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Garey A. Fox John W. Fuchs Victor F. Medina Kaumudi Atapattu 《Canadian Metallurgical Quarterly》2007,133(3):255-262
Recent research has proposed the use of asphalt and tall-oil-pitch emulsions for stabilizing radioactive contamination deposited on surfaces in urban areas. The objective of this project was to investigate whether surface applied emulsions could capture airborne radioactive particulate. Laboratory experiments included wind-blown particulate capture studies using an acrylic column and particulate retainment experiments using a wind box capable of producing wind speeds of 96?km/h. A probe methodology was developed to relate particulate retainment to a tack force on the emulsion surface. Experiments were also performed to determine the potential for such emulsions to absorb particulate matter into their emulsion matrix. Tall-oil-pitch emulsions outperformed asphalt emulsions in terms of particulate retention, tack force, and the ability to absorb magnesium silicate. Both tall-oil-pitch and asphalt emulsions were capable of extracting 22–24?g?m?2 of powder from particulate-laden airflow. Tall-oil-pitch emulsions were capable of retaining as much as 5–10% of magnesium silicate powder applied (i.e., retainment densities of 10–20?g?m?2) even after seven?days of curing and after applying 96.5?km/h (60?mph) wind. Tall-oil-pitch emulsions were able to absorb surface-applied magnesium silicate (approximately 0.1–0.2?g of magnesium silicate per 1.0?g of emulsion within three?days) into their emulsion matrix, preventing the magnesium silicate from being exposed to the external environment. Initial results with these five different emulsion formulations suggested particulate capture was feasible. Future emulsion formulations (i.e., longer curing times with greater acid concentrations) should be tested to optimize this postdetonation response strategy. 相似文献
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H. Y. R. Atapattu D. S. M. De Silva K. A. S. Pathiratne I. M. Dharmadasa 《Journal of Materials Science: Materials in Electronics》2018,29(8):6236-6244
Electrodeposition (ED) has been recognized as a low cost and scalable technique available for fabrication of CdS/CdTe solar cells. Photovoltaic activity of these electrodeposited semiconductor materials drastically depends on the ED growth parameters namely; electrodeposition potential, concentrations and ratios of concentrations of precursors used to prepare the bath electrolyte, pH of the electrolyte, deposition temperature and rate of stirring of the electrolyte. In order to grow thin films with good photovoltaic properties, it is essential to maintain these variables at their optimum ranges of values during electrodepositions. Hence, this study was conducted to investigate the dependence of the properties of electrodeposited CdTe thin film material on the rate of stirring of the bath electrolyte. The CdTe material was grown on glass/FTO (2?×?3 cm2) and glass/FTO/CdS (2?×?3 cm2) surfaces in bath electrolytes containing 1.0 mol/L CdSO4 and 1.0 mmol/L TeO2 solutions at different rates of stirring within the range of 0–350 rpm while keeping the values of pH of the electrolyte, deposition temperature and cathodic deposition potential with respect to the saturated calomel electrode at 2.3, 65 °C and 650 mV respectively. After the heat treatment at 400 °C in air atmosphere, the deposited samples with a good visual appearance were selected and evaluated based on their morphological, elemental, structural, optical and electrical properties in order to identify the optimum range of rate of stirring for electrodeposition of CdTe thin film semiconductors. Results revealed that, rates of stirring in the range of 60–85 rpm in a 100 mL volume of electrolyte containing the substrate and the counter electrodes in the center of the bath with a separation of 2.0 cm between them can electrodeposit CdTe layers exhibiting required levels of morphological, structural, optical and electrical properties on both glass/FTO and glass/FTO/CdS surfaces. 相似文献
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Atapattu S. Rajatheva N. Tellambura C. 《Vehicular Technology, IEEE Transactions on》2010,59(1):93-104
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Khaokaew S Landrot G Chaney RL Pandya K Sparks DL 《Environmental science & technology》2012,46(7):3957-3963
Zinc is an important nutrient for plants, but it can be toxic at high concentrations. The solubility and speciation of Zn is controlled by many factors, especially soil pH and Eh, which can vary in lowland rice culture. This study determined Zn speciation and release kinetics in Cd-Zn cocontaminated alkaline and acidified paddy soils, under various flooding periods and draining conditions, by employing synchrotron-based techniques and a stirred-flow kinetic method. Results showed almost no change in Zn speciation and release kinetics in the two soils, although the soils were subjected to different flooding periods and draining conditions. The mineral phases in which Zn is immobilized in the soil samples were constrained by linear least squares fitting (LLSF) analyses of bulk X-ray absorption fine structure (XAFS) spectra. Only two main phases were identified by LLSF, i.e., Zn-layered double hydroxides (Zn/Mg-hydrotalcite-like, and ZnAl-LDH) and Zn-phyllosilicates (Zn-kerolite). Under all soil pHs, flooding, and draining conditions, less than 22% of Zn was desorbed from the soil after a two-hour desorption experiment. The information on Zn chemistry obtained in this study will be useful in finding the best strategy to control Cd and Zn bioavailability in the Cd-Zn cocontaminated paddy soils. 相似文献
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