• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.617-622
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• 2011

The policy of total maximum daily load (TMDL) was introduced to manage wasteload within the loading capacity to achieve water quality standards in the watershed. While the TMDL was implemented, the institutional and technical correction for the improvement of procedure was accomplished even though there were various problems and basically through the process of trial & error. However, a fundamental improvement of this policy is needed to implement the TMDL. This study has come up with a new viewpoint on improving this procedure for reasonable implementation of TMDL. First of all, the water quality and flowrate monitoring of the tributaries should be implemented. This should be done through the establishment of a monitoring system which will include standards of scope, a set time period, water quality parameters and frequency follow ups for the implementation of TMDL. The basic plan in all of the watersheds should be developed based on the establishment of water quality parameters and standards for water use and ecological purposes according to the results of the water quality and flowrate monitoring in the watersheds. The implementation plan for water quality improvement should be established in the watersheds where exceeds the targeted water quality standards. The performance assessment of TMDL should be conducted every year to meet the satisfaction assessment of water quality standards in the watersheds. Finally, if the water quality standards in the watersheds can not be attained or the water quality parameters and standards should be changed, the implementation procedure will be performed according to the iterative process. On the contrary, the policy of TMDL in the watersheds where the water quality standards have been met the goal will be finished.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.19-26
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• 2019

The masonry infill walls are one of the most popular components that are used for dividing and arranging spaces in building construction. In spite of the fact that the masonry infills have many advantages, the system needs to be used with caution when the earthquake load is to be considered. The infills tend to develop diagonal compression struts during earthquake and increase the demand in surrounding RC frames. If there are openings in the infill walls, the loading path gets even complicated and the engineering judgements are required for designing the system. In this study, a masonry infill system was investigated through finite element analysis (FEA) and the results were compared with the current design standard, ASCE 41. It is noted that the equivalent width of the compression strut estimated by ASCE 41 could be 32% less than that using detailed FEA. The global load resisting capacity was also estimated by 28% less when ASCE 41 was used compare to the FEA case. Rather than using expensive FEA, the adapting ASCE 41 for the analysis and design of the masonry infills with openings would provide a good estimation by about 25% conservatively.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1687-1698
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• 2021

This study is to produce multiple layers of liposomes in a supercritical state and encapsulates active ingredients in order to stably encapsulate thermodynamically unstable active ingredients. In order to form a liposome in a supercritical state, a mixed surfactant development including vegetable-derived hydrogenated phosphatidyl choline and their delivative, hydrogenated sucrose distearate was synthesized as high purity. It describes a manufacturing method of injecting liquid carbon dioxide into a reactor to create a supercritical state and stirring to produce a giant liposome, and adding and loading genistein and quercetin. The HLB of the mixed lipid complex (SC-Lipid Complex) was 12.50, and multiple layers of liposome vesicles were formed even at very low concentrations. This surfactant had a specific odor with a pale yellow flake, the specific gravity was 0.972, and the acid value was 0.12, indicating that it was synthesized with high purity. As a result of the emulsifying capacity experiment using 20 wt% capric/capric triglyceride and triethylhexanoin using SC-Lipid Complex, it was found to have 96.2% emulsifying power. SC LIPOSOME GENISTEIN was confirmed that a multi-layer liposome vesicle was formed through a transmission electron microscope (Cryo-TEM) for the supercritical liposome encapsulated with genistein. The primary liposome particle size in which genistein was encapsulated was 253.9 nm, and the secondary capsule size was 18.2 ㎛. Using genistein as the standard substance, the encapsulation efficiency of supercritical liposomes was 99.5%, and general liposomes were found to have an efficiency of 93.6%. In addition, the antioxidant activity experiment in which quercetin was sealed was confirmed by the DPPH method, and it was found that the supercritical liposome significantly maintained excellent antioxidant activity. In this study, thermodynamically unstable raw materials were sealed into liposomes without organic solvents in a supercritical state. Based on these results, it is expected that it can be applied to various forms such as highly functional skincare cosmetics, makeup cosmetics, and scalp protection cosmetics.