Sky effect on solar cells calibrated at 80,000 feet

Sky radiation effects on output of solar cells at 80,000 fee

Multiphase smoothed-particle hydrodynamics

We adapt the smoothed-particle hydrodynamics (SPH) technique to allow a multiphase fluid in which SPH particles of widely differing density may be freely intermixed. Applications include modelling of galaxy formation and cooling flows

Solar battery with interconnecting means for plural cells Patent

Solar battery with interconnecting means for plural cell

Slide release mechanism

A releasable support device is described which is comprised of a hollow body with a sleeve extending transversely there-through for receiving the end of a support shank. A slider-latch, optionally lubricated, extends through side recesses in the sleeve to straddle the shank, respectively, in latched and released positions. The slider-latch is slid from its latched to its unlatched position by a pressure squib whereupon a spring or other pressure means pushes the shank out of the sleeve. At the same time, a follower element is lodged in and closed the hole in the body wall from which the shank was discharged. The mechanism was designed for the shuttle orbiter/external tank connection device

An evaluation of photovoltaic devices for future spacecraft power demands

Cadmium sulfide and dendritic silicon cells for photovoltaic power systems of spacecraf

The massive binary population of the starburst cluster Westerlund 1

We present initial results from a long-baseline radial velocity survey for massive binaries in the cluster Westerlund 1. Four systems are examined: the dust-producing WC binary W239, the double-lined eclipsing binary W13, and the single-lined B0 supergiants W43a and W3003. Finally, the evolutionary implications for the population of massive stars in Westerlund 1 are discussed

Fracture toughness and fatigue-crack propagation in a Zr–Ti–Ni–Cu–Be bulk metallic glass

The recent development of metallic alloy systems which can be processed with an amorphous structure over large dimensions, specifically to form metallic glasses at low cooling rates (similar to 10 K/s), has permitted novel measurements of important mechanical properties. These include, for example, fatigue-crack growth and fracture toughness behavior, representing the conditions governing the subcritical and critical propagation of cracks in these structures. In the present study, bulk plates of a Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy, machined into 7 mm wide, 38 mm thick compact-tension specimens and fatigue precracked following standard procedures, revealed fracture toughnesses in the fully amorphous structure of K(lc)similar to 55 MPa root m, i.e., comparable with that of a high-strength steel or aluminum ahoy. However, partial and full crystallization, e.g., following thermal exposure at 633 K or more, was found to result in a drastic reduction in fracture toughness to similar to 1 MPa root m, i.e., comparable with silica glass. The fully amorphous alloy was also found to be susceptible to fatigue-crack growth under cyclic loading, with growth-rate properties comparable to that of ductile crystalline metallic alloys, such as high-strength steels or aluminum alloys; no such fatigue was seen in the partially or fully crystallized alloys which behaved like very brittle ceramics. Possible micromechanical mechanisms for such behavior are discussed

Data compilation and evaluation of space shielding problems. Radiation hazards in space, volume III

Radiation hazards of interplanetary space and related shielding problem

That Smell in the Vaults

THAT SMELL IN THE VAULTS: THE DEGRADATION OF POLYMERS IN AV MATERIALS VINEGAR Syndrome(1), Rancid Butter Syndrome(2), Rotten Fish Syndrome -- evocative but accurate descriptions of the pervasive killers of our sound and moving image heritage. Leaving aside the well-known problems of nitrate film we are faced with the stability problems of our polymer-based supports. All polymers are subject to decay; and the cellulose nitrate, cellulose diacetate, cellulose butyrate, cellulose propionate and cellulose triacetate bases are no exception. The problem is not limited to film -- audiotape, videotape, computer tape, computer disk and other formats are subject to the same inevitable decay and destruction. Over the last few years it has come to the attention of archivists around the world that the life expectancy of our audio-visual heritage is not what we once thought it should be. Storage conditions naturally have dramatic impacts on life expectancy. We..