Electroweak Tests at Beta-beams

We explore the possibility of measuring the Weinberg angle from (anti)neutrino-electron scattering using low energy beta beams, a method that produces single flavour neutrino beams from the beta-decay of boosted radioactive ions. We study how the sensitivity of a possible measurement depends on the intensity of the ion beam and on a combination of different Lorentz boosts of the ions.Comment: 10 pages, 6 figure

Contexts for questioning: Two zones of teaching and learning in undergraduate science

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ Springer Science+Business Media B.V. 2012.Higher education institutions are currently undertaking a challenging process in moving from teacher-orientated to student-focused approaches. Students’ ability to asking questions is fundamental to developing critical reasoning, and to the process of scientific enquiry itself. Our premise is that questioning competences should become a central focus of current reforms in higher education. This study, part of a broader naturalistic research project, aims at developing a theoretical framework for conceptualizing different contexts for questioning, illustrating the application of the proposed framework (contextual questioning zones) and reflecting about some of the dimensions of teaching and learning, for overcoming some of the challenges that higher education institutions are facing presently. The discussion of two ‘opposite’ contexts of enquiry is based on qualitative data, gathered through close collaboration with four teachers of undergraduate biology at a Portuguese university. These teachers were observed during their ‘daily activity’ during an academic year. Data was also gathered by interviewing these teachers and 8 selected students, at the end of the year, and used to sustain the argumentation. The paper concludes with some reflections and suggestions to promote authentic enquiry-based learning experiences.Portuguese Fundação para a Ciência e a Tecnologi

Low-energy neutrinos at off-axis from a standard beta-beam

We discuss a scenario to extract up to 150 MeV neutrinos at a standard beta-beam facility using one and two detectors off-axis. In particular we show that the high-energy component of the neutrino fluxes can be subtracted through a specific combination of the response of two off-axis detectors. A systematic analysis of the neutrino fluxes using different detector geometries is presented, as well as a comparison with the expected fluxes at a low-energy beta-beam facility. The presented option could offer an alternative way to perform low-energy neutrino experiments.Comment: 9 pages, 6 figure

Experimental and numerical rolling contact fatigue study on the 32CrMoV13 steel

The aim of this work is to study pure rolling contact fatigue in 32CrMoV13 quenching and tempering steel. The study involves both experimental and numerical work. The influence of the roughness and the residual stresses on the mechanisms and zones of cracking were studied. The results show a rapid reduction in roughness during the first minute of test but even so there will be specimen deterioration. The residual stress profile after rolling contact tests have high compression values in the surface and at a depth of approximately 240 μm, which is related with the Hertzian maximal shear stress. The numerical simulation of the Hertzian loading was used both to determine the elastic shakedown of thematerial and to apply a high-cycle multiaxial fatigue criterion. The threedimensional finite element analysis used in the numerical calculation includes elastic-linear kinematic hardening plastic material and allows the introduction of an initial residual stress state. Taking into account the elastoplastic load induced by the Hertz pressure, low-cycle fatigue tests were used to characterize the mechanical properties of the material. In order to validate the numerical simulation, the results of the calculation after elastic shakedown were compared with the values measured by X-ray diffraction after rolling contact tests. The results showed a reasonable agreement between calculated and measured stresses. The Dang Van high-cycle multiaxial fatigue criterion showed a good relationship with the experimental findings

Spectra and Symmetry in Nuclear Pairing

We apply the algebraic Bethe ansatz technique to the nuclear pairing problem with orbit dependent coupling constants and degenerate single particle energy levels. We find the exact energies and eigenstates. We show that for a given shell, there are degeneracies between the states corresponding to less and more than half full shell. We also provide a technique to solve the equations of Bethe ansatz.Comment: 15 pages of REVTEX with 2 eps figure

Diversidade genética entre acessos de maracujazeiros avaliados a partir de caracteres morfoagronômicos.

A análise conjunta de variáveis qualitativas e quantitativas tem sido apontada como uma ferramenta útil na estimativa da divergência genética entre os acessos de uma coleção de germoplasma. O presente trabalho teve como objetivo quantificar a diversidade genética entre acessos de maracujazeiros mantidos no BAG-Maracujá da Embrapa Mandioca e Fruticultura, utilizando uma lista de descritores mínimos para a cultura

Efeito de diferentes lâminas de irrigação em bananeira Grande Naine sobre a comunidade de nematóides.

A banana é a fruta mais produzida e consumida no mundo atualmente. O Brasil encontra-se como o segundo maior produtor, com a produção estimada em sete milhões de toneladas anuais de banana. Como toda cultura praticada em extensa área,a bananicultura é infestada por várias pragas, cujo controle pode elevar o custo de produção e trazer sérios riscos ao ambiente. Entre as pragas, os nematóides ocupam lugar de destaque. No Brasil, são relatadas muitas espécies de fitonematóides na cultura da bananeira, causando uma série de danos, como lesões nas raízes, nanismo de planta, prolongamento do estádio vegetativo, redução no número de raízes ativas, clorose foliar, redução do tamanho e produção dos frutos e tombamento, podendo provocar até a morte das plantas (Ritzinger & Costa, 2004). Numa área irrigada é possível a obtenção de colheitas em períodos distintos, já que é possível manter condições de alta produção durante todo o ano, pelo fato da irrigação proporcionar umidade adequada durante todo ano favorecendo, assim, a formação de frutos de melhor qualidade em qualquer época.pdf 193

MAC protocol for low-power real-time wireless sensing and actuation

This paper presents LPRT, a new medium access control (MAC) protocol for wireless sensing and actuation systems. Some of the characteristics of the proposed protocol are low power consumption, support for real-time and loss intolerant traffic through contention-free operation and a retransmission scheme, flexibility, and high throughput efficiency. The LPRT protocol was implemented it in the MICAz motes, a platform for the development of wireless sensor networks. We also briefly describe a wireless hydrotherapy application that benefits from the use of the proposed protocol. This paper also provides experimental results and comparison of the proposed protocol with the CSMA/CA protocol of IEEE 802.15.4.Agência de Inovação (ADI)Fundação para a Ciência e a Tecnologia (FCT