bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphene microwave absorber: Transparent, lightweight, flexible, and cost‐effective
Authors: Barbosa Gelza M. , Mosso Marbey M. , Vilani Cecilia , Larrudé Dunieskys R. G. , Romani Eric C. , Junior Fernando L. F. 
Published: January 2014

AbstractThis article presents the graphene as microwave absorber using polyurethane as substrate. The samples were characterized with Raman spectrometer, optical microscope, and vectorial network analyser. The results show a chemical vapor deposition‐grown graphene‐based device that can be used as microwave absorber for its unique characteristics of flexibility, transparency, light‐weight, cost‐effectiveness, and RF shielding. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:560–563, 2014
Forward‐backward method with a spectral acceleration algorithm for capacitance extraction of planar structures on a single‐layered medium
Authors: Pakasiri Chatrpol , Torrungrueng Danai 
Published: January 2014

AbstractAcceleration of the capacitance extraction of planar structures on a single‐layered medium is reported in this article, using the forward‐backward (FB) method with a spectral acceleration (SA) algorithm. The conventional spectral‐layered medium Green's function is modified appropriately so that it can be effectively incorporated into this method. The SA algorithm substantially speeds up the computational time involving in performing matrix‐vector multiplications in the iterative method of moments (MM). However, the memory requirement for the SA algorithm is comparable to that of the FB method. The computational complexity and the memory requirement are shown to be O(N) for large capacitance extraction problems, where N is the total number of unknowns in the MM for increasing one of the surface dimensions of planar structures and fixed neighborhood distance. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:694–700, 2014
The natural resonant singularity expansion method (SEM) poles for a dielectric sphere in various environments
Authors: Mei Zicong , Lee Woojin , Sarkar Tapan K. , Salazar‐Palma Magdalena 
Published: January 2014

ABSTRACTWhen one computes the natural resonant singularity expansion method (SEM) poles for a dielectric sphere composed of different materials, one is surprised to observe that these SEM poles do change too much with corresponding changes in the value of the permittivity and permeability. This article provides an analytical solution as to why it is so. The Mie's series is applied to solve for the resonant frequencies of a dielectric sphere composed of different materials and embedded in various dielectric materials. The variations in the resonant frequencies related to the poles are tabulated along with the material parameters to illustrate the nature of the variation. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:690–694, 2014
A compact dual‐band bandpass filter with high design flexibility using fully isolated coupling paths
Authors: Li Y. , Wang C. , Kim N.Y. 
Published: January 2014

AbstractA second‐order dual‐band bandpass filter using two outer folding open‐loop resonators and two embedded anchor‐shaped stepped impedance resonators is presented in this letter. The proposed scheme provides sufficient isolation between the two specific passbands, thus each passband can be individually turned. Electric couplings are adopted among the four resonators. By adjusting the spacing of resonators, the electric coupling of two different coupling feeding paths can be independently controlled, which allows flexible control of each bandwidth. The embedded structure which is introduced can further miniaturize the dimensions of the overall structure. In addition, the proposed filter has three transmission zeros at each passband, which exhibit high skirt selectivity. Good agreement between the simulated and measured results validates the correctness of the proposed design approach and shows that the two central frequencies of the fabricated filter are located at 2.5 and 5.1 GHz as desired, with 3 dB fractional bandwidths of 13.8 and 13.6%, respectively. The measured return losses are greater than 18.5 dB, while insertion losses are less than 0.9 dB in each of the two passbands. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:642–646, 2014
Cancer comortality patterns in schizophrenia and psychotic disorders: a new methodological approach for unique databases
Authors: Ajdacic‐Gross Vladeta , Tschopp Alois , Bopp Matthias , Gutzwiller Felix , Rössler Wulf 
Published: January 2014

AbstractThe aim of this study was to determine the pattern of cancer comortality in deaths registered with schizophrenia and psychotic disorders. It focused on the question of whether the proportions of different types of cancer diverge when they are co‐registered with schizophrenia/psychotic disorders or with other causes of death in mortality statistics. We developed an analysis approach applicable to common mortality statistics data when no linkage with morbidity databases or other registers is possible. The analysis covered Swiss mortality data from a 39‐year period (1969 − 2007) and was confined to the most frequent cancers. We applied a two‐step case‐control analysis with bootstrapping (1000 repetitions). The cases were defined by the cancer‐schizophrenia registrations for each specific cancer, whereas the controls were matched from the remaining cases (matching criteria: sex, age, region, subperiod). Cancers with deviant standardized mortality ratios (SMRs) included stomach cancer (1.6; 2.2 after reweighting), lung cancer (0.8; 0.5 after reweighting) and breast cancer (1.6; 1.5 after reweighting). The comortality pattern of cancers in schizophrenia and psychotic disorders diverges from the pattern found in other co‐registered causes of death. The relatively low frequency of lung cancers is particularly paradoxical in view of the smoking habits of schizophrenia patients. Copyright © 2014 John Wiley & Sons, Ltd.
A projected Newton algorithm for the dual convex program of elastoplasticity
Authors: Lotfian Z. , Sivaselvan M.V. 
Published: January 2014

SUMMARYIn this paper, we study a dual optimization problem that arises when taking a mathematical programming approach to incremental state update in nonlinear problems. The mathematical programming approach stems from energy‐based descriptions of constitutive models. We describe a projected Newton algorithm to solve the dual optimization problem. This algorithm requires solution of an unconstrained optimization problem at the integration point level, rather than a constrained one as carried out by classical return‐mapping schemes. Especially, implementation of multi‐surface plasticity models is no more involved than that of single‐surface models. We explore characteristics and performance of the projected Newton algorithm through numerical examples. Insights gained from such a further exploration of mathematical programming algorithms are likely to aid in development of successive convex programming approaches to geometric nonlinear and other non‐convex problems such as non‐associated flow models. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling of flow‐induced sound in porous materials
Authors: Beck S. C. , Langer S. 
Published: January 2014

SUMMARYThe impact of flow on a structure plays a crucial part when considering structural behavior, for example, in aviation. As structural vibrations (also denominated as structural sound) propagate within a structure, sound radiation is a likely consequence. To reduce the emission of noise, the use of poroelastic material is investigated. The approach consists in applying a poroelastic layer on the surface submitted to flow, as such utilizing the damping properties of poroelastic material.To predict flow‐induced sound, a computational model has been developed to account for (1) flow‐induced sound immission into a structure; (2) sound propagation; and (3) possible resulting sound radiation. Consistent formulation of the interactions between the components—that is, flow, poroelastic material, elastic structure, and acoustic fluid—allows to apply different simulation techniques for each component and thus to exploit each method's advantages. The key aspect of this work is the formulation of the interface conditions to couple flow with poroelastic material. The proposed and implemented coupling conditions are studied. The given example shows a possible application and demonstrates the effectiveness of poroelastic material to reduce flow‐induced sound emission. Copyright © 2014 John Wiley & Sons, Ltd.
On best‐fit corotated frames for 3D continuum finite elements
Authors: Mostafa M. , Sivaselvan M.V. 
Published: January 2014

SUMMARYWe discuss a strategy to construct corotated frames for three‐dimensional continuum finite elements by minimizing deformations within the frame. We find that irrespective of the type of element and the number of nodes, using a quaternion parametrization of rotations, this minimization is naturally stated as computing the smallest eigenvalue of a 4 × 4 matrix. The simplicity of this smallest eigenvalue plays a crucial role when linearizing the kinematics. Ensuant quaternion algebra, although lengthy, results in remarkably simple formulas for projections that arise in the linearized kinematics. The exact stiffness matrix does not require computation of the second derivative of the rotation function and is also given by a simple formula. As a result, the implementation of this corotational formulation becomes particularly straightforward. Furthermore, in contrast to other results in the literature, the stiffness matrix for elements with translational DOFs is symmetric. For illustration, this corotational formulation is applied to a solid‐shell finite element, and numerical results are presented. Copyright © 2014 John Wiley & Sons, Ltd.
A decoupling two‐grid algorithm for the mixed Stokes‐Darcy model with the Beavers‐Joseph interface condition
Authors: Zuo Liyun , Hou Yanren 
Published: January 2014

AbstractIn this article, a decoupling scheme based on two‐grid finite element for the mixed Stokes‐Darcy problem with the Beavers‐Joseph interface condition is proposed and investigated. With a restriction of a physical parameter α, we derive the numerical stability and error estimates for the scheme. Numerical experiments indicate that such two‐grid based decoupling finite element schemes are feasible and efficient. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1066–1082, 2014
Maternal body composition and birth weight
Authors: Connor Clare O' , O' Higgins Amy , Segurado Ricardo , Turner Michael J. , Stuart Bernard , Kennelly Máireád M. 
Published: January 2014

What's already known about this topic?

Birth weight (BW) prediction is an important part of obstetric management.
It is a key determinant of perinatal outcome with poor outcomes resulting from delivering macrosomic neonates or growth‐restricted neonates.
Maternal obesity, assessed by BMI, has been associated with an increased risk of fetal macrosomia, neonatal adiposity and metabolic syndrome.
There is a paucity of data in the literature on maternal body composition and its relationship to BW.What does this study add?

First trimester maternal body composition was assessed accurately and objectively by bioelectrical impedance analysis and correlated to BW.
We accurately identify which maternal body composition parameters including visceral fat and waist circumference independently influence BW.
We also explore customised centiles and population based centiles at birth.
Potentially, this study may help to identify a modifiable risk factor to reduce the incidence of macrosomia and neonatal adiposity.
Efficiency loss prevention in monolithically integrated thin film solar cells by improved front contact
Authors: van Deelen Joop , Barink Marco , Klerk Lennaert , Voorthuijzen Pim , Hovestad Arjan 
Published: January 2014

AbstractFor thin film solar cells, there is a large gap between the record efficiencies and panel power output. It was found that for a “typical industrial” CIGS cell efficiency of 15.5%, the efficiency drops to 11.7% when it is operating under the circumstances of a monolithically integrated solar panel. Part of this gap is due to limited conductivity and transmittance of the front contact. By application of a metallic grid, the conductivity can be improved by over two order of magnitude at a transmittance loss of only a few percent as was shown experimentally. In addition, modeling was used to quantify the impact of such approach on the power output of monolithically integrated solar panels. This model includes optical and resistive losses, as well as related losses caused by the inhomogeneity of the operating voltage over the surface. Both power output and the different types of losses are mapped out for various cell configurations. Optimization of transparent conductive oxide resistance, cell length, finger width, and finger spacing of grids was performed and led to an efficiency improvement from 11.7% to 13.8% when the front contact is upgraded with a metallic grid consisting of 20 µm wide parallel fingers positioned perpendicular to the interconnect. Further optimization for a wide variety of cell and grid configurations show that for a technically more feasible size of 100 µm wide fingers, the calculated efficiency is still 13.5%. Finally, the power output is mapped out for a large number of configurations as to create an overview and insight in the interdependencies of cell configuration and finger dimensions. Copyright © 2014 John Wiley & Sons, Ltd.
Associations between accurate prognostic understanding and end‐of‐life care preferences and its correlates among Taiwanese terminally ill cancer patients surveyed in 2011–2012
Authors: Tang Siew Tzuh , Liu Tsang‐Wu , Chow Jyh‐Ming , Chiu Chang‐Fang , Hsieh Ruey‐Kuen , Chen Chen H. , Liu Li Ni , Feng Wei‐Lien 
Published: January 2014

AbstractObjectiveAdequate knowledge of prognosis is a prerequisite for planning appropriate end‐of‐life (EOL) care. However, questions remain about whether the association between prognostic understanding and EOL‐care intensity reflects terminally ill cancer patients' preferences for EOL care. This study investigated the associations between accurate prognostic understanding and EOL‐care preferences, and identified correlates of accurate prognostic understanding.MethodsA cross‐sectional survey of 2452 terminally ill cancer patients from 23 hospitals throughout Taiwan.ResultsNearly half the participants (49.80%) accurately understood their prognosis. These patients were significantly more likely to prefer comfort‐oriented care as their goal for EOL care, but less likely to prefer life‐prolonging treatments. Accurately understanding prognosis decreased the likelihood of preferring intensive care unit care, cardiac pulmonary resuscitation, cardiac massage, intubation, and mechanical ventilation support, but increased preference for hospice care. Participants were significantly more likely to accurately understand their prognosis if they were male, younger, better educated, with a stronger preference for physicians to disclose their prognosis to them, and receiving care at a hospital accredited as a medical center and in northwest Taiwan. The likelihood of accurate prognostic understanding was lower for patients recently (≤12 months) diagnosed with cancers with better prognosis and hematologic malignancies than for lung cancer patients.ConclusionsAccurately understanding prognosis is associated with fewer preferences for life‐sustaining treatments and is correlated with both patient and institutional characteristics. Interventions should be developed to improve accurate prognostic understanding, thus facilitating informed EOL‐care decisions that may limit the use of aggressive interventions. Copyright © 2014 John Wiley & Sons, Ltd.
Non‐Invasive Geophysical Investigation and Thermodynamic Analysis of a Palsa in Lapland, Northwest Finland
Authors: Kohout Tomas , Bućko Michał S. , Rasmus Kai , Leppäranta Matti , Matero Ilkka 
Published: January 2014

ABSTRACTNon‐invasive geophysical prospecting and a thermodynamic model were used to examine the structure, depth and lateral extent of the frozen core of a palsa near Lake Peerajärvi in northwest Finland. A simple thermodynamic model verified that the current climatic conditions in the study area allow sustainable palsa development. A ground penetrating radar (GPR) survey of the palsa under both winter and summer conditions revealed its internal structure and the size of its frozen core. GPR imaging in summer detected the upper peat/core boundary, and imaging in winter detected a deep reflector that probably represents the lower core boundary. This indicates that only a combined summer and winter GPR survey completely reveals the lateral and vertical extent of the frozen core of the palsa. The core underlies the active layer at a depth of ~ 0.6 m and extends to about 4 m depth. Its lateral extent is ~ 15 m x ~ 30 m. The presence of the frozen core could also be traced as minima in surface temperature and ground conductivity measurements. These field methods and thermodynamic models can be utilised in studies of climate impact on Arctic wetlands. Copyright © 2014 John Wiley & Sons, Ltd.
Reduction of threading dislocation by recoating GaN island surface with SiN for high‐efficiency GaN‐on‐Si‐based LED
Authors: Hikosaka Toshiki , Yoshida Hisashi , Sugiyama Naoharu , Nunoue Shinya 
Published: January 2014

AbstractWe have demonstrated low‐threading‐dislocation‐density (low‐TDD) GaN grown on Si substrate using the technique of multiple modulation of dislocation behavior that combines GaN island formation on SiN interlayer with recoating GaN island surface with SiN cap layer. TEM analysis showed the dislocation bending and/or blocking is brought about at the surface of GaN islands by recoating GaN island surface with SiN cap layer. TDD was found to be as low as 2.6×108/cm2 with FWHMs of 289 and 256 arcsec for (0002) and (10–12) X‐ray rocking curves (XRCs), respectively, which is a value comparable to that for GaN grown on a sapphire substrate. By reducing TDD, the light output power at 20 mA (12.5 A/cm2) was enhanced by a factor of 1.5 and the maximum EQE increased up to 59% for the blue LED. This result indicates that the reduction of TDD is an effective approach for obtaining the high‐efficiency GaN‐on‐Si‐based LED. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transmission electron microscopy of indium gallium nitride nanorods grown by molecular beam epitaxy
Authors: Webster Richard F. , Cherns David , Novikov Sergei V. , Foxon C. Thomas 
Published: January 2014

AbstractThis paper demonstrates the growth of InGaN nanorods and lateral growth over nanorod arrays using molecular beam epitaxy. It is shown that nitrogen rich growth conditions result in a nanorod array and that, by changing to metal rich conditions, lateral growth may be enhanced to coalesce the nanorods into a continuous overgrown film. Energy dispersive X‐ray spectroscopy has been used to demonstrate that the nanorods display a core‐shell structure with In‐rich cores and In‐poor edges. Transmission Electron Microscopy has shown that the nanorods are free of dislocations. However, when lateral growth occurs basal plane stacking faults are generated. It is shown that this stacking fault generation leads to a change in structure from hexagonal to cubic. When coalescence has occurred large angle grain boundaries are present. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InGaN doping for high carrier concentration in plasma‐assisted molecular beam epitaxy
Authors: Gherasoiu Iulian , Yu Kin Man , Reichertz Lothar A. , Walukiewicz Wladek 
Published: January 2014

AbstractMagnesium is the only known effective p‐type dopant for nitride semiconductors. Although the p‐doping is challenging for AlN and GaN, requiring the activation of the Mg acceptors, in the case of the MOCVD growth, methods for obtaining reliable and high level doping have been developed. Similarly for n‐type doping silicon has been used successfully for more than a decade. More recently germanium has been found to be as effective for n‐type doping, with the additional advantage of inducing less strain in the host lattice due its size similarity to gallium. Doping of InGaN is more challenging due the difficulty in controlling the donor background associated with material extended defects and the incorporation of impurities. Although successful p‐type doping of InGaN with Mg has been demonstrated, quantitative limits for the magnesium incorporation and its behavior have not been analyzed. In this paper we investigate both, Mg and Ge doping of InGaN. We also discuss the challenges posed by the growth and measurement of the InGaN pn‐junctions characteristics as well as we demonstrate the fabrication of large area long wavelength LEDs on silicon (111) by PA‐MBE. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface stability of n‐type GaN depending on carrier concentration and electrolytes under photoelectrochemical reactions
Authors: Koike Kayo , Nakamura Akihiro , Sugiyama Masakazu , Nakano Yoshiaki , Fujii Katsushi 
Published: January 2014

AbstractPhotoelectrochemical properties and stabilities of n‐type GaN dependent on the carrier concentration and electrolytes were investigated. Flatband potential obtained from Mott‐Schottky plot shifted to positive direction with lowering the carrier concentration. The GaN surface morphologies after the reaction with H2SO4 were changed to rough. In contrast, the surface morphologies were not much changed and were mirror like for the case of NaOH electrolytes. These results show the GaN surface absorbed materials during the photoelectrochemical reactions were changed by the electrolyte and carrier concentration. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wafer curvature, temperature inhomogeneity, plastic deformation and their impact on the properties of GaN on silicon power and opto‐electronic structures
Authors: Schulz Oliver , Dadgar Armin , Hennig Jonas , Krumm Oliver , Fritze Stephanie , Bläsing Jürgen , Witte Hartmut , Diez Annette , Krost Alois 
Published: January 2014

AbstractA high device production yield requires accurate strain engineering during the epitaxial growth by different reasons. The maximum usable wafer area for subsequent processing is reached for zero curvature at room temperature. Besides this production process fact, the homogeneity of the growth demands a constant growth regime across the whole wafer, especially for ternary or quaternary compounds. Due to the dominant mismatch of the thermal expansion, these factors are of special importance for the growth of GaN devices on Silicon wafers. This work presents a step‐by‐step analysis of the correlation between in‐situ growth monitoring results (temperature, growth rate, and curvature) and the layer properties of power‐ and opto‐electronic device structures. Several methods as XRD, PL and electrical measurements are used to prove this relationship. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)