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921.
Paranhos Gazineu MH de Araújo AA Brandão YB Hazin CA de O Godoy JM 《Journal of environmental radioactivity》2005,81(1):47-54
Scales and sludge generated during oil extraction and production can contain uranium, thorium, radium and other natural radionuclides, which can cause exposure of maintenance personnel. This work shows how the oil content can influence the results of measurements of radionuclide concentration in scale and sludge. Samples were taken from a PETROBRAS unit in Northeast Brazil. They were collected directly from the inner surface of water pipes or from barrels stored in the waste storage area of the E&P unit. The oil was separated from the solids with a Soxhlet extractor by using aguarras at 90+/-5 degrees C as solvent. Concentrations of 226Ra and 228Ra in the samples were determined before and after oil extraction by using an HPGe gamma spectrometric system. The results showed an increase in the radionuclide concentration in the solid (dry) phase, indicating that the above radionuclides concentrate mostly in the solid material. 相似文献
922.
Godoy JM Carvalho F Cordilha A Matta LE Godoy ML 《Journal of environmental radioactivity》2005,83(1):101-111
The present work was carried out to assess the (210)Pb content in "black-powder" found in pigging operations on gas pipelines in Brazil, in particular, on the Campos Basin gas pipeline. Additionally, the chemical composition of such deposits was determined and an eventual correlation with (210)Pb concentration evaluated. Typical "black-powder" generated in the natural gas pipeline from Campos Basin oilfield contains mainly iron oxide ( approximately 81%) and residual organic matter ( approximately 9%). The (210)Pb content ranges from 4.9 to 0.04k Bqkg(-1) and seems to be inversely correlated with the distance to the platforms. On the other hand, (226)Ra concentration is higher on the pipeline branch between the platform and the onshore installations. (228)Ra was only observed in few samples, in particular, in the samples with the highest (226)Ra content. 相似文献
923.
Margulies TD Schonbeck ND Morin-Voillequé NC James KA LaVelle JM 《Journal of environmental radioactivity》2004,75(2):143-157
The Rocky Flats Nuclear Weapons Plant near Golden, CO released plutonium into the environment during almost 40 years of operation. Continuing concern over possible health impacts of these releases has been heightened by lack of public disclosure of the US Department of Energy (DOE) activities. A dose reconstruction study for the Rocky Flats facilities, begun in 1990, provided a unique opportunity for concerned citizens to design and implement field studies without participation of the DOE, its contractors, or other government agencies. The Citizens Environmental Sampling Committee was formed in late 1992 and conducted a field sampling program in 1994. Over 60 soil samples, including both surface and core samples, were collected from 28 locations where past human activities would have minimal influence on contaminant distributions in soil. Cesium-137 activity was used as a means to assess whether samples were collected in undisturbed locations. The distribution of plutonium (as (239,240)Pu) in soil was consistent with past sampling conducted by DOE, the Colorado Department of Public Health and Environment, and others. Elevated levels of (239,240)Pu were found immediately east of the Rocky Flats Plant, with concentrations falling rapidly with distance from the plant to levels consistent with background from fallout. Samples collected in areas south, west, and north of the plant were generally consistent with background from fallout. No biases in past sampling due to choice of sampling locations or sampling methodology were evident. The study shows that local citizens, when provided sufficient resources, can design and implement technical studies that directly address community concerns where trust in the regulated community and/or regulators is low. 相似文献
924.
Pilar D. S. C. Mariani Antonio P. Vinagre Neto José P. da Silva Jr. Elke J. B. N. Cardoso Elisa Esposito Lucia H. Innocentini-Mei 《Journal of Polymers and the Environment》2007,15(1):19-24
The biodegradability properties of poly(ɛ-caprolactone) (PCL) and modified adipate-starch (AS) blends, using Edenol-3203 (E)
as a starch plasticizer, were investigated in laboratory by burial tests of the samples in previously analyzed agricultural
soil. The biodegradation process was carried out using the respirometric test according to ASTM D 5988-96, and the mineralization
was followed by both variables such as carbon dioxide evolution and mass loss. The results indicated that the presence of
AS-E accelerated the biodegradation rate as expected. 相似文献
925.
Public Perception as a Barrier to Introducing Wood in Rivers for Restoration Purposes 总被引:2,自引:0,他引:2
Piégay H Gregory KJ Bondarev V Chin A Dahlstrom N Elosegi A Gregory SV Joshi V Mutz M Rinaldi M Wyzga B Zawiejska J 《Environmental management》2005,36(5):665-674
Reintroduction of wood in rivers for restoration purposes is now recognized in a positive way by scientists. Nevertheless,
the perception of wood in riverscapes is strongly affected by the socio-cultural environment. This cultural influence might
explain why wood reintroduction is accepted and promoted in some regions of the world but not in others, despite the demonstrated
ecological benefits. From an extensive student perception survey, we show that most of the groups from nine countries in the
world considered riverscapes with wood to be less aesthetic, more dangerous, and needing more improvement than riverscapes
without wood. By contrast, this way of thinking was not observed in Germany, Sweden, and Oregon (USA), where the first instances
of wood reintroduction occurred. 相似文献
926.
927.
Grande JA Borrego J de la Torre ML Sáinz A 《Environmental geochemistry and health》2003,25(2):233-246
The combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel rivers. This estuary is in the southwest of the Iberian Peninsula and is one of the estuarine systems on the northwest coast of the Gulf of Cádiz. From the statistical treatment of data obtained by analyzing samples of water from this system, which is affected by industrial and mining pollution processes, we can see how the sampling points studied form two large groups depending on whether they receive tidal or fluvial influences. Fluvial input contributes acid water with high concentrations of heavy metal, whereas industrial effluents are responsible for the presence of phosphates, silica and other nutrients. The estuarine system of the Tinto and Odiel Rivers can be divided into three areas – the Tinto estuary, the Odiel estuary and the area of confluence – based on the physical – chemical characteristics of the water. 相似文献
928.
Among the many factors that contribute to overexploitation of marine fisheries, the role played by uncertainty is important. This uncertainty includes both the scientific uncertainties related to the resource dynamics or assessments and the uncontrollability of catches. Some recent works advocate for the use of marine reserves as a central element of future stock management. In the present paper, we study the influence of protected areas upon fisheries sustainability through a simple dynamic model integrating non-stochastic harvesting uncertainty and a constraint of safe minimum biomass level. Using the mathematical concept of invariance kernel in a robust and worst-case context, we examine through a formal modeling analysis how marine reserves might guarantee viable fisheries. We also show how sustainability requirement is not necessarily conflicting with optimization of catches. Numerical simulations are provided to illustrate the main findings. 相似文献
929.
Rodrigues Izabella Almirante Porto Tiburcio Alves Roberta Vianna Guimarães Maria José de Oliveira Cavalcanti Gomes Thiago Santiago Pacheco Elen Beatriz Acordi Vasques 《Environment, Development and Sustainability》2022,24(8):9705-9730
Environment, Development and Sustainability - This review aimed to analyze plastic lumber manufacturing in Brazil, a country with a large amount of natural wood, and devise strategies to boost... 相似文献
930.
Jacqueline Selva Jean Philippe Wolf Patricia Rince Daniel Rodrigues René Frydman Pierre Jouannet 《黑龙江环境通报》1993,13(5):311-321
Subzonal insemination has been proposed to achieve fertilization in cases where standard in vitro fertilization has failed. We present the results of chromosome analysis of oocytes after subzonal insemination. Our data suggest that the main cause (76 per cent) of the absence of cleavage after subzonal insemination is the total absence of sperm nucleus evolution of the injected spermatozoa. Our results also suggest that spermatozoa chromatin development is normal after subzonal insemination. Aneuploidy does not seem to be increased in zygotes after subzonal insemination. However, polyploidy was often more important than predicted by the observation of pronuclei (PN). Pronucleus development might be asynchronous and can appear earlier or later than after standard IVF. The cytogenetic risk after subzonal insemination might therefore be triploidy (if a triploid egg is transferred, because only 2 PN were seen) rather than aneuploidy or structural abnormalities. 相似文献