57,020 research outputs found

    Creating an Institutional Repository

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    Creating an institutional repository (IR) requires much forethought and planning. Setting up a university IR committee will help direct policy and collection goals, and will encourage faculty participation. There are many things to consider in design such as branding, policy, copyright, collection development, author submissions and discoverability. Publishing in an IR requires original works, and copyright issues arise, especially if authors wish to publish in other journals. Our IR goal was to promote scholarship and encourage faculty to create publishing profile space in SelectedWorks, which can become a virtual curricula vita. The ultimate goal is discoverability and open access contribution to scholarship in the field. This article is a personal recounting of our experience in setting up FireScholars, our institutional repository at Southeastern University

    Abating exhaust noises in jet engines

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    A noise abating improvement for jet engines including turbojets, turbofans, turboprops, ramjets, scramjets, and hybrid jets is introduced. A provision is made for an apparatus in the primary and/or secondary flow streams of the engines; the apparatus imparts to the exhaust gases a component rotation or swirl about the engine's longitudinal axis. The rotary component in the exhaust gases causes a substantial suppression of sound energy build up normally produced by an axial flow exhaust system

    Minimization of jet and core noise by rotation of flow

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    Jet and core noise can be reduced and flame lengths may be significantly decreased when exhaust gases are caused to rotate or swirl about longitudinal axis of exhaust. Combustion in rotating flows is steady and quiet, and is not accompanied by pulsations or violent fluctuations

    The radio telescope RATAN 600

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    A six-meter radio antenna having 900 reflector elements arranged on a 579 -meter diameter circle and located in the northern part of the Caucasian Mountains is described. The elements are about 7.4 m by 2 m resulting in a total reflector surface of about 10,000 sq m. Individual elements can be adjusted by changing 260 screws and can be rotated both horizontally and vertically as well as being moved translationally in the radial direction. The circular area is equipped with a grid of tracks where four asymmetric cylindrical paraboloids serving as subreflectors are located. The directional profile or observational direction of the antenna is achieved by shifting the subreflectors and changing the position of the reflecting elements with respect to the subreflectors. Different radio sources can be observed at the same time by using different subreflectors and their associated reflector sectors. Each subreflector is connected to a receiving station. Capabilities for spectroscopic observation are discussed

    Low-excitation Herbig-Haro objects and interstellar extinction

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    Previous work on low-excitation Herbig-Haro (HH) objects has confirmed the existence of a strongly-enhanced hydrogen two-photon continuum which is produced by low-velocity shocks in neutral material. The theoretical two-photon energy distribution was compared with that observed for HH 43. With the addition of optical (3300 lambda 7000A) data to the ultraviolet (1200 lambda 3100A) data obtained with the I.U.E, the wavelength dependence of interstellar extinction toward HH 43 has been determined

    Ultraviolet observations of low-excitation Herbig-Haro objects

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    The Herbig-Haro (HH) objects rank among the faintest objects (v approx. 17) observed with the I.U.E. Expectations that the low-excitation shock-excited HHs should be dominated by H two-photon (2q) UV emission were borne out in the first observation of HH 43 and 47 obtained in 1982. The UV continuous energy distributions in the SWP spectra of these objects were found to peak near 1500 Angstroms as predicted by the 2q hypothesis. In addition, emission lines in the Lyman band of H sub 2, excited by Lyman alpha fluorescence, were detected in HH 43. It is not clear if the molecular gas is coextensive with the atomic gas responsible for the optical emission, or if the molecular gas is immediately adjacent to the region of optical emission. The two-photon energy distribution and H sub 2 fluorescent emission were previously discussed

    A study of digital techniques for signal processing

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    Analysis and definition of digital techniques for signal processin

    A study of digital techniques for signal processing Semiannual status report, 1 Feb. - 30 Jun. 1968

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    Recursive techniques for digital signal processing, data smoothing and compression, and computer simulation of low error rate communicatio

    A study of digital techniques for signal processing Final status report, 1 Jul. 1968 - 31 Jan. 1969

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    Digital signal processing, data smoothing, and computer simulatio
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