bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stable modelling of arbitrary thin slots in the finite‐element time‐domain method
Authors: Edelvik F. , Weiland T. 
Published: July 2004

AbstractA subcell model for arbitrarily located thin wires in the finite‐element time‐domain (FETD) method using modified telegraphers equations has been developed by Edelvik et al. Recently a dual set of equations has been proposed for modelling of thin slots. In this paper, we show that using a similar algorithm as for thin wires we can take thin slots of arbitrary location into account. Previous thin slot models have been susceptible for instabilities. We prove that a symmetric coupling between field and slot yields a stable time‐continuous field–slot system and that the fully discrete field–slot system is unconditionally stable. The proposed method is demonstrated for scattering from straight and circular slots in an infinite conducting wall and for calculating the power delivered to a shielding enclosure including a slot. The results are in good agreement with published experimental data. Copyright © 2004 John Wiley & Sons, Ltd.
A general stability analysis of FIT/FDTD applied to lossy dielectrics and lumped elements
Authors: Edelvik F. , Schuhmann R. , Weiland T. 
Published: July 2004

AbstractStability analysis of the finite‐difference time‐domain (FDTD) method is usually performed using von Neumann analysis, where a necessary condition for stability is obtained by requiring the amplitude of discrete Fourier modes defined on the grid to remain bounded. However, this limits the analysis to homogeneous materials, equidistant grids and unbounded domains. A rare situation in practical computations. In this paper we analytically derive sufficient conditions for stability of FDTD using the energy method. This method does not have the restrictions of von Neumann analysis and we are therefore able to derive closed‐form conditions for stability in the case of non‐homogeneous and lossy dielectrics, non‐homogeneous permeability and varying cell sizes. Moreover, the analysis is applied to different lumped elements. In addition, a discussion of advantages and disadvantages of different discrete energy definitions in FDTD is included. Copyright © 2004 John Wiley & Sons, Ltd.
Neutralization of the chemokine CXCL10 enhances tissue sparing and angiogenesis following spinal cord injury
Authors: Glaser Janette , Gonzalez Rafael , Perreau Victoria M. , Cotman Carl W. , Keirstead Hans S. 
Published: July 2004

AbstractAfter spinal cord injury, there is a chemoattractant‐mediated inflammatory response that is associated with secondary degeneration. The chemoattractant CXCL10 recruits CD4 Th1 cells via the CXCR3A receptor and inhibits growth and chemotaxis of endothelial cells via the CXCR3B receptor. To test the hypothesis that CXCL10 inhibits angiogenesis following spinal cord injury, we assayed the brainstems and spinal cords of spinal cord‐injured mice treated with anti‐CXCL10 antibodies for expression of angiogenesis‐associated genes and quantified blood vessels within their spinal cords. Brainstem microarray analysis indicated eight angiogenesis‐associated genes that had significantly higher expression levels in the treated mice than in the untreated mice. Ribonuclease protection assays of the spinal cords showed a significant increase in eight angiogenesis‐associated genes in treated animals compared with untreated animals. Histological analysis of the spinal cords of treated and untreated mice showed a significant increase in the number of blood vessels in treated animals. We conclude that CXCL10 plays a critical role in vasculature remodeling following spinal cord injury and that angiogenesis is enhanced following anti‐CXCL10 treatment of spinal cord injuries. Improved blood flow and oxygen supply to the injury site may contribute to the functional improvement associated with this treatment. © 2004 Wiley‐Liss, Inc.
Microarray analysis of postmortem temporal cortex from patients with schizophrenia
Authors: Aston Christopher , Jiang Lixin , Sokolov Boris P. 
Published: July 2004

AbstractTo examine molecular mechanisms associated with schizophrenia this study measured expression of approximately 12,000 genes in the middle temporal gyrus from 12 subjects with schizophrenia and 14 matched normal controls. Among the most consistent changes in genes with robust expression were significant decreases in the expression of myelination‐related genes MAG, PLLP (TM4SF11), PLP1, ERBB3 in subjects with schizophrenia. There was also altered expression of genes regulating neurodevelopment (TRAF4, Neurod1, histone deacetylase 3), a circadian pacemaker (PER1), and several other genes involved in regulation of chromatin function and signaling mechanisms. These findings support the hypothesis that schizophrenia is associated with abnormalities in oligodendroglia and provide initial evidence suggesting a role for epigenetic mechanisms and altered circadian rhythms in this disorder. © 2004 Wiley‐Liss, Inc.
Interpreting shock tube ignition data
Authors: Davidson D. F. , Hanson R. K. 
Published: July 2004

AbstractChemical kinetic modelers make extensive use of shock tube ignition data in the development and validation of combustion reaction mechanisms. These data come from measurements using a range of diagnostics and a variety of shock tubes, fuels, and initial conditions. With the wide selection of data available, it is useful to realize that not all of the data are of the same type or quality, nor are all the data suitable for simple, direct comparison with the predictions of reaction mechanisms. We present here a discussion of some guidelines for the comparison of shock tube ignition time data with reaction mechanism modeling. Areas discussed include definitions of ignition time; ignition time correlations (with examples taken from recent n‐heptane and isooctane measurements); shock tube constant‐volume behavior; shock tube diameter and boundary layer effects; carrier gas and impurity effects; and future needs and challenges in shock tube research. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36:510–523, 2004
Polymerization Catalysis in Liquid Propylene: High Activities and Molecular Weights in Propylene/CO Copolymerization Reactions
Authors: Hollmann Frank , Meier Uwe W. , Pérez‐Foullerat David , Rieger Bernhard 
Published: July 2004

AbstractSummary: The dicationic [(dppp)Pd(NCCH3)2](BF4)2 catalyst (dppp = 1,3‐bis(diphenylphosphino)propane) was applied in a liquid monomer, two phase process for the CO/propene copolymerization reaction. For the first time it was possible to synthesize propene/CO copolymers with an activity up to 7 500 g/(mol · h) and molecular weights of 500 000 g/mol. Activities up to 40 000 g/(mol · h) could be obtained with the use of the unsymmetric catalyst [(CF3‐dppp)Pd(NCCH3)](BF4)2 (CF3‐dppp = 1‐diphenylphosphino‐3‐bis[3,5‐di(trifluormethyl)phenyl]phosphinopropane) in homogeneous liquid propene solution.Granules found after copolymerization.magnified imageGranules found after copolymerization.
Tetrathiophene on Graphite: Molecular Dynamics Simulations
Authors: Marcon Valentina , Raos Guido , Allegra Giuseppe 
Published: July 2004

AbstractSummary: We describe molecular dynamics simulations of α‐tetrathiophene molecules deposited on a flat graphite substrate, at two different temperatures (300 K and 400 K) and several degrees of coverage (from approximately one to three molecular layers). The simulations employ a modified version of the CFF91 force field, with the torsion parameters tailored on high‐level ab initio calculations on 2,2′‐bithiophene. We found that the molecules in the first layer were relatively planar and packed against the underlying surface, while those outside it were not arranged in well‐defined layers and were more conformationally disordered. On the time scale of the simulation, the molecules did not crystallize but rather achieved a liquid crystalline‐like state with their average director parallel to the surface.Side view of the final configuration in the simulation of 24 tetrathiophenes at 300 K. Molecules are depicted with different shades of gray according to their z coordinate (first, second or third layer).imageSide view of the final configuration in the simulation of 24 tetrathiophenes at 300 K. Molecules are depicted with different shades of gray according to their z coordinate (first, second or third layer).
Effects of upper‐patch displacement on the operation of dual‐band stacked microstrip patch antennas
Authors: Akhavan H. G. , Mirshekar‐Syahkal D. 
Published: July 2004

AbstractThe displacement of the upper patch in the resonant direction in a dual‐band stacked microstrip patch antenna controls the centre frequencies of the bands, their separation, the input impedance, and the radiation pattern at the upper band. The radiation pattern has low sensitivity to the displacement and, hence, dual‐band stacked microstrip patch antennas can be designed with have similar radiation patterns at both bands. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 351–353, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20302
Dispersion‐compensation techniques for the PSTD algorithm
Authors: Gao Xiang , Mirotznik Mark S. , Prather Dennis W. 
Published: July 2004

AbstractIn this paper, simple modifications to the pseudospectral time‐domain (PSTD) algorithm that offer dispersion compensation are presented. In a homogeneous lossless medium, the compensation offers an exact solution for one‐dimensional (1D) propagation. For 2D and 3D propagation, the proposed method can compensate dispersion for a central frequency in any direction. The techniques are then extended to inhomogeneous materials containing piecewise constant electromagnetic properties and are shown to offer dispersion compensation. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 357–361, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20304
Sommerfeld integrals for left‐handed materials
Authors: Chew W. C. 
Published: July 2004

AbstractWe study the properties of left‐handed materials (LHMs) with the precise help of Sommerfeld integrals. First we argue by energy conservation principles that LHM has to be a backward‐wave material (BWM). Then we derive the equivalence of the loss and the Sommerfeld far‐field radiation conditions for a BWM. Next, we solve the realistic Sommerfeld problem of a point source over an LHM half‐space and an LHM slab. This analysis lends physical insight into the interaction of a point source field with an LHM, showing that super‐resolution is possible with an LHM slab. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 369–373, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20307
An improved electronic selector circuit for WDM optical receivers in packet‐switched PON networks
Authors: Manfrin S. K. , De Dominicis M. , Orengo G. , Giannini F. , Romero M. A. 
Published: July 2004

AbstractIn this work, we revisit a tunable optical‐receiver configuration based on nontunable wavelength demultiplexing and electronic channel selection. Compared to previous designs, our novel electronic selector circuit provides a significant reduction in the average noise current, while simultaneously achieving the high tuning speed required at the optical network unit (ONU) of packet‐switched WDM‐PON networks. Also, for the first time (to our knowledge), this kind of circuit is demonstrated to operate well above one GB/s. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 373–377, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20308
Experimental characterization of light polarization in active erbium‐doped fiber
Authors: Quintela M. A. , Jauregui C. , Madruga F. J. , López‐Higuera J. M. 
Published: July 2004

AbstractExperimental results on the dependence of the polarization state of the optical signal upon pump power, signal wavelength, and optical‐signal power in active erbium‐doped fibers (EDFs) are reported in this paper. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 395–397, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20315
Temperature characterisation of long‐period gratings for sensor applications
Authors: O'Flaherty F. J. , Ghassemlooy Z. , Mangat P. S. , Dowker K. P. 
Published: July 2004

AbstractLong‐period gratings, which display sensitivity to ambient temperature variations, are proposed as sensors. Therefore, full temperature characterisation is essential. In this paper, the effects of temperature upon the spectral profiles of two sets of long period gratings (LPGs) of different periods are investigated. The results obtained show that the shorter‐period LPGs were found to be less sensitive than the longer‐period LPGS over identical temperature ranges. The coupling wavelength shifts due to temperature are also seen to be linear and in opposite directions in each set of LPGs. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 402–405, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20317
Studies of the microstrip monopole antenna with windowed ground plane
Authors: Wang Chien‐Jen , Hsu De‐Fu 
Published: July 2004

AbstractIn this paper, the effects of the monopole antenna with windowed ground plane have been studied, including the impedance condition and the radiation patterns. A circularly microstrip monopole antenna is used as a radiated element. By utilizing a circular or rectangular slot of the extended ground plane to change the distribution of the electrical field, the injected power radiates from the slot and patch regions. According to the measured results, the radiation patterns and the antenna gain have been improved. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 407–411, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20319
A synthetic‐aperture algorithm for ground‐penetrating radar imaging
Authors: Ozdemir Caner , Lim Sungkyun , Ling Hao 
Published: July 2004

AbstractA formulation for ground‐penetrating radar (GPR) imaging using the synthetic‐aperture concept is introduced. We show that it is possible to form a 3D image by inverse Fourier transforming the multifrequency, multispatial scattered field. The proposed algorithm for GPR imaging is tested with measured and simulated data. The resultant images demonstrate good agreement between the measured and simulated cases. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 412–414, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20320
An injection locked sub‐harmonic self‐oscillating mixer for multi‐band operation
Authors: Chiu L. , Yum T. Y. , Cheng T. F. , Xue Q. , Chan C. H. 
Published: July 2004

AbstractA high‐performance X‐band subharmonic self‐oscillating mixer (SOM) is proposed. By using a reconfigurable transistor pair in conjunction with open‐ and short‐circuit stubs, the proposed SOM is capable of down‐converting four RF frequency bands with center frequencies at 7.35, 8.65, 11.35, and 12.65 GHz with a conversion gain ranging from 7.83 to 18.7 dB. The measured phase noise of the free‐running oscillation is −85.4 dBc/Hz at an offset frequency of 100 kHz. With injection locking, the phase noise is reduced to less than −100 dBc/Hz at 10 kHz, without affecting the conversion gains. This is the first demonstration of a multiband subharmonic SOM. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 415–419, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20321
Dielectric permittivity and loss factor of tap water at 915 MHz
Authors: Komarov Vyacheslav V. , Tang Juming 
Published: July 2004

AbstractReal and imaginary parts of complex dielectric permittivity of hot tap water are measured at 915 MHz. The obtained results are compared with theoretical and experimental data available in the literature. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 419–420, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20322
Series‐coupled microring resonator filters with embedded semiconductor optical amplifiers
Authors: Schwelb Otto , Frigyes István 
Published: July 2004

AbstractBack reflections from series‐coupled optical microring resonator filters caused by waveguide discontinuities are numerically investigated and optimized. The focus is on small discontinuities, such as those that can be expected from GaInAsP/InP‐based semiconductor optical amplifiers (SOAs) embedded in ring resonators. Significant improvement of the return loss is obtained when the length of the SOA is appropriately chosen. The design principle is applied to both all‐pass (two‐port) and add/drop (four‐port) filters. The sensitivity of the design to fabrication parameters is discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 427–432, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20326
Application of micropolar plasticity to post failure analysis in geomechanics
Authors: Manzari Majid T. 
Published: July 2004

AbstractA micropolar elastoplastic model for soils is formulated and a series of finite element analyses are employed to demonstrate the use of a micropolar continuum in overcoming the numerical difficulties encountered in application of finite element method in standard Cauchy–Boltzmann continuum. Three examples of failure analysis involving a deep excavation, shallow foundation, and a retaining wall are presented. In all these cases, it is observed that the length scale introduced in the polar continuum regularizes the incremental boundary value problem and allows the numerical simulation to be continued until a clear collapse mechanism is achieved. The issue of grain size effect is also discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Overcoming Cynicism: Youth Participation and Electoral Politics
Authors: Strama Mark 
Published: July 2004

AbstractYoung people have not lost their civic spirit. Studies indicate a much higher level of volunteerism in today's generation of young people than in that of their more politically active parents thirty years ago.Yet voter turnout among youth is lower than ever before. Structural barriers to youth voting account for some of the problem, but attempts to engage youth in politics must take into account the need for fundamental reforms to make the system more open, fairer, and more accountable.
Four Communities on the Cutting Edge of Change: Seattle, Washington; Lee's Summit, Missouri; Lima, Ohio; and Bronx County, New York
Authors: Bainter Ric , Lhevine Paul , Okubo Derek , Leighninger Matt , McGrath Michael 
Published: July 2004

AbstractCivic activists are breaking new ground on a wide variety of public concerns—everything from political reform to the need to bridge the racial gaps in our communities. From the community‐based work of the National Civic League and the Study Circles Resource Center come four examples of cutting‐edge approaches to problem‐solving efforts at the local level.
Perspectives on Public Participation
Authors: Stephens John B. 
Published: July 2004

AbstractDealing with an Angry Public: The Mutual Gains Approach to ResolvingDisputes
, by Lawrence Susskind and Patrick FieldInvolving Citizens in Community Decision Making: A Guidebook
, by James L.CreightonPublic Participation in Public Decisions: New Skills and Strategies forPublic Managers
, by John Clayton Thomas
Social Capital and Community Building: Part Two
Authors: Wallis Allan 
Published: July 2004

AbstractPart One (NCR Vol. 87, No. 3) presented three perspectives on the idea of social capital: the points of view of academicians, advocates, and grantmakers. Part Two begins with a fourth perspective on social capital, that of practitioners working in communities. The article concludes by considering how empowerment evaluation can be used as a way of bringing these four perspectives together to advance formation of social capital in support of effective community building.
Molecular design of functional polymer surfaces
Authors: Koberstein Jeffrey T. 
Published: July 2004

AbstractThree design principles are presented that allow for the molecular design of functional polymer surfaces: surface segregation, surface structure, and surface reorganization. These design principles are illustrated by a description of the behavior of model end‐functional polymers that accurately reflect the general behavior of essentially all possible linear functional polymer architectures. Several applications of the design principles are described to show how they may be used to provide molecular engineering solutions for problems of practical interest. The applications include the optimization of functional polymer architectures for producing adhesive and release surfaces, the suppression of dewetting by the use of functional additives to lower the surface tension of a coating, and the creation of smart polymer surfaces with selective adhesion properties. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2942–2956, 2004
Density functional method based on wavelets for quantum classical systems
Authors: Chuev G. N. , Fedorov M. V. 
Published: July 2004

AbstractDiscrete wavelets are applied to calculate distribution functions of quantum classical system treated by the density functional method. The Coifman basis set is used for approximating the correlation functions and the minimization of the free energy functional of the system. The scheme is applied to calculate properties of coupled hydrated electrons. The quality of approximation is verified by calculations of the solvation energy of the single hydrated electron and bipolaron. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
DC strong field stark effect for nonhydrogenic atoms: Consistent quantum mechanical approach
Authors: Glushkov Alexander V. , Ambrosov Sergey V. , Ignatenko Anna V. , Korchevsky Dmitry A. 
Published: July 2004

AbstractA DC Stark effect for nonhydrogenic atoms in an external uniform electric field is calculated within a consistent quantum mechanical approach: the modified operator perturbation theory. The positions of the high‐excited Stark resonances for the Na atom are calculated in good agreement with known experimental data. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Cooperative laser‐electron‐nuclear processes: QED calculation of electron satellites spectra for multi‐charged ion in laser field
Authors: Glushkov Alexander V. , Malinovskaya Svetlana V. , Chernyakova Yulia G. , Svinarenko Andrey A. 
Published: July 2004

AbstractA consistent quantum electrodynamics (QED) perturbation theory approach is developed and applied to calculation of the electron‐nuclear γ‐transition spectra of nucleus in the multi‐charged ion. The intensities of satellites are defined in the relativistic version of the energy approach (S‐matrix formalism). Decay and excitation probabilities are linked with an imaginary part of the energy of the “nuclei nucleons‐electron shells‐field” system. As an example, the nuclear transition in the isotope Fe with an energy of 14.41 keV is considered. The results of the relativistic calculation for the electron‐nuclear γ‐transition spectra (set of electron satellites) of the nucleus in a multi‐charged atomic ion FeXIX are presented and compared with the corresponding nonrelativistic estimates. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
A Model for Staff Development in Student Affairs
Authors: Grace‐Odeleye Beverlyn 
Published: July 2004

AbstractIn the last decade, there has been an increased understanding of the necessity for staff development and training for student affairs personnel. This chapter provides a historical and current overview of staff development program models in higher education. It also traces the establishment of the Ball State University Division of Student Affairs staff development program as a model in staff development design and functional program services.