Procedimentos de cálculo para a quantificação da necessidade hídrica e do suprimento de água à cultura do amendoim no município de Barbalha-CE.

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General approach for studying first-order phase transitions at low temperatures

By combining different ideas, a general and efficient protocol to deal with discontinuous phase transitions at low temperatures is proposed. For small $T$'s, it is possible to derive a generic analytic expression for appropriate order parameters, whose coefficients are obtained from simple simulations. Once in such regimes simulations by standard algorithms are not reliable, an enhanced tempering method, the parallel tempering -- accurate for small and intermediate system sizes with rather low computational cost -- is used. Finally, from finite size analysis, one can obtain the thermodynamic limit. The procedure is illustrated for four distinct models, demonstrating its power, e.g., to locate coexistence lines and the phases density at the coexistence.Comment: 5 page

Aplicação fracionada de nitrogênio no algodoeiro irrigado.

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Quantum Dynamics in a Time-dependent Hard-Wall Spherical Trap

Exact solution of the Schr\"{o}dinger equation is given for a particle inside a hard sphere whose wall is moving with a constant velocity. Numerical computations are presented for both contracting and expanding spheres. The propagator is constructed and compared with the propagator of a particle in an infinite square well with one wall in uniform motion.Comment: 6 pages, 4 figures, Accepted by Europhys. Let

Improving light harvesting in polymer photodetector devices through nanoindented metal mask films

To enhance light harvesting in organic photovoltaic devices, we propose the incorporation of a metal (aluminum) mask film in the system’s usual layout. We fabricate devices in a sandwich geometry, where the mask (nanoindented with a periodic array of holes of sizes d and spacing s) is added between the transparent electrode and the active layer formed by a blend of the semiconducting polymer P3HT and substituted fullerene. Its function is to promote trapping of the incident light into the device’s cavity (the region corresponding to the active layer). For d, we set a value that allows light diffraction through the holes in the relevant absorption range of the polymer. To optimize the mask structure, we consider a very simple model to determine the s leading to trapped fields that are relatively intense and homogeneous within the device. From measurements of the action spectra, we show that, indeed, such architecture can considerably improve the resulting photocurrent efficiencies—one order of magnitude in the best situation studied.

A Física do solo aplicada à irrigação: metodologia para otimização do manejo de água.

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Irrigação e drenagem de terras agrícolas com sustentabilidade ecológica.

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Métodos de inoculação de Beauveria bassiana na colonização endofítica de mudas de bananeira.

A cultura da bananeira possui grande expressão econômica e social em todo o mundo, onde é cultivada por pequenos, médios e grandes produtores. O principal inseto-praga da cultura é a broca do rizoma (Cosmopolites sordidus), conhecido vulgarmente como moleque dabananeira

Identificação de demandas por informação na Embrapa Algodão.

Identificação de demandas por informação na Embrapa Algodão; Introdução; Informações demandados, Perfil dos clientes; Considerações; Anexos;bitstream/CNPA/15807/1/DOC96.pd