15,205 research outputs found

    Formal aspects of component software

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    This is the pre-proceedings of 6th International Workshop on Formal Aspects of Component Software (FACS'09)

    Electrical control of metallic heavy-metal/ferromagnet interfacial states

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    Voltage control effects provide an energy-efficient means of tailoring material properties, especially in highly integrated nanoscale devices. However, only insulating and semiconducting systems can be controlled so far. In metallic systems, there is no electric field due to electron screening effects and thus no such control effect exists. Here we demonstrate that metallic systems can also be controlled electrically through ionic not electronic effects. In a Pt/Co structure, the control of the metallic Pt/Co interface can lead to unprecedented control effects on the magnetic properties of the entire structure. Consequently, the magnetization and perpendicular magnetic anisotropy of the Co layer can be independently manipulated to any desired state, the efficient spin toques can be enhanced about 3.5 times, and the switching current can be reduced about one order of magnitude. This ability to control a metallic system may be extended to control other physical phenomena.Comment: 20 pages, 7 figures, Accepted by Physical Review Applied (2017

    Lambda and Anti-Lambda Hypernuclei in Relativistic Mean-field Theory

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    Several aspects about Λ\Lambda-hypernuclei in the relativistic mean field theory, including the effective Λ\Lambda-nucleon coupling strengths based on the successful effective nucleon-nucleon interaction PK1, hypernuclear magnetic moment and Λˉ\bar\Lambda-hypernuclei, have been presented. The effect of tensor coupling in Λ\Lambda-hypernuclei and the impurity effect of Λˉ\bar\Lambda to nuclear structure have been discussed in detail.Comment: 8 pages, 2 figures, Proceedings of the Sendai International Symposium "Strangeness in Nuclear and Hadronic Systems SENDAI08

    Effects of the triaxial deformation and pairing correlation on the proton emitter 145Tm

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    The ground-state properties of the recent reported proton emitter 145Tm have been studied within the axially or triaxially deformed relativistic mean field (RMF) approaches, in which the pairing correlation is taken into account by the BCS-method with a constant pairing gap. It is found that triaxiality and pairing correlations play important roles in reproducing the experimental one proton separation energy. The single-particle level, the proton emission orbit, the deformation parameters beta = 0.22 and gamma = 28.98 and the corresponding spectroscopic factor for 145Tm in the triaxial RMF calculation are given as well.Comment: 17 pages, 7 figures and 1 table. accepted by Physical Review

    Bringing class diagrams to life

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    Research in formal methods emphasizes a funda- mental interconnection between modeling, calculation and prototyping, made possible by a common unambiguous, mathematical semantics. This paper, building on a broader research agenda on coalgebraic semantics for Unified Modeling Language diagrams, concentrates on class diagrams and discusses how such a coalgebraic perspective can be of use not only for formalizing their specification, but also as a basis for prototyping.This research was partially supported by a grant from the GLANCE funding program of NWO, through project CooPer (600.643.000.05N12), aswell as by Fct (the Portuguese Foundation for Science and Technology) under contract PTDC/EIA/73252/2006

    Comparative Raman Studies of Sr2RuO4, Sr3Ru2O7 and Sr4Ru3O10

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    The polarized Raman spectra of layered ruthenates of the Srn+1RunO3n+1 (n=1,2,3) Ruddlesden-Popper series were measured between 10 and 300 K. The phonon spectra of Sr3Ru2O7 and Sr4Ru3O10 confirmed earlier reports for correlated rotations of neighboring RuO6 octahedra within double or triple perovskite blocks. The observed Raman lines of Ag or B1g symmetry were assigned to particular atomic vibrations by considering the Raman modes in simplified structures with only one double or triple RuO6 layer per unit cell and by comparison to the predictions of lattice dynamical calculations for the real Pban and Pbam structures. Along with discrete phonon lines, a continuum scattering, presumably of electronic origin, is present in the zz, xx and xy, but not in the x'y' and zx spectra. Its interference with phonons results in Fano shape for some of the lines in the xx and xy spectra. The temperature dependencies of phonon parameters of Sr3Ru2O7 exhibit no anomaly between 10 and 300 K where no magnetic transition occurs. In contrast, two B1g lines in the spectra of Sr4Ru3O10, corresponding to oxygen vibrations modulating the Ru-O-Ru bond angle, show noticeable hardening with ferromagnetic ordering at 105 K, thus indicating strong spin-phonon interaction.Comment: 9 pages, 12 figure

    Estimativa da produção de biogás a partir de dejetos suínos: Avaliação e comparação entre metodologias, aplicadas a um estudo de caso

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    Trabalho de Conclusão de Curso apresentado ao Instituto Latino-Americano de Tecnologia, Infraestrutura e Território da Universidade Federal da Integração Latino-Americana, como requisito parcial à obtenção do título de Bacharel em Engenharia de Energia. Orientadora: Prof.a Dra. Andreia Cristina FurtadoA busca por uma matriz energética mais sustentável com a utilização de uma menor quantidade de combustíveis fosseis é centro de pesquisa e estudos nos dias atuais. Nesse contexto, o biogás é uma ótima fonte energética, visto que é um biocombustível totalmente renovável oriundo da degradação de matéria orgânica por agentes microbiológicos. No presente estudo é avaliado e estimado a produção de biogás em uma instituição de ensino publica, com atividades voltadas para a prática e manejo na agropecuária. Atualmente a instituição possui diversas cabeças de suínos, bovinos, equinos e aves, porém a delimitação do trabalho será acerca da produção de biogás a partir dos dejetos de suínos. A estimativa de produção foi calculada a partir de três metodologias disponíveis na literatura (CIBiogás, EMBRAPA e uma adaptação da CETESB), além da estimativa futura com a criação de três cenários. No intuito de trazer dados mais fide-dignos ao estudo de caso, foi avaliado também parâmetros físico-químicos dos dejetos como sólidos totais, sólidos voláteis e pH e replicados nas metodologias apresentadas. Ao final foi estimado o volume do biodigestor necessário para atender as demandas calculas e o consumo do biogás como fonte térmica para a instituição como substituto do gás de cozinha (GLP).La búsqueda de una matriz energética más sustentable con el uso de una menor cantidad de combustibles fósiles es un centro de investigación y estudios en la actualidad. En este contexto, el biogás es una excelente fuente de energía, ya que es un biocombustible completamente renovable proveniente de la degradación de la materia orgánica por los agentes microbiológicos. En el presente estudio, se evalúa y estima la producción de biogás en una institución de educación pública, con actividades centradas en la práctica y la gestión en la agricultura. Actualmente, la institución cuenta con varias cabezas de cerdos, vacas, caballos y aves, sin embargo la delimitación del trabajo será sobre la producción de biogás a partir de estiércol. La estimación de producción se calculó a partir de tres metodologías disponibles en la literatura (CIBiogás, EMBRAPA y una adaptación de CETESB), además de la estimación futura con la creación de tres escenarios. Con la finalidad de aportar datos más fidelignos al estudio de caso, fueran evaluados tambien los parámetros fisicoquímicos de los desechos como sólidos totales, sólidos volátiles y pH también se evaluaron y replicaron en las metodologías presentadas. Al final, se estimó el volumen del biodigestor necesario para satisfacer las demandas de cálculo y el consumo de biogás como fuente térmica para la institución como sustituto del gas de cocina (GLP)

    Reexamining the temperature and neutron density conditions for r-process nucleosynthesis with augmented nuclear mass models

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    We explore the effects of nuclear masses on the temperature and neutron density conditions required for r-process nucleosynthesis using four nuclear mass models augmented by the latest atomic mass evaluation. For each model we derive the conditions for producing the observed abundance peaks at mass numbers A ~ 80, 130, and 195 under the waiting-point approximation and further determine the sets of conditions that can best reproduce the r-process abundance patterns (r-patterns) inferred for the solar system and observed in metal-poor stars of the Milky Way halo. In broad agreement with previous studies, we find that (1) the conditions for producing abundance peaks at A ~ 80 and 195 tend to be very different, which suggests that, at least for some nuclear mass models, these two peaks are not produced simultaneously; (2) the typical conditions required by the critical waiting-point (CWP) nuclei with the N = 126 closed neutron shell overlap significantly with those required by the N=82 CWP nuclei, which enables coproduction of abundance peaks at A ~ 130 and 195 in accordance with observations of many metal-poor stars; and (3) the typical conditions required by the N = 82 CWP nuclei can reproduce the r-pattern observed in the metal-poor star HD 122563, which differs greatly from the solar r-pattern. We also examine how nuclear mass uncertainties affect the conditions required for the r-process and identify some key nuclei including76Ni to 78Ni, 82Zn, 131Cd, and 132Cd for precise mass measurements at rare-isotope beam facilities.Comment: 28 pages,9 figures,1 tabl
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