Proposicion para un proyecto de pesquisa en funciones de produccion del agua y el nitrogeno para sistemas de produccion bajo condiciones de irrigacion.

El objetivo de incorporar variables y constantes de suelos y clima en el análisis de las funciones de producción, es permitir Ia predicción de Ia respuesta en rendimiento de los cultivos sobre una gama amplia de condiciones de su elo'clima y ubícación, de tal forma de hacer innecesario llevar a cabo experimentos en cada tipo de suelos en particular, cuya validez para condiciones de clima variable será discutible en cualquier caso.bitstream/item/136388/1/34361-1.pd

Uso de tensiometros como metodo de determinacion de frecuencias y laminas de irrigacion.

Medición del potencial del agua en el suelo.bitstream/item/133754/1/34360-1.pd

Confeccion de curvas de humedad, determinacion de dias de stress, estimacion del uso-consumo y de coeficientes de evapotranspiracion del cultivo, para el analisis cuantitativo de pesquisa en irrigacion.

Las curvas de humedad permiten, al mismo tiempo, visualizar y calcular la evapotranspiración real (uo-consumo) total y parcial de cada tratamiento de irrigación y comparar estos valores entre si, a lo largo del periodo de cultivo, senalandose los excesos de agua, por sobre la capacidad de almacenamiento del suelo, ya sean intencionales (con el objeto de producir un lavado de sales) o resultante de un manejo poco adecuado del experimiento.bitstream/item/136386/1/34346-1.pd

Quantum Evolution of the Bianchi Type I Model

The behaviour of the flat anisotropic model of the Universe with a scalar field is explored within the framework of quantum cosmology. The principal moment of the account of an anisotropy is the presence either negative potential barrier or positive repelling wall. In the first case occur the above barrier reflection of the wave function of the Universe, in the second one there is bounce off a potential wall. The further evolution of the Universe represents an exponential inflating with fast losses of an anisotropy and approach to the standard cosmological scenario.Comment: Latex, 18 pages, 5 figure

Homogeneous Solutions of Quadratic Gravity

It is believed that soon after the Planck time, Einstein's general relativity theory should be corrected to an effective quadratic theory. In this work we present the 3+1 decomposition for the zero vorticity case for arbitrary spatially homogenous spaces. We specialize for the particular Bianchi $I$ diagonal case. The 3- curvature can be understood as a generalized potential, and the Bianchi $I$ case is a limiting case where this potential is negligible to the dynamics. The spirit should be analogous, in some sense to the BKL solution. In this sense, a better understanding of the Bianchi $I$ case could shed some light into the general Bianchi case.Comment: talk presented in the 8th Friedmann Seminar, 30 May - 03 June 2011, Rio de Janeiro, Brazi

Formation of High-quality Aluminum Oxide under Ion Beam Irradiation

In this work we used the radiation–induced technique of selective association of atoms (SAA) to create the aluminum oxide layer on the surface of metallic Al under oxygen ion beam irradiation. Optimal conditions for carrying out the radiation-induced aluminum oxidation process were established to minimize the target sputtering. An aluminum oxide layer of 20 nm thickness was obtained after irradiation of aluminum target with oxygen ions with 0.2 keV energy up to a dose of ∼2.6 ⋅ 1018 ions/cm2 at room temperature. HRTEM and EELS techniques were used to characterize the chemical compositional changes after irradiation. It was found that aluminum oxide layer after irradiation contained an excessive amount (∼10 at.%) of implanted oxygen. Keywords: ion beam irradiation, aluminum thin films, EELS, HRTE