Soares D.S.C.,Av. Marechal Rondon |
Silva G.F.,Programa de Pos Graduacao em Engineering Quimica |
Silva T.C.S.,Programa de Pos Graduacao em Engineering Quimica |
Nunes T.P.,Av. Marechal Rondon |
Junior A.M.O.,Programa de Pos Graduacao em Engineering Quimica
Chemical Engineering Transactions | Year: 2012
The plant mangabeira (term referred for trees of mangaba fruit) is a tropical plant, native of Brazil, which has a great potential for economic exploration. In the state of Sergipe situated in the northeast region of Brazil, mangaba is one of the major fruit and very much sought in open markets, attaining even a price higher than that of grape and other noble fruits The freezing, in general, offer several advantages over other methods of food preservation, among them, the maintenance of color, flavor and nutritional qualities, when the freezing is done properly and the process storage follows strict criterious to keep product quality. Generally, the experimental determination of thermal properties of foods is the major difficulty of the large dependence of these properties and their large deviations of low temperature characteristics of the freezing process. Due to various complications encountered in the experimental evaluation of thermal properties during freezing, efforts are concentrated on building mathematical models based on the thermodynamic properties of an ideal solution. The mathematical correlations of the thermal properties of food as a function of its basic chemical composition and water content have been an alternative to experimental procedures. Models for estimation of thermo physical properties for systems with and without phase changes are easily found in the literature. The values of specific heat, density and thermal conductivity were estimated using Choi and Okos model from the composition of mangaba experimentally determined. The lack of tabulated values of thermal properties of mangaba has restricted the use of equations in mathematical models for the calculation of thermal properties. The heat transfer at steady state is normally used as a hypothesis. In this work we used the hypothesis of heat transfer dynamics to estimate the coefficient of heat transfer using the Biot number relating to food thermal conductivity and the heat transfer coefficient. Afterwards, it was estimated the coefficient of heat transfer. This study aimed to evaluate the kinetics of freezing mangaba in half-ripe maturation stage. The diameters were 27.96 ± 0,7 mm for small ones and 52.63 ±., 36 mm for the big ones. The freezing time for small mangabas was 40 min while for the larger fruit was 69 min. The Plank model predicted freezing time of 39 min and 65 min respectively. The model proposed by Pham was not more suitable for the prediction of freezing time with average deviations between 14.5 % - 27.5 % compared to the experimental data. Copyright © 2012, AIDIC Servizi S.r.l.
Telles R.,Av. Marechal Rondon |
Guimaraes A.,Federal University of Minas Gerais |
Macedo H.,Av. Marechal Rondon
Proceedings of the 6th Euro American Conference on Telematics and Information Systems, EATIS 2012 | Year: 2012
Mashups is a new way to develop Web applications by combining preexistent Web services, features and content in order to provide new features and services. Location systems are maybe the most popular mashups. An example of a location system is RotaCerta. This system makes use of Google Maps API to generate textual route descriptions between two locations within a city. RotaCerta novelty is the use of Points of Interest (POI) in the generated descriptions so to facilitate the route comprehension and assimilation by the user. RotaCerta suffers, however, from a severe limitation on the need for manual feeding of the POI's base for each city of interest. This work is exhausting, costly, and greatly limits its usage. This paper proposes a mechanism for automated feeding of POI base for RotaCerta system by means of Google Places. Experiments were performed for three different cities in Brazil and the results confirm the gain of intuitiveness in the textual description of the generated paths and demonstrated the elimination of previous limitation and the consequent encouragement of its large scale usage. © 2012 ACM.
e Silva C.D.S.,av. Marechal Rondon |
Santos P.A.A.,Federal University of Lavras |
Lira J.M.S.,Federal University of Lavras |
de Santana M.C.,av. Marechal Rondon |
da Silva Junior C.D.,av. Marechal Rondon
Revista Caatinga | Year: 2010
This work had the objective of checking the echophysiological behavior of cowpea [Vigna unguiculata (L.) Walp.] cv. BRS Xique-xique cultivated under different levels of hydric deficit. The plants were cultivated in vases with capacity for 10L, containing one substratum composed by: 88,45% sand, 3,71% of clay, 7,84 % of silte. The experimental design was entirely randomized with three treatments (TO- reposition of 100% of lost water by evapotranspiration, T1- reposition of 50% and T2- reposition of 25%) and five repelicates. Previously, T1 and T2 suffered a period of stress and were later rehydrated. In the day of the assessment, the plants of T1 had been undergone to stress for three days, while the plants T2 for 5 days. The variables analyzed were: leaf water potential, net photosynthesis, stomatal conductance, transpiration, internal CO2 concentration and foliar temperature. The fewest availability of water caused reductions in the net photosynthesis rates, stomatal conductance and transpiration in T1 and T2 when they were compared to T0. The internal CO2 concentration in T2 was the greater among analyzed treatments. The reposition of 50 % of the lost water hasn't caused any damage in the net photosynthesis.