19,515 research outputs found

    Zero gravity liquid transfer screen

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    A liquid transfer device for use in a zero gravity environment, for transferring liquid from one container to another is described. The device includes a spiral shaped screen type member which is carried in the container for collecting the randomly dispersed liquid and transferring such to an exit port

    Floating baffle to improve efficiency of liquid transfer from tanks

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    When liquid tank is full, baffle is held up against a stop on top of shaft to prevent restriction of flow from outlet. As tank is being emptied, baffle, floating on top of liquid surface, descends with liquid level toward outlet until it reaches its bottom stop. Baffle prevents gas pull-through until practically all liquid is emptied from tank

    Steady-state MreB helices inside bacteria: dynamics without motors

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    Within individual bacteria, we combine force-dependent polymerization dynamics of individual MreB protofilaments with an elastic model of protofilament bundles buckled into helical configurations. We use variational techniques and stochastic simulations to relate the pitch of the MreB helix, the total abundance of MreB, and the number of protofilaments. By comparing our simulations with mean-field calculations, we find that stochastic fluctuations are significant. We examine the quasi-static evolution of the helical pitch with cell growth, as well as timescales of helix turnover and denovo establishment. We find that while the body of a polarized MreB helix treadmills towards its slow-growing end, the fast-growing tips of laterally associated protofilaments move towards the opposite fast-growing end of the MreB helix. This offers a possible mechanism for targeted polar localization without cytoplasmic motor proteins.Comment: 7 figures, 1 tabl

    Persistence in the zero-temperature dynamics of the QQ-states Potts model on undirected-directed Barab\'asi-Albert networks and Erd\"os-R\'enyi random graphs

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    The zero-temperature Glauber dynamics is used to investigate the persistence probability P(t)P(t) in the Potts model with Q=3,4,5,7,9,12,24,64,128Q=3,4,5,7,9,12,24,64, 128, 256,512,1024,4096,16384256, 512, 1024,4096,16384 ,..., 2302^{30} states on {\it directed} and {\it undirected} Barab\'asi-Albert networks and Erd\"os-R\'enyi random graphs. In this model it is found that P(t)P(t) decays exponentially to zero in short times for {\it directed} and {\it undirected} Erd\"os-R\'enyi random graphs. For {\it directed} and {\it undirected} Barab\'asi-Albert networks, in contrast it decays exponentially to a constant value for long times, i.e, P(∞)P(\infty) is different from zero for all QQ values (here studied) from Q=3,4,5,...,230Q=3,4,5,..., 2^{30}; this shows "blocking" for all these QQ values. Except that for Q=230Q=2^{30} in the {\it undirected} case P(t)P(t) tends exponentially to zero; this could be just a finite-size effect since in the other "blocking" cases you may have only a few unchanged spins.Comment: 14 pages, 8 figures for IJM

    Properties of Intercalated 2H-NbSe2, 4Hb-TaS2 and 1T-TaS2

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    The layered compounds 2H-NbSe, 24Hb-TaS, 2and 1T-TaS2 have been intercalated with organic molecules; and the resulting crystal structure, heat capacity, conductivity, and superconductivity have been studied. The coordination in the disulfide layers was found to be unchanged in the product phase. Resistance minima appear and the superconducting transition temperature is reduced in the NbSe2 complex. Conversely, superconductivity is induced in the 4Hb-TaS2 complex. Corresponding evidence of a large change of the density of states, negative for 2H-NbSe2 and positive for 4Hb-TaS2, was also observed upon intercalation. The transport properties of all the intercalation complexes show a pronounced dependence upon the coordination of the transition metal

    The Residual Hearsay Exceptions: Maryland\u27s Lukewarm Welcome

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    On July 1, 1994 Maryland codified its rules of evidence, bringing them into accord with the substance of the Federal Rules of Evidence. In doing so, Maryland followed the trend set by thirty-seven other states. The codified evidence rules, known collectively as Title 5 of the Maryland Rules, were made applicable to all actions and proceedings in the courts of this State, with some exceptions

    A model for hand-over-hand motion of molecular motors

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    A simple flashing ratchet model in two dimensions is proposed to simulate the hand-over-hand motion of two head molecular motors like kinesin. Extensive Langevin simulations of the model are performed. Good qualitative agreement with the expected behavior is observed. We discuss different regimes of motion and efficiency depending of model parameters.Comment: 8 pages, Phys. Rev. E (in press

    The Residual Hearsay Exceptions: Maryland\u27s Lukewarm Welcome

    Get PDF
    On July 1, 1994 Maryland codified its rules of evidence, bringing them into accord with the substance of the Federal Rules of Evidence. In doing so, Maryland followed the trend set by thirty-seven other states. The codified evidence rules, known collectively as Title 5 of the Maryland Rules, were made applicable to all actions and proceedings in the courts of this State, with some exceptions

    The significance and technique of dry matter determinations in yield tests of Alfalfa and red clover

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    In comparative yield tests of species, varieties, strains, sources or lots\u27, or of cultural treatments of forage crops, the objective of the investigator is to obtain the most accurate results possible with funds available. The methods employed must be capable of distinguishing differences in yields of dry matter of individual plots attributable not only to the lot but also to soil heterogeneity and other environmental conditions. Accurate dry matter determination of forage on the plots of an experiment is of major importance to the experimenter. Under humid conditions reliable comparisons cannot be made from the weights of field cured forage, except on rare occasions that cannot be predicted. Some investigators believe that with fairly homogeneous forages the error introduced from the use of green weights without dry matter determinations is not great
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