bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of analysis methods for performance of cavity‐backed slot antennas using the FDTD technique
Authors: Hikage Takashi , Omiya Manabu , Itoh Kiyohiko 
Published: August 2002

AbstractBy applying the FDTD method to the evaluation of the characteristics of a cavity‐backed slot antenna, a design considering the feed structure is possible. In this paper, a feed model suitable for the design and analysis of a cavity‐backed slot antenna is presented. As feed models, a gap voltage model and a coaxial model are used and results of their analysis are compared. From the analysis of the input characteristics, it is revealed that characteristic evaluation is possible in the coaxial model with fewer time steps than the gap voltage model. In the evaluation of the radiation characteristics, the absolute gain evaluation method is presented with a sinusoidal excitation. From the results of analysis of the absolute gain, the results converge within about 15 periods in the case of the coaxial model. The obtained radiation characteristics agree with the experimental results. In the gap voltage model, undulations of the absolute gain values are observed. From a comparison of these characteristic evaluations, the coaxial model is found to be suitable for FDTD analysis of a cavity‐backed slot antenna. © 2001 Scripta Technica, ElectronComm Jpn Pt 1, 84(8): 70–77, 2001
Determination of a structure of one‐dimensional dual‐periodic photonic crystal from an energy spectrum
Authors: Ueta Tsuyoshi 
Published: August 2002

AbstractAn inverse problem is treated for determination of the structure of a one‐dimensional dual‐periodic photonic crystal from the optical characteristics specified for practice. Under the assumption that the light is localized in the higher permittivity layer, a general formulation is obtained for determining the permittivity in the modulated high‐permittivity layer from the structure of the energy spectrum by means of the tight‐binding approximation. The problem is reduced to an algebraic equation. Numerical examples are given for determination of the permittivity. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(5): 1–9, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10029
A measurement of complex permittivity of lossy dielectrics by using flanged rectangular waveguide
Authors: Hirano Makoto , Takahashi Masaharu , Abe Minoru 
Published: August 2002

AbstractIf it is possible to derive the complex permittivity of a dielectric material by measurement of the coefficient of reflection from the aperture of a flanged rectangular waveguide attached to a conductor‐backed lossy dielectric sheet, an effective nondestructive measurement method can be established. In this paper, by solving simultaneous equations derived by an application of the spectral domain method, contour maps for derivation of the complex permittivity of a lossy dielectric from the reflection coefficient are formed and their characteristics are studied. The effectiveness of these contour maps is confirmed by experiments. In the region within the contour chart where the permittivity can be determined with good accuracy, it can be determined with an error of about 5% by means of a general‐purpose network analyzer. Further, the attenuation of the electromagnetic wave within the lossy dielectric in the direction of propagation is studied in order to derive the dimensions of the sample and flange needed for actual measurement. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(4): 59–67, 2001
The influence of SiON film composition on HIGFET characteristics
Authors: Ohshika Katsushi , Kuroda Jun , Yanazawa Hiroshi 
Published: August 2002

AbstractThis paper evaluates the characteristics of a 0.35‐µm WSi gate HIGFET which uses SiON insulation films for passivation, and also evaluates their reliability. The SiON film was formed by applying plasma CVD using the refractive index of SiON film for the film composition. The best FET characteristics have been obtained with a SiON film with a refractive index of 1.58. The authors have described [1,2] a deterioration mode of 0.35‐µm HIGFETs in which the gate leak current increases in the gate‐drain reversed‐bias stress test. No deterioration occurred this time in the same test with the SiON film having a refractive index of 1.58. It is concluded from the test results of spectroscopic ellipsometric analysis, Auger electron spectroscopy, and XPS that this excellent result is due to the thermal stability of the film, and not to characteristics such as film composition and SiON/GaAs reaction; and that SiON films with a refractive index other than 1.58 often form As, AsO, As2O3, and Ga2O3 on the interface between the insulation film and the GaAs. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(5): 50–58, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1107
A model of the neuron based on dendrite mechanisms
Authors: Tang Zheng , Tamura Hiroki , Kuratu Makoto , Ishizuka Okihiko , Tanno Koichi 
Published: August 2002

AbstractIn this paper, a model of the neuron based on the dendrite mechanism is proposed. The neuron model takes the form of a dendrite, and the interaction between synapses and so on, which are not considered by the conventional model, is taken into account. In this paper, the form of a dendrite is assumed to be arbitrary and interaction is assumed to exist among all synapses. That is, a superfluous synapse is formed, and is expressed in a logical network, then the equivalence between them is shown. The ripened dendrite is formed during learning by screening unnecessary dendrites, and strengthening and fixing the useful dendrites. The model proposed in this paper can correspond to the linearly unseparated problem, unlike the one‐layer traditional neuron. Moreover, learning of this model suggests the form of the dendrites and the positions of the excitation and inhibition synapses. This may give some very useful suggestions for biologists. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(8): 11–24, 2001
Experimental investigation of discharge characteristics of a surface‐wave‐produced planar plasma
Authors: Yanagita Norihito , Itagaki Toshifumi , Katsurai Makoto 
Published: August 2002

AbstractExperimental investigations of the discharge characteristics of planartype surfacewaveproduced plasmas (SWP) have been carried out. On this apparatus, the efficiency of microwave power absorption into the plasma depends strongly on the thickness of the dielectric window. Especially at a thickness of 12 mm, it has been found that more than 80% of microwave power is absorbed into the plasma. In order that the uniform power absorption is brought about effectively in a wide range of gas pressures, the dielectric waveguide that is placed above the dielectric window needs the air gap between them. These experimental results will enable us to improve the apparatus configuration to achieve better operational performances of surface wave plasmas. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 9–18, 2002
A unified strategy for building simple air quality indices
Authors: Bruno Francesca , Cocchi Daniela 
Published: August 2002

AbstractInterest in air quality indices has been increasing in recent years. This is strictly connected with the development and the easy availability of web‐communication and on‐line information. By means of web pages it is indeed possible to give quick and easy‐to‐consult information about air quality in a specific area. We propose a class of air quality indices which are simple to read and easy to understand by citizens and policy‐makers. They are constructed in order to be able to compare situations that differ in time and space. In particular, interest is focused on situations where many monitoring stations are operating in the same area. In this case, which occurs frequently, air pollution data are collected according to three dimensions: time, space and type of pollutant. In order to obtain a synthetic value, the dimensions are reduced by means of aggregation processes that occur by successively applying some aggregating function. The final index may be influenced by the order of aggregation. The hierarchical aggregation here proposed is based on the successive selection of order statistics, i.e. on percentiles and on maxima. The variety of pollutants measured in each area imposes a standardization due to their different effects on the human health. This evaluation comes from epidemiological studies and influences the final value of the index. We propose to use simultaneously more than one index of the selected class and to associate a measure of variability with every index. Such measures of dispersion account for very important additional information. Copyright © 2002 John Wiley & Sons, Ltd.
Simplified analysis of asymmetric structures with supplemental damping
Authors: Goel Rakesh K. 
Published: August 2002

AbstractThis study investigated the effects of neglecting off‐diagonal terms of the transformed damping matrix on the seismic response of non‐proportionally damped asymmetric‐plan systems with the specific aim of identifying the range of system parameters for which this simplification can be used without introducing significant errors in the response. For this purpose, a procedure is presented in which modal damping ratios computed by neglecting off‐diagonal terms of the transformed damping matrix are used in the traditional modal analysis. The effects of the simplification are evaluated first by comparing the aforementioned modal damping ratios with the apparent damping ratios obtained from the complex‐valued eigenanalysis. The variation of a parameter that was defined by Warburton and Soni as an indicator of the errors introduced by the simplification is examined next. Finally, edge deformations obtained from the simplified procedure are compared with those obtained from the direct integration of the equations of motion. It is found that the simplified procedure may be used without introducing significant errors in response for most practical values of the system parameters. Furthermore, estimates of the edge deformations, in general, tend to be on the conservative side. Copyright © 2001 John Wiley & Sons, Ltd.
Runoff‐induced sediment yield over dune slopes in the Negev Desert. 1: Quantity and variability
Authors: Kidron Giora J. , Yair Aaron 
Published: August 2002

AbstractAlthough extensive data exist on runoff erosion and rates for non‐sandy hillslopes, data for arid dune slopes are scarce, owing to the widespread perception that the high infiltrability of sand will reduce runoff. However, runoff is generated on sandy dunes in the Hallamish dune field, western Negev Desert, Israel (P  ≈ 95 mm) due to the presence of a thin (usually 1–3 mm) microbiotic crust. The runoff in turn produces erosion.Sediment yield was measured on ten plots (140–1640 m2) on the north‐ and south‐facing slopes of longitudinal dunes. Two plots facing north and two facing south were subdivided into three subplots. The subplots represented the crest of the active dune devoid of crust, the extensively crusted footslope of the dune, and the midslope section characterized by a patchy crust. The remaining plots extended the full length of the dune slope.No runoff and consequently no water‐eroded sediments were obtained from the crest subplots devoid of crust. However, runoff and sediment were obtained from the mid‐ and footslope crusted subplots. Sediment yield from the footslope subplots was much higher than from the midslopes, despite the higher sediment concentration that characterized the midslope subplots.The mean annual sediment yield at the Hallamish dune field was 432 g per metre width and was associated with high average annual concentrations of 32 g l−1. The data indicate that owing to the presence of a thin microbiotic crust, runoff and water erosion may occur even within arid sandy dune fields. Copyright © 2001 John Wiley & Sons, Ltd.
Enantioselective analysis of monoterpene compounds in essential oils by stir bar sorptive extraction (SBSE)–enantio‐MDGC–MS
Authors: Kreck Mirjam , Scharrer Annette , Bilke Steffi , Mosandl Armin 
Published: August 2002

AbstractStir bar sorptive extraction (SBSE), a recently introduced solventless extraction technique, was applied for the enantioselective analysis of chiral monoterpenes in tea tree oil, eucalyptus oil and thyme oil using enantioselective multidimensional gas chromatography–mass spectrometry (enantio‐MDGC–MS). In addition, headspace sorptive extraction (HSSE) and in vivo headspace sorptive extraction (in vivo HSSE) of the chiral monoterpenes in three aromatic and medicinal plants, thyme [Thymus vulgaris (L.)], eucalyptus [Eucalyptus globulus (L.)] and tea tree [Melaleuca alternifolia (C.)], was investigated and the results of the different sampling techniques were compared and discussed. This method was utilized in order to establish characteristic authenticity profiles of the essential oils. Moreover, the enantiomeric ratios of the major and minor chiral components emitted in living plants were determined. Copyright © 2001 John Wiley & Sons, Ltd.
Essential oils from aerial parts of Aristolochia gibertii Hook.
Authors: Priestap Horacio A. , van Baren Catalina M. , Leo Lira Paola Di , Prado Héctor J. , Neugebauer Michael , Mayer Ralf , Bandoni Arnaldo L. 
Published: August 2002

AbstractThe leaf and stem volatile constituents of Aristolochia gibertii Hook., obtained by hydrodistillation, were analysed by GC and GC–MS. Monoterpenes and sesquiterpenes (20–21), amounting to 77.8–80.3% of the total oil, were identified in the leaf oils, bicyclogermacrene being the main component (38.1–42.2%). Components (28–35) were identified in the oils isolated from the stems, constituting 86.6–92.3% of the total volatiles. These oils were dominated by limonene (38.5–56.8%). The leaf and stem oils were also found to contain the sesquiterpene lactone, aristolactone, in varying amounts (1.6–9.9%). The olfactory profiles of these oils were characterized and found to have very interesting organoleptic qualities. Copyright © 2001 John Wiley & Sons, Ltd.
High resolution flux‐difference‐splitting scheme on adaptive grid for open‐channel flows
Authors: Jha Akhilesh Kumar , Akiyama Juichiro , Ura Masaru 
Published: August 2002

AbstractThe effectiveness and usefulness of further enhancing the shock resolution of a second‐order accurate scheme for open‐channel flows by using an adaptive grid is investigated. The flux‐difference‐splitting (FDS) scheme based on the Lax–Wendroff numerical flux is implemented on a fixed as well as on a self‐adjusting grid for this purpose. The grid‐adjusting procedure, developed by Harten and Hyman, adjusts the grid by averaging the local characteristic velocities with respect to the signal amplitude in such a way that a shock always lies on a mesh point. This enables a scheme capable of perfectly resolving a stationary shock to capture a shock that moves from mesh point to mesh point. The Roe's approximate Jacobian is used for conservation and consistency, while theoretically sound treatment for satisfying entropy inequality conditions ensures physically realistic solutions. Details about inclusion of source terms, often left out of analyses for the homogeneous part of governing equations, are also explained. The numerical results for some exacting problems are compared with analytical as well as experimental results for examining improvements in resolution of discontinuities by the adaptive grid. Copyright © 2001 John Wiley & Sons, Ltd.
Parallel solution of a coupled flow and transport model for shallow water
Authors: Sommeijer B. P. , van der Houwen P. J. 
Published: August 2002

AbstractWe present an integrated approach for the concurrent solution of a 3D hydrodynamical model coupled with a 3D transport model. Since both models are quite similar in nature, the same numerical method has been employed. This leads to a code that is more efficient than when two existing codes would have been combined.Discretization of the spatial differential operators, and the boundary conditions, results in a stiff initial value problem. To cope with the stiffness, we select an implicit time‐integration formula, viz. the second‐order, L‐stable BDF method because of its excellent stability properties. To reduce the huge amount of linear algebra involved in solving the implicit relations, an Approximate Factorization technique has been used. Essentially, this technique replaces a ‘multi‐dimensional’ system by a series of ‘one‐dimensional’ systems.Since the output of the hydrodynamical model (i.e., the flow field) serves as input for the transport model, we solve the hydrodynamical model one time step ahead in time. This allows us to solve the models in parallel, using two different groups of processors. By a little tuning of the parameters in the algorithm, a load‐balancing has been obtained that is close to optimal. As a result, both models require roughly the same amount of CPU time, so that one of them, effectively, can be considered as obtained ‘for free’. Copyright © 2002 John Wiley & Sons, Ltd.
A three‐dimensional boundary layer scheme: stability and accuracy analyses
Authors: Horri‐Naceur Jalil , Buisine Daniel 
Published: August 2002

AbstractWe present a numerical scheme for the calculation of incompressible three‐dimensional boundary layers (3DBL), designed to take advantage of the 3DBL model's overall hyperbolic nature, which is linked to the existence of wedge‐shaped dependence and influence zones. The proposed scheme, explicit along the wall and implicit in the normal direction, allows large time steps, thus enabling fast convergence. In order to keep this partly implicit character, the control volumes for the mass and momentum balances are not staggered along the wall. This results in a lack of numerical viscosity, making the scheme unstable. The implementation of a numerical diffusion, suited to the local zone of influence, restores the stability of the boundary layer scheme while preserving second‐order space accuracy. The purpose of this article is to present the analytical and numerical studies carried out to establish the scheme's accuracy and stability properties. Copyright © 2002 John Wiley & Sons, Ltd.
Double minute chromosomes in acute myeloid leukemia and myelodysplastic syndrome: Identification of new amplification regions by fluorescence in situ hybridization and spectral karyotyping
Authors: Sait Sheila N.J. , Qadir Misbah U. , Conroy Jeffrey M. , Matsui Sei‐Ichi , Nowak Norma J. , Baer Maria R. 
Published: August 2002

AbstractDouble minute chromosomes (dmin) are small chromatin bodies consisting of genes amplified in an extrachromosomal location. dmins are uncommon in hematologic malignancies; they are seen primarily in acute myeloid leukemia, with amplification of the MYC oncogene or, less frequently, the MLL transcription factor. Nine patients with hematologic malignancies with dmin were seen at the Roswell Park Cancer Institute between 1985 and 2000; eight had acute myeloid leukemia and one a myelodysplastic syndrome. Fluorescence in situ hybridization (FISH) demonstrated MYC amplification on dmin in four patients, but MLL amplification was not seen. Spectral karyotyping showed that the dmin derived from chromosome 11 in one patient and from chromosome 19 in two others without MYC or MLL amplification; derivation from these chromosomes was confirmed by FISH with chromosome paint probes. The dmin of chromosome 11 origin hybridized to a bacterial artificial chromosome (BAC) RP11‐112M22 that maps to 11q24.3 and is predicted to contain ETS1 and other markers, including D11S11351 and D11S4091. The dmin of chromosome 19 origin in one patient hybridized to BACs RP11‐46I12 and RP11‐110J19; in the other patient, these clones did not hybridize with the dmin, but were found to be amplified on a marker chromosome that was derived from chromosome 19 in that patient's cells. These BACs have been mapped to 19q12–19q13.1 and 19q11–19q13.1, respectively, and are predicted to contain the markers D19S409 and D19S919 and the gene for ubiquinol‐cytochrome C reductase, Rieske iron‐sulfur polypeptide1 (UQCRFS1). dmin originating from chromosome 19 have not been reported previously in hematologic malignancies. © 2002 Wiley‐Liss, Inc.
Low levels of Sry transcripts cannot be the sole cause of B6‐YTIR sex reversal
Authors: Lee Chung‐Hae , Taketo Teruko 
Published: August 2002

AbstractSummary: Sry, a single‐copy gene on the Y‐chromosome, triggers the fetal gonad to begin testis differentiation in mammals. On the other hand, mutation or absence of Sry results in ovary differentiation and the female phenotype. However, cases of XY sex reversal in the presence of wild‐type Sry exist in mice and man. One such example is the B6‐YTIR mouse, whose autosomes and X‐chromosome are from the C57BL/6J mouse (an inbred strain of Mus musculus molossinus), whereas the Y‐chromosome is from a Mus musculus domesticus mouse originating in Tirano, Italy. The B6‐YTIR mouse never develops normal testes and instead develops ovaries or ovotestes in fetal life. It has been suggested that low levels of Sry transcription may account for the aberrant testis differentiation in the B6‐YTIR mouse. In this study, however, we observed relatively low levels of Sry transcripts not only in B6‐YTIR but also in B6 mice, which develop normal testes. We conclude that low dosage of Sry transcripts cannot be the sole cause of sex reversal in the B6‐YTIR gonad. genesis 30:7–11, 2001. © 2001 Wiley‐Liss, Inc.
Carbohydrate source influences gelatinase production by mouse astrocytes in vitro
Authors: Massengale Justin L. , Gasche Yvan , Chan Pak H. 
Published: August 2002

AbstractMolecular mediators of ischemic brain injury include intercellular adhesion molecule‐1 (ICAM‐1) and matrix metalloproteinase‐9 (MMP‐9), involved in the alteration of blood‐brain barrier permeability and induced in astroglial cultures by tumor necrosis factor‐α (TNF‐α). Hyperglycemia is known to aggravate in vivo ischemic brain damage, while treatment with sorbitol shows benefit in reducing vasogenic brain edema. This study investigated whether a culture medium carbohydrate source could alter the astrocyte production of MMP‐9 and ICAM‐1 in vitro. The growth of astrocytes in 12.5 mM glucose, 25 mM glucose, or 25 mM sorbitol for 14 days did not alter cellular release of lactate dehydrogenase, uptake of Trypan blue, or surface expression of glial fibrillary acidic protein (GFAP). ICAM‐1 levels were similar in astrocytes grown in glucose or sorbitol both under basal conditions and after TNF‐α stimulation for 48 h. In contrast, levels of proMMP‐9 released from astrocytes cultured for 14 days in 25 mM sorbitol reached only 55–28% of those obtained from cultures in 25 mM glucose after stimulation with 1,000 U/ml (P = 0.05) or 5,000 U/ml (P < 0.025) TNF‐α, respectively. Limiting the duration of pre‐stimulation sorbitol exposure to 48 h resulted in lower proMMP‐9 levels than in glucose cultures after 5,000, but not 1,000, U/ml TNF‐α, and differences were not significant when sorbitol exposure was further reduced to 24 h. Incubation in mixed glucose/sorbitol media did not affect the release of proMMP‐9. These findings suggest that MMP‐9 production may be increased in astrocytes as a consequence of glucose metabolism, which can be avoided by growth in sorbitol alone. GLIA 38:240–245, 2002. © 2002 Wiley‐Liss, Inc.