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81.
Santos RG Martins AS Farias Jda N Horta PA Pinheiro HT Torezani E Baptistotte C Seminoff JA Balazs GH Work TM 《Marine pollution bulletin》2011,62(6):1297-1302
To show the influence of coastal habitat degradation on the availability of food for green turtles (Chelonia mydas), we assessed the dietary preferences and macroalgae community at a feeding area in a highly urbanized region. The area showed low species richness and was classified as degraded. We examined stomach contents of 15 dead stranded turtles (CCL = 44.0 cm (SD 6.7 cm)). The diet was composed primarily of green algae Ulva spp. (83.6%). In contrast, the macroalgae community was dominated by the green alga Caulerpa mexicana. We found a selection for red algae, seagrass and Ulva spp., and avoidance for C. mexicana and brown alga Dictyopteris delicatula. The low diversity of available food items, possibly a result of environmental degradation, likely contributed to the low dietary diversity. The nutritional implications of this restricted diet are unclear. 相似文献
82.
Alexandre A. Costa António Arêde Aníbal Costa Jo?o Guedes Bruno Silva 《Bulletin of Earthquake Engineering》2012,10(1):135-159
Stone masonry is one of the oldest building techniques used worldwide and it is known to exhibit poor behaviour under seismic
excitations. In this context, this work aims at assessing the in-plane behaviour of an existing double-leaf stone masonry
pier by experimental testing. Additionally, a detailed 3D finite element numerical analysis based on micro-modelling of the
original pier is presented (fully describing the geometry and division of each individual elements, namely infill, blocks
and joints) aiming at simulating the experimental test results. This numerical strategy can be seen as an alternative way
of analysing this type of constructions, particularly useful for laboratory studies, and suitable for the calibration of simplified
numerical models. As part of a wider research activity, this work is further complemented with the presentation of an effective
retrofit/strengthening technique (reinforced connected plaster) to achieve a significant improvement of its in-plane cyclic
response which is experimentally verified in the results presented herein. 相似文献
83.
Cantarero S Camino-Sánchez FJ Zafra-Gómez A Ballesteros O Navalón A Vílchez JL Verge C Reis MS Saraiva PM 《Marine pollution bulletin》2012,64(3):587-594
The contamination of aquatic environments has become the focus of increasing regulation and public concern due to their potential and unknown negative effects on the ecosystems. The present work develops a monitoring and statistical study, based on the analysis of variance test (ANOVA) and the multivariable analysis, both for insoluble soap and LAS in order to compare the behavior of different anionic surfactants in this environmental compartment. First, a novel and successfully validated methodology to analyze insoluble soap in these samples is developed. The matrix effect and the comparison of different extraction techniques were also performed. The optimized analytical methodologies were applied to 48 representative samples collected from the Almeria Coast (Spain) and then a statistical analysis to correlate anionic surfactant concentration and several variables associated with marine sediment samples was also developed. The results obtained showed relevant conclusions related to the environmental behavior of anionic surfactants in marine sediments. 相似文献
84.
Martins CC Bícego MC Mahiques MM Figueira RC Tessler MG Montone RC 《Marine pollution bulletin》2011,63(5-12):452-458
Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950's, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50 years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubat?o industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area. 相似文献
85.
Luis Alejandro Morales-Marín Kwok Pan Chun Howard Simon Wheater Karl-Erich Lindenschmidt 《水文科学杂志》2017,62(4):657-679
Nutrient loadings in many river catchments continue to increase due to rapid expansion of agriculture, urban and industrial development, and population growth. Nutrient enrichment of water bodies has intensified eutrophication which degrades water quality and ecosystem health. In this study, we carried out a trend analysis of total phosphorus and total nitrogen loads in the South Saskatchewan River (SSR) catchment using a novel approach to analyse nutrient time series. Seasonal analysis of trends at each of the water quality stations was performed to determine the relationships between annual flow regimes and nutrient loads in the catchment, in particular, the influence of the high spring runoff on nutrient export. Decadal analysis was also performed to determine the long-term relationships of nutrients with anthropogenic changes in the catchment. Although it was found that seasonal and historical variability of nutrient load trends is mainly determined by streamflow regime changes, there is evidence that increases in nitrogen concentration can also be attributed to anthropogenic changes. 相似文献
86.
Seismic events can affect the physico-chemical characteristics of groundwater. These anomalies are of a pre-seismic, co-seismic and post-seismic nature and correspond to pulse variations, sudden increases and decreases without return to initial values and upward or downward changes in trend. Continuous and in situ conductivity and temperature monitoring and periodic water sampling at a hot spring associated with neotectonic activity are of great interest for establishing predictive methods. This method is limited to the seismic activity affecting the fracturing system with which the hot spring is associated. The Region of Murcia and surroundings (southeast Spain) was selected as the study area for exploring the nature of these influences on groundwater. A hot spring in the Leana spa (Murcia) was equipped and monitored during the period 2006–2008, allowing for the in situ determination of conductivity and temperature as well as of major and minor constituents at the laboratory. Due to its proximity and related with fault network, we suggest that 86 % of earthquakes located between 0 and 10 km may affect in situ parameters of groundwater, and 75 % may affect laboratory determinations. This percentage drops in more distant zones. Of all earthquakes that seem to influence groundwater, 55 % of the in situ parameter anomalies and 53 % of laboratory were of a pre-seismic nature. 相似文献
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