bluuebunny/crossref_metadata_2025_split huggingface dataset:
Topology optimization of MEMS considering etching uncertainties using the level‐set method
Authors: Jang Gang‐Won , van Dijk Nico P. , van Keulen Fred 
Published: June 2012

SUMMARYBecause of the specific fabrication process of microsystems, the geometric uncertainties are relatively large compared with the size of the structures. However, the performance of microstructures is very sensitive to these uncertainties especially when slender structural members are included in the design. This paper presents a level‐set‐based topology optimization method for robust microelectromechanical systems. The presented method focuses on the effects of geometric uncertainties on the performance of microelectromechanical systems in the topology optimization. The geometric uncertainties arising from the etching process are treated as bounded‐but‐unknown uncertainties. This approach can be used to obtain designs with optimal performance for the worst‐case. The etching uncertainties can be conveniently included in topology optimization using the level‐set method. The signed distance property of the level‐set function allows easy construction of under‐etched and over‐etched structures. Therefore, models with variable etching‐induced uncertainties can be easily constructed. The effectiveness of the proposed approach is demonstrated using benchmark problems including compliance minimization and compliant‐mechanism design problems. Although the reinitialization scheme used to maintain the signed‐distance property can cause problems in the optimization process, this effect is limited using an approximate Heaviside function with a relatively large bandwidth. Copyright © 2012 John Wiley & Sons, Ltd.
Adaptive atomistic‐to‐continuum modeling of propagating defects
Authors: Moseley Philip , Oswald Jay , Belytschko Ted 
Published: June 2012

SUMMARYAn adaptive atomistic‐to‐continuum method is presented for modeling the propagation of material defects. This method extends the bridging domain method to allow the atomic domain to dynamically conform to the evolving defect regions during a simulation, without introducing spurious oscillations and without requiring mesh refinement. The atomic domain expands as defects approach the bridging domain method coupling domain by fine graining nearby finite elements into equivalent atomistic subdomains. Additional algorithms coarse grain portions of the atomic domain to the continuum scale, reducing the degrees of freedom, when the atomic displacements in a subdomain can be approximated by FEM or extended FEM elements to within a certain homogeneity tolerance. The extended FEM approximations are created by fitting the broken inter‐atomic bonds of fractured surfaces and dislocation slip planes. Because atomic degrees of freedom are maintained only where needed for each timestep, the solution retains the advantages of multiscale modeling, with a reduced computational cost compared with other multiscale methods. Copyright © 2012 John Wiley & Sons, Ltd.
A fast method for binary programming using first‐order derivatives, with application to topology optimization with buckling constraints
Authors: Browne P. A. , Budd C. , Gould N. I. M. , Kim H. A. , Scott J. A. 
Published: June 2012

SUMMARYWe present a method for finding solutions of large‐scale binary programming problems where the calculation of derivatives is very expensive. We then apply this method to a topology optimization problem of weight minimization subject to compliance and buckling constraints. We derive an analytic expression for the derivative of the stress stiffness matrix with respect to the density of an element in the finite‐element setting. Results are presented for a number of two‐dimensional test problems.Copyright © 2012 John Wiley & Sons, Ltd.
Outcomes of fetuses with small head circumference on second‐trimester ultrasonography
Authors: Deloison Benjamin , Chalouhi Gihad E. , Bernard Jean‐Pierre , Ville Yves , Salomon Laurent J. 
Published: June 2012

ABSTRACTObjectiveWe examined the outcomes of pregnancies in which the fetal head circumference (HC) was below the 5th centile at the routine second‐trimester scan.Materials and MethodsWe retrospectively analysed outcomes of 18 377 women according to HC Z scores at second‐trimester ultrasound examination between 2001 and 2008. We collected all major malformations, intrauterine deaths and other abnormal outcomes.ResultsSix hundred seventy‐four fetuses (3.7%) had an HC below the 5th centile. Twenty‐one major malformations were noted, consisting mainly of neurological abnormalities (3.1%). There were seven intra uterine fetal death (1.3%). Of all the fetuses, 26% were lost to follow‐up. Outcome and neurological development was normal in 467 cases, based on neonatal examination and/or parent or general practitioner reports. Major abnormalities were noted in respectively 26.2%, 3.0% and 1.1% of fetuses with Z scores < −2.5, ‐2.5 to −2.0, and −2 to −1.645, compared with 0.3% of fetuses with normal HC (p < 10–4).ConclusionA head circumference below the 5th centile at second‐trimester scan is associated with various abnormalities, especially neurological disorders. The outcome was worse when the HC was smaller. An HC Z score below −2.5 was strongly associated with neurological and chromosomal abnormalities. Conversely, an HC Z score below −1.645 but above −2, excluding cases with prenatally diagnosed malformations, seems to be reassuring for favorable neonatal outcome. © 2012 John Wiley & Sons, Ltd.
Doctors' understanding of antipsychotic associated hyperprolactinaemia
Authors: Walsh James , Lees Emma 
Published: June 2012

AbstractHyperprolactinaemia secondary to antipsychotic use is associated with numerous shortand long‐term side‐effects. Unfortunately, there is some concern that clinicians tend to underestimate these side‐effects and also fail to fully inform patients or monitor them adequately. In view of these concerns, we carried out a survey to assess psychiatrists' and trainees' knowledge and practice regarding hyperprolactinaemia associated with antipsychotic use.
Synthesis and photovoltaic properties of conjugated side chains polymers with different electron‐withdrawing and donating end groups
Authors: Gu Zhaojie , Deng Lijun , Luo Hao , Guo Xia , Li Haohao , Cao Zhencai , Liu Xunshan , Li Xinwei , Huang Hongyan , Tan Yingzi , Pei Yong , Tan Songting 
Published: June 2012

AbstractA series of novel low band gap polymers containing conjugated side chains with 4,7‐dithien‐5‐yl‐2,1,3‐benzodiathiazole and different electron‐withdrawing end groups of aldehyde (PT‐DTBTCHO), 2‐ethylhexyl cyanoacetate (PT‐DTBTCN), 1,3‐diethyl‐2‐thiobarbituric acid (PT‐DTBTDT), and electron‐donating end group of 2‐methylthiophene (PT‐DTBTMT) have been designed and synthesized. All polymers exhibit good solubility in common organic solvents, film‐forming ability, and thermal stability. These conjugated polymers show the broad ultraviolet‐visible absorption and the narrow optical band gaps in the range of 1.65–1.90 eV. Through changing the end group of conjugated side chains, the photophysical properties and energy levels of the polymers were tuned effectively. Bulk heterojunction solar cells based on the blend of these polymers and (6,6)‐phenyl‐C61‐butyric acid methyl ester (PC61BM) reached the best power conversion efficiency (PCE) of 2.72%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis and characterization of electrophosphorescent jacketed conjugated polymers
Authors: Zhang Wei , Jin Hao , Zhou Feng , Shen Zhihao , Zou Dechun , Fan Xinghe 
Published: June 2012

AbstractA monomer containing bent side chains with oxadiazole unit was synthesized. And it was copolymerized with polyfluorene at different ratios. The photophysical and electrochemical properties of the copolymers were characterized. The results show that the introduction of the oxidiazole‐containing side chains into the polymer reduces the lowest unoccupied molecular orbital level. And the steric hindrance of the side groups can effectively suppress the aggregation of the polymer backbones. Electroluminescent devices were fabricated with a configuration of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene (PEDOT):PSS/Sample/Ca/Al. All of the devices emit blue light. The device of the copolymer PFOXD50 shows the best performance with the maximum luminance of 1033 cd/m2 and the maximum current efficiency of 0.29 cd/A. Then a cyclometalated iridium complex monomer (ppy)2Ir(BrPhPyBr) was copolymerized with PFOXD50 at different ratios. The devices with the same configuration emit orange light. The efficiency generally increases with the increasing Ir content. Among them, the device of the copolymer PFOXDIr7 shows the best performance with the maximum luminance of 846 cd/m2 and the maximum current efficiency of 0.61 cd/A. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Combined Resistance and Aerobic Exercise is Better than Resistance Training Alone to Improve Functional Performance of Haemodialysis Patients — Results of a Randomized Controlled Trial
Authors: Orcy Rafael B , Dias Pamela S , Seus Thamires LC , Barcellos Franklin C , Bohlke Maristela 
Published: June 2012

AbstractBackground and PurposeThis study aims to compare the effects of combined resistance and aerobic exercise with a resistance programme alone on functional performance among haemodialysis patients.DesignThe design was a randomized controlled trial.SettingThe setting was the dialysis unit of a Brazilian university hospital.PatientsHaemodialysis patients were assigned to one kind of intervention or another.InterventionThe patients were assigned to receive the resistance exercise combined with an aerobic training or to maintain an ongoing resistance programme alone for a period of 10 weeks.Main outcome measureThe functional performance of patients was assessed before and after the intervention through the 6‐minute walk test (6MWT). The difference over time of the 6MWT was compared between the groups through two‐way repeated‐measures ANOVA.ResultsThirteen patients were allocated for each group of intervention. The difference in distance walked before and after intervention in the combined training group was of +39.7 ± 61.4 m, and the difference in the resistance training group was of −19.2 ± 53.9 m, p = 0.02.ConclusionsAlthough the best protocol of exercise for patients on dialysis is not yet clear, in our sample of haemodialysis patients the combination of aerobic and resistance training was more effective than resistance training alone to improve functional performance. Copyright © 2012 John Wiley & Sons, Ltd.
Comprehensive quantitative measurement of folate polyglutamates in human erythrocytes by ion pairing ultra‐performance liquid chromatography/tandem mass spectrometry
Authors: van Haandel Leon , Becker Mara L. , Williams Todd. D. , Stobaugh John F. , Leeder J. Steven 
Published: June 2012

RATIONALEThe erythrocyte folate pool is reflective of an individual's long‐term folate status; however, comprehensive quantitative determination of the various folate isoforms including polyglutamation (Glun) status has posed an analytical problem. Factors complicating such analysis are the absence of authentic (isotope‐labeled) standards and the large number of potential analytes. The present work presents high‐throughput analytical methodology for the indirect comprehensive quantitation of the erythrocyte folate pool with commercially available standards.METHODSThe erythrocyte folate pool was determined comprehensively by utilizing a cascade of three complementary ultra‐performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) assays. In a first assay utilizing ion‐pairing UPLC/MS/MS the relative (%) polyglutamation distribution (Glu3‐10) of 5‐methyltetrahydrofolate, tetrahydrofolate and 5‐formyltetrahydrofolate is determined in a thermal extract obtained from packed erythrocytes, not requiring analytical standards. Quantitation of the erythrocyte folate pool was accomplished by performing two additional stable isotope dilution UPLC/MS/MS assays to determine whole blood and plasma folate content, utilizing commercially available [13C5]‐labeled analogs of the Glu1 analytes. Based on the values provided by each individual assay the comprehensive erythrocyte folate content could be calculated.RESULTSThe various assays have been validated for intra‐ and inter‐run precision, accuracy, linearity and are robust. The method was sensitive enough to measure the comprehensive erythrocyte folate distribution in a Down's syndrome patient with extremely low folate, bearing the C677T mutation in the gene encoding for methylenetetrahydrofolate reductase.CONCLUSIONSThe erythrocyte folate pool can be comprehensively quantitated by running three complementary UPLC/MS/MS assays. The present assays are robust and allow for high‐throughput analysis. The method can be utilized to support larger investigations that investigate the relationship between folate isoform and polyglutamation distribution and disease pathogenesis. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of Anionic Spin Crossover Complexes with Schiff Base like Ligands
Authors: Schlamp Stephan , Schulten Johanna , Betz Richard , Bauch Tobias , Mudring Anja Verena , Weber Birgit 
Published: June 2012

AbstractThe reaction of neutral iron(II) complexes of tetradentate Schiff base like ligands with the pseudohalogenides SCN–, OCN–, and CN– as monodentate axial ligands was investigated. In solution the formation of octahedral complexes could be confirmed and it was possible to follow a spin transition by T‐dependent 1H NMR spectroscopy. In the solid only pentacoordinate complexes were obtained and the X‐ray structure of five monoanionic pentacoordinate iron(II) complexes and an interesting trinuclear complex are discussed.
Evolution of a stratified rotating shear layer with horizontal shear. Part I. Linear stability
Authors: Arobone Eric , Sarkar Sutanu 
Published: June 2012

AbstractLinear stability analysis is used to investigate instability mechanisms for a horizontally oriented hyperbolic tangent mixing layer with uniform stable stratification and coordinate system rotation about the vertical axis. The important parameters governing inviscid dynamics are maximum shear $S$, buoyancy frequency $N$, angular velocity of rotation $\Omega $ and characteristic shear thickness $L$. Growth rates associated with the most unstable modes are explored as a function of stratification strength $N/ S$ and rotation strength $2\Omega / S$. In the case of strong stratification, growth rates exhibit self-similarity of the form $\sigma ({k}_{1} L, S{k}_{3} L/ N, 2\Omega / S)$. In the case of rapid rotation we also observe self-similar scaling of growth rates with respect to the vertical wavenumber and rotation rate. The unstratified cases show $\sigma ({k}_{1} L, 2\vert \tilde {\Omega } \vert {k}_{3} L/ S)$ dependence while the strongly stratified cases show $\sigma ({k}_{1} L, 2\vert \tilde {\Omega } \vert {k}_{3} L/ N)$ dependence where $\tilde {\Omega } $ represents the difference between the angular velocity of rotation and least stable anticyclonic angular velocity, $\Omega = S/ 4$. Stratification was found to stabilize the inertial instability for weak anticyclonic rotation rates. Near the zero absolute vorticity state, stratification and rotation couple in a destabilizing manner increasing the range of unstable vertical wavenumbers associated with barotropic instability. In the case of rapid rotation, stratification prevents the stabilization of low ${k}_{1} $, high ${k}_{3} $ modes that occurs in a homogeneous fluid. The structure of certain unstable eigenmodes and the coupling between horizontal vorticity and density fluctuations are explored to explain how buoyancy stabilizes or destabilizes inertial and barotropic modes.
Unstable Richtmyer–Meshkov growth of solid and liquid metals in vacuum
Authors: Buttler W. T. , Oró D. M. , Preston D. L. , Mikaelian K. O. , Cherne F. J. , Hixson R. S. , Mariam F. G. , Morris C. , Stone J. B. , Terrones G. , Tupa D. 
Published: June 2012

AbstractWe present experimental results supporting physics-based ejecta model development, where our main assumption is that ejecta form as a special limiting case of a Richtmyer–Meshkov (RM) instability at a metal–vacuum interface. From this assumption, we test established theory of unstable spike and bubble growth rates, rates that link to the wavelength and amplitudes of surface perturbations. We evaluate the rate theory through novel application of modern laser Doppler velocimetry (LDV) techniques, where we coincidentally measure bubble and spike velocities from explosively shocked solid and liquid metals with a single LDV probe. We also explore the relationship of ejecta formation from a solid material to the plastic flow stress it experiences at high-strain rates ($1{0}^{7} ~{\mathrm{s} }^{\ensuremath{-} 1} $) and high strains (700 %) as the fundamental link to the onset of ejecta formation. Our experimental observations allow us to approximate the strength of Cu at high strains and strain rates, revealing a unique diagnostic method for use at these extreme conditions.
Analytically approximate natural sloshing modes for a spherical tank shape
Authors: Faltinsen Odd M. , Timokha Alexander N. 
Published: June 2012

AbstractThe multimodal method requires analytical (exact or approximate) natural sloshing modes that exactly satisfy the Laplace equation and boundary condition on the wetted tank surface. When dealing with the nonlinear sloshing problem, the modes should also allow for an analytical continuation throughout the mean free surface. Appropriate analytically approximate modes were constructed by Faltinsen & Timokha (J. Fluid Mech., vol. 695, 2012, pp. 467–477) for the two-dimensional circular tank. The present paper extends this result to the three-dimensional, spherical tank shape and, based on that, establishes specific properties of the linear liquid sloshing.
Dietary surveys indicate vitamin intakes below recommendations are common in representative Western countries
Authors: Troesch Barbara , Hoeft Birgit , McBurney Michael , Eggersdorfer Manfred , Weber Peter 
Published: June 2012

Vitamins play a crucial role in health, but modern lifestyles may lead to suboptimal intakes even in affluent countries. The aim of the present study is to review vitamin intakes in Germany, the UK, The Netherlands and the USA and to compare them with respective national recommendations. Data on adults from the most recently published national dietary intake surveys for the first three countries and data for adults from the US National Health and Nutrition Examination Survey from 2003 to 2008 for the USA were used as a basis for the analysis. The proportions of the populations with intakes below recommendations were categorised as < 5, 5–25, >25–50, >50–75 and >75 % for each vitamin. The data generated are presented in a ‘traffic light display’, using colours from green to red to indicate degrees of sufficiency. The trends found were compared with the results from the European Nutrition and Health Report 2009, even though in that report, only information on mean intakes in the different countries was available. We showed that, although inter-country differences exist, intakes of several vitamins are below recommendations in a significant part of the population in all these countries. The most critical vitamin appears to be vitamin D and the least critical niacin. The variation between the countries is most probably due to differences in recommendations, levels of fortification and local dietary habits. We show that a gap exists between vitamin intakes and requirements for a significant proportion of the population, even though diverse foods are available. Ways to correct this gap need to be investigated.
The oldest Zoophycos and implications for Early Cambrian deposit feeding
Authors: SAPPENFIELD AARON , DROSER MARY , KENNEDY MARTIN , MCKENZIE RYAN 
Published: June 2012

AbstractZoophycos-group burrows are prevalent elements of the post-Cambrian trace fossil record. Here we report the oldest specimens of Zoophycos from Lower Cambrian strata of the Lower Member Wood Canyon Formation in southeastern California. In addition to these being the oldest examples of this well-known trace fossil, the discovery of these specimens also reveals the presence of deposit feeding considerably earlier than has been suggested for the advent of this feeding style. This type of activity may have had a significant impact on sediment mixing during the Precambrian–Cambrian transition, though the rarity and shallow tier position of these specimens suggests otherwise.
The Prevalence of the Disposition Effect in Mutual Funds’ Trades
Authors: Cici Gjergji 
Published: June 2012

AbstractU.S. equity mutual funds, on average, prefer realization of capital losses to capital gains. Nevertheless, a substantial fraction exhibits the disposition effect of realizing gains more readily than losses. My analysis suggests that learning effects have reduced the manifestation of the disposition effect over time, implying that academic research has influenced industry practices. When funds experience outflows and are managed by teams of portfolio managers, they are more susceptible to selling disproportionately more winners than losers. Disposition-driven behavior affects investment style, causing lower market betas and characteristics of value-oriented and contrarian styles, but has no observable effect on fund performance.
Sell-Side Information Production in Financial Markets
Authors: Chen Zhaohui , Wilhelm William J. 
Published: June 2012

AbstractWe study decisions to sell nonexcludable private information in the presence of a trading opportunity. Sell-side agents heighten competition among agents who buy their signals to combine with their own for proprietary trading purposes and thereby promote financial market efficiency. This result holds even when the sell-side production technology is not unique. But sell-side information is subject to underinvestment if producers do not internalize the benefits. The model suggests that fee-based compensation for corporate advisory services diminishes this problem and that market efficiency is undermined by forces steering investment-banking resources toward proprietary trading.
Molecular characterization of livestock and human isolates of Echinococcus granulosus from south-west Iran
Authors: Khademvatan S. , Yousefi E. , Rafiei A. , Rahdar M. , Saki J. 
Published: June 2012

AbstractHydatidosis is an important public health problem in several parts of Iran. The aim of this molecular study is to investigate Echinococcus granulosus genotypes as the causative agents of hydatidosis in the south-west of Iran (Khuzestan province). In this study, isolates of 334 hydatid cysts were collected from the liver and lungs of 141 sheep, 104 cattle, 84 goats and 5 human cases. DNA was extracted and examined by nested polymerase chain reaction (PCR) of ribosomal DNA (rDNA) internal transcribed spacer 1 (ITS1) and restriction fragment length polymorphism (RFLP)-PCR. In addition, fragments of genes coding for ITS1 were sequenced. The results of RFLP-PCR analysis revealed the presence of the G1 genotype in all human, cattle, goat and sheep isolates. Furthermore, no camel strain (G6) was detected among all samples in the regions studied. The molecular findings indicate that the predominant genotype involved in E. granulosus transmission in south-west Iran is the common sheep strain (G1 genotype), which occurs in human, cattle, sheep and goat populations. In conclusion, these results may have important implications for hydatid disease control in the areas studied.