333 research outputs found

    Eigenmode computation for the GSI SIS 18 ferrite cavity

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    Eigenmode Computation for Biased Ferrite-Loaded Cavity Resonators

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    Numerical Investigation of the Flow Angularity Effects of the NASA Langley UPWT on the Ares I DAC1 0.01-Scale Model

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    Investigation of the non-uniform flow angularity effects on the Ares I DAC-1 in the Langley Unitary Plan Wind Tunnel are explored through simulations by OVERFLOW. Verification of the wind tunnel results are needed to ensure that the standard wind tunnel calibration procedures for large models are valid. The expectation is that the systematic error can be quantified, and thus be used to correct the wind tunnel data. The corrected wind tunnel data can then be used to quantify the CFD uncertainties

    Measurement of the magnetic properties of the Ferroxcube 8C12m material

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    Simulation of Blast Waves with Headwind

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    The blast wave resulting from an explosion was simulated to provide guidance for models estimating risks for human spacecraft flight. Simulations included effects of headwind on blast propagation, Blasts were modelled as an initial value problem with a uniform high energy sphere expanding into an ambient field. Both still air and cases with headwind were calculated

    Aerodynamic Analyses and Database Development for Ares I Vehicle First Stage Separation

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    This paper presents the aerodynamic analysis and database development for first stage separation of Ares I A106 crew launch vehicle configuration. Separate 6-DOF databases were created for the first stage and upper stage and each database consists of three components: (a) isolated or freestream coefficients, (b) power-off proximity increments, and (c) power-on proximity increments. The isolated and power-off incremental databases were developed using data from 1% scaled model tests in AEDC VKF Tunnel A. The power-on proximity increments were developed using OVERFLOW CFD solutions. The database also includes incremental coefficients for one BDM and one USM failure scenarios

    Using Simulations as a Starting Point for Constructing Meaningful Learning Games

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    For many school administrators and decision makers, the term “video games” holds numerous cultural associations which make their adoption in the education space challenging. Additionally, the term is so broad that it can sometimes be difficult to communicate explicitly a desire to build learning experiences that go beyond the Drill and Kill edutainment titles that currently dominate most people’s perceptions of educational games. By contrast, the term “simulations” is often well respected among educators, particularly in the natural sciences. With “simulation” already being a full genre of video games, it would seem natural that researchers are beginning to explore the overlaps between simulation games and pedagogical goals that go beyond those found in Drill and Kill games. In this chapter, we survey some of the relevant research concerning both simulations and video games and outline practical pathways through which we can leverage the interest and frameworks designed for simulation construction to facilitate the introduction of video game concepts and experiences into the classroom environment. In particular, we report on the use of Starlogo TNG, a graphical programming environment in which kids themselves can create simulation-based video games, for deepening children’s understanding of scientific concepts

    TMEM45A, SERPINB5 and p16INK4A transcript levels are predictive for development of high-grade cervical lesions

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    Women persistently infected with human papillomavirus (HPV) type 16 are at high risk for development of cervical intraepithelial neoplasia grade 3 or cervical cancer (CIN3+). We aimed to identify biomarkers for progression to CIN3+ in women with persistent HPV16 infection. In this prospective study, 11,088 women aged 20-29 years were enrolled during 1991-1993, and re-invited for a second visit two years later. Cervical cytology samples obtained at both visits were tested for HPV DNA by Hybrid Capture 2 (HC2), and HC2-positive samples were genotyped by INNO-LiPA. The cohort was followed for up to 19 years via a national pathology register. To identify markers for progression to CIN3+, we performed microarray analysis on RNA extracted from cervical swabs of 30 women with persistent HPV16-infection and 11 HPV-negative women. Six genes were selected and validated by quantitative PCR. Three genes were subsequently validated within a different and large group of women from the same cohort. Secondly, Kaplan-Meier and Cox-regression analyses were used to investigate whether expression levels of those three genes predict progression to CIN3+. We found that high transcript levels of TMEM45A, SERPINB5 and p16INK4a at baseline were associated with increased risk of CIN3+ during follow-up. The hazard ratios of CIN3+ per 10-fold increase in baseline expression level were 1.6 (95% CI: 1.1-2.3) for TMEM45A, 1.6 (95% CI: 1.1-2.5) for p16INK4a, and 1.8 (95% CI: 1.2-2.7) for SERPINB5. In conclusion, high mRNA expression levels of TMEM45A, SERPINB5 and p16INK4a were associated with increased risk of CIN3+ in persistently HPV16-infected women

    Effects of experience and body size on refuge choice in the crayfish Orconectes immunis

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    We investigated whether refuge size or experience with a refuge affected the refuge use of male Orconectes immunis crayfish. Individuals were given choices among seven refuges for 10 consecutive days. Refuges were formed from equal length but different diameter PVC pipe and placed in an array in a random sequence. Three treatments were used. In the Novel Refuge treatment, individuals were placed in a new test arena with a new arrangement of cleaned refuges every day. In the Nonremoval treatment, individuals were left in the same arena with the same set of refuges each day. In the Removal treatment, individuals were removed from the refuges each day but placed back in the same arena with the same set of refuges after the refuges had been cleaned. We found that refuge occupation was correlated with an individual\u27s size; smaller crayfish tended to use smaller refuges than larger crayfish, even though all crayfish could fit in all of the different sized refuges. When first tested, individuals initially chose larger refuges than they would subsequently settle in, suggesting that under duress, they were not as particular about refuge characteristics. Individuals in the Nonremoval and Removal treatments were significantly more consistent in their refuge use than those in the Novel Refuge treatment, suggesting that experience with a particular refuge increased use of that refuge. Individuals from the Novel Refuge treatment that were housed for a month with a single refuge did not increase their use of that sized refuge more than those that were housed without a refuge, indicating that simply occupying a refuge of a given size did not affect refuge preference

    Can air pollution affect tear film stability? a cross-sectional study in the aftermath of an explosion accident

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    <p>Abstract</p> <p>Background</p> <p>After an explosion and fire in two tanks containing contaminated oil and sulphur products in a Norwegian industrial harbour in 2007, the surrounding area was polluted. This caused an intense smell, lasting until the waste was removed two years later. The present study reports examinations of tear film break up time among the population. The examinations were carried out because many of the people in the area complained of sore eyes. The purpose of the study was to assess the relationship between living or working close to the polluted area and tear film stability one and a half years after the explosion.</p> <p>Methods</p> <p>All persons working or living in an area less than six kilometres from the explosion site were invited to take part in the study together with a similar number of persons matched for age and gender living more than 20 kilometres away. Three groups were established: workers in the explosion area and inhabitants near the explosion area (but not working there) were considered to have been exposed, and inhabitants far away (who did not work in the explosion area) were considered to be unexposed. A total of 734 people were examined, and the response rate was 76 percent. Tear film stability was studied by assessing non-invasive break-up time (NIBUT) using ocular microscopy. In addition Self-reported Break Up Time (SBUT) was assessed by recording the time the subject could keep his or hers eyes open without blinking when watching a fixed point on a wall. Background information was obtained using a questionnaire. Non-parametric Wilcoxon-Mann-Whitney-tests with exact p-values and multiple logistic regression analyses were performed.</p> <p>Results</p> <p>Both NIBUT and SBUT were shorter among the male exposed workers than among the inhabitants both near and far away from the explosion area. This was also found for SBUT among males in a multiple logistic regression analysis, adjusting for age and smoking.</p> <p>Conclusions</p> <p>Reduced tear film stability was found among workers in an area where an explosion accident had occurred.</p
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