• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.338-350
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• 2010

As existing materials for ground reinforcement, chemical grout material using cementitous materials and waterglass was used. But many problems in terms of ground reinforcement effects were implicated. In this study, for development and applicability verification of new materials, viscosity, fluidity, permeability, Self-Leveling, keeping of drilled hole, antiwashout underwater, resistance of water (groundwater dilution and minimize material eluting) and the early strength and long-term strength characteristics of developed materials was confirmed, and material standards, and establishing construction standards for the various model tests were conducted. As a result, high viscosity, flowability, permeability and keeping of drilled hole characteristics are excellent, in addition to the early strength properties, dilution does nat occur to groundwater, including groundwater is available for dealing with environmental issues. Application of basic and reinforcement method by Filler function in addition to structure can also or development of a new concept can be expected. In addition, middle and large-diameter drilled shaft, micropile, ground anchors, soil-nailing, steel pipes multi-grouting reinforcement for cement injection process could be used enough to even be considered.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1279-1287
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• 2009

An increasingly competitive business environment has been concentrated on industries to reduce the operating costs. Industries such as gas, oil, petrochemical, chemical, and electric power have employed for the operation and used for large equipment or structures that require a high capital investment. In order to meet these requirements, the industries are increasingly moving toward saving the experimental verification and computer simulation. Therefore industries to reduce the maintenance costs without compromising the operational safety have been forced on finding for better and more efficient methods to inspect their equipment and structures. In this study, it focused on the development the real-time non-contract monitoring system as an efficient tool for the experimental study of weld defects based on the relationship between the measured voltage and input parameters.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.3
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• pp.177-184
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• 2002

The most tunnel damage such as cracks or leakage which exist in tunnel lining commonly, is caused by the cavities where exist behind the tunnel lining, through the tunnel safety inspections. These cavities were analysed to affect a stability of a running-tunnel seriously. This study is on the development of the controlled low-strength and flowable filling material which is able to apply to the cavity behind the tunnel lining. The major materials of backfilling developed are a crushed sand and a stone-dust which exists as a cake-state and is a by-product obtained in the producting process of aggregate. It is conformed with the design standard to the physical characteristics of backfilling. The backfilling material developed is designed to reduce the fair amount of cement. According to the designed compound ratio, it is carried out the laboratory tests such as a compressive strength and a chemical analyses and is applied to dilapidated old tunnel for an application assessment.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.151-160
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• 2011

There have been many efforts to prevent accidents in Korea for the last 25 years. Many measures in the area of hardware sciences including electrical, mechanical, chemical engineering, etc. were applied to eliminate or at least reduce causes of accidents. However, the accidents rate has not been reduced much despite of these measures. This research aimed to find real causes of these accidents and to suggest a comprehensive model that can mainly be applied to industrial fields to find potential or existence of human errors during the pre-installation stage or after an accident. We tried to explain sequences of an operator's information process that might cause human errors on one hand, and life cycle stages of facilities involved when human errors occur on the other hand. With this comprehensive model presented in this research, one can follow up the sequence of human errors caused by operators. Further, errors made at the design stage which could be a main cause of accidents can be tracked. It is recommended that this comprehensive model should be used to prevent human errors in industrial fields since safety personnel can easily find out errors or error potentials through the life cycle stages of manmachine facilities.

• Journal of the Korean Institute of Gas
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• v.21 no.3
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• pp.9-16
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• 2017

Toxic release is one of the most interested area in evaluating consequence to the vicinity of industry facilities handling hazardous materials. Chloric acid production facility is selected and toxic release is evaluated to assess the risk impacted to its off-site. Accident scenarios were listed using process safety information. The scenarios having effect to the off-site were selected and assessed further according to guideline provided by Korea government. Worst case and alternative scenarios including other interested scenarios were evaluated using ALOHA. Each evaluated scenario was assessed further considering countermeasures. The results showed that the facility handling chloric acid is safe enough and needed no further protections at the moment.

• Ceramist
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• v.21 no.4
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• pp.349-365
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• 2018

Since the electrification of vehicles has been extended, solid-state batteries have been attracting a lot of interest because of their superior safety. Especially, polymer, sulfide, and oxide based materials are being studied as solid electrolytes, and each type of materials has advantaged and disadvantages over others. Oxide electrolytes has higher chemical and electrochemical stability compared to the other types of electrolytes. However, ionic conductivity isn't high enough as much as that of organic liquid electrolytes. Also, there are many difficulties of fabricating solid-state batteries with oxide based electrolytes because they require a sintering process at very high temperature (above ${\sim}800^{\circ}C$). Herein, we review recent studies of solid-state batteries with oxide based electrolytes about the ionic conductivity, interfacial reactions with Li metal, and preparation of solid-state cell.

• International Journal of Stem Cells
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• v.16 no.2
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• pp.156-167
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• 2023

Background and Objectives: Cellular reprogramming in regenerative medicine holds great promise for treating patients with neurological disorders. In this regard, small molecule-mediated cellular conversion has attracted special attention because of its ease of reproducibility, applicability, and fewer safety concerns. However, currently available protocols for the direct conversion of somatic cells to neurons are limited in clinical application due of their complex nature, lengthy process, and low conversion efficiency. Methods and Results: Here, we report a new protocol involving chemical-based direct conversion of human fibroblasts (HF) to matured neuron-like cells with a short duration and high conversion efficiency using temporal and strategic dual epigenetic regulation. In this protocol, epigenetic modulation by inhibition of histone deacetylase and bromodomain enabled to overcome "recalcitrant" nature of adult fibroblasts and shorten the duration of neuronal reprogramming. We further observed that an extended epigenetic regulation is necessary to maintain the induced neuronal program to generate a homogenous population of neuron-like cells. Conclusions: Therefore, our study provides a new protocol to produce neurons-like cells and highlights the need of proper epigenetic resetting to establish and maintain neuronal program in HF.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.334-346
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• 2022

There is a lack of knowledge and information on the understanding and application of the Process Safety Management (PSM) system, recognized as a major cause of industrial accidents in small-and medium-sized workplaces. Hence, it is necessary to prepare a protocol to secure the practical and continuous levels of implementation for PSM and eliminate human errors through tracking management. However, insufficient research has been conducted on this. Therefore, this study investigated and analyzed the various violations in the administrative measures, based on the regulations announced by the Ministry of Employment and Labor, in approximately 200 small-and medium-sized PSM workplaces with fewer than 300 employees across in korea. This study intended to contribute to the prevention of major industrial accidents by developing a facility maintenance web program that removed human errors in small-and medium-sized workplaces. The major results are summarized as follows. First, It accessed the web via a QR code on a smart device to check the equipment's specification search function, cause of failure, and photos for the convenience of accessing the program, which made it possible to make requests for the it inspection and maintenance in real time. Second, it linked the identification of the targets to be changed, risk assessment, worker training, and pre-operation inspection with the program, which allowed the administrator to track all the procedures from start to finish. Third, it made it possible to predict the life of the equipment and verify its reliability based on the data accumulated through the registration of the pictures for improvements, repairs, time required, cost, etc. after the work was completed. It is suggested that these research results will be helpful in the practical and systematic operation of small-and medium-sized PSM workplaces. In addition, it can be utilized in a useful manner for the development and dissemination of a facility maintenance web program when establishing future smart factories in small-and medium-sized PSM workplaces under the direction of the government.

• The Journal of Engineering Geology
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• v.27 no.1
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• pp.67-79
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• 2017

Evaluation of the weathering index using the quantitative element composition of rocks is very effective in predicting the degree of weathering of rocks and the secondary weathering residuals. While the process of weathering varies according to the types of rocks, the study of weathering in Korea is concentrated on acidic igneous rocks. This study calculated the weathering indices using whole rock analysis (X-ray fluorescence analysis) of sandstone, mudstone, and shale belonging to clastic sedimentary rocks. The statistical significance of the indices was examined based on the correlation of the calculated weathering indices. Clastic sedimentary rocks showed higher significance of Wp, CIA, CIW and PIA weathering index indicating weathering of feldspar. Chemical Index of alteration (CIA) has the advantage of predicting weathering pathway and clay mineral production, but it is effective to consider chemical index of weathering index (CIW) simultaneously to improve accuracy. In order to reduce uncertainties due to carbonate rocks and to estimate the accurate weathering index, rock samples with high CaO content should be excluded from the evaluation of weathering index.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.556-561
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• 2019

In this study, the physical and chemical analyses of petroleum residues (pyrolized fuel oil, PFO) were conducted and major components were selected to investigate their fire and explosion characteristics. Major component distribution areas of the PFO were identified via the GC-SIMDIS and MALDI-TOF analyses. In addition, the qualitative analysis of major component distribution areas was performed by GC-MS analysis. Major components of pyrolysis residue were selected based on the results of various analyses such as EA, SARA and TGA. As a result, benzene, toluene and xylene were selected as major components. Finally, the process hazard analysis software tool (PHAST) analysis was performed to investigate the range of maximum damage effect in case of fire and explosion. Toluene presented the highest risk due to the radiation effect of $227kW/m^2$ and 118 m in the case of jet fire. Xylene and benzene showed the maximum radiant heat values of 114 and $151kW/m^2$, respectively. It was also confirmed from the analysis of pasquill stability and wind speed that the radiant heat increased up to 55% according to wind speed in benzene, which was considered to be a main factor increasing the influence range.