• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.102-104
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• 2008

Natural indigo dye was prepared by extracting from Polygonum tintorium, precipitating with calcium hydroxide, and dried. Dyeing was carried out using sodium hydrosulfite as a reducing agent for the prepared natural indigo powder. K/S value, color property, and colorfastness of dyed fabrics were investigated. Optimum dyeing conditions obtained were 60$^{\circ}C$, 20min. Regardless of indigo dye and sodium hydrosulfite concentration, Munsell hue of dyed fabrics was PB color. Compared to the dyed fabric with both sodium hydroxide and sodium hydrosulfite, those with sodium hydrosulfite only showed higher color strength(K/S value). Colorfastness of dyed fabrics showed high rating except of wash/dry cleaning fastness of silk fabrics dyed low color strength.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.331-335
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• 2009

A novel multi-staged waste pyrolysis & gasification system of pilot scale (~1 ton/day) is designed and constructed in Korea Institute of Industrial Technology. The pyrolysis & gasification system is composed of pyrolysis & gasification system, syngas reformer, syngas cleaning system, gas engine power generation system and co-combustion system. For each unit process, experimental approaches have been conducted to find optimal design and operating conditions. As a result, We can produce syngas with a calorific value of ~4000 kcal/$Nm^3$ and cold gas efficiency of the system is more than 55 % in case of waste plastic and oxygen as a gasifying agent.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.139-147
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• 2019

Incorporation of CuO nanoparticles during the polymerization of aniline in the presence of ammonium peroxydisulphate as an oxidizing agent and sodium salt of dodecylbenzene sulphonic acid as dopant as well as surfactant yielded water soluble CuO-PANI composite. Comparison of recorded spectra like FTIR, XRD and SEM with reported one confirm the formation of the composite. Analysis by gravimetric method exposes that the synthesized composite is having resistivity against corrosion, with slight variation in efficiency on extending the time duration up to eight hours in strong acidic condition. OCP measurement, potentiodynamic polarization and EIS studies also confirms the suppression ability of composite against corrosion. Riskless working environment could be provided by the synthesized composite during industrial cleaning process.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.15 no.1
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• pp.62-70
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• 2019

The APR1400 reactor may be operated for a long time under high temperature and pressure conditions, causing damage to the stud holes and causing stud bolts and holes to stick. The present practice is to manually remove the anti-sticking agent and foreign matter remaining in the APR1400 reactor stud hole and to visually check the surface condition of the thread to check the damage status of the threads. In the case of the APR1400 reactor stud holes, manually cleaning the threads increases the risk of radiation exposure and operator's fatigue. To avoid this, the autonomous mobile robot is used to automatically clean the reactor stud holes. The purpose of this study is to optimize the cleaning performance of the mobile robot by looking at the behavior of the surface roughness of the stud surface cleaned by the brush attached to the mobile robot due to changes in brush material, thickness of wire, and rotation speed. A microscopic approach to the surface roughness of the flank is needed to investigate the effects of the newly proposed brush of the autonomous mobile robot on the thread holes. According to this experiment, it is reasonable to use STS brush rather than Carbon one. Optimal operating conditions are derived and the safety of APR1400 reactor stud holes maintenance can be improved.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.19-28
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• 2021

Corrosion is the degradation of metals by reaction with the environment. It is difficult to completely remove. Corrosion proceeds rapidly after the protective barrier is destroyed, and several reactions occur that alter the composition and properties of the metal surface and local environments, such as diffusion of metal cations into the matrix, the formation of oxides, and local pH changes. The study of corrosion of steel and iron is of theoretical and practical interest and is receiving considerable attention. Acid solutions, which are widely used in industrial pickling, acid descaling, cleaning and acidification of oil wells, require the use of corrosion inhibitors to suppress corrosion attacks on metallic materials. Physical removal of rust requires expensive special equipment, and chemical removal of it can cause corrosion or shorten the life of the metal. In this study, an eco-friendly rust cleaner was developed using cosmetics and food materials by applying the concept of perm reducing agent and chelate, and applied to remove rust from industrial and hot water pipes and various industrial devices. As a result, it was found that rust cleaners remove rust more effectively and safely compared to conventional treatment methods. At the same time, the rust removal efficiency was 1.75 to 2.5 times better for industrial piping and 1.56 to 2.2 times better for boiler hot water than conventional methods.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.664-671
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• 2005

In this study, the effect of sosurfactant on microemulsion phase behavior was investigated in ternary systems containing alkyl ethoxylates nonionic surfactant, water and d-limonene. The addition of a cosurfactant produced a microemulsion phase over a wide range of temperature and promoted formation of a microemulsion phase at lower temperatures. In particular, small amounts of n-propanol, as a cosurfactant, were found to be the most effective in extending a microemulsion phase region over a wide range of temperature. Temperature sensitivity of a nonionic surfactant system was effectively relieved by addition of the anionic surfactant sodium dodecyl sulfate. And the formation of one phase microemulsion was not affected by pH, hardness concentration and addition of an antioxidation agent. The cleaner candidates were determined from microemulsion phase behavior study, and their cleaning efficiency was tested using a dipping method. All the cleaner candidates selected during this study showed excellent removal efficiency for abietic acid over a temperature range from 30 to $40^{\circ}C$ presumably due to a decrease in interfacial tension.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.1
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• pp.54-62
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• 2015

Small scale paint overspray booths are being operated nationwidely, for repair of passenger car body parts. paint aerosols are emitted from the paint overspray booth in operations. In paint overspray booth operations without ventilation system and air pollutants collection unit, it may land on nearby equipment. In this study a removal of sticky paint aerosol for application of the small-scale overspray paint booth. it's cause the surface of filter bag from generated sticky paint aerosol. To remove adhesion of paint aerosol the agglomerating agents are injected and mixed with sticky paint aerosols prior to reach the filter bag. The paint spray rate was set as $10{\pm}5g/min$ from air-atomized spray guns in the spray booth, injection rate of agglomerating was $10{\pm}5g/min$ in the mixing chamber. The filtration velocity including air pollutants varied from 0.2 m/min to 0.4 m/min. Bag cleaning air pressure was set as $5.0kg_f/min$ for detaching dust cake from surface of filter bag. Bag cleaning interval at the filtration velocity of 0.2 m/min was around 3 times longer than that of the 0.4 m/min. The residual pressure drop maintained highest value at the highest filtration velocity. Fractional efficiency of 99.952%~99.971% was possible to maintain for the particle size of 2.5 microns. Total collection efficiency at the filtration velocity of 0.2 m/min was 99.42%. During this study we could confirm high collection efficiency and long cleaning intervals for the test with filtration velocity of 0.2 m/min indicating an optimal value for the given dimensions of the test unit and test operating conditions.

• Tribology and Lubricants
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• v.28 no.6
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• pp.315-320
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• 2012

For proper functioning, general machines usually need lubricant oil as a cooling, cleaning, and sealing agent at points of mechanical contact. The quality of lubricant oil can deteriorate during operation owing to various causes such as high temperature, combustion products and extraneous impurities. In this study, a heavy load stopped during operation, and the oil was analyzed to check whether any impurities were added. Extraction using acetonitrile followed by reaction with BSTFA(bistrimethylsilyl trifluoroacetamide) showed that, trimethylsilylated ethylene glycol was present in the lubricant oil. To quantify the ethylene glycol in the oil, deuterium-substituted ethylene glycol, which acted as an internal standard, was added to the sample and then extracted with the solvent. Next, the extract was reacted with the derivatizing agent(BSTFA) and then analyzed with GC/MS. The detection limit of this method was found to be $0.5{\mu}g/g$ and the recovery of oil containing $20,000{\mu}g/g$ of ethylene glycol was measured to be 94.8%. A damaged O-ring and eroded cylinder liner were found during the overhaul, which implied the leakage of coolant containing ethylene glycol into the lubricating system. The erosion of the cylinder liner was assumed to be due to cavitation of the coolant in the cooling system.

• Textile Coloration and Finishing
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• v.30 no.4
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• pp.294-303
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• 2018

In this study, eco-friendly natural dyeing for pig leather was explored by using onion skin which is food waste. Sodium caseinate was used as a pre-treatment agent to improve dyeability of pig leather and its effect on dye uptake was investigated according to treatment concentration. Dye uptake of the pre-treated pig leather was increased by about two times compared to untreated one at 0.2% pre-treatment concentration. Onion skin colorant imparted YR color on pig leather. After mordanting, the color of pretreated/dyed pig leather was varied from brick-red to khaki shades. However, mordanting did not improved dye uptake of the pre-treated/dyed pig leather significantly. The color-fastnesses of un-mordanted samples to light, dry cleaning, rubbing were grades 3-4, 5, and 4, respectively, which is good enough to meet all Korean Standard for Fastness of leather products. After mordanting, the light fastness of pig leather was improved to 4, 4-5 grade. The efficacy of sodium caseinate as a pre-treatment agent for pig leather was verified by improved dye uptake and good colorfastness. And, the natural dyeing of pig leather using food waste would be a significant sustainable way in terms of eco-friendliness and reuse of biomass to reduce environmental pollution.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.57-65
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• 2019

In this study, the quality characteristics of the mother material of panel were evaluated for the production of moss panel using alumina cement and biological characteristics and environmental impact characteristics of moss panel were evaluated. The ratio of W/B 10%, Vs/Vm 20% and foaming agent 0.5% were selected as the basic mixing ratio for the mother panel of moss panel through pretest and SAP was added to improve the moisture content of panel. The optimal mixing ratio of SAP was considered to be less than 0.5% considering the quality characteristics. Also, through the use of alumina cement, the pH of the panel could be lowered to 10~11. The panel was able to improve the surface roughness through the foaming agent, and it was confirmed that the SAP had an effect of improving the moisture content of the panel. For the environmental impact characteristics of the moss panel, the moss panel evaluated the carbon dioxide reduction performance and the fine dust cleaning performance.