Beryllium aluminum cyclosilicate, an ore of beryllium was reinforced in Aluminum matrix to fabricate Al-beryl composites using powder metallurgy. Effect of the content of beryllium aluminum cyclosilicate on microstruc...Beryllium aluminum cyclosilicate, an ore of beryllium was reinforced in Aluminum matrix to fabricate Al-beryl composites using powder metallurgy. Effect of the content of beryllium aluminum cyclosilicate on microstructural hardness and thermal expansion was studied. The coefficient of thermal expansion of Al-beryl composite was measured in the temperature range between 50oC to 360oC using dilatometer and was theoretically studied using thermo-elastic models, and these models were used to explain abnormalities observed experimentally. The hardness of Al-beryl metal matrix composites increased with the increase in beryl percentage. Vacuum sintering of Al-beryl metal matrix composites at 600oC inhibited excellent bonding between the matrix and the particulate increasing the strength of the composite. The result shows the CTE significantly increased with increasing temperature but decreased with increasing reinforcement. At higher temperatures, CTE of Al-beryl metal matrix composites with 5 wt%, 10 wt% and 15 wt% of beryllium aluminum cyclosilicate was 21 ppm/K, 18.2 ppm/K, and 16.8 ppm/K. The CTE values were found to be comparable with theoretical results. The turner model showed conformance with experimental results, was well suited to the experimental results.展开更多
A mathematical model has been developed to numerically model the risk of developing Alzheimer’s disease and Chronic Traumatic Encephalopathy (CTE) as a person ages. The model was programmed in Excel to provide a work...A mathematical model has been developed to numerically model the risk of developing Alzheimer’s disease and Chronic Traumatic Encephalopathy (CTE) as a person ages. The model was programmed in Excel to provide a working prototype computer simulation model. The model provides estimates of the cumulative risk of developing Alzheimer’s disease and CTE as age increases. A one-year step size was used. The model has two major parts: one predicts changes in slow-wave sleep as a person ages and the second component adjusts the flushing efficiency of waste products from the brain. The two components work together and interact to lower the flushing of waste components as age increases. The development of the model provides an overview of how the various factors work together that lead to the onset of Alzheimer’s disease and the associated CTE. Calibration of the coefficients in the model is based on published data sets presented in the literature. Further research and refinement of calibration coefficients should be explored.展开更多
文摘Beryllium aluminum cyclosilicate, an ore of beryllium was reinforced in Aluminum matrix to fabricate Al-beryl composites using powder metallurgy. Effect of the content of beryllium aluminum cyclosilicate on microstructural hardness and thermal expansion was studied. The coefficient of thermal expansion of Al-beryl composite was measured in the temperature range between 50oC to 360oC using dilatometer and was theoretically studied using thermo-elastic models, and these models were used to explain abnormalities observed experimentally. The hardness of Al-beryl metal matrix composites increased with the increase in beryl percentage. Vacuum sintering of Al-beryl metal matrix composites at 600oC inhibited excellent bonding between the matrix and the particulate increasing the strength of the composite. The result shows the CTE significantly increased with increasing temperature but decreased with increasing reinforcement. At higher temperatures, CTE of Al-beryl metal matrix composites with 5 wt%, 10 wt% and 15 wt% of beryllium aluminum cyclosilicate was 21 ppm/K, 18.2 ppm/K, and 16.8 ppm/K. The CTE values were found to be comparable with theoretical results. The turner model showed conformance with experimental results, was well suited to the experimental results.
文摘A mathematical model has been developed to numerically model the risk of developing Alzheimer’s disease and Chronic Traumatic Encephalopathy (CTE) as a person ages. The model was programmed in Excel to provide a working prototype computer simulation model. The model provides estimates of the cumulative risk of developing Alzheimer’s disease and CTE as age increases. A one-year step size was used. The model has two major parts: one predicts changes in slow-wave sleep as a person ages and the second component adjusts the flushing efficiency of waste products from the brain. The two components work together and interact to lower the flushing of waste components as age increases. The development of the model provides an overview of how the various factors work together that lead to the onset of Alzheimer’s disease and the associated CTE. Calibration of the coefficients in the model is based on published data sets presented in the literature. Further research and refinement of calibration coefficients should be explored.
