990 resultados para 338.09


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e argue that the extraordinary fact that all three known millisecond pulsars are very close to the galactic plane implies that there must be ~100 potentially observable millisecond pulsars within ~4 kpc from the Sun. Our other main conclusion is that the dipole magnetic fields or old neutron stars probably saturate around 5 x 108 gauss.

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This paper reports measurements of turbulent quantities in an axisymmetric wall jet subjected to an adverse pressure gradient in a conical diffuser, in such a way that a suitably defined pressure-gradient parameter is everywhere small. Self-similarity is observed in the mean velocity profile, as well as the profiles of many turbulent quantities at sufficiently large distances from the injection slot. Autocorrelation measurements indicate that, in the region of turbulent production, the time scale of ν fluctuations is very much smaller than the time scale of u fluctuations. Based on the data on these time scales, a possible model is proposed for the Reynolds stress. One-dimensional energy spectra are obtained for the u, v and w components at several points in the wall jet. It is found that self-similarity is exhibited by the one-dimensional wavenumber spectrum of $\overline{q^2}(=\overline{u^2}+\overline{v^2}+\overline{w^2})$, if the half-width of the wall jet and the local mean velocity are used for forming the non-dimensional wavenumber. Both the autocorrelation curves and the spectra indicate the existence of periodicity in the flow. The rate of dissipation of turbulent energy is estimated from the $\overline{q^2}$ spectra, using a slightly modified version of a previously suggested method.

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This thesis report attempts to improve the models for predicting forest stand structure for practical use, e.g. forest management planning (FMP) purposes in Finland. Comparisons were made between Weibull and Johnson s SB distribution and alternative regression estimation methods. Data used for preliminary studies was local but the final models were based on representative data. Models were validated mainly in terms of bias and RMSE in the main stand characteristics (e.g. volume) using independent data. The bivariate SBB distribution model was used to mimic realistic variations in tree dimensions by including within-diameter-class height variation. Using the traditional method, diameter distribution with the expected height resulted in reduced height variation, whereas the alternative bivariate method utilized the error-term of the height model. The lack of models for FMP was covered to some extent by the models for peatland and juvenile stands. The validation of these models showed that the more sophisticated regression estimation methods provided slightly improved accuracy. A flexible prediction and application for stand structure consisted of seemingly unrelated regression models for eight stand characteristics, the parameters of three optional distributions and Näslund s height curve. The cross-model covariance structure was used for linear prediction application, in which the expected values of the models were calibrated with the known stand characteristics. This provided a framework to validate the optional distributions and the optional set of stand characteristics. Height distribution is recommended for the earliest state of stands because of its continuous feature. From the mean height of about 4 m, Weibull dbh-frequency distribution is recommended in young stands if the input variables consist of arithmetic stand characteristics. In advanced stands, basal area-dbh distribution models are recommended. Näslund s height curve proved useful. Some efficient transformations of stand characteristics are introduced, e.g. the shape index, which combined the basal area, the stem number and the median diameter. Shape index enabled SB model for peatland stands to detect large variation in stand densities. This model also demonstrated reasonable behaviour for stands in mineral soils.

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Sr1-xMnxTiO3 (where x=0.03, 0.05, 0.07 and 0.09) was synthesized via different routes that include solid-state, oxalate precipitation and freeze drying. In oxalate precipitation technique, compositions corresponding to 3 and 5 mol% doping of Mn were monophasic whereas the higher compositions revealed the presence of the secondary phases such as MnO, Mn3O4 etc., as confirmed by high resolution X-ray diffraction (XRD) studies. The decomposition behavior of the precursors prepared using oxalate precipitation method corresponding to the above mentioned compositions was studied. Nanopowders of compositions pertaining to 5 to 9 mol% of Mn doping were obtained using freeze-drying technique. The average crystallite size of these nanopowders was found to be in the 35 to 65 nm range. The microstructural studies carried out on the sintered ceramics, fabricated using powders synthesized by different routes established the fine grained nature ( < 1 mu m) of the one obtained by freeze drying method. Raman scattering studies were carried out in order to complement the observations made from XRD regarding the phase purity. The dielectric properties of the ceramics obtained by different synthesis routes were studied in the 80-300 K temperature range at 100 kHz and the effect of grain size has been discussed. (C) 2012 Elsevier Inc. All rights reserved.

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In the search for more efficacious and less toxic cancer drugs, the tumor suppressor p53 protein has long been a desirable therapeutic target. In the recent past, few independent studies have demonstrated that the antitumor activity of wild-type p53 can be restored in cancer cells harboring mutant form of p53 using small molecule activators. In this study, we describe a novel small molecule MPK-09, which is selective and highly potent against allele specific p53 mutations mainly, R175H, R249S, R273H, R273C, and E285K. Except E285K, all other mutations tested are among the six ``hot spot'' p53 mutations reported in majority of human cancer. Furthermore, our study conclusively demonstrates that the apoptotic activity of the small molecule MPK-09 against cancer cells harboring R273C and E285K mutations is due to restoration of the wild-type conformation to the corresponding mutant form of p53.

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We report large scale deposition of tapered zinc oxide (ZnO) nanorods on Si(100) substrate by using newly designed metal-organic complex of zinc (Zn) as the precursor, and microwave irradiation assisted chemical synthesis as a process. The coatings are uniform and high density ZnO nanorods (similar to 1.5 mu m length) grow over the entire area (625 mm(2)) of the substrate within 1-5 min of microwave irradiation. ZnO coatings obtained by solution phase deposition yield strong UV emission. Variation of the molecular structure/molecular weight of the precursors and surfactants influence the crystallinity, morphology, and optical properties of ZnO coatings. The precursors in addition with the surfactant and the solvent are widely used to obtain desired coating on any substrate. The growth mechanism and the schematics of the growth process of ZnO coatings on Si(100) are discussed. (c) 2013 Elsevier B.V. All rights reserved.

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Consultoria de Orçamento e Fiscalização Financeira - Núcleo de Assuntos Econômico-Fiscais.

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Defende a necessidade de complementar a autonomia política do Distrito Federal, através da eleição direta para Governador, Vice-governador e Legislativo local.

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Questiona as reclamações de deputados quanto às condições de trabalho e de habitabilidade de Brasília e alerta quanto às manifestações para o retorno da Capital para o Rio de Janeiro.

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Discussão do Projeto de Lei nº 1.234, de 1956, que dispõe sobre a mudança da Capital Federal e dá outras providências. Reparos à natureza jurídica e aos plenos poderes dados à Companhia Urbanizadora da Nova Capital. Apresentação de emendas ao PL 1.234/56. Apartes: Emival Caiado, Wagner Estelita, Fonseca e Silva e Corrêa e Costa.