Temat: coefficient of concentration - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Accumulation of heavy metals in soil and litter of roadside plantations in Western Polissia of Ukraine
Autorzy:: Maksimtsev, Serhii
Dudarets, Serhii
Yukhnovskyi, Vasyl
Powiązania:: https://bibliotekanauki.pl/articles/2041023.pdf
Data publikacji:: 2021
Wydawca:: Instytut Badawczy Leśnictwa
Tematy:: coefficient of concentration
forest belt
highway
maximum allowable concentration
belt composition
pollutants
Opis:: The article presents the results of a study on the influence of roadside forest belts of different species composition on the accumulation of heavy metals in soil and litter along roads of international and national importance in the conditions of Western Polissia of Ukraine. Mobile forms of Cd, Cu, Pb and Zn in soil and forest litter samples were determined in ammonium acetate extract buffer by atomic absorption spectrometry. The analysis of the content of heavy metals, their comparison with the maximum allowable concentrations depending on the composition of plantations and the category of the highway have been done. It is confirmed that roadside forest belts perform important functions in the accumulation of heavy metals in soil and forest litter. It is confirmed that roadside forest belts perform important functions in the accumulation of heavy metals in soil and forest litter. Among all the pollutants studied, the concentration of cadmium was the lowest and that of zinc the highest (especially in forest litter). Lead and copper in this indicator occupied an intermediate position. Despite the different species composition of plantations, the coefficient of concentration of heavy metals in the soil did not exceed the maximum allowable concentrations and was on average in the range of 0.10–0.20 of these indicators. The greatest effect of delaying the migration of heavy metals was observed in forest litter. Therefore, in order to effectively use the biological barrier along the roads, it is necessary to create linear protective belts of deciduous species with Acer platanoides, Betula pendula, Carpinus betulus and Tilia cordata, which give a rich annual litterfall.
Źródło:: Folia Forestalia Polonica. Series A . Forestry; 2021, 63, 3; 232-242
0071-6677
Pojawia się w:: Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Radar coefficient of concentration
Autorzy:: Binderman, Zbigniew
Borkowski, Bolesław
Szczesny, Wiesław
Powiązania:: https://bibliotekanauki.pl/articles/453724.pdf
Data publikacji:: 2012
Wydawca:: Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:: Gini index
Schutz’s measure
radar coefficient of concentration
radar method
radar measure of conformability
measure of similarity
synthetic measures
classification
cluster analysis
Opis:: In the following work we have described a process of using radar charts to measure concentration of a distribution. The process utilises the idea of Gini index based on a Lorenz curve as well as a method presented by the authors in [Binderman, Borkowski, Szczesny 2010]. The presented technique can also be used by analysts to create new coefficients of concentration based on measures of similarity and dissimilarity of objects so that from the set of constructed coefficients one that best fulfils the required criteria of sensitivity can be chosen.
Źródło:: Metody Ilościowe w Badaniach Ekonomicznych; 2012, 13, 2; 7-21
2082-792X
Pojawia się w:: Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Modeling the movement of broadcast on the concentration table
Autorzy:: Feliks, Jacek
Krawczyk, Magdalena
Powiązania:: https://bibliotekanauki.pl/articles/2064429.pdf
Data publikacji:: 2019
Wydawca:: STE GROUP
Tematy:: concentration table
coefficient of friction
enrichment
tabela koncentracji
współczynnik tarcia
wzbogacanie
Opis:: The article attempts to analyze the work of the concentration table, on which the distribution of the material under investigation takes place. The efficiency of separation or otherwise enrichment depends on the drive that puts the concentration table plate into an asymmetrical reciprocating movement. The most frequently used solutions are concentration tables, on which the distribution of enriched material takes place in an aqueous medium commonly called wet enrichment. The AGH University of Science and Technology conducted simulation tests of material enrichment on a concentration table using the differences in friction coefficient commonly referred to as dry enrichment, i.e. without an additional medium. The article presents the effects of simulations that have been carried out for reference materials characterized by different friction coefficients and densities. The summary presents the analysis of obtained effects of computer simulations of material movement with different coefficients of friction. The simulations were carried out for variables: the frequency of vibrations of the concentration table and the angle of inclination of the table of the concentration table. It has been shown that it is possible to enrich the material by changing the above-mentioned operating parameters of the device.
Źródło:: New Trends in Production Engineering; 2019, 2, 1; 304--311
2545-2843
Pojawia się w:: New Trends in Production Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Methods of enlarging material to the concentration table
Autorzy:: Feliks, Jacek
Krawczyk, Magdalena
Powiązania:: https://bibliotekanauki.pl/articles/2064376.pdf
Data publikacji:: 2019
Wydawca:: STE GROUP
Tematy:: concentration table
coefficient of friction
enrichment
tabela koncentracji
współczynnik tarcia
wzbogacanie
Opis:: Concentration tables are one of the oldest oscillatory enrichments with over 100 years of tradition. On this type of distribution tables are made according to material mass in many recurring cycles induced by appropriate drives. So-called wet tables are the devices most often used for coal enrichment in Polish mines because this process generates very high costs, high water consumption and pollution of the environment, as well as the need for, among others, water and mud management is increasingly being replaced mainly in areas poor in water by the modern model of the air concentration table - FGX produced in China. The process of enrichment on this type of table itself runs in a manner comparable to the method of wet enrichment with the difference that the FGX is distributed on a perforated plate, in this case we deal with air pollution. Department of Machinery Engineering and Transport's attempts to use the differences in coefficients of friction in over-resonance screens have shown that it is possible effective separation of grains with different coefficients of friction. The article presents a theoretical analysis and presents the results of performed dry enrichment trials using different coefficients of friction. The summary presents the advantages of using the enrichment method using the differences in friction coefficients and test results.
Źródło:: New Trends in Production Engineering; 2019, 2, 1; 59--68
2545-2843
Pojawia się w:: New Trends in Production Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: ZMIANY STRUKTURY OBSZAROWEJ GOSPODARSTW EKOLOGICZNYCH W POLSCE W LATACH 2004-2012
CHANGES OF THE STRUCTURE OF AREA OF THE ORGANIC FARMS IN POLAND IN YEARS 2004-2012
Autorzy:: Luty, Lidia
Powiązania:: https://bibliotekanauki.pl/articles/453860.pdf
Data publikacji:: 2014
Wydawca:: Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:: gospodarstwo ekologiczne
dynamika struktur
współ-czynnik koncentracji
organic farm
dynamics of structures
concentration coefficient
Opis:: Celem opracowania będzie przedstawienie zmian struktury obszarowej gospodarstw ekologicznych w Polsce, w latach 2004-2012. Wykorzystane mierniki taksonomiczne, pozwolą ocenić stopień i kierunek zmian strukturalnych. Łańcuchowe miary zmienności struktur pozwolą ocenić także przebieg zmian strukturalnych dla województw Polski. Dla analizowanych addytywnych struktur oszacowane zostaną współczynniki koncentracji w układzie rodzajowym i przestrzennym. Ponadto, wyznaczone zostaną prognozy struktury obszarowej gospodarstw ekologicznych dla Polski na trzy kolejne lata.
Organic farming production methods are part of the concept of sustainable development, therefore it becomes important to study the level of organic farming, its development, regional diversification and the trend and rate of change. The aim of this paper was to present changes to the structure of the area of organic farms in Poland in the years 2004-2012. Used taxonomic meters, allowed to assess the degree and direction of structural changes in the Polish voivodeships. For analyzed additive structures concentration coefficients were estimated. In addition, there is forecast for the structure of area for organic farms for the next three years in Poland.
Źródło:: Metody Ilościowe w Badaniach Ekonomicznych; 2014, 15, 3; 208-218
2082-792X
Pojawia się w:: Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Wpływ rodzaju powierzchni próbki na współczynnik dyfuzji jonów chlorkowych w betonie
Influence of the sample surface on the chloride ion diffusion coefficient in concrete
Autorzy:: Kuziak, Justyna
Kryszczyński, Artur
Powiązania:: https://bibliotekanauki.pl/articles/160332.pdf
Data publikacji:: 2020
Wydawca:: Polski Związek Inżynierów i Techników Budownictwa
Tematy:: beton
jon chlorkowy
wnikanie chlorków
próbka betonowa
powierzchnia próbek
współczynnik dyfuzji
stężenie chlorków
wyniki badań
concrete
chloride ion
chloride penetration
concrete sample
surface of sample
diffusion coefficient
chloride concentration
test results
Opis:: W pracy przedstawiono wyniki badań wyznaczania efektywnego współczynnika jonów chlorkowych w betonie o w/c = 0,3. Próbki betonu po 14 miesiącach twardnienia poddano 39-41 dniowemu wnikaniu jonów chlorkowych z 3% roztworu NaCl. Badania przeprowadzono na trzech rodzajach powierzchni: powierzchni górnej, powierzchni bocznej i ciętej. Największy efektywny współczynnik dyfuzji jonów chlorkowych (4,7⋅10-12 m2/s) otrzymano w przypadku wnikania chlorków do betonu od powierzchni formowanej, nieco mniejszy dla powierzchni zacieranej (4,2⋅10-12 m2/s), a najmniejszy (1,2⋅10-12 m2/s) dla powierzchni ciętej.
The results of tests for determining the chloride ion effective diffusion coefficient in concrete with w/c = 0.3 were presented. Concrete samples after 14 months of hardening were subjected to 39-41 days ingress of chloride ions from 3% NaCl solution. The tests were carried out on three types of surfaces: top, side and sawn surface. The highest chloride ion effective diffusion coefficient (4,7⋅10-12 m2/s) was obtained in the case of chloride penetration into the concrete from the side surface, slightly smaller for the top surface (4,2⋅10-12 m2/s) and the smallest (1,2⋅10-12 m2/s) for the sawn surface.
Źródło:: Przegląd Budowlany; 2020, 91, 6; 32-35
0033-2038
Pojawia się w:: Przegląd Budowlany
Dostawca treści:: Biblioteka Nauki