Invertebrate Fauna of Devils Den, a Sandstone Cave in Northwestern Arkansas

The same invertebrate fauna of 17 species was found in Devils Den Cave, Washington County, Arkansas, in 1969 and 1979. The fauna consists of 1 trogloxene, 14 troglophiles, and 2 troglobites, a spider, Porrhomma cavernicolum, and a collembolan, Pseudosinella dubia. Devils Den Cave has a well developed cavernicolous fauna, although it is in sandstone which generally supports a poor cave adapted fauna. The troglobites probably evolved in the vicinity of northwestern Arkansas in limestone caves or in deep forest soils of the Ozark region. They then dispersed overland, perhaps as recently as the late Wisconsinan, to occupy this sandstone cave

High temperature glass thermal control structure and coating

A high temperature stable and solar radiation stable thermal control coating is described which is useful either as such, applied directly to a member to be protected, or applied as a coating on a re-usable surface insulation (RSI). It has a base coat layer and an overlay glass layer. The base coat layer has a high emittance, and the overlay layer is formed from discrete, but sintered together glass particles to give the overlay layer a high scattering coefficient. The resulting two-layer space and thermal control coating has an absorptivity-to-emissivity ratio of less than or equal to 0.4 at room temperature, with an emittance of 0.8 at 1200 F. It is capable of exposure to either solar radiation or temperatures as high as 2000 F without significant degradation. When used as a coating on a silica substrate to give an RSI structure, the coatings of this invention show significantly less reduction in emittance after long term convective heating and less residual strain than prior art coatings for RSI structures