bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of Aqueous‐Phase catalytic dehydration of 2‐Propanol
Authors: Rivard Jean‐Marc , Zhang Qinglin , Chuang Karl T. 
Published: March 2009

AbstractThe aqueous‐phase catalytic dehydration of 2‐propanol was investigated in a batch slurry reactor. Alumina, zeolite 13X, SAPO‐5 and silicalite are all active in the liquid phase dehydration of 2‐propanol at 463 K with silicalite being the most active catalyst. Propylene was found to be the major reaction product, with diisopropyl ether and acetone formed in trace amounts. The reaction kinetics over silicalite was determined at a temperature range of 434 to 463 K and at a concentration range of 4 to 10 mol% 2‐propanol in water. A single site Langmuir‐Hinshelwood‐Hougen‐Watson (LHHW) type mechanism was found to describe the kinetic data well. Water was found to inhibit the dehydration reaction. The activation energy over silicalite was determined to be 226.8 kJ/mol while the heat of adsorption for 2‐propanol and water was –45.5 and –9.6 kJ/mol, respectively.
Operability of a thermally driven magnesium oxide/water chemical heat pump
Authors: Kato Yukitaka , Minakami Atsushi , Li Guangzhe , Yoshizawa Yoshio 
Published: March 2009

AbstractThe operability of a thermally driven chemical heat pump using the magnesium oxide/water reaction system was demonstrated experimentally. The heat pump system, consisting of a packed bed reactor and a water reservoir, was operated thermally with no mechanical work. The thermal output performance of the reactor bed was measured under pressures between SO and 202 kPa. The heat pump was expected to be applicable as a heat storage system for high efficiency energy utilization in cogeneration.
Optimization of a model IV fluidized catalytic cracking unit
Authors: Luus Rein , Woo Stephen S. 
Published: March 2009

AbstractMaximization of a profit function related to a fluidized catalytic cracking unit model was carried out by Luus‐jaakola optimization procedure. A 7‐dimensional search is carried out on a FCC unit described by 113 nonlinear algebraic equations and 9 differential equations. Despite the low sensitivity and the existence of several local optima, the global optimum was obtained with reasonable amount of computational effort. At the optimum, the profit function is 1% higher than when the air blowers are constrained to operate at their maximum capacity.
Lag phase model for transient growth of pseudomonas putida on phenol
Authors: Tarighian Alireza , Hill Gordon , Lin Yen‐Han 
Published: March 2009

AbstractThe successful design of large‐scale bioreactors requires the ability to predict both steady‐state and dynamic operating conditions. At the same time, mathematical models should not be too complex in order to reduce experimental work required to determine kinetic parameters. A simple model which predicts the behaviour of batch and transient continuous culture operations is presented and experimentally verified. The model is based on two regions of metabolic activity: the lag phase and the active phase. Pseudomonas putida growing on phenol as a substrate in a well‐mixed bioreactor was tested in three modes of operation: batch, continuous start‐up and continuous step‐change. The model is demonstrated to predict all the qualitative aspects of the dynamic phases of growth and is quantitatively accurate.
Rate equations for the fischer‐tropsch reaction on a promoted iron catalyst
Authors: Rahmati Montazer , Mehdi Mohammad , Bargah‐Soleimani Mehdi 
Published: March 2009

AbstractIntrinsic rates for the Fischer‐Tropsch synthesis reaction over a promoted iron catalyst fabricated at the Research Institute of the Petroleum Industry (RIPI) have been obtained in the temperature range of 290°C to 310°C, pressure range of 1500 to 2300 kPa, molar hydrogen to carbon monoxide ratio of 0.76 to 1.82, and a space velocity of 3300 h−1 under conditions of constant catalyst activity. To this end, the initial reaction rates have been measured at constant temperature (±1°C) in the absence of diffusion limitations, and power‐law equations have been fitted in terms of the hydrogen and carbon monoxide partial pressures for the reaction rates.
Pseudoischemic Electrocardiogram in Myasthenia Gravis with Thymoma: Reversibility After Thymectomy
Authors: Chiavistelli Patrizio , Cei Marco , Carmignani Giovanni , Bartolomei Carlo , Mumoli Nicola 
Published: March 2009

AbstractAbnormal ST T‐wave changes can be found at presentation in various noncoronary disorders; misinterpretation of these patterns as ischemic heart disease can lead to erroneous diagnosis and treatment. Here we present a case of myasthenia gravis (MG) with thymoma, in which the resting electrocardiogram (ECG) led to a misleading diagnosis of myocardial ischemia. After thymectomy, the ECG resumed a normal pattern. Myasthenia gravis is not usually considered in the differential diagnosis of conditions associated with an abnormal ECG. The combination of dysphagia, dyspnoea, ECG changes, and creatine kinase (CK) elevations may easily bring to mind an erroneous and possibly deleterious diagnosis of myocardial ischemia. Copyright © 2009 Wiley Periodicals, Inc.
Higher arterial stiffness, greater peripheral vascular resistance and lower blood flow in lower‐leg arteries are associated with long‐term hyperglycaemia in type 2 diabetic patients with normal ankle‐brachial index
Authors: Suzuki Eiji , Yoshimura Toru , Omura Yasushi , Sakaguchi Masayoshi , Nishio Yoshihiko , Maegawa Hiroshi , Hisatomi Akitaka , Fujimoto Kazuma , Takeda Jun , Kashiwagi Atsunori 
Published: March 2009

AbstractBackgroundHigher arterial stiffness and greater peripheral vascular resistance reduce blood flow in lower‐leg arteries and contribute to the development of ischaemic limb in diabetic patients even without peripheral artery occlusive disease. The aim of this study was to clarify whether these vascular parameters are associated with long‐term hyperglycaemia in diabetic patients.MethodsWe examined 45 type 2 diabetic patients and 38 age‐matched nondiabetic subjects without peripheral artery occlusive disease assessed by ankle‐brachial index consecutively admitted to our hospital, and followed them over a 3‐year period (3.7 ± 0.7 years) with no vasodilative medication. Blood flow and resistive index, a measure of peripheral vascular resistance, at the popliteal artery were evaluated using gated two‐dimensional cine‐mode phase‐contrast magnetic resonance imaging. Brachial‐ankle pulse wave velocity was measured to assess arterial stiffness.ResultsAt baseline, consistent with our previous report, diabetic patients showed higher brachial‐ankle pulse wave velocity (p < 0.0001) and resistive index (p < 0.0001) and lower flow volume (p = 0.0044) than those of nondiabetic subjects. Stepwise multiple regression analysis revealed that duration of diabetes, mean HbA1c during the study, use of renin‐angiotensin system inhibitors and change per year in resistive index were identified as significant independent variables predicting change per year in blood flow (r2 = 0.733, p < 0.0001) in diabetic patients. Mean HbA1c during the study was positively correlated with changes per year in brachial‐ankle pulse wave velocity (p = 0.00007) and resistive index (p = 0.0014) and was negatively correlated with that in blood flow (p < 0.0001) in diabetic patients.ConclusionsLong‐term hyperglycaemia is a major cause of impaired peripheral circulation in lower‐leg arteries in diabetic patients without peripheral artery occlusive disease. Copyright © 2009 John Wiley & Sons, Ltd.
Working map of the lampbrush chromosomes of Xenopus tropicalis: A new tool for cytogenetic analyses
Authors: Penrad‐Mobayed May , El Jamil Anwar , Kanhoush Rasha , Perrin Caroline 
Published: March 2009

AbstractThe amphibian Xenopus tropicalis, whose genome has been recently sequenced, has become an important model organism for vertebrate developmental genetics. The development of cytogenetic tools in this new model organism should contribute to an understanding of the organization of the amphibian genome and the mapping of a variety of loci of interest. In this respect, oocyte lampbrush chromosomes are particularly useful for the localization of genomic sequences expressed during oogenesis. We have constructed a working map of X. tropicalis lampbrush chromosomes, which allows the 10 bivalents of the oocyte karyotype to be readily identified by distinctive combinations of specific landmark structures composed of lateral loops, spheres, and granules. We have also established the patterns of RNA Pol III sites over the chromosomes by immunofluorescence using antibodies directed against two Pol III subunits. Specific staining patterns were found for each chromosome, which constitute a supplementary tool for their identification. Developmental Dynamics 238:1492–1501, 2009. © 2009 Wiley‐Liss, Inc.
Biocatalytic Cascade for the Synthesis of Enantiopure β‐Azidoalcohols and β‐Hydroxynitriles
Authors: Schrittwieser Joerg H. , Lavandera Iván , Seisser Birgit , Mautner Barbara , Kroutil Wolfgang 
Published: March 2009

AbstractA three‐step, two‐enzyme, one‐pot reaction sequence starting from prochiral α‐chloroketones leading to enantiopure β‐azidoalcohols and β‐hydroxynitriles is described. Asymmetric bioreduction of α‐chloroketones by hydrogen transfer catalysed by an alcohol dehydrogenase (ADH) established the stereogenic centre in the first step to furnish enantiopure chlorohydrin intermediates. Subsequent biocatalysed ring closure to the epoxide and nucleophilic ring opening with azide, N3–, or cyanide, CN–, both catalysed by a nonselective halohydrin dehalogenase (Hhe) proceeded with full retention of configuration to give enantiopure β‐azidoalcohols and β‐hydroxynitriles, respectively. Both enantiomers of various optically pure β‐azidoalcohols and β‐hydroxynitriles were synthesised. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Chemiluminescent PEG‐PCL micelles for imaging hydrogen peroxide
Authors: Dasari Madhuri , Lee Dongwon , Erigala Venkata Reddy , Murthy Niren 
Published: March 2009

AbstractHydrogen peroxide is one of the fundamental molecules of biology, regulating key cell signaling pathways and the development of numerous inflammatory diseases. There is therefore great interest in developing contrast agents that can detect hydrogen peroxide in vitro and in vivo. In this report, we present a new contrast agent for imaging hydrogen peroxide, termed the chemiluminescent poly(ethylene glycol)‐b‐poly(ϵ‐caprolactone) (PEG‐PCL) micelles (CPMs), which can detect hydrogen peroxide at nanomolar concentrations and chemiluminesce in the near IR range (676 nm) in the presence of hydrogen peroxide. The CPMs are composed of a PEG‐PCL scaffold and have fluorescent dyes and peroxalate esters in their hydrophobic PCL core. The CPMs image hydrogen peroxide by undergoing a three‐component chemiluminescent reaction involving a peroxalate ester, a fluorescent dye, and hydrogen peroxide. The CPMs also have a stealth PEG corona to enhance their circulation half life. The CPMs should find numerous applications for imaging hydrogen peroxide because of their nanomolar sensitivity, small size, and stealth pegylated surface. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Synthesis and Properties of Homologous Series of Polyallylcarbosilane Dendrimers with Dense Macromolecular Structure
Authors: Tatarinova E. A. , Voronina N. V. , Bystrova A. V. , Buzin M. I. , Muzafarov A. M. 
Published: March 2009

AbstractSynthesis of the six generations of polyallylcarbosilane dendrimers with tetrafunctional branching center and tetrafunctional base reagent is reported. Obtained dendrimers are compared to carbosilane dendrimers with less dense molecular structure synthesized before. Densification of the dendrimer structure alters some basic dendrimer properties as well as their dependence on generation.
QoS provision in wireless access networks: a routing perspective considering mobility
Authors: Samdanis Konstantinos , Aghvami A. Hamid 
Published: March 2009

AbstractFuture wireless communications are expected to provide mobile users access to the desired service with the appropriate quality at any place. The essential elements for assembling such a vision are mobility, quality of service (QoS) provision and scalability, which are expected to be merged into the design process of wireless access networks. Internet mobility support is currently entering a mature phase in which scalable solutions provide low loss or even seamless handovers in cellular and heterogeneous mobile environments. Wireless and mobile QoS architectures extend the equivalent Internet approaches in order to accommodate the requirements associated with the presence of wireless links and mobility. Nevertheless, none of the popular mobility proposals combined with wireless and mobile QoS architectures encounter QoS in the routing function, leaving the QoS provision underutilized. QoS routing (QoSR) complements existing QoS architectures, enhancing application performance especially in the case of congestion, while providing efficient resource management. However, QoSR was originally designed for fixed IP networks without taking mobility into account. This paper investigates the interaction of QoSR in wireless access networks, identifying key points for the efficient cooperation with mobility and existing QoS architectures. Copyright © 2009 John Wiley & Sons, Ltd.
Evaluation of curing and physical properties of NR/SBR blends using radiation‐grafting copolymer
Authors: Hassan Medhat M. , Abd El‐Megeed Anhar. A. , Maziad Nabila A. 
Published: March 2009

AbstractThe curing characterizations of natural rubber (NR) and styrene butadiene rubber (SBR) lattices and their blends with and without NR‐g‐MA and SBR‐g‐MA were studied by using oscillating disc rheometer methods. The minimum value for torque decreases with increasing NR in the blends and with the incorporation ofNR‐g‐MA and SBR‐g‐MA. The value of maximum torque increases with increasing of SBR in the blend and with the presence of (NR‐g‐MA and SBR‐g‐MA) is decreased. The mechanical properties of the samples were studied. The tensile strengths increased steadily with an increase of NR content in the blend. Thermal characteristics of these latex blends were studied by thermogravimetric analysis. Thermal degradation of these individual lattices and their blends were investigated with special reference to blend ratio and vulcanization techniques. As the SBR content in the blends increased their thermal stability was also found to increase. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Giant enhancement of material damage associated to electronic excitation during ion irradiation: The case of LiNbO3
Authors: Rivera A. , Olivares J. , García G. , Cabrera J. M. , Agulló‐Rueda F. , Agulló‐López F. 
Published: March 2009

AbstractThe structural damage induced by ion irradiation on dielectric materials and associated device degradation has been, so far, explained on the basis of collisional processes mostly ignoring the electronic excitation. Recent work, focused on lithium niobate, offers conclusive evidence that at high ion energy and moderate mass (A ≥ 15) electronic excitation may induce a giant enhancement over the damage rate due to nuclear collisions. As a consequence the material becomes amorphized at irradiation fluences far below those required for nuclear collisions alone. These results are expected to have a deep impact on many technologies including storage of radioactive waste, radiation‐resistant materials for fusion reactors, lifetime of components and devices in space missions, nano‐patterning in electronics and photonics, and possibly heavy‐ion therapy in medicine. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inkjet printed, conductive, 25 μm wide silver tracks on unstructured polyimide
Authors: Meier Henning , Löffelmann Ute , Mager Dario , Smith Patrick J. , Korvink Jan G. 
Published: March 2009

Abstract25 μm wide, conductive silver tracks on untreated and unstructured polyimide have been produced by inkjet printing using standard 10 pL printheads. This was achieved by reducing the droplet size to ∼2 pL by tailoring the waveform and by heating the print cartridge and the substrate to 55 °C. A simple formula was used to predict the track width. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport characteristics of indium nitride (InN) films grown by plasma assisted molecular beam epitaxy (PAMBE)
Authors: Knübel Andreas , Aidam Rolf , Cimalla Volker , Kirste Lutz , Baeumler Martina , Leancu Crenguta‐Columbina , Lebedev Vadim , Wallauer Jan , Walther Markus , Wagner Joachim 
Published: March 2009

AbstractWe report on the PAMBE‐growth of high‐quality InN layers with In polarity and on the influence of growth parameters such as Indium‐to‐nitrogen flux ratio as well as substrate temperature on the electronic transport characteristics of these layers. The flux ratio was changed between 0.94 to 1.18 near stoichiometric conditions and the growth temperature was varied between 400 and 485 °C as measured by calibrated pyrometer temperature. The InN films were grown on metal‐organic vapour deposition (MOCVD) GaN templates 3″ in diameter with InN layer thicknesses of 700 nm as determined by spectroscopic ellipsometry (SE). Under In‐rich and near stoichiometric growth conditions a minimum surface root mean square roughness of 0.6 nm was achieved. High resolution X‐ray diffraction show purely hexagonal phase growth and no evidence for the presence of cubic inclusions. InN layers grown under optimized growth conditions exhibit a narrow (FWHM 20 meV) near band edge low temperature photoluminescence (PL) spectrum with a PL peak energy of 0.67 eV, indicating an InN band gap energy of ≈ 0.7 eV, consistent with the dielectric function spectrum derived from SE measurements. Room temperature van‐der‐Pauw Hall measurements reveal high electron mobilities up to 1910 cm2/Vs with mean bulk electron concentrations as low as 5 x 1017 /cm3. Furthermore, efficient surface emission of THz radiation has been demonstrated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Clique percolation
Authors: Bollobás Béla , Riordan Oliver 
Published: March 2009

AbstractDerényi, Palla and Vicsek introduced the following dependent percolation model, in the context of finding communities in networks. Starting with a random graph Ggenerated by some rule, form an auxiliary graph G′ whose vertices are the k‐cliques of G, in which two vertices are joined if the corresponding cliques share k – 1 vertices. They considered in particular the case where G = G(n,p), and found heuristically the threshold function p = p(n) above which a giant component appears in G′. Here we give a rigorous proof of this result, as well as many extensions. The model turns out to be very interesting due to the essential global dependence present in G′. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Smart Pectin‐based Superabsorbent Hydrogel as a Matrix for Ibuprofen as an Oral Non‐steroidal Anti‐inflammatory Drug Delivery
Authors: Pourjavadi Ali , Barzegar Shahram 
Published: March 2009

AbstractThe purpose of this study was to produce an intelligent superabsorbent polymer (SAP) to be used as a pH sensitive matrix for the controlled delivery of drugs. Novel types of highly swelling SAPs were prepared by grafting crosslinked acrylic acid‐co‐acrylamide (AA‐co‐AAm) chains onto pectin by free‐radical polymerization. The superabsorbent formation was confirmed by Fourier transform infrared spectroscopic (FT‐IR) and scanning electron microscopy (SEM). The controlled release behavior of ibuprofen (IBU) from the superabsorbent polymer was investigated. SAP structural‐property relationships that affect its controlled release behavior were determined. Analysis of the results indicated that it is possible to optimize ibuprofen (IBU) controlled release by adjusting the SAP composition and the crosslinking degree of the copolymer. The results revealed that the release profiles of IBU from the superabsorbent polymer were slow (lower than 2%) in simulated gastric fluid (SGF, pH 1.2) over 3 h, but nearly all of the initial drug content (more than 84%) was released in simulated intestinal fluid (SIF, pH 7.4) within 85 h after changing media. Overall the results demonstrated that biodegradable superabsorbents could successfully deliver a drug to the intestine without losing the drug in the stomach, and could be potential candidates as an orally administrated drug delivery system.
A bandwidth‐efficient cooperative relaying scheme with hard interference cancellation and iterative decoding
Authors: Van Khuong Ho , Le‐Ngoc Tho 
Published: March 2009

AbstractThis paper considers a coded cooperative relaying scheme in which all successfully decoded signals from multiple sources are simultaneously forwarded by a multi‐antenna relay to a common multi‐antenna destination to increase bandwidth efficiency. Iterative decoding with hard interference cancellation is used at destination to recover user information. By using orthogonal transmission from sources to avoid their mutual interference, the multi‐antenna relay offers receive space diversity that greatly enhances the decoding performance at the relay. This makes the source‐relay transmission more robust, less sensitive to the source‐relay link SNR, and hence increases the contribution of the relay in cooperative transmission. Simulation results show that the proposed scheme significantly outperforms direct transmission under the same transmit power and bandwidth efficiency. Copyright © 2009 John Wiley & Sons, Ltd.
Separation of Extracellular Esterases from Pellet Cultures of the Basidiomycete Pleurotus sapidus by Foam Fractionation
Authors: Linke Diana , Nimtz Manfred , Berger Ralf G. , Zorn Holger 
Published: March 2009

AbstractTwo extracellular esterases were produced in submerged cultures of the basidiomycete Pleurotus sapidus. A foam fractionation device was designed and employed for the isolation of the esterolytic enzymes. The recovery of enzyme activity in the liquefied foam strongly depended on the superficial gas velocity. High purification and enrichment factors (Ea = 62.0, P = 15.5) were achieved using nitrogen at 1.87 cm min−1 within 100 min. Increasing the superficial gas velocity to 2.49 cm min−1 improved the recovery of total esterase activity in the foam to >95% at the expense of reduced enrichment and purification factors. Differences in their physicochemical characteristics resulted in differing foaming properties of the two esterases secreted by P. sapidus. By variation of the pH value of the culture medium and addition of Triton X‐100, both esterases were successively and quantitatively transferred into the foam in a two‐step fractionation process.
Validation of the Hypomania Checklist (HCL‐32) in a nonclinical sample of German adolescents
Authors: Holtmann Martin , Pörtner Franca , Duketis Eftichia , Flechtner Hans‐Henning , Angst Jules , Lehmkuhl Gerd 
Published: March 2009

ABSTRACTWe tested the psychometric properties of the Hypomania Checklist (HCL‐32) in a sample of nonclinical adolescents, examined the association with current psychopathology, and tested if “hypomanic” adolescents differ from other participants regarding HCL‐scores and psychopathology. A total of 294 students completed the HCL‐32 and the SDQ, a screening for psychopathology. In adolescence, the internal structure of hypomania seems to be represented by a triple structure. The first factor “active‐elated” is an indicator of symptoms related to energy and activity. The adult factor “irritable‐risk taking” is better reflected by two separate factors (“disinhibited/stimulation‐seeking” and “irritable‐erratic”). These factors were associated with externalizing problems. “Hypomanic” adolescents showed higher HCL total and disinhibited/stimulation‐seeking scores and reported more conduct problems than “non‐hypomanic” youngsters. The internal structure of the HCL in adolescents mirrors the association of juvenile bipolarity with substance use and symptoms of ADHD and conduct disorder and presents preliminary evidence for its validity.