34 research outputs found
Influence of thermal stratification in useful volume and in hydrodinamic behavior of stabilization pond: theoretical and experimental evaluation
Lagoas de estabilização localizadas em regiões com variações elevadas de temperatura ao longo do dia tendem a apresentar estratificação térmica, um fenômeno que altera o volume útil da lagoa. Neste trabalho, apresentam-se resultados experimentais obtidos em duas lagoas, facultativa e maturação, construídas na região central do estado de São Paulo. O acompanhamento do perfil de temperatura mostrou a ocorrência de estratificação térmica com ciclo nictimeral nas duas lagoas. Os ensaios hidrodinâmicos indicaram comportamento semelhante ao de reatores com mistura completa, com zonas mortas, volume útil de aproximadamente 60% na lagoa facultativa e 30% na lagoa de maturação. Os experimentos corroboraram os resultados teóricos obtidos com o modelo matemático para previsão da estratificação térmica.Stabilization ponds located in places that present high temperature variations along the day have a tendency to present thermal stratification, a phenomenon that changes the useful volume of the pond. This paper presents experimental results from two stabilization ponds, facultative and maturation, built in the central area of the state of São Paulo, Brazil. The observation of the temperature profile showed the occurrence of thermal stratification with the nictimeral cycle in both ponds. Hydrodynamic tests showed a pattern that resembles the behavior of complete mixing reactors with dead zones, resulting in useful volumes close to 60% for the facultative pond and 30% for the maturation pond. The experiments confirm the theoretical results obtained based on a mathematical model to predict thermal stratification.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Application of sustainability indicators to stabilization ponds
A escolha de uma alternativa tecnológica para tratamento de efluentes, assim como o local para implantação deve ser precedida de um estudo de sustentabilidade do ambiente. Foi proposto um método para avaliação da sustentabilidade de estações de tratamento de esgoto, baseado nas características ambientais, sociais e econômico-financeiras dessas unidades. O método foi aplicado em três ETE, constituídas por lagoas de estabilização, localizadas nos municípios de Cajati, Jacupiranga e Pariquera-Açu, todas pertencentes à bacia do Baixo Ribeira de Iguape (SP). A falta de dados para alguns parâmetros considerados na composição dos indicadores prejudicou a obtenção de valores mais realistas. O método proposto mostrou-se de fácil visualização da condição de sustentabilidade das ETE constituídas por lagoas de estabilização.The choice of an alternative technology for effluent treatment as well as the location for deployment must be preceded by a study of environmental sustainability. A method for assessing the sustainability of wastewater treatment plants, based on environmental, social and economic-financial characteristics was proposed. The method was applied to three wastewater treatment plants using stabilization ponds, located in the municipalities of Cajati, Jacupiranga and Pariquera-Açu, all belonging to the Lower Ribeira de Iguape River basin, in the state of São Paulo, Brazil. The lack of values for some parameters considered in the formulation of indicators undermined the achievement of more realistic values. The proposed method proved to be easy to visualize the condition of sustainability of wastewater treatment stations using stabilization ponds.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
The metrology system of the VLTI instrument GRAVITY
The VLTI instrument GRAVITY combines the beams from four telescopes and
provides phase-referenced imaging as well as precision-astrometry of order 10
microarcseconds by observing two celestial objects in dual-field mode. Their
angular separation can be determined from their differential OPD (dOPD) when
the internal dOPDs in the interferometer are known. Here, we present the
general overview of the novel metrology system which performs these
measurements. The metrology consists of a three-beam laser system and a
homodyne detection scheme for three-beam interference using phase-shifting
interferometry in combination with lock-in amplifiers. Via this approach the
metrology system measures dOPDs on a nanometer-level.Comment: 9 pages, 5 figure
Influência da estratificação térmica no volume útil e no comportamento hidrodinâmico de lagoa de estabilização: determinação experimental e teórica
Instrumentação para Educação Ambiental e a Prática Interdisciplinar
Material em formato .pdf -- Parte do material do curso de Especialização em Educação Ambiental com Ênfase em Espaços Educadores Sustentáveis– COMFOR – SEB – SECADI – MINISTÉRIO DA EDUCAÇÃOCoordenação pedagógica do curso: Coordenadora: Romilda Fernández Felisbino / Vice-Coordenadora: Sarah Isabel Pinto Monteiro do Nascimento AlvesEquipe de Produção - SEAD – UNIFESP -- Felipe Vieira Pacheco - Coordenador de Produção / Fábio Gongora Freire - Designer Instrucional / Margeci Leal de Freitas Alves - Designer Instrucional / Fabrício Sawczen - Designer Gráfico• Módulo 5: Instrumentação para Educação Ambiental e a Prática Interdisciplinar -- Este módulo aborda a formação de professores e a Educação Ambiental, englobando saberes ambientais e interdisciplinaridade, percepção ambiental, concepção e produção de material didático, didática e metodologia de ensino. Apresenta os principais problemas socioambientais em aspectos inter e transdisciplinares, e os desafios da Educação Ambiental a partir de tais concepções.Outr
Multiple star systems in the Orion nebula
This is the author accepted manuscript. The final fersion is available from EDP Sciences via the DOI in this record.This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium cluster with the recently comissioned GRAVITY instrument. We observed a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for θ1 Ori B, θ2 Ori B, and θ2 Ori C. We determined a separation for the previously suspected companion of NU Ori. We confirm four companions for θ1 Ori A, θ1 Ori C, θ1 Ori D, and θ2 Ori A, all with substantially improved astrometry and photometric mass estimates. We refined the orbit of the eccentric high-mass binary θ1 Ori C and we are able to derive a new orbit for θ1 Ori D. We find a system mass of 21.7 M⊙ and a period of 53 days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about two, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints toward a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We excluded collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion.Marie Skłodowska-Curie Grant AgreementFCT-PortugalERC Starting Gran
Trichloroacetic acid in the vegetation of polluted and remote areas of both hemispheresFPart I. Its formation, uptake and geographical distribution
Trichloroacetic acid (TCA; CCl3COOH) is a phytotoxic chemical. Although TCA salts and derivatives were once deployed as herbicides against perennial grasses and weeds, their use has since been banned because of their indiscriminate herbicidal effects on woody plant species. However, TCA can also be formed in the atmosphere. For instance, high-volatile C2-chlorohydrocarbons tetrachloroethene (TECE, C2Cl4) and 1,1,1-trichloroethane (TCE, CCl3CH3) can react to TCA and other substances under oxidative conditions here. Owing to further industrialisation of Southeast Asia, South Africa and South America, a rise can be expected in the use of TECE as solvents in the metal and textile industries of these regions in the southern hemisphere (SH). The increasing emissions of this substance-together with the rise in the atmospheric oxidation potential caused by urban activities, slash and burn agriculture and forest fires in the SH-will result in the increased input/formation of TCA in the vegetation located on the lee side of these emission sources. By means of biomonitoring studies, inputs/formation of TCA related to the climatic conditions were detected at various locations in South America, Africa, and Europe.Fil: Weissflog, Ludwig. Helmholtz Zentrum Für Umweltforschung; AlemaniaFil: Pfennigsdorff, Andrea. Helmholtz Zentrum Für Umweltforschung; AlemaniaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Puliafito, Enrique. Universidad de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Figueroa, Dante. Universidad de Concepción; ChileFil: Elansky, Nikolai. Russian Academy Of Sciences; RusiaFil: Nikonov, Vyasheslav. The Russian Academy Of Sciences. Institute Of North Industrial Ecology Problems Kola Science Centre; RusiaFil: Putz, Erich. Karl-franzens-universitat Graz; AustriaFil: Krüger, Gert. Potchefstroom University; SudáfricaFil: Kellner, Klaus. Potchefstroom University; Sudáfric