3,203 research outputs found

    Uncertainty Quantification Visualization Tool to Simulate Porous Lithium-Ion Batteries

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    To maintain people’s fast-paced lifestyles, a more powerful and reliable rechargeable battery is critical. During the manufacturing process, electrode parameters such as cathode thickness, the porosity of the positive electrode and radius of negative active materials are subject to uncertainty. Such uncertainty may have a dramatic impact on the performance of the battery. To optimize its performance, it is critical to quantify uncertainty due to variation in electrode parameters and measure the response of the system through multiscale computer simulation. To achieve this goal, a porous lithium-ion battery uncertainty quantification and visualization tool has been created. This tool consists of three components: 1) a generator of uncertainty input; 2) an electrochemical system simulator; 3) a statistical analysis and visualization module. This project focuses on the first and the third components. First, the uncertainty input generator provides the option of selecting one of two statistical models for the input parameter distributions: Gaussian and lognormal. For Gaussian and lognormal distributions, sample points and weights are generated based on Gauss-Hermite quadrature formula. Each module provides a GUI, built using an open source, class-oriented environment, the Virtual Kinetics of Materials Lab [1]. Ensemble simulations are performed using the electrochemical system simulator that in turn uses the data distributions obtained from the uncertainty input generator. In the statistics analysis and visualization component, the simulation results are quantified graphically through error bar plots that visualize the impact of the uncertainties that were introduced into the system. The variation of power and energy densities as a function of current density of the battery electrode is presented, enabling the user to visualize the uncertainty propagation from the three electrode uncertainty inputs and its impact on the battery performance. [1] Alex Bartol; R. Edwin García; David R. Ely; Jon Guyer (2015), The Virtual Kinetics of Materials Laboratory, https://nanohub.org/resources/vkmllive. (DOI: 10.4231/D3B853J85)

    Whatcom transportation authority: WWU shuttle bus analysis

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    The purpose of this environmental impact assessment is to evaluate the current conditions of WTA bus routes that service the Western Washington University campus. This assessment also weighs the impacts of alternatives to determine possible ways to address issues with the current conditions, and analyzes the affected environments concerning the existing conditions and alternatives, which include, but are not limited to air, water runoff, energy and natural resources, transportation, public services and utilities, and environmental health. The objectives of this project are to: • Relieve congestion of WWU routes during peak hours, • Reduce environmental impacts by finding greener alternatives to the added shuttle buses, • Balance added economic costs between WTA and WWU, and • Promote walking and biking as alternative forms of transportation

    KSU Holiday Concert 2017

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    Kick off your holiday season with the School of Music as we celebrate the season and present holiday favorites performed by the KSU Symphony Orchestra, Wind Ensemble, and choirs. This performance will feature carols sung by KSU choirs, a special Christmas at the Movies medley performed by the KSU Symphony Orchestra including music from Home Alone, How the Grinch Stole Christmas, Polar Express, and more.https://digitalcommons.kennesaw.edu/musicprograms/1992/thumbnail.jp

    The complex gas kinematics in the nucleus of the Seyfert 2 galaxy NGC 1386: rotation, outflows and inflows

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    We present optical integral field spectroscopy of the circum-nuclear gas of the Seyfert 2 galaxy NGC 1386. The data cover the central 7×9^{\prime\prime} \times 9^{\prime\prime} (530 ×\times 680 pc) at a spatial resolution of 0.9" (68 pc), and the spectral range 5700-7000 \AA\ at a resolution of 66 km s1^{-1}. The line emission is dominated by a bright central component, with two lobes extending \approx 3^{\prime\prime} north and south of the nucleus. We identify three main kinematic components. The first has low velocity dispersion (σˉ\bar \sigma \approx 90 km s1^{-1}), extends over the whole field-of-view, and has a velocity field consistent with gas rotating in the galaxy disk. We interpret the lobes as resulting from photoionization of disk gas in regions where the AGN radiation cones intercept the disk. The second has higher velocity dispersion (σˉ\bar \sigma \approx 200 km s1^{-1}) and is observed in the inner 150 pc around the continuum peak. This component is double peaked, with redshifted and blueshifted components separated by \approx 500 km s1^{-1}. Together with previous HST imaging, these features suggest the presence of a bipolar outflow for which we estimate a mass outflow rate of M˙\mathrm{\dot M} \gtrsim 0.1 M_{\odot} yr1^{-1}. The third component is revealed by velocity residuals associated with enhanced velocity dispersion and suggests that outflow and/or rotation is occurring approximately in the equatorial plane of the torus. A second system of velocity residuals may indicate the presence of streaming motions along dusty spirals in the disk.Comment: 24 pages, 16 figures, 3 tables, interesting results, accepted for publication in Ap

    Ultraluminous infrared galaxies: mergers of sub-L* galaxies?

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    A sample of 27 low-redshift, mostly cool, ultraluminous infrared galaxies (ULIRGs) has been imaged at 1.6 μm with the Hubble Space Telescope (HST) Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). The majority (67%) of the sample's galaxies are multiple-nucleus galaxies with projected separations of up to 17 kpc, and the rest of the sample (33%) are single-nucleus galaxies, as determined by the NICMOS angular resolution limit. The average observed, integrated (host+nucleus) H magnitude of our HST H sample ULIRGs is -24.3, slightly above that of an L* galaxy (MH = -24.2), and 52% of the sample's galaxies have sub-L* luminosities. The ULIRGs in the HST H sample are not generated as a result of the merging of two luminous (i.e., ≥L*) spiral galaxies. Instead, the interactions and mergers occur in general between two, or in some cases more, less massive sub-L* (0.3-0.5L*) galaxies. Only one out of the 49 nuclei identified in the entire HST H sample has the properties of a bright quasar-like nucleus. On average, the brightest nuclei in the HST H sample galaxies (i.e., cool ULIRGs) are 1.2 mag fainter than warm ULIRGs and low-luminosity Bright Quasar Survey quasars (BQS QSOs) and 2.6 mag fainter than high-luminosity BQS QSOs. Since the progenitor galaxies involved in the merger are sub-L* galaxies, the mass of the central black hole in these ULIRGs would be only about (1-2) × 107 M☉, if the bulge-to-black hole mass ratio of nearby galaxies holds for ULIRGs. The estimated mass of the central black hole is similar to that of nearby Seyfert 2 galaxies but at least 1 order of magnitude lower than the massive black holes thought to be located at the center of high-luminosity QSOs. Massive nuclear starbursts with constant star formation rates of 10-40 M☉ yr-1 could contribute significantly to the nuclear H-band flux and are consistent with the observed nuclear H-band magnitudes of the ULIRGs in the HST H sample. An evolutionary merging scenario is proposed for the generation of the different types of ULIRGs and QSOs on the basis of the masses of the progenitors involved in the merging process. According to this scenario, cool ULIRGs would be the end product of the merging of two or more low-mass (0.3L*-0.5L*) disk galaxies. Warm ULIRGs and low-luminosity QSOs would be generated by a merger involving intermediate-mass (0.5 L*) disk galaxies. Under this scenario, warm ULIRGs could still be the dust-enshrouded phases of UV-bright low-luminosity QSOs, but cool ULIRGs, which are most ULIRGs, would not evolve into QSOs
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