244,096 research outputs found

    CMF-13 research on carbon and graphite Summary progress report, 1 May - 31 Jul. 1970

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    Microstructural research on carbon and graphite for use as engineering material

    CMF-13 research on carbon and graphite Progress summary report, 1 May - 31 Jul. 1968

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    Physical and mechanical properties of carbon and graphit

    Progress of the LASL dry hot rock geothermal energy project

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    The possibilities and problems of extracting energy from geothermal reservoirs which do not spontaneously yield useful amounts of steam or hot water are discussed. The system for accomplishing this which is being developed first is a pressurized-water circulation loop intended for use in relatively impermeable hot rock. It will consist of two holes connected through the hot rock by a very large hydraulic fracture and connected at the surface through the primary heat exchanger of an energy utilization system. Preliminary experiments in a hole 2576 ft (0.7852 km) deep, extending about 470 ft (143 m) into the Precambrian basement rock underlying the Jemez Plateau of north-central New Mexico, revealed no unexpected difficulties in drilling or hydraulically fracturing such rock at a temperature of approximately 100 C, and demonstrated a permeability low enough so that it appeared probable that pressurized water could be contained by the basement rock. Similar experiments are in progress in a second hole, now 6701 ft (2.043 km) deep, about 1.5 miles (2.4 km) south of the first one

    CMF-13 research on carbon and graphite Progress report, 1 Feb. - 30 Apr. 1969

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    Carbon and graphite research and development, with detailed data on Santa Maria coke as filler materia

    Preliminary estimates of operating costs for lighter than air transports

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    A preliminary set of operating cost relationships are presented for airship transports. The starting point for the development of the relationships is the direct operating cost formulae and the indirect operating cost categories commonly used for estimating costs of heavier than air commercial transports. Modifications are made to the relationships to account for the unique features of airships. To illustrate the cost estimating method, the operating costs of selected airship cargo transports are computed. Conventional fully buoyant and hybrid semi-buoyant systems are investigated for a variety of speeds, payloads, ranges, and altitudes. Comparisons are made with aircraft transports for a range of cargo densities

    Study made of pneumatic high pressure piping materials /10,000 psi/

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    Evaluations of five types of steel for use in high pressure pneumatic piping systems include tests for impact strength, tensile and yield strengths, elongation and reduction in area, field weldability, and cost. One type, AISI 4615, was selected as most advantageous for extensive use in future flight vehicles

    Shallow Surveying in Hazardous Waters

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    Of order one importance to any study of nearshore processes is knowledge of the bathymetry in shallow water. This is true for studies on open coast sandy beaches where surf zone dynamics drive the system, inlet environments where bathymetric evolution can rapidly change navigation channels, and in more benign, lower-energy coastal environments that evolve slowly over 10’s to 100’s of years. Difficulties in obtaining shallow bathymetry where depth-limited wave breaking occurs, submerged hazards are present, or other harsh environments has led to the development of survey systems on highly maneuverable personal watercraft (Beach, et al., 1994; Cote, 1999; Dugan, et al., 1999; MacMahan, 2001). In this work we discuss shallow water surveying from the Coastal Bathymetry Survey System (CBASS), a Yamaha Waverunner equipped with differential GPS, single-beam 192 KHz acoustic echo-sounder, and onboard navigation system. Data obtained with the CBASS in three regions will be discussed, including an energetic surf zone located in southern California during the 2003 Nearshore Canyon Experiment (NCEX), on Lake Erie in 2002 (and compared with historical surveys dating back 150 years), and around Piscataqua River Inlet, NH, in 2007. Estimated accuracy (for sandy bottoms) in water depths ranging 1–10 m are 0.07-0.10 m in the vertical, and on the order of 0.1-1 m horizontally depending on water depth and bottom slope. The high maneuverability of the personal watercraft makes very shallow water bathymetric surveys possible with acoustic altimeters, particularly in regions where airborne remote sensing systems fail (owing to water clarity issues) or where repeated high resolution surveys are required (e.g., where an erodible bottom is rapidly evolving)

    An alternative method of analysis for base accelerated dynamic response in NASTRAN

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    An alternative method of analysis to determine the dynamic response of structures subjected to base accelerations is presented. The method is exact as opposed to the approximate technique of using unusually large masses and loads to enforce desired base accelerations. This paper presents the relevant equations to motion, ALTERs for direct and modal frequency-, random- and transient-response rigid formats, and illustrative examples
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