Analytical results for a Bessel function times Legendre polynomials class integrals

When treating problems of vector diffraction in electromagnetic theory, the evaluation of the integral involving Bessel and associated Legendre functions is necessary. Here we present the analytical result for this integral that will make unnecessary numerical quadrature techniques or localized approximations. The solution is presented using the properties of the Bessel and associated Legendre functions.Comment: 4 page

Resposta de cultivares de tomateiro para processamento industrial a fertirrigacao por gotejamento subterraneo.

bitstream/item/103100/1/pa-6.pd

1D Aging

We derive exact expressions for a number of aging functions that are scaling limits of non-equilibrium correlations, R(tw,tw+t) as tw --> infinity with t/tw --> theta, in the 1D homogenous q-state Potts model for all q with T=0 dynamics following a quench from infinite temperature. One such quantity is (the two-point, two-time correlation function) when n/sqrt(tw) --> z. Exact, closed-form expressions are also obtained when one or more interludes of infinite temperature dynamics occur. Our derivations express the scaling limit via coalescing Brownian paths and a ``Brownian space-time spanning tree,'' which also yields other aging functions, such as the persistence probability of no spin flip at 0 between tw and tw+t.Comment: 4 pages (RevTeX); 2 figures; submitted to Physical Review Letter

Majority Dynamics and Aggregation of Information in Social Networks

Consider n individuals who, by popular vote, choose among q >= 2 alternatives, one of which is "better" than the others. Assume that each individual votes independently at random, and that the probability of voting for the better alternative is larger than the probability of voting for any other. It follows from the law of large numbers that a plurality vote among the n individuals would result in the correct outcome, with probability approaching one exponentially quickly as n tends to infinity. Our interest in this paper is in a variant of the process above where, after forming their initial opinions, the voters update their decisions based on some interaction with their neighbors in a social network. Our main example is "majority dynamics", in which each voter adopts the most popular opinion among its friends. The interaction repeats for some number of rounds and is then followed by a population-wide plurality vote. The question we tackle is that of "efficient aggregation of information": in which cases is the better alternative chosen with probability approaching one as n tends to infinity? Conversely, for which sequences of growing graphs does aggregation fail, so that the wrong alternative gets chosen with probability bounded away from zero? We construct a family of examples in which interaction prevents efficient aggregation of information, and give a condition on the social network which ensures that aggregation occurs. For the case of majority dynamics we also investigate the question of unanimity in the limit. In particular, if the voters' social network is an expander graph, we show that if the initial population is sufficiently biased towards a particular alternative then that alternative will eventually become the unanimous preference of the entire population.Comment: 22 page

Impacto socioambiental da inserção da cultura do girassol nas atividades produtivas de um estabelecimento rural.

Resumo: Os impactos sócio-ambientais resultantes da inserção da cultura do girassol em um estabelecimento rural foram avaliados em um empreendimento da região sul de Minas Gerais, incentivada pelo uso na produção de biodiesel. Nesta avaliação foi utilizado o Sistema de Avaliação Ponderada do Impacto Ambiental do Novo Rural (APOIA-NovoRural), que integra 62 indicadores de desempenho sócio-ambiental. Observaram-se impactos positivos sobre a água, a atmosfera e sobre o sistema produtivo, entretanto, os efeitos sobre o solo não foram satisfatórios. Com relação ao aspecto econômico, houve incremento de renda e de investimentos, mas sob o ponto de vista social não foram observadas alterações significativas. Assim, conclui-se que a inserção da cultura do girassol no estabelecimento rural apresenta importante contribuição para o desenvolvimento econômico e ambiental do empreendimento, confirmada pelo índice de sustentabilidade de 0,77, que está acima da linha de base preconizada pelo Sistema APOIA-NovoRural. Entretanto, ainda não se identifica impacto significativo desta atividade sobre o aspecto social no estabelecimento rural, conforme preconizado pelo Programa Nacional de Produção e Uso de Biosdiesel. Abstract: The social and environmental impacts of sunflower insertion at rural establishment activities were evaluated in one representative farm located at the south region of Minas Gerais state. This insertion was encouraged by biodiesel production. In this study was used a sustainability toll named Environmental impact assessment of rural activities system (APOIA- NovoRural), which integrates sixty-two objective indicators of social and environmental assessment. The evaluation showed positive impacts of this insertion at water and atmosfhere quality; however soil impacts were not satisfactory. About economic issues, there was an increase of generation of income and investments, on the other hand, social issues were not changed with sunflower activity. Consequently, it is concluded that sunflower insertion at rural establishment activities contributes for the economic and environmental development of the farm, and this is confirmed by the high index sustainability (0,77) obtained in APOIA-NovoRural evaluation. However, it is still impossible to identify social impacts of this insertion, which is recommended by Brazilian Biodiesel Production and Use Program

Optimization of linoleic acid emulsion preparation to reduce substrate losses after filter-sterilization

info:eu-repo/semantics/publishedVersio

Aging in the random energy model

In this letter we announce rigorous results on the phenomenon of aging in the Glauber dynamics of the random energy model and their relation to Bouchaud's 'REM-like' trap model. We show that, below the critical temperature, if we consider a time-scale that diverges with the system size in such a way that equilibrium is almost, but not quite reached on that scale, a suitably defined autocorrelation function has the same asymptotic behaviour than its analog in the trap model.Comment: 4pp, P

Mineralogy of some soils from the Amazonia Sedimentary Basin.

ABSTRACT: The Amazonia Forest is an important biome that possesses great diversity of fauna and flora, which can play a significant role in several science areas, specially, the gene reserve for the future of humankind. Nevertheless, it is a very poorly understood environment, particularly the basis of this ecosystem, its soils. This study was conducted to gain insight in the mineralogy of important soils classes of the Amazonia sedimentary basin. The soils in the upland position in the landscape are developed from tertiary sediments belonging to the Alter do Chão series and those in the floodplain position are derived from quaternary, more specifically, Holocene´s sediments. Sand, silt and clay fractions were separated and X-ray diffraction analysis was conducted. Very simple mineralogy composed basically of quartz in the coarser fractions and kaolinite, goethite and anatase for the finer fraction was found for the Oxisol, the Ultisol and the Entisol from an upland toposequence but differences in kaolinite crystallography could be noticed among them. Gibbsite was virtually absent, in spite of the advanced degree of development of most of these soils. More distinctive mineralogy was revealed for the soils developed in the more recent sediments with quartz and feldspars in the sand and silt fractions and a suite of 2:1 minerals also appearing in their clay fraction, besides kaolinite and goethite. In one upland soil petroplinthite is the main feature and its mineralogy reflected its environment of formation which is usually associated with level to gently sloping areas with fluctuating water table