Wyniki wyszukiwania - BazTech

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A particle size distribution measurements of selected building materials using laser diffraction method

Prałat K., Krymarys E.

Technical Transactions

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2018

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Vol. 115, iss. 5

95--108

EN

This article presents the results of experimental research to determine the size of powder graining in building materials, specifically, gypsums (Dolina Nidy, Pinczow) and adhesives (Atlas Sp. z o.o., Lodz, and Weber Saint-Gobain, Warsaw). A modern laser diffraction method for measuring the distribution of particle sizes with respect to their diameters was applied. During the experiment, three series of measurements were conducted for each material. Data relating to the graining of building materials is crucial because it is one of many aspects that directly affects the binding time and defines its potential applications in the construction industry.

PL

W artykule zawarto wyniki badań eksperymentalnych, określających wielkość ziaren w pylistych materiałach budowlanych: gipsach (Dolina Nidy, Pinczów) i klejach (Atlas Sp. z o.o., Łódź oraz Weber Saint-Gobain, Warszawa). W pomiarach zastosowano nowoczesną metodę dyfrakcji laserowej do pomiaru średnic cząstek. Podczas eksperymentu przeprowadzono trzy serie pomiarów dla każdego materiału. Ziarnistość materiałów budowlanych stanowi jeden z wielu aspektów, które bezpośrednio wpływają na czas wiązania, a zatem określają ich użyteczność w budownictwie.

2

Carbon accumulation in the bulk soil and different soil fractions during the rehabilitation of desertified grassland in Horqin Sandy Land (Northern China)

Li Y., Zhao X., Wang S., Zhang F., Lian J., Huang W., Mao W.

Polish Journal of Ecology

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2015

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Vol. 63, nr 1

88--101

EN

Desertification, which affects more than two-thirds of the world’s arid and semi-arid regions, is a significant global ecological and environmental problem. There is a strong link between desertification of the drylands and emission of CO2 from soil and vegetation to the atmosphere. The Horqin Sandy Land is a severely desertified area in China’s agro-pastoral ecotone due to its fragile ecology, combined with unsustainable land management. We estimated changes of organic carbon content in the bulk soil (0–5 cm), in the light-fraction of soil organic matter (based on density fractionation), and in the various particle-size fractions in areas with mobile sand dunes after implementing grazing exclusion (12 and 27 years) and tree and shrub planting (22 and 24 years). Carbon stocks in the bulk soil and all soil density and particle-size fractions increased significantly in the exclosure and plantation plots. The average rates of carbon accumulation in the bulk soil in the exclosure and plantation plots were 16.0 and 17.8 g m-2 y-1, respectively, versus corresponding values of 2.3 and 7.1 g m-2 y-1 for the light fraction, 4.3 and 8.0 g m-2 y-1 for the coarse fraction, 5.0 and 3.4 g m-2 y-1 for the fine sand, 4.5 and 4.2 g m-2 y-1 for the very fine sand, and 1.8 and 1.8 g m-2 y-1 for the silt+clay fraction. The older the exclosure and plantation, the more carbon accumulated in the bulk soil and in each fraction. The carbon pool exceeded the level in non-desertified grasslands after 27 years of grazing exclosure and 24 years of the shrub plantation. Our results suggest that both grazing exclusion and planting trees and shrubs can restore desertified grassland, creating a high potential for sequestering soil carbon, but that the plantations appeared to accumulate soil carbon faster than the exclosures.

3

Content of respirable and inhalable fractions in dust created at sawing beech wood and its modifications

Hlásková L., Rogoziński T., Dolny S., Kopecký Z., Jedinák M.

Drewno : prace naukowe, doniesienia, komunikaty

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2015

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vol. 58, nr 194

135--146

EN

This paper presents the results of the granulometric analysis of sawdust, created during the sawing of modified and unmodified beech wood with a circular saw. The aim of this work was to analyze the effect of the treatment of beech wood (Fagus sylvatica L.) on the content of respirable and inhalable particles in sawdust generated during the sawing process using a modern circular saw. Different methods of particle-size determination were used. The results obtained from the sieve analysis prove that the sawdust created during the cutting of DMDHEU was finer than the sawdust from native beech and other modified materials. It was also discovered that the dust created during the cutting of Bendywood was finer than when machining native beech and Lignamon. There was an increase in the share of fine fraction in the range of granularity x < 100 μm at the expense of the fraction x = 0.25–1 mm. The properties of Lignamon are primarily based on the properties of raw wood material, therefore this modified material had a similar cumulative particle-size distribution to the native beech dust.

4

Kompleksowa analiza fragmentacji usypu urobku

Biessikirski A., Dworzak M., Pyra J., Sołtys A., Twardosz M.

Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie

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2015

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nr 8

25--33

PL

Pośrednie metody oceny fragmentacji urobku, wykorzystujące m.in. oprogramowanie komputerowe (np. Split Desktop 2.0.), znajdują coraz szersze zastosowanie przy ocenie efektów prowadzonych robót strzałowych. W artykule przedstawiono kompleksową ocenę fragmentacji urobku uzyskaną z wykorzystaniem wyników dodatkowych analiz przeprowadzonych w przekroju usypu. Ponadto, zaprezentowano wynik analizy kształtu oraz odrzucenia usypu, które uzyskano z wykorzystaniem modelu cyfrowego sporządzonego metodą SfM.

EN

Indirect methods of the output’s fragmentation evaluation e.g. the Split Desktop 2.0. software, are finding right now much more wide application in blasting works assessment. The complex method of the muck pile fragmentation assessment is being presented in the article. The assessment was performed according to the addition analysis in the muck’s pile cross-section According to the conducted research there were on average 3% more of the oversize rocks in the output. In the output’s cross-section there were more fines product – around 18%. Results of the muck pile shape and it’s throwback according to the SfM (Structure from Motion) modeling was included in the article. The SfM model has allowed to perform a detail evaluation of the output’s geometrical parameters such as: height, length etc. The digital model together with the on-site vision allowed to determine that the blasting parameter were chosen properly.

5

Analiza oddziaływania wybranych parametrów na proces rozdrabniania materiału ziarnistego

Sowiak J, Bilard P, Przybył A., Kordas M., Rakoczy R.

Inżynieria i Aparatura Chemiczna

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2013

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Nr 4

370--371

PL

mieszalniku wstęgowym. W badaniach użyto cząstek węgla aktywnego, a proces mielenia przeprowadzono dla wybranych prędkości obrotów mieszadła: 2; 50 oraz 100 obr min -1. Określono wpływ wybranych parametrów operacyjnych (prędkość obrotowa mieszadła, czas mielenia) na uzyskany skład ziarnowy produktu. Otrzymane wyniki umożliwiły ocenę efektywności prowadzonych prób mielenia.

EN

Experimental results dealing with the grinding process of granular material in a ribbon mixer are presented. Activated carbon particles were used in the research. Milling process was performed for the selected stirrer rotational frequencies: 2, 50 and 100 rpm min-1. An influence of selected operational parameters (stirrer rotational frequency, grinding time) on the size distribution of granular material is presented. The results enabled the assessment of grinding test efficiency.

6

Performance of soil particle-size distribution models for describing deposited soils adjacent to constructed dams in the China Loess Plateau

Zhao P., Shao M., Horton R.

Acta Geophysica

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2011

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Vol. 59, no. 1

124-138

EN

Soil particle-size distributions (PSD) have been used to estimate soil hydraulic properties. Various parametric PSD models have been proposed to describe the soil PSD from sparse experimental data. It is important to determine which PSD model best represents specific soils. Fourteen PSD models were examined in order to determine the best model for representing the deposited soils adjacent to dams in the China Loess Plateau; these were: Skaggs (S-1, S-2, and S-3), fractal (FR), Jaky (J), Lima and Silva (LS), Morgan (M), Gompertz (G), logarithm (L), exponential (E), log-exponential (LE), Weibull (W), van Genuchten type (VG) as well as Fredlund (F) models. Four-hundred and eighty samples were obtained from soils deposited in the Liudaogou catchment. The coefficient of determination (R2), the Akaike’s information criterion (AIC), and the modified AIC (mAIC) were used. Based upon R2 and AIC, the three- and four-parameter models were both good at describing the PSDs of deposited soils, and the LE, FR, and E models were the poorest. However, the mAIC in conjunction with R2 and AIC results indicated that the W model was optimum for describing PSD of the deposited soils for emphasizing the effect of parameter number. This analysis was also helpful for finding out which model is the best one. Our results are applicable to the China Loess Plateau.