5,458 research outputs found

    Gay-Straight Alliances as Settings to Discuss Health Topics: Individual and Group Factors Associated with Substance Use, Mental Health, and Sexual Health Discussions

    Get PDF
    Sexual minority (e.g. lesbian, gay, bisexual, questioning; LGBQ) and gender minority (e.g. transgender) youth experience myriad health risks. Gay-Straight Alliances (GSAs) are school-based settings where they may have opportunities to discuss substance use, mental health, and sexual health issues in ways that are safe and tailored to their experiences. Attention to these topics in GSAs could aid in developing programming for these settings. Among 295 youth from 33 Massachusetts high-school GSAs (69% LGBQ, 68% cisgender female, 68% White, Mage = 16.06), we examined how often youth discussed these topics within their GSA and identified factors associated with having more of these discussions. Youth and GSAs as a whole varied in their frequency of discussing these topics. Youth who accessed more information/resources in the GSA and did more advocacy more frequently engaged in discussions around substance use, mental health and sexual health. Youth who reported greater victimization more often discussed substance use and mental health, but not sexual health. Finally, GSAs whose members collectively reported greater victimization more frequently discussed these topics. These findings can assist the development of health programming to be delivered within GSAs

    Acoustic tests of duct-burning turbofan jet noise simulation

    Get PDF
    The results of a static acoustic and aerodynamic performance, model-scale test program on coannular unsuppressed and multielement fan suppressed nozzle configurations are summarized. The results of the static acoustic tests show a very beneficial interaction effect. When the measured noise levels were compared with the predicted noise levels of two independent but equivalent conical nozzle flow streams, noise reductions for the unsuppressed coannular nozzles were of the order of 10 PNdB; high levels of suppression (8 PNdB) were still maintained even when only a small amount of core stream flow was used. The multielement fan suppressed coannular nozzle tests showed 15 PNdB noise reductions and up to 18 PNdB noise reductions when a treated ejector was added. The static aerodynamic performance tests showed that the unsuppressed coannular plug nozzles obtained gross thrust coefficients of 0.972, with 1.2 to 1.7 percent lower levels for the multielement fan-suppressed coannular flow nozzles. For the first time anywhere, laser velocimeter velocity profile measurements were made on these types of nozzle configurations and with supersonic heated flow conditions. Measurements showed that a very rapid decay in the mean velocity occurs for the nozzle tested

    Acoustic tests of duct-burning turbofan jet noise simulation: Comprehensive data report. Volume 2: Model design and aerodynamic test results

    Get PDF
    The selection procedure is described which was used to arrive at the configurations tested, and the performance characteristics of the test nozzles are given

    Simulation of Ultra-High Energy Photon Propagation in the Geomagnetic Field

    Full text link
    The identification of primary photons or specifying stringent limits on the photon flux is of major importance for understanding the origin of ultra-high energy (UHE) cosmic rays. We present a new Monte Carlo program allowing detailed studies of conversion and cascading of UHE photons in the geomagnetic field. The program named PRESHOWER can be used both as an independent tool or together with a shower simulation code. With the stand-alone version of the code it is possible to investigate various properties of the particle cascade induced by UHE photons interacting in the Earth's magnetic field before entering the Earth's atmosphere. Combining this program with an extensive air shower simulation code such as CORSIKA offers the possibility of investigating signatures of photon-initiated showers. In particular, features can be studied that help to discern such showers from the ones induced by hadrons. As an illustration, calculations for the conditions of the southern part of the Pierre Auger Observatory are presented.Comment: 41 pages, 9 figures, added references in introduction, corrected energy in row 1 of Table 3, extended caption of Table

    User manual for Streamtube Curvature Analysis: Analytical method for predicting the pressure distribution about a nacelle at transonic speeds, appendix

    Get PDF
    The computer program listing of Streamtube Curvature Analysis is presented. The listing includes explanatory statements and titles so that the program flow is readily discernable. The computer program listing is in CDC FORTRAN 2.3 source language form, except for three subroutines, GETIX, GETRLX, and SAVIX, which are in COMPOSE 1.1 language

    Inertial electrostatic confinement as a power source for electric propulsion

    Get PDF
    The potential use of an INERTIAL ELECTROSTATIC CONFINEMENT (IEC) power source for space propulsion has previously been suggested by the authors and others. In the past, these discussions have generally followed the charged-particle electric-discharge engine (QED) concept proposed by Bussard, in which the IEC is used to generate an electron beam which vaporizes liquid hydrogen for use as a propellant. However, an alternate approach is considered, using the IEC to drive a 'conventional' electric thruster unit. This has the advantage of building on the rapidly developing technology for such thrusters, which operate at higher specific impulse. Key issues related to this approach include the continued successful development of the physics and engineering of the IEC unit, as well as the development of efficient step-down dc voltage transformers. The IEC operates by radial injection of energetic ions into a spherical vessel. A very high ion density is created in a small core region at the center of the vessel, resulting in extremely high fusion power density in the core. Experiments at the U. of Illinois in small IEC devices (is less than 60 cm. dia.) demonstrated much of the basic physics underlying this concept, e.g. producing 10(exp 6) D-D neutrons/sec steady-state with deuterium gas flow injection. The ultimate goal is to increase the power densities by several orders of magnitude and to convert to D-He-3 injection. If successful, such an experiment would represent a milestone proof-of-principle device for eventual space power use. Further discussion of IEC physics and status are presented with a description of the overall propulsion system and estimated performance

    Constraining the fundamental parameters of the O-type binary CPD-41degr7733

    Get PDF
    Using a set of high-resolution spectra, we studied the physical and orbital properties of the O-type binary CPD-41 7733, located in the core of \ngc. We report the unambiguous detection of the secondary spectral signature and we derive the first SB2 orbital solution of the system. The period is 5.6815 +/- 0.0015 d and the orbit has no significant eccentricity. CPD-41 7733 probably consists of stars of spectral types O8.5 and B3. As for other objects in the cluster, we observe discrepant luminosity classifications while using spectroscopic or brightness criteria. Still, the present analysis suggests that both components display physical parameters close to those of typical O8.5 and B3 dwarfs. We also analyze the X-ray light curves and spectra obtained during six 30 ks XMM-Newton pointings spread over the 5.7 d period. We find no significant variability between the different pointings, nor within the individual observations. The CPD-41 7733 X-ray spectrum is well reproduced by a three-temperature thermal mekal model with temperatures of 0.3, 0.8 and 2.4 keV. No X-ray overluminosity, resulting e.g. from a possible wind interaction, is observed. The emission of CPD-41 7733 is thus very representative of typical O-type star X-ray emission.Comment: Accepted by ApJ, 15 pages, 9 figure
    corecore