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Search Results: 1 - 10 of 37703 matches for " Jorge Augusto Mendes Burak "
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Biomass Production and Ester Synthesis by In Situ Transesterification/Esterification Using the Microalga Spirulina platensis
Tatiana Rodrigues da Silva Baumgartner,Jorge Augusto Mendes Burak,Dirceu Baumgartner,Gisella Maria Zanin,Pedro Augusto Arroyo
International Journal of Chemical Engineering , 2013, DOI: 10.1155/2013/425604
Abstract: The increasing energy demand and reduction in the availability of nonrenewable energy sources, allied with an increase in public environmental awareness, have stimulated a search for alternative energy sources. The present study was aimed at producing biomass from the microalga Spirulina platensis and at assessing in situ synthesis of alkyl esters via acid transesterification/esterification of biomass to produce biodiesel. Two alcohols (ethanol and methanol) and two cosolvents (hexane and chloroform) were tested, at different temperatures (30, 45, 60, 75, and 90°C) and reaction times (10, 20, 30, 60, and 120?min). The factorial analysis of variance detected an interaction between the factors ( ): temperature, reaction time, alcohol, and cosolvent. The best yields were obtained with the combination ethanol and chloroform at 60°C, after 30?min of reaction, and with hexane at 45°C, after 10?min of reaction. In situ transesterification/esterification of alga biomass to form esters for biodiesel production adds unconventional dynamics to the use of this feedstock. 1. Introduction The global concern about future availability of energy comes from national security, economic stability, and environmental sustainability issues [1, 2]. In this context, the demand for petroleum derivatives has increased, but the current concern about reduction in pollution and the energy crisis has stimulated the global biofuel market. The global economy keeps increasing and so does the need for clean, renewable energy sources [3]. In the sector of automotive fuels, the inclusion of renewable fuels, such as biodiesel, has several advantages, such as a reduction in pollution caused by exhaust emissions. Furthermore, biodiesel is an alternative to petroleum and contributes to regional development and social security, mainly in developing countries [4, 5]. A wide variety of feedstocks are currently used for biodiesel production, and microalgae have been considered a potentially useful and promising biodiesel source, because they are photosynthesizing organisms very efficient in the process of converting light into chemical energy [6–8]. In addition, microalgae stand out for presenting high productivity, exceeding that of any commercially produced plant in the world [9–11]. Microalgae have a life cycle of a few days and they may use CO2 from polluting companies as an input for photosynthesis, which helps decrease the emission of greenhouse gases; hence, microalgae may contribute significantly to the global energy matrix [9–11]. Microalgae contain lipids and fatty acids as membrane
Desenvolvimento relativo das partes do corpo de zebuínos de quatro ra?as
Jorge, André Mendes;Fontes, Carlos Augusto de Alencar;
Ciência Rural , 2001, DOI: 10.1590/S0103-84782001000500019
Abstract: sixty-three intact males, 16 gyr, 16 guzerat, 15 nellore and 16 'mocho tabapu?', averaging, respectively, 376.4, 357.6, 362.0 and 368.6kg initial live weight and twenty-four months of age, were used. the animals from each breed were divided into five groups (categories). one group was ramdomly assigned to immediate slaughter (ab), three groups were full-fed a ration containing 50% concentrate, dry matter basis until reaching the slaughter weights of 405, 450 and 500kg, respectively (group i, ii and iii). the fifth group was fed a restricted amount of the same ration to supply levels of protein and energy 15% above maintenance (ar). each ar animal was slaughtered when an animal correspondent to group ii reached the slaughter weight. at slaughter, the empty body weight was determined and the weight of internal organs were recorded. regression equations of log content of internal organs, carcass and their tissues, as a function of log empty-body-weight (ebw), were fitted. the internal organs developed slower in relation to ebw.
Desenvolvimento relativo das partes do corpo de zebuínos de quatro ra as
Jorge André Mendes,Fontes Carlos Augusto de Alencar
Ciência Rural , 2001,
Abstract: Utilizaram-se 63 machos n o-castrados, sendo 16 de cada, das ra as Gir, Guzerá, e Mocho Tabapu e 15 da ra a Nelore, com média de idade 24 meses e média de pesos vivos iniciais de 376,4; 357,6, 362,0 e 368,6kg, respectivamente. Os animais de cada ra a foram divididos, aleatoriamente, em cinco categorias. Uma categoria foi abatida imediatamente (AB), três receberam, em baias individuais, ra o contendo 50% de concentrado na matéria seca "ad libitum" (I, II e III) e uma recebeu a mesma ra o, em quantidade restrita, suprindo níveis de proteína e energia 15% acima da manten a (AR). Os animais das categorias I, II e III foram abatidos ao atingirem pesos vivos individuais de 405, 450 e 500kg, respectivamente. No abate, determinou-se o peso de corpo vazio, e pesaram-se os órg os e vísceras. Adotou-se a equa o de regress o do logaritmo da quantidade corporal de órg os e vísceras em fun o do logaritmo do peso do corpo vazio. Os componentes do trato gastrintestinal e os outros órg os internos, excetuando-se o fígado e o ba o, revelaram um menor ímpeto de crescimento em rela o ao do peso corporal vazio.
Crescimento relativo e composi??o do ganho de tecidos da carca?a de zebuínos de quatro ra?as
Jorge, André Mendes;Fontes, Carlos Augusto de Alencar;Cervieri, Rafael da Costa;
Revista Brasileira de Zootecnia , 2003, DOI: 10.1590/S1516-35982003000400026
Abstract: sixty four uncastrated males from zebu breeds gyr, guzerat, mocho de tabapu? and nellore were used. the animals from each breed were divided into five groups (categories). one group was ramdomly assigned to immediate slaughter, three groups were full-fed a ration containing 50% concentrate, dry matter basis until reaching the slaughter weights of 405, 450 and 500 kg, respectively (group i, ii and iii). the fifth group was fed a restricted amount of the same ration to supply levels of protein and energy 15 % above maintenance. regression equations of log content of carcass and their tissues (muscle, adipose tissue and bone), as a function of log empty-body-weight, were fitted. adipose, bone and muscular tissue presented higher growth in late, early and intermediary age, respectively. carcass presented positive allometry reflecting greater proporcional development in relation to empty-body-weight.
Utiliza??o de método indireto para predi??o da composi??o química corporal de zebuínos
Jorge, André Mendes;Fontes, Carlos Augusto de Alencar;Paulino, Mário Fonseca;Gomes Júnior, Paulo;
Revista Brasileira de Zootecnia , 2000, DOI: 10.1590/S1516-35982000000600035
Abstract: the objective of this study was to develop equations to predict chemical body composition from zebu cattle, based on chemical composition from carcass representative section. sixty-three young bulls from gyr, guzera, nellore and mocho de tabapu? breeds were used. body content of protein, fat and minerals were determined on samples from the carcass section that included the 9th, 10th and 11th rib joint (hh joint), and from the remaining body tissues. protein, fat, energy and ash contents from the hh joint, except for magnesium, were closely related to protein, fat, energy and ash contents in the body. prediction equations based on chemical composition from hh joint showed to be reliable for comparative studies of body composition of zebu cattle.
Crescimento relativo e composi o do ganho de tecidos da carca a de zebuínos de quatro ra as
Jorge André Mendes,Fontes Carlos Augusto de Alencar,Cervieri Rafael da Costa
Revista Brasileira de Zootecnia , 2003,
Abstract: Utilizaram-se 64 machos n o-castrados das ra as Gir, Guzerá, Mocho de Tabapu e Nelore. Em cada ra a, os animais foram divididos, aleatoriamente, em cinco categorias. Uma categoria foi abatida imediatamente, três receberam, em baias individuais, ra o contendo 50% de concentrado na MS ad libitum (I, II e III) e uma recebeu a mesma ra o, em quantidade restrita, suprindo níveis de proteína e energia 15% acima da manten a. Os animais I, II e III foram abatidos ao atingirem pesos vivos individuais de 405, 450 e 500 kg, respectivamente. Adotou-se a equa o de regress o do logaritmo da quantidade corporal de carca a e de seus tecidos (muscular, adiposo e ósseo), em fun o do logaritmo do peso de corpo vazio. Na carca a, o tecido adiposo, ósseo e muscular tiveram maior impulso para crescimento em idade mais tardia, precoce e intermediário, respectivamente. A carca a apresentou alometria positiva, refletindo o seu desenvolvimento proporcionalmente maior que o do peso corporal vazio.
Utiliza o de método indireto para predi o da composi o química corporal de zebuínos
Jorge André Mendes,Fontes Carlos Augusto de Alencar,Paulino Mário Fonseca,Gomes Júnior Paulo
Revista Brasileira de Zootecnia , 2000,
Abstract: O objetivo deste trabalho foi desenvolver equa es de predi o da composi o química corporal de zebuínos, por intermédio da análise química de amostra de se o representativa da carca a. Utilizaram-se sessenta e três animais n o-castrados das ra as Gir, Guzerá, Mocho de Tabapu e Nelore. Os conteúdos corporais de proteína, gordura e macroelementos minerais (cálcio, fósforo, potássio, magnésio e sódio) foram determinados analisando-se amostras de se o da carca a incluindo a 9a, 10a e 11a costelas (se o HH) e dos demais tecidos corporais. Os teores de proteína, gordura, energia e macroelementos minerais da sec o HH, com exce o para o magnésio, mostraram-se altamente correlacionados com a composi o química corporal. As equa es de predi o baseadas na composi o química da sec o HH mostraram-se confiáveis para estudos comparativos da composi o corporal de zebuínos.
Uma metaheurística para a programa o de projectos com multi-modos e recursos limitados A metaheuristic for project scheduling with multi-modes and limited resources Uma metaheurística para a programa o de projectos com multi-modos e recursos limitados
Jorge Magalh?es Mendes
Iberoamericana de Engenharia Industrial , 2009,
Abstract: Este artigo apresenta uma nova abordagem (MM-GAV-FBI), aplicável ao problema da programa o de projectos com restri es de recursos e vários modos de execu o por actividade, problema conhecido na literatura anglo-saxónica por MRCPSP. Cada projecto tem um conjunto de actividades com precedências tecnológicas definidas e um conjunto de recursos limitados, sendo que cada actividade pode ter mais do que um modo de realiza o. A programa o dos projectos é realizada com recurso a um esquema de gera o de planos (do inglês Schedule Generation Scheme - SGS) integrado com uma metaheurística. A metaheurística é baseada no paradigma dos algoritmos genéticos. As prioridades das actividades s o obtidas a partir de um algoritmo genético. A representa o cromossómica utilizada baseia-se em chaves aleatórias. O SGS gera planos n o-atrasados. Após a obten o de uma solu o é aplicada uma melhoria local. O objectivo da abordagem é encontrar o melhor plano (planning), ou seja, o plano que tenha a menor dura o temporal possível, satisfazendo as precedências das actividades e as restri es de recursos. A abordagem proposta é testada num conjunto de problemas retirados da literatura da especialidade e os resultados computacionais s o comparados com outras abordagens. Os resultados computacionais validam o bom desempenho da abordagem, n o apenas em termos de qualidade da solu o, mas também em termos de tempo útil. As the complexity of projects increases, the requirement of an organized planning and scheduling process is enhanced. The need for organized planning and scheduling of a construction project is influenced by a variety of factors (e.g., project size and number of project activities). To plan and schedule a construction project, activities must be defined sufficiently. The level of detail determines the number of activities contained within the project plan and schedule. So, finding feasible schedules which efficiently use scarce resources is a challenging task within project management. In this context, the well-known Resource Constrained Project Scheduling Problem (RCPSP) has been studied during the last decades. In the RCPSP the activities of a project have to be scheduled such that the makespan of the project is minimized. So, the technological precedence constraints have to be observed as well as limitations of the renewable resources required to accomplish the activities. Once started, an activity may not be interrupted. This problem has been extended to a more realistic model, the multi-mode resource constrained project scheduling problem (MRCPSP), where eac
A importancia da avalia??o nutricional no controle da dieta de uma equipe de jogadores de futebol juniores
Rebello, Luciana Collet Winther;Silva, Paulo Roberto Santos;Teixeira, Alberto Azevedo Alves;Vidal, José Roberto Rivelino;Oberg, Alexandre Augusto Ribeiro Barros;Fonseca Jr., Alcides;Rocha, Francisco Oliveira;Sousa, Jorge Mendes;
Revista Brasileira de Medicina do Esporte , 1999, DOI: 10.1590/S1517-86921999000500003
Abstract: the aim of this study was to verify, through a food questionnaire covering a 24-hour recollection range, the adequacy of the daily caloric intake of macronutrients in 19 soccer players whose mean age was 18.6 ± 1.1 (16-20). all athletes belonged to the amateur soccer department of associa??o portuguesa de desportos in s?o paulo. the soccer players were submitted to a food inquiry by means of personalized interviews. the ideal weight of the athletes was calculated by the mean body mass index (bmi) = 22.5 kg.m2 multiplied by the stature in square meters. the basal metabolic rate was then calculated, the fao/who/un chart having been used. after that, by anamnesis carried out at the sector of athletic preparation, the volume of physical activity was quantified, which made it possible to determine the minimum, mena and maximum caloric value suitable for athletes. in addition, all soccer players were submitted to laboratory tests. by calculating the daily caloric needs according to the training, the following result and parameters were verified: minimum = 3,298 ± 177 kcal.day-1; mean = 3,689 ± 207 kcal.day-1 and maximum = 3,991 ± 225 kcal.day-1. the mean caloric consumption reached by the players used to be 2,584 ± 421 kcal.day-1. when a comparison was made between the mean intake they consumed with the minimal, mean and maximal values necessary, the percentage of caloric deficiency which they presented - 22%, 30% and 35%, respectively - was highly significant (p < 0.05). the laboratory tests revealed in one of the athletes the presence of anemia with 11.1% of hb and 35% of hematocrit. the results of this study allow to conclude that both nutritional education intended to correct food behavior disorders, and severe control of the caloric needs, constitute procedures of prime importance for an adequate diet of soccer players.
Oswaldo Cruz e a controvérsia da sorologia
Carreta, Jorge Augusto;
História, Ciências, Saúde-Manguinhos , 2011, DOI: 10.1590/S0104-59702011000300005
Abstract: this analysis of the discussion surrounding the efficacy of the plague serum produced by manguinhos institute in the early twentieth century begins with an overview of oswaldo cruz's service as head of the public health directorship (diretoria de saúde pública). the controversy itself is then addressed, through an exploration of correspondence exchanged by physicians oswaldo cruz, miguel pereira, vital brazil, chapot prévost, and francisco fajardo. their letters reveal how bacteriology in brazil was then marked by uncertainty and experimentation, even while this field of knowledge publicly touted itself as safe and incontestable. the article shows how arguments of an extra-scientific nature interfere with both research development and the acceptance of medical products.
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