22,138 research outputs found

    High voltage solid-state relay

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    Hybrid microelectronics relay has characteristics significantly superior to conventional solid state relays. Relay provides 2500 Vdc input to output isolation and operates from high threshold logic signal to switch load of 400 Vdc at 2 mA. Technology should be of interest to manufacturers of discrete components

    Public Impacts of Rural Water Systems: A Case Study

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    A case study of the Brookings-Deuel Rural Water System was undertaken to estimate the effects of the system on the revenues and expenditures of the local governments which serve its members

    Households and Rural Water Systems

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    This bulletin reports household impacts of rural water system development based on a case study of the Brookings-Deuel Rural Water System. This study was conducted as part of Project B-056-S.Dak. funded by the United States Department of the Interior, Office of Water Research and Technology. This bulletin is written audiences. One audience is made of rural water system planners, public officials, and policy-makers who have worked with rural water systems. These readers will understand the results and findings, although the description of specific statistical procedures may not be exactly clear to them. The other audience consists of community rural development specialists and other researchers doing work in rural water systems

    Deep spectroscopic luminosity function of Abell 85: no evidence for a steep upturn of the faint-end slope

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    We present a new deep determination of the spectroscopic LF within the virial radius of the nearby and massive Abell\,85 (A85) cluster down to the dwarf regime (M* + 6) using VLT/VIMOS spectra for ∼2000\sim 2000 galaxies with mr≤21_r \leq 21 mag and ⟨μe,r⟩≤24\langle \mu_{e,r} \rangle \leq 24 mag arcsec−2^{-2}. The resulting LF from 438 cluster members is best modelled by a double Schechter function due to the presence of a statistically significant upturn at the faint-end. The amplitude of this upturn (αf=−1.58−0.15+0.19\alpha_{f} = -1.58^{+0.19}_{-0.15}), however, is much smaller than that of the SDSS composite photometric cluster LF by Popesso et al. 2006, αf∼\alpha_{f} \sim -2. The faint-end slope of the LF in A85 is consistent, within the uncertainties, with that of the field. The red galaxy population dominates the LF at low luminosities, and is the main responsible for the upturn. The fact that the slopes of the spectroscopic LFs in the field and in a cluster as massive as A85 are similar suggests that the cluster environment does not play a major role in determining the abundance of low-mass galaxies.Comment: 6 pages, 4 figures, accepted at MNRAS lette

    The granular silo as a continuum plastic flow: the hour-glass vs the clepsydra

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    The granular silo is one of the many interesting illustrations of the thixotropic property of granular matter: a rapid flow develops at the outlet, propagating upwards through a dense shear flow while material at the bottom corners of the container remains static. For large enough outlets, the discharge flow is continuous; however, by contrast with the clepsydra for which the flow velocity depends on the height of fluid left in the container, the discharge rate of granular silos is constant. Implementing a plastic rheology in a 2D Navier-Stokes solver (following the mu(I)-rheology or a constant friction), we simulate the continuum counterpart of the granular silo. Doing so, we obtain a constant flow rate during the discharge and recover the Beverloo scaling independently of the initial filling height of the silo. We show that lowering the value of the coefficient of friction leads to a transition toward a different behavior, similar to that of a viscous fluid, and where the filling height becomes active in the discharge process. The pressure field shows that large enough values of the coefficient of friction (≃\simeq 0.3) allow for a low-pressure cavity to form above the outlet, and can thus explain the Beverloo scaling. In conclusion, the difference between the discharge of a hourglass and a clepsydra seems to reside in the existence or not of a plastic yield stress.Comment: 6 pages, 6 figure

    Prerequisites for Affective Signal Processing (ASP)

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    Although emotions are embraced by science, their recognition has not reached a satisfying level. Through a concise overview of affect, its signals, features, and classification methods, we provide understanding for the problems encountered. Next, we identify the prerequisites for successful Affective Signal Processing: validation (e.g., mapping of constructs on signals), triangulation, a physiology-driven approach, and contributions of the signal processing community. Using these directives, a critical analysis of a real-world case is provided. This illustrates that the prerequisites can become a valuable guide for Affective Signal Processing (ASP)

    Disordered Electrons in a Strong Magnetic Field: Transfer Matrix Approaches to the Statistics of the Local Density of States

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    We present two novel approaches to establish the local density of states as an order parameter field for the Anderson transition problem. We first demonstrate for 2D quantum Hall systems the validity of conformal scaling relations which are characteristic of order parameter fields. Second we show the equivalence between the critical statistics of eigenvectors of the Hamiltonian and of the transfer matrix, respectively. Based on this equivalence we obtain the order parameter exponent α0≈3.4\alpha_0\approx 3.4 for 3D quantum Hall systems.Comment: 4 pages, 3 Postscript figures, corrected scale in Fig.

    Monolithic microwave integrated circuit water vapor radiometer

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    A proof of concept Monolithic Microwave Integrated Circuit (MMIC) Water Vapor Radiometer (WVR) is under development at the Jet Propulsion Laboratory (JPL). WVR's are used to remotely sense water vapor and cloud liquid water in the atmosphere and are valuable for meteorological applications as well as for determination of signal path delays due to water vapor in the atmosphere. The high cost and large size of existing WVR instruments motivate the development of miniature MMIC WVR's, which have great potential for low cost mass production. The miniaturization of WVR components allows large scale deployment of WVR's for Earth environment and meteorological applications. Small WVR's can also result in improved thermal stability, resulting in improved calibration stability. Described here is the design and fabrication of a 31.4 GHz MMIC radiometer as one channel of a thermally stable WVR as a means of assessing MMIC technology feasibility

    The relation between bar formation, galaxy luminosity, and environment

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    We derive the bar fraction in three different environments ranging from the field to Virgo and Coma clusters, covering an unprecedentedly large range of galaxy luminosities (or, equivalently, stellar masses). We confirm that the fraction of barred galaxies strongly depends on galaxy luminosity. We also show that the difference between the bar fraction distributions as a function of galaxy luminosity (and mass) in the field and Coma cluster are statistically significant, with Virgo being an intermediate case. We interpret this result as a variation of the effect of environment on bar formation depending on galaxy luminosity. We speculate that brighter disk galaxies are stable enough against interactions to keep their cold structure, thus, the interactions are able to trigger bar formation. For fainter galaxies the interactions become strong enough to heat up the disks inhibiting bar formation and even destroying the disks. Finally, we point out that the controversy regarding whether the bar fraction depends on environment could be resolved by taking into account the different luminosity ranges of the galaxy samples studied so far.Comment: 4 pages, 2 figures. To appear in the proceedings of EWASS 2012 Special Session 4, Structure of galaxy disks shaped by secular evolution and environmental processes, ed. P. Di Matteo and C. Jog, Memorie della Societ\`a Astronomica Italiana Supplement Serie
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