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Tytuł:
Some considerations on horizontal displacement and horizontal displacement coefficient B
Autorzy:
Tajduś, K.
Tajduś, A.
Powiązania:
https://bibliotekanauki.pl/articles/178663.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
horizontal displacement coefficient
horizontal displacement
mining exploitation
Opis:
Mining-induced deformations of the ground surface and within the rock mass may pose danger not only for surface constructions but also for underground objects (e.g., tunnels, underground storages, garages), diverse types of pipelines, electric cables, etc. For a proper evaluation of hazard for surface and underground objects, such parameters as horizontal displacement and horizontal deformations, especially their maximum values, are of crucial importance. The paper is an attempt at a critical review of hitherto accomplished studies and state of the art of predicting horizontal displacement u, in particular the coefficient B, whose value allows determination of the value of maximum displacement if the value of maximum slope is known, or the value of maximum deformation if the value of maximum trough slope is recognized. Since the geodesic observations of fully developed subsidence troughs suggest that the value of the coefficient depends on the depth H, radius of main influences range r and properties of overburden rock, in particular the occurrence of sub-eras Paleogene and Neogene layers (old name: Quaternary and Tertiary) with low strength parameters, therefore a formula is provided in the present paper allowing for the estimation of the influence of those factors on the value of coefficient B.
Źródło:
Studia Geotechnica et Mechanica; 2015, 37, 4; 75-82
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of horizontal displacements measured over the mining operations in longwall No. 537 at the Girondelle 5 seam of the BW Friedrich Heinrich-Rheinland coal mine
Analiza przemieszczeń poziomych pomierzonych nad eksploatacją ściany 537 pokładu Girondelle 5 kopalni BW Friedrich Heinrich-Rheinland
Autorzy:
Tajduś, K.
Powiązania:
https://bibliotekanauki.pl/articles/219888.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
przemieszczenia poziome
deformacja powierzchni
wpływ eksploatacji na powierzchnię
współczynnik przemieszczeń B
horizontal displacements
surface deformations
mining exploitation
horizontal displacement coefficient
Opis:
The article presents an analysis of the horizontal land surface displacements taking place as an effect of coal exploitation on the Girondelle 5 seam in the Friedrich Heinrich-Rheinland mine in Germany. The paper presents changes in displacement vectors measured on the surface following the progress of the exploitation face and an analysis of horizontal displacement measurements assuming that their magnitude is proportional to the profile of subsidence trough slope. Then, the values of horizontal displacement coefficient B are assessed for selected longitudinal and transversal calculation cross-sections of longwall No. 537.
AArtykuł przedstawia analizę przebiegu przemieszczeń poziomych powierzchni terenu powstałych w wyniku eksploatacji górniczej kopalni Niemieckiej Friedrich Heinrich-Rheinland w pokładzie Girondelle 5. Autor przedstawił zarówno zmiany wektorów przemieszczeń powierzchni terenu wraz z postępem frontu eksploatacji, jak również analizę pomiarów przemieszczeń poziomych zakładając, że ich wielkość jest proporcjonalna do nachylenia profilu niecki osiadania. Następnie dla określonych przekrojów obliczeniowych wzdłuż oraz w poprzek analizowanej ściany 537 oszacowano wartości współczynnika przemieszczeń poziomych B.
Źródło:
Archives of Mining Sciences; 2016, 61, 1; 157-168
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Definition of dimensionless coefficient of resistance and coefficient of roughness in cross-section of stream with large roughness element
Autorzy:
Michalec, B.
Strutynski, M.
Powiązania:
https://bibliotekanauki.pl/articles/59718.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:
Rudawa River
Bedkowka Stream
stream
large roughness grain
dimensionless coefficient
roughness coefficient
hydraulic condition
water flow
flow channel bottom
flow channel distribution
Opis:
The results of investigations carried out in the stream Będkówka – a left bank tributary of the Rudawa River are presented in this paper. A stream sector with large roughness element was chosen for investigations. The performed measurements included cross-section leveling and longitudinal leveling of the stream channel, bed load (sediment) sampling, and hydrometric measurements. Cross section leveling included five cross-sections in the 19-m long stream sector; these were located upstream and downstream the large roughness element and in its region. Differentiation of flow velocity in the region of large roughness element and its influence on differentiation of the load granulometric composition in the stream channel was shown. Immediately downstream the large roughness grain zone a fine grain sediment was frapped, its diameter d50 was seven to ten times smaller than that of the sediment in bed present in the stream channel. The dimensionless coefficient of resistance was calculated taking into account the equivalent bottom roughness determined in each of the examined sections by use of Gladki`s formulae. It was found that the large roughness element in the Będkówka stream caused a change of hydraulic conditions of water flow and, in consequence, the dimensionless coefficient of resistance in the grain section increased by about four times. The coefficient of channel roughness was also determined and it was shown that the coefficient of roughness in the section of large roughness element determined with consideration of the determined dimensionless coefficient of resistance increased on the average in the section of large roughness grain by over 34% in relation to the coefficient of channel roughness.
Źródło:
Infrastruktura i Ekologia Terenów Wiejskich; 2010, 11
1732-5587
Pojawia się w:
Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coefficient of thermal expansion as a component quality estimation of alloys on pistons of combustion engines
Autorzy:
Sieminska, B.
Powiązania:
https://bibliotekanauki.pl/articles/245892.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
engine pistons
thermal expansion
coefficient of thermal expansion
Opis:
The aim of realized works in the area of materials on pistons is: low thermal expansion, small differences of coefficient of thermal expansion between heating and cooling, high stiffness at elevated temperatures, high hardness and wear resistance. Changes in thermal expansion coefficient during heating and cooling may be very large, as well as during subsequent cycles of heating and cooling of an internal combustion engine pis ton with respect to standard silumin alloys usedfor pistons of internal combustion engines. The paper presents: coefficient of linear expansion a for the AlSi standard alloy, coefficient of linear expansion a for the AlSi alloy with the apositive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the a negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive and negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive, negative and positive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the very small a differences between cooling and heating, coefficient relative elongation as afunction of temperature with the positive elongation differences between cooling and heating, coefficient relative elongation with the very small elongation differences between cooling and heating, coefficient the course of derivative as a function of temperature (T) during heating and cooling with the positive elongation differences.
Źródło:
Journal of KONES; 2009, 16, 4; 575-583
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of flow boiling heat transfer coefficient for carbon dioxide in minichannels and conventional channels
Autorzy:
Mikielewicz, D.
Jakubowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/240733.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat transfer coefficient
flow boiling
carbon dioxide
minichannels
współczynnik przewodnictwa cieplnego
wrzenie w przepływie
dwutlenek węgla
minikanał
Opis:
In the paper presented are the results of calculations using authors own model to predict heat transfer coefficient during flow boiling of carbon dioxide. The experimental data from various researches were collected. Calculations were conducted for a full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house model. The results show the importance of taking into account the surface tension as the parameter exhibiting its importance in case of the flow in minichannels as well as the influence of reduced pressure. The calculations were accomplished to test the sensitivity of the heat transfer model with respect to selection of the appropriate two-phase flow multiplier, which is one of the elements of the heat transfer model. For that purpose correlations due to Müller-Steinhagen and Heck as well as the one due to Friedel were considered. Obtained results show a good consistency with experimental results, however the selection of two-phase flow multiplier does not significantly influence the consistency of calculations.
Źródło:
Archives of Thermodynamics; 2016, 37, 2; 89-106
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on some physico-chemical parameters of cyanophycean members and correlation coefficient of eutrophic ponds in Chidambaram, Tamil Nadu, India
Autorzy:
Elayaraj, B.
Selvaraju, M.
Powiązania:
https://bibliotekanauki.pl/articles/10938.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
physicochemical parameter
phytoplankton
correlation coefficient
eutrophic pond
pond
Chidambaram town
Tamil Nadu
India
Opis:
The present study deals with the statistical analysis of physico-chemical parameters and cyanophycean members of two pond water quality of Chidambaram, Cuddalore district (Tamil Nadu). The qualities of pond water were analyzed for six months. Eleven important parameters were included in statistical analysis. The qualities of pond water have been assessed by calculating mean, standard deviation and correlation coefficient. Correlation studies of hydrobiology with physico-chemical parameters revealed that the relationship between phytoplankton density in general and that of the specific groups are highly complex and often controlled by interactions of different factors. In the both pond water the correlation coefficient test revealed that cyanophycean members positively correlated with temperature, pH, CO2, alkalinity, hardness, nitrate, BOD and COD at 1 % and 5 % level significant, where as it is negatively correlated with acidity and dissolved oxygen. In the present study it can be concluded that the cyanophycean members are highly tolerant organisms. They prefer to grow at higher temperatures and in highly alkaline, BOD and COD waters. Hence they can with stand high levels of contaminated waters of Thillai Kali Kovil pond, when compared to Ilamiyakkinar Kovil pond.
Źródło:
International Letters of Natural Sciences; 2014, 11, 2
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of Beck’s method combined with FEM and Trefftz functions to determine the heat transfer coefficient in a minichannel
Autorzy:
Maciejewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/281153.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Beck’s method
FEM
Trefftz functions
heat transfer coefficient
inverse heat conduction problem
flow boiling
Opis:
The aim of this study is to determine the heat transfer coefficient between the heated surface and the boiling fluid flowing in a minichannel on the basis of experimental data. The calculation model is based on Beck’s method coupled with the FEM and Trefftz functions. The Trefftz functions used in the Hermite interpolation are employed to construct the shape functions in the FEM. The unknown local values of the heat transfer coefficient at the foil- -fluid contact surface are calculated from Newton’s law. The temperature of the heated foil and the heat flux on the foil surface are determined by solving a two-dimensional inverse heat conduction problem. The study is focused on the identification of the heat transfer coefficients in the subcooled boiling region and the saturated nucleate boiling region. The results are compared with the data obtained through the one-dimensional method. The investigations also reveal how the smoothing of measurement data affects calculation results.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 1; 103-116
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of heat transfer coefficient of synthetic and natural ester in the aspect of their application in power transformer
Autorzy:
Gościński, P.
Dombek, G.
Nadolny, Z.
Bródka, B.
Powiązania:
https://bibliotekanauki.pl/articles/97728.pdf
Data publikacji:
2015
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
heat transfer coefficient
high voltage power transformers
synthetic ester
natural ester
Opis:
Insulating liquids due to their properties are used in electrical power transformers, capacitors, connectors and high voltage power cables. One of the most important tasks for electrical insulating liquids is a heat transport out of the device. The heat transfer in the liquids depends on heat transfer coefficient. The heat transfer coefficient depends on a viscosity, thermal conductivity coefficient and thermal expansion coefficient. This paper shows results of calculations for heat transfer coefficient of insulating liquids used as insulation in electrical equipment, depending on the kind of liquid and temperature. Synthetic ester oil and natural ester oil were analyzed. The range of the temperature was changing from 25°C to 80°C.
Źródło:
Computer Applications in Electrical Engineering; 2015, 13; 376-385
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability Assessment and Composition of Tree Species in Nigerian University
Autorzy:
Chukwu, Onyekachi
Chenge, Iveren B.
Powiązania:
https://bibliotekanauki.pl/articles/1178080.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Tree stability
slenderness coefficient
species composition
windthrow
Opis:
Wind remains a strong abiotic agent associated with damages of forest trees. The vulnerability of a tree to windthrow is highly influenced by the ratio of tree total height to its stem diameter (RHD). However, RHD has been identified as an index and measure of tree and stand stability. This study assessed the stability and composition of open grown tree species in the University of Ibadan, Nigeria. Diameter at breast height (Dbh) and total height (THt) of one hundred and thirty-nine (139) trees species with Dbh ≥5.0 cm found within three departments of the University were measured. A total of 36 species from 17 families were identified with Myrtaceae and Combretaceae families having highest (28.8% and 21.6%, respectively) numbers of tree. RHD was found to have negative correlation with all the tree growth variables investigated except THt. However, this study reveals that about 79 % of the trees found in the study area had RHD <80, indicating stable and low risk or susceptibility to windthrow, wind-induced bending and breakage. Hence, trees with RHD >80 (21%) were recommended for felling as they pose threat to human life and properties in the study area.
Źródło:
World Scientific News; 2018, 95; 235-245
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic Genre Classification Using Fractional Fourier Transform Based Mel Frequency Cepstral Coefficient and Timbral Features
Autorzy:
Bhalke, D. G.
Rajesh, B.
Bormane, D. S.
Powiązania:
https://bibliotekanauki.pl/articles/177599.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
feature extraction
Timbral features
MFCC
Mel Frequency Cepstral Coefficient
FrFT
fractional Fourier transform
Fractional MFCC
Tamil Carnatic music
Opis:
This paper presents the Automatic Genre Classification of Indian Tamil Music and Western Music using Timbral and Fractional Fourier Transform (FrFT) based Mel Frequency Cepstral Coefficient (MFCC) features. The classifier model for the proposed system has been built using K-NN (K-Nearest Neighbours) and Support Vector Machine (SVM). In this work, the performance of various features extracted from music excerpts has been analysed, to identify the appropriate feature descriptors for the two major genres of Indian Tamil music, namely Classical music (Carnatic based devotional hymn compositions) & Folk music and for western genres of Rock and Classical music from the GTZAN dataset. The results for Tamil music have shown that the feature combination of Spectral Roll off, Spectral Flux, Spectral Skewness and Spectral Kurtosis, combined with Fractional MFCC features, outperforms all other feature combinations, to yield a higher classification accuracy of 96.05%, as compared to the accuracy of 84.21% with conventional MFCC. It has also been observed that the FrFT based MFCC effieciently classifies the two western genres of Rock and Classical music from the GTZAN dataset with a higher classification accuracy of 96.25% as compared to the classification accuracy of 80% with MFCC.
Źródło:
Archives of Acoustics; 2017, 42, 2; 213-222
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chezy’s resistance coefficient in an egg-shaped conduit
Współczynnik oporu Chezy’ego w rurach o kształcie jajowatym
Autorzy:
Loukam, I.
Achour, B.
Djemili, L.
Powiązania:
https://bibliotekanauki.pl/articles/292764.pdf
Data publikacji:
2018
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
Chezy’s resistance coefficient
egg-shaped conduit
maximum resistance coefficient
rough model method
simplified method
uniform flow
maksymalny współczynnik oporu
metoda rough model
metoda uproszczona
przepływ jednorodny
rura o jajowatym przekroju
współczynnik oporu Chezy’ego
Opis:
When calculating uniform flows in open conduits and channels, Chezy’s resistance coefficient is not a problem data and its value is arbitrarily chosen. Such major disadvantage is met in all the geometric profiles of conduits and channels. Knowing the value of this coefficient is essential to both the design of the channel and normal depth calculation. The main objective of our research work is to focus upon the identification of the resistance coefficient relationship. On the basis of the rough model method (RMM) for the calculation of conduits and channels, a general explicit relation of the resistance coefficient in turbulent flow is established with different geometric profiles, particularly the egg-shaped conduit. Chezy’s resistance coefficient depends strongly on the filling rate, the discharge, the longitudinal slope, the absolute roughness of the internal walls of the conduit and the kinematic viscosity of the liquid. Moreover, in this work, a simplified method is presented to determine Chezy’s resistance coefficient with a limited number of data, namely the discharge, the slope of the conduit, the absolute roughness and the kinematic viscosity. Last but not least, after studying the variation of Chezy’s resistance coefficient as a function of the filling rate, an equally explicit expression is given for the easy calculation of this coefficient when its maximum value is reached. Examples of calculation are suggested in order to show how the Chezy’s coefficient can be calculated in the egg-shaped conduit.
Kiedy oblicza się jednorodne przepływy w otwartych rowach i kanałach, współczynnik oporu Chezy’ego nie stanowi problemu, a jego wartość dobiera się arbitralnie. Tę niedogodność spotyka się w przypadku wszystkich profili geometrycznych rur i kanałów. Znajomość współczynnika jest istotna zarówno podczas projektowania kanału, jak i obliczania głębokości. Główny cel pracy skupia się na identyfikacji zależności między współczynnikiem oporu a kształtem rur. Wykorzystując metodę rough model (RMM) ustalono ogólną zależność między współczynnikiem oporu w warunkach turbulencyjnego przepływu a różnymi profilami geometrycznymi, w szczególności jajowatym przekrojem rur. Współczynnik oporu Chezy’ego silnie zależy od tempa napełniania, odpływu, nachylenia wzdłużnego, bezwzględnej szorstkości ścian i lepkości kinematycznej płynu. Ponadto przedstawiono w pracy uproszczoną metodę obliczania współczynnika oporu w warunkach ograniczonej liczby danych, na przykład odpływu, nachylenia rury, bezwzględnej szorstkości czy lepkości kinematycznej. Na końcu, po zbadaniu zmienności współczynnika oporu Chezy’ego w funkcji tempa napełniania, podano wyrażenie służące do łatwego obliczenia tego współczynnika, kiedy osiąga on maksymalną wartość. Sugeruje się przykłady obliczeń, aby pokazać, jak można obliczyć współczynnik Chezy’ego w przekrojach jajowatych.
Źródło:
Journal of Water and Land Development; 2018, 37; 87-96
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance evaluation of non-water absorption coefficient partitioning algorithms in optically complex coastal waters of Kochi and Goa, India
Autorzy:
Kolluru, S.
Gedam, S.S.
Inamdar, A.B.
Powiązania:
https://bibliotekanauki.pl/articles/2078824.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
absorption coefficient
phytoplankton
coloured dissolved organic matter
partitioning
algorithm
coastal water
particulate matter
optical property
India
Opis:
Absorption coefficient partitioning algorithms (APAs) were developed to partition the total absorption coefficient (a(λ)) or total non-water absorption coefficient (anw (λ)) into the absorption subcomponents, i.e., absorption due to phytoplankton aph(λ), colored dissolved organic matter (CDOM) ag(λ) and non-algal particulate matter ad (λ), λ is the wavelength. Absorption coefficients of CDOM and non-algal particulate matter are generally combined due to a similarity in exhibited spectral shape and represented as colored detrital matter (CDM) absorption coefficient, adg(λ). This study focuses on the applicability of five APAs Schofield’s, Lin’s, Zhang’s, Stacked Constraints Model (SCM) and Generalized Stacked Constraints Model (GSCM), in deriving the absorption subcomponents from anw (λ) in optically complex coastal waters of Kochi and Goa, India. The average spectral Mean Absolute Percentage Errors (MAPE) obtained for all models in the retrieval of aph(λ), ad (λ), ag(λ) and adg(λ) lie in the ranges of 26—44%, 37—45%, 34—65% and 42—56%. Slopes of adg(λ), ag(λ) and ad (λ) as indicated by Sdg, Sg and Sd are derivable from GSCM, Schofield and Lin’s models only. GSCM model exhibited good retrieval capability of Sd with MAPE values of 22% and a correlation coefficient of 0.74. In retrieval of Sg parameter, none of the models demonstrated satisfactory performance. Overall, the GSCM and Schofield’s models demonstrated good performance in the retrieval of absorption subcomponents, aph(λ), adg(λ), ad (λ) and Sd. Effect of applying baseline correction to ad (λ) on model performance is studied. Tuning with in situ data can further improve the absorption subcomponent and slope parameter retrieval capability of the models.
Źródło:
Oceanologia; 2021, 63, 4; 420-437
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adjustment calculus and Trefftz functions applied to local heat transfer coefficient determination in a minichannel
Zastosowanie rachunku wyrównawczego i funkcji Trefftza do wyznaczenia lokalnego współczynnika przejmowania ciepła w minikanale
Autorzy:
Grysa, K.
Hożejowska, S.
Maciejewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/281729.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
flow boiling
liquid crystals
heat transfer coefficient
Opis:
The paper presents results of numerical calculations conducted in order to define the heat transfer coefficient in flow boiling in a vertical minichannel with one side made of a heating foil with liquid crystals. During the experiment, we measured the local temperature of the foil, inlet and outlet liquid temperature and pressure, current and voltage drop of the electric power supplied to the heater. Local measurements of foil temperature were approximated with a linear combination of the Trefftz functions. The known temperature measurement errors allowed application of the adjustment calculus. The foil temperature distribution was determined by the FEM combined with the Trefftz functions. Local heat transfer coefficients between the foil and the boiling fluid were calculated from the third-kind condition.
Przedstawiono wyniki obliczeń numerycznych przeprowadzonych w celu określenia współczynnika przejmowania ciepła przy przepływie wrzącej cieczy w pionowym minikanale, którego jedna ściana wykonana jest z folii grzewczej pokrytej ciekłymi kryształami. Podczas eksperymentu mierzono: lokalną temperaturę folii, temperaturę cieczy na wlocie i wylocie z minikanału, ciśnienie cieczy w minikanale oraz spadek natężenia i napięcia prądu stałego dostarczanej do folii grzewczej. Lokalne pomiary temperatury folii aproksymowano kombinacją liniową funkcji Trefftza. Znane błędy pomiaru temperatury pozwoliły na stosowanie rachunku wyrównawczego. Rozkład temperatury folii został określony przy zastosowaniu MES w powiązaniu z funkcjami Trefftza. Lokalne współczynniki wymiany ciepła pomiędzy folią i wrzącym płynem zostały wyliczone z warunku trzeciego rodzaju.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 4; 1087-1096
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of surface soil moisture from SMOS satellite and ground measurements
Autorzy:
Usowicz, B.
Marczewski, W.
Usowicz, J.B.
Lukowski, M.I.
Lipiec, J.
Powiązania:
https://bibliotekanauki.pl/articles/25959.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
comparison
soil surface
soil moisture
SMOS satellite
ground
measurement
correlation coefficient
Opis:
Soil moisture datasets at various scales are needed for sustainable land use and water management. The aim of this study was to compare soil moisture ocean salinity satellite and in situ soil moisture data for the Podlasie and Polesie regions in Eastern Poland. Both regions have similar climatic and topo- graphic conditions but are different in land use, vegetation, and soil cover. The test sites were located on agricultural fields on sandy soils and natural vegetation on marshy soils that prevail in the Podlasie and Polesie regions, respectively. The soil moisture ocean salinity soil moisture data were obtained from radiometric measurements (1.4 GHz) and the ground soil moisture from sensors at a depth of 5 cm during the years 2010-2011. In general, temporal patterns of soil moisture from both satellite and ground measurements followed the rainfall trend. The regression coeffi- cients, Bland-Altman analysis, concordance correlation coefficient, and total deviation index showed that the agreement between ground and soil moisture ocean salinity derived soil moisture data is better for the Podlasie than the Polesie region. The lower agre- ement in Polesie was attributed mostly to the presence of the widespread natural vegetation on the wetter marsh soil along with minor contribution of agriculturally used drier coarse-textured soils.
Źródło:
International Agrophysics; 2014, 28, 3
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 84

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