bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Efficient Solvent‐Free Route to Silyl Esters and Silyl Ethers
Authors: Ojima Yuko , Yamaguchi Kazuya , Mizuno Noritaka 
Published: June 2009

Abstractmagnified imageDinuclear metal complexes, especially (p‐cymene)ruthenium dichloride dimer {[RuCl2(p‐cymene)]2}, have been found to exhibit high catalytic performance for the dehydrosilylation of various kinds of carboxylic acids and alcohols. The dehydrosilylation with [RuCl2(p‐cymene)]2 proceeded efficiently with only one equivalent of silane with respect to substrate (carboxylic acids or alcohols) under solvent‐free conditions to give the corresponding silyl esters and ethers in excellent yields with a high turnover number (TON) and frequency (TOF). The 1H NMR spectrum of a toluene‐d8 solution of [RuCl2(p‐cymene)]2 and a silane showed a signal assignable to the ruthenium hydride species. In contrast, no new signals were detected in the 1H NMR spectrum of a toluene‐d8 solution of [RuCl2(p‐cymene)]2 and a carboxylic acid or an alcohol. Therefore, the ruthenium metal in [RuCl2(p‐cymene)]2 activates a silane to afford the hydride intermediate, possibly a silylmetal hydride species. Then, the nucleophilic attack of a substrate (carboxylic acid or alcohol) to the hydride intermediate proceeds to give the corresponding silylated product. The present dehydrosilylation with an optically active silane proceeded exclusively under inversion of stereochemistry at the chiral silicon center, suggesting that the nucleophilic attack of a substrate to the hydride intermediate occurs from the backside of the ruthenium‐silicon bond.
Synergistic routes to liquid fuel for a petroleum‐deprived future
Authors: Agrawal Rakesh , Singh Navneet R. 
Published: June 2009

AbstractWhen compared with biomass gasification/Fischer‐Tropsch synthesis, hydropyrolysis/hydrodeoxygenation (HDO)‐based processes have a potential to achieve high biomass carbon conversion to liquid fuel with much lower amounts of supplementary H2. On the basis of this observation, we suggest a Hydrogen Bio‐oil (H2Bioil) process using fast hydropyrolysis/HDO that has a potential to produce nearly double the amount of liquid fuel when compared with the existing biofuel processes while requiring only modest quantities of supplementary H2. The optimal operating mode for the H2Bioil process is suggested to be in an entrained bed mode in presence of H2 with gas phase HDO of hydropyrolyzed vapors. A remarkable result due to reduced need for the supplementary H2 is that it provides synergistic integration of the H2Bioil process with a coal gasification power plant or a small scale steam natural gas (NG) reformer leading to a dramatic increase in the liquid fuel production from biomass and coal or NG. Here, hot synthesis gas (T>500°C) from a coal gasifier or methane reformer supplies H2/CO for hydropyrolysis and deoxygenation as well as heat for the process. This result is exciting, because it presents us with an option to build integrated H2Bioil processes sooner rather than later when the cost effective H2 becomes available from a carbon‐free energy source such as solar or nuclear. The H2Bioil process and its integrated version with a small scale NG reformer have strong potential to be attractive on a small scale while being more efficient than any current biomass to liquid fuel process in operation. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Sorption dynamics in fixed‐beds of inert core spherical adsorbents including axial dispersion and Langmuir isotherm
Authors: Koocheksarayi M. Khosravi , Shams K. , Liu Y. Z. 
Published: June 2009

AbstractThe effects of axial dispersion and Langmuir isotherm on transient behavior of sorption and intraparticle diffusion in fixed‐beds packed with monodisperse shell‐type/inert core spherical sorbents are studied. The system of partial differential equations of the mathematical model is solved numerically using finite difference methods. Results are presented in the form of breakthrough curves for adsorption and desorption processes. Results reveal that the shape of the breakthrough curves is influenced by both hydrodynamic and kinetic factors. Hydrodynamic factor is governed by axial dispersion and is controlled by changes of Peclet number. Simulation results reveal that when linear adsorption isotherm is used, the effect of axial dispersion on breakthrough curves of the system is important for Peclet numbers smaller than 50, whereas, for Langmuir isotherm axial dispersion is considerable for Peclet numbers less than 80. In addition, effects of type of adsorption isotherms and size of adsorbents on breakthrough curves are investigated, and results are compared with existing reports in the pertinent literature. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Suprapolymer Structures from Nanostructured Polymer Particles
Authors: Higuchi Takeshi , Tajima Atsunori , Motoyoshi Kiwamu , Yabu Hiroshi , Shimomura Masatsugu 
Published: June 2009

AbstractVernetzen und Auflösen: Einzigartige Suprapolymerstrukturen wurden aus Polymernanopartikeln mit phasenseparierten, aus Blockcopolymeren oder Homopolymerblends erzeugten Strukturen erhalten. Die Überstrukturen entstehen, indem man ein Polymersegment vernetzt und ein anderes auflöst (siehe Schema; PI=Polyisopren, PSt=Polystyrol).magnified image
Hydrogen Evolution at Liquid–Liquid Interfaces
Authors: Hatay Imren , Su Bin , Li Fei , Partovi‐Nia Raheleh , Vrubel Heron , Hu Xile , Ersoz Mustafa , Girault Hubert H. 
Published: June 2009

Abstract„Seifenblasen“: Protonen werden an einer weichen Grenzfläche zwischen Wasser und 1,2‐Dichlorethan (DCE) unter Wasserstoffentwicklung durch [(C5Me5)2Fe] reduziert. Dabei folgt auf einen durch [(C5Me5)2Fe] unterstützten Protonentransfer durch die Grenzfläche die Reduktion der Protonen in DCE. Die Grenzfläche dient vorrangig als Protonenpumpe, mit deren Hilfe bei der Wasserstoffentwicklung direkt auf die wässrigen Protonen zugegriffen werden kann.magnified image
Structural Basis and Enzymatic Mechanism of the Biosynthesis of C9‐ from C10‐Monoterpenoid Indole Alkaloids
Authors: Yang Liuqing , Hill Marco , Wang Meitian , Panjikar Santosh , Stöckigt Joachim 
Published: June 2009

AbstractCutting carbons: The three‐dimensional structure of polyneuridine aldehyde esterase (PNAE) gives insight into the enzymatic mechanism of the biosynthesis of C9‐ from C10‐monoterpenoid indole alkaloids (see scheme). PNAE is a very substrate‐specific serine esterase. It harbors the catalytic triad S87‐D216‐H244, and is a new member of the α/β‐fold hydrolase superfamily. Its novel function leads to the diversification of alkaloid structures.magnified image
The Thermodynamic Influence of Trapped Water Molecules on a Protein–Ligand Interaction
Authors: Stegmann Christian M. , Seeliger Daniel , Sheldrick George M. , de Groot Bert L. , Wahl Markus C. 
Published: June 2009

AbstractWater molecules doing time: Atomic‐resolution crystal structures of the PPIase domain of cyclophilin G, alone and in complex with cyclosporin A, and together with MD simulations and calorimetry, reveal how trapped water molecules influence the thermodynamic profile of a protein–ligand interaction.magnified image
Cover Picture: Toroidal Micelles of Uniform Size from Diblock Copolymers (Angew. Chem. Int. Ed. 25/2009)
Authors: Huang Haiying , Chung Bonghoon , Jung Jueun , Park Hae‐Woong , Chang Taihyun 
Published: June 2009

AbstractPure toroidal micelles of highly uniform shape and size are presented by T. Chang et al. in their Communication on page 4594 ff. The donut‐shaped micelles are prepared by spontaneous self‐assembly of a polyisoprene‐block‐poly(2‐vinylpyridine) copolymer, and are stable enough to act as a template for the growth of gold nanoparticles along the ring surface.magnified image
Inside Cover: Multicompartmental Microcylinders (Angew. Chem. Int. Ed. 25/2009)
Authors: Bhaskar Srijanani , Hitt Jonathon , Chang Sei‐Won Laura , Lahann Joerg 
Published: June 2009

AbstractMulticompartmental microcylinders can be produced by a combination of electrohydrodynamic co‐spinning and microsectioning, as described by J. Lahann et al. in their Communication on page 4589 ff. The number of individual compartments, relative compartment orientation, chemical composition and functionality, and aspect ratio can be precisely tuned. Each color in the longitudinal and cross‐sectional micrograph images depicts an individual compartment.magnified image
Effect of the degree of clay delamination on the phase morphology, surface chemical aspects, and properties of hydrolyzable polyurethanes for periodontal regeneration
Authors: Pereira I. M. , Carvalho S. , Pereira M. M. , Leite M. F. , Oréfice R. L. 
Published: June 2009

AbstractIn recent years, there has been increased interest in biodegradable polyurethanes for use in regenerative medicine because of their versatility and biocompatibility. Nevertheless, these polymers are usually produced using organic solvents that can lead to the release of toxic components. In this work, polyurethane/montmorillonite nanocomposites were designed to work as guided tissue regeneration membranes to treat periodontal diseases. Polyurethanes were synthesized in an aqueous environment. The composition, morphology, and mechanical properties of the biomaterials were evaluated. The cellular viability, proliferation, and morphology changes of rat culture cementoblasts were also investigated using a montmorillonite assay. Small‐angle X‐ray scattering, X‐ray diffraction, and infrared spectroscopy results showed that the degree of clay delamination within the polymer was able to tailor the phase morphology of the polymer, the chemical aspects of the surface, the mechanical properties, and the kinetics of hydrolysis of the materials. The produced scaffolds provided a good environment for the adhesion and proliferation of cementoblasts and thus can be considered suitable biomaterials for participating in procedures associated with periodontal regeneration. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polymer electrolyte membranes having sulfoalkyl grafts into ETFE film prepared by radiation‐induced copolymerization of methyl acrylate and methyl methacrylate
Authors: Hanh Truong Thi , Takahashi Shuichi , Chen Jinhua , Sawada Shin‐ichi , Maekawa Yasunari 
Published: June 2009

AbstractPolymer electrolyte membranes (PEMs) containing alkylsulfonic acid grafts can be prepared by radiation‐induced graft copolymerization of methyl acrylate (MA) and methyl methacrylate (MMA) into a poly(ethylene‐co‐tetrafluoroethylene) film followed by sulfonation of the MA units in the copolymer grafts using an equimolar complex of chlorosulfonic acid and 1,4‐dioxane (ClSO3H‐Complex). PEMs with MA/MMA copolymer grafts that are 33%–79% MA units were prepared by preirradiation with a dose of 20 kGy and grafting in bulk comonomers at 60°C. The grafted films are treated with ClSO3H‐Complex to obtain PEMs with ion exchange capacity of 0.36‐0.81 mmol/g (sulfonation degrees of 20%–40%) and proton conductivity of 0.04‐0.065 S/cm. These values can be controlled by changing the MA content the sulfonation occurring at an α‐carbonyl carbon. The PEMs with higher MMA content showed higher durability in water (80°C) and under oxidative conditions (3% H2O2) at 60°C. This is because the PMMA grafts in the PEMs have no proton at an α‐carbonyl carbon, which is considered to be a trigger of the degradation of grafting polymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Dependence of biodegradation and release behavior on physical properties of poly(caprolactone)‐based polyurethanes
Authors: Watanabe Atsushi , Takebayashi Yoshihiro , Ohtsubo Toshiro , Furukawa Mutsuhisa 
Published: June 2009

AbstractSimultaneous pursuit of long accurate release control and high biodegradation rate is required as the membrane of controlled‐release devices in agriculture. The effect of the physical properties of poly(caprolactone) based polyurethanes as a polymer membrane on their biodegradation characteristics and the release profile was evaluated. The soil burial test at 28°C resulted that the biodegradation rate of the polyurethanes increased as the number of average molecular weight (Mn) of poly(caprolactone) diol used increased from 500 to 1000, whereas it decreased as the Mn of poly(caprolactone) diol increased from 1200 to 2000. The biodegradation behavior was different when the Mn of poly(caprolactone) diols was used because of the recrystallization of long straight poly(caprolactone) chains. Poly(caprolactone) triol prevented recrystallization and led the high degradation ratio. The release rate of urea from the polyurethane‐coated granules decreased as the Mn of poly(caprolactone) polyol decreased. These results indicated that the release profile was affected by the urethane content, and the biodegradation characteristic was affected by the glass transition temperature and the recrystallization of polyurethane membrane. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Chemical recycling of polymers from Waste Electric and Electronic Equipment
Authors: Achilias D.S. , Antonakou E.V. , Koutsokosta E. , Lappas A.A. 
Published: June 2009

AbstractThis research is focused on the recycling of three types of polymers, namely polycarbonate (PC), poly(acrylonitrile‐butadiene‐styrene) (PABS), and polystyrene (PS) from Waste Electric and Electronic Equipment (WEEE). Initially, the chemical structure of each polymeric material in a variety of WEEE was identified by Fourier Transform Infra Red (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC). The potential recycling of these polymers from these wastes was examined by employing two different approaches, the dissolution/reprecipitation method and the more challenging technique of pyrolysis. During the first, the polymer is separated and recycled through a solvent/non‐solvent system. It is a simple and economic technique leading to high recovery of pure polymer. Both, model polymers and plastic parts from WEEEs were studied and optimum experimental conditions, including dissolution temperature and time, polymer concentration and type of solvent were proposed to achieve significant recovery of the polymer (>90 wt %). Furthermore, pyrolysis of waste Compact Disks (CD) was investigated and compared with model poly(bisphenol A carbonate) (PC) through a laboratory‐scale fixed bed reactor. The appropriate pyrolysis temperature was selected after measuring the thermal degradation of model PC by Thermogravimetric analysis (TGA). A large amount of oil was measured, together with a smaller amount of gaseous product, leaving also a solid residue. For both samples, the gaseous fraction consisted mainly of CO2 and CO whereas in the liquid fraction a large amount of different phenolic compounds, including the monomer bisphenol A, was measured. It seems that recycling of used CDs by pyrolysis is a very promising technique having the potential of producing useful high‐value chemicals, which may find applications in the petrochemical industry. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Catalytic conversion of postconsumer PE/PP waste into hydrocarbons using the FCC process with an equilibrium FCC commercial catalyst
Authors: Yang M.‐H. , Lin Y.‐H. 
Published: June 2009

AbstractA mixture of postconsumer polyolefin waste (PE/PP) was pyrolyzed over cracking catalysts using a fluidizing reaction system similar to the fluid catalytic cracking (FCC) process operating isothermally at ambient pressure. Experiments carried out with various catalysts gave good yields of valuable hydrocarbons with differing selectivity in the final products dependent on reaction conditions. Greater product selectivity was observed with a commercial FCC equilibrium catalyst (Ecat‐F1) with more than 50 wt % olefins products in the C3‐C6 range. A kinetic model based on a lumping reaction scheme for the observed products and catalyst coking deactivations has been investigated. The model gave a good representation of experiment results. Moreover, this model provides the benefits of lumping product selectivity, in each reaction step, in relation to the performance of the FCC equilibrium catalyst used, the effect of reaction temperature, and the particle size selected. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Trophic mass balanced models and dynamic simulations of benthic communities from La Rinconada Marine Reserve off northern Chile: network properties and multispecies harvest scenario assessments
Authors: Ortiz Marco , Avendaño Miguel , Cantillañez Marcela , Berrios Fernando , Campos Leonardo 
Published: June 2009

Abstract

Mass balanced trophic models and dynamic simulations of two benthic ecological systems from La Rinconada Marine Reserve (Antofagasta Bay, SE Pacific) were constructed.
The scallop Argopecten purpuratus is the most important benthic resource in La Rinconada Marine Reserve, followed by the carnivorous snail Thais chocolata, and the filter‐feeder bivalves Tagelus dombeii and Transennella pannosa.
Information on biomass, P/B ratios, catches, food spectrum, consumption, and dynamics of commercial and non‐commercial species was obtained and examined using Ecopath with an Ecosim software package.
The bivalves A. purpuratus and T. dombeii represented the most abundant compartments in the studied subsystems. Of the carnivores, the snail T. chocolata was dominant, followed by the crabs Cancer spp. and the functional group of large epifauna.
The two subsystems presented similar values of system throughput. The mean trophic level of their fisheries also reached similar magnitudes (2.0), showing that the harvests in each system concentrated on secondary producers. Likewise, both subsystems presented similar A/C ratios (29.9 and 30.3), suggesting that they were immature.
The results obtained using mixed trophic impact (MTI) and Ecosim (increasing the fishing mortality Fi by four times) showed that only four species propagated the highest direct and indirect effects. Coincidentally, these species are the most economically important and the changes produced by the scallop A. purpuratus are noteworthy.
With regard to the system recovery time (SRT) estimates, only three species or functional groups presented the highest magnitudes, from highest to lowest: the sea star Luidia magallanica, the scallop A. purpuratus, and the crabs Cancer spp.
The topological keystone indexes of Jordán and Libralato had divergent results. According to Jordán's index, the keystone species were L. magallanica, Cancer spp., and detritus; whereas Libralato's index showed phytoplankton to be the keystone species.
Based on the results obtained, it is concluded that trophic mass balanced models and simulated management scenarios have considerable value for planning interventions and manipulations or for planning more sustainable management strategies in La Rinconada Marine Reserve. Copyright © 2009 John Wiley & Sons, Ltd.
A need for logical and consistent anatomical nomenclature for cutaneous nerves of the limbs
Authors: Gest Thomas R. , Burkel William E. , Cortright Gerald W. 
Published: June 2009

AbstractThe system of anatomical nomenclature needs to be logical and consistent. However, variations in translation to English of the Latin and Greek terminology used in Nomina Anatomica and Terminologia Anatomica have led to some inconsistency in the nomenclature of cutaneous nerves in the limbs. An historical review of cutaneous nerve nomenclature reveals that there are two general naming conventions: one primarily American and one primarily British. The American convention presents cutaneous nerves of the limbs in the format “medial brachial cutaneous nerve,” while the British convention presents the same nerve as “medial cutaneous nerve of the arm,” thereby translating “brachii” to “of the arm.” If logically and consistently applied throughout the body, the British convention would rename the sural nerve to the “nerve of the calf,” the brachial artery would become the “artery of the arm,” the femoral nerve would be “nerve of the thigh,” and femur would be “bone of the thigh” or “thigh bone.” The British convention leads to many other nomenclatural inconsistencies, which would seem to make learning anatomy more difficult for the beginning student. In this era of contracting anatomy curricula, every effort should be made to keep anatomical nomenclature simple, logical, and consistent. Anat Sci Ed 2:126–134, 2009. © 2009 American Association of Anatomists.
Situating logic and information in information science
Authors: Karamuftuoglu Murat 
Published: June 2009

AbstractInformation Science (IS) is commonly said to study collection, classification, storage, retrieval, and use of information. However, there is no consensus on what information is. This article examines some of the formal models of information and informational processes, namely, Situation Theory and Shannon's Information Theory, in terms of their suitability for providing a useful framework for studying information in IS. It is argued that formal models of information are concerned with mainly ontological aspects of information, whereas IS, because of its evaluative role with respect to semantic content, needs an epistemological conception of information. It is argued from this perspective that concepts of epistemological/aesthetic/ethical information are plausible, and that information science needs to rise to the challenge of studying many different conceptions of information embedded in different contexts. This goal requires exploration of a wide variety of tools from philosophy and logic.
Optimization of dependently controlled jump rates of JLQG problem
Authors: Xu Yankai , Chen Xi 
Published: June 2009

AbstractThe Jump Linear Quadratic Gaussian (JLQG) model is well studied due to its wide applications. However, JLQG with controlled jump rates are rarely researched, while the existing studies usually impose an assumption that jump rates are independent and separately controlled. In practical systems, their jump rates may not be independent of each other. In this paper, we consider a continuous‐time JLQG model with dependently controlled jump rates and formulate it as a two‐level control problem. The low‐level problem is a standard JLQG problem, thus we focus on solution of high‐level problem. We propose a Markov decision process‐based approach to calculate performance gradient with respect to jump rates control variable and develop a gradient‐based optimization algorithm. We present an application of manufacturing system to illustrate the main results of this paper. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
The role of atmosphere feedbacks during ENSO in the CMIP3 models
Authors: Lloyd James , Guilyardi Eric , Weller Hilary , Slingo Julia 
Published: June 2009

AbstractSeveral studies using ocean‐atmosphere GCMs suggest that the atmospheric component plays a dominant role in the modelled ENSO. To help elucidate these findings, the two main atmosphere feedbacks relevant to ENSO, the Bjerknes positive feedback (µ) and the heat flux negative feedback (α), are analysed here in 12 coupled GCMs.We find that the models generally underestimate both feedbacks, leading to an error compensation. The strength of α is inversely related to the ENSO amplitude in the models and the latent heat and shortwave flux components of this feedback dominate. Furthermore, the shortwave component could help explain the model diversity in both overall α and ENSO amplitude. Copyright © 2009 Royal Meteorological Society and Crown copyright.