23,774 research outputs found
Additions to fused-fluoride lubricant coatings for reduction of low-temperature friction
Additions to fused-fluoride lubricant coatings for reduction of low temperature frictio
Pulsation of EE Cam
EE Cam is a previously little studied Delta Scuti pulsator with amplitudes
between those of the HADS (High-Amplitude Delta Scuti stars) group and the
average low-amplitude pulsators. Since the size of stellar rotation determines
both which pulsation modes are selected by the star as well as their
amplitudes, the star offers a great opportunity to examine the astrophysical
connections. Extensive photometric measurements covering several months were
carried out. 15 significant pulsation frequencies were extracted. The dominant
mode at 4.934 cd was identified as a radial mode by examining the phase
shifts at different wavelengths. Medium-dispersion spectra yielded a
value of km s. This shows that EE Cam belongs to the
important transition region between the HADS and normal Delta Scuti stars.Comment: 13 pages, 3 figures, 3 table
Remote sensing of changes in morphology and physiology of trees under stress Annual progress report
Remote sensing of morphological and physiological changes in trees under stres
Aerodynamic characteristics of the 40- by 80/80- by 120-foot wind tunnel at NASA Ames Research Center
The design and testing of vane sets and air-exchange inlet for the 40 x 80/80 x 120-ft wind tunnel at NASA Ames are reported. Boundary-layer analysis and 2D and 3D inviscid panel codes are employed in computer models of the system, and a 1/10-scale 2D facility and a 1/50-scale 3D model of the entire wind tunnel are used in experimental testing of the vane sets. The results are presented in graphs, photographs, drawings, and diagrams are discussed. Generally good agreement is found between the predicted and measured performance
Troposphere-stratosphere (surface-55 km) monthly general circulation statistics for the Northern Hemisphere-four year averages
This report presents four year averages of monthly mean Northern Hemisphere general circulation statistics for the period from 1 December 1978 through 30 November 1982. Computations start with daily maps of temperature for 18 pressure levels between 1000 and 0.4 mb that were supplied by NOAA/NMC. Geopotential height and geostrophic wind are constructed using the hydrostatic and geostrophic formulae. Fields presented in this report are zonally averaged temperature, mean zonal wind, and amplitude and phase of the planetary waves in geopotential height with zonal wavenumbers 1-3. The northward fluxes of heat and eastward momentum by the standing and transient eddies along with their wavenumber decomposition and Eliassen-Palm flux propagation vectors and divergences by the standing and transient eddies along with their wavenumber decomposition are also given. Large annual and interannual variations are found in each quantity especially in the stratosphere in accordance with the changes in the planetary wave activity. The results are shown both in graphic and tabular form
Remote sensing of changes in morphology and physiology of trees under stress
Measurements on foliage samples collected from several drought and salt treated plants revealed that leaf thickness decreased with increasing severity of the drought treatment and increased with increasing severity of treatment with NaCl, but remained essentially unaffected by treatment with CaCl2. Airborne data collected by multispectral scanner indicated that false color images provide selective enhancement of a diseased area. Comparison of simulated and actual aerial color and color IR photography revealed that the color renditions of the MSS simulations agreed closely with those of the actual photography
Remote sensing applications in forestry - Remote sensing of changes in morphology and physiology of trees under stress Annual progress report
Remote sensing of changes in morphology and physiology of trees under stres
Understanding the measurement of hunger and food insecurity in the elderly
The elderly are one of the population subgroups at greatest risk for hunger and food insecurity. To date, no accurate measures of this problem have been developed. What is needed are a thorough understanding of the phenomenon, and an assessment of how the elderly perceive and answer items commonly used to measure hunger and food insecurity in other subgroups. In-depth, open-ended interviews were conducted with forty-one low-income urban black and rural white residents of upstate New York. Results suggest a conceptual framework of food insecurity in the elderly with two significant differences from frameworks proposed for younger families: the major role of health problems and physical disabilities, and the impact of personal history on perceptions of food insecurity. In a telephone follow-up (approximately six months after the initial interviews) twenty-four respondents were asked commonly used food insecurity questionnaire items from six different sources. Results suggest that hunger and food insecurity among the elderly can be measured directly. The commonly used measures tested here will help categorize the stages of food insecurity. However, these direct measures might underestimate the prevalence of food insecurity because of a perceived reluctance to report problems with food.
Electron Capture In Pseudo-two-electron Systems: Ar8++He
Molecular-structure calculations using the pseudopotential method have been performed on the (ArHe)8+ system. The cross section for single-electron capture in Ar8++He collisions was calculated for energies from 20 eV to 10 keV/amu. The perturbed-stationary-state method [M. Kimura, H. Sato, and R. E. Olson, Phys. Rev. A 28, 2085 (1983)], modified to include electron translation factors appropriate to two-electron systems, was used. The total cross section is relatively energy independent with a value of approximately 2.5x10-15 cm2. The n=4 level of Ar7+ is found to be preferentially populated, with the 4f level being dominant. © 1985 The American Physical Society
Angular Scattering In Slow Multiple-charged Ion, Atom Collisions
The C6++H system is used to illustrate the importance of large-angle scattering in collisions between slow multiply charged ions and atoms. A quantum mechanical description based on a diabatic formalism of the collision system is used to obtain differential cross sections for electron capture in the relative velocity range nu =1*107 to 3*107 cm s-1 (Ecm approximately=48 to 430 eV). The threshold for angular scattering is at E theta approximately=0.2 keV deg which correlates with the curve crossing between initial and final molecular states located at Rx approximately=8a0. The centre-of-mass acceptance angles required to observe fixed fractions of the total electron capture cross sections are presented. Representative examples for the detection of 90% of the total electron capture cross section requires angular acceptances of 78 degrees at 1*107 cm s-1 and 8.5 degrees at 3*107 cm s-1
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