Microbiological composition of native and exotic clams from Tagus estuary: Effect of season and environmental parameters

The influence of seasonal and environmental parameters on the occurrence of bacteria was investigated in two clam species (Venerupis pullastra and Ruditapes philippinarum), water and sediment from the Tagus estuary. Total viable counts (TVC), Escherichia coli, Salmonella spp. and Vibrio spp. were evaluated during one-year. Overall, significant seasonal variations were found in both sampling sites, especially for E. coli and Vibrio spp. levels. In summer, significantly higher Vibrio spp. levels were found in R. philippinarum and sediment samples, but not in V. pullastra clams and water samples. In contrast, significantly higher TVC and E. coli levels were observed in winter months in water and sediment samples. Salmonella spp. was generally isolated when higher levels of E. coli were detected, particularly in R. philippinarum. This study is useful for authorities to develop monitoring strategies for coastal contamination and to estimate human health risks associated with the consumption of bivalves.     

Identification of precipitation zones within São Francisco River basin (Brazil) by global wavelet power spectra

Abstract

The definition of rainfall behaviour at the regional level is of great importance in planning policy for the rational use of water resources for both agricultural and urban uses. It allows the delimitation of areas of homogeneous rainfall features and shows the system dynamics in the area, so providing more comprehensive knowledge about the rainfall. Precipitation zones were identified within the São Francisco River basin, Northeast Brazil, by analysing the rainfall frequencies by means of global wavelet power spectra. Data from 200 raingauges were analysed and the results of the overall power spectra showed a high annual frequency throughout the basin; however, other frequencies are present with minor significance that represent changes in the rainfall regime. Although, the computed global wavelet power spectra presented an annual frequency, they showed peculiar patterns (denoted A and B) that could be used to characterize the region. Thus, three sub-regions with homogeneous rainfall patterns were identified as: Region A (south part of the basin) and Region B (north part of the basin), with frequency patterns A and B, respectively, and a Transition Zone in the central part that shows both frequency patterns.

Citation Santos, C.A.G. and Morais, B.S., 2013. Identification of precipitation zones within São Francisco River basin (Brazil) by global wavelet power spectra. Hydrological Sciences Journal, 58 (4), 789–796.     

Observational Investigation of the Statistical Properties of Surface-Layer Turbulence in a Suburban Area of São Paulo,Brazil: Objective Analysis of Scaling-Parameter Accuracy and Uncertainties

Boundary-Layer Meteorology - Statistical properties of turbulence, specifically variances of velocity components, temperature, water vapor, and carbon dioxide densities, are observationally...     

Applicability and dynamical characterization of the associated sets of the algorithmic weak stability boundary in the lunar sphere of influence

The present contribution investigates the applicability of the associated initial condition sets generated by the algorithmic definition of the weak stability boundary in the lunar sphere of influence in the context of Earth-to-Moon low-energy capture transfers. First, we test the applicability of the initial condition sets in view of two mission strategies, namely, direct inner transfers in the Planar Circular Restricted Three-Body Problem and external transfers based in the Patched Three-Body approach. Then, we check the consistency of the stability classification regarding the selection of captured solutions, identifying the stable subsets which provide temporary capture solutions. Additionally, we show the diversity of behaviors classified as stable by the current stability criteria of the algorithmic definition, which indicates that the algorithmic criteria must be reviewed in order to guarantee that the stable solutions correspond solely to low-energy capture orbits. The combination of our analyses allows the detection of the subsets of stable initial conditions that provide feasible Earth-to-Moon transfer solutions. Specifically, we show an external low-energy Earth- to-Moon transfer with zero midcourse correction at the patching section.     

A model for pushover analysis of confined masonry structures: implementation and validation

Confined masonry (CM) is a typical building technique in Latin American countries. This technique, due to its simplicity of construction and similarity with traditional practices of reinforced concrete building, presents a potential of use in European regions with moderate-to-high seismicity. However, most of the procedures for seismic design in codes for Latin America are force-based, which appears to be inadequate due to the high dissipative response observed for CM. This paper presents a simplified numerical-analytical approach to model CM structures using pushover analysis, aiming to apply performance-based design procedures. First, a data mining process is performed on a database of experimental results collected from lateral tests on CM walls to adjust prediction models for the wall shear strength and to determine the input relevance through a sensitivity analysis. Then, an analytical model of CM structures for pushover analysis is proposed with basis on a wide-column approach that employs an adaptive shear load-displacement constitutive relation. The proposed method is compared with a discrete element model that represents explicitly the confinements-masonry interaction, against the experimental results obtained in a quasi-static test of a full-scale tridimensional CM structure. The accuracy of the predictions from both methods is very satisfactory, allowing to capture the base shear-displacement envelope and also the damage patterns of the structure, thus, demonstrating the ability of the methods to be used in performance-based seismic assessment and design of CM buildings.     

Airports and Environment: Proposal of Wastewater Reclamation at São Paulo International Airport

One way to reduce water consumption in urban areas is by using alternative sources of supply that can be provided by collecting rainwater and reusing wastewater for less restricted purposes. Thus, this study evaluated the characteristics of effluents produced by the wastewater treatment plant (WWTP) of São Paulo International Airport (SPIA), Brazil, in order to reuse it in non‐potable situations. The results achieved, indicated high efficiency in the biological system utilized by SPIA. The removal rates is equal to or >90% for most of the parameters analyzed, among them, fluoride, salinity, nitrite, nitrate, ammonium nitrogen, total nitrogen, phosphorus, sedimentable solids, turbidity, conductivity, apparent color, chemical oxygen demand, biochemical oxygen demand, total organic carbon, fecal coliforms, and oils and greases. Despite the final effluents were good enough to be launched in the local streams, they shall be submitted to a complementary treatment in order to fit some quality parameters to be reused for specific demands (landscape irrigation, toilet flushing, vehicle washing, fire fighting, and dust control).     

Development of an innovative seismic strengthening technique for traditional load-bearing masonry walls

Traditional non-reinforced masonry walls are particularly prone to failure when subjected to out-of-plane loads and displacements caused by earthquakes. Moreover, singularities such as openings in fa?ades may trigger local collapse, for either in-plane or out-of plane motion. Bearing in mind all the former limitations, STAP, with the scientific support of ICIST and LNEC, has been developing a reduced intrusiveness seismic strengthening methodology for traditional masonry structures. The technique consists in externally applying Glass Fibre Reinforced Polymer (GFRP) composite strips to one or both faces of walls. Connection between GFRP composite strips and masonry substrate is enhanced through specifically detailed anchorages or confinement connectors. This technique has been developed and studied through an extensive series of experimental tests, which are briefly reviewed. This paper focuses more deeply on the latest experimental program, aimed at the characterization of the masonry-GFRP composite interface behaviour. This testing program comprised 29 masonry specimens, strengthened with externally bonded GFRP composite strips with anchorages. The testing variables were the number and spacing of anchorages as well as the loading history type: monotonic or repeated. Results clearly show that the use of anchorages dramatically enhances bond behaviour and that its number and spacing have a significant effect on deformation capacity and a less pronounced effect on strength. Based on experimental evidence, this paper also provides a calculation model and ULS safety assessment procedure for out-of-plane strength of reinforced masonry walls. This calculation model leads to interaction curves on strengthened masonry walls subjected to compression and out-of-plane flexure.     

Organotin levels in Nazaré canyon (west Iberian Margin, NE Atlantic) and adjacent coastal area

Organotin compounds (OTs) are ubiquitous in the marine environment and high concentrations (μg g(-1) range) in sediments from different coastal areas around the world have been reported. However, few reports have described the OTs contamination status in the offshore and deep sea environment. This work investigated organotin levels in Nazaré canyon for the first time. Levels of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT), triphenyltin (TPT), dioctyltin (DOT) and trioctyltin (TOT) were quantified in sediment samples from the upper flanks of the canyon and from the adjacent coastal area. TBT levels detected in the canyon flanks are about two to three orders of magnitude lower than those found in the coastal area. Nevertheless, when quantifiable, TBT levels in the canyon samples were higher than the Environmental Assessment Criteria set for TBT in sediments by the OSPAR Commission indicating that at those locations negative ecological impacts are likely to occur.