4,220 research outputs found
Space processing of crystalline materials: A study of known methods of electrical characterization of semiconductors: Bibliography
A selective bibliography is given on electrical characterization techniques for semiconductors. Emphasis is placed on noncontacting techniques for the standard electrical parameters for monitoring crystal growth in space, preferably in real time with high resolution
Space processing of crystalline materials: A study of known methods of electrical characterization of semiconductors
A literature survey is presented covering nondestructive methods of electrical characterization of semiconductors. A synopsis of each technique deals with the applicability of the techniques to various device parameters and to potential in-flight use before, during, and after growth experiments on space flights. It is concluded that the very recent surge in the commercial production of large scale integrated circuitry and other semiconductor arrays requiring uniformity on the scale of a few microns, involves nondestructive test procedures which could well be useful to NASA for in-flight use in space processing
Computer program for calculation of oxygen uptake
A description and operational precedures are presented for a computer program, written in Super Basic, that calculates oxygen uptake, carbon dioxide production, and related ventilation parameters. Program features include: (1) the option of entering slope and intercept values of calibration curves for the O2 and CO2 and analyzers; (2) calculation of expired water vapor pressure; and (3) the option of entering inspured O2 and CO2 concentrations. The program is easily adaptable for programmable laboratory calculators
Measurements of material properties for solar cells
Measurements on two candidate materials for space flight are reported. The observed optical transmittance of aluminum films vapor deposited on fused quartz showed anomalously high transmittance thru 400 A and 600 A and showed an effective skin depth of 110 A in the latter part of the 1000 A thickness. KAPTON films are shown by their optical transmission spectra to have an energy gap for electron excitation of approximately 2.5 eV, which value depends on the thickness as manufactured. The resistance of KAPTON film to ionizing radiation is described by their optical spectra and their electron spin resonance spectra
Improved electrodes for skin contacts
Design is described of thick, flexible electrodes with appropriate metal surfaces which prevent unnecessary skin motion. Electrodes provide sufficient radial pressure directed toward body surface to depress skin a noticeable portion of its normal resilient thickness
Impact of infection preventionists on Centers for Medicare and Medicaid quality measures in Maryland nursing homes.
BackgroundHealth care-associated infections are the leading cause of morbidity and mortality in US nursing homes (NHs). The objective of the research is to assess the impact of Maryland NH infection preventionists (IPs) on NH quality measures.MethodsTwo hundred thirty-four NHs were queried through mailed survey. These survey data were then linked with 2008 quality data from Nursing Home Compare and the On-line Survey Certification of Automated Records.ResultsThree of the 8 quality measures examined-influenza vaccination for both short- and long-stay residents and pressure ulcer prevention in high-risk residents-were significantly associated with the number of IPs. None of the quality measures were shown to be significant with IPs who received specialized training on infection prevention and management compared with those who did not receive specialized training.ConclusionIPs play a critical role in preventing and managing health care-associated infections in nursing homes, especially in the areas of influenza vaccination and pressure ulcer prevention among high-risk nursing home residents. Quality measures that reflect the effects of IP training may not have been elucidated yet. Further research is needed to support the IP role in order for policy to advocate for increased IP funding
Electrical characterization of GaAs single crystal in direct support of M555 flight experiment
The exploration of several nondestructive methods of electrical characterization of semiconductor single crystals was carried out during the period ending May 1974. Two methods of obtaining the microwave skin depth, one for the mapping flat surfaces and the other for analyzing the whole surface of small single crystal wafers, were developed to the stage of working laboratory procedures. The preliminary 35 GHz data characterizing the two types of space-related single crystal surfaces, flat slices of gallium arsenide and small wafers of germanium selenide, are discussed. A third method of nondestructive mapping of donor impurity density in semiconductor surfaces by scanning with a light beam was developed for GaAs; its testing indicates reasonable precision at reasonable scan rates for GaAs surfaces at room temperature
Subsatellite Orbital Analysis Program (SOAP) user's guide
The features and use of the subsatellite operational analysis are examined. The model simulates several Earth-orbiting vehicles, their pilots, control systems, and interaction with the environment. The use of the program, input and output capabilities, executive structures, and properties of the vehicles and environmental effects which it models are described
Grazing Management and Nitrogen Fertilizer Effects in Grazing Systems for Beef Cows
Four 8-ha areas, primarily Cynodon dactylon forage, were overseeded in autumn with annual ryegrass (Lolium multiflorum) and clover (Trifolium incarnatum and Trifolium repens). Two areas received no nitrogen (N) fertilizer and two received 168 kg N/ha annually. Within N level (2 x 2 factorial), one area was divided into 4 paddocks (pad) and the other into 16 pad for rotational grazing. Spring-calving beef cows were stocked (2.5/ha) year-round on each area with calves weaned in October. Annual dry matter forage accumulation was greater where N was applied (18.2 vs 14.2 Mg/ha, P=.02) but was unaffected by pad number. Forage availability and annual days of grazing were affected positively both by N and pad number (P\u3c.05). N x pad number interaction affected forage quality (P\u3c.07), cowcalf performance and net returns (P\u3c.01). Generally, responses were similar between 4 and 16 pad at 0 N, but at 168 N, responses were greater for 4 compared with 16 pad. Overall, there was little benefit of increasing pad number from 4 to 16 irrespective of N level, although increased carrying capacity was indicated particularly where N was applied
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