supplements her doubts with a counterconsideration that explains and motivates her position of critical doubt, yet without supporting any opposite thesis, thereby assisting, as it were, the proponent in his attempt to develop a responsive argumentation, tailor-made to convince this particular opponent. First, I elaborate on the notion of an explanatory counterconsideration. Second, I discuss Walton's distinction between premises that can be challenged by mere questioning ("ordinary premises" and "assumptions" and premises that must be challenged by incurring the obligation to offer counter-argumentation (somewhat confusingly labeled "exceptions". I contend that the latter type of premises, that I would label "normality premises," can be attacked without incurring a genuine burden of proof. Instead, it can be attacked by means of incurring a burden of criticism (Van Laar and Krabbe, 2013 that amounts to the obligation to offer an explanatory counterconsideration, rather than a convincing ex concessis argument. Of course, providing the opponent with the right to discharge her burden of criticism with explanatory counterconsiderations brings a clear strategic ad- vantage to her. It is much less
Analysis of Defects in Castings Cast by Rheocasting Method SEED
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Bryksi Stunova B.
Full Text Available The paper analyses specific defects of castings produced by semi-solid casting process, especially rheocasting method SEED, which uses mechanical swirling for reaching proper structure in semisolid state with high content of solid fraction. Heat treated alloy AlSi7Mg0.3 was applied for producing an Engine Bracket casting part. For observing structure, metallographic observation by light and SEM microscopy was used. To analyse the process, software ProCAST was used to simulate the movements in shot chamber and filling of the mold.
Fracture Mechanisms in Steel Castings
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Stradomski Z.
Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.
Cast dielectric composite linear accelerator
Sanders, David M [Livermore, CA; Sampayan, Stephen [Manteca, CA; Slenes, Kirk [Albuquerque, NM; Stoller, H M [Albuquerque, NM
A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.
Improved Casting Furnace Conceptual Design
Energy Technology Data Exchange (ETDEWEB)
Fielding, Randall Sidney [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tolman, David Donald [Idaho National Lab. (INL), Idaho Falls, ID (United States)
In an attempt to ensure more consistent casting results and remove some schedule variance associated with casting, an improved casting furnace concept has been developed. The improved furnace uses the existing arc melter hardware and glovebox utilities. The furnace concept was designed around physical and operational requirements such as; a charge sized of less than 30 grams, high heating rates and minimal additional footprint. The conceptual model is shown in the report as well as a summary of how the requirements were met.
Fiber-Reinforced Slip Castings
Blome, J. C.; Drennan, D. N.; Keeser, H. M.
Addition of silica fibers greatly reduces shrinkage and cracking during casting of ceramics. Fiber-reinforced slip-cast silica ceramics are also tougher and have lower dielectric loss. Silica fibers are hyperpure material containing only 1 part per million total metal-ion impurities. Hyperpure fibers ensure high reflectance and allow casting to be fired at temperature greater than 2,200 degrees F without loss of strength from devitrification.
Altered Source Memory Retrieval is Associated with Pathological Doubt in Obsessive-Compulsive Disorder
Olson, Christy A.; Hale, Lisa R.; Hamilton, Nancy; Powell, Joshua N.; Martin, Laura E.; Savage, Cary R.
Individuals with obsessive-compulsive disorder (OCD) often complain of doubt related to memory. As neuropsychological research has demonstrated that individuals with OCD tend to focus on details and miss the larger context, the construct of source (contextual) memory may be particularly relevant to memory complaints in OCD. Memory for object versus contextual information relies on partially distinct regions within the prefrontal cortex, parietal and medial temporal lobe, and may be differentially impacted by OCD. In the present study we sought to test the hypothesis that individuals with OCD exhibit impaired source memory retrieval using a novel memory paradigm-The Memory for Rooms Test (MFRT)- a four-room memory task in which participants walk through four rooms and attempt to encode and remember objects. Demographically matched individuals with OCD and healthy controls studied objects in the context of four rooms, and then completed a memory retrieval test while undergoing functional magnetic resonance imaging (fMRI). While no differences were observed in source memory accuracy, individuals with OCD exhibited greater task related activation in the posterior cingulate cortex (PCC) relative to healthy controls during correct source memory retrieval. During correct object recognition, individuals with OCD failed to recruit the dorsolateral prefrontal(DLPFC)/premotor, left mPFC, and right parietal regions to the same extent as healthy controls. Our results suggest abnormal recruitment of frontal-parietal and PCC regions during source verses object memory retrieval in OCD. Within the OCD group, activation in the PCC and the premotor/DLPFC was associated with greater pathological doubt. This finding is consistent with the observation that OCD patients often experience extreme doubt, even when memory performance is intact. PMID:26315458
An experimental re-examination of the inferential confusion hypothesis of obsessive-compulsive doubt.
Gangemi, Amelia; Mancini, Francesco; Dar, Reuven
The inferential confusion hypothesis postulates that obsessive doubt is perpetuated by a subjective form of reasoning characterized primarily by a distrust of reality and an overreliance on imagined possibilities. However, experimental evidence for this hypothesis may be compromised by a potential confound between type of information (reality vs. possibility) and its valence (danger vs. safety). In the present study we aimed to untangle this potential confound. Forty OCD and 40 non-clinical participants underwent two versions of the Inferential Processes Task (Aardema, F., et al. (2009). The quantification of doubt in obsessive-compulsive disorder. International Journal of Cognitive Therapy, 2, 188-205). In the original version, the reality-based information is congruent with the safety hypothesis, whereas the possibility-based information is congruent with the danger hypothesis. In the modified version incorporated in the present study, the reality-based information is congruent with the danger hypothesis, whereas the possibility-based information is congruent with the safety hypothesis. Our findings did not support the inferential confusion hypothesis: both OCD and control participants changed their estimations of the probability of unwanted events based on the type of information they received (whether it conveyed danger or safety) regardless of whether it was framed as reality or possibility. The design of the present study does not lend itself to examining alternative explanations for the persistence of doubt in OCD. The hypothesized inferential confusion in OCD requires further validation. It is particularly important to demonstrate that findings do not reflect a prudential reasoning strategy. Copyright © 2015 Elsevier Ltd. All rights reserved.
Altered source memory retrieval is associated with pathological doubt in obsessive-compulsive disorder.
Olson, Christy A; Hale, Lisa R; Hamilton, Nancy; Powell, Joshua N; Martin, Laura E; Savage, Cary R
Individuals with obsessive-compulsive disorder (OCD) often complain of doubt related to memory. As neuropsychological research has demonstrated that individuals with OCD tend to focus on details and miss the larger context, the construct of source (contextual) memory may be particularly relevant to memory complaints in OCD. Memory for object versus contextual information relies on partially distinct regions within the prefrontal cortex, parietal and medial temporal lobe, and may be differentially impacted by OCD. In the present study, we sought to test the hypothesis that individuals with OCD exhibit impaired source memory retrieval using a novel memory paradigm - The Memory for Rooms Test (MFRT) - a four-room memory task in which participants walk through four rooms and attempt to encode and remember objects. Demographically matched individuals with OCD and healthy controls studied objects in the context of four rooms, and then completed a memory retrieval test while undergoing functional magnetic resonance imaging (fMRI). While no differences were observed in source memory accuracy, individuals with OCD exhibited greater task related activation in the posterior cingulate cortex (PCC) relative to healthy controls during correct source memory retrieval. During correct object recognition, individuals with OCD failed to recruit the dorsolateral prefrontal(DLPFC)/premotor, left mPFC, and right parietal regions to the same extent as healthy controls. Our results suggest abnormal recruitment of frontal-parietal and PCC regions during source verses object memory retrieval in OCD. Within the OCD group, activation in the PCC and the premotor/DLPFC was associated with greater pathological doubt. This finding is consistent with the observation that OCD patients often experience extreme doubt, even when memory performance is intact. Copyright © 2015 Elsevier B.V. All rights reserved.
Creating snags with explosives.
Evelyn L. Bull; Arthur D. Partridge; Wayne G. Williams
The tops of ponderosa pine (Pinus ponderosa) trees were blown off with dynamite to create nest sites for cavity-nesting wildlife. The procedure included drilling a hole almost through the trunk, inserting the dynamite, and setting the charge with primacord and fuse. Trees were simultaneously innoculated with a decay organism. The average cost was $...
theory of batchwise centrifugal casting
Biesheuvel, P.M.; Biesheuvel, Pieter Maarten; Nijmeijer, Arian; Verweij, H.
In batchwise centrifugal casting a cylindrical mold is filled with suspension and rotated rapidly around its axis. This results in the movement of the particulate phase toward the cylinder wall and the formation of a tubular cast. Theory is presented for particle transport in the suspension phase
Doubts of caregivers of children with cleft lip and palate on postoperative care after cheiloplasty and palatoplasty
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Armando dos Santos Trettene
Full Text Available Objective To identify the main doubts of caregivers of children with cleft lip and palate on postoperative care after cheiloplasty and palatoplasty. Method Cross-sectional study carried out in a reference hospital, between September and November 2012. The sample was composed of 50 individuals divided in two groups, of which 25 caregivers of children submitted to cheiloplasty, and 25 of children submitted to palatoplasty. The doubts were identified by an interview applied during the preoperative nursing consultation and were then categorized by similarity. Descriptive statistics was used for analysis of the outcomes. Results Concerning cheiloplasty, the doubts were related to feeding (36%, hygiene and healing (24% each, pain and infection (8% each. With regard to palatoplasty, the doubts were related to feeding (48%, hygiene (24%, pain (16%, bleeding (8% and infection (4%. Conclusion The study evidenced the concern of caregivers in relation to feeding and care of the postoperative wound.
Cast and splint immobilization: complications.
Halanski, Matthew; Noonan, Kenneth J
During the past three decades, internal fixation has become increasingly popular for fracture management and limb reconstruction. As a result, during their training, orthopaedic surgeons receive less formal instruction in the art of extremity immobilization and cast application and removal. Casting is not without risks and complications (eg, stiffness, pressure sores, compartment syndrome); the risk of morbidity is higher when casts are applied by less experienced practitioners. Certain materials and methods of ideal cast and splint application are recommended to prevent morbidity in the patient who is at high risk for complications with casting and splinting. Those at high risk include the obtunded or comatose multitrauma patient, the patient under anesthesia, the very young patient, the developmentally delayed patient, and the patient with spasticity.
Sixty Years of Casting Research
Campbell, John
The 60 years of solidification research since the publication of Chalmer's constitutional undercooling in 1953 has been a dramatic advance of understanding which has and continues to be an inspiration. In contrast, 60 years of casting research has seen mixed fortunes. One of its success stories relates to improvements in inoculation of gray irons, and another to the discovery of spheroidal graphite iron, although both of these can be classified as metallurgical rather than casting advances. It is suggested that true casting advances have dated from the author's lab in 1992 when a critical surface turbulence condition was defined for the first time. These last 20 years have seen the surface entrainment issues of castings developed to a sufficient sophistication to revolutionize the performance of light alloy and steel foundries. However, there is still a long way to go, with large sections of the steel and Ni-base casting industries still in denial that casting defects are important or even exist. The result has been that special ingots are still cast poorly, and shaped casting operations have suffered massive losses. For secondary melted and cast materials, electro-slag remelting has the potential to be much superior to expensive vacuum arc remelting, which has cost our aerospace and defense industries dearly over the years. This failure to address and upgrade our processing of liquid metals is a serious concern, since the principle entrainment defect, the bifilm, is seen as the principle initiator of cracks in metals; in general, bifilms are the Griffith cracks that initiate failures by cracking. A new generation of crack resistant metals and engineering structures can now be envisaged.
Energy Technology Data Exchange (ETDEWEB)
Imhoff, Seth D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
LANL was approached to provide material and design guidance for a fan-shaped fuel element. A total of at least three castings were planned. The first casting is a simple billet mold to be made from high carbon DU-10Mo charge material. The second and third castings are for optimization of the actual fuel plate mold. The experimental scope for optimization is only broad enough for a second iteration of the mold design. It is important to note that partway through FY17, this project was cancelled by the sponsor. This report is being written in order to capture the knowledge gained should this project resume at a later date.
Slip-Cast Superconductive Parts
Wise, Stephanie A.; Buckley, John D.; Vasquez, Peter; Buck, Gregory M.; Hicks, Lana P.; Hooker, Matthew W.; Taylor, Theodore D.
Complex shapes fabricated without machining. Nonaqueous slip-casting technique used to form complexly shaped parts from high-temperature superconductive materials like YBa(2)Cu(3)O(7-delta). Such parts useful in motors, vibration dampers, and bearings. In process, organic solvent used as liquid medium. Ceramic molds made by lost-wax process used instead of plaster-of-paris molds, used in aqueous slip-casting but impervious to organic solvents and cannot drain away liquid medium. Organic-solvent-based castings do not stick to ceramic molds as they do to plaster molds.
The primacy of doubt: Evolution of numerical weather prediction from determinism to probability
Palmer, Tim
Over the last 25 years, the focus of operational numerical weather prediction has evolved from that of estimating the most likely evolution of weather to that of estimating probability distributions of future weather associated with inevitable uncertainties in both initial conditions and model equations. This evolution from determinism to uncertainty has not only increased the scientific rigor of weather prediction, it has also increased the value of weather forecasts for users. In addition, it has opened up a new approach to solving the equations of motion, likely to be of importance for both weather and climate prediction in an age where high-performance computing is limited by power consumption. However, despite all this, the numerical weather prediction community has yet to embrace fully the concept of the primacy of doubt. It is now time to take the final step in this direction.
Problem-based learning in children's nursing: transcending doubts to exceeding expectations.
Raftery, Sara E C; Clynes, Mary P; O'Neill, Colleen; Ward, Emer; Coyne, Imelda
Problem-based learning (PBL) is well established in health education. It is regarded as a constructionist approach to education that emphasizes students' active engagement with the learning process, self-direction, and learning in a meaningful context. This article details the experiences of nurse lecturers in one university in the Republic of Ireland during the introduction of a PBL module to students enrolled in a higher diploma in children's nursing program. All lecturers attended a three-day training program on the principles and processes of PBL. The lecturers, all experienced nurse educators, had no prior experience in implementing PBL. Data collection involved the use of reflective journals and group meetings. Thematic content analysis revealed key themes that chart the journey from transcending doubts to exceeding expectations of the PBL process.
Anodization of cast aluminium alloys produced by different casting methods
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K. Labisz
Full Text Available In this paper the usability of two casting methods, of sand and high pressure cast for the anodization of AlSi12 and AlSi9Cu3 aluminium cast alloys was investigated. With defined anodization parameters like electrolyte composition and temperature, current type and value a anodic alumina surface layer was produced. The quality, size and properties of the anodic layer was investigated after the anodization of the chosen aluminium cast alloys. The Alumina layer was observed used light microscope, also the mechanical properties were measured as well the abrasive wear test was made with using ABR-8251 equipment. The researches included analyze of the influence of chemical composition, geometry and roughness of anodic layer obtained on aluminum casts. Conducted investigations shows the areas of later researches, especially in the direction of the possible, next optimization anodization process of aluminum casting alloys, for example in the range of raising resistance on corrosion to achieve a suitable anodic surface layer on elements for increasing applications in the aggressive environment for example as materials on working building constructions, elements in electronics and construction parts in air and automotive industry.
UK's Brexit battle casts shadow over funding for international fusion projects
Energy Technology Data Exchange (ETDEWEB)
Shepherd, John [nuclear 24, Redditch (United Kingdom)
The ramifications of Brexit - the UK's decision to leave the European Union - have continued to send shockwaves through the nuclear energy community, since I explained in this column recently that the move also means withdrawing from the Euratom Treaty. Now the UK's divorce from the EU is posing a threat that could deal a major blow to international efforts in fusion research. In fact, confusing signals from the UK have cast doubt on future funding and support for two key areas of world fusion cooperation: the Oxfordshire-based Joint European Torus (Jet) programme and the International Thermonuclear Experimental Reactor (Iter) project at Cadarache in France.
14 CFR 23.621 - Casting factors.
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Casting factors. 23.621 Section 23.621... Casting factors. (a) General. The factors, tests, and inspections specified in paragraphs (b) through (d... structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and...
Modelling of flow phenomena during DC casting
Zuidema, J.
Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an
The biogeochemistry of selenium in Sunan grassland, Gansu, Northwest China, casts doubt on the belief that Marco Polo reported selenosis for the first time in history.
Shao, Shuxun; Zheng, Baoshan
In order to clarify the historic academic problem of whether or not livestock poisoning in ancient Suzhou of Northwest China, recorded by Marco Polo in 1295, was selenosis, this study deals with the biogeochemistry of selenium in Sunan County in the Hexi Corridor, which is part of ancient Suzhou in China. It was found that quite a number of farm animals had suffered from intoxication and died as a result of grazing poisonous grasses, mostly Oxytropis DC, Stellera chamaejasme, and Achnatheru inebrians. Toxic symptoms of livestock grazing on Oxytropis DC are similar to those of selenium toxicity, for instance, hair loss and hoof lesions as described by Marco Polo. Therefore, we thought that toxic grass, probably Oxytropis DC, led to the intoxication of livestock recorded by Marco Polo. Average Se concentrations in two members of this species were 0.112 +/- 0.038 mg/kg for the root of Oxytropis glabra, 0.102 +/- 0.027 mg/kg for the stem and leaf of Oxytropis glabra, and 0.066 +/- 0.009 mg/kg for Oxytropis ochrocephala. The average soil selenium concentration was 0.205 +/- 0.127 mg/kg on grassland producing Oxytropis glabra and 0.152 +/- 0.024 mg/kg on grassland producing Oxytropis ochrocephala. The average Se concentration in other plants was 0.076 mg/kg in the root of Ephedra monosperma Mey, 0.029 mg/kg in the root of Rheum palmatum, 0.031 mg/kg in the root of Stellera chamaejasme, 0.037 mg/kg in Achnatherum inebrians, and 0.067 mg/kg in forage grass (Achnatherum splendens ohwi). Selenium concentrations in soils and plants in Sunan County are far less than the thresholds causing selenium toxicity in livestock. As a result, this study concludes that the livestock poisoning recorded by Marco Polo in 1295 might not have been selenosis.
Some Theoretical Considerations on Caste
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Madhusudan Subedi
Full Text Available Caste as a system of social stratification was an encompassing system in the past. There was reciprocal system of exchange goods and services. With time, occupation and mode of generation of livelihood of various caste groups changed, and the traditional form of jajmani system fizzled out. This paper provides an account of changing perspectives of caste relations in social science writing and political discourse. The discourse of caste has been shifted from ritual hierarchy and social discrimination to an instrument to mobilize people for economic and political gain. DOI: http://dx.doi.org/10.3126/dsaj.v7i0.10437 Dhaulagiri Journal of Sociology and Anthropology Vol. 7, 2013; 51-86
The CAST Time Projection Chamber
Autiero, D.; Carmona, J.M.; Cebrian, S.; Chesi, E.; Davenport, M.; Delattre, M.; Di Lella, L.; Formenti, F.; Irastorza, I.G.; Gomez, H.; Hasinoff, M.; Lakic, B.; Luzon, G.; Morales, J.; Musa, L.; Ortiz, A.; Placci, A.; Rodriguez, A.; Ruz, J.; Villar, J.A.; Zioutas, K.
One of the three X-ray detectors of the CAST experiment searching for solar axions is a Time Projection Chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity X-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is safely set during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62 %. Shielding has been installed around the detector, lowering the background level to 4.10 x 10^-5 counts/cm^2/s/keV between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion-photon coupling and mass.
Machine Casting of Ferrous Alloys
unit 23 7 Rear view of casting unit 23 8 Induction coil with crucible in place 24 9 Refractory components of casting system 24 10 Multiple...used in small, bottom-pour ladles . The stirring required by the Rheocasting proce- dures is to be accomplished by the paddle assembly shown in Figure...bonded carbide coating with refractory oxide layer on the final sur- face. (c) Diffusion bonded carbide coating 'ith diffusion bonded oxide layer m
AGARD handbook on advanced casting
Mietrach, Dietmar
The need to improve aircraft performance and, simultaneously, to reduce costs has led to a re-examination of the use of casting processes in aircraft manufacture. The Structures and Materials Panel of AGARD has provided practical information about design, mechanical values, applications, quality assurance and damage tolerance. By providing the data in this form it is hoped that the designer will be encouraged to exploit the many recent advances in casting to optimum effect.
Inoculation of chromium white cast iron
D. Kopyciński
It has been proved that an addition of boron carbide introduced as an inoculant to the chromium white cast iron changes the structureof castings. Castings after inoculation revealed a different structure with numerous grains. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.
Inoculation of chromium white cast iron
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D. Kopyciński
Full Text Available It has been proved that an addition of boron carbide introduced as an inoculant to the chromium white cast iron changes the structureof castings. Castings after inoculation revealed a different structure with numerous grains. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.
Staff's normative attitudes towards coercion: the role of moral doubt and professional context-a cross-sectional survey study.
Molewijk, Bert; Kok, Almar; Husum, Tonje; Pedersen, Reidar; Aasland, Olaf
The use of coercion is morally problematic and requires an ongoing critical reflection. We wondered if not knowing or being uncertain whether coercion is morally right or justified (i.e. experiencing moral doubt) is related to professionals' normative attitudes regarding the use of coercion. This paper describes an explorative statistical analysis based on a cross-sectional survey across seven wards in three Norwegian mental health care institutions. Descriptive analyses showed that in general the 379 respondents a) were not so sure whether coercion should be seen as offending, b) agreed with the viewpoint that coercion is needed for care and security, and c) slightly disagreed that coercion could be seen as treatment. Staff did not report high rates of moral doubt related to the use of coercion, although most of them agreed there will never be a single answer to the question 'What is the right thing to do?'. Bivariate analyses showed that the more they experienced general moral doubt and relative doubt, the more one thought that coercion is offending. Especially psychologists were critical towards coercion. We found significant differences among ward types. Respondents with decisional responsibility for coercion and leadership responsibility saw coercion less as treatment. Frequent experience with coercion was related to seeing coercion more as care and security. This study showed that experiencing moral doubt is related to some one's normative attitude towards coercion. Future research could investigate whether moral case deliberation increases professionals' experience of moral doubt and whether this will evoke more critical thinking and increase staff's curiosity for alternatives to coercion.
Development of vacuum die-casting process
Directory of Open Access Journals (Sweden)
Masashi Uchida
Full Text Available The vacuum die-casting process, started 25 years ago in Japan, has been widely applied. This technology contributes very much to improvement of castings quality. The main factor causing the defects of die castings is the trapped air in the mold cavity, while the key technology of vacuum die-casting process is to avoid the trapped air effectively by evacuating the cavity before casting. At the same time, due to the shot speed and the casting pressure reduced in half, the service life of the die is prolonged and the productivity is enhanced, as well. Vacuum die-casting process is of great signifi cance in improving the die castings quality and making up the shortcomings of super-high-speed shot casting.
Analysis of Portuguese language blogs about bariatric surgery: key doubts of internauts regarding the postoperative period.
Barros, Lívia Moreira; Frota, Natasha Marques; de Araújo, Thiago Moura; Tellez, Michelle; Ciqueto, Heloisa Helena Peres; Caetano, Joselany Áfio
The Internet, particularly blogs have become an important tool for patients to disseminate and exchange information on a variety of health topics, including bariatric surgery. By virtue of its interactivity being free of judgement from health care providers, blogs expose gaps in patients' knowledge and understanding. This study analyzes the main doubts expressed in blogs by patients in the postoperative period of bariatric surgery. This is a qualitative exploratory study of 11 blogs of patients, who underwent bariatric surgery, that were available on the Internet between October 2013 and May 2017. The data were collected through a structured instrument and analyzed according to Bardin's suggestions. The sampling method used was intentional. Evolution of diet, weight loss, plateau effect, weight regain, physical exercises, physiological changes, complications, use of contraceptive and pregnancy were the main areas of concern. More needs to be done to educate and prepare bariatric patients for the postoperative period. The content found in blogs serves towards building better links with patients, helps them make better decisions, and provides them an opportunity to be active participants in their own treatment.
Doubtful records of reptile species in some areas of the Danube Delta Biosphere Reserve (Romania
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TÖRÖK Zsolt Csaba
Full Text Available In the present paper there are provided details on the doubtful data on the occurrence of some reptile species in various parts of the Danube Delta Biosphere Reserve. Testudo graeca was indicated by mistake at Sfântu Gheorghe (probably the authors saw the species in some places from the continental plateau nearby of Sfântu Gheorghe branch, not inside the Danube Delta. Lacerta viridis was mentioned in the so-called "maritime Delta" and at the ruins of Histria fortress (due to confusion with specimens of Lacerta agilis. Also, Podarcis muralis was "recorded" at the ruins of Histria fortress (due to misidentification of specimens belonging to species P. taurica. A corps of snake found at Letea forest was considered by mistake as belonging to species Eryx jaculus. In several official reports (grey literature the species Elaphe longissima (Zamenis longissimus was mentioned by mistake as occurring at Letea forest. Elaphe (quatuorlineata sauromates was "recorded" at the ruins of Histria fortress and at Sfântu Gheorghe due to confusion with specimens belonging to other snake species. Specimens of Vipera urisnii from the Danube Delta were considered as belonging to the species Vipera berus. Also, Vipera ursinii was metioned by mistake at Caraorman marine levee and at Chituc marine levee, based only on the idea that if the species occurs on other marine levees, it has to be present on these two marine levees, too.
Why are male social relationships complex in the Doubtful Sound bottlenose dolphin population?
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David Lusseau
Full Text Available BACKGROUND: Access to oestrus females tends to be the main driver of male sociality. This factor can lead to complex behavioural interactions between males and groups of males. Male bottlenose dolphins may form alliances to consort females and to compete with other males. In some populations these alliances may form temporary coalitions when competing for females. I examined the role of dyadic and group interactions in the association patterns of male bottlenose dolphins in Doubtful Sound, New Zealand. There is no apparent mating competition in this population and no consortship has been observed, yet agonistic interactions between males occur regularly. METHODOLOGY/PRINCIPAL FINDINGS: By comparing the network of male interactions in several social dimensions (affiliative, agonistic, and associative I show that while agonistic interactions relate to dyadic association patterns, affiliative interactions seem to relate to group association patterns. Some evidence suggests that groups of males also formed temporary coalitions during agonistic interactions. While different groups of males had similar relationships with non-oestrus females, the time they spent with oestrus females and mothers of newborns differed greatly. CONCLUSIONS/SIGNIFICANCE: After considering several hypotheses, I propose that the evolution of these complex relationships was driven by sexual competition probably to out-compete other males for female choice.
Odd complaints and doubtful conditions: norms of hypochondria in Jane Austen and Catherine Belling.
Nelson, James Lindemann
In her final fragmentary novel Sanditon, Jane Austen develops a theme that pervades her work from her juvenilia onward: illness, and in particular, illness imagined, invented, or self-inflicted. While the "invention of odd complaints" is characteristically a token of folly or weakness throughout her writing, in this last work imagined illness is also both a symbol and a cause of how selves and societies degenerate. In the shifting world of Sanditon, hypochondria is the lubricant for a society bent on turning health into a commodity. As a result, people's rationality and their moral character come under attack. Catherine Belling's recent subtle study, A Condition of Doubt: The Meanings of Hypochondria, unveils hypochondria's discursive and cultural character. Running sharply against the tenor of Austen's treatment, however, she argues in defense of the rationality of hypochondriacs; the notion that the condition may involve morally significant defects is not entertained; any connection to the commercialization of health care is muted. Here, I contrast Austen's morally and epistemically negative rendering of her hypochondriacal characters in Sanditon with Belling's efforts to create a sympathetic understanding of people with hypochondria. I will argue that, despite time gaps and genre differences, joint consideration of these texts can help bioethicists better appreciate how medicine can intensify, pathologize, and exploit anxieties about illness and death, thus adding to the challenges of living well in the face of mortality and morbidity.
Lights, shadows and doubts on the policies for R&D in Italy
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Ferdinando Terranova
Full Text Available This article addresses the issue of R&D in Italy, the institutions that finance it, its operational tools, spin-offs and start-ups, put in place to ensure that the R&D can be transformed into productive innovation, both of the process and the product. The question that is addressed concerns the funding streams for the launch and development of the operational instruments. The picture that emerges is extremely diverse and irregular between sources of income from the European Union, national Government, national research bodies and agencies, both public and private, the Italian regions and local entities (EELL directly and through their subsidiary companies. It leads to the question that this article attempts to answer: is the assertion that insufficient resources are devoted to R&D true? With regard to this, there are numerous legitimate doubts, and there is reason to believe that the fact there are so many channels for dispersing the resources devoted to R&D is primarily related to the excessive number of sources of funding, not to mention the evaluative procedures and timing for allocating funds. This is one aspect. The main issue is the lack of a widely shared programming policy, based on the priorities of the national and local communities for responses to their human needs.
Students' perceptions and doubts about menstruation in developing countries: a case study from India.
Chothe, Vikas; Khubchandani, Jagdish; Seabert, Denise; Asalkar, Mahesh; Rakshe, Sarika; Firke, Arti; Midha, Inuka; Simmons, Robert
Menstrual education is a vital aspect of adolescent health education. Culture, awareness, and socioeconomic status often exert profound influence on menstrual practices. However, health education programs for young women in developing countries do not often address menstrual hygiene, practices, and disorders. Developing culturally sensitive menstrual health education and hygiene programs for adolescent females has been recommended by professional health organizations like the World Health Organization and UNICEF. These programs cannot be developed without understanding existing myths and perceptions about menstruation in adolescent females of developing countries. Thus, the purpose of this qualitative study from India was to document existing misconceptions regarding menstruation and perceptions about menarche and various menstrual restrictions that have been understudied. Out of the 612 students invited to participate by asking questions, 381 girls participated by asking specific questions about menstruation (response rate = 62%). The respondents consisted of 84 girls from sixth grade, 117 from seventh grade, and 180 from eighth grade. The questions asked were arranged into the following subthemes: anatomy and physiology, menstrual symptoms, menstrual myths and taboos, health and beauty, menstrual abnormalities, seeking medical advice and home remedies; sanitary pads usage and disposal; diet and lifestyle; and sex education. Results of our study indicate that students had substantial doubts about menstruation and were influenced by societal myths and taboos in relation to menstrual practices. Parents, adolescent care providers, and policy makers in developing countries should advocate for comprehensive sexuality education and resources (e.g., low-cost sanitary pads and school facilities) to promote menstrual health and hygiene promotion.
Taxonomic revision of doubtful Brazilian freshwater shrimp species of genus Macrobrachium (Decapoda, Palaemonidae
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Leonardo G. Pileggi
Full Text Available The freshwater prawns of the genus Macrobrachium Spence Bate, 1868 are widely distributed in rivers of tropical and subtropical regions and represent an interesting group with controversial taxonomy. The morphological characters traditionally used to separate species have shown a high intraspecific variation. Doubts about the status of M. birai Lobão, Melo & Fernandes, 1986, M. holthuisi Genofre & Lobão, 1978 and M. petronioi Melo, Lobão & Fernandes, 1986 have been arisen due to the high resemblance of the former two species with M. olfersi (Wiegmann, 1836, and the latter one with M. potiuna (Müller, 1880. Therefore, we performed a detailed morphological analysis of these species, including new characters not usually used in the species recognition. The present results here with molecular data lead us to conclude that M. birai and M. holthuisi are junior synonyms of M. olfersi, and M. petronioi is a junior synonym of M. potiuna. Considering these synonymies, 17 valid species are now reported for the Brazilian territory.
Enhancing Stand Structure through Snag Creation in Northeastern U.S. Forests: Using Ethanol Injections and Bark Beetle Pheromones to Artificially Stress Red Maple and White Pine
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Kevin J. Dodds
Full Text Available We investigated two methods to create white pine and red maple snags in a forested setting. The first involved injecting trees with ethanol at two times (single Ethanol (ETOH and double ETOH injections to increase attractiveness to insects and elicit attacks on trees. The second method was unique to white pines and involved both injection treatments in combination with baiting trees with Ips-specific pheromones. Three of five white pines from the double ETOH treatment died in the second year. Species including Ips pini (Say, Ips grandicollis Eichhoff, Orthotomicus caelatus Eichhoff, Crypturgus borealis Swaine and Monochamus notatus (Drury responded more strongly to at least one of the treatments over control trees. However, there were no differences found in individual Scolytinae or Cerambycidae species response to treatments in red maple. Fitness (FV/FM and vitality (PIabs were both significantly reduced in both ETOH treatments compared to controls in white pine. In red maple, fitness was reduced in the double ETOH treated trees but the final mean FV/FM values were within the approximate optimal of health. Ethanol injections, in combination with Ips-specific semiochemicals, show promise for creating standing coarse woody debris (CWD in white pine. Injecting ethanol was not effective for stressing red maple.
Cast Aluminum Structures Technology (CAST) Phase VI. Technology Transfer.
Composition PERCENT, PERCENT, ELEMENTS MINIMUM MAXIMUM COPPER -- 0.20 SILICON 6.5 7.5 IRON -- 0.10 MANGANESE -- 0.10 ZINC -- 0.10 MAGNESIUM 0.55 0.65...effects on fluidity of pouring temperature, silica sand grain size (AFS 53, 70, and 140), sand type (silica, chromite , and zircon), and mold coating...to 1.5 inches and included both copper and aluminum chills. Parts were cast with A357 at 1425 and 1450OF and inspected for 33 casting defects. Test
Development of vacuum die-casting process
Masashi Uchida
The vacuum die-casting process, started 25 years ago in Japan, has been widely applied. This technology contributes very much to improvement of castings quality. The main factor causing the defects of die castings is the trapped air in the mold cavity, while the key technology of vacuum die-casting process is to avoid the trapped air effectively by evacuating the cavity before casting. At the same time, due to the shot speed and the casting pressure reduced in half, the service life of the di...
Magnesium-lithium casting alloys
Latenko, V. P.; Silchenko, T. V.; Tikhonov, V. A.; Maltsev, V. P.; Korablin, V. P.
The strength properties of magnesium-lithium alloys at room, low, and high temperatures are investigated. It is found that the alloys may have practical application at ambient temperatures up to 100 C, that negative temperatures have a favorable influence on the alloy strength, and that cyclic temperature variations have practically no effect on the strength characteristics. The influence of chemical coatings on corrosion resistance of the MgLi alloys is examined. Several facilities based on pressure casting machines, low-pressure casting machines, and magnetodynamic pumps were designed for producing MgLi alloy castings. Results were obtained for MgLi alloys reinforced with fibers having a volumetric content of 15%.
CAST, Collaboration
The CAST experiment has the potential to search for solar axions (dark matter particle candidates) or other particles with similar coupling. E.g., paraphtons (Hidden Sector), chameleons (dark energy), while considering the possibility whether CAST could be transformed to an antenna for relic axions with rest mass up to 0.1 to 1meV. While axion searches suggest detectors with lower background, paraphoton and chameleon searches require detectors with sub-keV threshold energy and the use of transparent windows in front of the Micromegas detectors, which cover 3 out of the 4 CAST magnet exits. Ongoing theoretical estimates and experimental investigations will define the priorities of the suggested 4 physics items of this proposal for the period 2012-2014.
Titanium Aluminide Casting Technology Development
Bünck, Matthias; Stoyanov, Todor; Schievenbusch, Jan; Michels, Heiner; Gußfeld, Alexander
Titanium aluminide alloys have been successfully introduced into civil aircraft engine technology in recent years, and a significant order volume increase is expected in the near future. Due to its beneficial buy-to-fly ratio, investment casting bears the highest potential for cost reduction of all competing production technologies for TiAl-LPTB. However, highest mechanical properties can be achieved by TiAl forging. In view of this, Access e.V. has developed technologies for the production of TiAl investment cast parts and TiAl die cast billets for forging purposes. While these parts meet the highest requirements, establishing series production and further optimizing resource and economic efficiency are present challenges. In order to meet these goals, Access has recently been certified according to aircraft standards, aiming at qualifying parts for production on technology readiness level 6. The present work gives an overview of the phases of development and certification.
Geralis, T.
We present results from the CERN Axion Solar Telescope (CAST) and the Axion Dark Matter eXperiment (ADMX), together with a brief review on prospects on Axion searches with a variety of experimental techniques. CAST has explored masses up to 0.64 eV setting the most stringent limit on the axion-photon coupling, apart for the micro-eV region where ADMX is the most competitive experiment. CAST is aiming at surpassing the 1eV WMAP upper limit and possibly revisiting the operation in vacuum with extra sensitive X-ray detectors, while ADMX, using improved extra sensitive SQUID amplifiers will explore the micro-eV mass range.
Energy Consumption of Die Casting Operations
Energy Technology Data Exchange (ETDEWEB)
Jerald Brevick; clark Mount-Campbell; Carroll Mobley
Molten metal processing is inherently energy intensive and roughly 25% of the cost of die-cast products can be traced to some form of energy consumption [1]. The obvious major energy requirements are for melting and holding molten alloy in preparation for casting. The proper selection and maintenance of melting and holding equipment are clearly important factors in minimizing energy consumption in die-casting operations [2]. In addition to energy consumption, furnace selection also influences metal loss due to oxidation, metal quality, and maintenance requirements. Other important factors influencing energy consumption in a die-casting facility include geographic location, alloy(s) cast, starting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting machine, related equipment (robots, trim presses), and downstream processing (machining, plating, assembly, etc.). Each of these factors also may influence the casting quality and productivity of a die-casting enterprise. In a die-casting enterprise, decisions regarding these issues are made frequently and are based on a large number of factors. Therefore, it is not surprising that energy consumption can vary significantly from one die-casting enterprise to the next, and within a single enterprise as function of time.
Electromagnetic segregation of cast parts
Langejurgen, M.; Nacke, B.
The Electromagnetic Induced Segregation (EIS) of cast parts is an innovative technology for diecasting aluminium alloys. Using numerical simulation, an inductor system has been developed to produce a primary silicon concentration gradient during casting. The report shows the advantages of numerical simulation in research and development. A suitable inductor has been designed and its electromagnetic field optimized for the EIS. The numerical model is 2D for geometries with cylindrical symmetry and 3D for non-symmetric products. The inductor system is implemented in a pilot installation. With the metallurgical results, the interaction between the electromagnetic field and the location of primary silicon is investigated. Figs 7, Refs 1.
A neuropsychological test of belief and doubt: Damage to ventromedial prefrontal cortex increases credulity for misleading advertising
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Erik eAsp
Full Text Available We have proposed the False Tagging Theory as a neurobiological model of belief and doubt processes. The theory posits that the prefrontal cortex is critical for normative doubt toward properly comprehended ideas or cognitions. Such doubt is important for advantageous decisions, for example in the financial and consumer purchasing realms. Here, using a neuropsychological approach, we put the False Tagging Theory to an empirical test, hypothesizing that focal damage to the ventromedial prefrontal cortex would cause a doubt deficit that would result in higher credulity and purchase intention for consumer products featured in misleading advertisements. We presented 8 consumer ads to 18 patients with focal brain damage to the ventromedial prefrontal cortex, 21 patients with focal brain damage outside the prefrontal cortex, and 10 demographically similar healthy comparison participants. Patients with ventromedial prefrontal cortex damage were (1 more credulous to misleading ads; and (2 showed the highest intention to purchase the products in the misleading advertisements, relative to patients with brain damage outside the prefrontal cortex and healthy comparison participants. The pattern of findings was obtained even for ads in which the misleading bent was corrected by a disclaimer. The evidence is consistent with our proposal that damage to the ventromedial prefrontal cortex disrupts a false tagging mechanism which normally produces doubt and skepticism for cognitive representations. We suggest that the disruption increases credulity for misleading information, even when the misleading information is corrected for by a disclaimer. This mechanism could help explain poor financial decision-making when persons with ventromedial prefrontal dysfunction (e.g., caused by neurological injury or aging are exposed to persuasive information.
A neuropsychological test of belief and doubt: damage to ventromedial prefrontal cortex increases credulity for misleading advertising.
Asp, Erik; Manzel, Kenneth; Koestner, Bryan; Cole, Catherine A; Denburg, Natalie L; Tranel, Daniel
We have proposed the False Tagging Theory (FTT) as a neurobiological model of belief and doubt processes. The theory posits that the prefrontal cortex is critical for normative doubt toward properly comprehended ideas or cognitions. Such doubt is important for advantageous decisions, for example in the financial and consumer purchasing realms. Here, using a neuropsychological approach, we put the FTT to an empirical test, hypothesizing that focal damage to the ventromedial prefrontal cortex (vmPFC) would cause a "doubt deficit" that would result in higher credulity and purchase intention for consumer products featured in misleading advertisements. We presented 8 consumer ads to 18 patients with focal brain damage to the vmPFC, 21 patients with focal brain damage outside the prefrontal cortex, and 10 demographically similar healthy comparison participants. Patients with vmPFC damage were (1) more credulous to misleading ads; and (2) showed the highest intention to purchase the products in the misleading advertisements, relative to patients with brain damage outside the prefrontal cortex and healthy comparison participants. The pattern of findings was obtained even for ads in which the misleading bent was "corrected" by a disclaimer. The evidence is consistent with our proposal that damage to the vmPFC disrupts a "false tagging mechanism" which normally produces doubt and skepticism for cognitive representations. We suggest that the disruption increases credulity for misleading information, even when the misleading information is corrected for by a disclaimer. This mechanism could help explain poor financial decision-making when persons with ventromedial prefrontal dysfunction (e.g., caused by neurological injury or aging) are exposed to persuasive information.
Directory of Open Access Journals (Sweden)
K. E. Baranovskij
Full Text Available Casting of wear-resistant chrome cast irons in combined molds and iron chills is studied. Application of these ways of casting results in blending of carbides and increasing of hardness of castings.
Comprehending Adverbs Of Doubt And Certainty In Health Communication: A Multidimensional Scaling Approach
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Norman S. Segalowitz
Full Text Available This research explored the feasibility of using multidimensional scaling (MDS analysis in novel combination with other techniques to study comprehension of epistemic adverbs expressing doubt and certainty (e.g., evidently, obviously, probably as they relate to health communication in clinical settings. In Study 1, Australian English speakers performed a dissimilarity-rating task with sentence pairs containing the target stimuli, presented as doctors' opinions. Ratings were analyzed using a combination of cultural consensus analysis (factor analysis across participants, weighted-data classical-MDS, and cluster analysis. Analyses revealed strong within-community consistency for a 3-dimensional semantic space solution that took into account individual differences, strong statistical acceptability of the MDS results in terms of stress and explained variance, and semantic configurations that were interpretable in terms of linguistic analyses of the target adverbs. The results confirmed the feasibility of using MDS in this context. Study 2 replicated the results with Canadian English speakers on the same task. Semantic analyses and stress decomposition analysis were performed on the Australian and Canadian data sets, revealing similarities and differences between the two groups. Overall, the results support using MDS to study comprehension of words critical for health communication, including in future studies, for example, second language speaking patients and/or practitioners. More broadly, the results indicate that the techniques described should be promising for comprehension studies in many communicative domains, in both clinical settings and beyond, and including those targeting other aspects of language and focusing on comparisons across different speech communities.
Cytomegalovirus infection and cervical cancer: from past doubts to present questions.
Marinho-Dias, Joana; Sousa, Hugo
Since early 60's that Cytomegalovirus was studied for its possible role in cervical cancer development. Despite several decades of studies and the description of CMV DNA in cervical samples, it is still doubtful what is the prevalence of Cytomegalovirus in cervix and if CMV can act as a co-factor in cervical carcinogenesis. In this Systematic Review we intend to summarize the frequency of Cytomegalovirus in cervical samples by revising all published studies between 1980 and 2011 regarding the detection of Cytomegalovirus in cervical samples and the development of lesions/ invasive cervical cancer. Crude and adjusted frequencies of Cytomegalovirus infection were calculated according to country and world region. This study revealed that the worldwide crude frequency of Cytomegalovirus infection in the cervix was 18.9% in all cervical samples and 36.5% in HPV positive women. Cytomegalovirus infection was present in all different types of lesions: 17.4% in normal/ cervicitis, 28.0% in LSIL, 19.7% in HSIL and 44.4% in CIS/ICC. The overall rate of Cytomegalovirus infection varied from 1.58% to 61.0% with an increased incidence in less developed countries. In this study we described a high frequency of positive Cytomegalovirus cases in all types of cervical samples, with increased incidence in both HPV-infected women and CIS/ICC cases. Hence, despite results showed that Cytomegalovirus shedding in cervical samples is frequent more studies should be performed to clarify if Cytomegalovirus infection is an opportunistic infection in HPV-infected cases, or if it contributes for cervical immunosuppression that will favor HPV-associated carcinogenesis.
Directory of Open Access Journals (Sweden)
A. N. Krutilin
Full Text Available The results of investigations of physical-mechanical characteristics of cast iron slugs, received by semicontinuos way of casting, at temperatures from 850 up to 1100^ С are given.
Developing technological process of obtaining giality casts
Directory of Open Access Journals (Sweden)
A. Issagulov
Full Text Available The article considers the process of manufacturing castings using sand-resin forms and alloying furnace. Were the optimal technological parameters of manufacturing shell molds for the manufacture of castings of heating equipment. Using the same upon receipt of castings by casting in shell molds furnace alloying and deoxidation of the metal will provide consumers with quality products and have a positive impact on the economy in general engineering.
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cast cover. 880.6185 Section 880.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES....6185 Cast cover. (a) Identification. A cast cover is a device intended for medical purposes that is...
14 CFR 25.621 - Casting factors.
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Casting factors. 25.621 Section 25.621... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.621 Casting factors. (a... meet approved specifications. Paragraphs (c) and (d) of this section apply to any structural castings...
14 CFR 27.621 - Casting factors.
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Casting factors. 27.621 Section 27.621... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.621 Casting factors. (a) General... approved specifications. Paragraphs (c) and (d) of this section apply to structural castings except...
14 CFR 29.621 - Casting factors.
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Casting factors. 29.621 Section 29.621... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.621 Casting factors. (a... approved specifications. Paragraphs (c) and (d) of this section apply to structural castings except...
Inoculation Effects of Cast Iron
Directory of Open Access Journals (Sweden)
E. Fraś
Full Text Available The paper presents a solidification sequence of graphite eutectic cells of A and D types, as well as globular and cementite eutectics. The morphology of eutectic cells in cast iron, the equations for their growth and the distances between the graphite precipitations in A and D eutectic types were analyzed. It is observed a critical eutectic growth rate at which one type of eutectic transformed into another. A mathematical formula was derived that combined the maximum degree of undercooling, the cooling rate of cast iron, eutectic cell count and the eutectic growth rate. One type of eutectic structure turned smoothly into the other at a particular transition rate, transformation temperature and transformational eutectic cell count. Inoculation of cast iron increased the number of eutectic cells with flake graphite and the graphite nodule count in ductile iron, while reducing the undercooling. An increase in intensity of inoculation caused a smooth transition from a cementite eutectic structure to a mixture of cementite and D type eutectic structure, then to a mixture of D and A types of eutectics up to the presence of only the A type of eutectic structure. Moreover, the mechanism of inoculation of cast iron was studied.
Cure shrinkage in casting resins
Energy Technology Data Exchange (ETDEWEB)
Spencer, J. Brock [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
A method is described whereby the shrinkage of a casting resin can be determined. Values for the shrinkage of several resin systems in frequent use by Sandia have been measured. A discussion of possible methods for determining the stresses generated by cure shrinkage and thermal contraction is also included.
Social Education, 2005
Thomas Crawford, an American Sculptor, created the full-size figure of Freedom in clay. Molds were made, from which a full-size positive plaster model was cast in five main sections. This model is on view today in the basement rotunda of the Russell Senate Office Building. Clark Mills was a self-taught American sculptor with experience in casting…
Advanced Lost Foam Casting Technology
Energy Technology Data Exchange (ETDEWEB)
Charles E. Bates; Harry E. Littleton; Don Askeland; Taras Molibog; Jason Hopper; Ben Vatankhah
This report describes the research done under the six tasks to improve the process and make it more functional in an industrial environment. Task 1: Pattern Pyrolysis Products and Pattern Properties Task 2: Coating Quality Control Task 3: Fill and Solidification Code Task 4: Alternate Pattern Materials Task 5: Casting Distortion Task 6: Technology Transfer
Low Background Micromegas in CAST
DEFF Research Database (Denmark)
Garza, J G; Aune, S.; Aznar, F.
of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led...
Tape casting of magnesium oxide.
Energy Technology Data Exchange (ETDEWEB)
Ayala, Alicia; Corral, Erica L.; Loehman, Ronald E.; Bencoe, Denise Nora; Reiterer, Markus; Shah, Raja A.
A tape casting procedure for fabricating ceramic magnesium oxide tapes has been developed as a method to produce flat sheets of sintered MgO that are thin and porous. Thickness of single layer tapes is in the range of 200-400 {micro}m with corresponding surface roughness values in the range of 10-20 {micro}m as measured by laser profilometry. Development of the tape casting technique required optimization of pretreatment for the starting magnesium oxide (MgO) powder as well as a detailed study of the casting slurry preparation and subsequent heat treatments for sintering and final tape flattening. Milling time of the ceramic powder, plasticizer, and binder mixture was identified as a primary factor affecting surface morphology of the tapes. In general, longer milling times resulted in green tapes with a noticeably smoother surface. This work demonstrates that meticulous control of the entire tape casting operation is necessary to obtain high-quality MgO tapes.
New Casting Method for Improving Billet Quality
Faunce, John P.; Wagstaff, Frank E.; Shaw, Howard
Extrusion billet cast by the direct chill (DC) casting process frequently has inconsistent quality. This can adversely affect extrudability of the billet, for example, by causing a poor as-extruded surface. A recent development, the Wagstaff AIR-SLIP™ casting mold, incorporating several proprietary features, overcomes the problem of inconsistent quality and produces billet to exceptional metallurgical standards. Samples of 6xxx alloy aluminum billet cast by the AIR-SLIP™ process have had 0.005" peripheral segregation and an extremely smooth as-cast surface.
Prediction of Part Distortion in Die Casting
Energy Technology Data Exchange (ETDEWEB)
R. Allen Miller
The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.
Process development of thin strip steel casting
Energy Technology Data Exchange (ETDEWEB)
Sussman, R.C.; Williams, R.S.
An important new frontier is being opened in steel processing with the emergence of thin strip casting. Casting steel directly to thin strip has enormous benefits in energy savings by potentially eliminating the need for hot reduction in a hot strip mill. This has been the driving force for numerous current research efforts into the direct strip casting of steel. The US Department of Energy initiated a program to evaluate the development of thin strip casting in the steel industry. In earlier phases of this program, planar flow casting on an experimental caster was studied by a team of engineers from Westinghouse Electric corporation and Armco Inc. A subsequent research program was designed as a fundamental and developmental study of both planar and melt overflow casting processes. This study was arranged as several separate and distinct tasks which were often completed by different teams of researchers. An early task was to design and build a water model to study fluid flow through different designs of planar flow casting nozzles. Another important task was mathematically modeling of melt overflow casting process. A mathematical solidification model for the formation of the strip in the melt overflow process was written. A study of the material and conditioning of casting substrates was made on the small wheel caster using the melt overflow casting process. This report discusses work on the development of thin steel casting.
Benefit of the doubt: a new view of the role of the prefrontal cortex in executive functioning and decision making
Asp, Erik; Manzel, Kenneth; Koestner, Bryan; Denburg, Natalie L.; Tranel, Daniel
The False Tagging Theory (FTT) is a neuroanatomical model of belief and doubt processes that proposes a single, unique function for the prefrontal cortex. Here, we review evidence pertaining to the FTT, the implications of the FTT regarding fractionation of the prefrontal cortex, and the potential benefits of the FTT for new neuroanatomical conceptualizations of executive functions. The FTT provides a parsimonious account that may help overcome theoretical problems with prefrontal cortex mediated executive control such as the homunculus critique. Control in the FTT is examined via the "heuristics and biases" psychological framework for human judgment. The evidence indicates that prefrontal cortex mediated doubting is at the core of executive functioning and may explain some biases of intuitive judgments. PMID:23745103
Emulsion based cast booster - a priming system
Energy Technology Data Exchange (ETDEWEB)
Gupta, R.N.; Mishra, A.K. [National Institute of Rock Mechanics, KGF (India)
This paper explores the potential of emulsion based cast booster to be used as primer to initiate bulk delivered emulsion explosives used in mines. An attempt has been made for comparative study between conventional cast booster and emulsion based cast booster in terms of the initiation process developed and their capability to develop and maintain the stable detonation process in the column explosives. The study has been conducted using a continuous velocity of detonation (VOD) measuring instrument. During this study three blasts have been monitored. In each blast two holes have been selected for study, the first hole being initiated with conventional cast booster while the other one with emulsion based cast booster. The findings of the study advocates that emulsion based cast booster is capable of efficient priming of bulk delivered column explosive with stable detonation process in the column. Further, the booster had advantages over the conventional PETN/TNT based cast booster. 5 refs., 2 figs., 1 tab., 1 photo.
Taboo thoughts and doubt/checking: a refinement of the factor structure for obsessive-compulsive disorder symptoms.
Pinto, Anthony; Eisen, Jane L; Mancebo, Maria C; Greenberg, Benjamin D; Stout, Robert L; Rasmussen, Steven A
The purpose of this report was to improve upon earlier factor analyses of obsessive-compulsive disorder (OCD) symptom categories by minimizing the heterogeneity in the aggressive obsessions category. An exploratory factor analysis was conducted on data from 293 adults with primary OCD. The resulting five factors (Symmetry/Ordering, Hoarding, Doubt/Checking, Contamination/Cleaning, and Taboo Thoughts) are phenomenologically more homogeneous than prior category-based factors and are consistent with those derived in previous item-level analyses.
[Relevance of urinary protein/creatinine ratio and urinary abnormal casts].
Wakita, Mitsuru; Tabe, Yoko; Ishii, Kiyoshi; Miyake, Kazunori; Horii, Takashi; Miida, Takashi; Osaka, Akimichi
The quantification of 24 hrs urinary protein excretion is valuable for diagnosing and monitoring renal disease. However, because of its practical difficulties, the spot urinary protein/creatinine (P/C) ratio has been utilized. We aimed to evaluate the analytical performance of P/C ratio by comparing with the qualitative urinary protein values and the microscopic urine sediment analysis. We obtained 5,538 urinary samples from the outpatients of Juntendo University Hospital. Testing for urinary P/C ratio was performed by Atlas Pro12 (cut-off 150 mg/g x Cr), urinary protein (proteinuria) was detected quantitatively by full-automated system ATLAS XL (cut-off 30 mg/dL). Microscopic exams were conducted following to the JCCLS reference method. The P/C ratio demonstrated higher sensitivity but lower specificity for urinary abnormal casts detected by microscopic exams compared to proteinuria (sensitivity; P/C 87%, proteinuria 77%. specificity; P/C 74%, proteinuria 93%). From the comparative study with microscopic exams, both P/C and proteinuria performed high positive rate (> 80%) for the granular cast type and mixture cast type. For the cellular cast type, however, the positive rate of P/C was 56% and that of proteinuria was only 36%. The overall abnormal casts by microscopic exams showed better correlation with the positive P/C ratio than proteinuria. This study emphasizes that a spot urine P/C ratio is useful in screening for the further microscopic exams. P/C ratio can be a convincing index of urinary protein excretion when attenuation urine is doubted.
Search for chameleons with CAST
DEFF Research Database (Denmark)
Anastassopoulos, V.; Arik, M.; Aune, S.
In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter (βm) and to photons (βΥ) via the Primako eect. By reducing the X-ray detection...... energy threshold used for axions from 1 keV to 400 eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600 eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of βΥ≤1011...
Search for chameleons with CAST
Anastassopoulos, V; Aune, S; Barth, K; Belov, A; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Christensen, F; Collar, J I; Dafni, T; Davenport, M; Desch, K; Dermenev, A; Eleftheriadis, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Garza, J G; Gazis, E N; Geralis, T; Giomataris, I; Hailey, C; Haug, F; Hasinoff, M D; Hofmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakobsen, A; Jakovčić, K; Kaminski, J; Karuza, M; Kavuk, M; Krčmar, M; Krieger, C; Krüger, A; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Luzón, G; Neff, S; Ortega, I; Papaevangelou, T; Pivovarov, M J; Raffelt, G; Riege, H; Rosu, M; Ruz, J; Savvidis, I; Solanki, S K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K; Brax, P; Lavrentyev, I; Upadhye, A
In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter ($\\beta_{\\rm m}$) and to photons ($\\beta_{\\gamma}$) via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1$\\,$keV to 400$\\,$eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600$\\,$eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of $\\beta_{\\gamma}\\!\\lesssim\\!10^{11}$ for $1<\\beta_{\\rm m}<10^6$.
Pressure rig for repetitive casting
Vasquez, Peter; Hutto, William R.; Philips, Albert R.
The invention is a pressure rig for repetitive casting of metal. The pressure rig performs like a piston for feeding molten metal into a mold. Pressure is applied to an expandable rubber diaphragm which expands like a balloon to force the metal into the mold. A ceramic cavity which holds molten metal is lined with blanket-type insulating material, necessitating only a relining for subsequent use and eliminating the lengthy cavity preparation inherent in previous rigs. In addition, the expandable rubber diaphragm is protected by the insulating material thereby decreasing its vulnerability to heat damage. As a result of the improved design the life expectancy of the pressure rig contemplated by the present invention is more than doubled. Moreover, the improved heat protection has allowed the casting of brass and other alloys with higher melting temperatures than possible in the conventional pressure rigs.
Search for chameleons with CAST
Directory of Open Access Journals (Sweden)
V. Anastassopoulos
Full Text Available In this work we present a search for (solar chameleons with the CERN Axion Solar Telescope (CAST. This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter (βm and to photons (βγ via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1 keV to 400 eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600 eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of βγ≲1011 for 1<βm<106.
Mourning and Affirmation: Recuperating Religious Pluralism through "Faith and Doubt at Ground Zero"
Directory of Open Access Journals (Sweden)
Christine Muller
Full Text Available Televisado un año después de los ataques del 11 de Septiembre, el documental del Servicio Público de Transmisión Frontline, "Certezas e incertidumbres en la Zona Cero", se centró especialmente en como ese día ha afectado las actitudes de cada religión. Formalizado como una narración dramática, enmarca su contenido en luchas individuales con la fe, ofreciendo realmente una dramática crítica retórica. La serie, dentro de escenas con un ostensible foco neutral, pero con un posicionamiento contextualizado, publica los affaires del suceso. El acto del documental pende sobre las agencias y sus premisas, tonos y ediciones para facilitar la participación de los agentes –los televidentes- en la mediación de los entrevistados, una invitación basada en una inclusión a todo el mundo. En esta línea, los televidentes, reorganizados como testigos del 11 de Septiembre, juegan más directamente afectados por el día en confrontación con lo que pudieron haber perdido y considerando que pueden recuperar en términos de responsabilidad hacía los Estados Unidos. Por último, esta película propone un pluralismo religioso como fuerza curativa y una afirmación de la identidad americana en respuesta al absolutismo religioso creado por las investigaciones de los ataques del 11 de septiembre y que promueven crisis desesperantes en la confianza.Palabras clave: 11/S, Crisis de confianza, pluralismo religioso, identidad americana___________________________ABSTRACT:Televised one year after the September 11 attacks, the Public Broadcasting Service's Frontline documentary "Faith and Doubt at Ground Zero" focuses specifically on how that day has affected attitudes toward religion. With its form as a dramatic narrative framing its content of individuals' struggles with faith, the documentary lends itself readily to a dramatistic rhetorical critique. Set within the scene of an ostensibly neutral, but contextually positioned, public affairs
Effect of cast steel production metallurgy on the emergence of casting defects
Directory of Open Access Journals (Sweden)
L. Čamek
Full Text Available The paper documents metallurgical possibilities of high alloy cast steel production in open induction medium frequency furnaces and an electric arc furnace in a gravity die casting foundry. The observation was focused on the emergence of gas defects in steel castings. The content of gases achieved during the metallurgical processes was evaluated for every unit of the production equipment and the casting ladle before casting into disposable sand moulds. The sand mould area was considered to be constant. The aim was to evaluate the current metallurgical possibilities of affecting the content of gases in high alloy cast steel in the current technical conditions of the foundry.
The evaluation of working casts prepared from digital impressions.
Hwang, Y C; Park, Y S; Kim, H K; Hong, Y S; Ahn, J S; Ryu, J J
The aim of this study is to evaluate the reproducibility of working casts of a digital impression system by comparing them with the original, virtual, and rapid prototyping casts. A total of 54 cast sets in clinically stable occlusion were used. They were scanned by an iTero intraoral scanner and converted into STL format virtual casts. Rapid prototyping casts and polyurethane casts were fabricated from the iTero milling system based on the virtual casts. Several horizontal and vertical measurements were performed from the four types of casts, that is, original stone casts, virtual casts, rapid prototyping casts, and polyurethane casts of iTero. Measurement error, intraclass correlation coefficient (ICC), and differences among the casts were calculated and compared. Casts from iTero milling machines exhibited greater dimensional differences and lower ICC values than did other casts. In addition, many of the measurements of the iTero working casts showed statistically significant differences in comparison to the three other types of casts. In contrast, there were no statistically significant differences between the virtual and original casts. Virtual casts made by the iTero intraoral scanner exhibited excellent reproducibility. However, the casts from the iTero milling machine showed greater dimensional differences and lower reproducibility compared to other types of casts.
Method for casting thin metal objects
Pehrson, Brandon P; Moore, Alan F
Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.
Gating of Permanent Molds for ALuminum Casting
Energy Technology Data Exchange (ETDEWEB)
David Schwam; John F. Wallace; Tom Engle; Qingming Chang
This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.
Homogenity of Die Casting and Returning Material
Directory of Open Access Journals (Sweden)
J. Malik
Full Text Available Homogeneity of die castings is influenced by wide range of technological parameters as piston velocity in filling chamber of die casting machine, filling time of mould cavity, temperature of cast alloy, temperature of the mould, temperature of filling chamber, surface pressure on alloy during mould filling, final pressure and others. Based on stated parameters it is clear, that main parameters of die casting are filling time of die mould cavity and velocity of the melt in the ingates. Filling time must ensure the complete filling of the mould cavity before solidification process can negatively influence it. Among technological parameters also belong the returning material, which ratio in charge must be constrained according to requirement on final homogeneity of die castings. With the ratio of returning material influenced are the mechanical properties of castings, inner homogeneity and chemical composition.
[The surface roughness analysis of the titanium casting founding by a new titanium casting investment material].
Liang, Qin-ye; Wu, Xia-yi; Lin, Xue-feng
To investigate the surface roughness property of the titanium castings cast in a new investment for titanium casting. Six wax patterns (20 mm × 20 mm × 0.5 mm) were invested using two investments: three in a new titanium investment material and three in the control material (Rematitan Plus). Six titanium specimens were obtained by conventional casting. After casting, surface roughness of the specimens were evaluated with a surface profilometer. The surface roughness of the specimens cast in new titanium investment material was (1.72 ± 0.08) µm, which was much smaller than that from Rematitan Plus [(1.91 ± 0.15) µm, P cast using these two investment materials are both smooth enough to fulfill the demand of the titanium precision-casting for prosthodontic clinical use.
Accuracy of Casting Single Crowns in Titanium
variable affecting fit of cast dental restorations continued to be the focus of research. Taylor (1931) was the first to report on cristobalite ...Hollenback (1943) recommended a "hybrid investing and casting technique". He employed setting, hygroscopic, and thermal expansion with cristobalite investment...minor beta phase. Oxygen diffusion for pure Ti extended Imm into the casting for both the facecoating materials. Waterstrat and Giuseppetti (1985
A Benchmark Study on Casting Residual Stress
Energy Technology Data Exchange (ETDEWEB)
Johnson, Eric M. [John Deere -- Moline Tech Center; Watkins, Thomas R [ORNL; Schmidlin, Joshua E [ORNL; Dutler, S. A. [MAGMA Foundry Technologies, Inc.
Stringent regulatory requirements, such as Tier IV norms, have pushed the cast iron for automotive applications to its limit. The castings need to be designed with closer tolerances by incorporating hitherto unknowns, such as residual stresses arising due to thermal gradients, phase and microstructural changes during solidification phenomenon. Residual stresses were earlier neglected in the casting designs by incorporating large factors of safety. Experimental measurement of residual stress in a casting through neutron or X-ray diffraction, sectioning or hole drilling, magnetic, electric or photoelastic measurements is very difficult and time consuming exercise. A detailed multi-physics model, incorporating thermo-mechanical and phase transformation phenomenon, provides an attractive alternative to assess the residual stresses generated during casting. However, before relying on the simulation methodology, it is important to rigorously validate the prediction capability by comparing it to experimental measurements. In the present work, a benchmark study was undertaken for casting residual stress measurements through neutron diffraction, which was subsequently used to validate the accuracy of simulation prediction. The stress lattice specimen geometry was designed such that subsequent castings would generate adequate residual stresses during solidification and cooling, without any cracks. The residual stresses in the cast specimen were measured using neutron diffraction. Considering the difficulty in accessing the neutron diffraction facility, these measurements can be considered as benchmark for casting simulation validations. Simulations were performed using the identical specimen geometry and casting conditions for predictions of residual stresses. The simulation predictions were found to agree well with the experimentally measured residual stresses. The experimentally validated model can be subsequently used to predict residual stresses in different cast
Thermal gradient analysis of solidifying casting
Directory of Open Access Journals (Sweden)
J. Suchoń
Full Text Available For description of casting solidification and crystallization process the thermal derivative analysis (TDA is commonly used. Besides the process kinetics considered in TDA method to describe the solidification process, the thermal gradient analysis can be also used for this purpose [1, 2]. In conducted studies analysis of thermal gradient distribution inside the solidifying wedge casting was shown which enabled determination of heat flow intensity on casting section.
Preferential dissolution behaviour in Ni–Cr dental cast alloy
Indian Academy of Sciences (India)
A Ni–Cr–Mo dental alloy was fabricated by three different casting methods, viz. centrifugal casting, high frequency induction casting and vacuum pressure casting. The dependence of cast microstructure on the electrochemical corrosion behaviour was investigated using potentiodynamic cyclic and potentiostatic polarization ...
Accuracy of stereolithography additive casts used in a digital workflow
DEFF Research Database (Denmark)
Al-Imam, Hiba; Gram, Mia; Benetti, Ana R
additive (SLA) casts from 2 manufacturers: 9 Dreve SLA casts and 9 Scanbiz SLA casts. All casts were then scanned 9 times with an extraoral scanner to produce the reference data set. Trueness was evaluated by superimposing the data sets obtained by scanning the casts with the reference data set. Precision...
Mechanism and application of a newly developed pressure casting process: horizontal squeeze casting
Li Peijie; Huang Xiusong; He Liangju
Compared to traditional high-pressure die casting (HPDC), horizontal squeeze casting (HSC) is a more promising way to fabricate high-integrity castings, owing to a reduced number of gas and shrinkage porosities produced in the casting. In this paper, the differences between HSC and HPDC are assessed, through which it is shown that the cavity filling velocity and the size of the gating system to be the most notable differences. Equipment development and related applications are also reviewed. ...
Cast Iron And Mineral Cast Applied For Machine Tool Bed - Dynamic Behavior Analysis
Directory of Open Access Journals (Sweden)
Kępczak N.
Full Text Available Cast iron and mineral cast are the materials most often used in the machine structural elements design (bodies, housings, machine tools beds etc.. The materials significantly differ in physical and mechanical properties. The ability to suppress vibration is one of the most important factors determining the dynamic properties of the machine and has a significant impact on the machining capabilities of a machine tool. Recent research and development trends show that there is a clear tendency to move away from the traditional iron casting to the mineral casting, due to better dynamic properties of the latter. However mineral cast as a structural material for the whole machine tools bed turns out to be insufficient due to its poor mechanical strength properties. The best solution should benefit from the advantages of the cast iron and mineral cast materials while minimizing their drawbacks. The paper presents numerical modal analysis of two lathe beds: the first one made of gray cast iron and the second one made of hybrid connection of cast iron and mineral cast. The analysis was conducted in order to determine the dynamic properties of two bodies of similar shapes made in the traditional (cast iron and innovative hybrid (cast iron and mineral cast technology. In addition, an analysis of the static structure rigidity of the two beds was performed. During the simulation studies it was found a significant increase in dynamic stiffness and static rigidity of the machine tool body made of hybrid connection of cast iron and mineral cast. The results of numerical simulations have confirmed the desirability of using hybrid construction because the dynamic properties of such a body are more advantageous in comparison with the conventional body made of cast iron.
Technological Aspects of Low-Alloyed Cast Steel Massive Casting Manufacturing
Directory of Open Access Journals (Sweden)
Szajnara J.
Full Text Available In the paper authors have undertaken the attempt of explaining the causes of cracks net occurrence on a massive 3-ton cast steel casting with complex geometry. Material used for casting manufacturing was the low-alloyed cast steel with increased wear resistance modified with vanadium and titanium. The studies included the primary and secondary crystallization analysis with use of TDA and the qualitative and quantitative analysis of non-metallic inclusions.
Friction Stir Processing of Cast Superalloys Project
National Aeronautics and Space Administration — This SBIR effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...
Pressure generation beneath a new thermoplastic cast.
Mohler, L R; Pedowitz, R A; Byrne, T P; Gershuni, D H
A new cast immobilizer that is heat-shrunk to conform to an injured extremity was examined. The purpose of these studies was to compare pressures beneath the thermoplastic cast with those beneath fiberglass casts on a laboratory model and on the forearms of human volunteers. Pressures measured beneath fiberglass casts on metal cylinders averaged 36 mm Hg. Thermoplastic casts on the smaller cylinder that allowed 42% shrinkage produced a mean pressure of 25 mm Hg; those placed on the larger cylinder that allowed 17% shrinkage produced a mean pressure of 39 mm Hg. Pressures measured on the forearms of healthy volunteers averaged 22 mm Hg beneath fiberglass casts and 31 mm Hg beneath the thermoplastic casts. These pressures were considerably less than pressures that have been shown to occlude the microcirculation of the skin. Acute compartment syndromes result from swelling within a limited space and remain a serious concern clinically when swelling is anticipated under any type of constraining cast. The results of these studies indicate that the new cast should not produce a greater risk of circulatory compromise to the limb than previously used fiberglass materials.
Spray casting project final report
Energy Technology Data Exchange (ETDEWEB)
Churnetski, S.R.; Thompson, J.E.
Lockheed Martin Energy Systems, Inc. (Energy Systems), along with other participating organizations, has been exploring the feasibility of spray casting depleted uranium (DU) to near-net shape as a waste minimization effort. Although this technology would be useful in a variety of applications where DU was the material of choice, this effort was aimed primarily at gamma-shielding components for use in storage and transportation canisters for high-level radioactive waste, particularly in the Multipurpose Canister (MPC) application. In addition to the waste-minimization benefits, spray casting would simplify the manufacturing process by allowing the shielding components for MPC to be produced as a single component, as opposed to multiple components with many fabrication and assembly steps. In earlier experiments, surrogate materials were used to simulate the properties (specifically reactivity and density) of DU. Based on the positive results from those studies, the project participants decided that further evaluation of the issues and concerns that would accompany spraying DU was warranted. That evaluation occupied substantially all of Fiscal Year 1995, yielding conceptual designs for both an intermediate facility and a production facility and their associated engineering estimates. An intermediate facility was included in this study to allow further technology development in spraying DU. Although spraying DU to near-net shape seems to be feasible, a number of technical, engineering, and safety issues would need to be evaluated before proceeding with a production facility. This report is intended to document the results from the spray-casting project and to provide information needed by anyone interested in proceeding to the next step.
The temperature gradient on section of casting in process of primary crystallization of chromium cast iron
Directory of Open Access Journals (Sweden)
A. Studnicki
Full Text Available The methodology of defining in article was introduced the temperature gradient in process of primary crystallization during cooling the casting from chromium cast iron on basis of measurements of thermal field in test DTA-K3. Insert also the preliminary results of investigations of influence temperature gradient on structure of studied wear resistance chromium cast iron.
Squeeze-casting of magnesium alloys; Pressgiessen (Squeeze-Casting) von Magnesium-Legierungen
Energy Technology Data Exchange (ETDEWEB)
Kainer, K.U. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Werkstoffkunde und Werkstofftechnik; Boehm, E.
The mechanical properties of squeeze castings are superior to other castings. Usually the properties are isotropic due to the homogenity of the microstructure. For these reasons squeeze castings are wellsuited for safety parts. It is possible to use conventional casting alloys, with limited improvements compared to other casting techniques, as well as conventional wrought or newly developed alloys, which are usually not castable, for squeeze-casting. The production of composite materials by infiltration of porous preforms of fibres or particles is possible. The properties of a casting can be locally improved using this technique. Squeeze-casting needs more machinery than sand- or diecasting. Compared to high pressure diecasting, the machinery is compareable, but the effort depends on the geometrie of the cast part. (orig.) [Deutsch] Im Squeeze-Cast-Verfahren hergestellte Leichtmetallbauteile zeichnen sich durch verbesserte mechanische Eigenschaften gegenueber durch andere Giessverfahren hergestellte Bauteile aus. Insbesondere die Ermuedungsfestigkeit wird durch den homogenen, isotropen, nahezu fehlerfreien Gefuegeaufbau verbessert. Aus diesen Gruenden sind Squeeze-Cast-Teile besonders fuer Sicherheitsanwendungen geeignet. Es koennen sowohl konventionelle Gusslegierungen, mit begrenzten Verbesserungen gegenueber anderen Giessverfahren, als auch klassische Knet- sowie neu entwickelte Legierungen vergossen werden, welche mit Hilfe anderer Giessverfahren nur eingeschraenkt verarbeitbar sind. Die Herstellung von Verbundwerkstoffen durch Infiltration poroeser Faser- oder Partikelformkoerper, sogenannter Preforms, ist moeglich. Hierdurch koennen die Eigenschaften eines Bauteils lokal erheblich verbessert werden. Das Squeeze-Cast-Verfahren benoetigt gegenueber Sand- und Kokillenguss einen groesseren maschinellen Aufwand. Im Vergleich zum Druckguss ist der Aufwand etwa gleich, jedoch von der Geometrie des Gussstueckes abhaengig. (orig.)
Microdefects in cast multicrystalline silicon
Energy Technology Data Exchange (ETDEWEB)
Wolf, E.; Klinger, D.; Bergmann, S. [Inst. of Crystal Growth Berlin (Germany)
The microdefect etching behavior of cast multicrystalline BAYSIX and SILSO samples is mainly the same as that of EFG silicon, in spite of the very different growth parameters applied to these two techniques and the different carbon contents of the investigated materials. Intentional decorating of mc silicon with copper, iron and gold did not influence the results of etching and with help of infrared transmission microscopy no metal precipitates at the assumed microdefects could be established. There are many open questions concerning the origin of the assumed, not yet doubtless proved microdefects.
Machine Casting of Ferrous Alloys
1976 g DTIC 8 AELECTEI% UJ %AUG2 31985|| —J mjfr %M ^ B rra M B5 8 23 151 l-TT-WFtf.^ viH »<.wil»t«^lvi»wmrgT1i^^V\\'.-'\\'.^VA' ,T...Slurry Producer . . 13 4. Laboratory Casting Machine 15 IV. STRUCTURE, SEGREGATION, HOMOGENIZATION HEAT TREATMENT , AND MECHANICAL PROPERTIES OF...RHEOCAST ALLOYS 18 1. Effect of Process Variables on Structure 18 2. Segregation, Homogenization Heat Treatment and Mechanical Properties 22 V
Yield Improvement in Steel Casting (Yield II)
Energy Technology Data Exchange (ETDEWEB)
Richard A. Hardin; Christoph Beckermann; Tim Hays
This report presents work conducted on the following main projects tasks undertaken in the Yield Improvement in Steel Casting research program: Improvement of Conventional Feeding and Risering Methods, Use of Unconventional Yield Improvement Techniques, and Case Studies in Yield Improvement. Casting trials were conducted and then simulated using the precise casting conditions as recorded by the participating SFSA foundries. These results present a statistically meaningful set of experimental data on soundness versus feeding length. Comparisons between these casting trials and casting trials performed more than forty years ago by Pellini and the SFSA are quite good and appear reasonable. Comparisons between the current SFSA feeding rules and feeding rules based on the minimum Niyama criterion reveal that the Niyama-based rules are generally less conservative. The niyama-based rules also agree better with both the trials presented here, and the casting trails performed by Pellini an d the SFSA years ago. Furthermore, the use of the Niyama criterion to predict centerline shrinkage for horizontally fed plate sections has a theoretical basis according to the casting literature reviewed here. These results strongly support the use of improved feeding rules for horizontal plate sections based on the Niyama criterion, which can be tailored to the casting conditions for a given alloy and to a desired level of soundness. The reliability and repeatability of ASTM shrinkage x-ray ratings was investigated in a statistical study performed on 128 x-rays, each of which were rated seven different times. A manual ''Feeding and Risering Guidelines for Steel Castings' is given in this final report. Results of casting trials performed to test unconventional techniques for improving casting yield are presented. These use a stacked arrangement of castings and riser pressurization to increase the casting yield. Riser pressurization was demonstrated to feed a casting up to
The Role of Indian Caste Identity and Caste Inconsistent Norms on Status Representation
Sankaran, Sindhuja; Sekerdej, Maciek; von Hecker, Ulrich
The Indian caste system is a complex social structure wherein social roles like one's profession became 'hereditary,' resulting in restricted social mobility and fixed status hierarchies. Furthermore, we argue that the inherent property of caste heightens group identification with one's caste. Highly identified group members would protect the identity of the group in situations when group norms are violated. In this paper, we were interested in examining the consequence of caste norm violation and how an individual's status is mentally represented. High caste norms are associated with moral values while the lower caste norms are associated with immorality. We predicted a 'black sheep effect,' that is, when high caste individuals' group identity (caste norm violation condition) is threatened their salient high caste identity would increase, thereby resulting in devaluing the status of their fellow in-group member if the latter is perceived as perpetrator. We presented participants with a social conflict situation of a victim and a perpetrator that is 'Caste norm consistent' (Lower caste individual as a perpetrator and higher caste individual as a victim) and vice versa 'Caste norm inconsistent' condition (higher caste individual as perpetrator and lower caste individual as a victim). Then, participants had to choose from nine pictorial depictions representing the protagonists in the story on a vertical line, with varying degrees of status distance. Results showed evidence for the black sheep effect and, furthermore, revealed that no other identity (religious, national, and regional) resulted in devaluing the status of fellow in-group member. These results help us understand the 'black sheep' effect in the context of moral norms and status representation and are discussed in the framework of the Indian society. PMID:28408896
Energy use in selected metal casting facilities - 2003
Energy Technology Data Exchange (ETDEWEB)
Eppich, Robert E. [Eppich Technologies, Syracuse, IN (United States)
This report represents an energy benchmark for various metal casting processes. It describes process flows and energy use by fuel type and processes for selected casting operations. It also provides recommendations for improving energy efficiency in casting.
Thin section casting program. Volume 2: Horizontal TSC (Thin-Section Casting) approach
In horizontal thin-section casting (HTSC), 1-inch-thick steel sections are produced at speeds up to 600 ipm or about 60 tons per hour per foot of width (tphf). Liquid steel is fed from the ladle, and flows through a specially designed tundish, then flows through a refractory feeding tube and nozzle, with approximately the same external dimensions as the cast section, into a near-horizontal rectangular mold whose all four sides are traveling in the same direction and speed as the steel casting. This report is the second of a six volume set on thin section casting. This volume covers the research on horizontal thin section casting (TSC).
Technological parameters of die casting and quality of casting from EN AC46500 alloy
Directory of Open Access Journals (Sweden)
Š. Gašpár
Full Text Available Die casting represents the highest technological level of metal mold casting. This technology enables production of almost all final products without necessity of further processing. The important aspect of efficiency and production is a proper casting parameters setting. In the submitted paper following die casting parameters are analyzed: plunger pressing speed and pressure. The studied parameters most significantly affect a qualitative of castings from EN AC46500 alloy and they influence the most a gained porosity level as well as basic mechanical properties represented by permanent deformations.
Casting fine grained, fully dense, strong inorganic materials
Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.
Methods and apparatuses for casting inorganic materials are provided. The inorganic materials include metals, metal alloys, metal hydrides and other materials. Thermal control zones may be established to control the propagation of a freeze front through the casting. Agitation from a mechanical blade or ultrasonic energy may be used to reduce porosity and shrinkage in the casting. After solidification of the casting, the casting apparatus may be used to anneal the cast part.
Detection of Cast Shadows in Surveillance Applications
DEFF Research Database (Denmark)
Erbou, Søren G.; Sørensen, Helge Bjarne Dissing; Stage, Bjarne
Cast shadows from moving objects reduce the general ability of robust classification and tracking of these objects, in outdoor surveillance applications. A method for segmentation of cast shadows is proposed, combining statistical features with a new similarity feature, derived from a physics...
Geometric aspects of the casting process
Ahn, H.-K.
Manufacturing is the process of converting raw materials into useful products. Among the most important manufacturing processes, casting is a commonly used manufacturing process for plastic and metal objects. The industrial casting process consists of two stages. First, liquid is filled into a
Fundamentals of Numerical Modelling of Casting Processes
DEFF Research Database (Denmark)
Pryds, Nini; Thorborg, Jesper; Lipinski, Marek
Fundamentals of Numerical Modelling of Casting Processes comprises a thorough presentation of the basic phenomena that need to be addressed in numerical simulation of casting processes. The main philosophy of the book is to present the topics in view of their physical meaning, whenever possible...
The CAST (Childhood Asperger Syndrome Test)
Williams, Jo; Scott, Fiona; Stott, Carol; Allison, Carrie; Bolton, Patrick; Baron-Cohen, Simon; Brayne, Carol
The Childhood Asperger Syndrome Test (CAST) is a parental questionnaire to screen for autism spectrum conditions. In this validation study, the CAST was distributed to 1925 children aged 5-11 in mainstream Cambridgeshire schools. A sample of participants received a full diagnostic assessment, conducted blind to screen status. The sensitivity of…
... 20, 2015. Boyd AS, et al. Principles of casting and splinting. American Family Physician. 2009;79:16. McDowell M, et al. A comparison of various contemporary methods to prevent a wet cast. The Journal of Bone & Joint Surgery. 2014;96:e99. Beutler ...
Directory of Open Access Journals (Sweden)
F. I. Rudnitsky
Full Text Available The composition, structure, methods of receipt of ultradisperse materials (UDM and the prospect of their application in engineering procedures of foundry production are considered. Positive influence of UDM when entering in fusion on structure and properties of the gray cast iron intended for production of castings of motor group is established.
Model castings with composite surface layer - application
Directory of Open Access Journals (Sweden)
J. Szajnar
Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in foundingprocess a composite surface layer on the basis of Fe-Cr-C alloy. Technology of composite surface layer guarantee mainly increase inhardness and aberasive wear resistance of cast steel castings on machine elements. This technology can be competition for generallyapplied welding technology (surfacing by welding and thermal spraying. In range of studies was made cast steel test castings withcomposite surface layer, which usability for industrial applications was estimated by criterion of hardness and aberasive wear resistance of type metal-mineral and quality of joint cast steel – (Fe-Cr-C. Based on conducted studies a thesis, that composite surface layer arise from liquid state, was formulated. Moreover, possible is control of composite layer thickness and its hardness by suitable selection of parameters i.e. thickness of insert, pouring temperature and solidification modulus of casting. Possibility of technology application of composite surface layer in manufacture of cast steel slide bush for combined cutter loader is presented.
Engineering design of centrifugal casting machine
Kusnowo, Roni; Gunara, Sophiadi
Centrifugal casting is a metal casting process in which metal liquid is poured into a rotating mold at a specific temperature. Given round will generate a centrifugal force that will affect the outcome of the casting. Casting method is suitable in the manufacture of the casting cylinder to obtain better results. This research was performed to design a prototype machine by using the concept of centrifugal casting. The design method was a step-by-step systematic approach in the process of thinking to achieve the desired goal of realizing the idea and build bridges between idea and the product. Design process was commenced by the conceptual design phase and followed by the embodiment design stage and detailed design stage. With an engineering design process based on the method developed by G. E. Dieter, draft prototype of centrifugal casting machine with dimension of 550×450×400 mm, ¼ HP motor power, pulley and belt mechanism, diameter of 120-150mm, simultaneously with the characteristics of simple casting product, easy manufacture and maintenance, and relatively inexpensive, was generated.
Slip casting and nitridation of silicon powder
Seiko, Y.
Powdered Silicon was slip-cast with a CaSO4 x 0.5H2O mold and nitrided in a N atm. containing 0 or 5 vol. % H at 1000 to 1420 deg. To remove the castings, the modeling faces were coated successively with an aq. salt soap and powdered cellulose containing Na alginate, and thus prevented the sticking problem.
The quality of the joint between alloy steel and unalloyed cast steel in bimetallic layered castings
Directory of Open Access Journals (Sweden)
T. Wróbel
Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic unalloyed cast steel, whereas working part (layer is plate of austenitic alloy steel sort X2CrNi 18-9. The ratio of thickness between bearing and working part is 8:1. The aim of paper was assessed the quality of the joint between bearing and working part in dependence of pouring temperature and carbon concentration in cast steel. The quality of the joint in bimetallic layered castings was evaluated on the basis of ultrasonic non-destructive testing, structure and microhardness researches.
Optimization of casting conditions for heat and abrasion resistant large grey iron castings
Directory of Open Access Journals (Sweden)
C. C. Lee
Full Text Available Numerical simulation technology was applied for optimizing the casting design and conditions in large cast iron castings for marine engine. By the simulation of mold filling and solidification sequences the problems of the previous casting conditions were analyzed and marked improvements for large cylinder liner parts were derived from these results. Especially the amount and positions of chills were optimized to increase the mechanical properties and to minimize the shrinkage and microporosity in the castings. Ultrasonic testing, penetration testing and mechanical property testing were carried out for the parts with the modified casting conditions. It showed that no defects in the castings were found and the productivity could be distinctly increased.The mechanical properties satisfied also the specification demanded.
Standard digital reference images for titanium castings
American Society for Testing and Materials. Philadelphia
1.1 The digital reference images provided in the adjunct to this standard illustrate various types and degrees of discontinuities occurring in titanium castings. Use of this standard for the specification or grading of castings requires procurement of the adjunct digital reference images, which illustrate the discontinuity types and severity levels. They are intended to provide the following: 1.1.1 A guide enabling recognition of titanium casting discontinuities and their differentiation both as to type and degree through digital radiographic examination. 1.1.2 Example digital radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications and drawings. 1.2 The digital reference images consist of seventeen digital files each illustrating eight grades of increasing severity. The files illustrate seven common discontinuity types representing casting sections up to 1-in. (25.4-mm). 1.3 The reference radiographs were developed for casting sections up to 1...
Reinforcing cast iron with composite insert
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Dulska A.
Full Text Available The paper presents a proprietary method of making composite cast iron (eutectic locally reinforced with ceramics. The research included making casts with a ceramic layer, its percentage of the surface was 30%. The research included abrasive wear resistance according to ASTM G 65-00. As a result of the research it has been found that the infiltration of the molten metal into the ceramic preform mainly affects the correct production of the cast with local reinforcement. The research results also have proven that the application of a lattice ceramic insert placed in the mould is the most appropriate option, due to the even distribution of the particles in the cast and obtaining a sound cast.
Directory of Open Access Journals (Sweden)
O. S. Komarov
Full Text Available The influence of the complex modifier by chemical – active and surface-active additives of gray cast iron on the size of chill and on the width of molted iron zone was researched. The width of a chill zone and molted iron zones were measured at chank ends of various diameter cores. The cores were casted on a massive steel plate and also in standard chill tests. It was established that additional adding of surface-active bismuth in structure of various graphitizing modifiers promoted to reduce the width a chill zone and molted iron zones. It was established that the complex modifiers consisting of chemical – active and surfaceactive components are effective in fight with chill in cast iron castings and can be recommended for application in foundry shops of the entities of a machine-building profile for production of high-quality castings.
The role of water in slip casting
Mccauley, R. A.; Phelps, G. W.
Slips and casting are considered in terms of physical and colloidal chemistry. Casting slips are polydisperse suspensions of lyophobic particles in water, whose degree of coagulation is controlled by interaction of flocculating and deflocculating agents. Slip casting rate and viscosity are functions of temperature. Slip rheology and response to deflocculating agents varies significantly as the kinds and amounts of colloid modifiers change. Water is considered as a raw material. Various concepts of water/clay interactions and structures are discussed. Casting is a de-watering operation in which water moves from slip to cast to mold in response to a potential energy termed moisture stress. Drying is an evaporative process from a free water surface.
Numerical modelling of stresses and deformations in casting processes
DEFF Research Database (Denmark)
Hattel, Jesper Henri
Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method......Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method...
The possibility of increasing cast steel machinability by introducing sodium sulfur compounds into the ladle containing melted steel immediately before casting the metal into an ingot is investigated.
Development of steel plate - cast iron hybrid casting process for recycling of low level radioactive metal waste
Energy Technology Data Exchange (ETDEWEB)
Nakamura, H.; Hirabayashi, T. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Akimoto, J.; Takahashi, K.; Shindo, H.; Sakurai, D. [Mitsubishi Materials Corp., Tokyo (Japan); Almansour, A.; Okane, T.; Umeda, T. [Univ. of Tokyo (Japan)
For the purposes of recycling low-level radioactive waste arising from dismantling of nuclear reactors, applicability of steel plate - cast iron hybrid casting process has been investigated as a measure for producing a waste container using radioactive metal waste. This investigation consists of casting tests and analyses on the solidification and distortion of castings. This paper describes the concept of the casting process, casting test results, and understandings obtained from the analyses. (orig.)
Stanford's gene patents hit snags.
Sun, M
Background information is presented on the preliminary rejection of a 1978 recombinant DNA patent application by Stanley Cohen and Herbert Boyer. The Patent Office is concerned about the omission of important information from the application, the exclusion of a third collaborator as co-inventor, and the interval between public disclosure and the date of filing. The dispute could lead to a challenge of a related Cohen-Boyer patent issued in 1980, posing a financial threat to Stanford University, which holds the lucrative patent rights, and the University of California, which shares the licensing fees and royalties.
Latest advances and developments in aluminum shape casting
Directory of Open Access Journals (Sweden)
Qigui Wang
Full Text Available With the increasing use of aluminum shape castings in structural applications in the automotive and aerospace industries, assurance of cast product integrity and performance has become critical in both design and manufacturing. In this paper, the latest understanding of the relationship between casting quality and mechanical properties of aluminum castings is summarized. Newly developed technologies for alloy design, melting and melt treatment, casting and heat treatment processes in aluminum casting are reviewed. The mechanical properties of aluminum castings strongly depend upon their microstructure constituents and particularly cast defect population and distribution. To produce quality castings with quantifiable properties, the key is to control multi-scale defects and microstructure in the casting. Robust design and development of high integrity aluminum castings through Integrated Computational Materials Engineering (ICME approach is also discussed. The most effective way to optimize the processes and achieve the desirable mechanical properties is through the development and exploitation of robust and accurate multi-scale computational models.
Fibreglass Total Contact Casting, Removable Cast Walkers, and Irremovable Cast Walkers to Treat Diabetic Neuropathic Foot Ulcers: A Health Technology Assessment
Costa, Vania; Tu, Hong Anh; Wells, David; Weir, Mark; Holubowich, Corinne; Walter, Melissa
Background Diabetic neuropathic foot ulcers are a risk factor for lower leg amputation. Many experts recommend offloading with fibreglass total contact casting, removable cast walkers, and irremovable cast walkers as a way to treat these ulcers. Methods We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences for offloading devices. We performed a systematic literature search on August 17, 2016, to identify randomized controlled trials that compared fibreglass total contact casting, removable cast walkers, and irremovable cast walkers with other treatments (offloading or non-offloading) in patients with diabetic neuropathic foot ulcers. We developed a decision-analytic model to assess the cost-effectiveness of fibreglass total contact casting, removable cast walkers, and irremovable cast walkers, and we conducted a 5-year budget impact analysis. Finally, we interviewed people with diabetes who had lived experience with foot ulcers, asking them about the different offloading devices and the factors that influenced their treatment choices. Results We identified 13 randomized controlled trials. The evidence suggests that total contact casting, removable cast walkers, and irremovable cast walkers are beneficial in the treatment of neuropathic, noninfected foot ulcers in patients with diabetes but without severe peripheral arterial disease. Compared to removable cast walkers, ulcer healing was improved with total contact casting (moderate quality evidence; risk difference 0.17 [95% confidence interval 0.00–0.33]) and irremovable cast walkers (low quality evidence; risk difference 0.21 [95% confidence interval 0.01–0.40]). We found no difference in ulcer healing between total contact casting and irremovable cast walkers (low quality evidence; risk difference 0.02 [95% confidence interval −0.11–0.14]). The economic analysis showed that total contact casting and irremovable
Fibreglass Total Contact Casting, Removable Cast Walkers, and Irremovable Cast Walkers to Treat Diabetic Neuropathic Foot Ulcers: A Health Technology Assessment.
Diabetic neuropathic foot ulcers are a risk factor for lower leg amputation. Many experts recommend offloading with fibreglass total contact casting, removable cast walkers, and irremovable cast walkers as a way to treat these ulcers. We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences for offloading devices. We performed a systematic literature search on August 17, 2016, to identify randomized controlled trials that compared fibreglass total contact casting, removable cast walkers, and irremovable cast walkers with other treatments (offloading or non-offloading) in patients with diabetic neuropathic foot ulcers. We developed a decision-analytic model to assess the cost-effectiveness of fibreglass total contact casting, removable cast walkers, and irremovable cast walkers, and we conducted a 5-year budget impact analysis. Finally, we interviewed people with diabetes who had lived experience with foot ulcers, asking them about the different offloading devices and the factors that influenced their treatment choices. We identified 13 randomized controlled trials. The evidence suggests that total contact casting, removable cast walkers, and irremovable cast walkers are beneficial in the treatment of neuropathic, noninfected foot ulcers in patients with diabetes but without severe peripheral arterial disease. Compared to removable cast walkers, ulcer healing was improved with total contact casting (moderate quality evidence; risk difference 0.17 [95% confidence interval 0.00-0.33]) and irremovable cast walkers (low quality evidence; risk difference 0.21 [95% confidence interval 0.01-0.40]). We found no difference in ulcer healing between total contact casting and irremovable cast walkers (low quality evidence; risk difference 0.02 [95% confidence interval -0.11-0.14]). The economic analysis showed that total contact casting and irremovable cast walkers were less expensive and
Characterization of Technetium Speciation in Cast Stone
Energy Technology Data Exchange (ETDEWEB)
Um, Wooyong; Jung, Hun Bok; Wang, Guohui; Westsik, Joseph H.; Peterson, Reid A.
This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, "Production and Long-Term Performance of Low Temperature Waste Forms" to provide additional information on technetium (Tc) speciation characterization in the Cast Stone waste form. To support the use of Cast Stone as an alternative to vitrification for solidifying low-activity waste (LAW) and as the current baseline waste form for secondary waste streams at the Hanford Site, additional understanding of Tc speciation in Cast Stone is needed to predict the long-term Tc leachability from Cast Stone and to meet the regulatory disposal-facility performance requirements for the Integrated Disposal Facility (IDF). Characterizations of the Tc speciation within the Cast Stone after leaching under various conditions provide insights into how the Tc is retained and released. The data generated by the laboratory tests described in this report provide both empirical and more scientific information to increase our understanding of Tc speciation in Cast Stone and its release mechanism under relevant leaching processes for the purpose of filling data gaps and to support the long-term risk and performance assessments of Cast Stone in the IDF at the Hanford Site.
Cracks in high-manganese cast steel
Directory of Open Access Journals (Sweden)
A. Chojecki
Full Text Available The reasons which account for the formation of in service cracks in castings made from Hadfield steel were discussed. To explain the source of existence of the nuclei of brittle fractures, the properties of cast steel were examined within the range of solidification temperatures, remembering that feeding of this material is specially difficult, causing microporosity in hot spots. This creates conditions promoting the formation of microcracks which tend to propagate during service conditions involving high dynamic stresses, and explains why the cracks are mainly characterized by a brittle nature. The reason for crack formation in service are micro-porosities formed during casting solidification.
Methods for Casting Subterranean Ant Nests
Tschinkel, Walter R.
The study of subterranean ant nests has been impeded by the difficulty of rendering their structures in visible form. Here, several different casting materials are shown to make perfect casts of the underground nests of ants. Each material (dental plaster, paraffin wax, aluminum, zinc) has advantages and limitations, which are discussed. Some of the materials allow the recovery of the ants entombed in the casts, allowing a census of the ants to be connected with features of their nest architecture. The necessary equipment and procedures are described in the hope that more researchers will study this very important aspect of ant natural history. PMID:20673073
Sonic testing in assessment of casting quality
Directory of Open Access Journals (Sweden)
A. Białobrzeski
Full Text Available The aim of the present study has been designing and putting in operation of a stand for sonic testing equipped with modern and readily available numerical devices and with the author's own computer program, which enables recording and analysis of acoustic fields and of the frequency of free vibrations in selected castings made from Fe and Al alloys, and specifically also from magnesium alloys, and mastering the technique of making such tests along with their practical application in assessment of the quality of castings made from magnesium alloys and investment castings made from carbon steel.
Improved Slip Casting Of Ceramic Models
Buck, Gregory M.; Vasquez, Peter; Hicks, Lana P.
Improved technique of investment slip casting developed for making precise ceramic wind-tunnel models. Needed in wind-tunnel experiments to verify predictions of aerothermodynamical computer codes. Ceramic materials used because of their low heat conductivities and ability to survive high temperatures. Present improved slip-casting technique enables casting of highly detailed models from aqueous or nonaqueous solutions. Wet shell molds peeled off models to ensure precise and undamaged details. Used at NASA Langley Research Center to form superconducting ceramic components from nonaqueous slip solutions. Technique has many more applications when ceramic materials developed further for such high-strength/ temperature components as engine parts.
Direct Cast U-6Nb – 2017 Progress on Cylindrical Castings
Energy Technology Data Exchange (ETDEWEB)
Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
This report describes work to further develop a sound technical basis and best practices for mold design and process parameters for the Direct Casting of U-6wt%Nb components. One major challenge to the production of U-6Nb components is the propensity for niobium segregation during casting and solidification. This is especially true for cylindrical castings where the vertical side walls allow flotation of Nb resulting in severe inverse macrosegregation. In this work, a small (120 mm diameter by 180 mm tall) and large cylinder (250 mm diameter by 310 mm tall) are examined with a focus on reducing, or eliminating, niobium segregation. It is demonstrated that counter gravity casting (top-to-bottom solidification) can be used to minimize segregation in the small cylinder. Attempts to counter gravity cast the large cylinder were unsuccessful, in large part due to size limitations of the current furnace. A path forward for casting of the large cylinders is discussed.
The effects of different casting techniques on the hardness, energy ...
African Journals Online (AJOL)
The effect of casting technique on the impact strength, energy absorbance and hardness of sand cast Pb-Sb-Cu alloys was studied following casting of the alloys using three techniques. Cooling of the alloys after casting was carried out in water, air and furnace in order to vary the micro-structure of the alloys produced.
Gating Systems for Sizeable Castings from Al Alloys Cast into Ceramic Moulds
Stachovec I.; Horáček M.; Zemčík L.; Kolda V.; Horenský J.
In contrast to casting to conventional non-reusable "sand" moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly) on the basis of experience. However, this approach is not sustainable with ever growing demand...
The change of temperature gradient in solidification of hypereutectic chromium cast iron casting
Directory of Open Access Journals (Sweden)
A. Studnicki
Full Text Available In article the analysis of temperature gradient of solidification in section of hypereutectic chromium cast iron model casting was introduced. On this example was presented the method (DTGA – derivative and thermal gradient analysis, which was worked out in Department of Foundry Silesian University of Technology enabling the record of indispensable data to execution of analysis the temperature gradient and its derivative after time on section of model casting. It multichanneled apparatus to registration of data was used Crystaldigraph - PC.
Casting directly from a computer model by using advanced simulation software FLOW-3D Cast ®
M. Sirviö; M. Woś
ConiferRob - A patternless casting technique, originally conceived at VTT Technical Research Centre of Finland and furtherdeveloped at its spin-off company, Simtech Systems, offers up to 40% savings in product development costs, and up to two months shorterdevelopment times compared to conventional techniques. Savings of this order can be very valuable on today's highly competitivemarkets. Casting simulation is commonly used for designing of casting systems. However, most of the software are ...
Skin irritation and exposure to diisocyanates in orthopedic nurses working with soft casts.
Larsen, T H; Gregersen, P; Jemec, G B
Diisocyanates are widely used in industry, for example at hospitals as a constituent of Scotch Cast soft casts (3M, Glostrup, Denmark). They are a cause of occupational asthma and have been described as causing cutaneous problems both as irritants and as sensitizers. The sensitizing potential of diisocyanates has previously only sporadically been described, predominantly in case reports. Therefore, we conducted this study to investigate eventual work-related skin sensitization to diisocyanates in a regularly exposed population. The nursing staff of an orthopaedic outpatient clinic, consisting of 10 persons, were interviewed and subjected to patch testing using 5 types of diisocyanates and the TRUE Test (ECDRG Standard Series) to elucidate possible other type IV allergies with similar symptoms. Patch test results were evaluated according to the guidelines of the International Contact Dermatitis Group. We found no relationship between exposure time and severity of symptoms. Symptoms were mild, consisting of redness, itching, or both, lasting about 30 minutes. There was no suggestion that they result in any chronic skin problems. One nurse presented a doubtful reaction towards diaminophenylmethane (MDA) and isophorene diisocyanate (IPDI). Nine persons had no reactions to the 5 diisocyanates used in the patch test. Positive reactions were seen to nickel (4/10), thiomersal (2/10), and perfume mix (1/10). Our observations suggest that diisocyanates are primarily irritants rather than sensitizers in the professional setting studied. The skin symptoms of irritation were all mild and temporary. Copyright 2001 by W.B. Saunders Company
Examination and Elimination of Defects in Cone Casting Made of Ductile Cast Iron
Directory of Open Access Journals (Sweden)
Guzik E.
Full Text Available In the scope of existing cooperation with the Foundry of Cast Iron ZM "WSK Rzeszów" Ltd. there was carried out research work of microstructure and mechanical properties in the walls of a cone casting made of ductile cast iron. The particular attention was being put to the search of the potential brittle phases which have deleterious effect on ductility and dynamic properties of highly strained use of the casting prone to the potential risk of cracks during the highly strained use.
Friction Stir Processing of Cast Superalloys Project
National Aeronautics and Space Administration — This SBIR Phase I effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...
U.S. Environmental Protection Agency — ToxCast is used as a cost-effective approach for efficiently prioritizing the toxicity testing of thousands of chemicals. It uses data from state-of-the-art high...
Bonding of Aluminum Alloys in Compound Casting
Feng, Jian; Ye, Bing; Zuo, Lijie; Wang, Qudong; Wang, Qigui; Jiang, Haiyan; Ding, Wenjiang
The influence of the coating materials, coating thickness, and casting process on the interfacial microstructure and mechanical properties of the overcast A6061 bars with aluminum A356 and A6061 alloys was studied by OM, SEM/EDS, and mechanical testing. Results indicate that Ni coating has better thermal stability than Cu coating that heavily reacts with liquid Al alloy and forms a reaction zone around 130-150 μm during gravity casting. In the gravity casting, coarse and cracked Al3Ni phase distributes along the interfacial region and degrades the mechanical properties of the overcast joints. In squeeze casting, however, fine and dispersed Ni-rich strengthening phases form uniformly in the interfacial zone and improve the metallurgical bonding of the joints. The heat transition and application of pressure during solidification are two key factors in determining the integrity and mechanical properties of the overcast joints.
Solidification control in continuous casting of steel
Indian Academy of Sciences (India)
/lubrication at solid–liquid interface, high temperature properties of the solidifying shell etc. is necessary to control the continuous casting process. The present paper elaborates upon the knowledge developed in the areas of initial shell ...
Solidification control in continuous casting of steel
Indian Academy of Sciences (India)
lubrication at solid-liquid interface, high temperature properties of the solidifying shell etc. is necessary to control the continuous casting process. The present paper elaborates upon the knowledge developed in the areas of initial shell formation, mode ...
Advanced lost foam from casting technology
Energy Technology Data Exchange (ETDEWEB)
Bates, C. E.; Littleton, H. E.; Askeland, D.; Griffin, J.; Miller, B. A.; Sheldon, D. S.
Previous research made significant advances in understanding the Lost Foam Casting (LFC) Process and clearly identified areas where additional research was needed to improve the process and make it more functional in an industrial environment. The current project focused on five areas listed as follows: Task 1: Precision Pattern Production Task 2: Pattern Coating Consistency Task 3: Sand Fill and Compaction Effects Task 4: Pattern Gating Task 5: Mechanical Properties of Castings. This report summarizes the work done under the current contract in all five areas in the period of October 1, 1994 through December 31, 1995. Twenty-eight (28) companies jointly participate in the project. These companies represent a variety of disciplines, including pattern designers, pattern producers, coating manufacturers, plant design companies, compaction equipment manufacturers, casting producers, and casting buyers.
Microbiological Study of Cast Posts before Cementation
National Research Council Canada - National Science Library
Vallejo-Labrada, Maricela; Ojeda-Garces, Juan Carlos
This study identifies the most common microorganisms present in type III gold cast posts related to pulpal disease and evaluates the sterilization/disinfection method before cementation in the root canal...
Thermal transport properties of grey cast irons
Energy Technology Data Exchange (ETDEWEB)
Hecht, R.L. [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.; Dinwiddie, R.B.; Porter, W.D.; Wang, Hsin [Oak Ridge National Lab., TN (United States)
Thermal diffusivity and thermal conductivity of grey cast iron have been measured as a function of graphite flake morphology, chemical composition, and position in a finished brake rotor. Cast iron samples used for this investigation were cut from ``step block`` castings designed to produce iron with different graphite flake morphologies resulting from different cooling rates. Samples were also machined from prototype alloys and from production brake rotors representing a variation in foundry practice. Thermal diffusivity was measured at room and elevated temperatures via the flash technique. Heat capacity of selected samples was measured with differential scanning calorimetry, and these results were used to calculate the thermal conductivity. Microstructure of the various cast iron samples was quantified by standard metallography and image analysis, and the chemical compositions were determined by optical emission spectroscopy.
Panchromatic Sequentially Cast Ternary Polymer Solar Cells.
Ghasemi, Masoud; Ye, Long; Zhang, Qianqian; Yan, Liang; Kim, Joo-Hyun; Awartani, Omar; You, Wei; Gadisa, Abay; Ade, Harald
A sequential-casting ternary method is developed to create stratified bulk heterojunction (BHJ) solar cells, in which the two BHJ layers are spin cast sequentially without the need of adopting a middle electrode and orthogonal solvents. This method is found to be particularly useful for polymers that form a mechanically alloyed morphology due to the high degree of miscibility in the blend. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Research of linear contraction during continuous aluminum casting
Таран, Юрій Павлович
Research works of plenty of scientists are dedicated to issues of continuous metals casting and rolling. Nevertheless there are no scientific papers, dealing with research of impact of continuous aluminum crystallization on the length of the casted billet and its velocity after casting.The speed process of continuous aluminum casting is characterized by an uneven heat exchange lengthwise the billet which is crystallized in the mould of the casting wheel in the temperatures range. It results i...
Vermicular graphite cast iron current state of the art
Murthy, VSR; Seshan, S; Seshan, K.
Vermicular graphite cast iron is a new addition to the family of cast irons. Various methods for producing vermicular graphite cast iron are briefly discussed in this paper. The mechanical and physical properties of cast irons with vermicular graphite have been found to be intermediate between those of gray and ductile irons. Other properties such as casting characteristics, scaling resistance, damping capacity and machinability have been compared with those of gray and ductile irons. Probabl...
Numerical modelling of the tilt casting processes of titanium alumindes
Wang, Hong
This research has investigated the modelling and optimisation of the tilt casting process of Titanium Aluminides (TiAl). This study is carried out in parallel with the experimental research undertaken in IRC at the University of Birmingham. They propose to use tilt casting inside a vacuum chamber and attempt to combine this tilt casting process with Induction Skull Melting (ISM). A totally novel process is developing for investment casting, which is suitable for casting gamma TiAl.\\ud \\ud As ...
The first major contract signed for the LHC is drawing to a close. Belgian firm Cockerill Sambre (a member of the Arcelor Group) has just completed production of 50,000 tonnes of steel sheets for the accelerator's superconducting magnet yokes, in what has proved to be an exemplary partnership with CERN. Philippe Lebrun, Head of the AT Department, Lyn Evans, LHC Project Leader, and Lucio Rossi, Head of the AT-MAS Group, in front of the last batch of steel for the LHC at Cockerill Sambre. It was a bright red-letter day at the end of May, when Belgian firm Cockerill Sambre of the Arcelor Group marked the completion of one of the largest contracts for the LHC machine by casting the last batch of steel sheets for the LHC superconducting magnet yokes in the presence of LHC Project Leader Lyn Evans, AT Department Head Philippe Lebrun, Magnets and Superconductors (AT-MAS) Group Leader Lucio Rossi and Head of the AT-MAS Group's components centre Francesco Bertinelli. The yokes constitute approximately 80% of the acc...
Low Background Micromegas in CAST
Garza, J.G.; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.
Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...
Latest results of cast and future prospects
Vafeiadis, Theodoros
CERN Axion Solar Telescope (CAST) is currently the most sensitive axion helioscope designed to search for axions and axion-like particles produced in the Sun. CAST completed successfully the second part of CAST phase II where the magnet bores were lled with 3He gas at variable pressure scanning axion masses up to 1.2 eV In the absence of signal it has set the best experimental limit on the axion-photon coupling constant over a broad range of axion masses. In 2013 CAST has improved its sensitivity to solar axions with rest mass below 0.02 eV by upgrading the Micromegas detectors and it will continue in 2014 with the implementation of a second X-ray optic and a new type detector (InGRID). In addition, CAST has extended its sensitivity into the sub-keV energy range using a silicon detector (SDD), to search for solar chameleons. Thus, CAST also became sensitive to dark energy particles. A new generation axion helioscope (IAXO) aims to improve the current axion-photon coupling by 1-1.5 orders of magnitude. This wi...
Directory of Open Access Journals (Sweden)
Marco A. Frangiotti
Full Text Available This article aims at showing that contemporary attempts to rehabilitate Pyrrhonian scepticism do not hold water. I claim that a sceptic of this trend gets stuck in two major dilemmas. The first regards her object of investigation. I argue that, if she holds that her object of investigation is the non-evident truth, she will not be able to distance herself from dogmatism. In turn, if she holds that she seeks to establish sense data propositions, she will not be able to pose herself as an investigator. The second dilemma stems from the sceptical attempt to wipe out dogmatism by developing arguments to the effect that no (dogmatic proof exists. I contend that those arguments can be viewed either as "good" arguments, in which case the sceptic will be considered just another theorist in possession of an explanation; or as expendable devices, in which case the sceptic will be incapable of carrying out her anti-dogmatic programme. Either way the sceptical position crumbles.
DEFF Research Database (Denmark)
Cohen, Michael; O'Neil, Andrew
. The Howard government coveted a US tripwire force presence, and the Clinton administration's unwillingness to provide this raised serious concerns among Australian political leaders about the alliance. While this says little about the separate question of whether Washington would use nuclear or conventional...... weapons in defense of Australian sovereignty, the Timor case indicates the existence of an extended deterrence credibility deficit regarding the more probable low intensity conflicts that Australia finds itself in....
Musial, G
Starting with two statements made by two great artists and witnesses of the XXth century - Joseph Brodsky and the Polish poet, Tadeusz Rozewicz - the author discusses the roots of our current moral crisis to which we ourselves bear witness: in the unchecked population explosion (Brodsky), and in the sinister legacy of World War II, the effects of which we witness on a daily basis (Rozewicz). The author recalls a third witness: Czeslaw Milosz, who wrote that the world's progress exhibits an inevitable tendency toward nihilism. In his discourse with the three statements mentioned, the author refers to certain XXth century intellectuals - Ortega y Gasset, Cardinal Joseph Ratzinger, Mircea Eliade, Herbert Read - who confirm and develop the thesis of man s spiritual fall and rejection of transcendence through technology. The author further illustrates his thesis with examples taken from the scientific research concerning IT, cloning, euthanasia, as well as from the world of the arts from the apocalyptic works of Hieronymous Bosch and Pieter Bruegel the Elder to the latest performers. He invokes a worldview which, by rejecting the metaphysics of man s birth, aging, and death, also rejects the judeo-christian taboo of the human body as a "dwelling place for the spirit" (porno festivals, exhibitions of human corpses by Prof. von Hagens in Germany).
DEFF Research Database (Denmark)
Abrahamsen, Bo; Einhorn, Thomas A
In May 2011, we were privileged to debate on behalf of the ECTS and the ASBMR in a Clinical Debate hosted by the IBMS and the ECTS with the motion "Atypical femoral shaft fractures are a consequence of bisphosphonate therapy". The evidence presented for and against the motion is summarized...... and discussed in this joint commentary. The hypothetical chain of evidence between bisphosphonates, decreased toughness of bone, microcrack accumulation in man and atypical fractures is plausible but unproven. However, the combination of consistent clinical features (which may include a stress reaction...
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Filipe Ferreira Ghidetti
Full Text Available It treats a peripheral aspect of teaching soccer in physical education classes: the (unpredictability. It builds on "Veneno Remédio", by José Miguel Wisnik, and "Guardiola Confidential", by Martí Perarnau, to discuss issues surrounding the subject, treating soccer as a practice that expresses particularities of Brazilian culture. It concludes that the investment in teaching the know-how of a coach presents an ethical and political advantage and is countercultural in contemporary Brazil.
National Metal Casting Research Institute final report. Volume 2, Die casting research
Energy Technology Data Exchange (ETDEWEB)
Jensen, D. [University of Northern Iowa, Cedar Falls, IA (United States). Dept. of Industrial Technology] [comp.
Four subprojects were completed: development and evaluation of die coatings, accelerated die life characterization of die materials, evaluation of fluid flow and solidification modeling programs, selection and characterization of Al-based die casting alloys, and influence of die materials and coatings on die casting quality.
Mechanical properties of homogenized twin-roll cast and conventionally cast AZ31 magnesium alloys
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Mariia Zimina
Full Text Available The improvement of mechanical properties of magnesium alloys nowadays is very important, because of the variety of industrial applications. For this goal, the number of casting techniques and further treatments were developed. Among the continuous casting techniques, which allow producing long strips of the alloys, is twin-roll casting. Using this process one can get the magnesium alloy with finest microstructure and higher specific strength. In this paper the comparison of tensile properties of conventionally cast and twin-roll cast AZ31 magnesium alloys was made. Tensile tests were carried out with constant strain rate 10-3 s-1 at temperatures ranging from 100 to 300 °C. Both materials were tested in as-cast state and after homogenization treatment at 450 °C for 10 hours. The investigation showed that there are no significant changes in ductility of AZ31 conventionally cast alloy even after heat treatment, while the ductility of twin-roll cast alloy increases.
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E. I. Marukovich
Full Text Available The analysis of thermal processes of formation of castings from wearproof chromic cast irons for replaceable details of centrifugal mills and crushers is carried out. Influence of protective and dividing coverings on intensity of heating of the chill mold is investigated.
Stereological parameters of carbides on section of casting made from modified chromium cast iron
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A. Studnicki
Full Text Available The analysis of stereological parameters of carbides on the section of the model castingmade from modified (the mixture FeNb+FeV+RE wear resistance chromium cast iron was introduced in the article. The jump change of some stereological parameters of carbides in certain distance from the surface of the casting was observed.
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O. S. Komarov
Full Text Available The technological process of the cast-iron IChH28H2 alloying by means of insertion into burden composition of briquettes of dead nickel-chromic catalysts is developed. This technology allows to carry out recycling of expensive metals such as nickel, and in that way to decrease the cost price of castings.
Precision Casting via Advanced Simulation and Manufacturing
A two-year program was conducted to develop and commercially implement selected casting manufacturing technologies to enable significant reductions in the costs of castings, increase the complexity and dimensional accuracy of castings, and reduce the development times for delivery of high quality castings. The industry-led R&D project was cost shared with NASA's Aerospace Industry Technology Program (AITP). The Rocketdyne Division of Boeing North American, Inc. served as the team lead with participation from Lockheed Martin, Ford Motor Company, Howmet Corporation, PCC Airfoils, General Electric, UES, Inc., University of Alabama, Auburn University, Robinson, Inc., Aracor, and NASA-LeRC. The technical effort was organized into four distinct tasks. The accomplishments reported herein. Task 1.0 developed advanced simulation technology for core molding. Ford headed up this task. On this program, a specialized core machine was designed and built. Task 2.0 focused on intelligent process control for precision core molding. Howmet led this effort. The primary focus of these experimental efforts was to characterize the process parameters that have a strong impact on dimensional control issues of injection molded cores during their fabrication. Task 3.0 developed and applied rapid prototyping to produce near net shape castings. Rocketdyne was responsible for this task. CAD files were generated using reverse engineering, rapid prototype patterns were fabricated using SLS and SLA, and castings produced and evaluated. Task 4.0 was aimed at developing technology transfer. Rocketdyne coordinated this task. Casting related technology, explored and evaluated in the first three tasks of this program, was implemented into manufacturing processes.
Predicting Pattern Tooling and Casting Dimensions for Investment Casting - Phase II
Energy Technology Data Exchange (ETDEWEB)
Sabau, Adrian S [ORNL
The investment casting process allows the production of complex-shape parts and close dimensional tolerances. One of the most important phases in the investment casting process is the design of the pattern die. Pattern dies are used to create wax patterns by injecting wax into dies. The wax patterns are used to create a ceramic shell by the application of a series of ceramic coatings, and the alloy is cast into the dewaxed shell mold (Fig. 1.1). However, the complexity of shape and the close dimensional tolerances required in the final casting make it difficult to determine tooling dimensions. The final linear dimension of the casting depends on the cumulative effects of the linear expansions or contractions in each step of the investment casting process (Fig. 1.2). In most cases, the mold geometry or cores restrict the shrinkage of the pattern or the cast part, and the final casting dimensions may be affected by time-dependent processes such as viscoelastic deformation of the wax, and viscoplastic creep and plastic deformations of the shell and alloy. The pattern die is often reworked several times to produce castings whose dimensions are within acceptable tolerances. To date, investment casting technology has been based on hands-on training and experience. Technical literature is limited to experimental, phenomenological studies aimed at obtaining empirical correlations for quick and easy application in industry. The goal of this project was to predict casting dimensions for investment castings in order to meet blueprint nominal during the first casting run. Several interactions have to be considered in a coupled manner to determine the shrinkage factors: these are the die-wax, wax-shell, and shell-alloy interactions (as illustrated in Fig. 1.3). In this work, the deformations of the die-wax and shell-alloy systems were considered in a coupled manner, while the coupled deformation of the wax-shell system was not considered. Future work is needed in order to
Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅰ
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Zhou Jiyang
Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour
Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅳ
Directory of Open Access Journals (Sweden)
Zhou Jiyang
Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour
Applying RP-FDM Technology to Produce Prototype Castings Using the Investment Casting Method
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Macků M.
Full Text Available The research focused on the production of prototype castings, which is mapped out starting from the drawing documentation up to the production of the casting itself. The FDM method was applied for the production of the 3D pattern. Its main objective was to find out what dimensional changes happened during individual production stages, starting from the 3D pattern printing through a silicon mould production, wax patterns casting, making shells, melting out wax from shells and drying, up to the production of the final casting itself. Five measurements of determined dimensions were made during the production, which were processed and evaluated mathematically. A determination of shrinkage and a proposal of measures to maintain the dimensional stability of the final casting so as to meet requirements specified by a customer were the results.
Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear
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D. Kopyciński
Full Text Available It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B4C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.
Gating Systems for Sizeable Castings from Al Alloys Cast into Ceramic Moulds
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I. Stachovec
Full Text Available In contrast to casting to conventional non-reusable "sand" moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly on the basis of experience. However, this approach is not sustainable with ever growing demands on quality of castings and also the economy of their fabrication as well as with new types of complex sizeable castings introduced to the production gradually (by new customers from the aircraft industry above all any more. The simulation software may be used as a possible tool for making the process of optimising gating systems more effective.
Mechanism and application of a newly developed pressure casting process: horizontal squeeze casting
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Li Peijie
Full Text Available Compared to traditional high-pressure die casting (HPDC, horizontal squeeze casting (HSC is a more promising way to fabricate high-integrity castings, owing to a reduced number of gas and shrinkage porosities produced in the casting. In this paper, the differences between HSC and HPDC are assessed, through which it is shown that the cavity filling velocity and the size of the gating system to be the most notable differences. Equipment development and related applications are also reviewed. Furthermore, numerical simulation is used to analyze the three fundamental characteristics of HSC: slow cavity filling, squeeze feeding and slow sleeve filling. From this, a selection principle is given based on the three related critical casting parameters: cavity filling velocity, gate size and sleeve filling velocity. Finally, two specific applications of HSC are introduced, and the future direction of HSC development is discussed.
Applying RP-FDM Technology to Produce Prototype Castings Using the Investment Casting Method
Directory of Open Access Journals (Sweden)
M. Macků
Full Text Available The research focused on the production of prototype castings, which is mapped out starting from the drawing documentation up to theproduction of the casting itself. The FDM method was applied for the production of the 3D pattern. Its main objective was to find out whatdimensional changes happened during individual production stages, starting from the 3D pattern printing through a silicon mouldproduction, wax patterns casting, making shells, melting out wax from shells and drying, up to the production of the final casting itself.Five measurements of determined dimensions were made during the production, which were processed and evaluated mathematically.A determination of shrinkage and a proposal of measures to maintain the dimensional stability of the final casting so as to meetrequirements specified by a customer were the results.
Evaluation of porosity in Al alloy die castings
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M. Říhová
Full Text Available Mechanical properties of an Al-alloy die casting depend significantly on its structural properties. Porosity in Al-alloy castings is one of the most frequent causes of waste castings. Gas pores are responsible for impaired mechanical-technological properties of cast materials. On the basis of a complex evaluation of experiments conducted on AlSi9Cu3 alloy samples taken from the upper engine block which was die- cast with and without local squeeze casting it can be said that castings manufactured without squeeze casting exhibit maximum porosity in the longitudinal section. The area without local squeeze casting exhibits a certain reduction in mechanical properties and porosity increased to as much as 5%. However, this still meets the norms set by SKODA AUTO a.s.
Casting: Pearls and pitfalls learned while caring for children's fractures.
Nguyen, Shawn; McDowell, Mitchell; Schlechter, John
Casting is a routine procedure used for fracture care in the pediatric population. The purpose of this review is to provide pearls and pitfalls that our institution has learned from previous literature. When applying the cast, we recommend using cotton padding for the liner and fiberglass or plaster depending on how much swelling is expected. A well-molded cast must be applied in order to prevent further fracture displacement. Cast valving is a valuable technique that allows a decrease in pressure which prevents discomfort and complications like compartment syndrome. Preventing thermal injuries, skin complications, and a wet cast are other important considerations when caring for casts. Appropriate use of a cast saw, avoiding pressure spots, and properly covering the cast are ways to respectively prevent those complications. Lastly, patient education remains one of the most valuable tools in ensuring proper cast maintenance.
CASTing light on dark matter particles
CERN's CAST collaboration recently released first results from its search for solar axions, a candidate dark matter particle. Though they haven't found any axions yet, they have done much to narrow the hunt. The CAST experiment. Physicists think the universe is permeated with dark matter, particles that don't emit or absorb radiation and so are invisible to traditional telescopes. So far no one has found direct signs of dark matter. A different breed of telescope, however, may be able to see such particles. CERN's Axion Solar Telescope (CAST), currently the world's only working axion helioscope, is a superconducting test magnet from the Large Hadron Collider (LHC) that has been refurbished and outfitted with X-ray detectors, plus a focusing mirror system for X-rays that was recovered from the German space program. CAST stares into the sun in search of particles called axions, one of the leading candidates for dark matter. On 9 November, the CAST collaboration released the results of their first experimen...
Improvement of Artistic Cast Production System
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Władysiak R.
Full Text Available The paper presents the technology and organization of the artistic cast production. On the basis of the actual cast production system, the manufacturing process was shown, in particular sand–piece moulding, which is a very important process and a time-consuming part of the entire manufacture of the casts. The current state of the production process as well as the organization of the work and production technology were analysed with the use of methods and techniques of production improvement, the Lean Manufacturing concept and computer systems. The results of the analysis and studies were shown with use of schemes and graphs of the layout of the production resources, a flow chart of the production process, value stream mapping, and a costs table for the production and modernization of the moulding stage. The work has shown that there are possibilities to improve the artistic cast production system. This improvement leads to increased productivity, lower production costs of artistic casts and increased competitiveness of the foundry.
Kuster, M.; Cebrian, S.; Davenport, M.; Elefteriadis, C.; Englhauser, J.; Fischer, H.; Franz, J.; Friedrich, P.; Hartmann, R.; Heinsius, F.H.; Hoffmann, D.H.H.; Hoffmeister, G.; Joux, J.N.; Kang, D.; Konigsmann, Kay; Kotthaus, R.; Papaevangelou, T.; Lasseur, C.; Lippitsch, A.; Lutz, G.; Morales, J.; Rodriguez, A.; Struder, L.; Vogel, J.; Zioutas, K.
The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and 7 keV. The most sensitive detector system of CAST is a pn-CCD detector combined with a Wolter I type X-ray mirror system. With the X-ray telescope of CAST a background reduction of more than 2 orders off magnitude is achieved, such that for the first time the axion photon coupling constant g_agg can be probed beyond the best astrophysical constraints g_agg < 1 x 10^-10 GeV^-1.
Staff's normative attitudes towards coercion: the role of moral doubt and professional context—a cross-sectional survey study
Molewijk, Bert; Kok, Almar; Husum, Tonje; Pedersen, Reidar; Aasland, Olaf
Background The use of coercion is morally problematic and requires an ongoing critical reflection. We wondered if not knowing or being uncertain whether coercion is morally right or justified (i.e. experiencing moral doubt) is related to professionals' normative attitudes regarding the use of coercion. Methods This paper describes an explorative statistical analysis based on a cross-sectional survey a...
Cast construction elements for heat treatment furnaces
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B. Piekarski
Full Text Available The study presents sketches and photos of the cast creep-resistant components used in various types of heat treatment furnaces. The shape of the elements results from the type of the operation carried out in the furnace, while dimensions are adjusted to the size of the furnace working chamber. The castings are mainly made from the high-alloyed, austenitic chromium-nickel or nickel-chromium steel, selecting the grade in accordance with the furnace operating conditions described by the rated temperature, the type and parameters of the applied operating atmosphere, and the charge weight. Typical examples in this family of construction elements are: crucibles, roller tracks, radiant tubes and guides. The majority of castings are produced in sand moulds.
Land-based turbine casting initiative
Energy Technology Data Exchange (ETDEWEB)
Mueller, B.A.; Spicer, R.A. [Howmet Corp., Whitehall, MI (United States)
The Advanced Turbine Systems (ATS) program has set goals which include a large-scale utility turbine efficiency that exceeds 60 percent (LHV) on natural gas and an industrial turbine system heat rate improvement of 15 percent. To meet these goals, technological advances developed for aircraft gas turbine engines need to be applied to land based gas turbines. These technological advances include: directionally solidified and single crystal castings, alloys tailored to exploit these microstructures, complex internal cooling schemes, and coatings. Equiaxed and directionally solidified castings are employed in current land based power generation equipment. These castings do not possess the ability to meet the efficiency targets as outlined above. The production use of premium single crystal components with complex internal cooling schemes in the latest generation of alloys is necessary to meet the ATS goals. However, at present, the use of single crystal components with complex internal cooling schemes is restricted to industrial sized or aeroderivative engines, and prototype utility sized components.
Controlled Precipitation Gaseous Cavities in Aluminium Castings
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Roučka J.
Full Text Available At thermal junctions of aluminium alloy castings and at points where risering proves to be difficult there appear internal or external shrinkages, which are both functionally and aesthetically inadmissible. Applying the Probat Fluss Mikro 100 agent, which is based on nano-oxides of aluminium, results in the appearance of a large amount of fine microscopic pores, which compensate for the shrinking of metal. Experimental tests with gravity die casting of AlSi8Cu3 and AlSi10Mg alloys have confirmed that the effect of the agent can be of advantage in foundry practice, leading to the production of castings without local concentrations of defects and without the appearance of shrinkages and macroscopic gas pores. Also, beneficial effect on the mechanical properties of the metal has been observed.
Cast Aluminum Alloy for High Temperature Applications
Lee, Jonathan A.
Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450 F (232 C) to about 750 F (400 C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. It can be very economically produced from conventional permanent mold, sand casting or investment casting, with silicon content ranging from 6% to 18%. At high silicon levels, the alloy exhibits excellent dimensional stability, surface hardness and wear resistant properties.
Maintenance system improvement in cast iron foundry
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S. Kukla
Full Text Available The work presents the issue of technical equipment management in an iron foundry basing on the assumptions of the TPM system (Total Productive Maintenance. Exploitation analysis of automatic casting lines has been carried out and their work's influence on the whole production system's functioning has been researched. Within maintenance system improvement, implementation of autonomic service and planned lines' review have been proposed in order to minimize the time of breakdown stoppages. The SMED method was used to optimize changeover time, and the OEE (Overall Equipment Effectiveness was applied to evaluate the level of resources usage before and after implementing changes. Further, the influence of the maintenance strategy of casting devices' efficiency on own costs of casting manufac- ture was estimated.
Discussion on Usability of the Niyama Criterion for Porosity Predicting in Cast Iron Castings
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Ignaszak Z.
Full Text Available The paper refers to previous publications of the author, focused on criteria of casting feeding, including the thermal criterion proposed by Niyama. On the basis of this criterion, present in the post-processing of practically all the simulation codes, danger of casting compactness (in the sense of soundness in form of a microporosity, caused by the shrinkage phenomena, is predicted. The vast majority of publications in this field concerns shrinkage and feeding phenomena in the cast steel castings – these are the alloys, in which parallel expansion phenomenon does not occur as in the cast irons (graphite crystallization. The paper, basing on the simulation-experimental studies, presents problems of usability of a classic, definition-based approach to the Niyama criterion for the cast iron castings, especially of greater massiveness, for prediction of presence of zones of dispersed porosity, with relation to predictions of the shrinkage type defects. The graphite expansion and its influence on shrinkage compensation during solidification of eutectic is also discussed.
[Study concerning the influence of the casting parameters of dental alloys on the cast prosthetic rehabilitation].
Viţalariu, Anca Mihaela; Tatarciuc, Monica Silvia
The integration of a cast rehabilitation into the oral environment and its clinical longevity are mainly determined by the accuracy reproduction of the technological parameters. The aim of this study was to evaluate the structural defects induced by the modification of the technological conditions of casting the conventional and titanium alloys. We used 35 cast prosthetic rehabilitation, divided into 7 groups. For each group we modified one parameter: the width of the wax pattern, the design and topography of the casting channels, the absence of the cleanliness of the wax pattern, the preparation of the investment material, the thermal system for the mold preparation and reduced quantity of metal used for casting. For the 7-th group, represented by titanium cast rehabilitation, we modified the design and dimensions of the casting channels. The changes in the technological conditions induced porosity, incomplete frameworks or plus on the prosthetic appliances. The fundamental theoretical knowledge of the clinician and dental technician and the strictly application of the technologies assure the premises of the satisfaction of the patient.
Diffusion of C and Cr During Creation of Surface Layer on Cast Steel Casting
Directory of Open Access Journals (Sweden)
Szajnar J.
Full Text Available In paper a method of improvement in utility properties of unalloyed cast steel casting in result of diffusion of C and Cr in process of creation of surface layer is presented. The aim of paper was determination of diffusion range of basic elements of alloyed surface layer. Moreover a quantitative analysis of carbides phase strengthens alloyed surface layer of casting was carried out. The results of studies shown that important factors of surface layer creation are maximal temperature Tmax on granular insert – cast steel boundary dependent of pouring temperature, granularity Zw of Fe-Cr-C alloy insert and thickness of casting wall gśo. On the basis of obtained results was affirmed that with increase of thickness of casting wall increases range of diffusion in solid state in Fe-Cr-C grains and in liquid state. Moreover the range of Tmax = 13001500oC favours creation of the proper alloyed surface layers on cast steel.
Technetium Getters to Improve Cast Stone Performance
Energy Technology Data Exchange (ETDEWEB)
Neeway, James J.; Lawter, Amanda R.; Serne, R. Jeffrey; Asmussen, Robert M.; Qafoku, Nikolla
The cementitious material known as Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. Two radionuclides of particular concern in these waste streams are technetium-99 (99Tc) and iodine-129 (129I). These radioactive tank waste components contribute the most to the environmental impacts associated with the cleanup of the Hanford site. A recent environmental assessment of Cast Stone performance, which assumes a diffusion controlled release of contaminants from the waste form, calculates groundwater in excess of the allowable maximum permissible concentrations for both contaminants. There is, therefore, a need and an opportunity to improve the retention of both 99Tc and 129I in Cast Stone. One method to improve the performance of Cast Stone is through the addition of "getters" that selectively sequester Tc and I, therefore reducing their diffusion out of Cast Stone. In this paper, we present results of Tc and I removal from solution with various getters with batch sorption experiments conducted in deionized water (DIW) and a highly caustic 7.8 M Na Ave LAW simulant. In general, the data show that the selected getters are effective in DIW but their performance is comprised when experiments are performed with the 7.8 M Na Ave LAW simulant. Reasons for the mitigated performance in the LAW simulant may be due to competition with Cr present in the 7.8 M Na Ave LAW simulant and to a pH effect.
Quality control of cast brake discs
Directory of Open Access Journals (Sweden)
M. Stawarz
Full Text Available The largest industrial application so far have the gray cast irons which are characterized by low tensile and bending strength, while at the same time they have good ultimate comprehensive strength. Additionally, the fatigue strength of gray cast irons is comparatively low and they are only to some extend sensitive for the surface waters effects. Cast iron is the material, which is comparatively easy to be processed, and for this reason – it is not expensive. Brake discs are exploited in particularly hard conditions. They must be resistant both against the thermal fatigue and abrasion wearing (at dry friction as well as against seizing, corrosion and mechanical load [1-3]. The gray cast iron, better than other materials, fulfills all the requirements necessary for making the material for the casts resistant against such tough conditions. This work reflects the researches aiming to define the quality of cast brake discs (ventilated and non-ventilated ones upon a period of their exploitation in real conditions. The following researches were performed: evaluations of the disc surface condition, measurement of disc thickness, examination of run – out flank and metallographic analysis. In order to more detailed recognition of mechanisms and reasons of brake discs wearing in real conditions, one should conduct additional examinations: computer analysis of the microstructure, chemical composition analysis, etc., as well as study of the technology of their production in foundries, where they are manufactured [4]. By obtaining the full set of the mentioned above data one can draw final conclusions and remove causes of possible defects.
Casting of microstructured shark skin surfaces and possible applications on aluminum casting parts
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Todor Ivanov
Full Text Available Within the project Functional Surfaces via Micro- and Nanoscaled Structures?which is part of the Cluster of Excellence 揑ntegrative Production Technology?established and financed by the German Research Foundation (DFG, an investment casting process to produce 3-dimensional functional surfaces down to a structural size of 1 μm on near-net-shape-casting parts has been developed. The common way to realize functional microstructures on metallic surfaces is to use laser ablation, electro discharge machining or micro milling. The handicap of these processes is their limited productivity. The approach of this project to raise the efficiency is to use the investment casting process to replicate microstructured surfaces by moulding from a laser-microstructured grand master pattern. The main research objective deals with the investigation of the single process steps of the investment casting process with regard to the moulding accuracy. Actual results concerning making of the wax pattern, suitability of ceramic mould and core materials for casting of an AlSi7Mg0.3 alloy as well as the knock-out behavior of the shells are presented. By using of the example of an intake manifold of a gasoline race car engine, a technical shark skin surface has been realized to reduce the drag of the intake air. The intake manifold consists of an air-restrictor with a defined inner diameter which is microstructured with technical shark skin riblets. For this reason the inner diameter cannot be drilled after casting and demands a very high accuracy of the casting part. A technology for the fabrication and demoulding of accurate microstructured castings are shown. Shrinkage factors of different moulding steps of the macroscopic casting part as well as the microscopic riblet structure have been examined as well.
Optimization of the investment casting process
Directory of Open Access Journals (Sweden)
M. Martinez-Hernandez
Full Text Available Rapid prototyping is an important technique for manufacturing. This work refers to the manufacture of hollow patterns made of polymeric materials by rapid prototyping technologies for its use in the preparation of ceramic molds in the investment casting process. This work is focused on the development of a process for manufacturing patterns different from those that currently exist due to its hollow interior design, allowing its direct use in the fabrication of ceramic molds; avoiding cracking and fracture during the investment casting process, which is an important process for the foundry industry.
Fatigue behaviour of synthetic nodular cast irons
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A. Vaško
Full Text Available The paper shows the influence of charge composition on microstructure, fatigue properties and failure micromechanisms of nodular cast irons. The additive of metallurgical silicon carbide (SiC in analysed specimens increases the content of ferrite in the matrix, decreases the size of graphite and increases the average count of graphitic nodules per unit of area. Consequently, the mechanical and fatigue properties of nodular cast iron are improved. The best fatigue properties (fatigue strength were reached in the melt which was created by 60 % of steel scrap and 40 % of pig iron in the basic charge with SiC additive.
Repair welding of cast iron coated electrodes
Żuk, M.; Górka, J.; Dojka, R.; Czupryński, A.
Welding cast iron is a complex production procedure. Repair welding was used to repair damaged or poorly made castings. This is due to a tendency to cracking of the material during welding as well as after it. Welding cast iron can be carried out on hot or on cold. Hot welding requires high heat material and the use of welding material in the form of cast iron. In the case of cold welding, it is possible to use different materials. Mostly used filler metals are nickel and copper based. The work shows the course of research concerning repairmen of ductile iron with arc welding method. For the reparation process four types of ESAB company coated electrodes dedicated for cast iron were used with diameter 3.2 and 4 mm: ES 18-8-6B (4mm), EB 150 (4mm), OK NiCl, EŻM. In the cast iron examined during the testing grooves were made using plasma methods, in order to simulate the removed casting flaws. Then the welding process with coated electrodes was executed. The process utilized low welding current row of 100A, so there would only be a small amount of heat delivered to the heat affected zone (HAZ). Short stitches were made, after welding it was hammered, in order to remove stresses. After the repair welding the part of studies commenced which purpose was finding surface defects using visual testing (VT) and penetration testing (PT). In the second part, a series of macro and microscopic studies were executed witch the purpose of disclosuring the structure. Then the hardness tests for welds cross sections were performed. An important aspect of welding cast iron is the colour of the padding weld after welding, more precisely the difference between the base material and padding weld, the use of different materials extra gives the extra ability to select the best variant. The research of four types of coated electrode was executed, based on the demands the best option in terms of aesthetic, strength and hardness.
Casting defects analysis by the Pareto method
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B. Borowiecki
Full Text Available On the basis of receive results formed of diagram Pareto Lorenz. On the basis of receive graph it affirmed, that for 70% general number casting defects answered 3 defects (9 contribution – 100% defects. For 70% general number defects of influence it has three type of causes: sand holes, porosity and slaginclusions. Thedefects show that it is necessary to take up construction gatingsystem. The remaining 8 causes have been concerned only 25%, with general number of casting defects. Analysis of receive results permit to determine of direction of correct actions in order to eliminate or to limit the most defects.
Fundamentals of Numerical Modelling of Casting Processes
DEFF Research Database (Denmark)
Pryds, Nini; Thorborg, Jesper; Lipinski, Marek
Fundamentals of Numerical Modelling of Casting Processes comprises a thorough presentation of the basic phenomena that need to be addressed in numerical simulation of casting processes. The main philosophy of the book is to present the topics in view of their physical meaning, whenever possible......) presents the most important aspects of solidification theory related to modelling. Part III (Chapter 5) describes the fluid flow phenomena and in part IV (Chapter 6) the stress-strain analysis is addressed. For all parts, both numerical formulations as well as some important analytical solutions...
Directory of Open Access Journals (Sweden)
E. I. Marukovich
Full Text Available It is shown that cooling of casting molds by water with water flow of 0,42 m3/h and internal surfaces of castings with thickness of a wall 12–14 mm with water quantity 2,5×10–4–5×10–4 m3 allows to receive procurements with completely modified microstructure without use of modifiers. External layers of the produced castings consist of the eutectic silumin with compact crystals of silicon, and internal layers – of hypereutectic silumin with crystals of high-disperse primary and compact eutectic silicon.
Structure Distribution in Precise Cast Iron Moulded on Meltable Model
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Skrbek B.
Full Text Available Topic of this work is to compare metalurgy of cast irons poured into sand moulds and into shell molds at IEG Jihlava company and from it following differencies in structures of thin- and thick-walled castings. This work is dealing with investigation and experimental measurement on surfaces and sections suitable thin- and thick-walled investment castings at IEG Jihlava. Cast irons with flake graphite (grey cast iron and cast irons with spheroidal graphite (ductile cast iron. Both mechanical and physical properties are determined using calculations from as measured values of wall thicknesses L and Lu, Vickers hardness and remanent magnetism. Measurement results are discussed, findings are formulated and methods for castings metallurgical quality improvement are recommended finally.
Development of vacuum continuous casting technology for uranium
Energy Technology Data Exchange (ETDEWEB)
Lee, Y.S.; Kim, C. K.; Kim, K. H.; Lee, D. B.; Kim, J. D.; Jang, S. J.; Ahn, H. S.; Shin, Y. J
The spent fuel disposal process of new dry storage concept has been developed in KAERI, in which the uranium metal abstracted by Li-reduction of spent fuel will be formed to long rods and then the rods will be arranged uniformly in canister. The objective of this study is to review the feasibility of applying the continuous casting method to cast a long rod with modifying the vacuum high-frequency induction furnace to vacuum continuous casting system, which was normally used to cast the uranium. The results are as follows. With the nozzle size of 3mm and the withdrawal speed of 3.5 mm/sec, the length of 160mm, diameter of 30 mm continuous casting uranium bar was successfully cast. This result shows there might be a possibility of continuous casting of uranium and helps the design and fabrication of new continuous casting equipment.
Enhancements in Magnesium Die Casting Impact Properties
Energy Technology Data Exchange (ETDEWEB)
David Schwam; John F. Wallace; Yulong Zhu; Srinath Viswanathan; Shafik Iskander
The need to produce lighter components in transportation equipment is the main driver in the increasing demand for magnesium castings. In many automotive applications, components can be made of magnesium or aluminum. While being lighter, often times the magnesium parts have lower impact and fatigue properties than the aluminum. The main objective of this study was to identify potential improvements in the impact resistance of magnesium alloys. The most common magnesium alloys in automotive applications are AZ91D, AM50 and AM60. Accordingly, these alloys were selected as the main candidates for the study. Experimental quantities of these alloys were melted in an electrical furnace under a protective atmosphere comprising sulfur hexafluoride, carbon dioxide and dry air. The alloys were cast both in a permanent mold and in a UBE 315 Ton squeeze caster. Extensive evaluation of tensile, impact and fatigue properties was conducted at CWRU on permanent mold and squeeze cast test bars of AZ91, AM60 and AM50. Ultimate tensile strength values between 20ksi and 30ksi were obtained. The respective elongations varied between 25 and 115. the Charpy V-notch impact strength varied between 1.6 ft-lb and 5 ft-lb depending on the alloy and processing conditions. Preliminary bending fatigue evaluation indicates a fatigue limit of 11-12 ksi for AM50 and AM60. This is about 0.4 of the UTS, typical for these alloys. The microstructures of the cast specimens were investigated with optical and scanning electron microscopy. Concomitantly, a study of the fracture toughness in AM60 was conducted at ORNL as part of the study. The results are in line with values published in the literature and are representative of current state of the art in casting magnesium alloys. The experimental results confirm the strong relationship between aluminum content of the alloys and the mechanical properties, in particular the impact strength and the elongation. As the aluminum content increases from about 5
Effect of Isothermal Aging on the Long-Term Reliability of Fine-Pitch Sn-Ag-Cu and Sn-Ag Solder Interconnects With and Without Board-Side Ni Surface Finish
Lee, Tae-Kyu; Duh, Jeng-Gong
The combined effects on long-term reliability of isothermal aging and chemically balanced or unbalanced surface finish have been investigated for fine-pitch ball grid array packages with Sn-3.0Ag-0.5Cu (SAC305) (wt.%) and Sn-3.5Ag (SnAg) (wt.%) solder ball interconnects. Two different printed circuit board surface finishes were selected to compare the effects of chemically balanced and unbalanced structure interconnects with and without board-side Ni surface finish. NiAu/solder/Cu and NiAu/solder/NiAu interconnects were isothermally aged and thermally cycled to evaluate long-term thermal fatigue reliability. Weibull plots of the combined effects of each aging condition and each surface finish revealed lifetime for NiAu/SAC305/Cu was reduced by approximately 40% by aging at 150°C; less degradation was observed for NiAu/SAC305/NiAu. Further reduction of characteristic life-cycle number was observed for NiAu/SnAg/NiAu joints. Microstructure was studied, focusing on its evolution near the board and package-side interfaces. Different mechanisms of aging were apparent under the different joint configurations. Their effects on the fatigue life of solder joints are discussed.
Microabrasion of cast metal margins--a warning.
Mansueto, Michael A; Verrett, Ronald G; Phoenix, Rodney D
Plastic test patterns were milled to simulate casting margins and were cast in a variety of dental alloys. The cast specimens were exposed to horizontal and vertical streams of low-pressure microabrasion with 50 microm aluminum oxide particles. Post-exposure measurements show all specimens were affected by microabrasion. Dentists and laboratory technicians who use microabrasion must be aware of the potential damage to casting margins.
Understanding sexual violence as a form of caste violence
Prachi Patil
The paper attempts to understand narratives of sexual violence anchored within the dynamics of social location of caste and gender. Apparent caste-patriarchy and gender hierarchies which are at play in cases of sexual violence against lower-caste and dalit women speak about differential experiences of rape and sexual abuse that women have in India. The paper endeavours to establish that sexual violence is also a form of caste violence by rereading the unfortunate cases of Bhanwari Devi, Khair...
Directory of Open Access Journals (Sweden)
V. M. Ilyushenko
Full Text Available The article presents the results of the tests on the wear resistance of chromium cast irons of different compositions obtained in sand forms. It has been shown that increase of the wear resistance and mechanical properties of the cast iron is possible to obtain using the casting in metal molds. A further increase in wear resistance of parts produced in metal molds is possible by changing the technological parameters of casting and alloying by titanium.
Awareness Programs and Change in Taste-based Caste Prejudice
DEFF Research Database (Denmark)
Banerjee, Ritwik; Gupta, Nabanita Datta
in his seminal work on taste based discrimination, in the context of caste in India, with management students (potential employers in the near future) as subjects. First, we measure caste prejudice and show that awareness through a TV social program reduces implicit prejudice against the lower caste...
46 CFR 153.239 - Use of cast iron.
... 46 Shipping 5 2010-10-01 2010-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet the...
29 CFR 452.131 - Casting of ballots; delegate elections.
... 29 Labor 2 2010-07-01 2010-07-01 false Casting of ballots; delegate elections. 452.131 Section 452... REPORTING AND DISCLOSURE ACT OF 1959 Election Procedures; Rights of Members § 452.131 Casting of ballots; delegate elections. The manner in which the votes of the representatives are cast in the convention is not...
Clean Cast Steel Technology - Machinability and Technology Transfer
Energy Technology Data Exchange (ETDEWEB)
C. E. Bates; J. A. Griffin
There were two main tasks in the Clean Cast Steel Technology - Machinability and Technology Transfer Project. These were (1) determine the processing facts that control the machinability of cast steel and (2) determine the ability of ladle stirring to homogenize ladle temperature, reduce the tap and pouring temperatures, and reduce casting scrap.
A 2-dimensional finite element simulation of cooling in castings ...
African Journals Online (AJOL)
In this work we present a 2 dimensional finite element simulation of the cooling process in castings. A one way coupling +technique was used to predict the behavior of thermal strains and stresses from the temperature history of casting. The temperature distribution across the casting at different times, the cooling pattern of ...
Genetic study of scheduled caste populations of Tamil Nadu
Indian Academy of Sciences (India)
Home; Journals; Journal of Genetics; Volume 87; Issue 2. Genetic study of scheduled caste populations of Tamil Nadu. M. Vijaya S. Kanthimathi A. Ramesh. Research Note Volume 87 Issue 2 ... Keywords. caste system; genetic affinity; scheduled castes; socio-economic groups; Tamil Nadu; principal component analysis.
Effects of calpastain (CAST) polymorphisms on carcass and meat ...
African Journals Online (AJOL)
Calpastain (CAST) activity plays a major role in muscle growth and proteolytic changes post-mortem and the CAST gene has been considered as a candidate gene for carcass and pork quality characteristics. The aim of this study was to analyze the association of two polymorphisms namely CAST_HinfI (allele A and B) and ...
Structure and mechanical properties of vermicular cast iron in cylinder head casting
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E. Guzik
Full Text Available The paper discusses the problem of grain density and ferrite content in microstructure of vermicular graphite iron cast in bars of different section diameters and cylinder head casting. The experimental results regarding the section effect demonstrate that the nodule count, grain density and ferrite content are all function of the cast bar diameter in this particular case ranging from 0.6 to 8.0 cm and microstructure and mechanical properties in the cylinder head. The nodule count (or grain density has been reported to increase, while ferrite content was decreasing with decreasing casting diameter. The density number of the grains Nv has been related (by regression analysis to the undercooling degree
Effects of Casting Conditions on End Product Defects in Direct Chill Casted Hot Rolling Ingots
Yorulmaz, Arda; Yüksel, Çağlar; Erzi, Eraz; Dispinar, Derya
Direct chill casting is a reliable casting process for almost any wrought aluminum alloy for subsequent deformation via hot rolling to supply vital industries such as aerospace, automotive, construction, packaging and maritime. While some defects occur during casting, like hot tearing, some others like surface defect causing blisters, appear after hot rolling process or annealing after final cold rolling steps. It was found that some of these defects are caused by melt impurities formed from entrained folded aluminum oxides or bifilms. A study in a hot rolling casting facility was carried out with different melt cleaning practices, launder and molten metal transferring designs. Bifilm index and reduced pressure test were used for determining melt cleanliness measurement. It was found that porous plug gas diffusons for degassing are more effective than lance type degassers and a design towards less turbulent molten metal flow from furnace to mould cavity are necessary for reducing defects caused by bifilms.
Casting directly from a computer model by using advanced simulation software FLOW-3D Cast ®
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M. Sirviö
Full Text Available ConiferRob - A patternless casting technique, originally conceived at VTT Technical Research Centre of Finland and furtherdeveloped at its spin-off company, Simtech Systems, offers up to 40% savings in product development costs, and up to two months shorterdevelopment times compared to conventional techniques. Savings of this order can be very valuable on today's highly competitivemarkets. Casting simulation is commonly used for designing of casting systems. However, most of the software are today old fashioned and predicting just shrinkage porosity. Flow Science, VTT and Simtech have developed new software called FLOW-3D Cast ® , whichcan simulate surface defects, air entrainment, filters, core gas problems and even a cavitation.
Carburizer Effect on Cast Iron Solidification
Janerka, Krzysztof; Kondracki, Marcin; Jezierski, Jan; Szajnar, Jan; Stawarz, Marcin
This paper presents the effect of carburizing materials on cast iron solidification and crystallization. The studies consisted of cast iron preparation from steel scrap and different carburizers. For a comparison, pig iron was exclusively used in a solid charge. Crystallization analysis revealed the influence of the carburizer material on the crystallization curves as well as differences in the solidification paths of cast iron prepared with the use of different charge materials. The carburizers' influence on undercooling during the eutectic crystallization process was analyzed. The lowest undercooling rate was recorded for the melt with pig iron, then for synthetic graphite, natural graphite, anthracite, and petroleum coke (the highest undercooling rate). So a hypothesis was formulated that eutectic cells are created most effectively with the presence of carbon from pig iron (the highest nucleation potential), and then for the graphite materials (crystallographic similarity with the carbon precipitation in the cast iron). The most difficult eutectic crystallization is for anthracite and petroleum coke (higher undercooling is necessary). This knowledge can be crucial when the foundry plant is going to change the solid charge composition replacing the pig iron by steel scrap and the recarburization process.
Gelcasting Alumina Cores for Investment Casting
Energy Technology Data Exchange (ETDEWEB)
Janney, M A; Klug, F J
General Electric currently uses silica investment casting cores for making superalloy turbine blades. The silica core technology does not provide the degree of dimensional control needed for advanced turbine system manufacture. The sum of the various process variables in silica core manufacturing produces cores that have more variability than is allowed for in advanced, power-generation gas turbine airfoils.
Esthetic Rehabilitation with a Cast Partial Denture
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Suraksha Shrestha
Full Text Available Removable partial denture is a treatment option where fixed prosthesis is not indicated. Due to its esthetic problems in the anterior region various modifications have been designed for its fabrication. This article describes an esthetic alternative using a round rest distal depression clasp for maxillary anterior teeth abutment while restoring the missing teeth with a cast partial denture.
Palatal Surface Area of Maxillary Plaster Casts
DEFF Research Database (Denmark)
Darvann, Tron Andre; Hermann, Nuno V.; Ersbøll, Bjarne Kjær
-dimensional measurements of selected linear distances, curve lengths, and (surface) areas were carried out on maxillary plaster casts from individuals with unilateral or bilateral cleft lip and palate. The relationship between two-dimensional and three-dimensional measurements was investigated using linear regression...... ratio may be converted to a three-dimensional measurement by use of a multiplication factor of 0.75....
Fermilab joins in global live Web cast
Polansek, Tom
From 2 to 3:30 p.m., Lederman, who won the Nobel Prize for physics in 1988, will host his own wacky, science-centered talk show at Fermi National Accelerator Laboratory as part of a lvie, 12-hour, international Web cast celebrating Albert Einstein and the world Year of Physics (2/3 page)
... are not waterproof, so keeping them dry for the whole time the cast is in place is very important. It ... Nemours Foundation. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart. ...
Status and perspectives of the CAST experiment
Lakic, B; Aune, S; Barth, K; Belov, A; Borghi, S; Brauninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galan, J; Garcia, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Gruber, E; Guthorl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovcic, K; Karuza, M; Konigsmann, K; Kotthaus, R; Krcmar, M; Kuster, M; Laurent, J M; Liolios, A; Ljubicic, A; Lozza, V; Lutz, G; Luzon, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomas, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K
The CERN Axion Solar Telescope (CAST) is currently the most sensitive axion helioscope designed to search for axions produced by the Primakoff process in the solar core. CAST is using a Large Hadron Collider (LHC) test magnet where axions could be converted into X-rays with energies up to 10 keV. During the phase I, the experiment operated with vacuum inside the magnet bores and covered axion masses up to 0.02 eV. In the phase II, the magnet bores were filled with a buffer gas (first (4)He and later (3)He) at various densities in order to extend the sensitivity to higher axion masses (up to f .18 eV). The phase II data taking was completed in 2011. So far, no evidence of axion signal has been found and CAST set the most restrictive experimental limit on the axion-photon coupling constant over a broad range of axion masses. The latest CAST results with (3)He data in the mass range 0.39 eV < ma < 0.64 eV will be presented.
Deliberate deformation of concrete after casting
Grunewald, S.; Janssen, B.; Schipper, H.R.; Vollers, K.J.; Walraven, J.C.
This paper discusses the effect of intentional deformation of a flexible formwork after casting of the concrete and the influence of the characteristics of concrete in the fresh state on the quality of a concrete element. This deformation is intended to bring the concrete element in its desired
Genetics studies involving Swiss needle cast.
R. Johnson; F. Temel; K. Jayawickrama
Three studies were analyzed this year that examined genetic aspects of Swiss needle cast (SNC) tolerance . Families sampled across the Siuslaw National forest showed differences in foliage health traits, but very little of the variation could be explained by environmental or climatic conditions at the parent tree location. Five test sites of the Nehalem series of...
Internal Casting Stresses and Dimensional Stability
DEFF Research Database (Denmark)
Andriollo, Tito; Vedel-Smith, Nikolaj Kjelgaard; Thorborg, Jesper
It is common knowledge that cast iron components may be affected by the presence of residual stresses. This often represents a serious threat, because residual stresses almost invariably cause a significant degradation of the most important material properties, such as reduced fracture toughness,...
Modal Vibration Analysis of Large Castings
Werlink, Rudolph J.; Margasahayam, Ravi N.
The art of experimental modal vibration analysis (MVA) has been extended to apply to large castings. This extension was made to enable the use of experimental MVA as a relatively inexpensive, simple means of assessing the internal structural integrity of tread shoes of crawler transporters used to move spacecraft to the launch pad at Kennedy Space Center. Each tread shoe is made from cast iron and weighs about a ton (has a mass .907 kg). The present extended version of experimental MVA could also be applied to other large castings. It could be especially useful to manufacturers as a means of rapidly discriminating against large castings that contain unacceptably large concentrations of internal defects. The use of experimental MVA to assess structural integrity is not new. What are new here are those aspects of the extension of experimental MVA that pertain to the application of MVA to objects so massive that it may not be practical or cost effective to mount them in special test fixtures that impose special test boundary conditions to test them in place under normal conditions of use.
Costs Analysis of Iron Casts Manufacturing
Directory of Open Access Journals (Sweden)
S. Kukla
Full Text Available The article presents the issues of costs analysis of iron casts manufacturing using automated foundry lines. Particular attention was paid to departmental costs, conversion costs and costs of in-plant transport. After the Pareto analysis had been carried out, it was possible to set the model area of the process and focus on improving activities related to finishing of a chosen group of casts. In order to eliminate losses, the activities realised in this domain were divided into activities with added value, activities with partially added value and activities without added value. To streamline the production flow, it was proposed to change the location of workstations related to grinding, control and machining of casts. Within the process of constant improvement of manufacturing processes, the aspect of work ergonomics at a workstation was taken into account. As a result of the undertaken actions, some activities without added value were eliminated, efficiency was increased and prime costs of manufacturing casts with regard to finishing treatment were lowered.
The Micromegas detector of the CAST experiment
Abbon, P.; Aune, S.; Dafni, T.; Davenport, M.; Delagnes, E.; de Oliveira, R.; Fanourakis, G.; Ferrer Ribas, E.; Franz, J.; Geralis, T.; Gros, M.; Giomataris, Y.; Irastorza, I.G.; Kousouris, K.; Morales, J.; Papaevangelou, T.; Ruz, J.; Zachariadou, K.; Zioutas, K.
A low background Micromegas detector has been operating in the CAST experiment at CERN for the search of solar axions during the first phase of the experiment (2002-2004). The detector, made out of low radioactivity materials, operated efficiently and achieved a very low level of background rejection (5 x 10^-5 counts/keV/cm^2/s) without shielding.
CAST reaches milestone but keeps on searching
CERN Courier (september 2011 issue)
After eight years of searching for the emission of a dark matter candidate particle, the axion, from the Sun, the CERN Axion Solar Telescope (CAST) has fulfilled its original physics programme. Members of the CAST collaboration in July, together with dipole-based helioscope. CAST, the world's most sensitive axion helioscope, points a recycled prototype LHC dipole magnet at the Sun at dawn and dusk, looking for the conversion of axions to X-rays. It incorporates four state-of-the-art X-ray detectors: three Micromegas detectors and a pn-CCD imaging camera attached to a focusing X-ray telescope that was recovered from the German space programme (see CERN Courier April 2010). Over the years, CAST has operated with the magnet bores - the location of the axion conversion - in different conditions: first in vacuum, covering axion masses up to 20 meV/c2, and then with a buffer gas (4He and later 3He) at various densities, finally reaching the goal of 1.17 eV/c2 on 22 ...
Casting the Spirit: A Handmade Legacy
Rutenberg, Mona
This article discusses how an art therapist working in a hospital palliative care unit has incorporated a ritual of hand casting to help bring closure to dying patients and family members who are grieving as death approaches. The finished hand sculptures depict the hands of the patients and, sometimes, of their loved ones. They are faithful and…
Earthworm Cast Biomass Under Three Managed Ecosystems ...
African Journals Online (AJOL)
The study was conducted to determine earthworm cast biomass under three managed ecosystems, Gmelina, Cashew and Banana plantations at Federal University of Agriculture, Abeokuta and its impact on the soil physicochemical parameters. Seven, five and four plots of 3 m2 each were sampled in Gmelina, Cashew and ...
Cast erosion from the cleaning of debris after the use of a cast trimmer.
Hansen, Paul A; Beatty, Mark W
Whether using tap water to rinse off debris will make a clinical difference to the surface detail of a gypsum cast is unknown. In addition, how best to remove debris from the cast is unknown. The purpose of this in vitro study was to evaluate the efficiency of different methods of cleaning a gypsum cast after trimming and the effect of short-term exposure to tap water on the surface quality of the cast. A die fitting American National Standards Institute/American Dental Association specification 25 (International Standards Organization specification 6873) for dental gypsum products was embedded in a Dentoform with the machined lines positioned at the same level as the occlusal surface of the posterior teeth. A flat plate was used to ensure that the plane of occlusion for the die was at the same position as the posterior teeth. Forty polyvinyl siloxane impressions of the Dentoform were made and poured with vacuum-mixed improved Type IV dental stone. Each cast was inspected for the accurate reproduction of the lines. The base of the 2-stage pour was trimmed with a cast trimmer with water, and surface debris was removed by rinsing by hand under tap water for 10 seconds, by brushing the cast with a soft toothbrush for 10 seconds, or by resoaking the cast and using a soft camel hair brush in slurry water for 10 seconds. The amount of debris was evaluated on a scale of 1 to 4, and the quality of the 20-μm line was evaluated on a scale of 1 to 4 under ×15 magnification. The nonparametric Kruskal-Wallis ranks test was used to identify significant differences among the different cleaning methods (α=.05). Results of the Kruskal-Wallis and Kruskal-Wallis Z-value tests demonstrated that all cleaning methods produced cleaner casts than were observed for uncleansed controls (Pcleaning methods (.065≤P≤.901). The ability to see the quality of a 20-μm line (P=.974) was not statistically different among the groups. Rinsing the cast under flowing tap water and brushing, or
Doubtful outcome of the validation of the Rome II questionnaire: validation of a symptom based diagnostic tool
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Nylin Henry BO
the Rome II is of doubtful value for clinical practice and research. The results for reproducibility and reliability were acceptable but the outcome of the predictability test was poor with IBS as an exception. The agreement between the digital and the paper questionnaire was good.
The influence of solidification speed during heating on allotropic transformations of chromium cast iron casting
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M. Przybył
Full Text Available The unique stand to founding dilatometric samples ("on ready" which solidify with different cooling speeds was presented. The dilatometric investigations, X-ray, metallographic they disclosed the occurrence in matrix of chromium cast iron of considerable quantity of austenite in dependence from concentration of chromium (18% and 23% and the speed of solidification. Castings these despite large part of austenite mark with high hardness in raw state.
The Configurable Aperture Space Telescope (CAST)
Ennico, Kimberly; Bendek, Eduardo A.; Lynch, Dana H.; Vassigh, Kenny K.; Young, Zion
The Configurable Aperture Space Telescope, CAST, is a concept that provides access to a UV/visible-infrared wavelength sub-arcsecond imaging platform from space, something that will be in high demand after the retirement of the astronomy workhorse, the 2.4 meter diameter Hubble Space Telescope. CAST allows building large aperture telescopes based on small, compatible and low-cost segments mounted on autonomous cube-sized satellites. The concept merges existing technology (segmented telescope architecture) with emerging technology (smartly interconnected modular spacecraft, active optics, deployable structures). Requiring identical mirror segments, CAST's optical design is a spherical primary and secondary mirror telescope with modular multi-mirror correctors placed at the system focal plane. The design enables wide fields of view, up to as much as three degrees, while maintaining aperture growth and image performance requirements. We present a point design for the CAST concept based on a 0.6 meter diameter (3 x 3 segments) growing to a 2.6 meter diameter (13 x 13 segments) primary, with a fixed Rp=13,000 and Rs=8,750 mm curvature, f/22.4 and f/5.6, respectively. Its diffraction limited design uses a two arcminute field of view corrector with a 7.4 arcsec/mm platescale, and can support a range of platescales as fine as 0.01 arcsec/mm. Our paper summarizes CAST, presents a strawman optical design and requirements for the underlying modular spacecraft, highlights design flexibilities, and illustrates applications enabled by this new method in building space observatories.
Aluminium Foam and Magnesium Compound Casting Produced by High-Pressure Die Casting
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Iban Vicario
Full Text Available Nowadays, fuel consumption and carbon dioxide emissions are two of the main focal points in vehicle design, promoting the reduction in the weight of vehicles by using lighter materials. The aim of the work is to evaluate the influence of different aluminium foams and injection parameters in order to obtain compound castings with a compromise between the obtained properties and weight by high-pressure die cast (HPDC using aluminium foams as cores into a magnesium cast part. To evaluate the influence of the different aluminium foams and injection parameters on the final casting products quality, the type and density of the aluminium foam, metal temperature, plunger speed, and multiplication pressure have been varied within a range of suitable values. The obtained compound HPDC castings have been studied by performing visual and RX inspections, obtaining sound composite castings with aluminium foam cores. The presence of an external continuous layer on the foam surface and the correct placement of the foam to support injection conditions permit obtaining good quality parts. A HPDC processed magnesium-aluminium foam composite has been developed for a bicycle application obtaining a suitable combination of mechanical properties and, especially, a reduced weight in the demonstration part.
The influence of modification and squeeze casting on properties of AlSi11 alloy castings
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A. Zyska
Full Text Available The results of structural examinations and tests of mechanical properties of AlSi11 alloy, either gravity or squeeze cast, have beenpresented. The investigations have been carried out for both the non-modified silumin and the alloy modified with AlSr10 strontiummaster alloy. The measurements have been carried out for the cast plates of dimensions 200×100×25 mm. It has been found out that themodification combined with squeeze casting provides an advantageous set of strength and plastic properties (RBmB ≈ 270 MPa, AB5B ≈ 16%.The metallographic examination has revealed a significant refinement of both the primary α-phase dendrites and the silicon eutectics,however being dependent on the method of modification and casting. It has been found that the refinement of the primary crystals resultsfrom the influence of external pressure exerted on the solidifying casting, while the refinement observed for silicon eutectics is an effect of combined influence of modification and squeeze casting.
Characterization of Bimetallic Castings with an Austenitic Working Surface Layer and an Unalloyed Cast Steel Base
Wróbel, Tomasz
The paper presents the technology of bimetallic castings based on the founding method of layer coating directly in the cast process of the so-called method of mold cavity preparation. The prepared castings consist of two fundamental parts, i.e., the base and the working surface layer. The base part of the bimetallic casting is typical foundry material, i.e., unalloyed cast steel, whereas the working layer is a plate of austenitic alloy steel sort X2CrNi 18-9. The quality of the joint between the base part and the working layer was evaluated on the basis of ultrasonic non-destructive testing and structure examinations containing metallographic macro- and microscopic studies with the use of a light microscope (LOM) with microhardness measurements and a scanning electron microscope (SEM) with microanalysis of the chemical composition (energy dispersive spectroscopy—EDS). On the basis of the obtained results it was confirmed that the decisive phenomena needed to create a permanent joint between the two components of the bimetallic casting are carbon and heat transport in the direction from the high-carbon and hot base material which was poured into the mold in the form of liquid metal to the low-carbon and cold material of the working layer which was placed in the mold cavity in the form of a monolithic insert.
Temperature and microstructure characteristics of silumin casting AlSi9 made with investment casting method
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S. Pietrowski
Full Text Available This work presents the research result of the temperature distribution and the microstructure in certain parts of the field-glass body frame casting made from silumin AlSi9 using the investment casting method in the ceramic mould. It was proved that the highest temperature of the silumin appears in the sprue in which the silumin is in the liquid-solid state, though the process of silumin crystallization in the casting is finished. It was stated that in certain elements of the casting the side opposite to the runner crystallizes and cools fastest. The differences in the rate of crystalline growth and cooling of certain casting elements cause differ- ent microstructure in them which can also influence the mechanic properties.It is necessary to state that the temperature of the initial heating of the ceramic mold equal to 60oC guarantees obtaining of the castings without defects and of little porosity. Incomplete modification of the silumin with strontium causes silica precipitation to appear close to the spherical ones.
Mechanical Properties of Magnesium Die Castings Produced Utilizing Process Scrap
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Fajkiel A.
Full Text Available Magnesium alloys are one of the lightest of all the structural materials. Because of their excellent physical and mechanical properties the alloys have been used more and more often in various branches of industry. They are cast mainly (over 90% on cold and hot chamber die casting machines. One of the byproducts of casting processes is process scrap which amounts to about 40 to 60% of the total weight of a casting. The process scrap incorporates all the elements of gating systems and fault castings. Proper management of the process scrap is one of the necessities in term of economic and environmental aspects.
Summary of thermal properties for casting alloys and mold materials
Pehlke, R. D.; Jeyarajan, A.; Wada, H.
A review of thermal properties of casting alloys and mold materials was conducted for the purpose of stimulating activity in computer aided design for castings. A summary of thermal data; thermal conductivity, specific heat, density, and heats of fusion was prepared for metals and casting alloys, and for primary molding materials. This summary represents an initial step in the development of data bases for support of computer aided design systems for castings. Additional information is required, in particular for thermal properties of commercial casting alloy systems.
Understanding sexual violence as a form of caste violence
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Prachi Patil
Full Text Available The paper attempts to understand narratives of sexual violence anchored within the dynamics of social location of caste and gender. Apparent caste-patriarchy and gender hierarchies which are at play in cases of sexual violence against lower-caste and dalit women speak about differential experiences of rape and sexual abuse that women have in India. The paper endeavours to establish that sexual violence is also a form of caste violence by rereading the unfortunate cases of Bhanwari Devi, Khairlanji, Lalasa Devi and Delta Meghwal Keywords: caste-patriarchy, Dalit women, POA Act, rape, sexual violence
Novel technologies for the lost foam casting process
Jiang, Wenming; Fan, Zitian
Lost foam casting (LFC) is a green precision casting process categorized as a near net forming technology. Yet, despite its popularity, it still suffers from some technological problems, such as poor filling ability of the castings, coarse and non-dense microstructure, low mechanical properties for the Al and Mg LFC processes, and defective carburization for the low carbon steel LFC process. These drawbacks restrict the development and widespread application of the LFC process. To solve these problems, the present study developed several novel LFC technologies, namely, LFC technologies under vacuum and low pressure, vibration solidification, and pressure solidification conditions; expendable shell casting technology; and preparation technology of bimetallic castings based on the LFC process. The results showed that the LFC under vacuum and low pressure evidently improved the filling ability and solved the oxidization problem of the alloys, which is suitable for producing complex and thinwall castings. The vibration and pressure solidifications increased the compactness of the castings and refined the microstructure, significantly improving the mechanical properties of the castings. The expendable shell casting technology could solve the pore, carburization, and inclusion defects of the traditional LFC method, obtaining castings with acceptable surface quality. Moreover, the Al/Mg and Al/Al bimetallic castings with acceptable metallurgical bonding were successfully fabricated using the LFC process. These proposed novel LFC technologies can solve the current technological issues and promote the technological progress of the LFC process.
Novel technologies for the lost foam casting process
Jiang, Wenming; Fan, Zitian
Lost foam casting (LFC) is a green precision casting process categorized as a near net forming technology. Yet, despite its popularity, it still suffers from some technological problems, such as poor filling ability of the castings, coarse and non-dense microstructure, low mechanical properties for the Al and Mg LFC processes, and defective carburization for the low carbon steel LFC process. These drawbacks restrict the development and widespread application of the LFC process. To solve these problems, the present study developed several novel LFC technologies, namely, LFC technologies under vacuum and low pressure, vibration solidification, and pressure solidification conditions; expendable shell casting technology; and preparation technology of bimetallic castings based on the LFC process. The results showed that the LFC under vacuum and low pressure evidently improved the filling ability and solved the oxidization problem of the alloys, which is suitable for producing complex and thinwall castings. The vibration and pressure solidifications increased the compactness of the castings and refined the microstructure, significantly improving the mechanical properties of the castings. The expendable shell casting technology could solve the pore, carburization, and inclusion defects of the traditional LFC method, obtaining castings with acceptable surface quality. Moreover, the Al/Mg and Al/Al bimetallic castings with acceptable metallurgical bonding were successfully fabricated using the LFC process. These proposed novel LFC technologies can solve the current technological issues and promote the technological progress of the LFC process.
Opportunities and challenges of Chinese die-casting market
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Caifei SONG
Full Text Available The present status and prospectives of Chinese die-casting market were commented. In 2003, the total output of die castings in the whole country was 708 000 tons, in which the output of Al-alloy, Zn-alloy, Mg-alloy, Cu-alloy die casitngs were 474 600 tons, 222 000 tons, 5 800 tons, 5 600 tons, respectively, each accounted for 67%, 31.35%, 0.85%, 0.8% of the total. The annual sale volume of die-casting machines was approximately 1 800. And the gross output value of dies approached RMB 38 billion, in which die-casting dies accounted for about 10%. In the die-casting industry of the entire country, the foreign capital enterprises, public-run enterprises, township and village enterprises, private enterprises accounted for over 80% of the total die-casting enterprises. Super huge die-casting enterprises are forming.
Stereological Analysis of Carbides in Hypoeutectic Chromium Cast Iron
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Gromczyk M.
Full Text Available The results of research on stereological parameters of carbides in modified hypoeutectic chromium cast iron were shown in the paper. The effect of distance the casting heat centre of casting to the carbide phase morphology was examined. The samples for metallographic examination were taken from various locations of the model casting prepared in a special tester. This model casting was designed to simulate the solidification of heavy castings. Using the proposed methodology the relation of the distance from the model mould and the size, perimeter, length, width and the shape factor of carbides was examined. During the analysis, the values of stereological parameters of carbides changed on various sections of the model casting.
Undercooling and nodule count in thin walled ductile iron castings
DEFF Research Database (Denmark)
Pedersen, Karl Martin; Tiedje, Niels Skat
Casting experiments have been performed with eutectic and hypereutectic castings with plate thicknesses from 2 to 8 mm involving both temperature measurements during solidification and microstructural examination afterwards. The nodule count was the same for the eutectic and hypereutectic castings...... in the thin plates (≤4.3 mm) while in the 8 mm plate the nodule count was higher in the hypereutectic than in the eutectic castings. The minimum temperature before the eutectic recalescence (Tmin) was 15 to 20ºC lower for the eutectic than for the hypereutectic castings. This is due to nucleation of graphite...... nodules which begins at a lower temperature in the eutectic than in the hypereutectic castings. The recalescence ∆Trec was however also larger for the eutectic casting and in the thin plates the maximum temperature after recalescence (Tmax) was the same in the eutectic and hypereutectic plates...
Die Casting Part Distortion: Prediction and Attenuation
Energy Technology Data Exchange (ETDEWEB)
Dr, R. Allen Miller
The goal of this research was to predict the part deformation and residual stresses after ejection from the die and cooling to room temperature. A finite element model was built to achieve this goal and several modeling techniques were investigated throughout this research. Die-casting is a very complex process and the researchers are faced with a large number of hard to solve physical problems when modeling the process. Several assumptions are made in our simulation model. The first significant assumption is the instantaneous cavity filling. This means that the cavity filling stage is not considered in our model. Considering the cavity filling stage increases the modeling complexity as a result of different flow patterns. expected in the shot sleeve, gate, runner and different cavity features. The flow of gas from the cavity through the vents is another problem that is ignored in our model as a result of this assumption. Our second assumption is that the cast metal has uniform temperature distribution inside the cavity, at the starting point of simulation. This temperature is assumed to be over liquidus limit, i.e. the solid fraction is 0.0% of the cast metal. The third assumption is due to ABAQUS (commercial software used in this research) limitations. ABAQUS cannot deal with multi-phase models; therefore we use solid elements to define the casting instead of multi-phase (liquid/solid) elements. Liquid elements can carry the hydrostatic pressure from the shot sleeve and apply it on the cavity surfaces, while the solid elements do not have this capability. To compensate for this assumption we add the cavity pressure as a boundary condition and apply it on the cavity surface separately from the part. Another issue with this assumption is that, liquid casting can follow the cavity shape when it distorts. With the use of solid elements to represent the casting during its liquid state, it loses this capability to follow the cavity. Several techniques were tested to
Noise Reduction to Reduce Patient Anxiety During Cast Removal: Can We Decrease Patient Anxiety With Cast Removal by Wearing Noise Reduction Headphones During Cast Saw Use?
Mahan, Susan T; Harris, Marie S; Lierhaus, Anneliese M; Miller, Patricia E; DiFazio, Rachel L
Noise reduction headphones decrease the sound during cast removal. Their effectiveness in decreasing anxiety has not been studied. Compare pediatric patients' anxiety levels during cast removal with and without utilization of noise reduction headphones combined with use of a personal electronic device. Quality improvement project. Patients randomly assigned to noise reduction headphone group or standard care group during cast removal. Faces, Legs, Activity, Cry, and Consolability Scale and heart rate were evaluated prior to, during, and after cast removal. Data were compared across groups. Fifty patients were included; 25 per group. No difference detected between the 2 groups in Faces, Legs, Activity, Cry, and Consolability Scale score prior to (p = .05) or after cast removal (p = .30). During cast removal, the headphone group had lower FLACC Scale scores (p = .03). Baseline heart rate was lower in the headphone group prior to (p = .02) and after (p = .005) cast removal with no difference during cast removal (p = .24). Utilizing noise reduction headphones and a personal electronic device during the cast removal process decreases patient anxiety.
Numerical and Experimental Study on Residual Stress in Gray Cast Iron Stress Lattice Shape Casting
Motoyama, Yuichi; Takahashi, Hiroki; Okane, Toshimitsu; Fukuda, Yoya; Yoshida, Makoto
The prediction of residual stress in a stress lattice shape casting (stress lattice) has been conducted and discussed by some researchers via the Finite Element Method (FEM). However, most of the previous studies used the first-order tetrahedral element, which has poor analysis accuracy in problems including bending. The use of the first-order tetrahedral element makes the verification of these studies uncertain because the bending deformation essentially occurs in the stress lattice casting. This study first shows that the thermal stress analysis for the stress lattice should use the element that can represent the bending deformation in principle for bending of the thin parts. Second, the simulated residual stress was compared with the measured value. The thermal stress analysis successfully predicted the residual stress of the stress lattice casting with and 11 pct difference. In addition to the prediction of the residual stress, it is important from the viewpoint of the productivity of castings to reveal the effect of the shake-out temperature on the residual stress. However, in the previous studies, conclusions concerning the effect of the shake-out temperature on the residual stress were not consistent ( i.e., the one study said the higher shake-out temperature decreased the residual stress, and another study said a higher shake-out temperature increased the residual stress). Therefore, the current study first discusses the reason for the inconsistent conclusions in the previous studies. Second, stress lattice castings were cast and shaken out at various shake-out temperatures. Then, the current study validated the effect of the shake-out temperature on the residual stress. Consequently, the experimental results supported the conclusion of Kasch and Mikelonis that the shake-out at higher temperature contributed to the increase of the residual stress in the casting.
Determining the Temperature Variation of the on the Wall of the Casting Mould during the casting of the Hadfield Steel
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Constantin Marta
Full Text Available The present paper approaches the analysis of the metal temperature variation during the filling and solidification of steel in the casting mould. Furthermore we made determinations upon the heat transfer through the wall of the casting mould. The casting temperature, the casting speed and the heat transfer through the walls of the mould have a remarkable impact upon the shrinkage process for the prevention of casting defects (heat cavities and cracks. These cavities are also development cores for the heat cracks and the concentration of strains, which reduce the chemical, physical and mechanical properties of the cast parts. The shrinkage cavities represent one of the main defects of the cast product, and their reduction should be made up to the limits of technical possibilities.
Modelling of Tape Casting for Ceramic Applications
DEFF Research Database (Denmark)
Jabbari, Masoud
of functional ceramics research. Advances in ceramic forming have enabled low cost shaping techniques such as tape casting and extrusion to be used in some of the most challenging technologies. These advances allow the design of complex components adapted to desired specific properties and applications. However...... of ceramic processing are generally focused on the control of the microstructure while the importance of shaping is often underestimated. Improved performance requires the design and shaping of both controlled architectures and microstructures. Novel functionally graded ceramic materials may be formed...... process of functionally graded ceramic materials for fuel cell applications as well as magnetic refrigeration. Models to simulate the shaping of monolayer/multilayer and graded materials by tape casting are developed. The emphasis is on analyzing the entry flow of multiple slurries from the reservoir...
Solar axion search with the CAST experiment
Aune, S.
The CAST (CERN Axion Solar Telescope) experiment is searching for solar axions by their conversion into photons inside the magnet pipe of an LHC dipole. The analysis of the data recorded during the first phase of the experiment with vacuum in the magnet pipes has resulted in the most restrictive experimental limit on the coupling constant of axions to photons. In the second phase, CAST is operating with a buffer gas inside the magnet pipes in order to extent the sensitivity of the experiment to higher axion masses. We will present the first results on the $^4{He}$ data taking as well as the system upgrades that have been operated in the last year in order to adapt the experiment for the $^3{He}$ data taking. Expected sensitivities on the coupling constant of axions to photons will be given for the recent $^3{He}$ run just started in March 2008.
Chameleon Search in CAST Experiment at CERN
AUTHOR|(CDS)2200384; Cetin, Serkant
Chameleons are hypothetical particles that are proposed as a scalar field to account for the accelerated expansion of the universe, the so-called `dark energy problem'. They are proposed to be produced in the high magnetic field regions inside the Sun and they propagate through or reflect from a medium with the interaction strength depending on the ambient density. The models which characterize the interaction of the chameleons provide two interaction channels: direct coupling to matter dependent on the density and coupling to electromagnetic field by Primakoff effect. CAST Experiment probes the coupling of chameleons with matter with opto-mechanical KWISP detector which is based on Fabry-Perot and Michelson interferometers. In this thesis, starting with an overview of the experimental search efforts of the CAST experiment, theoretical background of the dark energy and the chameleon mechanism will be provided. Then, the detection mechanism based on KWISP detector will be discussed and the versions of the dete...
Phase Transformation in Cast Superaustenitic Stainless Steels
Energy Technology Data Exchange (ETDEWEB)
Lee Phillips, Nathaniel Steven [Iowa State Univ., Ames, IA (United States)
Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.
Friction Stir Welding of Magnesium Die Castings
Skar, Jan Ivar; Gjestland, Haavard; Oosterkamp, Ljiljana Djapic; Albright, Darryl L.
Friction stir welding (FSW), being a solid-state process, is an attractive method for joining magnesium die castings. In this study, FSW of AZ91D and AM50A plates was performed both on the individual alloys and to join them together. The welds were sound and free from defects, except for small surface cracks in AM50A; a fine microstructure characterized the weld zones. The tensile properties of specimens transverse to the weld zone were measured, as were the corrosion properties. The tensile properties were somewhat lower than the base metal, with the largest percentage decrease found in the elongation of AM50A, perhaps due to the surface cracking. The corrosion resistance of the weld zone was relatively poor, most likely due to iron contamination from wearing of the tool. Further optimization of the FSW tool design and process parameters must take place to improve the reliability of FSW for magnesium die castings.
Sharatchandra's Caste and Gender Consciousness
Directory of Open Access Journals (Sweden)
Narasingha Sil
Full Text Available Sharatchandra Chattopadhyay's attitude to the prevalent caste system and social ethos, especially concerning sex, love, and marriage and chastity of married as well as widowed women, shows a marked ambivalence. On one hand, his work demonstrates his progressive and liberal ideas emanating from Western contact and impact on late colonial India, and on Bengal in particular. On the other hand, and by the same token, his attitude to love, marriage, and sex shows marked affinity with the Victorian morality emanating from the society of colonial India's metropolitan masters. The upshot of this historical and social context is that Sharatchandra was basically a caste conscious Hindu Brahmin and a firm believer in the patriarchal ethos of his contemporary society, his reputation as a compassionate (daradī or maramī writer exposing the ills of his society notwithstanding.
Squeeze Casting of Steel Weapon Components
is not washed into the casting when the molten metal is poured into the die or mold. As can be expected, the mold coatings have refractory ...melted in an alumina liner which is fixed inside the coil using refractory plaster. The alumina liner is a closed bottom tube approximately 9 in. long...of molten metal from the furnace to the die. In fact, if this transfer can be achieved without any manual handling by means of a transfer ladle
Freeze Casting for Assembling Bioinspired Structural Materials.
Cheng, Qunfeng; Huang, Chuanjin; Tomsia, Antoni P
Nature is very successful in designing strong and tough, lightweight materials. Examples include seashells, bone, teeth, fish scales, wood, bamboo, silk, and many others. A distinctive feature of all these materials is that their properties are far superior to those of their constituent phases. Many of these natural materials are lamellar or layered in nature. With its "brick and mortar" structure, nacre is an example of a layered material that exhibits extraordinary physical properties. Finding inspiration in living organisms to create bioinspired materials is the subject of intensive research. Several processing techniques have been proposed to design materials mimicking natural materials, such as layer-by-layer deposition, self-assembly, electrophoretic deposition, hydrogel casting, doctor blading, and many others. Freeze casting, also known as ice-templating, is a technique that has received considerable attention in recent years to produce bioinspired bulk materials. Here, recent advances in the freeze-casting technique are reviewed for fabricating lamellar scaffolds by assembling different dimensional building blocks, including nanoparticles, polymer chains, nanofibers, and nanosheets. These lamellar scaffolds are often infiltrated by a second phase, typically a soft polymer matrix, a hard ceramic matrix, or a metal matrix. The unique architecture of the resultant bioinspired structural materials displays excellent mechanical properties. The challenges of the current research in using the freeze-casting technique to create materials large enough to be useful are also discussed, and the technique's promise for fabricating high-performance nacre-inspired structural materials in the future is reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Modelling the Cast Component Weight in Hot Chamber Die Casting using Combined Taguchi and Buckingham's π Approach
Singh, Rupinder
Hot chamber (HC) die casting process is one of the most widely used commercial processes for the casting of low temperature metals and alloys. This process gives near-net shape product with high dimensional accuracy. However in actual field environment the best settings of input parameters is often conflicting as the shape and size of the casting changes and one have to trade off among various output parameters like hardness, dimensional accuracy, casting defects, microstructure etc. So for online inspection of the cast components properties (without affecting the production line) the weight measurement has been established as one of the cost effective method (as the difference in weight of sound and unsound casting reflects the possible casting defects) in field environment. In the present work at first stage the effect of three input process parameters (namely: pressure at 2nd phase in HC die casting; metal pouring temperature and die opening time) has been studied for optimizing the cast component weight `W' as output parameter in form of macro model based upon Taguchi L9 OA. After this Buckingham's π approach has been applied on Taguchi based macro model for the development of micro model. This study highlights the Taguchi-Buckingham based combined approach as a case study (for conversion of macro model into micro model) by identification of optimum levels of input parameters (based on Taguchi approach) and development of mathematical model (based on Buckingham's π approach). Finally developed mathematical model can be used for predicting W in HC die casting process with more flexibility. The results of study highlights second degree polynomial equation for predicting cast component weight in HC die casting and suggest that pressure at 2nd stage is one of the most contributing factors for controlling the casting defect/weight of casting.
Modelling the Cast Component Weight in Hot Chamber Die Casting using Combined Taguchi and Buckingham's π Approach
Singh, Rupinder
Hot chamber (HC) die casting process is one of the most widely used commercial processes for the casting of low temperature metals and alloys. This process gives near-net shape product with high dimensional accuracy. However in actual field environment the best settings of input parameters is often conflicting as the shape and size of the casting changes and one have to trade off among various output parameters like hardness, dimensional accuracy, casting defects, microstructure etc. So for online inspection of the cast components properties (without affecting the production line) the weight measurement has been established as one of the cost effective method (as the difference in weight of sound and unsound casting reflects the possible casting defects) in field environment. In the present work at first stage the effect of three input process parameters (namely: pressure at 2nd phase in HC die casting; metal pouring temperature and die opening time) has been studied for optimizing the cast component weight `W' as output parameter in form of macro model based upon Taguchi L9 OA. After this Buckingham's π approach has been applied on Taguchi based macro model for the development of micro model. This study highlights the Taguchi-Buckingham based combined approach as a case study (for conversion of macro model into micro model) by identification of optimum levels of input parameters (based on Taguchi approach) and development of mathematical model (based on Buckingham's π approach). Finally developed mathematical model can be used for predicting W in HC die casting process with more flexibility. The results of study highlights second degree polynomial equation for predicting cast component weight in HC die casting and suggest that pressure at 2nd stage is one of the most contributing factors for controlling the casting defect/weight of casting.
Twin Roll Casting of Aluminium: The Occurrence of Structure Inhomogeneities and Defects in as Cast Strip
Westengen, H.; Nes, K.
Continuous strip casting provides an attractive shortcut from the liquid metal to final gauge sheet. Twin roll casters are by far the most widespread machines in commercial operation, mainly due to their flexibility and relatively low investment costs. Strip produced by these casters is presently appreciated as a well suited alternative to conventional material for a number of applications, and in some instances improved properties are obtained (1). Twin roll casters have been in commercial operation for nearly three decades, however, the literature on the subject is rather incomplete. Most of the available information has been published by the machine producers, hence attention is mainly paid to the positive aspects of the methods. However, some interesting papers have recently been published. A general description of casting and annealing structures is given by Nes and Slevolden (2), while Jin et. al. (3) consider the formation of centreline segregates during casting. Althoff (1) summarizes some aspects of mechanical properties, and a couple of papers desribe new alloys which are especially suitable for strip casting (4,5). A contribution to the understanding of the influence of casting parameters on the solidification zone is presented by Iricibar and Jin (6).
EBR-II fuel slug casting experience
Energy Technology Data Exchange (ETDEWEB)
Wilkes, C. W.; Batte`, G. L.; Tracy, D. B.; Griffiths, V.
The following paper presents a chronology of EBR-II fuel slug casting experience. Starting with the early vendor campaigns, the paper explains how production of EBR-II fuel, as well as fuel for off-site reactors, has evolved. The production facilities (i.e., EFL, Room 20, FMF, etc.) and casting techniques are discussed in detail. The paper also presents how the original casting operations have improved and the problems encountered as the techniques were developed. Extensive descriptions and data are given on the major experimental programs currently ongoing at EBR-II. Major programs include the IFR lead subassemblies, large diameter slugs, IFR metal fuel RBCB, and the FFTF subassembly program. Concluding the paper is a brief description of future development projects being considered and a summation of how EBR-II Fuels and Materials has been able to overcome various administration obstacles (i.e., improved security and safeguards measures) to continue to meet the increasing demands of fuel production while maintaining an aggressive and active research and development program in fuel slug production.
Successful magnet quench test for CAST.
Brice Maximilien
The CERN Axion Solar Telescope (CAST) consists of a prototype LHC dipole magnet with photon detectors at each end. It searches for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. The telescope, located at Point 8, can move vertically within its wheeled platform, which travels horizontally along tracks in the floor. In this way, the telescope can view the Sun at sunrise through one end and at sunset through the other end. It has been cooled down to below 1.8 K and reached ~95% of its final magnetic field of 9 tesla before a quench was induced to test the whole cryogenic system under such conditions. The cryogenic system responded as expected to the magnet quench and CAST is now ready to start its three-year search for solar axions. Photos 01 & 02 : Members of the LHC cryogenics team pose in front of the axion telescope on the day of the first quench test, together with some of the CAST collaboration.
The CAST experiment: status and perspectives
Ferrer Ribas, Esther
The status of the solar axion search with the CERN Axion Solar Telescope (CAST) will be discussed. Results from the first part of CAST phase II where the magnet bores were filled with \\hefour gas at variable pressure in order to scan \\ma up to 0.4 eV will be presented. From the absence of excess X-rays when the magnet was pointing to the Sun, we set a typical upper limit on the axion-photon coupling of $\\gag \\lesssim 2.17 \\times10^{-10}$GeV$^{-1}$ at 95% CL for \\ma$<0.4$ eV, the exact result depending on the pressure setting. Our search for axions with masses up to about 1.2 eV using \\hethree as a buffer gas is, since last year, in progress in the second part of CAST phase II. Expectations for sensibilities will be given. Near future perspectives as well as more long term options for a new helioscope experiment will be evoked.
Biomechanical assessment of gait in below-knee walking casts.
White, R; Schuren, J; Wardlaw, D; Diamandopoulos, Z; Anderson, R
The introduction of modern synthetic casting bandages for splinting of fractures and soft tissue injuries has allowed the development of new casting techniques. Casts can be constructed with a greater degree of function so that controlled motion and stabilisation can be provided within the same cast. This study has shown that a very efficient gait can be achieved with modern synthetic bandages, if they are correctly applied. The authors have compared the gait of volunteer subjects fitted respectively with below-knee walking casts constructed from a rigid glass fibre bandage and a flexible glass fibre bandage which is reinforced. These casts were wrapped so that minimal amounts of bandage were used whilst appropriate strength and stiffness was provided. The temporal and spatial factors of cast gait were not statistically different from normal gait. The cast gait was found to be slightly more asymmetrical (dominant versus non-dominant leg) when a cast was worn and there was also a greater Physiological Cost Index (PCI). The flexible bandage has some advantages compared with the rigid bandage as normal footwear can be worn, the casts are more comfortable and they could be removed with shears, obviating the need for a power saw.
Hot mold casting process of ancient East India and Bangladesh
Directory of Open Access Journals (Sweden)
Barnali Mandal
Full Text Available Ancient casting process for production of brass or bronze utensils and icons were made in hot molds using clay molded investment casting or piece mold process, as presumed by archaeologists. Piece mold process is still traditionally practiced in many parts of Eastern India and Bangladesh along with investment casting process. Incidentally, Bengal artisans are more accustomed to piece mold process unlike tribal artisans who practiced investment casting process. This piece mold casting process has been reconstructed to get the idea of metal characteristics in order to investigate ancient casting process of Bengal and Bangladesh. The characterization of ancient archaeo-metal products come to a type of cast Cu-Sn-Zn-Pb type quaternary alloy produced by a slow freezing process. Though these alloys physically differ from the traditional cast alloy of binary Cu-Zn type brass, the physical characteristics are similar to the binary cast alloy character. This investigation throws light on the similarity of the production processes by which ancient artisans probably produced cast metal products.
Infant Perception of Incongruent Shapes in Cast Shadows
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Kazuki Sato
Full Text Available A cast shadow occurs when an object blocks the light from an illumination and projects a dark region onto a surface. Previous studies have reported that adults are slower to identify an object when the object has an incongruent cast shadow than when it has a congruent cast shadow (Castiello, 2001. Here, we used the familiarization-novelty preference procedure to examine whether 5- to 8-month-old infants could detect the relationship between object shapes and cast shadows. In Experiment 1, we examined the infants' ability to detect incongruency between objects and cast shadows. Results showed that 7- to 8-month olds could detect incongruence between the object shapes and the cast shadows, whereas 5- to 6-month olds did not. Yet, our control experiment showed that infants could not detect this incongruence from stimuli in which a white outline had been added to the original cast shadow to decrease the possibility of it being perceived as a cast shadow (Experiment 2. The results of these experiments demonstrate that 7- to 8-month olds responded to the congruence of cast shadows and to consistent contrast polarity between the cast shadow and its background.
Thin wall ductile iron casting as a substitute for aluminum alloy casting in automotive industry
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M. Górny
Full Text Available In paper it is presented thin wall ductile iron casting (TWDI as a substitute of aluminium alloy casting. Upper control arm made of ductile iron with wall thickness ranging from 2 – 3.7 mm was produced by inmold process. Structure, mechanical properties and computer simulations were investigated. Structural analysis of TWDI shows pearlitic-ferritic matrix free from chills and porosity. Mechanical testing disclose superior ultimate tensile strength (Rm, yield strength (Rp0,2 and slightly lower elongation (E of TWDI in comparison with forged control arm made of aluminium alloy (6061-T6. Moreover results of computer simulation of static loading for tested control arms are presented. Analysis show that the light-weight ductile iron casting can be loaded to similar working conditions as the forged Al alloy without any potential failures.
The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings
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D. Kopyciński
Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showeda heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived.Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.
The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings
Directory of Open Access Journals (Sweden)
Kopyciński D.
Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showed a heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at 450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived. Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.
Abrasion Resistance of as-Cast High-Chromium Cast Iron
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Pokusová Marcela
Full Text Available High chromium cast irons are widely used as abrasion resistant materials. Their properties and wear resistance depend on carbides and on the nature of the matrix supporting these carbides. The paper presents test results of irons which contain (in wt.% 18-22 Cr and 2-5 C, and is alloyed by 1.7 Mo + 5 Ni + 2 Mn to improve the toughness. Tests showed as-cast irons with mostly austenitic matrix achieved hardness 36-53 HRC but their relative abrasion-resistance was higher than the tool steel STN 19436 heat treated on hardness 60 HRC.
Steel castings Ultrasonic examination, Part 2: Steel castings for highly stressed components
International Organization for Standardization. Geneva
This European Standard specifies the requirements for the ultrasonic examination of steel castings (with ferritic structure) for highly stressed components and the methods for determining internal discontinuities by the pulse echo technique. This European Standard applies to the ultrasonic examination of steel castings which have usually received a grain refining heat treatment and which have wall thicknesses up to and including 600 mm. For greater wall thicknesses, special agreements apply with respect to test procedure and recording levels. This European Standard does not apply to austenitic steels and joint welds.
Ultrasonic Inspection Techniques Possibilities for Centrifugal Cast Copper Alloy
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Konar R.
Full Text Available The article deals with ultrasonic testing possibilities of the copper alloy centrifugal casts. It focused on the problems that arise when testing of castings is made of non-ferrous materials. Most common types of casting defects is dedicated in theoretical introduction of article. Ultrasonic testing technique by conventional ultrasound system is described in the theoretical part too. Practical ultrasonic testing of centrifugal copper alloy cast - brass is in experimental part. The experimental sample was part of centrifugally cast brass ring with dimensions of Ø1200x34 mm. The influence of microstructure on ultrasonic attenuation and limitations in testing due to attenuation is describes in experimental part. Conventional direct single element contact ultrasound probe with frequencies of 5 MHz, 3.5 MHz and 2 MHz were used for all experimental measurements. The results of experimental part of article are recommendations for selecting equipment and accessories for casting testing made of non-ferrous metals.
Method and mold for casting thin metal objects
Pehrson, Brandon P; Moore, Alan F
Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.
Properties shaping and repair of selected types of cast iron
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J. Szajnar
Full Text Available The paper presents research results of twofold use of TIG - Tungsten Inert Gas also known as GTA - Gas Tungsten Arc. First is surfacing by welding on cold and hot-cold to repair chromium cast iron with chromium content about 15%. Second is remelting with electric arc of selected gray (with pearlitic matrix and ductile (with ferritic-pearlitic matrix cast iron. Repair of cast iron elements was realized in order to cut out a casting defects. Defects decrease a usability of castings for constructional application and increase a manufacturing costs. Application of surface heat treatment guarantees mechanical properties i.e. hardness and wear resistance improvement. The result of investigations show possibility of castings repair by put on defects a good quality padding welds, which have comparable properties with base material. Use of electric arc surface heat treatment resulted in increase of hardness and wear resistance, which was measured on the basis of ASTM G 65 - 00 standard.
Modeling of TiAl Alloy Grating by Investment Casting
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Yi Jia
Full Text Available The investment casting of TiAl alloys has become the most promising cost-effective technique for manufacturing TiAl components. This study aimed to investigate a series of problems associated with the investment casting of TiAl alloys. The mold filling and solidification of this casting model were numerically simulated using ProCAST. Shrinkage porosity was quantitatively predicted by a built-in feeding criterion. The results obtained from the numerical simulations were compared with experiments, which were carried out on Vacuum Skull Furnace using an investment block mold. The investment casting of TiAl grating was conducted for verifying the correctness and feasibility of the proposed method. The tensile test results indicated that, at room temperature, the tensile strength and elongation were approximately 675 MPa and 1.7%, respectively. The microstructure and mechanical property of the investment cast TiAl alloy were discussed.
Pressing Speed, Specific Pressure and Mechanical Properties of Aluminium Cast
Directory of Open Access Journals (Sweden)
Gaspar S.
Full Text Available Recent research in the process of aluminum alloy die castings production, which is nowadays deeply implemented into the rapidly growing automobile, shipping and aircraft industries, is aimed at increasing the useful qualitative properties of the die casting in order to obtain its high mechanical properties at acceptable economic cost. Problem of technological factors of high pressure die casting has been a subject of worldwide research (EU, US, Japan, etc.. The final performance properties of die castings are subjected to a large number of technological factors. The main technological factors of high pressure die casting are as follows: plunger pressing speed, specific (increase pressure, mold temperature as well as alloy temperature. The contribution discusses the impact of the plunger pressing speed and specific (increase pressure on the mechanical properties of the casting aluminum alloy.
Obtaining of High Cr Content Cast Iron Materials
Florea, C.; Bejinariu, C.; Carcea, I.; Cimpoesu, N.; Chicet, D. L.; Savin, C.
We have obtained, through the classic casting process, 3 highly chromium-based experimental alloys proposed for replacing the FC 250 classical cast iron in braking applications. Casting was carried out in an induction furnace and cast into moulds made of KALHARTZ 8500 resin casting mixture and HARTER hardener at SC RanCon SRL Iasi. It is known that the microstructure of the cast iron is a combination of martensite with a small amount of residual austenite after the heat treatment of the ingot. In the case of high-alloy chromium alloys, the performance of the material is due to the presence of M7C3 carbides distributed in the iron matrix Resistance to machining and deformation is based on alloy composition and microstructure, while abrasion resistance will depend on properties and wear conditions.
[Slip casting of stainless steel powder (author's transl)].
Okawa, S; Ota, M; Kondo, S
Slip casting of stainless steel powder (AISI type 316 L) was investigated as means of forming medical and dental porous restorations. This research was undertaken to evaluate the effects of the particle size and aging of casting slip and firing conditions. Bulk density was used as a measure of the degree of sintering. Water contents of casting bodies decreased with the particle size and its casting rates, bulk densities and bending strengths increased. Aging of slip decreased casting rates, water contents and bending strengths of the casts. The bulk densities of the sintered stainless steel increased with sintering time and temperature. The porosities of the materials decreased with the particle size and the elevating temperature. The bending strengths of the materials increased sharply with the decreasing particle size. The optical micrographs did not always show the uniform elimination of pores in the sintered. Aging of slip increased a little the bulk densities of the materials and decreased the porosity and the bending strength.
Clout or doubt? Perspectives on an infant mental health service for young children placed in foster care due to abuse and neglect.
Turner-Halliday, Fiona; Kainth, Gary; Young-Southward, Genevieve; Cotmore, Richard; Watson, Nicholas; McMahon, Lynn; Minnis, Helen
Despite knowledge about the profound effects of child abuse and neglect, we know little about how best to assess whether maltreated children should return home. The effectiveness of the New Orleans Intervention Model (NIM) is being tested in a randomized controlled trial where the comparison is social work 'services as usual.' The future trial results will tell us which approach produces the best outcomes for children; meanwhile qualitative process evaluation is generating intriguing findings about the perceived impact of NIM on decision-making about childrens' futures. Interviews and focus groups were conducted with social workers, foster carers, legal decision-makers and the NIM team (n=63). Data were analysed thematically. Findings suggest that NIM is seen as bringing greater influence ('clout') to decision-making due to its depth of focus, provision of treatment for the family, health professional input and perceived objectivity. Simultaneously, the NIM approach and the detailed information it produces potentially throws judgments into doubt in the legal system. Clout/doubt perceptions permeate opinions about NIM and are inter-related with a historical discourse about 'health versus social' models of information gathering, with implications for assessment of child abuse and neglect that extend beyond the study context. The juxtaposition of 'clout versus doubt' both highlights and is strengthened by an intense focus among social workers and legal professionals on how evidence will be regarded within legal fora when making decisions about children. There is continuing uncertainty in the child welfare system about the best ways of assessing maltreated children, underscoring a continued need for the trial. Copyright © 2017 Elsevier Ltd. All rights reserved.
25 CFR 217.6 - Method of casting votes.
... 25 Indians 1 2010-04-01 2010-04-01 false Method of casting votes. 217.6 Section 217.6 Indians.... § 217.6 Method of casting votes. Within 30 days after an issue and any analysis provided for in §§ 217.4... superintendent in writing of the number of votes cast for and against the proposed or alternative solutions. If...
Caste Discrimination, Land Reforms and Land Market Performance in Nepal
Aryal, Jeetendra P.; Holden, Stein T.
This paper assesses the implications of caste discrimination and past land reforms on the land rental market performance, land productivity and land use intensity in Nepal. The most severely discriminated group in the caste system is the Dalits, the so-called "untouchables". Dalits faced religious, occupational and even, territorial discrimination. The study uses data from western Nepal. The low-caste households remain poorer than other households, have significantly smaller land endowments, ...
Effect of different casting methods on adolescent idiopathic scoliosis.
Wong, M S; Lee, J T C; Luk, K D K; Chan, L C K
Scoliosis is a three-dimensional spinal deformity. Although orthotic treatment for moderate adolescent idiopathic scoliosis (AIS) has been well recognized, there are few studies documenting the effectiveness of different casting methods in the fabrication of thoracolumbo-sacral orthoses (TLSO). The current study was a retrospective clinical evaluation of the effectiveness of two commonly used casting methods namely, the frame casting method and the supine with traction casting method in the treatment of AIS. Eighty (80) female patients with AIS were recruited and they were all treated by TLSOs. The frame casting method was used in 37 patients while the remaining 43 patients were under the supine with traction casting method. The responses of spinal deformities under the two different casting methods were analyzed for the period from pre-brace to 2 years after bracing. The studied parameters included the AP Cobb's angle, the apical vertebral rotation and the trunk listing (cervico-sacral lateral offset). The results of the current study showed that the orthoses manufactured from the two casting methods could provide an effective control of AIS (change of Cobb's angle within (+/- 5 degrees). For the frame casting, the Cobb's angles at pre-brace and 2 years after off-brace were 36.0 degrees and 33.8 degrees respectively while for the supine with traction casting, the corresponding Cobb's angles were 32.7 degrees and 34.0 degrees. The frame casting method could give a better control of the apical vertebral rotation at the early stage of treatment (pre-brace = 18.2 degrees and the 4th month = 13.8 degrees while the supine with traction casting method was more effective in the long-term control of the trunk listing (pre-brace = 10mm and 2 years after off-brace = 3.3mm).
Effect of Melting Techniques on Ductile Iron castings Properties
Bockus, S.; Dobrovolskis, A.
The study was designed to investigate the effects of the charge, melting conditions, nodularizing and inoculation on the ductile iron castings properties. Results showed that the temperature and holding time of the melt in an induction furnace and the intensity of spheroidizing effect on the carbon and residual magnesium contents in the ductile iron castings. The same grade of ductile iron may be obtained using different chemical compositions. The castings of ductile iron will be ferritic as-...
Abrasive Wear of Alloyed Cast Steels Applied for Heavy Machinery
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Studnicki A.
Full Text Available In the paper the results and analysis of abrasive wear studies were shown for two grades of cast steels: low-alloyed cast steel applied for heavy machinery parts such as housing, covers etc. and chromium cast steels applied for kinetic nodes of pin-sleeve type. Studies were performed using the modified in Department of Foundry pin-on-disc method.
Numerical Simulation of the Upward Continuous Casting of Magnesium Alloys
Landaberea, Aitor; Pedrós, Pablo; Anglada, Eva; Garmendia, Iñaki
The continuous casting of magnesium alloys in vertical upward direction is a novel technology which can be employed for the production of semi-finished materials circumventing the main disadvantages of using conventional casting processes since the risks of burning and explosion are practically eliminated. The present investigation deals with the simulation of the upward continuous casting of round billets of magnesium alloys. The equations for the flow field with heat transfer are numericall...
Analysis of the upward direct chill casting of magnesium alloys
Landaberea, Aitor; Pedrós, Pablo; Anglada, Eva; Garmendia, Iñaki
The upward direct chill casting, where the continuous casting is operated vertically against the gravity, is a novel technology which has been applied to the production of high quality magnesium alloys circumventing the main disadvantages of using conventional continuous casting processes since the risks of burning and explosion are practically eliminated. This represents a key aspect to increase the industrial application of magnesium wrought products. In order to help on the understanding o...
A Direct Refractory Die Technique for Cast Gold Restorations.
Smith, C T; Diefenderfer, K E
Fabricating accurate cast gold restorations can be challenging for both clinicians and laboratory technicians. Removing the wax pattern from the master die often distorts the pattern, which, in turn, compromises the overall fit and marginal adaptation of the casting. This article demonstrates a laboratory technique in which the final restoration is cast directly on the refractory die without removing the wax pattern. Thus, distortion of the wax pattern is avoided, enabling the production of superbly fitting gold castings for both intracoronal and extracoronal restorations.
Mechanical Properties of Magnesium Die Castings Produced Utilizing Process Scrap
Fajkiel A.; Dudek P.; Reguła T.
Magnesium alloys are one of the lightest of all the structural materials. Because of their excellent physical and mechanical properties the alloys have been used more and more often in various branches of industry. They are cast mainly (over 90%) on cold and hot chamber die casting machines. One of the byproducts of casting processes is process scrap which amounts to about 40 to 60% of the total weight of a casting. The process scrap incorporates all the elements of gating systems and fault c...
Casting materials and their application in research and teaching.
Haenssgen, Kati; Makanya, Andrew N; Djonov, Valentin
From a biological point of view, casting refers to filling of anatomical and/or pathological spaces with extraneous material that reproduces a three-dimensional replica of the space. Casting may be accompanied by additional procedures such as corrosion, in which the soft tissue is digested out, leaving a clean cast, or the material may be mixed with radiopaque substances to allow x-ray photography or micro computed topography (µCT) scanning. Alternatively, clearing of the surrounding soft tissue increases transparency and allows visualization of the casted cavities. Combination of casting with tissue fixation allows anatomical dissection and didactic surgical procedures on the tissue. Casting materials fall into three categories namely, aqueous substances (India ink, Prussian blue ink), pliable materials (gelatins, latex, and silicone rubber), or hard materials (methyl methacrylates, polyurethanes, polyesters, and epoxy resins). Casting has proved invaluable in both teaching and research and many phenomenal biological processes have been discovered through casting. The choice of a particular material depends inter alia on the targeted use and the intended subsequent investigative procedures, such as dissection, microscopy, or µCT. The casting material needs to be pliable where anatomical and surgical manipulations are intended, and capillary-passable for ultrastructural investigations.
Advanced precision expendable pattern casting technology. 1994 Summary report
Energy Technology Data Exchange (ETDEWEB)
Casting technology is described. The following areas are reported on: precision pattern production; pattern coating; sand fill and compaction; pattern gating; mechanical properties; and technology transfer efforts.
Effect of Melting Techniques on Ductile Iron castings Properties
Directory of Open Access Journals (Sweden)
Bockus, S.
Full Text Available The study was designed to investigate the effects of the charge, melting conditions, nodularizing and inoculation on the ductile iron castings properties. Results showed that the temperature and holding time of the melt in an induction furnace and the intensity of spheroidizing effect on the carbon and residual magnesium contents in the ductile iron castings. The same grade of ductile iron may be obtained using different chemical compositions. The castings of ductile iron will be ferritic as-cast only when large amount of pig iron in the charge and in addition some-steps inoculating treatment are used.
Manufacturing of thin walled near net shape iron castings
DEFF Research Database (Denmark)
Larsen, Per Leif
The demand for near net shape thin walled iron castings is growing. This has several reasons, the main one is the need for lowering the fuel consumption of cars; the easiest way to do that is to lower the weight of the cars. The best way to do this was for a period of time believed to be substitu.......000.000 cars produced world wide each year consumes enormous amounts of cast parts ! The aim of the project is to develop the green sand molding method on DISAMATIC to be able to deal with the new demands for thin walled near net shape castings in iron.......The demand for near net shape thin walled iron castings is growing. This has several reasons, the main one is the need for lowering the fuel consumption of cars; the easiest way to do that is to lower the weight of the cars. The best way to do this was for a period of time believed...... to be substituting iron casings with aluminum castings. Substituting iron castings with aluminum castings is not as easy as first believed, and hence the substitution is very slow. This combined with the lack of fully exploiting the potential in iron castings, makes research in iron castings interesting. The 60...
Reengineering of Permanent Mould Casting with Lean Manufacturing Methods
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R. Władysiak
Full Text Available At the work were introduced main areas of production system project of casts produced in permanent moulds, that constitutes reengineering of conventional production system according to Lean Manufacturing (LM methods. New resolution of cooling of dies with water mist was shown to casting of car wheels made from aluminium alloys in low pressure casting process. It was implemented as a part of goal-oriented project in R.H. Alurad Sp.z o.o. in Gorzyce. Its using intensifies solidification and self-cooling of casts shortening the time of casting cycle by the 30%. It was described reorganizing casting stations into multi-machines cells production and the process of their fast tool's exchange with applying the SMED method. A project of the system was described controlling the production of the foundry with the computer aided light Kanban system. A visualization of the process was shown the production of casts with use the value stream mapping method. They proved that applying casting new method in the technology and LM methods allowed to eliminate down-times, to reduce the level of stocks, to increase the productivity and the flow of the castings production.
Numerical study of porosity in titanium dental castings.
Wu, M; Sahm, P R; Augthun, M; Spiekermann, H; Schädlich-Stubenrauch, J
A commercial software package, MAGMASOFT (MAGMA Giessereitechnologie GmbH, Aachen, Germany), was used to study shrinkage and gas porosity in titanium dental castings. A geometrical model for two simplified tooth crowns connected by a connector bar was created. Both mold filling and solidification of this casting model were numerically simulated. Shrinkage porosity was quantitatively predicted by means of a built-in feeding criterion. The risk of gas pore formation was investigated using the numerical filling and solidification results. The results of the numerical simulations were compared with experiments, which were carried out on a centrifugal casting machine with an investment block mold. The block mold was made of SiO2 based slurry with a 1 mm thick Zr2 face coat to reduce metal-mold reactions. Both melting and casting were carried out under protective argon (40 kPa). The finished castings were sectioned and the shrinkage porosity determined. The experimentally determined shrinkage porosity coincided with the predicted numerical simulation results. No apparent gas porosity was found in these model castings. Several running and gating systems for the above model casting were numerically simulated. An optimized running and gating system design was then experimentally cast, which resulted in porosity-free castings. Copyright 1999 Kluwer Academic Publishers
Digital management technology and its application to investment casting enterprises
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Xiao-yuan Ji
Full Text Available With the advent of Industry 4.0, more and more investment casting enterprises are implementing production manufacturing systems, especially in the last two years. This paper summarizes three new common requirements of the digital management aspect in precision casting enterprises, and puts forward three corresponding techniques. They are: the production process tracking card technology based on the main-sub card mode; the workshop site production process processing technology based on the barcode; and the equipment data integration technology. Then, this paper discusses in detail the principle, application and effect of these technologies; to provide the reference for enterprises to move towards digital casting and intelligent casting.
Tribological Properties of Al-SiC Metal Matrix Composites: A Comparison Between Sand Cast and Squeeze Cast Techniques
Ghosh, S.; Sahoo, P.; Sutradhar, G.
Tribological behaviour of Al-SiC metal matrix composites prepared using two different fabrication techniques, viz. sand cast and squeeze cast techniques are studied in a multi- tribotester (TR-25, DUCOM, India) under dry sliding conditions and ambient atmosphere for varying volume fraction of reinforcement, applied load and sliding speed. Friction increases with increase in applied load and sliding speed and volume fraction of reinforcement. Wear test results show increased wear rates at higher load and speed, while increase in SiC volume fraction yields decrease in wear rate. Corrosion study conducted in 3.5 % NaCl solution shows that squeeze cast composites have better corrosion resistance than sand cast composites. Vickers's microhardness test shows improved hardness properties for squeeze cast composites compared to sand cast ones. The microstructure study of wear tracks reveals domination of abrasive wear with minor traces of adhesive wear.
Material Properties of Various Cast Aluminum Alloys Made Using a Heated Mold Continuous Casting Technique with and without Ultrasonic Vibration
Directory of Open Access Journals (Sweden)
Mitsuhiro Okayasu
Full Text Available This work was carried out to develop high-quality cast aluminum alloys using a new casting technology. For this purpose, commercial Al alloys were created by heated mold continuous casting (HMC with ultrasonic vibration (UV. With the HMC process, the grain size and the crystal orientation of the Al alloys were controlled, i.e., fine grains with a uniformly organized lattice formation. In addition, an attempt was made to modify the microstructural formation by cavitation. These microstructural characteristics made excellent mechanical properties. Using UV in the continuous casting process, more fine and spherical grains were slightly disordered, which was detected using electron backscattered diffraction. The mechanical properties of the UV HMC Al alloys were slightly higher than those for the related cast Al alloys without UV. Moreover, the severe vibration caused higher mechanical properties. The lattice and dislocation characteristics of the cast samples made with and without UV processes were analyzed systematically using electron backscattered diffraction.
Centerline Depletion in Direct-Chill Cast Aluminum Alloys: The Avalanche Effect and Its Consequence for Turbulent Jet Casting
Wagstaff, Samuel R.; Allanore, Antoine
Avalanche dynamics of sedimenting grains in direct-chill casting of aluminum ingots is investigated as a primary driving force for centerline segregation. An analytical model predicting the importance of avalanche events as a function of casting parameters is proposed and validated with prior art results. New experimental results investigating the transient and steady-state centerline segregation of DC casting with a turbulent jet are reported.
Evaluation of the Inertness of Investment Casting Molds Using Both Sessile Drop and Centrifugal Casting Methods
Cheng, Xu; Yuan, Chen; Green, Nick; Withey, Paul
The investment casting process is an economic production method for engineering components in TiAl-based alloys and offers the benefits of a near net-shaped component with a good surface finish. An investigation was undertaken to develop three new face coat systems based on yttria, but with better sintering properties. These face coat systems were mainly based on an yttria-alumina-zirconia system (Y2O3-0.5 wt pct Al2O3-0.5 wt pct ZrO2), an yttria-fluoride system (Y2O3-0.15 wt pct YF3), and an yttria-boride system (Y2O3-0.15 wt pct B2O3). After sintering, the chemical inertness of the face coat was first tested and analyzed using a sessile drop test through the metal wetting behavioral change for each face coat surface. Then, the interactions between the shell and metal were studied by centrifugal investment casting TiAl bars. Although the sintering aids in yttria can decrease the chemical inertness of the face coat, the thickness of the interaction layer in the casting was less than 10 μm; therefore, these face coats still can be possible face coat materials for investment casting TiAl alloys.
Directory of Open Access Journals (Sweden)
L. E. Rovin
Full Text Available The analysis of efficiency and technological peculiarities of the ways of the electric power costs reduction at melting of cast iron and steel in electroarc and induction furnaces is presented. The most perspective for embedding in operating houses for conditions of RB is heating of burden due to natural gas in self-sufficient plants directly in loading bucket (baskets.
High temperature corrosion of cast irons and cast steels in dry air
Energy Technology Data Exchange (ETDEWEB)
Tholence, F.; Norell, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Engineering Metals
The oxidation in dry air of four cast alloys intended for exhaust gas systems has been examined. Particular interest was directed to how the oxide growth was related to the microstructures. The examined alloys were two cast ductile irons, a SiMo alloy (Fe3,86Si0,6Mo3C) and a Ni-Resist alloy (Fe32Ni5,3Si2,1C), and two cast stainless steels, one ferritic (Fe18Cr2,1Mn0,32C) and one austenitic (Fe20Cr9Ni0,47C). Coupons were oxidised for 50 h at temperatures between 650 C and 1050 C. The samples were characterised by using XRD, SEM/EDX and AES. As expected, the overall oxide thickness increased with temperature and partial spallation occurred at the highest temperatures for all alloys. Porous Fe oxide nodules nucleate at the graphite nodules on the ductile irons. These Fe-oxide nodules formed above a continuous layer of Fe-Si-oxide for the SiMo and mixed Fe-Ni-Si oxides for the Ni-Resist. The total oxide thickness is about (60 {mu}m). Thick oxides at the interdendritic regions in the cast steels were attributed to non-Cr-carbides. Segregation of Cr directed the formation of iron oxide nodules to the centre of the dendrites in the austenitic alloy. (orig.)
Nonaqueous slip casting of high temperature ceramic superconductors using an investment casting technique
Hooker, Matthew W. (Inventor); Taylor, Theodore D. (Inventor); Wise, Stephanie A. (Inventor); Buckley, John D. (Inventor); Vasquez, Peter (Inventor); Buck, Gregory M. (Inventor); Hicks, Lana P. (Inventor)
A process for slip casting ceramic articles that does not employ parting agents and affords the casting of complete, detailed, precision articles that do not possess parting lines is presented. This process is especially useful for high temperature superconductors and water-sensitive ceramics. A wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell mold of the calcium sulfate-bonded investment material. The shell mold is cooled to room temperature, and a ceramic slip, created by dispersing a ceramic powder in an organic liquid, is poured therein. After a ceramic shell of desired thickness or a solid article has set up in the shell mold, excess ceramic slip is poured out. The shell mold is misted with water and peeled away from the ceramic article, after which the ceramic is fired to provide a complete, detailed, precision, high temperature superconductive ceramic article without parting lines. The casting technique may take place in the presence of a magnetic field to orient the ceramic powders during the casting process.
Materials on dies for pressure die casting
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E. Ragan
Full Text Available In the contribution the stress of die materials of thermal fatigue is defi ned and material life is derived theoretically and compared with the measured values. The important properties of the die materials as thermal conductivity, coeffi cient of thermal expansivity, modulus of elasticity and mechanical properties are described. Binding to it single die materials as carbon steels and chrome-tungsten steels are analyzed. As the perspective die material for pressure die casting of ferrous metals appears molybdenum with regard to advantageous properties.
CAST begins its search for solar axions.
Maximilien Brice
The CERN Axion Solar Telescope (CAST) consists of a prototype LHC dipole magnet with photon detectors at each end. It has started searching for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. Photos 01 02: The telescope, located at Point 8, can move vertically within its wheeled yellow platform, which travels horizontally along tracks in the floor. In this way, the telescope can view the Sun at sunrise through one end (left) and at sunset through the other. Photos 03 04: Sunrise photon detectors at one end of the telescope.
Internal adaptation of cast titanium crowns
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Sicknan Soares da Rocha
Full Text Available As the adaptation of titanium crowns obtained by Rematitan Plus investment, specific for titanium, is not recognized to be suitable, this study evaluated the effect of the concentration of the specific liquid and the temperature of the mold of investments on the internal misfit of crowns cast on commercially pure titanium. Individual dies of epoxy resin were obtained, representing teeth prepared for full-crown restoration with a 6-degree axial surface convergence angle and shoulder (1.0 mm. For the waxing of each crown, a ring-shaped stainless steel matrix (8.0mm internal diameter; 7.5 mm height was adapted above the individual dies of epoxy resin. The Rematian Plus investment was mixed according to the manufacturer's instructions using two different concentrations of the specific liquid: 100%, 75%. Casting was performed in a Discovery Plasma Ar-arc vacuum-pressure casting machine with molds at temperatures of 430ºC, 515ºC and 600ºC. The crowns were cleaned individually in a solution (1% HF + 13% HNO3 for 10 min using a ultrasonic cleaner, with no internal adaptations, and luted with zinc phosphate cement under a 5 kg static load. The crown and die assemblies were embedded in resin and sectioned longitudinally. The area occupied by cement was observed using stereoscopic lens (10X and measured by the Leica Qwin image analysis system (mm². The data for each experimental condition (n=8 were analyzed by Kruskal-Wallis non-parametric test (á=0.05. The results showed that liquid dilution and the increase in mold temperature did not significantly influence the levels of internal fit of the cast titanium crowns. The lowest means (±SD of internal misfit were obtained for the 430ºC/100%: (7.25 mm² ±1.59 and 600ºC/100% (8.8 mm² ±2.25 groups, which presented statistically similar levels of internal misfit.
Continuation of Crosscutting Technology Development at Cast
Energy Technology Data Exchange (ETDEWEB)
Yoon, Roe-Hoan
This Final Technical Report describes progress made on the sub-projects awarded in the Cooperative Agreement DE-FC26-05NT42457: Continuation of Crosscutting Technology Development at Center for Advanced Separation Technologies (CAST). The final reports for each sub-project are attached in the appendix. Much of the research to be conducted with Cooperative Agreement funds will be longer-term, high-risk, basic research and will be carried out in five broad areas: a) Solid-solid separation b) Solid-liquid separation c) Chemical/Biological Extraction d) Modeling and Control, and e) Environmental Control.
Sharing casting technological data on web site
Directory of Open Access Journals (Sweden)
Li Hailan
Full Text Available Based on database and asp.net technologies, a web platform of scientific data in the casting technology fi eld has been developed. This paper presents the relevant data system structure, the approaches to the data collection, the applying methods and policy in data sharing, and depicts the collected and shared data recently fi nished. Statistics showed that there are about 20,000 visitors in China every day visiting the related data through the web, proving that many engineers or other relevant persons are interested in the data.
Phase Transformations in Cast Duplex Stainless Steels
Energy Technology Data Exchange (ETDEWEB)
Kim, Yoon-Jun [Iowa State Univ., Ames, IA (United States)
Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as σ and χ can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (σ + χ) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, σ was stabilized with increasing Cr addition and χ by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by
Effect of Selected Parameters of Pressure Die Casting on Quality of AlSi9Cu3 Castings
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Pałyga Ł.
Full Text Available This paper presents the results on the effects of die-casting process on the strength parameters of castings of the aluminium AlSi9Cu3 alloy belonging to the group of EN AB-46000, made on renovated high pressure die-casting machine. Specimens for quality testing were taken from the places of the casting most loaded during the service. The aim of a research was to prove how the new die-casting process control capabilities influence on the tensile strength of the cast material defined as a value of the breaking force of the specimens. It has been found that it is possible to specify a set of recommended settings valves of second (II and third (III phase, which are responsible for filling the metal mould on die-casting pressure machine. From the point of view of the finished cast element, it was noticed that exceeding the prescribed values of valve settings does not bring further benefits and even causes unnecessary overload and reduce the durability of the mold. Moreover, it was noticed that reduction of the predetermined setting of the second phase (II valve leads to the formation of casting defects again.
Puerto del Pendulo, doubtful sound: the Malaspina expedition's visit to New Zealand in quest of the true figure of the earth
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King, Robert J.
Full Text Available The Malaspina expedition was assigned the task of conducting a series of experiments using the pendulum to measure the strength of gravity at different locations during the course of its voyage. The immediate objective was to establish the length of a pendulum beating at seconds at latitude 45º as the basic unit of a new universal system of measures. Although the new unit, the metre, was eventually established on a different principle, the gravity experiments carried out by the expedition resulted in useful geodesic information and incidentally led to the first charting of Doubtful Sound in New Zealand.
La expedición Malaspina tuvo por misión realizar una serie de experimentos utilizando un péndulo para medir la fuerza de la gravedad en los diferentes lugares recorridos durante el viaje. El objetivo inmediato consistió en establecer la longitud de un péndulo oscilando durante unos segundos a una latitud de 45º como unidad básica de un nuevo sistema métrico universal. Aunque la nueva unidad, el metro, fue finalmente establecida por otro principio diferente, los experimentos que llevó a cabo la expedición sobre la gravedad proporcionaron una información geodésica muy útil y por casualidad dieron lugar al primer trazado de mapa de Doubtful Sound, en Nueva Zelanda.
How can I know what I'm feeling? Obsessive-compulsive tendencies and induced doubt are related to reduced access to emotional states.
Dar, Reuven; Lazarov, Amit; Liberman, Nira
People's feelings are not always accessible to them, and this might be especially the case for some individuals and in some situations. Based on our model of obsessive-compulsive disorder, we predicted that obsessive-compulsive (OC) tendencies and situationally induced doubt would be associated with decreased access to one's own emotions. In the first two studies we examined the relationships between OC tendencies and performance on the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). In Study 3 we undermined participants' confidence in their ability to accurately assess their own emotions and assessed the effect of this manipulation on MSCEIT performance. As predicted, OC tendencies were associated with lower scores on the Experiential area of the MSCEIT, which relies on access to experienced emotions, but not on the Strategic area, which relies on semantic knowledge about emotions. Similarly, undermining participants' confidence in their own emotions reduced their scores on the Experiential, but not on the Strategic area of the MSCEIT. The findings should be replicated with a clinical OCD population and with other measures of emotional experience. These studies suggest that impaired access to emotional states may be caused by doubting those states, that it characterizes people with high OC tendencies, and that it might be a manifestation of a more general difficulty in accessing internal states. Copyright © 2016 Elsevier Ltd. All rights reserved.
Spall behavior of cast iron with varying microstructures
Plume, Gifford; Rousseau, Carl-Ernst
The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94-1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.
Horizontal electromagnetic casting of thin metal sheets
Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.
Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.
Horizontal electromagnetic casting of thin metal sheets
Energy Technology Data Exchange (ETDEWEB)
Hull, John R. (Hinsdale, IL); Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)
Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.
Advanced Lost Foam Casting Technology - Phase V
Energy Technology Data Exchange (ETDEWEB)
Wanliang Sun; Harry E. Littleton; Charles E. Bates
Previous research, conducted under DOE Contracts DE-FC07-89ID12869, DE-FC07-93ID12230 and DE-FC07-95ID113358 made significant advances in understanding the Lost Foam Casting (LFC) Process and clearly identified areas where additional developments were needed to improve the process and make it more functional in industrial environments. The current project focused on eight tasks listed as follows: Task 1--Computational Model for the Process and Data Base to Support the Model; Task 2--Casting Dimensional Accuracy; Task 3--Pattern Production; Task 4--Improved Pattern Materials; Task 5--Coating Control; Task 6--In-Plant Case Studies; Task 7--Energy and the Environmental Data; and Task 8--Technology Transfer. This report summarizes the work done on all tasks in the period of October 1, 1999 through September 30, 2004. The results obtained in each task and subtask are summarized in this Executive Summary and details are provided in subsequent sections of the report.
Aluminum Alloy and Article Cast Therefrom
Lee, Jonathan A. (Inventor); Chen, Po-Shou (Inventor)
A cast article from an aluminum alloy, which has improved mechanical properties at elevated temperatures, has the following composition in weight percent: Silicon 14 - 25.0, Copper 5.5 - 8.0, Iron 0.05 - 1.2, Magnesium 0.5 - 1.5, Nickel 0.05 - 0.9, Manganese 0.05 - 1.0, Titanium 0.05 - 1.2, Zirconium 0.05 - 1.2, Vanadium 0.05 - 1.2, Zinc 0.05 - 0.9, Phosphorus 0.001 - 0.1, and the balance is Aluminum, wherein the silicon-to-magnesium ratio is 10 - 25, and the copper-to-magnesium ratio is 4 - 15. The aluminum alloy contains a simultaneous dispersion of three types of Al3X compound particles (X=Ti, V, Zr) having a LI2, crystal structure, and their lattice parameters are coherent to the aluminum matrix lattice. A process for producing this cast article is also disclosed, as well as a metal matrix composite, which includes the aluminum alloy serving as a matrix and containing up to about 60% by volume of a secondary filler material.
Casting routes for porous metals production
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P. Lichy
Full Text Available The last decade has seen growing interest in professional public about applications of porous metallic materials. Porous metals represent a new type of materials with low densities, large specific surface, and novel physical and mechanical properties, characterized by low density and large specific surface. They are very suitable for specific applications due to good combination of physical and mechanical properties such as high specific strength and high energy absorption capability. Since the discovery of metal foams have been developed many methods and techniques of production in liquid, solid and gas phases. Condition for the use of metal foams - advanced materials with unique usability features, are inexpensive ways to manage their production. Mastering of production of metallic foams with defined structure and properties using gravity casting into sand or metallic foundry moulds will contribute to an expansion of the assortment produced in foundries by completely new type of material, which has unique service properties thanks to its structure, and which fulfils the current demanding ecological requirements. The aim of research conducted at the department of metallurgy and foundry of VSB-Technical University Ostrava is to verify the possibilities of production of metallic foams by conventional foundry processes, to study the process conditions and physical and mechanical properties of metal foam produced. Two procedures are used to create porous metal structures: Infiltration of liquid metal into the mold cavity filled with precursors or preforms and two stage investment casting.
Variability of study cast assessment among orthodontists.
Pair, J W; Luke, L; White, S; Atchinson, K; Englehart, R; Brennan, R
This study examined the accuracy and reliability with standardized definitions among 30 orthodontists in assessing different aspects of malocclusion from the study casts of 10 patients. Previous studies have indicated a lack of consistency among orthodontists in describing malocclusions. The diagnostic subcategories measured in this study included maxillary and mandibular crowding, overbite, overjet, and a modified molar, premolar, and canine Angle classification. Intraclass correlations indicated that the reliability of all parameters was good (intraclass correlation > 0.80), with overbite being the most reliable (0.98) and maxillary crowding and canine classification somewhat less reliable (0.89 and 0.87, respectively). Among Angle classifications, molar classification was the highest (0.95), followed by premolar (0.92) and canine (0.87). This study also measured the accuracy of the orthodontists' measurements compared with established true values (validity). T tests indicated that mandibular arch crowding and overbite were not statistically different from the true values. Overjet and molar classification were assessed very close to the true values. Although premolar and canine classifications were statistically different from the true values, they were within a one-eighth cusp of the true value (a clinically insignificant difference). The orthodontists consistently overestimated the amount of maxillary arch crowding or spacing. The results suggest that high reliability and reasonable accuracy can be expected for assessing study casts when using standardized definitions for the diagnostic subcategories.
The Caries Assessment Spectrum and Treatment (CAST) instrument: construct validation
Souza, A.L. de; Leal, S.C.; Chaves, S.B.; Bronkhorst, E.M.; Frencken, J.E.F.M.; Creugers, N.H.J.
The Caries Assessment Spectrum and Treatment (CAST) is a newly developed epidemiological instrument. The aim of this study was to investigate its construct validity. Four calibrated examiners, using CAST codes 0-6, visually examined 109 surfaces of extracted and exfoliated teeth. These teeth were
Casting Porosity-Free Grain Refined Magnesium Alloys
Energy Technology Data Exchange (ETDEWEB)
Schwam, David [Case Western Reserve University
The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings.
Genetic study of scheduled caste populations of Tamil Nadu
Indian Academy of Sciences (India)
The present study aims to describe the genetic structure of the scheduled caste populations in Tamil Nadu state, ... phisms) in DNA samples from five Tamil Nadu caste groups using phylogenetic and principal component analysis ... 1997), a mitochondrial DNA insert in the human nuclear genome (Zischler et al. 1995), and ...
design, construction and performance evaluation of multiple casting
African Journals Online (AJOL)
there is a significant improvement in tensile strength and wear resistance. Logistic performance evaluation of squeeze casting technique has been used to analyze simulation of squeeze casting equipment [4]. It was identified that the utilization rate of feeding robot, take-out robot and spray device decreases with increase of ...
Cast net design characteristics, catch composition and selectivity in ...
African Journals Online (AJOL)
Cast net design characteristics, construction, operational techniques and selectivity in Lagos lagoon, Nigeria was examined between September and December 2005. Netting materials for cast net construction in Lagos lagoon were monofilament nylon, poly-ethylene (PE) and polyester (PES). The conventional ratio 1:2 of ...
Calpastatin (CAST) gene polymorphism in Kajli, Lohi and Thalli ...
African Journals Online (AJOL)
Jun 12, 2012 ... Calpastatin-encoding gene (CAST) is located on the fifth chromosome of sheep and it plays an important role in the development of muscles and in meat tenderness. The present study was conducted to investigate a calpastatin (CAST) gene polymorphism in Pakistani Thalli, Lohi and Kajli sheep breed.
Examination of Ife Bronze Casting Culture and Its Decline in ...
African Journals Online (AJOL)
Ile-Ife, the Yoruba ancient city is known for its vibrant cultural environment. This city of ancient civilization and one of the home for bronze casting in the Western region of Nigeria have made significant contributions to the world of culture through its great artistic traditions in terracotta, bead making, bronze and brass casting ...
Solidification and microstructure of thin walled ductile cast iron
DEFF Research Database (Denmark)
Pedersen, Karl Martin
In the recent years there has been an increasing interest in light constructions in order to save weight in e.g. cars. Ductile cast iron has good mechanical properties but it is necessary to reduce the wall thicknesses of the castings in order to reduce the weight. Reducing the wall thicknesses...
Rapid Tooling via Investment Casting and Rapid Prototype Patterns
Energy Technology Data Exchange (ETDEWEB)
Baldwin, Michael D.
The objective of this work to develop the materials processing and design technologies required to reduce the die development time for metal mold processes from 12 months to 3 months, using die casting of Al and Mg as the example process. Sandia demonstrated that investment casting, using rapid prototype patterns produced from Stereo lithography or Selective laser Sintering, was a viable alternative/supplement to the current technology of machining form wrought stock. A demonstration die insert (ejector halt) was investment cast and subsequently tested in the die casting environment. The stationary half of the die insert was machined from wrought material to benchmark the cast half. The two inserts were run in a die casting machine for 3,100 shots of aluminum and at the end of the run no visible difference could be detected between the cast and machined inserts. Inspection concluded that the cast insert performed identically to the machined insert. Both inserts had no indications of heat checking or degradation.
A mechanical signal biases caste development in a social wasp
Sainath Suryanarayanan; John C. Hermanson; Robert L. Jeanne
Understanding the proximate mechanisms of caste development in eusocial taxa can reveal how social species evolved from solitary ancestors. In Polistes wasps, the current paradigm holds that differential amounts of nutrition during the larval stage cause the divergence of worker and gyne (potential queen) castes. But nutrition level alone cannot explain how the first...
Effect of blow-holes on reliability of cast component
Indian Academy of Sciences (India)
Cast component; blow-holes; reliability; univariate response surface approximation; failure probability. 1. Introduction. Metal casting process begins by creating a mold, which is the 'reverse' shape of the part that is needed. The mold is made from a refractory material like sand. The metal is heated in an oven until it melts, ...
The Childhood Autism Spectrum Test (CAST): Sex Differences
Williams, Joanna G.; Allison, Carrie; Scott, Fiona J.; Bolton, Patrick F.; Baron-Cohen, Simon; Matthews, Fiona E.; Brayne, Carol
The Childhood Autism Spectrum Test (CAST) (formally known as the Childhood Asperger Screening Test) identifies autism spectrum conditions by measuring social and communication skills. The present study explored the sex distribution of scores. The CAST was distributed to 11,635 children aged 4-9 years in Cambridgeshire primary schools (UK). 3,370…
The Childhood Asperger Syndrome Test (Cast): Test--Retest Reliability
Williams, Jo; Allison, Carrie; Scott, Fiona; Stott, Carol; Bolton, Patrick; Baron-Cohen, Simon; Brayne, Carol
The Childhood Asperger Syndrome Test (CAST) is a 37-item parental self-completion questionnaire to screen for autism spectrum conditions in research. Good test accuracy was demonstrated in studies with primary school aged children in mainstream schools. The aim of this study was to investigate the test-retest reliability of the CAST. Parents of…
Evaluation of solid–liquid interface profile during continuous casting ...
Indian Academy of Sciences (India)
Home; Journals; Bulletin of Materials Science; Volume 24; Issue 4. Evaluation of solid–liquid interface profile during continuous casting by a spline based formalism. S K Das. Metals and Alloys Volume ... Keywords. Continuous casting; solidification; solid–liquid interface; front tracking algorithm; phase change; heat transfer.
The history and present of art casting in China
Directory of Open Access Journals (Sweden)
Derui Tan
Full Text Available History of art casting in China has been over 5000 years. In the past few thousand years, numerous forming and decorating skills of art castings has been created, and left behind precious treasures in the world metal arts and crafts. In individual historical period and at different terrain, a unique artistic style formed, which flashed brilliant light in world artistic treasury.
Laser surface treatment of grey cast iron for automotive applications
Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI
The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast
ToxCast HTS Assay Development and Retrofitting: Strategies ...
A presentation to EC JRC partners on new ToxCast HTS assay methods and strategies to address current limitations to HTS methods Slide presentation to EC JRC partners on new ToxCast HTS assay methods and strategies to address current limitations to HTS methods.
Design And Construction Of A Die Casting Mould Suitable For ...
African Journals Online (AJOL)
Design And Construction Of A Die Casting Mould Suitable For Production Of Various Sizes Of Key Blanks. ... Nigeria Journal of Pure and Applied Physics ... A suitable die casting method is used taking into account such limitations as the sizes of the keys, their serviceability, rate of production, as they affect the method of ...
Undercooling and nodule count in thin walled ductile iron castings
DEFF Research Database (Denmark)
Pedersen, Karl Martin; Tiedje, Niels Skat
of graphite nodules which begins at a lover temperature in the eutectic than in the hypereutectic castings The recalescence (Trec) was however also larger for the eutectic casting and in the thin plates the maximum temperature after recalescence (Tmax) was the same in the eutectic and hypereutectic plates...
Comparative Microbial Analysis of Earthworm Casts Collected From ...
African Journals Online (AJOL)
A comparative assessment of the physicochemical parameters and microbial profile of three types of earthworm casts (Pellet, Mass and Turret) were determined. The total viable count (TVC), coliform counts, yeast and mould counts were determined using standard procedures. The pH ranged from 7.8 for Mass cast to 8.6 for ...
Growth response of Amaranthus caudatus to earthworm casts and ...
African Journals Online (AJOL)
The effect of earth worm cast on the physiomorphological differences of Amaranthus caudatus was studied in the green house of the Department of Agronomy, University of Ibadan for seven weeks in 1998. Earthworm casts were collected from soils cultivated with maize, cassava and oil palm fields and secondary forest.
Preferential dissolution behaviour in Ni–Cr dental cast alloy
Indian Academy of Sciences (India)
Ni–Cr–Mo; dental cast alloy; microstructure; corrosion; cyclic polarization. 1. Introduction. Co and Ni based alloys are widely used in dental skeletal structures and orthopedic implants such as screws, pins and plates (Wataha 2000). The advantages of these alloys include low cost of casting, matching thermal expansion.
Colour Metallography of Cast Iron - Chapter 1: Introduction (Ⅰ
Directory of Open Access Journals (Sweden)
Zhou Jiyang
Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour
Grain Refinement of Permanent Mold Cast Copper Base Alloys
Energy Technology Data Exchange (ETDEWEB)
M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo
Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.
Development of Cloud Based Casting Defects Categorization System (CDCS
Directory of Open Access Journals (Sweden)
Sata Amit V.
Full Text Available Defects affect the properties and behavior of the casting during its service life. Since the defects can occur due to different reasons, they must be correctly identified and categorized, to enable applying the appropriate remedial measures. several different approaches for categorizing casting defects have been proposed in technical literature. They mainly rely on physical description, location, and formation of defects. There is a need for a systematic approach for classifying investment casting defects, considering appropriate attributes such as their size, location, identification stage, inspection method, consistency, appearance of defects. A systematic approach for categorization of investment casting defects considering multiple attributes: detection stage, size, shape, appearance, location, consistency and severity of occurrence. Information about the relevant attributes of major defects encountered in investment casting process has been collected from an industrial foundry. This has been implemented in a cloud-based system to make the system freely and widely accessible.
Casting metal microstructures from a flexible and reusable mold
Cannon, Andrew H.; King, William P.
This paper describes casting-based microfabrication of metal microstructures and nanostructures. The metal was cast into flexible silicone molds which were themselves cast from microfabricated silicon templates. Microcasting is demonstrated in two metal alloys of melting temperature 70 °C or 138 °C. Many structures were successfully cast into the metal with excellent replication fidelity, including ridges with periodicity 400 nm and holes or pillars with diameter in the range 10-100 µm and aspect ratio up to 2:1. The flexibility of the silicone mold permits casting of curved surfaces, which we demonstrate by fabricating a cylindrical metal roller of diameter 8 mm covered with microstructures. The metal microstructures can be in turn used as a reusable molding tool.
Numerical simulation and optimization of casting process for complex pump
Liu, Xueqin; Dong, Anping; Wang, Donghong; Lu, Yanling; Zhu, Guoliang
The complex shape of the casting pump body has large complicated structure and uniform wall thickness, which easy give rise to casting defects. The numerical simulation software ProCAST is used to simulate the initial top gating process, after analysis of the material and structure characteristics of the high-pressure pump. The filling process was overall smooth, not there the water shortage phenomenon. But the circular shrinkage defects appear at the bottom of casting during solidification process. Then, the casting parameters were optimized and adding cold iron in the bottom. The shrinkage weight was reduced from 0.00167g to 0.0005g. The porosity volume was reduced from 1.39cm3 to 0.41cm3. The optimization scheme is simulated and actual experimented. The defect has been significantly improved.
Thermodynamic stability of austenitic Ni-Mn-Cu cast iron
Directory of Open Access Journals (Sweden)
A. Janus
Full Text Available The performed research was aimed at determining thermodynamic stability of structures of Ni-Mn-Cu cast iron castings. Examined were 35 alloys. The castings were tempered at 900 °C for 2 hours. Two cooling speeds were used: furnace-cooling and water-cooling. In the alloys with the nickel equivalent value less than 20,0 %, partial transition of austenite to martensite took place. The austenite decomposition ratio and the related growth of hardness was higher for smaller nickel equivalent value and was clearly larger in annealed castings than in hardened ones. Obtaining thermodynamically stable structure of castings requires larger than 20,0 % value of the nickel equivalent.
Research on Accuracy of Automatic System for Casting Measuring
Directory of Open Access Journals (Sweden)
Jaworski J.
Full Text Available Ensuring the required quality of castings is an important part of the production process. The quality control should be carried out in a fast and accurate way. These requirements can be met by the use of an optical measuring system installed on the arm of an industrial robot. In the article a methodology for assessing the quality of robotic measurement system to control certain feature of the casting, based on the analysis of repeatability and reproducibility is presented. It was shown that industrial robots equipped with optical measuring systems have the accuracy allowing their use in the process of dimensional control of castings manufactured by lost-wax process, permanent-mould casting, and pressure die-casting.
Nail changes in casted and braced clubfoot: A preliminary study.
Agarwal, Anil; Kumar, Anubrat; Khanna, Deepshikha; Shaharyar, Abbas; Bhat, Mohd Shafi; Mishra, Madhusudan
The study aimed at finding whether there are any nail changes specific to treatment in clubfoot. Sixty new, 26 undergoing serial corrective casting, and 247 clubfoot patients using foot abduction braces were prospectively studied. The casted and braced group formed the basis of the study to observe nail changes, if any. The new patients and opposite normal foot (in unilateral casted cases) were taken as controls. Acute paronychia, ingrown toe nail, onychoshizia, onychorrhexis, nail plate concavity, latent onychomadesis, and distal onycholysis were observed in feet undergoing corrective casting and bracing. Micronychia, malalignment and thinning of nail plate were the observed congenital nail anomalies. Nail changes in clubfeet are not infrequent. Certain nail changes might be etiologically linked to casting and bracing. Some of nail changes might require urgent medical care. Copyright © 2015 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.
Integrated Modeling of Process, Structures and Performance in Cast Parts
DEFF Research Database (Denmark)
Kotas, Petr
This thesis deals with numerical simulations of gravity sand casting processes for the production of large steel parts. The entire manufacturing process is numerically modeled and evaluated, taking into consideration mould filling, solidification, solid state cooling and the subsequent stress build...... up. The thermal analysis is then combined with evolutionary multi-objective optimization techniques in a search for the optimal thermal aspects and conditions for producing sound and competitive castings. The goals of the optimization procedure are related to the casting and rigging design...... and to defects occurrence. In other words, it is desired to eliminate all of the potential casting defects and at the same time to maximize the casting yield. The numerical optimization algorithm then takes these objectives and searches for a set of the investigated process, design or material parameters e...
Casting of Hearth Plates from High-chromium Steel
Directory of Open Access Journals (Sweden)
Drotlew A.
Full Text Available The paper presents the results of studies on the development of manufacturing technologies to cast hearth plates operating in chamber furnaces for heat treatment. Castings made from the heat-resistant G-X40CrNiSi27-4 steel were poured in hand-made green sand molds. The following operations were performed: computer simulation to predict the distribution of internal defects in castings produced by the above mentioned technology with risers bare and coated with exothermic and insulating sleeves, analysis of each variant of the technology, and manufacture of experimental castings. As a result of the conducted studies and analysis it was found that the use of risers with exothermic sleeves does not affect to a significant degree the quality of the produced castings of hearth plates, but it significantly improves the metal yield.
Relationship Between Casting Distortion, Mold Filling, and Interfacial Heat Transfer in Sand Molds
Energy Technology Data Exchange (ETDEWEB)
J. K. Parker; K. A. Woodbury; T. S. Piwonka; Y. Owusu
This project sought to determine the relationship between casting dimensions and interfacial heat transfer in aluminum alloy sand castings. The program had four parts; measurement of interfacial heat transfer coefficients in resin bonded and green sand molds, the measurement of gap formation in these molds, the analysis of castings made in varying gatings, orientations and thicknesses, and the measurement of residual stresses in castings in the as-cast and gate removed condition. New values for interfacial heat transfer coefficients were measured, a novel method for gap formation was developed, and the variation of casting dimensions with casting method, gating, and casting orientation in the mold was documented.
The Influence of Casting Conditions on the Microstructure of As-Cast U-10Mo Alloys: Characterization of the Casting Process Baseline
Energy Technology Data Exchange (ETDEWEB)
Nyberg, Eric A.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas
Sections of eight plate castings of uranium alloyed with 10 wt% molybdenum (U-10Mo) were sent from Y-12 to the Pacific Northwest National Laboratory (PNNL) for microstructural characterization. This report summarizes the results from this study.
Gating of Permanent Molds for Aluminum Casting
Energy Technology Data Exchange (ETDEWEB)
David Schwam; John F. Wallace; Tom Engle; Qingming Chang
This report summarizes a two-year project, DE-FC07-011D13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. Other studies have been conducted using water flow and behavior of liquid aluminum in sand mold using real time photography. This investigation utilizes graphite molds transparent to X-Rays making it possible to observe the flow pattern through a number of vertically oriented grating systems. These have included systems that are choked at the base of a rounded vertical sprue and vertical gating systems with a variety of different ingates into the bottom of a mold cavity. These systems have also been changed to include gating systems with vertical and horizontal gate configurations. Several conclusions can be derived from this study. A sprue-well, as designed in these experiments, does not eliminate the vena contracta. Because of the swirling at the sprue-base, the circulating metal begins to push the entering metal stream toward the open runner mitigating the intended effect of the sprue-well. Improved designs of
Cast Stone Formulation At Higher Sodium Concentrations
Energy Technology Data Exchange (ETDEWEB)
Fox, K. M.; Roberts, K. A.; Edwards, T. B.
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Cast Stone Formulation At Higher Sodium Concentrations
Energy Technology Data Exchange (ETDEWEB)
Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Roberts, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Cast Stone Formulation At Higher Sodium Concentrations
Energy Technology Data Exchange (ETDEWEB)
Fox, K. M.; Edwards, T. A.; Roberts, K. B.
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Under Pressure: The Utility of Spacers in Univalved Fiberglass Casts.
Kleis, Kevin; Schlechter, John A; Doan, Joshua D; Farnsworth, Christine L; Edmonds, Eric W
Univalving fiberglass casts after fracture manipulation or extremity surgery reduces the risk of developing compartment syndrome (CS). Previous experiments have demonstrated that univalving decreases intracompartmental pressures (ICPs), but increases the risk for loss of fracture reduction due to altering the mechanical properties of the cast. The purpose of this study was to correlate cast valve width within a univalved cast model to decreasing ICP. Saline bags (1 L) were covered with stockinette, Webril, and fiberglass tape then connected to an arterial pressure line monitor. Resting pressure was recorded. A water column was added to simulate 2 groups (n=5 each) of clinical CS: low pressure CS (LPCS range, 28 to 31 mm Hg) and high pressure CS (HPCS, range, 64 to 68 mm Hg). After the designated pressure was reached, the fiberglass was cut (stockinette and Webril remained intact). Cast spacers were inserted into each univalve and secured with varying widths: position #1 (3 mm wide), #2 (6 mm), #3 (9 mm), and #4 (12 mm). Pressure was recorded after cutting the fiberglass and following each spacer placement. In LPCS and HPCS groups, after univalve and placement of spacer position #1, pressure dropped by a mean of 52% and 58%, respectively. Spacer #2, decreased the pressure by a mean of 78% and 80%, respectively. Both spacer sizes significantly decreased the underlying pressure in both groups. Spacer #3 and #4 progressively reduced pressure within the cast, but not statistically significantly more than the previous spacer widths. This experimental model replicates the iatrogenic elevation in interstitial compartment pressure due to rigid cast application, not necessarily a self-sustained true CS. Increasing the univalved cast spread by ≥9 mm of the initial cast diameter will reduce pressure to a pre-CS level; however, a spread of only 6 mm can effectively reduce the pressure to fiberglass casts has been previously demonstrated, we present evidence highlighting the
Comparative study of two commercially pure titanium casting methods.
Rodrigues, Renata Cristina Silveira; Faria, Adriana Claudia Lapria; Orsi, Iara Augusta; Mattos, Maria da Gloria Chiarello de; Macedo, Ana Paula; Ribeiro, Ricardo Faria
The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior. This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure. 72 frameworks were cast from CP Ti (n=36) and Co-Cr alloy (n=36; control group). For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6) were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey's to compare materials and cast methods (α=0.05). Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (pcasted. Although both casting methods produced satisfactory CP Ti RPD frameworks, the occurrence of porosities was greater in the plasma/vacuum-pressure than in the induction/centrifugation method, the latter resulting in higher clasp rigidity, generating higher retention force values.
Studies on the Castability of Pure Titanium (Part 3) Influence of casting pressure and sprue diameter on the titanium castability
YONEDA, TAKANORI; KUROIWA, AKIHIRO; IGARASHI, YOSHIMASA; OHNO, TAKAFUMI; SEKIGUCHI, YUUJI; Inoue, Yoshihisa; MIGO, SHINYA
We analyzed the external defects of castings with mesh grid patterns with 3 different kinds of phosphate bonded casting molds with 2 parameters (sprue diameter and casting pressure). Castability with pure titanium was affected by the parameters of sprue diameter, and casting pressure with different casting molds. The sprue condition was the most affective casting condition in the all directional pressure type casting machine. In 2 types of casting molds, one was strongly affected by the casti...
Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts
DEFF Research Database (Denmark)
Sonne, Mads Rostgaard; Frandsen, J. O.; Hattel, Jesper Henri
In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than...
Quality criteria for pure titanium casting, laboratory soldering, intraoral welding, and a device to aid in making uncontaminated castings.
Hruska, A R; Borelli, P
Procedures for casting, laboratory soldering, and intraoral welding of titanium for dental restorations are described and illustrated. Pure titanium and titanium 6A1-4Va alloy castings may be used for virtually any prosthodontic rehabilitation as well as for implants, with the proper equipment and technique.
The Effect of a Thin-Wall Casting Mould Cavity Filling Conditions on the Casting Surface Quality
Directory of Open Access Journals (Sweden)
Trytek A.
Full Text Available The paper presents results of metallographic examination of faults occurring in the course of founding thin-walled cast-iron castings in furan resin sand molds. A non-conformance of the scab type was Observed on surface of the casting as well as sand buckles and cold shots. Studied the chemical composition by means of a scanning electron microscope in a region of casting defects: microanalysis point and microanalysis surface. Around the observed defects discloses high concentration of oxides of iron, manganese and silicon. A computer simulation of the casting process has been carried out with the objective to establish the cause of occurrence of cold shots on casting surface. The simulation was carried out with the use of NovaFlow & Solid program. We analyzed the flowing metal in the mold cavity. The main reason for the occurrence of casting defects on the surface of the casting was gating system, which caused turbulent flow of metal with a distinctive splash stream of liquid alloy.
Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering
Directory of Open Access Journals (Sweden)
Lim Sang-Sub
Full Text Available In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.
Thickness control and interface quality as functions of slurry formulation and casting speed in side-by-side tape casting
DEFF Research Database (Denmark)
Bulatova, Regina; Jabbari, Mirmasoud; Kaiser, Andreas
A novel method of co-casting called side-by-side tape casting was developed aiming to form thin functionally graded films with varying properties within a single plane. The standard organic-based recipe was optimized to co-cast slurries into thick graded tapes. Performed numerical simulations...... identified the stable flow beneath the blade with a shear rate profile independent of slurry viscosity as long as the slurry load in the casting tank was low. Thickness and interface shape could be well predicted if the rheological behaviour of slurries is known and the processing parameters are well......-controlled. A well-defined steep interface was obtained by co-casting slurries with similar viscosities above 4000mPas at a speed of 40cm/min. The elastic properties of green tapes were proven to be defined by the binder concentration in the recipe formulation. The interfaces in graded tapes were shown to withstand...
Friction wear cast iron casting surface hardened by concentrated source of heat
Directory of Open Access Journals (Sweden)
W. Orlowicz
Full Text Available In this study surface fusion by the GTAW (in argon atmosphere surfacing process on plate of cast iron with electric arc advance speedsfrom 200 to 800 mm/min and current range I=300A were performed. The geometry, microstructure, hardness, friction wear intensity weremeasured. A stepwise regression method was used to develop relationships between the electric arc advance speed, parameters of fusion geometry, microhardness and friction wear intensity.
Casting inorganic structures with DNA molds.
Sun, Wei; Boulais, Etienne; Hakobyan, Yera; Wang, Wei Li; Guan, Amy; Bathe, Mark; Yin, Peng
We report a general strategy for designing and synthesizing inorganic nanostructures with arbitrarily prescribed three-dimensional shapes. Computationally designed DNA strands self-assemble into a stiff "nanomold" that contains a user-specified three-dimensional cavity and encloses a nucleating gold "seed." Under mild conditions, this seed grows into a larger cast structure that fills and thus replicates the cavity. We synthesized a variety of nanoparticles with 3-nanometer resolution: three distinct silver cuboids with three independently tunable dimensions, silver and gold nanoparticles with diverse cross sections, and composite structures with homo- and heterogeneous components. The designer equilateral silver triangular and spherical nanoparticles exhibited plasmonic properties consistent with electromagnetism-based simulations. Our framework is generalizable to more complex geometries and diverse inorganic materials, offering a range of applications in biosensing, photonics, and nanoelectronics. Copyright © 2014, American Association for the Advancement of Science.
Energy Technology Data Exchange (ETDEWEB)
Yoon, Roe-Hoan; Hull, Christopher
The U.S. is the largest producer of mining products in the world. In 2011, U.S. mining operations contributed a total of $232 billion to the nation's GDP plus $138 billion in labor income. Of this the coal mining industry contributed a total of $97.5 billion to GDP plus $53 billion in labor income. Despite these contributions, the industry has not been well supported with research and development funds as compared to mining industries in other countries. To overcome this problem, the Center for Advanced Separation Technologies (CAST) was established to develop technologies that can be used by the U.S. mining industry to create new products, reduce production costs, and meet environmental regulations.
MotionCast for mobile wireless networks
Wang, Xinbing
MotionCast for Mobile Wireless Networks provides an overview on the research for mobile ad-hoc networks regarding capacity and connectivity. Wireless ad-hoc networks are useful when there is a lack of infrastructure for communication. The proposed notion "MotionCast" is for the capacity analysis of multicast in MANET. A new kind of connectivity (k;m)-connectivity, is also defined, and its critical transmission range for i.i.d. (independently and identically distributed) and random walk mobility models are derived respectively. This book also investigates the related issues of connectivity in mobile and static circumstances. In addition, it provides a survey of the capacity scaling research, which gives a good summary of this field.
Restoring Functional Areas of Continuously Casted Cylinders
Brezinová, Janette; Balog, Peter; Viňáš, Ján
the paper proposes the fourth restoration of a roller in continuous casting production lines which can enhance production efficiency and lowers costs. The roller was forged from the material 24CrMoV55 - DIN 17240. The roller has been restored three times and is chosen for further restoration. The roller was restored by submerged arc welding (SAW) where the first layer was made from UP-5-200-CZ wire and the covering layers made from UP-5-45-CZ wire. Quality of the weld deposits were evaluated by measuring the hardness, mixing the weld with basic material and by setting the basic mechanical properties in the critical under-weld deposit area. Structures of the weld deposits were evaluated by light microscopy and their chemical composition was determined by EDX analysis. Based on experiments it can be concluded that rollers can be restored for the fourth time, but the limiting factor is the extent of damage.
Acoustic energy transmission in cast iron pipelines
Kiziroglou, Michail E.; Boyle, David E.; Wright, Steven W.; Yeatman, Eric M.
In this paper we propose acoustic power transfer as a method for the remote powering of pipeline sensor nodes. A theoretical framework of acoustic power propagation in the ceramic transducers and the metal structures is drawn, based on the Mason equivalent circuit. The effect of mounting on the electrical response of piezoelectric transducers is studied experimentally. Using two identical transducer structures, power transmission of 0.33 mW through a 1 m long, 118 mm diameter cast iron pipe, with 8 mm wall thickness is demonstrated, at 1 V received voltage amplitude. A near-linear relationship between input and output voltage is observed. These results show that it is possible to deliver significant power to sensor nodes through acoustic waves in solid structures. The proposed method may enable the implementation of acoustic - powered wireless sensor nodes for structural and operation monitoring of pipeline infrastructure.
FInal Report - Investment Casting Shell Cracking
Energy Technology Data Exchange (ETDEWEB)
Von Richards
This project made a significant contribution to the understanding of the investment casting shell cracking problem. The effects of wax properties on the occurrence of shell cracking were demonstrated and can be measured. The properties measured include coefficient of thermal expansion, heating rate and crystallinity of the structure. The important features of production molds and materials properties have been indicated by case study analysis and fractography of low strength test bars. It was found that stress risers in shell cavity design were important and that typical critical flaws were either oversize particles or large pores just behind the prime coat. It was also found that the true effect of fugitive polymer fibers was not permeability increase, but rather a toughening mechanism due to crack deflection.
The Abrasive Wear Resistance of Chromium Cast Iron
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Kopyciński D.
Full Text Available The resistance of cast iron to abrasive wear depends on the metal abrasive hardness ratio. For example, hardness of the structural constituents of the cast iron metal matrix is lower than the hardness of ordinary silica sand. Also cementite, the basic component of unalloyed white cast iron, has hardness lower than the hardness of silica. Some resistance to the abrasive effect of the aforementioned silica sand can provide the chromium white cast iron containing in its structure a large amount of (Cr, Fe7C3 carbides characterised by hardness higher than the hardness of the silica sand in question. In the present study, it has been anticipated that the white cast iron structure will be changed by changing the type of metal matrix and the type of carbides present in this matrix, which will greatly expand the application area of castings under the harsh operating conditions of abrasive wear. Moreover, the study compares the results of abrasive wear resistance tests performed on the examined types of cast iron. Tests of abrasive wear resistance were carried out on a Miller machine. Samples of standard dimensions were exposed to abrasion in a double to-and-fro movement, sliding against the bottom of a trough filled with an aqueous abrasive mixture containing SiC + distilled water. The obtained results of changes in the sample weight were approximated with a power curve and shown further in the study.
Simulation of mould filling process for composite skeleton castings
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M. Dziuba
Full Text Available In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of skeleton casting and mould filling process. The aim of conducted simulations was the choice of thermal and geometrical parameters for the needs of designed calculations of the skeleton castings and the estimation of the guidelines for the technology of manufacturing. The subject of numerical simulation was the analysis of ability of filling the channels of core by liquid metal at estability technological parameters.. Below the assumptions and results of the initial simulated calculations are presented. The total number of the nodes in the casting was 1920 and of the connectors was 5280 what gave filling of 100% for the nodes and 99,56% for the connectors in the results of the simulation. Together it resulted as 99,78 % of filling the volume of the casting. The nodes and connectors were filled up to the 30 level of the casting in the simulation. The all connectors were filled up to the 25 level of the casting in the simulation. Starting from the 25 level individual connectors at the side surface of the casting weren't filled up. The connectors weren't supplied by multi-level getting system. The differences of filling the levels are little (maximally 5 per cent.
Investigation of Shrinkage Defect in Castings by Quantitative Ishikawa Diagram
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Chokkalingam B.
Full Text Available Metal casting process involves processes such as pattern making, moulding and melting etc. Casting defects occur due to combination of various processes even though efforts are taken to control them. The first step in the defect analysis is to identify the major casting defect among the many casting defects. Then the analysis is to be made to find the root cause of the particular defect. Moreover, it is especially difficult to identify the root causes of the defect. Therefore, a systematic method is required to identify the root cause of the defect among possible causes, consequently specific remedial measures have to be implemented to control them. This paper presents a systematic procedure to identify the root cause of shrinkage defect in an automobile body casting (SG 500/7 and control it by the application of Pareto chart and Ishikawa diagram. with quantitative Weightage. It was found that the root causes were larger volume section in the cope, insufficient feeding of riser and insufficient poured metal in the riser. The necessary remedial measures were taken and castings were reproduced. The shrinkage defect in the castings was completely eliminated.
The use of porcine corrosion casts for teaching human anatomy.
Eberlova, Lada; Liska, Vaclav; Mirka, Hynek; Tonar, Zbynek; Haviar, Stanislav; Svoboda, Milos; Benes, Jan; Palek, Richard; Emingr, Michal; Rosendorf, Jachym; Mik, Patrik; Leupen, Sarah; Lametschwandtner, Alois
In teaching and learning human anatomy, anatomical autopsy and prosected specimens have always been indispensable. However, alternative methods must often be used to demonstrate particularly delicate structures. Corrosion casting of porcine organs with Biodur E20® Plus is valuable for teaching and learning both gross anatomy and, uniquely, the micromorphology of cardiovascular, respiratory, digestive, and urogenital systems. Assessments of casts with a stereomicroscope and/or scanning electron microscope as well as highlighting cast structures using color coding help students to better understand how the structures that they have observed as two-dimensional images actually exist in three dimensions, and students found using the casts to be highly effective in their learning. Reconstructions of cast hollow structures from (micro-)computed tomography scans and videos facilitate detailed analyses of branching patterns and spatial arrangements in cast structures, aid in the understanding of clinically relevant structures and provide innovative visual aids. The casting protocol and teaching manual we offer can be adjusted to different technical capabilities and might also be found useful for veterinary or other biological science classes. Copyright © 2017 Elsevier GmbH. All rights reserved.
The structure of high-quality aluminium cast iron
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D. Kopyciński
Full Text Available In this study presents the analyse of aluminium iron cast structure (as-cast condition which are used in high temperature. While producing the casts of aluminium iron major influence has been preserve the structure of technological process parameters. The addition to Fe-C-Al alloy V, Ti, Cr leads to the improvement of functional and mechanical cast qualities. In this study, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a aluminium cast iron structure and thus improve the production process. V and Ti additions in aluminium cast iron allows to development of FeAl - VC or TiC alloys. In particular, V or Ti contents above 5 wt.% were found to totally eliminate the presence of Al4C3. In addition, preliminary work indicates that the alloy with the FeAl - VC or TiC structure reveals high oxidation resistance. The introduction of 5 wt.% chromium to aluminium cast iron strengthened Al4C3 precipitate. Thus, the resultant alloy can be considered an intermetallic FeAl matrix strengthened by VC and TiC or modified Al4C3 reinforcements.
Development of a thin steel strip casting process. Final report
Energy Technology Data Exchange (ETDEWEB)
Williams, R.S.
This is a comprehensive effort to develop direct strip casting to the point where a pilot scale program for casting carbon steel strip could be initiated. All important aspects of the technology were being investigated, however the program was terminated early due to a change in the business strategy of the primary contractor, Armco Inc. (focus to be directed at specialty steels, not low carbon steel). At termination, the project was on target on all milestones and under budget. Major part was casting of strip at the experiment casting facility. A new caster, capable of producing direct cast strip of up to 12 in. wide in heats of 1000 and 3000 lb, was used. A total of 81 1000-1200 lb heats were cast as well as one test heat of 3000 lb. Most produced strip of from 0.016 to 0.085 in. thick. Process reliability was excellent for short casting times; quality was generally poor from modern hot strip mill standards, but the practices necessary for good surface quality were identified.