15,310 research outputs found

    Electrochemical capacitors for energy management

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    Rapid storage and efficient delivery of electrical energy in heavy-duty applications are being enabled by electrochemical capacitors

    Vertically-Oriented Graphene Electric Double Layer Capacitor Designs

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    High-voltage electric double layer capacitors (EDLCs) capable of efficient AC line-filtering have been developed. They were fabricated with vertically-oriented graphene nanosheet (VOGN) electrodes using a planar design. Two approaches were examined to series connect EDLC cells and thus achieve high-voltage operation. Electrical performance of VOGN electric double layer capacitors fabricated with an ionic liquid electrolyte was measured at temperatures up to 125 degrees C. Volume comparisons are made between VOGN electric double layer capacitors and aluminum electrolytic capacitors. A practical design is presented that provides the VOGN electric double layer capacitor with more than an order-of-magnitude higher ripple-current filtering performance (120-Hz) than available from present capacitor technology. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.orellicenses/by-nc-ndA.0/), which permits non-commercial reuse, distribution, and reproduction in an); medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: [email protected]. All rights reserved

    SONTRAC—a scintillating plastic fiber tracking detector for neutron and proton imaging spectroscopy

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    SONTRAC (SOlar Neutron TRACking imager and spectrometer) is a conceptual instrument intended to measure the energy and incident direction of 20–150 MeV neutrons produced in solar flares. The intense neutron background in a low-Earth orbit requires that imaging techniques be employed to maximize an instrument’s signal-to-noise ratio. The instrument is comprised of mutually perpendicular, alternating layers of parallel, scintillating, plastic fibers that are viewed by optoelectronic devices. Two stereoscopic views of recoil proton tracks are necessary to determine the incident neutron’s direction and energy. The instrument can also be used as a powerful energetic proton imager. Data from a fully functional 3-d prototype are presented. Early results indicate that the instrument’s neutron energy resolution is approximately 10% with the neutron incident direction determined to within a few degrees

    Sewing the Seeds of Passion: A Study on Effectively Communicating Vision in a Volunteer Based Non Profit Organization

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    This thesis will focus on the study of modem nonprofit organization and the crucial role which leader hip and vision play in fueling these organizations. Recent literature. written both specifically about nonprofit and about corporate culture in the general business world. suggests that there is a direct correlation between the strength of leadership al the executive and board levels, and the degree to which volunteers and paid staff will buy-in to the philosophy and work of the nonprofit . And because of the nature of the nonprofit business, that is, that it exists for the public good as opposed to the good of the tock holder. the concept of employee and volunteers embracing the vision of the organization and carrying it with them passionately in the delivery of the service to the community, is even more compelling than in the private sector. The purpose of this study is to postulate that there is a pattern of success which can be established in the nonprofit organization which will lead to a positive embrace of the corporate vision among staff. both paid and volunteer. and ultimately result in a fruitful delivery of the service which the nonprofit seeks to provide. Experts in the study of nonprofits believe this pattern begins with the Executive Director, who in a very real sense. assumes the central position of authority. responsibility and accountability within the organization. But the ED must work in conjunction with a board of directors which seeks to stay informed. involved and committed to the success of the organization. Together the ED and the board must then seek organization wide consensus on a strategic plan which encompasses every part of the nonprofit. both in the implementation of the service itself. and in the support system which drives that implementation. But this paper theorizes that the pattern for success does nor end there. It is also suggested in present corporate culture literature that strong leadership will do more than merely provide the framework or success in the traditional sphere of management tasks such as controlling. delegating, planning. and organizing. Recent studies confirm that it is vital that leadership nourish the human side of business, as well. And again. this seems to be almost doubly important in the world of nonprofits. This writing establishes four crucial leadership elements as essential for a passionate embrace of the nonprofit vision. They are strength. transparency. ethical behavior, and a personal connection of employee or volunteer to the lifeblood of the organization. These points are packaged together as the STEP plan. The purpose of this paper. then, is to establish these vital element. of strong organizational leadership as the building blocks of a successful nonprofit agency. which can dynamically meet the purpose for which it was formed

    Internal fluid mechanics research on supercomputers for aerospace propulsion systems

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    The Internal Fluid Mechanics Division of the NASA Lewis Research Center is combining the key elements of computational fluid dynamics, aerothermodynamic experiments, and advanced computational technology to bring internal computational fluid mechanics (ICFM) to a state of practical application for aerospace propulsion systems. The strategies used to achieve this goal are to: (1) pursue an understanding of flow physics, surface heat transfer, and combustion via analysis and fundamental experiments, (2) incorporate improved understanding of these phenomena into verified 3-D CFD codes, and (3) utilize state-of-the-art computational technology to enhance experimental and CFD research. Presented is an overview of the ICFM program in high-speed propulsion, including work in inlets, turbomachinery, and chemical reacting flows. Ongoing efforts to integrate new computer technologies, such as parallel computing and artificial intelligence, into high-speed aeropropulsion research are described

    De-novo design of complementary (antisense) peptide mini-receptor inhibitor of interleukin 18 (IL-18).

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    Complementary (antisense) peptide mini-receptor inhibitors are complementary peptides designed to be receptor-surrogates that act by binding to selected surface features of biologically important proteins thereby inhibiting protein-cognate receptor interactions and subsequent biological effects. Previously, we described a complementary peptide mini-receptor inhibitor of interleukin-1beta (IL-1beta) that was designed to bind to an external surface loop (beta-bulge) of IL-1beta (Boraschi loop) clearly identified in the X-ray crystal structure of this cytokine. Here, we report the de-novo design and rational development of a complementary peptide mini-receptor inhibitor of cytokine interleukin-18 (IL-18), a protein for which there is no known X-ray crystal structure. Using sequence homology comparisons with IL-1beta, putative IL-18 surface loops are identified and used as a starting point for design, including a loop region 1 thought to be equivalent with the Boraschi loop of IL-1beta. Only loop region 1 complementary peptides are found to be promising leads as mini-receptor inhibitors of IL-18 but these are prevented from being properly successful owing to solubility problems. The application of "M-I pair mutagenesis" and inclusion of a C-terminal arginine residue are then sufficient to solve this problem and convert one lead peptide into a functional complementary peptide mini-receptor inhibitor of IL-18. This suggests that the biophysical and biological properties of complementary peptides can be improved in a rational and logical manner where appropriate, further strengthening the potential importance of complementary peptides as inhibitors of protein-protein interactions, even when X-ray crystal structural information is not readily available

    SONTRAC: an imaging spectrometer for solar neutrons

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    An instrument capable of unambiguously determining the energy and direction of incident neutrons has important applications in solar physics-as well as environmental monitoring and medical/radiological sciences. The SONTRAC (SOlar Neutron TRACking) instrument is designed to operate in the neutron energy range of 20-250 MeV. The measurement principle is based on non-relativistic double scatter of neutrons off ambient protons (n-p scattering) within a block of densely packed scintillating fibers. Using this double-scatter mode it is possible to uniquely determine neutron energy and direction on an event-by-event basis. A fully operational science model of such an instrument has been built using 300 μm (250 μm active) scintillating fibers. The science model consists of a 5×5×5 cm cube of orthogonal plastic scintillating fiber layers. Two orthogonal imaging chains, employing image intensifiers and CCD cameras, allow full 3-dimensional reconstruction of scattered proton particle tracks. We report the results of the science model instrument calibration using 35-65 MeV protons. The proton calibration is the first step toward understanding the instrument response to n-p scatter events. Preliminary results give proton energy resolution of 2% (6%) at 67.5 (35) MeV, and angular resolution of 2° (4.5°) at 67.5 (35) MeV. These measurements are being used to validate detailed instrument simulations that will be used to optimize the instrument design and develop quantitative estimates of science return. Based on the proton calibration, neutron energy and angular resolution for a 10×10×10 cm version of SONTRAC is expected to be ~5% an

    Tricarbonylchlorido(6'7'-dihydro-5’H-spiro[cyclopentane-1,6'-dipyrido-[3,2-d:2',3'-f][1,3]diazepine]-κ2N1,N11)-rhenium(I)

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    In the title compound, [ReCl(C15H16N4)(CO)3], the ReI ion is coordinated in a distorted octahedral geometry by one Cl atom, two N atoms of the bidentate ligand and three carbonyl groups. The cyclopentane group is orientated in a transoid fashion with respect to the chloride ligand. The dihedral angle between the pryridine rings is 10.91 (12)°. In the crystal, N-H...Cl hydrogen bonds link complex molecules, forming a two-dimensional network parallel to (001)

    General Relativistic Simulations of Magnetized Plasmas around Merging Supermassive Black Holes

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    Coalescing supermassive black hole binaries are produced by the mergers of galaxies and are the most powerful sources of gravitational waves accessible to space-based gravitational observatories. Some such mergers may occur in the presence of matter and magnetic fields and hence generate an electromagnetic counterpart. In this Letter, we present the first general relativistic simulations of magnetized plasma around merging supermassive black holes using the general relativistic magnetohydrodynamic code Whisky. By considering different magnetic field strengths, going from non-magnetically dominated to magnetically dominated regimes, we explore how magnetic fields affect the dynamics of the plasma and the possible emission of electromagnetic signals. In particular we observe a total amplification of the magnetic field of ~2 orders of magnitude which is driven by the accretion onto the binary and that leads to much stronger electromagnetic signals, more than a factor of 10^4 larger than comparable calculations done in the force-free regime where such amplifications are not possible.Comment: 7 pages, 5 figures. Minor changes to match version accepted for publication on The Astrophysical Journal Letter

    J. H. Miller, Jr. to H. R. Miller (27 July 1862)

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    Describes his feeling during recent retreat, preparing for an upcoming march rumored as heading either Chattanooga or Savannah, destruction in his father\u27s town and knowledge they will pass through Mobile.https://egrove.olemiss.edu/ciwar_corresp/1577/thumbnail.jp
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