76,679 research outputs found
Technique for predicting the thermal expansion coefficients of cryogenic metallic alloys
Series of measurements on the thermal expansion coefficients of several aerospace alloys and standard materials establish relationships between related alloys that would aid in predicting their thermal expansion reliability. Thermal expansion data are also necessary for the reduction of electrical resistivity measurements of those same materials
Discrimination of gravitational stimuli
The construction and installation of an animal centrifuge and its electronic support system was completed. Experimental procedures for obtaining data on the relationship between the discriminability of g differences and location along the continuum of effective weight were initiated. Data were obtained under two successive discriminations showing discrimination among g levels. In addition, there was some indication that the discriminability of differences between g levels associated with reinforcement was the same at two locations along the g continuum, although there were differences in measures of absolute discrimination at these locations
AJAE Appendix: The Profitability of Transitioning to Organic Grain Crops in Indiana
The material contained herein is supplementary to the article named in the title and published in the American Journal of Agricultural Economics.Crop Production/Industries, Farm Management,
Development of an 8000 bps voice codec for AvSat
Air-mobile speech communication applications share robustness and noise immunity requirements with other mobile applications. The quality requirements are stringent, especially in the cockpit where air safety is involved. Based on these considerations, a decision was made to test an intermediate data rate such as 8.0 and 9.6 kb/s as proven technologies. A number of vocoders and codec technologies were investigated at rates ranging from 2.4 kb/s up to and including 9.6 kb/s. The proven vocoders operating at 2.4 and 4.8 kb/s lacked the noise immunity or the robustness to operate reliably in a cabin noise environment. One very attractive alternative approach was Spectrally Encoded Residual Excited LPC (SE-RELP) which is used in a multi-rate voice processor (MRP) developed at the Naval Research Lab (NRL). The MRP uses SE-RELP at rates of 9.6 and 16 kb/s. The 9.6 kb/s rate can be lowered to 8.0 kb/s without loss of information by modifying the frame. An 8.0 kb/s vocoder was developed using SE-RELP as a demonstrator and testbed. This demonstrator is implemented in real time using two Compaq 2 portable computers, each equipped with an ARIEL DSP016 Data Acquisition Processor
Global climate evolution during the last deglaciation
Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth’s climate system to external and internal forcings. During this interval of global warming, the decay of ice sheets caused global mean sea level to rise by approximately 80 m; terrestrial and marine ecosystems experienced large disturbances and range shifts; perturbations to the carbon cycle resulted in a net release of the greenhouse gases CO_2 and CH_4 to the atmosphere; and changes in atmosphere and ocean circulation affected the global distribution and fluxes of water and heat. Here we summarize a major effort by the paleoclimate research community to characterize these changes through the development of well-dated, high-resolution records of the deep and intermediate ocean as well as surface climate. Our synthesis indicates that the superposition of two modes explains much of the variability in regional and global climate during the last deglaciation, with a strong association between the first mode and variations in greenhouse gases, and between the second mode and variations in the Atlantic meridional overturning circulation
Thermal pump-compressor for space use Patent
Thermal pump-compressor for converting solar energ
Advanced dosimetry systems for the space transport and space station
Advanced dosimetry system concepts are described that will provide automated and instantaneous measurement of dose and particle spectra. Systems are proposed for measuring dose rate from cosmic radiation background to greater than 3600 rads/hr. Charged particle spectrometers, both internal and external to the spacecraft, are described for determining mixed field energy spectra and particle fluxes for both real time onboard and ground-based computer evaluation of the radiation hazard. Automated passive dosimetry systems consisting of thermoluminescent dosimeters and activation techniques are proposed for recording the dose levels for twelve or more crew members. This system will allow automatic onboard readout and data storage of the accumulated dose and can be transmitted to ground after readout or data records recovered with each crew rotation
Development of a polyimide for use as a temperature and solvent resistant sealant
Polyimide developed by the interaction of benzophenone tetracarboxylic dianhydride, polyoxypropylene diamine, and oxydianiline is used for fuel tanks that are exposed to extreme temperatures
Predicting the effects of basepair mutations in DNA-protein complexes by thermodynamic integration
AbstractThermodynamically rigorous free energy methods in principle allow the exact computation of binding free energies in biological systems. Here, we use thermodynamic integration together with molecular dynamics simulations of a DNA-protein complex to compute relative binding free energies of a series of mutants of a protein-binding DNA operator sequence. A guanine-cytosine basepair that interacts strongly with the DNA-binding protein is mutated into adenine-thymine, cytosine-guanine, and thymine-adenine. It is shown that basepair mutations can be performed using a conservative protocol that gives error estimates of ∼10% of the change in free energy of binding. Despite the high CPU-time requirements, this work opens the exciting opportunity of being able to perform basepair scans to investigate protein-DNA binding specificity in great detail computationally
Broadening the Mission: Research Activity among University Labor Education/Labor Studies Professionals
[Excerpt] This study examines research activity among university and college labor education/labor studies professionals. Using data gathered in a survey of faculty employed in the field, the paper presents information concerning the extent and focus of these research activities, the methodologies employed, the outlets for the research products that result, and the factors limiting such work. The findings of this study indicate that research, of both an applied and scholarly nature, is an increasingly significant part of the work of labor education/labor studies professionals. The study concludes with a discussion of the implications this trend has for the labor education/labor studies field, with special attention being given to the role research activity can play in meeting the needs of unions, union members, and union leaders
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