• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.332-340
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• 2016

Sunken ships cause damage to the environment due to the dispersal of fuel oil and harmful cargo goods in the hull. Since the sunken ship is mostly flooded by the seabed, it tends to be in a relatively stable condition. However, the heavy body, together with the load of remaining goods in the cargo hold, the constant contact with the seabed, and ocean currents and tidal waves, can affect dispersal of residual fuel oils out of the sunken ship. Corrosion of the sunken ship starts upon sinking, decreasing the thickness of the hull structure and sub-materials. Therefore, it is necessary to assess the structural stability against the potential breakdown of the sunken ship. Whilst evaluating the danger of the sunken ship, this result should be reflected in 'the possible discharge'. This study was undertaken to suggest a procedure for a step by step evaluation to assess the structural stability a sunken ship. The structural stability assessment to estimate the collapsibility of the hull was structure targeted at the sunken ship 'No. 7 HaeSung', which was classified as the prime example for the intensive management of sunken ships. This study was undertaken to suggest a procedure for a step by step evaluation to assess the structural stability a sunken ship and to propose a method to conduct a structural safety assessment that estimates the collapsibility of the hull by targeting the sunken ship 'No. 7 HaeSung',which was classified as the prime example for the intensive management of sunken ships. The collapsibility of the hull structure was estimated Based on the damage size of the hull structure, and the corrosion rate of the hull structure and sub-materials due to the seawater after sinking. It was confirmed that there was a low possibility of the total destruction of the hull structure at the current time. However, there is a high possibility in the potential failure of the hull structure due to increased rate of corrosion thereafter. Therefore, we believe continuous study on influence of corrosion and marine environment change to sunken ship's structural safety is necessary.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.3
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• pp.96-102
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• 2017

Glycogen storage disease type IX (GSD IX) is caused by deficiency of phosphorylase kinase which plays a role in breakdown of glycogen. Mutations in PHKA2 are the most common cause of GSD IX (GSD IXa). Clinical manifestations of GSD IXa include hepatomegaly, elevation of liver enzyme, growth retardation, fasting hypoglycemia, and fasting ketosis. However, the symptoms overlap with those of other types of GSDs. Here, we report Korean familial cases with GSD IXa whose diagnosis was confirmed by targeted exome sequencing. A 4-year old male patient was presented with hepatomegaly and persistently elevated liver enzyme. Liver biopsy revealed swollen hepatocyte filled with glycogen storage, suggesting GSDs. Targeted exome sequencing was performed for the differential molecular diagnosis of various types of GSDs. A hemizygous mutation in PHKA2 were detected by targeted exome sequencing and confirmed by Sanger sequencing: c.3632C>T (p.Thr121Met), which was previously reported. The familial genetic analysis revealed that his mother was heterozygous carrier of c.3632C>T mutation and his 28-month old brother had hemizygous mutation. His brother also had hepatomegaly and elevated liver enzyme. The hypoglycemia was prevented by frequent meals with complex carbohydrate, as well as cornstarch supplements. Their growth and development is in normal range. We suggest that targeted exome sequencing could be a useful diagnostic tool for the genetically heterogeneous and clinically indistinguishable GSDs. A precise molecular diagnosis of GSD can provide appropriate therapy and genetic counseling for the family.

• Journal of Energy Engineering
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• v.28 no.2
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• pp.18-35
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• 2019

The Korea District Heating Corporation operates a gas engine generator with a capacity of $4500m^3 /day$ of biogas generated from the sewage treatment plant of the Nanji Water Recycling Center and 1,500 kW. However, the actual operation experience of the biogas power plant is insufficient, and due to lack of accumulated technology and know-how, frequent breakdown and stoppage of the gas engine causes a lot of economic loss. Therefore, it is necessary to prepare technical fundamental measures for stable operation of the power plant In this study, a series of process problems of the gas engine plant using the biogas generated in the sewage treatment plant of the Nanji Water Recovery Center were identified and the optimization of the actual operation was made by minimizing the problems in each step. In order to purify the gas, which is the main cause of the failure stop, the conditions for establishing the quality standard of the adsorption capacity of the activated carbon were established through the analysis of the components and the adsorption test for the active carbon being used at present. In addition, the system was applied to actual operation by applying standards for replacement cycle of activated carbon to minimize impurities, strengthening measurement period of hydrogen sulfide, localization of activated carbon, and strengthening and improving the operation standards of the plant. As a result, the operating performance of gas engine # 1 was increased by 530% and the operation of the second engine was increased by 250%. In addition, improvement of vent line equipment has reduced work process and increased normal operation time and operation rate. In terms of economic efficiency, it also showed a sales increase of KRW 77,000 / year. By applying the strengthening and improvement measures of operating standards, it is possible to reduce the stoppage of the biogas plant, increase the utilization rate, It is judged to be an operational plan.