26,034 research outputs found
Combustion chamber struts can be effectively transpiration cooled
Vapor-deposited sintering technique increases the feasible temperature range of transpiration-cooled structural members in combustion chambers. This technique produces a porous mass of refractory metal wires around a combustion chamber structural member. This mass acts as a transpiration-cooled surface for a thick-walled tube
Possible applications of soaring technology to drag reduction in powered general aviation aircraft
A brief examination of the performance figures achieved by modern soaring machines and a little reflection on the often huge disparity in L/D values between sailplanes and GA aircraft indicates that careful attention to lessons learned in sailplane design and manufacture hold realistic promise for substantial gains in the aerodynamic efficiency of several GA types
Spring separation of spacecraft
IBM 7090 digital computer program for solving equations of motion for spacecraft separating from final rocket stage or another spacecraft by means of precision helical compression spring
Cost-Effectiveness of Electricity Energy Efficiency Programs
We analyze the cost-effectiveness of electric utility rate payer–funded programs to promote demand-side management (DSM) and energy efficiency investments. We develop a conceptual model that relates demand growth rates to accumulated average DSM capital per customer and changes in energy prices, income, and weather. We estimate that model using nonlinear least squares for two different utility samples. Based on the results for the most complete sample, we find that DSM expenditures over the last 18 years have resulted in a central estimate of 1.1 percent electricity savings at a weighted average cost to utilities (or other program funders) of about 6 cents per kWh saved. Econometrically-based policy simulations find that incremental DSM spending by utilities that had no or relatively low levels of average DSM spending per customer in 2006 could produce 14 billion kWh in additional savings at an expected incremental cost to the utilities of about 3 cents per kWh saved.energy efficiency, demand-side management, negawatt cost
Cost-Effectiveness of Electricity Energy Efficiency Programs
We analyze the cost-effectiveness of electric utility ratepayer-funded programs to promote demand-side management (DSM) and energy efficiency (EE) investments. We specify a model that relates electricity demand to previous EE DSM spending, energy prices, income, weather, and other demand factors. In contrast to previous studies, we allow EE DSM spending to have a potential long-term demand effect and explicitly address possible endogeneity in spending. We find that current period EE DSM expenditures reduce electricity demand and that this effect persists for a number of years. Our findings suggest that ratepayer-funded DSM expenditures between 1992 and 2006 produced a central estimate of 0.9 percent savings in electricity consumption over that time period and 1.8 percent savings over all years. These energy savings came at an expected average cost to utilities of roughly 5 cents per kWh saved when future savings are discounted at a 5 percent rate.energy efficiency, demand-side management, electricity demand
Cost-Effectiveness of Electricity Energy Efficiency Programs
We analyze the cost-effectiveness of electric utility ratepayer–funded programs to promote demand-side management (DSM) and energy efficiency (EE) investments. We specify a model that relates electricity demand to previous EE DSM spending, energy prices, income, weather, and other demand factors. In contrast to previous studies, we allow EE DSM spending to have a potential long-term demand effect and explicitly address possible endogeneity in spending. We find that current period EE DSM expenditures reduce electricity demand and that this effect persists for a number of years. Our findings suggest that ratepayer funded DSM expenditures between 1992 and 2006 produced a central estimate of 0.9 percent savings in electricity consumption over that time period and a 1.8 percent savings over all years. These energy savings came at an expected average cost to utilities of roughly 5 cents per kWh saved when future savings are discounted at a 5 percent rate.
Research Notes : United States : A new mutation at the ms1 locus
Five different populations have been recognized as sources of ms1 alleles. Genetic studies of male-sterile, female-fertile mutations conducted by Palmer et al. (1978) showed that ms1-North Carolina (T260), ms1-Urbana (T266), ms1-Tonica (T267), and ms1-Ames (T268) are independent mutations at the ms1 locus. Yee and Jian (1983) reported another mutation at the ms1 locus, designated Shennong Male-Sterile Soybean L-78-387
Study of combustion experiments in space
The physical bases and scientific merits were examined of combustion experimentation in a space environment. For a very broad range of fundamental combustion problems, extensive and systematic experimentation at reduced gravitational levels (0 g 1) are viewed as essential to the development of needed observations and related theoretical understanding
Developmental design, fabrication, and test of acoustic suppressors for fans of high bypass turbofan engines
An analysis procedure was developed for design of acoustically treated nacelles for high bypass turbofan engines. The plan was applied to the conceptual design of a nacelle for the quiet engine typical of a 707/DC-8 airplane installation. The resultant design was modified to a test nacelle design for the NASA Lewis quiet fan. The acoustic design goal was a 10 db reduction in effective perceived fan noise levels during takoff and approach. Detailed nacelle designs were subsequently developed for both the quiet engine and the quiet fan. The acoustic design goal for each nacelle was 15 db reductions in perceived fan noise levels from the inlet and fan duct. Acoustically treated nacelles were fabricated for the quiet engine and quiet fan for testing. Performance of selected inlet and fan duct lining configurations was experimentally evaluated in a flow duct. Results of the tests show that the linings perform as designed
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