bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monomer and radical reactivity ratios in 4‐vinylbenzenesulfonic acid sodium salt–acrylamide copolymerization in 0.1M NaCl solution
Authors: Sünbül D. , Paril A. , Alb A. M. , Catalgil‐Giz H. , Giz A. T. 
Published: November 2010

AbstractReaction kinetics and composition of 4‐vinylbenzenesulfonic acid sodium salt (VB)–acrylamide (Aam) copolymerization in 0.1M NaCl solution are investigated. Data obtained by the automatic continuous monitoring of copolymerization system, up to 80% conversion, are analyzed by an “error‐in‐variables method” developed for obtaining the reactivity ratios by on‐line monitoring. Monomer reactivity ratios are found as rAam = 0.085 ± 0.020, rVB = 2.0 ± 0.33. Although the terminal model describes the composition data well, it is seen to be inconsistent with the reaction rates. This discrepancy is attributed to implicit penultimate effects and using the recently developed calculation method, effective radical reactivity ratios are found as sVB = 0.26 and sAam = 0.027, and both composition and rate data fit the implicit penultimate model extremely well. On‐line monitored data showed that in the reactions where the VB was completely consumed, the subsequent Aam homopolymerization was very rapid; thus, the reaction showed definitely two rate regimes, before and after VB depletion. Acrylamide take up rate also showed these two rate regimes. We conclude that low conversion results can be misleading and reactions must be monitored up to a high conversion for a robust control of composition and reaction kinetics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Modeling the degradation of natural rubber male condoms
Authors: Bó Maria Cristina , Gerofi John Paul , Nunes Regina Célia R. , Pinto José Carlos 
Published: November 2010

AbstractMost condom manufacturers claim a 5 year shelf‐life for their products; however, condoms can decay much more rapidly than the reported shelf‐life would suggest, because of the uncontrolled storage conditions. For this reason, development of mathematical model to predict condom shelf‐life as a function of storage conditions can be very useful. In this work, six brands of condoms were aged under subtropical ambient conditions for 5 years and under accelerated conditions at four temperatures for various times. The changes in burst pressure and burst volume were used as the main indicators of product degradation. Experimental data were analyzed and two mathematical models (both based on the reparameterized Arrhenius equation) were proposed to describe the obtained data. It is shown for the first time that it is possible to estimate and predict the degradation of natural rubber condoms with confidence with the help of the proposed models, based on data obtained from accelerated degradation experiments, provided that different activation energies are used for the burst pressure and volume. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A modified poly(aryle ether ketone sulfone) proton exchange membrane with in situ polymerized polypyrrole for the direct methanol fuel cells
Authors: Wang Zhe , Chang Hong , Ni Hongzhe , Wu Qinghai , Zhang Mingyao , Zhang Huixuan 
Published: November 2010

AbstractTo meet with the requirement of proton exchange membrane in direct methanol fuel cells (DMFCs), sulfonated poly(aryle ether ketone sulfone)/ polypyrrole(SPAEKS/Ppy) composite membranes with different contents of Ppy were prepared by chemically in situ polymerization. FT‐IR spectra suggested that the sulfonic groups on SPAEKS copolymers interacted with N groups of Ppy. SEM pictures showed that the Ppy particles were uniformly distributed throughout the SPAEKS membranes matrix. The composite membranes showed good thermal stability, low water uptake, and high proton conductive capability. The methanol diffusion coefficient (1.18 × 10−7 cm2/s) of the composite membrane with 15% Ppy was much lower than that of pure SPAEKS membrane (8.52 × 10−7 cm2/s). The composite membranes showed very good potential usage in direct methanol fuel cells (DMFCs). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Geschichtliche Entwicklung und aktuelle Praxis der Probebelastung — Teil 1: Geschichtliche Entwicklung im 19. und Anfang des 20. Jahrhunderts
Authors: Bolle Guido , Schacht Gregor , Marx Steffen 
Published: November 2010

AbstractSeit der Urzeit sind Menschen bestrebt, in allen Bereichen ihres Lebens ein möglichst großes Maß an Sicherheit zu erreichen. Für das Bauwesen gilt das in ganz besonderer Weise, denn das Versagen von Bauwerken ist in der Gesellschaft viel weniger akzeptiert, als zum Beispiel das Versagen von Kraftfahrzeugen oder elektronischen Geräten. Speziell empfinden wir das Gefühl von Sicherheit, wenn wir “wissen“ oder “sehen“, dass Bauteile den entsprechenden Lasten standhalten. Deshalb stellten Probebelastungen bis ins 19. und 20. Jahrhundert den ultimativen Nachweis der Tragsicherheit für Bauteile und Bauwerke dar. Besonders die Stahlbetonbauweise konnte sich in ihren Anfangsjahren nur deshalb durchsetzen, weil ihre Leistungsfähigkeit durch vielfältige Belastungsproben gegenüber einer großen Öffentlichkeit wirkungsvoll bewiesen wurde.Historical development and current practise of load tests in situ — part 1: historical development in the 19th and at the begin of the 20th century. Since prehistoric times people are striving to achieve the largest possible range of safety in all areas of their lives. For the construction industry this is important in a very special way, because the failure of structures is much less accepted in society, as for example the failure of motor vehicles or electronic devices. We especially feel a sense of security if we really “know“ or “see“ that components can withstand the appropriate loads. Therefore, load tests represented the ultimate proof of the safety of components and structures during the 19th and 20th Century. Especially, reinforced concrete could prevail in its early years only because its performance has been proven effective by a multitude of load tests to a wide public.
A dysmorphology score system for assessing embryo abnormalities in rat whole embryo culture
Authors: Zhang Cindy X. , Danberry Tracy , Jacobs Mary Ann , Augustine‐Rauch Karen 
Published: November 2010

AbstractBACKGROUND: The rodent whole embryo culture (WEC) system is a well‐established model for characterizing developmental toxicity of test compounds and conducting mechanistic studies. Laboratories have taken various approaches in describing type and severity of developmental findings of organogenesis‐stage rodent embryos, but the Brown and Fabro morphological score system is commonly used as a quantitative approach. The associated score criteria is based upon developmental stage and growth parameters, where a series of embryonic structures are assessed and assigned respective scores relative to their gestational stage, with a Total Morphological Score (TMS) assigned to the embryo. This score system is beneficial because it assesses a series of stage‐specific anatomical landmarks, facilitating harmonized evaluation across laboratories. Although the TMS provides a quantitative approach to assess growth and determine developmental delay, it is limited to its ability to identify and/or delineate subtle or structure‐specific abnormalities. Because of this, the TMS may not be sufficiently sensitive for identifying compounds that induce structure or organ‐selective effects. METHOD: This study describes a distinct morphological score system called the “Dysmorphology Score System (DMS system)” that has been developed for assessing gestation day 11 (approximately 20–26 somite stage) rat embryos using numerical scores to differentiate normal from abnormal morphology and define the respective severity of dysmorphology of specific embryonic structures and organ systems. This method can also be used in scoring mouse embryos of the equivalent developmental stage. RESULT AND CONCLUSION: The DMS system enhances capabilities to rank‐order compounds based upon teratogenic potency, conduct structure‐ relationships of chemicals, and develop statistical prediction models to support abbreviated developmental toxicity screens. Birth Defects Res (Part B) 89:485–492, 2010. © 2010 Wiley‐Liss, Inc.
Polylactic acid (PLA): Research, development and industrialization
Authors: Pang Xuan , Zhuang Xiuli , Tang Zhaohui , Chen Xuesi 
Published: November 2010

AbstractPolylactide (PLA) is a biodegradable, aliphatic polyester derived from lactic acid. It has similar mechanical properties to polyethylene terephthalate, but has a significantly lower maximum continuous use temperature. PLA products can be recycled after use either by remelting and processing the material a second time or by hydrolyzing to lactic acid, the basic chemical. In this review, the technologies for polymerization of the lactic acid and the comparison of physical, thermal and mechanical properties, biodegradability, and biocompatibility of the PLA and copolymers with other similar polymers are described.
Increased expression of recombinant human tissue plasminogen activator in Leishmania tarentolae
Authors: Hemayatkar Mahdi , Mahboudi Fereidoun , Majidzadeh‐A Keivan , Davami Fatemeh , Vaziri Behrouz , Barkhordari Farzaneh , Adeli Ahmad , Mahdian Reza , Davoudi Noushin 
Published: November 2010

AbstractRecombinant tissue plasminogen activator (rt‐PA) is one of the most important thrombolytic agents for treating cardiovascular obstructions such as stroke. Glycoprotein rt‐PA is a serine protease, consisting of 527 amino acids of which 35 are cysteine residues. A variety of recombinant protein expression systems have been developed for heterologous gene expression in prokaryotic and eukaryotic hosts. In recent years, Leishmania tarentolae has been considered because of its safety aspects and special attributes in expression of complex proteins. In this study, two expression cassettes, each one including two copies of t‐PA cDNA, were used for integration into the L. tarentolae genome by electroporation. Transformed clones were selected in the presence of appropriate antibiotics. Expression of active rt‐PA was confirmed by Western blot and Zymography tests. Real‐time PCR analysis was applied to investigate the presence of multiple t‐PA gene copies in the parasite genome. Correlation of t‐PA gene dosage and production rate was confirmed with real‐time PCR. It was shown that the expression level of rt‐PA in L. tarentolae is at least 480 IU/mL of culture media. This concentration of rt‐PA is seven times higher than what was reported in previous studies in L. tarentolae and some other eukaryotic systems.
Methodology for and the determination of the major constituents and metabolites of the Amazonian botanical medicine ayahuasca in human urine
Authors: McIlhenny Ethan H. , Riba Jordi , Barbanoj Manel J. , Strassman Rick , Barker Steven A. 
Published: November 2010

AbstractAyahuasca, also known as caapi or yage among various South American groups, holds a highly esteemed and millennia‐old position in these cultures' medical and religious pharmacopeia. There is now an increasing interest in the potential for modern medical applications of ayahuasca, as well as concerns regarding its increasing potential for abuse. Toxicological and clinical research to address these issues will require information regarding its metabolism and clearance. Thus, a rapid, sensitive and specific method for characterization and quantitation of the major constituents and of the metabolites of ayahuasca in urine is needed. The present research provides a protocol for conducting such analyses. The characteristics of the method, conducted by sample dilution and using HPLC–electrospray ionization (ESI)–selected reaction monitoring (SRM)–tandem mass spectrometry, are presented. The application of the analytical protocol to urine samples collected from three individuals that were administered ayahuasca has also been demonstrated. The data show that the major metabolite of the hallucinogenic component of ayahuasca,N,N‐dimethyltryptamine (DMT), is the correspondingN‐oxide, the first time this metabolite has been described inin vivostudies in humans. Further, very little DMT was detected in urine, despite the inhibition of monoamine oxidase afforded by the presence of the harmala alkaloids in ayahuasca. The major harmala alkaloid excreted was tetrahydroharmine. Other excretion products and metabolites were also identified and quantified. The method described would be suitable for use in further toxicological and clinical research on ayahuasca. Copyright © 2010 John Wiley & Sons, Ltd.
Remarkable Luminescence Properties of Lanthanide Complexes with Asymmetric Dodecahedron Structures
Authors: Miyata Kohei , Nakagawa Tetsuya , Kawakami Ryuhei , Kita Yuki , Sugimoto Katsufumi , Nakashima Takuya , Harada Takashi , Kawai Tsuyoshi , Hasegawa Yasuchika 
Published: November 2010

AbstractThe distorted coordination structures and luminescence properties of novel lanthanide complexes with oxo‐linked bidentate phosphane oxide ligands—4,5‐bis(diphenylphosphoryl)‐9,9‐dimethylxanthene (xantpo), 4,5‐bis(di‐tert‐butylphosphoryl)‐9,9‐dimethylxanthene (tBu‐xantpo), and bis[(2‐diphenylphosphoryl)phenyl] ether (dpepo)—and low‐vibrational frequency hexafluoroacetylacetonato (hfa) ligands are reported. The lanthanide complexes exhibit characteristic square antiprism and trigonal dodecahedron structures with eight‐coordinated oxygen atoms. The luminescence properties of these complexes are characterized by their emission quantum yields, emission lifetimes, and their radiative and nonradiative rate constants. Lanthanide complexes with dodecahedron structures offer markedly high emission quantum yields (Eu: 55–72 %, Sm: 2.4–5.0 % in [D6]acetone) due to enhancement of the electric dipole transition and suppression of vibrational relaxation. These remarkable luminescence properties are elucidated in terms of their distorted coordination structures.
An economically viable removal of methylene blue by adsorption on activated carbon prepared from rice husk
Authors: Sharma Y. C. , Uma  , Upadhyay S. N. 
Published: November 2010

AbstractApplication of an agricultural waste material, rice husk, has been investigated for preparation of activated carbon. The rice husk‐activated carbon (RHAC) was successfully utilised for the removal of a cationic dye, methylene blue (MB) from aqueous solutions. The activated carbon was prepared in presence of ZnCl2 as an activating agent under inert nitrogen atmosphere. RHAC was characterised for surface area, pore structural parameters, and point zero charge (pHZPC). The activated carbon was further characterised by Fourier transformation infrared (FT‐IR) spectrometer, X‐ray diffractometer (XRD), and scanning electron microscope (SEM).The effect of different parameters such as contact time and initial concentration, adsorbent dose, and temperature on removal of the dye from aqueous solutions was investigated. The experimental data fitted well in both the Freundlich and Langmuir isotherm models. The maximum adsorption capacity for MB was found to be 9.73 mg g−1 at 303 K. During the study of effect of adsorbent dose, almost a 100% removal was achieved at a higher dose of RHAC. Most of the experiments were carried out at an initial concentration of MB of 60 mg/L and at 303 K. Different thermodynamic parameters, viz., changes in free energy (G°), enthalpy (H°), and entropy (S°) have also been determined to explain feasibility of the process of removal. The sorption of MB on RHAC was found to be feasible, spontaneous, and endothermic in nature.
Intelligent fitting of minimum spout‐fluidised velocity in spout‐fluidised bed
Authors: Wang Chun‐Hua , Zhong Zhao‐Ping , Li Rui , E Jia‐Qiang 
Published: November 2010

AbstractThe experiments were carried on to study the minimum spout‐fluidised velocity in the spout‐fluidised bed. It was found that the minimum spout‐fluidised velocity increased with the rise of static bed height, spout nozzle diameter, particle density, particle diameter, fluidised gas velocity but decreased with the rise of carrier gas density. Based on the experiments, least square support vector machine (LS‐SVM) was established to predict the minimum spout‐fluidised velocity, and adaptive genetic algorithm and cross‐validation algorithm were used to determine the parameters in LS‐SVM. The prediction performance of LS‐SVM is better than that of the empirical correlations and neural network.
Controllable synthesis of novel In2O3 nanostructures and their field emission properties
Authors: Huang Yanjun , Yu Ke , Zhu Ziqiang 
Published: November 2010

AbstractThree kinds of novel indium oxide (In2O3) nanostructures, namely, nanorods, nanoflowers and nanowhiskers were synthesized on silicon substrate via a simple vapor‐phase transport method under atmospheric pressure. The In2O3nanostructures were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy‐dispersive X‐ray spectrometer (EDS) spectrum. The Raman spectra of these nanostructures showed four sharp scattering peaks centered at 308, 365, 522, and 628 cm‐1, whose position and intensity were characteristic of standard Raman spectra for In2O3. The Room‐temperature photoluminescence (PL) spectra showed visible emissions centered around 576, 592, and 624 nm. Field emission measurements demonstrated that the nanoflowers possessed the best performance with a turn‐on field of 3.54 V/µm and a threshold field of 9.83 V/µm. And the field enhancement factors of these nanostructures are high enough for the application of field emission display devices. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of Fe3O4 octahedra by a triethanolamine‐assisted hydrothermal process
Authors: Liang Jun , Li Li , Luo Min , Wang Yuan 
Published: November 2010

AbstractOctahedral Fe3O4microcrystals were synthesized using a triethanolamine‐assisted route under hydrothermal conditions. The chemical compositions and morphologies of the as‐prepared samples were characterized in detail by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). During the hydrothermal process for the preparation of Fe3O4 octahedra, the possible mechanism was discussed to elucidate the formation of the octahedral Fe3O4microcrystals. Triethanolamine and hydrazine hydrate play important roles in the formation of the final products. The magnetic property of sample was evaluated on a vibrating sample magnetometer (VSM) at room temperature. The values of saturation magnetization and coercivity of octahedral Fe3O4are about 103 emu/g and 157 Oe, respectively. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and Crystal Structure of Novel Biheterometal and Triheterometal Alkoxide Clusters – Highly Active Catalysts for the Polymerization of ϵ‐Caprolactone
Authors: Sheng Hongting , Feng Yan , Zhang Yong , Shen Qi 
Published: November 2010

AbstractThe effect of the alkali metal on the synthesis, crystal structure, and catalytic reactivity of lanthanide–alkali metal alkoxide clusters is reported. Anhydrous LnCl3 reacts with 6.5 equiv. of KOCH2CH2N(CH3)2 and 1.5 equiv. of KOH in tetrahydrofuran (THF) to give the corresponding lanthanide–potassium biheterometal alkoxide clusters [Ln4K20(OCH2CH2NMe2)26(OH)6] [Ln = Nd (1), Pr (2), Yb (3)] in high yield. Anhydrous YbCl3 reacts with KOCH2CH2N(CH3)2 and NaOH with different molar ratios of 1:9:3 and 1:9:4 to afford the lanthanide–potassium–sodium triheterometal alkoxide clusters [Yb2K10Na6(OCH2CH2NMe2)18(OH)4] (4) and [Yb2K8Na8(OCH2CH2NMe2)18(OH)4] (5), respectively. These clusters were fully characterized by elemental analysis, IR, 1H NMR, and single‐crystal structural analysis. The heterometal alkoxide clusters 1–5 exhibited good catalytic activity for the ring‐opening polymerization of ϵ‐caprolactone (ϵ‐CL). It is interesting to note that the catalytic activity of these heterometal alkoxide clusters increases with the increase of the molar ratio of alkali metal to lanthanide metal. For the same molar ratio of alkali metal to lanthanide metal, however, the catalytic activity of the heterometal clusters is highly dependent on the type and molar ratio of the alkali metal centers. The higher the molar ratio of potassium to sodium, the higher the catalytic activity.
Ruthenium‐Catalyzed Synthesis of 1,5‐Dichlorides by Sequential Intermolecular Kharasch Reactions
Authors: Thommes Katrin , Fernández‐Zúmel Mariano A. , Buron Charlotte , Godinat Aurélien , Scopelliti Rosario , Severin Kay 
Published: November 2010

AbstractSequential intermolecular atom transfer radical addition reactions of activated dichlorides Cl2CRR′ (R = CN, CO2Et, R′ = H, CN, CO2Et) with two olefins catalyzed by [Cp*RuCl2(PPh3)] in the presence Mg allow the synthesis of linear 1,5‐dichlorides. Different olefins can be employed in the first and in the second addition reaction. The reaction products are interesting synthetic precursors as demonstrated by the synthesis of two cyclopentanes by Mg‐induced dechlorination. The structure of trans‐3,4‐diphenylcyclopentanecarbonitrile was determined by single‐crystal X‐ray diffraction.
A bandwidth assignment polling algorithm to enhance the efficiency in QoS long‐reach EPONs
Authors: Merayo N. , Jiménez T. , Fernández P. , Durán R.J. , Lorenzo R.M. , de Miguel I. , Abril E.J. 
Published: November 2010

AbstractA novel polling algorithm is proposed to provide subscriber differentiation at the upstream channel in long‐reach EPONs. As operators and service providers prefer to operate at loads with no congestion and losses, the developed algorithm has been designed to improve the efficiency for those loads at which the network is likely to work. This new scheme permits to anticipate the transmission of some packets in order to take advantage of the wasted bandwidth between consecutive transmissions of ONUs. As a result, not only does this algorithm behave alike other polling algorithms for high loads, but it also improves the efficiency at low and medium loads, leading to a reduction in the mean packet delay. The new algorithm has been tested in different scenarios, motivated by the increasing interest in enlarging the long‐reach EPON distances. Simulation results show that as the distance increases, the algorithm achieves a significant reduction of the mean packet delay for an extended range of loads. Copyright © 2010 John Wiley & Sons, Ltd.
Open interest, cross listing, and information shocks
Authors: Aguenaou Samir , Gwilym Owain Ap , Rhodes Mark 
Published: November 2010

AbstractThis study examines the characteristics and behavior of the demand for hedging, proxied by open interest, for the cross‐listed Euribor futures contract traded at Euronext‐LIFFE and Eurex. The study is unique in its investigation of the simultaneous determinants of open interest in a cross‐listed setting. It also assesses the impact of shocks on traders' demand for hedging and shows how the 9/11 terrorist attacks and the credit crunch influence the level of dependency between Euronext‐LIFFE and Eurex. Differences of opinion, ECB Governing Council meetings, days of the week, contract maturity, illiquidity, and volatility are investigated as potential determinants of open interest. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark 31:755–778, 2011