4,674 research outputs found

    Stress-wave analysis technique study on thick-walled type A302B steel pressure vessels, July 1968 - July 1969

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    Stress wave analysis and crack opening displacement to monitor subcritical crack growth for grade B alloy steel pressure vessel

    Current-driven and field-driven domain walls at nonzero temperature

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    We present a model for the dynamics of current- and field-driven domain-wall lines at nonzero temperature. We compute thermally-averaged drift velocities from the Fokker-Planck equation that describes the nonzero-temperature dynamics of the domain wall. As special limits of this general description, we describe rigid domain walls as well as vortex domain walls. In these limits, we determine also depinning times of the domain wall from an extrinsic pinning potential. We compare our theory with previous theoretical and experimental work

    A to Z of the Muon anomalous magnetic moment in the MSSM with Pati-Salam at the GUT scale

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    We analyse the low energy predictions of the minimal supersymmetric standard model (MSSM) arising from a GUT scale Pati-Salam gauge group further constrained by an A4 × Z5 family symmetry, resulting in four soft scalar masses at the GUT scale: one left-handed soft mass m0 and three right-handed soft masses m1, m2, m3, one for each generation. We demonstrate that this model, which was initially developed to describe the neutrino sector, can explain collider and non-collider measurements such as the dark matter relic density, the Higgs boson mass and, in particular, the anomalous magnetic moment of the muon (g − 2)μ. Since about two decades, (g − 2)μ suffers a puzzling about 3σ excessoftheexperimentallymeasuredvalueoverthetheoreticalprediction,whichour model is able to fully resolve. As the consequence of this resolution, our model predicts specific regions of the parameter space with the specific properties including light smuons and neutralinos, which could also potentially explain di-lepton excesses observed by CMS and ATLAS

    The health impacts of poor housing conditions and thermal discomfort

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    On summer and winter months, cardiovascular morbidity and mortality rates vary throughout Europe. For example, areas with mild winters seem to be the ones with higher number of seasonal mortality. In fact, Portugal is one of the southern countries together with Ireland that have higher mortality in winter. However, the number of studies relating cold weather with morbidity/mortality is still very rare. These occurrences are suspected to be associated with housing quality especially thermal insulation. In order to assess the relation between the incidence of coronary events and housing conditions in Portugal, a survey on inpatients with any form of acute coronary syndromes was undertaken during winter months, in order to get some data about houseability and residents behavior attitudes against cold exposure. It remained clear that poor housing conditions and/or lack of protective measures against cold exposure are common in Portugal. A better knowledge about the impact of weather and climate on health may be applied to built up a set of regulations for housing design (for new but also for old dwellings restoration); but also it is essential for the establishment of adaptation and mitigation policies and strategies, as well as on health planning and on the development of early warning systems.info:eu-repo/semantics/publishedVersio

    Espermatogênese de tambaqui (Colossoma macropomum) criado em cativeiro.

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    No Amazonas, o constante aumento da pressão da pesca extrativista sobre os estoques de populações naturais de peixe, associado ao aumento da demanda pelo pescado, vêm contribuindo para a propagação da piscicultura no Estado. Neste cenário destaca-se o tambaqui, representando o melhor candidato nativo para a piscicultura intensiva na Amazônia e em outras áreas do Brasil. Devido a crescente relevância desta espécie na aqüicultura da região Norte e nacional, o presente trabalho propõe-se a detalhar o processo espermatogênico de tambaquis criados em cativeiro, através de estudos histológicos e de estimativas dos níveis plasmáticos de esteróides sexuais

    Topological phase transitions between chiral and helical spin textures in a lattice with spin-orbit coupling and a magnetic field

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    We consider the combined effects of large spin-orbit couplings and a perpendicular magnetic field in a 2D honeycomb fermionic lattice. This system provides an elegant setup to generate versatile spin textures propagating along the edge of a sample. The spin-orbit coupling is shown to induce topological phase transitions between a helical quantum spin Hall phase and a chiral spin-imbalanced quantum Hall state. Besides, we find that the spin orientation of a single topological edge state can be tuned by a Rashba spin-orbit coupling, opening an interesting route towards quantum spin manipulation. We discuss the possible realization of our results using cold atoms trapped in optical lattices, where large synthetic magnetic fields and spin-orbit couplings can be engineered and finely tuned. In particular, this system would lead to the observation of a time-reversal-symmetry-broken quantum spin Hall phase.Comment: 8 pages, 3 figures, Accepted in Europhys. Lett. (Dec 2011
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