71,026 research outputs found

    Decomposition unit Patent

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    Unit for generating thrust from catalytic decomposition of hydrogen peroxide, for high altitude aircraft or spacecraft reaction contro

    Theoretical mean colors for RR Lyrae variables

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    A hydrodynamically pulsating 0.6 solar mass model of a typical RR Lyrae variable was studied with a radiation transport-hydrodynamic computer program to predict theoretical T sub 3 and colors at many phases and to find the proper methods for getting mean colors and the consequent mean effective temperatures. The variable Eddington radiation approximation method was used with gray and with multifrequency absorption coefficients to represent the radiation flow in the outer optically thin layers. Comparison between observed and computed B-V colors indicate that these low Z population 2 models are reasonably accurate using King 1A composition opacities. The well known Oke, Giver, and Searle relation between B-V and T sub e reproduced. Mean colors were found by four different averaging methods. The method that gives a mean color and the mean T sub e closest to the nonpulsating model was the separate intensity means of B and V

    Controlled Natural Language Generation from a Multilingual FrameNet-based Grammar

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    This paper presents a currently bilingual but potentially multilingual FrameNet-based grammar library implemented in Grammatical Framework. The contribution of this paper is two-fold. First, it offers a methodological approach to automatically generate the grammar based on semantico-syntactic valence patterns extracted from FrameNet-annotated corpora. Second, it provides a proof of concept for two use cases illustrating how the acquired multilingual grammar can be exploited in different CNL applications in the domains of arts and tourism

    Chiral Vortons and Cosmological Constraints on Particle Physics

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    We investigate the cosmological consequences of particle physics theories that admit stable loops of current-carrying string - vortons. In particular, we consider chiral theories where a single fermion zero mode is excited in the string core, such as those arising in supersymmetric theories with a D-term. The resulting vortons formed in such theories are expected to be more stable than their non-chiral cousins. General symmetry breaking schemes are considered in which strings formed at one symmetry breaking scale become current-carrying at a subsequent phase transition. The vorton abundance is estimated and constraints placed on the underlying particle physics theories from cosmological observations. Our constraints on the chiral theory are considerably more stringent than the previous estimates for more general theories.Comment: minor corrections made. This version will appear in PR

    Inverting Ray-Knight identity

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    We provide a short proof of the Ray-Knight second generalized Theorem, using a martingale which can be seen (on the positive quadrant) as the Radon-Nikodym derivative of the reversed vertex-reinforced jump process measure with respect to the Markov jump process with the same conductances. Next we show that a variant of this process provides an inversion of that Ray-Knight identity. We give a similar result for the Ray-Knight first generalized Theorem.Comment: 18 page

    Debris/ice/TPS assessment and integrated photographic analysis for Shuttle Mission STS-54

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    A Debris/Ice/TPS assessment and integrated photographic analysis was conducted for Shuttle Mission STS-54. Debris inspections of the flight elements and launch pad were performed before and after launch. Ice/frost conditions on the External Tank were assessed by the use of computer programs, nomographs, and infrared scanner data during cryogenic loading of the vehicle followed by on-pad visual inspection. High speed photography was analyzed after launch to identify ice/debris sources and evaluate potential vehicle damage and/or in-flight anomalies. This report documents the debris/ice/TPS conditions and integrated photographic analysis of Shuttle Mission STS-54, and the resulting effect on the Space Shuttle Program

    Debris/ice/TPS assessment and integrated photographic analysis for Shuttle Mission STS-46

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    A Debris/Ice/TPS assessment and integrated photographic analysis was conducted for Shuttle Mission STS-46. Debris inspections of the flight elements and launch pad were performed before and after launch. Ice/frost conditions on the External Tank were assessed by the use of computer programs, nomographs, and infrared scanner data during cryogenic loading of the vehicle followed by on-pad visual inspection. High speed photography was analyzed after launch to identify ice/debris sources and evaluate potential vehicle damage and/or in-flight anomalies. This report documents the debris/ice/TPS conditions and integrated photographic analysis of Shuttle Mission STS-46, and the resulting effect on the Space Shuttle Program

    Debris/ice/TPS assessment and photographic analysis for Shuttle Mission STS-42

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    A Debris/Ice/TPS (Thermal Protection System) assessment and photographic analysis was conducted for Shuttle Mission STS-42. Debris inspection of the flight elements and launch pad were performed before and after launch. Ice/frost conditions on the External Tank were assessed by the use of computer programs, nomographs, and infrared scanner data during cryogenic loading of the vehicle followed by on-pad visual inspection. High speed photography was analyzed after launch to identify ice/debris sources and evaluate potential vehicle damage and/or in-flighr anomalies. The debris/ice/TPS conditions are documented along with photographic analysis of Mission STS-42, and their overall effect on the Space Shuttle Program

    Debris/ice/TPS assessment and integrated photographic analysis for Shuttle mission STS-47

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    A debris/ice/TPS assessment and integrated photographic analysis was conducted for Shuttle Mission STS-47. Debris inspections of the flight elements and launch pad were performed before and after launch. Ice/frost conditions on the External Tank were assessed by the use of computer programs, nomographs, and infrared scanner data during cryogenic loading of the vehicle followed by on-pad visual inspection. High speed photography was analyzed after launch to identify ice/debris sources and evaluate potential vehicle damage and/or in-flight anomalies. This report documents the debris/ice/TPS conditions and integrated photographic analysis of Shuttle Mission STS-47, and the resulting effect on the Space Shuttle Program
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