Intermolecular forces in globular molecules. V - Transport collision integrals.
Transport collision integrals tabulated for spherical shell potential describing intermolecular forces in globular molecules
De Rocco, A. G.↗
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Intermolecular forces in globular molecules. VI - Octopole moments of tetrahedral molecules.
Octopole moments for methane and carbon tetrafluoride derived from second virial coefficients temperature dependence, using spherical shell potential model
De Rocco, A. G.↗
The buckling and post-buckling behavior of spherical caps under axisymmetric load.
Elastic buckling and initial postbuckling behavior of clamped shallow spherical shells under axisymmetric load
Budiansky, B.↗
On the postbuckling behavior of imperfection- sensitive structures in the plastic range
Plastic postbuckling and imperfection sensitivity of spherical shells under axisymmetric bifurcation
Hutchinson, J. W.↗
Intermolecular forces in globular molecules. VIII - Binary gaseous mixtures
Spherical shell potential extension to shells of differing diameters for intermolecular forces in globular molecules, considering binary gaseous mixtures
De Rocco, A. G.↗
On the postbuckling behavior of imperfection- sensitive structures in the plastic range
Axisymmetric plastic deformation of imperfection sensitive spherical shell after elastic buckling, considering load carrying capacity
Hutchinson, J. W.↗
Thermal-mechanical response of nearly opaque materials exposed to continuous radiation
Thermal stress distribution and temperature profiles in nearly opaque spherical shell under radiant and convective heating flux
Howe, J. T.↗
The risk of solar proton events to space missions
The total dose in rads-tissue from solar protons was tabulated for weekly time intervals, and the number of weeks which gave a dose above 25 rads behind 10 g/sq cm of aluminum for the active 6 years of the 19th cycle were called dangerous or large event weeks. The number of such event weeks was found to be only 3 weeks for the past 20 years. Even though the chance for smaller events is examined, it was found that for any reasonable, high confidence level (95%), the smaller events could be ignored. Consequently, the total particle flux for the 19th cycle was divided by a factor of 3 and determined a single large event week. Using this spectrum, the tissue dose in rads is calculated at the center of an aluminum spherical shell.
Burrell, M. O.↗
The estimation of galactic cosmic ray penetration and dose rates
This study is concerned with approximation methods that can be readily applied to estimate the absorbed dose rate from cosmic rays in rads - tissue or rems inside simple geometries of aluminum. The present work is limited to finding the dose rate at the center of spherical shells or behind plane slabs. The dose rate is calculated at tissue-point detectors or for thin layers of tissue. This study considers cosmic-rays dose rates for both free-space and earth-orbiting missions.
Burrell, M. O.↗
Bipropellant shut-off valve
An advanced design of an all metal, fast response, bipropellant, shut-off valve for use on long duration space missions is reported. The valve provides the flow control capability for a 1,000 lb thrust, bipropellant engine using oxygen difluoride and diborane as propellants. The shutoff seal selection is a soft-on-hard metal concept. The soft seal is a spherical shell that seats against a hard conical seat. Beryllium copper and beryllium nickel seals were selected to seal against an electrolyzed Inconel 718 seat. Poppet shaft sealing is achieved by use of hydroformed, Inconel 718 bellows. Two valve assemblies were fabricated and subjected to a series of tests including leak, response time, flow capacity, dry cycles, water cycles, liquid nitrogen cycles, liquid fluorine cycles, and lead-lag operation cycles. These tests demonstrated the ability of the valve to meet design goals.
Smith, J. V.↗
The influence of ozone and aerosols on the brightness and color of the twilight zone
The radiance and color of the twilight sky are calculated for single scattered radiation with the use of spherically symmetric models of the earth's atmosphere. Spherical geometry is used throughout the calculations with no plane parallel approximations. Refraction effects are taken into account through fine subdivision of the atmosphere into spherical shells of fixed index of refraction. Shell's law of refraction is used to calculate a direction of travel each time that a photon traverses the interface between layers. Five different models of the atmosphere were used: a pure molecular scattering atmosphere; molecular atmosphere plus ozone absorption; and three models with aerosol concentrations of 1, 3, and 10 times normal together with molecular scattering and ozone absorption. The results of the calculations are shown for various observation positions and local viewing angles in the solar plane for wavelengths in the range of 0.40 microns to 0.75 microns.
Adams, C. N.↗
Antiferromagnetic inclusions in lunar glass
The magnetic susceptibility of eleven glass spherules from the Apollo 15, 16, and 17 fines and two specimens of a relatively large glass spherical shell were studied as a function of temperature from room temperature to liquid helium temperatures. All but one specimen showed the presence of antiferromagnetic inclusions. Closely spaced temperature measurements of the magnetic susceptibility below 77 K on five of the specimens showed antiferromagnetic temperature transitions (Neel transitions). With the exception of ilmenite in one specimen, these transitions did not correspond to any transitions in known antiferromagnetic compounds.
Thorpe, A. N.↗
The influence of ozone and aerosols on the brightness and color of the twilight sky
The radiance and color of the twilight sky are calculated for single scattered radiation with the use of spherically symmetric models of the earth's atmosphere. Spherical geometry is used throughout the calculations with no plane-parallel approximations. Refraction effects are taken into account through fine subdivision of the atmosphere into spherical shells of fixed index of refraction. Snell's law of refraction is used to calculate a new direction of travel each time that a photon traverses the interface between layers. Five different models of the atmosphere were used: a pure molecular scattering atmosphere; molecular atmosphere plus ozone absorption; and three models with aerosol concentrations of one, three, and ten times normal together with molecular scattering and ozone absorption. The results of the calculations are shown for various observation positions and local viewing angles in the solar plane for wavelengths in the range from 0.40 to 0.75 micron.
Adams, C. N.↗
Induced anisotropy of thermal conductivity of polymer solids under large strains
A simple analytical form of induced anisotropy of heat conductivity of initially isotropic polymer solids results from employing the simplified theory of the three-chain model of the non-Gaussian network. The analytical form appears to be valid up to a stretch ratio of 2.65, which is the limit of existing experimental data. The effect of induced anisotropy on the temperature distribution, due to the large deformations, is illustrated for a highly expanded spherical shell and a cylindrical tube under a steady-state heat flow using the derived analytical form of the strain-dependent heat conductivity.
Peng, S. T. J.↗
Fuel injector for jet-stirred combustors
Simple and inexpensive method of making quartz injectors yields injectors of superior characteristics. Quartz injector is fabricated by heating quartz rod and blowing and forming sphere on end. As with metal injectors, orifices are then drilled in spherical shell. Time required to form quartz is only 0.5 man-hour and 7.5 man-hours are required to drill holes. Total time of fabrication, 8 man-hours, is fraction of 40 man-hours required to complete metal injector. Success with technique and material is such that further substitutions for other related components are being contemplated.
Anderson, S. G.↗
A method of inversion of satellite magnetic anomaly data
A method of finding a first approximation to a crustal magnetization distribution from inversion of satellite magnetic anomaly data is described. Magnetization is expressed as a Fourier Series in a segment of spherical shell. Input to this procedure is an equivalent source representation of the observed anomaly field. Instability of the inversion occurs when high frequency noise is present in the input data, or when the series is carried to an excessively high wave number. Preliminary results are given for the United States and adjacent areas.
Mayhew, M. A.↗
Constrained sloshing of liquid mercury in a flexible spherical tank
The mercury propellant tank system developed for use with solar electric propulsion was studied to analytically determine the resonant frequencies of the tank system and compare them with the anticipated control natural frequency of the spacecraft. The system consisted of a stainless steel spherical shell and a hemispherical elastometric diaphragm. The major analytical tool used was the NASTRAN program. Six mathematical models were developed. Resonant frequencies for six harmonics were obtained for each of the six models considered. The results show that the lowest resonant frequency for the tank system is about an order of magnitude greater than the anticipated control frequency of the spacecraft.
Lestingi, J.↗
Constrained sloshing of liquid mercury in a flexible spherical tank
The mercury propellant tank system developed for use with solar electric propulsion was studied to analytically determine the resonant frequencies of the tank system and compare them with the anticipated control natural frequency of the spacecraft. The system consisted of a stainless steel spherical shell and a hemispherical elastomeric diaphram which separates the mercury propellant and the gaseous nitrogen pressurant. The major analytical tool used was the NASTRAN program. Six mathematical models, which represent various amounts of mercury in the tank system were developed. Resonant frequencies for six harmonics were obtained for each of the six models considered. The results show that the lowest resonant frequency for the tank system is about an order of magnitude greater than the anticipated control frequency of the spacecraft.
Lestingi, J.↗