scholarly journals Physical chemistry research of a concrete dam with over 50 years of operation

Cerâmica ◽  
2012 ◽  
Vol 58 (347) ◽  
pp. 374-380 ◽  
Author(s):  
K. F. Portella ◽  
A. Joukoski ◽  
V. Swinka Filho ◽  
M. A. Soares ◽  
E. S. Ferreira
Keyword(s):  
Hydroelectric Power Plant ◽  
Xrd Analysis ◽  
Mechanical Tests ◽  
Hydroelectric Power ◽  
Reservoir Water ◽  
Concrete Dam ◽  
Chemistry Research ◽  
Alkali Aggregate Reaction ◽  
Water Analyses ◽  
South Of Brazil

Guaricana hydroelectric power plant concrete dam, located in the South of Brazil, was investigated after 49 years of operation. A part of the mortar was altered to ettringite, and other by-products. The inner defects in the fracture and polished sample surfaces were detected by CT and SEM. The samples were extracted from two parts of the dam from top to valley. Elemental chemical composition and phases were determined by EDS and XRD analysis. The reservoir water showed that it was less aggressive to the concrete structure. Percolated dam water analyses revealed a mortar-mass loss of 3 kg/year. Onsite visual inspection, mechanical tests, and other usual forms of investigation confirmed concrete deterioration, such as leaching, stalactites and stalagmites formation, alkali-aggregate reaction and ettringite. Furthermore, mortar damage was detected in a particular area according to the dam depth, and autogenous healing of cracks were visible in some parts of the inspected galleries.

scholarly journals Kualitas Fisik dan Kimia Sungai Citarum yang bermuara ke Waduk Cirata di Wilayah Kabupaten Cianjur

2019 ◽  
Vol 19 (3) ◽  
pp. 628
Author(s):  
Bramantiyo Eko Putro ◽  
Isma Masrofah
Keyword(s):  
Water Quality ◽  
River Flow ◽  
Pollution Prevention ◽  
Hydroelectric Power Plant ◽  
Fish Farming ◽  
Middle Part ◽  
Clean Water ◽  
Hydroelectric Power ◽  
Reservoir Water ◽  
Pollutant Sources

Pollution prevention must be carried out in the upstream, middle and downstream parts. One of the Citarum watersheds located in the middle part is the Cirata reservoir. Pollution in the Cirata reservoir does not only originate from the reservoir environment, but also from rivers that flow into the Cirata reservoir. Cirata Reservoir besides being a Hydroelectric Power Plant (PLTA) unit, this reservoir is also used by the community for fish farming in the Floating Net Pool (KJA) technique. This study aims to determine the most dominant pollutants contaminating the Cirata reservoir. Test of river and reservoir water quality is carried out with the help of lab tests by Labkesda. The research data was obtained by obtaining clean water quality test data from several 3 estuary points of the river flow to the Cirata reservoir and 4 centers of Cirata reservoir number of 40 samples. Data processing techniques are carried out using data mining, namely Exploratory Data Analysis. The lab parameter test results, which are compared with the Permenkes No. 32 Year 2017 standard, show that the majority of the physical and chemical quality parameters of the Citarum River which empties into the Cirata Reservoir are still within the required threshold. Most river and reservoir water samples have water quality that qualifies as clean water. Five samples (12.5%) in turbidity parameters and 1 sample (2.5%) in color samples did not qualify as clean water. This is possible because the sampling is too close to the mainland. Temperature parameters of 20 samples (50%) do not qualify as clean water is possible because of the lag time of sampling. The results of the analysis showed that the distance of pollutant sources, the amount of pollutant sources, and environmental conditions around the sampling significantly with temperature, TDS, turbidity, color, pH, nitrogen, iron, hardness, manganese, fluoride, and cyanide.

scholarly journals Problems, methods and technologies of combined 3D model construction for underwater and above-water relief

2020 ◽  
Vol 149 ◽  
pp. 02002
Author(s):  
Andrey Gachenko ◽  
Alexei Hmelnov
Keyword(s):  
Power Plant ◽  
Water Level ◽  
Water Flow ◽  
Lake Baikal ◽  
3D Model ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Delaunay Triangulations

In the article we describe the methods for construction of underwater 3D relief (bathymetry) and combining it with the corresponding ground relief (terrain) when the bathymetry information is of much lower quality than that of terrain. We have developed an algorithm for combining the low quality underwater relief with the higher quality ground relief using Delaunay triangulations. The resulting combined 3D model of relief has no noticeable artifacts and can be used to solve various hydrological tasks, such as computation of the HPP reservoir water level in dependence to the water discharges of the hydroelectric power plant. We have tested the technology for building combined relief 3D model in several scientific projects intended to estimate the changes in the coastline under various water flow scenarios in the basins of Angara River and Lake Baikal.

scholarly journals Current State of High 120 m Concrete Dam Bratsk Hydroelectric Power Plant

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Mark A. Sadovich ◽  
Tatyana F. Shlyakhtina ◽  
Sofia M. Ginzburg ◽  
Alexander M. Yudelevich
Keyword(s):  
Power Plant ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Concrete Dam ◽  
Current State

Using SEM and EDS for material’s analysis of the small hydroelectric power plant: case study/ Utilizando MEV e EDS para análise do material de uma pequena central hidrelétrica: estudo de caso

2021 ◽  
Vol 7 (7) ◽  
pp. 70032-70050
Author(s):  
Gláucia Nolasco de Almeida Mello ◽  
Cynara Fiedler Bremer ◽  
Fernanda Gallotti Costa ◽  
Raissa Pinheiro Dutra
Keyword(s):  
Power Plants ◽  
Socioeconomic Development ◽  
Chemical Elements ◽  
Energy Dispersive Spectrometer ◽  
Microstructural Analysis ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Alkali Aggregate Reaction ◽  
Isolated Points ◽  
Installed Capacity

Small Hydroelectric Power Plants (SHPPs) are hydroelectric of reduced size and power, i.e., less than thirteen square kilometres of reservoir area and power less than 30 MW (megawatts). SHPPs account for about 3.7% of all installed capacity of the Brazilian power generation system, which demonstrates their relevance in the national scenario. In addition to this function, SHPPs also influence the socioeconomic development of the region by helping to create direct and indirect jobs. In this context, the goal of this work was the microstructural analysis of the concrete of the dam of SHPP Ponte Queimada, installed in Rio Casca, Minas Gerais, Brazil. Ponte Queimada was built in 1936; over the years it underwent some interventions and, currently, it undergoes a new intervention for maintenance and repairs. By means of visual inspection, the sites for collecting the samples were identified. The samples were analysed regarding the morphology and chemical composition of the concrete using Scanning Electron Microscope (SEM) and energy dispersive spectrometer (EDS). Based on the collected samples, isolated points of occurrence of alkali-aggregate reaction (AAR) were identified. The observed samples, besides possessing chemical elements compatible with manifestations of AAR, also presented shapes that visually resemble to them. It was concluded that the use of SEM is an effective and relatively simple alternative for the identification of pathological manifestations that could compromise the durability of the structures, often allowing the determination of repair measures in anticipation of the prevention of future problems.

scholarly journals Environmental DNA from a small sample of reservoir water can tell volumes about its biodiversity.

2021 ◽  
Author(s):  
André L. Q. Torres ◽  
Danielle L. A. S. Amaral ◽  
Murilo Guimaraes ◽  
Henrique B. Pinheiro ◽  
Camila M. Pereira ◽  
...  
Keyword(s):  
Population Genetics ◽  
Power Plant ◽  
Hydroelectric Power Plant ◽  
Environmental Dna ◽  
Small Sample ◽  
Sequence Variants ◽  
Hydroelectric Power ◽  
Base Pairs ◽  
Reservoir Water ◽  
Study Population

We evaluated the potential of metabarcoding in assessing the environmental DNA (eDNA) biodiversity profile in the water column of an hydroelectric power plant reservoir in southeast Brazil. Samples were obtained in three technical replicates at 1 km from the dam at 1, 13 and 25 m depths. For each minibarcodes -- COI, 12S and 16S -- 1.5 million paired-reads (150 base pairs) were sequenced. A total of 44 unique taxa were found. COI identified most of the taxa (34 taxa; 77.2 %) followed by 16S (14; 31.8 %) and 12S (10; 22.7 %). All minibarcodes identified fishes (13 taxa), however, COI detected other aquatic macro-invertebrates (18), algae (3) and amoebas (2). Richness was the same across the three depths (35 taxa), although, beta diversity suggested slightly divergent profiles. In just one location we identified 15 taxa never reported previously, 50% of the fish species identified in the last year of fishery monitoring and 13% of the species in biodiversity surveys performed from 2012 to 2021. Clustering into Amplicon Sequence Variants (ASV) showed that 12S and 16S are able to detect predominant haplotypes of fishes, suggesting they are suitable to study population genetics of this group. In this study we reviewed the species occurring within the Tr&ecircs Irm&atildeos reservoir according to previous conventional surveys and demonstrated that eDNA metabarcoding can be applied to monitor its biodiversity.

scholarly journals Oxygen uptake from aquatic macrophyte decomposition from Piraju Reservoir (Piraju, SP, Brazil)

2011 ◽  
Vol 71 (1) ◽  
pp. 27-35 ◽  
Author(s):  
I. Bianchini Jr. ◽  
MB. Cunha-Santino ◽  
RS. Panhota
Keyword(s):  
Oxygen Consumption ◽  
Rate Constants ◽  
Aquatic Macrophyte ◽  
Oxygen Demand ◽  
Hydroelectric Power Plant ◽  
Order Kinetic ◽  
Hydroelectric Power ◽  
Myriophyllum Aquaticum ◽  
Reservoir Water ◽  
Eichhornia Azurea

The kinetics of oxygen consumption related to mineralisation of 18 taxa of aquatic macrophytes (Cyperus sp, Azolla caroliniana, Echinodorus macrophyllus, Eichhornia azurea, Eichhornia crassipes, Eleocharis sp1, Eleocharis sp2, Hetereanthera multiflora, Hydrocotyle raniculoides, Ludwigia sp, Myriophyllum aquaticum, Nymphaea elegans, Oxycaryum cubense, Ricciocarpus natans, Rynchospora corymbosa, Salvinia auriculata, Typha domingensis and Utricularia foliosa) from the reservoir of Piraju Hydroelectric Power Plant (São Paulo state, Brazil) were described. For each species, two incubations were prepared with ca. 300.0 mg of plant (DW) and 1.0 L of reservoir water sample. The incubations were maintained in the dark and at 20 ºC. Periodically the dissolved oxygen (DO) concentrations were measured; the accumulated DO values were fitted to 1st order kinetic model and the results showed that: i) high oxygen consumption was observed for Ludwigia sp (533 mg g-1 DW), while the lowest was registered for Eleocharis sp1 (205 mg g-1 DW) mineralisation; ii) the higher deoxygenation rate constants were verified in the mineralisation of A. caroliniana (0.052 day-1), H. raniculoides (0.050 day-1) and U. foliosa (0.049 day-1). The oxygen consumption rate constants of Ludwigia sp and Eleocharis sp2 mineralisation (0.027 day-1) were the lowest. The half-time of oxygen consumption varied from 9 to 26 days. In the short term, the detritus of E. macrophyllus, H. raniculoides, Ludwigia sp, N. elegans and U. foliosa were the critical resources to the reservoir oxygen demand; while in the long term, A. caroliniana, H. multiflora and T. domingensis were the resources that can potentially contribute to the benthic oxygen demand of this reservoir.

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