The simultaneous diffusion of inorganic components in the olive pulp in wet brine was modeled based on Fick’s generalized 2nd Law and simulated using the finite element method. The main and crossed ...diffusion coefficients, the film coefficient and the Biot number were determined, with the application of the simplex optimization method, through the minimization of the percentage errors. The errors between the simulated and experimental data were 5.35% for NaCl and 4.77% for KCl and the adjusted main diffusion coefficients were 0.4358 × 10-12 m2 s-1 for NaCl and 0.5408 × 10-12 m2 s-1 for KCl. The system developed to simulate diffusion allows the control and modulation of the salts content that diffuses through the olive pulp.
Olive samples were subjected to the salting process in brine containing 1196 mol m-3 of NaCl and 402 mol m-3 of KCl. Samples were collected during 60 h and salt concentration values were determined. ...With the finite element method (FEM) and the minimization of the errors percentage between the simulated and experimental values, the mass transfer coefficients in the film (hm) were obtained, being 1.0072 × 10-8 and 1.2499 × 10-8 for NaCl and KCl, respectively. The salts concentration at the olive/brine interface was simulated by FEM and analyzed via SOFM. A network with 4 × 4 topology and 10000 training epochs was used. It was observed that the influence of the stationary film formed on the surface of the olives during the salting process depends on the position, the salt involved in the diffusion and that the concentration of the salts, at each point, varies according to the immersion time.
Natural additives with antioxidant properties can be used as biodegradable and sustainable alternatives to synthetic products, because they can inhibit the biodiesel oxidation reaction, increasing ...oxidative stability and extending its storage period. This research evaluated the efficiency of jabuticaba peels, gabiroba leaves, and hibiscus flowers in ethanolic extracts, analyzing through the simplex-centroid design, the induction periods (IP) and rate constants (k) of the biodiesel oxidation reaction at 110 °C. Antioxidant activity was observed in all extracts, either decreasing k or increasing the IP. The mathematical models obtained showed coefficients of determination greater than 0.9400, a non-significant lack of fit at the 5% level, and low dispersion between predicted and experimental data, indicating that the 1st order reaction fit was appropriate and can be used for predictive purposes. In this work, the optimization was performed with maximization of IP and minimization of k showing that the mixture containing 25% of jabuticaba peels extract and 75% of gabiroba leaves extract was the most suitable, because proportionally increased the IP and decreased k of the biodiesel oxidation reaction. It is possible to suggest the use of jabuticaba peels extract or gabiroba leaves extract as well as various combinations between them as antioxidant additives.
The objective of the present work was to apply self-organizing feature maps (SOFM) and multilayer perceptron (MLP) to evaluate the protective capacity of tert-butylhydroquinone (TBHQ), ...butylhydroxyanisole (BHA), and butylhydroxytoluene (BHT) antioxidants against the biodiesel oxidation reaction. For this, the antioxidant concentration and the biodiesel compliance parameters were used as continuous input variables and the type of antioxidant as a categorical. The SOFM proved to be an adequate tool for the classification of biodiesel samples containing antioxidants. The performance of the 5 most active networks of the model ranged from 89 to 99% for training, testing, and validation with an error below 1.42 × 10-4. Statistical tests applied to validate the model showed no significant difference between predicted and experimental values. The global sensitivity analysis showed that the relative protection factor (RPF) contributed with 34.89%, the antioxidant with 31.49%, the induction period with 10.69%, the water content with 6.00%, and the others all together with 16.93% in the construction of the regression models by MLP.
Radon gas concentrations in ferruginous, quartzitic/conglomeratic and carbonatic caves were measured and the results obtained in each lithology were compared. Three representatives of each formation ...(nine caves in total) were studied. The caves are located in three environmental preserved areas in the Ferriferous-Aquifer Quadrangle and in its regional surrounding, in the center-south portion of Minas Gerais State, Brazil. It was found that the average concentration in quartzitic/conglomeratic caves (4,759 Bq/m3) was much higher than those obtained in carbonatic (844 Bq/m3) and ferruginous (945 Bq/m3) caves. This result most likely reflects differences in the uranium content of the rock types. Also, for a better understanding of the radon distribution inside the caves, concentration maps with their interpolated values were generated using geospatial analysis tools.
•For the first time, radon (222Rn) gas was measured in non-carbonatic caves.•The quartzitic caves had the highest average 222Rn concentration (4.8 kBq/m3).•Ferruginous and carbonatic caves had average values of 945 and 884 Bq/m3, respectively.•222Rn levels correlated to uranium concentration in the studied lithologies.
The main goal of this article is to evaluate the relationship between the spatial distribution of the population of the city of Belo Horizonte, one of the largest cities in South America, and its ...public transport network, seeking to ascertain whether the current bus network is able to meet the needs of the population. The methodology was based on data processing and vector information from different sources through spatial analysis tools. As expected, the results revealed a greater concentration of routes and bus stops in the central region of Belo Horizonte, which is the main commercial center of the municipality and its metropolitan region. However, the results suggest evidences of a disadvantage for the population with lower income, especially those living on the periphery. A possible explanation for this disadvantage is the invisibility of these communities due to their high level of irregular occupation. Under the eyes of public transport planning, they are not recognized, and, theoretically, do not generate demand for lines and bus stops
The interconnected system has become the need of the hour in the present day industrial automation. Interconnection is established by conventional wired or by wireless techniques. In either case for ...the ease of data transmission discretization is essential as process variables are analog. This paper discusses the design of an observer to estimate the effects of Data Acquisition Cards (DAQ) like transmission delay and quantizer delay on a networked liquid level control loop. The objective of the proposed work is to accurately control the level of liquid in a tank, even if there are variations in the performance of the data acquisition card used to transmit the data in between the actual plant and computer. This can be achieved by designing an observer that will estimate the effect of data acquisition card parameters like transmission delay and quantizer delay on the system behavior of the process. A difference of observer output and existing process which is affected by the transmission parameter is filtered, so as eliminate the effect of variation in data acquisition parameters on the process. In the proposed work observer is designed using techniques like Luenberger and Kalman filter approach. Performance analysis shows that a Kalman filter-based observer produces better results as compared to a Luenberger observer. Results show that a Kalman filter-based observer produced a root mean square error of 0.015, and the root mean square of percentage overshoot of 1.16 for the test with the practical setup.
The cultivation of apple tree is highly dependent on meteorological variables, especially temperature. The link between accumulation of degree-days (DD) and accumulation of chilling hours (CH) are ...determinant to field success, in the context of climate change. The objective of this study was to quantify the accumulation of DD necessary during the reproductive phenological stages for cultivar IAPAR 75 Eva, considering the accumulation of CH during the period of dormancy. The study was carried out at the Experimental Station from the Rural Development Institute of Parana IAPAR-EMATER, in the municipality of Palmas, Parana State, Brazil. The evaluations were from 2013 to 2019, showing for each three days, the phenological phases and the value of DD and CH. The results were submitted the simple and multiple correlation by the R software. We verified the influence of the increase in temperature on the cycle acceleration, in addition, it was verified a tendency of less requirement for DD to advance the cultivar cycle. Were verified the value of chilling hours as 281, 156, 84, 326, 96, 76 and 11 hours of chill, respectively, and the consequent accumulation of DD to breaking dormancy was appointed as 1093, 1156, 1574, 1157, 1834, 1096 and 1838 DD, respectively. We concluded that CH causes impact in DD accumulation to development of apple tree. Higher temperatures accelerate the apple tree development. With the information of CH accumulation in dormancy, it is possible estimate the quantity of DD to develop the phenological phases. This information contributes to agricultural planning for cultivar Eva farmers.
This study aimed to evaluate the effects of essential oils from the fruits of Citrus sinensis and Xylopia aromatica, included in broiler feed, on blood parameters, the biometrics of digestive organs, ...bone analyses, and the biochemical profiles of the viscera, as well as the histomorphometry of the small intestine. In this study, 180 one-day-old male chicks of the Cobb 500 strain were fed a corn and soybean meal over three treatments and six replications, and the experimental design was completely randomized. The data were subjected to an analysis of variance and a Tukey test at a 5% significance level. The effect of the experimental diets on performance, blood parameters, biometrics of the digestive organs, bone analysis, and biochemical profiles of the viscera, as well as the histomorphometry of the small intestine, were evaluated. The compounds identified in the essential oil of X. aromatica were sylvestrene, α-pinene, and β-pinene, while in C. sinensis they were limonene and myrcene. The essential oils of C. sinensis and X. aromatica had no significant effect on performance at 14 days. The effects of the presence of the essential oils of C. sinensis and X. aromatica on the response were beneficial: there were reductions in liver lipids, cholesterol, and triglycerides, and in the depths of the crypts in the jejunum of chickens. So, the essential oils from the fruits of C. sinensis and X. aromatica can be used in broiler chickens to improve the lipid profiles of birds without affecting their performance.
The spineless cactus has high production of green matter. Its major importance is utilized for production of flour in agro-industrial processes as well as its nutritional characteristics. The ...objective of this work was to evaluate the quality of the flour of the spineless cactus bud produced under different temperatures and to describe the drying process by means of mathematical models. The spineless cactus genotype 'Miúda' (Nopalea cochenilifera (L.) Salm-Dyck) was used in this study. The buds approximately with 20 cm in length were harvested. Drying was carried out at different temperatures (55, 65, 75 and 85 degrees C). Evaluations were done with the application of mathematical models to the data obtained from the drying kinetics, using determination of coefficients (R2) and chi-square (X2). The chemical and toxicological composition of flour was evaluated. The temperature treatments influenced the flour quality. The flour obtained at the temperature of 55 degrees C presented the best chemical percentages and showed no toxic effect. The studied models presented good statistical indices as a function of the adjustments to the experimental data. The Wang and Singh model presented the best R2 and X2 for the drying kinetics of the palm shoots. The Peleg model presented a unique graphical behavior, reaching to cross the field of negative water quantity before reaching the equilibrium point of the dehydration process. Therefore, this model cannot be used to simulate the drying process of 'Miuda' shoots within the studied temperature range.
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