2,339 research outputs found

    Theoretical backgrounds of durability analysis by normalized equivalent stress functionals

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    Generalized durability diagrams and their properties are considered for a material under a multiaxial loading given by an arbitrary function of time. Material strength and durability under such loading are described in terms of durability, safety factor and normalized equivalent stress. Relations between these functionals are analysed. We discuss some material properties including time and load stability, self-degradation (ageing), and monotonic damaging. Phenomenological strength conditions are presented in terms of the normalized equivalent stress. It is shown that the damage based durability analysis is reduced to a particular case of such strength conditions. Examples of the reduction are presented for some known durability models. The approach is applicable to the strength and durability description at creep and impact loading and their combination

    On the isospin dependence of the mean spin-orbit field in nuclei

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    By the use of the latest experimental data on the spectra of 133^{133}Sb and 131^{131}Sn and on the analysis of properties of other odd nuclei adjacent to doubly magic closed shells the isospin dependence of a mean spin-orbit potential is defined. Such a dependence received the explanation in the framework of different theoretical approaches.Comment: 52 pages, Revtex, no figure

    Measuring the Magnetic Field on the Classical T Tauri Star TW Hydrae

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    We present infrared (IR) and optical echelle spectra of the Classical T Tauri star TW Hydrae. Using the optical data, we perform detailed spectrum synthesis to fit atomic and molecular absorption lines and determine key stellar parameters: Teff = 4126 \pm 24 K, log g = 4.84 \pm 0.16, [M/H] = -0.10 \pm 0.12, vsini = 5.8 \pm 0.6 km/s. The IR spectrum is used to look for Zeeman broadening of photospheric absorption lines. We fit four Zeeman sensitive Ti I lines near 2.2 microns and find the average value of the magnetic field over the entire surface is 2.61 \pm 0.23 kG. In addition, several nearby magnetically insensitive CO lines show no excess broadening above that produced by stellar rotation and instrumental broadening, reinforcing the magnetic interpretation for the width of the Ti I lines. We carry out extensive tests to quantify systematic errors in our analysis technique which may result from inaccurate knowledge of the effective temperature or gravity, finding that reasonable errors in these quantities produce a 10% uncertainty in the mean field measurement.Comment: The tar file includes one Tex file and four .eps figures. The paper is accepted and tentatively scheduled for the ApJ 1 December 2005, v634, 2 issue. ApJ manuscript submission # 6310

    Geomorphological mapping and land use and land cover in vale dos vinhedos designation of origin -Rio Grande do Sul state, Brazil by geotechnologies.

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    The objective of this study was to investigate the land use and land cover patterns in the region Vale dos Vinhedos designation of origin and to relate them to the geomorphological mapping aiming to contribute to the implementation, monitoring and management of the areas intended to Geographical Indications for winesandsparkling wines. For this purpose, the geomorphology and the classes of land cover and land use were mapped. Both mappings were carried out usinggeotechnologiestechniques. The shape pattern similar to high Hills is the most representative in the study area, occupying 77.13%. In the mapping of land use and land cover, the most representative class is forests (native or not), occupying 36% of the study area. The intersection between of the geomorphological mapping with land use and land coverclassesresulted in the identification of morpho-environmental units. Keywords: Geographical indications.Space occupation.Management of the areas.Vineyards. MAPEAMENTO GEOMORFOLÓGICO E DE USO E COBERTURA DA TERRAPOR MEIO DE SENSORIAMENTO REMOTO E GEOPROCESSAMENTO O objetivo deste estudo foi investigar os padrĂ”es de uso e cobertura da terra na regiĂŁo da denominação de origem Vale dos Vinhedos e relaciona-los com omapeamento geomorfolĂłgico, visando contribuir para a implantação, monitoramento e gestĂŁo das ĂĄreas de indicaçÔes geogrĂĄficas para vinhose espumantes.Para esse estudo, mapeou-sea geomorfologia e as classes de uso e cobertura da terra. Ambos os mapeamentos foram realizados utilizando tĂ©cnicas desensoriamento remoto e geoprocessamento. O padrĂŁo de relevo em forma de morros, na ĂĄrea de estudo, possui maior representatividade,ocupando 77,13% da mesma. No mapeamento de uso e cobertura da terra a classeFloresta (nativa ou nĂŁo)ocupou cerca de 36% da mesma.O cruzamento entre o mapeamento geomorfolĂłgico e as classesde uso cobertura da terra permitiu identificar 35 classesde unidades morfoambientais. Palavras-chave: IndicaçÔes geogrĂĄficas.Ocupação do espaço.Gerenciamento de ĂĄreas.Vinhedos

    Exploring the psychological rewards of a familiar semirural landscape: connecting to local nature through a mindful approach

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    This study analyses a 53,000 word diary of a year engaging with nature through over 200 trips to a semi-rural landscape. Thematic analysis revealed two themes; the transition from observer to nature connectedness and the ways in which the natural environment was experienced once a connection was made. These themes are discussed in relation to theories that seek to explain the positive effect of nature and nature connectedness. The findings are important as they suggest that repeated engagement with local semi-rural countryside can lead to a mindful approach and psychological rewards that do not require travel into the wilderness. The work informs further research into outcomes and processes of nature based interventions such as: trip frequency, duration and diary keeping

    Information from physicians and retention of information by patients – Obstacles to the awareness of patients of progressing disease when life is near the end

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    <p>Abstract</p> <p>Background</p> <p>Discrepancies between the information that patients have received and the patients' awareness of their condition have frequently been observed in literature and given a number of different explanations. The chief contribution of this study is that by following patients over time it is possible not only to notice any changes in the patients' knowledge or awareness of their disease, but also to investigate the interview material for possible reasons for those changes. Since the study is based on two different groups of patients it will also be possible to notice if the category of disease matters for patients' awareness of their condition.</p> <p>Methods</p> <p>Twelve patients with malign haematological diseases or lung cancer were followed with interviews from diagnosis to cure or death, or at most for two years. The method is qualitative. Semi-structured interviews were conducted, transcribed into written text, and then used for a qualitative content analysis.</p> <p>Results</p> <p>During the process of analysis four different expressions (subcategories) emerged about the awareness of patients concerning their health status: informed and aware, not informed and not aware, aware though not informed, or not aware though informed. Then the search started for obstacles to the awareness of patients regarding their progressing disease and approaching death. Four kinds of obstacles were found: due to the physician, the patient, the physician and the patient in collusion, or neither to the physician nor the patient but the insidious way in which lung cancer (mostly) and haematological malignancies (occasionally) progress.</p> <p>Conclusion</p> <p>To optimize the care of patients who wish to be informed and aware during their disease, it is important that the health care staff recognizes potential obstacles to the awareness of patients in order to minimize such obstacles. The physicians could improve their communication with patients with life-threatening diseases, and avoid having a narrow focus on the treatment calendar. The patients could be encouraged to have a more proactive attitude in their communication with their physician.</p

    First Observation of the Rare Decay Mode K-long -> e+ e-

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    In an experiment designed to search for and study very rare two-body decay modes of the K-long, we have observed four examples of the decay K-long -> e+ e-, where the expected background is 0.17+-0.10 events. This observation translates into a branching fraction of 8.7^{+5.7}_{-4.1} X 10^{-12}, consistent with recent theoretical predictions. This result represents by far the smallest branching fraction yet measured in particle physics.Comment: 9 pages, 3 figure

    Dependence of direct neutron capture on nuclear-structure models

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    The prediction of cross sections for nuclei far off stability is crucial in the field of nuclear astrophysics. We calculate direct neutron capture on the even-even isotopes 124−145^{124-145}Sn and 208−238^{208-238}Pb with energy levels, masses, and nuclear density distributions taken from different nuclear-structure models. The utilized structure models are a Hartree-Fock-Bogoliubov model, a relativistic mean field theory, and a macroscopic-microscopic model based on the finite-range droplet model and a folded-Yukawa single-particle potential. Due to the differences in the resulting neutron separation and level energies, the investigated models yield capture cross sections sometimes differing by orders of magnitude. This may also lead to differences in the predicted astrophysical r-process paths. Astrophysical implications are discussed.Comment: 25 pages including 12 figures, RevTeX, to appear in Phys. Rev.

    Search for the Weak Decay of an H Dibaryon

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    We have searched for a neutral HH dibaryon decaying via H→ΛnH\to\Lambda n and H→Σ0nH\to\Sigma^0 n. Our search has yielded two candidate events from which we set an upper limit on the HH production cross section. Normalizing to the inclusive Λ\Lambda production cross section, we find (dσH/dΩ)/(dσΛ/dΩ)<6.3×10−6(d\sigma_H/d\Omega) / (d\sigma_\Lambda/d\Omega) < 6.3\times 10^{-6} at 90% C.L., for an HH of mass ≈\approx 2.15 GeV/c2c^2.Comment: 11 pages, 6 postscript figures, epsfig, aps, preprint, revte
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