On the space of generalized fluxes for loop quantum gravity

We show that the space of generalized fluxes - momentum space - for loop quantum gravity cannot be constructed by Fourier transforming the projective limit construction of the space of generalized connections - position space - due to the non-abelianess of the gauge group SU(2). From the abelianization of SU(2), U(1)^3, we learn that the space of generalized fluxes turns out to be an inductive limit, and we determine the consistency conditions the fluxes should satisfy under coarse-graining of the underlying graphs. We comment on the applications to loop quantum cosmology, in particular, how the characterization of the Bohr compactification of the real line as a projective limit opens the way for a similar analysis for LQC

Modeling extreme wave heights from laboratory experiments with the nonlinear Schrödinger equation

Spatial variation of nonlinear wave groups with different initial envelope shapes is theoretically studied first, confirming that the simplest nonlinear theoretical model is capable of describing the evolution of propagating wave packets in deep water. Moreover, three groups of laboratory experiments run in the wave basin of CEHIPAR (Canal de Experiencias Hidrodinámicas de El Pardo, known also as El Pardo Model Basin) was founded in 1928 by the Spanish Navy. are systematically compared with the numerical simulations of the nonlinear Schrödinger equation. Although a little overestimation is detected, especially in the set of experiments characterized by higher initial wave steepness, the numerical simulation still displays a high degree of agreement with the laboratory experiments. Therefore, the nonlinear Schrödinger equation catches the essential characteristics of the extreme waves and provides an important physical insight into their generation. The modulation instability, resulting from the quasi-resonant four-wave interaction in a unidirectional sea state, can be indicated by the coefficient of kurtosis, which shows an appreciable correlation with the extreme wave height and hence is used in the modified Edgeworth–Rayleigh distribution. Finally, some statistical properties on the maximum wave heights in different sea states have been related with the initial Benjamin–Feir index

Variações anuais na produção de frutos de castanha-da-amazônia no sul do Amapá.

A castanha-da-amazônia é uma espécie típica da região. Além da sua importância para o setor alimentício e de cosméticos, também é considerada alimento funcional e pode prevenir algumas enfermidades. Com isso, tem aumentado a demanda pela produção de castanha. Todavia, estudos sobre a variação anual na oferta de castanha ainda são incipientes. Assim, o objetivo do presente estudo foi avaliar a produção de frutos da castanheira, ao longo dos anos e em diferentes ambientes no sul do Amapá

Estudos CTS e construções em agroecologia: expansão de comunidade epistêmica ou processos transepistêmicos?

Apresenta e discute a obra Ciência, tecnologia e sociedade (CTS) para a construção da Agroecologia, publicada pela Editora da UnB em 2014, uma coletânea de 14 capítulos sequenciais que se destinam a um público abrangente, das ciências sociais aplicadas aos campos dos estudos sociais da ciência e da tecnologia e, sobretudo, a formuladores, operadores e avaliadores de políticas agrícolas, de C&T, inovação e desenvolvimento social.Obra resenhada: NEDER, R. T.; COSTA, F. M. P. (Org.). Ciência tecnologia sociedade (CTS) para a construção da agroecologia. Brasília, DF: Ed. da UnB, 2014 . 261 p. il. (Cadernos construção social da tecnologia, série 1, número 7, primeira versão, 4)

Impacto do fogo na macrofauna e insetos sociais do solo.

Resumo 5

A genetic algorithm for resizing and sampling reduction of non-stationary soil chemical attributes optimizing spatial prediction

Aim of study: To evaluate the influence of the parameters of the geostatistical model and the initial sample configuration used in the optimization process; and to propose and evaluate the resizing of a sample configuration, reducing its sample size, for simulated data and for the study of the spatial variability of soil chemical attributes under a non-stationary with drift process from a commercial soybean cultivation area.Area of study: Cascavel, BrazilMaterial and methods: For both, the simulated data and the soil chemical attributes, the Genetic Algorithm was used for sample resizing, maximizing the overall accuracy measure.Main results: The results obtained from the simulated data showed that the practical range did not influence in a relevant way the optimization process. Moreover, the local variations, such as variance or sampling errors (nugget effect), had a direct relationship with the reduction of the sample size, mainly for the smaller nugget effect. For the soil chemical attributes, the Genetic Algorithm was efficient in resizing the sampling configuration, since it generated sampling configurations with 30 to 35 points, corresponding to 29.41% to 34.31% of the initial configuration, respectively. In addition, comparing the optimized and initial configurations, similarities were obtained regarding spatial dependence structure and characterization of spatial variability of soil chemical attributes in the study area.Research highlights: The optimization process showed that it is possible to reduce the sample size, allowing for lesser financial investments with data collection and laboratory analysis of soil samples in future experiments

Desenvolvimento e eficiência de um fungicita triazol a partir do líquido da casca da castanha (LCC) do cajueiro.

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