EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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6 resultados
Resultados da Pesquisa
Item Optimization and scale-up of an LED-illuminated microalgal photobioreactor for wastewater treatment.(2020) Silva, Ludymyla Marcelle Lima; Santiago, Aníbal da Fonseca; Castro, Ana Leticia Pilz de; Bastos, Leonardo de Souza; Periard, Lucas; Vassoler, FábioThe use of light-emitting diode (LED)-illuminated photobioreactors with microalgae has been extensively studied for wastewater treatment. Most studies have used isolated microalgae species; however, this practice does not match the reality of conditions in wastewater treatment plants. Operational conditions that promote greater growth of algal biomass and that remove pollutants most effectively are disputed in the literature. In this context, LED-illuminated photobioreactors with microalgae were evaluated using multivariate analysis in order to optimize removal of pollutants (nitrogen, phosphorus, and carbonaceous organic matter). Three variables were evaluated: operating time, LED wavelength, and luminous flux intensity. A microalgae consortium was used in the photobioreactor. In addition to the LED-illuminated photobioreactors, control photobioreactors illuminated by sunlight were also operated. Using the results obtained in the optimization, a scaled-up reactor approximately 8.5 times larger in volume was operated to evaluate if the behavior would be maintained. The best operational conditions for the removal of pollutants were observed in LED-illuminated photobioreactors operated under a light intensity of 700 μmol·m 2 s 1 for 15 days. Under these conditions, it was possible to remove 89.97% of carbonaceous organic matter, 86.50% of nitrogen, and 30.64% of phosphorus. The scaled-up photobioreactor operated with similar performance.Item Hydraulic and auto-depurative characteristics of the Gualaxo do Norte River after the Fundão dam rupture.(2021) Reis, Deyse Almeida dos; Silva, Priscila Kelly da; Azevedo, Igor Andrade; Castro, Ana Leticia Pilz de; Santiago, Aníbal da FonsecaThe hydraulic characteristics of the Gualaxo do Norte River (RGN), a tributary of the upper Rio Doce basin, were affected in November 2015 by the rupture of the iron ore tailings dam at Fundão, in Bento Rodrigues, Mariana, Minas Gerais. We analyzed two sections of the RGN, located upstream and downstream of the Fundão dam. Measurements were taken at 11 stations along the main river in distinct seasonal periods, including river depth, river width, velocity, and flow. We also calculated the deoxygenation coefficient (K1) and the reaeration coefficient (K2) and collected elaborate bathymetric profiles of the sections. Anthropogenic interference influenced the river’s hydraulic characteristics mainly in relation to the depth. In upstream sections, the changes are believed to be due to mining activities at the head of the river, while downstream effects were due to the introduction of iron ore tailings coming from the rupture of the Fundão dam. Despite these influences, deoxygenation coefficient values were typical for clean water, and the reaeration coefficient findings show that the RGN is efficient at biological degradation of the organic matter even receiving untreated domestic sewage from riparian communities. With the results obtained in this work, we seek to replicate a source of information about the current state of the region and to contribute information to future river planning, control, and restoration projects.Item Aferição de parâmetros de labirinto hidráulico em turbinas Francis: proposta de uma bancada de teste.(2020) Castro, Ana Leticia Pilz de; Serrano, Rodrigo Otávio Peréa; Sampaio, Mila Correa; Coelho, Stenio Augusto; Pinto, Maria Aparecida; Mancilla Rico, Edwin Andres; Viana, Edna Maria de Faria; Martinez, Carlos BarreiraA geração de energia elétrica no Brasil é fortemente dependente da hidroeletricidade. As turbinas hidráulicas são máquinas responsáveis em transformar a maior parte da energia do escoamento contínuo da água que a atravessa a usina hidrelétrica em trabalho mecânico. Os principais componentes das turbinas do tipo Francis são: o rotor, o distribuidor e a caixa espiral, e é no rotor onde estão localizados os anéis de desgaste superior e inferior, e entre os anéis de desgaste os labirintos inferior e superior. Contudo, a fuga de fluido que ocorre nos labirintos das turbinas hidráulicas um dos responsáveis pelas perdas de geração de energia elétrica, vislumbrou-se a necessidade de se desenvolver um aparato que permita simular um labirinto de uma turbina Francis, afim de obter parâmetros que poderão auxiliar na tomada de decisões de projetos nesse segmento.Item Case study : abrasive capacity of Limnoperna fortunei (golden mussel) shells on the wear of 3 different steel types.(2019) Castro, Ana Leticia Pilz de; Serrano, Rodrigo Otávio Peréa; Pinto, Maria Aparecida; Silva, Gilberto Henrique Tavares Álvares da; Ribeiro, Livia de Andrade; Viana, Edna Maria de Faria; Martinez, Carlos BarreiraThe impact of particles suspended in the water is responsible for the wear of mechanical surfaces in hydraulic systems. The characteristics and concentrations of these particles in the flow directly influence the intensity of the abrasion processes. Within this context, knowledge of the abrasive power of a particle is of great importance. It is known that an invasive species, known as golden mussel shell, has become embedded in several hydroelectric plants of the South and Southeast of Brazil, provoking an increase of the wear caused by shells that pass through the hydraulic system. In this context, the abrasive capacity of ground golden mussel shells on the three metallic materials used in the labyrinth component of the hydraulic turbines was analyzed. To determine the wear pattern and the relationship of the specific wear coefficient of the material (k), due to the increased concentration of golden mussel shell, micro-scale abrasive wear tests were performed on three different steel plates using abrasive suspensions at different concentrations of ground golden mussel shell in distilled water. The abrasivity of the golden mussel shell was also compared with the abrasivity of silicon carbide (SiC), commonly used as standard material in microabrasion tests. The analyses showed that the golden mussel shell is around 16 times less abrasive than the silicon carbide, taking into account the average obtained for the three different materials tested. In addition, the wear mechanisms acting on the SiC tests and those with the golden mussel shell were the same.Item Abrasive effects of sediments on impellers of pumps used for catching raw water.(2018) Serrano, Rodrigo Otávio Peréa; Castro, Ana Leticia Pilz de; Mancilla Rico, Edwin Andres; Pinto, Maria Aparecida; Viana, Edna Maria de Faria; Martinez, Carlos BarreiraThis study presents an analysis of the abrasive effects of sediments from the bed of the Acre River, Brazil, on the wear of three different ferrous materials employed in the manufacture of impellers of centrifuge pumps used to catch raw water. In order to evaluate the abrasive wear and specific wear coefficient (k) as a function of sediment concentration, tests were conducted in samples of SAE 8620 steel, nodular cast iron and gray cast iron by using a rotary-ball abrasion meter. These tests employed abrasive slurry with concentration of 1, 2, 3, 5 and 10 g L-1 of sediments in distilled water. The volume of worn material as a function of the relative velocity of water flow in relation to the impeller blades was mathematically estimated. The experimental results showed that: i) The semi-angular and semi-rounded shapes of the sediments from the Acre River produced evidence of micro-grooving and plastic deformation in the three metallic alloys; ii) SAE 8620 steel showed higher resistance to abrasive wear than samples of gray and nodular cast iron; iii) the increase in the volume of worn material due to increment in sediment concentration and the relative velocity of the mixture (water + sediment) to the rotor pads.Item Integração de sistemas fotovoltaicos e aquecedores de água solar em telhados residenciais.(2017) Serrano, Rodrigo Otávio Peréa; Moreira, José Genivaldo do Vale; Castro, Ana Leticia Pilz de; Mesquita, Anderson Azevedo; Martinez, Carlos BarreiraO aumento da demanda de energia elétrica no Brasil para os próximos 10 anos é de 4,25% ao ano, demandando assim uma expansão do sistema de 3,8% a.a., com previsão de crescimento médio da carga de energia de 2.900 MW ano-1. O aumento da demanda, somado aos recorrentes déficits hídricos em várias usinas hidrelétricas e a lentidão da expansão do sistema de geração sustentável, acarretará aumento do consumo de energia gerada por meio de combustíveis fósseis. Neste contexto, a implantação de sistemas híbridos (energia elétrica fotovoltaica e aquecedor de água solar) integrados a rede de distribuição de energia elétrica, apresenta-se como uma alternativa para reduzir essa demanda, com um potencial de produção média de cerca de 3.000 MWh mês-1 a cada 10 mil casas, que corresponde a energia produzida por uma pequena central hidrelétrica de 6 MW (FC = 0,7) de capacidade instalada.