bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid–Liquid Extraction
Authors: Müller Eckart , Berger Rosemarie , Blass Eckhart , Sluyts Domien , Pfennig Andreas 
Published: January 2008

AbstractThe article contains sections titled:1.Fundamentals and Fields of Application2.Thermodynamic Fundamentals2.1.Graphic Representation of Phase Equilibria2.1.1.Triangular Diagrams2.1.2.Other Graphic Representations2.2.Measuring Methods of Phase Equilibria2.3.Correlation of Phase Equilibria2.4.Selection of Solvent2.5.Determination of Mass‐Transfer Performance2.5.1.Specific Methods for Determining the Theoretical Number of Stages2.5.2.Determining Equipment Behavior Based on Drop‐Population Balances2.5.3.Evaluation of Stage‐Number Calculation for Process Design3.Apparatus3.1.Survey3.1.1.Columns without Energy Input3.1.2.Pulsed Columns3.1.3.Columns with Rotating Internals3.1.4.Mixer – Settlers3.1.5.Centrifugal Extractors3.2.Fluid‐Dynamic Fundamentals3.2.1.Problems and Process Strategy3.2.2.Operating Characteristics of Pulsed Columns and Columns with Rotating Internals3.2.3.Fluid Dynamic Calculation Methods3.3.Apparatus Design3.3.1.Internals and Operating Conditions3.3.2.Column Diameter3.3.3.Column Height3.4.Criteria for Equipment Selection4.Phase‐Separation Equipment4.1.Gravity Settlers without Inserts4.2.Settlers with Coalescing Aids5.Liquid – Liquid Extraction Processes5.1.General5.2.Combined Processes of Extraction and Distillation5.3.Reactive Extraction5.3.1.Introduction5.3.2.Extraction Mechanism of Different Types of Solvent5.3.3.Uses5.3.4.Setting up an Extraction System5.3.5.Diluents and ModifiersLiquid–liquid or solvent extraction is the separation method of choice where distillation fails, e.g., for azeotropic mixtures or temperature‐sensitive components. Separation is achieved by adding a liquid solvent phase to the original liquid carrying the component(s) to be extracted. One of the phases must be dispersed into droplets in the other, continuous phase to achieve a sufficiently large mass‐transfer interface. Extraction is performed in mixer–settler equipment or extraction columns, which are frequently equipped with rotating internals or pulsators for energy input to positively influence droplet size. Here the different principles for equipment design are presented: coupling thermodynamic equilibrium and balances for determination of required number of theoretical stages, fluid‐dynamic design, and selection of equipment and operating conditions. Additionally, a modern method for linking these aspects more efficiently is shown. A method to characterize coalescence behavior for settler design is explained. Finally, reactive extraction is presented, which is applied, e.g., for metal separation or purification. The separation efficiency in reactive extraction is enhanced by a chemical reaction.
Polyaspartates and Polysuccinimide
Authors: Klein Thomas , Moritz Ralf‐Johann , Graupner René 
Published: January 2008

Abstract
The article contains sections titled:

1.

Introduction

2.

Synthesis and Production of Polyaspartates

3.

Analytical Characterization and Detection

3.1.

NMR Spectroscopy

3.2.

NMR Spectroscopy

3.3.

Gel Permeation Chromatography

3.4.

Isotachophoresis

3.5.

Fluorescence Spectroscopy

3.6.

Precipitation Titration

3.7.

Polyelectrolyte Titration

4.

Toxicological Properties and Environmental Fate

5.

Function and Applications

5.1.

Functionality

5.1.1.

Dispersing Effect

5.1.2.

Threshold Effect

5.1.3.

Crystal Distortion

5.1.4.

Complexing Effect

5.1.5.

Corrosion Inhibition

5.2.

Applications and Uses of Polyaspartates

5.2.1.

Water Treatment

5.2.2.

Detergents and Cleaners

5.2.3.

Mining and Oil Recovery

5.2.4.

Other Uses

6.

Polysuccinimide

6.1.

Introduction

6.2.

Chemical Properties and Analytic Characterization

6.3.

Applications and Uses of Polysuccinimide

7.

References

Polyaspartates are biodegrable polyanions which can substitute the currently used polycarboxylates or polyacrylates as inhibitors of mineral formation and scaling, widely occurring problems in various industrial processes. Polyaspartates can be used in many applications such as detergents and cleaners, water treatment agents, or as agents in mining and oil recovery. Production in commercial scale is possible by polycondensation of enzymatically produced
l
‐aspartic acid. However, complete substitution of polycarboxylates, which are mainly non‐biodegradable, would only be possible by using chemical precursors of aspartic acid. Polyaspartates have excellent toxicological properties.
Enzyme Kinetics
Authors: Cleland W. Wallace 
Published: January 2008

Abstract
Enzyme kinetics is an important tool for assaying enzyme activities and for determining enzyme mechanisms. Although other techniques can provide useful information on enzyme mechanisms, the kinetics has to be the ultimate arbiter because it looks at the reaction while it is taking place. Initial velocity patterns, inhibition patterns, patterns of isotopic exchange, pH profiles, and isotope effects are all kinetic tools that allow one to determine kinetic mechanisms, chemical mechanisms, and transition state structures.
Carbohydrate– Carbohydrate Interactions
Authors: Seah Nicole , Basu Amit 
Published: January 2008

AbstractCarbohydrate–carbohydrate interactions have been suggested as mediators of cell adhesion and aggregation. Studies of four different interactions— sponge cell aggregation, embryo and myelin compaction, and melanoma cell adhesion— have provided insights into the role of the saccharides in these events. The biological context of these associations as well as the results of experiments using biophysical and chemical model systems are described.
Sliding mode control of switched hybrid systems with time‐varying delay
Authors: Wu Ligang , Lam James 
Published: January 2008

AbstractThis paper is concerned with the sliding mode control of a continuous‐time switched system with time‐varying delay in its state. By using the average dwell time approach and the piecewise Lyapunov function technique, a sufficient condition is first proposed to guarantee the exponential stability of the unforced system with the decay estimate explicitly given. A sufficient condition of the existence of a reduced‐order sliding mode dynamics is derived, and an explicit parametrization of the desired sliding surface is also given. The obtained conditions will be solved using the cone complementary linearization (CCL) method. An adaptive sliding mode controller for the reaching motion is then designed such that the trajectories of the resulting closed‐loop system can be driven onto a prescribed sliding surface and maintained there for all subsequent times. All the conditions obtained in this paper are delay dependent. Finally, two numerical examples are given to illustrate the effectiveness of the proposed theory. Copyright © 2008 John Wiley & Sons, Ltd.
Aerobic Ligand‐Free Suzuki Coupling Reaction of Aryl Chlorides Catalyzed by In Situ Generated Palladium Nanoparticles at Room Temperature
Authors: Han Wei , Liu Chun , Jin Zilin 
Published: February 2008

AbstractAn aerobic, ligand‐free Suzuki coupling reaction catalyzed by in situ generated palladium nanoparticles in polyethylene glycol with an average molecular weight of 400 Da (PEG‐400) at room temperature has been developed. This catalytic system is a very simple and highly active protocol for the Suzuki coupling of aryl chlorides with arylboronic acids, which proceed smoothly in excellent yields in short times using low catalyst loadings. Control experiments demonstrated that the Suzuki reaction catalyzed by the in situ generated palladium nanoparticles can be carried out much quicker than that using the preprepared particles under the same conditions. The formation of palladium nanoparticles in PEG‐400 was promoted by arylboronic acids.
Lack of association of the dopamine transporter gene in a French ADHD sample
Authors: Wohl M. , Boni C. , Asch M. , Cortese S. , Orejarena S. , Mouren M.C. , Gorwood P. , Purper‐Ouakil D. 
Published: January 2008

AbstractDiscrepancies in the role of the 40 bp VNTR polymorphism of the dopamine transporter gene (DAT1) in attention‐deficit hyperactivity disorder (ADHD) could be due to various sources of genetic or phenotypical heterogeneity. We therefore analyzed a sample of 146 ADHD children and their parents, with a transmission disequilibrium test (TDT) design, assessing age, inattention, and hyperactivity dimensions and total score of the ADHD Rating Scale, the number of errors and the total score at Stroop Color‐Word test, and the total score at the Trail Making Test. The TDT for 10‐repeat (10‐R) allele shows a perfect lack of transmission bias (Mc Nemar χ2 = 0) and PBAT analyses showed no role of this polymorphism for any of the studied endophenotypes. Lack of statistical power is always a possibility, but with a sample size above the average of the majority of previous studies, and an odds ratio (number of transmitted versus untransmitted 10‐R allele) of 1.00 exactly, this possibility may be considered as not very likely. © 2008 Wiley‐Liss, Inc.
Ferrocenylalkyl azoles: bioactivity, synthesis, structure
Authors: Snegur Lubov' V. , Nekrasov Yury S. , Sergeeva Nataliya S. , Zhilina Zhanna V. , Gumenyuk Vera V , Starikova Zoya A. , Simenel Alexander A. , Morozova Nataliya B. , Sviridova Irina K. , Babin Valery N. 
Published: January 2008

AbstractThe toxicity of ferrocenylethyl benzotriazole (1) and other ferrocene compounds including ferrocenylmethyl benzimidazoles (4,5,6,11), ferricenium salts (3,9,10) and ferrocenylmethyl adenine (7), was studied. All ferrocene complexes under investigation showed low or medium toxicities. On the basis of an earlier model of chemical carcinogenesis, the antitumor activity of ferrocenylalkyl azoles 1, 8 and ferricenium salts 9, 10 was studied in vivo in the so‐called sub‐capsular test on human tumors. This effectiveness was compared with that of cisplatin. A series of ferrocenylalkyl azoles were synthesized by interacting azoles either with α‐hydroxyalkyl ferrocenes FcC(OH)R1R2 in organic solvent in the presence of aqueous HBF4 in quantitative yields or with trimethyl(aminomethyl)ferrocene iodide in an aqueous‐basic medium in good yields. The X‐ray determinations of molecular and crystal structures of α‐(1‐benzotriazolyl)ethylferrocene (1) and α‐(1‐naphthatriazolyl)ethylferrocene (12) were performed. Copyright © 2008 John Wiley & Sons, Ltd.
Reactive dyeing of cellulosic fibers: Use of cationic surfactants and their interaction with reactive dyes
Authors: Mouxiou E. , Eleftheriadis I. , Nikolaidis N. , Tsatsaroni E. 
Published: January 2008

AbstractCotton fabrics were dyed with three reactive dyes, C.I Reactive Blue 263, C.I Reactive Red 269, and C.I Reactive Yellow 208, after pretreatment of the fabrics with three alkyl trimethyl‐ammonium bromides (tmabs) having 12, 14, and 16 carbon atoms in the alkyl chain. The pretreated samples were dyed with standard dyeing methods using conventional, reduced amounts of electrolyte, and no electrolyte. Pretreatment with the three cationics (tmabs) resulted in an increase in dye exhaustion with all dyes used, whereas total dye fixation was lower for both red and blue dye and equal for the yellow, when compared to the reference untreated samples dyed according to the same standard dyeing method. The interaction between dodecyl trimethyl‐ammonium bromide and the three dyes was studied and the stoichiometry of the various dye/dodecyl trimethyl‐ammonium bromide (12‐tmab) complexes formed has been deduced. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Microwave‐induced enhancement of the dissolution rate of poorly water‐soluble tibolone from poly(ethylene glycol) solid dispersions
Authors: Papadimitriou Sofia Anastasios , Bikiaris Dimitrios , Avgoustakis Konstantinos 
Published: January 2008

AbstractIn this study, solid dispersions of poorly water‐soluble Tibolone in a poly(ethylene glycol) matrix were prepared with conventional melt mixing and microwave irradiation. The results of the assay content, LC–MS, and 1H‐NMR indicated that microwave irradiation did not affect drug stability when a relatively low irradiation power (440 W) was used. Fourier transform infrared spectroscopy indicated that there were no hydrogen bonds formed between Tibolone and poly(ethylene glycol), and this affected the drug's crystallinity and its particle size distribution. The dissolution rate of the drug was slightly higher in the case of dispersions prepared by microwave irradiation. This enhancement of the drug dissolution rate was probably due to the lower size of the Tibolone particles in the dispersions prepared by microwave irradiation. The application of microwaves represents a promising alternative to conventional preparative methods of drug dispersions. The main advantage in comparison with conventional melt mixing is that solid dispersions can be prepared in much shorter times. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Multiscale mechanical phenomena in electrospun carbon nanotube composites
Authors: Agic Ante 
Published: January 2008

AbstractThe carbon nanotube (CNT) structure is a promising building block for future nanocomposite structures. Mechanical properties of the electrospun butadiene elastomer reinforced with CNT are analyzed by multiscale method. Nanofiber diameter dependence on electric field and solution concentration is estimated from experimental data. The fiber microscale effective properties are determined by homogenization procedure using modified shear‐lag model, while the point‐bonded stochastic fibrous network on the mesoscale replaced by continuum effective sheet. Random fibrous network was generated according experimentally determined stochastic quantifiers. The influence of CNT reinforcement on elastic modulus of electrospun sheet on macroscopic level is determined by finite element method. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Deflection behaviors of polymer mortar sandwich panels reinforced with GFRP
Authors: Yeon Kyu‐Seok , Yi Jaichul , Lee Hyun‐Jong 
Published: January 2008

AbstractThis study prepared sandwich panel specimens composed of methyl methacrylate (MMA)‐modified polymer mortar at the core and reinforced with high‐tensile GFRP on both faces to propose a method to predict the deflection of polymer mortar sandwich panels under flexural load. Nine experimental specimens of different thickness at the core and face were prepared for the flexural load test to determine the moment‐deflection relationship, and the experimental results were compared with existing theoretical models. The comparison study revealed that the deflection behavior of the specimens in response to the variation in the thickness of the specimens at the core and face could be well predicted. Additionally, an analytical model, which revised a bilinear method, to explain the tension stiffening effect of the prepared sandwich panel specimens under the influence of flexural load is proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
ESR study of silica‐filled SBR with different rubber/filler interactions
Authors: Ito Masayoshi , Isago Hiroyuki , Suzuki Nozomu 
Published: January 2008

AbstractSilica‐filled styrene–butadiene rubber (SBR) unvulcanizates and their vulcanizates with different rubber/filler interactions were prepared by using several kinds of coupling agents. Tensile tests and electron spin resonance (ESR) measurements were carried out for both unvulcanized and vulcanized samples to get information on the effects of filler/rubber interactions on the breakdown of carbon–carbon (CC) linkages in SBR and carbon–sulfur (CSC, CSSC) linkages at the crosslinked points between rubber and sulfur by a tensile force. The combination of ESR results and stress–strain data suggested that with increasing the mechanical energy applied to the samples by the stretching, the carbon–sulfur linkages around silica particles were broken first, followed by the breakdown of carbon–sulfur and CC linkages in the rubber matrix. The assignment of ESR spectrum was also discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Design, Synthesis, and Biological Testing of 4β‐[(4‐Substituted)‐1,2,3‐triazol‐1‐yl]podophyllotoxin Analogues as Antitumor Agents
Authors: Reddy Pitta B. , Paul David V. , Agrawal Satyam K. , Saxena Ajit K. , Kumar Halmuthur M. S. , Qazi Ghulam N. 
Published: January 2008

AbstractA series of 4β‐[(4‐substituted)‐1,2,3‐triazol‐1‐yl]podophyllotoxin analogues have been synthesized with high regio‐selectivity by employing copper(I)‐catalyzed 1,3‐dipolar cycloaddition of 1‐O‐propargyl monosaccharides with C4β‐azido podophyllotoxin and C4β‐azido‐4′‐O‐demethyl podophyllotoxin. All the compounds were evaluated for their anticancer activity against a panel of six human cancer cell lines. Among these, 4′‐O‐demethyl podophyllotoxin congeners are showing promising anticancer activity mainly against HCT‐15 (colon) and DU‐145 (prostate) cells.
Improved high‐performance liquid chromatographic method for simultaneous determination of 12 cytotoxic caged xanthones in gamboges, a potential anticancer resin from Garcinia hanburyi
Authors: Li Song‐Lin , Song Jing‐Zheng , Han Quan‐Bin , Qiao Chun‐Feng , Xu Hong‐Xi 
Published: February 2008

AbstractThe potential anti‐tumor activity of gamboges, a herbal medicine derived from Garcinia hanburyi, has increasingly gained the interest of scientist worldwide. The major components of gamboges are cytotoxic caged xanthones. In the present study, an improved HPLC method was developed to simultaneously quantify 12 caged xanthones, including three pairs of epimers and four pairs of trans–cis isomers, i.e. forbesione, isomorellic acid, morellic acid, R‐30‐hydroxygambogic acid, S‐30‐hydroxygambogic acid, isogambogenic acid, gambogenic acid, gambogellic acid, R‐isogambogic acid, S‐isogambogic acid, R‐gambogic acid and S‐gambogic acid. This method was validated to be sensitive, precise and accurate with limits of detection of 0.03–0.08 µg/mL, overall intra‐day and inter‐day variations less than 7.9% and overall recovery over 93.2%. The correlation coefficients (r2) of the calibration curves were higher than 0.995 for all analytes. The newly established method was successfully applied to reveal the difference in the chemical profiles and contents of these analytes in gamboges from different origins. It can be concluded that this method was not only an effective quality control method to ensure the safety and efficacy consistency of gamboges, but also a useful tool for screening and determining more potent cytotoxic xanthones with potential anticancer activity. Copyright © 2008 John Wiley & Sons, Ltd.
A Mixed‐Valence, Hexadecamolybdenum Cluster With an MoVI Cubane “Jewel” in a “Setting” of Five MolybdateVI‐Linked Dinuclear MoV Units
Authors: Hill Lyndal M. R. , Abrahams Brendan F. , Young Charles G. 
Published: January 2008

AbstractThe hexadecanuclear, mixed‐valence cluster [Mo16O42(OH)2(3‐iPrC3H3N2)12]⋅n H2O (1), has been synthesized and characterized by X‐ray crystallography, IR spectroscopy and mass spectrometry. The C2‐symmetric complex consists of a cubane MoVI4O4 “jewel” held in a 10‐point “setting” comprised of five dinuclear MoV units tethered together by two tetrahedral MoVI centers. The dinuclear units are ligated by twelve 3‐isopropylpyrazole units that interact with the MoO framework through a network of hydrogen bonds. Structural parameters, charge requirements, and bond valence sum analyses support the assignment of +5 and +6 oxidation states to the dinuclear and cubane/tetrahedral Mo centers, respectively. Space filling models reveal that the pyrazole groups coat much of the surface of the molecule, apart from a number of oxo‐rich seams that trace a chiral pattern across the surface. Complex 1 exhibits a unique structure that combines moieties generally atypical of polyoxometalates, viz., a Mo cubane containing only two terminal oxo ligands, and three distinct MoV2 units (including a 5‐coordinate Mo center) tethered into a 10‐point “setting” by tetrahedral MoVI centers.
ChemInform Abstract: Synthesis and Characterization of Layered Zinc Hydroxychlorides.
Authors: Tanaka Hidekazu , Fujioka Akiko , Futoyu Aya , Kandori Kazuhiko , Ishikawa Tatsuo 
Published: January 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: Preparation and Lithium Doping of Gallium Oxynitride by Ammonia Nitridation via a Citrate Precursor Route.
Authors: Kikkawa Shinichi , Nagasaka Kazuteru , Takeda Takashi , Bailey Mark , Sakurai Toshitaka , Miyamoto Yoshinari 
Published: January 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: Hydrothermal Synthesis, Crystal Structure and Properties of 2‐D and 3‐D Lanthanide Sulfates.
Authors: Xu Yan , Ding Shaohua , Zheng Xuefang 
Published: January 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: Cobalt‐Catalyzed Asymmetric Cyclopropanation of Electron‐Deficient Olefins.
Authors: Chen Ying , Ruppel Joshua V. , Zhang X. Peter 
Published: January 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: Cobalt‐Catalyzed Reductive Coupling of Activated Alkenes with Alkynes.
Authors: Chang Hong‐Tai , Jayanth Thiruvellore Thatai , Wang Chun‐Chih , Cheng Chien‐Hong 
Published: January 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: Directed ortho Insertion (DoI): A New Approach to Functionalized Aryl and Heteroaryl Zinc Reagents.
Authors: Boudet Nadege , Sase Shohei , Sinha Pradipta , Liu Ching‐Yuan , Krasovskiy Arkady , Knochel Paul 
Published: January 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: Synthesis of 5‐Cyano‐1,3‐dioxoalkanes by Reaction of 1,3‐Dicarbonyl Dianions with Bromoacetonitrile.
Authors: Holtz Edith , Langer Peter 
Published: January 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.