2,542 research outputs found

    Archilestes neblina, a new damselfly from Costa Rica, with comments on the variability of A. latialatus Donnelly (Odonata: Lestidae)

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    http://deepblue.lib.umich.edu/bitstream/2027.42/57138/1/OP702.pd

    An evaluation of oxygen-hydrogen propulsion systems for the Space Station

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    Conceptual designs for O2/H2 chemical and resistojet propulsion systems for the space station was developed and evaluated. The evolution of propulsion requirements was considered as the space station configuration and its utilization as a space transportation node change over the first decade of operation. The characteristics of candidate O2/H2 auxiliary propulsion systems are determined, and opportunities for integration with the OTV tank farm and the space station life support, power and thermal control subsystems are investigated. OTV tank farm boiloff can provide a major portion of the growth station impulse requirements and CO2 from the life support system can be a significant propellant resource, provided it is not denied by closure of that subsystem. Waste heat from the thermal control system is sufficient for many propellant conditioning requirements. It is concluded that the optimum level of subsystem integration must be based on higher level space station studies

    On the physical association of the peculiar emission: Line stars HD 122669 and HD 122691

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    Spectroscopic and photometric observations indicate a physical association between the peculiar early-type emission-line stars HD 122669 and HD 122691. The latter has undergone a drastic change in the strength of its emission lines during the past twenty years. There is some indication that both stars vary with shorter time scales

    Study of instabilities in linear Hall current accelerators

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    Ion and electron conservation equations used in analysis of instability of linear Hall current accelerato

    Riccati parameter modes from Newtonian free damping motion by supersymmetry

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    We determine the class of damped modes \tilde{y} which are related to the common free damping modes y by supersymmetry. They are obtained by employing the factorization of Newton's differential equation of motion for the free damped oscillator by means of the general solution of the corresponding Riccati equation together with Witten's method of constructing the supersymmetric partner operator. This procedure leads to one-parameter families of (transient) modes for each of the three types of free damping, corresponding to a particular type of %time-dependent angular frequency. %time-dependent, antirestoring acceleration (adding up to the usual Hooke restoring acceleration) of the form a(t)=\frac{2\gamma ^2}{(\gamma t+1)^{2}}\tilde{y}, where \gamma is the family parameter that has been chosen as the inverse of the Riccati integration constant. In supersymmetric terms, they represent all those one Riccati parameter damping modes having the same Newtonian free damping partner modeComment: 6 pages, twocolumn, 6 figures, only first 3 publishe

    An annotated list of the name-bearing types of species-group names in Odonata preserved in the University of Michigan Museum of Zoology

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    http://deepblue.lib.umich.edu/bitstream/2027.42/57172/1/OP736.pd

    Telecommunications systems design techniques handbook

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    Handbook presents design and analysis of tracking, telemetry, and command functions utilized in these systems with particular emphasis on deep-space telecommunications. Antenna requirements are also discussed. Handbook provides number of tables outlining various performance criteria. Block diagrams and performance charts are also presented

    The effect of udder irrigation and milking interval on milk secretion

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    Publication authorized February 6, 1936.Digitized 2007 AES.Includes bibliographical references (pages 38-39)
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