572 research outputs found

    Overview of Current Activities within NASA's Kennedy Space Center Materials Science Division

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    Release of presentation summarizing current activities within the KSC Materials Science Division. Will be presented at Speakers Bureau Event in Peoria, I

    Summary of Activities for Health Monitoring of Composite Overwrapped Pressure Vessels

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    This new start project (FY12-14) will design and demonstrate the ability of nondestructive evaluation sensors for the measurement of stresses on the inner diameter of a Composite Overwrapped Pressure Vessel overwrap. Results will be correlated with other nondestructive evaluation technologies such as Acoustic Emission. The project will build upon a proof of concept study performed at KSC which demonstrated the ability of Magnetic Stress Gages to measure stresses at internal overwraps and upon current acoustic emission research being performed at WSTF; The gages will be produced utilizing Maundering Winding Magnetometer and/or Maundering Winding Magnetometer-array eddy current technology. The proof-of-concept study demonstrated a correlation between the sensor response and pressure or strain. The study also demonstrated the ability of Maundering Winding Magnetometer technology to monitor the stresses in a Composite Overwrapped Pressure Vessel at different orientations and depths. The ultimate goal is to utilize this technology for the health monitoring of Composite Overwrapped Pressure Vessels for all future flight programs

    Judicial Notice of the Validity of Horizontal Gaze Nystagmus in Texas: Emerson v. State

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    This note first explains how officers use the HGN test in determining field sobriety. Next, this note reviews judicial standards for the admissibility of novel scientific evidence in Texas. Last, after a discussion of Emerson\u27s rationale, this note explores the arguments against the propriety of taking judicial notice of the validity of the HGN test

    Identity crime and misuse in Australia: results of the 2014 online survey

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    Misuse of personal information lies at the heart of identity crime and continues to affect all sectors of the Australian community. Abstract To understand the trends associated with identity crime and misuse in Australia, the Australian Institute of Criminology (AIC) was, in 2014, commissioned by the Commonwealth Attorney-General’s Department to undertake a national survey of the problem for the second time. The study is one of a series of initiatives being implemented as part of the National Identity Security Strategy, Australia’s national response to enhancing identity security, which seeks to prevent identity crime and misuse, contribute to national security and facilitate the benefits of the digital economy

    Summary of Activities for Health Monitoring of Composite Overwrapped Pressure Vessels

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    This three-year project (FY12-14) will design and demonstrate the ability of new Magnetic Stress Gages for the measurement of stresses on the inner diameter of a Composite Overwrapped Pressure Vessel overwrap. The sensors are being tested at White Sands Testing Facility (WSTF) where the results will be correlated with a known nondestructive technique acoustic emission. The gages will be produced utilizing Meandering Winding Magnetometer (MWM) and/or MWM array eddy current technology. The ultimate goal is to utilize this technology for the health monitoring of Composite Overwrapped Pressure Vessels for all future flight programs. The first full-scale pressurization test was performed at WSTF in June 2012. The goals of this test were to determine adaptations of the magnetic stress gauge instrumentation that would be necessary to allow multiple sensors to monitor the vessel's condition simultaneously and to determine how the sensor response changes with sensor selection and orientation. The second full scale pressurization test was performed at WSTF in August 2012. The goals of this test were to monitor the vessel's condition with multiple sensors simultaneously, to determine the viability of the multiplexing units (MUX) for the application, and to determine if the sensor responses in different orientations are repeatable. For both sets of tests the vessel was pressured up to 6,000 psi to simulate maximum operating pressure. Acoustic events were observed during the first pressurization cycle. This suggested that the extended storage period prior to use of this bottle led to a relaxation of the residual stresses imparted during auto-frettage. The pressurization tests successfully demonstrated the use of multiplexers with multiple MWM arrays to monitor a vessel. It was discovered that depending upon the sensor orientation, the frequencies, and the sense element, the MWM arrays can provide a variety of complementary information about the composite overwrapped pressure vessel load conditions. For example, low frequency measurements can be used to monitor the overwrap thickness and changes associated with pressure level. High frequency data is dominated by the properties of the overwrap, including the fiber orientations and lay-up of the layers

    Students’ Expectations Within a Nontraditional College of Business Classroom

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    Students in a college of business classroom have various expectations regarding the faculty member and the course. If the faculty member fails to meet those expectations, the resulting misalignment can cause misunderstandings and other issues. This study attempts to understand the expectations of nontraditional students to assist faculty in identifying the potential areas of misalignment. Using a series of modified questions from Schmitt, Larsen, Miller, Badawy, Dougherty, Sharma & Benson (2013), this study reports the results of a survey of 152 upper-division undergraduate and graduate students from the college of business at a regional university with a teaching mission. The findings indicate that students’ primary expectations included in-class discussions and text-book use, faculty interactions with students while in class, and timely responses by faculty to questions

    Robust post-stall perching with a simple fixed-wing glider using LQR-Trees

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    Birds routinely execute post-stall maneuvers with a speed and precision far beyond the capabilities of our best aircraft control systems. One remarkable example is a bird exploiting post-stall pressure drag in order to rapidly decelerate to land on a perch. Stall is typically associated with a loss of control authority, and it is tempting to attribute this agility of birds to the intricate morphology of the wings and tail, to their precision sensing apparatus, or their ability to perform thrust vectoring. Here we ask whether an extremely simple fixed-wing glider (no propeller) with only a single actuator in the tail is capable of landing precisely on a perch from a large range of initial conditions. To answer this question, we focus on the design of the flight control system; building upon previous work which used linear feedback control design based on quadratic regulators (LQR), we develop nonlinear feedback control based on nonlinear model-predictive control and 'LQR-Trees'. Through simulation using a flat-plate model of the glider, we find that both nonlinear methods are capable of achieving an accurate bird-like perching maneuver from a large range of initial conditions; the 'LQR-Trees' algorithm is particularly useful due to its low computational burden at runtime and its inherent performance guarantees. With this in mind, we then implement the 'LQR-Trees' algorithm on real hardware and demonstrate a 95 percent perching success rate over 147 flights for a wide range of initial speeds. These results suggest that, at least in the absence of significant disturbances like wind gusts, complex wing morphology and sensing are not strictly required to achieve accurate and robust perching even in the post-stall flow regime.United States. Office of Naval Research. Multidisciplinary University Research Initiative (N00014-10-1-0951)National Science Foundation (U.S.) (Award IIS-0915148

    Sustaining Human Space Flight: From the Present to the Future

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    This slide presentation reviews some of the efforts to ensure that human space flight continues in NASA. With the aging shuttle orbiter fleet, some actions have been taken to assure safe operations. Some of these are: (1) the formation of a Corrosion Control Review Board (CCRB) that will assess the extent and cause of corrosion to the shuttle, and provide short term and long term corrective actions, among other objectives, (2) a formalization of an aging vehicle assessment (AVA) as part of a certification for the Return-to-Flight, (3) an assessment of the age life of the materials in the space shuttle, and (4) the formation of the Aging Orbiter Working Group (AOWG). There are also slides with information about the International Space Station. There is also information about the need to update the Kennedy Space Center, to sustain a 21st century launch complex and the requirement to further the aim of commercial launch capability

    Failure Analysis of Space Shuttle Orbiter Valve Poppet

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    The poppet failed during STS-126 due to fatigue cracking that most likely was initiated during MDC ground-testing. This failure ultimately led to the discovery that the cracking problem was a generic issue effecting numerous poppets throughout the Shuttle program's history. This presentation has focused on the laboratory analysis of the failed hardware, but this analysis was only one aspect of a comprehensive failure investigation. One critical aspect of the overall investigation was modeling of the fluid flow through this valve to determine the possible sources of cyclic loading. This work has led to the conclusion that the poppets are failing due to flow-induced vibration

    Bayesian Techniques for Surface Fuel Loading Estimation

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    In previous work, researchers compared three sampling techniques for estimating the biomass of surface fine woody fuels by using them on known distributions. An important result was that precise estimates of fuel biomass required intensive sampling for both planar intercept and fixed-area methods. This study explores Bayesian statistical methods as a means to reduce the sampling effort needed to obtain a desired precision. We examined how initial estimates of the minimum and maximum fuel loading at a site could be used as prior information in a Bayesian framework. We found that, under certain scenarios, Bayesian techniques dramatically increased the precision of the estimator compared to using no prior information from the site.Faculty Sponsor: Kathy Gra
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