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Wyszukujesz frazę "water transfer" wg kryterium: Temat


Tytuł:
A data-driven approach to predict hydrometeorological variability and fluctuations in lake water levels
Autorzy:
Tan Kesgin, Remziye I.
Demir, Ibrahim
Kesgin, Erdal
Abdelkader, Mohamed
Agaccioglu, Hayrullah
Powiązania:
https://bibliotekanauki.pl/articles/28411608.pdf
Data publikacji:
2023
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
evaporation
lake water level
precipitation
stochastic time series models
water transfer
Opis:
Beyşehir Lake is the largest freshwater lake in the Mediterranean region of Turkey that is used for drinking and irrigation purposes. The aim of this paper is to examine the potential for data-driven methods to predict long-term lake levels. The surface water level variability was forecast using conventional machine learning models, including autoregressive moving average (ARMA), autoregressive integrated moving average (ARIMA), and seasonal autoregressive integrated moving average (SARIMA). Based on the monthly water levels of Beyşehir Lake from 1992 to 2016, future water levels were predicted up to 24 months in advance. Water level predictions were obtained using conventional time series stochastic models, including autoregressive moving average, autoregressive integrated moving average, and seasonal autoregressive integrated moving average. Using historical records from the same period, prediction models for precipitation and evaporation were also developed. In order to assess the model’s accuracy, statistical performance metrics were applied. The results indicated that the seasonal autoregressive integrated moving average model outperformed all other models for lake level, precipitation, and evaporation prediction. The obtained results suggested the importance of incorporating the seasonality component for climate predictions in the region. The findings of this study demonstrated that simple stochastic models are effective in predicting the temporal evolution of hydrometeorological variables and fluctuations in lake water levels.
Źródło:
Journal of Water and Land Development; 2023, 58; 158--170
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New pedotransfer function (“CRC”) for the prediction of unsaturated soil hydraulic conductivity using soil water retention data
Autorzy:
Bohne, K.
Renger, M.
Wessolek, G.
Powiązania:
https://bibliotekanauki.pl/articles/2082651.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
soil texture
hydraulic conductivity
transfer
function
soil water retention
Opis:
Several review articles have emphasized, that a comprehensive set of pedotransfer functions may be applied throughout a wide range of disciplines of Earth system sciences and are of great importance for land surface models. Most pedotransfer functions deducing soil hydraulic data from nonhydraulic soil data such as soil texture and bulk density, yield soil water retention predictions, but do not provide information concerning soil hydraulic conductivity. For this reason, a simple method was developed to estimate soil hydraulic conductivity using soil water retention information. Empirical equations are established to predict soil hydraulic conductivity from soil water retention information. These equations are relatively straightforward and do not require the fitting of nonlinear functions. Predictions of soil hydraulic conductivity using 106 soil samples indicates the reliable performance of the new method. The prediction quality of the new method was estimated from the calibration data set, which produced equivalent results to the Zacharias and Wessolek pedotransfer function, which were even better than the predictions obtained from the original Mualem-van Genuchten model, the Soto fractal model, and the pedotransfer function reported by Weynants and Vereecken. The stochastic structure of the calibration data reflects the presence of important soil structural properties, which are not represented by the soil water retention characteristics.
Źródło:
International Agrophysics; 2019, 33, 4; 503-510
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Slab Temperature, Thermal Stresses and Fractures Computed with the Implementation of Local and Average Boundary Conditions in the Secondary Cooling Zones
Autorzy:
Hadała, B.
Malinowski, Z.
Telejko, T.
Powiązania:
https://bibliotekanauki.pl/articles/355729.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous casting of slabs
water spray cooling
local heat transfer coefficient
Opis:
The numerical simulations of the temperature fields have been accomplished for slab casting made of a low carbon steel. The casting process of slab of 1500 mm in width and 225 mm in height has been modeled. Two types of boundary condition models of heat transfer have been employed in numerical simulations. The heat transfer coefficient in the first boundary condition model was calculated from the formula which takes into account the slab surface temperature and water flow rate in each secondary cooling zone. The second boundary condition model defines the heat transfer coefficient around each water spray nozzle. The temperature fields resulting from the average in zones water flow rate and from the nozzles arrangement have been compared. The thermal stresses and deformations resulted from such temperature field have given higher values of fracture criterion at slab corners.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 2027-2036
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical study of proton-transfer energy surfaces in small water clusters and cubic ice
Autorzy:
Czaplewski, C.
Powiązania:
https://bibliotekanauki.pl/articles/1954062.pdf
Data publikacji:
1998
Wydawca:
Politechnika Gdańska
Tematy:
proton-transfer energy surface
small water clusters
cubic ice
density functional theory
Opis:
The energetics of proton transfer in water clusters consisting of two to six molecules and in cubic ice was analyzed in detail using both Hartree Fock and gradient-corrected density functional theory. Since the energy of the ion-pair structure created by proton transfer is always higher than that of the neutral water structure grid calculations and constrained geometry optimization are needed. In the case of cubic ice various arrangements of the hydrogen atoms on a fixed oxygen lattice were investigated. In this system proton transfer leads to the creation of ionic point defects which are saddle points on the potential energy surface.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 1; 31-45
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charge-pumping characterization of SOI devices fabricated by means of wafer bonding over pre-patterned cavities
Autorzy:
Głuszko, G.
Łukasiak, L.
Kilchytska, V.
Chung, T. M.
Olbrechts, B.
Flandrie, D.
Raskin, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/308669.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
charge-pumping
electrical characterization
interface traps
SOI
water bonding
Si layer transfer
Opis:
The quality of the silicon-buried oxide bonded interface of SOI devices created by thin Si film transfer and bonding over pre-patterned cavities, aiming at fabrication of DG and SON MOSFETs, is studied by means of chargepumping (CP) measurements. It is demonstrated that thanks to the chemical activation step, the quality of the bonded interface is remarkably good. Good agreement between values of front-interface threshold voltage determined from CP and I-V measurements is obtained.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 3; 61-66
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transfer function for a controllable pitch propeller with added water mass
Autorzy:
Leshchev, Volodimir
Maslov, Igor
Palagin, Oleksandr
Naydyonov, Andrii
Powiązania:
https://bibliotekanauki.pl/articles/34604683.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propulsion system
torsional vibrations
shaft line
added water mass
transfer function
propeller screw
Opis:
The relevance of this study lies in the fact that it presents a mathematical model of the dynamics of the propulsion system of a ship that takes into consideration the mass of water added to it. The influence of this phenomenon on the resonant frequencies of the propeller shaft is examined, and a transfer function for a controllable-pitch propeller is obtained for various operating modes. The purpose of the study is to improve the calculation of the dynamic operating modes of a controllable-pitch propeller by examining the features of a visual models. The VisSim software package is used in the study. A visual model is developed that considers the influence of the rotational speed on the value of the rotational inertia attached to the variable-pitch screw of the mass of water, and a special transfer function is proposed. The study shows that a transfer function of this type has a loop enabling negative feedback. An analysis of the operation of the propeller shaft at its resonant frequency is conducted based on the application of frequency characteristics using the transfer functions obtained. We show that in the low-frequency region, a consideration of the added rotational inertia using the proposed transfer function leads to a significant difference compared to the result obtained with the existing calculation method.
Źródło:
Polish Maritime Research; 2023, 4; 74-80
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An experimental and numerical study of supercavitating flows around axisymmetric cavitators
Autorzy:
Javadpour, S. M.
Farahat, S.
Ajam, H.
Salari, M.
Nezhad, A. H.
Powiązania:
https://bibliotekanauki.pl/articles/949307.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
natural cavitation
mass transfer
water tunnel
finite element method
drag coefficient
axisymmetric cavitators
Opis:
It has been shown that developing a supercavitating flow around under-water projectiles has a significant effect on their drag reduction. As such, it has been a subject of growing attention in the recent decades. In this paper, a numerical and experimental study of supercavitating flows around axisymmetric cavitators is presented. The experiments are conducted in a semi-open loop water tunnel. According to the Reynolds-Averaged Navier-Stokes equations and mass transfer model, a three-component cavitation model is proposed to simulate the cavitating flow. The corresponding governing equations are solved using the finite element method and the mixture Rayleigh-Plesset model. The main objective of this research is to study the effects of some important parameters of these flows such as the cavitation number, Reynolds number and conic angle of the cavitators on the drag coefficient as well as the dimensions of cavities developed around the submerged bodies. A comparison of the numerical and experimental results shows that the numerical method is able to predict accurately the shape parameters of the natural cavitation phenomena such as cavity length, cavity diameter and cavity shape. The results also indicate that the cavitation number declines from 0.32 to 0.25 leading to a 28 percent decrease in the drag coefficient for a 30° cone cavitator. By increasing the Reynolds number, the cavity length is extended up to 322% for a 60° cone cavitator.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 3; 795-810
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancement of the pool boiling heat transfer coefficient using the gas injection into the water
Autorzy:
Sarafraz, M.M.
Peyghambarzadeh, S.M.
Alavi Fazel, S.A.
Powiązania:
https://bibliotekanauki.pl/articles/778947.pdf
Data publikacji:
2012
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
heat transfer
pool boiling
Gas-liquid solution
Nucleation site density
SO2
water
Opis:
In this paper, a new method for enhancing the pool boiling heat transfer coefficient of pure liquid, based on the gas injection through the liquids has been introduced. Hence, the effect of gas dissolved in a stagnant liquid on pool boiling heat transfer coefficient, nucleation site density, and bubble departure diameter has experimentally been investigated for different mole fractions of SO2 and various heat fluxes up to 114 kW/ m2. The presence of SO2 in captured vapor inside the bubbles, particularly around the heat transfer surface increases the pool boiling heat transfer coefficient. The available predicted correlations are unable to obtain the reasonable values for pool boiling heat transfer coefficient in this particular case. Therefore, to predict the pool boiling heat transfer coefficient accurately, a new modified correlation based on Stephan-Körner relation has been proposed. Also, during the experiments, it is found that nucleation site density is a strictly exponential function of heat flux. Accordingly, a new correlation has been obtained to predict the nucleation site density. The major application of the nucleation site density is in the estimating of mean bubble diameters as well as local agitation due to the rate of bubble frequency.
Źródło:
Polish Journal of Chemical Technology; 2012, 14, 4; 100-109
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of the average and local boundary condition of heat transfer during cooling with a water spray under surface boiling
Autorzy:
Jasiewicz, Elżbieta
Hadała, Beata
Malinowski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/29520235.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
water spray cooling
heat transfer coefficient
heat flux
inverse problem
heat conduction equation
Opis:
The study determined the local and average heat transfer coefficient and the heat flux on the surface of a cylinder cooled with a water nozzle. The inverse method was used to identify the heat transfer coefficient. An objective function was defined to determine the distance between the measured and calculated temperatures. Two models describing the heat transfer coefficient on the cooled surface were considered. The first model described changes in the heat transfer coefficient as a function of the sample radius and cooling time, and the second one assumed the dependence of the heat transfer coefficient solely on time. Numerical simulations showed significant differences in the determined heat transfer coefficients depending on the adopted model of the boundary condition. The performed tests included experimental temperature measurements at selected points of the sensor, numerical simulations of temperature changes, and the inverse solution.
Źródło:
Computer Methods in Materials Science; 2020, 20, 4; 147-155
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emulsified fuels of machine origin in seawater - a contribute to remote detection
Autorzy:
Rudz, K.
Powiązania:
https://bibliotekanauki.pl/articles/246040.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
oil pollution
remote sensing reflectance
Monte Carlo simulation
radiative transfer
oil-in-water emulsion
Opis:
Development of industry and trade in the last few decades caused a huge increase in the pollution of the world's oceans. Substantial contributors to marine pollution come with the rivers from land-based sources including the by products of industry, run-off from agriculture activities such as biocides as well as effluents from urban areas. Moreover, a significant amount of marine pollution is caused by shipping and maritime activities. The operation of ship plants gives a real possibility for engine oils and fuels to reach the marine environment. Discharge waters contain a certain amount of petroleum derivatives in the form of dispersed droplets (oil-in-water emulsion). The presence of oil emulsion cause measurable changes in the optical properties of seawater. It is conceptually possible to detect these changes using a standard radiance or irradiance reflectance meter. Hence, a set of radiative transfer simulation has been carried out. This paper presents a computed photon trace simulation based on the Monte Carlo code, applied to the marine environment. The results are presented as reflectance spectra for the models of Baltic Sea and ocean water both pure and polluted by oil emulsion. It is shown that even small amounts of petroleum pollution raise the values of irradiance reflectance and cause a spectral shift by certain conditions. A possibility for remote evaluation of oil pollution is discussed as well as the perspective for improving the interpretation of shipboard and offshore light field analyses.
Źródło:
Journal of KONES; 2011, 18, 3; 375-381
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emulsified fuels of machine origin in seawater - a contribute to remote detection
Autorzy:
Rudz, K.
Powiązania:
https://bibliotekanauki.pl/articles/242232.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
oil pollution
remote sensing reflectance
Monte Carlo simulation
radiative transfer
oil-in-water emulsion
Opis:
Development of industry and trade in the last few decades caused a huge increase in the pollution of the world's oceans. Substantial contributors to marine pollution come with the rivers from land-based sources including the by-products of industry, run-off from agriculture activities such as biocides as well as effluents from urban areas. Moreover, a significant amount of marine pollution is caused by shipping and maritime activities. The operation of ship plants gives a real possibility for engine oils and fuels to reach the marine environment. Discharge waters contain a certain amount of petroleum derivatives in the form of dispersed droplets (oil-in-water emulsion). The presence of oil emulsion cause measurable changes in the optical properties of seawater. It is conceptually possible to detect these changes using a standard radiance or irradiance reflectance meter. Hence, a set of radiative transfer simulation has been carried out. This paper presents a computed photon trace simulation based on the Monte Carlo code, applied to the marine environment. The results are presented as reflectance spectra for the models of Baltic Sea and ocean water both pure and polluted by oil emulsion. It is shown that even small amounts of petroleum pollution rise the values of irradiance reflectance and cause a spectral shift by certain conditions. A possibility for remote evaluation of oil pollution is discussed as well as the perspective for improving the interpretation of shipboard and offshore light field analyses.
Źródło:
Journal of KONES; 2011, 18, 2; 385-390
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of seawater polluted by light and heavy crude oil droplets
Autorzy:
Rudź, K.
Darecki, M.
Toczek, H.
Powiązania:
https://bibliotekanauki.pl/articles/246668.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
oil pollution
remote sensing reflectance
Monte Carlo simulation
radiative transfer
oil-in-water emulsion
Opis:
Significant amounts of crude oil transported from offshore fields to the refineries using tankers or pipelines, demand increased control of seawater pollution. Tanker accidents resulting in oil spills drive much attention, as they influence local marine life and coastal industry. However, the most significant annual amount of crude oil enters the sea in the form of oilin- water emulsion as a result of standard tanker operations, offshore oil extraction and daily work of refineries. Many branches of science are challenged to provide new methods for oil detection, less expensive, more sensitive and more accurate. Remote satellite or airborne detection of large oil spills is possible using joint techniques as microwave radars, ultraviolet laser fluorosensors and infrared radars. Some methods are capable to deal with oil streaks detection and estimation of oil thickness. Although there is currently, no method to detect small concentration of oil droplets dispersed in seawater. Oil droplets become additional absorbents and attenuators in water body. They significantly change seawater inherent optical properties, which imply the change of apparent optical properties, detectable using remote sensing techniques. To enable remote optical detection of oil-in-water emulsion, a study of optical properties of two types of crude oil was conducted. Radiative transfer theory was applied to quantify the contribution of oil emulsion to remote sensing reflectance (Rrs). Spectra of Rrs from in situ measurements in Baltic Sea were compared to Rrs spectra of seawater polluted by 1 ppm of crude oil emulsion, collected using radiative transfer simulation. The light crude oil caused a 9-10% increase of Rrs while the heavy one reduced Rrs up to 30% (model accuracy stayed within 5% for considered spectral range). Results are discussed concerning their application to shipboard and offshore oil content detection.
Źródło:
Journal of KONES; 2012, 19, 2; 473-480
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of a solid product with high water content and water retention properties
Autorzy:
Cvijić, Marko
Golob, Janvit
Powiązania:
https://bibliotekanauki.pl/articles/778509.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
water in organic phase emulsion
phase equilibrium
mass transfer
Luikov’s parameters
theory of drying
Opis:
This work presents the development of a solid product with a high water content (99.08%) and water retention properties. Water was chosen as a potential carrier of a volatile active substance and water retaining properties of material were studied at a temperatures and relative air humidity values with the support of the theory of drying. The study first confirmed the role of Gibbs’ phase rule in the research of solid-gas phase equilibrium, and second presented drying kinetics developed from Fick’s second law and expressed with the first term of the Fourier equation. Solutions of equations for phase equilibrium and mass transfer enabled the calculation of Luikov’s parameters, which are important for equilibrium relations and for the diffusivity of water in a solid for mass transfer prediction. The obtained thermodynamic and kinetic parameters enabled product characterisation that may be important for the prediction of retention times.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 3; 17-23
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the influence of wind-driven rain on moisture in cellular concrete wall boards
Autorzy:
Alsabry, A.
Nikitsin, V. I.
Kofanov, V. A.
Backiel-Brzozowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/264373.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
cellular concrete
wind-driven rain
capillary transfer
water sorption coefficient
moisture content
beton komórkowy
sorpcja wody
wilgotność
Opis:
The non-stationary moisture level of a cellular concrete wall board in a heated utility building located in the northern part of the town of Brest (Belarus), depending on the climatic influence, was assessed in this work. The results were obtained both in a calculation experiment and a physical test. It was observed that the main reason for the high moisture levels in cellular concrete is wind-driven rain intensifying the process of free capillary moisture transfer. A comparative analysis of the results of the physical test and the calculation experiment showed that the THSS software elaborated by the authors was able to predict the actual moisture levels of the shielding structure under study accurately enough when precise data concerning the thermal and physical characteristics of the materials as well as the occurring climatic influences were submitted.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 3; 509-519
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of water-water type heat pump operation in a building object
Analiza pracy pompy ciepła typu woda-woda w obiekcie budowlanym
Autorzy:
Knaga, J.
Szul, T.
Powiązania:
https://bibliotekanauki.pl/articles/793704.pdf
Data publikacji:
2011
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
heating system
heat pump
central heating
hot domestic water
scroll type compressor
heat transfer coefficient
building
statistical analysis
Opis:
The paper presents operation examination results of a heating system equipped with a heat pump, manufactured by the Sekut company, equipped with a scroll type compressor. The performed statistical analysis has shown a significant influence of external temperature and heat transfer coefficient to the COP value. Within the analysed period, the COP maintained a level of 2.6 at an average monthly temperature of -6°C, with a transfer coefficient of 15%.
W opracowaniu przedstawiono wyniki badań eksploatacyjnych systemy grzewczego wyposażonego w pompę ciepła wyprodukowaną przez firmę Sekut ze sprężarką typu scrol. Przeprowadzona analiza statystyczna wykazała istotny wpływ temperatury zewnętrznej, oraz wskaźnika przekazania ciepła na wartość COP. W analizowanym okresie COP kształtowało się na poziomie 2.6 przy średniej miesięcznej temperaturze –6OC i wskaźniku przekazania 15%.
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2011, 11C
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł

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