Penetration of high energy radiation
Computer programs for calculating penetration and diffusion of electrons and associated bremsstrahlung through extended media
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Results for “PENETRATION”
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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Launch vehicle gust penetration loads
Saturn launch vehicle gust penetration loads, presenting separated flow and associated time lag effects
Ericsson, L. E.↗
Penetration to second order of an electrostatic field into a warm plasma
Electrostatic field second order penetration into Vlasov warm electron plasma, using electron velocity distribution models
Lewak, G. J.↗
Measurement of the surface inductance and penetration depth of superconducting aluminum
Pure superconducting Al wire surface inductance measurement as function of temperature, noting penetration depth value
Faraci, G.↗
'Vegetation penetration' with K-band imaging radars
Vegetation penetration with K-band side-looking airborne imaging radars, noting multifrequency multipolarization system application for terrain reconnaissance
Macdonald, H. C.↗
Design of a probe for deep penetration into Jupiter's atmosphere
Jupiter probe design and communication for deep penetration into atmosphere, concerning mission phases through entry and descent to sample altitudes
Cross, D.↗
Cone penetration resistance test - An approach to evaluating in-place strength and packing characteristics of lunar soils
Cone penetration resistance tests on granular lunar soil simulants for in-place shear strength and packing characteristics under various gravity conditions
Cohron, G. T.↗
An empirical relationship for the penetration of 1 to 3 MeV electrons
Empirical correlation of high energy electrons into materials allows predictions of practical ranges (measure of electron penetration) for different elements and alloys.
Stevenson, F. R.↗
Atomization, drop size, and penetration for cross-stream water injection at high-altitude reentry conditions with application to the RAM C-1 and C-3 flights
Atomization, drop size, and penetration data are presented for cross stream water injection at conditions simulating high altitude reentry (low Weber number, high static temperature, high Knudsen number, and low static pressure). These results are applied to the RAM C-1 and C-3 flights. Two primary breakup modes are considered, vapor pressure or flashing and aerodynamic atomization. Results are given for breakup boundaries and mean drop size for each of these atomization mechanisms. Both standard and flight orifice geometries are investigated. The data were obtained in both a static environment and in conventional aerodynamic facilities at Mach numbers of 4.5 and 8. The high temperature aspects of reentry were simulated in a Mach 5.5 cyanogen-oxygen tunnel with total temperature of 4500 K.
Gooderum, P. B.↗
Microwave properties of geological materials: Studies of penetration depth and moisture effects
Summarized are the results of two of a series of controlled experiments performed during the summer of 1970. The first series of experiments to determine penetration depth showed the value of having a modeled response and data reduced in real time for examination in the field. The results suggest a radiometric method for measuring the microwave properties of materials in bulk and are applicable to studies of sea ice and other naturally layered media. The sensitivity of the microwave emission to changes in moisture content has inspired a number of airborne and ground based investigations. Although the effect is dominent under certain conditions, the complicating factors of soil type, roughness, vegetation, etc. seem to govern the conclusions regarding its application at this time.
Blinn, J. C., III↗
Dye penetrant indications caused by superficial surface defects in 2014 aluminum alloy welds.
Demonstration that dye penetrant indications on the heat-affected zone of 2014-T6 aluminum GMA weldments are frequently caused by superficial surface conditions and are less than 0.007 in. deep. The following methods are suggested for minimization of these surface defects: stabilization of the arc, application of dc ?GTA' welding procedures, reduction of the caustic etch time, and use of fine grain materials.
Hocker, R. G.↗
Penetration of solar irradiances through the atmosphere and plant canopies.
The equation of radiative transfer is applied to an analysis of solar irradiances penetrating into a plant canopy covered by a turbid atmosphere. The method of discrete coordinates is applied to vertically inhomogeneous atmospheres and plant canopies. It is shown that four-point quadrature yields results with an accuracy that is consistent with irradiance measurements. It is believed that the presented computational scheme may have considerable agricultural applications.
Weinman, J. A.↗
Magnetic flux penetration into superconducting thin films.
The quantum-interference technique developed by Meservey (1965) is used to measure directly the absolute value of the penetration depth in lead in tin superconducting thin films. The technique assumes that the change in phase of the superconducting wave function around any contour within the superconductor must be 2 pi n, where n is a nonnegative integer. Results show that the critical current of a superconducting interferometer with two parallel junctions is not strictly periodic in the applied magnetic flux with a period equal to the flux quantum because of the magnetic field dependence of the critical currents of the junctions.
Peabody, G. E.↗
Effects of buried obstacles on penetration resistance in cohesionless soils
Recent experiments concerning penetration of cohesionless soils in special molds that include solid obstacles embedded within the soil matrix are reported. The relative effects of these obstacles with respect to the soil properties of relative density, texture, and gradation are also discussed. Because lunar soil is fairly cohesionless, special attention was given to the Apollo lunar simulant, AP-12.
Deluca, E. W.↗
Correlation of new hypervelocity impact data by threshold penetration relations
Threshold penetration data are established by impacting spherical projectiles onto 2024 aluminum single-wall targets. Nylon and cadmium projectiles were used at impacting velocities from 3.0 to 6.8 km/s and 7.9 to 8.5 km/s respectively. These data are combined with existing data and compared with three threshold relations to assess their respective validities over a wide range of projectile densities. Two of these relations were validated over the extended range of projectile densities.
Hayduk, R. J.↗
Pioneer Mars surface penetrator mission. Mission analysis and orbiter design
The Mars Surface Penetrator mission was designed to provide a capability for multiple and diverse subsurface science measurements at a low cost. Equipment required to adapt the Pioneer Venus spacecraft for the Mars mission is described showing minor modifications to hardware. Analysis and design topics which are similar and/or identical to the Pioneer Venus program are briefly discussed.
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Water penetration study
Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.
Lockwood, H. E.↗
Factors influence flexibility resistivity and zinc dendrite penetration rate of inorganic separators for alkaline batteries
Developmental work resulted in a formulation which can improve the flexibility of the inorganic-organic-type separator for silver-zinc and nickel-zinc alkaline batteries. The effects of various fillers and reactive organic additives on separator volume resistivity are described. The effects of various inert fillers on the zinc dendrite penetration rate of the separator are shown. Conclusions regarding the operating mechanism of the separator are presented.
Sheibley, D. W.↗