A balloon-borne diffusing system for infrared radiation from 1 mu to 5 mu.
Balloon-borne diffusing system designed to measure absorption of minor atmospheric constituents, as sun set and passed below horizon
SOLAR RADIATION↗
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Results for “DIFFUSION EFFECT”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Present status of lithium-diffused silicon solar cells.
Spontaneous annealing models of lithium- diffused Si solar cells, discussing defect compensation and metastable defect formation
SOLAR CELL↗
Diffusive separation in shock waves and freejets of nitrogen-helium mixtures.
Diffusive separation effects measured in shock waves and underexpanded freejets for nitrogen- helium mixtures by electron beam techniques
Sebacher, D. I.↗
Discussion of ''A model for concentrated interstitial solid solutions - Its application to solutions of carbon in gamma iron.''
Interstitial solid solutions models, noting thermodynamic activity of carbon in austenite and dual site effects on diffusion kinetics
Aaronson, H. I.↗
Venturi meter with separable diffuser.
Venturi meter with separable diffuser and radial outward step at transition from throat to diffuser, noting effect of step on efficiency
Dudzinski, T. J.↗
Venturi meter with separable diffuser.
Venturi meter with separable diffuser and radial outward step at transition from throat to diffuser, noting effect of step on efficiency
Dudzinski, T. J.↗
Nucleosynthesis in neutron star atmospheres
Neutron star atmospheric composition as function of time, including effects of diffusion, cooling and nucleosynthesis
Rosen, L. C.↗
Thermal emission from grains in H-II regions
H II region dust grains thermal emission, examining effect on diffuse nebulae
Krishna Swamy, K. S.↗
A model for analysis of the temperature field downstream of a heated jet injected into an isothermal crossflow at an angle of 90 deg
The temperature distribution downstream of a heated jet entering an isothermal crossflow at an angle of 90 deg is predicted using two conduction models with energy sources above the point of injection, in one case a point source and in the second a line source. The models use effective turbulent diffusivities that are determined empirically from previous measurements. Temperatures predicted by the models are compared to experimental results.
Eriksen, V. L.↗
Investigation of the Ignition and Burning of Materials in Space Cabin Atmospheres. Part 2: Ignition of a Combustible Mixture by a Hot Body with the Effects of Gravity
The ignition of a combustible gas mixture by a hot cylinder under the effect of a gravity field for steady state conditions is examined. For this purpose a horizontal cylinder is considered with gravity as a parameter together with a finite chemical reacting flow generated by free convection with the additional effect of diffusion. Both mass transfer and zero mass transfer cases are considered. By defining an ignition criterion the surface temperature and species are obtained from the analysis as a function of the gravity field. It is supposed that at the point of ignition the heat evolved in the gas is sufficiently high to attain a sustained combustion without any energy from the hot cylinder.
Lew, H. G.↗
Galactic cosmic ray modulation from 1965-1970.
Numerical solutions of the cosmic-ray equation of transport within the solar cavity and including the effects of diffusion, convection, and energy losses due to adiabatic deceleration, have been used to reproduce the modulation of galactic electrons, protons, and helium nuclei observed during the period from 1965 to 1970. Kinetic energies between 10 and 10,000 MeV/nucleon are considered. Computed and observed spectra are given for the years 1965, 1968, 1969, and 1970 together with the diffusion coefficients. These diffusion coefficients are assumed to be of separable form in rigidity and radial dependence, and are consistent with the available magnetic-field power spectra. The force-field solutions are given for these diffusion coefficients and galactic spectra and are compared with the numerical solutions. It is shown that the energy losses and convection lead to near-earth nuclei spectra at kinetic energies less than or equal to 100 MeV/nucleon in which the differential intensity is proportional to the kinetic energy with little dependence on the form of the galactic spectrum. This dependence is in agreement with the observed spectra of all species of atomic nuclei and it is argued that this provides strong observational evidence for the presence of energy losses in the propagation process, and for the exclusion of low-energy galactic nuclei from near earth.
Urch, I. H.↗
Linear viscous stability theory for stably stratified shear flow - A review.
In this paper the linear viscous stability theory for stably stratified parallel shear flow is reviewed and some new results are presented. Attention is focused on recent work on unbounded flows with emphasis placed on results which demonstrate apparent destabilizing effects of diffusivity which lie beyond the scope of inviscid theory. In particular it is shown that self-excited disturbances may exist with phase speeds lying outside the range of basic flow speed and that with strong thermal diffusivity, instability may occur even though the local Richardson number exceeds 0.25 throughout the flow.
Gage, K. S.↗
Concentration changes during eutectic solidification
Thermotransport (or thermal diffusion, Soret effect) is shown to cause significant amount of segregation during the directional solidification of aluminum-copper eutectic. The concentration changes are predicted quantitatively and they are a function of temperature gradient, rate of melting and solidification and the time of soaking. There is a fair agreement between the experiments and calculations. A process is suggested where these concentration changes may be minimized.
Bhat, B. N.↗
Further analysis of field effects on liquids and solidification
Numerical calculations of the magnitude of external field effects on liquids are presented to describe how external fields can influence the substructure of the field. Quantitative estimates of magnetic and gravitational effects are reported on melts of metals and semiconductors. The results are condensed in tables which contain the input data for calculation of the field effects on diffusion coefficient, solidification rate and for calculation of field forces on individual molecules in the melt.
Seiler, R. F.↗
Data on incident solar energy
Instrumentation for solar irradiance monitoring, and radiation scales are discussed in a survey of incident solar energy data. The absolute accuracy and intrinsic reliability of the values of the solar constant and zero air mass solar spectrum proposed by the Institute of Environmental Sciences as an ASTM standard are evaluated. Extraterrestrial observations are used for deriving solar irradiance data at ground level for widely varying atmospheric parameters, with special reference to air pollution. The effects of diffuse sky radiance and those of varying slopes of the solar energy collecting surface are examined. Average values of solar energy available at different locations in the United States are included.
Thekaekara, M. P.↗
Effect of inducer inlet and diffuser throat areas on performance of a low pressure ratio sweptback centrifugal compressor
A low-pressure-ratio centrifugal compressor was tested with nine combinations of three diffuser throat areas and three impeller inducer inlet areas which were 75, 100, and 125 percent of design values. For a given inducer inlet area, increases in diffuser area within the range investigated resulted in increased mass flow and higher peak efficiency. Changes in both diffuser and inducer areas indicated that efficiencies within one point of the maximum efficiency were obtained over a compressor specific speed range of 27 percent. The performance was analyzed of an assumed two-spool open-cycle engine using the 75 percent area inducer with a variable area diffuser.
Klassen, H. A.↗
Motion of charged particles normal to an irregular magnetic field
The motion is analyzed of charged particles in a fluctuating magnetic field which varies only in directions normal to its mean direction, such as that which would be generated by an ensemble of magnetosonic waves propagating normal to an ambient magnetic field. The appropriate generalization of gradient-drift motion is derived in terms of the power spectrum of the magnetic fluctuations, and an effective spatial diffusion coefficient is obtained. Several special cases are considered, including a Gaussian power spectrum, a power-law spectrum with a cutoff, and a general power-law spectrum. A possible magnitude is calculated for the spatial diffusion coefficient of the solar wind.
Jokipii, J. R.↗
Inlet total pressure loss due to acoustic wall treatment
The effect of diffuser wall acoustic treatment on inlet total pressure loss was experimentally determined. Data were obtained by testing an inlet model with 10 different acoustically treated diffusers differing only in the design of the Helmholtz resonator acoustic treatment. Tests were conducted in a wind tunnel at forward velocities to 41 meters per second for inlet throat Mach numbers of .5 to .8 and angles of attack as high as 50 degrees. Results indicate a pressure loss penalty due to acoustic treatment that increases linearly with the porosity of the acoustic facing sheet. For a surface porosity of 14 percent the total pressure loss was 21 percent greater than that for an untreated inlet.
Miller, B. A.↗