The Experts below are selected from a list of 443499 Experts worldwide ranked by ideXlab platform
Aldo Steinfeld - One of the best experts on this subject based on the ideXlab platform.
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high temperature thermal storage using a packed bed of rocks heat transfer analysis and experimental validation
Applied Thermal Engineering, 2011Co-Authors: Markus Hanchen, Sarah Bruckner, Aldo SteinfeldAbstract:High-temperature thermal storage in a packed bed of rocks is considered for air-based concentrated solar power plants. The unsteady 1D two-Phase energy conservation equations are formulated for combined convection and conduction heat transfer, and solved numerically for charging/discharging cycles. Validation is accomplished in a pilot-scale experimental setup with a packed bed of crushed steatite (magnesium silicate rock) at 800 K. A parameter study of the packed bed dimensions, fluid flow rate, particle diameter, and solid Phase Material was carried out to evaluate the charging/discharging characteristics, daily cyclic operation, overall thermal efficiency and capacity ratio.
A. N. Gennadiev - One of the best experts on this subject based on the ideXlab platform.
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Quantification of the vertical translocation rate of soil solid-Phase Material by the magnetic tracer method
Eurasian Soil Science, 2016Co-Authors: A. P. Zhidkin, A. N. GennadievAbstract:Approaches to the quantification of the vertical translocation rate of soil solid-Phase Material by the magnetic tracer method have been developed; the tracer penetration depth and rate have been determined, as well as the radial distribution of the tracer in chernozems (Chernozems) and dark gray forest soils (Luvisols) of Belgorod oblast under natural steppe and forest vegetation and in arable lands under agricultural use of different durations. It has been found that the penetration depth of spherical magnetic particles (SMPs) during their 150-year-occurrence in soils of a forest plot is 68 cm under forest, 58 cm on a 100-year old plowland, and only 49 cm on a 150-year-old plowland. In the chernozems of the steppe plot, the penetration depth of SMPs exceeds the studied depth of 70 cm both under natural vegetation and on the plowlands. The penetration rates of SMPs deep into the soil vary significantly among the key plots: 0.92–1.32 mm/year on the forest plot and 1.47–1.63 mm/year on the steppe plot, probably because of the more active recent turbation activity of soil animals.
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Lateral migration of soil solid-Phase Material within a landscape-geochemical arena detected using the magnetic tracer method
Eurasian Soil Science, 2013Co-Authors: A. N. Gennadiev, T. S. Koshovskii, A. P. Zhidkin, R. G. KovachAbstract:Thorough studies of the lateral migration of the solid soil Material and the large-scale mapping of the soil cover have been performed within a landscape-geochemical arena in the small catchment area of the Lokna River basin (Tula oblast). Podzolized clay-illuvial agrochernozems are the predominant soils in the catchment area. Nine soil types from four orders according to the 2004 soil classification have also been described. The morphological analysis of the soil profile structures revealed their changes related to the lateral migration of the solid-Phase products of the pedogenesis. From the estimated reserves of the spherical magnetic particles as tracers of the mass transfer, the accumulation and dispersion zones of the solid-Phase Material in the soil cover have been separated and conclusions about the genesis of these zones and their place in the migration structure of the catchment basin have been drawn. The soil catenas within the landscape-geochemical arena have been classified in accordance with the migration intensity of the soil solid-Phase Material, the localization of deposits, and the degree of openness of the soil-geochemical conjugations. The effect of the lateral migration of the soil solid-Phase Material on the structure of the microarena soil cover and the soil genetic profiles has been revealed.
Steven L Ceccio - One of the best experts on this subject based on the ideXlab platform.
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three Phase Material distribution measurements in a vertical flow using gamma densitometry tomography and electrical impedance tomography
International Journal of Multiphase Flow, 2001Co-Authors: D L George, K A Shollenberger, J R Torczynski, T J Ohern, Steven L CeccioAbstract:Experiments are presented in which electrical-impedance tomography (EIT) and gamma-densitometry tomography (GDT) measurements were combined to simultaneously measure the solid, liquid, and gas radial distributions in a vertical three-Phase flow. The experimental testbed was a 19.05-cm diameter bubble column in which gas is injected at the bottom and exits out the top while the liquid and solid Phases recirculate. The gas Phase was air and the liquid Phase was deionized water with added electrolytes. Four different particle classes were investigated for the solid Phase: 40--100 {micro}m and 120--200 {micro}m glass beads (2.41 g/cm{sup 3}), and 170--260 {micro}m and 200--700 {micro}m polystyrene beads (1.04 g/cm{sup 3}). Superficial gas velocities of 3 to 30 cm/s and solid volume fractions up to 0.30 were examined. For all experimental conditions investigated, the gas distribution showed only a weak dependence on both particle size and density. Average gas volume fraction as a function of superficial gas velocity can be described to within {+-} 0.04 by curve passing through the center of the data. For most cases the solid particle appeared to be radically uniformly dispersed in the liquid.
Bin Xu - One of the best experts on this subject based on the ideXlab platform.
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concurrent topological design of composite thermoelastic macrostructure and microstructure with multi Phase Material for maximum stiffness
Composite Structures, 2016Co-Authors: Bin Xu, Xiaodong Huang, Shiwei ZhouAbstract:A method for the multi-scale design of composite thermoelastic macrostructure and periodic microstructure with multi-Phase Materials is proposed. A concurrent topology optimization model of macrostructure and microstructure is established, where the objective is to maximize the macrostructural stiffness subject to volume constraints on the macro-Material distribution and Phase Materials. Based on the Material interpolation scheme of the solid isotropic Material with penalization (SIMP), the sensitivity of the mean compliance of the composite macrostructure with respect to design variables on two scales, i.e., macro and micro scales, is derived. The optimization problem is solved using a bi-directional evolutionary structural optimization (BESO) method and the corresponding optimization procedure for the concurrent topology optimization is proposed. Several examples are presented to demonstrate the effectiveness of the proposed method.
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concurrent design of composite macrostructure and multi Phase Material microstructure for minimum dynamic compliance
Composite Structures, 2015Co-Authors: Bin Xu, Jie Sheng JiangAbstract:A method for the concurrent topology optimization of composite macrostructure and periodic microstructure with multi-Phase Materials is proposed, where the objective is to minimize the dynamic compliance of the macro structure under harmonic excitation force. Based on a Material interpolation scheme with multiple Materials, the sensitivity of the dynamic compliance with respect to the design variables on the two scales is analyzed. The concurrent topology optimization model of composite macrostructure and multi-Phase periodic microstructure is built, where constraints are imposed on the Material volumes. Correspondingly, a numerical technique and an optimization procedure based on the bi-directional evolutionary structural optimization (BESO) method are presented. Results of numerical examples show that the proposed method is effective for the concurrent design of composite macrostructure and Material microstructure for minimum dynamic compliance.
W. Pabst - One of the best experts on this subject based on the ideXlab platform.
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Sea Urchin Spines as a Model-System for Permeable, Light-Weight Ceramics with Graceful Failure Behavior. Part II. Mechanical Behavior of Sea Urchin Spine Inspired Porous Aluminum Oxide Ceramics under Compression
Journal of Bionic Engineering, 2009Co-Authors: V. Presser, C. Kohler, Z. Živcová, C. Berthold, K. G. Nickel, S. Schultheiß, E. Gregorová, W. PabstAbstract:Sea urchin spines were chosen as a model system for biomimetic ceramics obtained using starch-blended slip casting. Porous alumina ceramics with cap-shaped layers with different alternating porosities were found to have superior fracture behavior under bulk compression compared to ceramics with uniform porosity. They fail in a cascading manner, absorbing high amounts of energy during extended compression paths. The porosity variation in an otherwise single Phase Material mimicks the architectural microstructure design of sea urchin spines of Heterocentrotus mammillatus , which are promising model Materials for impact protection.
