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Planktic Cyanobacteria from S?o Paulo State, Brazil: Chroococcales
Sant'Anna, Célia L.;Azevedo, Maria Teresa de P.;Senna, Pedro Américo C.;Komárek, Jirí;Komárková, Jaroslava;
Brazilian Journal of Botany , 2004, DOI: 10.1590/S0100-84042004000200002
Abstract: the biodiversity studies of planktic cyanobacteria started in 1997 with intensive collecting in different water bodies of s?o paulo state. due to the problems brougth by eutrophication and cyanobacterial blooms, the samplings were concentrated in reservoirs of alto tietê region that supply drinking water to millions of people. the samples were collected with 20 μm plankton net or van dorn's bottle. part of each one was preserved in formaldehyde or lugol solution and part was isolated. the culture strains were kept in bg11 and/or ams1 media. based on natural and culture material, 26 species were identified belonging to the families chroococcaceae (2 taxa), merismopediaceae (12), microcystaceae (7) and synechococcaceae (5). among these species, six are potentialy toxic: aphanocapsa incerta (lemmerm.) cronberg & komárek, microcystis aeruginosa (kütz.) kütz., m. botrys teiling, m. panniformis komárek et al., m. wesenbergii (komárek) komárek, and radiocystis fernandoi komárek & komár.-legn. bacularia and coelosphaeriopsis are genera reported for the first time in brazil.
Analysis of artisanal fisheries in two reservoirs of the upper Paraná River basin (Southeastern Brazil)
José Luís Costa Novaes,Edmir Daniel Carvalho
Neotropical Ichthyology , 2013,
Abstract: We compared the artisanal fisheries, in terms of catch strategies, productivity, and gross per capita income, at two reservoirs: the Barra Bonita (an eutrophic reservoir with some introduced species), and the Jurumirim (an oligotrophic reservoir, with no introduced species). Published data and structured interviews with fishers were used to evaluate fishing activity, fish biomass, and the financial performance of the fisheries. In the Barra Bonita Reservoir we analysed data from 745 fishing trips, from which 86,691.9 kg of fish were landed, with a mean CPUE of 62.4 kg/fisher-1 day-1. The main type of fish caught was tilapia (71,513.5 kg; CPUE of 51.5 kg/fisher-1 day-1), which constituted 82.5% of the biomass caught. In the Jurumirim Reservoir, we analysed data from 2,401 fishing trips, from which 25,093.6 kg of fish were landed, with a mean CPUE of 10.4 kg/fisher-1 day-1. The main type of fish caught was "traíra" (6,158.6 kg; CPUE of 2.6 kg/fisher-1 day-1), which constituted 24.5% of the biomass caught. Ordination analysis (PCA) indicated that there was a difference in composition between the fishing reservoirs and ANCOVA showed that there was a significant difference in fish production between the reservoirs. A Student's t-test showed that fishers in the Barra Bonita Reservoir had a significantly higher gross per capita income than those from the Jurumirim Reservoir. Although the Barra Bonita Reservoir has a higher fish production and the fishers earn a higher gross per capita income, we recommend the Jurumirim Reservoir as a model for artisanal fishery management because fishing activity in this reservoir is viable in the long term and such a model would promote conservation and sustainability. This contrasts with the Barra Bonita Reservoir, in which the fishery is not viable in the long term, due to environmental problems caused by artificial eutrophication and the introduction of alien species. It is also noted that in many countries, management of fisheries based on exotic species has not been viable in the long term. Nós comparamos a pesca artesanal, em termo de estratégia de captura, produtividade e renda per capita bruta em dois reservatórios: Barra Bonita (reservatório eutrófico e com espécies introduzidas) e Jurumirim (reservatório oligotrófico e sem espécies introduzidas). Dados publicados e entrevistas estruturadas mensais com os pescadores sobre a atividade de pesca, quilo pescado e rendimento financeiro, foram usados para as análises. No reservatório de Barra Bonita foram analisados dados de 745 viagens pesqueiras, que desembarcaram 86.691,
Research Note: Use of a distributed erosion model (AGNPS) for planning small reservoirs in the Upper Torysa basin
P. Miklanek,P. Pekarova,A. Konicek,J. Pekar
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2004,
Abstract: This paper assesses the vulnerability to erosion of the soils in the upper Torysa catchment down to the planned drinking water reservoir at Tichy Potok (Slovakia). Experimental observations in the Torysa catchment, together with the outputs of the AGricultural Non-Point Source pollution model (AGNPS), have been used to select optimal sites for small sediment-trapping dams on the Torysa tributaries. The rainfall scenario for the upper Torysa was determined from records at the Plavec climate station from 1980–1998. In addition, an extreme rainfall event scenario was envisaged (100 mm rainfall in three hours); AGNPS model simulations suggest that such an event might produce as much as half or even the total amount of sediment generated by all the rainfalls over the whole period of simulation, 1980–1998. Keywords: erosion, sediment transport, simulation, AGNPS model, Torysa basin
Toxic Cyanobacteria in Four Brazilian Water Supply Reservoirs  [PDF]
Viviane Piccin-Santos, Maria do Carmo Bittencourt-Oliveira
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.31009
Abstract: Cyanobacterial blooms have become a worldwide concern due to the production of toxins harmful to humans and animals. In Brazil and worldwide, microcystins are the most frequently found cyanotoxin in water bodies. Four important reservoirs in Brazil’s Southeast and Northeast regions were sampled to identify the cyanobacteria community and the occurrence of potential toxin-producing species in the country’s public supply reservoirs. A total of 14 taxa were identi-fied, 11 of which are known as potential toxin producers. Potentially toxic cyanobacteria were recorded at concentra-tions above 20,000 cells.ml-1 in all samples from all four reservoirs, thus requiring microcystin monitoring in drinking water according to Brazilian legislation. Although the sample from Mundaú reservoir showed the highest concentration of microcystins in water, it had one of the lowest values of cells.ml-1, which demonstrates the non-correspondence between these two parameters. This calls into question the existence of a minimum level of potentially toxic cyanobacteria cells to merit the monitoring of microcystins in the treated water from these sources.
Toxic cyanobacteria in reservoirs in northeastern Brazil: detection using a molecular method
Bittencourt-Oliveira, MC.;Santos, DMS.;Moura, NA.;
Brazilian Journal of Biology , 2010, DOI: 10.1590/S1519-69842010000500012
Abstract: cyanobacterial blooms are a frequent occurrence in northeastern brazil and constitute a serious public health problem. using the polymerase chain reaction (pcr) method, eleven environmental samples with cyanobacteria from seven reservoirs were used to determine the presence of the gene involved in microcystin biosynthesis (mcyb). two sets of oligonucleotide primers were designed from the sequencing of brazilian populations of microcystin producing cyanobacteria (mcyb-f/r and mcyb-f/r-a). the presence of the mcyb gene involved in microcystin biosynthesis was found in all samples, indicating the potential of this gene for producing the toxin. the pcr method proved sensitive and appropriate for the detection of potential producers of microcystins in environmental samples. its ability to reveal potentially toxic cyanobacteria demonstrates that it can be a valuable tool in the monitoring of blooms.
Assessment of trap efficiency of the reservoirs in the Siret Basin (Romania)
GEOREVIEW : Scientific Annals of Stefan cel Mare University of Suceava. Geography Series , 2013, DOI: 10.4316/georeview.2012.21.1.60
Abstract: In this paper we calculate the trap efficiency of the reservoirs in the Siret Basin and we make also a briefly analysis to show the way this reservoirs influence the sediment discharge of the rivers by sedimentation. Trap efficiency (TE) is an indicator and parameter of sediment yield from upstream and of sedimentation rate from the reservoirs. In consequence we calculate for 14 reservoirs in the Siret Basin this parameter. The values of TE vary between 42 – 98% and correlates very well with the capacity of the reservoirs. In reservoirs with the high capacity the values approach to 100% while in small reservoirs, the value of TE is decreasing. Capacity and operating mode lakes are important factors controlling the degree of retention of sediment from the source area. Sedimentation within reservoirs is a problem as it decrease the storage capacity and, hence, makes the structure less efficient. For small reservoirs, sedimentation can become a severe problem as the rate of siltation is generally much higher in comparison to large dams
Environmental Interpretation of Upper Triassic Bioturbation Structures and Correlation with Petrophysical Properties of Reservoirs in Sichuan Basin

Lin Shi-guo,Shi Zhen-sheng,Li Jun,Wang Zong-li,Gao Yang,Li Wen-zheng,

天然气地球科学 , 2012,
Abstract: Recent exploration of Sichuan basin manifests that there exists thick sand bodies but thin reservoirs in Xujiahe Formation and controlling factors of favorable reservoirs are complex.Most researchers considered the sedimentary facies,lithofacies and diagenetic facies to be key factors of favorable reservoir,but paid little attention to other factors.Based on observation and measurement of outcrops,cores and rock slices,we consider that bioturbation give certain contribution to improve the reservoir properties and is also an important factor.Based on the bioturbation distribution in the cores of upper Triassic Sichuan basin,four types of lithology-bioturbation assemblage can be subdivided as follows: ① Bioturbation produced by single trace fossils,developing mainly in thick bedded mudstone,and presents shallow lake and shore lake swamp sedimentary environments;② Bioturbation near boundary between sandstone and mudstone,which occurs mainly in sediments of thick-bedded mudstone interbed with thin-layered siltstone,with bioturbation index between 2 and 3 reflecting the upper distal sand bar sediments;③ Bioturbation interbedded mudstones and sandstones,which exists in thin-bedded sandstone and mudstone,with sandstone thickness of 2-8cm and bioturbation index between 4 and 5,representing the middle shallow lake depositional environment;④ Bioturbation produced by single trace fossils,which develops predominantly in thick-bedded sandstone,with bioturbation index between 1 and 2,indicating shore lake sedimentary environments with high wave energy.Based on bioturbation,sandstone diagenesis and porosity structures,there suggests that the more strong the bioturbation is,the better the reservoir petrophysical property is,namely a positive correlation between the bioturbation structures and the reservoir petrophysical properties.The primary porosity in the place of strong bioturbation,is preserved greatly to form the high porosity and high permeability reservoirs,since the bioturbation increases the homogeneity and grain gradation of rocks.
Characteristics and distribution of inside volcanic reservoirs of the Carboniferous in upper-plate of Ke-Bai fault zone in Junggar Basin

- , 2017, DOI: 10.7605/gdlxb.2017.04.053
Abstract: 准噶尔盆地克—百断裂带上盘最新钻井发现,在石炭系顶面之下较深的内幕火山岩区域获得工业油流。通过岩心、薄片、扫描电镜、主量元素和岩石物性等资料,明确了研究区石炭系内幕火山岩储集层特征及展布。研究表明,克—百断裂带上盘石炭系内幕储集层顶面最大深度位于石炭系不整合面以下800 m,岩相(岩性)以爆发相空落亚相(凝灰岩)和溢流相下部亚相(安山岩)为主,储集空间以次生溶孔和构造缝为主。不同岩相具有不同类型和程度的成岩作用,经历了不同的孔隙演化过程。溢流相上部亚相和溢流相下部亚相孔隙演化程度最高。冷凝固结作用控制其原生孔隙的形成,构造破碎作用及溶蚀作用至关重要。受构造和溶蚀作用控制的类和类储集层为有效储集层,主要分布于克—百断裂附近。
From the latest drilling results of Ke-Bai fault zone in Jungger Basin,commercial oil are found in inside volcanic rocks of the Caboniferous which is far away beneath the Carboniferous unconformity. Based on the date of core,thin section,scanning electron microscopy,main elements and the physical properties,the characteristics and distribution of the inside volcanic reservoirs of the Caboniferous are definited. The study suggests the inside volcanic reservoirs are 800 m below the Caboniferous unconformity. The main types of lithofacies(lithology) are air fall subfacies of explosion facies(tuff)and lower subfacies of effusive facies(andesite). The main types of reservoir space are dissolved pore and tectonic fracture. Different kinds of lithofacies have different types of diagenesis and degrees of porosity evolution process. Upper effusive subfacies and lower effusive subfacies have the highest degree of pore evolution. Original interstice are controlled by the condensation. Tectonic broken and dissolution is essential to the reservoirs. Level-Ⅰ and level-Ⅱ reservoirs controlled by tectonic broken and dissolution are the effective reservoirs,which are distributed by the Ke-Bai Fault
Seasonal Fluctuation of Cyanobacteria Population in Tropical Through-flowing Reservoirs in South Asia

Lin Qiu-qi,Han Bo-ping,

热带亚热带植物学报 , 2007,
Abstract: The seasonal fluctuation of cyanobacteria population in the through-flowing reservoirs of Shenzhen and Feilaixia in Guangdong Province was investigated in 2004. Seventeen genera of cyanobacteria composed mainly of filamentous ones were obtained. The common genera were Pseudanabaena, Microcystis and Dactylococcopsis. Cyanobacteria density ranged from 5 to 2 052 cells ml-1. The maximum cell density was found in Shenzhen Reservoir in June with filamentous species abundance over 75%. The peak of cyanobacteria abundance was present in Feilaixia Reservoir in December with filamentous species occupying 90%. Cyanobacteria abundance and composition were limited mainly by hydraulic parameters. The seasonal fluctuation of cyanobacteria population was more affected in Feilaixia Reservoir than in Shenzhen Reservoir since the hydraulic retention time of Feilaixia Reservoir had a greater variation than that of Shenzhen Reservoir. Filamentous cyanobacterias, especially Pseudanabaena, are more suitable to the reservoirs than the other cyanobacteria species under high levels of nitrogen and phosphorus conditions. And their abundances will greatly increase when the retention time is prolonged.
Post-depositional effects on the microstructure and stable isotopes composition of planktic foraminiferal tests from the Miocene of the Pelotas Basin, south Brazilian continental margin
Anjos-Zerfass, Geise de Santana dos;Chemale Jr, Farid;Moura, Candido A. V.;
Revista mexicana de ciencias geológicas , 2011,
Abstract: an integrated study of planktic foraminiferal tests (orbulina universa and globigerinoides trilobus) imaging techniques and chemical/isotopic analyses has been carried out at the miocene section of the pelotas basin (south brazil) with the purpose of record and evaluate the effects of the diagenesis in its wall texture and isotopic composition. the characterization of the foraminiferal tests preservation prior performing isotopic analysis for paleoceanographic studies is essential to ensure the choice of suitable material for obtaining reliable data. scanning electron microscopy, backscatter scanning electron microscopy, energy-dispersive x-ray spectrometry and stable isotope measurements were used to evaluate the post-depositional effects on the tests. it was possible to identify features of dissolution, neomorphism (recrystallization) and coating of autigenic minerals. the stable isotopic data define two compositional groups. the heavier and less scattered values characterize a preserved paleoenvironmental signal as the lighter and scattered ones indicate a signal derived from post-depositional alterations. additionally, the characterization of the distinct types of diagenetic changes and their textural products provide a guideline for the evaluation of the diagenetic effects of deeply buried fossil foraminifera.
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