bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compression behavior of woven glass/epoxy specimens using a new end‐loaded hybrid specimen
Authors: Neves V.V. , de Morais A.B. , Pereira A.B. , Faria R.D. 
Published: January 2011

AbstractA new compression specimen was applied to woven glass/epoxy laminates. The specimen consists of epoxy layers cast on the sides of the laminate to prevent buckling. Thin‐sheet aluminum ends enable alignment and avoid crushing under end loading, which does not require any special fixture. The compression stress–strain behavior of the laminate was obtained from the specimens by discounting the previously measured stress–strain curve of the epoxy backings. Despite the higher scatter in compression tests, the average modulus was practically identical to the tensile modulus. Moreover, failure occurred away from the ends in nearly all of the specimens tested. The average compressive strength was 84% of the tensile strength and consistent with the flexural strength measured in four‐point bending tests. The present compression specimen could, therefore, become an interesting alternative to the more elaborate standard test methods available. Nevertheless, this new compression testing approach needs further evaluation involving application to other materials. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Prenatal diagnosis of abnormal cardinal systemic venous return without other heart defects: a case series
Authors: Barrea Catherine , Ovaert Caroline , Moniotte Stéphane , Biard Jean‐Marc , Steenhaut Patricia , Bernard Pierre 
Published: January 2011

AbstractObjectivesTo describe fetal spectrum and echocardiographic characteristics of anomalous systemic venous return (ASVR, cardinal veins) without other structural heart defects (isolated ASVR), evaluate associated extracardiac and genetic anomalies and review neonatal outcome.MethodsFrom 2003 to 2009, 369 consecutive fetuses were diagnosed with cardiac malformation, including 27 cases with an isolated ASVR. The following variables were collected: type of ASVR, extracardiac anomalies, karyotype and short‐term outcome.ResultsThe most common forms of ASVR were persistent left superior vena cava (SVC) (n = 15) and interrupted inferior vena cava (IVC) (n = 6). The other ASVR types were a persistent left SVC without a right SVC (n = 4), bilateral agenesis of the SVC with cephalic venous drainage toward the IVC through the azygos system (n = 1) and total ASVR to the coronary sinus (n = 1). Genetic disorders were confirmed in five cases, all with a persistent left SVC, with extracardiac anomalies present in four of them. Ten other patients had extracardiac anomalies detected prenatally or postnatally. When available, ASVR diagnosis was confirmed postnatally in all cases.ConclusionIsolated ASVRs can be accurately diagnosed prenatally and are frequently associated with extracardiac and genetic anomalies. A detailed morphological ultrasound and fetal karyotype should be suggested. Neonatal outcome was mainly related to the associated anomalies. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of poly(2‐furyloxirane) with high molecular weight and improved regioregularity using macrocyclic ether as a cocatalyst to potassium tert‐butoxide
Authors: Su Riting , Qin Yusheng , Qiao Lijun , Li Ji , Zhao Xiaojiang , Wang Pixin , Wang Xianhong , Wang Fosong 
Published: January 2011

Abstract2‐Furyloxirane (FO), a monomer usually obtained from a nonpetroleum route, was prepared from the epoxidation reaction of furfural and trimethylsulfonium chloride. About 200–300 g FO can be obtained in each preparation process. Although anionic polymerization of FO generally gives low‐ molecular‐weight polymers even after long periods of polymerization, the reaction was greatly improved when macrocyclic ether was used as a cocatalyst to potassium tert‐butoxide. When 18‐crown‐6 was used as a cocatalyst, poly(2‐furyloxirane) (PFO) with a number‐average molecular weight (Mn) of 41.5 kg/mol and a polydispersity index of 1.3 was obtained at 94% yield after polymerization at 40 °C for 72 h. The PFO obtained contained a 61.7% head‐to‐tail (H‐T) structure in the absence of the macrocyclic ether, and it reached 70.6% when cryptand[2,2,2] was used as a cocatalyst. PFO with higher regioregular structures showed improved thermal properties. For PFO with Mn of around 20.0 kg/mol, its glass transition temperature (Tg) increased from −3 to 6 °C when the H‐T content was increased from 61.7 to 70.6%. Raising the Mn of PFO also raised Tg. For PFO with 68.9% H‐T structure, its Tg could reach 7 °C when Mn was increased to 40 kg/mol. This study shows two effective ways to improve the thermal and mechanical performances of the polymer. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Structure and X‐ray spectrum of crystalline poly(3‐hexylthiophene) from DFT‐van der Waals calculations
Authors: Colle Renato , Grosso Giuseppe , Ronzani Alberto , Zicovich‐Wilson Claudio M. 
Published: January 2011

AbstractThe minimum‐energy geometrical structure of the regioregular head‐to‐tail poly(3‐hexylthiophene) (rr‐HT‐P3HT) polymer has been addressed by means of density functional theory (DFT) calculations which include long‐range (van der Waals) interactions. The problem of the P3HT structure has been debated in the literature in the last decades mainly for what concerns the arrangement of the alkyl side chains of the polymer and the type and content of the crystalline primitive cell. The main result of our calculations is that the energetically favored structure of the crystalline polymer at T = 0 K corresponds to polythiophene chains with slightly (∼16°) non co‐planar rings and a fishbone arrangement of tilted alkyl side chains with complex internal structure. The alkyl side chains are negligibly interdigitated with those of the adjacent polymer layers; moreover the five terminal carbon atoms of each alkyl side chain are co‐planar in all‐trans staggered conformation. The optimized geometrical structure obtained for the rr‐HT‐P3HT polymer is in agreement with measured X‐ray spectra of high molecular weight P3HT crystalline samples, and confirms that two non‐equivalent polymer chains, mutually shifted along the backbone axis, are contained in an orthorhombic primitive cell.
Ga co‐doping in Cz‐grown silicon ingots to overcome limitations of B and P compensated silicon feedstock for PV applications
Authors: Forster Maxime , Fourmond Erwann , Einhaus Roland , Lauvray Hubert , Kraiem Jed , Lemiti Mustapha 
Published: January 2011

AbstractIn this paper, we investigate gallium co‐doping during CZ crystallization of boron and phosphorus compensated Si. It is shown that the addition of gallium yields a fully p‐type ingot with high resistivity despite high B and P contents in the silicon. Segregation of doping impurities is consistent with theory. Minority carrier lifetime and majority carrier mobility measurements indicate that this material is suitable for the realization of solar cells with comparable efficiencies to standard material. Significant light‐induced degradation of minority carrier lifetime is however revealed to occur in this material. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhanced iron gettering by short, optimized low‐temperature annealing after phosphorus emitter diffusion for industrial silicon solar cell processing
Authors: Hofstetter Jasmin , Lelièvre Jean‐François , Fenning David P. , Bertoni Mariana I. , Buonassisi Tonio , Luque Antonio , del Cañizo Carlos 
Published: January 2011

AbstractThe introduction of a low‐temperature (LT) tail after P emitter diffusion was shown to lead to considerable improvements in electron lifetime and solar cell performance by different researchers. So far, the drawback of the investigated extended gettering treatments has been the lack of knowledge about optimum annealing times and temperatures and the important increase in processing time. In this manuscript, we calculate optimum annealing temperatures of Fe‐contaminated Si wafers for different annealing durations.Subsequently, it is shown theoretically and experimentally that a relatively short LT tail of 15 min can lead to a significant reduction of interstitial Fe and an increase in electron lifetime. Finally, we calculate the potential improvement of solar cell efficiency when such a short‐tail extended P diffusion gettering is included in an industrial fabrication process. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Decoupling of a strained 3C‐SiC(111) thin film on silicon by He+ and O+ ion implantation
Authors: Häberlen Maik , Murphy Brian , Stritzker Bernd , Lindner Jörg K. N. 
Published: January 2011

AbstractThis paper reports the successful reduction of tensile strain in a thin ion‐beam‐synthesized 3C‐SiC(111) layer on silicon. Significant relaxation is achieved by creating a near‐interface defect structure containing nanometric voids and dislocation loops by the implantation of He ions and subsequent thermal annealing. The structural features of this defect microstructure are investigated by transmission electron microscopy. High‐resolution X‐ray diffraction in a parallel beam configuration is used to quantify the strain state of the top SiC layer. Further annealing experiments were carried out in order to emulate typical process conditions for the growth of wide‐band‐gap semiconductors like, for example GaN. It is found that prolonged annealing at elevated temperatures leads to coarsening of the voids and to a much less efficient strain reduction. We show that this issue can be resolved by the co‐implantation of oxygen to form highly thermally stable cavity/extended defect structures. The technique presented here may be useful for a variety of other thermally mismatched bulk/thin film couples as well (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of current‐voltage characteristics of p‐type silicon during electrochemical anodization and application to doping profiling
Authors: Gharbi Ahmed , Remaki Boudjemaa , Halimaoui Aomar , Bensahel Daniel , Souifi Abdelkader 
Published: January 2011

AbstractThe analysis of anodic current‐potential I‐V characteristics of p‐type silicon in concentrated hydrofluoric acid solution shows that the mechanism at the origin of porous silicon PS formation is determined by the charge exchange at the silicon surface over a Schottky barrier formed at the interface through a thermionic emission process. In addition, a negative potential shift in the I‐V characteristics is observed with increasing doping concentration which can explain the selective formation of PS towards the doping level of silicon. In fact, when a silicon wafer of different regions of doping concentration is anodized at a fixed current or potential, the dissolution current will be more important in regions of higher doping level and PS formation can only take place there. The property of selectivity is used in this work in order to determine the p‐type doping impurity profiles. During anodization under galvanostatic conditions of a specific test sample presenting dopant concentration variations, it is shown that the measured anodization potential varies according to silicon doping concentration. Consequently, by converting potential values to dopant concentration, and the electrolysis time to a depth scale, a doping impurity profile can be extracted. The profile using this technique appears to be in a good agreement with the secondary ion mass spectrometry (SIMS) analysis. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stoichiometry of silicon‐rich dielectrics for silicon nanocluster formation
Authors: Barreto Jorge , Morales Alfredo , Perálvarez Mariano , Garrido Blas , Domínguez Carlos 
Published: January 2011

AbstractSilicon photonics has been bred by several techniques including Chemical Vapour Deposition (CVD) and ion implantation amongst others in order to synthesize silicon nanoclusters with CMOS‐compatible technologies. Most of these techniques end up relying on the formation of nanoclusters through the diffusion and segregation of silicon atoms in a silicon‐rich dielectric matrix. In this work we present a parallel analysis on silicon rich dielectric layers obtained by different methods. X‐Ray Photoelectron Spectroscopy, ellipsometry and photoluminescence are used to characterize Low Pressure CVD and Plasma Enhanced CVD samples in the same theoretical silicon excess range. The analysis shows that independently on the obtaining method the initial concentration of silicon excess can be used to estimate some properties. The actual binding of the atoms can change as well regardless of their initial quantity. However secondary parameters such as the obtaining temperature and the nitrogen concentration in the layer have to be taken into account. Therefore, experimental parameters such as the flow ratio between reactant gases or the refractive index prove to be insufficient if samples obtained by different methods are compared. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Economies and diseconomies of scale in software development
Authors: Comstock Craig , Jiang Zhizhong , Davies Jim 
Published: January 2011

AbstractEconomies and diseconomies of scale—gains and losses in productivity arising from increases in project size—are of considerable, practical importance in software engineering. However, there is no consensus as to whether, in general, economies or diseconomies exist with respect to project size; neither is there any consensus on the relationship among project size, team size, and overall productivity. Using evidence from a large database of projects, this paper derives a simple parametric model for estimating development effort in terms of size and productivity factors. The model is compared with popular estimation models—the Putnam model and COCOMO II—and a possible explanation is provided for the lack of consensus. By considering also the value of the software produced, the model provides a basis for the calculation of the optimal team size for a given task, with respect to the anticipated net benefit from the development activity. Copyright © 2011 John Wiley & Sons, Ltd.
Model checking timed properties of healthcare processes
Authors: Miller Keith , MacCaull Wendy 
Published: January 2011

AbstractHealthcare workflows (careflows) involve complex, distributive processes with a high degree of variability. There are ubiquitous communication and enormous data and knowledge management requirements and the processes involve complex timing requirements, and are safety critical. Designing these processes and managing their performance is difficult and error‐prone. Using verification techniques such as model checking, which are mathematical methods of proving correctness, we can reduce errors by ensuring that process designs satisfy their specifications. We describe a prototype next generation multithreaded model checker to reason about processes in careflows, sensitive to patient preferences and the goals of the careteam using a timed temporal logic extended with modalities of beliefs, desires, and intentions. Copyright © 2011 John Wiley & Sons, Ltd.
Oxidative damage and OGG1 expression induced by a combined effect of titanium dioxide nanoparticles and lead acetate in human hepatocytes
Authors: Du Hairong , Zhu Xiaoling , Fan Chuangang , Xu Song , Wang Youjie , Zhou Yikai 
Published: January 2011

AbstractTitanium dioxide (TiO2) is a widely used nanomaterial that can cause biological damage through oxidative stress. At low concentrations, TiO2can interact with lead acetate (PbAc) to produce different toxic responses, compared with TiO2or PbAc alone. In this study, we utilized the following as indicators of toxic responses in human embryo hepatocytes (L02): reactive oxygen species (ROS), reduced glutathione (GSH), superoxide dismutase (SOD), and the DNA adducts 8‐hydroxydeoxyguanosine (8‐OHdG) and 8‐oxoguanine DNA glycosylase homolog 1 (OGG1). These were used to evaluate the oxidative stress of TiO2(at 0.001, 0.01, 0.1, 1, and 10 μg mL−1) mixed with PbAc (1 μg mL−1) on L02 cells without photoactivation. Compared with the negative control (1‰ dimethyl sulfoxide), TiO2mixed with PbAc induced increased release of ROS (at 0.001, 0.01, 0.1, 1, 10 μg mL−1TiO2), intracellular SOD activity (at 0.1 and 0.01 μg mL−1TiO2), GSH levels (at 0.01–1 μg mL−1TiO2), 8‐OHdG levels (at 1 and 10 μg mL−1TiO2), OGG1 expression (at 0.001–1 μg mL−1TiO2), and cytotoxicity (at 0.1, 1, and 10 μg mL−1TiO2) in L02 cells. There were no significant changes in ROS, GSH, SOD, 8‐OHdG, or OGG1 levels when L02 cells were treated with TiO2alone or PbAc alone. These findings indicate that TiO2and PbAc in combination induce cytotoxicity and oxidative stress in L02 cells in the absence of photoactivation. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Sources of variability in estimates of the prevalence of Alzheimer's disease in the United States
Authors: Wilson Robert S. , Weir David R. , Leurgans Sue E. , Evans Denis A. , Hebert Liesi E. , Langa Kenneth M. , Plassman Brenda L. , Small Brent J. , Bennett David A. 
Published: January 2011

BackgroundThe prevalence of Alzheimer's disease (AD) in the United States was estimated at 2.3 million in 2002 by the Aging, Demographics, and Memory Study (ADAMS), which is almost 50% less than the estimate of 4.5 million in 2000 derived from the Chicago Health and Aging Project.MethodsWe considered how differences in diagnostic criteria may have contributed to these differences in AD prevalence.ResultsWe identified several important differences in diagnostic criteria that may have contributed to the differing estimates of AD prevalence. Two factors were especially noteworthy. First, the Diagnostic and Statistical Manual of Mental Disorders III‐R and IV criteria of functional limitation documented by an informant used in ADAMS effectively concentrated the diagnosis of dementia toward a relatively higher level of cognitive impairment. ADAMS separately identified a category of cognitive impairment not dementia and within that group there were a substantial number of cases with “prodromal” AD (a maximum of 1.95 million with upweighting). Second, a substantial proportion of dementia in ADAMS was attributed to either vascular disease (representing a maximum of 0.59 million with upweighting) or undetermined etiology (a maximum of 0.34 million), whereas most dementia, including mixed dementia, was attributed to AD in the Chicago Health and Aging Project.ConclusionThe diagnosis of AD in population studies is a complex process. When a diagnosis of AD excludes persons meeting criteria for vascular dementia, when not all persons with dementia are assigned an etiology, and when a diagnosis of dementia requires an informant report of functional limitations, the prevalence is substantially lower and the diagnosed cases most likely have a relatively higher level of impairment.
Sex differences and developmental stability in genetic and environmental influences on psychoactive substance consumption from early adolescence to young adulthood
Authors: Baker J. H. , Maes H. H. , Larsson H. , Lichtenstein P. , Kendler K. S. 
Published: January 2011

BackgroundGenetic and environmental factors are important in the etiology of substance use. However, little is known about the stability of these factors across development. We aimed to answer three crucial questions about this etiology that have never been addressed in a single study: (1) Is there a general vulnerability to substance consumption from early adolescence to young adulthood? (2) If so, do the genetic and environmental influences on this vulnerability change across development? (3) Do these developmental processes differ in males and females?MethodSubjects included 1480 twin pairs from the Swedish Twin Study of Child and Adolescent Development who have been followed since 1994. Prospective, self-reported regular smoking, alcohol intoxication and illicit drug use were assessed at ages 13–14, 16–17 and 19–20 years. Structural modeling was performed with the program Mx.ResultsAn underlying common factor accounted for the association between smoking, alcohol and illicit drug consumption for the three age groups. Common genetic and shared environmental effects showed substantial continuity. In general, as participants aged, the influence of the shared environment decreased, and genetic effects became more substance specific in their effect.ConclusionsThe current report answers three important questions in the etiology of substance use. The genetic and environmental risk for substance consumption is partly mediated through a common factor and is partly substance specific. Developmentally, evidence was strongest for stability of common genetic effects, with less evidence for genetic innovation. These processes seem to be the same in males and females.
The Legend of ʿAbdallāh ibn Sabaʾ and the Date ofUmm al-Kitāb
Authors: ANTHONY SEAN W. 
Published: January 2011

AbstractʿAbdallāh ibn Sabaʾ is a figure generally regarded as Islam's first heretic by Sunnī scholars and also vilified by Shīʿī scholars. In this article an anonymous, esoteric work known as Umm al-Kitāb is examined as it contains an exceptional narrative that adopts a strikingly sympathetic approach to Ibn Sabaʾ. It is also argued that the work's unique take on the Ibn Sabaʾ legend sheds considerable light on the date and elusive provenance of this early Shīʿī text.
Illustrations of Human Effigies in Tibetan Ritual Texts: With Remarks on Specific Anatomical Figures and Their Possible Iconographic Source
Authors: CUEVAS BRYAN J. 
Published: January 2011

AbstractThe ritual use of objects and images designed to serve as effigies or surrogates of specific persons, animals or spirits is more or less universal across cultures and time. In Tibet, recent archaeological evidence attests to the use of illustrated effigies possibly dating from the eleventh century. Other early Tibetan images include anthropomorphic figures inscribed on animal skulls. The practical use of effigies in Tibetan ritual, both Buddhist and Bon-po, was almost certainly derived from much older Indian practices transmitted to Tibet. In this article illustrated effigies, their iconography and ritual use are discussed and the article concludes with the translation and transliteration of a short work by the fifteenth-century treasure revealer (gter-ston) and patron saint of Bhutan Padma-gling-pa (1450–1521), which gives instructions on how to draw a liṅga for a ritual of defence against human adversaries.
Comparison of BMI and anthropometric measures among South Asian Indians using standard and modified criteria
Authors: Vasudevan Deepa , Stotts Angela L , Mandayam Sreedhar , Omegie L Anabor 
Published: January 2011

AbstractObjectiveTo compare the prevalence rates of obesity based on BMI/anthropometric measures, using WHO standard and ethnicity-specific criteria, the National Cholesterol Education Program–Adult Treatment Panel III (NCEP-ATPIII) and the International Diabetes Federation (IDF) definitions, among a migrant South Asian Indian population.DesignCross-sectional study conducted in October 2007.SubjectsA total of 213 participants of South Asian descent over the age of 18 years. Measures included a questionnaire with basic demographic information and self-reported histories of diabetes, coronary artery disease and/or hypercholesterolaemia. Height, weight, waist and hip circumference and blood pressure measurements were obtained.SettingHouston and surrounding suburbs.ResultsWHO-modified (WHO-mod) BMI and IDF waist circumference (WC) criteria independently identified higher numbers of overweight/obese participants; however, when the WHO-mod BMI or IDF WC criteria were applied, nearly 75 % of participants were categorized as overweight/obese – a proven risk factor for the future development of metabolic syndrome.ConclusionsObesity is likely under-diagnosed using the standard WHO and NCEP-ATPIII guidelines. Stressing the use of modified criteria more universally to classify obesity among South Asian Indians may be optimal to identify obesity and help appropriately risk stratify for intervention to prevent chronic diseases.