The Experts below are selected from a list of 535770 Experts worldwide ranked by ideXlab platform
Qingyan Chen - One of the best experts on this subject based on the ideXlab platform.
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a Two Dimensional Model for calculating heat transfer in the human body in a transient and non uniform thermal environment
Energy and Buildings, 2016Co-Authors: Dayi Lai, Qingyan ChenAbstract:Abstract A thermal Model for the human body is used to assess the temperature of the body and a person’s thermal comfort level. Most Models available in the literature were developed for a uniform thermal environment and have limited applications. This study developed a 12-segment Model for transient and non-uniform surrounding conditions by considering Two-Dimensional heat transfer in each segment of a human body. This heat transfer included convection, radiation, and evaporation on bare skin and skin covered with clothing. The Model allows non-uniform clothing insulation across different body segments. The heat transfer between Two body segments was estimated from blood circulation through counter-current heat exchange. This study evaluated the Model’s performance for subjects with and without clothing under a wide range of transient and non-uniform thermal environmental conditions. Good agreement was observed between the measured and calculated skin and rectal temperatures, although there were small discrepancies. The Two-Dimensional Model developed in this study is a step forward in predicting thermal comfort under transient and non-uniform environmental conditions.
Evangelos Tsotsas - One of the best experts on this subject based on the ideXlab platform.
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Two phase and Two Dimensional Model describing heat and water transfer during solid state fermentation within a packed bed bioreactor
Chemical Engineering Journal, 2016Co-Authors: Fernanda Perpetua Casciatori, Andreas Buck, Joao Claudio Thomeo, Evangelos TsotsasAbstract:Abstract In the current paper, a Two-phase and Two-Dimensional Model describing heat and water transfer in a packed-bed bioreactor (PBB) for solid-state fermentation (SSF) is proposed. The Model considers most of the transport mechanisms taking place in solid and gas phases and for axial and radial directions. For simulation, realistic physical properties of the particles and of the bed were employed, as well as interface coefficients were calculated based on classical correlations. The case-study was the solid-state cultivation of the newly isolated thermophilic fungus Myceliophthora thermophila I-1D3b in a mixture of sugarcane bagasse (SCB) and wheat bran (WB) within a narrow cylindrical and jacketed PBB. For non-saturated aeration, results showed that substrate drying near the inlet of the bioreactor harms fungal growth. For narrow PBB, jacket plays important rule on heat removal; for large-diameter PBB, radial heat removal becomes negligible. Simulated results agreed with experimental ones. The novel Model here proposed is a powerful tool for guiding the scale-up of PBB for SSF.
R. Young - One of the best experts on this subject based on the ideXlab platform.
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Two-Dimensional Model for thermal plasma chemical vapor deposition
Plasma Chemistry and Plasma Processing, 1995Co-Authors: D. Kolman, Joachim V. R. Heberlein, Emil Pfender, R. YoungAbstract:A formulation of a global mathematical Two-Dimensional Model for Thermal Plasma Chemical Vapor Deposition (TPCVD) is reported. Both gas-phase and surface chemical kinetics as well as ordinary and thermal diffusion are incorporated. Flow is assumed to be steady, laminar and swirlless at this stage. The results include velocity, pressure, density, temperature and chemical species distributions in the reactor, and the heat flux and the film growth characteristics at the substrate.
S Kakac - One of the best experts on this subject based on the ideXlab platform.
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Two Dimensional Model for proton exchange membrane fuel cells
Aiche Journal, 1998Co-Authors: Vladimir Gurau, Hongtan Liu, S KakacAbstract:A 2-D mathematical Model for the entire sandwich of a proton-exchange membrane fuel cell including the gas channels was developed. The self-consistent Model for porous media was used for the equations describing transport phenomena in the membrane, catalyst layers, and gas diffusers, while standard equations of Navier-Stokes, energy transport, continuity, and species concentrations are solved in the gas channels. A special handling of the transport equations enabled us to use the same numerical method in the unified domain consisting of the gas channels, gas diffusers, catalyst layers and membrane. It also eliminated the need to prescribe arbitrary or approximate boundary conditions at the interfaces between different parts of the fuel cell sandwich. By solving transport equations, as well as the equations for electrochemical reactions and current density with the membrane phase potential, polarization curves under various operating conditions were obtained. Modeling results compare very well with experimental results from the literature. Oxygen and water vapor mole fraction distributions in the coupled cathode gas channel-gas diffuser were studied for various operating current densities. Liquid water velocity distributions in the membrane and influences of various parameters on the cell performance were also obtained.
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Two‐Dimensional Model for proton exchange membrane fuel cells
Aiche Journal, 1998Co-Authors: Vladimir Gurau, Hongtan Liu, S KakacAbstract:A 2-D mathematical Model for the entire sandwich of a proton-exchange membrane fuel cell including the gas channels was developed. The self-consistent Model for porous media was used for the equations describing transport phenomena in the membrane, catalyst layers, and gas diffusers, while standard equations of Navier-Stokes, energy transport, continuity, and species concentrations are solved in the gas channels. A special handling of the transport equations enabled us to use the same numerical method in the unified domain consisting of the gas channels, gas diffusers, catalyst layers and membrane. It also eliminated the need to prescribe arbitrary or approximate boundary conditions at the interfaces between different parts of the fuel cell sandwich. By solving transport equations, as well as the equations for electrochemical reactions and current density with the membrane phase potential, polarization curves under various operating conditions were obtained. Modeling results compare very well with experimental results from the literature. Oxygen and water vapor mole fraction distributions in the coupled cathode gas channel-gas diffuser were studied for various operating current densities. Liquid water velocity distributions in the membrane and influences of various parameters on the cell performance were also obtained.
Andrew Spann - One of the best experts on this subject based on the ideXlab platform.
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application of a Two Dimensional Model for predicting the pressure flow and compression properties during column packing scale up
Journal of Chromatography A, 2007Co-Authors: Justin T Mccue, Douglas Cecchini, Andrew SpannAbstract:A Two-Dimensional Model was formulated to describe the pressure-flow behavior of compressible stationary phases for protein chromatography at different temperatures and column scales. The Model was based on the assumption of elastic deformation of the solid phase and steady-state Darcy flow. Using a single fitted value for the empirical modulus parameters, the Model was applied to describe the pressure-flow behavior of several adsorbents packed using both fluid flow and mechanical compression. Simulations were in agreement with experimental data and accurately predicted the pressure-flow and compression behavior of three adsorbents over a range of column scales and operating temperatures. Use of the described theoretical Model potentially improves the accuracy of the column scale-up process, allowing the use of limited laboratory scale data to predict column performance in large scale applications.
