16,391 research outputs found

    A historical who\u27s who of Vermont theatre

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    Occasional paper (University of Vermont. Center for Research on Vermont) ; no. 13

    Wind tunnel model damper

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    Damper system for alleviating air flow shock loads on wind tunnel models

    Aggregation characteristics and maturity of Peak District soils

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    Soil aggregation and aggregate stability are fundamental factors in determination of soil erodibility. The aggregation characteristics of soils in a region of high erosion potential are measured, and controlling factors examined. A relationship between increasing soil maturity and decreasing aggregate stability is described, and its significance in relation to Penck’s Aufbereitung concept is discussed

    Development of laboratory instrumentation for the study of soil erodibility

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    In order to carry out a study of the relative efficiency of various erodibility indices, and of the relative erodibility of soils developed in the Peak District of Derbyshire (England), three instruments were developed. These instruments were: a wet-sieve aggregate analyser of the Yoder pattern, a compact laboratory rainfall simulator using spray nozzles, a radiant drying unit using infra-red lamps. The efficiency of the instruments and the validity of the operating -techniques are critically evaluated and suggestions for improvement are advanced

    Deep sea mega-geomorphology: Progress and problems

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    Historically, marine geologists have always worked with mega-scale morphology. This is a consequence both of the scale of the ocean basins and of the low resolution of the observational remote sensing tools available until very recently. In fact, studies of deep sea morphology have suffered from a serious gap in observational scale. Traditional wide-beam echo sounding gave images on a scale of miles, while deep sea photography has been limited to scales of a few tens of meters. Recent development of modern narrow-beam echo sounding coupled with computer-controlled swath mapping systems, and development of high-resolution deep-towed side-scan sonar, are rapidly filling in the scale gap. These technologies also can resolve morphologic detail on a scale of a few meters or less. As has also been true in planetary imaging projects, the ability to observe phenomena over a range of scales has proved very effective in both defining processes and in placing them in proper context

    Volcanology and morphology

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    Apollo 15 photographs of the southern parts of Serenitatis and Imbrium were used for a study of the morphology and distribution of wrinkle ridges. Volcanic and structural features along the south margin of Serenitatis were also studied, including the Dawes basalt cinder cones. Volcanic and structural features in crater Aitken were investigated as well. Study of crater Goclenius showed a close relationship between morphology of the impact crater and grabens which tend to parallel directions of the lunar grid. Similar trends were observed in the walls of crater Tsiolkovsky and other linear structures. Small craters of possible volcanic origin were also studied. Possible cinder cones were found associated with the Dawes basalt and in the floor of craters Aitken and Goclenius. Small pit craters were observed in the floors of these craters. Attempts were made to obtain contour maps of specific small features and to compare Orbiter and Apollo photographs to determine short term changes associated with other processes

    Subsurface Irrigation Research in Arkansas

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    A pilot study conducted in 1963 indicated that (1) cotton yields could be increased by subirrigation, (2) drilled orifices were unsatisfactory because of internal plugging caused by burrs and drilling particles, and (3) operating pressures of 5 and 10 psi were excessive, and 5 psi probably should be considered as an upper-limit pressure. A greenhouse study of a subirrigation system indicated that 2 psi should, in general, for in-wall orifices, be considered as a lower-limit pressure when orifices are built into the pipe wall. The greenhouse study also indicated that a placement depth of 12 inches was preferable to 18 inches in terms of the amount of water required. Twelve inches was used as the depth of placement for the field subirrigation system. A device was developed for forming orifices with a hot needle. This method has advantages over the drilled orifices used in the pilot study in that the forming process does not produce loose particles to fall inside the pipe or burrs which remain attached to the inner edge of the orifice and later cause stoppage problems. This method also seems preferable to punched orifices which tend to become smaller with time due to rebound of the plastic

    Inventory and Assessment of Cultural Resources Above the 1,551.5-Foot Contour Line, Stacy Reservoir Recreation Areas, Concho, Coleman, and Runnels Counties, Texas

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    In August and September 1986, personnel from Prewitt and Associates, Inc. conducted an inventory and assessment of cultural resources in five recreational area tracts above the conservation pool elevation of the proposed Stacy Reservoir in Concho, Coleman. and Runnels counties, Texas. These investigations were sponsored by the Colorado River Municipal Water District in compliance with federal requirements for a construction permit from the Corps of Engineers. Approximately 1,690 acres were surveyed. and five previously unrecorded sites were discovered and documented. Cairn feature sites 41CC213 and 41CC237 are deemed potentially significant and should be preserved or investigated to determine their significance if preservation cannot be assured. In the course of the survey. 16 previously recorded sites were encountered and. in the case of 5 of these sites. adjustments were made in their boundaries. Concurrent with the survey. 11 localities and 34 sites within the previously surveyed conservation pool area were revisited. A preliminary examination of the geologic context of these sites was conducted which resulted in recognition of important geoarcheological data potential for sites in the alluviated valleys of the project area

    The effect of prewhirl on the internal aerodynamics and performance of a mixed flow research centrifugal compressor

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    The internal three-dimensional steady and time-varying flow through the diffusing elements of a centrifugal impeller were investigated using a moderate scale, subsonic, mixed flow research compressor facility. The characteristics of the test facility which permit the measurement of internal flow conditions throughout the entire research compressor and radial diffuser for various operating conditions are described. Results are presented in the form of graphs and charts to cover a range of mass flow rates with inlet guide vane settings varying from minus 15 degrees to plus 45 degrees. The static pressure distributions in the compressor inlet section and on the impeller and exit diffuser vanes, as well as the overall pressure and temperature rise and mass flow rate, were measured and analyzed at each operating point to determine the overall performance as well as the detailed aerodynamics throughout the compressor
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