bluuebunny/crossref_metadata_2025_split huggingface dataset:
To compact ring branch‐line coupler using nonuniform transmission line
Authors: Hosseini F. , Hosseini M. Khalaj‐Amir , Yazdany M. 
Published: August 2009

AbstractA compact ring Branch‐Line Coupler (BLC) with size reduction of about 50%(in circuit area) of conventional BLCs at frequency 2 GHz is introduced. The coupler is designed by using nonuniform transmission lines (NTL) instead of Uniform Transmission Lines in each arm. The normalized width w (z)/h function of the NTLs is expanded in a truncated Fourier series. The reduced size couplers are potential building blocks for the growing wireless communication markets. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2679–2682, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24703
Multi split‐step unconditionally stable finite difference time domain methods
Authors: Kusaf Mehmet , Oztoprak Abdullah Y. 
Published: August 2009

AbstractNew unconditionally stable split‐step FDTD methods with 6 and 8 split‐steps are introduced. A new definition of the stability factor is used for fair comparison of multi split‐step methods, which takes into account the number of split‐steps as well. When different methods are compared, on equal time basis using this definition, it is found that the new methods have the best dispersion error performance. Dispersion performances of some of the previously reported “improved” multi split‐step FDTD methods do not seem to be as good as claimed. It has also been shown that for each space step value, the new methods have zero anisotropic error at certain large stability factor (time step) values. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2646–2649, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24704
A 57‐GHz CMOS VCO with 185.3% tuning‐range enhancement using tunable LC source‐degeneration
Authors: Tsou Chuan‐Wei , Chen Chi‐Chen , Lin Yo‐Sheng 
Published: August 2009

AbstractA 57‐GHz CMOS voltage‐controlled oscillator (VCO) using tunable LC source‐degeneration for operation frequency and tuning‐range enhancement is demonstrated. The tunable LC source‐degeneration is made by adding two tunable LC tanks, where varactors are used as the needed capacitors, to the source terminals of the cross‐coupled transistor pair of the VCO. Compared with the traditional cross‐coupled transistor pair, the proposed one significantly decreases the equivalent parallel capacitance (CEQ). This in turn results in the increase of both the operation frequency and the tuning range of the VCO. The measurement result shows the tunable LC source‐degeneration achieved a 185.3% enhancement [from 1.36 GHz (53.36–54.72 GHz) to 3.88 GHz (53.36–57.24 GHz)] in tuning range by tuning the varactors of the proposed cross‐coupled transistor pair. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2682–2685, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24706
A low‐power CMOS receiver for wireless sensor networks
Authors: Chen Yen‐Jen , Lin Yu‐Tso , Liao Fang‐Ren , Chen Hsiao‐Chin , Lu Shey‐Shi 
Published: August 2009

AbstractA monolithic on‐off keying receiver is presented for wireless sensor network applications. By employing the self‐mixing technique, the demodulator is constructed from a voltage multiplier instead of a rectifier in this work. The proposed receiver can achieve a data rate upto 1 Mb/s at a power consumption of 15.4 mW while occupying a die area of only 0.25 mm2. For a bit rate of 5 kb/s and a pseudo‐random sequence of 29 − 1, the receiver exhibits a sensitivity of −60 dBm at 433 MHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2618–2620, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24707
Design of a new wideband low‐profile conical antenna
Authors: Ma Jie , Yin Y.‐Z. , Zhou S.‐G. , Zhao L.‐Y. 
Published: August 2009

AbstractA very low‐profile conical antenna with a simple structure and wideband characteristic is proposed in this article. The antenna structure consists of a monoconical conducting body, a parasitic ring shorted to a finite‐sized ground plate to achieve low‐profile characteristic (Nakano et al., IEEE Trans Antennas Propag 56 (2008) 1187‐1192), and a sleeve attached to the ground for yielding an extreme wide VSWR bandwidth. The experimental result shows that the proposed antenna, with a height of only 0.0625 wavelength at the lower edge frequency of the bandwidth, exhibits a 7.9:1 impedance bandwidth from 747 to 5900 MHz with VSWR below 2.5. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2620–2623, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24713
Microwave circuit miniaturization with complementary spiral resonators: Application to high‐pass filters and dual‐band components
Authors: Selga Jordi , Sisó Gerard , Gil Marta , Bonache Jordi , Martín Ferran 
Published: August 2009

AbstractIn this contribution, it is shown that complementary spiral resonators (CSRs) are useful particles for the miniaturization of planar microwave components based on metamaterial concepts. Specifically, we will focus on two different applications: (i) the design of high pass filters based on balanced composite right/left handed microstrip lines and (ii) the design of dual band impedance inverters, which can be applied to many different devices such as couplers and power dividers, among others. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2741–2745, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24715
Circular dielectric cantor fibers
Authors: Chiadini F. , Fiumara V. , Gallina I. , Scaglione A. 
Published: August 2009

AbstractCantor fibers having a multilayered cladding structured according to the Cantor fractal scheme are introduced. In each layer the radial field distribution is determined solving a boundary value problem. The mode propagation constant is calculated minimizing the outgoing power flux. Such fibers suffer from low losses even for few cladding layers. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2726–2728, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24716
Plasmonic and non‐plasmonic layered structures for cloaking applications at visible frequencies
Authors: Tricarico Simone , Bilotti Filiberto , Vegni Lucio 
Published: August 2009

AbstractIn this letter, we present the theoretical analysis and the design principles of electromagnetic cloaking devices working at optical frequencies. The cloaking approach is based on the scattering cancellation principle. The robustness of the cloaking devices is also discussed, proposing a proper figure of merit and validating the design through a set of full‐wave numerical simulations. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2713–2717, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24718
Guest editorial: Special issue on metamaterials and special materials for electromagnetic applications and telecommunications
Authors: Andreone Antonello , Galdi Vincenzo 
Published: August 2009

Abstract© 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2694–2695, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24722
Light confinement in coherently driven defect states in solids
Authors: Wu Jin‐Hui , Artoni Maurizio , La Rocca Giuseppe C. 
Published: August 2009

AbstractInhomogeneously broadened optical transitions in nitrogen‐vacancy color centers in diamond and Pr3+ doped yttrium orthosilicate may be employed to attain all‐optically controlled Bragg structures with photonic band‐gaps of high reflectivities and large bandwidths. Such a control mechanism is valuable for improving performance and scalability of solid quantum memory devices. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2722–2726, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24723
Slow microwave waveguide made of negative permeability metamaterials
Authors: Lu Wentao T. , Savo Savatore , Casse B. Didier F. , Sridhar Srinivas 
Published: August 2009

AbstractThe framework for designing a slow light waveguide structure which operates in the GHz and up to THz frequencies is outlined. The design for the structure consists of a dielectric core layer cladded with negative permeability metamaterials. The parameter space for the metamaterial has been identified for the waveguide to stop light and the negative permeability is achieved by split‐ring resonator (SRR) metallic elements. A prototype structure operating at 8.5 GHz is proposed. Numerical simulations of electromagnetic waves interacting with SRRs have been performed to extract scattering parameters and a parameter retrieval method has been used to verify the designed window for negative permeability. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2705–2709, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24727
Metamaterial applications in RFID
Authors: Toscano A. , Vegni L. 
Published: August 2009

AbstractIn this article, we discuss various requirements of antenna design for passive radio frequency identification (RFID) tags, we outline a generic design process and show how RFID tags loaded with a metamaterial slab are able to increase the read range and to decouple the tag with the tagged objects. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2745–2748, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24728
Efficient numerical analysis of large planar high impedance surface by the synthetic function expansion technique
Authors: Matekovits Ladislau , Vecchi Giuseppe , Bercigli Mirko , Bandinelli Mauro 
Published: August 2009

AbstractApplication is presented of the Synthetic Function eXpansion (SFX) method to the accurate analysis of devices that incorporate microstrip‐technology electromagnetic band‐gap structures of large but finite size. The strong reduction of the dimension of the system matrix achieved employing the SFX technique reduces the solution time and the memory occupation, making it possible to analyze large structures on standard computational hardware. Experimental verification confirms the validity of the approach. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2763–2769, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24729
Modeling of diamond field‐effect transistors for RF IC development
Authors: Pasciuto B. , Ciccognani W. , Limiti E. , Serino A. , Calvani P. , Corsaro A. , Conte G. , Rossi M. C. 
Published: August 2009

AbstractOn the basis of RF characteristics and measured small‐signal parameters, an equivalent circuit model was formulated and characterized for metal‐semiconductor field effect transistors based on H‐terminated polycrystalline diamond. Starting from on‐wafer measurements, a bias‐dependent transistor behavior representation was fully determined. Such an equivalent circuit model is the first important step to realize an RF IC based on diamond. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2783–2786, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24734
Unidimensional EBG cavities as superstrates of a patch antenna
Authors: Frezza Fabrizio , Pajewski Lara , Ponti Cristina , Schettini Giuseppe 
Published: August 2009

AbstractIn this article, a design of both high‐selectivity and compact one‐dimensional electromagnetic band‐gap (1D‐EBG) cavities is presented, considering the effect of the layers' thickness and of the permittivity of the constitutive materials. Compact and high‐selectivity cavities are proposed, to be employed as spatial filters. In particular, EBG antennas can be obtained when the ground plane of a patch antenna is placed in the symmetry plane of these cavities. An effect of enlargement of the equivalent‐aperture area is determined, resulting in high‐gain radiation. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2769–2774, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24737
Scattering analysis of frequency selective shields for electromagnetic indoor isolation
Authors: Stefanelli Riccardo , Trinchero Daniele 
Published: August 2009

AbstractThe article illustrates numerical and experimental analyses of microwave spatial filters, designed to reduce human exposure to electromagnetic fields in living environments. The identified technological solution makes use of periodic structures with frequency selective behavior. To demonstrate its applicability, some prototypes were designed, manufactured, and measured, thanks to the identification of a dedicated setup. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2758–2762, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24739
Berkson's bias and the mood dimensions of bipolar disorder
Authors: Regeer E.J. , Krabbendam L. , De Graaf R. , Ten Have M. , Nolen W.A. , Van Os J. 
Published: August 2009

AbstractIn this paper we examined whether manic and depressive dimensions independently contribute to mental health service use and determined the degree of comorbidity between manic and depressive dimensions in individuals with and without mental health service use. If both depressive and manic episodes independently influence help‐seeking behaviour, a higher level of comorbidity between these dimensions would be found in clinical as compared to non‐clinical samples (i.e. Berkson's Bias). Data were derived from the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a prospective epidemiological survey in a representative sample of the Dutch population (N = 7076). Dimensions of depression and mania and mental health service use (MHSU) were assessed with the Composite International Diagnostic Interview (CIDI) at baseline, and prospectively one and three years later. Logistic regression was used to test whether depressive and manic dimensions both had independent effects on mental health service use. The degree of mania‐comorbidity given the presence of depressive dimension was assessed as a function of MHSU, both retrospectively and prospectively. Manic and depressive dimensions contributed independently to mental health service use. Mania‐comorbidity given the presence of depressive dimension was significantly higher in individuals with mental health service use than in those without, both retrospectively (16.7% versus 7.1%, p = 0.000) and prospectively (10.8% versus 6.6%, p = 0.017). We conclude that the bipolar phenotype consists of manic and depressive dimensions that may be much more loosely associated than (Berkson) biased clinical observations suggest. A dimension‐specific approach may be more productive in clarifying the aetiology of mood dysregulation. Copyright © 2009 John Wiley & Sons, Ltd.
Facile construction of multivalent targeted drug delivery system from Boltorn® series hyperbranched aliphatic polyester and folic acid
Authors: Wang Jinrong , Xu Tongwen 
Published: August 2009

AbstractThe conjugation of PAMAM dendrimer and folic acid is a well‐studied multivalent targeted drug delivery system, but it is expensive and difficult to be synthesized. To construct an inexpensive and well‐defined multivalent targeted drug delivery system, a cheap carrier — Boltorn® series hyperbranched aliphatic polyester — was proposed as the nanodevice to carry fluorescein, folic acid, and methotrexate. The construction follows a facile route: (1) synthesizing the carrier — a hybrid hyperbranched polymer with acyclic hydroxyls and cyclic carbonate, (2) linking fluorescein to the hyperbranched polymer via the acyclic hydroxyls, (3) opening the ring of the cyclic carbonate with the amino group of folic acid, and (4) attaching the drug methotrexate to the resulting hydroxyls by ring‐opening reaction. In this route, the peripheral hydroxyls of the hyperbranched polymer are divided into two groups and reacted with three reagents in sequence to form the desired multivalent targeted drug delivery system. Copyright © 2009 John Wiley & Sons, Ltd.
Flexible modeling of the cumulative effects of time‐dependent exposures on the hazard
Authors: Sylvestre Marie‐Pierre , Abrahamowicz Michal 
Published: August 2009

AbstractMany epidemiological studies assess the effects of time‐dependent exposures, where both the exposure status and its intensity vary over time. One example that attracts public attention concerns pharmacoepidemiological studies of the adverse effects of medications. The analysis of such studies poses challenges for modeling the impact of complex time‐dependent drug exposure, especially given the uncertainty about the way effects cumulate over time and about the etiological relevance of doses taken in different time periods. We present a flexible method for modeling cumulative effects of time‐varying exposures, weighted by recency, represented by time‐dependent covariates in the Cox proportional hazards model. The function that assigns weights to doses taken in the past is estimated using cubic regression splines. We validated the method in simulations and applied it to re‐assess the association between exposure to a psychotropic drug and fall‐related injuries in the elderly. Copyright © 2009 John Wiley & Sons, Ltd.
Using Image Analysis to Identify Acetylated Distarch Adipate in a Mixture
Authors: Šárka Evžen , Bubník Zdeněk 
Published: August 2009

AbstractThe NIS‐Elements image analysis system, together with microscopic observation, was used to measure the particle size of acetylated distarch adipate (ADA) in three suspensions; a commercial mixture containing other additives and two pure commercial ADA starches. From these data, the particle size distribution was calculated. The starch in the mixture was identified as wheat ADA, and the normality of the size distribution for volume fraction tested. Image analysis can be recommended as a simple and rapid method for identifying the origin of modified starches in commercial powder mixtures.
Validation and modification of the Blade Element Momentum theory based on comparisons with actuator disc simulations
Authors: Madsen Helge Aa. , Bak Christian , Døssing Mads , Mikkelsen Robert , Øye Stig 
Published: August 2009

AbstractA comprehensive investigation of the Blade Element Momentum (BEM) model using detailed numerical simulations with an axis symmetric actuator disc (AD) model has been carried out. The present implementation of the BEM model is in a version where exactly the same input in the form of non‐dimensional axial and tangential load coefficients can be used for the BEM model as for the numerical AD model. At a rotor disc loading corresponding to maximum power coefficient, we found close correlation between the AD and BEM model as concerns the integral value of the power coefficient. However, locally along the blade radius, we found considerable deviations with the general tendency, that the BEM model underestimates the power coefficient on the inboard part of the rotor and overestimates the coefficient on the outboard part. A closer investigation of the deviations showed that underestimation of the power coefficient on the inboard part could be ascribed to the pressure variation in the rotating wake not taken into account in the BEM model. We further found that the overestimation of the power coefficient on the outboard part of the rotor is due to the expansion of the flow causing a non‐uniform induction although the loading is uniform. Based on the findings we derived two small engineering sub‐models to be included in the BEM model to account for the physical mechanisms causing the deviations. Finally, the influence of using the corrected BEM model, BEMcor on two rotor designs is presented. Copyright © 2009 John Wiley & Sons, Ltd.
Comparison between XRF and EPMA applied to study the ionic exchange in zeolites
Authors: Galván V. , Torres Deluigi M. , Mentasty L. , De Vito I. , Riveros J. A. 
Published: August 2009

AbstractZeolites are crystalline aluminosilicates consisting of SiO4 and AlO4 tetrahedral as primary units. One peculiar characteristic of zeolites is the ion exchange capacity defined as the capacity to locate specific cations in the framework of zeolites; it depends on the chemical composition and varies with the structure of the zeolite and with the cation nature.This work studies the exchange of the Na+ monovalent cation of 5A and 13X synthetic zeolites by the Ca2+ bivalent cation present in a CaCl2 solution. X‐ray fluorescence (XRF) and electron probe microanalysis (EPMA) techniques were used to determine the cation exchange capacity (CEC). The efficiencies of the two X‐ray detectors were compared and the minimum detection limits of the zeolite elements were calculated.Although both techniques differ in the sample excitation mode, the results obtained were compatible. The results showed that the CEC was higher for the 5A zeolite, in agreement with its lower SiO2/Al2O3 ratio and its greater BET area. It was also found that the amount of Na+ ions exchanged by Ca2+ ions was in complete agreement with the corresponding molar balance. The determination of the CEC using X‐ray spectroscopy techniques can be considered a novelty as XRF and EPMA techniques permit to analyze the sample directly. Copyright © 2009 John Wiley & Sons, Ltd.
Implementing Fast‐Track Protocol for Colorectal Surgery: A Prospective Randomized Clinical Trial
Authors: Ionescu Daniela , Iancu Cornel , Ion Daniela , Al‐Hajjar Nadim , Margarit Simona , Mocan Lucian , Mocan Teodora , Deac Delia , Bodea Raluca , Vasian Horatiu 
Published: August 2009

AbstractBackgroundFast‐track protocols are followed by an enhanced recovery, early return to bowel function and to complete nutrition, and a reduced hospital stay. Our study was designed to implement fast‐track protocol in our university hospital.MethodsThe 96 consecutive patients with colorectal neoplasm included in the study were randomized in two equal groups: group 1 (FT) included patients undergoing colorectal surgery in a fast‐track protocol, and group 2 (C) included patients undergoing colorectal surgery with a conventional care protocol. As with other fast‐track protocols, our protocol included carbohydrate fluids load before operation, early mobilization and oral feeding, regular prokinetics, and multimodal postoperative analgesia. Time to restoration of bowel function, to complete mobilization and feeding, length of hospital stay, and incidence of complications and readmissions were monitored.ResultsTime to mobilization, restoring of bowel function, and complete oral feeding were significantly shorter with fast‐track protocol (p = 0.001, p = 0.042, and p = 0.01, respectively). Hospital stay also was shorter in the fast‐track group (p = 0.001). The incidence of complications did not significantly differ with the study groups.ConclusionsIn our study, fast‐track protocol resulted in a shorter time to mobilization, complete feeding, and discharge from hospital. Fast‐track protocol did not increase the incidence of complications. However, we consider that our data require further confirmation with powered multicenter national studies.