bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rheological behaviour of suspensions prepared from plate‐shaped titanium dioxide particles in (hydroxypropyl) methylcellulose aqueous solution
Authors: Maeyama Kaoru , Yamaguchi Hiroshi , Mukouhara Tomohiro , Kawaguchi Masami , Kato Tadaya 
Published: January 2005

AbstractSuspensions were prepared by homogeneously mixing titanium dioxide particles in (hydroxypropyl) methylcellulose (HPMC) aqueous solutions. Thin plate‐shaped particles were made from balloon materials crushed to pieces. The other three types of particles used as references were plate‐shaped samples surface‐modified with alumina, and two types of spherical particles of anatase and rutile forms. Plateau adsorption amounts of HPMC onto particles depended on their surface properties. Comparisons of rheological behaviour were carried out among the residual three samples except for the sample having the rutile form. Within the concentration range used, the viscosity values of suspensions were rather lower than that of HPMC aqueous solutions. The reason for such low values was attributed to the decrease of entanglements in the semi‐dilute regime and also to steric stabilization resulting from the formation of the HPMC adsorbed layer. The change of structural viscosity and its recovery were evaluated by observation of the decrease of viscosity and its recovery as an indicator. It was confirmed that suspensions of thin plate‐shaped particles had superior structural recovery performance.© 2002 Society of Chemical Industry
Synthesis and photopolymerization of hyperbranched polyurethane acrylates applied to UV curable flame retardant coatings
Authors: Zhu Sheng‐Wu , Shi Wen‐Fang 
Published: January 2005

AbstractA series of hyperbranched polyurethane acrylates containing phosphorus were prepared by reaction of a phosphorus‐containing triol with toluene‐2,4‐diisocyanate and hydroxylethyl acrylate at given ratios. The resins obtained were found to polymerize rapidly in the presence of a photofragmenting initiator under UV irradiation, and the maximum polymerization rate increased with temperature up to 125 °C, then decreased quickly. The UV cured films have flame retardancy with a limiting oxygen index of 27.0.© 2002 Society of Chemical Industry
Synthesis of novel polyurethanes containing dioxybenzylidenecyanoacetate, as non‐linear optical chromophores and their properties
Authors: Lee Ju‐Yeon , Park Eun‐Ju 
Published: January 2005

AbstractMethyl 3,4‐di‐(2′‐hydroxyethoxy)benzylidenecyanoacetate (3) was prepared by hydrolysis of methyl 3,4‐di‐(2′‐vinyloxyethoxy)benzylidenecyanoacetate (2). Diol 3 was condensed with 2,4‐toluenediisocyanate, 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate, and 1,6‐hexamethylenediisocyanate to yield polyurethanes 4, 5 and 6 containing the non‐linear optical (NLO) chromophore 3,4‐dioxybenzylidenecyanoacetate. The resulting polyurethanes 4–6 were soluble in common organic solvents such as acetone and DMF. Tg values of the polymers obtained from DSC thermograms were in the range 80–102 °C. Polymers 4–6 showed thermal stability up to 300 °C in TGA thermograms, and electro‐optic coefficients (r33) of the poled polymer films were in the range 10–12 pm V−1 at 633 nm, which are acceptable for NLO device applications.© 2002 Society of Chemical Industry
Effect of pH on gelatin self‐association investigated by laser light scattering and atomic force microscopy
Authors: Lin Wei , Yan Lifeng , Mu Changdao , Li Wan , Zhang Mingrang , Zhu Qingshi 
Published: January 2005

AbstractThe effect of pH on gelatin self‐association in dilute solution has been investigated for the first time to the authors' knowledge by laser light scattering (LLS) and atomic force microscopy (AFM). It shows that, at the isoelectric point (IEP) of gelatin, the ampholyte macromolecules collapse due to electrostatic attraction forces of oppositely charged groups, and self‐association occurs in turn by an intermolecular association process. The soluble aggregates are stabilized by ionic contacts, hydrogen bonds and hydrophobic interactions, and are protected from precipitation by hydrophilic groups on the surface of the particles. For gelatin‐B away from the IEP, pH ≥ 6.0 or pH ≤ 4.0, the molecular chains behave more like random coils. As expected, the association–disassociation based mainly on electrostatic interactions appears reversible to some certain extent. The experimental results indicate that LLS and AFM, especially a combination of the two, play an important role in obtaining integrated and direct information on the structure and properties of this natural biopolymer.© 2002 Society of Chemical Industry
ZnS as fire retardant in plasticised PVC
Authors: Schartel Bernhard , Kunze Ralf , Neubert Dietmar , Tidjani Adams 
Published: January 2005

AbstractThe flame retardant effect of zinc sulphide (ZnS) in plasticised poly(vinyl chloride) (PVC‐P) materials was investigated. PVC‐P containing different combinations of additives such as 5% ZnS, 5% of antimony oxide (Sb2O3) and 5% of mixtures based on Sb2O3 and ZnS were compared. The thermal degradation and the combustion behaviour were studied using thermogravimetry (TG), coupled with FTIR (TG–FTIR) or with mass spectroscopy (TG–MS), and a cone calorimeter, respectively. A detailed and unambiguous understanding of the decomposition and release of the pyrolysis products was obtained using both TG–MS and TG–FTIR. The influence of ZnS, Sb2O3 and the corresponding mixtures on the thermal decomposition of PVC‐P was demonstrated. Synergism was observed for the combination of the two additives. The combustion behaviour (time to ignition, heat release, smoke production, mass loss, CO production) was monitored versus external heat fluxes between 30 and 75 kW m−2 with the cone calorimeter. Adding 5% of ZnS has no significant influence on the fire behaviour of PVC‐P materials beyond a dilution effect, whereas Sb2O3 works as an effective fire retardant. Synergism of ZnS and Sb2O3 allows the possibility of replacing half of Sb2O3 by ZnS to reach equivalent fire retardancy.© 2002 Society of Chemical Industry
Crystallization behaviour of poly(butylene succinate) copolymers
Authors: Park Jun Wuk , Kim Dong Kook , Im Seung Soon 
Published: January 2005

AbstractPoly(butylene succinate‐co‐butylene 2‐methyl succinate) (PBSMS) random copolymers were synthesized with various comonomer compositions and their crystallization behaviour and morphology were investigated by differential scanning calorimeter, small angle X‐ray scattering and polarized optical microscopy. The equilibrium melting temperature obtained by the Hoffman–Weeks plot significantly decreased with increasing comonomer concentration containing methyl side‐groups. Spherulitic growth rates were strongly dependent on comonomer concentration and were analyzed using the Lauritzen–Hoffman kinetic theory. The surface free energy (σσe) dramatically decreased with comonomer contents. From analysis of the SAXS data, the dependence of the lamellar thickness on crystallization temperature decreased with increasing comonomer concentration.© 2002 Society of Chemical Industry
Effects of trans‐polyoctylene rubber on rheological and green tensile properties of natural rubber/acrylonitrile–butadiene rubber blends
Authors: Nah Changwoon 
Published: January 2005

AbstractThe influence of trans‐polyoctylene rubber (TOR) on the flow property, die swell behaviour and green tensile property of NR (natural rubber)/NBR (acrylonitrile–butadiene rubber) blend compound was investigated as a function of TOR loading level. The pure TOR, NR and NBR compounds were also investigated for comparison with the blend compounds. The shear viscosity of TOR strongly depended on the temperature as well as shear rate. The viscosity of the NR/NBR blend compound was even lower than that of the constituent components at relatively lower shear rates, and the viscosity difference became smaller as the shear rate was increased. The viscosity of the NR/NBR blend compounds was strongly affected by the addition of TOR but the effect became negligible with increasing the shear rate. Both the die‐swell ratio and the surface topology of extrudates were also affected by TOR addition; the dependence on shear rate was much stronger for higher TOR level. The NR/NBR blend compound showed much higher green tensile strength and elongation at break than those of the constituent components. Both the green tensile modulus and strength of the NR/NBR blend compound were greatly enhanced, while the elongation at break was reduced with the addition of TOR.© 2002 Society of Chemical Industry
Highest efficiency rapid thermal processed multicrystalline silicon solar cells
Authors: Noël S. , Lautenschlager H. , Muller J. C. 
Published: January 2005

AbstractThe formation of pn junctions and surface passivation by rapid thermal processing is being proved as a new and competitive method for silicon solar cell production. As the main process mechanisms are enhanced, the total process time at high temperature can be kept in the minute range, for the realization of emitter, back surface field (BSF) and surface passivation. In this work, we demonstrate for the first time that this knowledge, avoiding any in‐situ annealing step acquired on the sc‐Si, can also be applied on industrial mc‐Si (Polix©) without bulk degradation, leading to a record conversion efficiency of 16·7%. Copyright © 2001 John Wiley & Sons, Ltd.
Photovoltaic market and costs forecast based on a demand elasticity model
Authors: Luque Antonio 
Published: January 2005

AbstractA model of the increase in sales of photovoltaic modules is presented, based on coupling the learning curve and the demand elasticity equations. The model, solved for constant demand elasticity, shows good agreement with past sales data, better than any exponential growth curve. We have used this model, properly refined, to extrapolate the market evolution for the next half century, and we have compared the results with the goals of the RIGES scenario for CO2abatement, presented to the Rio Conference of 1992. The model predicts a very fast growth that will slow down when a certain level of annual sales is reached. It is uncertain if the size of the photovoltaics industry will reach a level with a major environmental impact. New technological findings may be the fastest way to reach the environmental goals, but changes of the present marketing scheme or electricity price increases may also lead to the desired environmental impact in the first half of the century.Se presenta un modelo basado en el acoplamiento de las ecuaciones de la curva de aprendizaje y la curva de elasticidad de la demanda. El modelo, resuelto para elasticidad de la demanda constante, muestra un buen acuerdo con las ventas pasadas, mejor que cualquier exponencial. Hemos usado este modelo, refinado adecuadamente, para extrapolar la evolución del mercado al próximo medio siglo y hemos comparado los resultados con los objetivos del escenario RIGES para reducción del CO2presentados en la cumbre de Río de 1992. El modelo predice un crecimiento muy rápido que se ralentizará cuando se alcance un cierto nivel de ventas anuales. Aunque este negocio ha de llegar a ser muy grande, no es seguro si alcanzará un impacto ambiental significativo. Nuevos hallazgos tecnológicos pueden constituir el medio más rápido para alcanzar los objetivos ambientales, pero cambios en el actual modo de comercialización, o incrementos del precio de la electricidad pueden también conducir a alcanzar los impactos ambientales significativos deseados en la primera mitad del siglo. Copyright © 2001 John Wiley & Sons, Ltd.
Limiting photovoltaic monochromatic light conversion efficiency
Authors: Green Martin A. 
Published: January 2005

AbstractNotwithstanding the relatively low energy conversion efficiencies typical of standard solar photovoltaic systems, photovoltaic cells are shown, in principle, to be capable of converting well‐collimated monochromatic light at efficiencies arbitrarily close to 100%. To approach such efficiencies, radiative recombination must be the main recombination process within the cell. The intensity of the monochromatic light must be high, and the cell should be designed so that it does not absorb or emit light outside the range of angles and wavelengths required to accept the incident monochromatic light. The thermodynamic basis of such high efficiency is also briefly discussed. Copyright © 2001 John Wiley & Sons, Ltd.
A photovoltaic solar home system dissemination model
Authors: Barua Dipal C. , Urmee Tania P. , Kumar S. , Bhattacharya S. C. 
Published: January 2005

AbstractDissemination of photovoltaic (PV) electricity generation systems in developing countries faces a multitude of financial, technical, institutional and policy barriers. Demonstration of the system by appropriately selecting sites and users, providing an appropriate financial mechanism and technical support, and creating awareness among users can serve to trigger significant spontaneous propagation of PV systems. A strategy/approach adopted in promoting dissemination of solar home systems (SHSs) in Bangladesh is described, together with details of the methodology, including the planning, maintenance and training efforts undertaken. Progress in propagation of PV systems has been monitored since the installation of the demonstration systems; the success of the approach adopted can be gauged by the fact that since the installation of ten demonstration units in the selected area, a tremendous increase in the sale of PV SHSs has been observed. Copyright © 2001 John Wiley & Sons, Ltd.
Bulk resistivity optimization for low‐bulk‐lifetime silicon solar cells
Authors: Brody Jed , Rohatgi Ajeet , Yelundur Vijay 
Published: January 2005

AbstractGuidelines are presented which are designed to achieve planar solar cell efficiencies as high as 17.5% using existing fabrication technologies and silicon substrates with lifetimes as low as 20 μs. Device simulations are performed to elucidate the need and impact of base doping optimization for different back‐surface passivation schemes, cell thicknesses, emitter profiles, and degrees of dopant–defect interaction. Results indicate that optimal resistivity is a function of back‐surface passivation, with the aluminum back‐surface field (BSF) requiring the highest resistivity, the oxide/nitride stack passivation excelling at an intermediate resistivity, and the ohmic contact needing the lowest resistivity. A comparison of simulated 300 and 100 μm cells shows that thinner cells magnify the differences in optimal resistivity for the three back‐surface passivation schemes. A lifetime model is used to account for dopant–defect interaction that can lower bulk lifetime at higher doping levels. It is demonstrated that cell efficiency decreases and optimal resistivity increases at higher levels of dopant–defect interaction. Simulated devices with an optimized base doping showed an efficiency improvement of as much as 2% (absolute) compared with identical devices with a typical base doping level (1.6 or 1.8 Ω cm) and bulk lifetime of 20 μs. Copyright © 2001 John Wiley & Sons, Ltd.
Solar cell efficiency tables (version 18)
Authors: Green Martin A. , Emery Keith , King David L. , Igari Sanekazu , Warta Wilhelm 
Published: January 2005

AbstractConsolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries, since January 2001, are reviewed. Copyright © 2001 John Wiley & Sons, Ltd.
Proteomic analysis of salt stress‐responsive proteins in rice root
Authors: Yan Shunping , Tang Zhangcheng , Su Weiai , Sun Weining 
Published: January 2005

AbstractSalt stress is one of the major abiotic stresses in agriculture worldwide. We report here a systematic proteomic approach to investigate the salt stress‐responsive proteins in rice (Oryza sativa L. cv. Nipponbare). Three‐week‐old seedlings were treated with 150 mM NaCl for 24, 48 and 72 h. Total proteins of roots were extracted and separated by two‐dimensional gel electrophoresis. More than 1100 protein spots were reproducibly detected, including 34 that were up‐regulated and 20 down‐regulated. Mass spectrometry analysis and database searching helped us to identify 12 spots representing 10 different proteins. Three spots were identified as the same protein, enolase. While four of them were previously confirmed as salt stress‐responsive proteins, six are novel ones, i.e. UDP‐glucose pyrophosphorylase, cytochrome c oxidase subunit 6b‐1, glutamine synthetase root isozyme, putative nascent polypeptide associated complex alpha chain, putative splicing factor‐like protein and putative actin‐binding protein. These proteins are involved in regulation of carbohydrate, nitrogen and energy metabolism, reactive oxygen species scavenging, mRNA and protein processing, and cytoskeleton stability. This study gives new insights into salt stress response in rice roots and demonstrates the power of the proteomic approach in plant biology studies.
Phosphoprotein profiling of erythropoietin receptor‐ dependent pathways using different proteomic strategies
Authors: Körbel Sandra , Büchse Tom , Prietzsch Holger , Sasse Tilo , Schümann Michael , Krause Eberhard , Brock Josef , Bittorf Thomas 
Published: January 2005

AbstractProteomic techniques provide new tools for the global analysis of protein profiles but also for the investigation of specific protein functions. The analysis of signaling cascades has traditionally been performed by the determination of enzymatic or transcription factor activities representing a certain pathway. Functional proteomics now allows more comprehensive approaches to study cellular responses induced during ligand/receptor interactions. In this study we evaluated proteomic strategies for the investigation of structure‐function relationships in the erythropoietin receptor signalling complex. After expression of epidermal growth factor/erythropoietin receptor mutant molecules in an identical cellular background we characterized their potential to induce cellular activities. Using this system we focused our efforts on post‐translational modifications of signalling proteins reflecting a substantial part of receptor‐dependent signaling events. Although tyrosine phosphorylated proteins were enriched by immunoprecipitation the analysis using the classical approach combining two‐dimensional gel electrophoresis and identification by matrix assisted laser desorption/ionization‐time of flight‐mass spectrometry revealed that low expressed signaling proteins cannot be detected by this technique. An alternative strategy using one‐dimensional gel separation of phosphoproteins and liquid chromatography‐tandem mass spectrometry, however, allowed us to identify multiple proteins involved in intracellular signalling representing already established pathways but also proteins which have not been linked to EPO‐induced signaling so far. This approach offers the potential to extend functional proteomic studies to complex signaling processes.
A comparison of immobilized pH gradient isoelectric focusing and strong‐cation‐exchange chromatography as a first dimension in shotgun proteomics
Authors: Essader Amal S. , Cargile Benjamin J. , Bundy Jonathan L. , Stephenson James L. 
Published: January 2005

AbstractRecently, we have developed a high‐resolution two‐dimensional separation strategy for the analysis of complex peptide mixtures. This methodology employs isoelectric focusing of peptides on immobilized pH gradient (IPG) gels in the first dimension, followed by reversed‐phase chromatography in the second dimension, and subsequent tandem mass spectrometry analysis. The traditional approach to this mixture problem employs strong‐cation‐exchange (SCX) chromatography in the first dimension. Here, we present a direct comparison of these two first‐dimensional techniques using complex protein samples derived from the testis of Rattus norvegicus. It was found that the use of immobilized pH gradients (narrow range pH 3.5–4.5) for peptide separation in the first dimension yielded 13% more protein identifications than the optimized off‐line SCX approach (employing the entire pI range of the sample). In addition, the IPG technique allows for a much more efficient use on mass spectrometer analysis time. Separation of a tryptic digest derived from a rat testis sample on a narrow range pH gradient (over the 3.5–4.5 pH range) yielded 7626 and 2750 peptides and proteins, respectively. Peptide and protein identification was performed with high confidence using SEQUEST in combination with a data filtering program employing pI and statistical based functions to remove false‐positives from the data.
Density functional theory calculations of 17O and 13C NMR chemical shifts for aromatic acyl chlorides
Authors: Chao Ito , Chen Ko‐Wen , Hwang Tsong‐Song , Liu Kwang‐Ting 
Published: January 2005

AbstractDensity functional theory (DFT) at the B3LYP/6–31 + G(d,p)//B3LYP/6–31G(d) level was used to calculate 17O and 13C NMR chemical shifts of the carbonyl group of aromatic acyl chlorides 1a–n. The aryl groups included substituted phenyl, furyl, thienyl and naphthyl. The calculated 17O chemical shifts correlated well with the experimental values and with Hammett‐type σ+ constants. Therefore, in many cases it is possible to deduce σ+ constants of substituted aryl groups via gas‐phase calculation of 17O chemical shifts of the carbonyl groups. The σ+ values obtained in the gas‐phase calculation show the intrinsic property of substituents, so they provide a good reference set for systematic comparison to evaluate the effect of the environment. Furthermore, the concept of n–π* mixing can be used to understand the sensitivity of the O and Cl atoms and the insensitivity of the C atom towards substituent effects in aromatic acyl chlorides. Copyright © 2001 John Wiley & Sons, Ltd.
Substituent effects on benzyne electronic structures
Authors: Johnson William T. G. , Cramer Christopher J. 
Published: January 2005

AbstractThe effect of inductive strength and π‐conjugating tendency on the structure and energetics of singly substituted benzynes is studied for different substituents. For amino and cyano substituents, all possible isomers are examined. For silyl and ammonio substituents, meta isomers are examined. Copyright © 2001 John Wiley & Sons, Ltd.
Applications of non‐steady‐state kinetics in physical organic chemistry: guidelines for the resolution of the kinetics of complex reaction mechanisms
Authors: Parker Vernon D. , Zhao Yixing 
Published: January 2005

AbstractThe resolution of the kinetics of the reversible consecutive second‐order reaction mechanism

involving the formation of a kinetically significant intermediate, which does not reach steady state before late in the first half‐life, followed by an irreversible product‐forming reaction is discussed. It is shown that an apparent second‐order rate constant kapp and an extent of reaction–time profile are the only experimental data necessary for the evaluation of kf and kb (the forward and reverse rate constants) as well as kp (the microscopic rate constant for the product forming reaction). When the product‐forming step involves the cleavage of a CH bond, for which there is a deuterium kinetic isotope effect on kp, the resolution of the kinetics is enhanced. In this case, the experimental data include two apparent rate constants ($k_{\rm app}^{\rm H}$ and $k_{\rm app}^{\rm D}$) and two extent of reaction–time profiles, one for normal reactants and the other for isotopically substituted reactants. Under these circumstances, a unique highly resolved experimental to theoretical data fit is found that results in the evaluation of all four microscopic rate constants: $k_{\rm f},\,k_{\rm b},\,k_{\rm p}^{\rm H}$ and $k_{\rm p}^{\rm D}$. An alternative, when a kinetic isotope effect is not involved, is to fit the extent of reaction–time profiles for two or more concentrations of reactants concurrently. This procedure results in the resolution of the three microscopic rate constants for the reaction. Copyright © 2001 John Wiley & Sons, Ltd.