The Experts below are selected from a list of 130167 Experts worldwide ranked by ideXlab platform
Marijke Vandewal - One of the best experts on this subject based on the ideXlab platform.
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transient radar method novel illumination and blind electromagnetic Geometrical Parameter extraction technique for multilayer structures
IEEE Transactions on Microwave Theory and Techniques, 2017Co-Authors: Ali Pourkazemi, Johan H Stiens, Mathias Becquaert, Marijke VandewalAbstract:A novel technique enabling ultrafast nondestructive characterization of multilayer dielectric structures is proposed. Actual estimations indicate that the data acquisition performance of electronic measurement systems of today allow deep submillimeter depth resolution, almost independently of the frequency. For a 10 GHz signal, e.g., this corresponds to significant subwavelength depth resolution. By means of a novel blind analysis method of the time-dependent reflected electromagnetic (EM) signal, detailed information on the Geometrical and EM Parameters such as the complex valued dielectric permittivity and magnetic susceptibility of each layer of the structure can be extracted. We validate the novel technique for different materials in the 10 GHz range and compare the results obtained with S-Parameter measurements in the 9.5–10.5 GHz range using a vector network analyzer. We will discuss the impact of nonidealities on the accuracy of the retrieved Parameters. The novel technique has the potential for deployment in a wide range of applications ranging from the piping industry, wind energy industry, automotive, biotechnology, food industry, pharmacy, and so on.
F Lozesdupuy - One of the best experts on this subject based on the ideXlab platform.
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analysis of the sensitivity of a monolithic optical phase shift detector to Geometrical Parameter variations
International Semiconductor Conference, 2005Co-Authors: J Valentin, Philippe Arguel, O Bouchard, F Lozesdupuy, S BonnefontAbstract:Modelling of a novel monolithic optical phase-shift detector is presented. The device consists of a diffraction grating etched at the surface of a p-n photodiode on silicon. The photodiode generates a current depending on the relative phase between two incident beams collimated toward the diffraction grating. It is shown that the photocurrent contrast, given by the whole range of the phase variation, can be optimised by a precise determination of the period, depth and filling factor of the grating. Detailed analysis of the device performance for TE and TM polarization shows its high sensitivity to the above Geometrical Parameter variations.
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analysis of the sensitivity of grating coupled surface emitting lasers to Geometrical Parameter variations
IEEE Journal of Quantum Electronics, 1996Co-Authors: S Bennefont, Philippe Arguel, Beatrice Dagens, H Martinot, F LozesdupuyAbstract:A complete modeling of a second-order grating surface-emitting laser is presented. It is shown that the device performance is highly sensitive to the oscillating-mode Bragg deviation and that several mode hops occur when the gain-section length or the position of the first grating tooth is changed. Given the state of the art of the technological processes, it has been shown that a stable mode laser operation requires a modification of the device configuration.
Ali Pourkazemi - One of the best experts on this subject based on the ideXlab platform.
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transient radar method novel illumination and blind electromagnetic Geometrical Parameter extraction technique for multilayer structures
IEEE Transactions on Microwave Theory and Techniques, 2017Co-Authors: Ali Pourkazemi, Johan H Stiens, Mathias Becquaert, Marijke VandewalAbstract:A novel technique enabling ultrafast nondestructive characterization of multilayer dielectric structures is proposed. Actual estimations indicate that the data acquisition performance of electronic measurement systems of today allow deep submillimeter depth resolution, almost independently of the frequency. For a 10 GHz signal, e.g., this corresponds to significant subwavelength depth resolution. By means of a novel blind analysis method of the time-dependent reflected electromagnetic (EM) signal, detailed information on the Geometrical and EM Parameters such as the complex valued dielectric permittivity and magnetic susceptibility of each layer of the structure can be extracted. We validate the novel technique for different materials in the 10 GHz range and compare the results obtained with S-Parameter measurements in the 9.5–10.5 GHz range using a vector network analyzer. We will discuss the impact of nonidealities on the accuracy of the retrieved Parameters. The novel technique has the potential for deployment in a wide range of applications ranging from the piping industry, wind energy industry, automotive, biotechnology, food industry, pharmacy, and so on.
A Kohyama - One of the best experts on this subject based on the ideXlab platform.
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effect of Geometrical Parameters in micro grooved crosshatch pattern under lubricated sliding friction
Tribology International, 2010Co-Authors: Younghun Chae, Tatsuya Hinoki, A KohyamaAbstract:Abstract Tribological test was carried out using a pin-on-disc geometry with textured SKD11 pin on bearing steel disc, under sliding in paraffin oil. Micro-grooved crosshatch pattern has been fabricated with various angles and widths. The effects of Geometrical Parameters on friction were mainly examined in mixed and elastohydrodynamic lubrication. The results show that friction control can be achieved by fabricating the micro-grooved crosshatch pattern on a contact surface. It is observed that each Geometrical Parameter of texture influence on friction, especially decrease of groove aspect ratio and increases of groove sliding length show friction reduction performance. Crucial Parameter G l was proposed for micro-grooved crosshatch texture. The friction mechanism is explained by micro fluid flow with limited theoretical approach.
Ali J Chamkha - One of the best experts on this subject based on the ideXlab platform.
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cfd study of heat and mass transfer and entropy generation in a 3d solar distiller heated by an internal column
International Journal of Mechanical Sciences, 2019Co-Authors: Abdullah A A A Alrashed, Hakan F Oztop, Lioua Kolsi, Attia Boudjemline, Mohammed A Almeshaal, Ali J ChamkhaAbstract:Abstract Three-dimensional computational analysis has been performed to investigate the double diffusive natural convection inside a cubical solar distiller heated by of a square basis column. Governing equations were developed using the 3D vector potential-vorticity and solved using the finite volume method. Different governing Parameters are tested as Rayleigh number 10 3 ≤ Ra ≤ 10 5 , buoyancies ratio -10 ≤ N ≤ 10, Geometrical Parameter 0.1 ≤ L h ≤ 0.7 for Le = 0.85 and Pr = 0.7 corresponding to humid air. It is found that both heat and mass transfer are strongly affected by the change of buoyancy ratio, Geometrical Parameter and Rayleigh number.