bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave frequency selective surface with controllable high Q‐factor transmission resonance
Authors: Dmitriev Victor , Kawakatsu Marcelo N. 
Published: September 2012

AbstractA thin layer with a high quality factor trapped‐mode resonance and control of its resonance frequency is investigated.The structure consists of array of two metal concentric rings in a unit cell supported by a ferrite substrate. We consider magnetization normal to the array plane and two orthogonal in‐plane directions. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2762–2766, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27194
Design of graded index flat lenses with integrated antireflective properties
Authors: Good Brandon , Ransom Paul , Simmons Shaun , Good Austin , Mirotznik Mark S. 
Published: September 2012

AbstractWe describe a new methodology for designing graded index lenses at microwave wavelengths with integrated antireflective properties. The method leads to a flat lens with minimal reflection losses at a frequency of interest. Both numerical and experimental results for two different design goals are shown to demonstrate the capabilities of the methodology. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2774–2781, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27198
Generation of quaternary‐amplitude microwave signals by using a new optical heterodyne technique
Authors: Villena A. T. P. , Arismar Cerqueira S. , Abbade Marcelo L.F. , Hernandez‐Figueroa H. E. , Fragnito Hugo L. 
Published: September 2012

AbstractWe propose and experimentally investigate a new technique, based on optical heterodyne generation, which converts two optical binary amplitude‐shift keyed (2‐ASK) into a single microwave quaternary ASK (4‐ASK) one. Results show that 4‐ASK signals are properly generated even when the 2‐ASK signals are propagated through 40 km optical links from a geographically distributed optical network under real conditions of temperature, pressure, humidity, and wind. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2738–2743, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27199
Textile patch antennas using double layer fabrics for wrist‐wearable applications
Authors: Ha Sang‐jun , Jung Young‐Bae , Kim Dong ho , Jung Chang Won 
Published: September 2012

AbstractThis article introduces a performance investigation of textile patch antennas using double layer fabrics for wrist‐wearable applications. Two fabric substrates [top layer: conducting part (CP), bottom layer: fabric part (FP)] are used for an antenna design, and these are assembled using an adhesive. We chose polyester (PES) as the top fabric layer (CP) because the PES is a cloth of fine texture, which is useful for the steady screen printing of the antenna geometry. Four fabric samples (Fabric 1–4) were selected from actual clothes (i.e., pants and shirts), and these were used for the bottom fabric layer (FP). The textile antennas were simulated and measured to verify their performance and to compare this with that of the common microwave substrate. Moreover, a textile antenna was tested under various bent conditions as well as regarding its specific absorption rate for on‐body environments, such as the wrist and ankle. Based on the measurement results, it was confirmed that the textile antennas with double layer fabrics have good electrical performance, even in bent conditions, and can be used in wearable‐fabric applications, including body centric communications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2697–2702, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27200
A differential BiCMOS divide‐by‐4 injection‐locked frequency divider
Authors: Chang Chia‐Wei , Jang Sheng‐Lyang 
Published: September 2012

AbstractA low power wide locking range divide‐by‐4 injection‐locked frequency divider (ILFD) is proposed in the letter and was implemented in the TSMC 0.18 μm SiGe BiCMOS process. The divide‐by‐4 ILFD uses a cross‐coupled voltage‐controlled oscillator with an active inductor and a three‐transistor composite consisted of two nMOSFETs and one pMOSFET to serve as an injection device with the function of linear and nonlinear mixers. At the supply voltage of 1.5 V and at the incident power of 0 dBm, the operation range of the divide‐by‐4 is 2.3 GHz, from the incident frequency 14.5 to 16.8 GHz, the percentage is 14.7%. The locking range of the divide‐by‐4 is 1.7 GHz, from the incident frequency from 14.6 to 16.3 GHz, the percentage is 11%. The core power consumption is 1.5 mW. The die area is 0.465 × 0.317 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2825–2828, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27204
A switch controlled dual‐band band pass ΔΣ modulator
Authors: Park Bonghyuk , Jang Seunghyun , Jung Jaeho 
Published: September 2012

AbstractA switch controlled fourth‐order dual‐band bandpass delta‐sigma modulator (BPDSM) is proposed. It consists of two stage second‐order resonator, high‐speed comparator, multifeedback current digital‐to‐analog converter, and clock distributer. The band selection is controlled by capacitor bank, and fine frequency tuning is done by varactor. The implemented BPDSM shows a peak signal‐to‐noise‐ratio is 41.6 dB, 42.5 dB, an error vector magnitude is 3.06%, 2.4% in 882 MHz, 955 MHz, respectively, and a differential output voltage swing is 1.32Vp‐p with dc power consumption of 389 mW. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2784–2787, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27207
1‐6 GHz 4 W MMIC GaAs high power amplifier
Authors: Pingue Massimiliano , Orobello Barbara , Diciomma Rossella , Pisa Stefano 
Published: September 2012

AbstractThis article presents the design of a monolithic high power amplifier with 4 W output power in the 1–6 GHz band (2.5 octave).The amplifier uses two gain stages composed by four and eight transistors. Power united monolithic semiconductor PPH25x process, on GaAs substrate with 70 μm thickness, has been used. The Montecarlo analysis shows a small‐signal gain's average value of 24 dB and output power levels higher than 36 dBm. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2747–2751, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27208
Compact and high selectivity dual‐mode dual‐band microstrip BPF with QWR and SLR
Authors: Deng Hong‐wei , Zhao Yong‐jiu , Fu Yong , Zhou Xiao‐jun , Liu Yan‐yun 
Published: September 2012

AbstractIn this letter, a novel compact and high selectivity dual‐mode dual‐band microstrip bandpass filter (BPF) with quarter‐wavelength resonator and stub‐loaded resonator is proposed using extended feed lines.Either of the SIRs cannot only separately generate one passband but also mainly control the passband performance. Due to the extended feed lines, parasitic coupling and intrinsic characteristics of the resonators, multiple transmission zeros can be created to improve the selectivity. Meanwhile, the BPF can obtain compact size due to the folded resonators and feed lines. A dual‐mode dual‐band BPF with the fractional bandwidth 15.6 and 6.4% is designed and fabricated. The simulated and measured results show a better agreement and validate the proposed theory. The size is only 0.185λg × 0.130λg in which λgis the guided wavelength at the first passband center frequency. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 2702:2705, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27211
Frequency of Complete Cleft Sacra in a Native American Sample
Authors: Mulhern D. M. , Wilczak C. A. 
Published: September 2012

AbstractThe purpose of this paper is to contribute to the current understanding of the variability of complete sacral clefts in human populations by presenting new data on a large prehistoric and historic Native American skeletal sample (n = 1943). Results are examined by age, sex, time period, and regional distribution and compared with reported frequencies of complete sacral clefts in other modern, historic, and ancient populations.In all, 1.6% of the sample exhibited complete sacral clefts, including 2.1% of males and 1.1% of females. Although males exhibit a frequency twice as high as females, this difference is not statistically significant. However, within the Alaskan sample, the sex difference was significant (p = 0.002), with 3.4% of males and 0.5% of females exhibiting complete clefts; these differences may be related to mechanical influences during growth and development in males. Differences among age groups are not significant. Regional comparisons among Alaska, Eastern Woodlands, Great Basin/Northwest/California, Great Plains, and Southwest showed no significant differences overall, but Alaska (2.2%) and Great Plains (0.5%) do show a significant difference (p = 0.024). No significant differences were found between prehistoric, protohistoric, and historic/recent samples, suggesting a lack of a secular trend in frequency of complete sacral clefts in Native American populations. One individual exhibited an enlarged canal, which may be indicative of a more severe condition. Copyright © 2012 John Wiley & Sons, Ltd.
New advances in polysilicon processes correlating feedstock properties and good crystal and wafer performances
Authors: Ceccaroli Bruno , Lohne Otto , Øvrelid Eivind J. 
Published: September 2012

AbstractMetallurgical purification routes to solar grade silicon have gained a respectable success for the manufacture of standard multicrystalline solar cells. However, gas phase chemically refined silicon (commonly designated as polysilicon) remains unchallenged for semiconductor applications and for the manufacture of monocrystalline solar cells, particularly the most popular high efficiency cell architectures. Therefore, in the medium term future virgin polysilicon should keep a predominant share of the silicon feedstock to electronic and photovoltaic wafers. For photovoltaic to meet the grid parity cost target, significant efforts have been deployed during the past years aiming at drastically reducing the cost of polysilicon. This has been achieved not only through massive capacity expansions but also through simplifying the process as well as developing new gas/solid purification and deposition processes. The replacement of the historical Siemens by the Fluidized Bed Reactor is the most accomplished example of such attempts. Worth noting is also the replacement of chlorine by other halogens in the volatile silicon bearing compound or hydrogen by metal in the deposition/reduction process. However, such cost efficient progress might have been on the expense of the ultimately desirable purity. This contribution will review the most accomplished and promising attempts to develop the polysilicon process. The potential and the limitations of the emerging polysilicon products will be illustrated with respect to their ability to produce high quality wafers for semiconductor or high efficiency solar cells (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of thermal annealing on the properties of PECVD hydrogenated silicon nitride
Authors: Bousbih Rabaa , Dimassi Wissem , Haddadi Ikbel , Ezzaouia Hatem 
Published: September 2012

AbstractSilicon nitride (SiNx) thin films were grown on silicon by plasma‐enhanced chemical vapor deposition (PECVD) method at low temperature by varying the silane (SiH4) to nitrogen (N2) ratio in the plasma. As‐deposited samples were investigated by varying annealing temperature from 400 °C to 950 °C in infrared (IR) heated belt furnace, in order to study their properties and correlate them to the chemical composition of the layers to find the optimized condition for application in silicon solar cells (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An orbital localization criterion based on the topological analysis of the electron localization function
Authors: Oña Ofelia B. , Alcoba Diego R. , Tiznado William , Torre Alicia , Lain Luis 
Published: September 2012

AbstractThis work proposes a new molecular orbital localization procedure. The approach is based on the decomposition of the overlap matrix in accordance with the partitioning of the three‐dimensional physical space into basins with clear chemical meaning arising from the topological analysis of the electron localization function. The procedure is computationally inexpensive, provides a straightforward interpretation of the resulting orbitals in terms of their localization indices and basin occupancies, and preserves the σ/π‐separability in planar N‐electron systems. The localization algorithm is tested on selected molecular systems. © 2012 Wiley Periodicals, Inc.
Quantum chemistry studies of adenosine 2503 methylation by S‐adenosylmethionine‐dependent enzymes
Authors: Wang Chunling , Yang Xiaoke , Wang Endong , Li Baiqing 
Published: September 2012

AbstractRibosome methylation is important for life processes and is mainly catalyzed by radical S‐Adenosylmethionine (SAM) enzymes. Two SAM molecules serve as the cofactor by providing the 5 ′‐deoxyadenosyl radical for substrate activation and the methyl. Recently, Booker and coworkers (Science 2011, 332, 604) proposed an alternative mechanism for a pair of radical SAM enzymes, RlmN and Cfr, which respectively methylate the C2 and C8 of adenosine 2503. Their deuterium labeling experiments reveal that methyl group does not transfer directly from SAM to adenosine, instead it passes to Cys355 first, then onto adenosine. In this article, this new reaction mechanism is studied using density functional theory with B3LYP hybrid functional. The reaction system is simulated using small model compounds in the gas phase, and the protein environment is approximated using polarizable continuum model. The structures of the transition states and the intermediates are identified, and their free energies are calculated. The activation barriers indicate that the proposed reaction mechanism is plausible. The formation of a disulfide bond is found to be the rate‐limiting step. © 2012 Wiley Periodicals, Inc.
Analysis of the differentially expressed low molecular weight peptides in human serum via an N‐terminal isotope labeling technique combining nano‐liquid chromatography/matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Leng Jiapeng , Zhu Dong , Wu Duojiao , Zhu Tongyu , Zhao Ningwei , Guo Yinlong 
Published: September 2012

RATIONALEPeptidomics analysis of human serum is challenging due to the low abundance of serum peptides and interference from the complex matrix. This study analyzed the differentially expressed (DE) low molecular weight peptides in human serum integrating a DMPITC‐based N‐terminal isotope labeling technique with nano‐liquid chromatography and matrix‐assisted laser desorption/ionization mass spectrometry (nano‐LC/MALDI‐MS).METHODSThe workflow introduced a [d6]‐4,6‐dimethoxypyrimidine‐2‐isothiocyanate (DMPITC)‐labeled mixture of aliquots from test samples as the internal standard. The spiked [d0]‐DMPITC‐labeled samples were separated by nano‐LC then spotted on the MALDI target. Both quantitative and qualitative studies for serum peptides were achieved based on the isotope‐labeled peaks.RESULTSThe DMPITC labeling technique combined with nano‐LC/MALDI‐MS not only minimized the errors in peptide quantitation, but also allowed convenient recognition of the labeled peptides due to the 6 Da mass difference. The data showed that the entire research procedure as well as the subsequent data analysis method were effective, reproducible, and sensitive for the analysis of DE serum peptides.CONCLUSIONSThis study successfully established a research model for DE serum peptides using DMPITC‐based N‐terminal isotope labeling and nano‐LC/MALDI‐MS. Application of the DMPITC‐based N‐terminal labeling technique is expected to provide a promising tool for the investigation of peptides in vivo, especially for the analysis of DE peptides under different biological conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Tandem mass spectrometric analysis and density functional theory calculations on the fragmentation behavior of two tetradecanoylingenol regioisomers from Euphorbia wallichii
Authors: Xia Bing , Xu Kaijie , Liu Xin , Chai Yunfeng , Sun Cuirong , Gu Yucheng , Ding Lisheng , Zhou Yan 
Published: September 2012

RATIONALETwo structurally similar bioactive regioisomers, 3‐O‐tetradecanoylingenol and 20‐O‐tetradecanoylingenol, from Euphorbia wallichii presented quite different fragmentation behaviors. Revealing the related fragmentation pathways may improve the efficiency of characterization and identification of such type of compounds.METHODSThe two regioisomers were subjected to collision‐induced dissociation (CID) on Finnigan LCQDECA and LTQ Orbitrap XL instruments. Based on the CID results, the possible fragmentation pathways were proposed and investigated with density functional theory (DFT) calculations.RESULTSElimination of C14H28O2 (tetradecanoic acid) for 3‐O‐tetradecanoylingenol and the sequential losses of C4H8 (butylene) for 20‐O‐tetradecanoylingenol were observed in ESI‐MS/MS, witnessed also by HR‐ESI‐MS/MS. The fragmentation pathways were proposed and verified by calculating the activation energy of their transition states by DFT calculations.CONCLUSIONSBased on the observations, fragmentation pathways for the two regioisomers were proposed and verified by calculating the energy of the reactants, products and the corresponding transition states using DFT. This report should have value in rapid identification of the derivatives of ingenol and other regioisomers in natural products. Copyright © 2012 John Wiley & Sons, Ltd.
Approximate controllability of stochastic nonlinear third‐order dispersion equation
Authors: Muthukumar P. , Rajivganthi C. 
Published: September 2012

SUMMARYIn this work, we consider a class of control systems governed by the stochastic nonlinear third‐order dispersion equation in Hilbert spaces. We first prove the existence of mild solutions of stochastic nonlinear third‐order dispersion equation by using fixed point theory, infinite dimensional semigroup properties, stochastic analysis techniques, and then a new set of sufficient conditions are formulated which guarantees the approximate controllability of the main problem. Finally, an example is provided to illustrate the application of the obtained results.Copyright © 2012 John Wiley & Sons, Ltd.
SPAWNING OF THE ENDANGERED AUSTRALIAN LUNGFISH (NEOCERATODUS FORSTERI) IN A HEAVILY REGULATED RIVER: A PULSE FOR LIFE
Authors: Espinoza T. , Marshall S. M. , McDougall A. J. 
Published: September 2012

ABSTRACTThe Australian lungfish is an endangered native species currently protected under various state, federal and international agreements. Scarce information on their early life history is available due to the absence of juveniles collected in the wild. This has led to concerns about the sustainability of the species and become a driver for the conservation effort for Australian lungfish. This study aimed to consolidate knowledge on the critical hydraulic habitat requirements of this species within a water resource management context. In this study, spawning of Australian lungfish was found to be a seasonal strategy that is highly reliant on a variable low‐flow regime within riverine habitat. Suitable conditions for spawning were characterized by small flow events in early‐to‐mid spring when water temperatures are between 18 and 28 °C, leading to oviposition on short dense macrophytes in shallow water. Importantly, many of the key environmental factors driving the ecological response are manageable through existing water resource infrastructure. Specifically, releases from water storages within the current distribution of Australian lungfish should mimic the natural inflow and temperature regime within the spawning period, and also provide suitable riverine habitat within projected full supply limits. Copyright © 2012 John Wiley & Sons, Ltd.
Type 2 diabetes in men: facing the challenges
Authors: Karet Brian 
Published: September 2012

AbstractThe challenges posed by men with type 2 diabetes differ from those of women with the condition. Men are more prone to being overweight, leading to a higher incidence of diabetes, which in turn is associated with lower testosterone levels. Brian Karet discusses the implications for commissioners of primary care diabetes services. Copyright © 2012 John Wiley & Sons
Effects of temporal heterogeneity of water supply and nutrient levels on plant biomass growth depend on the plant's relative size within its population
Authors: Hagiwara Yousuke , Kachi Naoki , Suzuki Jun‐Ichirou 
Published: September 2012

AbstractTemporal heterogeneity of water supply can alter the biomass growth of plants, even when the same total amount of water is provided. Most studies of heterogeneous watering have focused on responses of whole populations rather than individuals in a population. The effects of water supply heterogeneity may also depend on nutrient levels. Thus, we investigated the integrated effects of water supply heterogeneity and nutrient levels on plants within a population. Six plants of Perilla frutescens per pot were grown under different combinations of frequency of water supply and nutrient level. The effects on yield per pot, individual biomass, and allocation to roots were analyzed after a 44‐day watering regime. A homogeneous water supply resulted in a greater yield per pot and greater biomass of individual plants than a heterogeneous supply. However, the interaction between water supply heterogeneity and nutrient level was significant only in larger individuals, not in smaller plants or at the p. Water supply heterogeneity affected the growth of all plants, but the effects differed among individuals depending on their relative size within their population. It is therefore important to focus not only on whole‐population characteristics such as yield but also on individuals in a population in order to reveal the detailed effects of water supply heterogeneity.
Vacuum Refining of Molten Silicon
Authors: Safarian Jafar , Tangstad Merete 
Published: September 2012

AbstractMetallurgical fundamentals for vacuum refining of molten silicon and the behavior of different impurities in this process are studied. A novel mass transfer model for the removal of volatile impurities from silicon in vacuum induction refining is developed. The boundary conditions for vacuum refining system—the equilibrium partial pressures of the dissolved elements and their actual partial pressures under vacuum—are determined through thermodynamic and kinetic approaches. It is indicated that the vacuum removal kinetics of the impurities is different, and it is controlled by one, two, or all the three subsequent reaction mechanisms—mass transfer in a melt boundary layer, chemical evaporation on the melt surface, and mass transfer in the gas phase. Vacuum refining experimental results of this study and literature data are used to study the model validation. The model provides reliable results and shows correlation with the experimental data for many volatile elements. Kinetics of phosphorus removal, which is an important impurity in the production of solar grade silicon, is properly predicted by the model, and it is observed that phosphorus elimination from silicon is significantly increased with increasing process temperature.