Optical Measurements on Solid Specimens of Solid Rocket Motor Exhaust and Solid Rocket Motor Slag

Samples of aluminum slag were investigated to aid the Earth Science and Applications Division at the Marshall Space Flight Center (MSFC). Alumina from space motor propellant exhaust and space motor propellant slag was examined as a component of space refuse. Thermal emittance and solar absorptivity measurements were taken to support their comparison with reflectance measurements derived from actual debris. To determine the similarity between the samples and space motor exhaust or space motor slag, emittance and absorbance results were correlated with an examination of specimen morphology

Operational performance of the photovoltaic-powered grain mill and water pump at Tangaye, Burkina Faso (formerly Upper Volta)

A photovoltaic (PV) system powering a grain mill and water pump was installed in the remote African village of Tangaye, Burkina Faso (formerly Upper Volta) under the sponsorship of the U.S. Agency for International Development (AID) and by the National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) in early 1979. The presence reports covers the second two years of operation from April 1981 through June 1983. During this time, the grain mill and water pump were operational 96 and 88 percent of the time respectively, and the PV system generated sufficient electricity to enable the grinding of about 111 metric tons of finely ground flow and the pumping of over 5000 cm sq of water from the 10 m deep well. The report includes a description of the current configuration of the system, a review of system performance, a discussion of the socioeconomic impact of the system on the villagers and a summary of results and conclusions covering the entire four-year period

Wave heating from proto-neutron star convection and the core-collapse supernova explosion mechanism

Our understanding of the core-collapse supernova explosion mechanism is incomplete. While the favoured scenario is delayed revival of the stalled shock by neutrino heating, it is difficult to reliably compute explosion outcomes and energies, which depend sensitively on the complex radiation hydrodynamics of the post-shock region. The dynamics of the (non-)explosion depend sensitively on how energy is transported from inside and near the proto-neutron star (PNS) to material just behind the supernova shock. Although most of the PNS energy is lost in the form of neutrinos, hydrodynamic and hydromagnetic waves can also carry energy from the PNS to the shock. We show that gravity waves excited by core PNS convection can couple with outgoing acoustic waves that present an appreciable source of energy and pressure in the post-shock region. Using one-dimensional simulations, we estimate the gravity wave energy flux excited by PNS convection and the fraction of this energy transmitted upwards to the post-shock region as acoustic waves. We find wave energy fluxes near 10⁵¹ergs⁻¹ are likely to persist for ∼1s post-bounce. The wave pressure on the shock may exceed 10 per cent of the thermal pressure, potentially contributing to shock revival and, subsequently, a successful and energetic explosion. We also discuss how future simulations can better capture the effects of waves, and more accurately quantify wave heating rates

MOST Space Telescope Photometry of the 2010 January Transit of Extrasolar Planet HD80606b

We present observations of the full January 2010 transit of HD80606b from the Canadian microsatellite, Microvariability and Oscillations of Stars (MOST). By employing a space-based telescope, we monitor the entire transit thus limiting systematic errors that result from ground observations. We determine measurements for the planetary radius (R_{p}=0.987\pm0.061R_{Jup}) and inclination (i=89.283^{o}\pm0.024) by constraining our fits with the observed parameters of different groups. Our measured mid-transit time of 2455210.6449\pm0.0034 HJD is consistant with the 2010 Spitzer results and is 20 minutes earlier than predicted by groups who observed the June 2009 transit.Comment: 3 figure

The Case of the Unwary Home Buyer: The Housing Merchant Did It

The author points up the decline of caveat emptor as a viable doctrine governing the sale of new homes and analyzes the emergence of implied warranty as a remedy for both structural deficiencies and personal injuries. He argues that the concept of implied warranty tends to obfuscate real distinctions between the builder-vendor’s responsibility for the material integrity of a new home and for personal injuries occasioned by defects therein, concluding that legislation is needed to reestablish a system of order in the law

Rapid fitting of particle cascade development data from X-ray film densitometry measurements

A semiautomatic method of fitting transition curves to X-ray film optical density measurements of electromagnetic particle cascades is described. Several hundred singly and multiple interacting cosmic ray events from the JACEE 8 balloon flights were analyzed using this procedure. In addition to greatly increased speed compared to the previous manual method, the semiautomatic method offers increased accuracy through maximum likelihood fitting

Property

A Survey can be a wine list inventorying the entire stock in the house or a selective list of vintages worth spending some time to savour. The reader will be able in a thrice to make his or her own judgment about the policy of this house