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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:
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
Tytuł:
The influence of meteorological factors on the hazel (Corylus L.) pollen concentration in Sosnowiec in the years 1997-2007
Wpływ warunków meteorologicznych na stężenie pyłku leszczyny (Corylus L.) w Sosnowcu w latach 1997-2007
Autorzy:
Dabrowska-Zapart, K.
Powiązania:
https://bibliotekanauki.pl/articles/26708.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
meteorological factor
hazel
Corylus
pollen concentration
Sosnowiec town
1997-2007 period
pollen season
Opis:
An analysis of hazel pollen seasons in Sosnowiec was presented on the basis of data from the years 1997–2007. The research was conducted by means of the volumetric method using a Burkard-type spore trap. The duration of pollen seasons was determined by means of the 98% method. The research demonstrated statistically significant correlations between the average, maximum and minimum temperature, relative humidity as well as the number of days with sub-zero temperature and the beginning of the hazel pollen season. It was demonstrated that the duration of the pollen season depended on air relative humidity, insolation and precipitation during the season and the annual sum depended on the weather conditions of the year preceding pollen production and also the weather conditions two years earlier. Significant correlations were also found between weather conditions and the daily concentration of pollen grains. The daily concentration decreased when relative humidity was high and increased with high insolation and air temperature.
Analizę sezonów pyłkowych leszczyny w Sosnowcu przedstawiono na podstawie danych z lat 1997 –2007. Badania prowadzono metodą wolumetryczną aparatem typu Burkard. Długość sezonów pyłkowych wyznaczono metodą 98%. Badania wykazały statystycznie istotne korelacje pomiędzy temperaturą średnią, maksymalną i minimalną, wilgotnością względną oraz liczbą dni z temperaturą poniżej zera a początkiem sezonu pyłkowego leszczyny. Wykazano, że długość sezonu pyłkowego zależała od wilgotności względnej powietrza, usłonecznienia i opadu atmosferycznego w sezonie zaś suma roczna od warunków pogodowych roku i dwóch lat poprzedzających pylenie. Znaleziono również istotne korelacje pomiędzy warunkami pogodowymi a stężeniem dobowym ziarn pyłku. Stężenie dobowe malało, kiedy wilgotność względna była wysoka a wzrastało przy wysokim usłonecznieniu i temperaturze powietrza.
Źródło:
Acta Agrobotanica; 2008, 61, 2
0065-0951
2300-357X
Pojawia się w:
Acta Agrobotanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indoor and outdoor 222Rn and 220Rn and their progeny levels surrounding Bayan Obo mine, China
Autorzy:
Wang, Nanping
Hu, Miao
Zeng, Weihua
Yu, Cong
Jia, Binlin
Yang, Zhijie
Powiązania:
https://bibliotekanauki.pl/articles/146589.pdf
Data publikacji:
2020
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radon
thoron
thoron progeny
equilibrium equivalent thoron concentration
Rn equilibrium factor
Bayan Obo
Opis:
More than half of the total natural ionizing radiation dose received by the human population is caused by radon and thoron (Rn and Tn) and their progeny. To estimate the level of radiation due to radon and thoron and their progeny, an investigation was conducted in a residential area near the world’s largest open-pit mine of Bayan Obo in Inner Mongolia, China. The concentration of Rn, Tn, and their decay products in air and soil were studied by using AlphaGUARD, RAD7, and ERS-RDM-2S for a discrete period of time in three different locations. The average indoor concentration of radon and thoron was 62.6 ± 44.6 Bq/m3 and 108.3 ± 94.5 Bq/m3 respectively, and the outdoor concentration was 12.9 ± 6.3 Bq/m3 and 55.8 ± 18.5 Bq/m3 , respectively. Relatively high concentrations were recorded in the area near to the mine, with a significant increasing trend observed in indoor thoron concentration. A prominent hotspot in thoron concentration was found in a single-story house with values 747 ± 150 Bq/m3 . The equilibrium equivalent thoron concentration (EECTn) varies from 0.48 Bq/m3 to 2.36 Bq/m3 with an arithmetic mean of 1.37 ± 0.64 Bq/m3 , and comparatively higher than EECRn. Concluding that the mining activity at Bayan Obo mine is significantly increasing the level of indoor thoron and its progeny in surroundings. It is suggested to further systematically investigate the indoor Rn and Tn progeny concentrations in the residential dwellings of the Bayan Obo mining area, and 232Th content of the building materials, to provide a basis for calculating the radiation dose.
Źródło:
Nukleonika; 2020, 65, 2; 145-148
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relation between Poaceae pollen concentrations and meteorological factors during 2000-2010 in Timisoara, Romania
Zależność pomiędzy stężeniami ziaren pyłku Poaceae a czynnikami meteorologicznymi w latach 2000-2010 w mieście Timisoara w Rumunii
Autorzy:
Ianovici, N.
Powiązania:
https://bibliotekanauki.pl/articles/27817.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
relation
Poaceae
pollen concentration
allergen
pollinosis
meteorological factor
2000–2010 period
Timisoara city
Romania
Opis:
This paper presents the results of Poaceae pollen seasons from 2000–2010 in Timisoara, Romania. Airborne Poaceae pollen concentrations was high. An increasing trend in the annual totals was observed. The longest pollen season was recorded in the year 2000. The period in which the Poaceae pollen count exceeded the threshold value of 30 grains/m3 lasted from 9 to 46 days. The present study analyzed the dynamics of pollen seasons in relation to meteorological factors. On the basis of Spearman’s correlation test, the strongest positive correlation was found between the Poaceae pollen counts and temperature; and sunshine hours. Daily average relative humidity, atmospheric pressure and precipitation had a negative effect. A multiple regression analysis was applied to determine how much of the total variance in Poaceae pollen counts can be explained by meteorological parameters. The coefficient of determination ranged from 0.245 to 0.460. Our data illustrate the contrasting effects of temperature, wind, relative humidity and rainfall on the concentration of pollen in the air. The optimum conditions for Poaceae pollen release occur during late spring and early summer. The Poaceae pollen remains one of the major aeroallergens in Timisoara area.
Praca przedstawia wyniki analizy sezonów pyłkowych Poaceae w latach 2000–2010 w mieście Timisoara w Rumunii. W badanym okresie stężenie ziaren pyłku Poaceae w powietrzu było wysokie. Najdłuższy sezon pyłkowy zanotowano w roku 2000. Obserwowano tendencję wzrostową w sumach rocznych pyłku traw. Okres, w którym suma ziaren pyłku Poaceae przekraczała wartość progową, wynoszącą 30 ziaren/m3, trwał od 9 do 46 dni. Analiza dynamiki sezonów pyłkowych Poaceae na tle czynników meteorologicznych wykazała korelację dodatnią pomiędzy sumami ziaren pyłku Poaceae a temperaturą i usłonecznieniem. Korelację ujemną stwierdzono pomiędzy sumami ziaren pyłku a średnią dobową wilgotnością względną powietrza, ciśnieniem atmosferycznym oraz opadami atmosferycznymi. Zastosowano analizę regresji wielokrotnej, aby określić, jaką część całkowitej zmienności sum ziaren pyłku Poaceae można wyjaśnić parametrami meteorologicznymi. Współczynnik determinacji wahał się od 0.245 do 0.460. Wykazano negatywny wpływ temperatury, wiatru, wilgotności względnej i opadów na stężenie pyłku w powietrzu. Optymalne warunki do pylenia Poaceae występują późną wiosną i wczesnym latem. Pyłek traw jest jednym z głównym aeroalergenów w Rumunii.
Źródło:
Acta Agrobotanica; 2015, 68, 4
0065-0951
2300-357X
Pojawia się w:
Acta Agrobotanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grass pollen [Poaceae] in the air of Sosnowiec [Poland], 1997-2006
Pylek traw [Poaceae] w powietrzu Sosnowca w latach 1997-2006
Autorzy:
Chlopek, K
Powiązania:
https://bibliotekanauki.pl/articles/28179.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
pollen concentration
pollen
Sosnowiec town
Polska
meteorological factor
Poaceae
grass pollen
pollen season
air
Opis:
The article presents the analysis results of the grass pollen seasons from 1997 to 2006 in Sosnowiec. The research was carried out by means of the volumetric method with the use of a Burkard device. The duration of the pollen seasons was determined by means of the 98% method. The influence of meteorological conditions on the starting date and duration of the grass pollen seasons has been estimated in the article. The beginning of the pollen seasons was recorded between 23 April and 23 May. It has been demonstrated that the average duration of the pollen season amounted to 138 days. The period of maximum concentrations was recorded in June and the first half of July. The highest daily concentration was found in 2000 (495 grains in m³) and the highest annual sums in 2002 and 2000. The daily concentration distribution curve has shown three peaks. The highest values were recorded from 7 am until 11 am, from 13 pm until 17 pm and from 19 pm until 21 pm. It has been found that there is a significant influence of weather conditions (temperature, precipitation and relative humidity) on the beginning and duration of the pollen seasons and the period of maximum concentrations.
Praca przedstawia wyniki analizy sezonów pylenia traw w latach 1997-2006 w Sosnowcu. Badania prowadzono metodą wolumetryczną aparatem typu Burkard. Długość sezonów pyłkowych wyznaczono metodą 98%. W pracy oceniono wpływ warunków meteorologicznych na termin rozpoczęcia i długość sezonów pyłkowych traw. Początek sezonów pyłkowych rejestrowano między 23.04-23.05. Wykazano że średnia długość sezonu pyłkowego wynosiła 138 dni. Najwyższe stężenie dobowe stwierdzono w 2000 roku (495 ziarn w m³), najwyższe sumy roczne w 2002 i 2000 roku. Okres maksymalnych stężeń notowano w czerwcu i pierwszej połowie lipca. Badania rytmiki dobowej pyłku traw wykazały najwyższe wartości pomiędzy 7⁰⁰-11⁰⁰, 13⁰⁰-17⁰⁰ i 19⁰⁰-21⁰⁰.
Źródło:
Acta Agrobotanica; 2007, 60, 2
0065-0951
2300-357X
Pojawia się w:
Acta Agrobotanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Element enrichment and provenance of the detrital component in Holocene sediments from the Western Black Sea
Autorzy:
Dekov, V.M.
Darakchieva, V.Y.
Billstrom, K.
Garbe-Schonberg, C.D.
Kamenov, G.D.
Gallinari, M.
Dimitrov, L.
Ragueneau, O.
Kooijman, E.
Powiązania:
https://bibliotekanauki.pl/articles/2079273.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
trace element concentration
isotope analysis
enrichment factor
Holocene sediment
catchment area
geochemical analysis
Black Sea
Opis:
Concentrations of a large set of major and trace elements, and Sr, Nd and Pb isotope ratios were measured in Holocene sediments cored in the western deep Black Sea in order to unravel: (1) the controls of element enrichment, and (2) sources of the detrital component. The transition of the basin from oxic to euxinic resulted in enrichment or depletion in a number of elements in the deep-sea sediments. Authigenic Fe enrichment appears to depend on the amount of Fe mobilized from the sediment through the benthic redox shuttle mechanism and free H2S in the water column (degree of “euxinization”). Manganese enrichment is controlled by diagenetic reactions within the sediment: the dissolution of Mn minerals, Mn2+ diffusion upward and reprecipitation. Barium enrichment is also controlled by diagenetic reactions, sulfate reduction and methanogenesis, that take place above and below the sulfate-methane transition, respectively. The major part of V, Co, Ni, Cu, Zn, Cr, Mo, Cd and Sb is inferred to have co-precipitated with Fe in the euxinic deep waters and to have been incorporated into authigenic Fe-sulfides. Basin reservoir effect additionally influences the Mo enrichment. The U enrichment is interpreted to have a different origin in the two organic-rich stratigraphic units (II and I). It is inferred to be: (i) at the expense of the U inventory of the deepwater pool and a result of inorganic reduction of U at euxinic conditions in the lower Unit II; and (ii) at the expense of the U inventory of the surface water pool and a result of biogenic uptake and transfer to the sediment by the plankton in the upper Unit I. The high field strength elements are closely linked to the detrital component and their depletion in the organic-rich sediments reflects a dilution of the detrital component by the biogenic one. The enrichments of REE, Sn and Th are likely controlled by adsorption on clay minerals. Sr-Nd-Pb isotope compositions of the alumino-silicate component of the studied sediments are relatively uniform. They are most likely controlled by riverine suspended matter supplied mainly in the NW Black Sea (Danube Delta) and transported southward by marine currents, and to a lesser degree by suspended matter from the small rivers draining SE Bulgaria and NW Turkey. Wind-blown dust from the Sahara Desert appears to have a minor contribution to the alumino-silicate component of the sediments. The slight shift in the Pb isotopes in Unit I upper layers is possibly caused by the addition of anthropogenic Pb.
Źródło:
Oceanologia; 2020, 62, 2; 139-163
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sewage sludge combustion – experimental and theoretical analysis
Autorzy:
Turkiene, N.
Zigmontiene, A.
Buinevicius, K.
Pleckaitiene, R.
Powiązania:
https://bibliotekanauki.pl/articles/185058.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sewage sludge
combustion
NOx concentration
conversion factor
CO
osad ściekowy
spalanie
stężenie NOx
współczynnik konwersji
Opis:
Whereas the use of biofuels has attracted increasing attention, the aim of this paper is to investigate the possibility of using sewage sludge as biofuel. Preparation of untreated and stabilised sludge with natural additives is described, as well as combusting method applied and experimental results of combusting are presented based on the assessment of composition of emitted pollutants and their concentrations in the exhaust gas. NOx formation in the exhaust gas has been analysed in depth. The results of investigations have shown that the use of dried sewage sludge possesses a positive energy balance. Therefore, the sludge may be used as fuel. The obtained experimental results demonstrate that during combustion, pollutant concentrations vary depending on oxygen content (O2), while formation of nitrogen oxides is strongly influenced by fuel-bound nitrogen. Also, a generalized equation of calculating fuel bound nitrogen conversion into NOx is presented.
Źródło:
Chemical and Process Engineering; 2013, 34, 2; 203-214
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Meteorological factors and airborne Rumex L. pollen concentration in Lublin
Czynniki meteorologiczne a stężenie pyłku Rumex L. w powietrzu Lublina
Autorzy:
Piotrowska, K.
Powiązania:
https://bibliotekanauki.pl/articles/28031.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
meteorological factor
meteorological condition
Rumex
pollen concentration
Lublin city
airborne pollen
seasonal variation
pollen season
Opis:
The aim of the present study was to analyse the Rumex pollen season dynamics in Lublin in 2001-2010 and to find relationships between season parameters and meteorological conditions. This study was carried out by the volumetric method using a Lanzoni VPPS 2000 trap. The start and end dates of each season were determined based on the 98% method. The effects of meteorological factors on the Rumex pollen seasons were analysed by employing Spearman’s correlation test. On average, the sorrel pollen season started on 13 May (±7 days), ended on 7 September (±6 days), and lasted nearly four months (±9 days). The highest pollen concentrations were recorded in June and July. A significantly negative correlation was found between season duration and Seasonal Pollen Index (SPI). During shorter pollen seasons, higher pollen counts were recorded. In all study years, the seasons were right-skewed. The pollen concentration was most strongly correlated with humidity and mean air temperature. The season parameters (onset, end, peak date, peak value, SPI value) were primarily dependent on air temperature before and during the pollen season.
Celem badań była analiza dynamiki sezonów pyłkowych Rumex w Lublinie w latach 2001-2010 oraz znalezienie zależności między parametrami sezonu a warunkami meteorologicznymi. Badania prowadzono metodą wolumetryczną przy użyciu aparatu Lanzoni VPPS 2000. Początek i koniec sezonu ustalono w oparciu o metodę 98%. Wpływ czynników meteorologicznych na sezony pyłkowe szczawiu analizowano stosując test korelacji Spearmana. Sezon pyłkowy szczawiu rozpoczynał się średnio 13.05 (±7 dni), kończył 7.09 (±6 dni) i trwał prawie cztery miesiące (±9 dni). Najwyższe stężenia pyłku notowano w czerwcu i lipcu. Stwierdzono negatywną istotną statystycznie korelację między długością sezonu a wartością SPI. W czasie krótszych sezonów pyłkowych notowano wyższe sumy ziaren pyłku. We wszystkich latach badań sezony były prawostronnie asymetryczne. Stężenie ziaren pyłku szczawiu w sezonie było najsilniej skorelowane z wilgotnością i średnią temperaturą powietrza. Cechy sezonu (początek, koniec, data wartości maksymalnej, wartość maksymalna, SPI) uzależnione były przede wszystkim od temperatury powietrza przed lub w czasie sezonu pyłkowego.
Źródło:
Acta Agrobotanica; 2012, 65, 1
0065-0951
2300-357X
Pojawia się w:
Acta Agrobotanica
Dostawca treści:
Biblioteka Nauki
Artykuł

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