1,854 research outputs found

    Raptor Gas Gun Testing Experiment

    Full text link

    BE YOUR OWN BOSS: A CHRONIC DISEASE SELF-MANAGEMENT PROGRAM

    Get PDF
    poster abstractObjective: Describe the pilot of a peer-led chronic disease self-management workshop for youth aged 13-24 years old. Background: Fifteen to eighteen percent of children in the United States live with a chronic health condition (Perrin et al., Journal of the American Medical Association 2007, 297:2755). The Stanford chronic disease self-management program (CDSMP) has demonstrated improved self-care and health outcomes in older adults. Alberta Health Services has adapted this program from Stanford University for youth and young adults. CYACC is col-laborating with Alberta to evaluate the effectiveness of the adapted version in adolescents and young adults. Methods: Train the trainer sessions were completed to develop an initial cadre of lay leaders to implement the workshop sessions. Participants with any chronic condition attend 2 hour peer-led sessions once per week for six weeks. During the sessions, individuals with a variety of chronic diseases learn the skills needed in self-management of their condition and mainte-nance of general well-being and life’s activities. Data is collected on self-efficacy, pain, adherence, and other outcomes through pre- and post- as-sessment surveys. Results: Fourteen individuals participated in the pilot phase of the pro-gram; 5 in Lafayette, IN and 8 in Indianapolis, IN. A total of 14 pre-surveys were collected, while 10 post-surveys were collected. Analyses of the sur-veys show beneficial topics , while also indicating which topics should receive additional focus. Areas of the program identified as needing attention include recruitment, risk management, transportation issues, participant dropout rates, logistics of workshops, continued training of lay leaders, and stand-ardization of survey responses. Conclusion: The pilot study identified the importance and need for a self-management program for youth and young adults with chronic conditions. This program has the potential to improve health and self-management in the study population. Limitations of the program were addressed and will be improved for the next round of workshops

    Simultaneous OH-PLIF and schlieren imaging of flame acceleration in an obstacle-laden channel

    Get PDF
    Flame acceleration in stoichiometric H_2/O_2 at 12 and 25 kPa initial pressure in an obstacle-laden square cross-section channel was studied experimentally using planar laser-induced fluorescence imaging of hydroxyl radicals (OH-PLIF) and simultaneous high-speed schlieren imaging. Results were obtained resolving the explosion front structure as it develops immediately after ignition as a slow-flame to the eventual formation of a shock-flame complex in the fast-flame regime. The images provide a novel level of detail and allow for the determination of the effects of turbulence-flame and shock-flame interaction. In the slow-flame regime, vortex shedding off obstacle edges occurs over long time-scales, vortices are convected downstream and turbulent combustion takes place in the obstacle wakes. The fast-flame regime is marked by the presence of compression waves (and shock waves) which interact with the flame and cause macroscopic deformation of the flame and small-scale wrinkling due to Richtmyer-Meshkov instability. A quasi-steady fast-flame is characterized by the close proximity of the precursor shock and the turbulent flame. The flow-field that governs the flame shape is established impulsively by the precursor shock. Shock-flame interactions lead to flame front perturbations on both small and large scales. The OH-PLIF technique makes it possible to discern the flame front from other density interfaces that appear in the complex fast-flame structure observed in schlieren images and also eliminates the line-of-sight integration limitation

    Spin gating electrical current

    Full text link
    We use an aluminium single electron transistor with a magnetic gate to directly quantify the chemical potential anisotropy of GaMnAs materials. Uniaxial and cubic contributions to the chemical potential anisotropy are determined from field rotation experiments. In performing magnetic field sweeps we observe additional isotropic magnetic field dependence of the chemical potential which shows a non-monotonic behavior. The observed effects are explained by calculations based on the kâ‹…p\mathbf{k}\cdot\mathbf{p} kinetic exchange model of ferromagnetism in GaMnAs. Our device inverts the conventional approach for constructing spin transistors: instead of spin-transport controlled by ordinary gates we spin-gate ordinary charge transport.Comment: 5 pages, 4 figure

    Flame propagation across an obstacle: OH-PLIF and 2-D simulations with detailed chemistry

    Get PDF
    Flame propagation across a single obstacle inside a closed square channel is studied experimentally and numerically using a stoichiometric H_2/O_2 mixture at initial conditions 15 kPa and 300 K. The 50% blockage obstacle consists of a pair of fence-type obstacles mounted on the top and bottom walls of the channel. Direct optical visualization was performed using single-image measurement of the planar laser-induced fluorescence of the OH radical (OH-PLIF) and simultaneous high-speed schlieren video to study the flame topology and the flame tip velocity along the channel streamwise axis, respectively. The OH-PLIF images provide a novel level of detail and permit a thorough evaluation of the simulation accuracy. The flame tip accelerates to a peak velocity of 590 m/s just downstream of the obstacle followed by a deceleration and subsequent re-acceleration. The unburnt gas flow ahead of the flame is subsonic at all times. The flame does not show any signs of diffusive-thermal instability. Vortex–flame interactions in the recirculation zones downstream of the obstacle wrinkle the flame. The numerical simulations, based on solving the 2-D compressible reactive Navier–Stokes equations with detailed chemistry, predict the flame tip velocity accurately. However, differences in flame topology are observed, specifically, wrinkling is over-estimated. The over-prediction of flame wrinkling suggests a lower dissipation rate in the numerical simulations than in reality, which could be a consequence of neglecting the third channel dimension. Conditional means of the fuel consumption rate are similar to the consumption rates of 1-D unstretched laminar flames at all times. The increase in pressure during flame propagation causes an increase in fuel consumption rate which needs to be accounted for in simplified modeling approaches

    Reward preferences of pathological gamblers under conditions of uncertainty: an experimental study

    Get PDF
    Among many personality traits, impulsivity represents one of the most important traits associated with pathological gambling. Empirical research has highlighted the multidimensional nature of impulsivity, which includes different heterogeneous traits and behavioral tendencies. The present study experimentally examined reward preferences of pathological gamblers under conditions of uncertainty using the Balloon Analogue Risk Task. Furthermore it also examined the relationship between impulsivity, time perspective, inability to tolerate delay in gratification, and risktaking. The present study is the first to simultaneously examine all these variables simultaneously in a sample of pathological gamblers (n=54) and healthy controls (n=54) from Italy. All participants participated in the Balloon Analogue Risk Task (BART) and were also administered Italian versions of the South Oaks Gambling Screen, the Barratt Impulsiveness Scale, the Consideration of Future Consequences, and the Monetary Choice Questionnaire. Analyses revealed that compared to HCs, PGs were more risk prone on the BART, and reported elevated levels of impulsivity, steeper discounting rates and a shorter time perspective. All the measures correlated with the gambling severity and strong correlations between the BIS, CFC-14 and BART were observed. Logistic regression analysis demonstrated that impulsivity and risk-taking were strong predictors of pathological gambling

    Fire Weather Index application in north-western Italy

    Get PDF
    International audiencePiedmont region is located in North-Western Italy and is surrounded by the alpine chain and by the Appennines. The region is covered by a wide extension of forests, mainly in its mountain areas (the forests cover 36% of the regional territory). Forested areas are interested by wildfire events. In the period 1997?2005 Piedmont was interested by an average 387 forest fires per year, covering an average 1926 ha of forest per year. Meteorological conditions like long periods without precipitation contribute to create favourable conditions to forest fire development, while the fire propagation is made easier by the foehn winds, frequently interesting the region in winter and spring particularly. The meteorological danger index FWI (Fire Weather Index) was developed by Van Wagner (1987) for the Canadian Forestry Service, providing a complete description of the behaviour of the different forest components in response to the changing weather conditions. We applied the FWI to the Piedmont region on warning areas previously defined for fire management purposes. The meteorological data-set is based on the data of the very-dense non-GTS network of weather stations managed by Arpa Piemonte. The thresholds for the definition of a danger scenarios system were defined comparing historical FWI data with fires occurred on a 5 years period. The implementation of a prognostic FWI prediction system is planned for the early 2008, involving the use of good forecasts of weather parameters at the station locations obtained by the Multimodel SuperEnsemble post-processing technique

    Reconfigurable Boolean Logic using Magnetic Single-Electron Transistors

    Full text link
    We propose a novel hybrid single-electron device for reprogrammable low-power logic operations, the magnetic single-electron transistor (MSET). The device consists of an aluminium single-electron transistors with a GaMnAs magnetic back-gate. Changing between different logic gate functions is realized by reorienting the magnetic moments of the magnetic layer which induce a voltage shift on the Coulomb blockade oscillations of the MSET. We show that we can arbitrarily reprogram the function of the device from an n-type SET for in-plane magnetization of the GaMnAs layer to p-type SET for out-of-plane magnetization orientation. Moreover, we demonstrate a set of reprogrammable Boolean gates and its logical complement at the single device level. Finally, we propose two sets of reconfigurable binary gates using combinations of two MSETs in a pull-down network
    • …
    corecore