• Resources Recycling
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• v.21 no.2
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• pp.53-58
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• 2012

A laboratory study was carried out to recover KI crystals with high purity from a waste solution generated from the production of polarizing film for LCD industry. The waste solution contains 1 to 4% KI, and other impurities such as B, PVA and etc. More than 95% purity of KI crystals were produced through refining process such as vacuum evaporation and fractional crystallization. Most of B compounds and impurities were removed by concentrating the waste solution until KI content reached about 50%. The KI crystals were washed with solvents to remove most of PVA which gave result in producing 99.5% purity of crystals. The overall recovery of KI was about 90% during the concentration process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1367-1375
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• 2010

In this study, optimization of the process parameters of the resistance spot welding of a sheet of aluminum-coated boron alloyed steel, 22MnB5, used in hot stamping has been performed by a Taguchi method to increase the strength of the weld joint. The process parameters selected were current, electrode force, and weld time. The heating temperature and heating time of 22MnB5 are considered to be noise factors. It was known that the variation in the thickness of the intermetallic compound layer between the aluminum-coated layer and the substrate, which influences on the formation of nugget, was generated due to the difference of diffusion reaction according to heating conditions. From the results of spot weld experiment, the optimum weld condition was determined to be when the current, electrode force, and weld time were 8kA, 4kN, and 18 cycles, respectively. The result of a test performed to verify the optimized weld condition showed that the tensile strength of the weld joint was over 32kN, which is considerably higher than the required strength, i.e., 23kN.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.97-103
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• 1975

In order to use the glutamic acid fermentation residuum in agriculture effectively, comparison experiments of the residua liquid and dried solid, and compost on radish (Raphanus Sativus) and chinese cabbage (Brassica chinesis) were carried out, together with an investigation on some physical property changes of soil brought about by the use of the residua and compost. 1. An equal or somewhat superior effect of the glutamic acid fermentation residua solid and liquid, to urea was observed. 2. Both residua liquid and dried solid, tended to acidify soil and the tendency was observed to be somewhat servere in the latter. 3. The liquid fermentation residuum compounded with minor elements such as iron, manganese, zinc, copper and boron increased the yield of chinese cabbage compared with the liquid residuum alone. 4. Not only as a N, K fertilizer, the liquid residuum of glutamic acid fermentation could also be used as a source for liquid or solid compound fertilizer.