• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.1133-1140
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• 2009

The purpose of this study is to determine the most efficient method of removing sulfur dioxide from traditional herbal medicine (hanyak) by slow boiling using a traditional pipkin and an electronic slow boiler. By boiling a hanyak batch containing] 56.4ppm of sulfur dioxide for one hour using a traditional pipkin, 96.7 percent of the sulfur dioxide was removed, while two hours of slow boiling removed ]00 percent. Among different cover materials placed over the pipkin during the slow boiling process including the traditional Korean paper (hanji), regular hanji, filter paper and regular paper, the traditional hanji produced the best performance of sulfur dioxide removal. The initial pH level of the traditional hanji was] 0.03. After one hour of slow boiling hanyak batches in a traditional pipkin covered with traditional hanji, where each batch contained sulfur dioxide of 48ppm, 193ppm, 753ppm and 1,506ppm respectively, the pH level of the hanji cover material was reduced to 9.37, 9.14, 8.9 and 8.03 in respective cases. Our experiment using an electronic medicine slow boiler showed 82.8 percent removal of sulfur dioxide after one hour of slow boiling a hanyak batch containing 753ppm of sulfur dioxide. When hanyak batches were boiled by placing traditional hanji, filter paper, active carbon and hardwood charcoal separately in the middle area within the electronic slow boiler, the sulfur dioxide removal rate was 73.6 percent, 72.8 percent, 73.9 percent and 69.5 percent, respectively. When charcoal was added so as to remove toxic materials from the hanyak, its presence impeded the sulfur dioxide flow and thus reduced the removal efficiency contrary to our anticipation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.649-656
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• 2019

Flux cored arc welding (FCAW), which is used widely in many fields, such as shipyards, bridge structures, construction machinery, and plant industry, is an alternative to shielded metal arc welding (SMAW). FCAW is used largely in the welding of carbon and alloy steel because it can be welded in all poses and obtain excellent quality in the field under a range of working conditions. In this study, the mechanical properties of welded parts were analyzed after different welding of SS400 and SM490A using FCAW. The following conclusions were drawn. The tensile test results satisfied the KS standard tensile strength in the range of 400~510 N/mm2 in all welding positions. The bending test confirmed that most of the specimens did not show surface breakage or other defects during bending and exhibited sufficient toughness, even after plastic deformation. The hardness test results were lower than the standard value of 350 Hv of KS B 0893. Similar to the hardness test, were greater than the KS reference value. The macro test revealed no internal flaws, non-metallic inclusions, bubbles or impurities on the entire cross section of the weld, and there were no concerns regarding lamination.