Leakage detection in water pipe networks using electromechanical impedance (EMI) based technique

The electromechanical impedance (EMI) technique has been successfully used in structural health monitoring (SHM) systems on a wide variety of structures. The basic concept of this technique is to monitor the structural integrity by exciting and sensing a piezoelectric transducer, usually a lead zirconate titanate (PZT) wafer bonded to the structure to be monitored and excited in a suitable frequency range. Because of the piezoelectric effect, there is a relationship between the mechanical impedance of the host structure, which is directly related to its integrity, and the electrical impedance of the PZT transducer, obtained by a ratio between the excitation and the sensing signals.This work presents a study on damage (leaks) detection using EMI based method. Tests were carried out in a rig water system built in a Hydraulic Laboratory for different leaks conditions in a metallic pipeline. Also, it was evaluated the influence of the PZT position bonded to the pipeline. The results show that leaks can effectively be detected using common metrics for damage detection such as RMSD and CCDM. Further, it was observed that the position of the PZT bonded to the pipes is an important variable and has to be controlled.

Population biology and distribution of the portunid crab Callinectes ornatus (Decapoda: Brachyura) in an estuary-bay complex of southern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biodiversity, distribution and abundance of shrimps Penaeoidea and Caridea communities in a region the vicinity of upwelling in Southeastern of Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Environmental factors modulating the abundance and distribution of Callinectes danae (Decapoda: Portunidae) from two areas of the southeastern coast of Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

How marine upwelling influences the distribution of Artemesia longinaris (Decapoda: Penaeoidea)?

Upwelling events can occur in most of the oceans altering the water physical, chemical and sediment conditions and consequently the species communities dwelling the areas. For better understanding the behavior of populations inhabiting upwelling regions, the spatial and temporal distribution of a Penaeoidea shrimp was studied correlating it with the abiotic factors that vary during upwelling and non-upwelling periods in an area under influence of Cabo Frio upwelling. Bottom salinity and temperature, organic matter and sediment type from each station were sampled from March 2008 to February 2010, in six stations located between 5 and 45 m depth. The lowest temperatures were recorded during spring and summer for both years with temperature values lower than 19 degrees C. A total of 26,466 Artemesia longinaris shrimps were captured mainly in 10-35 m depth. Upwelling periods showed significant differences in abundance in relation to non-upwelling periods. The spatial distribution among stations varied according to the temperature with higher abundance in stations with values between 19 and 21 degrees C. The highest abundance of A. longinaris was recorded in spring and summer when intrusions of the cold waters of South Atlantic Central Waters (SACW) were frequent. Thus, the effect of cold water of SACW boosted by the upwelling was a determinant factor in the spatial and temporal distribution of A. longinaris in the studied region.

Estimation of Submerged Aquatic Vegetation Height and Distribution in Nova Avanhandava Reservoir (São Paulo State, Brazil) Using Bio-Optical Modeling

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise estrutural de tubos de concreto armado com resíduo de borracha de pneu

Pós-graduação em Engenharia Civil - FEIS

Weather variables, water balance, growth, and agro industrial yield of sugarcane

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Rehydration after water stress in forager workers of coptotermes gestroi (wasmann) (blattaria: rhinotermitidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exploring the water-energy nexus in Brazil: the electricity use for water supply

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

How the fluctuations of water levels affect populations of invasive bivalve Corbicula fluminea (Muller, 1774) in a Neotropical reservoir?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Does the plankton community follow the horizontal water quality heterogeneity in a tropical urban reservoir (Guarapiranga reservoir, Sao Paulo, Brazil)?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribution, composition and seasonality of aquatic birds in the Nhecolandia sub-region of South Pantanal, Brazil

Despite remarkable significance of Pantanal for the conservation of aquatic birds, the status of their populations, the spatiotemporal patterns of distribution and habitat use and structure of communities are little known. Thus, we studied three aquatic environments (Negro river, bays and salines) from 2007 to 2009 in the Nhecolandia Pantanal to verify the distribution and composition of aquatic birds and also if there is significant seasonal influence on these aspects. We adopted the transect method (288 hours of sampling) and recorded 135 species (7.834 individuals). The Negro river showed the highest diversity, while the salines the lowest. The similarity of aquatic bird communities was higher between bays and salines, followed by Negro river and bays and lower between salines and Negro river. The equidistribution is more variable in the salines and more stable in the Negro river. The environments strongly differ from each other in aquatic bird composition in space (habitat use and distribution) and time (seasonal water fluctuations). The diversity of bird community in the dry season varies significantly in the salines, followed by the bays and more stable in the Negro river. The Negro river, regardless of large annual amplitude of flow, is more seasonally stable since its riparian vegetation is continuous (not isolated) and constant. These aspects provide better conditions to stay all year, contributing to decrease the seasonal nomadic tendencies of aquatic birds. Finally, all these data provide strong arguments to the preservation of all phytophysiognomies in the Nhecolandia sub-region of Pantanal, but with special attention to the salines widely used by many flocks of aquatic birds (mainly in the dry season) and migrant and/or rare species restricted to this habitat.

Ecological distribution of the shrimp Pleoticus muelleri (Bate, 1888) and Artemesia longinaris Bate, 1888 (Decapoda, Penaeoidea) in the southeastern Brazilian littoral

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Monte Carlo simulation of water-tetrahydrofuran mixtures

Monte Carlo simulations of water-tetrahydrofuran (THF) mixtures were performed in the isothermal-isobaric ensemble (NPT) at T = 298 K and p = 1 atm. The interaction energy was calculated using the TIP4P model for water and a five-site united atom representation for the THF molecule. The potential energy surfaces for water-THF interactions were obtained by using combining rules and the original potential functions used for pure liquids. Theoretical values obtained for the average interaction energy as a function of concentration are in good agreement with available experimental data. Results from the partitioning of the total interaction energy into water-water, water-THF and THF-THF contributions are presented. These results are useful to distinguish between the quantitative contributions of these molecular interactions to the energetic behavior of the water-THF mixing process. The radial distribution functions for HW-OTHF and OW-OTHF site-site interactions show the salient features of hydrogen-bonded liquids. Comparison of the average number of water-water complexes interacting through hydrogen bonding in water-THF and water-methanol mixtures shows an enhancement of the water-water coordination number in a THF rich environment. © 1995.