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A semidetailed mechanism (137 species and 633 reactions) and new experiments in a homogeneous charge conic pression ignition (HCCI) engine on the autoignition of toluene reference fuels are presented. Skeletal mechanisms for isooctane and n-heptane were added to a detailed toluene submechanism. The model shows generally good agreement with ignition delay times measured in a shock tube and a rapid compression machine and is sensitive to changes in temperature, pressure, and mixture strength. The addition of reactions involving the formation and destruction of benzylperoxide radical was crucial to modeling toluene shock tube data. Laminar burning velocities for benzene and toluene were well predicted by the model after some revision of the high-temperature chemistry. Moreover, laminar burning velocities of a real gasoline at 353 and 500 K Could be predicted by the model using a toluene reference fuel as a surrogate. The model also captures the experimentally observed differences in combustion phasing of toluene/n-heptane mixtures, compared to a primary reference fuel of the same research octane number, in HCCI engines as the intake pressure and temperature are changed. For high intake pressures and low intake temperatures, a sensitivity analysis at the moment of maximum heat release rate shows that the consumption of phenoxy radicals is rate-limiting when a toluene/n-heptane fuel is used, which makes this fuel more resistant to autoignition than the primary reference fuel. Typical CPU times encountered in zero-dimensional calculations were on the order of seconds and minutes in laminar flame speed calculations. Cross reactions between benzylperoxy radicals and n-heptane improved the model prediction,,; of shock tube experiments for phi = 1.0 and temperatures lower than 800 K for an n-heptane/toluene fuel mixture, but cross reactions had no influence on HCCI Simulations.
The mechanism of a base-catalyzed one-pot reaction of 2-cyanobenzaldehyde and primary nitroalkanes, to produce 3-substituted isoindolinones, has been investigated. A route starting with a nitroaldol (Henry) reaction, followed by a subsequent cyclization and rearrangement, was supported by intermediate analogue synthesis and DFT calculations. Direct diastereoselective crystallization from the reaction mixture was also achieved and studied for a number of substrates. Furthermore, the 3-substituted isoindolinones are an interesting group of compounds, both present important natural products, as well as being precursors to other valuable building blocks.
Adsorption and desorption of methanol on the (111) and (100) surfaces of Cu2O have been studied using high-resolution photoelectron spectroscopy in the temperature range 120–620 K, in combination with density functional theorycalculations and sum frequency generation spectroscopy. The bare (100) surfaceexhibits a (3,0; 1,1) reconstruction but restructures during the adsorption process into a Cu-dimer geometry stabilized by methoxy and hydrogen binding in Cu-bridge sites. During the restructuring process, oxygen atoms from the bulk that can host hydrogen appear on the surface. Heating transforms methoxy to formaldehyde, but further dehydrogenation is limited by the stability of the surface and the limited access to surface oxygen. The (√3 × √3)R30°-reconstructed (111) surface is based on ordered surface oxygen and copper ions and vacancies, which offers a palette of adsorption and reaction sites. Already at 140 K, a mixed layer of methoxy, formaldehyde, and CHxOy is formed. Heating to room temperature leaves OCH and CHx. Thus both CH-bond breaking and CO-scission are active on this surface at low temperature. The higher ability to dehydrogenate methanol on (111) compared to (100) is explained by the multitude of adsorption sites and, in particular, the availability of surfaceoxygen.
Vertical excitation energies for the lowest eleven singlet states of T-d N-4 were calculated using the TD-DFT method with the B3LYP functional, and at the EOM-CCSD level of theory. The vertical excitation energies for the five lowest-lying excited states were also obtained using the state-averaged CASSCF, CASPT2, CASPT3, and MRCI + Q methods. Our results show that the five lowest-lying states are of valence character. EOM-CCSD/d-aug-cc-pVTZ calculations predict that there are two weakly allowed optical transitions of T-2 symmetry at 10.44 and 10.82 eV. The transition to the third T-2 state, which is predicted to be at 10.89 eV, has an oscillator strength about one order of magnitude higher.
The N-4 molecule in its triplet state has been studied using the DFT-B3LYP, CASSCF, and CCSD(T) computational methods. The previously reported C-s ((3)A ) minimum was not found to be stable using these methods. A D-2d ((3)A(1)) minimum was found to be the lowest energy triplet with a closed structure. This minimum is 20.2 kcal/mol higher in energy than T-d ((1)A(1)) N-4 at the CCSD(T)/cc-pVTZ//CCSD(T)/DZP level of theory. The barrier to dissociation has been estimated to ca. 7.5 kcal/mol from CAS(8,8)+MR-ACPF and CAS(8,8)+MR-AQCC calculations. CASSCF(12,12) calculations indicate that the open-chain N-4 Of C-2h (B-3(u)) symmetry is not stable. The open-chain C-s((3)A ) structure has been found to be a true minimum at all investigated levels of theory. It is 13.4 kcal/mol lower in energy than T-d ((1)A(1)) N-4 at the CCSD(T)/cc-pVTZ//CCSD(T)/DZP level.
The potential energy surfaces for the low-lying doublet states of the azide radical (N-3) have been computed at the complete active space self-consistent field (CASSCF) level with the CAS(15,12) active space. The cc-pVTZ and aug-cc-pVTZ basis sets have been employed throughout the present work. Energies, geometries and harmonic frequencies were determined for the N-3 linear ground electronic state ((2)Pi(g)), a stable C-2v ring structure (B-2(1)), and a C-s transition state ((2)A(')) connecting the ring and linear structures. Other N-3 (C-2v) stationary points ((2)A(2), B-2(1), and (2)A(1)) have been characterized, as well. The vertical excitation energies for the doublet excited states of the N-3 linear ((2)Pi(g)) and stable ring (B-2(1)) isomers were calculated using CASSCF and multireference configuration interaction [MRCI-SD(Q)] methods. A new route to tetraazatetrahedrane [N-4(T-d)] has been proposed on the N-4 singlet potential energy surface within C-s symmetry. MRCI-SD(Q) calculations predict that N-4 (T-d) can be formed from atomic nitrogen in the D-2 state and N-3 (C-2v, B-2(1)) in a barrierless exothermic reaction. The energy difference (D-0) is 135.4 kcal/mol at the MRCI-SD(Q) level.
The dissociation pathway of D-2h N-4 has been investigated at the CASSCF level of theory. A new C-2v transition state to dissociation was found and characterized on the potential energy surface. The effective barrier of dissociation from D-2h N-4 to 2N(2) is estimated to 6.5 kcal/mol from MR-AQCCNTZ//CAS(12,12)/VTZ calculations. Vertical excitation energies and oscillator strengths for the lowest 20 singlet states of D-2h N-4 have been calculated using the EOM-CCSD method. The geometry of the first excited state B-1(3u), considered as the lowest optically accessible state, has been optimized and characterized at various computational levels. This state might be useful for detection of D-2h N-4 by means of laser-induced fluorescence (LIF) spectroscopy.
The binding of zinc (Zn) ions to proteins is important for many cellular events. The theoretical and computational description of this binding (as well as that of other transition metals) is a challenging task. In this paper the binding of the Zn ion to four cysteine residues in the structural site of horse liver alcohol dehydrogenase (HLADH) is studied using a synthetic peptide mimic of this site. The study includes experimental measurements of binding constants, classical free energy calculations from molecular dynamics (MD) simulations and quantum mechanical (QM) electron structure calculations. The classical MD results account for interactions at the molecular level and reproduce the absolute binding energy and the hydration free energy of the Zn ion with an accuracy of about 10%. This is insufficient to obtain correct free energy differences. QM correction terms were calculated from density functional theory (DFT) on small clusters of atoms to include electronic polarisation of the closest waters and covalent contributions to the Zn-S coordination bond. This results in reasonably good agreement with the experimentally measured binding constants and Zn ion hydration free energies in agreement with published experimental values. The study also includes the replacement of one cysteine residue to an alanine. Simulations as well as experiments showed only a small effect of this upon the binding free energy. A detailed analysis indicate that the sulfur is replaced by three water molecules, thereby changing the coordination number of Zn from four (as in the original peptide) to six (as in water).
A Ser105Ala mutant of Candida antarctica lipase B has previously been shown to catalyze aldol additions. Quantum chemical calculations predicted a reaction rate similar to that of natural enzymes, whereas experiments showed a much lower reaction rate. Molecular dynamics simulations, presented here, show that the low reaction rate is a consequence of the low frequencies of near attack complexes in the enzyme. Equilibrium was also considered as a reason for the slow product formation, but could be excluded by performing a sequential reaction to push the reaction towards product formation. In this paper, further experimental results are also presented, highlighting the importance of the entire active site for catalysis.
Enzymes are efficient catalysts in synthetic chemistry, and their catalytic activity with unnatural substrates in organic reaction media is an area attracting much attention. Protein engineering has opened the possibility to change the reaction specificity of enzymes and allow for new reactions to take place in their active sites. We have used this strategy on the well-studied active-site scaffold offered by the serine hydrolase Candida antarctica lipase B (CALB, EC 126.96.36.199) to achieve catalytic activity for aldol reactions. The catalytic reaction was studied in detail by means of quantum chemical calculations in model systems. The predictions from the quantum chemical calculations were then challenged by experiments. Consequently, Ser105 in CALB was targeted by site-directed mutagenesis to create enzyme variants lacking the nucleophilic feature of the active site. The experiments clearly showed an increased reaction rate when the aldol reaction was catalyzed by the mutant enzymes as compared to the wild-type lipase. We expect that the new catalytic activity, harbored in the stable protein scaffold of the lipase, will allow aldol additions of substrates, which cannot be reached by traditional aldolases
Since the end of the 20th century it has been increasingly realised that the use, or production, of many energetic materials leads to the release of substances which are harmful to both humans and the environment. To address this, the principles of green chemistry can be applied to the design of new products and their manufacturing processes, to create green energetic materials that are virtually free of environmental hazards and toxicity issues during manufacturing, storage, use and disposal. Active research is underway to develop new ingredients and formulations, green synthetic methods and non-polluting manufacturing processes. Green Energetic Materials provides a detailed account of the most recent research and developments in the field, including green pyrotechnics, explosives and propellants. From theoretical modelling and design of new materials, to the development of sustainable manufacturing processes, this book addresses materials already on the production line, as well as considering future developments in this evolving field. Topics covered include: • Theoretical design of green energetic materials • Development of green pyrotechnics • Green primary and secondary explosives • Oxidisers and binder materials for green propellants • Environmentally sustainable manufacturing technologies for energetic materials • Electrochemical methods for synthesis of energetic materials and waste remediation Green Energetic Materials is a valuable resource for academic, industrial and governmental researchers working on the development of energetic materials, for both military and civilian applications.
This chapter begins with a short summary of the history of energetic materials. It is emphasized that developments generally have been driven by the objectives of improving performance and safety of handling. In addition to these objectives, new materials should also be green. This requirement is considered in relation to green chemistry and other tools for improving the sustainability of new products. A definition of a green energetic materials from the principles of green chemistry is presented. The chapter goes on to analyze past and present attempts to introduce green propulsion technologies to civil space travel. This analysis shows that the development of a green propellant system and its associated engine system is a lengthy and expensive process. The chances of succeeding seem to largely depend on the size of the engine system.
The solvation of substituted phenylsulfenium ions and thiophenoxides in acetonitrile has been analyzed on the basis of experimental and theoretical data. Experimental solvation energies are obtained from previously reported oxidation and reduction potentials of the corresponding arylthiyl radicals in combination with theoretically calculated ionization potentials and electron affinities at the B3LYP/6-31+G(d) level. These calculations provide a consistent set of values in contrast to the data sets obtained in our previous paper (Larsen et al., J. Am. Chem. Soc. 2001, 123, 1723). The extracted solvation data show the expected substituent dependency for both kinds of ions, i.e., the absolute value of the solvation energy decreases as the charge becomes more delocalized. For the thiophenoxides there is good agreement between the experimental solvation energies and solvation energies computed using the polarizable continuum model (PCM). The solvation of the arylsulfenium ions, is much stronger than predicted by the PCM method. This can be attributed to the formation of a strong covalent bond of the Ritter type between the arylsulfenium ion and one molecule of acetonitrile. When this interaction is included in the solvation energy calculations by means of a combined supermolecule and PCM approach the experimental data are reproduced within a few kcal mol(-1). While the energy difference of the singlet and triplet spin states of the arylsulfenium ions is almost negligible in gas phase, the singlet cation is undoubtedly the dominating species in solution, since the triplet cation lacks the ability to form a covalent bond with acetonitrile.
A new local property, the local electron attachment energy [E(r)], is introduced and is demonstrated to, be a useful guide to predict intermolecular interactions and chemical reactivity. The E(r) is analogous to the average local ionization energy but indicates susceptibility toward interactions with nucleophiles rather than electrophiles. The functional form E(r) is motivated based on Janak's theorem and the piecewise linear energy dependence of electron addition to atomic and molecular systems. Within the generalized Kohn-Sham method (GKS-DFT), only the virtual orbitals with negative eigenvalues contribute to E(r). In the, present study, E(r) has been computed from orbitals obtained from GKS-DFT computations with a hybrid exchange correlation functional. It is shown that E(r) computed on a molecular isodengty surface, E-S(r), reflects the regioselectivity and relative reactivity for nucleophilic aromatic substitution, nucleophilic addition to activated double bonds, and formation of halogen bonds. Good to excellent correlations between experimental or theoretical measures of interaction strengths and minima in E-S(r) (E-S,E-min) are demonstrated.
We have recently shown that the anti-HIV activities of reverse transcriptase inhibitors can be related quantitatively to properties of the electrostatic potentials on their molecular surfaces. We now introduce the technique of using only segments of the drug molecules in developing such expressions. If an improved correlation is obtained for a given family of compounds, it would suggest that the segment being used plays a key role in the interaction. We demonstrate the procedure for three groups of drugs, two acting on reverse transcriptase and one on HIV protease. Segmental analysis is found to be definitely beneficial in one case, less markedly so in another, and to have a negative effect in the third. The last result indicates that major portions of the molecular surfaces are involved in the interactions and that the entire molecules need to be considered, in contrast to the first two examples, in which certain segments appear to be of primary importance. This initial exploratory study shows that segmental analysis can provide insight into the nature of the process being investigated, as well as possibly enhancing the predictive capability.
The solvation of carbanions in the solvents N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) has been analyzed on the basis of experimental and theoretical data. Experimental solvation energies are obtained from present and previously reported electrochemical measurements of reduction potentials of the corresponding radicals. Theoretical solvation energies are obtained from quantum chemical calculations using the polarizable continuum model (PCM). It is found that the solvation energy is relatively independent of molecular size and structure for the saturated carbanions. This indicates that the negative charge is strongly localized to the anionic carbon. The conjugated carbanions have considerably lower absolute solvation energies (\ DeltaG degrees (sol)\) than the saturated carbanions. This is a consequence of the strong delocalization of the negative charge in the former group. The propargyl anion is also found to have a surprisingly low absolute solvation energy. However, high-level quantum chemical calculations show that the electronic structure has large contributions from two different resonance structures, CH=CCH2- and -CH=C=CH2, which results in a significant charge delocalization. There is good agreement between calculated and experimental solvation energies for both the conjugated and nonconjugated primary anions. However, the PCM method consistently underestimates the absolute solvation energies of the secondary and tertiary carbanions. This is attributed to an insufficient treatment of first-layer solvation effects in the method. According to the experimental measurements, the absolute solvation energies are on average 2-3 kcal mol(-1) lower in THF than in DMF. The theoretical data indicate a considerably larger solvent effect, 7-10 kcal mol(-1). The discrepancy between theory and experiment may partly be attributed to the use of a supporting electrolyte in the measurements, but the main cause seems to be that the short-range interaction tendencies of the solvent cannot be Fully characterized by its dielectric constant.
A series of 20 halogen bonded complexes of the types R-Br center dot center dot center dot Br- (R is a substituted methyl group) and R '-CC-Br center dot center dot center dot Br- are investigated at the M06-2X/6-311+G(d,p) level of theory. Computations using a point-charge (PC) model, in which Br- is represented by a point charge in the electronic Hamiltonian, show that the halogen bond energy within this set of complexes is completely described by the interaction energy (E-PC) of the point charge. This is demonstrated by an excellent linear correlation between the quantum chemical interaction energy and E-PC with a slope of 0.88, a zero intercept, and a correlation coefficient of R-2=0.9995. Rigorous separation of E-PC into electrostatics and polarization shows the high importance of polarization for the strength of the halogen bond. Within the data set, the electrostatic interaction energy varies between 4 and-18kcal mol(-1), whereas the polarization energy varies between -4 and-10kcal mol(-1). The electrostatic interaction energy is correlated to the sum of the electron-withdrawing capacities of the substituents. The polarization energy generally decreases with increasing polarizability of the substituents, and polarization is mediated by the covalent bonds. The lower (more favorable) E-PC of CBr4---Br- compared to CF3Br center dot center dot center dot Br- is found to be determined by polarization as the electrostatic contribution is more favorable for CF3Br center dot center dot center dot Br-. The results of this study demonstrate that the halogen bond can be described accurately by electrostatics and polarization without any need to consider charge transfer.
The objective of this chapter is to illustrate the use of modern quantum chemical methods in the rational design of energetic materials with targeted properties. In the first part we discuss the methods that are used for prediction of thermochemical data, and for analysis of decomposition pathways and kinetic stabilities of new compounds. We also describe how quantum chemical methods can be used for predicting spectroscopic data, synthesis pathways, and performance characteristics of energetic materials. In the remaining part of the chapter we provide examples of the theoretical characterization of a number of compounds with promising properties for use in green propellants. Two of these, 1-nitro-2-oxo-3-amino-triazene and tetraazatetrahedrane, combine high kinetic stabilities with excellent propulsion performance.
The current status of the molecular surface property approach (MSPA) and its application for analysis and prediction of intermolecular interactions, including chemical reactivity, are reviewed. The MSPA allows for identification and characterization of all potential interaction sites of a molecule or nanoparticle by the computation of one or more molecular properties on an electronic isodensity surface. A wide range of interactions can be analyzed by three properties, which are well-defined within Kohn-Sham density functional theory. These are the electrostatic potential, the average local ionization energy, and the local electron attachment energy. The latter two do not only reflect the electrostatic contribution to a chemical interaction, but also the contributions from polarization and charge transfer. It is demonstrated that the MSPA has a high predictive capacity for non-covalent interactions, for example, hydrogen and halogen bonding, as well as organic substitution and addition reactions. The latter results open u p applications within drug design and medicinal chemistry. The application of MSPA has recently been extended to nanoparticles and extended surfaces of metals and metal oxides. In particular, nanostructural effects on the catalytic properties of noble metals are rationalized. The potential for using MSPA in rational design of heterogeneous catalysts is discussed.
We describe a procedure for performing quantitative analyses of fields f(r) on molecular surfaces, including statistical quantities and locating and evaluating their local extrema. Our approach avoids the need for explicit mathematical representation of the surface and can be implemented easily in existing graphical software, as it is based on the very popular representation of a surface as collection of polygons. We discuss applications involving the volumes, surface areas and molecular surface electrostatic potentials, and local ionization energies of a group of 11 molecules.
The reaction between disulfides and phosphines generates a reversible disulfide metathesis process.
The pH-dependent mutarotation of 1-thioaldopyranoses in aqueous media has been investigated. Anomerization readily occurred at lower and neutral pH for all aldopyranoses studied, whereas mainly for (2S)-D-aldopyranoses at higher pH. 1-Thio-D-mannopyranose and 1-thio-D-altropyranose showed very strong pH dependence where the anomeric equilibrium ratios changed dramatically from a preference for the beta-anomer at lower pH to the alpha-anomer at higher pH.
The mechanisms for the uncatalyzed and boron trifluoride (BF3) assisted Baeyer-Villiger reactions between acetone and hydrogen peroxide have been investigated using high level ab initio [MP2 and CCSD(T)] and density functional theory (B3LYP) methods. Both steps in the uncatalyzed reaction are found to have very high transition state energies. It is clear that detectable amounts of the Crieege intermediate or the products cannot be formed without the aid of a catalyst. The main function of BF3 in both the addition step and the rearrangement (migration) step is to facilitate proton transfer. In the addition step the complexation of hydrogen peroxide with BF3 leads to an increased acidity of the attacking OH group, while in the rearrangement step BF3 takes active part in the proton-transfer process. This latter step is found to be rate determining with an activation free energy of 17.7 kcal/mol in organic solution. The products of the reaction are BF2OH, hydrogen fluoride, and methyl acetate. Thus, BF3 is not directly regenerated from the reaction.
The mechanism and potential energy surface for the Baeyer-Villiger oxidation of acetone with hydrogen peroxide catalyzed by a Ser105-Ala mutant of Candida antarctica Lipase B has been determined using ab initio and density functional theories. Initial substrate binding has been studied using an automated docking procedure and molecular dynamics simulations. Substrates were found to bind to the active site of the mutant. The activation energy for the first step of the reaction, the nucleophilic attack of hydrogen peroxide on the carbonyl carbon of hydrogen peroxide, was calculated to be 4.4 kcal mol(-1) at the B3LYP/6-31+G* level. The second step, involving the migration of the alkyl group, was found to be the rate-determining step with a computed activation energy of 19.9 kcal mol(-1) relative the reactant complex. Both steps were found to be lowered considerably in the reaction catalyzed by the mutated lipase, compared to the uncatalyzed reaction. The first step was lowered by 36.0 kcal mol(-1) and the second step by 19.5 kcal mol(-1). The second step of the reaction, the rearrangement step, has a high barrier of 27.7 kcal mol(-1) relative to the Criegee intermediate. This could lead to an accumulation of the intermediate. It is not clear whether this result is an artifact of the computational procedure, or an indication that further mutations of the active site are required.
Amination of halobenzenes, which proceeds via the benzyne intermediate (1), has been studied using quantum chemical methods. The computational data are in agreement with experimentally observed trends in reactivity and provide a qualitative explanation for the observed hydrogen isotope effects. To investigate if this is a viable way to isolate the pentazolate anion (2), the reactivities of the halobenzenes have been compared to phenylpentazole (3). The reaction energetics for phenylpentazole become favorable after complexation with Zn2+.
The stability of phenylpentazole along with para-substituted and ortho,para-substituted arylpentazoles have been studied using high-level density functional theory (DFT). The decomposition of arylpentazoles to N-2 and the corresponding azide is a first-order reaction, where the breaking of the N1-N2 bond is concomitant with cleavage of the N3-N4 bond. Calculations confirm that the stability of arylpentazoles increases with electron-donating groups and decreases with electron-withdrawing groups, in the para position, as found in experiments. The stabilizing effect of the electron-donating groups is shown to be due to a resonance interaction with the electron-withdrawing pentazole ring. Addition of solvation effects, using the polarizable continuum model to simulate the polar solvent methanol, increases the stability of arylpentazoles. This is due to a more polar ground state than transition state. The calculated free energies of activation for the arylpentazoles agree well with experimental results. From the calculations, the electron-withdrawing effect of the pentazole group is found to be similar to that of cyanide (-CN). Some new arylpentazoles with hydroxyl groups in the ortho position are proposed. These are predicted to be more stable than all previously synthesized neutral arylpentazoles.
Michael-type additions of various thiols and alpha,beta-unsaturated carbonyl compounds were performed in organic solvent catalyzed by wild-type and a rationally redesigned mutant of Candida antarctica lipase B. The mutant locks the nucleophilic serine 105 in the active-site; this results in a changed catalytic mechanism of the enzyme. The possibility of utilizing this mutant for Michael-type additions was initially explored by quantum-chemical calculations on the reaction between acrolein and methanethiol in a model system. The model system was constructed on the basis of docking and molecular-dynamics simulations and was designed to simulate the catalytic properties of the active site. The catalytic system was explored experimentally with a range of different substrates. The k(cat) values were found to be in the range of 10(-3) to 4 min(-1), similar to the values obtained with aldolase antibodies. The enzyme proficiency was 10(7). Furthermore, the Michael-type reactions followed saturation kinetics and were confirmed to take place in the enzyme active site.
A new anion-carbohydrate recognition system is described. Pyranosides with axial protons in 1-, 3-, and 5-position proved efficient, forming relatively strong complexes between the anion and the B-face of the carbohydrate. This system could furthermore be used in supramolecular control in Lattrell-Dax epimerization reactions, leading to either activation or deactivation effects.
In previous studies, it was reported that a neighbouring equatorial ester group is essential for a good yield of nitrite-mediated triflate inversion, whereas with neighbouring benzyl ether groups or axial ester groups, mixtures are generally produced. In the present study, the origin of this difference was addressed. The ambident reactivity of the nitrite ion has been found to be the cause of the complex product formation observed, which can be controlled by a neighbouring equatorial ester group. Both N-attack and O-attack occur in the absence of the ester group, whereas O-attack is favoured in its presence. A neighbouring group assistance mechanism is proposed, in addition to steric effects, based on secondary interactions between the neighbouring ester group and the incoming nucleophile. High-level quantum mechanical calculations were carried out in order to delineate this effect. The theoretical results are in excellent agreement with experiments, and suggest a catalytic role for the neighbouring equatorial ester group.
In radiolysis of water, three molecular products are formed (H2O2, O-2, and H-2). It has previously been shown that aqueous hydrogen peroxide is catalytically decomposed on many oxide surfaces and that the decomposition proceeds via the formation of surface-bound hydroxyl radicals. In this work, we have investigated the behavior of aqueous H-2 and O-2 in contact with ZrO2. Experiments were carried out in an autoclave with high H2 pressure and low O-2 pressure (40 and 0.2 bar, respectively). In the experiments the concentration of H-abstracting radicals was monitored as a function of time using tris(hydroxymethyl)aminomethane (Tris) as scavenger and the subsequent formation of formaldehyde to probe radical formation. The plausible formation of H2O2 was also monitored in the experiments. In addition, density functional theory (employing the hybrid PBE0 functional) was used to search for reaction pathways. The results from the,experiments show that hydrogen-abstracting radicals: are formed in the aqueous H2O2-system in contact with solid ZrO2. Formation of H2O2 is also detected, and the time dependent production of hydrogen-abstracting radicals follows the time-dependent H2O2 concentration, strongly:indicating that the radicals are produced upon catalytic decomposition of H2O2. The DFT study implies that H2O2 formation proceeds via a pathway where HO2 is a key intermediate. It is interesting to note that all the stable molecular products from aqueous radiolysis are precursors of quite intriguing radical reactions at water/oxide interfaces.
Predictions of solubility of nine different solid organic fine chemical compounds in water and organic solvents of relevance to industrial processing are examined. UNIFAC interaction parameters are taken from standard reference literature, extracted from liquid-vapor equilibria. For most systems, predicted solubilities deviate more than 15% from experimental values. Deviations are due to uncertainties in the estimation of the activity of the pure solid as well as to deficiencies in the estimation of activity coefficients in the solution. By comparison with results from ab initio quantum chemical calculations of the elecrostatic potential on the molecular surface of the solutes, it can be shown that a key assumption of the UNIFAC approach is not necessarily fulfilled. The properties of a functional group may depend significantly on the properties of the rest of the molecule.
Squalene–hopene cyclase catalyzes the cyclization of squalene to hopanoids. A previous study has identified a network of tunnels in the protein, where water molecules have been indicated to move. Blocking these tunnels by site-directed mutagenesis was found to change the activation entropy of the catalytic reaction from positive to negative with a concomitant lowering of the activation enthalpy. As a consequence, some variants are faster and others are slower than the wild type (wt) in vitro under optimal reaction conditions for the wt. In this study, molecular dynamics (MD) simulations have been performed for the wt and the variants to investigate how the mutations affect the protein structure and the water flow in the enzyme, hypothetically influencing the activation parameters. Interestingly, the tunnel-obstructing variants are associated with an increased flow of water in the active site, particularly close to the catalytic residue Asp376. MD simulations with the substrate present in the active site indicate that the distance for the rate-determining proton transfer between Asp376 and the substrate is longer in the tunnel-obstructing protein variants than in the wt. On the basis of the previous experimental results and the current MD results, we propose that the tunnel-obstructing variants, at least partly, could operate by a different catalytic mechanism, where the proton transfer may have contributions from a Grotthuss-like mechanism.
Quantum chemical studies (B3LYP) of the inversion of methyllithium in both tetrameric and dimeric aggregates have been carried out. Results show that inversion occurs either via dissociation of the tetramer into the dimers, passage of a four-membered-ring transition state, and association of the dimers to form the inverted tetramer, or via a nonconcerted route involving an eight-membered-ring transition state. The activation energies of these two mechanisms are similar. However, the dissociative mechanism is ruled out by NMR experiments.
A mechanism for the oxidation of a dimeric beta-amyloid copper ion complex is proposed based on DFT calculations. It involves the Met35 residue, which is believed to be important in the neurotoxicity causing Alzheimer's disease. Oxidation of Met35 is found to proceed readily with dioxygen when two Met35 residues are close to each other and the copper ion. This indicates that oxidants, such as hydrogen peroxide, are not necessary for oxidation of beta-amyloid copper ion complexes. Understanding these processes could be pivotal in gaining more knowledge of this complex disease and for the development of therapeutic treatments.
Three new sensitizers for photoelectrochemical solar cells were synthesized consisting of a triphenylamine donor, a rhodanine-3-acetic acid acceptor and a polyene connection. The conjugation length was systematically increased, which resulted in two effects: first, it led to a red-shift of the optical absorption of the dyes, resulting in an improved spectral overlap with the solar spectrum. Secondly, the oxidation potential decreased systematically. The excited state levels were, however, calculated to be nearly stationary. The experimental trends were in excellent agreement with density functional theory (DFT) computations. The photovoltaic performance of this set of dyes as sensitizers in mesoporous TiO2 solar cells was investigated using electrolytes containing the iodide/triiodide redox couple. The dye with the best absorption characteristics showed the poorest solar cell efficiency, due to losses by recombination of electrons in TiO2 with triiodide. Addition of 4-tert butylpyridine to the electrolyte led to a strongly reduced photocurrent for all dyes due to a reduced electron injection efficiency, caused by a 0.15 V negative shift of the TiO2 conduction band potential.
A series of organic chromophores have been synthesized in order to investigate the benefits of structural versus spectral properties as well as the absorption properties and solar cell performance when introducing unsymmetrical substituents in the chromophore. Exceptionally high Voc was found for the symmetrical, structural benefited dye, which also gave the best overall solar cell performance.
A series of organic chromophores have been synthesized in order to approach optimal energy level composition in the TiO2-dye-iodide/triiodide system in the dye-sensitized solar cells. HOMO and LUMO energy level tuning is achieved by varying the conjugation between the triphenylamine donor and the cyanoacetic acid acceptor. This is supported by spectral and electrochemical experiments and TDDFT calculations. These results show that energetic tuning of the chromophores was successful and fulfilled the thermodynamic criteria for dye-sensitized solar cells, electrical losses depending on the size and orientation of the chromophores were observed.
Crystalline surfaces of gold are chemically inert, whereas nanoparticles of gold are excellent catalysts for many reactions. The catalytic properties of nanostructured gold have been connected to increased binding affinities of reactant molecules to low-coordinated Au atoms. Here we show that the high reactivity at these sites is a consequence of the formation of Ï-holes, i.e. maxima in the surface electrostatic potential (Vs,max) due to the overlap of mainly the valence s-orbitals when forming the bonding Ï-orbitals. The Ï-holes are binding sites for Lewis bases, and binding energies correlate with magnitudes of the Vs,max. For symmetrical Au clusters, of varying size, the most positive Vs,max are found at corners, edges, and surfaces (facets) and decreasing in that order. This is in agreement with the experimentally and theoretically observed dependence of catalytic activity on local structure. The density of Ï-holes can explain the increasing catalytic activity with decreasing particle size also for other transition metal catalysts, such as platinum.
Understanding the molecular interaction behavior of transition metal nanoclusters lies at the heart of their efficient use in, e.g., heterogeneous catalysis, medical therapy and solar energy harvesting. For this purpose, we have evaluated the applicability of the surface electrostatic potential [VS(r)] and the local surface electron attachment energy [ES(r)] properties for characterizing the local Lewis acidity of a series of low-energy TM13 transition metal nanoclusters (TM = Au, Cu, Ru, Rh, Pd, Ir, Pt, Co), including also Pt7Cu6. The clusters have been studied using hybrid Kohn–Sham density functional theory (DFT) calculations. The VS(r) and ES(r), evaluated at 0.001 a.u. isodensity contours, are used to analyze the interactions with H2O. We find that the maxima of VS(r), σ-holes, are either localized or diffuse. This is rationalized in terms of the nanocluster geometry and occupation of the clusters's, p and d valence orbitals. Our findings motivate a new scheme for characterizing σ-holes as σs (diffuse), σp (localized) or σd (localized) depending on their electronic origin. The positions of the maxima in VS(r) (and minima in ES(r)) are found to coincide with O-down adsorption sites of H2O, whereas minima in VS(r) leads to H-down adsorption. Linear relationships between VS,max (and ES,min) and H2O interaction energies are further discussed.
Oxidative degradation of copper in aqueous environments is a major concern in areas such as catalysis, electronics and construction engineering. A particular challenge is to systematically investigate the details of this process for non-ideal copper surfaces and particles under the conditions found in most real applications. To this end, we have used hybrid density functional theory to study the oxidation of a Cu-7 cluster in water solution. Especially, the role of a large water coverage is explored. This has resulted in the conclusion that, under atmospheric H-2 pressures, the thermodynamically most favored state of degradation is achieved upon the generation of four H-2 molecules (i.e. Cu-7 + 8H(2)O -> Cu-7(OH)(8) + 4H(2)) in both condensed and gas phases. This state corresponds to an average oxidation state below Cu(I). The calculations suggest that the oxidation reaction is slow at ambient temperatures with the water dissociation as the rate-limiting step. Our findings are expected to have implication for, among other areas, the copper catalyzed water-gas shift reaction, and for the general understanding of copper corrosion in aqueous environments.
Using local DFT-based probes for electrostatic as well as charge transfer/polarization interactions, we are able to characterize Lewis basic and acidic sites on copper, silver and gold nanoparticles. The predictions obtained using the DFT-probes are compared to the interaction energies of the electron donating (CO, H2O, NH3 and H2S) and the electron accepting (BH3, BF3, HCl [H-down] and Na+) compounds. The probes include the local electron attachment energy [E(r)], the average local ionization energy [% I(r)], and the electrostatic potential [V(r)] and are evaluated on isodensity surfaces located at distances corresponding to typical interaction distances. These probes have previously been successful in characterizing molecular interactions. Good correlations are found between Lewis acidity and maxima in V(r), appearing as a consequence of sigma-holes, as well as minima in E(r), of the noble metal nanoparticles. Similarly are Lewis basic sites successfully described by surface minima in V(r) and % I(r); the former are indicative of sigma-lumps, i.e. regions of enhanced sigma-density. The investigated probes are anticipated to function as reliable tools in nanoparticle reactivity and interaction characterization, and may act as suitable descriptors in large-scale screenings for materials of specific properties, e.g. in heterogeneous catalysis. Because of the similarity between the noble metal nanoparticle's interactions with Lewis bases and the concepts of halogen and hydrogen bonding, a new class of bonds is introduced - regium bonds - taking place between a sigma-hole of a Cu, Ag or Au compound and an electron donor.
Two local reactivity descriptors computed by Kohn-Sham density functional theory (DFT) are used to predict and rationalize interactions of nucleophilic molecules (exemplified by CO and H2O) with transition metal (TM) and oxide surfaces. The descriptors are the electrostatic potential, V-S(r), and the local electron attachment energy, E-S(r), evaluated on surfaces defined by the 0.001 e Bohr(-3) isodensity contour. These descriptors have previously shown excellent abilities to predict regioselectivity and rank molecular as well as nanoparticle reactivities and interaction affinities. In this study, we generalize the descriptors to fit into the framework of periodic DFT computations. We also demonstrate their capabilities to predict local surface propensity for interaction with Lewis bases. It is shown that E-S(r) and V-S(r) can rationalize the interaction behavior of TM oxides and of fcc TM surfaces, including low-index, stepped and kinked surfaces spanning a wide range of interaction sites with varied coordination environments. Broad future applicability in surface science is envisaged for the descriptors, including heterogeneous catalysis and electrochemistry.


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Todays FDR is Isaiah 19-20 and Acts 19:1-22
Our Old Testament reading today continues with a range of messages (prophecies) to the nations, today Isaiah moves on to address Egypt. I found this chapter to be quite powerful, the might of the Lord is revealed against Egypt, bringing down their cities, crops, rivers, livelihoods, intellect and rulers. It is a dire scene of judgement that 'makes Egypt stagger as a drunkard staggers around in his vomit' (v14).
And yet, that is not the end of the story… God somehow, miraculously, turns judgement into healing. The Egyptians in their weakened state 'will turn to the Lord, and he will respond to their pleas and heal them' (v22).
And yet STILL it is not the end of the story…. Perhaps most baffling and miraculous of all, God not only heals Egypt but subsequently blesses them…'Blessed be Egypt my people, and Assyria the work of my hands, and Israel my inheritance'. These are the nations that oppressed the nation Israel, sold her into slavery, waged war upon her and systematically destroyed her… yet here is the Lord, including them as equals! What a stark and wonderful vision of God's intent to reconcile even gentiles into his salvation plan! God's plan of salvation history reconciles his enemies (us!) through Christ's death.
…but God shows his love for us in that while we were still sinners, Christ died for us (Rom 5:8)
This is indeed foolishness to the world's way of thinking, yet that very 'foolishness' – the wisdom of God – brings us life!
For the word of the cross is folly to those who are perishing, but to us who are being saved it is the power of God (1 Cor 1:18)
This is the eternal message of salvation – demonstrated throughout the millennia. Let us rejoice in Christ's victory and the wonderful, 'foolish' grace of God!
In our New Testament reading today, the gospel continues to spread out across 'all the residents of Asia' (v10). In some places this brings extraordinary miracles and change of life and in other places extraordinary imitation and deception… and through it all 'the word of the Lord continue to increase and prevail mightily' (v20)
As we read through the word each day, may we ask God to change our lives and allow his word to prevail mightily!

subset: commoncrawl


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Everyone eats food but not everyone enjoys eating. I once knew someone who would choose to take a pill every day for nourishment because eating takes too much time. I guess everyone has a right to their own opinion, but my goodness, how depressing is that?! Food, especially good food, makes me happy. Wine with the food is… Continue reading Travelers and Tasters
Life from a Suitcase
Just because you love traveling doesn't mean you love living out of a suitcase. I don't, and I think you would agree that this is one of the few unpleasant experiences of any long adventure. (I'm talking about land tours and adventures taking you to multiple destinations and various hotel rooms, here, not cruises.) The… Continue reading Life from a Suitcase
Disney Dream, Part 2: Pleasant Surprises for Adults and Kids
Starting with Disney's primary audience, here's a sample of what's onboard to thrill and surprise kids and teens. The three organized, chaperoned programs are highly rated and the new facilities will not disappoint. The Small World Nursery is for ages 3 months to 3 years and the facility is equipped with cribs, rocking chairs, toys, books,… Continue reading Disney Dream, Part 2: Pleasant Surprises for Adults and Kids
Disney Dream, Part 1: Pleasant Surprises for Adults and Kids
Disney's newest cruise ship just arrived in Port Canaveral last week and will begin its 3 and 4 night cruises on Jan. 26 to the Bahamas. The dream is much larger than Disney's other two ships, with a passenger capacity of 4000 (which would mean a completely full passenger count in each cabin) and she… Continue reading Disney Dream, Part 1: Pleasant Surprises for Adults and Kids
Skyline on the Beach – Finalists
Had a look at the carving progress at sunset on Saturday. The detail is had to capture, but here are a few that I thought stood out. The artists are spraying their creations with glue mixed with water which is meant to protect them against wind damage. A lot of the pieces have wires sticking… Continue reading Skyline on the Beach – Finalists
Friday Morning Sculpting
See the full gallery on Posterous Most of the sculptors are busy carving their creations from the top down. Five of the artists have told me that this is their full time job. Some say that sand sculpting competitions are part of what their business does in addition to creating exhibits for fairs or… Continue reading Friday Morning Sculpting
Emerging Beach Skyline a Treat
Every November in southwest Florida, the town of Ft. Myers Beach (which is also an island) holds a sandsculpting festival, http://www.sandsculptingfestival.com . This year there are 17 "Master Sand Sculptors" who come from Texas, California, Canada, the Carolinas St. Louis and even Eastern Europe to compete for the title and the chance to compete in… Continue reading Emerging Beach Skyline a Treat


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Archive for May, 2009
World Music in the Courtyard @ the Museum of Fine Arts – Wednesday Nights @ 7:30 p.m.
Come on out to the MFA and enjoy these well known popular world music artists in the pleasant setting of the museum's Calderwood Courtyard. The Elaine and Jerome Rosenfeld Concert Series will take place every Wednesday evening from June 24th thru August 26th. The courtyard opens to the public at 6:00 p.m. and the performance begins at 7:30. Bring your blanket or a low seating portable chair and be sure to come early as space is at a premium. Happily, the show is guaranteed to go on even if it rains, as the museum has a sizable indoor auditorium- just in case. Here is the star studded line-up:
July 17th – King Sunny Ade and his African Beats (Nigerian Juju)
July 22nd – Grupo Fantasma (Latin )
July 29th – Alex Cuba (Cuban soul and rock)
August 19th – Buika (Flamenco fusion)
Concert Details:
When: Select Wednesday Eves. @ 7:30 p.m. – 9:00 p.m.
Where: Museum of Fine Arts
Tickets: Prices range from $24.00 – $38.00 (includes a discount for MFA members, seniors, and students)
For complete information as to how to make purchases online, in person, by phone, or for the special concert dining package check out their website.
Truly Local Sumertime Fun!!! – World Music in the Neighborhood Park
In keeping with my latest post on Titus Sparrow Park (5/24), I would encourage you to check out the summer events schedule for your local neighborhood park, as well as others close by. Most of these recreational areas host a web site that keeps the locals, and others who might be interested, informed of park happenings and other related issues. One way that I have found to be pretty effective in locating park web sites is to search Google under the keywords "the name of the park" and events. That will usually do the trick and you can see whether or not they are hosting any seasonal events involving live world music.
To me there is nothing quite like outdoor park summer entertainment. I always jump at the chance to get out and partake of the pleasent seasonal weather. In addition, I truly enjoy the totally laidback informal atmosphere these types of concerts provide, not to mention the free admission! During these tough economic times, this is a benifit that has become all the more appreciated.
Summer Concerts in the Park – Titus Sparrow Park (South End) – Wednesday Evenings @ 6:30 p.m.
I don't know about you, but summer is definitely my most favorite time of the year!!! Aside from the warm weather and outdoor fun that goes along with it, free music abounds in Boston in the form of open air concerts. Oh boy!!! And as you would expect, Boston's world music scene is very much a part of all this wonderful musical activity.
I'm particularly lucky that one of the outdoor performance venues just happens to be virtually right in my own backyard. I'm speaking here of Titus Sparrow Park in Boston's South End. I have a private roof deck, so I don't even have to leave home to enjoy this fine series of concerts. This year, I will be serenaded for about 90 minutes or so every Wednesday night at dusk, and I can hardly wait.
Sparrow Park has within it an amphitheater-style area of lawn where the concerts are held. This years series lasts from June 10th – August 12th. So come and bring your favorite lawn chair or blanket and enjoy the nice soft grass along with, of course, great music. For your information, I have listed here the world music performers who will be appearing and provided audio links to samples of their music.
June 17th – Boubacar Diabate and Sambalolo (West African vocals with guitar)
June 24th – Paulo Stagnaro and La Timbistica with Eleonora Bianchini (Italian vocals and Latin jazz)
July 1st – PanNeubean Steel (Reggae, Calypso, and Soul Steeldrum sounds)
July 8th – Trouz Bras (Breton bagpipes)
July 29th – Blue Moose and the Unbuttoned Zippers (Scandinavian, Celtic, and American fusion fiddle)
Concert Details:
When: Select Wednesday Eves. @ 6:30 p.m.
(Cancellations due to rain will be posted on the park's web site or you can join their mailing list in order to be notified personally)
Where: Titus Sparrow Park / (Directions)
Admission: Free
Little Shop of Horas – New England's #1 Destination for Folk Dance Music Recordings
Still searching for that elusive recording of folk dance music that just doesn't seem to be available anywhere??? Why not let the good folks at the Little Shop of Horas in Melrose lend you helping hand. They're experts and would love to make your search a success!
They boast the largest collection of traditional dance music recordings in the entire New England area. In addition, they have quite a comprehensive inventory of recordings of other genres of folk music as well. If your looking for kids music, you can find it here as well. While browsing their online catalog, I found their prices to be quite reasonable. Not only do they carry a wide selection of cds, cassettes and even, believe it or not at this stage, lps, but also DVDs, video cassettes, books, and sheet music as well. They even have a selection of T-shirts and such so that you can proudly share your love of folk arts with the rest of the world.
The shop's staff is always ready to tell you what's new, recommended, or on sale with respect to their inventory. More ever, you can conveniently make your purchases in a number of ways. The store is located at the Folk Arts Center of New England. Their hours and phone number are the same as those of the office. You can also take advantage of their online order form which coincides with the catalog. In addition, they appear at various folk events in the area, so keep an eye out for them when attending performances.
An aspect of the Folk Arts Center of New England that I am particularly enthused about is their genuine and whole hearted support of world culture from a promotional standpoint. All of the profits from the operation of Little Shop of Horas go towards the successful accomplishment of this mission. As a matter of fact, they are currently selling a children's songbook/cd set entitled Qu Qu Qu Barg-e-Chinaar: Children's Songs from Afghanistan. Proceeds from all sales of this item will go to the Afghan Children's Songbook Project in support of a revival of native juvenile folk music in the home country, as well as within the communities of its citizens and their ancesters living abroad. You can also make a direct donation to the shop's overall global cause if you choose. So, why not take some time out to indulge yourself at this intriguing little music shop, either in person or online, and make a contribution to world culture, while enjoying the exposure to some really great world music and dance!
Don't Miss Reggae Sensation Collie Buddz @ The House of Blues (June 13th – Saturday at 7:00 p.m.)
Collie Buddz is a reggae fusion artist from Bermuda/New Orleans who made it big with his hit single entitled "Come Around". I remember buying his album "Collie Buddz" for our world music collection at the Boston Public Library when it was at the top of the Billboard reggae charts.
He was raised in Bermuda where he developed his singing career. He likes to combine many styles of music with his heavily reggae-based sound which has become his trademark. Although hip-hop and soca are two major genres with which he experiments, he says that he aims to be successful at being able to blend any style of choice with reggae.
Aside from his successes as a solo artist, Collie Buddz has also collaborated musically with the likes of such major names as Beyonce, Lil' Flip, Kidd Cudi, Shaggy, and Busta Rhymes. In 2008, he was nominated for Jamaica's EME award for Top International Artist of the Year, an honor reserved for the artist who's releases are most successful in the international marketplace. Look for his new album Next Take, released this year.
Also appearing will be Brooklyn's top new reggae group, New Kingston. This quartet of three brothers and their best friend, originally from Jamaica, started as a backup act for such renowned reggae artists as Collie Buddz, Mr. Vegas, Morgan Heritage, Sister Carol, Shabba Ranks, and others. Eventually however, they began to blend the reggae style with pop, jazz, and R&B, to form a unique style of their own which is a form of "reggae crossover". With their new and original sound, they have become highly successful in their own right and now appear in concert "with" instead of as a backup to these other popular acts.
Concert Details :
When: June 13th – Saturday @ 7:00 p.m.
Where: House of Blues / (Map)
Tickets: $25.00
Check availability on website.
Enjoy Live Local Celtic Music Impromptu Style – Tuesday Nights @ John Harvard's in the Square
Join accomplished Celtic musicians Emerald Rae and Flynn Cohen as your hosts every Tuesday night from 9 p.m. 'til midnight for a traditional music jam session at the popular pub/restaurant John Harvard's Brew House in Harvard Square (directions). Ms. Rae, a former U.S. National Scottish Fiddle Champion, specializes in the area of Scottish and Cape Breton folk music and is an avid Cape Breton style stepdancer as well. This composer/performer is known for her great rapport with the audience and has appeared with such international recording stars as Natalie Haas, Alasdair Fraser, and Natalie MacMaster. She, along with her co-host, currently performs with the local band Annalivia. Acoustic guitarist Flynn Cohen is best known for his work as an accompanist for traditional fiddlers. He has also performed with Irish accordion great John Whelan and the well-known dance band The Sevens, amongst others. In addition to Annalivia, he also plays with the local fiddle trio Halali. Currently a member of the music faculty at Keene College in New Hampshire, he conducts numerous workshops, and participates as a visiting lecturer on the subject of traditional music.
Aside from being treated to your hosts' personal performances, as a member of the audience you will also get to hear local Celtic musicians from the area as they join in on the fun. If you want to participate in the session, you can call John Harvard's at (617) 868 – 3858 or fax or email them. Even if you're just a beginner, fear not! They welcome players of all instruments with any level of experience.
O.K., in my opinion, the music is always the best part, however while your listening you can indulge yourself in some pretty tasty fare at this eatery as well. John Harvard's offers a lot of the standard pub fare you would expect, including some really great "comfort" food, as well as some inventive dishes with an international flare. I would suggest that you checkout their full menu here, but I'll give you a few hints as to what to expect. For starters, there's a hummus platter (with pita bread, feta cheese, tomatoes, parsley oil, and Kalamata olives), yummy New England clam chowder, or Buffalo tenders (boneless chicken tenders tossed in Buffalo sauce, with bleu cheese dressing, cucumbers and celery). Then for a main course they offer some pretty interesting looking sliders (mini-sandwiches) including pulled pork (house-smoked pulled pork, chipotle BBQ, and pineapple salsa), BLT (crisp pancetta, tomato, lettuce, and a lemon garlic aioli), and ale-marinated steak and cheese (ale-marinated grilled flank steak, Roquefort cheese spread and roasted red peppers) selections. And here's an example of more of that "comfort" food I mentioned, grilled meat loaf (with BBQ sauce, garlic mashed potatoes, steamed asparagus spears, red wine sauce, and crispy fried onions). Their sinfully scrumptious desserts include a chocolate cobbler (triple layer of chocolate delight served warm, topped with vanilla ice cream and a drizzle of house-made raspberry sauce) as well as butterscotch bread pudding (a chef's special, served warm with vanilla bean ice cream and caramel sauce).
Last, but by no means least, I must point out their home-brewed ales. They are of course their biggest trademark! I myself do not drink beer, but a friend of mine assured me that they are indeed a cut well above average. On the evening that we were there, we found the place to be packed, which attests to it's popularity. I must say though that, even if they are well-known for their brews, still the food and the casual laid back atmosphere alone would be enough to attract a crowd to John Harvard's. I know that I intend to go back- and of course, make that on a Tuesday night!!!
Boston Public Library World Music Audio Collection – New CDs Ordered (4/25/09)
The cds in this order contain a wide variety of genres including Latin hits, Asian fusion, Indian popular and sacred music, Japanese anime, Koean pop, and Italian and gypsy music. Click on the links below to hear excerpts from them. As this is just a sampling of what we have to offer, come on in to the main library at Copley Square or any one of our branches conveniently located throughout the city of Boston and "check out" more of our fabulous world music collection. For your additional convenience, you can reserve copies online via our library catalog and you will be notified when the item is in and ready to be picked-up.
1. Melancholy of Haruhi Suzumiya (Vol. 3) – Various artists (Japan) (Review)
2. Bhangra Dance Hits – Various artists (India) (Review)
3. El Patron – Tito El Bambino (Puerto Rico) (Review – Scroll down)
4. Mas Adelante – La Arrolladora Banda El Limon (Mexico) (Review – Scroll down)
5. Now Latino 4 – Various artists (Global Latin) (Review)
6. Atmosphers – Deuter (Asian Fusion) (Review – Scroll down)
7. 'Aumakua – Amy Hanaiali'i (Hawaii) (Review – Scroll down)
8. BoA – BoA (South Korea) (Review – Scroll down)
9. Devotion – Cheb I Sabbah (India) (Review – Scroll down)
10. Putumayo: Italia – Various artists (Italy) (Review – Scroll down)
11. Rough Guide to Gypsy Music (2nd ed.) – Various artists (Global) (Review)


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Label is a piece of paper, polymer or other material affixed to a container or article, on which is printed a legend, information concerning the product, addresses, etc. A label may also be printed directly on the container or article.
Flexographic Printing Technology
At Holoflex Limited we have complete in-house production facility for label printing which uses the Flexographic Printing Technology. Flexography (often abbreviated to flexo) is a form of printing process which utilizes a flexible relief plate. It is essentially a modern version of letterpress which can be used for printing on almost any type of substrate, including plastic, metallic films, cellophane, and paper. It is widely used for printing on the non-porous substrates required for various types of food packaging, product labels, tags etc. The Flexographic Printing Technology involves the following processes:
Flexographic Printing Ink Technology
Formulating the right ink for the right substrate and application goes a long way in Flexographic Printing Ink Technology. Formulation of flexographic inks requires a detailed knowledge of the physical and chemical properties of the raw materials composing the inks, and how these ingredients affect or react with each other as well as with the environment. Flexographic printing inks are primarily formulated to remain compatible with the wide variety of substrates used in the process. Each formulation component individually fulfills a special function and the proportion and composition will vary according to the substrate.
There are five types of inks that can be used in flexography: Solvent-based inks
Water-based inks
Electron beam (EB) curing inks
Ultraviolet (UV) curing inks
Two-part chemically-curing inks
Ink Control Technology
The ink is controlled in the flexographic printing process by the inking unit. The inking unit can be either of the below:
Fountain Roll System
The fountain roll system is a simple old system yet if there is too much or too little ink this system would likely not control in a good way.
Doctor Blade System
The doctor blade inside the anilox roller uses cell geometry and distribution. These blades insure that the cells are filled with enough ink.
At Holoflex Limited we use the doctor blade system on our flexographic unit to achieve superior print quality.


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Posted 7 years, 7 months ago.
1st Bangor put on an impressive display in this match to beat a dogged Iveagh side 3-1 at the Drome.
Two superb goals from Marty Robinson and Ryan Oliver's 8th of the season gave 1st Bangor the win after dominating the game from start to finish.
More to follow...
1st Bangor: C O'Neill, J Bryson, M Corkum, J Sproule, B Gourley, A Caldwell, C Scott, M Robinson, R Oliver, A Welsh, D McPhillips (S McCormick)


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ELMHURST, Ill. – For the second-consecutive week, both Oral Roberts' Laura Milos and South Dakota's Anne Rasmussen locked down the #SummitVB Player of the Week awards. Milos nabbed the offensive honor after blasting her 2,000 career kill, while Rasmussen earned the defensive title after averaging 9.00 digs/set over the weekend.
The Golden Eagles (7-9, 4-0) won their fourth straight contest and remained undefeated in league play thanks in part to the historic efforts of Milos. After posting 19 kills in a road victory over South Dakota State, Milos stuffed the stat sheet with 30 kills to secure the win over then-undefeated in league play North Dakota State. Her fourth kill against the Bison was the 2,000 of her career, making her only the third athlete in #SummitVB history to accomplish such a feat.
Milos ended the weekend with 49 total kills, averaging 7.00 kills/set and hitting at a .438 clip. In the NCAA this season, Milos ranks third in kills/set (5.25), total kills (310) and points/set (5.82). She also ranks second in the nation in total points (343.5). With 2,026 kills for her career, Milos remains at No. 3 on The Summit League's all-time kills list (80 kills behind No. 2 on that list).
Like Milos, this is the second-consecutive Player of the Week award for Rasmussen, who guided the Coyotes (8-7, 2-1) to a three-set road victory over Fort Wayne on Friday. There, the sophomore defensive specialist dug out 27 balls, averaging nine per set. It was the third straight match for Rasmussen in which she logged 25-plus digs and her 9.00 digs/set average would rank No. 1 on the #SummitVB all-time single season list by nearly two full digs.
Nationally, Rasmussen ranks No. 29 in digs/set (5.18) and her 27 digs is tied for the ninth-most recorded in a three set-match this season.
Laura Milos, Oral Roberts
Sr. // Outside Hitter // Porec, Croatia
- In seven sets played, hit .438 with 49 kills (7.00 kills/set)
- Logged match-high kills versus SDSU (19) and NDSU (30)
- Became the third athlete in #SummitVB history to register 2,000 career kills
- Ranks No. 3 in the NCAA this season in kills/set (5.25)
- All-time league leader in career Player of the Week awards (14)
- Surpassed 30-plus kills for the second time this season
- Surpassed 20-plus kills for the seventh time this season
Also nominated: Becca Latham (Denver), Abby Bergsten (Omaha), Mackenzie Steckler (Western Illinois), Brittany Jessen (South Dakota), Katie Crowe (Fort Wayne), Allie Mauch (North Dakota State)
Previous Winners: Aug. 28 – Kayla Principato (Denver) | Sept. 5 – Brianna Rasmusson (NDSU) | Sept. 11 – Laura Milos (Oral Roberts) | Sept. 18 – Kelly Law (USD) | Sept. 25 – Laura Milos
Anne Rasmussen, South Dakota
So. // Defensive Specialist // Oak Creek, Wis.
- Tallied 27 digs (9.00 digs/set) in a three-set win over Fort Wayne
- In the NCAA, 27 digs is tied for the ninth-best total in a three-set match this season
- Summit League ranking (league matches): No. 1 in digs (87) and digs/set (7.25)
- Summit League ranking (all matches): No. 2 in digs (290) and digs/set (5.18)
- Third-straight 25-plus dig performance
- Second-career Summit League Defensive Player of the Week title
Also nominated: Tori Roe (Oral Roberts), Cassidy Rooke (Denver), Anna Blaschko (Omaha), Claire Grove (Western Illinois), Brianna Rasmusson (North Dakota State), Natalie Seiler (Fort Wayne)
Previous Winners: Aug. 28 – Mikaela Purnell (NDSU) | Sept. 5 – Bella Lien (NDSU) | Sept. 11 – Mikaela Purnell (NDSU) | Sept. 18 – Mikaela Purnell (NDSU) | Sept. 25 – Anne Rasmussen
Through 35 years of Division I athletics, The Summit League offers 19 championship sports and has a combined enrollment of nearly 100,000 at eight institutions, including three located in top 60 U.S. metro populations and two land-grant universities. Member institutions include: Denver (University of Denver), Fort Wayne (Indiana University-Purdue University-Fort Wayne), North Dakota State University, Omaha (University of Nebraska Omaha), Oral Roberts University, the University of South Dakota, South Dakota State University and Western Illinois University with the University of North Dakota becoming an official member on July 1, 2018. Previously known as the Mid-Continent Conference, The Summit League rebranded in 2007 and has since produced nine NCAA Champions along with over 90 Academic All-Americans, nearly 100 All-America selections and numerous former student-athletes competing at the highest professional level. For more information about the league, visit www.thesummitleague.org website, follow The Summit League on Twitter @thesummitleague.


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Brad and Ang - Don't Ask or we'll Sue
Brad and Ang - Don't Ask or we'll Sue
Page Six reports that the press was required to sign a legal document for upcoming interviews with Pitt and Jolie this week. They wanted to make sure no personal questions were asked or else they will sue. ET has an interview and they will be showing additional scenes of Mr and Mrs Smith this week (and I'm sure they will extend it out as long as possible).
Also of note, Diane Sawyer will have the first major exlusive interview with Mr Pitt on Primetime Live tomorrow night. In this interview he does address being in the media, the paparazzi and Jen. He spoke about how the tabloids know the love triangle is a good story so they went with it (even though it was "not real"). He also spoke about if they would stay in touch and he said, "It's difficult now as we determine what the next juncture is. But yeah, always, I predict."


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Do you love the chill in the air, the change of color? All reminders that it is apple harvest time! This recipe will remind you of apple pie, but in dessert bar form. Layers of a buttery crust, spiced apples and a lightly sweet topping. Let the aroma fill your kitchen!
Apple Harvest Bars
- 1 ½ cups flour
- 2/3 cup sugar, divided
- ½ teaspoon salt
- ½ cup cold butter, cut into 1-inch pieces
- 4 cups peeled and sliced apples (about 2-3 large apples)
- 2 tablespoons fresh lemon juice
- 1 teaspoon ground cinnamon
- ¼ teaspoon nutmeg
- 1 1/3 cups flaked coconut
- 1 egg, lightly beaten
- 1/3 cup condensed milk
- 1 teaspoon vanilla extract
- ¾ cup chopped pecans
Preheat oven to 375° and grease a 9 x 13″ baking pan.
In a food processor, add flour, 1/3 cup sugar and salt, pulsate once to combine. Add butter and pulse a few times until the mixture turns to dry crumbs. Press the crumb mixture evenly into the bottom of the prepared baking pan.
In a medium bowl, toss the sliced apples in lemon juice. Arrange the apples slices in rows on top of the crust.
In a small bowl, combine the remaining sugar, cinnamon and nutmeg. Sprinkle over the layer of apples. Bake for 20 minutes.
Meanwhile, combine the coconut, egg, condensed milk, vanilla and pecans in a medium bowl. Remove the pan from the oven and spoon the coconut mixture evenly over the layer of apples. Bake for an additional 20 minutes until the coconut is golden brown.
Slightly cool in pan and cut into bars while still warm.
The aroma of apple pie fills the house!
Tip: Cut dessert bars ahead of time to make an easy-to-serve dessert. Sweet Stackers layer your baked goods in one container so they are ready to serve or transport to a party! Visit sweetstackers.com to learn how you can convert your containers to multi-level.


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Host in Ireland
Host in Ireland, winner of the Datacloud Europe 2016 award for Innovative Data Center Location, is an industry-led marketing initiative that provides timely and accurate information about Ireland's digital asset hosting ecosystem at all times including demonstrating why Ireland is more cost-effective, efficient, reliable, secure and accessible than most other regions across the EU. There's a reason companies like Microsoft, Zendesk, Facebook, Twitter, Amazon, Adobe and beyond have sought to host their solutions in as well as to/from Ireland. Many of these reasons are immediately realized due to access to affordable power, redundant network and bandwidth capacity along with a variety of data center providers that offer an array of services sustained by the "5 Ps": Policy, People, Pedigree, Pipes, and Power. On top of that is a very attractive business management structure, implemented by Ireland, which is keenly interested to bring new businesses into the market. Ireland supports this initiative through attractive fiscal structures, access to a skilled workforce and full support of the U.S. Safe Harbor and Patriot Acts - ensuring data asset compliance for companies large and small. For more information about Host in Ireland, visit www.hostinireland.com.


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Some factors that affect the Earth's temperatures include clouds, fine particles, and oceans.
- Low, thick clouds primarily reflect solar radiation and cool the surface of the Earth.
- High, thin clouds primarily transmit incoming solar radiation; at the same time, they trap some of the outgoing infrared radiation emitted by the Earth and radiate it back downward, thereby warming the surface of the Earth.
- Whether a given cloud will heat or cool the surface depends on several factors, including the cloud's height, its size, and the make-up of the particles that form the cloud.
- The balance between the cooling and warming actions of clouds is very close - although, overall, cooling predominates.
Fine Particles (aerosols) in the atmosphere
The amount of fine particles or aerosols in the air has a direct effect on the amount of solar radiation hitting the Earth's surface. Aerosols may have significant local or regional impact on temperature.
Atmospheric factors shown in the image below include natural factors such as clouds, volcanic eruptions, natural biomass (forest) burning, and dust from storms. In addition, human-induced factors such as biomass burning (forest and agricultural fires) and sulfate aerosols from burning coal add tiny particles that contribute to cooling. Please watch the following 2:41 presentation: "The Cooling Factors."
When Mount Pinatubo erupted in the Philippines in 1991, an estimated 20 million tons of sulfur dioxide and ash particles blasted more than 12 miles high into the atmosphere. The eruption caused widespread destruction and human causalities. Gases and solids injected into the stratosphere circled the globe for three weeks.
Volcanic eruptions of this magnitude can impact global climate, reducing the amount of solar radiation reaching the Earth's surface, lowering temperatures in the troposphere, and changing atmospheric circulation patterns. The extent to which this occurs is an uncertainty.
Below is a picture of Mount Pinatubo next to a map of its location and how far the ash from its eruption spread.
Water vapor is a greenhouse gas, but at the same time, the upper white surface of clouds reflects solar radiation back into space. Albedo—reflections of solar radiation from surfaces on the Earth—creates difficulties in exact calculations. If, for example, the polar icecap melts, the albedo will be significantly reduced. Open water absorbs heat, while white ice and snow reflect it.
Oceans play a vital role in the energy balance of the Earth. It is known that the top 10 feet of the oceans can hold as much of the heat as the entire atmosphere above the surface. However, most of the incoming energy is incident on the equatorial region.
The water in the oceans in the equatorial regions is warmer and needs to be transported to the northern latitudes. This is done due to natural variations in the temperatures of the water and prevailing winds that cause the disturbances in the surface waters.
The Intergovernmental Panel on Climate Change (IPCC) states that even the low end of this warming projection "would probably be greater than any seen in the last 10,000 years, but the actual annual to decadal changes would include considerable natural variability."
Instructions: Click the play button to learn about the Ocean Conveyor Belt in the 2:52 presentation:


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Human Phonetic Alphabet
The Human Phonetic Alphabet is an alphabetic system of phonemic notation based on the Latin alphabet. It is used as the standard phonemic notation system by the Solar Union, and, consequently, most other Human groups have adopted the standards as well. Essentially, it is an extension of the previously existing International Phonetic Alphabet to cover recent linguistic developments. It is often used by Humans to learn how to approximately pronounce the names of foreign or alien words. Nevertheless, the HPA does not attempt to systematize the sounds of all alien languages, but only those of human languages, in an effort to spread Terran culture. Most alien species instead choose to rely upon their own transcription systems.
page revision: 5, last edited: 24 Jan 2012 02:35