• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.272-273
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• 2005

분리막 기술은 탁월한 처리효율뿐 아니라 안정적으로 용수를 생산할 수 있는 장점이 있기 때문에 용수의 생산을 전통적인 수처리 (Conventional water treatment) 공정에서 역삼투 공정(Reverse Osmosis) 및 나노여과 (Nanofiltration)와 같은 분리막 기술을 활용하는 공정으로 변환하는 추세에 있다. 그러나 분리막 공정은 항상 막오염 현상이 문제점으로 지목되고 있기 때문에 막오염 제어 기술의 확보가 시급한 실정이다. 따라서 본 연구에서는 화학물질의 사용에 따른 2차 환경오염 문제가 발생하는 화학약품이나 물리적인 세정이 아닌 고전압 임펄스 (HVI, High Voltage Impulse) 장치를 이용하여 막오염의 근본적인 문제를 제어하려 한다.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.409-414
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• 2016

The purpose of this study was to evaluate the antibacterial effect of tea tree oil in denture cleaners. A self-curing denture resin was used to make the experimental specimen ($12mm{\times}2mm$). A saline solution was used as the control. To observe surface changes after cleaning, the microhardness and color of the experimental specimen's surface were analyzed. For the antibacterial activity test, Candida albicans was used. The microhardness and color of the surface remained unchanged after cleaning. The result of the antibacterial activity test revealed that the tea tree oil-containing solutions had a more enhanced antibacterial effect than did the saline solution. Therefore, these results suggest that the tea tree oil-containing solution is a promising denture cleaners.

• Membrane Journal
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• v.27 no.1
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• pp.104-107
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• 2017

Among many methods in solving the organic contamination in the reverse osmosis operation, caustic soda (NaOH) wash method is efficient and commercially affordable. In continuation of our many organic pollution removal works, this study focused mainly on caustic soda wash with micro-bubble to removal the organic contamination of the spent membrane from reverse osmosis process. First, the membrane was forced the pollute using known organic pollutants such as Humic acid, Bovine serum albumin, Sodium alginate drug. The organic contamination on the membrane was monitored flux. The decontamination of organic contaminants was derived flux variation at individual caustic soda was injected micro-bubble methods and combined method as well. the found results explain removal of organic contaminants effective only by combined caustic soda wash with micro-bubble methods.

• Clean Technology
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• v.14 no.3
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• pp.193-203
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• 2008

A surfactant is used to assist the effect of cleaning, dispersibility and adhesion during leather manufacturing process. Existing surfactant for that process includes many hydrophilic groups that may cause problem such as stain, bad water resistance and poor durability, etc. It is potential problem to make high-performance property for future leather market. In this study, we have synthesized the fluorinated surfactant of which property decreases surface tension, increases dispersion, cleaning effect and the better chrome absorption by the high bond energy of C-F to complement weakness that the present alkyl derivative surfactants have. Using fluorinated surfactant, we can confirm that dispersion is increased, chrome absorption ratio is augmented with high osmosis and coherence, chrome content in the tanning waste water is reduced, BOD and COD contents are diminished and physical characteristics are improved.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.188-193
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• 2007

Semi-solvent type cleaning agents were prepared by mixing naphthenes, natural terpene oil, surfactant and water, and measured their physical properties. And also, cleaning efficiency for flux and grease was measured by gravimetric method. By measuring the physical properties, pH for cleaning agents were 6.0~6.7, surface tension, 27.4~28.4 dyne/cm, and wetting index, 8.65~12.46 (with water), 11.99~17.43 (without water). The cleaning agent composed of naphthene, 30 wt%, natural terpene oil, 45 wt%, surfactant, 13 wt%, co-surfactant, 12 wt%, and water, 0 wt% had the largest wetting index, and shown the most effective cleaning properties for flux (98.66%) and grease (93.44%). The conductivity with $0.5{\sim}0.9{\mu}s/cm$ to the cleaning agent containing small amount of water was found to form W/O type microemulsion.

• Journal of Conservation Science
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• v.34 no.6
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• pp.525-538
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• 2018

Myazedi Quadrilingual Stone Inscription of Myanmar, inscribed to the World Heritage List in 2015, is a rare historical artifact which has an exact date of inscription. It is a written record that displays the history, religion, and culture of Myanmar. Since the surface of the Stone Inscription has been rubbed with ink many times during the process of making printed copies for interpretation and academic research, it has developed a serious stain problem. Therefore, scientific analysis of the stain and research on the treatment for its removal have been conducted. In particular, an experiment was conducted on stain removal using laser cleaning and chemical treatment. The stains are mostly ink dirt, which accumulated from previous ink-rubbing processes. In order to conduct the experiment under similar conditions, a sample with similar stain has been reproduced, and a set of different conditions for treatment was applied to the sample to determine an effective solution. Laser cleaning was found to be effective in removing stains from most samples. However, chemical treatment showed different results. The physical friction method using ethanol provided the best result. In conclusion, laser cleaning is an effective universally-applicable technique but chemical treatment with laser cleaning can be considered an alternative method in certain situations.

• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.49-56
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• 2018

BACKGROUND: The mobile vortex wet scrubber was developed to remove the harmful chemicals from accidental releases. However, there was a disadvantage that it was limitedly used for volatile organic compounds (VOCs) such as toluene according to the physicochemical properties. This study compared the removal efficiencies of an improved mobile scrubber on toluene and ammonia by applying diverse adsorption and absorption methods. METHODS AND RESULTS: The removal efficiencies on harmful chemicals were examined using various adsorption and absorption methods of water vortex process (C), phosphoric acid-impregnated activated carbon adsorption (PCA), pH-controlled water (pH 2.5) vortex process absorption with sulfuric acid (SWA) after ammonia exposure, granular activated carbon adsorption (GCA), and activated carbon mat adsorption (CMA) after toluene exposure. As a result, the best removal efficiency was shown in the SWA for ammonia and GCA for toluene. Also, the SWA and GCA methods were compared with different concentration levels. In the case of ammonia exposure (5, 10 and 25%), there was no difference by concentration levels, and the concentration in the outlet gradually increased, with pH change from acid to base. In the case of toluene exposure (50, 75 and 100%), the outlet concentration was higher relative to the exposure concentration in the initial 10 min, but the outlet concentration was remained steady after 10 min. CONCLUSION: The newly improved mobile scrubber was also effective in removing VOCs through adsorption techniques (activated carbon, activated carbon fiber, carbon mat filter etc.), as well as removing acid-base harmful chemicals by neutralization reaction.

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.72-78
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• 2004

Cu seed layers deposited by magnetron sputtering onto tantalum nitride barrier films were treated with ECR plasma and then the copper films were electroplated and rapid thermal annealed in an argon or nitrogen atmosphere at various temperatures ranging from 200 to $500^{\circ}C$. Changes in the microstructure and physical properties of the copper films electroplated on the hydrogen ECR plasma cleaned copper seed layers were investigated using X-ray diffraction (XRD), electron back-scattered diffraction (EBSD), and atomic force microscopy (AFM) analyses. It was found that the copper film undergoes complete recrystallization during annealing at a temperature higher than $400^{\circ}C$. The resistivity of the Cu film tends to decrease and the degree of (111) preferred orientation tends to increase as the annealing temperature increases. Theoptimum annealing condition for obtaining the film with the lowest resistivity, the smoothest surface and the highest degree of the (111) preferred orientation is rapid thermal annealing in a nitrogen atmosphere at $400^{\circ}C$ for 120 s. The resistivity and the surface roughness of the electroplated copper film annealed under this condition are 1.98 $\mu$O-cm and 17.77 nm, respectively.

• Food Science and Preservation
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• v.12 no.6
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• pp.558-564
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• 2005

This study was carried out to investigate the cleaning effect of sesame leaf, the sterilization effect and physicochemical properties, treated with various electrolyzed water. Initial physicochemical properties could be kept more than 1 month in electrolyzed oxidizing water(EW-1) of diaphragm type and 15 days in electrolyzed water(EW-2 and EW-3) of non-diaphragm system, there was no significant difference by storage temperature. 4 kinds of microorganism (initial total counts, $10^7\~10^9$ CFU/mL) were sterilized within $0.5\~1$ minutes by electrolyzed water. In fresh sesame leaves, total viable cell count and coliform group in the treatment of electolyzed water were decreased to about $2\~3$ log scale comparing non-treated ones. Especially Bacillus cereus was not detected until 13th day when treated with EW-l. Decaying ratio of sesame leaf appears on day 6 of storage in the untreated but the treatments of electrolyzed water has no sign until day 10 of storage. Change in color difference(${\Delta}E$) during storage was observed the treatments of electrolyzed low-alkaline water(EW-2) and electrolyzed neutral water(EW-3) were very desirable at the level $1\~2$ after day 13 of storage comparative to the untreated Change of Chlorophyll content was biggest decreased to 6.8 $mg\%$ on the untreated and decreased least to 8.35 $mg\%$ on EW-3 treated group on 13th day from initial value of $9.0\~10.3\;mg\%$ The overall sensory evaluation appeared most acceptable in the treatments of EW-2 and EW-3.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.103-109
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• 2016

Efficacy of cosmetics has been mainly evaluated by qualitative and quantitative methods based on visual sense, tactile sense and skin structure until now. In this study, we suggested a novel evaluation method for skin status based on sound; measuring and analyzing the rubbing noise generated by applying cosmetics. First, the rubbing noise was measured at a close range by a high-sensitivity microphone in anechoic environment, and the noises were analyzed by 1/3 octave band analysis in frequency-domain. Three conditions, 1) before washing, 2) after washing and 3) after application of cosmetics, were compared. As a result, sound pressure level (SPL) of rubbing noise after washing was larger than that of before washing, and the SPL of rubbing noise after cosmetic application was the smallest. Furthermore, the energy of rubbing noise after application was higher than that of the before and after washing conditions in a low frequency band (lower than 2 kHz region). Conversely, the energy of rubbing noise after application was much lower than the others in a high-frequency band (upper than 2 kHz region). This change of energy distribution was described as a balloon-skin model. High SPL in the low frequency region after the cosmetic applications was due to the increase of "flexibility index", while SPL in the high frequency region significantly decreased because of the attenuation which is related to "softness index". Therefore, we developed two indices based on the spectrum-energy difference for evaluating skin conditions. This proposed method and indices were verified via skin flexibility and roughness measurement using cutometer and primos respectively. These results suggest that acoustic measurement of skin friction noise may be a new skin status evaluation method.