Results 191 to 200 of about 2,607 (224)
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, 2020
A genese dos solos esta ligada a fatores presentes na paisagem, a variacao nas suas caracteristicas morfologicas esta relacionada diretamente a diferentes processos de formacao.
José Guilherme de Oliveira +2 more
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A genese dos solos esta ligada a fatores presentes na paisagem, a variacao nas suas caracteristicas morfologicas esta relacionada diretamente a diferentes processos de formacao.
José Guilherme de Oliveira +2 more
semanticscholar +1 more source
Invariant BEM-SIBC formulations for time- and frequency-domain eddy current problems
IEEE Transactions on Magnetics, 2000We demonstrate that frequency- and time-domain boundary integral equation formulations involving the surface impedance boundary conditions (SIBCs) can be transformed to invariant forms that depend only on the geometry of the problem and do not contain temporary parameters of the field. Thus the integral equations have to be solved only once for a given
S. Yuferev, N. Ida, L. Kettunen
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Ceramics International, 2015
Abstract A series of SiBC matrix modified C/SiC composites (C/SiC–SiBC) with different pyrolytic carbon (PyC) interphase thicknesses (50–300 nm) were fabricated by a joint process of chemical vapor infiltration, slurry infiltration and liquid silicon infiltration.
Xiaoyu Cao +5 more
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Abstract A series of SiBC matrix modified C/SiC composites (C/SiC–SiBC) with different pyrolytic carbon (PyC) interphase thicknesses (50–300 nm) were fabricated by a joint process of chemical vapor infiltration, slurry infiltration and liquid silicon infiltration.
Xiaoyu Cao +5 more
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EFFECT OF OXIDATION ON MODULUS OF 2D-C/SiBC COMPOSITES
Modern Physics Letters B, 2010The effects of oxidation on the weight change (DW) and modulus change (DE) of an uncoated C / SiBC were investigated in 600–1000°C. The results show that larger DW does not mean larger damage. DE is more sensitive to the oxidation process than DW. At lower temperatures, a small DW can result in a large DE.
CHENGYU ZHANG +4 more
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Oxidation behaviour of a multi-layered ceramic-matrix composite (SiC)f/C/(SiBC)m
Composites Science and Technology, 2001Abstract The oxidation behaviour of a 2.5D multi-layered ceramic-matrix composite (SiC)f/C/(SiBC)m was investigated in a dry atmosphere O2 (20 vol.%) CO2 (5 vol.%) He and in the presence of water vapour H2O (2.3 vol.%). The matrix denoted (SiBC)m is constituted of three phases: silicon carbide, boron carbide and a SiBC phase.
J.P Viricelle +2 more
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Efficient Analysis of Electromagnetic Fields near Lightning Channel by Using SIBC in FDTD
2009 20th International Zurich Symposium on Electromagnetic Compatibility, 2009This paper presents an efficient finite difference time domain (FDTD) algorithm to calculate the transient electromagnetic fields above conductive ground near lightning channel. Significant computational time and memory savings are achieved by using surface impedance boundary condition (SIBC) to avoid simulating the underground region.
Jie Liu +4 more
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A novel algorithm of high order SIBC for the FDTD
IEEE Antennas and Propagation Society Symposium, 2004., 2004The technique of surface impedance boundary condition (SIBC) can avoid calculating the fields inside conductor and the results have been proved valid under certain conditions. More recently, some authors studied the surface impedance of a lossy dielectric with exponential approximation (J.G. Maloney and G.S. Smith, IEEE Trans.
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Structure, Mechanical Properties, and Oxidation Resistance of ZrB2, ZrSiB, and ZrSiB/SiBC Coatings
Protection of Metals and Physical Chemistry of Surfaces, 2018ZrB2, ZrSiB single-layer coatings, and ZrSiB/SiBC multilayer coatings have been fabricated by magnetron sputtering. The coating structure is studied by X-ray powder diffraction analysis, scanning electron microscopy, and glow-discharge optical emission spectroscopy. The mechanical properties of the coatings are identified by nanoindentation.
F. V. Kiryukhantsev-Korneev +4 more
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Improved tensile strength and toughness of dense C/SiC-SiBC with tailored PyC interphase
Journal of the European Ceramic Society, 2019Abstract In this study, in order to improve the tensile strength and toughness of dense C/SiC-SiBC, the thickness of PyC interphase (ePyC) was increased from 200 nm to 400 nm. C/SiC (ePyC≈200 nm) was also fabricated as a benchmark comparison. C/SiC-SiBC (ePyC≈200 nm) exhibited higher axial thermal residual stress (TRS) than C/SiC (ePyC≈200 nm ...
Xiaokang Ma +6 more
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EM scattering analysis by a loaded trough on a ground using the SIBC
IEEE Antennas and Propagation Society International Symposium. 1998 Digest. Antennas: Gateways to the Global Network. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.98CH36194), 2002Based on the formulation of Kobayashi and Nomura's method (1957), electromagnetic plane wave scattering by a loaded trough on a ground is approximately analyzed by applying the standard impedance boundary condition (SIBC). Similar approximations using impedance boundary conditions have been reported previously by Barkeshli and Volakis (1990) and by ...
R. Sato, H. Shirai
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