10 research outputs found
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Simple design tool for sizing solar ponds
This report presents a simple tool and method of analysis to aid practitioners in the planning and implementation of solar energy systems. This simple design tool for sizing solar ponds should aid analysts and planners in assessing the feasibility of solar ponds for any specified application, and in drawing up a preliminary plan for their implementation
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Strain and Damage in Silicon Due to a Deep Oxygen Implantation
ABSTRACTSilicon wafers, implanted with oxygen at 550°C to form a buried oxide layer have been examined with TEM and x-ray diffraction. Implantation damage increased with depth up to ~1500 Å where some amorphous regions were seen. The amorphous region extended for -4500 Å to a damaged crystalline region ~1000 Å thick. Double crystal x-ray rocking curves of the as-implanted and of annealed crystals were obtained and analyzed. The strain normal to the (100) surface in the as-implanted crystalline Si did not exceed +0.05%. After an argon anneal, the strain disappeared, leaving a crystal with a lower density of extended defects and no measureable misorientation of surface or deep layers. In marked contrast, an anneal in a hydrogen atmosphere exhibited no normal strain but contained regions above the oxide layer which differed in orientation from the substrate. The misorientation ranged up to ~0.1 degree.</jats:p
Solar ponds
The different types of solar ponds are described, including the nonconvecting salt gradient pond and various saltless pond designs. Then the availability and cost of salts for salt gradient ponds are discussed and costs are compared. A simple computational model is developed to approximate solar pond performance. This model is later used to size solar ponds for district heating and industrial process heat applications. For district heating, ponds are sized to provide space conditioning for a group of homes, in different regions of the United States. Size requirement is on the order of one acre for a group of 25 to 50 homes. An economic analysis is performed of solar ponds used in two industrial process heat applications. The analysis finds that solar ponds are competitive when conventional heat sources are priced at $5 per million Btu and expected to rise in price at a rate of 10% per year. The application of solar ponds to the generation of electricity is also discussed. Total solar pond potential for displacing conventional energy sources is estimated in the range of from one to six quadrillion Btu per year in the near and intermediate future
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Thermoelectric properties of bismuth-antimony thin films
Thermoelectrics have a wide range of potential applications in the temperature range of 0/sup 0/ to 100/sup 0/C. In an effort to enhance the feasibility of thermoelectrics, we have begun investigation of potentially cheaper materials and cheaper techniques for thermoelectrics. Two features of bismuth and antimony have influenced our work. First, Horst and Williams have reported quite respectable figure of merit values in bulk single crystals of bismuth-antimony, up to 2.5 x 10/sup -3/ at room temperature. Second, bismuth and antimony are an order of magnitude cheaper in cost compared to selenium and tellurium, making this binary alloy a natural candidate to reduce the cost of thermoelectric devices. Our avenue of approach involves a simplification of the fabrication process using an established technique of solid-state electronics: thin-film deposition. We have recently begun to investigate the extent to which the favorable properties of bulk Bi-Sb are preserved in thin films. Some of the preliminary data coming out of this ongoing investigation are reported
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Solar ponds for industrial process heat
Solar ponds offer perhaps the simplest technique for conversion of solar energy to thermal energy, which can be used for industrial process heat. It is unique in its capability in acting both as collector and storage. Further, the cost of solar pond per unit area is less than any active collectors available today. Combination of these economic and technical factors make solar ponds attractive as a fuel saver in IPH applications. Detailed calculations are given for solar ponds in two specific applications: providing hot water for aluminum can washing in a manufacturing plant and hot water for washing in a large commercial laundry. With the help of computer codes developed at SERI for other solar IPH systems, it is shown that solar ponds are far more cost effective than any other solar IPH technology for these applications
Operation of poly emitter bipolar npn and p-channel JFETs near liquid helium (10 K) temperature
New insights into the genetic etiology of Alzheimer’s disease and related dementias
Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele. © 2022, The Author(s)
New insights into the genetic etiology of Alzheimer’s disease and related dementias
Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ?4 allele
