MEA/A-1 experiment 81F01 conducted on STS-7 flight, June 1983. Containerless processing of glass forming melts

The space processing of containerless, glassforming melts on board the space shuttle flight STS-7 is investigated. Objectives include; (1) obtain quantitative evidence for the supression of heterogeneous nucleation/crystallization, (2) study melt homogenization without gravity driven convection, (3) procedural development for bubble free, high purity homogeneous melts inmicro-g, (4) comparative analysis of melts on Earth and in micro g, and (5) assess the apparatus for processing multicomponent, glass forming melts in a low gravity environment

Electrically Conductive Paints for Satellites

A program was conducted to develop and test electrically conductive paint coatings for spacecraft. A wide variety of organic and inorganic coatings were formulated using conductive binders, conductive pigments, and similar approaches. Z-93, IITRI's standard specification inorganic thermal control coating, exhibits good electrical properties and is a very space-stable coating system. Several coatings based on a conductive pigment (antimony-doped tin oxide) in silicone and silicate binders offer considerable promise. Paint systems using commercially available conductive polymers also appear to be of interest, but will require substantial development. Evaluations were made based on electrical conductivity, paint physical properties, and the stability of spectral reflectance in space environment testing

Containerless processing of glass forming melts: D-1, MEA/A-2 experiment 81F01 conducted on STS-61A flight, October 1985

Results of experiment 81F01, which was conducted in the Material Experiment Assembly MEA/A-2 on the D-1 Spacelab Mission (STS-61A), are presented. The general plan of the experiment was to heat, melt, and quench six spherical samples of different glass forming compositions while they were levitated in a single axis acoustic levitator furnace (SAAL). In addition, two non-melting sintered alumina samples were used to check the operational characteristics of the SAAL under reduced gravity conditions. Three of the eight samples were levitated between 1250 and 1500 C before the lack of coolant created an over-temperature condition that caused the SAAL to shut down prematurely. Two of the three samples processed were calcia-gallia-silica and soda-lime-silica glass forming compositions. Evidence of a two to three times increase in the tendency for glass formation was obtained for the calcia-gallia-silica. The final glass appeared reasonably homogeneous even though it was made from hot pressed powders containing deliberate heterogeneities. A photographic record was obtained of the microgravity sample processing sequences

High Reynolds number tests of the CAST-10-2/DOA 2 transonic airfoil at ambient and cryogenic temper ature conditions

The transonic airfoil CAST 10-2/DOA 2 was investigated in several major transonic wind tunnels at Reynolds numbers ranging from Re=1.3 x 10(exp 6) to 45 x 10(exp 6) at ambient and cryogenic temperature conditions. The main objective was to study the degree and extent of the effects of Reynolds number on both the airfoil aerodynamic characteristics and the interference effects of various model-wind-tunnel systems. The initial analysis of the CAST 10-2 airfoil results revealed appreciable real Reynolds number effects on this airfoil and showed that wall interference can be significantly affected by changes in Reynolds number thus appearing as true Reynolds number effects

Coupling between magnetic ordering and structural instabilities in perovskite biferroics: A first-principles study

We use first-principles density functional theory-based calculations to investigate structural instabilities in the high symmetry cubic perovskite structure of rare-earth (R $=$ La, Y, Lu) and Bi-based biferroic chromites, focusing on $\Gamma$ and $R$ point phonons of states with para-, ferro-, and antiferromagnetic ordering. We find that (a) the structure with G-type antiferromagnetic ordering is most stable, (b) the most dominant structural instabilities in these oxides are the ones associated with rotations of oxygen octahedra, and (c) structural instabilities involving changes in Cr-O-Cr bond angle depend sensitively on the changes in magnetic ordering. The dependence of structural instabilities on magnetic ordering can be understood in terms of how super-exchange interactions depend on the Cr-O-Cr bond angles and Cr-O bond lengths. We demonstrate how adequate buckling of Cr-O-Cr chains can favour ferromagnetism. Born effective charges (BEC) calculated using the Berry phase expression are found to be anomalously large for the A-cations, indicating their chemical relevance to ferroelectric distortions.Comment: 8 pages, 13 figure

An ecological survey of Berkey woods: A remnant of forest primeval in Kosciusko county, Indiana

In July 1942, we published results of a detailed study of Cox Woods, a remnant of forest primeval in Orange county, located in southern Indiana. In the present study we place on record quantitatively a relatively undisturbed stand of forest in the northern part of Indiana

The Cabin Creek raised bog, Randolph County, Indiana

High moors, or raised bogs are a rather common physiographic feature of northern Europe, but in North America they are more or less limited to coasal areas. Some of these American raised bogs are described by Ganong (5) for New Brunswick, by Nichols (10) and Dachnowski (2) for Maine, and by Rigg (11) for southeastern Alaska. In more recent years a few raised bogs have also been reported for inland areas in North America. Gordon (7) described one at Urbana, Ohio, and Rigg (11, 12) one at Itaska Park, Minnesota, and another at Yellowstone Park.All authors who described raised bogs stressed their infrequent occurrence, especially in interior locations. It was, therefore, more than the first thrill of contact with a raised bog which enthused the authors about discovery of a raised bog in centrally located Indiana. Naturally, a detailed study was planned at once. We called it Cabin Creek Raised Bog because of its location in the floodplain of Cabin Creek. The peat mass is a prominent feature of the landscape; it rises 10 feat above the floodplain at the maximum elevation. The answer to the question of its origin, nature of the peat, history of the development, and configuration of the topography now covered by the peat was sought in numerous borings and in pollen profile studies

Some Comparisons Between Virgin Forest and Adjacent Areas of Secondary Succession

The almost unbroken deciduous forest of Indiana of a century ago has been reduced to isolated patches, and few of the remaining timbered areas may truly be termed virgin forest. These small tracts of undisturbed forest are thus of great ecological importance. One such small area of undisturbed forest is owned by Mr. August Mauntel, six miles southwest of Holland in Dubois county. Mr. Mauntel is an old settler in Dubois county and has seen the region develop from forest primeval to a busy agricultural community. He says that the area in question has been disturbed very little by cultural influences

Survival of hemlock seedlings in a relict colony under forest conditions

It would thus appear that in areas where hemlock is a component of the climax, and not merely a relict, reproduction is dependent primarily upon a combination of three factors, viz. a good seed year followed by a good germinating year and these in turn followed by several years of favorable moisture conditions