2,686 research outputs found

    Rca's Planned Test Program to Compare the Performance and Life of Nicd Cells Containing Pellon 2536 in Contrast with Pellon 2505 Separator Material

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    RCA Astro-Electronics will be characterizing and life-testing two groups of hermetically-sealed aerospace nickel-cadmium cells to determine the effect, if any, of a separator change on cell performance. This test, designed to provide information for a specific low-Earth-orbit satellite application, will also add to the overall data-base for cells with the new separator

    RCA SATCOM Battery in Orbit Performance Update and Accelerated Life Test Results

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    No significant degradation of nickel cadmium battery performance in SATCOM F1 and F2 after almost 8 and 7-3/4 years in orbit was shown. Battery minimum discharge voltage data are presented for these spacecraft. In addition, 2 groups of nickel cadmium cells which are representative of those in orbit are undergoing real time eclipse-reduced suntime cycling in the laboratory. These groups of cells, which are being cycled at a maximum of 53% and 62% depth of discharge (based on actual capacity), have completed 14 and 15 eclipse seasons, respectively. Data for these groups of cells are presented and are compared with the in-orbit battery data

    The Rosary Of Hiroshima

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    Account of the survival of Jesuit priests (among them Father Hubert Schiffer) near the center of the atom bomb attack on Hiroshima. Their survival was considered by many to be a miracle. The Blue Army of Our Lady of Fatima was started by Rev. Harold V. Colgan when he was completely cured of a serious heart attack after praying to the Blessed Virgin Mary. If cured he promised to spend the rest of his life spreading devotion to her. Blue Army members promise to say the Rosary every day, consecrate themselves to the Blessed Virgin Mary, and offer sacrifices and penances to God in reparation for sin. All are encouraged in this text to participate in the Crusade for World Peace through prayer and sacrifice. Included are texts of the Morning Offering and Prayer of St. Francis Assisi for Peace

    Time Dependent Effects and Transport Evidence for Phase Separation in La_{0.5}Ca_{0.5}MnO_{3}

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    The ground state of La_{1-x}Ca_{x}MnO_{3} changes from a ferromagnetic metallic to an antiferromagnetic charge-ordered state as a function of Ca concentration at x ~ 0.50. We present evidence from transport measurements on a sample with x = 0.50 that the two phases can coexist, in agreement with other observations of phase separation in these materials. We also observe that, by applying and then removing a magnetic field to the mainly charge-ordered state at some temperatures, we can "magnetically anneal" the charge order, resulting in a higher zero-field resistivity. We also observe logarithmic time dependence in both resistivity and magnetization after a field sweep at low temperatures.Comment: 9 pages, LATEX, 3 postscript figure

    On Stability of a Distributed Averaging PI Frequency and Active Power Controlled Differential-Algebraic Power System Model

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    We consider the problems of stability, frequency restoration and optimal steady-state resource allocation in a heterogeneous and structure-preserving differential-algebraic equation (DAE) power system model. Thereby, we include constant-power-controlled loads (CPCLs) and constant-power-controlled sources (CPCSs) explicitly in the analysis and network control design. This results in a power system model with mixed algebraic as well as first- and second-order differential dynamics. We show that the abovementioned control objectives can be achieved via a distributed averaging proportional integral (DAPI) control and, in particular, extend the stability proof in [1] to the resulting closed-loop DAE system

    IUE spectra of a flare in HR 5110: A flaring RS CVn or Algol system?

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    Ultraviolet spectra of the RS CVn type binary system HR 5110 were obtained with IUE on May 31, 1979 during a period of intense radio flaring of this star. High temperature transition region lines are present, but are not enhanced above observed quiescent strengths. The similarities of HR 5110 to the Algol system, As Eri, suggest that the 1979 May to June flare may involve mass exchange rather than annihilation of coronal magnetic fields

    Semiclassical degeneracies and ordering for highly frustrated magnets in a field

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    We discuss ground state selection by quantum fluctuations in frustrated magnets in a strong magnetic field. We show that there exist dynamical symmetries -- one a generalisation of Henley's gauge-like symmetry for collinear spins, the other the quantum relict of non-collinear weathervane modes -- which ensure a partial survival of the classical degeneracies. We illustrate these for the case of the kagome magnet, where we find zero-point energy differences to be rather small everywhere except near the collinear `up-up-down` configurations, where there is rotational but not translational symmetry breaking. In the effective Hamiltonian, we demonstrate the presence of a term sensitive to a topological `flux'. We discuss the connection of such problems to gauge theories by casting the frustrated lattices as medial lattices of appropriately chosen simplex lattices, and in particular we show how the magnetic field can be used to tune the physical sector of the resulting gauge theories.Comment: 10 pages, 8 figure

    Orientational Ordering and Dynamics of Rodlike Polyelectrolytes

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    The interplay between electrostatic interactions and orientational correlations is studied for a model system of charged rods positioned on a chain, using Monte Carlo simulation techniques. It is shown that the coupling brings about the notion of {\em electrostatic frustration}, which in turn results in: (i) a rich variety of novel orientational orderings such as chiral phases, and (ii) an inherently slow dynamics characterized by stretched-exponential behavior in the relaxation functions of the system.Comment: 7 pages, 10 figure
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