951 research outputs found

    Analysis of the project fire re-entry package flow field final technical report

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    Theoretical prediction of state of gas in flow field surrounding Apollo type vehicle in reentry at hypersonic speed

    Investigating powerful jets in radio-loud Narrow Line Seyfert 1s

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    We report results on multiband observations from radio to gamma-rays of the two radio-loud narrow-line Seyfert 1 (NLSy1) galaxies PKS 2004-447 and J1548+3511. Both sources show a core-jet structure on parsec scale, while they are unresolved at the arcsecond scale. The high core dominance and the high variability brightness temperature make these NLSy1 galaxies good gamma-ray source candidates. Fermi-LAT detected gamma-ray emission only from PKS 2004-447, with a gamma-ray luminosity comparable to that observed in blazars. No gamma-ray emission is observed for J1548+3511. Both sources are variable in X-rays. J1548+3511 shows a hardening of the spectrum during high activity states, while PKS 2004-447 has no spectral variability. A spectral steepening likely related to the soft excess is hinted below 2 keV for J1548+3511, while the X-ray spectra of PKS 2004-447 collected by XMM-Newton in 2012 are described by a single power-law without significant soft excess. No additional absorption above the Galactic column density or the presence of an Fe line is detected in the X-ray spectra of both sources.Comment: 16 pages, 8 figures, accepted for publication in MNRA

    Ranching in Northwestern South Dakota

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    Space shuttle booster Data Management System (DMS) requirements analysis. Volume 2: Detail requirements

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    Space shuttle subsystem interface description, subsystem computational requirements, and analysis program - Vol.

    The Difference in Efficiency and Pulmonary Function While Performing Cycle Ergometry on Land and in Water

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    The purpose of this study was to quantify the difference in net efficiency and pulmonary function while performing cycle ergometry on land in water. Thirty healthy adults (mean ± SD, age, 20 ± 2 y; stature, 165 ± 10 cm; mass, 70 ± 5 kg) participated in one day of testing consisting of both land and water conditions. Heart rate, O2 consumption, CO2 production, rated perceived exertion, and minute ventilation were measured for both conditions at rest, pedaling at no resistance, 50, and 100 W for two minutes. A repeated measures two-way ANOVA with post hoc tests was used to analyzed the data. The magnitude of physiological functions (rated perceived exertion, minute ventilation, energy expenditure, & heart rate) increased at higher resistance levels (50 and 100W) in water as compared to land. Efficiency decreased at 50 and 100W in water. Energy expenditure and minute ventilation both increase while cycling in water, resulting in a decrease of efficiency by 4.61%. This is due to the drag forces associated with fluid dynamics. This study and its results add to the understanding of water exercise and are beneficial to the rehabilitation and the general well-being and health of the population.Faculty Sponsor: Dr. Shawn Henr

    A 10B-based neutron detector with stacked Multiwire Proportional Counters and macrostructured cathodes

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    We present the results of the measurements of the detection efficiency for a 4.7 \r{A} neutron beam incident upon a detector incorporating a stack of up to five MultiWire Proportional Counters (MWPC) with Boron-coated cathodes. The cathodes were made of Aluminum and had a surface exhibiting millimeter-deep V-shaped grooves of 45{\deg}, upon which the thin Boron film was deposited by DC magnetron sputtering. The incident neutrons interacting with the converter layer deposited on the sidewalls of the grooves have a higher capture probability, owing to the larger effective absorption film thickness. This leads to a higher overall detection efficiency for the grooved cathode when compared to a cathode with a flat surface. Both the experimental results and the predictions of the GEANT4 model suggests that a 5-counter detector stack with coated grooved cathodes has the same efficiency as a 7-counter stack with flat cathodes. The reduction in the number of counters in the stack without altering the detection efficiency will prove highly beneficial for large-area position-sensitive detectors for neutron scattering applications, for which the cost-effective manufacturing of the detector and associated readout electronics is an important objective. The proposed detector concept could be a technological option for one of the new chopper spectrometers and other instruments planned to be built at the future European Spallation Source in Sweden. These results with macrostructured cathodes generally apply not just to MWPCs but to other gaseous detectors as well.Comment: 14 pages, 9 figure

    The Difference in Efficiency and Pulmonary Function While Performing Cycle Ergometry on Land and in Water

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    The purpose of this study was to quantify the difference in net efficiency and pulmonary function while performing cycle ergometry on land in water. Thirty healthy adults (mean ± SD, age, 20 ± 2 y; stature, 165 ± 10 cm; mass, 70 ± 5 kg) participated in one day of testing consisting of both land and water conditions. Heart rate, O2 consumption, CO2 production, rated perceived exertion, and minute ventilation were measured for both conditions at rest, pedaling at no resistance, 50, and 100 W for two minutes. A repeated measures two-way ANOVA with post hoc tests was used to analyzed the data. The magnitude of physiological functions (rated perceived exertion, minute ventilation, energy expenditure, & heart rate) increased at higher resistance levels (50 and 100W) in water as compared to land. Efficiency decreased at 50 and 100W in water. Energy expenditure and minute ventilation both increase while cycling in water, resulting in a decrease of efficiency by 4.61%. This is due to the drag forces associated with fluid dynamics. This study and its results add to the understanding of water exercise and are beneficial to the rehabilitation and the general well-being and health of the population

    Quantifying cancer progression with conjunctive Bayesian networks

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    Motivation: Cancer is an evolutionary process characterized by accumulating mutations. However, the precise timing and the order of genetic alterations that drive tumor progression remain enigmatic

    Neurochemical Aftermath of Repetitive Mild Traumatic Brain Injury

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    IMPORTANCE: Evidence is accumulating that repeated mild traumatic brain injury (mTBI) incidents can lead to persistent, long-term debilitating symptoms and in some cases a progressive neurodegenerative condition referred to as chronic traumatic encephalopathy. However, to our knowledge, there are no objective tools to examine to which degree persistent symptoms after mTBI are caused by neuronal injury. OBJECTIVE: To determine whether persistent symptoms after mTBI are associated with brain injury as evaluated by cerebrospinal fluid biochemical markers for axonal damage and other aspects of central nervous system injury. DESIGN, SETTINGS, AND PARTICIPANTS: A multicenter cross-sectional study involving professional Swedish ice hockey players who have had repeated mTBI, had postconcussion symptoms for more than 3 months, and fulfilled the criteria for postconcussion syndrome (PCS) according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) matched with neurologically healthy control individuals. The participants were enrolled between January 2014 and February 2016. The players were also assessed with Rivermead Post Concussion Symptoms Questionnaire and magnetic resonance imaging. MAIN OUTCOMES AND MEASURES: Neurofilament light protein, total tau, glial fibrillary acidic protein, amyloid β, phosphorylated tau, and neurogranin concentrations in cerebrospinal fluid. RESULTS: A total of 31 participants (16 men with PCS; median age, 31 years; range, 22-53 years; and 15 control individuals [11 men and 4 women]; median age, 25 years; range, 21-35 years) were assessed. Of 16 players with PCS, 9 had PCS symptoms for more than 1 year, while the remaining 7 returned to play within a year. Neurofilament light proteins were significantly increased in players with PCS for more than 1 year (median, 410 pg/mL; range, 230-1440 pg/mL) compared with players whose PCS resolved within 1 year (median, 210 pg/mL; range, 140-460 pg/mL) as well as control individuals (median 238 pg/mL, range 128-526 pg/mL; P = .04 and P = .02, respectively). Furthermore, neurofilament light protein concentrations correlated with Rivermead Post Concussion Symptoms Questionnaire scores and lifetime concussion events (ρ = 0.58, P = .02 and ρ = 0.52, P = .04, respectively). Overall, players with PCS had significantly lower cerebrospinal fluid amyloid-β levels compared with control individuals (median, 1094 pg/mL; range, 845-1305 pg/mL; P = .05). CONCLUSIONS AND RELEVANCE: Increased cerebrospinal fluid neurofilament light proteins and reduced amyloid β were observed in patients with PCS, suggestive of axonal white matter injury and amyloid deposition. Measurement of these biomarkers may be an objective tool to assess the degree of central nervous system injury in individuals with PCS and to distinguish individuals who are at risk of developing chronic traumatic encephalopathy
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