Carlos Barreira Martinez

Black and Gray-Box Identification of a Hydraulic Pumping System

The use of auxiliary information during the identification of nonlinear systems can be handled in different ways and at different levels. In this brief, static information of a 15 kW hydraulic pumping system is used as a priori knowledge in the parameters estimation of polynomial models which are compared to polynomial and neural models obtained by black-box techniques. The aim is to find models with good performance in both transient and steady-state regimes. This brief presents a novel bi-objective problem that uses free-run simulation and a new decision-maker. The optimization problem is solved using a genetic algorithm. Compared with other techniques, the proposed approach can lead to models with better dynamic and static performance.

Efficiency and selectivity of a trap and truck fish passage system in Brazil

A construcao de passagens para peixes tem sido uma das estrategias adotadas pelo setor eletrico como forma de diminuir os efeitos de barramentos sobre as comunidades de peixes. No entanto, trabalhos de avaliacao da eficiencia destes mecanismos sao escassos. Neste trabalho sao avaliadas a eficiencia e seletividade do primeiro elevador com caminhao tanque instalado no Brasil, na Usina Hidreletrica de Santa Clara. A composicao de especies no elevador foi comparada com aquela original do rio, e com a das populacoes que se aglomeram a jusante da barragem, durante a estacao reprodutiva. A proporcao de individuos previamente marcados transpostos pelo elevador foi utilizada como forma de estimar sua eficiencia. Durante o periodo reprodutivo (2003/2004) 67841 individuos de 32 especies de peixes passaram pelo elevador, o que corresponde a 66% da riqueza do baixo curso do rio Mucuri. Destes, menos de 0,5% morreram ou foram feridos durante a passagem. Quando comparado com as populacoes do rio, foram observadas no elevador capturas menos representativas de individuos de pequeno porte e de especies marinhas. No entanto, a composicao e estrutura da comunidade no elevador foram bastante similares aquela observada a jusante da barragem durante o periodo reprodutivo. A eficiencia estimada para o elevador variou de 0,2% para Pogonopoma wertheimeri ate 16,1% para Leporinus conirostris, sendo de 7% para o conjunto de especies migradoras.

Incipient Detection of Cavitation Phenomenon in Centrifugal Pumps

The aim of this paper is to present a computer-based tool to aid in the process of detecting cavitation in centrifugal pumps. The method proposed in this paper, namely, the Load Torque Signature Analysis, employs electrical signals from the motor to estimate the torque developed by the pump and determines the occurrence and intensity of the phenomenon through its frequency spectrum information.

Downstream passage of fish larvae and eggs through a small-sized reservoir, Mucuri river, Brazil

In South America, one important symptom of the failure of fish passages to sustain fish migratory recruitment is the inability of eggs and larvae to reach the nurseries. This is especially so when the breeding areas are located upstream of a reservoir, and the floodplain is downstream of the dam. Therefore, the transport of fish larvae and eggs across reservoir barriers is a key factor in the development of effective conservation strategies. In this paper, we evaluate the potential for migratory fish larvae and egg transportation across a small size reservoir in eastern Brazil. We sampled fish daily between 15th October 2002 and 15th February 2003 (spawning period) in the Mucuri River, immediately upstream of the reservoir and downstream of the Santa Clara Power Plant dam. Our study was the first to indicate the possibility of successful larval passage through the reservoir of a hydroelectric reservoir and dam in South America, and showed that the passage of migratory fish larvae was associated significantly with residence time of water in the reservoir. The relatively short water residence time and elevated turbidity of the Santa Claras reservoir waters during the rainy season certainly contributed to the successful passage, and can be considered as key factors for a priori evaluations of the feasibility of a downstream larval passage.

Optimal swim speeds by respirometer: an analysis of three neotropical species

The swimming ability of neotropical fish species is an important aspect for fish ladder designs. Especially in Latin America, where fish ladders are highly selective, fish strategies to negotiate the passage should be studied focusing on target species. This paper shows the swimming ability of three neotropical species (Leporinus reinhardti, Pimelodus maculatus and Prochilodus costatus), from Sao Francisco river basin. Respirometer was employed for data collection. Regarding the critical and prolonged speeds, L. reinhardti was the fastest among the three neotropical species in relative values (body length/second). The performance of neotropical species was better when compared to critical and maximum prolonged speeds of fish species from temperate areas. Finally, regarding the experimental procedures, the optimization of swimming speed in respirometer is lower than the optimal processes obtained with free swimming in open channels.

Avaliação do impacto da variação da renda no consumo domiciliar de água

Este trabalho objetivou avaliar o impacto que a alteracao da renda das familias exerce sobre o consumo de agua tratada fornecida pela concessionaria (no caso, a Companhia de Saneamento de Minas Gerias - Copasa) no municipio de Belo Horizonte, ao longo de um historico de 35 meses, abrangendo o periodo de agosto de 2003 a junho de 2006. Para tal, utilizaram-se dados da Pesquisa Mensal de Emprego (PME) do Instituto Brasileiro de Geografia e Estatistica (IBGE), englobando 3.100 domicilios e 10.200 moradores, e os consumos residenciais micromedidos dos 6 distritos operacionais da Copasa. Os dados foram observados em seus periodos de forma que houvesse a compatibilizacao cronologica entre os mesmos. Os resultados mostraram relacao intrinseca entre o consumo per capita e a renda mensal, balizados pelos graficos de dispersao e pelos significativos coeficientes de determinacao obtidos (superiores a 0,8), alem do prognostico de saturacao do consumo demonstrado para classes sociais economicamente mais favorecidas.

Short-term toxicity of ammonia, sodium Hydroxide and a commercial biocide to golden mussel Limnoperna fortunei (Dunker, 1857)

Macrofouling bivalves are considered an ecological and technological problem worldwide. Control measures have been researched with Limnoperna fortunei, but without success. The aim of the manuscript is to test some alternatives to regulate this harmful invasive mollusk. Mortality and behavioral response (shell gaping) of Limnoperna fortunei exposed to three chemical compounds were evaluated. Values for LC50 96h were: 0.25 (0.24-0.27)mg/L NH3-N, 11.10 (7.45-16.55) mg/L MXD-100 and 88.51 (74.61-105.01)mg/L NaOH. Reduced gaping was observed beginning at concentrations of 0.31mg/L (NH3-N), 100mg/L (MXD-100) and 160mg/L (NaOH) and increased above these values. The percentage of individuals gaping after two hours at LC50 96h differed significantly (χ(2)=79.9; DF=3; p<0.001) in MXD-100 (50%), NaOH (0%), NH3-N (96.7%) and the controls (93.3%). This study contributes to the understanding of the relationship between toxicity and behavioral effects of some toxicants in L. fortunei.

Modelo para estimativa da geração de resíduos sólidos domiciliares em centros urbanos a partir de variáveis socioeconômicas conjunturais

Este trabalho apresenta um modelo matematico para estimar a geracao de residuos solidos residenciais urbanos. O modelo foi desenvolvido a partir de uma base fisica espacial de bairros de Belo Horizonte e dos indicadores socioeconomicos das respectivas populacoes, referentes ao periodo de janeiro de 2006 a dezembro de 2010. Verificou-se intrinseca relacao entre a geracao per capita de residuos e a renda per capita nas regioes estudadas, testificada por coeficiente de determinacao de 0,85. Posteriormente, efetuou-se a validacao do modelo com dados da capital de Minas Gerais e de Porto Alegre, na qual os valores estimados foram confrontados com a geracao real informada pelas prestadoras de servicos de limpeza urbana locais. A despeito de elaborado com dados de Belo Horizonte e aferido com os de Porto Alegre, os resultados abrem a perspectiva de emprego do modelo proposto na estimativa de geracao de residuos solidos em areas urbanas.Abstract This work presents a mathematical model to estimate the solid waste generation in urban areas. The model was developed based on spatial physic basis of neighborhoods of Belo Horizonte and of the respective economic indicators of their population. A strong relation between per capita solid waste generation and per capita income was confirmed due the high coefficient of the determination 0.85. Afterwards the model was validated by means of Belo Horizonte and Porto Alegre datasets in which the estimated values were compared with the real solid waste generation provided by the local services. Despite of data set from Belo Horizonte, the results open the perspective of the application of the model for estimating the solid waste generation in urban areas.Keywords: urban solid waste; solid waste generation; per capita income; model for solid waste generation. Endereco para correspondencia: Marcelo Libâneo – Universidade Federal de Minas Gerais – Escola de Engenharia – Bloco I – Avenida Antonio Carlos, 6.627 – 31270-901 – Belo Horizonte (MG), Brasil – E-mail: mlibanio@ehr.ufmg.brRecebido: 27/01/12 – Aceito: 07/11/12 – Reg. ABES: 206

Estudos de externalidades na área de saúde humana decorrentes de reservatórios hidrelétricos

The objective of this work was to present an estimation method of the values of the health externalities associated to the operation of hydro power plants reservoirs. The method was applied in the cities of Uberaba and Uberlândia, Minas Gerais, Brazil, partially flooded by Miranda reservoir. The number of hospital admittances in the Public Health System and the population growth in the flooded municipal districts were analyzed. If there is a cause-effect relation between the lake and the diseases, the costs of externalities in 2001 were estimated in R

Metodologia para estimação de externalidades agropecuárias decorrentes da construção de reservatórios

25,000 when US