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Utilização do metabissulfito de potássio no processo de fermentação etanólica para controle de leveduras e bactérias contaminantes
(Universidade Federal de São Carlos, 2017-04-11) Paraluppi, Anna Lívia; Ceccato-Antonini, Sandra Regina; https://lattes.cnpq.br/7600793543184032; https://lattes.cnpq.br/6027643222021867
One of the main concerns in the ethanol-producing industries is the growth control of undesirable microorganisms that can cause decrease in the fermentative yield. Among non-Saccharomyces yeasts which can contaminate the fermentation process, the genus Dekkera is the most important because it is able to grow in fermentation conditions and be adapted to the substrates. Regarding the bacteria, Lactobacillus is the most representative genus. In the wine industry, several antimicrobial agents are utilized to control the undesirable yeast and bacteria populations, among them the sulphur dioxide (SO2) which is used in the form of sulphite salts. However, the microbial control by this substance is not known yet in the sugar and alcohol industries, in which the acid treatment of the cells and antibiotics are largely utilized to control the growth of bacteria. In this context, this work aimed to verify the effect of the addition of potassium metabisulphite (PMB) in two steps of the fermentative process for fuel alcohol production: to the raw sugarcane juice and to the acid treatment of the cells. In the first step, PMB concentration and exposure time to the antimicrobial were determined to cause decrease in the number of native yeast and bacteria in the sugarcane juice. Secondly, the minimum inhibitory concentration of PMB was determined to control the growth of Dekkera bruxellensis, an important yeast contaminant of the alcoholic fermentation, when added to the acid treatment of the cells, both in pure culture and in co-culture with Saccharomyces cerevisiae and Lactobacillus fermentum. The effect of this treatment on the fermentative parameters was also analysed. The PMB was effective to control the growth of native yeast and bacteria in the sugarcane juice at the concentration of 800 mg/L with exposure time that varied from 3 to 6 hours, resulting in a maximal reduction of one log cycle for yeasts and from 1.5 to 1.9 log cycles for bacteria. When added to the acid treatment of the cells (pH 2.0), a reduction of approximately one log cycle of D. bruxellensis was verified from the concentration of 225 mg/L of PMB. However, in co-culture with S. cerevisiae and L. fermentum, this concentration also resulted in the decrease of S. cerevisiae cell number, with negative effect on ethanol production. In a cell-recycled batch fermentation, the combination of acid treatment and 150 mg/L of PMB caused a substantial decrease in S. cerevisiae viability as well in the growth of both contaminants, with reduction in the ethanol production and fermentative efficiency. Although the potassium metabisulphite is effective in the context of wine fermentation, it was not appropriate to the fuel ethanol production especially due to the peculiar characteristics of the substrate and the conditions in which the fermentation is carried out.
A construção da imagem de Hugo Chávez por documentários
(Universidade Federal de São Carlos, 2017-04-11) Paiva, Gabriela Pandeló; Chaia, Vera Lucia Michalany; https://lattes.cnpq.br/2351981436811918; Azevedo, Fernando Antonio Farias de; https://lattes.cnpq.br/6291864794986993; https://lattes.cnpq.br/1676514828142223
The 90s in Venezuela consists in the decline of the Punto Fijo Pact, an agreement between the political elites to maintain the democratic order. In the Latin American context, this period, followed by the transition to the 21th century, can be represented by important events such as the rupture with a liberal economy and a change in the political scenario that became more interested with social issues, such as the fight against poverty. In Venezuela, the government of Hugo Chávez, a leader which support divided the nation, represents this political moment. With a controversial representation by many means of communication around the world, the aim of this research is to analyze how his image as president and leader of the Bolivarian Revolution is built. To fulfill these goals, the empirical material used are the following documentaries: "South of the Border" (Oliver Stone, 2010), "Mi Amigo Hugo" (Oliver Stone, 2014) e "Chavez: Inside the Coup" (Kim Bartleyl e Donnacha O'Briain, 2003). These films are imagetic documents pro-Chávez which registry will stay for posterity and its analysis will register the positive aspects of his legacy.
Tecnologia e concepção de sistemas estruturais híbridos de concreto para edifícios de múltiplos pavimentos no Brasil
(Universidade Federal de São Carlos, 2017-04-11) Takata, Leandro Teixeira; Almeida Filho, Fernando Menezes de; https://lattes.cnpq.br/0447825383222965; Carvalho, Roberto Chust; https://lattes.cnpq.br/3633394168236221; https://lattes.cnpq.br/7402392342005625
Considered as a modern method of construction (Modern Methods of Construction, or simply MMC), the hybrid construction system presents several advantages over other systems. It combines the benefits of precast construction with the advantages of cast in place with lower costs and higher quality of the elements, in addition to offer competitive (compared to more traditional) structures with good quality and durability. There is a great tendency in construction in trying to use characteristics of different constructive systems that can bring benefits in buildings. In hybrid construction systems, the idea is to use advantages of more than one system with different characteristics. In this work, the proposal is to look for systems, in principle, with characteristics of precast and cast in place, to use them in the same building. Some advantages and disadvantages of this system are presented, as well as the national and international scenario of their application. It is attempted to show from the current condition of civil construction, as it is already possible to apply the union of the two systems: the precast and cast in place concrete for making of vertical constructions. The idea of the work is to present a study of how structures with hybrid construction system can be applied in buildings. The interactions of the chosen systems are studied, how they can be executed in the face of different needs and conditions, and what costs entail the beginning and end of the work. Some examples of calculation are presented to illustrate the differences and similarities with cast in place and precast. An example of the cost between the constructive systems is also presented, so that they can serve as base for an additional option in the definition and choice of the constructive system.