Recent advances in structural technology for large deployable and erectable spacecraft

Ultra-low mass deployable and erectable truss structure designs for spacecraft are identified using computerized structural sizing techniques. Extremely slender strut proportions are shown to characterize minimum mass spacecraft which are designed for shuttle transport to orbit. Discrete element effects using a recently developed buckling theory for periodic lattice type structures are presented. An analysis of fabrication imperfection effects on the surface accuracy of four different antenna reflector structures is summarized. The tetrahedral truss has the greatest potential of the structures examined for application to accurate or large reflectors. A deployable module which can be efficiently transported is identified and shown to have significant potential for application to future antenna requirements. Investigations of erectable structure assembly are reviewed

Supersonic flutter of a thermally stressed flat panel with uniform edge loads

Supersonic flutter of thermally stressed flat panel with uniform edge load

Market Day

Fiction by David Hear

Vibration and Instability of Plate-Assemblies including Shear and Anisotropy (VIPASA) user's guide, addendum

Extensions developed at Langley Research Center to the VIPASA computer program are described including a procedure for simple thermal stress analysis and options for graphical display of output. Input requirements for operation of the modified program are given in detail

The effect of ring distortions on buckling of blunt conical shells

A rigorous analytical study of cones stiffened by many thin-gage, open-section rings is presented. The results are compared with data previously obtained from uniform pressure tests of the Viking mission flight aeroshell and of the Viking structural prototype aeroshells. A conventional analysis, in which the rings are modeled as discrete rigid cross sections, is shown to lead to large, unconservative strength predictions. A more sophisticated technique of modeling the rings as shell branches leads to much more realistic strength predictions and more accurately predicts the failure modes. It is also shown that if a small initial imperfection proportional to the shape of the buckling mode is assumed, the critical buckling modes from analysis and test are in agreement. However, the reduction in buckling strength from the perfect-shell predictions is small

Review: Fiddler Crabs of the World by Jocelyn Crane

Review of Jocelyn Crane, Fiddler Crabs of the World. Ocypodidae: Genus Uca. XXIV+ 737 pp., 369 photographs, 101 figures, 21 maps. ISBN 08102-6, Princeton University Press, Princeton, New Jersey, 1975. $75.00

Filing Requirements under the Montana Uniform Commercial Code

Filing Requirements Under the Montana Uniform Commercial Cod

Calliax jonesi, N. Sp. (Decapoda: Thalassinidea: Callianassidae) from the Northwestern Bahamas

Two specimens of Calliax jonesi, n. sp., were collected from fine carbonate sediments in 3 to 5 m of water at Bimini Harbor, Bahamas. Of the species presently assigned to the genus Calliax de Saint Laurent, 1973, C. jonesi appears to be most closely related to C. quadracuta (Biffar, 1970), presently known from the Atlantic coast of Venezuela and the Florida Keys. Calliax jonesi is distinguished from C. quadracuta by: (1) the absence of a distal spinose process on the dorsal and ventral margins of the carpus of the first pair of chelipeds, (2) the armature and shape of uropods and telson, and (3) the shape of male first pleopod. Calliax jonesi, C. quadracuta, and at least two undescribed species from the northwestern Atlantic appear to form a closely related species complex which may not be congeneric with the type species, C. lobata (de Gaillande & Lagardère, 1966), and other species assigned to Calliax

Notes on the Genus Probythinella Thiele, 1928 (Gastropoda: Hydrobiidae) in the Coastal Waters of the Northern Gulf of Mexico and the Taxonomic Status of Vioscalba louisianae Morrison, 1965

The gastropod genus Probythinella Thiele, 1928, is considered a senior synonym of Vioscalba Morrison, 1965. Probythinella louisianae (Morrison, 1965) n. comb. tentatively is recognized as a valid species distinct from the closely related P. lacustris (Baker, 1928) and P. protera Pilsbry, 1953. The eastern range of P. louisianae is extended to Mobile Bay, Alabama. Limited observations on the habitat and reproduction of P. louisianae are reported

Observations on the Food and Food Habits of Clapper Rails (Rallus longirostris Boddaert) from Tidal Marshes Along the East and Gulf Coasts of the United States

The feeding habits of five nominal subspecies of clapper rails (Rallus longirostris Boddaert) collected in tidal marshes along the Gulf and Atlantic coasts of the United States are compared. Data on the food from the stomachs of 183 rails were analyzed and the earlier literature critically reviewed. During the warmer months (May through early fall), crabs, predominantly Uca spp., comprised the major part of the food items found. Limited data on a few rails collected during late fall and winter, when Uca spp. are not usually available, indicate that snails then become a major part of the clapper rail’s diet during that part of the year. Earlier studies, which describe the food or feeding habits of clapper rails, are reviewed and the food habits and trophic relationships of some other tidal marsh consumers are discussed. Data from this and previous studies indicate that clapper rails are opportunistic omnivores, and occupy a relatively broad niche within tidal marsh ecosystems. A comparison of available data of the food of five clapper rail subspecies of the eastern United States indicates no distinct differences in their feeding behavior. Differences in the kinds of food eaten appear to simply reflect the types of marsh habitat (fresh, brackish, polyhaline) or geographical location (temperate, subtropical, tropical) in which a particular clapper rail population occurs. The food habits of the king rail are compared with those of the clapper rail and problems concerning the taxonomic status of the “subspecies” of Rallus longirostris are briefly discussed