bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spreading and Dewetting of Single Bottle‐Brush Macromolecules on Nanofacetted SrTiO3 Substrate as Induced by Different Vapours
Authors: Gallyamov Marat O. , Tartsch Bernd , Börner Hans G. , Matyjaszewski Krzysztof , Khokhlov Alexei R. , Möller Martin 
Published: January 2013

AbstractResponsive bottle‐brush macromolecules undergo vapour‐induced spreading and dewetting cycles on facetted SrTiO3 surfaces with a saw‐toothed topography. The macromolecular transformations are followed by environmental scanning force microscopy in real time. A set of the wafers with different groove periods are tested as the substrates for the transforming macromolecules. In order to estimate the orienting influence of the anisotropic patterned substrate, an asymmetry factor is measured for the dewetting macromolecules at different groove periods. The most evident template influence of the substrate occurs when the period is in range of 20–40 nm. This range is commensurable with the typical lateral dimension of the adsorbed bottle‐brush macromolecules with a dense flat corona of extended side chains.magnified image
Tripod omnidirectional low profile antenna: A vertically polarized antenna with 90% bandwidth
Authors: Zürcher J.‐F. 
Published: January 2013

AbstractA new vertically polarized omnidirectional antenna, inspired by an old design, has been studied, optimized, realized, and measured. With a radiation pattern similar to the classical monopole on a ground plane, the proposed antenna concept provides a much larger bandwidth and a very low profile. This antenna has numerous potential applications for mobile communications, UWB, and others. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:516–521, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27340
Broadband phase shifters using complementary frequency‐dependent Δphase of low‐/high‐pass filters
Authors: Chung Younkyu , Deckman Blythe C. , DeLisio Michael P. 
Published: January 2013

AbstractThis letter presents a simple and compact design approach for broadband analog phase shifters and its demonstration. An octave bandwidth can be obtained by alternately cascading low‐pass filters (LPF) and high‐pass filters (HPF) that importantly provide complementary phase‐changing characteristics over “frequencies.” Achievable phase change per segment can be multiplied by cascading multiple segments that operate as independent phase shifters, thereby reaching 360 degrees of phase shift. We demonstrate one‐ and two‐segment phase shifters consisting of cascaded LPF‐HPF‐LPF structures, of which capacitors in each filter are implemented by varactors, over a frequency range from 0.7 GHz to 1.4 GHz. Measurements show 65.8 degree average phase shifts from the single‐segment and 128 degree from the double‐segment, which is about twice as much as the single‐segment shifter's. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:664–666, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27345
UWB printed plaque monopole antennas for tri‐band rejection
Authors: Mandal Tapan , Das Santanu 
Published: January 2013

AbstractIn this article, a printed plaque monopole antenna fed by a microstrip line for ultrawideband (UWB) width with triple notch band has been presented.The antenna is then modified to possess band rejection at the wireless local area network (5.1–5.8 GHz) by an inverted U‐shape slot or Π‐shape slot, or Λ–shape slot within the radiating patch. In addition, two half wavelength slots (U‐slot) are cut in the radiating patch to generate the first and third notch band in 3.25–3.75 GHz for WiMAX and 7.25–7.75 GHz for down link of X‐band satellite communication system. Surface current distributions and transmission line model are used to analyze the effect of these slots. The proposed antennas are simulated and fabricated. Radiation pattern shows good omnidirectional radiation patterns in the H‐plane and monopole like patterns in the E‐plane. The proposed antenna gain varies from 1.63 to 5.05 dB over the whole UWB region excluding at notch band. The design antenna has a compact size of 30 × 30 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:674–680, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27359
Dispersion characteristics of 1D PBG structures composed of subwavelength dipole elements
Authors: Khodami Maryam , Shaker Jafar , Yagoub Mustapha C. E. 
Published: January 2013

AbstractIn this article, an innovative approach for characterization of one dimensional photonic band gap (PBG) structures comprised of subwavelength dipole elements is presented.Through an efficient S‐ to T‐parameters conversion technique, polarization sensitivity of the subwavelength cell element was exploited to propose a novel combination of elements which allows achieving PBGs with simultaneous frequency and polarization selectivity. The proposed approach demonstrated that dispersion characteristics of each orthogonal polarization can be independently adjusted with dipole elements parallel to that same polarization. The structure has potential application in orthomode transducer and generally whenever the polarization of the incoming signal is to be used as a means of separating it from another signal in the same frequency band that is of orthogonal polarization. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:611–615, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27378
Small Wi‐Fi chip antenna using a backside ground capacitance
Authors: Oh Saewon , Kim Hyeongdong 
Published: January 2013

AbstractIn this article, a new small chip antenna for Wi‐Fi applications in mobile handsets is proposed. To achieve miniaturization, the proposed antenna is designed to have a backside ground. The proposed antenna has an S‐shaped structure, which is designed on liquid crystal polymer with εr = 3.5. The size of the proposed antenna is 6.0 × 3.0 × 1.2 mm3. The measured impedance bandwidth under a voltage standing wave ratio of 2 is 300 MHz (fractional bandwidth: 12.2%, 2.3–2.6 GHz), and the peak gain is 1.42 dBi. The proposed antenna is designed using a commercial software tool, CST Microwave Studio, and the fabricated antenna is measured using a network analyzer and an anechoic chamber. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:580–582, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27379
Far‐IR multiband dual‐polarization perfect absorber for wide incident angles
Authors: Yeo Woon‐Gi , Nahar Niru K. , Sertel Kubilay 
Published: January 2013

AbstractWe present a frequency selective surface (FSS) based, electrically thin perfect absorber with multiband and/or broadband performance in the Far‐IR band. We start by introducing small metallic loadings to the well‐known crossed‐dipole FSS structure. We demonstrate that these parasitic inclusions allow for much improved design flexibility for wide‐angle perfect absorbers using SiC and Silicon substrates. The numerical simulation results of proposed absorbers show that the design achieves dual‐band performance for wide incident angles in both transverse and transverse magnetic polarizations, with near perfect absorption characteristics. Furthermore, simple compositions of scaled versions of the proposed FSS elements are shown to achieve multiband and broadband characteristics. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:632–636, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27387
A dual‐band WLAN/UWB printed wide slot antenna for mimo/diversity applications
Authors: Mohammad Sajad , nezhad ali , Hassani Hamid Reza , Foudazi Ali 
Published: January 2013

AbstractIn this article, a dual‐band WLAN/ultrawideband (UWB) printed wide slot microstrip‐fed antenna is presented for multi‐input multi‐output (MIMO)/diversity applications.The proposed antenna consists of a U‐shaped patch, a T‐shaped monopole path, and a pentagonal wide slot in the ground plane. The antenna is designed to cover both the WLAN (2.4–2.485 GHz) and UWB (3.1–10.6 GHz) ranges, with value of S11 below −10 dB. The antenna is constructed on a FR4 substrate with overall dimensions of 28 × 28 × 1 mm3. It is shown that the proposed dual‐band antenna is suitable for diversity polarization applications. The simulation results show that the different configurations of the antenna in the MIMO/diversity have good S‐parameters over the operating frequency bands. The simulation and measured results of the proposed dual‐band antenna as well as that of the MIMO/diversity antenna configuration agree well. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:461–465, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27391
Design, measurement, and characterization of dual‐band left‐handed metamaterials with combined elements
Authors: Min‐Hua Li , He‐Lin Yang , Hai Lin , Bo‐Xun Xiao 
Published: January 2013

AbstractWe report on a new kind of planar left‐handed metamaterial with both simulations and experiments in this article. Dual electric and magnetic resonance frequency bands are experimentally realized by introducing two different metallic elements in one unit cell, which offers a convenient approach in building dual‐band or multiband negative‐index metamaterials. The effective electromagnetic parameters obtained from the measured S‐parameters indicate that negative refractive indexes are verified near 8.5 and 12 GHz with both negative permittivity and negative permeability. Field and current distribution at the dual resonances are also examined. At last, we calculated the radiated power of the magnetic dipole moments along y‐axis. The idea can help us to fabricate dual‐band or multiband metamaterial absorbers, filters, and antennas. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:493–497, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27399
Diffusion‐weighted 3D multislab echo planar imaging for high signal‐to‐noise ratio efficiency and isotropic image resolution
Authors: Engström Mathias , Skare Stefan 
Published: January 2013

PurposeTo acquire isotropic high‐resolution, signal‐to‐noise ratio (SNR) efficient, 3D encoded diffusion‐weighted MRI data.MethodsMultiple Fourier encoded slabs were combined into one full volume, using a generalized autocalibrating partially parallel acquisitions (GRAPPA) accelerated diffusion‐weighted 3D multislab echo planar imaging (EPI) sequence with 2D phase navigation and in‐plane motion correction.ResultsReconstructed data with 1.5‐mm3 nominal resolution is presented and shown under the influence of motion and with variable slab thicknesses. The SNR efficiency between diffusion‐weighted 3D multislab EPI and DW 2D ss‐EPI is compared. Finally, a 1.3‐mm3 full brain scan with 45 diffusion directions is presented.ConclusionsDiffusion‐weighted 3D multislab EPI has been presented as an alternative sequence for high‐resolution and high‐SNR full brain coverage diffusion studies. Compared with the gold standard 2D diffusion‐weighted single‐shot Echo Planar Imaging, the SNR efficiency is significantly higher. Magn Reson Med 70:1507–1514, 2013. © 2013 Wiley Periodicals, Inc.
Uric acid best predicts metabolically unhealthy obesity with increased cardiovascular risk in youth and adults
Authors: Mangge Harald , Zelzer Sieglinde , Puerstner Peter , Schnedl Wolfgang J. , Reeves Gloria , Postolache Teodor T. , Weghuber Daniel 
Published: January 2013

AbstractObjective:The obesity prevalence is growing worldwide and largely responsible for cardiovascular disease, the most common cause of death in the western world. The rationale of this study was to distinguish metabolically healthy from unhealthy overweight/obese young and adult patients as compared to healthy normal weight age matched controls by an extensive anthropometric, laboratory, and sonographic vascular assessment.Design and Methods:Three hundred fifty five young [8 to < 18 years, 299 overweight/obese(ow/ob), 56 normal weight (nw)] and 354 adult [>18‐60 years, 175 (ow/ob), 179 nw)] participants of the STYJOBS/EDECTA (STYrian Juvenile Obesity Study/Early DEteCTion of Atherosclerosis) cohort were analyzed. STYJOBS/EDECTA (NCT00482924) is a crossectional study to investigate metabolic/cardiovascular risk profiles in normal and ow/ob people free of disease except metabolic syndrome (MetS).Results:From 299 young ow/ob subjects (8‐< 18 years), 108 (36%), and from 175 adult ow/ob subjects (>18‐60 years), 79 (45%) had positive criteria for MetS. In both age groups, prevalence of MetS was greater among males. Overweight/obese subjects were divided into “healthy” (no MetS criterion except anthropometry fulfilled) and “unhealthy” (MetS positive). Although percentage body fat did not differ between “healthy” and “unhealthy” ow/ob, nuchal and visceral fat were significantly greater in the “unhealthy” group which had also significantly higher values of carotid intima media thickness (IMT). With MetS as the dependent variable, two logistic regressions including juveniles <18 years or adults >18 years were performed. The potential predictor variables selected with the exception of age and gender by t test comparisons included IMT, ultrasensitive c‐reactive protein (US‐CRP), IL‐6, malondialdehyde (MDA), oxidized LDL, leptin, adiponectin, uric acid (UA), aldosterone, cortisol, transaminases, fibrinogen. In both groups, uric acid and in adults only, leptin and adiponectin, turned out as the best predictor.Conclusion:Serum levels of UA are a significant predictor of unhealthy obesity in juveniles and adults.
Comparative Lung Function Performance of Stroke Survivors and Age‐matched and Sex‐matched Controls
Authors: Ezeugwu Victor Emeka , Olaogun Matthew , Mbada Chidozie Emmanuel , Adedoyin Rufus 
Published: January 2013

AbstractBackground and PurposeReduced endurance and excessive fatigue in stroke survivors (SS) during exercise may be linked to impairment of lung function and breathing mechanics, but little is known about lung function of SS. The purpose of this study is to determine lung function (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC ratio and peak expiratory flow [PEF]) and influence of anthropometrics on lung function in SS compared with healthy controls (CG).MethodsIn this case–control, cross‐sectional study, we recruited 70 participants (42 males, 28 females), comprising 35 SS and 35 CG (range 34–73 years). Anthropometrics were measured using standard instruments and procedure. Chest excursion was measured at the axilla, xiphoid and lower costal levels. Lung function indices were measured using a micro‐computerized spirometer. Ethical approval was obtained from the Ethics and Research Committee of Obafemi Awolowo University Teaching Hospital, Ile‐Ife, Nigeria.Results/FindingsCompared with the CG, the SS had significantly lower values for FEV1 (1.99 ± 0.66 vs. 2.36 ± 0.45 L, p = 0.004), FVC (2.55 ± 0.70 vs. 2.90 ± 0.54 L, p = 0.014), PEF (3.88 ± 1.38 vs. 5.24 ± 1.30 L second−1, p = 0.001) and chest excursion (3.0 ± 0.71 vs. 3.5 ± 0.91 cm, p = 0.018). Correlations between chest excursion, FEV1, FVC and PEF were not significant (p > 0.05).DiscussionThe weakness of respiratory muscles associated with stroke may have contributed to decreases in lung function observed. There was a significant reduction in chest excursion of SS compared with CG. Chest excursion has been used as an indicator of respiratory muscle function because the range of motion of the thorax serves the respiration. Movements of the thorax influence the content of the thorax cavity, leading to alterations in lung volumes.Implications for Physiotherapy PracticeStroke survivors have lower lung function when compared with CG; this has implications for clinicians in stroke rehabilitation, underscoring the importance for inclusion of interventions to improve lung function. Copyright © 2013 John Wiley & Sons, Ltd.
Physicochemical changes in phosphorylase kinase induced by its cationic activator Mg2+
Authors: Liu Weiya , Nadeau Owen W. , Sage Jessica , Carlson Gerald M. 
Published: January 2013

AbstractFor over four decades free Mg2+ ions, that is, those in excess of MgATP, have been reported to affect a wide variety of properties of phosphorylase kinase (PhK), including its affinity for other molecules, proteolysis, chemical crosslinking, phosphorylation, binding to certain monoclonal antibodies, and activity, which is stimulated. Additionally, for over three decades Mg2+ has been known to act synergistically with Ca2+, another divalent activator of PhK, to affect even more properties of the enzyme. During all of this time, however, no study has been performed to determine the overall effects of free Mg2+ ions on the physical properties of PhK, even though the effects of Ca2+ ions on PhK's properties are well documented. In this study, changes in the physicochemical properties of PhK induced by Mg2+ under nonactivating (pH 6.8) and activating (pH 8.2) conditions were investigated by circular dichroism spectroscopy, zeta potential analyses, dynamic light scattering, second derivative UV absorption, negative stain electron microscopy, and differential chemical crosslinking. The effects of the activator Mg2+ on some of the properties of PhK measured by these techniques were found to be quite different at the two pH values, and displayed both differences and similarities with the effects previously reported to be induced by the activator Ca2+ (Liu et al., Protein Sci 2008;17:2111–2119). The similarities may reflect the fact that both cations are activators, and foremost among their similarities is the dramatically less negative zeta potential induced by their binding to PhK.
317 GHz InAlGaN/GaN HEMTs with extremely low on‐resistance
Authors: Lee Dong Seup , Laboutin Oleg , Cao Yu , Johnson Wayne , Beam Edward , Ketterson Andrew , Schuette Michael , Saunier Paul , Kopp David , Fay Patrick , Palacios Tomás 
Published: January 2013

AbstractThis paper reports depletion‐mode In0.13Al0.83Ga0.04N/GaN high electron mobility transistors (HEMTs) on a SiC substrate with a record current gain cutoff frequency (fT) of 317 GHz. Thanks to the combination of high electron mobility, regrown n+ InGaN/GaN ohmic contacts and scaled source‐to‐drain distance, the devices have an very low on‐resistance of 0.4 Ω·mm. This very low resistance enables a significant reduction of the transistor parasitic delay and devices with a peak fT of 317 GHz have been demonstrated for a 26 nm gate length. The device performance is limited by a relatively thick top barrier which causes serious short‐channel effects (SCEs) in the devices with gate length below 50 nm. It is expected that a suppression of the SCEs will render further improvements in frequency performance in future devices. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Systematic theoretical investigations for the polytypism in SiC
Authors: Ito Tomonori , Akiyama Toru , Nakamura Kohji 
Published: January 2013

AbstractSiC polytypes in bulk form is systematically investigated using ab initio pseudopotential approach for the total energy calculations in four structures such as 3C (zinc blende), 6H, 4H, and 2H (wurtzite) structures with vacancy and nitrogen doping. Our calculated energy differences ΔE among four structures reveal that 3C and 4H are favorable for prefect SiC. The ΔE for SiC with vacancy suggests the most stable structures such as 6H with Si‐vacancy and 4H with C‐vacancy. The calculated vacancy formation energies suggest that C‐rich condition prefers 6H whereas 4H is favored under Si‐rich condition. Furthermore, nitrogen substituting for carbon and silicon respectively stabilizes 3C and 4H. These calculated results are consistent with experimental findings. The destabilization due to the vacancy formation and stabilization due to nitrogen of 3C‐SiC are discussed by bond charge calculations and our simple formula of ΔE. It is found that vacancy formation inducing large deficit of bond charges favors 6H‐ and 4H‐SiC and nitrogen‐doping increasing bond charges stabilizes 3C‐SiC. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
(111) InAs/GaSb type‐II strained layer superlattice material for high operating temperature detection
Authors: Plis Elena , Klein Brianna , Myers Stephen , Gautam Nutan , Krishna Sanjay 
Published: January 2013

AbstractWe report on the detailed radiometric characterization of the mid‐wave infrared InAs/GaSb type‐II strained layer superlattice detectors grown on GaSb (111) substrate. A red shift of 1.7 μm (at 295 K) was observed with respect to a similar detector grown on GaSb (100) substrate. We have measured, at 295 K and λ100% cut‐off = 5.6 μm, a dark current density of 0.53 A/cm2 (at ‐50 mV) and a Johnson noise limited D* of 8.5 x 109Jones, which are superior values to state‐of‐the‐art T2SL detectors with the same (pin) design grown on conventional GaSb (100) substrates and operating in a similar wavelength range. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultrafast transverse thermoelectric response in c‐axis inclined epitaxial La0.5Sr0.5CoO3 thin films
Authors: Yu Lan , Wang Yong , Zhang Pengxiang , Habermeier Hanns‐Ulrich 
Published: January 2013

AbstractUltrafast transverse thermoelectric voltage response has been observed in c‐axis inclined epitaxial La0.5Sr0.5CoO3thin films. Voltage signals with the rise time of 7 ns have been detected under the irradiation of pulse laser with duration of 28 ns. A concept, named response rate ratio, has been proposed to evaluate the intrinsic response rate, and this ratio in La0.5Sr0.5CoO3is smaller than that in other reported materials. The low resistivity is thought to be responsible for the ultrafast response, as low resistivity induces small optical penetration depth, and response time has a monotonous increasing relationship with this depth.magnified imageTransverse thermoelectric voltage with the rise time of 7 ns in La0.5Sr0.5CoO3thin film.(© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of Experimental Conditions for Applying Hot Wire Method to Thermal Conductivity of Slag
Authors: Glaser Björn , Ma Luyao , Sichen Du 
Published: January 2013

AbstractIn order to apply the hot wire method for metallurgical slags at steelmaking temperatures, a numerical model was developed, cold model experiments were conducted and test measurements using a high temperature experimental setup were carried out. To minimize natural convection and obtain more reliable measurements, the crucible diameter, the hot‐wire diameter, the applied current, the position of the wire in the crucible, and the cooling on the upper surface of the crucible were studied. Investigations into the choice of sheathing material of the circuit exposed to the slag were also made. It was found that only certain materials were suitable for slag measurements depending on slag composition and temperature. The electrical resistivity of the hot wire was measured to make the thermal conductivity calculation more reliable. The wire diameter also played a major role, because of the heat generation per surface area. The thermal conductivity should be derived from the values measured during the first seconds. In this initial stage, the effect of the natural convection as a function of the wire position in the crucible, the cooling on the top surface, and the diameter of the crucible are negligible. A compromise has to be made in choosing the electrical current, since higher current results in higher sensitivity but at the same time in more natural convection.