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Search Results: 1 - 10 of 52778 matches for " Vitor Augusto dos Santos Garcia "
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Continuous Catalyst-Free Esterification of Oleic Acid in Compressed Ethanol
Ana Carolina de Araujo Abdala,Vitor Augusto dos Santos Garcia,Caroline Portilho Trentini,Lúcio Cardozo Filho,Edson Antonio da Silva,Camila da Silva
International Journal of Chemical Engineering , 2014, DOI: 10.1155/2014/803783
Abstract: The esterification of oleic acid in a continuous catalyst-free process using compressed ethanol was investigated in the present study. Experiments were performed in a tubular reactor and variables investigated were temperature, pressure, and oleic acid to ethanol molar ratio for different residence time. Results demonstrated that temperature, in the range of 473?K to 573?K, and pressure had a positive effect on fatty acid ethyl esters (FAEE) production. In the experimental range investigated, high conversions can be obtained at low ethanol concentrations in the reaction medium and it was observed that oleic acid to ethanol molar ratios greater than 1?:?6 show no significant increase in conversion. Nonnegligible reaction conversions (>90%) were achieved at 573?K, 20?MPa, oleic acid to ethanol molar ratio of 1?:?6, and 20 minutes of residence time. 1. Introduction Fatty acid, methyl or ethyl, esters can be usually obtained from free fatty acid (FFA) esterification reaction, through vegetable oils hydrolysis followed by the fatty acid esterification or from direct vegetable oils transesterification [1]. The importance of examining the esterification reaction in a more detailed manner is justified by the huge amount and variety of vegetable oils worldwide available for biodiesel production which may have a high percentage of FFA making the conventional alkali-catalyzed transesterification impracticable, since for this process the percentage of FFA needs to be less than 0.5% [2]. Recent studies propose to obtain esters in two reaction steps of substrates with high acidity, consisting of two approaches: (a) esterification of FFA and subsequent transesterification of triglycerides [3–5] or (b) hydrolysis of triglycerides, followed by esterification of fatty acids obtained [6–8]. In these approaches are commonly used chemical catalysts (homogeneous or heterogeneous) or enzymatic catalysts. More recently, the noncatalytic process where is proposed the hydrolysis occurs primarily in subcritical water and subsequent esterification using a solvent in sub- or supercritical [9, 10]. According to the current literature, catalyst-free reactions at high temperature and pressure conditions provide improved phase solubility and decreased mass-transfer limitations; the reaction rate increases significantly in the supercritical state and, thus, the reaction is complete in shorter periods and simpler separation and purification steps [11, 12]. Some studies available in the literature reported the biodiesel production from free fatty acids (FFA) by noncatalytic method at sub-
Análise e quantifica??o do risco para a gest?o eficiente do portfólio agrícola das seguradoras
Ozaki, Vitor Augusto;Dias, Carlos Tadeu dos Santos;
Revista de Economia e Sociologia Rural , 2009, DOI: 10.1590/S0103-20032009000300001
Abstract: in the agricultural insurance, the presence of adverse events can compromise the financial health of the agricultural insurance companies. drought, for example, can affect not only one producer, but thousand of producers in a huge territorial extension. to skirt this problem, insurance companies diversify geographically their operations. this paper applies the cluster analysis in a corn yield data set for the regions of paraná state, considering the period from 1990 to 2005. in total, 39 groups were formed according to similar characteristics of expected yield and relative risk. based on one of insurability criteria, some high-risk regions were excluded, and groups were classified according to the degree of relative risk.
Desempenho silvicultural de clones de Eucalyptus grandis em rela??o às árvores matrizes
Santos, Glêison Augusto dos;Xavier, Aloisio;Leite, Hélio Garcia;
Revista árvore , 2006, DOI: 10.1590/S0100-67622006000500007
Abstract: aiming at evaluating the efficiency of initial selection of thirteen donor trees for eucalyptus grandis cloning and their performance in a clonal test, the characteristics diameter (dap), total height (ht), volume with bark, (vcc), volume without bark (vsc) and bark volume (vc) were assessed along with five "codominant" trees within a 10 m radius of the selected donor, to evaluate its superiority compared to their pairs. the silvicultural performance of these clones was evaluated at seven years of age in a clonal test arranged in randomized block design with three repetitions and a square plot of 25 plants, in a 3 x 2 spacing. results showed that the superior ht of donor tree compared to the "co-dominant" trees of the selection site is an important parameter for the initial selection of donor tress. multivariate analyzes was efficient for placing donor plants in divergent groups, as well as for the classification of donor trees selected afterwards, within the groups defined by the tocher method. there is a significant relationship among the characteristics used for the initial selection of donor trees and the performances of their clones in the final evaluation of the clonal test. these results allow the reduction in the number of genetic material to be evaluated, however, the tests are essential for the selection process, mainly because the genotype-environment interaction effects.
Common bean cultivars and lines interactions with environments
Carbonell Sérgio Augusto Morais,Azevedo Filho Joaquim Adelino de,Dias Luiz Ant?nio dos Santos,Garcia Antonio Augusto Franco
Scientia Agricola , 2004,
Abstract: The performance of bean lines brought forth in breeding programs or of cultivars in use can be affected by environmental variability. The adaptability and stability of grain yield of 18 common bean cultivars and lines in 23 environments (combinations of seasons, years and locations) were evaluated in the State of S o Paulo, Brazil. 'IAC-Carioca' and 'IAC-Carioca Eté' were used as standard cultivars for the carioca grain type, while 'FT-Nobre' and 'IAC-Una' represented the standard for black grains. The experiment was set up in a randomized complete block design with four replications and plots consisting of two, two central five meters rows flanked by border rows. Stability parameters were estimated by the methods Maximum Yield Deviations (MYD) and by the Additive Main Effects and Multiplicative Interaction Analysis (AMMI). For the identification of the most stable cultivars, the two methods led to consistent results, although by MYD the highest stability was always associated to the highest yield. 'MAC-733327' and 'LP 9637' were the most suitable cultivars and lines for the joint seasons, while 'LP 9637' and 'FT-Nobre' were the most suitable for the dry season. The MYD method combined a simple procedure, easiness of result interpretation, uniqueness of parameters, and association between stability and yield. On the other hand, the AMMI method simplified the identification of stable cultivars by visual inspection, also providing information on the environments. However, the complex nature which combines uni-and multivariate techniques hampers its widespread use in breeding programs.
The Role of CD4+ and CD8+ T-Cells during Angiostrongylus vasorum Infection in Dogs  [PDF]
Thales Augusto Bar?ante, Lis Ribeiro do Valle Antonelli, Kenneth Gollob, Thiago Pasqua Narciso, Silvio Divino de Oliveira Junior, Vitor Márcio Ribeiro, Ricardo Toshio Fujiwara, Ana Paula Peconick, Debora Negr?o-Correa, Walter dos Santos Lima, Joziana Muniz de Paiva Bar?ante
Open Journal of Animal Sciences (OJAS) , 2014, DOI: 10.4236/ojas.2014.45036
Abstract: A determinant factor in the pathology of canine angiostrongylosis seems to be related to the location of the parasite in the definitive host. Their presence inside the arteries and its branches, promoting mechanical and metabolic action on the wall of the vessels, may alter its homeostasis. Bronchoalveolar lavage (BAL) is a procedure that retrieves cells and other elements from de lungs for evaluation, and helps in the diagnosis of many pulmonary diseases. The aim of this study was to evaluate CD4+/CD8+ lymphocyte profile during the infection by Angiostrongylus vasorum, using cells retrieved using BAL. The identification of subpopulations of T lymphocytes by evaluating the co-expression of CD4 and CD8 receptor proteins has shown that despite the increase in both populations, there was a predominance of CD4+ T-cells, instead of CD8+ T-cells. These increases of CD4+ T-cells associated with the increase of the ratio between CD4+/CD8+ suggest polarization of a Th2 response. However, the immune cells, signaling factors, and cytokines that mediate such immunity and how and where they act within the body remain largely undefined during angiostrongylosis.
Efeito de níveis crescentes de uréia na dieta de vacas em lacta??o sobre a produ??o e a composi??o físico-química do leite
Aquino, Adriana Augusto;Botaro, Bruno Garcia;Ikeda, Flávio dos Santos;Rodrigues, Paulo Henrique Mazza;Martins, Maria de Fátima;Santos, Marcos Veiga dos;
Revista Brasileira de Zootecnia , 2007, DOI: 10.1590/S1516-35982007000400018
Abstract: the objective of this trial was to evaluate the effects of three different dietary levels of urea on milk yield and composition. nine lactating holstein cows were randomly assigned to three replicated 3 x 3 latin squares with three periods of 21 days each. treatments were: a) control diet formulated to meet 100% of the requirements of crude protein (cp), rumen undegradable protein (rup) and rumen degradable protein (rdp) according to the nrc (2001) model by feeding soybean meal and sugar cane; b) replacing soybean meal with 0.75% urea; or c) replacing soybean meal with 1.5% urea. diets were formulated to be isonitrogenous (16% cp) and isocaloric (1.53 mcal/kg of nel). no significant differences in dry matter intake, milk yield, 3.5% fat corrected milk, yields of milk protein and milk fat, and somatic cell count were observed among treatments when data were analyzed by simple polynomial regression. milk cryoscopy, ph and density were also not affected by increasing the proportion of urea in the diet treatments; however, milk acidity decreased linearly when the levels of urea were increased in the diet. milk contents of protein, fat, lactose, total solids and non-solids fat and concentration of milk urea all did not differ across diets. results obtained in this trial indicated that the inclusion of up to 1.5% of urea (% of diet dm) in the diet had no effect on milk yield, milk composition, and milk physical-chemical characteristics in lactating cows.
Remo??o de células somáticas pela microfiltra??o n?o afeta a composi??o e a proteólise do leite
Santos, Marcos Veiga dos;Oliveira, Carlos Augusto Fernandes;Lima, Ygor Vinícius Real de;Botaro, Bruno Garcia;
Ciência Rural , 2006, DOI: 10.1590/S0103-84782006000500022
Abstract: this study was aimed at evaluating the effects of raw milk somatic cell removal by microfiltration on the composition and proteolysis during refrigerated storage of pasturized milk. a completely randomized block design was used, in which repetitions (n=3) and milk fat level (skimmed and whole milks) were considered as blocks. a 2 x 2 factorial arrangement of treatments was used: milks with two different levels of somatic cell counts - low somatic cell count (lscc) and high somatic cell count (hscc) - and, microfiltration or not of milk. repeated measures during storage time were taken from pasteurized milk at days 1, 7, 14 and 21. lscc raw milk - 100,000cells ml-1 - and hscc raw milk - 1,000,000cells ml-1 - were obtained from selected cows, skimmed and submitted to vacuum microfiltration. milk was pasteurized and kept refrigerated at 6°c for 21 days. the application of milk microfiltration was efficient on somatic cell removal; however microfiltration had no effect on milk proteolysis which means the treatment did not reduce hscc milk proteolysis rate during refrigerated storage. significant effect of storage period on proteolysis was observed indicating that proteolytic activity remained despite milk pasteurization. hscc milk proteolytic activity was 1,42 times higher than in lscc milk, during the 21-day of refrigerated storage period. based on the results of the study, hscc milk shows a higher proteolytic activity than lscc milk, during the 6°c-21 day storage period. microfiltration, as a somatic cell removal process had no effect on decreasing proteolytic activity of pasteurized milk during the refrigerated storage period.
Influência da temperatura e do tipo de substrato na produ??o de larvas de Musca domestica linnaeus, 1758 (Diptera, Muscidae)
Weigert, Stefan Cruz;Figueiredo, Mario Roberto Chim;Loebmann, Daniel;Nunes, José Augusto Reis;Santos, Antonio Luís Garcia dos;
Revista Brasileira de Zootecnia , 2002, DOI: 10.1590/S1516-35982002000800003
Abstract: in room acclimatized in experimental frog-farm of funda??o universidade federal of rio grande (reurg) four flies cages were prepared, being put in each one about 5000 pupas of musca domestica. after the birth of the flies, each flie cage received, above the trays with food (sugar and milk), a tray with substratum for posture, constituted of humidified wheat flour. daily the substratum for posture were homogenized and distributed among 15 small trays, conditioned in acclimatized stoves and submitted to a combination of five temperatures (20, 23, 26, 29 and 32oc) and three substratum for the production of larvae (flours of rice, wheat and soy). the temperatures of 20, 23 and 26oc provided the best results of production of larvae, that decreased as temperature increased, indicating to be unnecessary the heating use in the larvae cages in places where the minimum temperature is not lower than 20oc. the wheat flour went the best substratum to the production of larvae of m. domestica. the largest productivity of larvae was verified in the 7th and 8th postures.
Remo o de células somáticas pela microfiltra o n o afeta a composi o e a proteólise do leite
Santos Marcos Veiga dos,Oliveira Carlos Augusto Fernandes,Lima Ygor Vinícius Real de,Botaro Bruno Garcia
Ciência Rural , 2006,
Abstract: O objetivo do presente estudo foi avaliar os efeitos da retirada mecanica das células somáticas do leite cru sobre a composi o e a proteólise durante o armazenamento refrigerado do leite pasteurizado. O delineamento experimental utilizado foi o de blocos generalizados ao acaso, no qual foram considerados como blocos as repeti es (n=3) e o nível de gordura do leite (desnatado e integral). Utilizou-se um arranjo fatorial de tratamento do tipo 2 x 2, constituído por: dois níveis de contagem de células somáticas - CCS (baixa e alta CCS) e pela aplica o ou n o da microfiltra o ao leite. Foram realizadas, ainda, medidas repetidas no tempo, as quais corresponderam aos dias de coleta do leite pasteurizado durante o período de armazenamento (1, 7, 14 e 21 dias). Os lotes de leite cru de alta (1.000.000cél. mL-1) e baixa (100.000cél. mL-1) CCS foram submetidos ao desnate centrífugo, à microfiltra o em sistema a vácuo e, em seguida, os lotes de todos os tratamentos foram pasteurizados e armazenados por 21 dias sob refrigera o a 6degreesC. N o foi identificado efeito da microfiltra o sobre a proteólise do leite, indicando que este tratamento n o reduziu a taxa de proteólise do leite de alta CCS durante o período de armazenamento. Foi observado efeito significativo do tempo de armazenamento sobre a proteólise, indicando a manuten o de atividade proteolítica mesmo após a pasteuriza o do leite. Pode-se concluir que o leite com alta contagem de células somáticas apresenta maior taxa de proteólise durante o período de armazenamento que o leite de baixa contagem de células somáticas. A microfiltra o como processo de retirada mecanica das células somáticas do leite n o reduz a proteólise do leite durante o armazenamento.
Common bean cultivars and lines interactions with environments
Carbonell, Sérgio Augusto Morais;Azevedo Filho, Joaquim Adelino de;Dias, Luiz Ant?nio dos Santos;Garcia, Antonio Augusto Franco;Morais, Lizz Kezzy de;
Scientia Agricola , 2004, DOI: 10.1590/S0103-90162004000200008
Abstract: the performance of bean lines brought forth in breeding programs or of cultivars in use can be affected by environmental variability. the adaptability and stability of grain yield of 18 common bean cultivars and lines in 23 environments (combinations of seasons, years and locations) were evaluated in the state of s?o paulo, brazil. 'iac-carioca' and 'iac-carioca eté' were used as standard cultivars for the carioca grain type, while 'ft-nobre' and 'iac-una' represented the standard for black grains. the experiment was set up in a randomized complete block design with four replications and plots consisting of two, two central five meters rows flanked by border rows. stability parameters were estimated by the methods maximum yield deviations (myd) and by the additive main effects and multiplicative interaction analysis (ammi). for the identification of the most stable cultivars, the two methods led to consistent results, although by myd the highest stability was always associated to the highest yield. 'mac-733327' and 'lp 9637' were the most suitable cultivars and lines for the joint seasons, while 'lp 9637' and 'ft-nobre' were the most suitable for the dry season. the myd method combined a simple procedure, easiness of result interpretation, uniqueness of parameters, and association between stability and yield. on the other hand, the ammi method simplified the identification of stable cultivars by visual inspection, also providing information on the environments. however, the complex nature which combines uni-and multivariate techniques hampers its widespread use in breeding programs.
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