bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal growth of the intermetallic compound Nd2PdSi3
Authors: Xu Y. , Löser W. , Tang F. , Blum C. G. F. , Liu L. , Büchner B. 
Published: January 2011

AbstractNd2PdSi3 single crystals were grown by a vertical floating zone method with radiation heating at a zone traveling rate of 3 mm/h. The compound exhibits congruent melting behavior at a liquidus temperature of about 1790 °C. The actual crystal composition (35.3 ± 0.5) at.% Nd, (16.2 ± 0.5) at.% Pd, and (48.5 ± 0.5) at.% Si is slightly depleted in Pd and Si with respect to the nominal stoichiometry. Therefore, the gradual accumulation of these elements in the traveling zone led to a decrease of the operating temperature during the growth process. Single crystalline samples exhibit a large anisotropy due to the crystal electric field effect and order ferromagnetically below the Curie temperature TC = 15.1 K. The [001] orientation was identified as the magnetic easy axis at low temperatures. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scaling Design and Experimental Study on Hall Thrusters with Curved Magnetic Field
Authors: Ding Y. J. , Yu D. R. , Jia D. C. , Yan G. J. , Li H. 
Published: January 2011

AbstractThe existing scaling theories of Hall thrusters are based on the hypothesis of a one‐dimensional straight magnetic field, which is not suitable for the design of modern thrusters with a two‐dimensional curved magnetic field. In this paper, using the equation analysis method, we derive new similarity criterions in a curved magnetic field by analyzing the momentum equations of charged particles; consequently, we propose a new modeling design method for Hall thrusters with a constant discharge voltage. This method is further validated by experiments. A designed model with a power of 1.5 kW is made based on our proposed method from a prototype model with a power of 1 kW. The experimental results demonstrate that these two thrusters have little differences in performance and physical processes as expected from the scaling. Therefore, our method is well suited for designing a Hall thruster with a curved magnetic field (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Contribution to Calculation of Ion Microfield Nonuniformity Effect on the Asymmetry of Lyman‐αLine in Dense Plasma
Authors: Chenini K. , Khelfaoui F. , Guerricha S. , Chihi S. , Ouahhab A. , Meftah M. T. 
Published: January 2011

AbstractThe high orders of Stark effects on spectral line shapes are examined in the ion‐static and electron‐impact ap‐proximations. At first the distribution functions of the spatial derivative of the ion microfield inHe+plasma are calculated for different plasma conditions when the coupling parameter is weak. We present new results about the spatial derivative ion microfield distributions and apply them to show the asymmetry of the Lyman‐α(Ly‐α) line inHe+plasma. At the second stage we show that asymmetry is affected by the spatial derivative tensor of the local ion electric field. We have used the Monte‐Carlo simulation (MCS) to compute the distribution functions for all tensor components and use them to solve the evolution equation of emitter whose solution serves to compute and therefore to show the line shape asymmetry. Good agreement of our distribution functions of ion microfield gradients and the line asymmetry with other results are obtained (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diagnostics of High‐Pressure Arc Plasmas by Hydrogen Balmer Spectra
Authors: Omar B. , Wierling A. , Röpke G. 
Published: January 2011

AbstractWe re‐examine several Balmer spectra obtained from high‐pressure arc discharges (Radtke and Günther, Contrib. Plasma Phys. 26, 143 (1986); Radtke, Günther, and Spanke, ibid. 26, 151 (1986)). By matching synthetic spectra to the experimental line profiles, we infer plasma parameters such as density, temperature, and composition. Spectral line modeling is based on a microscopic quantum statistical approach. Corrections accounting to the merging lines near the threshold are describe following a model of D'yachkov. Self‐absorption is clearly visible in the spectra and accounted for in one‐dimensional model assuming thermal equilibrium. A consistency check is performed by comparing to the broadening of silicon impurity lines, where present in some of the spectra. Furthermore, a comparison is made with predictions from a fluid variational model for the composition and the equation of state of the plasma (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polyhydroxybutyrate production by Saccharophagus degradans using raw starch as carbon source
Authors: González‐García Yolanda , Rosales Mario A. , González‐Reynoso Orfil , Sanjuán‐Dueñas Rubén , Córdova Jesús 
Published: January 2011

AbstractBiosynthesis of poly(3‐hydroxybutyrate) (PHB) from raw starch as the carbon source by the polysaccharide‐digesting bacteria Saccharophagus degradans was investigated in a fed‐batch culture. The production and properties of the PHB synthesized from starch were compared to those obtained using glucose as carbon source. In fed‐batch cultures, S. degradans accumulated 21.35 and 17.46% of PHB, using glucose or starch as carbon source, respectively. The physical properties of the biopolymer produced from each carbon source were similar between them. Molecular mass, melting temperature and heat of fusion were 54.23 kDa, 165.61°C and 59.59 J/g, respectively, using glucose; and 57.07 kDa, 174.31°C and 67.66 J/g, respectively, using starch. This is the first work describing the capability of S. degradans to utilize raw starch as the sole carbon source for the production of PHB.
A single‐point mutation enables lactate dehydrogenase from Bacillus subtilis to utilize NAD+ and NADP+ as cofactor
Authors: Richter Nina , Zienert Anke , Hummel Werner 
Published: January 2011

AbstractThe NAD+‐dependent lactate dehydrogenase from Bacillus subtilis (BsLDH) catalyzes the enantioselective reduction of pyruvate to lactate. BsLDH is highly specific to NAD+ and exhibits only a low activity with NADP+ as cofactor. Based on the high activity and good stability of LDHs, these enzymes have been frequently used for the regeneration of NAD+. While an application in the regeneration of NADP+ is not sufficient due to the cofactor preference of the BsLDH. In addition, NADP+‐dependent LDHs have not yet been found in nature. Therefore, a structure‐based approach was performed to predict amino acids involved in the cofactor specificity. Methods of site‐saturation mutagenesis were applied to vary these amino acids, with the aim to alter the cofactor specificity of the BsLDH. Five constructed libraries were screened for improved NADP+ acceptance. The mutant V39R was identified to have increased activity with NADP+ relative to the wild type. V39R was purified and biochemically characterized. V39R showed excellent kinetic properties with NADP(H) and NAD(H), for instance the maximal specific activity with NADPH was enhanced 100‐fold to 90.8 U/mg. Furthermore, a 249‐fold increased catalytic efficiency was observed. Surprisingly, the activity with NADH was also significantly improved. Overall, we were able to successfully apply V39R in the regeneration of NADP+ in an enzyme‐coupled approach combined with the NADP+‐dependent alcohol dehydrogenase from Lactobacillus kefir. We demonstrate for the first time an application of an LDH in the regeneration of NADP+.
Synthesis of 4,5‐dihydroimidazo[5,1‐c][1,4,2]benzodiazaphosphinines
Authors: Zarudnitskii Evgeniy V. , Kyrylchuk Andrey A. , Huryeva Anastasiia N. , Kostyuk Aleksandr N. , Yurchenko Aleksandr A. 
Published: January 2011

AbstractDerivatives of a novel phosphorus‐containing heterocyclic system, 4,5‐dihydroimidazo [5,1‐c][1,4,2]benzodiazaphosphinine, have been prepared by the direct phosphorylation of 1‐(2‐(aroyl/alkyl)aminophenyl)‐2‐methylthioimidazole with dibromophenylphosphine in a basic medium. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:91–95, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20658
Temperament and sleep–wake behaviour from infancy to toddlerhood
Authors: Hayes Marie J. , McCoy Shannon K. , Fukumizu Michio , Wellman Joseph D. , DiPietro Janet A. 
Published: January 2011

AbstractSleep–wake behaviours and temperament were examined longitudinally for trait stability and relationship to behavioural state regulation from infancy to early childhood. Subjects were 120 low‐risk, full‐term infants from a middle class sample. At 6 weeks, parents completed three consecutive days of the Baby's Day Diary which measures sleep, wake, fuss, feed and cry states and the Infant Characteristics Questionnaire. At 16 months, parents assessed sleep behaviours with the Sleep Habits Inventory and temperament with the Toddler Symptom Checklist. At 24 months, parents repeated 3 days of the Baby's Day Diary. Structural Equation Modelling was used to examine the cross‐age hypotheses for sleep–wake and temperament associations. From early infancy to toddlerhood, sleep–wake behaviours and irritable temperament were notably stable but independent in this cohort. Copyright © 2011 John Wiley & Sons, Ltd.
South Africa without apartheid: Estimates from general equilibrium simulations
Authors: Iyengar Murali , Porter Richard C. 
Published: January 2011

AbstractA general equilibrium model of the South African economy in the 1980s is constructed, focusing on the labour‐market distortions created by legal and customary restrictions on nonwhite labour mobility. The model is static and calibrated to the data of 1980; its simplified representation of the economy incorporates five production sectors, two race categories, two skill levels, and five kinds of labour‐market constraints. Three counter‐factual simulations are conducted:The labour‐market constraints are relaxed marginally, one at a time. Such change has little impact on either the level of GDP or its distribution.The constraints are derived that would be preferred by different white sub‐groups – were each sub‐group to choose the various constraints so as to maximize its own income. No such group hasuneconomicmotive in keeping so many Blacks in the reserves. Beyond that, interests diverge. Urban capital would like to expand the entry of nonwhites into the cities and into skilled jobs. White farmers, white mining labour, and white urban unskilled labour would like to keep nonwhites out of the cities and out of skilled jobs. White urban skilled labour stands between these groups.The outcome of perfectly free labour markets is examined, under the assumption that the education level of nonwhites permits them to move either slowly or rapidly into the newly accessible skilled jobs. GDP rises from five to ten per cent, and dramatic income redistribution is achieved. Some nonwhites experience wage increases up to one half; skilled whites are not much affected, and even the direction of the impact on them is unclear; profits increase by as much as one fifth; and the incomes of white farmers and unskilled white labourers my fall by more than one half.The measured changes owing to a transition to free labour markets, large as they are, represent no more than lower‐bound estimates of the effects of apartheid since the simulations deal only with the racial restraints on labour markets and do not contemplate possible racial redistribution of the ownership of land, physical capital, or human capital.
The impact of multilateral and tied bilateral aid on the UK economy
Authors: Morrissey Oliver 
Published: January 2011

AbstractIn line with their commitment to reduce public spending, the Conservative government under Thatcher cut the aid budget by some six per cent in real terms in their first five years in power, with the brunt of the cuts falling on bilateral aid. Business groups deplored this trend and argued that it be reversed because tied bilateral aid generated greater commercial benefits for the economy than multilateral aid, an argument which government ministers appeared to accept. We estimate and compare the impact of multilateral and tied bilateral aid on the UK economy in 1980 and 1985 using Input‐Output impact analysis. The results suggest, quite strongly, that multilateral aid generates greater benefits both in volume terms and per equivalent amount of aid expenditure. We conclude that the case for the increased use of tied bilateral aid is weaker than commonly supposed.
Who is afraid of choices? A proposal for multi‐criteria analysis as a tool for decision‐making support in development planning
Authors: Pétry Françoise 
Published: January 2011

AbstractThe thesis of this paper is that classical economic analysis and traditional optimisation techniques are not sufficient to assist decisionmakers in development planning and policy making, and that new multi‐criteria methodologies developed during the last decade would often provide useful additional tools.Rural development (RD) will be the main focus – due to the author's very limited experience in other technical fields. Some promising approaches will be described and proposals will be made for testing their applicability in various RD planning problems.
Review article: New forms of foreign investment in developing countries
Authors: Evers Barbara , Kirkpatrick Colin 
Published: January 2011

AbstractDeveloping with Foreign Investment. By VINCENT CABLE and BISHNODAT PERSAUD (eds.). (London, Croom Helm, 1987, pp.327, £25.00.)Transnational Corporations in World Development: Trends and Prospects. By UNITED NATIONS CENTRE ON TRANSNATIONAL CORPORATIONS. (New York, United Nations, ST/CTC/89, 1988, pp.623, £37.75.)
Construction of a thermodesorption injector for gas chromatography
Authors: Schröder Wolfgang 
Published: January 2011

AbstractA detailed description for the do‐it‐yourself construction of a high‐performance thermodesorption GC injector (HPTI) is presented. The injector consists of a heated desorption chamber, a cooled loop for focusing the desorbed volatiles as well as a heating control for sample injection into the separation column. The gas flow is controlled by valve switching during the steps of the operation. Two versions of the injector function either for the injection of highly volatile compounds or for compounds with extremely low volatility, e.g. lubricants. The sophisticated gas flow management allows injection of highly concentrated samples without memory effects in a sample gas split mode, while traces may be injected with virtually 1:1 sample transfer. A wide range of adsorbents appropriate for the compounds can be chosen due to homemade adsorbent tubes and the achievability of high desorption temperature. Solutions may be injected from a carrier material after solvent evaporation. The HPTI fulfills all multipurpose GC injector requirements and with the support of downloadable instruction files can be built by anyone working with conventional GC devices.
Kinetics of electropolymerization of 1‐amino‐9,10‐anthraquinone
Authors: Badawy Waheed A. , Ismail Khaled M. , Medany Shymaa S. 
Published: January 2011

Abstract1‐Amino‐9,10‐anthraquinone was electropolymerized on platinum substrates either from aqueous or nonaqueous electrolytes. The aqueous electrolyte was 6.0 mol L−1 H2SO4, and the nonaqueous solvent was acetonitrile containing lithium perchlorate, LiClO4, as a supporting electrolyte. The formed polyaminoanthraquinone was stable, and the polymerization process was reproducible. The kinetics of the electropolymerization process was investigated by determining the charge consumed during the electropolymerization as a function of time at different concentrations of the electrolyte components. The results of chronoamperometry have been used to determine the orders of reaction. In either aqueous or nonaqueous solution, the electropolymerization process follows first‐order kinetics with respect to the monomer concentration. In nonaqueous solution, the very small concentrations of water did not affect the order of reaction. The order of reaction with respect to the traces of water and the supporting electrolyte concentration was found to be zero. In aqueous solution, the order of the electropolymerization reaction with respect to the concentration of H2SO4 was found to be negative (−0.66), which means that the aqueous electrolyte inhibits the polymerization reaction. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 141–146, 2011
Direct Access to Mesoporous Crystalline TiO2/Carbon Composites with Large and Uniform Pores for Use as Anode Materials in Lithium Ion Batteries
Authors: Lee Jinwoo , Jung Yoon S. , Warren Scott C. , Kamperman Marleen , Oh Seung M. , DiSalvo Francis J. , Wiesner Ulrich 
Published: January 2011

AbstractMesoporous and highly crystalline TiO2 (anatase)/carbon composites with large (>5 nm) and uniform pores were synthesized using PI‐b‐PEO block copolymers as structure directing agents. Pore sizes could be tuned by utilizing block copolymers with different molecular weights. The resulting mesoporous TiO2/carbon was successfully used as an anode material for Li ion batteries. Without addition of conducting aid (Super P), the electrode showed high capacity during the first insertion/desertion cycle due to carbon wiring inside the walls of mesoporous TiO2/carbon. The electrode further showed stable cycle performance up to 50 cycles and the specific charge capacity at 30 C was 38 mA h (g of TiO2)−1, which indicates CCM‐TiO2/carbon can be used as a material for high rate use. magnified image
Poly(ethylene glycol)‐Coated Magnetite Nanoparticles: Preparation and Characterization
Authors: Amici Julia , Celasco Edvige , Allia Paolo , Tiberto Paola , Sangermano Marco 
Published: January 2011

AbstractThis paper reports a novel synthetic process to obtain poly(ethylene glycol)‐coated magnetite nanoparticles. Magnetite nanoparticles were synthesized by a chemical co‐precipitation of Fe2+ and Fe3+ ions under alkaline conditions, which were then coated with poly(ethylene glycol) diacrylate via UV‐curing in water. The nanoparticles were characterized by means of DLS, FT‐IR spectroscopy, TGA, TEM, and XPS. The magnetic properties of the magnetic nanoparticles at room temperature were also characterized by the measurement of hysteresis curves using a vibrating‐sample magnetometer. magnified image
Ring‐Opening Metathesis Polymerization‐Derived Materials for Separation Science, Heterogeneous Catalysis and Tissue Engineering
Authors: Buchmeiser Michael R. 
Published: January 2011

AbstractSummary: The chemistry of ring‐opening metathesis polymerization‐ (ROMP) derived monolithic materials is summarized. Since ROMP triggered by well‐defined transition metal alkylidenes is a living polymerization method, it allows for the controlled and highly reproducible synthesis of monolithic media in terms of total porosity, pore size distribution and specific surface area. In addition, the high functionality tolerance of ROMP allows for creating monolithic supports with an unprecedented diversity in terms of functional groups that may be introduced. Selected applications in the areas of separation science, heterogeneous catalysis and tissue engineering are presented and discussed within the context of ROMP.
The Role of Conformations in the Interplay of Structure and Dynamics in Macromolecular and Supramolecular Systems
Authors: Spiess Hans Wolfgang 
Published: January 2011

AbstractSummary: Following Paul J. Flory, the role of local chain conformation in determining the structure and dynamics of macromolecules is elucidated, employing advanced solid state NMR spectroscopy supported by X‐ray scattering and dielectric spectroscopy. Topics covered include the local conformation in amorphous polymers, conformational memory, chain organization and dynamics in semicrystalline polymers, polypeptides, and rod‐coil copolymers.
A Study on Structural, Mechanical and Thermal Properties of Polymer Composites of Poly(vinyl alcohol) with Inorganic Material
Authors: Nasar Gulfam , Khan Muhammad Saleem , Khalil Uzma 
Published: January 2011

AbstractSummary: In this paper we have tried to find the relationship of thermal and mechanical properties i. e. thermal conductivity, tensile strength and Young's Modulus of the composite material. Two systems were selected; poly(vinyl alcohol)/sodium sulphate composite, and poly(vinyl alcohol)/lithium sulphate composite. Various concentrations of these salts were used to make composites of poly(vinyl alcohol). Films were grown, dried at room temperature and were subjected to mechanical, structural and thermal characterization. Thermal conductivity was determined at room temperature using polyethylene, silicon and quartz as reference. It was found out that the thermal conductivity of both the systems is highly dependent on the nature and the concentration of added salt in the polymeric composite. Thermal conductivity of the poly vinyl alcohol/ sodium sulphate composite, and poly vinyl alcohol/lithium sulphate composite, decreased with concentration of the salts in the polymer composite. These composites were also analyzed by XRD. Observed roperties were explained on the bases of their structure. Machenical properties such as tensile strength and Young's Modulus were also found out to be a function of the compostion of the composite
Prediction of Interfacial Interactions between Polymer Layers
Authors: Varvarenko Sergiy , Samaryk Volodymyr , Nosova Nataliya , Puzko Nataliia , Taras Roman , Tarnavchyk Ihor , Voronov Andriy , Kohut Ananiy , Voronov Stanislav 
Published: January 2011

AbstractSummary: Results of a study on polymer surface modification using heterofunctional polyperoxides are presented. A prognostic model of the polymer surface modifier efficiency was developed on the basis of obtained data. It was shown that implementation of demands to the macromolecule composition during development of new peroxide‐containing modifiers in combination with sufficient peroxide group reactivity increased efficiency of the polymer surface modification.
Two‐Dimensional Chromatographic Analysis of Polystyrene‐block‐poly(methyl methacrylate) Copolymers Synthesized by Selective Oxidation of Polystrene‐9‐borabicyclo[3.3.1]nonane
Authors: Elhrari Wael K. , Mallon Peter E. 
Published: January 2011

AbstractSummary: The preparation of polystyrene block methyl methacrylate copolymers (PS‐b‐PMMA) is described. The polystyrene segment was prepared by anionic polymerization and the methylmethacrylate segment was prepared via free radical autoxidation of a borane agent attached to the styrene chain.1 The chemistry involves a transformation of the anionic polymerization process to borane chemistry by firstly producing polystyrene with chain end unsaturated alkyl functional groups prepared using a n‐butyllithium initiator and termination with allylchlorodimethylsilane. Secondly, the unsaturated macroinitiator end was hydroborated by 9‐borabicyclo[3.3.1]nonane (9‐BBN) to produce a borane terminated PS. Thirdly, the borane group at the chain end was selectively oxidized and converted to polymeric radicals in the presence of methyl methacrylate which then initiated radical polymerization to produce block copolymers. The polymer obtained was characterized using several chromatographic techniques including LC‐CC (liquid chromatography under critical conditions) for the polystyrene segments and two‐dimensional chromatography with LC‐CC in the first dimension and SEC in the second. The results show that block formation was successful although significant homopolymerization of methyl methacrylate is also obtained.