Experimental studies on the weatherability of the capivara dam basalts,rio paranapanema,brazil

The weatherability of the basalts in the Capivara Dam site, Rio Paranapanema, São Paulo State, Brazil, has been studied by means of saturation-drying tests. A great number of samples have disaggre — gated intensively with production of fines. The behavior of these rocks is related to their petrography, especially to their content in expansive clay minerals. These studies were performed in order to obtain data for the utilization of this material as rock fill, including ripraps.     

Lead contamination in tap water of households with children in Lower Saxony, Germany

Lead has numerous acute and chronic adverse effects on human beings. This is especially true for infants and children. The main path of lead ingestion in children can be different according to housing and living situation. The intake of lead through drinking water is commonly due to metal corrosion. The users plumbing can be an important factor. In recent years, many lead pipes in Germany have been replaced by pipes made of an alternative material. The aim of this study is to assess the present state of drinking water contamination and the resulting exposure of infants to lead. For this purpose mothers of new-born babies were offered a free examination of their drinking water. After a written declaration of consent had been obtained and after the infant in question had reached an age of 3 months, a stagnation sample of cold tap-water after overnight stagnation together with a random daytime sample was obtained from the family. The collected samples were analysed by atomic absorption spectrometry for their lead concentration. In total, 1485 samples from households were collected. Of the 1434 stagnation samples, 3.1% had lead concentrations greater than 0.01 mg/l (recommended limit of the WHO) and 0.6% had concentrations above the limit of the German drinking water regulation (0.04 mg/l). The values for the 1474 random daytime samples were 2.1% above 0.01 mg/l and 0.2% greater than 0.04 mg/l, respectively. By region, the areas Bovenden, Friedland, Duderstadt, Northeim and Rosdorf were particularly affected. The highest measured concentrations of lead in the stagnation samples were 0.11 mg/l and 0.15 mg/l in the random daytime samples, respectively.     

Spatial and temporal trends of petroleum hydrocarbons in wild mussels from the Galician coast (NW Spain) affected by the Prestige oil spill

Polycyclic aromatic hydrocarbons (PAHs) were determined in tissues of wild mussels (Mytilus galloprovincialis) from the Galicia coast (NW Spain) in order to assess the extent of the environmental impact caused by the Prestige oil spill (November 13, 2002). Three sampling campaigns were carried out in February, June and November 2003 at 24 stations along the Galicia coast, from La Guardia (Pontevedra) to Ribadeo (Lugo). The spatial distribution of PAHs found in the first sampling period, clearly revealed the central area (Costa da Morte) as the most affected by the oil spill. In these stations, concentrations up to 7780 microg/kg dw of the sum of 13 parent PAHs were found 2-3 months after the spill. Molecular parameters within the aliphatic and aromatic fractions confirmed the presence of the Prestige oil in these samples. The levels markedly decreased at most of the stations in the second sampling and recovered to levels found before the spill in November 2003, 1 year after the accident (29-279 microg/kg dw, av. 133+/-83 microg/kg dw). However, a certain increase was observed in some sites which could be related to the remobilization of oil residues from still unclean intertidal spots or sediments due to the winter marine weather conditions.     

A new methodology towards determining building performance under modified outdoor conditions

Great efforts have been made to establish the influence of the urban climate upon the energy consumption of buildings. While many scientific articles present measured data of increased energy consumption due to building surroundings, this paper aims to present a straightforward methodology for the assessment of building performance under modified outdoor conditions. Designers and urban planners should benefit from the results of this paper in their evaluation of proposals to decrease building energy consumption. A number of examples are discussed in order to illustrate the methodology outlined.     

Radon concentration in houses over a closed Hungarian uranium mine

High radon concentration (average 410 kBq m-3) has been measured in a tunnel of a uranium mine, located 15-55 m below the village of Kovágószolos, Hungary. The mine was closed in 1997; the artificial ventilation of the tunnel was then terminated and recultivation works begun. In this paper, a study has been made as to whether the tunnel has an influence on the radon concentration of surface dwellings over the mining tunnel. At different distances from the surface projection of the mining tunnel, radon concentration, the gamma dose, radon exhalation and radon concentration of soil gas were measured. The average radon concentration in the dwellings was 483 Bq m-3. Significantly higher radon concentrations (average 667 Bq m-3) were measured in houses within +/-150 m from the surface projection of the mining tunnel +50 m, compared with the houses further than the 300-m belt (average 291 Bq m-3). The average radon concentration of the soil gas was 88.8 kBq m-3, the average radon exhalation was 71.4 Bq m-2 s-1 and higher values were measured over the passage as well. Frequent fissures crossing the passage and running up to the surface and the high radon concentration generated in the passage (average 410 kBq m-3) may influence the radon concentration of the houses over the mining tunnel.     

Assessment of nitrification in groundwater filters for drinking water production by qPCR and activity measurement

In groundwater treatment for drinking water production, the causes of nitrification problems and the effectiveness of process optimization in rapid sand filters are often not clear. To assess both issues, the performance of a full-scale groundwater filter with nitrification problems and another filter with complete nitrification and pretreatment by subsurface aeration was monitored over nine months. Quantitative real-time polymerase chain reaction (qPCR) targeting the amoA gene of bacteria and archaea and activity measurements of ammonia oxidation were used to regularly evaluate water and filter sand samples. Results demonstrated that subsurface aeration stimulated the growth of ammonia-oxidizing prokaryotes (AOP) in the aquifer. Cell balances, using qPCR counts of AOP for each filter, showed that the inoculated AOP numbers from the aquifer were marginal compared with AOP numbers detected in the filter. Excessive washout of AOP was not observed and did not cause the nitrification problems. Ammonia-oxidizing archaea grew in both filters, but only in low numbers compared to bacteria. The cell-specific nitrification rate in the sand and backwash water samples was high for the subsurface aerated filter, but systematically much lower for the filter with nitrification problems. From this, we conclude that incomplete nitrification was caused by nutrient limitation.     

Development of Brazilian steel construction

This article presents a concise short overview of the development of the steel industry in Brazil, with the emphasis on civil construction. The relatively rapid increase in the application of steel structures for both low and tall buildings and the modern bridges in Brazil are the results of an extensive effort of the steel producers and the improvement of steel courses and research programmes in several universities and institutions during the last two decades. The steel industry in collaboration with the universities, which have provided the results of their recent studies, contributed to the improved steel technologies and composite construction. Data, supplied by the Brazilian Institute of Metallurgy, IBS, is presented on the actual steel production and fabrication with regard to application in civil engineering. Case studies of steel structures, such as multi-storey buildings, space structures, light gauge steel construction and bridges, are presented and commented on. Further, steel structures subjected to corrosion or to fire, as well as steel and composite semi-rigid joints, are mentioned and finally the Brazilian experience with steel architecture is introduced.     

Paleonutritional analysis of the pre-Hispanic population from Fuerteventura (Canary Islands)

In this study, from histological and chemical perspectives, we analyse the human remains belonging to the pre-Hispanic inhabitants from Fuerteventura (one of the Canary Islands) and compare the results with those obtained on a sample of pre-Hispanic inhabitants from Gran Canaria (Canary Islands). We observe that trabecular bone mass was normal in the samples from Fuerteventura except for an elderly woman; this result is in sharp contrast with the decreased bone mass observed in the population from Gran Canaria. The pre-Hispanic population from Fuerteventura showed lower bone strontium, Sr/Ca ratio, and bone barium, but slightly higher bone copper, than that from Gran Canaria. All these data indicate a greater consumption of marine products by the population of Fuerteventura. The high prevalence of osteoporosis observed in the population from Gran Canaria may be interpreted as a consequence of protein-calorie malnutrition, a condition which seemed to be not so prevalent in the population of Fuerteventura.