Thermodynamic properties of water sorption of jackfruit (Artocarpus heterophyllus Lam.) as a function of moisture content

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of the enthalpy-entropy mechanism from water sorption of orange seeds (C. sinensis cv. Brazilian) for the use of agro-industrial residues as a possible source of vegetable oil production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Energy efficiency for standard penetration tests

The need for standardization of the measured blow count number N-spt into a normalized reference energy value is now fully recognized. The present paper extends the existing theoretical approach using the wave propagation theory as framework and introduces an analysis for large displacements enabling the influence of rod length in the measured N-spt values to be quantified. The study is based on both calibration chamber and field tests. Energy measurements are monitored in two different positions: below the anvil and above the sampler. Both experimental and numerical results demonstrate that whereas the energy delivered into the rod stem is expressed as a ratio of the theoretical free-fall energy of the hammer, the effective sampler energy is a function of the hammer height of fall, sampler permanent penetration, and weight of both hammer and rods. Influence of rod length is twofold and produces opposite effects: wave energy losses increase with increasing rod length and in a long rod composition the gain in potential energy from rod weight is significant and may partially compensate measured energy losses. Based on this revised approach, an analytical solution is proposed to calculate the energy delivered to the sampler and efficiency coefficients are suggested to account for energy losses during the energy transference process.

Diffusion Model Applied to Postfeeding Larval Dispersal in Blowflies (Diptera: Calliphoridae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Soliton propagation in a medium with Kerr nonlinearity and resonant impurities: A variational approach

The soliton propagation in a medium with Kerr nonlinearity and resonant impurities was studied by a variational approach. The existence of a solitary wave was shown within the framework of a combined nonintegrable system composed of one nonlinear Schrödinger and a pair of Bloch equations. The analytical solution which was obtained, was tested through numerical simulations confirming its solitary wave nature.

Técnica alternativa de conformação de junção a partir de tubos metálicos

This work presents a technique for the cold forming of thin-walled cylindrical tubes, aimed at obtaining a symmetrical joint with an unconventional forming technique, using elastomer rod. The purpose of this work is to investigate the influence of the anisotropy on the total forming force, through the use of elastomer for obtaining T-junctions, in order to get a better result between experimental values and the analytical solution. For total forming force forecasting, it will be used the upper-bound theory and for a better understanding on the anisotropy behavior of the material, it will be employed the quadratic yielding criterion proposed by Hill. The employed materials for such investigation were Aluminum, Brass and Copper.

An overview on a nonideal system with three and a half degrees of freedom

The present paper studies a system comprised of two blocks connected by springs and dampers, and a DC motor with limited power supply fixed on a block, characterizing a non-ideal problem. This DC motor exciting the system causes interactions between the motor and the structure supporting it. Because of that, the non-ideal mathematical formulation of the problem has one and a half extra degree of freedom than the ideal one. A suitable choice of physical parameters leads to internal resonance conditions, that is, its natural frequencies are multiple of each other, by a known integer quantity. The purpose here is to study the dynamic behavior of the system using an analytical method based on perturbation techniques. The literature shows that the averaging method is the more flexible method concerning non-ideal problems. Summarizing, an steady state solution in amplitude and phase coordinates was obtained with averaging method showing the dependence of the structure amplitudes with the rotation frequency of the motor. Moreover, this solution shows that on of the amplitude coordinates has influence in the determination of the stationary rotation frequency. The analytical solution obtained shows the presence of the rotation frequency in expressions representing the oscillations of the structure, and the presence of amplitude coordinates in expressions describing the dynamic motion of the DC motor. These characteristics show the influence not only of the motor on structure but also of the response of the structure on dynamical behavior of the motor. Copyright © 2005 by ASME.

GIS_EM (Geographic information system for environmental monitoring) - A software implemented at Paulínia refinery (REPLAN) for management of environmental data

The computational program called GIS_EM (Geographic Information System for Environmental Monitoring), a software devised to manage geographic information for monitoring soil, surface, and ground water, developed for use in the Health, Safety, and Environment Division of Paulinia Refinery is presented. This program enables registering and management of alphanumeric information pertaining to specific themes such as drilling performed for sample collection and for installation of monitoring wells, geophysical and other tests, results of chemical analyses of soil, surface, and groundwater, as well as reference values providing orientation for soil and water quality, such as EPA, Dutch List, etc. Management of such themes is performed by means of alphanumeric search tools, with specific filters and, in the case of spatial search, through the selection of spatial elements (themes) in map view. Documents existing in digital form, such as reports, photos, maps, may be registered and managed in the network environment. As the system centralizes information generated upon environmental investigations, it expedites access to and search of documents produced and stored in the network environment, minimizing search time and the need to file printed documents. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).

Heating time required for an MgO-graphite refractory during a hot modulus of rupture test

In the work described in the present paper, an analytical solution of the general heat conduction equation was employed to assay the temperature profile inside a solid slab which is initially at room temperature and is suddenly plunged into a fluid maintained at a high temperature. The results were then extrapolated to a simulation of a hot modulus of rupture test of typical MgO-graphite refractory samples containing different amounts of graphite in order to evaluate how fast the temperature equilibrates inside the test specimens. Calculations indicated that, depending on the graphite content, the time to full temperature homogenization was in the range of 80 to 200 s. These findings are relevant to the high temperature testing of such refractories in oxidizing conditions in view of the graphite oxidation risks in the proper evaluation of the hot mechanical properties.

Chaos suppression in NEMs resonators by using nonlinear control design

In this work the chaotic behavior of a micro-mechanical resonator with electrostatic forces on both sides is suppressed. The aim is to control the system in an orbit of the analytical solution obtained by the Method of Multiple Scales. Two control strategies are used for controlling the trajectory of the system, namely: State Dependent Riccati Equation (SDRE) Control and Optimal Linear Feedback Control (OLFC). The controls proved effectiveness in controlling the trajectory of the system. Additionally, the robustness of each strategy is tested considering the presence of parametric errors and measurement noise in control. © 2012 American Institute of Physics.

Fenômenos não-lineares, incluindo-se os não-ideias, em captura de energia utilizando-se dispositivos piezoelétricos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Representação de linhas de transmissão monofásicas por meio de variáveis de estado: comparação das soluções numérica e analítica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação de propriedades de filmes finos de Sn'O IND. 2' e 'Al IND. 2''O IND. 3' para aplicação em dispositivos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Propagação da atitude de satélites artificiais estabilizados por rotação: torque residual médio com o modelo de quadripolo para o campo geomagnético

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aplicações de secagem para o aproveitamento de resíduos da banana, visando sua aplicação na indústria

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)