Wagner André dos Santos Conceição

Novo modelo de parâmetros concentrados aplicado à hidratação de grãos

A new first principle model with lumped parameters was developed for the hydration of soya beans. A transient mass balance was applied to the soya beans taking into consideration two basic hypotheses:1o) variation of the volume directly proportional to the variation of the mass of the grain during the process, 2o) Exponential variation of the apparent coefficient of mass transfer in function of water concentration in the soy. This model has got just two parameters, which were evaluated from adjustment of model to the measures of grain moisture along the time, at several temperatures. The results indicate that the proposed model was able to represent the hydration process, while the mass transfer coefficient depends on the temperature and it presents significant variations along the hydration.

Application of the Hsu model to soybean grain hydration

Abstract A comparative analysis of the theoretical-experimental study, developed by Hsu on the hydration of Amsoy 71 soybean grain, was performed through several soaking experiments using CD 202 soybean at 10, 20, 30, 40, and 50 °C, measuring moisture content over time. The results showed that CD 202 soybean equilibrium moisture content, X eq , does not depend on temperature and is 21% higher than that found by Hsu, suggesting that soybean cultivar exerts great influence on X eq . The Hsu model was numerically solved and its parameters were adjusted by the least squares method, with maximum deviations of +/– 10% relative to the experimental values. The limiting step in the mass transfer process during hydration corresponds to water diffusion inside the grain, leading to radial moisture gradients that decrease over time and with an increase in temperature. Regardless of the soybean cultivar, diffusivity increases as temperature or moisture content increases. However, the values of this transport property for Amsoy 71 were superior to those of CD 202, very close at the beginning of hydration at 20 °C and almost three times higher at the end of hydration at 50 °C.

Evaluation of two mathematical models applied to soybean hydration.

The predictions of the Hsu model of soybean hydration are compared with simulation results of the distributed parameter phenomenological model (DPP) that was developed in this study. The models were developed based on the same mass balance with one volume differential element of the Hsu model; however, the Hsu model admits an exponential variation of concentration while the DPP model admits equal diffusion and convection fluxes at the solid-fluid interface. The models are represented by a partial second order differential equation in relation to the radial position and a first order equation in relation to time, which were solved and numerically fitted using MATLAB routines and experimental data obtained from the hydration assays in the temperature range from 10 to 50 °C. The Hsu model has a smaller quadratic deviation; however, it employs three fitting parameters while DPP uses only one.

Use of Scilab and Arduino for data acquisition environmental

The present work shows the construction of a data acquisition system using the Arduino and Scilab for integrating the sensors and the computer. The use of this system has enabled communication with some sensors, which are easily read by the computer and stored in a file. The application of this system was conducted in a commercial poultry, collecting input, output, internal and external parameters. The distribution of temperature and humidity inside was determined with this system through the construction sensor arrangement.

Exergetic Analysis between a First-Generation Bioethanol Production Plant and a Second-Generation Plant Coupled to Conventional Process

Large consumption of non-renewable fuels in the world has strongly encouraged the search for biofuels, due to inevitable shortage of fossil energy sources and catastrophic problems generated by their use. Under these circumstances the so called second generation biofuel production has been highlighted, where lignocellulosic materials such as sugarcane bagasse are used to produce bioethanol, unlike the traditional first-generation process, whose feedstock is sugarcane. Therefore, this work aimed to perform a comparative exergetic analysis between first and second-generation bioethanol production processes, in order to evaluate from the exergetic point of view, which of these processes is the most feasible. It was found an overall exergetic efficiency of 60.89 % for the exclusively first-generation plant, whereas for the integrated plant, it was obtained 41.58 %. In this way, insertion of new stages in production process, required by the second generation, has caused consequently an increase of irreversibilities and losses.

Computer-aided visual inspection

The quality control in industrial processes and production lines is increasingly rigorous due to governmental issues and the competition among other industries. These make new studies in this field even more important, especially on defects analysis and visual inspection. Among the methods of inspections commonly used the highlighted ones include the direct inspection that is performed without the aid of optical devices, and the remote inspection that makes use of optical instruments, both having an inspector responsible for a subjective evaluation. Such methods are usually the first used in quality control of products. In this paper we propose a remote and automatic computational image analysis to verify the presence of defects in products in a production line.