5,972 research outputs found

    Study to determine an improved method for Apollo propellant system decontamination and propellant tank drying Summary report

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    Vapor phase cleaning method for Apollo propellant system decontamination and propellant tank dryin

    Simplifications to A New Approach to the Covering Radius...”

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    We simplify the proofs of four results in [3], restating two of them for greater clarity. The main purpose of this note is to give a brief transparent proof of Theorem 7 of [3], the main upper bound of that paper. The secondary purpose is to give a more direct statement and proof of the integer programming determination of covering radius of [3]. Theorem 7 of [3] follows from a simple result in [2], which we state with the notation (for the linear code A)

    Significance of low energy impact damage on modal parameters of composite beams by design of experiments

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    This paper presents an experimental study on the effects of multi-site damage on the vibration response of composite beams damaged by low energy impacts around the barely visible impact damage limit (BVID). The variation of the modal parameters with different levels of impact energy and density of damage is studied. Vibration tests have been carried out with both burst random and classical sine dwell excitations in order to compare that which of the methods among Polymax and Half Bandwidth Method is more suitable for damping estimation in the presence of damage. Design of experiments (DOE) performed on the experimental data show that natural frequency is a more sensitive parameter for damage detection than the damping ratio. It also highlighted energy of impact as the factor having a more significant effect on the modal parameters. Half Bandwidth Method is found to be unsuitable for damping estimation in the presence of damage

    Hypothermia associated with clobazam use in adult epilepsy

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    AbstractClobazam, a 1,5-benzodiazepine FDA-approved in 2011, is commonly used to treat anxiety and epilepsy. It has not been associated with hypothermia until very recently, in a case report involving two pediatric patients. Here, we report the first case of hypothermia development in an adult patient with epilepsy associated with clobazam use. A couple months after starting clobazam, the patient started developing episodes of hypothermia every several weeks, with temperatures ranging from 90°F–95°F. Normothermia was achieved with Bair Hugger therapy. Thyroid-stimulating hormone and cortisol levels were normal, and there was no evidence of infection in most instances. After 11 total episodes of hypothermia over a year of clobazam use, the drug was discontinued. It has now been 7months after discontinuation, and the patient has not experienced any more episodes of hypothermia. Early recognition of the link between clobazam and hypothermia may prevent avoidable Emergency Department visits and hospitalizations

    Orbital operations study. Appendix B: Operational procedures

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    Operational procedures for each alternate approach for each interfacing activity of the orbital operations study are presented. The applicability of the procedures to interfacing element pairs is identified

    Ozone Depletion from Nearby Supernovae

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    Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time, improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made in theoretical modeling of supernovae and of the resultant gamma-ray spectra. In addition, one now has better knowledge of the occurrence rate of supernovae in the galaxy, and of the spatial distribution of progenitors to core-collapse supernovae. We report here the results of two-dimensional atmospheric model calculations that take as input the spectral energy distribution of a supernova, adopting various distances from Earth and various latitude impact angles. In separate simulations we calculate the ozone depletion due to both gamma-rays and cosmic rays. We find that for the combined ozone depletion roughly to double the ``biologically active'' UV flux received at the surface of the Earth, the supernova must occur at <8 pc. Based on the latest data, the time-averaged galactic rate of core-collapse supernovae occurring within 8 pc is ~1.5/Gyr. In comparing our calculated ozone depletions with those of previous studies, we find them to be significantly less severe than found by Ruderman (1974), and consistent with Whitten et al. (1976). In summary, given the amplitude of the effect, the rate of nearby supernovae, and the ~Gyr time scale for multicellular organisms on Earth, this particular pathway for mass extinctions may be less important than previously thought.Comment: 24 pages, 4 Postscript figures, to appear in The Astrophysical Journal, 2003 March 10, vol. 58

    On Perfect Weighted Coverings with Small Radius

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    We extend the results of our previous paper [8] to the nonlinear case: The Lloyd polynomial of the covering has at least R distinct roots among 1, ... , n, where R is the covering radius. We investigate PWC with diameter 1, finding a partial characterization. We complete an investigation begun in [8] on linear PMC with distance 1 and diameter 2
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