bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel series‐fed microstrip array antenna with miniaturized feeding network for WLAN/RFID applications
Authors: Ku Chia‐Hao , Liu Hsien‐Wen , Lin Yu‐Shu 
Published: May 2011

AbstractA novel series‐fed microstrip array antenna with a miniaturized feeding network suitable for wireless local area network (WLAN) and radio frequency identification (RFID) applications is presented.This array works with 10 patch elements and utilizes artificial transmission lines (ATL) to design the feeding network to well reduce the whole size. Compared to conventional series‐fed array designs, the proposed array can achieve not only a small size of merely 14 (L) × 230 (W) mm2 but also a wide operating bandwidth from 5 to 5.94 GHz. Experimental results exhibit that fairly good broadside radiation pattern with adequate half‐power beamwidth for practical application can be obtained with our array design. Therefore, the proposed microstrip array antenna with a compact size is well suitable to be integrated within the WLAN/RFID systems as a transmitting antenna. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26120
Monopole antenna based on wrench‐shaped slot on circular disc patch for UWB application
Authors: Moosazadeh Mahdi , Ghobadi Changiz , Esmati Zahra 
Published: May 2011

AbstractA monopole antenna with circular‐shaped patch has been proposed for ultra wideband (UWB) applications.With lack of current at the center of circular‐shaped patch, a wrench‐shaped design has been used for modifying blind spot center of patch and reinforcement of currents. In ground plane, a square and circular shape linked notch has been placed for proper impedance matching. Proposed antenna has a small size, and operates in 3.1 to 11.91 GHz frequency band. Laboratory and simulated antenna results show that proposed antenna has an acceptable return loss level and radiation pattern characteristics for the UWB frequency band range. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26125
Design of a high‐resolution microfluidic microwave MEMS phase shifter
Authors: Ozbey Burak , Ozturk Sule , Aktas Ozgur 
Published: May 2011

AbstractIn this article, a novel microwave microelectromechanical phase shifter based on a microfluidic design is proposed and demonstrated.The design principles, the fabrication process, and experimental results (S‐parameters and phase shift plots) are presented. The proposed system has a high bandwidth, high‐power handling capacity, and a high‐resolution along with a small settling time. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26127
A band selected 3.1–30.1 GHz distributed amplifier in 0.18‐μm CMOS technology
Authors: Feng Wu‐Shiung , Wei Chien‐Cheng , Hsu Hui‐Chen , Chen Chia‐Hsun , Chatterjee Prasenjit , Kung Ling 
Published: May 2011

AbstractA band‐selected 3.1–30.1 GHz CMOS distributed amplifier (DA) for extended UWB application is presented in this article. The proposed circuit was designed and fabricated with a 0.18‐μm CMOS technology. This circuit uses a sharpening technique to improve the frequency response from low‐pass to bandpass property, for the requirement of limited frequency band. This DA also adopts the inductive peaking technique to increase circuit's gain and bandwidth. This DA has a measured maximum power gain of 7.5 dB. The supply voltage and biasing current are 1.8 V and 28.6 mA, with total DC power of 51.48 mW. When compared with the standard DAs published over the past years, this circuit offers good abilities in band selectivity, acceptable power gain, low noise figures, and large‐signal performances. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26139
Adhesive‐fixed microbend long‐period fiber gratings with bandpass filter response
Authors: Sakata Hajime , Saito Takuya 
Published: May 2011

AbstractWe demonstrate an adhesive‐fixed periodic microbending whose transmission spectrum shows a bandpass filter response with the help of a fiber coil.In addition to thermal shift of the resonance wavelength, the transmission peak amplitude is varied with ambient temperature due to thermal expansion of the adhesive that maintains the microbend. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26146
Novel microwave filters based on Epsilon Near Zero waveguide tunnels
Authors: Corona‐Chavez Alonso , Murthy D. V. B , Olvera‐Cervantes Jose Luis 
Published: May 2011

AbstractMicrowave filters based on the concept of Epsilon Near Zero (ENZ) tunneling effect are presented. ENZ metamaterials provide interesting phenomena such as anomalous tunneling and energy squeezing through ultra narrow waveguide channels. Using this concept two filters are demonstrated with Chebyshev response and one with a quasi‐elliptic response by adding transmission zeroes with hairpin resonators. Experimental and simulated responses are presented with good agreement. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26147
Novel dual‐mode square patch bandpass filter using slot‐type SRR perturbation for mode splitting
Authors: Fu Shu‐Hong , Tong Chuang‐Ming , Li Xi‐Min , Zhou Ming 
Published: May 2011

AbstractA slot‐type split‐ring resonator (SRR) as a new type of perturbation element for dual‐mode square patch resonator is introduced in this article.The slot‐type SRR used in the patch resonator allows coupling between the two degenerate modes. Moreover, coupling characteristics can be adjusted by the location of slot‐type SRR. By adding two notches in the dual‐mode filter with slot‐type SRR, the high degenerate mode near the passband is eliminated, and the center frequency is lowered slightly. It has been verified by both simulation and measurement. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26148
Demonstration of a two‐user time domain spectral phase encoding OCDMA system with variable‐bandwidth spectrum shaper‐based decoder
Authors: Gao Zhensen , Wang Xu , Kataoka Nobuyuki , Wada Naoya 
Published: May 2011

AbstractWe propose and experimentally demonstrate a 2.5‐Gb/s two‐user optical‐code‐division‐multiple‐access (OCDMA) system with a novel time domain spectral phase encoding scheme and variable‐bandwidth spectrum shaper (VBS)‐based spectral phase decoder. The spectral phase encoded OCDMA signal is generated by using a pair of dispersive fibers with opposite dispersion and a high speed phase modulator with rapid programmable 8‐chip, 20 Gb/s optical code patterns in time domain, and spectrally decoded using a VBS with high controlling precision of amplitude and phase. A total of 2.5‐Gb/s time domain spectral phase encoded on‐off‐keying OCDMA signal data has been successfully transmitted over 34 km fiber with error‐free. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26151
Heuristic uniform 2D double wedge diffraction based on generalized Fresnel integral
Authors: Legendre J. F. , Marsault T. , Velé T. , Cueff D. 
Published: May 2011

AbstractThis article describes an uniform 2D double wedge diffraction coefficient.The transition function is based on generalized Fresnel integral. First, a closed form of the dielectric single wedge diffraction based on classical heuristic TUD introduction by Luebbers is recalled. Its drawback when applied twice on double single edge diffraction is evaluated. Next, an uniform double edge diffraction based on Marhefka's spectral theory work is proposed. It is compared with other methods. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26154
Fast broadband analysis of microstrip by interpolating both impedance and preconditioning matrices with MBPE
Authors: Liu Zhiwei , Li Mengmeng , Zhang Guozhong , Chen Rushan 
Published: May 2011

AbstractAn interpolation scheme using model‐based parameter estimation (MBPE) for fast analysis of the microstrip structures over a wideband is proposed.The microstrip structures are analyzed by the mixed potential integral equation with the generated dense impedance matrix partitioned and compressed hierarchically by the UV method. The linear systems are solved by the generalized minimal residual method with its convergence accelerated by the sparse approximate inversion (SAI) preconditioning technique. Over a wide frequency band, both the near field impedance matrix and the SAI preconditioning matrix are interpolated by MBPE. Numerical results show that the proposed method can reduce the computation time significantly. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26155
Double modes characterization and incident light angle tuning on the photonic band gap of SiO2 colloid crystal
Authors: Wang Xin , Fan Huiqing , Ren Pengrong , Li Jin 
Published: May 2011

AbstractPhotonic crystal of packed monodisperse silica submicron spheres were synthesized in this article. We investigated the optical properties of packed monodisperse silica submicron spheres by means of both optical transmission and reflection measurements. Research suggests that the two methods are consistent in essence, and the reflection mode is more suitable for colloidal crystal assembled of smaller colloidal spheres. Accurately tuning of photonic band gap by incident light angle was also studied in our article. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26156
Effect of antenna envelope correlation for 2 × 2 multi‐input multioutput system in WiMAX field measurements
Authors: Kim Dongjin , Yang Taesik , Kim Minchan 
Published: May 2011

AbstractThis article describes the effect of antenna envelope correlation in the throughput of multi‐input multioutput (MIMO) antenna system.Despite the fact that antenna envelope correlation is a critical factor that determines the data transmitting capability of a MIMO antenna system, an appropriate level of envelope correlation for MIMO antennas in mobile communication devices has never been proposed yet. In this article, we have examined various MIMO antenna systems designed with different correlation values to provide a guideline for industrial WiMAX MIMO applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26158
Erratum: A broadband Fabry–Pérot cavity antenna designed using an improved resonance prediction method
Authors: Kim Dongho , Ju Jeongho , Choi Jaeick 
Published: May 2011

AbstractOriginally published Microwave Opt Technol Lett 53:1065–1069, 2011.© 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26229 (Original article DOI 10.1002/mop.25898)
Complete 1H and 13C NMR data assignment of protolimonoids from the stem barks of Aphanamixis grandifolia
Authors: Wang Junsong , Zhang Yao , Luo Jun , Kong Lingyi 
Published: May 2011

AbstractSeven new protolimonoids, named aphagranins A–G (1–7), along with four known compounds, were isolated from the ethanol extract of the stem barks of Aphanamixis grandifolia. Structure elucidation and signal assignments were achieved on the basis of spectral and chemical evidences. Copyright © 2011 John Wiley & Sons, Ltd.
Ca2+ signaling during maturation of cumulus–oocyte complex in mammals
Authors: Silvestre F. , Boni R. , Fissore R.A. , Tosti E. 
Published: May 2011

AbstractUnder the influence of gonadotropins or growth factors, a close cooperation develops between cumulus cells and the oocyte that is implicated in transmitting signals involved in maintaining or releasing the meiotic arrest in the oocyte. While cyclic adenosine 5′‐monophosphate (cAMP) is a key molecule in maintaining the meiotic arrest, calcium (Ca2+) may play a role in controlling either spontaneous or gonadotropin‐induced oocyte maturation, possibly by modulating intracytoplasmic cAMP concentrations via Ca2+‐sensitive adenylate cyclases. This review focuses on the mechanisms related to the origin of the Ca2+ wave that travels from the cumulus cells to the oocyte, and discusses the source of variations affecting the dynamics of this wave. Mol. Reprod. Dev. 78:744–756, 2011. © 2011 Wiley Periodicals, Inc.
Alternate ascending/descending directional navigation approach for imaging magnetization transfer asymmetry
Authors: Park Sung‐Hong , Duong Timothy Q. 
Published: May 2011

AbstractA new method for imaging magnetization transfer (MT) asymmetry with no separate saturation pulse is proposed in this article. MT effects were generated from sequential two‐dimensional balanced steady‐state free precession imaging, where interslice MT asymmetry was separated from interslice blood flow and magnetic field inhomogeneity with alternate ascending/descending directional navigation (ALADDIN). Alternate ascending/descending directional navigation provided high‐resolution multislice MT asymmetry images within a reasonable imaging time of ∼3 min. MT asymmetry signals measured with alternate ascending/descending directional navigation were 1–2% of baseline signals (N = 6), in agreement with those from the conventional methods. About 70% of MT asymmetry signals were determined by the first prior slice. The frequency offset ranges in this study were >8 ppm from the water resonance frequency, implying that the MT effects were mostly associated with solid‐like macromolecules. Potential methods to make alternate ascending/descending directional navigation feasible for imaging amide proton transfer (∼3.5 ppm offset from the water resonance frequency) were discussed. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
The feasibility of endorectal MR elastography for prostate cancer localization
Authors: Arani Arvin , Plewes Donald , Krieger Axel , Chopra Rajiv 
Published: May 2011

AbstractThe objectives of this study were to evaluate the feasibility of using a rigid radio‐frequency receiver endorectal coil for intracavitary prostate magnetic resonance elastography (MRE) and to demonstrate the capability of this technique for generating stiffness maps over a typical prostate volume. An endorectal coil is currently used to help improve the signal‐to‐noise ratio of images acquired with multiparametric magnetic resonance imaging. We propose that this same coil could also serve to generate shear waves in the prostate gland during imaging, opening up the possibility of incorporating prostate stiffness characterization into multiparametric magnetic resonance imaging. Prostate cancer has been shown to change the elasticity of tissue, suggesting that stiffness imaging (elastography) may provide supplementary diagnostic information. A rigid endorectal coil was mechanically coupled to a piezoceramic actuator and used to investigate full volume (27 slices, 2‐mm thick) endorectal MRE in a prostate mimicking phantom. The low‐amplitude vibrations (±8–38 μm displacements) necessary to perform endorectal MRE did not affect the signal‐to noise ratio of the coil and endorectal MRE was capable of resolving 0.1cc (0.6 cm diameter) spherical inclusion volumes. Therefore, the results of this study, in combination with current clinical practice, motivate clinical evaluation of endorectal MRE in patients. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Influence of shotcrete composition on load‐level estimation in NATM‐tunnel shells: Micromechanics‐based sensitivity analyses
Authors: Ullah S. , Pichler B. , Scheiner S. , Hellmich C. 
Published: May 2011

SUMMARYDisplacement measurement‐based estimations of loads and utilization degrees in shotcrete tunnel shells as part of the New Austrian Tunneling Method (NATM), have become standard tools in tunnel practice; their quality, however, may crucially depend on the knowledge of the actual shotcrete composition after spraying. To shed light on this issue, we here determine, based on experimentally validated micromechanical representations of shotcrete, the hydration degree‐dependent elastic, creep, and strength properties of different shotcretes, characterized by water cement ratios (w/c) between 0.4 and 0.6, aggregate cement ratios (a/c) between 3.5 and 5, and Young's modulus of aggregates (Eagg) between 40 and 80 GPa. These properties are fed into a structural shell model of the Sieberg tunnel, and this model is subjected to displacement fields approximated from daily displacement measurements at five selected points along the shell's inner surface. Resulting stresses and forces in the tunnel shell allow for analyzing the influence of shotcrete composition on load‐level estimation in NATM tunnel shells: The magnitudes of circumferential and longitudinal normal forces increase significantly with decreasing w/c, while a/c and Eagg have the inverse and relatively minor effect. The utilization degree is virtually insensitive to changes in w/c(especially at early ages), and only slightly decreases with decreasing a/c and Eagg. The location of maximum loading is unaffected by the shotcrete composition underlying the analysis. Conclusively, location and magnitude of maximum utilization degrees are very robust estimates (not affected by limited knowledge on the shotcrete composition), whereas realistic estimation of stresses and forces does require more accurate consideration of shotcrete composition. Copyright © 2011 John Wiley & Sons, Ltd.
Novel imidazolium‐based poly(ionic liquid)s: preparation, characterization, and absorption of CO2
Authors: Xiong Yu‐Bing , Wang Hong , Wang Yu‐Jiao , Wang Rong‐Min 
Published: May 2011

AbstractThe development of novel materials for carbon dioxide (CO2) capture is of great importance in resource utilization and environmental preservation. In this study, imidazolium‐based ionic liquids (ILs) with symmetrical ester and hydroxyl groups were prepared, and their corresponding polymer were synthesized by melt condensation polymerization. The structure and properties of the poly(ionic liquid)s (PILs) were characterized by proton nuclear magnetic resonance, gel permeation chromatograph, differential scanning calorimetry, X‐ray diffraction, and scanning electron microscopy. In addition, the CO2 sorption behavior of the IL monomers and PILs were studied at a low pressure (648.4 mmHg CO2) and under a temperature of 25°C using a thermogravimetric analyzer. The CO2 sorption capacity of 1,3‐bis(2‐hydroxyl ethyl)‐imidazolium hexafluorophosphate ([HHIm]PF6, 10 mol%) was the highest among all the IL monomers and PILs studied. This capacity is also much higher than those reflected of previously reported ILs. Moreover, the sorption equilibrium of [HHIm]PF6 was achieved within a short time. Copyright © 2011 John Wiley & Sons, Ltd.
Structure, thermal stability, and mechanical properties of nanocomposites based on an amorphous polyamide
Authors: Zabaleta A. , González I. , Eguiazábal J.I. , Nazábal J. 
Published: May 2011

AbstractPolymer nanocomposites based on an amorphous polyamide (aPA) modified with three organoclays were obtained in the melt state. The observed Tg decreases indicated that some organic modifier of the OMMT (surfactant) migrated to the matrix during mixing. The decrease in the thermal stability of the aPA in nitrogen atmosphere on organoclay addition was attributed to the instability of the organoclays. The smaller decrease in the thermal stability of the nanocomposites in air atmosphere was attributed to a barrier effect. The largest dispersion (an average of only 1.2 layers per particle) occurred using the octadecylamine‐modified organoclay (I30) that has the maximum uncovered surface; this indicates the basic importance of this parameter on exfoliation. Despite the bulky nature of the aPA that hinders the matrix/inorganic surface interactions, this dispersion level is comparable to that of semicrystalline polyamides with similar polarity. This indicates that the relation between high polarity of the matrix and high dispersion level also works in bulky aPAs, as that of this study. The significant modulus increases (56% for the nanocomposite with 5% I30) are consistent with the measured high dispersion level. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Fabrication of nanostructured polycarbonate/poly(methyl methacrylate) blends with improved optical and mechanical properties by high‐shear processing
Authors: Li Yongjin , Shimizu Hiroshi 
Published: May 2011

AbstractThe structure and properties of polycarbonate (PC)/poly(methyl methacrylate) (PMMA) blends fabricated using a high‐shear extruder at different shear rates were investigated. It was found that the morphologies of the blends were greatly dependent on the shear rate exerted during melt processing. High‐shear processing leads to a nanostructured PC/PMMA blend, in which PMMA domains with a size of less than 50 nm are homogeneously dispersed in the PC matrix. The prepared nanostructured blends exhibit not only excellent optical properties with a transmittance of more than 90% in the visible region but also a higher modulus than pure PC. In contrast, the PMMA domain size ranges from submicron to micrometer for the same blends processed at a low‐shear rate. These blends are opaque and display much lower elongation at break compared with the blends processed at a high‐shear rate. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Effects of acrylonitrile content and molecular weight on the scratch behavior of styrene‐acrylonitrile random copolymers
Authors: Browning Robert , Sue Hung‐Jue , Minkwitz Rolf , Charoensirisomboon Piyada 
Published: May 2011

AbstractFundamental understanding of the scratch behavior of styrene‐acrylonitrile (SAN) random copolymers with variation in acrylonitrile (AN) content and molecular weight (MW) is pursued using the methodology outlined in ASTM D7027‐05/ISO 19252:08. Two sets of SAN model systems are employed: One that varies the AN content with similar MW and another that varies the MW at the same AN content. Key scratch damage mechanisms (scratch groove formation, periodic micro‐cracking, and plowing) are identified and correlated with the compressive and tensile properties of the SAN systems. Scratch visibility is analyzed through the use of a commercial software package. A fundamental structure–property relationship of SAN scratch behavior is proposed by the fact that increasing the AN content or the MW can have a positive effect on increasing the scratch resistance of SAN as it improves its tensile strength and ductility. The implication of material properties and their effect on polymer scratch behavior is discussed. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers