bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cracking risk of partially saturated porous media—Part I: Microporoelasticity model
Authors: Pichler Bernhard , Dormieux Luc 
Published: May 2009

AbstractDrying of deformable porous media results in their shrinkage, and it may cause cracking provided that shrinkage deformations are hindered by kinematic constraints. This is the motivation to develop a thermodynamics‐based microporoelasticity model for the assessment of cracking risk in partially saturated porous geomaterials. The study refers to 3D representative volume elements of porous media, including a two‐scale double‐porosity material with a pore network comprising (at the mesoscale) 3D mesocracks in the form of oblate spheroids, and (at the microscale) spherical micropores of different sizes. Surface tensions prevailing in all interfaces between solid, liquid, and gaseous matters are taken into account. To establish a thermodynamics‐based crack propagation criterion for a two‐scale double‐porosity material, the potential energy of the solid is derived, accounting—in particular—for mesocrack geometry changes (main original contribution) and for effective micropore pressures, which depend (due to surface tensions) on the pore radius. Differentiating the potential energy with respect to crack density parameter yields the thermodynamical driving force for crack propagation, which is shown to be governed by an effective macrostrain. It is found that drying‐related stresses in partially saturated mesocracks reduce the cracking risk. The drying‐related effective underpressures in spherical micropores, in turn, result in a tensile eigenstress of the matrix in which the mesocracks are embedded. This way, micropores increase the mesocracking risk. Model application to the assessment of cracking risk during drying of argillite is the topic of the companion paper (Part II). Copyright © 2009 John Wiley & Sons, Ltd.
Physical aging of polycarbonate block copolymers: Ductility rejuvenation below the glass transition temperature
Authors: Dhara Dibakar , Purushotham A. , Rosenquist Niles , Richards William D. , Maruvada Krishna , Chatterjee Gautam 
Published: May 2009

AbstractThermal aging of block copolymers of bisphenol A polycarbonate and polydimethylsiloxane (BPAPC and PDMS) have been studied. Changes in notched izod impact performance and yield stress are reported following aging at 120°C and 130°C for up to 20 days. Retention of impact at 120°C of the block copolymers was found to improve with increasing size of siloxane domains in the polycarbonate matrix. Quite contrary to our expectation, the retention of impact for a given sample at 130°C was found to be better than that of at120°C. These block copolymers showed (thermo) reversible ductility rejuvenation behavior at 130°C when the samples heat‐aged at 120°C were shifted from 120 to 130°C. Transmission electron microscopy, small‐angle X‐ray scattering, and dynamic mechanical analysis techniques were used to probe the observed phenomenon. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Synthesis and characterization of open‐cell foams for sound absorption with rotational molding method
Authors: Chu Raymond K.M. , Naguib Hani E. , Atalla Noureddine 
Published: May 2009

AbstractFoams with open‐cell structures have improved sound absorption abilities over conventional closed‐cell foams. One technique to optimize the acoustic abilities of open‐cell foams is to control their cellular properties through the manipulation of processing parameters. This article presents a novel process to synthesize open‐cell polymeric foams for acoustic applications. The process combined rotational foam molding and particulate leaching to produce foams with open‐cell networks that are desirable for acoustic absorption. Open‐cell foams with open‐porosity of about 0.90 were successfully fabricated with this combined foaming process. Effects of processing parameters on the cellular and acoustic properties of the foam samples were examined and discussed. On the basis of the results from the study, the cellular and acoustic properties of the foam fabricated from the proposed method can be controlled through the use of different salt particle sizes in the process. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Improved melting strength of polypropylene by reactive compounding with ultrafine full‐vulcanized polybutadiene rubber (UFBR) particles
Authors: Liu Yuguang , Huang Yudong , Zhang Chengwu , Hou Jing , Zhang Xuequan 
Published: May 2009

AbstractUltrafine full‐vulcanized polybutadiene rubber (UFBR) in particle sizes of ca. 50–100 nm has been used for modifying mechanical and processing performances of polypropylene (PP), and PP‐g‐maleic anhydride (PP‐MA) has been used as a compatibilizer for enhancing the interfacial adhesion between the two components. The results show that PP/UFBR possesses rheological behaviors such as highly branched PP when UFBR content in blends reaches 10 wt%, while in contrast, the much low content of UFBR combining small amount of PP‐MA endows the material with rheological characteristics of high melt strength materials like highly branched PP. The mechanism accounting for the rheological behaviors of binary blends and effectiveness of PP‐MA on PP/UFBR blends has been proposed. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Hot embossing of discrete microparts
Authors: Kuduva‐Raman‐Thanumoorthy Ramasubramani , Yao Donggang 
Published: May 2009

AbstractThe hot embossing process has so far been developed mainly for replication of surface structures on thermoplastic substrates. Because of the lack of a through‐thickness action, fabrication of discrete microparts such as microgears is considered difficult. In this study, embossing molds having multiple microcavities were used in a through‐thickness embossing process with a rubber‐assisted ejection mechanism. Microparts made of HDPE and ABS with each part weighing approximately 1 and 1.4 mg, respectively, were produced. When in the mold, embossed microparts were intermittently connected to each other through thin residual films of a thickness approximately 20 μm. The residual films were detached from the microparts during a rubber‐assisted ejection stage. Because no resin delivery paths, e.g., runners and gates, are needed for microcavities on the multicavity embossing mold, this micropart fabrication process could replace micro injection molding in many applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
X‐ray crystallographic studies of RNase A variants engineered at the most destabilizing positions of the main hydrophobic core: Further insight into protein stability
Authors: Kurpiewska Katarzyna , Font Josep , Ribó Marc , Vilanova Maria , Lewiński Krzysztof 
Published: May 2009

AbstractTo investigate the structural origin of decreased pressure and temperature stability, the crystal structure of bovine pancreatic ribonuclease A variants V47A, V54A, V57A, I81A, I106A, and V108A was solved at 1.4–2.0 Å resolution and compared with the structure of wild‐type protein. The introduced mutations had only minor influence on the global structure of ribonuclease A. The structural changes had individual character that depends on the localization of mutated residue, however, they seemed to expand from mutation site to the rest of the structure. Several different parameters have been evaluated to find correlation with decrease of free energy of unfolding ΔΔGT, and the most significant correlation was found for main cavity volume change. Analysis of the difference distance matrices revealed that the ribonuclease A molecule is organized into five relatively rigid subdomains with individual response to mutation. This behavior consistent with results of unfolding experiments is an intrinsic feature of ribonuclease A that might be surviving remnants of folding intermediates and reflects the dynamic nature of the molecule. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Leaching behaviour of azoxystrobin and metabolites in soil columns
Authors: Ghosh Rakesh Kumar , Singh Neera 
Published: May 2009

AbstractBACKGROUND: Azoxystrobin [methyl (E)‐2‐{2‐[6‐(2‐cyanophenoxy)pyrimidin‐4‐yloxy]phenyl}‐3‐methoxyacrylate], a strobilurin fungicide, is a broad‐spectrum, systemic and soil‐applied fungicide. Azoxystrobin has been registered for rice cultivation in India, but no information is available on its leaching behaviour in Indian soils. Therefore, leaching behaviour of azoxystrobin was studied in packed and intact soil columns under different irrigation regimes.RESULTS: Azoxystrobin did not leach out of the 300 mm long columns after 126 and 362 mm rainfall. After percolating water equivalent to 362 mm rainfall, azoxystrobin leached down to 10–15 cm (packed columns) and 15–20 cm (intact columns) depth. Azoxystrobin was not detected in the leachate from the packed column leached with 94.5 mL water every week (140 mm rainfall per month) during the 28 weeks of the study period. However, azoxystrobin acid, formed by azoxystrobin degradation, was detected in the leachate after 18 weeks. At the end of the study, azoxystrobin had leached down to 5–10 cm depth, and only 60% of initially applied azoxystrobin was recovered from the soil.CONCLUSION: The results indicate that azoxystrobin is fairly immobile in sandy loam soil, but azoxystrobin acid, a major metabolite of azoxystrobin, is quite mobile and may pose a threat of soil and groundwater contamination. Copyright © 2009 Society of Chemical Industry
Effect of deposition temperature on the microstructure and dielectric properties of Ba0.6Sr0.4TiO3 thin film deposited by radio‐frequency magnetron sputtering
Authors: Feng Zuyong , Chen Wei , Tan Ooi Kiang 
Published: May 2009

AbstractBa0.6Sr0.4TiO3 (BST) thin films with the thickness of 300 nm were deposited on Pt/SiO2/Si substrates at various deposition temperatures by RF magnetron sputtering technique, and their electric properties were investigated. Due to the high temperature annealing process at substrate temperature of 600 °C, well‐crystallized BST film was deposited. The dielectric constant and dielectric loss of the film deposited at 600 °C are 300 and 0.033 at 100 kHz, respectively. Due to the good crystallinity of the BST films deposited by RF magnetron sputtering, high dielectric tunability up to 39.2% is achieved at a low applied voltage of 5 V. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the experimental evidence for a departure from first‐order photochemical kinetics in bistable photochromic materials
Authors: Perciante César D. , Ferrari José A. 
Published: May 2009

AbstractWe discuss the apparent discrepancy between experimental results and the mono‐exponential decay law (which is characteristic of first‐order kinetics) for two‐state photochromic materials during activation and bleaching. Although deviations from first‐order kinetics could be expected for realistic samples, we show that the experimental data presented are actually compatible with a mono‐exponential decay law, and that the apparent discrepancy is attributable to an inappropriate description of the photo‐stationary state. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Private computing on public platforms: portable application security
Authors: Morris Thomas H. , Nair V. S. S. 
Published: May 2009

AbstractAs cellular telephones and high capacity memory sticks emerge as users' primary repository for data and applications, users will often run applications and display data on remote hosts. The biggest challenge in supporting this mobile data, mobile applications, stationary platform model is ensuring the security and privacy of user applications and data during execution on the remote platforms. Private computing on public platforms (PCPP) is a new application security approach which isolates applications to allow for secure and private execution on third party systems. This paper introduces PCPP and details its five basic building blocks which together ensure that the PCPP protected application's executable code, context, and data remain unaltered, unmonitored, and unrecorded before, during, and after exposure to the remote platform. Copyright © 2009 John Wiley & Sons, Ltd.
Lévy base correlation
Authors: Garcia João , Goossens Serge , Masol Viktoriya , Schoutens Wim 
Published: May 2009

AbstractIn this paper we investigate one‐factor models that extend the classical Gaussian copula model for pricing tranches of CDOs. We introduce Lévy base correlation and compare it to the classical Gaussian copula. The results of a historical study of both models on the iTraxx Europe Main dataset are presented. Our focus is on the base correlation surface and on the deltas of the tranches with respect to the index. We observe that the Lévy base correlation curve is much flatter than the corresponding Gaussian one. With respect to the deltas we conclude that the Lévy model produces larger deltas for the equity tranche and smaller deltas for the senior tranches. Copyright © 2009 Wilmott Magazine Ltd
Neutral Hexacoordinate Mixed Trichelate Silicon Complexes, Structure and Stereodynamics
Authors: Kertsnus‐Banchik Evgenia , Sela Einat , Wagler Jörg , Kalikhman Inna , Kost Daniel 
Published: May 2009

AbstractNeutral hexacoordinate silicon trichelates have been synthesized by transsilylation, using two approaches: (i) The reaction of a dichloro‐monocyclic silane [2,5‐diphenyl‐2,5‐diazasilolidine] with two mol‐equivalents of O‐(trimethylsilyl)imidates. (ii) A dichloro‐dichelate reacted with one mol‐equivalent of the trimethylsilyl bidentate ligand precursor, bis(trimethylsilyl)benzhydroxamic acid imidate. The former group of complexes underwent inversion of configuration observed by the temperature dependence of the 1H NMR spectra and coalescence of signals due to diastereotopic N‐methyl‐ and CH2 groups, presumably by exchange of hydrazido chelate rings through a bicapped tetrahedral intermediate or transition state. The activation free energies range between 13.8 and 14.7 kcal·mol–1. Similar exchange in the hydroxamic acid derived complexes was not observed, because of much shorter and stronger dative N–Si bonds.
Use of Leukoreduced Blood Does Not Reduce Infection, Organ Failure, or Mortality Following Trauma
Authors: Englehart Michael S. , Cho S. David , Morris Melanie S. , Gee Arvin C. , Riha Gordon , Underwood Samantha J. , Differding Jerome A. , Luem Nick D. , Wiesberg Tracy T. , Boshkov Lynn K. , Schreiber Martin A. 
Published: May 2009

AbstractBackgroundLeukoreduced (LR) blood has been demonstrated to reduce morbidity and mortality in high‐risk surgical patients, but not in trauma patients. The objective of the present study was to determine the effect of LR blood on morbidity and mortality. We hypothesized that the use of LR blood does not improve outcome in trauma patients.MethodsThis study was a retrospective cohort analysis of trauma patients transfused at a level 1 Trauma Center from 2001 to 2004. Between 2002 and 2003, LR blood was transfused. Prior to that time and subsequent to it, non‐leukoreduced (NLR) blood was transfused. This created two historical comparison groups. Data collected included patient demographics, units of blood transfused, intensive care unit (ICU) and hospital days, ventilator days, injury severity score (ISS), mortality, presence of acute respiratory distress syndrome (ARDS), and infectious complications. A multiple organ dysfunction syndrome (MODS) score was calculated.ResultsThe distribution of patients was as follows: 284 patients received only NLR blood, 153 received only LR blood, and 58 received at least one unit of each. The mean ISS was similar (NLR: 26, LR: 24; P > 0.1). No differences were seen between groups in units transfused (6.2 vs. 5.5), number of ICU days (8.2 vs. 9.0), number of hospital days (16.9 vs. 18.6), number of ventilator days (6.1 vs. 5.7), incidence of ARDS (8.3% vs. 8.5%), MODS score (5.5 vs. 5.9), mortality rate (15.1% vs. 15.7%), or infection rate (36% vs. 30%) (P > 0.1).ConclusionsThis study represents the largest series comparing trauma patients who received either LR or standard blood transfusions. The use of LR blood does not improve outcome in trauma patients.
A Comparative Analysis of Ethical and Professional Challenges Experienced by Australian and U.S. Genetic Counselors
Authors: Alliman Sarah , McCarthy Veach Patricia , Bartels Dianne M. , Lian Fengqin , James Carolyn , LeRoy Bonnie S. 
Published: May 2009

AbstractEthical issues are an inevitable part of genetic counseling practice. Prior research identified 16 domains of ethical and professional challenges encountered by practitioners in the United States. In order to further validate these domains, the present study surveyed Australian genetic counselors. Sixty‐three respondents rated the frequency with which they encountered each domain, and 39 individuals also provided personal anecdotes detailing their most challenging ethical and professional dilemmas. Every domain reportedly was experienced by the Australian sample. However, there were some differences between Australian respondents and U.S. genetic counselors in frequencies of domain occurrence, and in strategies recommended for resolving them. Several anecdotes illustrate challenging situations due to Australia's geography, universal healthcare system, and the genetic counseling profession's evolution in that country. The results generally validate domains identified for U.S. genetic counselors. They further suggest that certain ethical issues may manifest in ways unique to a given country, and therefore they must be addressed in a culturally‐appropriate manner.
A Simplified Method to Distinguish Farmed (Salmo salar) from Wild Salmon: Fatty Acid Ratios Versus Astaxanthin Chiral Isomers
Authors: Megdal Peter Andrew , Craft Neal A. , Handelman Garry J. 
Published: May 2009

AbstractMislabeling of farmed and wild salmon sold in markets has been reported. Since the fatty acid content of fish may influence human health and thus consumer behavior, a simplified method to identify wild and farmed salmon is necessary. Several studies have demonstrated differences in lipid profiles between farmed and wild salmon but no data exists validating these differences with government‐approved methods to accurately identify the origin of these fish. Current methods are both expensive and complicated, using highly specialized equipment not commonly available. Therefore, we developed a testing protocol using gas chromatography (GC), to determine the origin of salmon using fatty acid profiles. We also compared the GC method with the currently approved FDA (United States Food and Drug Administration) technique that uses analysis of carotenoid optical isomers and found 100% agreement. Statistical validation (n = 30) was obtained showing elevated 18:2n‐6 (z = 4.56; P = 0.0001) and decreased 20:1n‐9 (z = 1.79; P = 0.07) in farmed samples. The method is suitable for wide adaptation because fatty acid methyl ester analysis is a well‐established procedure in labs that conduct analysis of lipid composition and food constituents. GC analysis for determining the origin of North American salmon compared favorably with the astaxanthin isomer technique used by the FDA and showed that the fatty acid 18:2n‐6 was the key indicator associated with the origin of these salmon.
Effect of ALA‐Enriched Food Supply on Cardiovascular Risk Factors in Males
Authors: Sioen Isabelle , Hacquebard Mirjam , Hick Gaëlle , Maindiaux Veronique , Larondelle Yvan , Carpentier Yvon A. , De Henauw Stefaan 
Published: May 2009

AbstractThe outcome of a total dietary approach using a wide range of n‐3 polyunsaturated fatty acids (PUFA) enriched food items on cardiovascular diseases called for further investigation. The study objective was to assess the effect of an ALA‐enriched food supply on cardiovascular risk factors in healthy males. A dietary intervention (single‐blind field trial with pre‐ and post‐measurements) was performed with 59 healthy males in a Belgian prison. Over a period of 12 weeks they were supplied with an n‐3 enriched diet (containing 6.5 g n‐3 PUFA/day compared to 4 g n‐3 PUFA/day in the standard diet) that was substituted for their regular diet, increasing mainly the α‐linolenic acid intake (from 2.8 to around 5 g/day). The results indicated no impact on subjects waist circumference, weight and BMI or systolic blood pressure. In contrast, the diastolic blood pressure significantly decreased during the intervention period (from 74.6 ± 8.2 to 71.7 ± 10.1 mmHg; P < 0.02). Moreover, the HDL‐cholesterol level increased in non‐smoking participants (from 0.97 ± 0.25 to 1.06 ± 0.23 mmol/l; P < 0.03). In summary, the study demonstrated that enrichment of commonly eaten food items with n‐3 fatty acids provides the opportunity to increase the n‐3 fatty acid intake and to decrease the n‐6/n‐3 ratio which results in a decreasing diastolic blood pressure and an increase of HDL‐cholesterol (in non‐smokers).
Differences in Sterol Composition between Male and Female Gonads of Dominant Limpet Species
Authors: Kawashima Hideki , Ohnishi Masao , Ogawa Satoshi 
Published: May 2009

AbstractThe present study demonstrated here for the first time that there are statistically significant differences in sterol composition between male and female gonads of the dominant limpets Cellana grata and Cellana toreuma, which are intertidal gastropods. Among 11 different sterols identified in this study, unusually high levels (11.2–19.8% of total sterols) of the Δ8‐sterols 5α‐cholest‐8‐en‐3β‐ol (zymostenol) and 5α‐cholesta‐8,24‐dien‐3β‐ol (zymosterol), which have never been reported in aquatic invertebrate gonads, were present in only the male gonads.
A late Holocene paleoclimatic history of Lake Tanganyika, East Africa
Authors: Stager J. Curt , Cocquyt Christine , Bonnefille Raymonde , Weyhenmeyer Constanze , Bowerman Nicole 
Published: May 2009

AbstractA nearshore core (LT03-05) from the north basin of Lake Tanganyika provides diatom, pollen, and sedimentary time series covering the last ca. 3800 yr at 15–36 yr resolution. A chronology supported by 21 AMS dates on terrestrial and lacustrine materials allows us to account for ancient carbon effects on14C ages and to propose refinements of the region's climatic history. Conditions drier than those of today were followed after ca. 3.30 ka by an overall wetting trend. Several century-scale climate variations were superimposed upon that trend, with exceptionally rainy conditions occurring 1.70–1.40 ka, 1.15–0.90 ka, 0.70–0.55 ka, and 0.35–0.20 ka. Around 0.55–0.35 ka, during the Spörer sunspot minimum, drier conditions developed in the northern Tanganyika basin while more humid conditions were registered at Lakes Victoria and Naivasha. This indicates significant variability in the nature and distribution of near-equatorial rainfall anomalies during much of the Little Ice Age.