bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional Chromium Wheel‐Based Hybrid Organic–Inorganic Materials for Dielectric Applications
Authors: Di Noto Vito , Boeer Angelika B. , Lavina Sandra , Muryn Christopher A. , Bauer Matthias , Timco Grigore A. , Negro Enrico , Rancan Marzio , Winpenny Richard E. P. , Gross Silvia 
Published: August 2009

AbstractThe first example of organic–inorganic hybrid materials based on the embedding of a chromium–nickel wheel cluster {[(n‐C3H7)2NH2]‐ [Cr7NiF8(O2C4H5)16]} (Cr7Ni) into poly(methyl methacrylate) (PMMA) and the characterization of the dielectric properties of the obtained material is described. By an optimized copolymerization of the methacrylate‐functionalized chromium–nickel wheel with methyl methacrylate in a cluster/monomer 1:200 molar mixture, a homogeneous hybrid material CrNi_MMA200 is obtained. The electrical responses of the non‐doped PMMA and of the hybrid material were studied by broadband dielectric spectroscopy (BDS) from 0.01 Hz to 10 MHz and over the temperature range of 5–115 °C. The permittivity profiles reveal two relaxation peaks in the materials, which correspond to the α and β relaxation modes of the PMMA matrix. The position of these modes shifts toward higher frequencies as temperature increases. BDS is a powerful tool revealing the intimate miscibility of the various components of the hybrid material, thus indicating that, on a molecular scale, the material proposed is a homogeneous system. Finally, a value of the dielectric constant of 2.9 at 25 °C and 1 kHz is determined. This value is noticeably lower than the value of 3.2 obtained for pristine PMMA prepared following the same synthesis protocol. Thus, these results classify the hybrid CrNi_MMA200 as an appealing starting material for the development of dielectric polymeric layers for the development of innovative capacitors, transistors, and other microelectronic devices. The vibrational properties of the hybrid materials are investigated by Fourier‐transform infrared (FT‐IR) and Raman spectroscopy, whereas the thermal behavior is analyzed by thermogravimetric analysis (TGA). Swelling experiments are used to qualitatively evaluate the crosslinking density of the hybrid materials. The integrity of the wheels once embedded in the macromolecular backbone is confirmed by extended X‐ray absorption fine structure (EXAFS) and electron spin resonance (EPR) spectroscopic measurements.
Template Deformation‐Tailored ZnO Nanorod/Nanowire Arrays: Full Growth Control and Optimization of Field‐Emission
Authors: Zeng Haibo , Xu Xijin , Bando Yoshio , Gautam Ujjal K. , Zhai Tianyou , Fang Xiaosheng , Liu Baodan , Golberg Dmitri 
Published: August 2009

AbstractHere, a facile and effective route toward full control of vertical ZnO nanorod (NR)/nanowire (NW) arrays in centimeter‐scale areas and considerable improvement of field‐emission (FE) performance is reported. Controlled deformation of colloidal crystal monolayer templates is introduced by heating near glass‐transition temperature. The NR/NW density, uniformity, and tapering were all adjusted through selection of template size and deformation, and electrolyte composition. In line with the adjustments, the field‐emission performance of the arrays is significantly improved. A low turn‐on electric field of 1.8 V µm−1, a field‐enhancement factor of up to 5 750, and an emitting current density of up to 2.5 mA cm−2 were obtained. These improved parameters would benefit their potential application in cold‐cathode‐based electronics.
Computational study of staged membrane reactor configurations for methane steam reforming. II. Effect of number of stages and catalyst amount
Authors: Caravella Alessio , Di Maio Francesco Paolo , Di Renzo Alberto 
Published: August 2009

AbstractThe present work complements part I of this article and completes a computational analysis of the performances of staged membrane reactors for methane steam reforming. The influence of the number of stages and catalyst amount is investigated by comparing the methane conversion and hydrogen recovery yield achieved by an equisized‐staged reactor to those of an equivalent conventional membrane reactor for different furnace temperatures and flow configurations (co‐ and counter‐current). The most relevant result is that the proposed configuration with a sufficiently high number of stages and a significantly smaller catalyst amount (up to 70% lower) can achieve performances very close to the ones of the conventional unit in all the operating conditions considered. This is equivalent to say that the staged configuration can compensate and in fact substitute a significant part of the catalyst mass of a conventional membrane reactor. To help the interpretation of these results, stage‐by‐stage temperature and flux profiles are examined in detail. Then, the quantification of the performance losses with respect to the conventional reactor is carried out by evaluating the catalyst amount possibly saved and furnace temperature reduction. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Pathologic changes of skin and hair in ankyloblepharon‐ectodermal defects‐cleft lip/palate (AEC) syndrome
Authors: Dishop Megan K. , Bree Alanna F. , Hicks M. John 
Published: August 2009

AbstractAnkyloblepharon‐Ectodermal defects‐Cleft lip/palate (AEC) syndrome is a rare disorder of hair, skin, nails, and dentition caused by mutations in the p63 gene. Pathologic changes of skin and hair in AEC syndrome have previously been described in isolated case reports. Biopsies of normal and lesional skin from 19 patients with AEC syndrome were examined by light microscopy. Hair samples from 18 patients were examined by light and scanning electron microscopy. Histopathologic changes identified within the skin biopsies from clinically unaffected skin include mild atrophy, focal orthokeratosis, and mild superficial perivascular lymphocytic dermatitis. Scattered melanophages in the superficial and deep dermis likely reflect post‐inflammatory change. One patient with a unilateral eruption of monomorphic papulopustules on the chest and shoulder demonstrated an acneiform intraepidermal pustule. Examination of the hair shafts revealed atrophy and loss of melanin pigment in some of the patients. Structural abnormalities included pili torti, pili trianguli et canaliculi, and irregular indentation and shallow grooves. Skin and hair findings in AEC syndrome were found to be generally similar to those described in other ectodermal dysplasia syndromes and corroborates the few prior descriptions in AEC syndrome specifically. © 2009 Wiley‐Liss, Inc.
Hypervitaminosis A in experimental nonhuman primates: evidence, causes, and the road to recovery
Authors: Dever Joseph T. , Tanumihardjo Sherry A. 
Published: August 2009

AbstractOne of the great underlying assumptions made by all scientists utilizing primate models for their research is that the optimal nutritional status and health of the animals in use has been achieved. That is, no nutrient deficiency or excess has compromised their health in any detectable way. To meet this assumption, we rely on the National Research Council's (NRC's) nutritional recommendations for nonhuman primates to provide accurate guidance for proper dietary formulations. We also rely on feed manufacturers to follow these guidelines. With that in mind, the purpose of this commentary is to discuss three related points that we believe have significant ramifications for the health and well being of captive primates as well as for their effective use in biomedical research. First, our laboratory has shown that most experimental primates are likely in a state of hypervitaminosis A. Second, it is apparent that many primate diets are providing vitamin A at levels higher than the NRC's recommendation. Third, the recommendation itself is based on inadequate information about nutrient needs and is likely too high, especially when compared with human requirements. Am. J. Primatol. 71:813–816, 2009. © 2009 Wiley‐Liss, Inc.
Ohmic heating of dairy fluids—effects of local electric field on temperature distribution
Authors: Tham Heng Jin , Chen XiaoDong , Young Brent R. , Duffy Geoffrey G. 
Published: August 2009

AbstractThis paper presents the heat transfer model of a continuous flow ohmic heating process. The model fluid used was a mixture of reconstituted skimmed milk and whey protein concentrate solution. Two‐dimensional numerical simulations of an annular ohmic heater were performed using a general purpose partial differential equation solver, FlexPDE. The momentum, energy, and electrical equations were solved for a laminar flow regime. Two models were used to determine the volumetric heating rate, one taking into account the local electric field by solving the Laplace equation while another model assumes an average voltage gradient applied between the two electrodes. Results show that while the wall temperature distribution is different for the two cases, the bulk fluid temperature and the average outlet temperature are the same. The predicted temperatures generally agree well with the measured temperatures. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Dynamic state reconciliation and model‐based fault detection for chemical processes
Authors: Olivier‐Maget Nelly , Hétreux Gilles , Le Lann Jean Marc , Le Lann Marie Véronique 
Published: August 2009

AbstractIn this paper, we present a method for the fault detection based on the residual generation. The main idea is to reconstruct the outputs of the system from the measurements using the extended Kalman filter. The estimations are compared to the values of the reference model and so, deviations are interpreted as possible faults. The reference model is simulated by the dynamic hybrid simulator, PrODHyS. The use of this method is illustrated through an application in the field of chemical processes. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Novel nickel‐based catalyst for low temperature hydrogen production from methane steam reforming in membrane reformer
Authors: Chen Yazhong , Cui Peng , Xiong Guoxing , Xu Hengyong 
Published: August 2009

AbstractHydrogen production from various hydrocarbon fuels, particularly biomass‐derived fuels, has attracted worldwide attention due to its potential for application to fuel cells, a device which converts chemical energy into electricity efficiently and cleanly. However, current technology, such as natural gas steam reforming, could not meet the specific requirements of hydrogen for fuel cells. Therefore, novel processes are intensively investigated, aiming to develop economic and efficient ones for the specific purpose. An important direction is the integrated membrane reformer for one‐step high‐purity hydrogen production. However, for the commercial realization of this technology, there are still some difficulties to overcome. By comparison with previous investigations with a similar membrane, this work showed that catalyst also played an important role in determining membrane reformer performance. We proposed that when thickness of membrane was several micrometers, the permeance of membrane became less important than the kinetics of catalyst, due to the fact that under such conditions, hydrogen permeation rate was faster than the kinetics of steam reforming reaction when commercial catalyst was applied, but further evidence is indispensable. In this initial work, we focused on developing efficient nickel catalyst for low temperature steam reforming. Nickel‐based catalyst was developed by deposition–coprecipitation and used as pre‐reduced, showing high performance for methane steam reforming at low temperatures and good durability, which may find practical application for the integrated membrane reforming process. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Production of hydrogen via glycerol steam reforming in a Pd‐Ag membrane reactor over Co‐Al2O3 catalyst
Authors: Iulianelli A. , Longo T. , Liguori S. , Basile A. 
Published: August 2009

AbstractGenerally, biodiesel fuel, when converted from vegetables oils, produces around 10 wt% of glycerol as a byproduct, which could be used for producing hydrogen by a steam‐reforming reaction. Different scientific works have been realized in conventional reactors on the steam reforming of glycerol (GSR) in the aqueous or the gas phase. High reaction pressure and a relatively small catalyst deactivation are noticed when GSR is carried out in an aqueous phase, whereas the catalyst deactivation is the main disadvantage in the gas phase. In this work, GSR reaction was performed in a perm‐selective Pd‐Ag membrane reactor (MR) packed with a Co‐Al2O3 commercial catalyst in order to extract a CO‐free hydrogen stream and also enhance the performances in terms of glycerol conversion and hydrogen yield with respect to a traditional reactor (TR), both working at weight hourly space velocity (WHSV) = 1.01 h−1, 400 °C and H2O/C3H8O3 = 6/1. In MR, a maximum glycerol conversion of around 45.0% was achieved at 1.0 bar as reaction pressure, whereas it was around 94% at 4.0 bar. Moreover, as best value, more than 60.0% of CO‐free hydrogen recovery was achieved in the MR at 4.0 bar and 22.8 of sweep factor (sweep gas to glycerol ratio). Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Effect of surface defects in Pd‐based membranes on the performance of a membrane reactor
Authors: Caravella Alessio , Di Maio Francesco Paolo , Di Renzo Alberto 
Published: August 2009

AbstractIn this work, the influence of superficial defects over the surface of a Pd‐based membrane is analyzed in a membrane reactor for the methane steam‐reforming process. In order to include the presence of defects in the permeation, a previous model of a defect‐free Pd‐based membrane reactor is extended and integrated to include a variable portion of area with defects in the form of pinholes. As a consequence, two different permeation mechanisms are taken into account, one through the Pd‐based surface and the other one through the pinholes, where a Knudsen‐like transport is considered to occur. The presence of the Knudsen transport causes the membrane separation factor between the hydrogen and the other species involved in the process to decrease, affecting the reactor performances significantly. Three reactor performance indices are investigated as functions of the fraction of the defected area and the mean pore diameter of defects, namely methane conversion, the hydrogen recovery factor, the hydrogen recovery yield and the net purity of hydrogen in the permeate. The results show that the hydrogen recovery factor is positively influenced by the decrease in hydrogen selectivity, whilst methane conversion and hydrogen net purity decrease significantly with it. On the contrary, regarding the hydrogen recovery yield, it is shown that in certain conditions (low furnace temperature, ≈ 550 °C) it decreases with hydrogen selectivity. However, it increases again at higher furnace temperatures (≈650 °C). Globally, this investigation helps in identifying acceptable defect levels on a Pd‐based membrane for methane steam‐reforming applications and highlights that even a very small defect level (in terms of the pinhole diameter and/or amount of the defected area) can importantly compromise the reactor performances. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Thermally stable polyureas and poly(urea‐imide)s containing zinc and nickel napthtrien complexes
Authors: Sridaeng Duangruthai , Chantarasiri Nuanphun 
Published: August 2009

AbstractTwo new napthtrien metal complexes, MNapth2trien; where M = Zn and Ni, were synthesized and used for the synthesis of metal‐containing polyureas and poly(urea‐imide)s. MNapth2trien underwent polymerization reaction with two diisocyanates, namely, 4,4′‐diphenylmethane diisocyanate and isophorone diisocyanate to yield polyureas. Poly(urea‐imide)s were obtained by the synthesis of metal‐containing isocyanate‐terminated polyurea prepolymers from the reaction between MNapth2trien and excess diisocyanates, which could then undergo further reaction with different dianhydrides. The dianhydrides used were pyromellitic dianhydride and benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride. The polymers were characterized by infrared, nuclear magnetic resonance, elemental analysis, X‐ray diffraction, solubility, and viscosity. Glass transition temperature of the polymers was obtained from differential scanning calorimetry and dynamic mechanical thermal analysis. Thermal stability of polymers was studied by thermogravimetric analysis in air. It was found that the resulting metal‐containing polymers exhibited good thermal stability. Initial decomposition temperatures of the polymers depend on the amount of MNapth2trien in the polymer composition. Char yields of metal‐containing poly(urea‐imide)s are higher than those of metal‐containing polyureas. Most metal‐containing polymers show good solubility in organic solvents. Shore D hardness test indicates that metal‐containing poly(urea‐imide)s are hard materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Miscibility, crystallization, and mechanical properties of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)/ poly(butylene succinate) blends
Authors: Zhu Wenfu , Wang Xiaojuan , Chen Xianyu , Xu Kaitian 
Published: August 2009

AbstractNaturally amorphous biopolyester poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P3/4HB) containing 21 mol % of 4HB was blended with semi‐crystal poly(butylene succinate) (PBS) with an aim to improve the properties of aliphatic polyesters. The effect of PBS contents on miscibility, thermal properties, crystallization kinetics, and mechanical property of the blends was evaluated by DSC, TGA, FTIR, wide‐angle X‐ray diffractometer (WAXD), Scanning Electron Microscope (SEM), and universal material testing machine. The thermal stability of P3/4HB was enhanced by blending with PBS. When PBS content is less than 30 wt %, the two polymers show better miscibility and their crystallization trend was enhanced by each other. The optimum mechanical properties were observed at the 5–10 wt % PBS blends. However, when the PBS content is more than 30 wt %, phase inversion happened. And the two polymers give lower miscibility and poor mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Prospects for management strategies of invasive crayfish populations with an emphasis on biological control
Authors: Freeman M. A. , Turnbull J. F. , Yeomans W. E. , Bean C. W. 
Published: August 2009

Abstract
The white‐clawed crayfish, Austropotamobius pallipes (Lereboullet), is the only freshwater crayfish indigenous to Great Britain and Ireland. It has a widespread, though declining distribution in England and parts of Wales but does not occur naturally in Scotland.
The North American signal crayfish, Pacifastacus leniusculus (Dana), is not native to Europe and was introduced to Britain in the 1970s. The signal crayfish out‐competes the native white‐clawed crayfish as it is larger and more aggressive. It is also responsible for the introduction and spread of crayfish plague, which has devastated white‐clawed crayfish populations in Europe.
Signal crayfish populations are causing significant changes to the equilibrium of native flora and fauna through increased grazing and predation pressures; they also contribute to habitat degradation through burrowing.
Manual removal of crayfish using traps and pond trials with biocides have met with moderate success in reducing crayfish numbers and containing populations. However, with new populations of signal crayfish being reported each year within the UK, there is now an urgent need to develop a strategy with which to eradicate or contain their spread.
Signal crayfish have populated many habitat types in the UK, each of which may require a different control strategy; hence no single strategy or universal solution is likely to be attainable.
Signal crayfish are susceptible to various biocides and microbial pathogens but significant scientific research will be required to develop safe biological control methods and integrated pest management (IPM) strategies to control these invasive organisms. Copyright © 2009 John Wiley & Sons, Ltd.
An update on cardiovascular malformations in congenital rubella syndrome
Authors: Oster Matthew E. , Riehle‐Colarusso Tiffany , Correa Adolfo 
Published: August 2009

AbstractBACKGROUND: Congenital rubella syndrome (CRS) has long been characterized by the triad of deafness, cataract, and cardiovascular malformations (CVMs). While initial reports identified patent ductus arteriosus (PDA) as the primary CVM in CRS, the exact nature of the CVMs found in CRS has not been well established. METHODS: We searched the English literature from 1941 through 2008 to identify studies that used cardiac catheterization or echocardiography to evaluate the CVMs in CRS. RESULTS: Of the 121 patients in the 10 studies with catheterization data, 78% had branch pulmonary artery stenosis, and 62% had a PDA. In 49% of cases, both branch pulmonary artery stenosis and PDA were present, whereas isolated branch pulmonary artery stenosis and isolated PDA were found in 29 and 13% of cases, respectively. Of the 12 patients in the 10 studies with echocardiographic data, PDA was more common than branch pulmonary artery stenosis, but this finding is greatly limited by the small numbers of patients and limitations of echocardiography. Although published studies of CVMs in CRS have in general reported PDA as the CVM phenotype most commonly associated with CRS, among CRS cases evaluated by catheterization, branch pulmonary artery stenosis was actually more common than PDA. Moreover, although the combination of branch pulmonary artery stenosis and PDA was more common than either branch pulmonary artery stenosis or PDA alone, isolated branch pulmonary artery stenosis was twice as common as isolated PDA. CONCLUSION: Among children with suspected CRS, clinical evaluations for the presence of CVMs should include examinations for both branch pulmonary artery stenosis and PDA. Birth Defects Research (Part A), 2010. © 2009 Wiley‐Liss, Inc.
Multistate study of the epidemiology of clubfoot
Authors: Parker Samantha E. , Mai Cara T. , Strickland Matthew J. , Olney Richard S. , Rickard Russel , Marengo Lisa , Wang Ying , Hashmi S. Shahrukh , Meyer Robert E. 
Published: August 2009

AbstractBACKGROUND: Although clubfoot is a common birth defect, with a prevalence of approximately 1 per 1000 livebirths, the etiology of clubfoot remains largely unknown. Studies of the prevalence and risk factors for clubfoot in the United States have previously been limited to specific states. The purpose of this study was to pool data from several birth defects surveillance programs to better estimate the prevalence of clubfoot and investigate its risk factors. METHODS: The 10 population‐based birth defects surveillance programs that participated in this study ascertained 6139 cases of clubfoot from 2001 through 2005. A random sample of 10 controls per case, matched on year and state of birth, was selected from birth certificates. Data on infant and maternal risk factors were collected from birth certificates. Prevalence was calculated by pooling the state‐specific data. Conditional logistic regression was used to investigate the association between risk factors and clubfoot. RESULTS: The overall prevalence of clubfoot was 1.29 per 1000 livebirths; 1.38 among non‐Hispanic whites, 1.30 among Hispanics, and 1.14 among non‐Hispanic blacks or African Americans. Maternal age, parity, education, and marital status were significantly associated with clubfoot. Maternal smoking and diabetes also showed significant associations. Several of these observed associations were consistent between surveillance programs. CONCLUSIONS: We estimated the prevalence of clubfoot using data from several birth defects programs, representing one‐quarter of all births in the United States. Our findings underline the importance of birth defects surveillance programs and their utility in monitoring population‐based prevalence and investigating risk factors. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.