bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental investigation of the catalytic cracking of methane over a supported Ni catalyst
Authors: Hazra M. , Croiset E. , Hudgins R. R. , Silveston P. L. , Elkamel A. 
Published: February 2009

AbstractTGA experiments on the catalytic cracking of methane and methane diluted with hydrogen over a 5 wt% Ni/γ‐alumina catalyst at 500°C and 1 and 10 bar are described. Carbon deposition on the catalyst, as expressed in specific weight of carbon, varies with time. Eventually, the deposition stops because of deactivation. The specific weight at this point depends on the hydrogen partial pressure and there is also a weak dependence on the degree of contact between catalyst particles. A model based on assuming carbon deposition proceeds through whisker formation and growth, and deactivation occurs through encapsulation adequately describes the experimental observations up to 20 vol% hydrogen in the feed.
Process modeling and optimization of industrial ethylene oxide reactor by integrating support vector regression and genetic algorithm
Authors: Lahiri Sandip Kumar , Khalfe Nadeem 
Published: February 2009

AbstractThis article presents an artificial intelligence‐based process modeling and optimization strategies, namely support vector regression–genetic algorithm (SVR‐GA) for modeling and optimization of catalytic industrial ethylene oxide (EO) reactor. In the SVR‐GA approach, an SVR model is constructed for correlating process data comprising values of operating and performance variables. Next, model inputs describing process operating variables are optimized using Genetic Algorithm (GAs) with a view to maximize the process performance. The GA possesses certain unique advantages over the commonly used gradient‐based deterministic optimization algorithms The SVR‐GA is a new strategy for chemical process modeling and optimization. The major advantage of the strategies is that modeling and optimization can be conducted exclusively from the historic process data wherein the detailed knowledge of process phenomenology (reaction mechanism, kinetics, etc.) is not required. Using SVR‐GA strategy, a number of sets of optimized operating conditions leading to maximized EO production and catalyst selectivity were obtained. The optimized solutions when verified in actual plant resulted in a significant improvement in the EO production rate and catalyst selectivity.
Thermal radiation effect on unsteady MHD free convection flow past a vertical plate with temperature‐dependent viscosity
Authors: Mahmoud Mostafa A. A. 
Published: February 2009

AbstractThis article investigates the influence of radiation and temperature‐dependent viscosity on the problem of unsteady MHD flow and heat transfer of an electrically conducting fluid past an infinite vertical porous plate taking into account the effect of viscous dissipation. The governing equations are converted into a system of nonlinear ordinary differential equations via a local similarity parameter which is taken as a function of time. The resulting system of coupled nonlinear ordinary differential equations is solved numerically using the fourth order Runge–Kutta integration scheme with the shooting method. The numerical results for the velocity and the temperature are displayed graphically showing the effects of various parameters. The results show that increasing the Eckert number and decreasing the viscosity of air leads to a rise in the velocity, while increasing in the magnetic or the radiation parameters is associated with a decrease in the velocity. Also, an increase in the Eckert number leads to an increase in the temperature, whereas an increase in radiation parameter leads to a decrease in the temperature.
Turbulence structure for plane Poiseuille–Couette flow and implications for drag reduction over surfaces with slip
Authors: Spencer Nicholas B. , Lee Lloyd L. , Parthasarathy Ramkumar N. , Papavassiliou Dimitrios V. 
Published: February 2009

AbstractDirect numerical simulations were used to simulate plane channel and plane Poiseuille–Couette flows. For Poiseuille–Couette flow, the walls of the channel were moving with a specified velocity. This is equivalent to forcing a slip velocity at the wall of the channel, and such flow behaviour can be viewed as the effect due to an ultra‐hydrophobic wall. It was found that the location of the zero Reynolds stress value shifted towards the wall moving in the streamwise direction. The near‐wall eddies were found to be longer and weaker than for the plane‐Poiseuille channel flow. It appears that such an eddy structure can lead to turbulence drag reduction.
Relationship between mass transport and the quality of cured hide
Authors: Kolomazník Karel , Fürst Tomáš , Uhlírová Michaela 
Published: February 2009

AbstractThe advantages of mathematical simulations of the process of cured hide desalination are presented. Full three‐dimensional model is presented and then its one‐dimensional and a two‐dimensional special cases are considered and compared. In the case of one‐dimensional approximation, the solution can be obtained in an analytic form, while for the two‐dimensional case only numerical solution is available. A possible occurrence of a concentration shock is modelled, and a method of its prevention is proposed to reduce losses in the hide substance. The predictions of the mathematical model are then compared with experimental data and found to be in good agreement.
CypScore: Quantitative Prediction of Reactivity toward Cytochromes P450 Based on Semiempirical Molecular Orbital Theory
Authors: Hennemann Matthias , Friedl Arno , Lobell Mario , Keldenich Jörg , Hillisch Alexander , Clark Timothy , Göller Andreas H. 
Published: February 2009

AbstractCypScore predicts the reactivity of competing positions in the same and different molecules to a variety of cytochrome P450 metabolic reactions on a single reactivity scale.magnified imageCypScore is an in silico approach for predicting the likely sites of cytochrome P450‐mediated metabolism of druglike organic molecules. It consists of multiple models for the most important P450 oxidation reactions such as aliphatic hydroxylation, N‐dealkylation, O‐dealkylation, aromatic hydroxylation, double‐bond oxidation, N‐oxidation, and S‐oxidation. Each of these models is based on atomic reactivity descriptors derived from surface‐based properties calculated with ParaSurfTM and based on AM1 semiempirical molecular orbital theory. The models were trained with data derived from Bayer Schering Pharma's in‐house MajorMetabolite Database with more than 2300 transformations and more than 800 molecules collected from the primary literature. The models have been balanced to allow the treatment of relative intramolecular, intra‐chemotype, and inter‐chemotype reactivities of the labile sites toward oxidation. The models were evaluated with promising hit rates on three public datasets of varying quality in the annotation of the experimental positions. For 39 well‐characterized compounds from 14 in‐house lead optimization programs, we could detect at least one major metabolite for the three highest‐ranked positions in 87 % of the compounds and overall more than 62 % of all major metabolites, with promising true‐ to false‐positive ratios of 0.9.
Phase I pharmacokinetic study of the vascular endothelial growth factor receptor tyrosine kinase inhibitor vatalanib (PTK787) plus imatinib and hydroxyurea for malignant glioma
Authors: Reardon David A. , Egorin Merrill J. , Desjardins Annick , Vredenburgh James J. , Beumer Jan H. , Lagattuta Theodore F. , Gururangan Sridharan , Herndon James E. , Salvado August J. , Friedman Henry S. 
Published: February 2009

AbstractBACKGROUND:This study determined the maximum tolerated dose (MTD) and dose‐limiting toxicities (DLT) of the oral vascular endothelial growth factor receptor (VEGFR) inhibitor, vatalanib, when administered with imatinib and hydroxyurea on a continuous daily schedule among recurrent malignant glioma patients.METHODS:All patients received 500 mg of hydroxyurea twice daily. Imatinib was dosed at 400 mg per day for patients not taking enzyme‐inducing antiepileptic drugs (EIAEDs; stratum A) and at 500 mg twice‐a‐day for patients taking EIAEDs (stratum B). Vatalanib was escalated from 500 mg to 1250 mg twice daily in successive cohorts, independently for each stratum. Pharmacokinetics of each drug were assessed.RESULTS:A total of 37 recurrent patients, 34 (92%) with glioblastoma and 3 (8%) with grade 3 malignant glioma, were enrolled. Nineteen patients (51%) were taking EIAEDs. The MTD of vatalanib for all patients was 1000 mg twice‐a‐day. DLTs were hematologic, gastrointestinal, renal, and hepatic. No patients developed intracranial hemorrhage. Concurrent administration of imatinib and hydroxyurea did not affect vatalanib exposure, but EIAEDs decreased vatalanib and imatinib plasma exposures.CONCLUSIONS:Vatalanib doses up to 1000 mg twice‐a‐day combined with imatinib and hydroxyurea were well tolerated. Strategies to target tumor blood vessel endothelial cells and pericytes by inhibiting VEGFR and platelet‐derived growth factor, respectively, were safe among recurrent malignant glioma patients and may enhance antiangiogenesis activity. Cancer 2009. © 2009 American Cancer Society.
Non‐Covalent Interactions in Supramolecular Assemblies Investigated with Electron Spectroscopies
Authors: Ruiz‐Osés Miguel , de Oteyza Dimas G. , Fernández‐Torrente Isabel , Gonzalez‐Lakunza Nora , Schmidt‐Weber Phillipp M. , Kampen Thorsten , Horn Karsten , Gourdon André , Arnau Andrés , Ortega J. Enrique 
Published: February 2009

AbstractA new view: A picture of the different non‐covalent interactions relevant for the self‐assembly of organic layers and their spectroscopic fingerprints is provided (see figure). In particular, state‐of‐the‐art spectroscopic measurements are performed for supramolecular assemblies, comparing the electronic structure of single‐component layers with that of binary organic layers.magnified image
Development and validation of a male specific body checking questionnaire
Authors: Hildebrandt Tom , Walker D. Catherine , Alfano Lauren , Delinsky Sherrie , Bannon Katie 
Published: February 2009

AbstractObjective:Body checking may be an important behavioral consequence of body image disturbance. Despite the importance of body checking, few measurements of this construct exist, particularly for males. This study describes the development and validation of the Male Body Checking Questionnaire (MBCQ).Method:Convergent and divergent validity, factor structure, and reliability were tested in three separate samples of men and women.Results:Factor analyses suggested a reliable four‐factor structure with evidence of a higher order global checking factor for men, but not women. The MBCQ demonstrated good concurrent and divergent validity. Short‐term test‐retest reliability was good with high internal consistency across time.Discussion:Interpretation of psychometrics and recommendations for subsequent research are discussed. The MBCQ is likely to be an appropriate tool for investigating body image‐based pathology in males. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
A simple framework for evaluating regional wetland ecohydrological response to climate change with case studies from Great Britain
Authors: Acreman M. C. , Blake J. R. , Booker D. J. , Harding R. J. , Reynard N. , Mountford J. O. , Stratford C. J. 
Published: February 2009

AbstractIt is widely accepted that the Earth's climate is changing more rapidly than it has in the past and that over the next 100 years temperatures will rise and patterns of precipitation will be altered. These predictions for the future have important implications for all ecosystems, particularly those, such as wetlands, whose ecological character is very dependent on its hydrological regime. The potential impacts of climate change on wetland hydrology are of interest to a wide range of stakeholders from wetland managers to international policy makers. Ecohydrological models that combine climate changes, hydrological processes and ecological response provide a means of estimating what might happen to some wetland functions and species in the future. This paper presents a framework that can be used for combining models and available data at a regional scale and is appropriate for different wetlands, in different countries and for different levels of data availability. The simple models are based on broad conceptual understanding of wetland hydrology and are intended to describe basic ecohydrological processes within the constraints of data availability; they are thus fit for the purpose of general assessment and do not pretend to provide precise results for specific wetland sites. Data from Great Britain (GB) have been used to demonstrate each step in the framework for two temperate wetland types: rain‐fed wetlands (wet heaths or degraded raised mires) and floodplain margins. Whilst GB may be considered to be relatively data rich, we believe that sufficient information is available in many countries to apply this framework for the regional assessment of climate change impacts on wetlands. Although the models successfully represent the baseline conditions, it is not possible to test whether they accurately predict the future vulnerability of the selected areas. Results for GB suggest that predictions of reduced summer rainfall and increased summer evaporation will put stress on wetland plant communities in late summer and autumn with greater impacts in the south and east of GB. In addition, impacts on rain‐fed wetlands will be greater than on those dominated by river inflows. Copyright © 2009 John Wiley & Sons, Ltd.
DAP10 associates with Ly49 receptors but contributes minimally to their expression and function in vivo
Authors: Tassi Ilaria , Le Friec Gaelle , Gilfillan Susan , Takai Toshiyuki , Yokoyama Wayne M. , Colonna Marco 
Published: February 2009

AbstractNK cells recognize target cells through activating receptors, many of which rely on the transmembrane adaptors DAP10, DAP12 and FcR‐γ to deliver intracellular signals. Because these adaptors initiate distinct signaling pathways, they dictate the type of response mediated by receptor engagement. DAP10, for example, primarily triggers cytotoxicity, whereas DAP12 induces both cytotoxicity and IFN‐γ secretion. In mice, NKG2D signals through both DAP10 and DAP12, which broadens and modulates the type of response engendered by encounter with ligand. Although initial studies indicated that Ly49H and Ly49D recruit only DAP12, a recent report suggested that they also associate with DAP10. We asked whether this association occurs and is functionally significant under physiologic conditions. Our data demonstrate that DAP10 does associate with Ly49H and Ly49D in primary NK cells. While this association contributes slightly to cell surface expression of both receptors, it has no significant impact on Ly49H‐mediated control of murine cytomegalovirus infection. Thus, while many activating NK‐cell receptors are promiscuous in terms of adaptor association, our data indicate that the functional consequences of such promiscuity may vary widely and may not be evident in all cases.
The Variable Strength of the Sulfur–Sulfur Bond: 78 to 41 kcal – G3, CBS‐Q, and DFT Bond Energies of Sulfur (S8) and Disulfanes XSSX (X = H, F, Cl, CH3, CN, NH2, OH, SH)
Authors: Denk Michael K. 
Published: February 2009

AbstractExperimental values for the strength of the sulfur–sulfur bond scatter over a wide range and are frequently in disagreement with each other. For S8, reliable experimental data seem to lack entirely. To check experimental data and establish the strength of the sulfur–sulfur bond in S8, high‐precision thermochemical calculations (G3, CBS‐Q) and DFT methods were employed. The calculations confirm a stunning range for the strength of the sulfur–sulfur bond with energies between 77.7 kcal for FSSF and only 41.8 kcal for tetrasulfane, HSS–SSH. For the pivotal bond energy of elemental sulfur, S8, the bond energy is 40.5 kcal but can be narrowed to 38.0–39.2 kcal mol–1 by including CBS‐QB3 data. While older DFT methods are not well suited to accurately reproduce the S–S bond energies, excellent data can be obtained with the recently introduced Boese–Martin (BMK) hybrid DFT method. Atoms in molecules (AIM) calculations reveal significant multiple bonding and spin delocalization in the sulfur radicals XS·. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
First Row Transition Metal Aminopyridinates – the Missing Complexes
Authors: Glatz Germund , Demeshko Serhiy , Motz Günter , Kempe Rhett 
Published: February 2009

AbstractLithiated 4‐methyl‐2‐[(trimethylsilyl)amino]pyridine (ApTMSH) undergoes a salt metathesis reaction with [ScCl3(thf)3] and FeCl3, at low temperature in thf, to yield the homoleptic complexes [Sc(ApTMS)3] (1) and [Fe(ApTMS)3] (2). An analogous reaction with MnCl2, CoCl2 and FeCl2 using two equivalents of 4‐tert‐butylpyridine (tBuPy) as additional donor ligand affords the structurally analogous cis complexes [Mn(ApTMS)2(tBuPy)2] (3), [Co(ApTMS)2(tBuPy)2] (4) and [Fe(ApTMS)2(tBuPy)2] (5). If FeCl2 is used without tBuPy, the highly symmetric trinuclear complex [Fe3(ApTMS)6Li2O] (6) is obtained. Furthermore, the use of ZnCl2 in a reaction with lithiated ApTMSH yields the dimeric complex [Zn2(ApTMS)4] (7) in which two ApTMS ligands bridge the two metals. All complexes have been characterised by X‐ray crystal structure analysis. To the best of our knowledge, complexes 1 and 2 and 5 are the first scandium and iron aminopyridinates, respectively, and complex 3 is the first manganese aminopyridinate complex which contains no additional anionic ligand. Complexes 4 and 7 are rare examples of cobalt and zinc aminopyridinates. This study proves that aminopyridinato ligands are highly universal ligands since they are able to stabilize early and late transition metals. Aminopyridinates of every first row transition metal are now available. The magnetic properties of all paramagnetic complexes were investigated. All complexes are high‐spin complexes and the trinuclear iron complex 6 exhibits a weak antiferromagnetic coupling.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Anionic Lanthanide Complexes Bearing a Bis(phenoxy)‐Functionalized N‐Heterocyclic Carbene Ligand: Syntheses and Molecular Structures
Authors: Yao Haisheng , Zhang Yong , Sun Hongmei , Shen Qi 
Published: February 2009

AbstractA series of anionic lanthanide complexes supported by bis(phenoxy)‐functionalized N‐heterocyclic carbene (NHC) ligand L, where L = 1,3‐bis[O‐4,6‐di‐tBu‐C6H2‐2‐CH2][C{N(CHCH)N}], were synthesized by the amine‐elimination reaction. The in situ reaction of LH3Cl with Li(thf)Ln(NiPr2)4 and nBuLi in a 2:1:2 molar ratio in thf afforded the discrete ion‐pair complexes [L2Ln][Li(dme)3] (Ln = Sm 1, Er 2, Yb 3) upon crystallization from dme/toluene (10 mL:15 mL). The reaction of LH3Cl with Li(thf)Sm(NiPr2)4 and nBuLi in a 2:1:2 molar ratio proceeded in thf, followed by crystallization from thf/toluene (2 mL:15 mL), to yield an “ate” complex [(thf)Li(μ‐L)SmL] (4). The analogous “ate” complex with sodium metal [(Et2O)Na(μ‐L)SmL] (5) was also prepared by the in situ treatment of LH3Cl with Sm[N(SiMe3)2]3 and NaN(SiMe3)2 in a 2:1:3 molar ratio. Single‐crystal X‐ray structural analyses of 1–5 revealed that complexes 1–3 have ion‐pair structure consisting of an anion [L2Ln]– and a cation [Li(dme)3]+, in which the coordination geometries about each lanthanide metal ion can be best described as a distorted octahedron, while the samarium ion and the alkali metal ion in complexes 4 and 5 are connected together by two phenoxide oxygen bridges, and each alkali metal ion is bound to anadditional oxygen atom of one thf (for 4) and one Et2O (for 5).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
2,3‐Di‐n‐undecylanthracene and 2,3‐Di‐n‐decyloxyanthracene (DDOA) – on the Connecting Link between the Aromatic Substrate and the Aliphatic Chain in Self‐Assembling Systems
Authors: Hopf Henning , Greiving Helmut , Bouas‐Laurent Henri , Desvergne Jean‐Pierre 
Published: February 2009

AbstractIn contrast to its bis(oxa) analog 1 (DDOA), the hydrocarbon 11 was not found to form organogels with linear alcohols, alkanes, toluene, acetonitrile and other solvents. Whereas the photoreactivity of 1 did not follow the usual behaviour of anthracene derivatives, compound 11, irradiated in cyclohexane, produced the two expected [4+4]cycloadducts 12 and 13 (anti and syn photodimers, respectively). These facts point to the role of the connecting link between the rigid core and the flexible chain for some self‐assembled systems.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Simulation of multiple shock–shock interference using implicit anti‐diffusive WENO schemes
Authors: Hsieh Tsang‐Jen , Wang Ching‐Hua , Yang Jaw‐Yen 
Published: February 2009

AbstractAccurate computations of two‐dimensional turbulent hypersonic shock–shock interactions that arise when single and dual shocks impinge on the bow shock in front of a cylinder are presented. The simulation methods used are a class of lower–upper symmetric‐Gauss–Seidel implicit anti‐diffusive weighted essentially non‐oscillatory (WENO) schemes for solving the compressible Navier–Stokes equations with Spalart–Allmaras one‐equation turbulence model. A numerical flux of WENO scheme with anti‐diffusive flux correction is adopted, which consists of first‐order and high‐order fluxes and allows for a more flexible choice of first‐order dissipative methods. Experimental flow fields of type IV shock–shock interactions with single and dual incident shocks by Wieting are computed. By using the WENO scheme with anti‐diffusive flux corrections, the present solution indicates that good accuracy is maintained and contact discontinuities are sharpened markedly as compared with the original WENO schemes on the same meshes. Computed surface pressure distribution and heat transfer rate are also compared with experimental data and other computational results and good agreement is found. Copyright © 2009 John Wiley & Sons, Ltd.
A streamfunction–velocity approach for 2D transient incompressible viscous flows
Authors: Kalita Jiten C. , Gupta Murli M. 
Published: February 2009

AbstractWe recently proposed (J. Comput. Phys. 2005; 207(1):52–68) a new paradigm for solving the steady‐state two‐dimensional (2D) Navier–Stokes (N–S) equations using a streamfunction–velocity (ψ–v) formulation. This formulation was shown to avoid the difficulties associated with the traditional formulations (primitive variables and streamfunction‐vorticity formulations). The new formulation was found to be second‐order accurate and was found to yield accurate solutions of a number of fluid flow problems.In this paper, we extend the ideas and propose a second‐order implicit, unconditionally stable ψ–v formulation for the unsteady incompressible N–S equations. The method is used to solve several 2D time‐dependent fluid flow problems, including the flow decayed by viscosity problem with analytical solution, the lid‐driven square cavity problem, the backward‐facing step problem and the flow past a square prism problem. For the problems with known exact solutions, our coarse grid transient solutions are extremely close to the analytical ones even for high Reynolds numbers (Re). For the driven cavity problem, our time‐marching steady‐state solutions up to Re=7500 provide excellent matches with established numerical results, and for Re=10000, our study concludes that the asymptotic stable solution is periodic as has been found by other authors in recent studies. For the backward step problem, our numerical results are in excellent agreement with established numerical and experimental results. Finally, for the flow past a square prism, we have very successfully simulated the von Kármán vortex street for Re=200. Copyright © 2009 John Wiley & Sons, Ltd.