19,433 research outputs found

    Alkaline battery separator characterization studies Quarterly report, 28 Apr. - 28 Jul. 1969

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    Absorber evaluation of alkaline battery separator systems with electrolyte wetting and wicking measuremen

    Alkaline battery separator characterization studies Quarterly report, 28 Jun. - 28 Sep. 1969

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    Membrane and absorber screening tests for alkaline battery separator

    New phenomena in the standard no-scale supergravity model

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    We revisit the no-scale mechanism in the context of the simplest no-scale supergravity extension of the Standard Model. This model has the usual five-dimensional parameter space plus an additional parameter ξ3/2m3/2/m1/2\xi_{3/2}\equiv m_{3/2}/m_{1/2}. We show how predictions of the model may be extracted over the whole parameter space. A necessary condition for the potential to be stable is StrM4>0{\rm Str}{\cal M}^4>0, which is satisfied if \bf m_{3/2}\lsim2 m_{\tilde q}. Order of magnitude calculations reveal a no-lose theorem guaranteeing interesting and potentially observable new phenomena in the neutral scalar sector of the theory which would constitute a ``smoking gun'' of the no-scale mechanism. This new phenomenology is model-independent and divides into three scenarios, depending on the ratio of the weak scale to the vev at the minimum of the no-scale direction. We also calculate the residual vacuum energy at the unification scale (C0m3/24C_0\, m^4_{3/2}), and find that in typical models one must require C0>10C_0>10. Such constraints should be important in the search for the correct string no-scale supergravity model. We also show how specific classes of string models fit within this framework.Comment: 11pages, LaTeX, 1 figure (included), CERN-TH.7433/9

    Qualitative Criterion for Interception in a Pursuit/Evasion Game

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    A qualitative account is given of a differential pursuit/evasion game. A criterion for the existence of an intercept solution is obtained using future cones that contain all attainable trajectories of target or interceptor originating from an initial position. A sufficient and necessary conditon that an opportunity to intercept always exist is that, after some initial time, the future cone of the target be contained within the future cone of the interceptor. The sufficient condition may be regarded as a kind of Nash equillibrium.Comment: 8 pages; revsions and corrigend

    Satellite power system: Concept development and evaluation program. Volume 3: Power transmission and reception. Technical summary and assessment

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    Efforts in the DOE/NASA concept development and evaluation program are discussed for the solar power satellite power transmission and reception system. A technical summary is provided together with a summary of system assessment activities. System options and system definition drivers are described. Major system assessment activities were in support of the reference system definition, solid state system studies, critical technology supporting investigations, and various system and subsystem tradeoffs. These activities are described together with reference system updates and alternative concepts for each of the subsystem areas. Conclusions reached as a result of the numerous analytical and experimental evaluations are presented. Remaining issues for a possible follow-on program are identified

    The pregnant worker: how much is too much? Assessing safe activity levels.

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    Physicians should be able to advise pregnant women about safe amounts of physical activity in the workplace. A computerized literature search was used to review reproductive risks of physical activity, proper clinical evaluation and recommendations of the pregnant worker regarding physical activity, and current State of Hawaii disability legislation pertinent to pregnant workers. This article highlights the importance of making accurate clinical assessments regarding the continuation of work for the healthy pregnant worker and also provides physicians with an approach to assessing physical exposure risks of pregnant workers

    Kinetic instability of drift-Alfven waves in solar corona and stochastic heating

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    The solar atmosphere is structured and inhomogeneous both horizontally and vertically. The omnipresence of coronal magnetic loops implies gradients of the equilibrium plasma quantities like the density, magnetic field and temperature. These gradients are responsible for the excitation of drift waves that grow both within the two-component fluid description (in the presence of collisions and without it) and within the two-component kinetic descriptions (due to purely kinetic effects). In the present work the effects of the density gradient in the direction perpendicular to the magnetic field vector are investigated within the kinetic theory, in both electrostatic and electromagnetic regimes. The electromagnetic regime implies the coupling of the gradient-driven drift wave with the Alfven wave. The growth rates for the two cases are calculated and compared. It is found that, in general, the electrostatic regime is characterized by stronger growth rates, as compared with the electromagnetic perturbations. Also discussed is the stochastic heating associated with the drift wave. The released amount of energy density due to this heating should be more dependent on the magnitude of the background magnetic field than on the coupling of the drift and Alfven waves. The stochastic heating is expected to be much higher in regions with a stronger magnetic field. On the whole, the energy release rate caused by the stochastic heating can be several orders of magnitude above the value presently accepted as necessary for a sustainable coronal heating.Comment: To appear in ApJ (2010
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