A RIEMANN INTEGRAL APPROACH TO FEYNMANS PATH-INTEGRAL

It is a well known result that the Feynman's path integral (FPI) approach to quantum mechanics is equivalent to Schrodinger's equation when we use as integration measure the Wiener-Lebesgue measure. This results in little practical applicability due to the great algebraic complexibity involved, and the fact is that almost all applications of (FPI) - ''practical calculations'' - are done using a Riemann measure. In this paper we present an expansion to all orders in time of FPI in a quest for a representation of the latter solely in terms of differentiable trajetories and Riemann measure. We show that this expansion agrees with a similar expansion obtained from Schrodinger's equation only up to first order in a Riemann integral context, although by chance both expansions referred to above agree for the free. particle and harmonic oscillator cases. Our results permit, from the mathematical point of view, to estimate the many errors done in ''practical'' calculations of the FPI appearing in the literature and, from the physical point of view, our results supports the stochastic approach to the problem.

Casimir effect for the scalar field under Robin boundary conditions: a functional integral approach

In this work we show how to define the action of a scalar field such that the Robin boundary condition is implemented dynamically, i.e. as a consequence of the stationary action principle. We discuss the quantization of that system via functional integration. Using this formalism, we derive an expression for the Casimir energy of a massless scalar field under Robin boundary conditions on a pair of parallel plates, characterized by constants c(1) and c(2). Some special cases are discussed; in particular, we show that for some values of cl and c(2) the Casimir energy as a function of the distance between the plates presents a minimum. We also discuss the renormalization at one-loop order of the two-point Green function in the philambda(4) theory subject to the Robin boundary condition on a plate.

PATH INTEGRAL AND OPERATOR APPROACH FOR THE PODOLSKY-SCHWINGER MODEL

We study the role of the thachyonic excitation which emerges from the quantum electrodynamics in two dimensions with Podolsky term. The quantization is performed by using path integral framework and the operator approach.

Características químicas do resíduo do leite de soja obtido a partir do farelo e da farinha do grão integral de soja

O objetivo do presente trabalho foi estudar os efeitos de diferentes tempos de processamento (duas, quatro e seis horas) e temperaturas (50°C, 65°C e 80°C) em dois substratos: farinha do grão integral de soja e farelo de soja. Para obtenção do resíduo, utilizou-se uma máquina de aço inoxidável com termostato para controle de temperatura e agitador constante. O delineamento estatístico utilizado na análise dos dados foi inteiramente casualizado, segundo o esquema fatorial 3 x 3 x 2 com duas repetições. Concluiu-se que os tratamentos não apresentaram diferenças marcantes na composição química e mineral do resíduo. O teor de proteína no resíduo do farelo foi 3,5% superior ao teor do farelo que lhe deu origem, o contrário ocorreu com o resíduo da farinha que foi 9,8% inferior. O teor de extrato etéreo no resíduo da farinha, aproximou-se bastante do teor da farinha do grão integral (21,41%) e no resíduo do farelo foi ligeiramente inferior.

Completeness of coherent states associated with self-similar potentials and Ramanujan's integral extension of the beta function

A decomposition of identity is given as a complex integral over the coherent states associated with a class of shape-invariant self-similar potentials. There is a remarkable connection between these coherent states and Ramanujan's integral extension of the beta function.

Valor nutricional da soja integral tostada e extrusada para poedeiras comerciais

An experiment was conducted to determine the apparent nitrogen-corrected metabolizable energy (AMEn) values and the coefficients' metabolization of the: dry matter, ether extract, calcium and phosphorus availabilities of experimental layer diets containing toasted (TSB) and extruded (ESB) soybeans. The soybean meal (SBM) was substituted at 0, 50, and 100% by TSB and ESB whole soybeans. The whole soybeans utilization in layer diets did not adversely affect calcium and phosphorus availability. The SBM and ESB, in diets with crude protein at 17%, showed the best ether extract coefficients of metabolization. When TSB replaced all SBM in the diets, it was observed the worst value for AMEn.