656 research outputs found

    Texture Modification of the Shuttle Landing Facility Runway at Kennedy Space Center

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    This paper describes the test procedures and the criteria used in selecting an effective runway-surface-texture modification at the Kennedy Space Center (KSC) Shuttle Landing Facility (SLF) to reduce Orbiter tire wear. The new runway surface may ultimately result in an increase of allowable crosswinds for launch and landing operations. The modification allows launch and landing operations in 20-knot crosswinds, if desired. This 5-knot increase over the previous 15-knot limit drastically increases landing safety and the ability to make on-time launches to support missions in which Space Station rendezvous are planned. The paper presents the results of an initial (1988) texture modification to reduce tire spin-up wear and then describes a series of tests that use an instrumented ground-test vehicle to compare tire friction and wear characteristics, at small scale, of proposed texture modifications placed into the SLF runway surface itself. Based on these tests, three candidate surfaces were chosen to be tested at full-scale by using a highly modified and instrumented transport aircraft capable of duplicating full Orbiter landing profiles. The full-scale Orbiter tire testing revealed that tire wear could be reduced approximately by half with either of two candidates. The texture-modification technique using a Humble Equipment Company Skidabrader(trademark) shotpeening machine proved to be highly effective, and the entire SLF runway surface was modified in September 1994. The extensive testing and evaluation effort that preceded the selection of this particular surface-texture-modification technique is described herein

    2018 ASME Student Design Competition - Group T Senior Design Project

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    The purpose of this project is to create a single soccer playing robot to compete in the 2018 ASME student design competition. The robot, along with spare parts and all other devices must fit inside a 50x50x50 cm box. This robot must be able to traverse the field via remote control and have the ability to control a tennis ball and shoot it with sufficient force

    A petrologic and mechanical analysis of the Lion Mountain and Welge sandstones of southern Mason County, Texas

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    Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Not availabl

    Blue fluorescent proteins with enhanced brightness and photostability from a structurally targeted library

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    The utility of blue fluorescent protein (BFP) has been limited by its low quantum yield and rapid photobleaching. A library targeting residues neighboring the chromophore yielded a variant with enhanced quantum yield (0.55 versus 0.34), reduced pH sensitivity and a 40-fold increase in photobleaching half-life. This BFP, named Azurite, is well expressed in bacterial and mammalian cells and extends the palette of fluorescent proteins that can be used for imaging

    Rowan County - Folklore

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    A series of interviews with Rowan County residents on local and regional folklore

    Depression, stigma and social isolation: The psychosocial trifecta of primary chronic cutaneous lupus erythematosus, a cross-sectional and path analysis

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    OBJECTIVE: Depression is common in individuals with chronic cutaneous lupus erythematosus (CCLE). However, how CCLE may impact patients\u27 psychological well-being is poorly understood, particularly among disproportionally affected populations. We examined the relationships between depression and psychosocial factors in a cohort of predominantly Black patients with primary CCLE (CCLE without systemic manifestations). METHODS: Cross-sectional assessment of individuals with dermatologist-validated diagnosis of primary CCLE. NIH-PROMIS short-forms were used to measure depression, disease-related stigma, social isolation and emotional support. Linear regression analyses (ɑ=0.05) were used to test an a priori conceptual model of the relationship between stigma and depression and the effect of social isolation and emotional support on that association. RESULTS: Among 121 participants (87.6% women; 85.1% Black), 37 (30.6%) reported moderate to severe depression. Distributions of examined variables divided equally among those which did (eg, work status, stigma (more), social isolation (more), emotional support (less)) and did not (eg, age, sex, race, marital status) significantly differ by depression. Stigma was significantly associated with depression (b=0.77; 95% CI0.65 to 0.90), whereas social isolation was associated with both stigma (b=0.85; 95% CI 0.72 to 0.97) and depression (b=0.70; 95% CI0.58 to 0.92). After controlling for confounders, stigma remained associated with depression (b=0.44; 95% CI0.23 to 0.66) but lost significance (b=0.12; 95% CI -0.14 to 0.39) when social isolation (b=0.40; 95% CI 0.19 to 0.62) was added to the model. Social isolation explained 72% of the total effect of stigma on depression. Emotional support was inversely associated with depression in the univariate analysis; however, no buffer effect was found when it was added to the multivariate model. CONCLUSION: Our findings emphasise the psychosocial challenges faced by individuals living with primary CCLE. The path analysis suggests that stigmatisation and social isolation might lead to depressive symptoms. Early clinical identification of social isolation and public education demystifying CCLE could help reduce depression in patients with CCLE

    On particle acceleration and very high energy gamma-ray emission in Crab-like pulsars

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    The origin of very energetic charged particles and the production of very high-energy (VHE) gamma-ray emission remains still a challenging issue in modern pulsar physics. By applying a toy model, we explore the acceleration of co-rotating charged particles close to the light surface in a plasma-rich pulsar magnetosphere and study their interactions with magnetic and photon fields under conditions appropriate for Crab-type pulsars. Centrifugal acceleration of particles in a monopol-like magnetic field geometry is analyzed and the efficiency constraints, imposed by corotation, inverse Compton interactions and curvature radiation reaction are determined. We derive expressions for the maximum particle energy and provide estimates for the corresponding high-energy curvature and inverse Compton power outputs. It is shown that for Crab-like pulsars, electron Lorentz factor up to γ∼107\gamma \sim 10^7 can be achieved, allowing inverse Compton (Klein-Nishina) up-scattering of thermal photons to TeV energies with a maximum luminosity output of ∼1031\sim10^{31} erg/s. Curvature radiation, on the other hand, will result in a strong GeV emission output of up to ∼(1034−1035)\sim(10^{34}-10^{35}) erg/s, quasi-exponentially decreasing towards higher energies for photon energies below ∼50\sim 50 GeV. Accordingly to the results presented only young pulsars are expected to be sites of detectable VHE γ\gamma-ray emission.Comment: 6 pages, 1 figur

    The Vehicle, 1961, Vol. 3 no. 2

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    Vol. 3, No. 2 Table of Contents The Voting CattleLinda Kay Campbellpage 5 But For the Passage of TimeDon Shepardsonpage 14 LoveJon Woodspage 16 Infinite JourneyJames E. Martinpage 19 The Clover ChainRichard W. Blairpage 20 SnowballSusan Daughertypage 24 Sureness Is NeverDon Shepardsonpage 26 ConceptionChristine McCollpage 34 Comedy: Relief and GriefTom McPeakpage 35 The Unspoken WordChristine McCollpage 35 CharmBenjamin Polkpage 36 Screaming SpiderTom McPeakpage 39 Just Once in an Early SpringE.J.B.page 39 HummingbirdPauline B. Smithpage 40 Willow TreesPauline B. Smithpage 40 MaturityChristine McCollpage 41 The New YearLinda Campbellpage 41 The StormMary-Jean Pitratpage 42 Ebony IvoryJean Danenbargerpage 42 The Fireball MailAllen Engelbrightpage 43 ExpectationChristine McCollpage 44 CatastropheChristine McCollpage 44 SophisticationBenjamin Polkpage 45 On Playing BridgeMyrna Jo Handleypage 46 SonnetMignon Stricklandpage 48https://thekeep.eiu.edu/vehicle/1009/thumbnail.jp

    The Vehicle, 1961, Vol. 3 no. 2

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    Vol. 3, No. 2 Table of Contents The Voting CattleLinda Kay Campbellpage 5 But For the Passage of TimeDon Shepardsonpage 14 LoveJon Woodspage 16 Infinite JourneyJames E. Martinpage 19 The Clover ChainRichard W. Blairpage 20 SnowballSusan Daughertypage 24 Sureness Is NeverDon Shepardsonpage 26 ConceptionChristine McCollpage 34 Comedy: Relief and GriefTom McPeakpage 35 The Unspoken WordChristine McCollpage 35 CharmBenjamin Polkpage 36 Screaming SpiderTom McPeakpage 39 Just Once in an Early SpringE.J.B.page 39 HummingbirdPauline B. Smithpage 40 Willow TreesPauline B. Smithpage 40 MaturityChristine McCollpage 41 The New YearLinda Campbellpage 41 The StormMary-Jean Pitratpage 42 Ebony IvoryJean Danenbargerpage 42 The Fireball MailAllen Engelbrightpage 43 ExpectationChristine McCollpage 44 CatastropheChristine McCollpage 44 SophisticationBenjamin Polkpage 45 On Playing BridgeMyrna Jo Handleypage 46 SonnetMignon Stricklandpage 48https://thekeep.eiu.edu/vehicle/1009/thumbnail.jp
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