• Journal of the Korean Burn Society
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• v.22 no.2
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• pp.53-57
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• 2019

Dichloromethane is widely used as a solvent in paint removers. Unlike inhalation injury, contact injury caused by dichloromethane is not well known. Two patients who had undergone skin grafting to treat chemical burn of the hand caused by dichloromethane exposure were evaluated, and a literature review was done. Two healthy men aged 37 and 40 years visited our hospital with chief complaints of pain on the hands due to dichloromethane exposure. The patients had not worn protective clothing. Multiple bullae were initially noted. On the next day, fluctuation in bullae and purulent discharge were observed, and central eschar change was noted. On the 18th day after the burn, escharectomy and full-thickness skin graft were performed. Therefore, workers who use dichloromethane should wear protective clothing at workplaces. If exposed to the chemical, the worker should be instructed to do a quick wash and visit the hospital.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1855-1862
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• 2023

Graphite crucibles are used for melting uranium and its alloys in VIM furnace. Various coating materials namely Al₂O₃, ZrO₂, MgO etc. are applied on the inner surface of the crucibles using paint brush or thermal spray technique to mitigate U-C interaction. These leads to significant amount of carbon pick-up in uranium. In this study, the attempts are made to develop multilayer coatings comprising of SiC/Y₂O₃ and Mo/Y₂O₃ on graphite to study the feasibility of minimizing U-C interaction. The parameters are optimized to prepare SiC coating of about 70㎛ thickness using CVD technique on graphite coupons and subsequently Y₂O₃ coating of about 250㎛ thickness using plasma spray technique. Molybdenum and Y₂O₃ layers were deposited using plasma spray technique with 70㎛ and 250㎛ thickness, respectively. Interaction studies of the coated graphite with molten uranium at 1450℃ for 20 min revealed that Y₂O₃ coating with SiC interlayer provides physical barrier for uranium-graphite interaction, however, this led to the physical separation of coating layer. Y₂O₃ coating with Mo interlayer provided superior barrier effect showing no degradation and the coatings remained intact after interaction tests. Therefore, the Mo/Y₂O₃ coating was found to be a promising solution for minimizing carbon pick-up during uranium/uranium alloy melting.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.157-157
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• 2021

2015년 파리에서 체결된 파리협정은 1850년 대비 2100년까지의 지구 평균기온 상승을 1.5℃ 이내로 제한하기 위해 5년마다 참여국에 상향된 온실가스 배출 감축 목표를 제출하게 하고, 탄소 배출 및 온도상승 저감 목표 달성을 위해 도시 내 그린인프라를 적극적으로 도입하는 등 국제사회 공동의 종합적인 이행을 예정하고 있다. 그린인프라의 유형 중 하나인 옥상녹화(Green Roof)는 기후변화 적응을 위한 도시 인프라 구축 방법의 하나로 국내에서도 많은 각광을 받고 있다. 옥상녹화(Green Roof)는 도시의 불투수층인 지붕 면적을 모두 혹은 일부 식생으로 덮어 표면층에 추가의 투수층을 조성하는 것을 지칭한다. 옥상녹화의 경우 별도의 토지면적 확보가 필요하지 않고 기존의 시설물에 추가적인 설치가 가능해 여분의 토지가 부족한 도심지의 녹지 확보를 위한 친환경적인 그린인프라로 각광받고 있다. 현재까지 옥상녹화(Green Roof) 관련 국내 연구 현황은 '옥상 녹화의 공법'을 다룬 비율이 높고 실증적인 결과를 가진 선행연구가 거의 없다. 따라서 본 연구는 동일한 조건하에 4개의 실험동을 설치하고 동질성 검사를 한 후 옥상에 설치된 재료[일반 콘크리트(Bare Concrete), 고반사 도장(High Reflective Paint), 사사(Short Bamboo), 잔디(Grass)]에 따른 건물 내 온도 변화 저감효과에 대한 분석을 수행하였다. 2020년 8월 17일부터 22일까지 측정된 지붕 표면 평균 최고온도 모니터링 결과를 일반 콘크리트 지붕과 비교했을 때. 고반사 도장 지붕의 경우 8.26℃, 옥상녹화(사사, short bamboo) 지붕의 경우 7.21℃, 옥상녹화(잔디, grass)의 경우 10.8℃ 낮은 것으로 측정되었다. 또한 실내 천정 표면 평균 온도의 경우 콘크리트 지붕과 비교하여 고반사 도장 지붕은 6.46℃, 옥상녹화(사사, short bamboo) 지붕은 13.52℃, 옥상녹화(잔디, grass)는 13.3℃ 낮은 것으로 나타났다. 본 연구결과는 옥상녹화의 온도저감 효과를 정량적으로 제시하고 있어, 향후 기후변화 대응 및 적응 전략적 수립에 기여할 수 있을 것으로 판단된다.

• Journal of People, Plants, and Environment
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• v.22 no.1
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• pp.31-38
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• 2019

Experiments were carried out to investigate the effects of mosses on the removal of particulate matter (PM 10) and volatile organic compounds (VOCs) in an indoor space and on the composition of air. For particulate matter removal experiments, 0.2 g mosquitto coil was burned in a glass chamber, where three kinds of mosses (Plagiomnium cuspidatum, Myuroclada maximowiczii, Etodon luridus) were placed. For VOCs removal experiments, 1 mL paint thinner was volatilized in a glass chamber, where Plagiomnium cuspidatum and Myuroclada maximowiczii were used. As a result, it was found that particulate matter was effectively removed by the three mosses, and the removal efficiency of particulate matter increased as the amount of mosses increased. The amount of VOCs was similar to the level in the control when a low amount of mosses (2 and 4 plates) was used. However, the removal efficiency of VOCs was significant when 6 plates of mosses were used. On the other hand, formaldehyde concentration was 40 times more than the control and carbon monoxide 30 times, when 0.2 g of mosquito repellent was completely burned in a glass chamber. Also formaldehyde removal effect was significant when 6 plates of mosses were placed. However, there was no change in the concentration of indoor oxygen, temperature and humidity by moss plants. In conclusion, the moss plants were effective in removing particulate matter and VOCs, and they are expected to be used for indoor decoration and landscape in order to improve indoor air quality in the future.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.23-31
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• 2023

In this study, a smart bench was developed and researched smart benches that can contribute to user convenience and satisfaction by installing them in parks, bus stops, and tourist attractions in line with the rapidly changing construction of smart cities. The smart bench is automatically operated by the control system according to the external temperature and provides additional functions such as charging, lighting, and advertising to improve general bench functions as well as heating in winter and cooling in summer, making it suitable for smart urbanization. The developed smart bench is designed to be strong enough to withstand loads of about 2,500 N. It minimizes the visible parts such as assembled bolts and 220V power supply wires, It can also give aesthetic effects. The development was carried out with the aim of waterproofing and dustproofing of IP44 grade in accordance with the climate of Republic of Korea, which has four seasons, and it is advantageous for long-term use because the paint was selected for the weather ability (discoloration) grade 3 or higher. If smart bench is commercialized, it is believed that various options can be provided to the smart bench market, where buyers had few product options, as the parts were developed in an assembled type so that all functions can be responded in an optional form according to the installation environment and the buyer's budget.

• Advances in nano research
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• v.15 no.5
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• pp.441-449
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• 2023

Heavy metals, widely present in the environment, have become significant pollutants due to their excessive use in industries and technology. Their non-degradable nature poses a persistent environmental problem, leading to potential acute or chronic poisoning from prolonged exposure. Recent research has focused on separating heavy metals, particularly from industrial and mining sources. Industries such as metal plating, mining operations, tanning, wood and chipboard production, industrial paint and textile manufacturing, as well as oil refining, are major contributors of heavy metals in water sources. Therefore, removing heavy metals from water is crucial, especially for safe water supply in swimming and water sports. Iron oxide nanoparticles have proven to be highly effective adsorbents for water contaminants, and efforts have been made to enhance their efficiency and absorption capabilities through surface modifications. Nanoparticles synthesized using plant extracts can effectively bind with heavy metal ions by modifying the nanoparticle surface with plant components, thereby increasing the efficiency of heavy metal removal. This study focuses on removing lead from industrial wastewater using environmentally friendly, cost-effective iron nanoparticles synthesized with Genovese basil extract. The synthesis of nanoparticles is confirmed through analysis using Transmission Electron Microscope (TEM) and X-ray diffraction, validating their spherical shape and nanometer-scale dimensions. The method used in this study has a low detection limit of 0.031 ppm for measuring lead concentration, making it suitable for ensuring water safety in swimming and water sports.

• Land and Housing Review
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• v.14 no.4
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• pp.103-110
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• 2023

People who spend most of their day indoors are continuously exposed to internally and externally generated indoor pollutants. According to a 2022 report from the World Health Organization (WHO), air pollution is the cause of more than 7 million deaths annually worldwide, emphasizing the seriousness of indoor air pollutants. Air pollutants include nitrogen oxides (NOx), formaldehyde (HCHO), and volatile organic compounds (VOCs), which have serious effects on the human body. Photocatalyst is a material that can remove these indoor air pollutants. Photocatalysts not only have the ability to remove dust precursors, but also have antibacterial, sterilizing, and deodorizing functions, making them effective in improving indoor air quality. This study suggests areas and methods in which photocatalysts can be applied to buildings. Fields of application include interior and exterior construction materials such as concrete, as well as organic paints and ventilation devices. If appropriate utilization plans are developed, it may be possible to improve the built environment through reduced indoor and outdoor pollutant levels.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.9-15
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• 2024

Hydrogen-based electricity and transportation systems are widely recognized as sustainable power sources. However, the low ignition energy of hydrogen, only 1/10th that of conventional fossil fuels, poses a safety concern involving the risk of ignition due to electrostatic discharge from facility workers. Therefore, anti-static systems are imperative for hydrogen-based electricity facilities. To address this, we propose a reliable conductive rubber mat (CRM) to ensure the safety of these facilities. Unlike conventional anti-static floors that utilize conductive paint (CP), the CRM features a uniform distribution of conductive components in chemically and mechanically stable rubber. As a result, the CRM is unyielding to polar solvents (such as ethanol and hydrosulfuric acid) and non-polar solvents (like mineral oil) without increasing its resistance. Moreover, the CRM can withstand mechanical stress. Consequently, the human-body voltage of workers on the CRM would be sufficiently low enough to protect them from hydrogen explosions, thereby enhancing overall safety.

• Archives of Plastic Surgery
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• v.50 no.6
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• pp.621-626
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• 2023

In the first half of the third century B.C., Herophilus and Erasistratus performed the first systematic dissection of the human body. For subsequent centuries, these cadaveric dissections were key to the advancement of anatomical knowledge and surgical techniques. To this day, despite various instructional methods, cadaver dissection remained the best way for surgical training. To improve the quality of education and research through cadaveric dissection, our institution has developed a unique method of perforator-preserving cadaver injection, allowing us to achieve high-fidelity perforator visualization for dissection studies, at low cost and high efficacy. Ten full body cadavers were sectioned through the base of neck, bilateral shoulder, and hip joints. The key was to dissect multiple perfusing arteries and draining veins for each section, to increase "capture" of vascular territories. The vessels were carefully flushed, insufflated, and then filled with latex dye. Our injection dye comprised of liquid latex, formalin, and acrylic paint in the ratio of 1:2:1. Different endpoints were used to assess adequacy of injection, such as reconstitution of eyeball volume, skin turgor, visible dye in subcutaneous veins, and seepage of dye through stab incisions in digital pulps. Dissections demonstrated the effectiveness of the dye, outlining even the small osseous perforators of the medial femoral condyle flap and subconjunctival plexuses. Our technique emphasized atraumatic preparation, recreation of luminal space through insufflation, and finally careful injection of latex dye with adequate curing. This has allowed high-fidelity perforator visualization for dissection studies.

• Food Science and Preservation
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• v.31 no.4
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• pp.554-564
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• 2024

The effects of extracting solvents on the physicochemical properties of vegetable oils extracted from four oil seed plants, namely Dennettia tripetala, Dacryodes edulis, Cola rostrata, and Persea americana, were studied. Vegetable oils were extracted using the Soxhlet method. The oils were used for determining % yield, acid value (AV), iodine value (IV), saponification value (SV), electrical conductivity (EC), and pH. The results revealed that the range of the mean % yield of oils extracted using hexane, carbon tetrachloride (CCl₄), petroleum ether, acetone, and methanol, respectively, were 7.5-12.0, 9.0-22.0, 7.5-27.5 and 12.0-37.5 for the four oil Seeds respectively. Mean AVs of oils in mg KOH/g across the solvents were 3.1-3.7, 3.1-3.8, 2.5-3.9 and 2.4-2.8 for Cola rostrata, Dacryodes edulis, Dennettia tripetala and Persea americana respectively. Mean IVs of oils in gI2/100 g across the solvents were 33.25-33.97, 33.06-33.35, 32.06-33.76 and 33.00-34.00 for the four oil seeds, respectively. Mean SVs in mg KOH/g across the solvents were 191.00-197.44, 190.74-198.31, 194.11-202.52, and 182.23-199.44, respectively. Mean EC values ranged 0.31-0.32, 0.30-0.33, 0.30-0.33, and 0.31-0.32 µS/cm across the solvents, respectively. Mean pH values ranged from 6.1-6.4, 4.6-6.3, 6.2-6.4, and 6.1-6.3 across the solvents for the oils, respectively. The AVs of the oils suggest that they are edible oils, the IVs classify the oils as non-drying oils suitable for paint making, and SVs reveal that the oils are good for soap making. Hexane, petroleum ether, and CCl4 are suitable for oil extraction industrially, while D. edulis, D. tripetala, and P. Americana oils are economically viable oil resources due to their high percentage yield, SV and IV.