bluuebunny/crossref_metadata_2025 huggingface dataset:
Applications of computational fluid dynamics in the chemical industry
Authors: Bode Jürgen
Published: August 2005

In order to illustrate the use of CFD in providing an understanding of mixing processes, three examples, mixing in a pipe, homogenization with a static mixer and flow in a mixing vessel with a Rushton turbine, are discussed and compared with experimental results. Special attention is focussed on the resultant concentration distribution, which is closely linked to turbulent properties. A semi‐empirical model is presented for a quantitative prediction of the initial turbulent conditions. Using special numerical techniques a mixing vessel with wall‐separated baffles, which represents a problem generally regarded as beyond the capabilities of numerical analysis, can be simulated.
Investigations on precious metal/alumina interactions on three‐way automotive emission control catalysts, BMA catalysts and model samples
Authors: Albers P. , Engler B. , Leyrer J. , Lox E. , Prescher G. , Seibold K.
Published: August 2005

Combined XPS and SIMS measurements, partly supplemented by XRD investigations, were utilized to detect precious metal/support interactions on catalysts containing various precious metals. The Klemm‐Bronger reaction between Pt and α‐Al2O3 on methane/ammonia catalysts was used as a standard reference. Evidence was found for different stages of Pt/Al interactions and changing electronic properties of Pt on the surfaces of these Pt/α‐Al2O3 catalysts by means of XPS and SIMS, and in the bulk material by XRD. The SIMS investigations on Pt and Rh on γ‐Al2O3 showed that, even at temperatures around 500 °C, Rh/Al interactions can appear to a small extent in the topmost atomic layers, whereas the Pt/γ‐Al2O3 specimens did not show any measurable effects. After on‐road operation, enhanced SIMS cluster‐ion signals as well as anomalous XPS signal contributions were measured on the surfaces of used three‐way automotive emission control catalysts. These signals did not appear for the fresh catalysts. By analogy with the related results reported on the methane/ammonia catalysts, the ion signals were used as qualitative surface probes indicating the presence of precious metal/support interactions, especially between Rh and Al.
Liquid phase oxidation of α‐pinene initiated by ozone. 2: Formation of verbenol, verbenone and acid products
Authors: Encinar José María , Beltrán Fernando J. , Frades Jesus María
Published: August 2005

The formation of verbenol, verbenone and acids during liquid phase ozone‐initiated oxidation of α‐pinene has been investigated; temperature, ozone partial pressure and ozone initiation time were the variables studied. While increasing temperature promotes the formation of secondary products, the other two variables affect mainly the selectivity. Thus, an ozone partial pressure and ozone initiation time of 1014 Pa and 10 min, respectively, lead to the highest selectivities. Kinetic expressions for the formation of verbenol and verbenone, which are consistent with experimental data, have also been developed from a free radical mechanism.
Kinetic study of the synthesis of n‐octyl octanoate using cobalt chloride as catalyst
Authors: Urteaga Laura , Sánchez Nieves , Martinez Mercedes , Aracil José
Published: August 2005

The kinetics of the pseudohomogeneous liquid phase synthesis of a high molecular weight ester in a stirred tank reactor using cobalt chloride as catalyst has been studied at various temperatures, catalyst concentrations, and acid/alcohol molar ratios. A kinetic model has been determined that predicts the experimental results quite well.
Pbs‐field‐effect‐transistor for heavy metal concentration monitoring
Authors: Kullick Thomas , Quack Ralf , Röhrkasten Cornelia , Pekeler Thomas , Scheper Thomas , Schügerl Karl
Published: August 2005

A simple and inexpensive Pbs‐FET with high sensitivity and short response time was developed which consists of a PbS layer on a pH‐sensitive gate of a field effect transistor. The PbS‐layer was prepared with simple wet precipitations technique. The PbS‐FET has about the same selectivities for Pb2+ ‐and for Cu2+ ‐ions, but only slight sensitivity for Cd2+ ‐and Zn2+ ‐ions. The sensor was integrated in a FIA system. By variing the injection time the measuring range varied between 10−1‐10−6 and 10−2‐10−8 mol Pb2+/1. The PbS‐FET‐FIA system is suitable for monitoring of Pb2+ concentrations in drinking water.
Interfacial area of mellapak packing: Absorption of 1,1,1‐trichloroethane by Genosorb 300
Authors: Brunazzi Elisabetta , Nardini Giuliano , Paglianti Alessandro , Petarca Luigi
Published: August 2005

In this work a Sulzer structured packing, Mellapak 250Y, was studied for applications in the field of absorption. A new model was proposed which makes it possible to estimate the packing surface that actually takes part in the process. In the course of these studies, new experimental data were obtained relating to the absorption of 1,1,1‐trichloroethane using Genosorb 300, a mixture of polyethylene glycol dimethyl ethers produced by Hoechst S.p.A., as absorption liquid. The results obtained with the proposed model are in agreement both with the experimental measurements made in the course of the work and with experimental absorption measurements reported by other authors on water systems.
Continuous enzyme‐catalyzed production of 6‐aminopenicillanic acid and product concentration by reverse osmosis
Authors: Danzig Joachim , Tischer Wilhelm , Wandrey Christian
Published: August 2005

The efficiency of 6‐aminopenicillanic acid (6‐APA) production by enzyme‐catalyzed hydrolysis of penicillin G using penicillin G amidase (E. C. 3.5.1.11) immobilized in polyacrylamide gel can be improved by using a lower substrate concentration and an optimized low buffer concentration. In a continuous process the combination of a stirred‐tank reactor and a plug‐flow reactor gives optimum productivity. Since precipitation of 6‐APA is the crucial step in downstream processing, the product concentration has to be as high as possible. This can be achieved by concentrating the product solution by reverse osmosis.
Deactivation kinetics and modelling of coke removal under supercritical conditions for the example of ethylbenzene disproportionation
Authors: Niu Fenghui , Kolb Gunther , Hofmann Hanns
Published: August 2005

Deactivation kinetics and coke removal kinetics were derived from experimental studies on the disproportionation of ethylbenzene with a protonated Y‐faujasite (Z‐14) in a loop reactor under supercritical conditions. Derivation of the steady state kinetics of ethylbenzene disproportionation permitted determination of the catalyst activity. At small educt mole fractions of ethylbenzene, owing to the modest removal of coke the deactivation kinetics can be described by a power relationship. The rate of coke removal can be correlated with the activity and the deactivation rate of the catalyst.
An efficient method for the calculation of chemical equilibrium composition in multicomponent gas mixtures
Authors: Metz Stefan W. , Aretz Wilfried , Wilhelmi Herbert
Published: August 2005

The determination of the composition of multi‐component mixtures is the basis by which a number of technical and physical problems in the field of power and process engineering are modelled. In order to calculate chemical states of equilibrium in the gas phase, a calculation method will be presented which is founded on a minimization of the Gibbs enthalpy. This method is characterized by a high reliability in convergency, considerable independence of starting vectors and by a moderate requirement for programming. These characteristics are achieved by a transformation of variables which results in numerically more favourable solutions to the non‐linear equation system. Calculated equilibrium compositions (including dissociation and ionisation) for a stochiometric mixture of hydrogen and oxygen in a temperature range of 300–12000 K and a pressure of 105 Pa as well as the application of the method will be demonstrated.
Simplified transient model of an upflow cocurrent packed bed bioreactor
Authors: Samb Falilou M. , Benthack Christina , Deront Marc , Adler Nevenka , Péringer Paul
Published: August 2005

A dynamic model incorporating biomass growth and liquid hold‐up evolution is developed to describe a fixed bed bioreactor operation with cocurrent upflow of water and air flows. The model permits to predict cycle time and optimal operation conditions for high substrate removal and long cycle times. Simulation results are compared with published experimental results and show good model accuracy.
A new continuous‐flow recycle microwave reactor for homogeneous and heterogeneous chemical reactions
Authors: Chemat Farid , Poux Martine , de Martino Jean‐Louis , Berlan Jacques
Published: August 2005

A new continuous‐flow recycle microwave reactor suitable for organic synthesis has been developed to handle 0.51 quantities of reagents. The apparatus, which is designed for laboratory use, operates at atmospheric pressure in open‐ or closed‐loop mode. It is fitted with a temperature control system. We describe this novel reactor and illustrate its efficiency with examples of organic syntheses carried out using both homogeneous and heterogeneous reactions.
Mass transfer studies in pneumatic reactors
Authors: Benyahia Farid , Jones Lynn , Petit Silvain , Plantaz David
Published: August 2005

Local mass transfer studies have been carried out in an external loop airlift reactor and indicated the existence of significant non‐uniformities in aeration capacity in the various sections of the reactor. The traditional assumption of a single well mixed unit with a single kL a value for external loop airlift reactors was found to be poor and cannot represent adequately the reactor as a whole. The liquid head in the gas/liquid separator was found to have a significant negative negative effect on the local mass transfer coefficient kL a. Visualization of flow patterns showed the existence of strong vortices in the riser and downcomer which contributed to a reduction in local aeration capacity. Mass transfer experiments in an aerated tank showed that the aeration capacity can be reduced by half in viscous media but improved significantly in the presence of salts.
A new method for the characterisation of the wettability of powders
Authors: Link Kersten Christoph , Schlünder Ernst‐Ulrich
Published: August 2005

The wetting characteristics of fine powders play an important role in a variety of processes. The most important way of characterising the wettability of a fluid/fluid/solid system is to measure the contact angle. This paper describes a relatively simple method for the determination of the contact angle on powdery materials. The technique involves the measurement of the dynamic contact angle which is formed when a liquid drop is placed on a horizontal porous surface. On the basis of the measured dynamic contact angle as a function of time an “apparent” static contact angle has been defined, which gives a measure of the wettability of porous solid systems by analogy with the wetting of non‐porous solids. Determinations with glass beads and NaCl‐powders as the test materials indicate that the measured value depends on the particle size of the powder, the porosity and the temperature. It was concluded that the capillary penetration of the liquid droplet into the porous media itself influences the wetting characteristics.
The use of statistical properties of transmission signals for particle characterization
Authors: Wessely Benno , Altmann Justus , Ripperger Siegfried
Published: August 2005

The measurement of transmission is an often used measuring principle in technology. The evaluation algorithms of fluctuating transmission signals are well known in the case of single particle measurement. By evaluating fluctuating transmission signals the particle characterization is also possible at high particle concentrations (0.01 to 30 vol.‐%). In comparison with conventional photometers a significant gain of information can be received. Fluctuating signals are caused by the statistical probability of a limited number of particles being present in a defined measuring volume. The evaluation of such signals allows the determination of particle concentration, particle size of monodisperse particles (extinction diameter) and information about structure of agglomerates independent from each other. Mathematical fundamentals and practical ways to measure these parameters are shown. Experimental results are examplarily presented for monodisperse, polydisperse and agglomerated suspensions.
EXSENSEL – a rule‐based approach to selection of sensors for process variables
Authors: Barua Alok , Sengupta Sumit
Published: August 2005

A novel expert‐system‐based method for selection of sensors for process variables is presented. EXSENSEL (expert system based sensor selection) deals with 12 process variables and currently has 94 rules in its knowledge base. Despite its large knowledge base, users have to answer a set of only a few questions regarding a particular process variable, which is selected from a menu of 12 variables. A general description of the chosen process variable can be viewed before invoking the rules. Once a sensor has been selected, a brief write up on that particular sensor is also available on user's request. EXSENSEL is the successor to TRANSELEX, which is a single expert system for selection of transducers in the area of temperature, pressure, and flow measurement.
Performance of a three‐phase fluidized bed as a reactive distillation device
Authors: Liang Wugeng , Wang Zhanwen , Jin Yong , Yu Zhiqing , Yang Sheng
Published: August 2005

A new reactive distillation device, the multistage gas/liquid/solid three‐phase fluidized bed, has been developed. The flow regimes of the multistage three‐phase fluidized bed have been studied and the regimes can be divided into the liquid leakage regime, the dispersed bubble regime, and the coalesced bubble regime. Liquid velocity has a much smaller effect on phase holdups in this device than in conventional three‐phase fluidized beds. The three phase fluidized bed is used as a reactive distillation device for the hydrolysis of methyl acetate. Much higher reaction conversion than the equilibrium value and high catalyst‐contacting efficiency are obtained. Different methods of feeding the water into the reactive distillation section are studied.
Natural gas compression factors calculated from relative density, heating value, and diluent compositions
Authors: Iglesias‐Silva Gustavo A. , Hall Kenneth R.
Published: August 2005

Knowledge of the compression factor is essential for the transport, storage and utilization of natural gas. The normal way to determine this property is by using an equation of state (EOS) which utilizes the gas temperature, pressure, volume, and composition. In many industrial situations, the composition of the natural gas is not available, yet it is still necessary to calculate the compression factor. In this paper, we present an EOS which uses relative density, heating value, and diluent compositions to determine the compression factor. The applicable ranges of conditions are 220 to 500 K up to 70 MPa (–60–450°F up to 10,000 psia). The calculations agree with data within 0.1% average absolute deviatation up to 10 MPa with a maximum deviation of 1.9% near pure component critical points or mixture cricondentherms. The equation also extrapolates through data up to 70 MPa within 1.9% We present comparisons to data of AGA Report No. 8 and to data in the paper.
Analysis of reactive distillation using the esterification of acetic acid as an example
Authors: Bock Heiko , Jimoh Mohammed , Wozny Günter
Published: August 2005

The uncatalyzed esterification of acetic acid is described in the literature as a typical example of reactive distillation. Many rigorous models were validated using this esterification as an example. Process proposals for the production of pure ethyl acetate from ethanol and acetic acid have been determined using short‐cut methods with the assumption of chemical equilibrium only. In this publication, the limitations of this esterification are clarified, using a rigorous model that was developed. The reasons why reactive distillation appears to be unfavorable for this esterification are explained. It is, however, theoretically possible to obtain ethyl acetate in high purity with different variants of the process. Different process variants are examined in this work. Construction variables that are important for the design of reactive columns, such as the number of reactive separation stages and the holdup in the column, are analyzed. Furthermore, the influence of variables dependent on the component system, such as the phase equilibrium of the reactive system and the reaction kinetics on the conversion in the column, are described. It can be shown that the short‐cut methods published so far for reactive distillation, which assume chemical equilibrium, are inadequate.
Non‐Isothermal mixing of rheologically complex fluids with close‐clearance impellers: Effect of natural convection
Authors: Fuente Edmundo Brito‐De La , Nuñez M. C. , Tanguy P. A.
Published: August 2005

Transient heat transfer in a mechanically agitated vessel is studied in the case of an anchor and an helical ribbon impeller using Newtonian and shear thinning fluids. Temperature stratification is found more pronounced with the anchor, making this impeller clearly inadequate for heat transfer. The impact of natural convection is evaluated first using the classical Gr/Re2 ratio. It is shown that the use of this criterion in viscous mixing is somewhat misleading. A new Grashof number is then proposed to assess the significance of the viscous and buoyancy effects in non‐isothermal, non‐Newtonian mixing applications. It is shown that the interpretation of this new number is strongly related to the concept of process viscosity.
Design rules for the wallcooled hydrothermal burner (WHB)
Authors: Roche H. Lucas La , Weber M. , Trepp Christian
Published: August 2005

The results of a process analysis and an experimental exploratory study of supercritical water oxidation (SCWO) show that elements of combustion technology are suitable to overcome the technical problems of SCWO. The Film Cooled Hydrothermal Burner (FCHB) which operates at 25 MPa up to 2000 K in the reaction zone keeping wall temperature under stress at 300 to 400 K shows further development potential of the Wallcooled Hydrothermal Burner (WHB) concept for SCWO, a still promising waste treatment process.
Radial solids fraction profiles in inlet region of high density circulating fluidized bed
Authors: Yang Guoqiang , Wei Fei , Jin Yong , Yu Zhiqing
Published: August 2005

The radial solids fraction profiles in the inlet region of a high density circulating fluidized bed (HDCFB) are studied by a dual‐beam optic density sensor. Three kinds of inlet structures are employed to examine the axial developing process of the profiles. The acceleration effect of solids is analyzed by comparing the cross‐sectional average solids fraction obtained by the density sensor and differential pressure method. The results show that the radial solids fraction profile is largely influenced by the inlet structure. The length for the inlet effect region is no more than 1.5 m above the air injection.
Group theoretical model of surface tension for binary solutions
Authors: An Wang Fu , Li Jiang Yuan , Chang Wang Wen , Gao Jiang Deng
Published: August 2005

From the group statistical theory, a new universal equation is proposed for calculating the surface tension of solution with surface thermodynamics of solution. The simple form of the equation makes it convenient to use and its parameters have obvious physical meanings. With this model, we have explained the experimental phenomenan and empirical rules in cited works. Tested for 302 kinds of binary system, the overall absolute average deviation for 3230 data sets is 0.49%, making the model more accurate than those found in the literature. It also accounts for systems unsuitable for reference models because the phase states of the pure components are different under solution condition.
Modelling of the reversed flow fixed bed reactor for catalytic decontamination of waste gases
Authors: Grozev Georgi G. , Sapundzhiev Christo G.
Published: August 2005

Catalytic decontamination of waste gases in a fixed bed reactor, operating at non‐steady state conditions achieved by periodic gas flow reversal, is simulated on the basis of a mathematical model. The opportunity to utilize a significant part of the reaction heat is discussed and the effect of catalyst inactivation upon reactor performance is analyzed. Stable temperature regime and conversion exceeding 99.5% could be ensured by a more than eightfold reduction of catalyst activity.
Absorption of NO in an alkaline solution of KMnO4
Authors: Brogren Charlotte , Karlsson Hans T. , Bjerle Ingemar
Published: August 2005

A packed column has been used to study the absorption of nitrogen oxide in an alkaline solution of potassium permanganate. The reactions taking place during the absorption have been examined and the rate constants have been estimated from experimental data. The experiments show that potassium permanganate is an excellent absorbent for nitrogen oxide. However, to avoid formation of MnO2, the hydroxide concentration has to be very high, i.e. > 3 mol/l. It was found that the reaction could be expressed as first‐order with respect to NO and with respect to KMnO4. The rate constant may be expressed in terms of the hydroxide concentration as follows: kmn = 6114.9 101.9208 CNaOH m3 mol−1 s−1.
Optimization of fermentation medium composition in substrate‐controlled continuous stirred tank reactors
Authors: Beste Harald , Fackeldey Martin , Willems Marc , Stockmann Lars , Weuster‐Botz Dirk
Published: August 2005

A ‘carbon source controlled shift technique’ was developed for fermentation medium optimization in continuous culture with the objective to maximize growth rate and growth‐linked product formation of a biological system. An automatic culture medium preparation system was operated together with 2 parallel stirred tank reactors and a HPLC system for on‐line analysis of the carbon source concentration in the reactors. A genetic algorithm was applied for experimental design. The concentrations of 7 medium components (mineral salts and vitamins) were optimized automatically within 40 continuous experiments to result in a maximum growth rate of the methylotrophic yeast Candida boidinii and growth‐linked production of the formate dehydrogenase enzyme (FDH). The specific growth rate of Candida boidinii and the specific activity of the FDH enzyme at a set‐point of 420 mM methanol in the reactor were, thus, improved by 19% to 0.16 h−1 and 26% to 164 U g−1, respectively, compared to the previously used medium, which has already been previously optimized in shake flask experiments. The results of the continuous medium optimization were evaluated with a full second order seven‐dimensional polynomial model (regression coefficient 96.8%).
Cover Picture: Precursors of Biological Cofactors from Ultraviolet Irradiation of Circumstellar/Interstellar Ice Analogues (Chem. Eur. J. 17/2005)
Authors: Meierhenrich Uwe J. , Muñoz Caro Guillermo M. , Schutte Willem A. , Thiemann Wolfram H.‐P. , Barbier Bernard , Brack André
Published: August 2005

A mosaic of Orion's Great Nebula (M42), a nearby starbirth region, is shown on the cover (Hubble space telescope; C. R. O'Dell (Vanderbilt University) and NASA). Dust grains covered by ice mantles are expected to be UV photoprocessed in the nebula, and in circumstellar regions during early phases of star formation. Experimental simulations revealed that precursors of biological cofactors, such as hexahydrotriazines, are constantly synthesized under these conditions. More details are given by G. M. Muñoz Caro et al. on page 4895 ff. Stéphane Le Saint at the University of Nice designed the picture.
Novel Superstructure in the High‐Concentrated Hydrogen Solid Solutions ZrV2Dx>4.
Authors: Bogdanova A. N. , Irodova A. V. , Andre G. , Bouree F.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Li(MoO2)2O(AsO4).
Authors: Hajji Mounir , Zid Mohamed Faouzi , Jouini Tahar
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Structure and Phase Relations of the Zn2x(CuIn)1‐xS2 Solid Solution Series.
Authors: Schorr S. , Wagner G.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Structural, Conductivity and Dielectric Studies in (NH4)2SeO4×Te(OH)6.
Authors: Litaiem H. , Dammak M. , Mhiri T. , Cousson A.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Magnetic Properties of Mn‐Doped Transparent CuAlO2 Semiconductor.
Authors: Zhang H. Y. , Li P. G. , Chen C. P. , Tu Q. Y. , Tang W. H.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Interaction of the Components in the Systems Ce—Ag—Si at 500 °C and Eu—Ag—Si at 400 °C.
Authors: Belan B. , Bodak O. , Gladyshevskii R. , Soroka I. , Kuzhel B. , Protsyk O. , Stets I.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
A Bicapped α‐Keggin Unit‐Supported Transition Metal Complex: Hydrothermal Synthesis and Characterization of [Cu(en)2(H2O)]2 [Cu(en)2]0.5 [Mo8V7O42{Cu(en)2}].
Authors: Zeng Qing‐Xin , Xu Ji‐Qing , Song Yu‐Jiang , Cui Xiao‐Bing , Shi Zhan
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Two Halogeno(cyano)cuprates with Long‐Lived and Strong Luminescence.
Authors: Liu Xi , Guo Guo‐Cong , Wu A‐Qing , Cai Li‐Zhen , Huang Jin‐Shun
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
2‐Aryl‐5,5‐bisoxazolin‐2‐yl[1,3]dioxanes as Solution Phase and Immobilized Ligands for Highly Enantioselective Cyclopropanations.
Authors: Knight Julian G. , Belcher Paul E.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
The Isopropyl‐ and tert‐Butylsulfinyl Groups in Asymmetric Synthesis: A Comparative Study
Authors: Fernandez Inmaculada , Gori Beatrice , Alcudia Felipe , Khiar Noureddine
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Intramolecular Iodoarylation Reaction of Alkynes: Easy Access to Derivatives of Benzofused Heterocycles.
Authors: Barluenga Jose , Trincado Monica , Marco‐Arias Maria , Ballesteros Alfredo , Rubio Eduardo , Gonzalez Jose M.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Oxidation of Aldehydes and Ketones into Carboxylic Acids and Esters Using 4‐Amino‐2‐chloroperbenzoic Acid Supported on Silica Gel.
Authors: Hashemi Mohammed M. , Ghazanfari Dadkhoda , Ahmadibeni Yousef , Karimi‐Jaberi Zahed , Ezabadi Ali
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Catalyst‐Free Gas‐Phase Epoxidation of Alkenes.
Authors: Berndt Torsten , Boege Olaf
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Green Approach for the Conversion of Olefins into vic‐Halohydrins Using N‐Halosuccinimides in Ionic Liquids.
Authors: Yadav J. S. , Reddy B. V. S. , Baishya Gakul , Harshavardhan S. J. , Chary Ch. Janardhana , Gupta Manoj Kumar
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Niobium Pentachloride—Silver Perchlorate as an Efficient Catalyst in the Friedel—Crafts Acylation and Sakurai—Hosomi Reaction of Acetals.
Authors: Arai Shigeru , Sudo Yukinori , Nishida Atsushi
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Stereoselective Allylation of Chiral Monoperoxyacetals.
Authors: Ahmed Aqeel , Dussault Patrick H.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Zn(OTf)2×6H2O Catalyzed Acylation of Aldehydes: Preparation of 1,1‐Diacetates and α‐Chloroalkyl Esters.
Authors: Su Weike , Can Jin
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Chlorotrimethylsilane as a Mild and Effective Source of Acid Catalyst in Reductive Benzylation.
Authors: Izumi Minoru , Fukase Koichi
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Ruthenium‐Catalyzed Hydrative Dimerization of Allenes.
Authors: Saito Shinichi , Dobashi Naotomo , Wakatsuki Yasuo
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Reduction of Nitro‐Aryl Compounds with Zinc in the Presence of Poly[N‐(2‐aminoethyl)acrylamido]trimethylammonium Chloride as a Phase‐Transfer Catalyst.
Authors: Mahdavi Hossen , Tamami Bahman
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Novel Approach to Pro‐Drugs of Lactones: Water Soluble Imidate and ortho‐Ester Derivatives of a Furanone‐Based COX‐2 Selective Inhibitor.
Authors: Poon Steve F. , Stock Nicholas , Payne Joseph E. , McGuire Angela R. , Stearns Brian , Yang Xiaoqing , Chen Weichao , Munoz Benito , Smith Nicholas D.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Yb(OTf)3‐Catalyzed Vinylogous Mannich Reaction of Trialkylsilyloxyfuran.
Authors: Oudeyer Sylvain , Dudot Bruno , Royer Jacques
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Novel Lead Structures for Antimalarial Farnesyltransferase Inhibitors.
Authors: Kettler K. , Sakowski J. , Wiesner J. , Ortmann R. , Jomaa H. , Schlitzer M.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of N‐Arylsulfonyl‐α‐thienylglycines from N‐(2,2,2‐Trichloro‐1‐thienylethyl)arenesulfonamides.
Authors: Aizina Yu. A. , Rozentsveig I. B. , Ushakova I. V. , Levkovskaya G. G. , Mirskova A. N.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Regioselective Reduction of β‐Enaminoesters.
Authors: Hussaini Syed Raziullah , Moloney Mark G.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Substituted Bis(heteroaryl)maleimides.
Authors: Dubernet Mathieu , Caubert Virginie , Guillard Jerome , Viaud‐Massuard Marie‐Claude
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Novel Pyrrolinones as N‐Methyl‐D‐aspartate Receptor Antagonists.
Authors: Poschenrieder Hermann , Stachel Hans‐Dietrich , Hoefner Georg , Mayer Peter
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Pyrazolino‐ and Thiopyrimido‐fused Carbazoles from 2‐Ethylidene‐3,4‐dihydrocarbazol‐1(2H)‐ones.
Authors: Danish Isravel Antony , Rajendra Prasad Karnam Jayarampillai
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of 3,5‐Diphenyl‐1H‐pyrazoles.
Authors: Bhat B. A. , Puri S. C. , Qurishi M. A. , Dhar K. L. , Qazi G. N.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Palladium Catalyzed Cross‐Coupling Reaction of 5‐Tributylstannyl‐4‐fluoropyrazole.
Authors: Hanamoto Takeshi , Koga Yukinori , Kido Eisaku , Kawanami Toshio , Furuno Hiroshi , Inanaga Junji
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Microwave‐Assisted Aromatization of 1,3,5‐Trisubstituted 2‐Pyrazolines by Silica‐Supported N‐Bromosuccinimide as a Useful Reagent under Solvent Free “Dry” Condition.
Authors: Azarifar Davood , Maleki Behrooz
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Antimicrobial Activity of Some New 2‐Methyl‐5‐nitroimidazole Derivatives.
Authors: Ganguly S. , Singh S. P. , Chandra R.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
3‐Alkyl‐2‐[3(4)‐pyridyl]‐5‐(2‐vinyloxyethoxymethyl)oxazolidines
Authors: Kukharev B. F. , Stankevich V. K. , Lobanova N. A. , Klimenko G. R. , Kukhareva V. A.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Phase Transfer Catalyst Mediated One‐Pot Synthesis of 4‐Hydroxy‐3‐phenylcoumarin.
Authors: Sripathi Shubashini K. , Sivakamasundari S.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Novel Amino‐ and Acetylamino‐4‐methylcoumarins and Evaluation of Their Antioxidant Activity.
Authors: Tyagi Yogesh K. , Kumar Ajit , Raj Hanumantharao G. , Vohra Parag , Gupta Garima , Kumari Ranju , Kumar Pankaj , Gupta Rajinder K.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
An Efficient Procedure for the Synthesis of Coumarin Derivatives Using TiCl4 as Catalyst under Solvent‐Free Conditions.
Authors: Valizadeh Hassan , Shockravi Abbas
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Ionic Liquid Promoted Palladium‐Catalyzed Suzuki Cross‐Couplings of N‐Contained Heterocyclic Chlorides with Naphthaleneboronic Acids.
Authors: Yang Cheng‐Hsien , Tai Chia‐Cheng , Huang Yu‐Ting , Sun I‐Wen
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Quinone Imines with a Fused Azine Ring. Part 3. Synthesis and Reactivity of 8‐p‐Tolylsulfonylimino‐5,8‐dihydroquinolin‐5‐one Derivatives.
Authors: Belov A. V. , Nichvoloda V. M.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and DNA‐Binding Properties of Aminoacetylhydrazones of 9‐Formylanthracene and 9‐Formylacridine.
Authors: Lyakhova E. A. , Lyakov S. A. , Litvinova L. A. , Andronati S. A. , Lebedyuk M. N. , Fedchuk V. P. , Khorokhorina G. A.
Published: August 2005

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An Expeditious Synthesis of 6‐Aminophenanthridines.
Authors: Gug Fabienne , Blondel Marc , Desban Nathalie , Bouaziz Serge , Vierfond Jean‐Michel , Galons Herve
Published: August 2005

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Synthesis of Fused Bicyclic Pyridines with Microwave‐Assisted Intramolecular Hetero‐Diels—Alder Cycloaddition of Acetylenic Pyrimidines.
Authors: Shao Bin
Published: August 2005

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Reduction of Indolo[2,3‐b]quinoxalines.
Authors: Engqvist Robert , Stensland Birgitta , Bergman Jan
Published: August 2005

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Synthesis of Novel Benzo‐1,2,5‐thiadiazines, Their Antimicrobial Activity and Isomerization into Benzo‐1,2,4‐triazines.
Authors: Deohate Pradip P. , Deohate Jyoti P. , Berad B. N.
Published: August 2005

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Selective Ir‐Catalyzed Borylation of Polycyclic Aromatic Hydrocarbons: Structures of Naphthalene‐2,6‐bis(boronate), Pyrene‐2,7‐bis(boronate) and Perylene‐2,5,8,11‐tetra(boronate) Esters.
Authors: Coventry David N. , Batsanov Andrei S. , Goeta Andres E. , Howard Judith A. K. , Marder Todd B. , Perutz Robin N.
Published: August 2005

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New Synthesis and Fungicidal Activity of the Phosphine Analogues of Serine and Threonine.
Authors: Zhukov Yurii N. , Vavilova Nelli A. , Osipova Tat'yana I. , Khurs Elena N. , Dzhavakhiya Vitaly G. , Khomutov Radii M.
Published: August 2005

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Metabolites of the Marine Fungus Humicola fuscoatra KMM 4629.
Authors: Smetanina O. F. , Kuznetsova T. A. , Gerasimenko A. V. , Kalinovsky A. I. , Pivkin M. V. , Dmitrenok P. C. , Elyakov G. B.
Published: August 2005

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A New Steroidal Glycoside Phrygioside A and Its Aglycone from the Starfish Hippasteria phrygiana
Authors: Levina E. V. , Kalinovskii A. I. , Andriyashchenko P. V. , Dmitrenok P. S. , Evtushenko E. V. , Stonik V. A.
Published: August 2005

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Synthesis of Steroidal Enamine‐Pyrrolidine Derivative.
Authors: Shamsuzzaman Shamsuzzaman , Siddiqui Nazish , Siddiqui Tabassum
Published: August 2005

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Synthesis of Thiazolyl and Thieno Cholestane Derivatives: A Novel Class of Potent Antiinflammatory Steroids.
Authors: Elmegeed G. A. , Wardakhan W. W. , Baiuomy A. R.
Published: August 2005

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Amino Acid Catalyzed Direct Enantioselective Formation of Carbohydrates: One‐Step de Novo Synthesis of Ketoses.
Authors: Ibrahem Ismail , Cordova Armando
Published: August 2005

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Syntheses of 4‐[(1H,3H)‐Pyrimidine‐2,4‐dion‐1‐yl]‐ and 4‐[(1H,3H)‐5‐Methylpyrimidine‐2,4‐dion‐1‐yl]‐1,6‐heptadienes.
Authors: Bouhadir Kamal H. , Zhou Jing‐Lan , Shevlin Philip B.
Published: August 2005

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Synthesis of 1‐[(2‐Hydroxyethoxy)methyl] ‐6‐(5,6,7,8‐tetrahydronaphthylmethyl‐1)thymine as Novel Inhibitor Against Drug‐Resistant HIV Mutants.
Authors: Meng Ge , Kuang Yun‐Yan , Ji Lei , Chen Fen‐Er
Published: August 2005

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Medizinische Chemie
Authors: Steinhilber Dieter , Schubert‐Zsilavecz Manfred , Roth Herrmann Josef
Published: August 2005

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Synthesis and Characterization of Highly Luminescent CdSe—Core CdS/Zn0.5Cd0.5S/ZnS Multishell Nanocrystals.
Authors: Xie Renguo , Kolb Ute , Li Jixue , Basche Thomas , Mews Alf
Published: August 2005

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Orbital Effects in Manganites
Authors: van den Brink Jeroen , Khaliullin Giniyat , Khomskii Daniel
Published: August 2005

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Magnetic Properties of (Ga,Mn)As
Authors: Sawicki M.
Published: August 2005

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Adsorption and Catalytic Reactions at Solid/Gas Interfaces
Authors: Schay Z.
Published: August 2005

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Al—Ni—Si
Authors: Raghavan V.
Published: August 2005

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Non‐Collinear Ferromagnetism: A Summary of Some Studies with Neutron Polarization Analysis
Authors: Wildes A. R. , Cowlam N.
Published: August 2005

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Chromium— and Manganese—Salen Promoted Epoxidation of Alkenes
Authors: McGarrigle Eoghan M. , Gilheany Declan G.
Published: August 2005

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Advances in Homogeneous and Heterogeneous Catalytic Asymmetric Epoxidation
Authors: Xia Q.‐H. , Ge H.‐Q. , Ye C.‐P. , Liu Z.‐M. , Su K.‐X.
Published: August 2005

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Intramolecular Involvement of an Oxygen‐Containing Nucleophilic Group in Epoxy Ring Opening
Authors: Salomatina O. V. , Yarovaya O. I. , Barkhash V. A.
Published: August 2005

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Organocatalytic Hydride Transfers: A New Concept in Asymmetric Hydrogenations
Authors: Adolfsson Hans
Published: August 2005

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Cellulose: Fascinating Biopolymer and Sustainable Raw Material
Authors: Klemm Dieter , Heublein Brigitte , Fink Hans‐Peter , Bohn Andreas
Published: August 2005

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Some New Nazarov Chemistry
Authors: Tius Marcus A.
Published: August 2005

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Accelerated Methods of Synthesis of Phosphorus‐Containing Dendrimers
Authors: Maraval Valerie , Laurent Regis , Marchand Patrice , Caminade Anne‐Marie , Majoral Jean‐Pierre
Published: August 2005

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Synthesis, Reactivity and Stereochemistry of New Phosphorus Heterocycles with 5‐ or 6‐Membered Rings
Authors: Cristau Henri‐Jean , Pirat Jean‐Luc , Virieux David , Monbrun Jerome , Ciptadi Ciptadi , Bekro Yves‐Alain
Published: August 2005

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Macrocycles Rapidly Produced by Multiple Multicomponent Reactions Including Bifunctional Building Blocks (MiBs)
Authors: Wessjohann Ludger A. , Ruijter Eelco
Published: August 2005

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What Can a Chemist Learn from Nature′s Macrocycles? A Brief, Conceptual View
Authors: Wessjohann Ludger A. , Ruijter Eelco , Garcia‐Rivera Daniel , Brandt Wolfgang
Published: August 2005

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Planar Dehydro[8]annulenes and Their Ramifications: Substituted Tribenzo[a,c,e]cyclooctenes and Tetrabenzo[a,c,e,g]cyclooctenes.
Authors: Hou Xue‐Long , Huang Hui , Wong Henry N. C.
Published: August 2005

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Chemistry of Domoic Acid, Isodomoic Acids, and Their Analogues
Authors: Clayden Jonathan , Read Benjamin , Hebditch Katherine R.
Published: August 2005

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Peptide Nucleic Acid (PNA): A Pseudopeptide with DNA‐like Properties
Authors: Nielsen Peter E. , Koppelhus Uffe , Beck Frederik
Published: August 2005

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β‐Peptides, γ‐Peptides and Isosteric Backbones: New Scaffolds with Controlled Shapes for Mimicking Protein Secondary Structure Elements
Authors: Guichard Gilles
Published: August 2005

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β‐Phosphono‐ and ‐Phosphinopeptides Derived from β‐Amino‐ Phosphonic and ‐Phosphinic Acids
Authors: Palacios Francisco , Alonso Concepcion , de los Santos Jesus M.
Published: August 2005

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Synthesis of 1,2,4‐Triazoline‐5‐thione Derivatives
Authors: Pitucha M. , Wujec M. , Dobosz M.
Published: August 2005

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Introduction to Chiral Crystallization of Achiral Organic Compounds
Authors: Matsuura Teruo , Koshima Hideko
Published: August 2005

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Organic Solid‐State Reactions with 100% Yield
Authors: Kaupp Gerd
Published: August 2005

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Coordination and Organometallic Polymers and Oligomers of Upper‐Rim Functionalized Calix[4]arenes by Transition Metals
Authors: Harvey Pierre D.
Published: August 2005

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Bioactive Triterpenes and Related Compounds from Celastraceae
Authors: Alvarenga Nelson , Ferro Esteban A.
Published: August 2005

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Endohedral Metal Complexes of Cyclophanes
Authors: Gleiter Rolf , Rausch Bernhard J. , Schaller Rolf J.
Published: August 2005

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Molecular Organization and Signal Transduction at Intermembrane Junctions
Authors: Groves Jay T.
Published: August 2005

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Arthur Eichengruen — Tribute to a Forgotten Chemist, Entrepreneur, and German Jew
Authors: Vaupel Elisabeth
Published: August 2005

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From NQR to NMR: The Complete Range of Quadrupole Interactions
Authors: Bain Alex D. , Khasawneh Maysoon
Published: August 2005

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Genetic expression profiles and biologic pathway alterations in head and neck squamous cell carcinoma
Authors: Choi Peter , Chen Chu
Published: August 2005

Head and neck squamous cell carcinoma (HNSCC) is associated with considerable mortality and morbidity and is a major public health concern worldwide. To date, > 20 studies incorporating DNA microarray analyses have examined genomewide genetic expression changes associated with the development of HNSCC. The authors identified published reports of genetic expression profiles of HNSCC by Medline database search. They performed a review of the reports to identify genes that have been found repeatedly to exhibit substantially altered expression in HNSCC. Genes with altered expression were subsequently examined in the context of defined biologic systems with the use of GenMapp 2.0 pathway analysis software. Genes most commonly found to exhibit altered expression were those encoding for cytoskeletal and extracellular matrix proteins, inflammatory mediators, proteins involved in epidermal differentiation, and cell adhesion molecules. Results of GenMapp 2.0 analysis suggested global down‐regulation of genes that encode for ribosomal proteins and enzymes in the cholesterol biosynthesis pathway; and up‐regulation of genes that encode for matrix metalloproteinases and genes that bear on the inflammatory response. The review indicated that there are several genes and pathways that exhibit substantially altered expression in cancerous versus noncancerous states across studies. Further investigation into the genomic, proteomic, and functional consequences of these gene expression alterations may provide insight into the pathophysiology of HNSCC. Cancer 2005. © 2005 American Cancer Society.
Liposome‐encapsulated curcumin
Authors: Li Lan , Braiteh Fadi S. , Kurzrock Razelle
Published: August 2005

BACKGROUND

Because a role for nuclear factor‐κB (NF‐κB) has been implicated in the pathogenesis of pancreatic carcinoma, this transcription factor is a potential target for the treatment of this devastating disease. Curcumin (diferuloylmethane) is a phytochemical with potent NF‐κB‐inhibitory activity. It is pharmacologically safe, but its bioavailability is poor after oral administration.

METHODS

The authors encapsulated curcumin in a liposomal delivery system that would allow intravenous administration. They studied the in vitro and in vivo effects of this compound on proliferation, apoptosis, signaling, and angiogenesis using human pancreatic carcinoma cells. NF‐κB was constitutively active in all human pancreatic carcinoma cell lines evaluated and liposomal curcumin consistently suppressed NF‐κB binding (electrophoretic mobility gel shift assay) and decreased the expression of NF‐κB‐regulated gene products, including cyclooxygenase‐2 (immunoblots) and interleukin‐8 (enzyme‐linked immunoassay), both of which have been implicated in tumor growth/invasiveness. These in vitro changes were associated with concentration and time‐dependent antiproliferative activity (3‐[4,5‐dimethylthiazol‐2‐yl]2,5‐diphenyltetrazolium bromide assay [MTT assay]) and proapoptotic effects (annexin V/propidium iodide staining [fluorescence‐activated cell sorting] and polyadenosine‐5′‐diphosphate‐ribose‐polymerase cleavage).

RESULTS

The activity of liposomal curcumin was equal to or better than that of free curcumin at equimolar concentrations. In vivo, curcumin suppressed pancreatic carcinoma growth in murine xenograft models and inhibited tumor angiogenesis.

CONCLUSIONS

Liposomal curcumin down‐regulated the NF‐κB machinery, suppressed growth, and induced apoptosis of human pancreatic cells in vitro. Antitumor and antiangiogenesis effects were observed in vivo. The experiments in the current study provide a biologic rationale for treatment of patients suffering from pancreatic carcinoma with this nontoxic phytochemical encapsulated in liposomes for systemic delivery. Cancer 2005. © 2005 American Cancer Society.
The implementation of boundary conditions of the type u equals unknown constant in finite element codes
Authors: Segal A.
Published: August 2005

In this note we present a method to incorporate boundary conditions of the type u equals unknown constant in existing finite element codes, without disturbing the structure of the resulting finite element matrices. The method is applied to the problem of a flow around an obstacle and to two problems from lubrication theory. It is shown that the method presented does not require any extra computing time compared to problems with other types of boundary conditions.
An explicit formula for the generalized Hermitian interpolation problem
Authors: El‐Zafrany A. M. , Cookson R. A.
Published: August 2005

This paper introduces an explicit expression for the one‐dimensional Hermitian interpolation problem with arbitrary nodal derivatives. The suggested formula can be used for the derivation of shape functions, for Hermitian finite elements.
On upwind collocation methods
Authors: Herbst B. M.
Published: August 2005

The upwind collocation method is analysed in a way which clearly demonstrates its similarities to other upwind schemes. The dispersion detected by Dougherty and Pinder5 is shown to be of little significance to the quality of the approximation.
A note on Marguerre shell finite elements
Authors: Prathap G. , Pillai S. R. , Eggers H.
Published: August 2005

Shallow shell elements based on Marguerre's theory do not recover the correct membrane strains along lines of zero slope of shell surface. Therefore, the in‐plane displacements may not converge in the vicinity of these lines except in pure bending states.