Search results for " reservoir"
showing 10 items of 166 documents
Changes in the flow and quality of water in the dam reservoir of the Mała Panew catchment (South Poland) characterized by multidimensional data analys…
2023
Multidimensional exploratory techniques, such as the Principal Component Analysis (PCA), have been used to analyze long-term changes in the fl ow regime and quality of water of the lowland dam reservoir Turawa (south-west Poland) in the catchment of the Mała Panew river (a tributary of the Odra). The paper proves that during the period of 1998–2016 the Turawa reservoir was equalizing the river’s water fl ow. Moreover, various physicochemical water quality indicators were analyzed at three measurement points (at the tributary’s mouth into the reservoir, in the reservoir itself and at the outfl ow from the reservoir). The water quality assessment was performed by analyzing physicochemical ind…
Combining a data-driven approach with seasonal forecast data to predict reservoir water volume in the Mediterranean area
2023
Prolonged droughts and water scarcity have become more frequent in recent years, exacerbating the problem of the artificial reservoirs management in the Mediterranean area. This study proposes a methodology which combines a Nonlinear AutoRegressive network with eXogenous input (NARX) data-driven model with Seasonal Forecasts (SFs) data, with the aim to predict the water volume stored in reservoirs at a mid-term scale, as requested by the local authority. The methodology is applied to four Sicilian reservoirs that experienced water scarcity in the recent past. SFs produced at the European Centre for Medium-Range Weather Forecasting are used to force the NARX models. Also, the reservoirs are …
Bedrock Characterisation of Four Candidate Repository Sites in Finland As Determined by He-Gas Methods
1999
AbstractAt the end of the year 2000, one of four sites will be chosen as the final repository site in Finland. Therefore accurate and comprehensive statistics of the bedrock characteristics such as porosity [% ] and effective diffusion coefficient [m2/s ] of these sites are of importance. Altogether 115 rock samples from the four sites were measured by different He-gas methods to achieve this goal.The results obtained indicate that the average bedrock properties at these sites are quite similar. Variations among individual samples and different rock types within one repository site were larger than variations among the averaged values of the four sites. Some indication of increased microfra…
Considerations on sand control in natural gas wells
2017
Mechanism of sand production in gas wells is complex and influenced by every operation performed into the well, starting from the opening of the production interval by drilling, and continuing with completion and putting into production as well as with the exploitation regime. Sand production along with fluids from gas reservoirs creates a series of potentially dangerous and costly problems. For selecting the most appropriate methods of sand-control all the data and information related to properties of reservoir rock, the history of sand production, the potential well flow rates as well as HSE and costs need to be evaluated. The conclusion of the authors is that the best results in sand con…
Theory of quantum-circuit refrigeration by photon-assisted electron tunneling
2017
We focus on a recently experimentally realized scenario of normal-metal-insulator-superconductor tunnel junctions coupled to a superconducting resonator. We develop a first-principles theory to describe the effect of photon-assisted electron tunneling on the quantum state of the resonator. Our results are in very good quantitative agreement with the previous experiments on refrigeration and heating of the resonator using the photon-assisted tunneling, thus providing a stringent verification of the developed theory. Importantly, our results provide simple analytical estimates of the voltage-tunable coupling strength and temperature of the thermal reservoir formed by the photon-assisted tunne…
Waveguide-QED-based measurement of a reservoir spectral density
2015
The spectral density (SD) function has a central role in the study of open quantum systems (OQSs). We discover a method allowing for a "static" measurement of the SD - i.e., it requires neither the OQS to be initially excited nor its time evolution tracked in time - which is not limited to the weak-coupling regime. This is achieved through one-dimensional photon scattering for a zero-temperature reservoir coupled to the OQS via the rotating wave approximation. We find that the SD profile is a universal simple function of the photon's reflectance and transmittance. As such, it can be straightforwardly inferred from photon's reflection and transmission spectra.
Dynamics of a Quantum Particle in Asymmetric Bistable Potential with Environmental Noise
2011
In this work we analyze the dynamics of a quantum particle subject to an asymmetric bistable potential and interacting with a thermal reservoir. We obtain the time evolution of the population distributions in both energy and position eigenstates of the particle, for different values of the coupling strength with the thermal bath. The calculation is carried out using the Feynman-Vernon functional under the discrete variable representation.
The bistable potential: An archetype for classical and quantum systems
2012
In this work we analyze the transient dynamics of three different classical and quantum systems. First, we consider a classical Brownian particle moving in an asymmetric bistable potential, subject to a multiplicative and additive noise source. We investigate the role of these two noise sources on the life time of the metastable state. A nonmonotonic behavior of the lifetime as a function of both additive and multiplicative noise intensities is found, revealing the phenomenon of noise enhanced stability. Afterward, by using a LotkaVolterra model, the dynamics of two competing species in the presence of Lévy noise sources is analyzed. Quasiperiodic oscillations and stochastic resonance pheno…
Using Macroelement Content to Characterize Surficial Water Quality of Artificial Reservoirs
2021
Abstract The quality of surface waters in the territory of Poland, despite the implemented remedial measures, is mostly classified as bad. This article presents the results of research on the composition of water macroelements in 24 artificial reservoirs located in Opole province (southern Poland), searching for the reasons behind their pollution. Concentrations of the anions F−, Cl−, Br−, NO2−, NO3−, PO43− and SO42− and cations Na+, NH4+, K+, Mg2+ and Ca2+ were taken into account. An analysis of seasonal changes was carried out and, on the example of a dam reservoir (Turawa Big Reservoir), a multi-point analysis of the distribution of ion concentrations in water at the reservoir surface w…
DISTRIBUTION OF PONTO-CASPIAN AMPHIPODPONTOGAMMARUS ROBUSTOIDESIN LATVIAN WATERS
2007
Data of the monitoring of inland waters, conducted during 1999–2005, show that the alien Ponto-Caspian amphipod Pontogammarus robustoides is quite widespread in Latvia. The species was detected at 15 monitoring sites. This non-indigenous amphipod occurs in the lower reaches and mouths of rivers emptying into the Baltic Sea, water reservoirs located on the Daugava River, and nearshore lakes which are connected to the brackish waters of the sea. The spread of P. robustoides in the lower reaches of the Daugava River and its water reservoirs must have originated from the intentional introduction of this amphipod into the Keguma Water Reservoir in the 1960s. Meanwhile, the invasion of this amphi…