12,819 research outputs found

    A Kam Theorem for Space-Multidimensional Hamiltonian PDE

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    We present an abstract KAM theorem, adapted to space-multidimensional hamiltonian PDEs with smoothing non-linearities. The main novelties of this theorem are that: ∙\bullet the integrable part of the hamiltonian may contain a hyperbolic part and as a consequence the constructed invariant tori may be unstable. ∙\bullet It applies to singular perturbation problem. In this paper we state the KAM-theorem and comment on it, give the main ingredients of the proof, and present three applications of the theorem .Comment: arXiv admin note: text overlap with arXiv:1502.0226

    Single nanoparticle measurement techniques

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    Various single particle measuring techniques are briefly reviewed and the basic concepts of a new micro-SQUID technique are discussed. It allows measurements of the magnetization reversal of single nanometer-sized particles at low temperature. The influence of the measuring technique on the system of interest is discussed.Comment: 3 pages, 3 figures, conference proceedings of MMM 1999, San Jose, 15-18 Nov., session number BE-0

    A Meta-Analysis of Political Advertising

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    Political advertising is one of the dominant media for reaching voters. Previous metaanalyses (Allen & Burrell, 2002; Lau, Sigelman, Heldman, & Babbitt, 1999) found little or no net benefit to negative versus positive ads. However, this finding does not reveal whether ads have effects (both or neither could be persuasive). A meta-analysis revealed that political spots increased issue knowledge, influenced perceptions of the candidates’ character, altered attitudes, and affected candidate preference; influenced agenda-setting, and altered vote likelihood (turnout). One moderator variable was detected: The effect size for learning was larger for studies of students than non-students; however, the effect size for both sub-groups was significant. On the other hand, political ads had larger effects on attitudes for non-students than students

    Chromatographic test facility. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

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    Test facility to verify design concepts and mathematical models of chromatograph for atmospheric composition analysis of Mar

    Photosynthetic Gas Exchange in the Closed Ecosystem for Space. Phase II, Part III. Screening for Thermophilic Algae and Mutation Studies

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    An algal screening and mutation study was undertaken to obtain algae superior to Chlorella 71105 for use in a photosynthetic gas exchanger. Of the forty-four thermophilic algae studied, eighteen appeared to have growth rates as great as Chlorella 71105. Optimization of the physical and chemical environments of these strains is recommended as a way to further improve growth rates and concomitant oxygen production. The mutation study revealed that Chlorella 71105 is relatively resistant to germicidal ultraviolet radiation. No high temperature mutants of Chlorella 71105 were found
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