The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Xinghong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Functionally graded materials under severe thermal environments
Journal of the American Ceramic Society, 2005Co-Authors: Baolin Wang, Yiuwing Mai, Xinghong ZhangAbstract:Thermal shock strengths of a plate of a functionally graded material (FGM) are analyzed when the plate is suddenly exposed to an Environmental Medium of different temperature. A finite element/mode superposition method is proposed to solve the time-dependent temperature field. The admissible temperature jump that the material can sustain is studied using the stress-based and fracture mechanics-based criteria. The critical parameters governing the level of the transient thermal stress in the Medium are identified. The strength of FGMs under transient thermal stresses is analyzed using both maximum local tensile stress and maximum stress intensity factor criteria.
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thermal shock resistance of functionally graded materials
Acta Materialia, 2004Co-Authors: Xinghong Zhang, Aoli Wang, Yiuwing MaiAbstract:Transient temperature field and associated thermal stresses in functionally graded materials (FGMs) are determined by a finite element/finite difference (FE/FD) method. Temperature-dependent material properties are taken into consideration. Explicit expressions for one-dimensional transient thermal conduction in some common elements, such as plate, shell and sphere, are given. These expressions are useful for material engineers and scientists to determine the thermal stresses and strength distributions in FGMs for high temperature applications. Thermal shock fracture of a FGM plate is analyzed when the plate is suddenly exposed to an Environmental Medium of a different temperature. The admissible temperature jump that the materials can sustain is studied using stress-based and fracture-toughness-based failure criteria. The critical parameters governing the level of the transient thermal stress in the Medium are identified. The thermal shock resistance of the FGMs is analyzed using both maximum local tensile stress and maximum stress intensity factor criteria.
Alexander Grünberger - One of the best experts on this subject based on the ideXlab platform.
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dMSCC: a microfluidic platform for microbial single-cell cultivation of Corynebacterium glutamicum under dynamic Environmental Medium conditions
Lab on a chip, 2020Co-Authors: Sarah Täuber, Corinna Golze, Eric Von Lieres, Alexander GrünbergerAbstract:In nature and in technical systems, microbial cells are often exposed to rapidly fluctuating Environmental conditions. These conditions can vary in quality, e.g., the existence of a starvation zone, and quantity, e.g., the average residence time in this zone. For strain development and process design, cellular response to such fluctuations needs to be systematically analysed. However, the existing methods for physically imitating rapidly changing Environmental conditions are limited in spatio-temporal resolution. Hence, we present a novel microfluidic system for cultivation of single cells and small cell clusters under dynamic Environmental conditions (dynamic microfluidic single-cell cultivation (dMSCC)). This system enables the control of nutrient availability and composition between two media with second to minute resolution. We validate our technology using the industrially relevant model organism Corynebacterium glutamicum. The organism was exposed to different oscillation frequencies between nutrient excess (feasts) and scarcity (famine). The resulting changes in cellular physiology, such as the colony growth rate and cell morphology, were analysed and revealed significant differences in the growth rate and cell length between the different conditions. dMSCC also allows the application of defined but randomly changing nutrient conditions, which is important for reproducing more complex conditions from natural habitats and large-scale bioreactors. The presented system lays the foundation for the cultivation of cells under complex changing Environmental conditions.
Aoli Wang - One of the best experts on this subject based on the ideXlab platform.
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thermal shock resistance of functionally graded materials
Acta Materialia, 2004Co-Authors: Xinghong Zhang, Aoli Wang, Yiuwing MaiAbstract:Transient temperature field and associated thermal stresses in functionally graded materials (FGMs) are determined by a finite element/finite difference (FE/FD) method. Temperature-dependent material properties are taken into consideration. Explicit expressions for one-dimensional transient thermal conduction in some common elements, such as plate, shell and sphere, are given. These expressions are useful for material engineers and scientists to determine the thermal stresses and strength distributions in FGMs for high temperature applications. Thermal shock fracture of a FGM plate is analyzed when the plate is suddenly exposed to an Environmental Medium of a different temperature. The admissible temperature jump that the materials can sustain is studied using stress-based and fracture-toughness-based failure criteria. The critical parameters governing the level of the transient thermal stress in the Medium are identified. The thermal shock resistance of the FGMs is analyzed using both maximum local tensile stress and maximum stress intensity factor criteria.
Yiuwing Mai - One of the best experts on this subject based on the ideXlab platform.
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Functionally graded materials under severe thermal environments
Journal of the American Ceramic Society, 2005Co-Authors: Baolin Wang, Yiuwing Mai, Xinghong ZhangAbstract:Thermal shock strengths of a plate of a functionally graded material (FGM) are analyzed when the plate is suddenly exposed to an Environmental Medium of different temperature. A finite element/mode superposition method is proposed to solve the time-dependent temperature field. The admissible temperature jump that the material can sustain is studied using the stress-based and fracture mechanics-based criteria. The critical parameters governing the level of the transient thermal stress in the Medium are identified. The strength of FGMs under transient thermal stresses is analyzed using both maximum local tensile stress and maximum stress intensity factor criteria.
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thermal shock resistance of functionally graded materials
Acta Materialia, 2004Co-Authors: Xinghong Zhang, Aoli Wang, Yiuwing MaiAbstract:Transient temperature field and associated thermal stresses in functionally graded materials (FGMs) are determined by a finite element/finite difference (FE/FD) method. Temperature-dependent material properties are taken into consideration. Explicit expressions for one-dimensional transient thermal conduction in some common elements, such as plate, shell and sphere, are given. These expressions are useful for material engineers and scientists to determine the thermal stresses and strength distributions in FGMs for high temperature applications. Thermal shock fracture of a FGM plate is analyzed when the plate is suddenly exposed to an Environmental Medium of a different temperature. The admissible temperature jump that the materials can sustain is studied using stress-based and fracture-toughness-based failure criteria. The critical parameters governing the level of the transient thermal stress in the Medium are identified. The thermal shock resistance of the FGMs is analyzed using both maximum local tensile stress and maximum stress intensity factor criteria.
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Strength Evaluation of Piezoelectric Ceramics under Transient Thermal Environments
Journal of the American Ceramic Society, 2004Co-Authors: Baolin Wang, Yiuwing MaiAbstract:The strength of piezoelectric ceramics is analyzed for a plate suddenly exposed to an Environmental Medium of different temperatures. The admissible temperature jump the material can sustain is studied using the stress- and fracture-toughness-based failure criteria. The critical parameters governing the level of the transient thermal stress in piezoelectric ceramics are identified. Solutions are obtained for the maximum thermal shock that the plate can sustain without failure, under the conditions that (i) maximum local tensile stress equals the tensile strength of the ceramic, and (ii) maximum stress intensity factor for representative pre-existing cracks equals the fracture toughness of the ceramic.
Sarah Täuber - One of the best experts on this subject based on the ideXlab platform.
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dMSCC: a microfluidic platform for microbial single-cell cultivation of Corynebacterium glutamicum under dynamic Environmental Medium conditions
Lab on a chip, 2020Co-Authors: Sarah Täuber, Corinna Golze, Eric Von Lieres, Alexander GrünbergerAbstract:In nature and in technical systems, microbial cells are often exposed to rapidly fluctuating Environmental conditions. These conditions can vary in quality, e.g., the existence of a starvation zone, and quantity, e.g., the average residence time in this zone. For strain development and process design, cellular response to such fluctuations needs to be systematically analysed. However, the existing methods for physically imitating rapidly changing Environmental conditions are limited in spatio-temporal resolution. Hence, we present a novel microfluidic system for cultivation of single cells and small cell clusters under dynamic Environmental conditions (dynamic microfluidic single-cell cultivation (dMSCC)). This system enables the control of nutrient availability and composition between two media with second to minute resolution. We validate our technology using the industrially relevant model organism Corynebacterium glutamicum. The organism was exposed to different oscillation frequencies between nutrient excess (feasts) and scarcity (famine). The resulting changes in cellular physiology, such as the colony growth rate and cell morphology, were analysed and revealed significant differences in the growth rate and cell length between the different conditions. dMSCC also allows the application of defined but randomly changing nutrient conditions, which is important for reproducing more complex conditions from natural habitats and large-scale bioreactors. The presented system lays the foundation for the cultivation of cells under complex changing Environmental conditions.