On quasiparticle lifetimes and transport in ordered and disordered metals

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Coherent State Path Integrals in the Weyl Representation

We construct a representation of the coherent state path integral using the Weyl symbol of the Hamiltonian operator. This representation is very different from the usual path integral forms suggested by Klauder and Skagerstan in \cite{Klau85}, which involve the normal or the antinormal ordering of the Hamiltonian. These different representations, although equivalent quantum mechanically, lead to different semiclassical limits. We show that the semiclassical limit of the coherent state propagator in Weyl representation is involves classical trajectories that are independent on the coherent states width. This propagator is also free from the phase corrections found in \cite{Bar01} for the two Klauder forms and provides an explicit connection between the Wigner and the Husimi representations of the evolution operator.Comment: 23 page

Extreme thermopower anisotropy and interchain transport in the quasi-one-dimensional metal Li(0.9)Mo(6)O(17)

Thermopower and electrical resistivity measurements transverse to the conducting chains of the quasi-one-dimensional metal Li(0.9)Mo(6)O(17) are reported in the temperature range 5 K = 400 K the interchain transport is determined by thermal excitation of charge carriers from a valence band ~ 0.14 eV below the Fermi level, giving rise to a large, p-type thermopower that coincides with a small, n-type thermopower along the chains. This dichotomy -- semiconductor-like in one direction and metallic in a mutually perpendicular direction -- gives rise to substantial transverse thermoelectric (TE) effects and a transverse TE figure of merit among the largest known for a single compound.Comment: PRL in press, manuscript (5pp, 4 Fig.'s) and Supplementary Material (3pp, 3 Fig.'s

Straight spinning cosmic strings in Brans-Dicke gravity

It is presented an exact solution of straight spinning cosmic strings in Brans-Dicke theory of gravitation. The possibility of the existence of closed timelike curves around these cosmic strings is analyzed. Furthermore, the stability about the formation of the topological defect discussed here is checked. It is shown the existence of a suitable choice for the integration constants in which closed timelike curves are not allowed. We also verify if it is possible that the obtained spacetime can be the source that describes the observed rotational curves in some galaxies.Comment: 13 pages, 1 figur

Evolução e perfil distributivo das aplicações do Fundo Constitucional de Financiamento do Norte (FNO) na pecuária leiteira paraense no período 2000-2009.

O crédito rural é uma política importante para viabilizar o desenvolvimento regional, pois propicia aos produtores recursos para custeio, investimento e comercialização, contribuindo para o fortalecimento das cadeias produtivas. O crescimento da demanda por produtos lácteos tem realçado a necessidade de medidas visando ampliar a produção leiteira em todo o país. Nos últimos anos os estados da Região Norte têm exibido um importante crescimento nessa atividade. No estado do Pará, um importante instrumento de apoio tem sido os recursos de crédito rural do Fundo Constitucional de Financiamento do Norte (FNO). Este trabalho analisou a evolução e o perfil distributivo das aplicações do FNO na pecuária leiteira paraense no período 2000-2009. Neste período foram alocados R$519,2 milhões na atividade, distribuídos entre 119 municípios. Essas aplicações cresceram a uma taxa de 10,61$ 52 milhões por ano

Deformation method for generalized Abelian Higgs-Chern-Simons models

We present an extension of the deformation method applied to self-dual solutions of generalized Abelian Higgs-Chern-Simons models. Starting from a model defined by a potential $V(| \phi |)$ and a non-canonical kinetic term $\omega(| \phi |) | D_{\mu}\phi |^2$ whose analytical domain wall solutions are known, we show that this method allows to obtain an uncountable number of new analytical solutions of new models defined by other functions $\widetilde{V}$ and $\widetilde{\omega}$. We present some examples of deformation functions leading to new families of models and their associated analytic solutions.Comment: 6 pages, 10 figure

Caracterização da agroindústria do leite na região oeste do estado do Pará.

O trabalho caracterizou a situação do setor agroindustrial ligado ao processamento de leite na região oeste do estado do Pará. A pesquisa abrangeu cinco laticínios localizados nos municípios de Itaituba, Rurópolis, Trairão e Placas. Os temas analisados envolveram estrutura de produção, mão de obra, gerenciamento, produção e comercialização, investimento e financiamento. Os resultados evidenciam uma estrutura produtiva tecnologicamente defasada, nível de ociosidade alto e mão de obra pouco qualificada. Contudo, apesar disso, atuam como elementos importantes na geração de emprego e renda na região estudada. Observou-se problemas no gerenciamento das empresas e para cumprir a legislação. A produção estava concentrada no queijo mussarela, destinado principalmente às cidades de Santarém e Itaituba. Investimentos na infraestrutura predial foram realizados e os proprietários desejavam aumentar essas inversões, mas enfrentavam dificuldades para acessar financiamento. Problemas relacionados à infraestrutura elétrica e rodoviária constituíam entraves ao melhor desenvolvimento das atividades. A sazonalidade na produção é expressiva. A produção é maior no verão, o que representa, também, uma oportunidade de mercado para os laticínios pesquisados, pois seus produtos teriam maior tempo de vida de prateleira para atender os mercados locais e de cidades próximas em comparação aos provenientes de outras regiões brasileiras

Fluctuating local moments, itinerant electrons and the magnetocaloric effect: the compositional hypersensitivity of FeRh

We describe an ab-initio Disordered Local Moment Theory for materials with quenched static compositional disorder traversing first order magnetic phase transitions. It accounts quantitatively for metamagnetic changes and the magnetocaloric effect. For perfect stoichiometric B2-ordered FeRh, we calculate the transition temperature of the ferromagnetic-antiferromagnetic transition to be $T_t =$ 495K and a maximum isothermal entropy change in 2 Tesla of $|\Delta S|= 21.1$ J~K$^{-1}$~kg$^{-1}$. A large (40\%) component of $|\Delta S|$ is electronic. The transition results from a fine balance of competing electronic effects which is disturbed by small compositional changes - e.g. swapping just 2\% Fe of `defects' onto the Rh sublattice makes $T_t$ drop by 290K. This hypersensitivity explains the narrow compositional range of the transition and impurity doping effects.Comment: 11 pages, 4 figure

Toward sustainable and smart cities in Africa: A review and challenges

The paper presents the main challenges to be overcoming in order in the future cities we have sustainable and smart cities in Africa. The analysis highlines confirm the existence of huge challenges, problems and restriction about social, economics, and environmental and political issues in Africa. This paper analysing the main constraints to urban development in the African Continent and confirms that smart cities only will be possible in Africa when the current problems of sustainable development (economic, social, environmental and political) are overcoming. However, the paper allows us understand why this is the first paper on the literature to address the topic of smart cities in Africa. Should be noted that in this continent there are at least two of the world's largest cities in terms of inhabitants and the growth of population rate of the African continent is about 2.5%. So, this is a world problem to minimize. The concern about the problems of sustainable development in this region and how to promote it towards sustainable cities competes to all and the follow way will affect all of the world sustainable development.info:eu-repo/semantics/acceptedVersio