11,606 research outputs found

    Update, comparing different plate treatments and design

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    Eight electrochemical cells were tested for precycling capacity and compared. The cell design variables included teflon treatment, silver treatment, light loading, and a polypropylene separator. Data are presented in tabular form

    Recharge unit provides for optimum recharging of battery cells

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    Percent recharge unit permits each cell of a rechargeable battery to be charged to a preset capacity of the cell. The unit automatically monitors and controls a rechargeable battery subjected to charge-discharge cycling tests

    Exact quantum cross sections for a three dimensional angle dependent model for three body reactions

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    Quantum mechanical reactive cross sections reported for three dimensional angle dependent model surfac

    21st Century Simulation: Exploiting High Performance Computing and Data Analysis

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    This paper identifies, defines, and analyzes the limitations imposed on Modeling and Simulation by outmoded paradigms in computer utilization and data analysis. The authors then discuss two emerging capabilities to overcome these limitations: High Performance Parallel Computing and Advanced Data Analysis. First, parallel computing, in supercomputers and Linux clusters, has proven effective by providing users an advantage in computing power. This has been characterized as a ten-year lead over the use of single-processor computers. Second, advanced data analysis techniques are both necessitated and enabled by this leap in computing power. JFCOM's JESPP project is one of the few simulation initiatives to effectively embrace these concepts. The challenges facing the defense analyst today have grown to include the need to consider operations among non-combatant populations, to focus on impacts to civilian infrastructure, to differentiate combatants from non-combatants, and to understand non-linear, asymmetric warfare. These requirements stretch both current computational techniques and data analysis methodologies. In this paper, documented examples and potential solutions will be advanced. The authors discuss the paths to successful implementation based on their experience. Reviewed technologies include parallel computing, cluster computing, grid computing, data logging, OpsResearch, database advances, data mining, evolutionary computing, genetic algorithms, and Monte Carlo sensitivity analyses. The modeling and simulation community has significant potential to provide more opportunities for training and analysis. Simulations must include increasingly sophisticated environments, better emulations of foes, and more realistic civilian populations. Overcoming the implementation challenges will produce dramatically better insights, for trainees and analysts. High Performance Parallel Computing and Advanced Data Analysis promise increased understanding of future vulnerabilities to help avoid unneeded mission failures and unacceptable personnel losses. The authors set forth road maps for rapid prototyping and adoption of advanced capabilities. They discuss the beneficial impact of embracing these technologies, as well as risk mitigation required to ensure success

    The Literacy of America's College Students

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    Measures the literacy of 1,827 graduating college and university students from eighty institutions. Looks at the ability to perform prose tasks such as read and use texts; search and comprehend forms; and conduct quantitative, computational tasks

    Fine-tuning favors mixed axion/axino cold dark matter over neutralinos in the minimal supergravity model

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    Over almost all of minimal supergravity (mSUGRA or CMSSM) model parameter space, there is a large overabundance of neutralino cold dark matter (CDM). We find that the allowed regions of mSUGRA parameter space which match the measured abundance of CDM in the universe are highly fine-tuned. If instead we invoke the Peccei-Quinn-Weinberg-Wilczek solution to the strong CP problem, then the SUSY CDM may consist of an axion/axino admixture with an axino mass of order the MeV scale, and where mixed axion/axino or mainly axion CDM seems preferred. In this case, fine-tuning of the relic density is typically much lower, showing that axion/axino CDM (a\tilde{a}CDM) is to be preferred in the paradigm model for SUSY phenomenology. For mSUGRA with a\tilde{a}CDM, quite different regions of parameter space are now DM-favored as compared to the case of neutralino DM. Thus, rather different SUSY signatures are expected at the LHC in the case of mSUGRA with a\tilde{a}CDM, as compared to mSUGRA with neutralino CDM.Comment: 23 pages with 17 .eps figure

    Payments system issues in financial markets that never sleep

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    Payment systems ; Foreign exchange ; Risk ; Stock market

    SUPERSYMMETRY REACH OF AN UPGRADED TEVATRON COLLIDER

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    We examine the capability of a s=2\sqrt{s}=2 TeV Tevatron ppˉp\bar p collider to discover supersymmetry, given a luminosity upgrade to amass 25 fb125\ fb^{-1} of data. We compare with the corresponding reach of the Tevatron Main Injector (1 fb11\ fb^{-1} of data). Working within the framework of minimal supergravity with gauge coupling unification and radiative electroweak symmetry breaking, we first calculate the regions of parameter space accessible via the clean trilepton signal from \tw_1\tz_2\to 3\ell +\eslt production, with detailed event generation of both signal and major physics backgrounds. The trilepton signal can allow equivalent gluino masses of up to mtg600700m_{\tg}\sim 600-700 GeV to be probed if m0m_0 is small. If m0m_0 is large, then mtg500m_{\tg}\sim 500 GeV can be probed for μ0\mu 0 and large values of m0m_0, the rate for \tz_2\to\tz_1\ell\bar{\ell} is suppressed by interference effects, and there is {\it no} reach in this channel. We also examine regions where the signal from \tw_1\overline{\tw_1}\to \ell\bar{\ell}+\eslt is detectable. Although this signal is background limited, it is observable in some regions where the clean trilepton signal is too small. Finally, the signal \tw_1\tz_2\to jets+\ell\bar{\ell} +\eslt can confirm the clean trilepton signal in a substantial subset of the parameter space where the trilepton signal can be seen. We note that although the clean trilepton signal may allow Tevatron experiments to identify signals in regions of parameter space beyond the reach of LEP II, the dilepton channels generally probe much the same region as LEP II.Comment: 19 page REVTEX file; a uuencoded PS file with PS figures is available via anonymous ftp at ftp://hep.fsu.edu/preprints/baer/FSUHEP950301.u

    The Reach of the Fermilab Tevatron and CERN LHC for Gaugino Mediated SUSY Breaking Models

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    In supersymmetric models with gaugino mediated SUSY breaking (inoMSB), it is assumed that SUSY breaking on a hidden brane is communicated to the visible brane via gauge superfields which propagate in the bulk. This leads to GUT models where the common gaugino mass m1/2m_{1/2} is the only soft SUSY breaking term to receive contributions at tree level. To obtain a viable phenomenology, it is assumed that the gaugino mass is induced at some scale McM_c beyond the GUT scale, and that additional renormalization group running takes place between McM_c and MGUTM_{GUT} as in a SUSY GUT. We assume an SU(5) SUSY GUT above the GUT scale, and compute the SUSY particle spectrum expected in models with inoMSB. We use the Monte Carlo program ISAJET to simulate signals within the inoMSB model, and compute the SUSY reach including cuts and triggers approriate to Fermilab Tevatron and CERN LHC experiments. We find no reach for SUSY by the Tevatron collider in the trilepton channel. %either with or without %identified tau leptons. At the CERN LHC, values of m1/2=1000m_{1/2}=1000 (1160) GeV can be probed with 10 (100) fb1^{-1} of integrated luminosity, corresponding to a reach in terms of mtgm_{\tg} of 2150 (2500) GeV. The inoMSB model and mSUGRA can likely only be differentiated at a linear e+ee^+e^- collider with sufficient energy to produce sleptons and charginos.Comment: 17 page revtex file with 9 PS figure
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