358 research outputs found

    Extravehicular mobility unit subcritical liquid oxygen storage and supply system

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    The storage of life support oxygen in the Extravehicular Mobility Unit in the liquid state offers some advantages over the current method of storing the oxygen as a high pressure gas. Storage volume is reduced because of the increased density associated with liquid. The lower storage and operating pressures also reduce the potential for leakage or bursting of the storage tank. The potential for combustion resulting from adiabatic combustion of the gas within lines and components is substantially reduced. Design constraints on components are also relaxed due to the lower system pressures. A design study was performed to determine the requirements for a liquid storage system and prepare a conceptual design. The study involved four tasks. The first was to identify system operating requirements that influence or direct the design of the system. The second was to define candidate storage system concepts that could possibly satisfy the requirements. An evaluation and comparison of the candidate concepts was conducted in the third task. The fourth task was devoted to preparing a conceptual design of the recommended storage system and to evaluate concerns with integration of the concept into the EMU. The results are presented

    The right of access to a lawyer at police stations: Making the European Union directive work in practice

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    Drawing on recent empirical research, the article examines the necessary conditions for effective implementation of the European Union Directive on the right of access to a lawyer. It discusses the range of complex and often inter-related factors that operate to help or hinder the process of ensuring that the right is 'practical and effective', and identifies the need for changes to the legal and occupational cultures of police, prosecutors and the criminal bar

    Phase Change Material Trade Study: A Comparison Between Wax and Water for Manned Spacecraft

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    Phase change material heat sinks have been recognized as an important tool in optimizing thermal control systems for space exploration vehicles and habitats that must deal with widely varying thermal loads and environments. In order to better focus technology investment in this arena, NASA has supported a trade study with the objective of identifying where the best potential pay-off can be found among identified aqueous and paraffin wax phase change materials and phase change material heat sink design approaches. The study used a representative exploration mission with well understood parameters to support the trade. Additional sensitivity studies were performed to ensure the applicability of study results across varying systems and destinations. Results from the study indicate that replacing a wax PCM heat sink with a water ice PCM heat sink has the potential to decrease the equivalent system mass of the mission s vehicle through a combination of a smaller heat sink and a slight 5% increase in radiator size or the addition of a lightweight heat pump. An evaluation of existing and emerging PCM heat sink technologies indicates that further mass savings should be achievable through continued development of those technologies. The largest mass savings may be realized by eliminating the melting and freezing pressure of wax and water, respectively

    Multifunctional Space Evaporator-Absorber-Radiator (SEAR)

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    A system for non-venting thermal control for spacesuits was built by integrating two previously developed technologies, namely NASA's Spacesuit Water Membrane Evaporator (SWME), and Creare's flexible version of the Lithium Chloride Absorber Radiator (LCAR). This SEAR system was tested in relevant thermal vacuum conditions. These tests show that a 1 sq m radiator having about three times as much absorption media as in the test article would be required to support a 7 hour spacewalk. The serial flow arrangement of the LCAR of the flexible version proved to be inefficient for venting non-condensable gas (NCG). A different LCAR packaging arrangement was conceived wherein the Portable Life Support System (PLSS) housing would be made with a high-strength carbon fiber composite honeycomb, the cells of which would be filled with the chemical absorption media. This new packaging reduce the mass and volume impact of the SEAR on the Portable Life Support System (PLSS) compared to the flexible design. A 0.2 sq m panel with flight-like honeycomb geometry is being constructed and will be tested in thermal and thermal vacuum conditions. Design analyses forecast improved system performance and improved NCG control. A flight-like regeneration system also is also being built and tested. Design analyses for the structurally integrated prototype as well as the earlier test data show that SEAR is not only practical for spacesuits but also has useful applications in spacecraft thermal control

    Spacesuit Evaporator-Absorber-Radiator (SEAR)

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    For decades advanced spacesuit developers have pursued a regenerable, robust nonventing system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA s Spacesuit Water Membrane Evaporator (SWME), and Creare s Lithium Chloride Absorber Radiator (LCAR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. This water vapor is then captured by solid LiCl in the LCAR with a high enthalpy of absorption, resulting in sufficient temperature lift to reject heat to space by radiation. After the sortie, the LCAR would be heated up and dried in a regenerator to drive off and recover the absorbed evaporant. A engineering development prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The LCAR was able to stably reject 75 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios

    Spacesuit Evaporator-Absorber-Radiator (SEAR)

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    For decades advanced spacesuit developers have pursued a regenerable, robust non-venting system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA's Spacesuit Water Membrane Evaporator (SWME), and Creare's lithium chloride Heat Pump Radiator (HPR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. The SEAR is evacuated at the onset of operations and thereafter, the water vapor absorption rate of the HPR maintains a low pressure environment for the SWME to evaporate effectively. This water vapor captured by solid LiCl in the HPR with a high enthalpy of absorption, results in sufficient temperature lift to reject most of the heat to space by radiation. After the sortie, the HPR would be heated up in a regenerator to drive off and recover the absorbed evaporant. A one-fourth scale prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The HPR was able to stably reject 60 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios

    Early marine survival of steelhead smolts in Puget Sound

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    Smolt-to adult survival rates for Puget Sound steelhead populations have declined substantially over the last 25 years and remain at or near historic lows. From 2006-2009, nearly 1,400 steelhead smolts from 9 watersheds within Puget Sound were tracked from river mouth to the Pacific Ocean using acoustic telemetry to: (1) estimate early marine survival through Puget Sound, (2) identify common areas of abnormally high mortality along the migration route, and (3) to identify factors that may influence survival. Cormac-Jolly-Seber mark-recapture models were used to jointly estimate survival and detection rate at telemetry arrays. Estimated survival rates from river mouths to near the Pacific Ocean ranged from 1.5% (Skokomish River hatchery smolts in 2009) to 34.0% (Big Beef Creek wild smolts in 2006), and averaged 14.9% for all populations. Factors influencing survival included population, migration segment, migration year, and rearing type (i.e., hatchery or wild), while geographic region, body length, and tag type (i.e., 7mm or 9mm) showed lesser effects. Comparison of survival rates between migration segments implicated central Puget Sound and Admiralty Inlet as potential areas of heightened mortality. Early marine survival rates estimated here are very low considering that steelhead smolts spend only about two to three weeks in Puget Sound before entering the Pacific Ocean. Mortality in Puget Sound may be a major driver behind low observed smolt-to adult survival rates. This study addresses a major gap in steelhead marine life history knowledge and can help to inform future Puget Sound steelhead recovery planning efforts

    Campus Vol III N 2

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    Olwin, Lynn. The Picture . Prose. 2.; Wittich, Hugh. Mister Diablos . Prose. 3.; Subler, Ed. A Backward Glance . Picture. 4.; Gilbert, Ralph. Going Uphill? Or, An India Ink Indictment of the Drag as the Air Gets Mighty Thin Towards the Top, Mother . Cartoon. 6. Blashill, John. Local Man Killed . Prose. 7. Stiverson, Jim and Terry Thurn. Sadie Hawkins Dance . Picture. 8. Shelford, Kenneth. Night and John Barlow -- A Sketch . Prose. 10. Fairless, Dave. \u27Twas The Night Before Christmas . Picture. 11. Ducro, George and Jack Mathews. The Case of the Consumptive Capon . Prose. 12. Hoyrn, Gene. Forty-Three years of Progress . Prose. 13. Hodgeson, Don. Debits and Credits of Christmas . Prose. 14. Gilles, Jean. Untitled. Cartoon. 14.; Gilles, Jean. Untitled. Cartoon. 15

    The Impossibility of a Perfectly Competitive Labor Market

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    Using the institutional theory of transaction cost, I demonstrate that the assumptions of the competitive labor market model are internally contradictory and lead to the conclusion that on purely theoretical grounds a perfectly competitive labor market is a logical impossibility. By extension, the familiar diagram of wage determination by supply and demand is also a logical impossibility and the neoclassical labor demand curve is not a well-defined construct. The reason is that the perfectly competitive market model presumes zero transaction cost and with zero transaction cost all labor is hired as independent contractors, implying multi-person firms, the employment relationship, and labor market disappear. With positive transaction cost, on the other hand, employment contracts are incomplete and the labor supply curve to the firm is upward sloping, again causing the labor demand curve to be ill-defined. As a result, theory suggests that wage rates are always and everywhere an amalgam of an administered and bargained price. Working Paper 06-0

    Campus Vol IV N 2

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    Hodgson, Don. Big Red On The Radio . Prose. 2. Hauser, Bill. After Hours Almanac . Prose. 4. Ide, Don and Bob Porter. I Remember D-Day . Picture. 6. Hawk, Bob. The Shysters: Drama in The Counselor\u27s Office a la Hemingway . Prose. 7. McGlone, Joe and Tom Rees. Terpischore Takes Over . Picture. 8. Parker, Chris. Nuns Fret Not . Prose. 9. Johnston, Ed. Fashions For Men . Prose. 10. Barton, Rusty. Fashions For Women . Prose. 11. Matthews, Jack and Joe McGlone. Campus Congratulates . Picture. 12. Rossi, Bob. Doane * 9:55 . Picture. 14. Bedell, Barrie and John Hodges. Ballroom to Boudoir . 15. Anonymous. Calender Girls For \u2750 . Picture. 16. Wittich, Hugh. Prelude . Prose. 20. Chase, Dick. The Intramural Saga . Prose. 21. Kruger, Ben. Column For Contributors . Prose. 22. Taggart, Marilou. Leaves, Oh Man! . Poem. 22. Taggart, Marilou. Christmas Fugue . Poem. 22. Froth. Untitled. Prose. 24. Anonymous. Untitled. Cartoon. 24. Optekar, Pat. Polyphemis\u27 Wrath . Prose. 5
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