1000 resultados para Airtraq(r)


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We present a search for tau sneutrino production using the Tevatron ppbar collision data collected with the CDF II detector and corresponding to an integrated luminosity of 1 fb^-1. We focus on the scenarios predicted by the R-parity violating (RPV) supersymmetric models in which tau sneutrinos decay to two charged leptons of different flavor. With the data consistent with the standard model expectations, we set the upper limits on sigma(ppbar -> tau sneutrino)*BR(tau sneutrino ->emu,mutau,etau) and use these results to constrain the RPV couplings as a function of tau sneutrino mass.

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Abstract (Irony as object of research: Is it possible to explore what is between the lines?): The main concern of this article is the interpretation of irony: how is it brought about and how can it be investigated? The method applied is based on authentic texts and their elicited interpretations − a method referred to in this article response analysis. Interpretation of irony in the approach taken is seen as being crucially dependent on the notion of coherence. A text is perceived as being coherent if it (a) makes sense and if it(b) hangs together. Incoherent texts can result in an ironic interpretation; however, the incoherence must also be perceived as being intentional, and intentionality in turn is a sign of the edge of the ironist. Ironic interpretation is defined as a combination of five factors: (1) an ironic edge that (2) reflects the intention of the ironist, and (3) has a target and (4) a victim too. Essential to irony is its fifth factor, the fact that one or more of these four factors must be inferred from co(n)text. This definition of irony is crucial in distinguishing irony from non-irony, and it also helps to discern the differences as well as the similarities between irony and related phenomena.

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Dimerization of thiolbenzoic acid has been studied by infra-red, ultra-violet and n.m.r. spectroscopy and cryoscopy. The results indicate that the tendency to form S - H. O hydrogen bonds is not appreciable.

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An analysis of eccentrically loaded short reinforced concrete columns using a variable failure strain criterion is presented. The method dispenses with the usual procedure of assuming a fixed value for the ultimate strain in concrete. The analysis is based on the use of a simple, single equation for the complete stress-strain curve of concrete and the adoption of a process of maximisation of moment with respect to extreme fibre concrete compressive strain. Columns of rectangular section and loaded eccentrically along one axis only are considered in this paper. A good agreement is observed between the theoretical and experimental values of some test results.

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Stress-strain characteristics of concrete confined in steel binders have been determined. A new factor “confinement index” has been introduced for a quantitative measure of the confinement and using these results a “stress-block” has been developed. Tests have been made on simply supported reinforced concrete beams with spiral binder confinement and analysed on the basis of the proposed stress-block. Tests have also been made oon reinforced concrete portal frames and continuous beams with spiral binder confinement at sections of possible plastic hinge formation. An analysis of these tests indicates that a full redistribution of moments has taken place at ultimate.

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A method is presented for obtaining lower bound on the carrying capacity of reinforced concrete foundation slab-structures subject to non-uniform contact pressure distributions. Functional approach suggested by Vallance for simply supported square slabs subject to uniform pressure distribution has been extended to simply supported rectangular slabs subject to symmetrical non-uniform pressure distributions. Radial solutions, ideally suited for rotationally symmetric problems, are shown to be adoptable for regular polygonal slabs subject to contact pressure paraboloids with constant edge pressures. The functional approach has been shown to be well suited even when the pressure is varying along the edges.

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The r.f. absorption experiment performed on YBa2Cu3O7-x ceramic pellets using a CW NMR spectrometer shows some novel observed in the microwave range.

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Mononuclear, binuclear and trinuclear silver(l) complexes were obtained unexpectedly while probing the reactivity of diphosphazane ligands of the type X2PN(Pr-i)PXY towards the ruthenium-based precursor Ru(bipy)(2)Cl-2 center dot 2H(2)O, in the presence of a silver salt as a chloride scavenger. Subsequently, the reactions of AgX [X = Cl, NO3 or CF3SO3] with Ph2PN(R)PPh(Y) [R = H, Y = Ph; R = Pr-i, Y = Ph or OC6H3Me2-2,6] in a 1: 1 or 1:2 molar ratio have been investigated. Mononuclear or binuclear Ag(I) complexes containing either chelating or bridging diphosphazane ligands are obtained. Trinuclear silver(l) complexes are accessible by the treatment of diphosphazane ligands, Ph2PN(R)PPh2 [R = H, Pr-i] with AgCl using piperidine as the solvent. In the presence of a suitable chloride donor species, the mononuclear and binuclear complexes of Ph2PN(Pr-i)PPh2 are transformed slowly to the trinuclear complex [Ag-3(mu-Cl)(2){Ph2PN(Pr-i)PPh2}(3)]X, over a period 20 h. The structures of representative complexes have been confirmed by X-ray crystallography and the salient structural features are discussed

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We construct an invariant of certain open four-manifolds using the Heegaard Floer theory of Ozsvath and Szabo. We show that there is a manifold X homeomorphic to R-4 for which the invariant is non-trivial,showing that X is an exotic R-4. This is the first invariant that detects exotic R-4' s. (C) 2009 Published by Elsevier GmbH.

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The first enantiospecific synthesis of a thapsane, containing three contiguous quaternary carbon atoms, is accomplished starting from R-carvone. An intramolecular alkylation and an intramolecular diazoketone cyclopropanation reaction were employed for the stereo- and regiospecific generation of three contiguous quaternary carbon atoms present in the thapsane framework.

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1S,5R,7R)-(-)-10, 10-Dimethyl-3-ethyl-4-oxa--atricyclo[5.2.1.0(1,5)]dec-2-ene 2 was prepared in 95% yield from (1S)-1-amino-2-exo-hydroxyapocamphane 1. The chiral oxazoline could be alkylated (Lhttp://eprints.iisc.ernet.in/cgi/users/home?screen=EPrint::Edit&eprintid=31175&stage=core#tDA/THF/-78 degrees C/RX, RX = ethyl, n-propyl, n-butyl iodides or benzyl bromide) to 3 in 95% yield and > 95% diastereoselectivity, and the products hydrolysed to (R)-2-methylalkanoic acids 4 (43-47% yield, 93-98% e.e.). (C) 2000 Elsevier Science Ltd. All rights reserved.