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Processo integrado de eletrocoagulação e cultivo mixotrófico de Desmodesmus subspicatus em vinhaça de cana-de-açúcar
(Universidade Federal de São Carlos, 2019-06-25) Saavedra, Mauricio Daniel Montaño; Concha, Viktor Oswaldo Cárdenas; https://lattes.cnpq.br/0661599261187131; Bastos, Reinaldo Gaspar; https://lattes.cnpq.br/9329363278429665; https://lattes.cnpq.br/6517700261856398
Brazil is the largest sugarcane ethanol biofuel producer of the world. The productive process generates a considerable quantity of vinasse, its main wastewater. Therefore, the vinasse disposal is one of the major challenges involved in the ethanol production. Although fertirrigation is permitted by environmental legislation, such volume is limited and the remaining vinasse needs to be treated for its disposal into the environment. Microalgae cultivation has been considered a promising vinasse treatment, because its biomass could be an interesting source of valuable bioproducts. However, due to the physicochemical characteristics of vinasse (high turbidity and acid pH), it would be advantageous to perform a pretreatment process in order to adequate the effluent as a culture medium and to allow better light incidence in it. By this way, the objective of the research was to evaluate the integrated process of electrocoagulation with subsequent Desmodesmus subspicatus microalgae mixotrophic culture in sugarcane vinasse. For this purpose, several electrocoagulation experiments were carried out with raw vinasse in a laboratory electrolytic reactor, evaluating the influence of the electrode material (aluminum or iron), spacing between plates (1-3 cm), current density (2.2-20.0 mA cm-2), agitation (0-680 rpm) and sludge separation method (sedimentation or filtration). The electrocoagulation results indicated high turbidity removal and pH adequation, from initially acid vinasse (vinasse pH ≈ 4) to values up to standard BG11 medium (BG11 pH ≈ 7.4) in all experimental conditions, which allowed direct culture of D. subspicatus without any additional treatment. At optimized conditions (aluminum electrodes spaced 1 cm, 6.1 mA cm-2 and 430 rpm) and using filtration for sludge separation, it was obtained 99.8, 40.3 and 55.5 turbidity, total organic carbon and total nitrogen removal. It was dosed dosage of 1.6 g L-1 of Al+3 by the electrolysis, which represented an electric consumption of 8.0 kWh m-3 and a process cost of R$ 14.10 m-3. The cultivation of D. subspicatus in the pre-treated vinasse showed better results using aluminum electrodes in relation to iron. The vinasse clarification achieved by the electrocoagulation process potentiated the microalga growth, achieving a higher productivity in mixotrophic cultivation (10.0 x106 cell mL-1 day-1) than heterotrophic cultivation (3.5 x106 cell mL-1 day-1). The total organic carbon and total nitrogen removal reached by the integrated process was 69.6 and 80.9%, respectively. The biomass characterization showed a lipid and protein content of 8.6 and 25.3%, respectively. It was obtained high lipid and protein productivities (75.3 and 208.2 mg L-1 day-1, respectively). Therefore, it was concluded that the integrated electrocoagulation process with subsequent D. subspicatus mixotrophic cultivation in sugarcane vinasse was technically feasible and would allow microalgae biomass, lipids and proteins production, and simultaneously, vinasse treatment.
O impacto da invasão por Hedychium coronarium J. König (Zingiberaceae) em áreas ripárias
(Universidade Federal de São Carlos, 2019-06-25) Zanatta, Mariane Patrezi; Boschi, Raquel Stucchi; https://lattes.cnpq.br/5774095142035730; Matos, Dalva Maria da Silva; https://lattes.cnpq.br/4728734263109138; https://lattes.cnpq.br/4905716963378752
Riparian environments are increasingly being modified by human activities and this causes changes in vegetation dynamics. Native species are being replaced by exotic and invasive ones. Impacts of plant invasions in these environments include changes in ecosystem processes, organic matter entry, nutrient cycling, microbial communities, decomposition, and soil attributes. We evaluated the impact of Hedychium coronarium on litter biomass production, nutrient cycling and decomposition in invaded and noninvaded areas. In addition, we have looked at general trends in research on plant invasions in riparian environments in last decades. The one-year study in two distinct riparian environments showed that litter production does not differ between invaded and non-invaded areas. Moreover, this production is not uniform throughout the year, and there is an increase in the dry season. The impact of H. coronarium invasion on litter and soil nutrients depends on the ecological context of the environment and soil attributes, mainly the texture; in nitrogen-poor soils with a sandy clay loam texture, H. coronarium appears to increase the total N concentration in the soil. In the decomposition, our results showed a significant effect of the environmental treatment (non-invaded area) and the interaction between the seasonal treatment and the type of detritus (higher decomposition in dry season with vegetal species and dry season with mixed detritus too). We also found a higher amount of organic matter (OM) in the non-invaded area. In addition, studies with invasion in riparian environments are recent, this topic had an increase in a number of publications only in 2007. We conclude that to better understand the invasion of H. coronarium in riparian environments it is necessary to consider the species in each context and environment of invasion; besides the importance of studying the soil in these types of studies.
Contribuição para determinação do módulo de deformação à compressão de aparelhos de apoio elastoméricos simples
(Universidade Federal de São Carlos, 2019-06-25) Merlos, Renata Soares; Ferreira, Marcelo de Araújo; https://lattes.cnpq.br/4199122391532470; https://lattes.cnpq.br/2768059855317468
The elastomers, also known as neoprene, have been widely used in the precast concrete constructions in Brazil, due to its good performance in connections subjected to compression. Thus elastomeric bearing pads are the most commonly used today, their behavior on compressed elements is complex. This complexity of behavior derives mainly from the difference in the properties of the elastomer relative to other commonly used materials and from the variation of stresses and deformations of the elastomers as the compression stresses are increased. In this sense, this study aimed to characterize, through an experimental program, the behavior to the simple compression of the plain elastomeric bearing pads, through the experimental determination of the tangent compression modulus of deformation (modulus of elasticity) and the compression stiffness of these elements. Through the experimental program proposed in this study, as well as the analysis of the tests results, it was confirmed that the calibration of the equation established by NBR 9062: 2017 was satisfactory to evaluate the deformability of the plain elastomeric bearing pads. Furthermore, the tests can be used to verify the conformity of the shear modulus values obtained experimentally, relative to the values indicative of correspondence with the Shore A hardness and, therefore, the quality control of the elastomer. Also, it was possible to adequacy a procedure that could be reproduced with simple equipment, that is, hydraulic actuator with constant force application. Finally, it was found that the higher the speed of application of the load in the test, the greater the rigidity obtained for a plain elastomeric bearing pad.
O elogio do logos em Gorgias
(Universidade Federal de São Carlos, 2019-06-25) Simoni, Luca dos Santos; Galgano, Nicola Stefano; https://lattes.cnpq.br/0264905850746909; Souza, Eliane Christina de; https://lattes.cnpq.br/5658382257368048; https://lattes.cnpq.br/7151504573829027
This work aims to discuss how, by an articulation between tree essays of Górgias, "On Nature", "Encomium of Helen" and "Defense of Palamedes", we can see logos as a central but even so problematic concept meaning, depending on the circumstances, "Speech\ lenguage" and "word". From the tree thesis enunciated on the essay "On Nature" we will try to show how the gorgian concept of logos can allow us to build an immage of lenguage wich,having a relativistic pattern, is unable to say the being of things: its dominium isn't the one of the knowledge of the Thruth but the one of the human relations giving priority on the action of the speech on the subjectivity of the ones who are listening, aiming create a belief through persuation. The central paragraphs of the Helena fit in this speculative cenario, when Gorgias shows logos as an instrument of persuation and ilusion by the fact of doxa being the only intelectual instance reachable by the man .
Estrutura e interpretação de situações-problema em matemática: uma análise baseada na semântica formal
(Universidade Federal de São Carlos, 2019-06-25) Agostini, Tainara Duro; Conde, Dirceu Cleber; https://lattes.cnpq.br/2630773088169073; https://lattes.cnpq.br/5722724183192283
This dissertation investigates the difficulty of interpreting mathematical story problems, considering the semantic relations established between the natural language in statements and the meaning in the mathematical language. The research was divided into two moments: firstly it has been a contact with four students of the junior school in order to understand how they have interpreted and how they related the meaning and reference in situations considered as simpler; secondly it has been the analysis of six story problem of three differentiated junior school years books with the thematic percentage. In this way, we had investigated the difficulties that occasionally arise in the interpretation of the statements of story problems, since the solution requires a logical-formal thought constitutive of the mathematical language. In order to avoid common sense, we have searched to understand and to analyze the various linguistic and structural reasons and aspects, which cause challenges, as well as competent individuals in mother tongue and mathematics. In addition, we had noticed that there was remarkable importance in the construction and form of the commands, sometimes composed by questions and others by imperative sentences, since they are always in search of a fulfillment to his x. Thus, some linguistic phenomena students can deal with in the wrong way, such as synonymy, paraphrase and logical entailment, have been worked on and can also be used in the interpretative process of the utterance. The analysis was based, firstly, on the questionnaire applied to some students, so that later it was possible to examine the statements of textbooks with a closer look.
Reconhecendo a geometria espacial: uma proposta de ensino a partir de atividades contextualizadas
(Universidade Federal de São Carlos, 2019-06-25) Moraes, Lucas Garcia de; Noel Filho, Antonio; https://lattes.cnpq.br/5234064498436000; https://lattes.cnpq.br/4307145163578435
The inspiration for this work comes from the observation in the difficulties of the majority of the students of the CEEJA in finding the literal sense of the study of the spatial geometry. In order to contribute to the development of the necessary skills to better understand the geometric concepts, we restructure a workshop a workshop related to the theme, giving it a new focus and searching through it, analyze the development of the participating students with the intent to respond the following question: do the practical activities bring significant results in the Youth and Adult Education of the CEEJA? All the elaboration of this work was carried out in agreement with the PCN, the resolution SE 75/2018 that regulates on the organization of the EJA courses, in the State Centers of Education of Youths and Adults, besides the internal rules of the CEEJA - Votorantim, place where all this happened. We carried out a survey on the profile of the students enrolled, as well as an analysis of the work already done in the place. The research on the profile of the students was carried out during the year of 208 in the act of enrollment of each one of them and the group that integrated the workshop was formed by students who registered by their own will, all the way when we arrived at the mark of 32 enrolled, we closed the inscriptions so that a very large group did not form, since this could hinder our analysis. The data collection was according to the devolution of the requested tasks to the students and we ended up making a comparison with the final results obtained by these students with the results of another group of students who did not participate in the workshop.