Swelling of U-Mo Monolithic Fuel: Developing a Predictive Swelling Correlation under Research Reactor Conditions
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Robinson, A. B. (ORCID:0000000196104039)↗
Engineering topics
Williams, W. J.
Publications and source records attributed to Williams, W. J..
Evaluation of Thermoregulation After Spaceflight
Altered thermoregulation has been reported following spaceflight simulations such as water immersion and bedrest but it has never been evaluated immediately after actual spaceflight. Impaired thermoregulation may have significant impact during various spaceflight activities such as countermeasure exercise, extravehicular activity (EVA), landing, and egress. It would be manifested as an increased body temperature and heart rate and decreased work capacity and endurance. In this study we evaluated the exercise responses of two crewmembers following a long duration spaceflight and measured their changes in body temperatures, skin blood flow, sweating and heat production during a mild submaximal exercise stress.
Schneider, S. M.↗
Temperature Regulation in Crewmembers After a 115-Day Space Flight
Impaired thermoregulation, which has been observed during exercise following bed rest, may significantly impact crewmembers during space flight operations by decreasing exercise capacity and orthostatic tolerance. Impaired temperature regulation would cause higher levels of core temperature, due to an attenuated cutaneous vasodilatory reflex and sweating response, for a given oxygen consumption. Two mate crewmembers of the Mir 18 mission performed supine cycle exercise se (20 min @ 40% and 20 min @ 65% preflight VO2pk) 145 days preflight and 5 days postflight. Core temperature (Tcore) was measured by an ingestible telemetry pill, skin blood flow (SBF) by laser Doppler velocimetry, and sweat rate (SR) by dew point hygrometry. Tcore at the time of test termination was similar (37.8 C) for both subjects before and after flight despite a shorter test duration (40 vs 28-29 minutes) postflight. The slopes of the SBF/Tcore relationship (Subj 1: 396 vs 214; Subj 2: 704 vs 143 Perfusion Unit/degC) and SR/Tcore relationship (Subj 1: 4.5 vs 2.1; Subj 2: 11.0 vs 3.6mg/min/sq cm/degC) were reduced postflight. Tcore thresholds for both SR (Subj 1: 37.4 vs 37.6; Subj 2: 37.6 vs 37.6 C) and SBF (Subj 1: 37.3 vs 37.5; Subj 2: 37.6 vs 37.7 C) were similar pre- to postflight. For these 2 crewmembers, it appeared that thermoregulation during exercise was impaired as evidenced by compromised heat loss responses after long-duration space flight.
Lee, S. M. C.↗
Thermal infrared spectra of the Moon
Contrary to recent assertions in the literature, lunar emission spectra obtained at an altitude of 32 km with a balloon-borne telescope are virtually undistorted by atmospheric absorption, except in the ozone region. These spectra have been found to correlate closely with laboratory emission spectra of returned lunar samples measured in a simulated lunar environment. Thus, lunar spectra obtained with the balloon-borne telescope system are the standards against which groundbased spectral measurements of the Moon should be compared. Comparison of balloon-borne measurements with recent groundbased spectral measurements suggests that the latter suffer from some source of systematic error. When high-quality lunar spectra are available, they will be best interpreted by comparison with returned lunar samples, rather than terrestrial minerals or rocks, because of subtle spectral differences between lunar and terrestrial minerals perhaps associated with incipient alteration of the latter.
Salisbury, John W.↗
HNO3 profiles obtained during the EASOE campaign
A small cryogenically cooled spectrometer system designed to obtain atmospheric emission spectra in the 7.5 micrometer to 13.0 micrometer region was flown piggyback on 9 balloon flights from ESRANGE (67.9 deg N, 21.2 deg E) during the European Arctic Stratospheric Ozone Experiment (EASOE) campaign. Initial analysis of the spectra obtained has been concentrated on obtaining HNO3 profiles for the various flights. HNO3 profiles for 17 December 1991, 9 January 1992, 22 January 1992, 5 February 1992 and 14 March 1992 are presented.
Murcray, F. J.↗
Human cardiovascular response to sympathomimetic agents during head-down bed rest: the effect of dietary sodium
Changes in sympathoadrenal function and cardiovascular deconditioning have long been recognized as a feature of the physiological adaptation to microgravity. The deconditioning process, coupled with altered hydration status, is thought to significantly contribute to orthostatic intolerance upon return to Earth gravity. The cardiovascular response to stimulation by sympathomimetic agents before, during, and after exposure to simulated microgravity was determined in healthy volunteers equilibrated on normal or high sodium diets in order to further the understanding of the deconditioning process.
NASA Discipline Number 18-10↗
Stratospheric nitrogen dioxide in the vicinity of Soufriere, St. Vincent
In April 1979, measurements of nitrogen dioxide in the upper atmosphere were made near Soufriere Volcano by twilight optical-absorption techniques. The derived value of 5 x 10 to the 15th molecules per square centimeter column implies an enhancement of 25 percent over earlier abundances measured in the same latitudinal regions. This enhancement may represent the normal stratospheric variability of nitrogen dioxide in the equatorial region, but in any case may be considered an upper limit to the volcano's effect on the total nitrogen dioxide abundance.
Romick, G. J.↗
Atmospheric ozone profiles from high resolution UV spectra obtained with a balloon-borne spectrometer
High resolution solar spectra at high and low sun angles are analyzed by a layer-by-layer three-wavelength differential absorption method. Ozone amounts are derived from the ratio of a low sun angle scan through a long atmosphere path to a high sun angle scan through a negligible atmosphere path. Ozone volume-mixing ratio profiles are derived and agree with standard profiles. The accuracy of the ozone profiles is found to be limited mostly by the accuracy of the ozone absorption coefficients, and suggestions are made for improving the accuracy of the results in future measurements.
Gillis, J. R.↗
Recent spectroscopic measurements of NOx in the lower stratosphere
High resolution (0.02 and 0.06 per cm) Fourier transform airborne systems were used for measurements of long path atmospheric absorption spectra, covering many of the NOx infrared bands. Atmospheric emission measurements with liquid helium cooled grating spectrometer systems at 0.5 per cm resolution were also carried out from different altitudes in the NOx bands region. Analysis of the absorption and emission spectra provides quantification of NOx in the lower stratosphere at different latitudes and seasons, as well as diurnal variability.
Goldman, A.↗
Stratospheric distribution of ClONO2
Balloon-borne infrared solar spectra in the 1292/cm region, at 0.02/cm resolution, obtained during sunset, are used to derive a mixing ratio altitude profile of ClONO2. Portions of the spectra covering the 1292/cm region are shown together with a laboratory spectrum of ClONO2 and HNO3 taken with a flight interferometer. The agreement of the atmospheric absorption feature in shape and position with the ClONO2 spectrum, along with the fact that the feature is not due to other known atmospheric compounds, results in the identification of the atmospheric absorption as being due to ClONO2.
Murcray, D. G.↗
Preliminary results from the University of Denver infrared spectrometer - 1977 intertropical convergence zone experiment
The Denver University Infrared Spectrometer (DUIRS) is a liquid-helium-cooled emission radiometer designed to study minor atmospheric constituents. DUIRS flew on 12 data flights during the 1977 Intertropical Convergence Zone experiment. No data were obtained on the flight from Wallops Island to Panama because of a power failure or on the return flight to Wallops Island because of a cryogen line freeze-up. The data coverage on the nine vertical profile flights that were flown before the freeze-up are shown. Typical spectra and variations as a function of U-2 (research aircraft) altitude are also shown. Radio metric data and rawinsonde temperature data were used to perform band model calculations to obtain molecular number densities in the column above the aircraft at each altitude.
Barker, D. B.↗
Vertical distribution of NO2 in the stratosphere as determined from balloon measurements of solar spectra in the 4500A region
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Goldman, A.↗
Remote sensing of trace constituents from atmospheric infrared emission and absorption spectra
Atmospheric infrared emission and absorption spectra obtained from aircraft and balloon-borne spectrometers are presented. From such spectra, mixing ratio vs altitude profiles are derived for several minor constituents. Recent results for HNO3, CF2Cl2, CFCl3, and HF are presented. In addition, the feasibility of infrared detection of other trace constituents, such as HCl, HF, NH3, NO and SO2, against the rest of the atmospheric background is studied. From this study, made on a line-by-line basis for 'state of the art' airborne spectrometers, potential spectral features for detection of the trace constituents are isolated.
Barker, D. B.↗
Measurements of atmospheric emission spectra in the 8.5mu m to 13.3mu m and 19.0mu m to 26.0mu m regions at high altitudes and various zenith angles
A balloon flight was conducted with a sensitive infrared spectral radiometer system in support of the LACATE balloon experiment. The instrumentation aboard the balloon is described along with data reduction techniques. Results obtained during the flight are presented.
Murcray, D. G.↗
Detection of fluorocarbons in the stratosphere
Infrared absorption spectral measurements are applied to selected balloon flight data to detect CF2Cl2 and CFCl3 in the stratosphere. Identification of the fluorocarbons from absorption spectra is described, and the results are compared with previous models of fluorocarbon content at 21 km. A volume mixing ratio is derived for CF2Cl3 and a probable ratio is estimated for CFCl3. An upper limit for HF in the lower stratosphere up to 30 km is set based on data from a balloon flight.
Murcray, D. G.↗
Absolute integrated intensity and individual line parameters for the 6.2-micron band of NO2
The absolute integrated intensity of the 6.2-micron band of NO2 at 40 C was determined from quantitative spectra at about 10 per cm resolution by the spectral band model technique. A value of 1430 plus or minus 300 per sq cm per atm was obtained. Individual line parameters, positions, intensities, and ground-state energies were derived, and line-by-line calculations were compared with the band model results and with the quantitative spectra obtained at about 0.5 per cm resolution.
Goldman, A.↗
Statistical-band-model analysis and integrated intensity for the 21.8 micrometer bands of HNO3 vapor
A large number of low-resolution quantitative spectra were obtained for a band-model analysis of 21.8-micrometer bands. The experimental investigations were conducted with pure nitric-acid vapor at 40 C, taking into account pressures in the range from a few torr to a pressure which is close to the saturation pressure. It is pointed out that the obtained data, in addition to those from the 11.3-micrometer band, can be used for an independent determination of the nitric acid vertical distribution in the stratosphere.
Goldman, A.↗