611 research outputs found

    A turbojet-boosted two-stage-to-orbit space transportation system design study

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    The concept to use twin turbo-powered boosters for acceleration to supersonic staging speed followed by an all rocket powered orbiter stage was proposed. A follow-on design study was then made of the concept with the performance objective of placing a 29,483 Kg payload into a .2.6 X 195.3 km orbit. The study was performed in terms of analysis and trade studies, conceptual design, utility and economic analysis, and technology assessment. Design features of the final configuration included: strakes and area rule for improved take off and low transonic drag, variable area inlets, exits and turbine, and low profile fixed landing gear for turbojet booster stage. The payload required an estimated GLOW of 1,270,000 kg for injection in orbit. Each twin booster required afterburning turbojet engines each with a static sea level thrust rating of 444,800 N. Life cycle costs for this concept were comparable to a SSTO/SLED concept except for increased development cost due to the turbojet engine propulsion system

    Thermal components for 1.8 K space cryogenics

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    Work of the summer 1986 is summarized in three areas. First, conceptual design of a laboratory system for heat exchanger evaluation in conjunction with the operation of a thermally activated fountain effect pump (FEP) is presented. Second, Knudsen effect evaluation of fine porous media useful for the pressurization plug which forms the main component of the FEP is described. Third, proof-of-principle test of the lab system selected on the basis of the evaluation is summarized

    A study of flight control requirements for advanced, winged, earth-to-orbit vehicles with far-aft center-of-gravity locations

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    Control requirements of Controlled Configured Design Approach vehicles with far-aft center of gravity locations are studied. The baseline system investigated is a fully reusable vertical takeoff/horizontal landing single stage-to-orbit vehicle with mission requirements similar to that of the space shuttle vehicle. Evaluations were made to determine dynamic stability boundaries, time responses, trim control, operational center-of-gravity limits, and flight control subsystem design requirements. Study tasks included a baseline vehicle analysis, an aft center of gravity study, a payload size study, and a technology assessment

    Vapor-liquid phase separator studies

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    A study of porous plug use for vapor-liquid phase seperation in spaceborne cryogenic systems was conducted. The three main topics addressed were: (1) the usefulness of porous media in designs that call for variable areas and flow rates; (2) the possibility of prediction of main parameters of porous plugs for a given material; and (3) prediction of all parameters of the plug, including secondary parameters

    Applicability of the control configured design approach to advanced earth orbital transportation systems

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    The applicability of the control configured design approach (CCV) to advanced earth orbital transportation systems was studied. The baseline system investigated was fully reusable vertical take-off/horizontal landing single-stage-to-orbit vehicle and had mission requirements similar to the space shuttle orbiter. Technical analyses were made to determine aerodynamic, flight control and subsystem design characteristics. Figures of merit were assessed on vehicle dry weight and orbital payload. The results indicated that the major parameters for CCV designs are hypersonic trim, aft center of gravity, and control surface heating. Optimized CCV designs can be controllable and provide substantial payload gains over conventional non-CCV design vertical take-off vehicles

    Separator plugs for liquid helium

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    Work performed during Summer 1984 (from June to Sept. 30) in the area of porous media for use in low temperature applications is discussed. Recent applications are in the area of vapor - liquid phase separation, pumping based on the fountain effect and related subsystems. Areas of potential applications of the latter are outlined in supplementary work. Experimental data have been developed. The linear equations of the two-fluid model are inspected critically in the light of forced convection evidence reported recently. It is emphasized that the Darcy permeability is a unique throughput quantity in the porous media application areas whose use will permit meaningful comparisons of data not only in one lab but also within a group of labs doing porous plug studies

    Vapor-liquid phase separator studies

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    Porous plugs serve as both entropy rejection devices and phase separation components separating the vapor phase on the downstream side from liquid Helium 2 upstream. The liquid upstream is the cryo-reservoir fluid needed for equipment cooling by means of Helium 2, i.e Helium-4 below its lambda temperature in near-saturated states. The topics outlined are characteristic lengths, transport equations and plug results

    Interpersonal interactions in instrumental lessons: teacher/students verbal and non-verbal behaviours

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    This study examined verbal and non-verbal teacher/student interpersonal interactions in higher education instrumental music lessons. Twenty-four lessons were videotaped and teacher/ student behaviours were analysed using a researcher-designed instrument. The findings indicate predominance of student and teacher joke among the verbal behaviours with no substantial gender differences between males and females. Deceit cues were the most frequent among the non-verbal behaviours, with the males displaying more gestures of deceit than the females. Other gender differences include the female students using courting signals towards both teacher groups and the female teachers showing interest towards the male students. The presence of positive verbal and negative non-verbal behaviours highlights the mixed messages present in teaching. Implications for instrumental teaching practice include greater focus on gender differences in interpersonal interactions and visual cues to improve communication and teacher/student relationship in the instrumental studio

    Blueberry Research Progress Report

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    The 1976 edition of the Blueberry Research Progress Report was prepared for the Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Effect of Plant-Water Stress on Lowbush Blueberry Growth, Yield and Quality 2. Insects Affecting the Blueberry 3. The Development of Blueberry Varieties Adapted to Maine 4. Weed Control in Blueberry Fields 5. Pruning of Blueberries 6. Integrated Management of Blueberry Fields 7. The Physiology and Biochemistry of the Development of the Lowbush Blueberry Fruit 8. Survey of Red Leaf Disease of Blueberries 9. Blossom Blight of Blueberries 10. Blueberry Marketing and Cost Analysis of Producing Blueberries 11. Factors Regulating Rhizome Initiation and Development in the Lowbush Blueberry 12. New Food Products and Servic

    Blueberry Progress Reports

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    The 1978 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Life Sciences and Agriculture Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include: 1. Weed Control in Blueberry Fields 2. Pruning of Blueberries 3. Integrated Management of Blueberry Fields 4. Factors Regulating Rhizome Initiation and Development in the Lowbush Blueberry 5. Effect of Plant-Water Stress on Lowbush Blueberry Growth Yield and Quality 6. Blossom Blight of Blueberries 7. Botrytis Blossom Blight of Lowbush Blueberries 8. Insects Affecting the Blueberry 9. Treatment of Blueberries with Potassium Sorbate to Reduce Spoilage During Temporary Storage 10. Cooperative Extension Activitie
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