• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.705-713
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• 2023

The phenomenon of abnormal climate conditions resulting from greenhouse gas-induced global warming is increasingly prevalent. To address this challenge, global initiatives are underway to adopt environmentally friendly, zero-emission fuels. In this study, we investigate the hydrogen embrittlement characteristics of materials used for eco-friendly hydrogen storage systems. The effects of hydrogen embrittlement on austenitic stainless steels of the FCC series and structural steel of the BCC series were examined. Initially, test samples of three different steel types were prepared in 2t and 3t sizes, and hydrogen was injected into the specimens using an electrochemical method over a 24-hour period. Subsequently, a universal material testing machine (UTM) was employed to monitor changes in mechanical strength and elongation. The FCC series stainless steels exhibited a tendency for elongation to decrease, indicating low sensitivity to hydrogen. In contrast, the mechanical strength and elongation of the BCC series steel changed significantly upon hydrogen charging, posing challenges for prediction. The results of the present study are expected to serve as a fundamental database for analyzing the impact of hydrogen embrittlement on both FCC and BCC series steel materials.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.70-77
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• 2010

In this paper, a case study of drivability and bearing capacity of large diameter steel pipe piles at PTT LNG site in Thailand is introduced. The LNG facilities were designed to be founded on steel pipe pile foundations driven into the weathered rock formation overlaid by sand layers. The drivability analyses of open ended pipe piles were carried out using GRL WEAP program and the bearing capacities of the piles were estimated. Dynamic load tests were performed to evaluate end bearing resistance, and it is shown that the measured end bearing resistance is smaller than the calculated end bearing because the plugging does not develop sufficiently in case of large diameter pipe piles.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1132-1140
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• 2007

As it recently appears that Life Cycle Cost Analysis may be considered as new methodology for economic valuation of infrastructure many researches have been made to assess LCC(Life Cycle Cost) of each facility based on a reasonable methods. In general, LCC is composed of construction cost and expected maintenance repair cost. And especially, maintenance repair cost must be estimated to enhance the reliability through systematic and reasonable methods. However in Korea, because high speed railway steel bridges are recently constructed no direct statistical data are available for the account of the maintenance cost and then their maintenance characteristics are not linear yet. Therefore, the approach proposed in the paper utilizes a theoretical determination and degradation of the corrosion and fatigue of the bridges based on Rahgozar et al.(2006)'s model on fatigue notch factor considering into the corrosion to incorporate the corrosion effect into the fatigue strength reduction model. And then, the corresponding probability of failure is calculated in terms of the reliability index using S-N curve to formulate the fatigue limit state. Therefore, this paper proposes the minimum Life Cycle Cost through optimum maintenance plan analysis of high-speed railway steel bridges under construction. Finally, this paper reviews the proposed model in oder to confirm the applicability and feasibility by appling it to high speed railway steel bridges under construction

• Journal of the Korean institute of surface engineering
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• v.41 no.1
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• pp.38-42
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• 2008

316L stainless steel welding tube was electrolytically polished and the inner surface characteristics of the tube were tested. Electro-polishing variables such as current, voltage, concentration of electrolyte and electropolishing time were changed to seek for optimum condition. These makes a optimum conditions for the electro-polishing as 4000 A, 9 V, 1.7 specific gravity of electrolyte, and 30 minute of electro-polishing time. It makes the surface roughness as Ra < $0.25{\mu}m$. XPS test resulted as the ratio of CrO/FeO equals or more to 3/1. AES test resulted as the thickness of CrO film of $38{\AA}$. DTA test resulted as the tube did not react with $N_2,\;H_2\;and\;O_2$ gas below 1073K. As summarize above results, the electro- polished 316L stainless steel welding tube satisfied the conditions to apply as a pipeline for semi- conductor production facility and clean room.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.5
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• pp.269-277
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• 2017

This study consists of an analysis of pre-existing ceiling construction systems as well as the development of a replacement unitary, lightweight steel ceiling system and related legal standards. Based on the material conditions and progression of the study, appropriate components were chosen and details were modified by mock-up test. A final study model was evaluated for performance and adaptability based on four parameters (indoor environment, constructability, budget economy, and aesthetics) and compared to the pre-existing ceiling system. As a result of the initial study, a lightweight steel design was created consisting of a reinforced structure with modular bars and entry holes for components. This system was hung directly on the suspension structure. The new design increased lighting and acoustic performance adapted to an indoor environment. Moreover, the speed of construction was increased by approximately 30%, the cost was decreased by approximately 20%, and ceiling aesthetics were improved.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.1
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• pp.52-61
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• 2008

The purpose of this study is to investigate the children's different responses on the playground and facilities by the materials. For the study, the overall satisfaction on the playgrounds, the visiting frequency, the staying time, and olfactory and tactile responses were collected and analyzed by the materials. The materials for the playing facilities were categorized into 3 different groups ; steel, regular form wood and natural wood. The each group was also estimated and analyzed through the SD (sematic differential) scale which consisted of landscape adjectives. According the results, children liked and most highly scored the playground and playing facilities with natural wood in every items; overall satisfaction, visiting frequency, the staying time, and olfactory and tactile. On the other hand, the steel facilities were most negatively assessed in almost every items. Especially children felt the steel facilities were not environmentally friendly and very boring, comparing to the others. However, only 6 cases were analyzed in this study, because there were few playgrounds with natural wood facilities, so it is necessary to research on more cases to generalize these results.

• Journal of the Korea Safety Management & Science
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• v.18 no.3
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• pp.9-15
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• 2016

Currently the forest area is 6,370,000 hectare (ha) which occupies 63.7% in Korea. The forest has good functions such as production of forest products, conservation of national land, prevention of disasters, etc. However constructing houses near the forest area make bad situation like illegal waste incineration by resident. So research subject is forest fire caused by waste incineration place including facility. And this study was conducted about statistical analysis and research analysis of the 100 waste incineration places including facilities at the country town. Statistical analysis shows that March is 27% which percentage is the highest number of forest fire in 10 years' average. The number of forest fire caused by waste incineration is 45 which is the third highest number in the fire statistic. The distance between waste incineration place including facility and forest area is 30m, 40m and 50m. That 40m (36%) is the most common distance from forest area. The types of waste incineration are ground (62%), the temporary facility made with oil drum can (35%) and other made with steel sheet, concrete, etc. The result of this study is that government and local government must conduct the improvement measure to reduce illegal incineration such as waste pickup area made with rain and wind proof type installed near residence, expenses for waste treatment, enlightenment and training, etc. Also considering their age and income are needed for realistic improvement.

• Nuclear Engineering and Technology
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• v.35 no.5
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• pp.482-496
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• 2003

effectiveness of the PAM graphite-electrode technology for the treatment of many types of low-level radioactive waste including : combustible material, solidified resins in cement, inorganic materials, steel, glass, and solidified boric acid cement. The objectives of PAM-200 evaluation were to verify that 1) the facility meets air emission regulations, 2) the facility can be safely operated when processing hazardous and radioactive materials and 3) satisfactory final waste forms can be produced. Results, derived from KAERI's(Korea Atomic Energy Research Institute) analyses for samples of vitrified product, scrubbing solution and offgas collected during test period, show that PAM-200 can treat radioactive wastes as well as hazardous wastes with toxic constituents and radionuclides contained in the offgas exiting from the stack to the environment controlled to be far lower than the limit regulated by air conservation law and atomic law.

• Journal of Korea Technology Innovation Society
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• v.6 no.3
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• pp.358-372
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• 2003

본 연구에서는 일관제철 공정의 철강산업과 같은 대규모 기계설비 집약적 산업 환경에 적합한 기술지식 경영시스템에 대해 고려하고자 한다. 기술경쟁력 확보를 위한 철강업체의 전략적 기술경영은 핵심기술에 대한 지식경영 활동과 연계될 때 비로소 시너지효과를 극대화할 수 있다. 또한 철강업체의 지식경영은 암묵적 혹은 형식적 제철공정 기술지식의 창출, 획득 및 공유 등의 활동을 통해 활성화되어야 한다. 본 연구에서는 먼저 철강산업 현장의 기술지식 관리대상으로 조업설비 프로세스 및 무형 지식자산의 범위를 정의하고, 일관제철 공정의 핵심기술 로드맵에 따라 기술지식 경영활동에 적합한 계층적 지식경영 조직구조를 구축하고자 한다. 또한 제철공정 노하우 등과 같이 암묵적 기술지식을 획득하고 이를 공유할 수 있는 형태로 변환하기 위한 기술지식 획득 방법론을 수립하고 이를 기초로 인터넷에 기반을 둔 제철공정 기술지식 경영시스템을 구축하고자 한다.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.298-301
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• 2006

The HIBRAND located in Yangjaedong, Seochogu, Seoul is a large complex shopping center of total space 48,000 p'yongs which consists of a nineteen-story business facility and a six-story sale facility. In the case of a big construction work in the downtown, they are suffered much difficulty by construction period and working space lack. They, however, can satisfy construction period, constructability and quality using a PC system in HIBRAND. Also, we maximized the advantage of each material being the abreast of a RC and steel structure method partially and devised a reasonable copula. A PC system with advantages of construction period, constructability and quality assurance should be actively practiced to big downtown construction work.