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Wyszukujesz frazę "concentration factor" wg kryterium: Temat


Tytuł:
Α Dynamics of Macro Elements Content in Eutric Podzoluvisols for Separation of Wastewater under Jerusalem Artichokes
Autorzy:
Lopushniak, Vasyl
Hrytsuliak, Halyna
Gamayunova, Valentina
Kozan, Natalia
Zakharchenko, Elina
Voloshin, Yurii
Lopushniak, Halyna
Polutrenko, Miroslava
Kotsyubynska, Yulia
Powiązania:
https://bibliotekanauki.pl/articles/2086370.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
nitrogen
phosphorus
potassium
concentration factor
compost
Opis:
The application of fertilizers based on sewage sludge significantly affects the formation of the nitrogen fund of sod-podzolic soil, as well as changes in the content of mobile compounds of phosphorus and potassium exchange. The application of such fertilizer under Jerusalem artichoke has a positive effect on the nitrogen content of alkaline hydrolyzed compounds, in particular on increasing the content of mineral and alkaline hydrolyzed nitrogen fractions. The application of sewage sludge at a dose of 20–40 t/ha and the appropriate compensatory dose of mineral fertilizers at the rate of N90P90K90 helps to increase the content of ammonium nitrogen compounds from 16 to 20–22 mg/kg of soil in the upper (0–20 cm) layer – 28% prevails over the control variant, as well as the content of nitrate nitrogen compounds in the layer 0–40 cm from 1.70 to 2.52–2.64 mg/kg of soil. The ratio of the content of alkaline hydrolyzed nitrogen compounds to the nitrogen content of mineral compounds in the experimental conditions changes insignificantly, which indirectly indicates a relatively stable value of this indicator, which changes little under the influence of fertilizers. The application of sewage sludge as a fertilizer significantly affects the change in the content of mobile phosphorus compounds and potassium exchange compounds in the upper (0–40 cm) layer of the soil. However, from a depth of 60 cm, their content decreases sharply and approaches the initial values of the control version. Depending on the application of fertilizers, the indicators of the coefficient of concentration of macronutrients in the soil change significantly, which reflects the ratio of the content of the element in the soil to its content in the control variant. As the rate of sewage sludge increases, the element concentration coefficient increases from 1.27 in the variant with the application of only mineral fertilizers to 2.36 for potassium and for phosphorus – from 1.02 to 1.31. There is a close correlation between the content of phosphorus and potassium in the soil and the coefficients of their concentration. This relationship reflects the multiple coefficient of determination, which for phosphorus and potassium is R2 = 0.69 and R2 = 0.90, respectively. The use of fertilizers in the form of compost with sewage sludge and straw of cereals causes similar trends as the introduction of uncomposted sewage sludge. However, this effect has less radical impact with lower absolute nutrient content compared to the introduction of fresh sewage sludge. The application of sewage sludge in the form of compost and uncomposted form contributes to a significant increase in the content of macronutrients in the soil, providing an improvement in the mineral nutrition of cultivated plants, including Jerusalem artichokes.
Źródło:
Journal of Ecological Engineering; 2022, 23, 4; 33--42
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Uncertainty Model Of Approximating The Analytical Solution To The Real Case In The Field Of Stress Prediction
Autorzy:
Gutiérrez, R.
Ramírez, M.
Olmeda, E.
Díaz, V.
Powiązania:
https://bibliotekanauki.pl/articles/220703.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
uncertainty
strain gage measurement
stress concentration factor
weighted least squares algorithm
Opis:
Deterministic mechanics has been extensively used by engineers as they needed models that could predict the behavior of designed structures and components. However, modern engineering is now shifting to a new approach where the uncertainty analysis of the model inputs enables to obtain more accurate results. This paper presents an application of this new approach in the field of the stress analysis. In this case, a two-dimensional stress elasticity model is compared with the experimental stress results of five different size tubes measured with resistive strain gages. Theoretical and experimental uncertainties have been calculated by means of the Monte Carlo method and a weighted least square algorithm, respectively. The paper proposes that the analytical engineering models have to integrate an uncertainty component considering the uncertainties of the input data and phenomena observed during the test, that are difficult to adapt in the analytical model. The prediction will be thus improved, the theoretical result being much closer to the real case.
Źródło:
Metrology and Measurement Systems; 2015, 22, 3; 429-442
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress concentration at load-carrying fillet welded cruciform joints subjected to tensile and bending loads
Autorzy:
Molski, Krzysztof L.
Powiązania:
https://bibliotekanauki.pl/articles/387288.pdf
Data publikacji:
2019
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
cruciform welded joint
load-carrying fillets
stress concentration factor
stress intensity factor
finite element method
Opis:
This article presents numerical finite element method (FEM) analysis of the stress concentration at toes and crack-like faults in load-carrying fillet welded cruciform joints with transversal slits resulting from non-fused root faces. Potential fatigue damage of such joints subjected to cyclic tensile and bending loads appears in the form of fatigue cracks starting from the weld roots or toes. The aim of this article is to find qualitative and quantitative relationships between geometrical parameters of the load-carrying fillet welded cruciform joint subjected to tensile and bending loads and the stress concentration at weld toes and roots. The results of the analysis represented by the stress concentration factors (SCFs) and the stress intensity factors KI and KII are shown in the form of tables, graphs and mathematical formulas, which may be applied for fatigue assessment of such joints.
Źródło:
Acta Mechanica et Automatica; 2019, 13, 4; 245-250
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress concentration on the contour of a plate opening: analytical, numerical and experimental approach
Autorzy:
Momcilovic, N.
Motok, M.
Maneski, T
Powiązania:
https://bibliotekanauki.pl/articles/279564.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
stress concentration factor (SCF)
digital image correlation (DIC)
plate opening
small radius of curvature
Opis:
The objective of the paper is to analyze the stress concentration factor (SCF) in the corner of a rectangular plate opening with small radii of curvature and various methods for its derivation. Besides the finite element method, as the most used approach today, there are some analytical and experimental procedures that can obtain stress concentration results in such spots. An analytical approach can deliver prediction of the SCF around the corner but cannot illustrate the stress field opposite to the finite element method. On the other hand, finite element analysis needs much computation time to deal with very sensitive and fine mesh generation around concentration zones. Experimental devices, such as strain gauges are not able to perform measurements on areas where high gradient of stress occurs due to their lack of sensitiveness and larger dimensions compared to the measured part of a structure. The paper presents Digital Image Correlation (DIC) technique that obtains not only stress concentration, where other devices fail, but also provides full displacement, strain and stress field’s even where a high gradient of stress exists. These three methods are discussed, compared and illustrated on the model of a plate with rectangular opening subjected to tension.
Źródło:
Journal of Theoretical and Applied Mechanics; 2013, 51, 4; 1003-1012
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study on the stress concentration factor induced in double countersunk holes due to uniaxial tension
Autorzy:
Gharaibeh, Mohammad A.
Powiązania:
https://bibliotekanauki.pl/articles/1839778.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
metoda elementów skończonych
naprężenie
rozciąganie
double countersunk holes
stress concentration factor
finite element method
response surface method
uniaxial tension
Opis:
Finite element and response surface methods were utilized to investigate the stress concentration factor induced in isotropic rectangular plates with two identical countersunk rivet holes due to uniaxial tension. In this investigation, the finite element model was constructed using ANSYS software and used to produce stress concentration factor (SCF) data. Additionally, the response surface method (RSM) was implemented to characterize the influence of the problem geometric parameters on the SCF. Besides, RSM combined with least squares regression methods were employed to formulate a simple and effective equation to mathematically compute the stress concentration factor […] value. This equation was consequently verified with finite element analysis (FEA) results. Lastly, an optimum plate and holes configuration that minimizes the SCF was suggested and hence recommended.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 4; 59-68
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ugięcie stropu bezpośredniego i zasadniczego nad eksploatowanym pokładem - współczynnik koncentracji naprężenia w obszarze propagującej szczeliny w przekroju zginanej belki stropowej
Deflection of the immediate and main roof during exploitation of deposit - stress concentration factor for a single opening edge
Autorzy:
Wosz, R.
Powiązania:
https://bibliotekanauki.pl/articles/350092.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
ugięcie belki na sprężystym podłożu
stan naprężenia w przekroju osłabionym szczeliną
koncentracja naprężenia
deflection of beam
brittle rock
single opening
stress concentration factor
Opis:
Praca stanowi, zrealizowany w 2008 roku, etap badań, polegający na opisie zachowania się warstw górotworu nad eksploatowanym, systemem komorowo-filarowym z ugięciem stropu, złożem rud miedzi w LGOM. Dotychczas dokonano próby opisu ugięcia warstwy stropu bezpośredniego i zasadniczego nad eksploatowanym złożem. W skonstruowanym modelu o wartości krzywizny osi belki decyduje moment zginający i siła ścinająca [5]. W pracy [17] przedstawiono koncepcję modelu opisującego powstanie i propagację szczeliny zniszczenia w przekroju belki stropu zasadniczego. Szczelina zniszczenia powstaje w wyniku działania dwóch par sił o tej samej wartości momentu zginającego M oraz M' i przeciwnych znakach. W pracy niniejszej zdefiniowano współczynnik koncentracji naprężenia w obszarze powstałej szczeliny. Wartość współczynnika zależy między innymi od geometrii szczeliny. Przyjęto eliptyczny kształt konturu szczeliny (Griffith theory).
This article is a continuation of the research works concerning the immediate and main roof strata deflection above the deposit mined by the chamber-pillar system with roof deflection in exploitation conditions of the copper deposits in LGOM. A model of the roof has been defined as a brittle rock with an unstable crack propagation. The destructive influence of cracks in a brittle material was determined by stresses around an elliptical crack. It has been shown that the maximum stress concentration occurs at the tip of long, narrow opening and the stress concentration factor depends on the shape of opening and its length.
Źródło:
Górnictwo i Geoinżynieria; 2009, 33, 3; 115-124
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza dynamicznego zachowania się belki stropu bezpośredniego będącego w jednoparametrowym kontakcie ze złożem w formie pokładu eksploatowanego na zawał
Analyze of the dynamic deflection of the direct roof during exploitation of deposit
Autorzy:
Paluch, M.
Wosz, R.
Powiązania:
https://bibliotekanauki.pl/articles/349138.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
ugięcie belki na sprężystym podłożu
kruche własności górotworu
dynamiczne równanie zachowania się ośrodka skalnego
deflection of beam
brittle rock
single opening
stress concentration factor
Opis:
W artykule przedstawiono model eksploatacji złoża typu pokładowego systemem ścianowym z zawałem stropu, w którym oprócz składnika statycznego, tzn. wielkości opisujących parametry geometryczne i odkształceniowe, uwzględniono składnik dynamiczny opisujący zmiany funkcji przemieszczeń w czasie. Do obliczeń przyjęto model w formie belki wspornikowej o długości wspornika 10 m i wysokości 12 m. Trzeci wymiar miał wartość jednostkową. W równaniu konstytutywnym uwzględniono wpływ na krzywiznę osi belki zarówno momentu zginającego, jak i siły poprzecznej. Przyjęto w założeniach, że wyróżnik równania charakterystycznego będzie miał wartość ujemną, a krzywa obrazująca funkcję ugięcia będzie linią falistą. Do analizy przyjęto rozkłady funkcji ugięcia w czasie i z odległością od czoła frontu eksploatacyjnego.
In the article was described effect of the works concerning the direct roof strata deflection above the deposit mined by means of the long-wall system with roof destruction in the exploitation conditions of the black coal. A model of the roof has been defined as a brittle rock. The main constitute equations of the model includyt the faktor whith discrabing the dynamic process of mooving direct roof. In calculation long of the cantilever was 10 m, tall 12 m and the third dimension was 1 m.
Źródło:
Górnictwo i Geoinżynieria; 2011, 35, 1; 81-91
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Economic factors of using the new protein concentrate in red deer feeding
Czynniki ekonomiczne związane z zastosowaniem nowego koncentratu proteinowego w żywieniu jelenia szlachetnego
Autorzy:
Proskina, L.
Powiązania:
https://bibliotekanauki.pl/articles/78705.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
economic factor
new concentration
protein concentration
red deer
animal feeding
feed cost
animal farming
Źródło:
Folia Pomeranae Universitatis Technologiae Stetinensis. Oeconomica; 2013, 73
2081-0644
Pojawia się w:
Folia Pomeranae Universitatis Technologiae Stetinensis. Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of some heavy metals contaminated soils around the Shahid Salimi power plant, Neka, Mazandaran Province, Iran
Autorzy:
Sedghi, M.
Torkashvand, A.M.
Asadi, M.E.
Pazira, E.
Powiązania:
https://bibliotekanauki.pl/articles/971564.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
background concentration
contamination factor
heavy metals
mazandaran prov-
ince
soil contamination
Opis:
One of the most important problems threatening the health of natural resources and, in turn, the food safety of societies is environmental contamination. Heavy metals are considered as the environmental pollutants. The entry of heavy metals into the soil is done through the atmospheric sources and mostly via melting plants, oil refieries and power plants. Due to the mazut consumption in some seasons, power plants are considered as a threat to the soil. This study was conducted with the aim of evaluating contamination of some heavy metals including copper, zinc, cadmium, lead, and nickel in the soils around the Shahid Salimi power plant, Neka located in Mazandaran province, north of Iran. One of the greatest threats is the possible contamination of cultivated paddy by pollutant elements. A number of 50 samples from the soil around the power plant were taken from a depth of 0–20 cm within the form of a regular grid and the concentration of the corresponding metals was measured in each of them. The mean background concentration of copper, nickel, lead, zinc, and cadmium was 36.2, 339.8, 90.8, 13.8, and 0.20 mg∙kg, respectively. The maximum mean contamination factor belongs to nickel, lead, copper, zinc, and cadmium, respectively. The frequency of the obtained contamination evaluation classes indicates that the majority of the analyzed samples have a medium level of contamination. Copper, nickel, and lead belong to the class of very high contaminants. By comparing the concentrations of the heavy metals of studied region with quality standard of Iranian soil resources, presented by the Department of Environment Protection of Iran, it was observed that the concentrations of cadmium, zinc, and copper have been signifiant at the level of 5% based on the standards determined by the agency for agricultural uses, environmental standard and groundwater level. In other words, they do not have conflct with the determined standard at any of the three levels.
Źródło:
Polish Journal of Soil Science; 2019, 52, 1; 129-136
0079-2985
Pojawia się w:
Polish Journal of Soil Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of magnetic field on the efficiency of a silicon solar cell under an intense light concentration
Autorzy:
Zoungrana, M.
Zerbo, I.
Soro, B.
Savadogo, M.
Tiedrebeogo, S.
Bathiebo, D. J.
Powiązania:
https://bibliotekanauki.pl/articles/102700.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
conversion efficiency
electric power
fill factor
light concentration
magnetic field
optimal charge load
Opis:
This work put in evidence, magnetic field effect the electrical parameters of a silicon solar cell illuminated by an intense light concentration: external load electric power, conversion efficiency, fill factor, external optimal charge load. Due to the high photogeneration of a carrier in intense light illumination mode, in addition of magnetic field, we took into account the carrier gradient electric field in the base of the solar cell. Taking into account this electric field and the applied magnetic field in our model led to new analytical expressions of the continuity equation, the photocurrent and the photovoltage. In this work, we used the electric power curves versus junction dynamic velocity (Sj) to determine, according to magnetic field, the maximum electric power Pelmax and we calculate the solar cell conversion efficiency (η). We also used the J-V characteristics to determine the solar cell short circuit density current (Jcc) and the open circuit voltage (Vco) under magnetic field and we calculate the fill factor (FF). Finally, we used simultaneously the J-V characteristics and equipower curves to determine the optimal external load resistance. The results of this study have showed that the maximum electric power and the conversion efficiency are higher than those of monofacial and bifacial silicon solar cells illuminated by conventional light but they decreased with the increase of magnetic field.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 2; 133-138
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł

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