5,873 research outputs found

    Ventilation Loss in the NASA Space Shuttle Crew Protective Garments: Potential for Heat Stress

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    The potential of the National Aeronautics and Space Administration (NASA) S1035 Launch/Entry suit (LES) for producing heat stress in a simulated Space Shuttle cabin environment has been studied. The testing was designed to determine if the NASA S1035 poses a greater threat of inducing heat stress than the NASA S1032. Conditions were designed to simulate an extreme prelaunch situation, with chamber temperatures maintained at dry bulb temperature 27.2 +/- 0.1 C, globe temperature - 27.3 +/- 0.1 C, and wet bulb temperature 21.1 +/- 0.3 C. Four males, aged 28-48, were employed in this study, with three subjects having exposures in all four conditions and the fourth subject exposed to 3 conditions. Test durations in the ventilated (V) and unventilated (UV) conditions were designed for 480 minutes, which all subjects achieved. No significant differences related to experimental conditions were noted in rectal temperatures, heart rates or sweat rates. The results indicate that the S1032 and S1035 garments, in either the V or UV state, poses no danger of inducing unacceptable heat stress under the conditions expected within the Shuttle cabin during launch or re-entry

    Implications of Scaling Violations of F2 at HERA for Perturbative QCD

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    We critically examine the QCD predictions for the Q2Q^2 dependence of the electron-proton deep-inelastic structure function F2(x,Q2)F_2(x,Q^2) in the small xx region, which is being probed at HERA. The standard results based on next-to-leading order Altarelli-Parisi evolution are compared with those that follow from the BFKL equation, which corresponds to the resummation of the leading log(1/x)(1/x) terms. The effects of parton screening are also quantified. The theoretical predictions are confronted with each other, and with existing data from HERA. (3 Postscript figures included).Comment: (8 Latex Pages) IFJ 1653/P

    Ventilation loss and pressurization in the NASA launch/entry suit: Potential for heat stress

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    The potential of the NASA Launch/Entry Suit (LES) for producing heat stress in a simulated Space Shuttle cabin environment was studied. The testing was designed to identify potential heat stress hazards if the LES were pressurized or if ventilation were lost. Conditions were designed to simulate an extreme pre-launch situation with chamber temperatures maintained at dry bulb temperature = 27.2 +/- 0.1 C, globe temperature = 27.3 +/- 0.1 C, and wet bulb temperature = 21.1 +/- 0.3 C. Two females and two males, 23 to 34 years of age, were employed in this study, with two subjects having exposures in all 3 conditions. Test durations in the ventilated (V) and unventilated (UV) conditions were designed for 480 minutes, which all subjects achieved. Pressurized runs (Pr) were designed for 45 minutes, which all subjects also achieved. While some significant differences related to experimental conditions were noted in rectal and mean skin temperatures, evaporation rates, sweat rates, and heart rate, these differences were not thought to be physiologically significant. The results indicate that the LES garment, in either the Pr or UV state, poses no danger of inducing unacceptable heat stress under the conditions expected within the Space Shuttle cabin during launch or reentry

    QCD Predictions for the Transverse Energy Flow in Deep-Inelastic Scattering in the Small x HERA Regime

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    The distribution of transverse energy, ETE_T, which accompanies deep-inelastic electron-proton scattering at small xx, is predicted in the central region away from the current jet and proton remnants. We use BFKL dynamics, which arises from the summation of multiple gluon emissions at small xx, to derive an analytic expression for the ETE_T flow. One interesting feature is an xϵx^{-\epsilon} increase of the ETE_T distribution with decreasing xx, where ϵ=(3αs/π)2log2\epsilon = (3\alpha_s/\pi)2\log 2. We perform a numerical study to examine the possibility of using characteristics of the ETE_T distribution as a means of identifying BFKL dynamics at HERA.Comment: 16 pages, REVTEX 3.0, no figures. (Hardcopies of figures available on request from Professor A.D. Martin, Department of Physics, University of Durham, DH1 3LE, England.) Durham preprint : DTP/94/0

    The effect of disgust and fear modeling on children’s disgust and fear for animals

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    Disgust is a protective emotion associated with certain types of animal fears. Given that a primary function of disgust is to protect against harm, increasing children’s disgust-related beliefs for animals may affect how threatening they think animals are and their avoidance of them. One way that children’s disgust beliefs for animals might change is via vicarious learning: by observing others responding to the animal with disgust. In Experiment 1, children (ages 7–10 years) were presented with images of novel animals together with adult faces expressing disgust. Children’s fear beliefs and avoidance preferences increased for these disgust-paired animals compared with unpaired control animals. Experiment 2 used the same procedure and compared disgust vicarious learning with vicarious learning with fear faces. Children’s fear beliefs and avoidance preferences for animals again increased as a result of disgust vicarious learning, and animals seen with disgust or fear faces were also rated more disgusting than control animals. The relationship between increased fear beliefs and avoidance preferences for animals was mediated by disgust for the animals. The experiments demonstrate that children can learn to believe that animals are disgusting and threatening after observing an adult responding with disgust toward them. The findings also suggest a bidirectional relationship between fear and disgust with fear-related vicarious learning leading to increased disgust for animals and disgust-related vicarious learning leading to increased fear and avoidance

    Insecticidal Control of the Sugar-Beet Root Maggot and Yield of Sugar Beets.

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    uploaded by Plazi from Taxodro

    Deep inelastic events containing a forward photon as a probe of small xx dynamics

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    We calculate the rate of producing deep inelastic events containing an energetic isolated forward photon at HERA. We quantify the enhancement arising from the leading log1/x\log 1/x gluon emissions with a view to using such events to identify the underlying dynamics.Comment: 11 pages, Latex, 7 ps figure

    The description of F2 at small x incorporating angular ordering

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    We study the perturbative QCD description of the HERA measurements of F2(x,Q2)F_2 (x, Q^2) using a gluon distribution that is obtained from an evolution incorporating angular ordering of the gluon emissions, and which embodies both GLAP and BFKL dynamics. We compare the predictions with recent HERA data for F2F_2. We present estimates of the charm component F2c(x,Q2)F_2^c (x, Q^2) and of FL(x,Q2)F_L (x, Q^2).Comment: 8 LaTeX pages + 4 uuencoded figure

    Transverse Energy Flow at HERA

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    We calculate the transverse energy flow accompanying small xx deep-inelastic events and compare with recent data obtained at HERA. In the central region between the current jet and the remnants of the proton we find that BFKL leading ln(1/x)\ln(1/x) dynamics gives a distinctively large transverse energy distribution, in approximate agreement with recent data.Comment: 8 LaTeX pages, 4 figures included as uuencoded postscript at the end of the LaTeX file, Durham preprint DTP/94/3
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