Detection of circular polarization in a second white dwarf
White dwarf G195-19 circular polarization measurements of continuum radiation in broad band, using electro-optically switched polarimeter
Angel, J. R. P.↗
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Discovery of circular polarization in the white dwarf G99-37
Circular polarization in white dwarf G99-37 continuum radiation as function of wavelength
Angel, J. R. P.↗
Discovery of periodic variations in the circular polarization of the white dwarf G195-19
Periodic variations in circular polarization of continuum radiation of white dwarf G195-19 from 3800 to 5400 A
Angel, J. R. P.↗
Magnetism in white dwarfs
White dwarf stars broadband circular polarization and normal/quadratic Zeeman effect
Angel, J. R. P.↗
Space radiation studies at the White Sands Missile Range Fast Burst Reactor
The operation of the White Sands Missile Range Fast Burst Reactor is discussed. Space radiation studies in radiobiology, dosimetry, and transient radiation effects on electronic systems and components are described. Proposed modifications to increase the capability of the facility are discussed.
Delapaz, A.↗
White blood cell counting system
The design, fabrication, and tests of a prototype white blood cell counting system for use in the Skylab IMSS are presented. The counting system consists of a sample collection subsystem, sample dilution and fluid containment subsystem, and a cell counter. Preliminary test results show the sample collection and the dilution subsystems are functional and fulfill design goals. Results for the fluid containment subsystem show the handling bags cause counting errors due to: (1) adsorption of cells to the walls of the container, and (2) inadequate cleaning of the plastic bag material before fabrication. It was recommended that another bag material be selected.
Source record↗
New measurements of circular polarization and an ephemeris for the variable white dwarf G195-19.
Observations of the white dwarf G195-19 made for over a year show that the periodic variation in circular polarization continues with constant frequency and amplitude; an accurate value of 1.3309 plus or minus 0.0004 days is obtained for the period. While the variation in blue-green light is sinusoidal, extensive measurements in red light show an asymmetric curve, reaching a minimum about 6 hours earlier than in the blue-green.
Angel, J. R. P.↗
Diurnal and seasonal behavior of discrete white clouds on Mars.
Two distinct types of discrete white 'clouds' on Mars are found to show periodic activity that is highly correlated with the Martian seasons. In addition to the seasonal cycle, Type I clouds exhibit a repetitive diurnal variation, forming in the late morning or early afternoon and continuing to brighten for several hours thereafter. They are still bright as they pass over the evening terminator, but are not visible at that time when they should be reappearing over the morning terminator. Type I clouds seem to be associated with warm regions on Mars and are believed to be true clouds of frozen water vapor. Type II 'clouds' show no diurnal variation, are associated with cold regions, and may be CO2 frost rather than clouds.
Smith, S. A.↗
Effect of hypergravity on the circadian rhythms of white rats.
The effects of artificial gravity on the circadian rhythm of white rats was observed by comparing feeding activity at 1.0 and 1.75 g. The feeding cycle data were obtained by observing the number of feeding switch responses, as well as the amount of food obtained, as a function of time. One of the three subjects clearly established a free-running cycle with a period of 24.742 hr. During a 40-day exposure to the 1.75 g environment, the subjects maintained the same feeding cycle period which was established at 1.0 g. While the results of this study indicate that the activity rhythms of rats are insensitive to gravity levels between 1.0 and 1.75 g, the effects of gravity levels below 1.0 g are yet to be determined.
Lafferty, J. F.↗
Helium-cold induced hypothermia in the white rat.
Hypothermia was induced in white rats by exposing them to low ambient temperatures (about 0 C) and a gaseous atmosphere of 80% helium and 20% oxygen (helox). Biological survival, in which revival from hypothermia to normothermia is achieved, and clinical survival, in which one or more functional attributes are monitored in the hypothermic animal until it dies, are examined. The helium-cold method appears to produce a hypothermic state in the rat quite similar to that resulting from such techniques as ice water immersion or hypercapnia + hypoxia. There is a direct relationship between body weight and percent survival. Despite the fact that they require a longer period to become hypothermic, the heavier animals are better able to survive.
Musacchia, X. J.↗
Viscous effects in rapidly rotating stars with application to white-dwarf models. I, II.
A general approximate numerical technique is proposed for constructing evolutionary sequences of rapidly rotating axisymmetric barytropic equilibrium configurations, with allowance for angular momentum transfer by a nonconstant isotropic viscosity. The principal physical assumption involved is the constancy of the angular momentum per unit mass on cylinders about the axis of rotation. Rapidly rotating nonmagnetic white-dwarf models with a zero-temperature degenerate-electron equation of state are considered as a particular application. The viscosity used in the analysis is that of the degenerate electrons.
Durisen, R. H.↗
Astronaut operations requirements document for the White Light Coronagraph experiment s-052 for the Apollo Telescope Mount
Information necessary for successful performance of the observer's function in the White Light Coronagraph portion of the Apollo Telescope Mount experiments is presented. The pre-flight, in-flight, and post-flight operations required to perform the S-052 experiment are described. A discussion of the scientific objectives of the experiment and a description of the hardware are provided.
Ross, C. L.↗
An all digital phase locked loop for synchronization of a sinusoidal signal embedded in white Gaussian noise
An all digital phase locked loop which tracks the phase of the incoming sinusoidal signal once per carrier cycle is proposed. The different elements and their functions and the phase lock operation are explained in detail. The nonlinear difference equations which govern the operation of the digital loop when the incoming signal is embedded in white Gaussian noise are derived, and a suitable model is specified. The performance of the digital loop is considered for the synchronization of a sinusoidal signal. For this, the noise term is suitably modelled which allows specification of the output probabilities for the two level quantizer in the loop at any given phase error. The loop filter considered increases the probability of proper phase correction. The phase error states in modulo two-pi forms a finite state Markov chain which enables the calculation of steady state probabilities, RMS phase error, transient response and mean time for cycle skipping.
Reddy, C. P.↗
An investigation of accretion of matter onto white dwarfs as a possible X-ray mechanism
The accretion flow onto white dwarfs is investigated by numerically integrating the full nonlinear hydrodynamic equations under the assumption of spherical symmetry to determine the short-term time-dependent behavior, to determine the effects on the flow when radial modes of oscillation of the star are excited, to see if X-rays are produced, and to determine the radiation spectrum. Some applications of the results to known X-ray sources are suggestive.
Degregoria, A. J.↗
Nucleosynthesis in white-dwarf atmospheres
Consideration of events by which both s- and r-process nucleosynthesis may occur on the surfaces of white-dwarf stars. The main requirement is that the accreted hydrogen be mixed with comparable numbers of C-12 (or other alpha nuclei) before a runaway capture of protons takes place. Subsequent events offer many possibilities for nucleosynthesis and stars of peculiar composition. A new mechanism for a surface s-process due to few-MeV protons is also described. Concluding comments concern cosmic gamma-ray bursts and the origin of anomalous low-energy galactic cosmic rays.
Hoyle, F.↗
Highly reflecting stable white paint for the detection of ultraviolet and visible radiations
Compositions, formulating procedures, and application techniques are presented for highly reflecting stable white paint coatings suitable for the detection of ultraviolet and visible radiations. For completeness, absolute and relative reflectance data are included for intrasystem and intersystem comparisons.
Schutt, J. B.↗
Evaluation of black and white microfilm system
Microfilms and processes suitable for microscopying black-and-white films from the Earth Resources Aircraft Program were selected. A further purpose was to chose duplication materials which are suitable for multiple generation copies for economical dissemination to satisfy index and reference purposes. The basic requirements are that the gamma of the negative film and the overall system gamma of the multistage duplication process should be near unity, and that there should be sufficient resolution to reproduce the major salient image features of the original 9 1/2-inch format film.
Gooding, R. A.↗
On the theory of thermal runaway in the hydrogen envelope of a white dwarf
An evolutionary sequence was calculated for a white dwarf on which a hydrogen rich envelope is assumed to increase with time. The stellar models were computed by integrating numerically the system of stellar structure equations by means of the Henyey method. The accretion of matter was assumed to be quasi-static. Near the point of the chemical discontinuity, a temperature maximum is shown to arise, and hydrogen ignites; a thin shell energy source is formed which is thermally unstable. The resulting thermal runaway was investigated numerically and by means of a simple approximation based on the energy balance in the hydrogen burning shell source.
Redkoborodyy, Y. N.↗