Optical depths in the interstellar and intergalactic media
Optical depths of the interstellar and intergalactic media for supernova remnants, stars, and galaxies are presented in tabular form.
Schocken, K.↗
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Height-depth ratios of lunar and terrestrial craters.
Quantitative analysis of Gilbert's (1893) observation regarding the surface geometry of lunar craters and terrestrial calderas. Topographic measurements were made using the ratio of exterior rim height to interior crater depth, and then extended to other types of crater. The morphometric data obtained as well as those presented elsewhere (Murray et al., 1970; Guest and Murray, 1969) verify Gilbert's contention that terrestrial calderas and most rimmed lunar craters are entirely unrelated phenomena. Auxiliary characteristics previously interpreted in terms of primary volcanic cratering on the moon are either of nonendogenic origin or are secondary endogenic features superposed on initial impact landforms (Pike, 1967).
Pike, R. J.↗
EEG monitoring of a free-swimming diver at a working depth of 15 meters.
Feasibility has been shown for underwater transmission of physiological signals, using frequency modulation of carriers transmitted by return-current-density methods, as part of a personal biotelemetry system. In the prototype system, a standard IRIG subcarrier frequency (2300 Hz) was used. Power requirements, antenna design, and signal attenuation are compatible with free-ranging diving activity at distances up to 15 meters from the receiver. Extrapolation from this study and further developments are expected to substantially increase the range. Advantages of this system include subcarrier compatibility with standard IRIG demodulators using channels 1 through 10, the absence of highly specialized antenna requirements, and reasonable attenuation characteristics for transmission through the turbidity of typical seawater. Moreover, the system would not appear to be depth limited, and to be compatible with use of high-powered transponders of the same type for long-distance transmission, with or without further encoding.
Zweizig, J. R.↗
Effects of voluntary eye movement and convergence on the binocular appreciation of depth.
Scaling techniques were employed to establish the relation between perceived distance ratio and physical distance ratio. Measurements were made both with and without free eye movement and under two states of convergence. The results were confirmed using a matching technique. With free eye movement, the perceived ratio is a monotonic increasing function of the physical ratio. Without eye movement, the perceived ratio generally increases, then decreases, as the physical ratio increases. For a given physical ratio, perceived distance ratio is less in the absence of voluntary eye movements. Convergence produces depth micropsia when eye movements are permitted, but not in their absence.
Foley, J. M.↗
Water depth estimation with ERTS-1 imagery
ERTS-1 imagery for water depth estimation around Great Bahama Bank
Ross, D. S.↗
Calculations of water depth from ERTS-MSS data
ERTS-1 multiscan data for calculating water depth around Bahama Islands
Polcyn, F. C.↗
Determining optical depth in different parts of the Fraunhofer line contour
The method of approximate determination of the optical depth tau in the profile of the Fraunhofer line is considered. In the method the observed profile and allocation of tau to the temperature in the photosphere must be known. If the source function B prime (tau) in the line seems not to be equal to the Planck function, the dependence B prime (tau) on tau is needed. The method for the determination of B prime (tau) using the center-to-limb observations of the central intensities of the line is suggested.
Gurtovenko, E. A.↗
Auger electron spectroscopy and depth profile study of oxidation of modified 440C steel
Auger electron spectroscopy (AES) and sputtering were used to study selective oxidation of modified 440C steel. The sample was polycrystalline. Oxidation was performed on initially clean surfaces for pressures ranging from 1 x 10 to the minus 7th power to 1 x 10 to the minus 5th power torr and temperatures ranging from room temperature to 800 C. AES traces were taken during oxidation. In situ sputtering depth profiles are also obtained. A transition temperature is observed in the range 600 to 700 C for which the composition of the outer surface oxide changed from iron oxide to chromium oxide. Heating in vacuum about 5 x 10 to the minus 10 power torr to 700 C causes conversion of the iron oxide surface to chromium oxide.
Ferrante, J.↗
Extracting depth information from a stereo pair
An approach to extracting depth information out of a stereo pair of images is described. Special camera pair configurations are shown to be effective in reducing complexity. A simple algorithm which pairs objects in the two images and allows verification is described.
Yakimovsky, Y.↗
Effects of inlet treatment location and treatment cavity depth on compressor noise
The ability of acoustic liners to reduce compressor noise inside and in front of an inlet was studied. An axial flow research compressor and a specially designed inlet were used inside an anechoic chamber. Acoustic and performance data were obtained for a range of inlet treatment locations and cavity depths to determine their effects on inlet noise over a range of blade passing frequencies. The greatest noise reductions in front of the inlet were obtained with acoustic treatment located close to the compressor and backed with the deepest cavities tested. Inside the inlet the maximum noise level reductions were obtained in the area of the treatment regardless of treatment location. No appreciable losses in compressor performance were measured.
Clark, L. R.↗
Lunar crater depths from Orbiter IV long-focus photographs
Determination of the depths of more than 1900 small lunar craters from measures of shadows on the long-focus pictures obtained by Lunar Orbiter IV. The method for converting the measured shadow length into the true length in nature of the shadow hypotenuse is new and is applicable to other planetary bodies, provided that comparable spacecraft ephemerides are available. The measures were made with a simple surveyor's plotting scale on the standard Orbiter IV photographic enlargements. The results indicate that the smaller lunar (D less than 30 km) crater are appreciably deeper than is indicated by earlier work using imagery obtained at terrestrial observatories.
Arthur, D. W. G.↗
Laser measure of sea salinity, temperature and turbidity in depth
A method is described in which a pulsed laser is used to probe the sea. Backscattered light is analyzed in time, intensity and wavelength. Tyndall, Raman and Brillouin scattering are used to obtain the backscatter turbidity, sound velocity, salinity, and the temperature as a function of depth.
Hirschberg, J. G.↗
Electro-optical liquid depth sensor
Transducer utilizes absorptive properties of water to determine variations in depth without disturbing liquid. Instrument is inexpensive, simple, and small and thus can be used in lieu of direct graduated scale readout or capacitive, ultrasonic, resistive or inducive sensors when these are impractical because of complexity or cost.
Heppner, D. B.↗
An elementary theory of eclipsing depths of the light curve and its application to Beta Lyrae
An elementary theory of the ratio of depths of secondary and primary eclipses of a light curve has been proposed for studying the nature of component stars. It has been applied to light curves of Beta Lyrae in the visual, blue, and far-ultraviolet regions with the purpose of investigating the energy sources for the luminosity of the disk surrounding the secondary component and determining the dominant radiative process in the disk. No trace of the spectrum of primary radiation has been found in the disk. Therefore, it is suggested that LTE is the main radiative process in the disk, which radiates at a temperature of approximately 12,000 K in the portion that undergoes eclipse. A small source corresponding to 14,500 K has also been tentatively detected and may represent a hot spot caused by hydrodynamic flow of matter from the primary component to the disk.
Huang, S.-S.↗
Umbral boundaries, convection, and the depth of sunspots
The boundary between the umbra and penumbra of a sunspot is consistently observed to be very sharp, on the order of 500 km. Approximating the sunspot as a static region in a homogeneous medium with a radiative surface, temperature distributions resulting from a variety of convective motions exterior to the sunspot are calculated. The calculations suggest that, for the exterior convection to produce the observed boundary, the maximum depth of the region of inhibited convection below a sunspot umbra is on the order of 1,000 km.
Isenberg, P. A.↗
Auger depth profiling of Au-Al/x/Ga/1-x/As interfaces and LPE Al/x/Ga/1-x/As-GaAs heterojunctions
An attempt is made to report Auger depth profiles produced in a UHF ion-milling Auger system for intentionally 'graded' Al(x)Ga(1-x)As-GaAs heterojunctions, 'abrupt' growth heterojunctions of the same material, and Au-Al(x)Ga(1-x)As interfaces. It is found that the interface widths of the 'abrupt' growth heterojunctions did not fluctuate greatly from an average value of 110 A and that 'graded' growth samples had interface widths of about 525 to 1500 A. The results for the Au-containing samples indicate that an oxide layer was present between the Au and the Al(x)Ga(1-x)As.
Garner, C. M.↗
Nondestructive determination of the depth of planar p-n junctions by scanning electron microscopy
A method was developed for measuring nondestructively the depth of planar p-n junctions in simple devices as well as in integrated-circuit structures with the electron-beam induced current (EBIC) by scanning parallel to the junction in a scanning electron microscope (SEM). The results were found to be in good agreement with those obtained by the commonly used destructive method of lapping at an angle to the junction and staining to reveal the junction.
Chi, J.-Y.↗
Depth-dose relations for heavy ion beams
Radiation transport of heavy ions in matter is of interest to radiological protection in space and high-altitude aircraft. In addition, heavy ion beams are expected to be of advantage in radiotherapy since their characteristic Bragg curve allows a relative reduction of the dose in reaching a tumor site and the near elimination of exposure beyond the tumor region as the beam exits the body. Furthermore, the radioresistance of tumorous cells due to their hypoxic state may be reduced or eliminated by the high specific ionization of heavy ion beams. The depth-dose distribution of heavy ion beams consists of energy deposited by the attenuated primary beam with its characteristic Bragg curve and a relatively unstructured background due to secondary radiations produced in nuclear reactions. As the ion mass increases, the secondary contribution becomes more structured and may add significantly to the Bragg peak of the primary ions. The result for heavy ions (z greater than 20) is a greatly broadened Bragg peak region, especially in comparison to straggling effects, which may prove to be of importance in radiotherapy and biomedical research.
Wilson, J. W.↗