Comparison of Orbiter PRCS Plume Flow Fields Using CFD and Modified Source Flow Codes

The Space Shuttle Orbiter will use Reaction Control System (RCS) jets for docking with the planned International Space Station (ISS). During approach and backout maneuvers, plumes from these jets could cause high pressure, heating, and thermal loads on ISS components. The object of this paper is to present comparisons of RCS plume flow fields used to calculate these ISS environments. Because of the complexities of 3-D plumes with variable scarf-angle and multi-jet combinations, NASA/JSC developed a plume flow-field methodology for all of these Orbiter jets. The RCS Plume Model (RPM), which includes effects of scarfed nozzles and dual jets, was developed as a modified source-flow engineering tool to rapidly generate plume properties and impingement environments on ISS components. This paper presents flow-field properties from four PRCS jets: F3U low scarf-angle single jet, F3F high scarf-angle single jet, DTU zero scarf-angle dual jet, and F1F/F2F high scarf-angle dual jet. The RPM results compared well with plume flow fields using four CFD programs: General Aerodynamic Simulation Program (GASP), Cartesian (CART), Unified Solution Algorithm (USA), and Reacting and Multi-phase Program (RAMP). Good comparisons of predicted pressures are shown with STS 64 Shuttle Plume Impingement Flight Experiment (SPIFEX) data

Spacecraft Orbital Debris Reentry: Aerothermal Analysis

In the past 40 years, thousands of objects have been placed in Earth orbit and are being tracked. Space hardware reentry survivability must be evaluated to assess risks to human life and property on the ground. The objective of this paper is to present results of a study to determine altitude of demise (burn-up) or survivability of reentering objects. Two NASA/JSC computer codes - Object Reentry Survival Analysis Tool (ORSAT) and Miniature ORSAT (MORSAT) were used to determine trajectories, aerodynamic aerothermal environment, and thermal response of selected spacecraft components. The methodology of the two codes is presented, along with results of a parametric study of reentering objects modeled as spheres and cylinders. Parameters varied included mass, diameter, wall thickness, ballistic coefficient, length, type of material, and mode of tumbling/spinning. Two fragments of a spent Delta second stage undergoing orbital decay, stainless steel cylindrical propellant tank and titanium pressurization sphere, were evaluated with ORSAT and found to survive entry, as did the actual objects. Also, orbital decay reentry predictions of the Japanese Advanced Earth Observing Satellite (ADEOS) aluminum and nickel box-type components and the Russian COSMOS 954 satellite beryllium cylinders were made with MORSAT. These objects were also shown to survive reentry

Predicting sexual problems in women: The relevance of sexual excitation and sexual inhibition

This is the post-print version of the article. The official published version can be obtained from the link below.Data from a non-clinical sample of 540 heterosexual women were used to examine the relationships between scores on the Sexual Excitation/Sexual Inhibition Inventory for Women (SESII-W) and ratings of current sexual problems, lifetime arousal difficulty, lifetime orgasm difficulty, and lifetime problems with low sexual interest. Multiple regression analyses also included several demographic/background variables as predictors: age, full-time employment, completed college, children in household, married, health ratings, importance of sex, and whether the woman was in a sexual relationship. The strongest statistical predictors of both current and lifetime sexual problems were the SESII-W inhibition factors Arousal Contingency and Concerns about Sexual Function. Demographic factors did not feature largely in any of the models predicting sexual problems even when statistically significant relationships were found. If future research supports the predictive utility of the SESII-W in identifying women who are more likely to experience sexual difficulties, these scales may be used as prognostic factors in treatment studies.This study was funded, in part, by a grant from the Lilly Centre for Women's Health

Combined cocaine hydrolase gene transfer and anti-cocaine vaccine synergistically block cocaine-induced locomotion.

Mice and rats were tested for reduced sensitivity to cocaine-induced hyper-locomotion after pretreatment with anti-cocaine antibody or cocaine hydrolase (CocH) derived from human butyrylcholinesterase (BChE). In Balb/c mice, direct i.p. injection of CocH protein (1 mg/kg) had no effect on spontaneous locomotion, but it suppressed responses to i.p. cocaine up to 80 mg/kg. When CocH was injected i.p. along with a murine cocaine antiserum that also did not affect spontaneous locomotion, there was no response to any cocaine dose. This suppression of locomotor activity required active enzyme, as it was lost after pretreatment with iso-OMPA, a selective BChE inhibitor. Comparable results were obtained in rats that developed high levels of CocH by gene transfer with helper-dependent adenoviral vector, and/or high levels of anti-cocaine antibody by vaccination with norcocaine hapten conjugated to keyhole limpet hemocyanin (KLH). After these treatments, rats were subjected to a locomotor sensitization paradigm involving a "training phase" with an initial i.p. saline injection on day 1 followed by 8 days of repeated cocaine injections (10 mg/kg, i.p.). A 15-day rest period then ensued, followed by a final "challenge" cocaine injection. As in mice, the individual treatment interventions reduced cocaine-stimulated hyperactivity to a modest extent, while combined treatment produced a greater reduction during all phases of testing compared to control rats (with only saline pretreatment). Overall, the present results strongly support the view that anti-cocaine vaccine and cocaine hydrolase vector treatments together provide enhanced protection against the stimulatory actions of cocaine in rodents. A similar combination therapy in human cocaine users might provide a robust therapy to help maintain abstinence

Combined vaccine and vector treatment reduces cocaine-induced locomotor activity even after repeated cocaine injections.

<p>Shown are beam breaks per 5 min interval (mean ± SEM). Left panels: initial two days of training phase. Middle panels: last day of training phase. Right panels: both days of challenge phase. Statistical significance: * significantly higher locomotor activity after cocaine injections compared to saline (p<0.05); <b>&</b> significantly higher cocaine-induced locomotor activity than in the VAC+VEC group (p<0.01); <b>@</b> significantly higher cocaine-induced locomotor activity after the last cocaine injection compared to first injection (p<0.01); <b>#</b> significantly greater cocaine-induced locomotor activity in control group compared to all others (p<0.05).</p

Scheme for testing locomotor responses to cocaine.

<p>Rat locomotor experiments were carried out in four distinct phases. Phase 1, “Acclimation", consisted of 3 consecutive days of 45-min in the test chamber with no interventions. Phase 2, “Training", involved 9 days of 90 min in the chamber with an i.p. injection of saline (S) or cocaine, 10 mg/kg C) at the 45-min time point. Phase 3, “No Drug", involved 15 “rest days" in the home cage with no interventions. Phase 4, “Challenge", was 2 days in the chamber with i.p. saline or cocaine at the respective 45-min time points.</p

Average antibody (µg/ml) and/or enzyme (mU/ml) levels for the VAC, VEC, VEC+VAC treated rats during the Training and Cocaine Challenge Phases.

<p>Cocaine hydrolase activity and anti-cocaine antibody levels were assessed midway through the training phase (day 8) and at the onset of the challenge phase (day 29). Means and standard errors are shown. Neither of the measured variables changed significantly across the course of the experiment, and there were no significant differences for either variable across treatment groups.</p

Mean daily beam breaks after cocaine during training phase.

<p>Data represent rat locomotor activity in 8 daily 45 min sessions immediately following cocaine injections. Statistical significance: * significantly <i>lower</i> locomotor activity in VEC+VAC group compared to all other groups (p<0.05); <b>†</b> significantly <i>greater</i> locomotor activity on the final training-phase day compared to the first day (p<0.05).</p

Selective enzyme inhibitor relieves CocH suppression of locomotor response.

<p>Mice (groups of 8) habituated to locomotor activity chambers were given enzyme (CocH, 1 mg/kg, i.p.) or inhibitor (iso-OMPA, 50 mg/kg, s.c.) or both, followed 3 hr later by cocaine (40 mg/kg, i.p.). Controls received either i.p. saline or iso-OMPA alone. ** p<0.01.</p