23,418 research outputs found

    DSIF station schedules

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    System manages Deep Space Instrumentation Facilities /DSIF/ equipment construction and modification planning. Versatile program applies to such tasks as employee time and task schedules, pay schedules, operations schedules, and plant and equipment procurement, construction, modification or service

    Numerical solutions of several reflected shock-wave flow fields with nonequilibrium chemical reactions

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    The method of characteristics for a chemically reacting gas is used in the construction of the time-dependent, one-dimensional flow field resulting from the normal reflection of an incident shock wave at the end wall of a shock tube. Nonequilibrium chemical reactions are allowed behind both the incident and reflected shock waves. All the solutions are evaluated for oxygen, but the results are generally representative of any inviscid, nonconducting, and nonradiating diatomic gas. The solutions clearly show that: (1) both the incident- and reflected-shock chemical relaxation times are important in governing the time to attain steady state thermodynamic properties; and (2) adjacent to the end wall, an excess-entropy layer develops wherein the steady state values of all the thermodynamic variables except pressure differ significantly from their corresponding Rankine-Hugoniot equilibrium values

    COASTAL ALABAMA RECREATIONAL LIVE BAIT STUDY

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    Recreational fishing is major industry and reasonably priced, high quality bait plays an important role in sustaining recreational fishing's popularity. This study provides a summary of Alabama's coastal live bait market including information on previous live bait studies and results of two surveys on the live bait shrimp, bull minnow and other bait markets. Results indicated there were periods of supply shortages, dealer willingness to pay more for shrimp that live longer and a dealers' use of multiple supply sources. Lost income was reported from not having live bait shrimp available for sale at peak demand periods. The economics of shrimp mariculture needs to be examined to determine its feasibility in augmenting the current supply of shrimp to the live bait industry.Resource /Energy Economics and Policy,

    Kinetics of the reaction of nitric oxide with hydrogen

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    Mixtures of NO and H2 diluted in argon or krypton were heated by incident shock waves, and the infrared emission from the fundamental vibration-rotation band of NO at 5.3 microns was used to monitor the time-varying NO concentration. The reaction kinetics were studied in the temperature range 2400-4500 K using a shock-tube technique. The decomposition of nitric oxide behind the shock was found to be modeled well by a fifteen-reaction system. A principle result of the study was the determination of the rate constant for the reaction H + NO yields N + OH, which may be the rate-limiting step for NO removal in some combustion systems. Experimental values of k sub 1 were obtained for each test through comparisons of measured and numerically predicted NO profiles

    A PROFITABILITY ANALYSIS OF DAIRY FEEDING SYSTEMS IN THE NORTHEAST

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    This study analyzes the use and profitability of three distinct feeding systems; confinement feeding, traditional grazing, and management-intensive grazing from a randomly selected sample of northeastern dairy farms. The confinement feeding farms were significantly larger and produced more milk per cow, while the farms using management-intensive grazing incurred the lowest production costs. Both confinement feeding and management-intensive grazing generated significantly higher rates of return to farm assets relative to farms using a mixed system. Multiple regression analysis confirms the critical importance of herd size, milk production per cow, debt level and veterinary expenses to farm profitability in all production systems.Livestock Production/Industries,

    Rollup subsolar array Quarterly technical report, 5 Mar. - 30 May 1969

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    Thermal cycling and environmental tests for solar arra

    Gravity from the extension of spatial diffeomorphisms

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    The possibility of the extension of spatial diffeomorphisms to a larger family of symmetries in a class of classical field theories is studied. The generator of the additional local symmetry contains a quadratic kinetic term and a potential term which can be a general (not necessarily local) functional of the metric. From the perspective of the foundation of Einstein's gravity our results are positive: The extended constraint algebra is either that of Einstein's gravity, or ultralocal gravity. If our goal is a simple modification of Einstein's gravity that for example makes it perturbatively renormalizable, as has recently been suggested, then our results show that there is no such theory within this class.Comment: 34 page

    Basic linear algebra subprograms for FORTRAN usage

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    A package of 38 low level subprograms for many of the basic operations of numerical linear algebra is presented. The package is intended to be used with FORTRAN. The operations in the package are dot products, elementary vector operations, Givens transformations, vector copy and swap, vector norms, vector scaling, and the indices of components of largest magnitude. The subprograms and a test driver are available in portable FORTRAN. Versions of the subprograms are also provided in assembly language for the IBM 360/67, the CDC 6600 and CDC 7600, and the Univac 1108

    Spin filling of a quantum dot derived from excited-state spectroscopy

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    We study the spin filling of a semiconductor quantum dot using excited-state spectroscopy in a strong magnetic field. The field is oriented in the plane of the two-dimensional electron gas in which the dot is electrostatically defined. By combining the observation of Zeeman splitting with our knowledge of the absolute number of electrons, we are able to determine the ground state spin configuration for one to five electrons occupying the dot. For four electrons, we find a ground state spin configuration with total spin S=1, in agreement with Hund's first rule. The electron g-factor is observed to be independent of magnetic field and electron number.Comment: 11 pages, 7 figures, submitted to New Journal of Physics, focus issue on Solid State Quantum Informatio
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