1,190 research outputs found

    High- and low-pressure pneumotachometers measure respiration rates accurately in adverse environments

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    Respiration-rate transducers in the form of pneumotachometers measure respiration rates of pilots operating high performance research aircraft. In each low pressure or high pressure oxygen system a sensor is placed in series with the pilots oxygen supply line to detect gas flow accompanying respiration

    Refinement of loss-on-ignition method for organic matter content in highly amended soils

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    The purpose of this study was to refine the loss-on-ignition method of organic matter determination based on the previous findings of David Cochran (1980). An additional objective was to develop a pretreatment of organic matter for the reduction or prevention of error due to sample loss from violent eruption caused by rapid exposure to high ignition temperatures. Pretreatment tests indicated that precharring samples at a temperature of 300° C for 10 minutes prevented loss of samples due to violent eruption at high ignition temperatures. The three sands and eight organic materials were then heated at different temperatures for different time periods. Two of the sands were washed river sands and the third was a mined silica sand. The eight organic materials used were corn stalk chop, cotton stalk chop, Michigan peat, oak sawdust, pine bark, sewage sludge, soybean stalk chop, and sphagnum peat. Temperatures used ranged from 350° to 450° C and time periods ranged from 2 to 8 hours. In all cases the best temperature and time combination was 400° C for 4 hours

    Spin-lattice Interaction in Ruby Measured by ESR in Uniaxially Stressed Crystals

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    Spin-lattice Hamiltonian determined for chromium ions in ruby single crystal

    In vitro micropropagation of white dasheen (Colocassia esculenta)

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    Plant regeneration for efficient vegetative propagation in white dasheen has been developed. Meristem cultured on Murashige and Skoog medium supplemented with 6-Benzyladenine (BA) and Indole-3-aceticacid (IAA) gave the best explants establishment and development. This in vitro system provides for a uniform production system which is easily managed and yields high quality cornels for commercial production

    Treadmill exercise within lower body negative pressure protects leg lean tissue mass and extensor strength and endurance during bed rest.

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    Leg muscle mass and strength are decreased during reduced activity and non-weight-bearing conditions such as bed rest (BR) and spaceflight. Supine treadmill exercise within lower body negative pressure (LBNPEX) provides full-body weight loading during BR and may prevent muscle deconditioning. We hypothesized that a 40-min interval exercise protocol performed against LBNPEX 6 days week(-1) would attenuate losses in leg lean mass (LLM), strength, and endurance during 6° head-down tilt BR, with similar benefits for men and women. Fifteen pairs of healthy monozygous twins (8 male and 7 female pairs) completed 30 days of BR with one sibling of each twin pair assigned randomly as the non-exercise control (CON) and the other twin as the exercise subject (EX). Before and after BR, LLM and isokinetic leg strength and endurance were measured. Mean knee and ankle extensor and flexor strength and endurance and LLM decreased from pre- to post-BR in the male CON subjects (P < 0.01), but knee extensor strength and endurance, ankle extensor strength, and LLM were maintained in the male EX subjects. In contrast, no pre- to post-BR changes were significant in the female subjects, either CON or EX, likely due to their lower pre-BR values. Importantly, the LBNPEX countermeasure prevents or attenuates declines in LLM as well as extensor leg strength and endurance. Individuals who are stronger, have higher levels of muscular endurance, and/or have greater LLM are likely to experience greater losses during BR than those who are less fit

    Venus/Mercury swingby with Venus capsule. Preliminary science objectives and experiments for use in advanced mission studies

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    Venus/Mercury swingby with Venus capsule - preliminary science objectives and experiments for use in advanced mission studie

    A program to develop a high-energy density primary battery with a minimum of 200 watt hours per pound of total battery weight Eighth quarterly report, 1 Apr. - 30 Jun. 1966

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    Electrochemical characteristics of lithium in various electrolytes and magnesium in aluminum chloride-acetonitrile studied by voltammetric sweep metho
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