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R. H. Higgy M. S. El-Tahawy A. T. Abdel-Fattah U. A. Al-Akabawy 《Journal of environmental radioactivity》2000,50(3)
Studies have been carried out to determine the natural radioactivity in some building materials (bricks, tiles, marble and ceramics) and their associated radiation hazard. The radioactivity concentrations of 226Ra 232Th and 40K were measured using a gamma spectrometer with a Hp–Ge detector. The activities of 238U and 234U were measured using an alpha-spectrometer with a surface barrier detector after applying a radiochemical procedure. The 234U/238U isotopic ratios were calculated. The radium equivalent activities and the radiation hazard index associated with the natural radionuclides were calculated. A computer program was developed and applied to calculate the dose rate a person will receive from the walls of a room constructed from the studied building materials. 相似文献
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Luisa Barbieri Fernanda Andreola Isabella Lancellotti Rosa Taurino 《Waste management (New York, N.Y.)》2013,33(11):2307-2315
In this work the feasibility of using woody agricultural biomass wastes as grapes and cherries seeds, sawdust, as pore forming agent, and sugar cane ash, as silica precursor, in bricks, were reported.Sawdust and grapes and cherries seeds, thanks to their organic substances content, during their combustion, bring an energetic support in the bricks firing phase and act as pore forming agent. Usually the addition of this kind of waste is limited to 10 wt.% in order to reach an equilibrium between positive (weight and shrinkage decrease and porosity increase) and negative (increase of water absorption and mechanical resistance decrease) effects. The results show that grapes and cherries seeds, added in a percentage of 5 wt.% to a brick formulation, have better influence with respect to the sawdust, maintaining the mechanical properties of the fired brick (950 °C), showing modulus of rupture around 21–23 MPa with a weight reduction of 3–10% (respect to the standard one). Regarding the sugar cane ash, the addition of 5 wt.% improves the mechanical properties (modulus of rupture around 27 MPa) and no weight decrease is observed. These results confirmed the role played by this kind of agricultural waste, which thanks to its high silica content (61 wt.%) is capable to demonstrate a filler and plasticity reducing effect on the brick bodies. Tests carried out highlighted that the addition of these by-products (5 wt.%) do not change negatively the main technological properties measured (water absorption, linear shrinkage, flexural resistance, etc.) and permit to hypothesize their use to obtain bricks with both insulating and higher mechanical properties using a pore agent forming or silica carrier alternative raw materials, respectively. 相似文献
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The Kathmandu Valley in Nepal has experienced a very rapid increase in population resulting in considerable land use/land
cover change and also a series of environmental problems. One of the results of the population increase is an expansion of
brick manufacturing within the Valley because most structures are brick. The brick kilns are intense in several locations
of the Valley and have an interesting pattern of using the same lands for bricks during the dry season and then conversion
to rice during the wet, summer monsoon months. The increase in brick production has contributed to environmental problems
including decreased soil productivity, lowered ground water levels, and particularly air pollution. Brick manufacturing has
little, if any, effective regulation. There is a lack of current, accurate data on brick production that could be resolved
by remote sensing methods. Controls should be established and more information acquired on the location and impacts of brick
production. 相似文献
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