• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.38-45
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• 2002

Hydrates are solid cryctallines resembling ice in appearance, which are consist of a gas molecule surrounded by a cage of water molecules. Because of containning a large amount of methane, hydrates have been considered as a future energy resource. However, the formation of hydrates in the oil and gas industries has been known as a serious problem for a long time. The formation of hydrate in pipeline is common in seasonally cold or sub-sea environments with low temperatures and high pressures. Especially, hydrate plug formation becomes a real menace to flow assurance in inadequately protected transmission lines. This study was carried out for the purpose of understanding mechanism of hydrate plugging and examining formation conditions of hydrate in high pressure gas pipeline. In this study, we measured hydrate equilibrium conditions under the various flowing conditions with the methane. The results were presented both the plugging tendency and the effect of flowing velocity.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.91-99
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• 2010

In order to strengthen RC structures, various strengthening methods have been used. Particularly, external tendon strengthening method is very popular method to strengthen damaged structures in terms of efficiency, ease, economics. In this study, improved anchorage elements using the lifting hole were proposed to strengthen PSC or RC girder without any damage. Two types of anchorage elements were proposed and these elements were applied on six RC beams. Also, three types of existing anchorage elements were applied on three RC beams. Otherwise, any anchorage element was not applied on one RC beam to used as a control beam. To analyse behavior of these elements, static load tests were carried out. Test variables were anchorage shapes, prestressing level on the steel bar and tendon profiles. Deflections, strains and modes of failure were recorded to examine the strengthening effects of the beams. Ductility index and tendon stress were analyzed by comparing cracking load, yielding load and ultimate load. As a result, proposed anchorage elements using lifting hole were superior to existing anchorage elements in terms of strengthening effect and furthermore, they showed ductile behavior based on energy method.

• Journal of Adhesion and Interface
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• v.13 no.4
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• pp.171-181
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• 2012

The demand characteristics of the conventional 12 kinds of epoxy resins which have been used for restoration of the ceramic relics were investigated to provide standards of the effective materials in this study. The result of durability analysis showed that a liquid type is more effective in ceramic relics (low damage, high strength), and a paste type is more effective in earthenware relics (high damage, low strength). The result of workability analysis appears that the liquid type is higher than the paste type, and a slow curing type is higher than a fast curing type in surface hardness. Therefore, in the case of the liquid type which is hard to reprocess due to high surface hardness, it is necessary to conduct a study on improving physical properties by adding filler. The result of the gloss analysis on epoxy resins showed that the liquid type (colorless) has higher gloss than the paste type, and the slow curing type has higher gloss than the fast curing type in liquid types. CDK-520A/520B and Araldite SV 427-2/HV 427-1 showed the most similar gloss to $700^{\circ}C$ earthenware, Devcon 5 minute, EPO-TEK 301-2, and Quik Wood showed the most similar gloss to celadon and whiteware, Quik Wood, EPO-TEK 301-2, and Devcon 5 minute showed the most similar gloss to buncheongware. It is necessary for conservator to decide the range of the restoration surface by predicting the increase and decrease of the restoration surface because most of the epoxy resins caused the volume change in curing process.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.1
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• pp.75-80
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• 2006

Purpose: To evaluate the efficiency of Acutrak screw fixation for radial head fracture (Mason type 2) without considering the safe Bone of radial head. Materials and Methods: Consecutive seven radial head fracture of Mason type II underwent internal fixation with Acutrak screws from May 2001 to February 2003. The mean follow-up period was 1.2years (ranged, $6 months{\sim}2.5 years$). The mean age of patients was 47 years old (ranged, $36{\sim}60years$ old). The cause of injury were fall down -4 cases and traffic accident -3 cases. The results were evaluated by Mayo Clinic results scoring system. Results: Functional Rating Index of Mayo Clinic was excellent- 2 cases and good- 5 cases. There were no nonunion, loosening, heterotopic ossification, infection or degenerative changes. The postoperative range of motion in elbow joint is nearly full for flexion, extension, pronation and supination in this study Conclusion: Consideration of safe zone is not necessary when Acutrak screws are used for radial head fracture. It seems to be a useful method that Acutrak screw fixation for radial head fracture (Mason type II) could achieve good radiologic and clinical results without influencing proximal radio-ulnar joint and has powerful fixation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1708-1716
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• 2016

The Akt/mammalian target of the rapamycin (mTOR) pathway is activated in the majority of human cancers. Activation of the Akt/mTOR pathway confers resistance to many types of cancer therapy. In this study, we evaluated the apoptotic effect of ethanol extract of Artemisia annua L. through down-regulation of Akt signal pathways and the mitochondrial pathway in hepato-carcinoma cells (HepG2). A. annua extract is known as a medicinal herb that is effective against cancer. We evaluated anti-proliferative activity by MTT-based viability assay and apoptotic effect by Annexin-V/PI staining, mitochondrial membrane potential (MMP), and caspase-3/7 activity as determined by flow cytometry. A. annua treatment led to loss of MMP, resulting in cytochrome c-inducible activation of caspase-3/7. Treatment with A. annua extract reduced activities of Akt/mTOR/anti-apoptotic proteins (such as Bcl-2 and $Bcl-X_L$), leading to increased activation of tumor suppressor p53 and pro-apoptotic proteins (such as Bax and Bak). We applied LY294002 (inhibitor of Akt) and rapamycin (inhibitor of mTOR) to determine the relationship between signal transduction of proteins associated with apoptosis. LY294002 and rapamycin significantly reduced cell viability and increased apoptosis. These results indicate that Bcl-2 and caspase-3 are key regulators in A. annua extract-induced apoptosis in HepG2 cells and are controlled through the Akt/mTOR signaling pathway.

• Journal of Life Science
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• v.16 no.1
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• pp.12-16
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• 2006

Genetic alternation of Brca1 predispose of breast and ovarian cancer. Brca1 plays critical role in cell cycle regulation following DNA damage. Previous studies revealed that Brca1 plays an important role in S phase and G2/M checkpoint regulation. However, whether Brca1 involves in spindle checkpoint is unclear. In this study, the role of Brca1 in cell cycle response following nocodazole, which is a reagent that depolymerizes microtubules and activates the spindle checkpoint, has been examined using wild type $p53^{-/-}\;and\;p53^{-/-}Brca1^{-/-}$ mouse embryonic fibroblasts (MEFs). While wild type and Brca1-proficient MEFs showed an acute mitotic arrest, Brca1-deficient MEFs failed to arrest at mitotic phase in response to nocodazole treatment. In double-thymidine block and nocodazole treatment experiment, a portion of $p53^{-/-}\;Brca1^{-/-}$ MEFs were clearly by-passed nocodazole induced mitotic arrest. Consistent with this, in morphologic analysis, $p53^{-/-}\;Brca1^{-/-}$ MEFs showed growing cell morphology after nocodazole treatment. Taken together, these results suggest that Brca1 protein is an important component for normal induction of spindlecheckpoint and impairment of Brca1 function could induce dysregulation of mitotic cell cycle that ultimately results in genomic instability.

• Journal of Conservation Science
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• v.26 no.1
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• pp.69-76
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• 2010

As the tangible evidence, documentary art records are permanent records to reflect the historical, symbolical, cultural and artistic value. Also, documentary art records are related with mission fulfillment of public institution and it is documentary with administrative, cultural and artistic values as the works of documentary production and application of the administrative image. "The public records management law" was the first time that administration documents were incorporated and in the act No. 3 of administrative records management, the preservation and management system of documentary art records became legislated. The management of documentary art records are difficult to categorize only by the reflect of characteristics or materials. Because documentary art records are collected in many ways and made with materials. It needs to be collected with many informations on basic materials and with the appropriate conservation and management category. Documentary art records do not have lots of demands but the level of consciousness is improving and the possibility of opening to public is increasing for improvement with the right to know. In near future, the documentary art records will be used for the interpretation of historical and cultural preservation and modern cultural heritage could have the value as it is expected. Primarily to prevent deterioration on documentary art records the standard survey card should be made to categorize the damage rate and to check the status on each documentary art records. In addition, establishing a systematic management plan for various documentary art records are needed with the training of professionals for the conservation of documentary art records.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.2
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• pp.33-41
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• 2019

Purpose: The purpose of this study is to improve the reduction of coverage of PTVs adjacent to organ at risk (OAR) by setting up overlapping Planning Target Volume (PTV) during Volumetric Modulated Arc Therapy(VMAT). Materials and Methods: In patients who received Whole Brain, Gall Bladder and Rectum radiation therapy, We compared the cover change, maximum dose, Homogenicity Index and Conformity Index of PTV and also compared the maximum dose and average dose change of Organ At Risk by organizing treatment plans that are not applied overlaped PTV and treatment plans that are applied overlaped PTV in areas where coverage is insufficient. Results: overage of treatment plans with overlapping PTVs was increased in all patients, and overall coverage was also increased in each of the four patients. The maximum dose for PTV was increased in five patients, and the Homogenicity Index and Conformity Index for all patients did not differ much. The maximum dose of the lens was increased by 1.12 times, and the maximum dose was decreased in two patients for brain stem. The mean dose of the eyeball was increased by a maximum of 1.15 times, and there was no significant difference between both parotid gland. In case of gallbladder cancer patients, the mean dose in the liver and colon was decreased, and the mean dose in the duodenum was increased. In the case of rectal cancer patients, the mean dose was reduced for both femur and bladder set as OARs. The overall MU was shown to be similar in four patients, excluding one. Conclusion: If the critical dose of OAR is considered and used properly, I think it is a useful way to improve coverage of PTV.

• Food Science and Preservation
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• v.21 no.2
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• pp.264-275
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• 2014

This study evaluated the improving efficacy of Lespedeza cuneata ethanol extract on skin photoaging induced by ultraviolet (UV) irradiation. The total polyphenol and flavonoid contents of the extract were respectively $134.98{\pm}1.70$ and $16.20{\pm}0.05$ mg/g, respectively. The superoxide anion radical scavenging activity and electron-donating ability of the extract were shown to be dependent on concentration, and the antioxidant ability was shown to be more effective in superoxide anion radical scavenging activity than in electron-donating ability under the same concentration conditions. In the in vivo test conducted using hairless mouse with skin photoaging induced by UVB irradiation, the skin erythema of the groups treated with the extract (AS) reduced to 28% of the control, and the skin moisture content increased to 131%.. The extract treatment of the UV-damaged skin improved the morphological and histopathological state of the skin. Furthermore, the SOD, GST and CAT activities in the skin tissue of the AS group increased, and the XO activity and TBARS generation decreased. With regard to the genes related to the photoaging skin, the expression of PAK, p38, c-Fos, c-Jun, TNF-${\alpha}$ and MMP-3 in the skin of the AS group were found to have decreased. It was therefore concluded that Lespedeza cuneata ethanol extract can reduce wrinkle formation in the skin due to the regulation of the gene expression caused by the exposure to UVB light.

• Journal of Conservation Science
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• v.24
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• pp.23-36
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• 2008

The stone Buddhas and Shrine of Unjusa temple (Korea Treasure No. 797) in Hwasun formed in Koryo Dynasty are unique style which the Buddha faces each other the back parts of south and north within the stone Shrine. The stone Buddhas and Shrine are highly evaluated in historical, artistic and academic respects. But, the stone properties have been exposed in the open system various aspects of degradations weathered for a long time without specific protective facilities. The rock materials of the stone Buddhas and Shrine are about 47 blocks, and total press load is about 56.6 metric ton. The host rocks composed mainly of white grey hyaline lithic tuff and rhyolitic tuff breccia. In addition, biotite granite used as part during the restoration works. The chemical index of alteration for host tuffaceous rocks and the replacement granites range from 52.1 to 59.4 and 50.0 to 51.0, respectively. Weathering types for the stone Buddhas and Shrine were largely divided with physical, chemical and biological weathering to make a synthetic deterioration map according to aspects of damage, and estimate share as compared with surface area. Whole deterioration degrees are represented that physical weathering appeared exfoliation. Chemical weathering is black coloration and biological weathering of grey lichen, which show each lighly deterioration degrees. According to deterioration degree by direction of stone Buddhas and Shrine, physical weathering mostly appeared by 39.1% on the sorthern part, and chemical weathering is 61.2% high share on the western part. Biological weathering showed 38.3% the largest distribution on the southern part. Therefore, it is necessary to try hardening for the parts with serious cracks or exfoliations, remove secondary contaminants and organisms through regular cleaning. Also necessary to make a plan to remove moisture of the ground which causes weathering, and estimate that need established and scientific processing through clinical demonstration of conservation plan that chooses suitable treatment.