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Wyświetlanie 1-15 z 325
Tytuł:
Measuring system for monitoring of concrete dam deformations
Autorzy:
Bryś, H.
Mirek, G.
Powiązania:
https://bibliotekanauki.pl/articles/224422.pdf
Data publikacji:
2007
Wydawca:
Politechnika Warszawska. Wydział Geodezji i Kartografii
Tematy:
zapora
zapora betonowa
deformacja zapory
pomiary geodezyjne
dam
concrete dam
concrete dam deformation
engineering surveying
Źródło:
Reports on Geodesy; 2007, z. 1/82; 39-45
0867-3179
Pojawia się w:
Reports on Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control network reliability reconstruction for Zatonie dam
Autorzy:
Nowak, E.
Odziemczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/106901.pdf
Data publikacji:
2018
Wydawca:
Politechnika Warszawska. Wydział Geodezji i Kartografii
Tematy:
network reliability
accuracy harmonisation
dam control network
Zatonie dam
niezawodność sieci
harmonizacja dokładności
tama Zatonie
Opis:
Absolute horizontal displacements are an important element of dam safety level assessment. Appropriate design of measurement network is a prerequisite for the acquisition of displacement values that meet the reliability requirements. A network of this kind, apart from ensuring the required precision of displacement determination, should be characterised by reliability allowing for elimination of gross errors in the results of geodetic surveys. This study aims to propose a method to improve reliability characteristic of surveying network used for horizontal displacement identification in Zatonie dam. The desired effect (increase in the network’s reliability) is obtained by the authors in two stages. The first stage concerns expansion of the existing network by addition of three free stations. As the obtained effect did not prove to be satisfactory, in the second stage so called observation accuracy harmonisation was carried out, which optimally utilises the reliability potential of the measurement construction. In order to successfully carry out the harmonisation, a modification to the procedure’s algorithm had to be introduced. A design of a network ensuring detection of a gross error in any given observation was obtained as the result of the performed actions.
Źródło:
Reports on Geodesy and Geoinformatics; 2018, 105; 1-5
2391-8365
2391-8152
Pojawia się w:
Reports on Geodesy and Geoinformatics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The studies on check dam restoration effectiveness
Autorzy:
Łopuszek, M.
Powiązania:
https://bibliotekanauki.pl/articles/101009.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:
mountain stream channel
sediment
check dam
restoration
Opis:
A check dam is a hydraulic structure, which is constructed in order to limit river sediment transport. A sedimentation reservoir is created upstream from the body of the dam, where river sediment is constantly accumulated. These structures were constructed starting in the early 20th century in upstream parts of mountain streams in the Polish part of the Carpathian Mountains. At present, the reservoirs of most check dams are already fully filled with sediment and the impact of these structures on the ecosystems of streams is unfavorable. Moreover, the dams that have not been renovated are in poor technical condition. In the paper two cases of check dam lowering and restored is discussed and the one hypothetical case of gradual check dam lowering is presented and discussed as well. The cases of Krzczonówka and Trzebuńka, where the method of removing sediment from reservoirs was different, showed that the sudden change of „established” hydrodynamic conditions for decades is not favorable for the stream. The results of hypothetic simulation of gradual check dam lowering for the case of Isepnica Stream leads to the conclusion that lowering the construction of check dam and removing sediment from its reservoir in a way that does not have a drastic impact on the hydrodynamic balance of the stream channel is possible. However, as it was shown in the case of Isepnica Stream, it is very complicated task.
Źródło:
Infrastruktura i Ekologia Terenów Wiejskich; 2018, IV/1; 1071-1085
1732-5587
Pojawia się w:
Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Failure simulation of Babar dam – Algeria and its impact on the valley downstream section
Autorzy:
Gaagai, Aissam
Boudoukha, Abderrahmane
Benaabidate, Lahcen
Powiązania:
https://bibliotekanauki.pl/articles/292897.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
dam
dam failure
Hec-Ras
sensitivity analysis
simulation
Opis:
A failure analysis of Babar dam on the El Arab River was performed to highlight the impact of flood wave and velocities on the four villages downstream of the dam; Hella, Khérenne, Chebla and El Oueldja. The simulation of wave propagation along the El Arab River under several scenarios was performed by the hydraulic HEC-RAS model. This model is dedicated to the description of floods at the dam following a breach in the dike. The main factors considered in this simulation include the level of flood water, the flood hydrograph, and the typical scenario for this breach. The flood risk analysis revealed that the maximum of flood wave flow registered at the breach is (Qmax = 9253.02 m3∙s–1), and is beginning to mitigate downstream of the dam along the El Arab River where it reached at the last village with a low flow (Q = 1110.64 m3∙s–1). This simulation allowed drawing the risk map which showed the areas threatened by flood wave resulting from a total failure of the work, and consequently required a plan of security measures to moderate as much as possible the consequences of floods. A sensitivity analysis was conducted to approach the parameters of impact of the breach on the dam failure scenario. It was confirmed that these parameters as formulation time, breach width and side slope have a great influence on the dam failure scenario with the four adjustments (±20 and ±50).
Źródło:
Journal of Water and Land Development; 2020, 44; 75-89
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przydatność modelu EDF w kontekście oceny bezpieczeństwa zapory Solina
Evaluate the usefulness of the edf model in the safety assessment on the example of the Solina dam
Autorzy:
Bąk, A.
Powiązania:
https://bibliotekanauki.pl/articles/110971.pdf
Data publikacji:
2016
Wydawca:
Centrum Rzeczoznawstwa Budowlanego Sp. z o.o.
Tematy:
zapora Solina
modelowanie
przemieszczenia
ÉDF
EDF
monitoring and control of a dam
dam safety
deformation modelling
Solina dam
Opis:
Eksploatacja zapór wiąże się z poważnym zagrożeniem dla przyległych terenów, jak i okolicznych mieszkańców. Niestety pomimo skali zagrożenia stan zapór w licznych przypadkach jest niezadowalający, dlatego tak istotne jest zapewnienie właściwej eksploatacji, a także podejmowanie działań zwiększających bezpieczeństwo. W tym celu prowadzone są regularne geodezyjne pomiary przemieszczeń i odkształceń. Prawidłowa ich interpretacja umożliwia wnioskowanie o stanie technicznym zapory, a także ustalenie bieżących parametrów eksploatacyjnych dla dopuszczalnych wartości deformacji. Przedmiotem analizy była zapora Solina, gdzie celem oceny bieżącego stanu wykorzystano model dopasowania zaproponowany przez Électricité de France. Model ÉDF uzależnia zachowania elementów zapór od zmienności poziomu zwierciadła wody górnej, cykliczności temperatur oraz wpływu czasu. Niniejszy artykuł jako kontynuacja badań poddaje ocenie przemieszczenia obserwowane na murach oporowych, korpusie oraz elektrowni. Wdrożenie modelowania przedstawionego w artykule znacznie usprawnia system kontroli, umożliwiając tym samym wczesne wykrywanie anomalii i procesów destrukcyjnych zachodzących w zaporach.
Exploitation of the dams entails serious risk to the adjacent areas, as well as local residents. Despite the scale of the threat condition of the dams is unsatisfactory. Therefore, it is important to ensure proper exploitation and to increase dam safety. To improve safety of the dams regular geodetic measurements of displacements and deformations are made. Correct interpretation of the measurement data allows inferences about technical state of the dam. The analysis was made on measurement data of Solina dam. The evaluation of the state of the dam was performed by using the model proposed by Electricité de France. The model assumes that behaviors the dams are dependent on the water level, temperatures and the influence of time. This article evaluates the displacement observed on retaining walls, main body of Solina dam and power plant. Implementation of the model presented in the article significantly improves control system, allows for the early detection of anomalies and destructive processes observed in the dams.
Źródło:
Inżynieria Bezpieczeństwa Obiektów Antropogenicznych; 2016, 2; 31-35
2450-1859
2450-8721
Pojawia się w:
Inżynieria Bezpieczeństwa Obiektów Antropogenicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problem zamulania zbiorników kaskady Soły
Sediment accumulation problem in Soła River dam cascade
Autorzy:
Jaguś, A.
Powiązania:
https://bibliotekanauki.pl/articles/399824.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
zbiornik zaporowy
kaskada Soły
osady denne
ochrona zasobów wodnych
dam water reservoir
Soła River dam cascade
bottom sediments
water resources protection
Opis:
W artykule przedstawiono problem zamulania zbiorników zaporowych. Studia dotyczyły kaskady rzeki Soły, składającej się z trzech zbiorników: Tresna, Porąbka, Czaniec. Pełni ona ważną rolę w gospodarce wodnej województwa śląskiego. Wykazano, że obszar zlewniowy jest niewłaściwie zagospodarowany, co w warunkach górskich sprzyja procesom spływu powierzchniowego i erozji. Soła, zwłaszcza podczas wezbrań, transportuje duże ilości rumowiska, które prawie w całości jest deponowane w zbiorniku Tresna. Tempo zamulania zbiornika Tresna wynosi 0,309 mln m3 rocznie, a zbiornika Porąbka 0,042 mln m3 rocznie. Zbiornik Czaniec jako silnie przepływowy nie gromadzi osadów. Działania zapobiegające zamulaniu są niewystarczające – powinny być realizowane systemowo zwłaszcza w zlewni Soły powyżej zbiornika Tresna, aby utrzymać jego możliwości retencyjne.
The paper focuses on the problem of sediment accumulation in dam reservoirs. The studies were conducted in Soła River dam cascade containing three reservoirs: Tresna, Porąbka, Czaniec. It plays an important role in the water management in Silesian province. It was revealed that the catchment area is improperly managed which, under the mountainous conditions, leads to surface runoff and erosion processes. Soła, especially during the floods, transports large quantities of debris that are almost entirely deposited in the Tresna reservoir. The rate of deposit accumulation in Tresna water body amounts to 0.309 million m,sup>3 per year, and in the Porąbka reservoir it is estimated to 0.042 million m3 per year. The Czaniec reservoir, as fast flow reservoir, does not accumulate deposits at all. The actions aiming at prevention of sediments accumulation are insufficient – they should be realized systemically particularly in the Soła catchment above Tresna reservoir in order to maintain its retention capability.
Źródło:
Inżynieria Ekologiczna; 2017, 18, 5; 92-102
2081-139X
2392-0629
Pojawia się w:
Inżynieria Ekologiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Additive Genetic Effect of Dam-sire, Dam, Common Maternal and Environmental Effect on Clutch Traits of Two Nigerian Local Chickens Populations
Autorzy:
Gwaza, D. S.
Dim, N. I.
Momoh, O. M.
Powiązania:
https://bibliotekanauki.pl/articles/1186738.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Tiv ecotypes
additive-effect
clutch-traits
dam-sire
Opis:
The study was conducted at Akpehe poultry farm, Makurdi. The objectives of the study were to assess the additive genetic effects of dam-sire, dam and maternal effects on clutch traits with the aim to apply these to selection and breeding in order to improve these traits.120 birds were used for the study, 60 each for the Fulani and the Tiv ecotypes. The birds were housed singly in identified cages and hand mated in the pen. Data were collected on clutch size, clutch number, pause length and number, month, sire, dam and ecotype. Ecotype significantly affected clutch size and clutch number. Pause length and number were not affected by ecotype. The additive genetic effect of the sire and dam significantly affected clutch size and clutch number. Heritability estimates due to sire on pulse length and pulse number were very low, while the heritability estimates for clutch number and clutch size were moderate. Non additive genetic effect of the dam ,other maternal environment as well as month significantly affected clutch number, pause length and number. Selecting superior birds based on clutch size and number due moderate heritability estimates will lead to genetic improvement in egg number especially when dam conditions and management employed are improved.
Źródło:
World Scientific News; 2016, 32; 1-12
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Msciwojow Pre-Dam Reservoir on Water Quality in the Water Reservoir Dam and Below the Reservoir
Wpływ zbiornika wstępnego Mściwojów na jakość wody w zbiorniku zaporowym i poniżej zbiornika
Autorzy:
Wiatkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/388250.pdf
Data publikacji:
2011
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
zbiornik wstępny
zbiornik wodny
skuteczność zbiornika wstępnego
jakość wody
pre-dam
water reservoir
pre-dam reservoir efficiency
water quality
water protection
Opis:
The paper presents results of research carried out in the period of November 2006 – October 2008 and focused on the influence of the Msciwojow pre-dam reservoir on the quality of water in the main reservoir and below. The following water quality indicators were determined: NO3 –, NO2–, NH4+, PO4, water temperature, pH, electrolytic conductivity, dissolved oxygen and chlorophyll a. The measurements were carried out for the Msciwojow reservoir, located on the Wierzbiak river in Lower Silesia province (south-western part of Poland). Contribution of the pre-dam reservoir to the reduction of pollutants in water of the Wierzbiak and Zimnik rivers flowing into the main reservoir was analyzed. During the performed analyzes the following reductions of the main physico-chemical indicators in the pre-dam reservoir were observed, ie nitrates(V) by 69.9 %, phosphates by 32.9 %, nitrates(III) by 63.2 % and ammonia by 62.9 %. The increase of water temperature, pH and dissolved oxygen was also recorded. In the study the quality of water flowing into the Msciwojow reservoir, outflowing water and water stored in the pre-dam and in the main reservoir was assessed. The obtained results showed that the pre-dam reservoir contributed to the improvement of the quality of water flowing into the main reservoir. Proposals for defining dimensions of pre-dam reservoirs and designing principles were presented.
W pracy przedstawiono wyniki badań, przeprowadzonych w okresie od listopada 2006 do października 2008 r., dotyczące wpływu zbiornika wstępnego na jakość wody w zbiorniku głównym Mściwojów i poniżej zbiornika. Pomiarami objęto następujące wskaźniki jakooeci wody: NO3–, NO2–, NH4+, PO4, temperaturę wody, pH, przewodność elektrolityczną (konduktywność), tlen rozpuszczony i chlorofil a. Badania przeprowadzono na zbiorniku Mściwojów zlokalizowanym na rzece Wierzbiak, w woj. dolnośląskim (Polska południowo-zachodnia). Influence of Msciwojow Pre-Dam Analizowano wpływ zbiornika wstępnego na zmniejszenie się zanieczyszczeń w wodach rzek zasilających zbiornik główny (Wierzbiak i Zimnik). Badania wykazały, że w zbiorniku wstępnym ma miejsce obniżanie się podstawowych wskaźników fizyczno-chemicznych wody: azotanów(V) o 69,9 %, fosforanów o 32,9 %, azotanów(III) o 63,2 % i amoniaku o 62,9 %. Zanotowano wzrost temperatury wody, odczynu i tlenu rozpuszczonego. W pracy przedstawiono ocenę jakości wód dopływających do zbiornika Mściwojów i z niego odpływających, wód retencjonowanych w zbiorniku wstępnym i głównym. Na podstawie otrzymanych wyników badań stwierdzono, że zbiornik wstępny przyczynia się do poprawy jakości wody dopływającej do zbiornika głównego. Podano propozycje zasad wymiarowania zbiorników wstępnych i zalecenia do ich projektowania.
Źródło:
Ecological Chemistry and Engineering. A; 2011, 18, 2; 289-300
1898-6188
2084-4530
Pojawia się w:
Ecological Chemistry and Engineering. A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis and Modeling the Streambed Evolution after the Check Dam Restoration: the Case of Krzczonówka Stream
Autorzy:
Łapuszek, Marta
Powiązania:
https://bibliotekanauki.pl/articles/124542.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
check dam
sediment movement
river restoration
Opis:
In the Upper Vistula Basin, series of check dams are located on almost each of mountain stream. These streams are strongly affected by the presence of dams that disrupt the sediment movement in the channel. Moreover, the check dams are in poor technical condition. The current study focuses on the Krzczonówka Stream, a left-bank tributary of the Raba River, where restoration works were undertaken in 2014 involving lowering of a check dam. The aim of the project was the continuity of the stream corridor for fish migration restoration. This paper aims to provide an analysis of the streambed evolution and a numerical analysis of the impact of check dam lowering and removal of sediment, previously accumulated upstream under the geomorphologic conditions in the studied stream after three years of project execution. A 1D sediment transport model was employed to estimate the areas of erosion and deposition throughout the river course. The calculations show that the thickness of the deposited sediment ranged from 0.20 up to 0.91 m at 1.5 km of the reach. The layer thickness deposited form 2.1 to 1.75 km of the reach, is rather thin; subsequently, the layer thickness increases and the highest values are reached at the area of 1.35 – 1.7 km. The local erosion is observed in 1.1 km of the reach. It is very important to note that the identified erosional and accumulation tendencies are the same at corresponding cross sections measured as calculated based on the model. This also provides a practical form of model validation. Additionally, the stream channel evolution on the base on low annual water stages in Krzczonów gauging station, located downstream the dam, indicates that the bottom has increased in this section by about 50 cm. The comparison of cross-sectional geometry in years of 2015–2016 (after flood event) shows that the stream channel moved in the transverse direction (bank erosion and deposition) and the streambed level has changed slightly. Currently, the stream channel does not seem to be in a state of hydrodynamic equilibrium. Thus, further field measurements will try to indicate when this balance is achieved.
Źródło:
Journal of Ecological Engineering; 2019, 20, 1; 188-196
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibration analysis of Kenyir Dam power station structure using a real scale 3D model
Autorzy:
Arbain, Azizi
Ahmad Mazlan, Ahmad Zhafran
Zawawi, Mohd Hafiz
Mohd Radzi, Mohd Rashid
Powiązania:
https://bibliotekanauki.pl/articles/396138.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
Kenyir Dam power
vibration analysis
dam structures
using 3D model
Frequency Response Function
Finite Element Method
moc Kenyir Dam
analiza drgań
konstrukcja zapory
model 3D
FRF
MES
Opis:
In this paper, the vibration analysis in terms of modal and harmonic responses are investigated for the power station structure of Kenyir Dam in Terengganu, Malaysia. Modal analysis is carried out to provide the dynamic characteristics of the power station which includes the natural frequencies and mode shapes. Meanwhile, the harmonic response analysis is performed by applying the force to the structure to obtain the Frequency Response Function (FRF) in certain range of frequencies. A real scale threedimensional (3D) model of the Kenyir Dam power station is constructed using Solid Works software and imported to ANSYS software for the Finite Element (FE) analysis. A proper boundary condition is taken into consideration to demonstrate the real behaviour of the power station structure. From the results, six most significant natural frequencies and mode shapes including the FRF in all three axes are selected. The highest natural frequency value occurred at 5.4 Hz with the maximum deflection of 0.90361 m in the z axis direction. This value is important in order to verify whether the structure can overcome the resonance phenomenon from the external disturbance forces in the future.
Źródło:
Civil and Environmental Engineering Reports; 2019, 29, 3; 48-59
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The variability of spatial distribution and density of fish in the Klimkówka dam reservoir
Autorzy:
Świerzowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/332221.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
Klimkówka Dam Reservoir
spatial distribution
density of fish
Opis:
The Klimkówka Dam Reservoir is situated on the Ropa River in southern Poland. The surface area of the reservoir is about 306 ha and its capacity is 43.5 hm3. Acoustic surveys were conducted both in the daytime and at night using a SIMRAD EY-500 split beam 120kHz echo sounder. Maps of the spatial distribution and density of fish were drawn up, and the fish species structure, size, number and biomass were estimated based on acoustic surveys and supervised net catches. The highest fish density at night occurred in the river tributary zones (836 fish/ha). In this area at night fish density was twice as high as in the central region of the reservoir. The density figure for the whole reservoir was 638 fish/ha and was 1.4 limes higher than that in the Solina Reservoir and from ten- to twenty-fold lower than in several other studied lakes. Fish catches performed with pelagic trawIs and net sets revealed the presence of nine fish species. Lake and river trout species which had been introduced to the reservoir were not noted. The fish biomass was estimated to be 11.5 tons, or 44.4 kg/ha, and was from three to 14 times lower in comparison to the estimated figure in several other lakes.
Źródło:
Hydroacoustics; 2003, 6; 69-78
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatiotemporal Assessment of the Water Quality of the Hammam Boughrara Dam (North-West Algeria)
Autorzy:
Djelita, Belkheir
Benadda, Lotfi
Powiązania:
https://bibliotekanauki.pl/articles/2028136.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
Hammam Boughrara Dam
pollution
eutrophication
phosphorus
modeling
Opis:
In this study, which contains a database covering the period from January 2008 to December 2010, on the water level of the Hammam Bougrara dam located in a semi-arid zone with moderate winter (western Algeria), we focused specifically on the mechanisms of eutrophication as well as the spatial and temporal variation of the physicochemical and biological characteristics of the reservoir. The diagnosis revealed high concentrations of certain elements such as $P, PO_4, NO_3, NO_2, NH_4, Na^+, Ca^{2+}, Mg^{2+}, K^+, Cl^-, HCO_3^– and SO_4^{–2}$, which characterizes highly mineralized waters with conductivities between 1100 and 1800 S/cm, therefore polluted and selenitic. These waters are rich in nutrients, such as phosphorus and with a slightly alkaline pH (between 7.1 and 9.1) favor the proliferation of organisms such as Chlorophyceae, Cyanophyceae and Diatomophycéeswhich together account 93 57% of the population of algae. This proliferation causes a decrease in transparency and dissolved oxygen which are also signs of eutrophication. This study will adopt a better methodological approach to reduce the number of stations and increase the sampling rate, for a thorough understanding of limnology operation of the dam to ensure its protection. Despite the very high phosphorus inlakes during those years, the symptoms of eutrophication in the reservoir (chlorophyll a.) They are far from achieving the expected levels of extreme loads on the flow-replies Vollenweider. This could be explained by the fact that, upon his arrival for restraint, ortho-phosphate is quickly rendered inaccessible due to algae efficient flocculation means of fine clay particles and a formation hydroxyapatite followed by precipitation. Consequently, one can conclude that it would be necessary to develop and deepen our knowledge of limnology of lakes and reservoirs in temperate climates, especially in arid and semi-arid areas, in order to embed processes in these lakes a general model describing the relationship load-response, similar to that of Vollenweider. The results could help set specific objectives to reduce phosphorus inputs depending on the intended use of the waters and allow better management of water quality in terms of trophic response and in the context of sustainable development and decision support.
Źródło:
Journal of Ecological Engineering; 2021, 22, 11; 92-103
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-dimensional vertical analysis of dam-break flow
Autorzy:
Zima, P.
Powiązania:
https://bibliotekanauki.pl/articles/1933149.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska
Tematy:
mathematical modeling
Reynolds-averaged Navier-Stokes equations
rapidly varied free surface flow
dam-break flow
Opis:
The paper concerns mathematical modeling of free surface open-channel water flow. Two-dimensional vertical Reynolds-averaged Navier-Stokes equations were used to simulate the flow. They were solved with the SIMPLE algorithm of the finite difference method using the Marker and Cell technique to trace free surface movement. The dam-break flow (water column collapse) problem on a horizontal and frictionless bottom was investigated as a test case. The mechanics of dam-break flow for wet and dry bed conditions was analyzed on the basis of numerical simulations. The obtained results are shown for varying head of water in the downstream channel. The possibility of using the shallow-water equations and the RANS model to simulate rapidly varied flows is discussed.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2007, 11, 4; 315-328
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Sedimentary Fe and Mn on the Oxygenation of Overlying Waters in Dam Reservoirs
Autorzy:
Koszelnik, P.
Bartoszek, L.
Powiązania:
https://bibliotekanauki.pl/articles/123078.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
manganese
iron
dissolved oxygen
dam reservoir
Opis:
This paper reports the work to determine the impact that concentrations of manganese (Mn) and iron (Fe) in the bottom sediments of shallow dam reservoirs exert upon the dissolved oxygen concentrations of overlying waters. Specifically, the work was conducted in the period of 2013–2014 in six shallow artificial reservoirs located in SE Poland. The waters of all the reservoirs studied are relatively well oxygenated, though both supersaturation and anoxic conditions are observed seasonally across the 50–150% range. The reported reactions of bottom sediments were between pH 7.7 and 8.2, while the mean concentrations of Mn and Fe were found to vary widely from site to site (Mn from 0.068 to 1.48 g/kg d.w. and Fe from 2.48 to 24.0 g/kg d.w.). It was not possible to demonstrate any direct relationship between sediment Fe and Mn concentrations, the Mn/Fe ratio or pH on the one hand and the oxygenation of reservoir waters on the other. However, multiple regression analysis did allow for the identification of a significant influence of both Mn content and sediment pH on the oxygen concentration in reservoir waters. In simple terms, both an increase in Mn and a decrease in pH can be said to result in more fully aerobic conditions in waters.
Źródło:
Journal of Ecological Engineering; 2018, 19, 5; 180-185
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 325

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