The Experts below are selected from a list of 13866 Experts worldwide ranked by ideXlab platform
A. P. Alimov - One of the best experts on this subject based on the ideXlab platform.
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Geometrical Characterization of Strict Suns in ℓ ∞ ( n )
Mathematical Notes, 2001Co-Authors: A. P. AlimovAbstract:A subset M of a normed linear space X is called a strict sun if, for any x ∈ X\M, the set of its nearest points from M is nonempty and for any point y ∈ M which is nearest to x, the point y is a nearest point from M to any point of the ray {λx + (1 - λ)y | ∈ > 0\}. We give an intrinsic Geometrical Characterization of strict suns in the space l∞(n).
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Geometrical Characterization of strict suns in l n
Mathematical Notes, 2001Co-Authors: A. P. AlimovAbstract:A subset M of a normed linear space X is called a strict sun if, for any x ∈ X\M, the set of its nearest points from M is nonempty and for any point y ∈ M which is nearest to x, the point y is a nearest point from M to any point of the ray {λx + (1 - λ)y | ∈ > 0\}. We give an intrinsic Geometrical Characterization of strict suns in the space l∞(n).
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Geometrical Characterization of Strict Suns in ℓ^∞(n)
Mathematical Notes, 2001Co-Authors: A. P. AlimovAbstract:A subset M of a normed linear space X is called a strict sun if, for any x ∈ X \ M , the set of its nearest points from M is nonempty and for any point y ∈ M which is nearest to x , the point y is a nearest point from M to any point of the ray {λ x + (1 - λ) y | ∈ > 0\}. We give an intrinsic Geometrical Characterization of strict suns in the space ℓ^∞(n).
Sungmo Moon - One of the best experts on this subject based on the ideXlab platform.
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numerical studies on the Geometrical Characterization of serpentine flow field for efficient pemfc
International Journal of Hydrogen Energy, 2011Co-Authors: Kapseung Choi, Hyungman Kim, Sungmo MoonAbstract:Geometrical Characterization of the serpentine flow-field is one of the key issues to be solved to enhance the performance of PEMFC in relation to pressure drop, discharge of condensed water, maximization of cell voltage, and uniformity of current density over the entire surface area. Three different channel heights and widths were compared with the base flow-field design of the serpentine channel whose width is 1 mm and 0.34 mm in height, each through a detailed numerical study of the distribution of temperature, pressure, water content, and local current density. As the channel height increases higher than the base design, the total pressure drop decreases and results in reduced load of BOP and accumulation of liquid water at the outlet of both anode and cathode. The accumulation of anode liquid water at the outlet caused by back diffusion is accelerated as the channel height increases. As the channel width expands wider than the base design, the pressure drop is lowered and the removal rate of liquid water becomes faster. The effect of the channel width increase on the water removal is greater than that of the channel height increase. Which can influence the dehydration and temperature of the MEA and thus cell performance and lifetime of PEMFC. The results obtained in this work are expected to be applied in developing an efficient serpentine flow-field channel with sub-channels and by-passes.
Frans D. Tichelaar - One of the best experts on this subject based on the ideXlab platform.
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Sculpting Nanoelectrodes with a Transmission Electron Beam for Electrical and Geometrical Characterization of Nanoparticles
Nano letters, 2005Co-Authors: Henny W. Zandbergen, Robert J. H. A. Van Duuren, Paul F. A. Alkemade, Günther Lientschnig, Oscar Vasquez, Cees Dekker, Frans D. TichelaarAbstract:A method to produce metal electrodes with a gap of a few nanometers with a highly focused electron beam in a transmission electron microscope (TEM) is described. With this method the electrical and Geometrical Characterization of the same particle is possible. The I-V characteristics of a gold particle trapped between such electrodes showed the expected single-electron tunneling behavior, with a Coulomb gap corresponding to the geometry of the particle as observed with high-resolution TEM.
Nico F. Declercq - One of the best experts on this subject based on the ideXlab platform.
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the effects of the transducer beam properties on the ultrasonic Geometrical Characterization of periodically corrugated surfaces
Journal of the Acoustical Society of America, 2013Co-Authors: Jingfei Liu, Nico F. DeclercqAbstract:Periodically corrugated structures are common in many technological applications and in most cases the geometry of these corrugated structures are crucial for the designed functionality. As an effective nondestructive Characterization method an ultrasonic imaging technique is investigated in this work for the purpose of accurately characterizing the geometry of periodic corrugations. Among many factors that affect the imaging quality the properties of the transducer beam dominate. The effects of the spatial and spectral properties of transducer beams on the accurate Characterization of the characteristic dimensions of corrugations are investigated in details both theoretically and experimentally. The possibility to accurately characterize the corrugation characteristic dimensions, the condition for accurate Characterization and the quantitative relationship between the Characterization accuracy and the beam parameters are given. The ways to avoid the diffraction effects and reduce possible errors are also...
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Ultrasonic Geometrical Characterization of periodically corrugated surfaces.
Ultrasonics, 2012Co-Authors: Nico F. DeclercqAbstract:Abstract Accurate Characterization of the characteristic dimensions of a periodically corrugated surface using ultrasonic imaging technique is investigated both theoretically and experimentally. The possibility of accurately characterizing the characteristic dimensions is discussed. The condition for accurate Characterization and the quantitative relationship between the accuracy and its determining parameters are given. The strategies to avoid diffraction effects instigated by the periodical nature of a corrugated surface are also discussed. Major causes of erroneous measurements are theoretically discussed and experimentally illustrated. A comparison is made between the presented results and the optical measurements, revealing acceptable agreement. This work realistically exposes the capability of the proposed ultrasonic technique to accurately characterize the lateral and vertical characteristic dimensions of corrugated surfaces. Both the general principles developed theoretically as well as the proposed practical techniques may serve as useful guidelines to peers.
Kapseung Choi - One of the best experts on this subject based on the ideXlab platform.
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numerical studies on the Geometrical Characterization of serpentine flow field for efficient pemfc
International Journal of Hydrogen Energy, 2011Co-Authors: Kapseung Choi, Hyungman Kim, Sungmo MoonAbstract:Geometrical Characterization of the serpentine flow-field is one of the key issues to be solved to enhance the performance of PEMFC in relation to pressure drop, discharge of condensed water, maximization of cell voltage, and uniformity of current density over the entire surface area. Three different channel heights and widths were compared with the base flow-field design of the serpentine channel whose width is 1 mm and 0.34 mm in height, each through a detailed numerical study of the distribution of temperature, pressure, water content, and local current density. As the channel height increases higher than the base design, the total pressure drop decreases and results in reduced load of BOP and accumulation of liquid water at the outlet of both anode and cathode. The accumulation of anode liquid water at the outlet caused by back diffusion is accelerated as the channel height increases. As the channel width expands wider than the base design, the pressure drop is lowered and the removal rate of liquid water becomes faster. The effect of the channel width increase on the water removal is greater than that of the channel height increase. Which can influence the dehydration and temperature of the MEA and thus cell performance and lifetime of PEMFC. The results obtained in this work are expected to be applied in developing an efficient serpentine flow-field channel with sub-channels and by-passes.