5,546 research outputs found

    Interface control scheme for computer high-speed interface unit

    Get PDF
    Control scheme is general and performs for multiplexed and dedicated channels as well as for data-bus interfaces. Control comprises two 64-pin, dual in-line packages, each of which holds custom large-scale integrated array built with silicon-on-sapphire complementary metal-oxide semiconductor technology

    Partnership assessment for the proposed Montana Yellowstone Information Center

    Get PDF

    Correlation of electrical conductivity and radiation-induced free radical concentration in poly/ethylene terephthalate/ and related compounds

    Get PDF
    Gamma and ultraviolet radiation effects on electronic properties of polyethylene terephthalate and related compound

    Effect of tip planform on blade loading characteristics for a two-bladed rotor in hover

    Get PDF
    A laser velocimeter was used to study the flow surrounding a 2.13 m diam. two-bladed, teetering model-scale helicopter rotor operating in the hover condition. The rotor system employed interchangeable blade tips over the outer 25% radius. A conventional rectangular planform and an experimental ogee tip shape were studied. The radial distribution of the blade circulation was obtained by measuring the velocity tangent to a closed rectangular contour around the airfoil section at a number of radial locations. A relationship between local circulation and bound vorticity was invoked to obtain the radial variations in the sectional lifting properties of the blade. The tip vortex-induced velocity was also measured immediately behind the generating blade and immediately before the encounter with the following blade. The mutual influence between blade loading, shed vorticity, and the structure of the encountered vortex are quantified by the results presented and are discussed comparatively for the rectangular and ogee planforms. The experimental loading for the rectangular tip is also compared with predictions of existing rotor analysis

    Piney Ridge

    Get PDF
    https://digitalcommons.library.umaine.edu/mmb-vp/2382/thumbnail.jp

    REIMR: A Process for Utilizing Propulsion-Oriented 'Lessons-Learned' to Mitigate Development Risk

    Get PDF
    This paper is a summary overview of a study conducted a t the NASA Marshall Space Flight Center (MSFC) during the initial phases of the Space Launch Initiative (SLI) program to evaluate a large number of technical problems associated with the design, development, test, evaluation and operation of several major liquid propellant rocket engine systems (i.e., SSME, Fastrac, J-2, F-1). The results of this study was the identification of the "Fundamental Root Causes" that enabled the technical problems to manifest, and practices that can be implemented to prevent them from recurring in future engine development efforts. This paper will discus the Fundamental Root Causes, cite some examples of how the technical problems arose from them, and provide a discussion of how they can be mitigated or avoided

    Reality Check: Instructing Patrons in CD-ROM Use

    Get PDF
    This is a two-part presentation given by reference librarians Rochelle Ballard and Meg Scharf. Meg first described UCF’s new CD-ROM services. Patron expectations were very high. Although a great deal of assistance was sometimes needed, patrons wanted to be able to search autonomously, which meant they needed instruction. Instruction was delivered to individual patrons at the time of need; through demonstrations held in the area that housed the CD Rooms; in workshops; and in the regular instruction classes delivered by librarians to students at the request of teaching faculty members. Rochelle, who was instrumental in establishing UCF’s end-user services with CD-ROMs, and later with online databases and the Internet, then gave the most important part of the presentation: how UCF librarians learned about searching the 13 CD-ROM databases, and the writing and use of “How to Search” handouts. New CD-ROMs were held back from the Reference floor, so librarians could learn to use them before they fielded questions from students, faculty, and community patrons. She describes workshops held for users in the Bibliographic Instruction classroom. Rochelle, UCF’s expert on the CD-ROMs at the time, describes getting “the shakes at the thought of a new CD-ROM with a different search system.” Some librarians in the audience came from libraries with no CD-ROMs available, and others were at the beginning of offering them to patrons. So while this presentation seems very elementary, at that time it was regarded as a bit “cutting edge”

    Appearance-based localization for mobile robots using digital zoom and visual compass

    Get PDF
    This paper describes a localization system for mobile robots moving in dynamic indoor environments, which uses probabilistic integration of visual appearance and odometry information. The approach is based on a novel image matching algorithm for appearance-based place recognition that integrates digital zooming, to extend the area of application, and a visual compass. Ambiguous information used for recognizing places is resolved with multiple hypothesis tracking and a selection procedure inspired by Markov localization. This enables the system to deal with perceptual aliasing or absence of reliable sensor data. It has been implemented on a robot operating in an office scenario and the robustness of the approach demonstrated experimentally

    Surfactant status and respiratory outcome in premature infants receiving late surfactant treatment.

    Get PDF
    BACKGROUND:Many premature infants with respiratory failure are deficient in surfactant, but the relationship to occurrence of bronchopulmonary dysplasia (BPD) is uncertain. METHODS:Tracheal aspirates were collected from 209 treated and control infants enrolled at 7-14 days in the Trial of Late Surfactant. The content of phospholipid, surfactant protein B, and total protein were determined in large aggregate (active) surfactant. RESULTS:At 24 h, surfactant treatment transiently increased surfactant protein B content (70%, p < 0.01), but did not affect recovered airway surfactant or total protein/phospholipid. The level of recovered surfactant during dosing was directly associated with content of surfactant protein B (r = 0.50, p < 0.00001) and inversely related to total protein (r = 0.39, p < 0.0001). For all infants, occurrence of BPD was associated with lower levels of recovered large aggregate surfactant, higher protein content, and lower SP-B levels. Tracheal aspirates with lower amounts of recovered surfactant had an increased proportion of small vesicle (inactive) surfactant. CONCLUSIONS:We conclude that many intubated premature infants are deficient in active surfactant, in part due to increased intra-alveolar metabolism, low SP-B content, and protein inhibition, and that the severity of this deficit is predictive of BPD. Late surfactant treatment at the frequency used did not provide a sustained increase in airway surfactant
    • …
    corecore