• Title/Summary/Keyword: heat-damage

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Cause Analysis for a Lining Damage in Sea Water System Piping Installed in a Korean Industrial Plant

  • Hwang, K.M.;Park, S.K.
    • Corrosion Science and Technology
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    • v.20 no.1
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    • pp.1-6
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    • 2021
  • Many Korean industrial plants including nuclear and fossil power plants use seawater as the ultimate heat sink to cool the heat generated by various facilities. Owing to the high corrosivity of seawater, facilities and piping made of metal material in contact with seawater are coated or lined with polymeric materials to avoid direct contact with seawater. However, polymeric materials used as coating and lining have some level of permeability to water and are degraded over time. Korean industrial plants have also experienced a gradual increase in the frequency of damage to pipes in seawater systems due to prolonged operating periods. In the event of a cavitation-like phenomenon, coating or lining inside the piping is likely to be damaged faster than expected. In this paper, the cause of water leakage due to base metal damage caused by the failure of the polyester lining in seawater system piping was assessed and the experience with establishing countermeasures to prevent such damage was described.

High-Temperature Design and Integrity Evaluation of Sodium-Cooled Fast Reactor Decay Heat Exchanger (소듐냉각고속로 붕괴열교환기의 고온 설계 및 건전성 평가)

  • Lee, Hyeong-Yeon;Eoh, Jae-Hyuk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.10
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    • pp.1251-1259
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    • 2013
  • In this study, high temperature design and creep-fatigue damage evaluation of a decay heat exchanger (DHX) in the decay heat removal systems of a sodium-cooled fast reactor (SFR) have been performed. Detail design and 3D finite element analysis have been conducted for the DHXs to be installed in active and passive decay heat removal systems in Korean Generation IV SFR, and the DHX installed in the STELLA-1(Sodium integral effect test loop for safety simulation and assessment) at KAERI (Korea Atomic Energy Research Institute). Evaluations of creep-fatigue damage based on full 3D finite element analyses were conducted for the two Mod.9Cr-1Mo steel heat exchangers according to the elevated temperature design codes of ASME Section III Subsection NH and RCC-MR code. Code comparisons were made based on the creep-fatigue damage evaluation and issues on conservatisms of the design codes were discussed.

Hyperthermia-induced Apoptosis is Independent upon DNA Strand Breaks in Human Lymphoid Cells

  • Jung, Hwa-Jin;Ka, Won-Hye;Hwang, Jee-Na;Seo, Young-Rok
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.6
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    • pp.345-349
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    • 2004
  • Heat shock ($43^{\circ}C$ for 60 minutes) is sufficient to induce apoptosis in a wide number of cell lines. In this study, we asked whether DNA strand breaks are responsible for this phenomenon. Using the highly sensitive comet assay for DNA damage detection, we were unable to demonstrate DNA breaks immediately after heat shock in Raji human Iymphoid cells. It showed that DNA breaks were not necessary for hyperthermic apoptosis, since its activity is indicative of DNA lesions. Here, we present a suggestion that a protein(s) is the major target for heat shock apoptosis. We firstly found glycerol, which reportedly stabilizes protein structure, showed a protective effect in Raji cells against hyperthermic apoptosis. In addition, quercetin, which modulates transcription of the heat shock protein family members, enhanced apoptotic death induced by hyperthermia. Furthermore, Raji cells are protected by a pre-mild heat treatment prior to the killing dose of heat shock.

A Study on Cold Damage(傷寒) in the Compendium of Prescription from the Countryside(鄕藥集成方) - Focusing on citation, medical theory, prescription, medicinal herbs - (조선 의서 『향약집성방』 중에 실린 상한(傷寒) 논의 연구 - 인용 문헌, 의론(醫論), 처방, 본초 등을 중심으로 -)

  • Oh, Chae-Kun
    • The Journal of Korean Medical History
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    • v.25 no.2
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    • pp.121-136
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    • 2012
  • The purpose of this paper is to derive the features of cold damage clinical medicine during the early days of the Chosun(朝鮮) period by analyzing discussions on cold damage published in the official medical book of the Chosun period, Compendium of Prescription from the Countryside(鄕藥集成方, CPC). Cold damage was one of the typical diseases in East Asia where there was constant seeking of the utilization of prescriptions, ways of preparations, and awareness regarding cold damage as shown in Zhang, Zhongjing(張仲景)'s Treatise on Cold Damage Disease(傷寒論, TCDD) below. Traditional Korean medicine which possessed the medical universality of East Asia also was no exception and through an analysis of the part on cold damage in CPC, it is expected that medical features of cold damage in Korea passed down from the Koryo(高麗) Dynasty to the early Chosun period will be revealed. For this, first there needs to be an organization of past discussions on cold damage surrounding the existence of infection and after checking the issues, exploring which of the writings related to TCDD and editions are being utilized through an analysis on citing literature of Cold Damage Disease Literature(傷寒門) and Heat Pathogen Disease Literature(熱病門) which have developed discussions on cold damage in CPC. In addition, by comparing Peaceful Holy Benevolent Prescription(太平聖惠方, PHBP) and Complete Record of Sacred Benevolence(聖濟總錄, CRSB), known to have greatly influenced CPC and Cold Damage Literature and Heat Pathogen Disease Literature, features of form and content used by CPC were analyzed. Features of form were examined through pattern of organization and number of citing literature were examined and for features of content, cold damage infection, classification, syndrome differentiation method, and utilization of materia medica among prescriptions were examined. Discussions on cold damage as being uninfectious as stated in Treatise on the Pathogenesis and Manifestations of All Diseases(諸病源候論) unlike pestilence, epidemic pathogen(時氣), warm pathogen disease(溫病), and heat pathogen disease were excluded in PHBP. PHBP opened the possibility of cold damage infection and later writings, CRSB and CPC also follow this. As a result of analyzing citing literature of the part on cold damage in CPC, it is uncertain which edition of TCDD is being utilized; however, the most distinctive feature was that Classified Emergency Materia Medica(證類本草) and not writings specializing in cold damage are in use. In general, although CPC in terms of form is similar to CRSB, content creation predominantly depended on PHBP. More specifically; first, in terms of the existence of cold damage infection, arguments of PHBP and CRSB are maintained. Second, in terms of cold damage classification, although CRSB is followed, heat pathogen disease is classified separately developing PHBP as is. Third, in terms of method, as Book of Keep Healthy(南陽活人書) and CRSB compiled in later times are cited, it is deemed that arguments were raised to a certain extent regarding six-meridian syndrome differentiation(六經辨證). Fourth, although the majority of utilized materia medica among cold damage prescriptions utilize Materia Medica from the Countryside(鄕藥本草) in CPC and materia medica from Korean Peninsula, this is due to the desire for the compilation performance of CPC to be propagated to ordinary citizens and not the ruling class. CPC as the official medical book compiled in the early days of the Chosun period was greatly influenced by the Song(宋) Dynasty's medical books, PHBP and CRSB shows that cold damage medicine in the early Chosun Period indeed possesses the medical universality of East Asia. Furthermore, the features of published medical theory and prescriptions reveal the existence of the cold damage medical tradition of the Chosun period serving as clues for cold damage research tradition among Korea's medical history.

Field Application of the Mass Concrete Utilizing Combined Method for Temperature Crack Reduction (온도균열 저감공법을 복합사용한 매스콘크리트의 현장적용)

  • Han, Sang-Yoon;Lee, Chung-Sub;Baek, Dae-Hyun;Jang, Duk-Bae;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.37-39
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    • 2010
  • In this study, with new office construction site of S Construction company as subject, to solve all the problems according to reduced hydration heat and temperature crack of mass concrete used mat foundation and placing time difference, low heat combination of coarse particle cement and fly-ash and setting time difference applied AE water reducing agent, and to prevent the early frost damage caused by low outdoor temperature, a heat insulation method using double bubble sheet was conducted. As a result, it was found that hydration heat and setting time difference was reduced by applying a low heat combination and setting time difference construction method, and that the high insulation capability of the double bubble sheet was able to not only prevent the early frost damage but also reduce temperature difference between the central part and the upper part of mass concrete.

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The Effect of Heat Curing Methods on the Protection against Frost Damage at Early Age of the Concrete Under Extremely Cold Climate

  • Jung, Eun-Bong;Shin, Hyun-Sup;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.6
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    • pp.513-521
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    • 2013
  • This study aimed to examine whether heat curing methods of concrete subjected to $-10^{\circ}C$ could be effective by varying the combination of heating cable and surface heat insulations. Three different concrete specimens incorporating 30% fly ash with 50% W/B were fabricated to simulate wall, column and slab members with dimensions of $1600{\times}800{\times}200$ mm for slab, $800{\times}600{\times}200$ mm for wall and $800{\times}800{\times}800$ mm for column. For heat curing combinations, Type-1 specimens applied PE film for slab, plywood for wall and column curing. Type-2 specimens applied double layer bubble sheet (2LB) and heating coil for slab, and 50 mm styrofoam for wall and column curing. Type-3 specimen applied 2LB for slab, electrical heating mat for wall and column inside heating enclosure. The test results revealed that the temperature of Type 1 specimen dropped below $0^{\circ}C$ beginning at 48 hours after placement due to its poor heat insulating capability. Type 2 and 3 specimens maintained a temperature of around $5{\sim}10^{\circ}C$ after placement due to favorable heat insulating and thermal resistance.

Heat Transfer Test of Tunnel Lining with Heat Insulation (단열재 적용에 따른 터널 라이닝 열전달량 시험)

  • Jin, Hyunwoo;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.7
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    • pp.5-12
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    • 2017
  • The surface of the tunnel lining issues various problems such as cracks due to the cold weather. It is necessary to reduce the recovery costs by means of developing new recovery techniques. However, the research on reducing the damage of road tunnel lining caused by cold weather has not actively been conducted. Hence, this paper analyzes the effectiveness of using insulating materials such as aerogel and heat insulating liquid in enhancing insulating capability. The results show that these materials are effective in reducing heat transfer, confirming damage reduction in cold weather.

The Research of Planning Method of Adaption for Old Residential Neighborhoods According to Heat wave and Urban Heat-island Phenomena - Focused on Gun-Ja Dong, Gwang-Jin Gu - (폭염 및 도시열섬현상에 따른 노후 주거지의 적응 계획기법에 관한 연구 - 광진구 군자동 중심으로 -)

  • Kim, Min-Young;Moon, Eun-Seol
    • KIEAE Journal
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    • v.16 no.4
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    • pp.31-39
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    • 2016
  • Purpose: Urban heat island and Heat wave raise urban temperature and create damage of human life. Growing up as quantitative supply to solve shortage of housing, Urban residential area in Korea have a low rate of nature surface and heavily population makes temperature rise. Most houses in the declined residential area are multi-family rental housing and have many factors congesting housing environment such as narrow in-between space, outdoor staircases, walls and semi-basement floor, which make thermal environment getting worse. Most of the residents in this area are small tenants vulnerable to climate change adaptation, This damage is expected to be even greater. This study focus on multiple dwelling in urban residential area prone to temperature rise and draw temperature adaption method that can apply to multiple dwelling.

Study on Real-Time Monitoring Platform for Countermeasures for Heatwave (폭염재난 대응 실시간 관제 플랫폼에 관한 연구)

  • Jung, Kang Hee;Kwak, Chang Hyeok
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.4
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    • pp.113-118
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    • 2022
  • Global warming has also increased the number of casualties caused by heat-related diseases caused by heat waves along with an increase in global temperature. The vulnerable groups from heat wave damage are outdoor workers and the elderly in particular, and it is necessary to respond the increasing heat wave damage. We propose a real-time control platform in order to reduce casualties of the vulnerable group from heatwaves, this research collects and analyzes user's vital signs data from wearable devices that generates alarms out of the suspected victims who are expected to be affected by heat-related illness and to respond quickly.

Cause of Corrosion and Evaluation of Material Corrosion Resistance on Underground Heat Transport Facilities Connected to Manhole (맨홀과 연결된 지하 열수송설비의 부식 원인 및 재질 내식성 평가)

  • Song, M.J.;Choi, G.;Kim, W.C.;Lee, S.Y.
    • Journal of the Korean Society for Heat Treatment
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    • v.35 no.4
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    • pp.193-202
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    • 2022
  • Manholes and underground spaces are installed to manage the buried heat transport pipes of the district heating system, and the corrosion damage of the equipment placed in this space often occurs. The purpose of this work is to identify locations with a high risk of corrosion damage in the air vent and to establish preventive measures based on precise analysis via sampling of heat transport pipes and air vents that have been used for about 30 years. The residual thickness of the air vent decreased significantly by reaching ~1.1 mm in thickness, and locations of 60~70 mm away from a transport pipe were the most vulnerable to corrosion. The energy dispersive X-ray spectroscopy (EDS) analysis was performed in the corroded oxides, and it was found that chloride ion was contained in the corrosion products. Anodic polarization tests were carried out on the air vent materials (SPPS250, SS304) with varying the amounts of chloride ions at two different temperatures (RT, 80℃). The higher concentration of chloride ions and temperature are, the lower corrosion resistances of both alloys are.