text:
The authors acknowledge financial assistance from the Australian Research Council and the Department of Education, Science and Training, and thank Derby Voon for research assistance and two anonymous referees for comments. Opinions expressed are those of the authors, and should not be attributed to either the sponsoring agencies or the University of Western Australia.
Participation in Higher Education: Equity and Access?*
Version of Record online: 18 MAY 2005
DOI: 10.1111/j.1475-4932.2005.00240.x
Economic Record
Volume 81, Issue 253, pages 152–165, June 2005
Additional Information
How to Cite
LE, A. T. and MILLER, P. W. (2005), Participation in Higher Education: Equity and Access?. Economic Record, 81: 152–165. doi: 10.1111/j.1475-4932.2005.00240.x
- *
Publication History
- Issue online: 18 MAY 2005
- Version of Record online: 18 MAY 2005
- Abstract
- References
- Cited By
The conventional wisdom in Australia is that policy aimed at reducing imbalances in the representation of different socioeconomic classes in the tertiary sector should be aimed at encouraging completion of high school. The analyses in this paper suggest, however, that most of the differences in the socioeconomic mix of tertiary students are due to different propensities of high school graduates to pursue tertiary studies. The relatively low rate of university participation among rural students, however, needs to be addressed by encouraging the completion of high school.


text:
STARmeterSEE RANK
Up 273,236 this week
Daniele Dublino (I)
Daniele Dublino was born on July 1, 1945 in Rome, Lazio, Italy. He is an actor, known for San Michele aveva un gallo (1972), The Scopone Game (1972) and The Killer Nun (1979). See full bio »
Born:in Rome, Lazio, Italy

subset: commoncrawl


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Death Notice & Guest Book Preview for Nellie M. Coons
Published in The Wichita Eagle on Apr. 19, 2012
First 25 of 214 words
: Coons, Nellie M., 89, passed away Wednesday, April 18, 2012. Visitation 6-8 p.m. Thursday, April 19, 2012, at the D.W. Newcomer's Sons Overland Park Chapel....
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Neiman Marcus breach hits 19,000 Bay Staters
The credit and debit card information of more than 19,000 Massachusetts residents was among the data accessed by hackers who breached Neiman Marcus Group's point-of-sales system.
The number likely is greater because the luxury retailer doesn't have the addresses for about 31 percent of the owners of the 1.1 million cards possibly compromised during the breach from last July 16 through Oct. 30, the company divulged in a letter to the state Office of Consumer Affairs and Business Regulation this week.
Of the approximately 2,400 payment cards that already have been used for fraudulent transactions, 47 of them belong to Massachusetts residents, Neiman's general counsel said in the Jan. 25 letter. That number also could grow, because Neiman has the addresses of just 71 percent of those card-holders.
The letter also revealed that while the malware that allowed hackers to collect, or "scrape," customer card data was installed on the company's system as early as last July, separate, related malware that enabled the scraping to occur "appears to have been clandestinely inserted earlier in 2013."


text:
Oct 05 -
Summary analysis -- Kingfisher PLC -------------------------------- 05-Oct-2012
CREDIT RATING: BBB-/Positive/A-3 Country: United Kingdom
Primary SIC: Miscellaneous
retail stores,
Mult. CUSIP6: 495724
Credit Rating History:
Local currency Foreign currency
15-Jan-2007 BBB-/A-3 BBB-/A-3
19-Sep-2006 BBB/A-3 BBB/A-3
The ratings on U.K.-headquartered home improvement retailer Kingfisher PLC reflect Standard & Poor's Ratings Services' view of the group's "satisfactory" business risk profile. Our assessment is underpinned by the group's strong portfolio of brands, resilient operating performance over recent years, and position as Europe's largest home improvement retailer and the third-largest in the world.
Our top photos from the past 24 hours. Full Coverage
Reuters special election issue
The key to understanding what's going on lies not with personalities, campaign strategies or party rules but rather with the voter. PDF Document
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Patents & Entrepreneurial Universities
Measuring and evaluating academic innovation


text: tag:blogger.com,1999:blog-1346912071602587127.post7399775505310615816..comments2015-07-13T08:19:06.844-07:00Comments on Bleed Black and Purple: Arco Arena erupts in home openerBlake Ellingtonhttp://email@example.com:blogger.com,1999:blog-1346912071602587127.post-56252604433392441142010-11-02T23:25:40.278-07:002010-11-02T23:25:40.278-07:00reke passed it to casspi not benoreke passed it to casspi not firstname.lastname@example.com:blogger.com,1999:blog-1346912071602587127.post-24301160468077057592010-11-02T21:06:10.661-07:002010-11-02T21:06:10.661-07:00I'm a big fan of letting players play through ...I'm a big fan of letting players play through foul trouble. They may have to sit and they may continue to play. By bringing them out prematurely you are ensuring that they will sit. Plus it is better to place the refs in a position where they have to decide whether to foul a player out. I cringe when a player finishes the game with four fouls after having sat with foul trouble early in the game.Jacobhttp://firstname.lastname@example.com


text:
|Publication number
|Publication type
|Publication date
|Jul 6, 1971
|Filing date
|Oct 27, 1969
|Priority date
|Oct 27, 1969
|Publication number
|Carden Douglas D
|Original Assignee
|Air Reduction
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (3), Referenced by (15), Classifications (6)
|External Links: USPTO, USPTO Assignment, Espacenet
[56] References Cited UNITED STATES PATENTS 2,785,923 3/1957 Hickman...................... 239/307 2,869,188 l/l959 Cameto........................ 239/338 X 3,206,175 9/1965 Boteler......................... 239/338 X Primary Examiner-Lloyd L. King Assistant Examiner-John J. Love Attorneys-H. Hume Mathews, Edmund W. Bopp, Larry R.
Cassett and Roger M. Rathoun ABSTRACT: A mechanical nebulizer having a first reservoir for containing bulk use fluid for nebulization and a second reservoir for containing a medicament whereby the medicament may be selectively and independently supplied for nebulizatien and wherein circulation of fluid is provided during nebulization of either the bulk fluid or the medicament.
I United States Patent Inventor DouglasD.Carden Bameveld,wis. Appl. No, 869,518 Filed Oct. 27, 1969 Patented July6,l97l Assignee Air Reduction Company New York, N.Y.
7 Claims, 5 Drawing Figs.
PMENIEU JUL am 3.591.' 090 |EN'roR D. GARDEN ATTORNEY NEBULIZER BACKGROUND OF TH E INVENTION The present invention relates to apparatus for the creation and administration of a fine aerosol mist, and more particularly, to a mechanical nebulizer having provision forseparately containing and dispensing a bulk use fluid such as water and a suitable medicament for therapeutic purposes.
Heretofore, various means of including the nebulization of medicaments have been used with aerosol dispensing apparatus. Among the known methods is the addition of a separate medicament container which selectively allows medicament to enter into an atomized mist to vthereafter be carried to the patient. Such containers were, however, generally small in size, were costly to include with a nebulizer and failed to provide for recirculatory circuits whereby large droplets, collected during nebulization from the mist stream, could be returned to the medicament container for further circulation.
Other prior art apparatus for nebulization of a medicament include the direct introduction into the normally very large main reservoir of the various medicaments. Such large reservoirs are, however, not generally suitable for use with medica ments in that such medicaments are usually very expensive and administered in relatively small quantities. It is, therefore, necessary to nebulize the maximum amount of medication in order to avoid waste and also to most accurately apply a prescribed quantity of such medicament to a user. Large reservoirs therefore, generally failed to utilize the maximum amount of medicament and caused waste and uncertain distribution of small quantities of medication.
Accordingly, it is an object of the present invention to provide high output aerosol administering device of a compact and convenient arrangement having provision to administer a medicament. medication.
A further object of the invention is to provide a high output nebulizer construction which is capable of independently receiving and dispensing a relatively large quantity of a medicament for nebulization, yet which efficiently utilizes the maximum quantity of such medicament and thereby almost eliminates waste or unused mediation.
A still further object of the invention is to provide a high output nebulizer apparatus having means to independently receive and nebulize a quantity of medicament, and whereby large droplets of medicament which are collected from the mist are returned through a recirculating circuit to be reintroduced to the mist.
Another object of the invention is to provide a high output nebulizer having a large reservoir for retaining a suitable liquid to be nebulized, and a relatively small separable reservoir which may selectively be used to retain another desired liquid to be nebulized, thereby isolating the large reservoir from the nebulization stream during use of the small reservoir.
Other objects and advantages of the present invention will be better understood by reference to the following description of the preferred embodiment taken in connection with the attached drawings wherein:
FIG. l is a side view of a nebulizer constructed in accordance with the present invention;
FIG. 2 is a plan view ofthe nebulizer;
FIG. 3 is a vertical sectional view, partially broken away, taken along the lines 3-3 of FIG. 2;
FIG. 4 is an enlarged view, partially in section, showing the end ofan aspirating tube of the present invention; and
FIG. 5 is an enlarged view, partially in section, showing thc same aspirating tube arranged for receiving a medicament.
Referring now to FIGS. 1-3, there is shown a nebulizer having an outer casing l0 which may be ofa generally high impact strength plastic material. For convenience of assembly and disassembly, the casing l0 is constructed in separable parts, as shown, and comprises a lower housing l2 and an upper housing 14 which is adapted to fit over and be supported by the lower housing l2.
The lower housing l2 is so constructed such that the interior thereof forms a large reservoir for containing a liquid to be nebulized. In an actual construction, the total usable volume of the large reservoir I6 may be in the order of 2500 cc. and may be filled through a suitably located opening 18 in the upper housing I4, into which is retained a plug 20.
An air inlet means is associated with the casing 10 and comprises an upstanding cylindrical intake tube 22 which, if desired, may be provided with a filter, not shown, to remove particulate impurities from the surrounding air. A control valve 24 having an external operating knob 26 is provided to control the quantity of air admitted through the intake tube 22 and normally allows fairly precise control thereof.
An outlet means is also provided in association with casing l0 and is also of upstanding cylindrically shaped outlet tube 28 which allows distribution of an aerosol to the surrounding atmosphere.
Both the inlet tube 22 and the outlet tube 28 are of a predetermined internal diameter at their outer extremities in order to be connectable, if desired, to conventional sized tubing, conduit, or used with standard adapters for any other sized tubing. In this manner, the nebulizer may be readily connected to a utilization means such as an oxygen tent without further alteration and facilitates replacement of existing nebulizers.
An intermediate, relatively small medicament reservoir 30 is provided within the casing l0, and may conveniently be located having its upper peripheral edge associated with the upper housing I4 as shown in FIG. l. The medicament reservoir 30 is also preferably formed of a high impact strength v plastic. At the lowermost extremity of medicament reservoir 30 is an opening 32 which normally provides open communication of the medicament reservoir 30 with large reservoir 16, the purpose of which will be explained later.
The nebulizer 34 is provided adjacent the air inlet means and comprises an external inlet connection 36`of standard design and which is adapted to be connected to a high pressure source of fluid, such as oxygen or compressed air which typically may be from 30 to 50 p.s.i. As shown, the inlet connection 36 is rigidly affixed to the body of the air inlet tube 22 and communicates with a passageway to cylindrical jet member 38 having an orifice 40 therein. A nebulizer body 42 is provided including a tube 44 having one end of tube 44 in open communication with the cylindrical jet member 38 and the other end thereof in communication with a downwardly extending aspirating tube 48. The aspirating tube 48 is of a flexible material, such as silicone rubber, and extends through an opening 50 in the bottom wall of medicament reservoir 30 downwardly such that its end is freely suspended adjacent a circular depression 52 in the bottom of the large reservoir 16. A flanged shroud 54 seals the opening 50 in the medicament reservoir 30 against the aspirating tube 48, thereby preventing other liquids from leaking through the opening 50 into the large reservoir t6, the purpose of which will be later explained. A baffle 56 is provided opposite and in alignment with the orifice 40. As shown, this baffle 56 is a cylindricalshaped stub; however, it may be of any desired configuration including a spherically shaped surface.
At the lowermost end of aspirating tube 48, there is in` cluded a filter 58 for eliminating undesirable impurities from the nebulizing liquid prior to its introduction into aspirating tube 48. In the preferred embodiment, as shown in FIG. 4, this filter 58 is removable from the aspirating tube 48 and may easily be made removable by a force ft between an inwardly tapered internal surface of the filter 58 and a complementary tapered external surface of fitting 60 attached tothe aspirating tube 48.
In the operation of the high output nebulizer of the present invention, high pressure air or oxygen is introduced into external inlet connection 36 and thereby through the cylindrical jet member 38 and emerges through orifice 40. As this gas flows through orifice 40, it creates a suction pressure acting through the tube 44 which causes fluid to thereby be drawn from the large reservoir 16, through the aspirating tube 48. The fluid is therefore drawn into the flow of high pressure air or oxygen and emerges from the orifice 40 in the form of a mist. Large droplets, generally undesirable for internally breathed aerosols, are ca'used to be impinged against baffle 56 and are allowed to drain downwardly and are collected in the medicament reservoir 30. This collected fluid is prevented from following the aspirating tube 48 through opening 50 in the medicament reservoir by means of the flanged shroud 54. The medicament reservoir 30 allows the collected fluid to. drain normally through the opening 32 into the large reservoir 16, thereupon creating a recirculation circuit for collected fluid.
Further large droplets may be collected as the aerosol mist passes through the medicament reservoir and exits through the outlet means through deposition of such droplets along the internal surface of the passageways, and again, these collected droplets will ultimately be returned to the large reservoir 16.
ln this manner, the unit functions as a high output nebulizer, taking outside atmosphere in through the inlet means and causing a fine aerosol mist to be exhausted through the outlet means. The aerosol fluid is withdrawn from the large reservoir and any large droplets that are collected and removed from the aerosol stream are eventually returned to the large reservoir.
ln order to dispense a medicament in the nebulized stream, means are provided to interrupt the normally open communication between the medicament reservoir 30 and the large reservoir 16 and also to allow the introduction of medicament only into the nebulizer to be dispersed in atomized form.
Such means are provided through the use of flexible aspirating tube 48 which is adapted to be affixed in operative position in the opening 32 in the base of the medicament reservoir 30. As shown in FIG. 3 by the broken lines, and in FlG. 5, this junction may be accomplished by removal of the filter 58 which, as previously explained, is held to the end of aspirating tube 48 through a force fit to tapered fitting 60. After the removal of filter 58, the aspirating tube 48 is force fitted into the opening 32 which is tapered to accept tapered fitting 60 in a closer fitted junction. The loss of filter 58 is not detrimental to the function of the nebulizer due to the fact that only a medicament will now be drawn through aspirating tube 48 as there is very little impurity in medicaments, therefore rendering a filter as unnecessary.
A suitable medicament may now be introduced into medicament reservoir 30 and, as shown, may be poured in through the outlet tube 28 which is in direct communication with medicament reservoir.
ln operation the medicament is thereupon withdrawn through sump opening 32 by the aspirating tube 48 to be nebulized in normal manner by the nebulizer 34, the mist produced leaving the apparatus through the outlet means.
Again, a recirculating circuit s provided for large droplets which are collected from the mist as they impinge against baffle 56 or are removed through deposition on the surface of passageways leading tothe outlet means.
The collected fluid is caused to drain back into the medicament reservoir 30 and is retained there for further nebulization. As noted, the collected fluid is not allowed to drain through to the large reservoir 16 since the opening 32 has been closed through introduction of fitting 60 and no further communication is allowed between the medicament reservoir 30 and the large reservoir 16.
Due primarily to the small size of the medicament reservoir 30 and the location of the opening 32 in the lowermost location in the bottom of reservoir 30, the medicament may be almost entirely nebulized. ln actual practice, a unit having a medicament reservoir 30 of a fluid capacity of about 150 cc. has been found to nebulize the fluid contained therein to all but 3 to 4 cc. of fluid, thus achieving almost complete nebulization of fluid such as an expensive medicament and also providing extremely accurate application of a prescribed dosage.
Thus, the construction of the apparatus provides a normally high output nebulizer having a means to dispense almost completely and independently a desired medicament easily and efficiently whenever desired, and therefore further' provides a highly advantageous compact unit for use in separately administering a normal nebulization mist and a nebulized medicament mist.
While a preferred embodiment of this invention has been shown and described herein, it will be understood that other modifications thereof will readily occur to those skilled in the art and that the invention is intended to be limited only to the appended claims and to equivalent structure thereto.
l. A nebulizer apparatus comprising a casing, inlet means and outlet means associated with said casing, nebulizer means adapted to produce a mist upon introduction of a fluid thereto, first and second fluid reservoirs associated with said casing, said first and second fluid reservoirs being normally in open communication with each other, tube means for normally withdrawing fluid from said first fluid reservoir to supply a first fluid to said nebulizer means, and means to block communication between first and second reservoirs whereby said tube meansl withdraws fluid from said second reservoir for supplying a second fluid to said nebulizer means.
2. A nebulizer apparatus as set forth in claim l further including means to collect and return excess first fluid droplets from the mist to said first fluid reservoir;
3. A nebulizer apparatus as set forth in claim 2, further including means to collect and return excess second fluid droplets from the mist to said second fluid reservoir.
4. A nebulizer apparatus of claim 1 wherein said tube means comprises a downwardly extending flexible tube normally terminating adjacent the lowermost area of said first fluid reservoir.
5. A nebulizer apparatus of claim 4, said flexible tube being adapted to be removed from association with said first fluid and rcpositioned to withdraw a second fluid within said second fluid reservoir, and wherein said flexible tube thereby blocks fluid communication between said second fluid reservoir and said first fluid reservoir.
6. A high output nebulizer apparatus comprising an outer casing, inlet means and outlet means associated with said casing, a first fluid reservoir and a second fluid reservoir within said casing, nebulizer means disposed intermediate said inlet means and said outlet means for producing a mist upon the introduction of a fluid thereto from said respective reservoirs, means for effectively and independently introducing a first fluid and a second fluid to said nebulizer means, and means to collect and return excess droplets of first and second fluid from the mist to said respective first and second reservoirs.
7. A nebulizer apparatus comprising a casing, inlet and outlet means associated with said casing, nebulizer means located intermediate said inlet and outlet means, said nebulizer means being adapted to produce a mist upon introduction of a fluid thereto, first and second fluid reservoirs within said casing for containing, respectively, a first and a second fluid, and means communicating with said nebulizer means for selectively and independently supplying fluid from either of said first and second fluid reservoirs whereby a mist may be produced having as a constituent either of the first or second fluids.
|Cited Patent
|Filing date
|Publication date
|Feb 18, 1955
|Mar 19, 1957
|Hickman Earl L
|Jun 6, 1950
|Jan 20, 1959
|Misto2 Gen Equipment Co
|Medicinal inhalant atomization
|Apr 18, 1960
|Sep 14, 1965
|Puritan Compressed Gas Corp
|Citing Patent
|Filing date
|Publication date
|Apr 5, 1976
|Sep 20, 1977
|Sobol Jacob M
|Jan 3, 1980
|Nov 10, 1981
|Haekkinen Taisto
|Apparatus for atomizing medicaments
|Jul 1, 1983
|Jan 28, 1986
|Plantorgan Werk Heinrich G. E. Christensen Kg
|Vapor inhalation device
|Jul 16, 1991
|Nov 24, 1992
|Small Jr John C
|Accuvent aerosol delivery system
|Jun 7, 1995
|Dec 17, 1996
|Salter Labs
|Breathing circuit apparatus for a nebulizer
|Jun 26, 2002
|Dec 17, 2013
|Profile Drug Delivery Limited
|Nebulizer metering chamber
|Jun 15, 2010
|Feb 2, 2016
|Basf Se
|Foam composition
|Jun 26, 2002
|Aug 7, 2003
|Profile Drug Delivery Limited
|Nebulizer metering chamber
|Jul 30, 2004
|Feb 2, 2006
|Elder Stewart T
|Encapsulated fluorescent whitening compositions for improved surface appearance
|Nov 2, 2010
|May 12, 2011
|Padilla Jesus N
|Timer for nebulizer compressor
|Oct 27, 2008
|May 26, 2011
|Ian Stuart Biggin
|Heat storage compositions and their manufacture
|Oct 19, 1999
|Dec 2, 2008
|Profile Respiratory Systems Limited
|Nov 15, 2011
|Ric Investments, Llc
|May 20, 2010
|Dec 9, 2010
|Basf Se
|Wall form units and systems
|Jun 15, 2010
|Jan 6, 2011
|Basf Se
|Foam composition
|U.S. Classification
|239/305, 239/307, 239/338
|International Classification
|Cooperative Classification
|European Classification


text:
Sugarloaf Lodge is actually on Sugarloaf Key. It doesn't look fancy on the outside. However, once you step into the lobby, you know it is a nice place. Very cute room with tropical mural on wall, very large Western King bed which was comfy with fridge right on the water. One note: room did not have a blow dryer or iron in it although the front desk may have had them avail? We had the downstairs room by the Tiki Bar and it still was quiet. Nice patio with chairs. We sunned on the slope right outside our room overlooking the water on the lounges provided (many avail) and we saw iguanas and pelicans right by the boat dock. The tiki bar is a local hang out and the drinks are dirt cheap. Music there too! They also have a pool. It is about 20 mi from Key West. We normally stay in Key West, but after staying here, Key West is too busy. We will return!
- Official Description (provided by the hotel):
- Sugarloaf Logde is a family run, 31 unit waterfront resort in the Florida Keys 13 miles from Key West. All of our rooms face the water with sunset views and if you have a boat you can park it behind your room. The lodge has a Tiki Bar, marina, pool, tennis courts, and airstrip. Unfortunately, we do not allow pets but we are perfect for families, kayakers and flats fisherman. A fifteen minute drive from all that Key West has to offer without the crowds and high prices. ... more less
- Reservation Options:
- TripAdvisor is proud to partner with Booking.com, Orbitz, Priceline, Hotwire, Expedia, Odigeo, Travelocity and Hotels.com so you can book your Sugarloaf Lodge reservations with confidence. We help millions of travelers each month to find the perfect hotel for both vacation and business trips, always with the best discounts and special offers.
- Also Known As:
- Sugarloaf Hotel Summerland Key


text:
Kris Radish is the bestselling author of four novels, The Elegant Gathering of White Snows, Dancing Naked at the Edge of Dawn, Annie Freeman's Fabulous Traveling Funeral, and The Sunday List of Dreams. She lives in Wisconsin, where she writes two nationally syndicated columns each week and is at work on her sixth novel, The Poetry of Emma's Salvation.
"Kris Radish sings the praises of sisterhood by creating an enticing world of women helping women to become the empowered individuals they were meant to be."—Booklist


text:
Republicans Want Guns In Schools But Not At Their National Convention
CREDIT: AP Photo/Jacquelyn Martin
In response to an epidemic of gun violence in America, Republicans reject any effort to control gun use. The solution, instead, is more guns.
"The only thing that can stop a bad guy with a gun is a good guy with a gun," the expression goes. It's available as a t-shirt from the NRA.
CREDIT: nrastore.com
One idea that is subject to particular derision is the idea of "gun-free zones." Instead of creating safe spaces, Republicans argue, gun-free zones just create attractive targets for criminals.
Here is Donald Trump deriding the idea at a rally earlier this month:
So it might come as some surprise that this year's Republican National Convention in Cleveland will completely bans guns. The event will be held at the Quicken Loans Arena where "firearms and other weapons of any kind are strictly forbidden." (Guns were banned at the 2012 Republican National Convention as well.)
At lot of people are trying to change that. More than 29,000 people have signed a petition demanding Republicans "allow open carry of firearms" during the convention.
CREDIT: Change.org
It's unclear if the person who started the petition really wants people to bring guns to the convention or is just trying to make a point — although it appears to be the latter. Many of the signatories, undoubtedly, are just trolling.
Ultimately, it won't matter. Security at the convention is controlled by the Secret Service. There is no evidence that gun-free zones provide an attractive target for mass shooters. Since the Secret Service is charged with protecting the safety of the candidates, not right-wing ideology, expect guns to remain banned.


text:
Co-Sourcing Improves Pharmaceutical Laboratory Productivity
Loss of Lives in Clinical Trials...
Keep the Opportunities, Lose the Opportunists
From our August issue: Clinical-Style Validation,...
I can always appreciate a website with a clever logo—such as the Genetic Alliance's DNA strand in which people substitute for the base pairs. And when the rest of the site delivers, well, that just makes my day. Genetic Alliance is a nonprofit health advocacy group that provides resources about health in general, but with a specific emphasis on genetic disorders. The disease info search provides links to disease-specific resources, categorized into five groups: organizations, arts and literature, clinical description, research, and general information. Unfortunately, though, some of the entries are bare. In addition to the large number of links provided through the infosearch and organization search options, Genetic Alliance also has an entirely separate "resource repository" containing a wealth of information for the global health community.
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*The opinions expressed are solely those of the author(s) and should not be construed as reflecting the viewpoints of the publisher, Genetic Engineering & Biotechnology News, Mary Ann Liebert, Inc., the publishing house, or employees and affiliates thereof.
MDMA (commonly known as the empathogen "ecstasy") is classified as a Schedule 1 drug, which is reserved for compounds with no accepted medical use and a high abuse potential. Two researchers from Stanford, however, call for a rigorous scientific exploration of MDMA's effects to identify precisely how the drug works, the data from which could be used to develop therapeutic compounds.Do you agree that ecstasy should be studied for its potential therapeutic benefits?
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text:
From Publishers Weekly
Copyright © Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.
This book is a must-read for those interested in educational or labor history.(Historian)
A thoroughly researched and engaging biography.(Arch Puddington The Wall Street Journal)
[A] fascinating biography.(Sol Stern City Journal)
At once exquisitely complex and grandly contextual.(Martin Peretz The New Republic)
A well-drawn portrait.(Scott McLemee Newsday)
Judicious and engaging.(Fred Siegel Weekly Standard)
[A] timely new biography.(Sara Mosle Slate)
An engaging book, and essential reading for anyone interested in the history of Cold War liberalism and its complicated legacy.(Scott McLemee Inside Higher Ed)
An excellent new biography.(Jal Mehta American Prospect)
A must read for unionists, educators, politicians and democracy internationalists trying to make sense of the persistent failings of U.S. education.(Eugenia Kemble Democratiya)
A spirited and readable biography.(Adam Fairclough Washington Post)
Named one of the American School Board Journal's must-reads of the year.(American School Board Journal)
[This book] is an important contribution to the history of American education reform.(Nathan Glazer Education Next)
An important new biography.(The Politico)
A must-read for those interested in educational or labor history.(Historian)


text:
Quick Care, located conveniently inside HyVee grocery stores throughout the metro, offers walk-in medical care.
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Something that a football club's board will say to the media about their coach 2-4 weeks before firing him.
Despite having gone 3-22 this season, Coach Furner has the full support of the board.
po Timbo Јул 6, 2010
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by Delirium619, published
Thing Info
Dante's main weapon from the games Devil May Cry 3 and 4. Initally made in zBrush then cleaned up in Maya.
I still need to tweak it a but more but when it is ready, I will make a stl file available to produce it in a physical form.
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i hope you make this thing ready to download soon .. thank you very much for giving us hope ^^
Are you going to upload the slt file?
A friend of mine wants the sword for a cosplay and you are de only one who has uploaded something about.
Thank you a lot!
I actually hacked this thing together quickly for a college assignment, I can definitely take the file, make it water tight and actually printable soon.
Can you share the model? I want to print the sword. shaileshprabhu at yahoo dot com
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1886-S $5 -- Obv Scratched -- NGC Details. UNC. NGC Census: (300/6435). PCGS Population (269/3098). Mintage: 3,268,000. Num...Click the image to load the highest resolution version.
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Description1886-S $5 -- Obv Scratched -- NGC Details. UNC. NGC Census: (300/6435). PCGS Population (269/3098). Mintage: 3,268,000. Numismedia Wsl. Price for problem free NGC/PCGS coin in MS60: $445. (#8370)(Registry values: P2) (NGC ID# 25XV, PCGS# 8370)
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The way i see religion
Channel: atheism
The way i see religious people is the same as i see a puppy with a squeaking bone. It takes its liking to it for what it associates with it, not what it is. It enjoys the bone because it's narrow mind is convincing it its real. It's leader says it's great, what other explanation would there be than that the bone is magnificent, why else would everyone make such a big fuzz out of it? it does not think of, nor care about what it really is, it is loved for what everyone makes of it. it follows it blindly, and is ready to give up a fight just for the idea of it.


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Jones to Shutter Toledo-Designed Anne Klein Collection
Jones Apparel Group is saying goodbye to the Anne Klein designer collection and its creative director, Isabel Toledo. On Tuesday, the apparel conglomerate said it was pulling the plug on the collection after just two seasons.
From This Issue
Higher Profile
Turbulent Times
Fashion Scoops: Deacon and Diego… Moving Pictures… A Sticky Web…
It's no secret that Gilles Deacon has been on Diego Della Valle's radar for months now. First, industry sources said the Italian owner of the Tod's, Hogan and Fay labels wanted the British designer for his Schiaparelli Collection.


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|Publication number
|Publication type
|Application number
|Publication date
|Jul 26, 1988
|Filing date
|Apr 23, 1986
|Priority date
|Apr 30, 1984
|Fee status
|Publication number
|David Farrar, John R. Field, Peter Flesher, Tony Whittaker
|Original Assignee
|Allied Colloids, Ltd.
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (14), Referenced by (27), Classifications (32), Legal Events (5)
|External Links: USPTO, USPTO Assignment, Espacenet
This application is a continuation-in-part of application Ser. No. 728,782 filed Apr. 30, 1985.
When synthetic polymers of water soluble monomers or monomer blends were first introduced as flocculants, in the early to mid-1950's, maximum molecular weights were relatively low compared to the present day. The initial polymers typically had molecular weights well below 500,000 and thus were of a value comparable to the molecular weight now associated with coagulants, rather than high molecular weight flocculants. These low molecular weights were probably caused by the presence of chain transfer agents and other impurities in the monomer or polymerisation mixture.
It was recognised that the polymers had to be in solution and if the polymers were not, despite their low molecular weight, spontaneously soluble in water (for instance due to excessive cross linking) it was appreciated to be necessary to homogenise them so as to put them into solution. For instance Miller described in U.S. Pat. No. 3,021,269 ultrasonic degradation of a highly cross linked insoluble polymer gel "having almost infinite molecular weight" to render it water soluble as a result of severing the polymeric structure. The end products were always of relatively low molecular weight and the highest quoted molecular weight for the end product is 630,000 and the highest intrinsic viscosity (IV) 2.54 dl/g.
Similarly, Goren described in a 1954 patent application (published as U.S. Pat. No. 3,235,490) dispersing various polymer gels into water using a Waring Blendor. Many of the gels were cross linked spontaneously or by the addition of cross linking agent and the cross linking appears to have caused the formation of some wholly insoluble, non-swellable, polymer that settled out of solution. Solutions of the polymers were also subjected to homogenisation in a hand homogeniser and it was observed that the effect on agglomeration performance of this homogenisation is drastic, with most of the products being useless after homogenisation. Again, all the polymers were of very low molecular weight as is indicated by the fact that the highest specific viscosity (measured by a capillary flow viscometer at 34� C. on a 0.5% solution in deionised water) is quoted as 0.77. This compares to values of well over 100, and usually over 1000, for modern high molecular weight flocculants.
Some polymers having molecular weights typical of those described by Miller and Goren can be used as coagulants, for instance for coagulating very fine suspended solids, e.g., for clearing turbidity or removing colour from aqueous solutions. For instance typical modern polymer coagulants have a molecular weight of up to about 500,000. Typical polymer coagulants may be formed by reaction of epichlorhydrin with dimethylamine. Since the resultant linear product may have extremely low molecular weight, it is known to include ethylene diamine in order to increase molecular weight by cross linking without rendering the polymer insoluble.
Goren postulated that agglomeration involved electrostatic attraction followed by a sweeping action of a filamentary network of the cross linked polymer. This mechanism has come to be recognised as the classical mechanism of coagulating turbidity and colour, namely very fine suspended solids. Goren made his polymer by bulk polymerisation followed by comminution and showed that his aqueous compositions tended to be non-homogeneous, in that there was a tendency for insoluble polymer to precipitate from the solution. Goren warned against cross linking too much and indicated that the optimum was the level at which the polymer is still readily dispersible in water. Since Goren was postulating a sweeping action by filamentary molecular networks this indicates that his dispersibility had to be on a molecular scale, i.e., true solution. Goren warned that the agglomerating effect of the polymer can be destroyed by homogenising it (column 13 line 74).
In contrast to these low molecular weight polymer coagulants, modern flocculants (for flocculating suspended solids such as sewage) are linear polymers of very high molecular weight. Most have an intrinsic viscosity above 4 and often above 10. The polymers have to be linear since cross linking renders them ineffective and often insoluble, although trivial amounts of cross linking may exist without detracting from the polymer properties (see for instance U.S. Pat. No. 3,557,061 column 3 line 35).
Whether or not a high molecular weight polymer is suitable for use as a flocculant is determined in part by observing the rheology of aqueous compositions of the polymer. Satisfactory polymers give a "long" or "stringy" rheology. This is recognised in the art and can be demonstrated in that when a 1% stable homogeneous composition of the polymer in deionised water is formed by conventional techniques, such as by stirring using a slowly rotating stirrer followed by ageing, and a glass rod is manually pulled endwise out of the solution the rod draws a long thread of composition with it. The thread is generally at least 5 cm long and the polymer can then be described as having a rheology of 5 cm. Often the rheology is above 10 cm. If, in contrast to this, the polymer gives a "short" or "granular" rheology (i.e., in the above test the rod pulls substantially no thread, for instance below 5 cm and often below 2 cm, of composition) the polymer will be rejected and will not be used as a flocculant. Experience has shown that polymers giving this short rheology are unsatisfactory in conventional flocculation processes since it indicates a high degree of cross-linking and/or a low molecular weight. The short polymers can also be characterised as non-film forming, in that when an aqueous composition is dried it does not form a film.
Similarly, the polymer is rejected if it has a large particle size and is cross linked sufficient to ensure that insoluble solid polymer does not go into stable suspension in the aqueous composition.
The stable homogeneous composition is stable in the sense that the polymer is in full equilibrium with the water, i.e., it has reached its ultimate degree of solution or swelling, for instance as a result of ageing for two hours or more. It is homogeneous in the sense that the polymer remains uniformly dispersed throughout the composition (usually in the total absence of dispersing agent although minor amounts may be present as a result of the manufacture of the polymer) with no tendency for material to precipitate from the composition on standing for a few days.
The unsuitability as flocculants of short rheology polymers (as defined above) and of polymers that do not go into stable suspension or solution are well understood in the art. Very high molecular weight, linear, truly dissolved, polymers are preferred.
Certain high molecular weight polymers, for instance polymers of Mannich bases, have a tendency to cross link spontaneously and acquire a rather short or very short rheology or become totally insoluble. It frequently happens that high molecular weight polymers are produced which have rheology that is shorter than is desirable. Polymers of very short rheology (below 2 cm), or that are insoluble, are rejected. Polymers with longer, but still rather poor, rheology may be used under the same conditions as if they had the desired long rheology but this leads to poor performance properties.
Polymers for use as flocculants are often supplied as powders or as dispersions in water-immiscible liquid and these polymers are converted to an aqueous solution by adding the powder or dispersion to water with initial agitation to promote distribution throughout the water, and then leaving the mixture to age for, for instance, an hour or more. During the ageing process low levels of agitation may be applied.
The need to avoid shearing the polymer is well established and is described in, for instance, Katzer U.S. Pat. No. 3,468,322. In EP 0102759, high shear is applied but it is said to be essential that it is applied for only a very short time (much less than 1 second) and so the shear does not have any effect on the structure of the polymer.
Flocculant polymer may alternatively be supplied as a concentrated solution, in which event it may be diluted to form the desired dilute solution by stirring with water, again using low levels of agitation.
Once the polymer has reached equilibrium with the water is it accepted that it must not be subjected to vigorous agitation, since it has been believed that this will damage the properties of the solution.
Many flocculation processes involve little or no agitation during the flocculation. For instance the flocculant solution may be added with gentle stirring to the suspension that is to be flocculated and the mix then allowed to stand. If flocculation is one step of a multi-stage process including steps which involve vigorous agitation, it is normal to add the flocculant after these earlier agitation steps, so as to avoid damaging the floc. For instance when the polymer is being used as a retention or dewatering aid in the production of paper the flocculant solution is generally added to the stock immediately prior to the screen through which the pulp is dewatered by drainage. In some dewatering processes, such as centrifugal dewatering, shear is inevitably applied during the dewatering stage but extra agitation or shear before dewatering is avoided.
It is therefore well established in the art of high molecular weight flocculant polymers that shear should not be applied to the polymers or flocs that are formed. If it is found that a polymer does not dissolve spontaneously into water by conventional techniques, for instance involving gentle stirring, then conventional practice is to reject the polymer as unsuitable for use as a flocculant. For instance, no attempt is ever made to modify the rheology of the polymer. If after reaching equilibrium with the water the solution of the polymer is shorter than normal, then either the polymer is used in that state or, if the rheology is too short, the polymer is rejected.
In our European patent application No. 85302925.4 (not published at the priority date of this application), we describe the surprising discovery that improved flocculation performance can be obtained from a solution of a polymeric flocculant if that solution is subjected to shear before use. We explain that the shear may result in reduction of the range of molecular weights within the solution and/or reduction in the intrinsic viscosity of the polymer within the solution and/or an increase in the measured ionicity of the polymer in the solution. Thus the shear could, and frequently did, result in reduction in intrinsic viscosity (and therefore of molecular weight) but the performance properties are improved because of other changes, notably a reduction in the range of molecular weights within the solution. This reduction in intrinsic viscosity is consistent with accepted thinking that the application of shear to a high molecular weight polymer will reduce molecular weight and intrinsic viscosity, for instance by breaking the linear chains.
It would be desirable to be able to improve the performance properties of polymers that have been accidentally or deliberately cross linked to a short rheology and/or to an intrinsic viscosity that is lower than is desired.
When using linear polymers having long rheology, the resultant flocs tend to be unstable to shear and/or performance is very dose sensitive. It would be desirable to be able to obtain flocs of higher shear resistance, especially by a process that is not so sensitive to dosage.
A flocculation process according to the invention is one in which a polymeric material is added to water to form an aqueous composition and is used to flocculate the suspended solids of an aqueous suspension, the polymeric material is a high molecular weight polymeric material formed from a water soluble monomer or blend of monomers, and the polymeric material is subjected to shear and the process is characterised in that the shearing is applied before or during flocculation and the polymeric material comprises cross linked water swellable polymer that can be sheared to an intrinsic viscosity of at least 4 dl/g and the aqueous composition of the polymeric material (a) is or can be a stable homogeneous composition and the shearing causes an increase in intrinsic viscosity of at least 1 dl/g and/or (b) includes non-dispersible, insoluble, polymer and the shearing converts it to a stable homogeneous aqueous composition.
The invention is based on the surprising discovery that it is easily possible to shear very high molecular weight cross linked polymer formed from water soluble monomer or monomer blend without reducing intrinsic viscosity and producing a low molecular weight product. Indeed IV can easily be increased by at least 1 dl/g and often more. This is directly contrary to the teachings of Miller and Goren who both had polymers in which the chain length was too short. In the invention, the chain length must be such that IV either is above 4 dl/g after the shearing or can be raised to above 4 dl/g by further shearing.
The process can involve converting a wholly insoluble polymer, that will not form a stable homogeneous aqueous composition on gentle stirring and ageing (because of excessive cross linking) and that is therefore non-dispersible in water, into a stable homogeneous aqueous composition. The IV of the insoluble polymer cannot be measured but the shearing generally results in a final IV of above 4 and/or results in IV increasing by at least 1 dl/g after the polymer is put into a stable homogeneous aqueous composition and before shearing is terminated.
Preferably the process of the invention involves shearing an aqueous stable homogeneous composition to cause an increase of at least 1 dl/g in IV. The composition may be formed by shearing insoluble polymer as discussed above or may be formed by shearing an aqueous composition that is not a stable homogeneous composition (for instance because it has not aged sufficiently) even though the polymer can form such a composition upon ageing and/or gentle stirring.
The polymeric material that is used to form the composition includes cross linked polymeric material that will swell in water and may also include polymeric material that is soluble in water, for instance being a blend of soluble polymer with swellable, insoluble, polymer. Any soluble material is generally present in a minor amount (below 50%) and often below 20% of total polymer.
In the process of the invention the polymeric material is generally such that if it is put in the form of a stable aqueous homogeneous composition of a concentration of 1% by weight in deionised water then this composition will generally have a rheology of below 2 cm and generally below 1 cm, i.e., it will be very short, and will usually be non-film forming.
A dried coating of the aqueous composition before the shearing will contain, and may consist substantially only of, discrete polymer particles.
After the shearings the polymer will usually have long (above 5 and usually above 10 cm) rheology and may be wholly soluble in water and may be wholly film forming.
During the process of the invention the polymeric material is subjected to shearing, preferably before flocculation. The final intrinsic viscosity can vary widely from, for instance, 2 up to 6, 10 or much higher. The polymeric material can, before the shearing, have IV above 4, in which event the shearing will cause IV to rise to a higher value above 4, or it can have an IV below 4 and the final IV typically is above 6. Even if the shearing does not result in the polymeric material having a final IV of above 4, the polymeric material must be such that shearing the polymeric material can increase IV to a value above 4. For instance even though the process may convert an insoluble polymer to a swellable polymer of IV 3 or may cause the IV of a swellable polymer to increase from, for instance, 2 to 3.5, the polymeric material must be such that further shearing could have lifted the IV to above 4.
The process of the invention can give very good flocculation performance even though the IV of the polymeric material and/or the rheology of the initial polymeric material (1% composition below 2 cm) and/or the solubility is such that the polymeric material would previously have been rejected as useless. It seems probable that the shearing is breaking cross links, so as to increase the proportion of soluble polymer, without significantly breaking chain lengths, and that the increase in IV follows from this increased proportion of truly soluble polymer.
Throughout this specification IV is measured at 25� C. in 3M NaCl according to the method described in Encyclopedia of Polymer Science and Technology, Editors Mark and Gaylord, published John Wiley & Sons, 1971, Volume 14, pages 717 to 740. If it is necessary, but difficult, to measure IV in a sheared flocculated suspension then the IV that is considered is the IV determined after subjecting the polymer to the same shearing conditions as the suspension (e.g., the same centrifuge at the same rotational velocity) at the same concentration as in the suspension but in the absence of suspended or flocculated solids.
One principal advantage of the invention therefore is that it permits the conversion of a cross linked polymer that would normally have been rejected or that would have been expected to have given poor flocculation properties to a form in which it will give very good flocculation properties. These properties are generally at least as good as the properties of a comparable polymer having the same final rheology and IV but which had been made by dissolving a truly linear polymer instead of a cross linked polymer followed by shearing. The process of the invention thus permits use of compositions that have been spontaneously or accidentally cross linked to a state at which they would previously have been considered unsatisfactory.
It is usually preferred for the intrinsic viscosity of the polymeric material to be increased by subjecting an aqueous composition of the polymeric material to the shear and then adding this aqueous composition to the suspension.
The shear may be applied by subjecting the composition to the effect of fast moving blades, for instance blades having a velocity of at least 500 meters per minute, typically 750 to 5,000 meters per minute. If the blades rotate, then these velocities are the peripheral velocities of the blades. It is particularly preferred to use blades that rotate at high speed, generally above 2,000 rpm preferably 3,000 to 20,000 rpm. Suitable apparatus for this is the Waring Blendor or apparatus similar to large scale versions of kitchen blenders such as the Moulinex, Kenwood, Hamilton Beach, Iona or Osterizer blenders.
Another suitable method of applying shear is by forcing the composition by impellers through a screen, for instance as in a Silverson mixer or other mixer having a similar method of operation. For instance, there may be an impeller 4 to 10 cm in diameter rotating at 1500 to 6000 rpm to force the solution under high shear through a screen. Preferably a Silverson 120L mixer is used and has a square hole high shear screen and an impellor of 6.8 cm diameter rotating at 3000 rpm.
True homogenisers, in which a liquid is forced through a very small gap while subjected to a very fast chopping action, may apply too much shear and may result in substantial reduction of IV. Similarly if shear is applied for too long, it may eventually cause a decrease in IV. The shear must be such that the IV is increased by the process, generally to a value above 4.
The duration of the application of shear will depend upon the amount of shear that is being applied and methods that apply lower amounts of shear will require longer durations of shear in order to raise IV and/or convert the rheology to the desired long rheology.
The aqueous composition is generally made by mixing dry or aqueous gel particles of the polymer with water. These particles may be dry gel particles formed by gel polymerisation followed by comminution and drying and may have particle sizes up to, for instance, 3 mm, preferably not more than 1200 microns, and compositions of these should preferably be sheared before use in order to form a true solution. Preferably however the particles have a dry particle size of below 10 μm, preferably below 2 μm and have been made by reverse phase polymerization or emulsion polymerisation. Emulsion polymerisation is suitable for monomers, such as certain amino monomers, which are soluble only in acidic water. These fine particles may be introduced suspended in the liquid medium in which they are made and may then be dry or aqueous gel particles or they may be dry powder, preferably agglomerated into pellets to reduce dusting.
The shear can be applied while the particles of the short rheology polymeric material are still dissolving (i.e., going into equilibrium with) dilution water and so the formation of the composition and the conversion of the rheology may be conducted simultaneously. Preferably however the shear is applied to a preformed stable homogeneous composition (as defined above), i.e., after the short rheology polymeric material has gone into equilibrium with the water. Typically this requires an ageing period of at least 30 minutes, often 1 to 5 hours and most usually about 2 hours. During ageing, the composition may be static or may be subjected to agitation, often gentle stirring.
The amount of polymeric material in the solution is generally below 3% by weight as otherwise the viscosity of the solution may be unacceptably high, at least at the end of the shearing.
If the composition is more concentrated than is desired for addition to the aqueous suspension, it may be diluted after shearing.
The sheared composition is generally added to the aqueous suspension in amounts and by techniques that are conventional for linear high molecular weight flocculants and the flocculation process may be conducted in conventional manner. Generally there is little or no agitation of the suspension during the addition of the polymer and during flocculation, as is conventional. The flocculated solids are generally removed by dewatering. Dewatering can be effected under shear, for instance on a centrifuge, filter press or belt press but it is often preferred for the suspension to be dewatered substantially without shear. For instance dewatering may be by sedimentation or by filtration, for instance under vacuum or low pressure. Dewatering substantially without shear is of particular value when substantially all the shear is applied before adding the polymeric material to the suspension and the polymeric material, when added to the suspension, has IV above 6. If the sheared polymer still has significant cross linking at the time when it is added to the suspension (e.g., absolute ionic regain, defined below, above 20% or 30%), the flocculation is preferably conducted under shear, as described in more detail below, but this shear need not cause a further rise in IV.
The aqueous medium that is sheared can be the suspension that is to be flocculated. Thus instead of or in addition to increasing IV by shearing the composition before addition to the suspension, it is also possible to apply some or all of the shear, that is required to increase IV, to the suspension after addition of the polymeric material. In general, when the polymeric material that is added to the suspension still contains a substantial degree of cross linking it is desirable to subject the suspension to shear after addition of the polymeric material. For instance when the polymeric material has rather low IV, typically IV below 4, at the time of addition to the suspension it is generally desirable to shear the suspension and this shearing preferably is sufficient to increase IV to above 6.
Accordingly, in the invention some or, less preferably, all of the shear necessary to achieve the desired rheology and/or IV can be applied after addition to the suspension. Thus a composition of cross linked polymer having short rheology can be formed by stirring in conventional manner (e.g., as described above), but without the application of significant shear, and this composition can then be added to the suspension and the suspension can then be subjected to shear sufficient to convert the polymer to the desired rheology and/or the desired IV.
Shear that is applied to a suspension to which the cross linked polymeric material has been added, either with or without prior shearing, can be applied by apparatus such as is used for applying shear to the polymer composition or can be applied as part of the flocculation process. For instance the suspension containing the added polymer may be passed through a high speed mixer, for instance in line to the final dewatering step. For instance in the production of paper and board the cross linked polymer may be added at an early stage in the pulp flow line so that the act of pumping the flocculated dispersion along the flow line towards the drainage or other dewatering stage involves the application of shear to the flocculated pulp. Alternatively, the suspension may be sheared in line as it approaches a centrifuge, filter press or belt press or other dewatering stage.
The shear may be applied during a dewatering process that is conducted under shear, preferably a centrifugal dewatering stage but alternatively a filter press or belt press dewatering stage.
The shear may also be applied solely or partly by prolonged agitation of the flocculated suspension, for instance as the suspension is transported along a pipe or held in a reaction vessel. For instance the suspension can be a flocculated catalyst, for instance it can be a copper catalyst in an acrylonitrile hydrolysis reaction medium for the production of acrylamide.
Processes in which shear is applied to the suspension after adding cross linked polymer can have certain process advantages. The flocs tend to have higher floc strength than is normally obtainable with truly linear flocculants and so can be sheared to a smaller, stable, size substantially without redispersion of the solids. The flocs tend to be larger than with conventional linear flocculants. The optimum dose can best be determined by ascertaining the dose that gives largest floc size and using this dose �50%, preferably �20%.
Although higher dosages of the polymer are generally required, the risk of overdosing the suspension is generally reduced as the suspension is more tolerant of a wide range of doses. Similarly, satisfactory results can be achieved even if the quality of the suspension changes, for instance due to variable metal content.
Particular processes in which a cross linked polymer is added to a suspension to cause flocculation and the suspension containing the polymer is subjected to shear are described in our application Ser. No. 855,509 filed even date herewith.
Various methods of measuring the ionicity of a polymer are known. When the polymer is cationic, an anionic test reagent is normally used and when the polymer is anionic, a cationic reagent is normally used. For instance the ionicity of a cationic polymer can be determined by the method described in BP No. 1,579,007 or can be measured by Colloid Titration as described by Koch-Light Laboratories Limited in their publication 4/77KLCD-1. If the polymer has a measurable ionicity value, the shearing that is applied to the polymer is preferably such that the ionicity of the polymer undergoes a regain of at least 15%, preferably at least 30% and usually at least 50% as a result of the shearing. The regain is calculated as (X-Y)/X�100 where X is the ionicity after the shearing that is conducted in the process of the invention and Y is the ionicity of the unsheared polymer.
If the polymer has measurable ionicity when applying a standard, constant, shear, the absolute ionic regain (IR) calculated on the same formula (except that X is the ionicity after shearing to a substantially constant ionicity) can be determined. Preferably the polymer has, before shear, an absolute IR value of at least 40% and usually above 60%. After the shearing of the invention, it preferably has an absolute IR value below 10% if flocculation is to be performed without shear but may have a selected higher value, e.g., 25 to 70%, if flocculation is to be performed with shear.
The absolute IR value is determined by forming a 1% solution of the polymer in deionised water, allowing this to age for 2 hours and then further diluting it to 0.1% active polymer. The ionicity of the polymer before shearing Y is measured and the ionicity X is then determined by measuring ionicity by the same technique but after subjecting the solution to a standard degree of shear.
The shear for this test is best applied to 200 ml of the solution in a substantially cylindrical pot having a diameter of about 8 cm and provided in its base with rotatable blade above 6 cm in diameter, one arm of the blade pointing upwards by about 45 degrees and the other downwards by about 45 degrees. The blade is about 1 mm thick and is rotated at 16,500 rpm in the base of the pot for a prolonged period. These conditions are best provided by the use of a Moulinex homogeniser but other satisfactory conditions can be provided using kitchen blenders such as Kenwood, Hamilton Beach, Iona or Osterizer blenders or a Waring Blendor.
In practice, when determining the absolute value IR of the polymer that is to be sheared the precise conditions of shear are relatively unimportant since, provided the degree of shear is of the same order of magnitude as specified, it will be found that IR is not greatly affected by quite large changes in the amount, for instance the duration, of shear, whereas at lower amounts of shear (for instance 1 minute at 16,500 rpm) IR is greatly affected by small changes in shear. Conveniently therefore the value of X is determined at the time when, with a high speed blade, further shear provides little or no further change in ionicity. This generally required shearing for 10 minutes, but sometimes longer periods, e.g., up to 30 minutes with cooling, may be desired.
The polymers for which ionicity values are best determined are dialkylaminoalkyl (meth) acrylate polymers (including acid addition and quaternary ammonium salts copolymerised with 0-95% acrylamide or other non-ionic monomers) and so these are one preferred class of polymers for use in the invention.
The polymers may, in general, be formed from any suitable water soluble monomer or monomer blend. The monomers may be non-ionic but generally part at least of the monomer used for forming the polymer is ionic. The monomers are normally monoethylenically unsaturated monomers, sometimes allyl monomers but generally vinyl monomers. They are generally acrylic (including methacrylic) monomers.
Suitable non-ionic monomers are acrylamide, methacrylamide, N-vinylmethylacetamide or formamide, vinyl acetate, vinyl pyrrolidone, methyl methacrylate or other acrylic (or other ethylenically unsaturated) ester or other water insoluble vinyl monomers such as styrene or acrylonitrile.
Suitable anionic monomers are sodium acrylate, methacrylate, itaconate, 2-acrylamido 2-methyl propane sulphonate, sulphopropylacrylate or methacrylate or other water soluble forms of these or other polymerisable carboxylic or sulphonic acids. Sulphomethylated acrylamide, allyl sulphonate, or sodium vinyl sulphonate may be used.
Suitable cationic monomers are dialkylaminoalkyl acrylates and methacrylates, especially dialkylaminoethyl acrylate, and their quaternary or acid salts, and dialkylaminoalkyl acrylamides or methacrylamides and their quaternary or acid salts, for instance methacrylamido-propyl trimethyl ammonium chloride and Mannich products such as quaternised dialkylaminomethyl acrylamides. Alkyl groups are generally C1-4 alkyl.
The monomers can contain hydrophobic groups, e.g., as described in EPO No. 172723A2 for instance on page 10. If the monomer is to impart insolubility to the polymer, the ethoxy chain should be short or absent, i.e., n=0. The allyl ether monomers are especially preferred.
Polymers made from pure monomers in the absence of cross linking agent will normally form polymers having a long rheology but if the monomers are contaminated with significant amounts of cross linking agent or if cross linking agent is added to the monomers or if the polymer is cross linked by, for instance, excessive heating during drying, such polymers may have a short rheology and are then suitable for use in the invention.
Cross linking may occur after polymerisation, for instance by reaction of two counterionic soluble polymers or by reaction with formaldehyde or a polyvalent metal compound. Often cross linking occurs during polymerisation due to the addition of cross linking agent, for instance to the polymerisation mixture. Added cross linking agents can include ionic cross linking agents such as polyvalent metal salts, formaldehyde, glyoxal or, preferably, covalent cross linking agents that will copolymerise with the monomers, preferably diethyleneically or polyethylenically unsaturated monomers of the type conventionally used for cross linking water soluble polymers, for instance methylene bis acrylamide or any of the other known acrylic cross linking agents. The amount of methylene bis acrylamide is generally below 100 ppm and equivalent amounts of other cross linking agents may be used.
The invention is of particular value when the polymer is a Mannich base polymer, preferably as the free base, thus being a dialkyl amino methyl (meth) acrylamide polymer. Mannich bases are notorious for spontaneously cross linking on storage for more than a few hours, especially when they are in relatively concentrated form, typically above 10 or 20% by weight polymer based on polymer plus water, or when they are dried to form a powder. For instance, an emulsion of gel particles of above 30% Mannich base with less than 70% water is usually considered unusable in conventional processes after one day's storage. Similarly, any attempt at removing all the water from the emulsion particles, or of making a dry polymer in some other way, generally renders the polymer unusable in conventional processes. By the invention, however, very effective flocculation performance can be achieved. The polymer can be sheared and then used in a low shear process or it can be used without prior treatment in a high shear flocculation process. The invention includes these processes even if IV is not observed or not increased during the process, and when operated using other high IR polymers instead of Mannich polymers.
The Mannich base units in the polymer may be copolymerised with other monomers, for instance acrylamide or other non-ionic or ionic monomer, in any desired proportions. The invention is also valuably applied to other polymers that are particularly liable to spontaneous cross linking including sulphomethylated polyacrylamides and polymers including units selected from
wherein R1 is hydrogen or methyl and each group R2 is C1-4 alkyl, usually methyl or ethyl and X is O or NH. Units of the formulae B and C are usually produced as glyoxal derivatives of polyacrylamides and so are usually copolymerised with acrylamide and optionally one or more other ethylenically unsaturated monomers. Polymers formed from units A are glycidyl derivatives of acrylamide or acrylic acid and are generally copolymerised with acrylamide and/or one or more other ethylenically unsaturated monomers. They are generally present as the quaternary ammonium salt formed with any suitable quaternising group such as methyl chloride or dimethyl sulphate.
The polymers may be made by any convenient polymerisation method including solution, gel, precipitation, emulsion or reverse phase polymerisation (either by emulsion or suspension kinetics).
The accompanying drawings are graphs of the results obtained in Example 3.
The following are some examples of the invention. In every instance, the polymer had a specific viscosity well above 100, with the un-cross linked polymers having specific viscosity above 1000. Every polymer, upon shearing to maximum IV, had IV above 4.
A range of copolymers of 42% w/w methyl chloride quaternised dimethylaminoethyl acrylate, 58% w/w acrylamide were prepared by gel polymerisation from substantially pure monomers and with various additions of methylene bisacrylamide (mba) as cross linker. They were then dried in air at a maximum temperature of about 40� C.
Each powdered product was dissolved in water with 2 hours mixing. Cationicity regain was measured applying standard shear, using the technique described above, and the sheared product had long rheology. The CST value was recorded at a dose of 60 g/m3 polymer on a digested primary activated sewage sludge after mixing the polymer for 25 seconds using a modified Triton stirrer timer type 131. CST was recorded for a 0.1% solution before any shearing and also for the 0.1% solution that had been subjected to the described standard shear. The results are shown in Table 1a.
TABLE 1a______________________________________ Cationicity Rheology CSTPro- Add Before After Re- Before Before Afterduct MBA Shear Shear gain Shear Shear Shear______________________________________1 0 ppm 1.46 1.52 4.3 long 130 1512 1 ppm 1.29 1.48 13.2 short 226 1693 2 ppm 0.78 1.46 46.4 short 276 1624 3 ppm 0.48 1.43 66.4 short 341 1665 5 ppm 0.42 1.45 71.2 short 449 163______________________________________
From Table 1a, it will be apparent that products 4 and 5, having totally unsatisfactory rheology by normal standards give very poor CST values without shearing but all the products after shearing give similar CST values that are similar to the value of the long rheology in cross linked product 1 before shearing. The IV of the products before shear was measured (for the soluble component) on the filtrate of an aqueous composition of the polymer, and the IV of the product after standard shear was measured on the product obtained by shearing the entire starting product (including insoluble component). The results are shown in Table 1b.
TABLE 1b______________________________________Product MBA IV before shear IV after shear______________________________________1 0 ppm 12.8 5.32 1 ppm 6.4 6.03 2 ppm 3.4 5.94 3 ppm 2.5 6.05 5 ppm 1.8 5.8______________________________________
This shows how standard shear reduces the IV of a truly soluble, linear polymer but increases the IV of the more cross linked polymers to about the same value.
A Mannich emulsion is made by mixing 133 parts of a dispersion of 53.2% active polyacrylamide in Pale Oil 150 containing emulsifier and dispersion stabiliser with 120 parts of Exsol (a trade mark of Exxon and indicating a D230/260 cut of a hydrocarbon oil), 10 parts of an amphipathic polymeric stabiliser, 75 parts of a 60% by weight dimethylamine solution, 75 parts of a 40% by weight formaldehyde solution together with 12 parts of emulsifier. The addition is conducted with vigorous stirring and reaction is left to go to equilibrium. The product is a 30% active emulsion of polyacrylamide Mannich free base dispersed in oil.
This emulsion was tested on day 1, its day of manufacture, and on sequential days thereafter. The tests consisted of using the emulsion to make a 1% solution. Part of the solution was used for CST tests on digested sewage sludge pH 6 and part was subjected to 10 minutes shear in an Iona blender, approximating to the standard shear conditions measured above.
Both the day 1 Mannich samples and all the sheared samples had rheology above 5 cm but the remaining unsheared Mannich samples had rheology below 2 cm.
The CST values were recorded at various dosages and mixing conditions and the average CST was calculated.
The commercial material Zetag 94 was used as a standard. "Zetag" is a trade mark of the Allied Colloids, Ltd. It had constant rheology, above 5 cm, throughout the experiment.
The CST results are given in Table 2a. Low values are preferred. The IV values before and after shearing and the IR values are given in Table 2b.
TABLE 2a______________________________________Product Day 1 Day 2 Day 3 Day 4 Day 5______________________________________Mannich (A) 61 173 303 404 592Sheared 59 41 53 111 191Mannich (B)Zetag 94 (C) 67 51 61 71 77______________________________________
TABLE 2b______________________________________ Day 1 Day 2 Day 3 Day 4 Day 5______________________________________IV Product A 10.1 4.1 2.3 1.9 1.4IV Product B 10.5 9.0 6.1 4.3 3.2IR Product A 12.3 59.9 62 57 43______________________________________
It is apparent that the Mannich emulsion changes adversely with storage and that the short rheology polymers are unsatisfactory but that the described shearing, to give long rheology, greatly restores the properties.
To determine the effectiveness in a flocculation process that is conducted under shear, flocculation performance is determined by visual observation on a laboratory centrifuge consisting of a cylindrical solid bowl closed at its base and open at its top but with an inwardly extending lip around its periphery. The bowl runs at 2,000 rpm and is, at this speed, filled with water (400 ml). Sewage sludge to which flocculant polymer solution has previously been added in conventional manner is fed at constant rate into the bowl while it is spinning. Some of the solid is trapped in the bowl whilst the remainder passes out in the overflow, as the centrate. Since the flocculated suspension is accelerated, in a very short period of time, to 2,000 rpm this centrifugal system of dewatering applies very high shear to the flocculated suspension. Best results are those wherein there is maximum retention of solids in the bowl, with least suspended solids content in the centrate.
The emulsions before and after shear obtained in Example 2 were subjected to this test, at various dosages. The floc size at various dosages was estimated on a scale of 1 to 10, 1 being the largest and the suspended solids in the centrate were recorded, all at various dosages of flocculant. The results are shown in the accompanying drawings.
In the accompanying drawings:
FIGS. 1A, 2A, 3A and 4A are graphs showing the relationship between dose (grams per cubic meter) and floc size (assessed on a scale of 1 to 7 where 1 is the largest) for the test samples A, B, C on, respectively, Day 1, Day 2, Day 3 and Day 4.
FIGS. 1B, 2B, 3B and 4B are graphs showing the relationship between dose (grams per cubic meter) and suspended solids (mg/1) in the centrate from the centrifuge for the test samples A, B, C on, respectively, Day 1, Day 2, Day 3 and Day 4.
The unsheared Day 1 sample A is less dose-sensitive than the standard C but slightly less efficient. The sheared sample B is less efficient. The unsheared Day 2 sample A is slightly more efficient than the standard C and is very dose tolerant. The unsheared Day 3 sample A gives greatly improved results compared to the standard C. The sheared sample B is slightly less effective than the standard C but very dose tolerant. The sheared and unsheared Day 4 samples A and B are both much more effective and dose tolerant than the standard C.
A range of anionic copolymers, having composition 40 wt% sodium acrylate, 60 wt% acrylamide, were prepared from monomer mix containing different amounts of methylene bis acrylamide, by reverse phase suspension polymerisation. The degree of cross linking incorporated into each copolymer increased in proportion to the amount of MBA in the monomer as indicated by depression of the intrinsic viscosity.
The above products were evaluated on coal fines in simulation of dewatering by belt filtration. This involved treating 400 cm3 portions of the coal fines with a solution of the flocculant followed by stirring for 120 seconds to apply shear and to induce flocculation. The stirring was by a Heidolph stirrer on setting 2 using a gate stirrer in a 600 cm3 beaker. The flocculated fines were then transferred to the belt press simulator and dewatered under the influence of pressure which was gradually increased to 1.6 bar. On completion of the dewatering cycle, the cake was removed for dry solids determination and calculation of the yield.
The MBA content, IV, results for cake solids and yield at the optimum dose established for each product are shown in Table 3.
TABLE 3______________________________________ OptimumPro- MBA content I.V. Dose Cake Solids Yieldduct (ppm of polymer) (dl/g) (mg/l) (%) (%)______________________________________AA 0 18.5 100 61.5 85.2BA 2.71 14.3 150 60.0 85.8CA 6.76 11.3 400 60.8 90.0DA 13.53 6.6 500 57.8 86.6EA 20.29 5.5 600 59.8 92.6FA 27.06 2.7 800 59.8 92.4GA 40.53 3.1 1200 58.6 93.7HA 67.60 -- 1600 59.1 89.4IA 135.30 -- 1600 59.7 84.9______________________________________
It can be seen that as the degree of cross linking increases, the general trend is for improvement in yield. Products HA and IA demonstrate decreasing yield either because they are too cross linked to be effective or the optimum dose has not been attained.
An emulsion in oil of polymeric particles below 2 μm in size is made by reverse phase polymerisation of a blend of 40% acrylamide and 60% MeCl diethylaminoethyl acrylate and methylene bis acrylamide in an amount sufficient to raise IR from near zero to between 35 and 40.
The emulsion is added to water with stirring and allowed to age to provide a stable composition. The rheology is very short, below 1 cm.
The composition is then added at a polymer dose of about 6 kg/t total solids to an aqueous suspension that is flowing towards a commercial sewage dewatering cetrifuge, the treated suspension is sheared in a Inline Mixer to reduce floc size without redispersing solids as discrete solids, and the sheared product is then dewatered in the centrifuge. The solids content of the centrate is typically below 0.2% (0% is ideal) and the degree of separation is above 98% (100% is ideal). When the process is repeated using un-cross linked polymer, the corresponding values are typically above 1% and below 75%.
The copolymers of 58% acrylamide and 42% dimethylaminoethyl acrylate quaternised with methyl chloride (DMAEA MeCl) and 5 and 12.5 ppm methylene bis acrylamide were prepared by reverse phase polymerisation to give a particle size below 2 μm followed by azeotropic distillation. The specific viscosities of the two polymers at 0.5% concentration in water at 35� C. were 750 and 3000 respectively.
0.1% aqueous solutions of the products were sheared using a Silverson Mixer Mold number L2R. The intrinsic viscosity (dl/g) of the polymers were measured as the shearing progressed. The results are shown in Table 6.
TABLE 6______________________________________ IV IVTime 5 ppm MBA 12.5 ppm MBA______________________________________ 0 mins 4.5 2.82 0.25 5.3 3.5 0.5 5.9 3.4 1.0 6.1 3.6 2.5 7.3 3.6 5.0 7.2 4.310.0 -- 5.0______________________________________
This clearly shows how IV increases as shearing proceeds.
A copolymer was made as in Example 6 except that the amount of MBA was 30 ppm. IV was 2.8 and IR 55. The reverse phase dispersion was mixed with water and aged, to give a stable 0.1% composition. This was sheared in a Waring Blendor until IV was 5 dl/g and IR was 21. This was then used as an effective flocculant for sewage sludge at a dose of 120 g/m3.
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|Filing date
|Publication date
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|Feb 15, 1966
|Kerr Mc Gee Oil Ind Inc
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|Apr 30, 1968
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|Method for polymer dilution
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|Process for rapidly dissolving water-soluble polymers
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|Mar 6, 1973
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|Method for clarifying titanium sulphate solutions
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|Process for the destabilization and separation of ilmenite (FEO TIO2) tailings
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|Jul 6, 1976
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|Jul 31, 2007
|Hercules Incorporated
|Anionic copolymers prepared in an inverse emulsion matrix and their use in preparing cellulosic fiber compositions
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|U.S. Classification
|210/734, 523/322, 162/168.2, 524/922, 210/738, 210/732, 162/168.3
|International Classification
|Cooperative Classification
|European Classification
|Apr 23, 1986
Owner name: ALLIED COLLOIDS LIMITED, P. O. BOX 38, LOW MOOR, B
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|Sep 30, 1991
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|Jan 16, 1996
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|Apr 23, 1999
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