bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyramidenbau im Alten Ägypten über Rampen und mit Seilwinden
Authors: Müller‐Römer Frank 
Published: September 2008

AbstractIn der Vergangenheit wurden von Ägyptologen und Archäologen, Ingenieuren und interessierten Laien verschiedenste Hypothesen zum Bau der Pyramiden im Alten Ägypten vorgelegt. Dennoch wurde für die Fragen, nach welchem Verfahren, in welchen Abschnitten, mit welchen Hilfsmitteln und innerhalb welcher Zeit die Pyramiden erbaut wurden, noch kein in sich geschlossener und widerspruchsfreier Lösungsvorschlag zur Diskussion gestellt.Ausgehend vom Stand der ägyptologischen Forschung und den archäologischen Befunden, wurden vom Autor bisher bekannt gewordene Hypothesen zum Bau und Bauvorschläge nach wissenschaftlichen Methoden analysiert und daraufhin überprüft, inwieweit die Pyramiden im Alten Ägypten danach hätten errichtet werden können. Darauf aufbauend wird eine neue, aus den archäologischen Befunden des AR abgeleitete und in sich widerspruchsfreie Hypothese für den Bau der Stufenpyramiden im Alten Reich entwickelt. Diese verbindet erstmals den Einsatz steiler, parallel zu den Stufen des inneren Kernmauerwerks angeordneter Rampen in Kombination mit der Walze in Form der Seilwinde für den Materialtransport und den Bau einer äußeren Arbeitsplattform für die gefahrlose Montage des Pyramidion und die Glättung der Pyramidenverkleidung von oben nach unten. Die danach berechneten Bauzeiten stimmen mit den belegten Regierungsjahren von drei Königen (Snofru, Cheops und Mykerinos) überein.
Expanding substrate specificity of GT‐B fold glycosyltransferase via domain swapping and high‐throughput screening
Authors: Park Sung‐Hee , Park Hyung‐Yeon , Sohng Jae Kyung , Lee Hee Chan , Liou Kwangkyoung , Yoon Yeo Joon , Kim Byung‐Gee 
Published: September 2008

AbstractGlycosyltransferases (GTs) are crucial enzymes in the biosynthesis and diversification of therapeutically important natural products, and the majority of them belong to the GT‐B superfamily, which is composed of separate N‐ and C‐domains that are responsible for the recognition of the sugar acceptor and donor, respectively. In an effort to expand the substrate specificity of GT, a chimeric library with different crossover points was constructed between the N‐terminal fragments of kanamycin GT (kanF) and the C‐terminal fragments of vancomycin GT (gtfE) genes by incremental truncation method. A plate‐based pH color assay was newly developed for the selection of functional domain‐swapped GTs, and a mutant (HMT31) with a crossover point (N‐kanF‐669 bp and 753 bp‐gtfE‐C) for domain swapping was screened. The most active mutant HMT31 (50 kDa) efficiently catalyzed 2‐DOS (aglycone substrate for KanF) glucosylation using dTDP‐glucose (glycone substrate for GtfE) with kcat/Km of 162.8 ± 0.1 mM−1 min−1. Moreover, HMT31 showed improved substrate specificity toward seven more NDP‐sugars. This study presents a domain swapping method as a potential means to glycorandomization toward various syntheses of 2‐DOS‐based aminoglycoside derivatives. Biotechnol. Bioeng. 2009;102: 988–994. © 2008 Wiley Periodicals, Inc.
Determination of acyclovir in horse plasma and body fluids by high‐performance liquid chromatography combined with fluorescence detection and heated electrospray ionization tandem mass spectrometry
Authors: Maes A. , Garré B. , Desmet N. , van der Meulen K. , Nauwynck H. , De Backer P. , Croubels S. 
Published: September 2008

AbstractTwo methods are presented for the determination of ‘respectively’ the plasma protein unbound and total concentration of acyclovir in horse plasma and body fluids: first, a liquid–liquid extraction was performed on plasma, combined with HPLC‐fluorescence detection for the total plasma concentration; second a more sensitive method using high‐performance liquid chromatography combined with heated electrospray ionization tandem mass spectrometry (LC‐HESI‐MS/MS) was described for plasma and for body fluids analysis. To obtain the unbound concentration of acyclovir in plasma, a simple deproteinization step using a Microcon® filter was performed. Ganciclovir was used as an internal standard. Analysis was carried out on an Inertsil 5 ODS‐3 column for the HPLC‐fluorescence method. For the LC‐HESI‐MS/MS method a PLRP‐S column was used. The limit of quantification (LOQ) for the total concentration was set at 50 and 2 ng mL−1 for the HPLC‐fluorescence method and the LC‐HESI‐MS/MS method, respectively. The limit of quantification for the unbound concentration was set at 5 ng mL−1 and at 2 ng mL−1 for body fluids. The methods were successfully used to perform pharmacokinetic and clinical studies in horses after intravenous and oral dosage of acyclovir and its prodrug valacyclovir. Copyright © 2008 John Wiley & Sons, Ltd.
A VR‐based simulation system for glass pressing
Authors: Shi Songxin , Zhang Guojun , Shao Xinyu 
Published: September 2008

AbstractThe integration with virtual reality is a new boost to CAD and CAE. This paper presents a research effort aimed at creating a desktop‐based, low‐cost and independent VR‐based simulation system for glass pressing, which integrates the forming process simulation and mold motion simulation. The skeletal animation technique is employed for motion simulation of the mold. The stereoscopic view of the virtual system is achieved by CrystalEyes shutter glasses, with C++ language and OpenGL support library selected as the development tool. With the stereoscopic display of the mold design, pressing motion and numerical CAE results, the system enables engineers to gain a cohesive view of mold structure, assembly issues, and possible forming faults. It can also support training of students and engineers to acquire the theoretical know‐how, practical skills, and the problem troubleshooting techniques of glass pressing. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 16: 315–320, 2008; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20216
Design of Gold Nanoparticle‐Based Colorimetric Biosensing Assays
Authors: Zhao Weian , Brook Michael A. , Li Yingfu 
Published: September 2008

AbstractGold nanoparticle (AuNP)‐based colorimetric biosensing assays have recently attracted considerable attention in diagnostic applications due to their simplicity and versatility. This Minireview summarizes recent advances in this field and attempts to provide general guidance on how to design such assays. The key to the AuNP‐based colorimetric sensing platform is the control of colloidal AuNP dispersion and aggregation stages by using biological processes (or analytes) of interest. The ability to balance interparticle attractive and repulsive forces, which determine whether AuNPs are stabilized or aggregated and, consequently, the color of the solution, is central in the design of such systems. AuNP aggregation in these assays can be induced by an “interparticle‐crosslinking” mechanism in which the enthalpic benefits of interparticle bonding formation overcome interparticle repulsive forces. Alternatively, AuNP aggregation can be guided by the controlled loss of colloidal stability in a “noncrosslinking‐aggregation” mechanism. In this case, as a consequence of changes in surface properties, the van der Waals attractive forces overcome interparticle repulsive forces. Using representative examples we illustrate the general strategies that are commonly used to control AuNP aggregation and dispersion in AuNP‐based colorimetric assays. Understanding the factors that play important roles in such systems will not only provide guidance in designing AuNP‐based colorimetric assays, but also facilitate research that exploits these principles in such areas as nanoassembly, biosciences and colloid and polymer sciences.
Surfactant Effects on Aeration Performance of Stirred Tank Reactors
Authors: Martinov M. , Gancel F. , Jacques P. , Nikov I. , Vlaev S. 
Published: September 2008

AbstractThe effect of surfactants on aeration performance in stirred tank reactors (STR) at high rates of foaming is studied. The volumetric oxygen transfer coefficient (kLa) and foaming activity estimated as foaming height (Hf) were determined. Biotechnology of lipopeptide biosurfactants from aerobic organisms, e.g., Bacillus subtilis were addressed. Using model solutions of known foam‐generating properties, high‐molecular weight surfactin and low‐molecular weight sodium dodecyl sulphate (SDS), as well as impellers of different types, with flat and fluid‐foil blades, clues on the concentration dependence of STR oxygen transfer and foaming as well as options for foam reduction in the presence of biosurfactant were sought. In response to a two‐fold decrease of surface tension by surfactin, kLa values decreased up to 30 % but remained within the range expected for the mixing system in water; the experiments with SDS showing stronger dependence on surfactant concentration and surface tension. Mixing of surfactant media by a standard six‐blade disc turbine (RT) imposed rate limitations on gassing. A low‐shear impeller Narcissus (NS) could be used to avoid bulk foam outflow, while preserving kLa values that remained unchanged. The ‘power per unit volume' correlation of kLa in stirred tanks is tested in the presence of surfactin.
Gas‐Liquid Mass Transfer in a Bench‐Scale Trickle Bed Reactor used for Benzene Hydrogenation
Authors: Metaxas K. , Papayannakos N. 
Published: September 2008

AbstractThe gas‐liquid mass transfer coefficients (MTCs) of a trickle bed reactor used for the study of benzene hydrogenation were investigated. The Ni/Al2O3 catalyst bed was diluted with a coarse‐grained inert carborundum (SiC) particle catalyst. Gas‐liquid mass transfer coefficients were estimated by using a heterogeneous model for reactor simulation, incorporating reaction kinetics, vapor‐liquid equilibrium, and catalyst particle internal mass transfer apart from gas‐liquid interface mass transfer. The effects of liquid axial dispersion and the catalyst wetting efficiency are shown to be negligible. Partial external mass transfer coefficients are correlated with gas superficial velocity, and comparison between them and those obtained from experiments conducted on a bed diluted with fine particles is also presented. On both sides of the gas‐liquid interface the hydrogen mass transfer coefficient is higher than the corresponding benzene one and both increase significantly with gas velocity. The gas‐side mass transfer limitations appear to be higher in the case of dilution with fine particles. On the liquid side, the mass transfer resistances are higher in the case of dilution with coarse inerts for gas velocities up to 3 · 10–2 cm/sec, while for higher gas velocities this was inversed and higher mass transfer limitations were obtained for the beds diluted with fine inerts.
A Comparison of Variational and Genetic Algorithm Performances in the Optimization of a Polymerization Process
Authors: Banu I. , Bozga G. , Nagy I. , Puaux J.‐P. 
Published: September 2008

AbstractThe aim of this work is to compare the performances of two well‐known methods, Minimum Principle and Genetic Algorithm, in the optimization of the methyl methacrylate polymerization process in solution. In order to select a kinetic model for this process, the published kinetic models were reviewed and compared by simulation in similar operating conditions. Based on the kinetic model proposed by Baillagou and Soong (1985), the temperature profile necessary to attain, in a given reaction time, specified values for monomer conversion, number‐average molecular weight and polydispersity index, was calculated. The temperature profiles calculated by the two optimization algorithms are practically identical, but they are obtained with different computational efforts. The results of this comparison are used to draw several conclusions regarding the proficiency of the two methods in the optimization of complex reaction processes.
Stochastic Modeling of the Particle Residence Time Distribution in an Opposed Multi‐Burner Gasifier
Authors: Ni J. J. , Liang Q. F. , Guo Q. H. , Yu Z. H. , Yu G. S. 
Published: September 2008

AbstractThe gasification technology of impinging streams has been extensively applied to chemical production and power generation. Particle residence time distribution (RTD) is an important parameter required for modeling, designing and optimization of an impinging stream gasifier. A stochastic mathematical model based on the Markov chains model is developed for the opposed multi‐burner gasifier (OMBG), which closely describes the behavior of the flow pattern and particle RTD in the gasification system. The model simulates the motion of single particle moving in the gasifier using the Markov chains. The predicted results give a reasonable fit to the experimental data. This shows that the flow process of particles in the gasifier has recirculation eddies, which have a downward flow direction near the downflow core and an upward flow direction near the wall, but no short‐circuit. Finally, the effect of particle flux rate on the RTD is predicted, and the contrast between gas and particles RTDs at a laboratory scale and in an industrial gasifier are presented.
Mathematical Modeling of Supercritical Extraction of Valerenic Acid from Valeriana officinalis L.
Authors: Salimi A. , Fatemi S. , Zakizadeh Nei Nei H. , Safaralie A. 
Published: September 2008

AbstractThe dynamic behavior of supercritical fluid extraction (SFE) of valerenic acid (VA) from valerian (Valeriana officinalis L.) roots was studied by mathematical modeling. The extraction yield of VA was considered as the most desirable compound among the other extracted constituents. A two‐phase desorption model was developed by considering a diffusion controlled regime in the particle and axial dispersion in the bed. The mass transfer parameters, i.e., pore diffusivity, film mass transfer coefficient and axial dispersion, along with the solubility parameters were chosen as the model parameters. The first three mass transfer parameters were predicted using nondimensional equations from the literature. The solubility equation and the parameters were studied using different equilibrium models, i.e., Henry, Langmuir, Freundlich, Langmuir‐Freundlich (L‐F) and Toth isotherms. The equilibrium parameters were correlated by comparing the outlet results of the dynamic SFE model with experiments. The experimental yield of the VA extraction was obtained at a pressure of 15.0–36.0 MPa, temperature of 310–334 K, solvent flow rate of 0.50–1.10 · 10–6 m3/min and different particle sizes ranging from 0.18–2.00 · 10–3 m in diameter, at a 20 min constant static period, in the presence of 46.9 μL/g ethanol as the co‐solvent, followed by dynamic time extraction for up to 50 min. From the results, the mathematical model using the L‐F equation exhibited the best agreement with the experimental yield of VA extraction in the range of studied conditions. The present model can be applied to design and scale up the SFE process of VA from Valeriana officinalis L. roots.
Portraying the Countercurrent Flow on Packings by Three‐Dimensional Computational Fluid Dynamics Simulations
Authors: Xu Y. Y. , Paschke S. , Repke J.‐U. , Yuan J. Q. , Wozny G. 
Published: September 2008

AbstractThe design of packed columns requires the detailed description of the hydrodynamics on the surface of the packings. To analyze the local flow behavior of the liquid phase, a three‐dimensional Computational Fluid Dynamics (CFD) model was developed that applies to the two‐phase countercurrent flow on an inclined and flat plate. This model, based on the volume‐of‐fluid (VOF) method, considers the gravity, the surface tension and the drag force between the two phases. The development of such a model allows investigation of the influences of the liquid and gas flow rates on the flow behavior such as the film flow and the rivulet flow. A validation of the model was performed using data from the literature and from experiments conducted in this work. Simulation and experimental results demonstrate that the specific wetted area on the plate decreases with decreasing liquid load. Moreover, CFD simulations reveal that the presence of the countercurrent gas phase tends to increase the fluctuation and the thickness of the film flow, which is in accordance with experimental data. It also affects the flow behavior of the rivulet flow and changes the velocity profiles for both film and rivulet flow behavior. On the other hand, the simulation results indicate that CFD is a potent tool for analyzing and investigating the flow phenomena in chemical engineering.
Two New Thermodynamic Constraints for a Solid/Supercritical Fluid System
Authors: Esmaeilzadeh F. , Bozorgi Y. 
Published: September 2008

AbstractOne of the phenomenological observations in any supercritical system is the common pressure where all the solubility isotherms intersect. Thus, this crossover pressure addresses a thermodynamic constraint or a key set of conditions for supercritical mixtures. In this paper, a phase stability analysis has been performed for the formulation and estimation of the crossover pressure. This absolute theoretical approach includes two subsequent steps. At the first step, it has been formulated in terms of an abstract quantity, i.e., Gibbs free energy. However, the system should be treated more quantitatively in order to estimate the crossover pressure. Therefore, at the second step, which is based on the solute behavior at the infinite dilution limit, the equations formerly used have been further manipulated, which ultimately leads to two equations that are given in terms of estimable properties. They are actually two thermodynamic constraints for solid/SCF mixtures. One of them has been used to predict the crossover pressure of certain mixtures. The other one has not been used for this task due to a theoretical restriction. However, the successfully prediction of the crossover pressure by using either of the equations confirms the other one since they are subsequent and related equations.
Anion‐Responsive Supramolecular Gels
Authors: Maeda Hiromitsu 
Published: September 2008

AbstractSupramolecular gels that change their state or structure in response to anion stimuli have been highlighted. Only a few examples exist of such supramolecular gels, the structures and properties of which can be controlled and modulated by interactions with anions. To form anion‐responsive dimensionally‐controlled organized structures, the constituent low‐molecular‐weight gelator molecules must act as anion receptors by possessing one or more of van der Waals interaction units (aliphatic chains), stacking π planes, hydrogen‐bonding sites, and metal‐coordination units. This Concept focuses on the gelation and transition behaviors of amide‐ and urea‐based anion‐stimulated systems, metal‐coordinated systems, and novel acyclic π‐conjugated oligopyrroles that act as “molecular flippers.”
ChemInform Abstract: High‐Pressure Synthesis and Structure of New Filled Skutterudite Compounds with Ge‐Substituted Host Network; LnRh4Sb9Ge3, Ln: La, Ce, Pr, and Nd.
Authors: Fukuoka Hiroshi , Yamanaka Shoji 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Sodium Iodine(V) Oxyfluoride, NaIO2F2.
Authors: Laval Jean‐Paul , Boukharrata Nefla Jennene 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Ce20Mg19Zn81: A New Structure Type with a Giant Cubic Cell.
Authors: Pavlyuk Volodymyr , Solokha Pavlo , Zelinska Oksana , Paul‐Boncour Valerie , Nowik‐Zajac Anna 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Interaction Between Components in Hf—Cu—Sb Ternary System at 770 K.
Authors: Melnychenko‐Koblyuk N. , Romaka L. , Akselrud L. , Romaka V. V. , Stadnyk Yu. 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A New Composite Anode, Fe—Cu—Si/C for Lithium Ion Battery.
Authors: Doh Chil‐Hoon , Shin Hye‐Min , Kim Dong‐Hun , Jeong Young‐Dong , Moon Seong‐In , Jin Bong‐Soo , Kim Hyun‐Soo , Kim Ki‐Won , Oh Dae‐Hee , Veluchamy Angathevar 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Thermal Decomposition Behavior of Calcium Borohydride Ca(BH4)2.
Authors: Kim Jae‐Hun , Jin Seon‐Ah , Shim Jae‐Hyeok , Cho Young‐Whan 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Structural, Magnetic and Electrical Properties of a Perovskite Containing Divalent Europium EuZrO3.
Authors: Viallet V. , Marucco J.‐F. , Saint J. , Herbst‐Ghysel M. , Dragoe N. 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Dawson‐Type Dirhenium(V)‐Oxido‐Bridged Polyoxotungstate: X‐Ray Crystal Structure and Hydrogen Evolution from Water Vapor under Visible Light Irradiation.
Authors: Kato Chika Nozaki , Hara Kazunobu , Hatano Ayumi , Goto Kazuhiro , Kuribayashi Tomonori , Hayashi Kunihiko , Shinohara Akira , Kataoka Yusuke , Mori Wasuke , Nomiya Kenji 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Polymer‐Supported Ytterbium Perfluorooctanesulfonate [Yb(OPf)3]: A Recyclable Catalyst for Organic Reactions.
Authors: Yi Wen‐Bin , Cai Chun 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.