Navegando por Data de Publicação, começando com "2014-11-25"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 3 de 3

Avaliação da vinhaça de cana-de-açúcar para produção de hidrogênio em reator anaeróbio de leito fluidizado em condição mesofílica: efeito de co-substrato, TDH, e concentração
(Universidade Federal de São Carlos, 2014-11-25) Reis, Cristiane Marques dos; Silva, Edson Luiz; https://lattes.cnpq.br/4438080540876126
study evaluated the production of hydrogen and methane from sugarcane vinasse in anaerobic fluidized bed reactor. Two fluidized bed reactors filled with expanded clay were operated under two different concentrations: R5 (5 gCOD.L-1) and R10 (10 g.CODL-1). During the first stage, glucose was used as the primary carbon source. Along the first step vinasse was added from 0% to 100% of the organic source under HRT of 6 h. In a second step with 100% of sugarcane vinasse, HRT was reduced to 4, 2 and 1 h. In another reactor R15 (15 gCOD.L-1) it was varied the substrate (100% glucose; 50 % glucose/ 50 % vinasse; 100 % vinasse) under HRT of 8 h. All reactors were operated in room temperature and a sludge from the treatment of swine wastewater was used. It was not observed methane production in R15. Hydrogen production rate and hydrogen yield reached, respectively: 0,01 L.h-1.L-1 e 0,10 mmolH2.g-1COD added. In reactors R5 and R10, biogas was formed by H2 and CO2 when glucose was present in the feed. Methane was formed when vinasse became the main substrate. The best operating condition occurred under HRT of 1 h, vinasse 100% at a concentration of 5 gCOD. L-1 with a hydrogen production rate of 0.57 L.h.-1L-1. As regards the yield, the best condition was under HRT of 6 h when the affluent comprised vinasse and glucose (3:1) reaching an yield of 3.07 mmolH2.g-1CODadded. Methane production in acidic conditions showed that the methanogens have adapted to a slightly acidic pH of 4.5. The principal metabolites were ethanol, butyric acid, propionic acid and methanol. Microbial characterization revealed the presence of Prevotella and Megasphaera belonging to the domain Bacteria and Methanobacterium and Methanosphaera belonging to the Archaea domain.
Estudo da cominuição na solubilidade da rocha fosfática Bayóvar
(Universidade Federal de São Carlos, 2014-11-25) Plotegher, Fábio; Oliveira, Cauê Ribeiro de; https://lattes.cnpq.br/5321313558714462; https://lattes.cnpq.br/5490465071052251
Phosphorus is a vital element for both animals and plants. In recent decades, the population growth boosted the production of food and technologies applied to the crops. The intense use of land for monoculture depletes the soil nutrients rapidly, requiring its replacement with fertilizer. Among the main macronutrients, phosphorus is the least required by plants. However, it is the one that most limits productivity in Brazilian soils, mainly because iron and aluminum ions in the soil immobilize this nutrient. The use of phosphate rocks in crops has been studied in recent years as an attempt to control the release of phosphorus in the soil. The present research aimed at studying the kinetics of phosphate release. Analysis were carried out on samples of milled phosphate rock and synthetic samples of two apatites. The results were compared to the kinetic analysis of a high solubility phosphate fertilizer widely used in the fields. The study was divided in three stages: the physical-chemical characterization of the simple superphosphate fertilizer; the physical-chemical characterization of the phosphate rock; and the characterization of apatite s synthetic phases. The results confirmed that the phosphate fertilizer has a phase already quite soluble in water. Through the calculated kinetic parameters it was observed that with a short milling time it was possible to increase the nutrient release. This study served mainly to determine the conditions of the test and also to confirm that the mechanical activation is one way to increase the solubility of less soluble materials. The results of the Bayóvar rock characterization showed that its major mineral phase is apatite which has a low solubility in water. Solubility tests in citric acid showed increased solubility of the material when increasing the milling time, with top system performance (mill/jar and alumina balls) in 20 minutes. As what happened to the fertilizer, the mechanical activation played a significant role to increase the material solubility, even with the material being little soluble. The mineralogical phase of phosphate is also crucial to the success of the release. To check if the mineralogical phase in fact influences the release kinetics, the isolated phases of two apatites were studied. Hydroxyapatite and fluorapatite samples were synthesized via coprecipitation and the particles were grown by hydrothermal treatment, varying time and temperature. The characterizations showed success in the synthesis of samples via co-precipitation. The results of XRD, SEM and BET also showed that temperature was more influential on the crystal growth than on the changes in its morphology. xii Solubility tests, also with citric acid, showed that indeed the mineralogical phase of phosphate is important and will be decisive in the choice of possible rock or natural phosphates to be used for direct soil fertilization.
Metodologia iterativa e modelos integradores para desenvolvimento de jogos sérios de treinamento e avaliação de desempenho humano
(Universidade Federal de São Carlos, 2014-11-25) Rocha, Rafaela Vilela da; Araujo, Regina Borges de; https://lattes.cnpq.br/8964123297688432; https://lattes.cnpq.br/1845113331963646
Training aims to improve the professional competences (knowledge, skills and attitudes) and it is essential particularly in risk activities to the life, property and environment. Due to the risk and cost of traditional practical training, serious games, which reproduce systems, processes and real-world objects in a safe virtual environment has been used as an effective tool for learning and training or motivation to learning, and support for assessment during and post-action. On the other hand, the development of serious games is a complex process, has development high cost (time, money, resources), need highly qualified professionals, who hold requirements of learning, assessment, simulation and game itself. Different methodologies have emerged for developing serious games, however, in general, they do not include the different dimensions and need to be combined and balanced with other methodologies to achieve the training and assessment objectives. This thesis presents a novel iterative methodology (named DevJSTA) for the development of serious games for training and human performance assessment (named JSTA), which integrates multidisciplinary teams by providing guidelines, artifacts, game elements and simulation models (formalisms of discrete events, automata and Fuzzy logic) to integrate and include concepts such as effective and experiential learning in serious games, besides providing feedback during the simulation and at the end. This methodology DevJSTA describes the professional roles, the development life cycle, the generated products and the technologies and tools that can be used to create these products, as well as a support architecture and generic components. The main differential of this methodology is its holistic approach that integrates pedagogical principles of learning and assessment in the development of simulation. The methodology was evaluated through interviews with software engineering experts, serious games developers and domain experts. The results were positive and confirmed the need of these new methodology that is integrative. To validate the methodology, one JSTA was created to train firefighters to control the cooking gas leak, and to evaluate the trainee’s perception and performance. Serious game fidelity and effectiveness were also validated. Moreover, the serious game development, with the use of the methodology DevJSTA, allowed to evaluate an opportunity for improvement in the current protocol that is used in the Fire Department.