• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.495-503
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• 2020

Objective: This study aimed to compare the characteristics of humidifier disinfectant-like products (HD-like products) and humidifier disinfectant products (HD products) and introduce actual cases of the usage of HD-like products in hospitals based on an on-site investigation. Methods: The characteristics, chemical components, and usage of HD-like products (Hichlor or Biospot) and HD products (N-with) containing NaDCC (sodium dichloroisocyanurate) were compared. In the process of conducting the on-site investigation, four hospitals were identified as previously using HD-like products. Each on-site investigation to identify the use of HD-like products was composed of four parts: 1) hospital infection control guidelines, 2) manual for humidifiers in patient's rooms, 3) interviews with nursing staff, infection managers, and purchase managers, 4) searching on the product purchase system. Results: Although HD-like products (Hichlor and Biospot) and HD products (N-with) were sold for different usage purposes, they were all white-colored and coin-shaped foaming tablets with the same chemical component, NaDCC. The manual for using HD-like products and HD products was similar (inserting the tablet in a humidifier container with water). Among the four hospitals, one had used Hichlor in the same manner as HD (N-with) by inserting a tablet in 1L of water in a filled humidifier container and Biospot as a kind of detergent for humidifier container cleaning. Another two hospitals had used Biospot and/or Aniosyme as a kind of detergent for humidifier container cleaning. The other hospital had used unknown product in the same manner as N-with, so we thus assumed it was either an HD products (N-with) or HD-like products (Hichlor, Biospot). Conclusion: This study raises the possibility of the development of adverse health effects similar to exposure to an HD-products when exposed to an HD-like products and the possibility of further use in other medical institutions or multi-use facilities. Therefore, an expansion of the investigation is needed in order to confirm whether there have been similar cases in the past.

• Journal of the Korean Ceramic Society
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• v.43 no.2 s.285
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• pp.114-120
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• 2006

Nano-size Au particle doped $TiO_2$ films were prepared with $Ti(OC_3H_7^i)_4$, polyvinylpyrrolidone(PVP), $HAuCl_4$ and $C_3H_7OH$ etc. by sol-gel method. $TiO_2$ gel films were obtained by the dip-coating method on the $SiO_2$ glass substrates, and then heat-treated at $700^{\circ}C$ for 10 min. The thickness of $TiO_2$ films were $0.7\~1.8\;{\mu}m$. It was found that the thickness of films prepared from PVP containing solution was about $2\~8$ times higher values than that of thin films without PVP. The size of Au particles doped in the films were about $350\~750\;nm$. Nano-size Au particle dispersed $TiO_2$ films showed high absorption peak at visible region 450nm, which made them good candidates for non-linear optical materials and photo-catalytic materials. The contact angle of $TiO_2$ film for water was $12.5^{\circ}$, and therefore it is clear that $TiO_2$ films have very high hydrophilic properties and the self-cleaning effects.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.425-428
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• 2013

In this paper, we present a novel hydrophilic coating material (Wellture Finetech, Korea) which can be utilized as a coating layer for anti-contamination for electrical and electronic system. The coating material was deposited on 4 inch silicon wafer with several different film thickness. The film thickness was controlled by spin coating speed. After curing of the film, we have scratched by permanent marker to check self-cleaning property of the film. Also we have executed several mechanical tests of the films. As the spin coating speed is increased, the film thickness was thinned from 230 nm to 125 nm. Contact angle of the film was lowered from $30^{\circ}$ to $12^{\circ}$ as the spin coating speed is increased from 700 to 2,500 rpm. On permanent marker scratched film surface coated at 1,000 rpm, we have poured regular city water to investigate self cleaning property of the film. The scratches were gradually separated from the film surface due to super-hydrophilicity of the film. Hardness of spin coated film was 9H measured by ASTM D3363 method. and adhesion of all film was 5B tested by ASTM D3359 method. Also, to get exact hardness value of the film, we have utilized a nano-indenter. As spin speed is increased, the hardness of film was increased from 3 GPa to 5 GPa.

• Journal of Adhesion and Interface
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• v.24 no.2
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• pp.69-75
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• 2023

Recently, the application of paint protection films (PPFs) for automobiles having a self-recovery coating layer has been grown up. In this study, we report the evaluation results on the basic physical properties of a poly(vinyl chloride)- based PPF containing poly(urea-urethane) hybrid self-recovery coating layer. Depending on the main chemical composition and the thickness of poly(urea-urethane)-based coating layer for PPF, the self-recovery performance by an optical microscope and the stain resistance through color difference value are measured. To improve the surface properties and show its easy-cleaning effect against the polluted things, silicone-modified polyacrylate is introduced to the self-recovery coating composition. The contact angle of water on the coated surface is confirmed to show its hydrophobic surface. Finally, accelerated weathering test of paint protection film with poly(urea-urethane) hybrid coating layer is performed to check the possibility of discoloration and deformation due to long-term exposure on harsh condition.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.117-119
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• 2008

This study was investigated for the dyeing properties of silk fabrics with Annatto Extract. The dye stuff was extracted by distilled water at 60$^{\circ}C$, 10minutes, 100:1 of bath ratio. The highest K/S value was showed at 25% dye concentration, 60minutes of dyed time at 50$^{\circ}C$ in the temperature. The post mordant conditions were better than that of pre mordant, especially post-Fe mordant showed highest K/S value. The laundering fastness was relatively good by Cu-mordant. Drying cleaning fastness appeared 4-5 grades.

• Journal of information and communication convergence engineering
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• v.6 no.3
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• pp.305-309
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• 2008

This paper presents an innovative prototype of a new conceptual electromagnetic induction eddy current based fluid heating appliance using voltage-fed quasi resonant zero voltage soft switching PWM high-frequency inverter using IGBTs, which can operate at a constant frequency variable power regulation scheme. The promising simple high efficient low noise inverter type electromagnetic induction eddy current based pipeline fluid heating appliance is proposed for saturated steam generator, superheated steam generator, hot water and hot air producer, metal catalyst heating for exhaust gas cleaning in engine. Under these technological backgrounds, a novel electromagnetic induction eddy current Dual Packs Heater(DPH) based pipeline fluid heating incorporates thin metal layer type package for continuous fluid heating appliances applying two types of voltage-fed quasi load resonant ZVS-PWM high frequency inverter. The unique features of a novel electromagnetic induction eddy current DPH based continuous pipeline fluid heating appliance is illustrated on the basis of simulation and discussed for the steady state operating characteristics and experimental results.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.417-431
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• 2016

Poly(vinylidene fluoride) (PVDF) powder was treated with aqueous sodium hydroxide to obtain partially defluorinated fluoropolymers with expected properties such as improving hydrophilicity and fouling resistance. Raman spectrum and FT-IR results confirmed the existence of conjugated carbon double bonds after alkaline treatment. As the concentration increased, the degree of defluorination increased. The morphology and structure of membranes were examined. The permeation performance was investigated. The results showed that membrane's hydrophilicity increased with increase of the percentage of alkaline treated PVDF powder. Moreover, in terms of the water contact angle, it decreased from $92^{\circ}$ to a minimum of $68^{\circ}$; while water up take increased from 128 to 138%. Fluxof pure water and the cleaning efficiency increased with the increase of alkaline treated PVDF powder. The fouling potential also decreased with the increase of the percentage of alkaline treated PVDF powder. The reason that makes blending PVDF show different characteristics because of partial defluorination, which led the formation of conjugated C = C bonds and the inclusion of oxygen functionalities. The polyene structure followed by hydroxide attack to yield hydroxyl and carbonyl groups. Therefore, the hydrophilicity of blending membrane was improved. The SEM and porosity measurements showed that no obvious variations of the pore dimensions and structures for blend membranes were observed. Mechanical tests suggest that the high content of the alkaline treated PVDF result in membranes with less tolerance of tensile stress and higher brittleness. TGA results exhibited that the blend of alkaline treated PVDF did not change membrane thermal stability.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2205-2213
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• 2000

To investigate removal efficiency of dissolved matter by NF and RO, a pilot plant was operated for six months using groundwater treated by UF membrane. After the pilot plant operation, we performed autopsy test to identify characteristics of foulant attached on the membrane surface applying the used NF and RO in the pilot plant test. In autopsy test, we measured permeate flux and recovery rate of flux by chemical cleaning in each membrane. We also analyzed chemical cleaning disposal to examine component of foulant. Permeate flux of NF and RO1 showed rapid decline after 100 days of operation. Especially, reduction of specific flux in RO1 was more serious than in NF. Specific flux of RO2 with a low recovery rate resulted in gradual flux decline. Removal efficiencies of dissolved inorganic matters as a conductivity were 76.3%, 88.2% and 95.3% respectively for NF, RO1 and RO2, and RO2 presented the highest removal efficiency. And those of dissolved organic matters as TOC were about 80% for both NF and RO. The specific flux of membranes declined gradually from the feed water inlet to outlet of the membrane module and it showed that membrane fouling increased along the feed flow direction. Namely, concentration of pollutants became higher and volume of feed water was less as the feed flow approached to the outlet. It seemed that major foul ants were Ca consolidated into inorganic material and Si consolidated into organic material on the membrane surface. Fe was a great contribution to irreversible fouling. The SEM results indicated that the organic matter was attached to the first layer, closer to the membrane, and then inorganic matter with tetragonal shape layered over them. We could not observe biofouling because microorganism, which was cause of biofouling, was almost pretreated in UF membrane.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.999-1005
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• 2015

Bacillus-based feed additive was evaluated for its efficacy on growth performance, nutrient digestibility, fecal gas emission, and the consumption of time and amount of water for cleaning the pen of growing finishing pigs. A total of 120 growing pigs ($23.59{\pm}1.41kg$) were used in a 16-wk feeding trial. Pigs were randomly distributed into 1 of 2 treatments on the basis of body weight and sex. There were 12 replicate pens per treatment, with 5 pigs (3 barrows and 2 gilts) per pen. Dietary treatments were CON which was basal diet, and T1 which was CON+62.5 ppm microbial feed additive that provided $1.47{\times}10^8cfu$ of Bacillus organisms per gram of supplement. During the weeks 0 to 6, average daily gain (ADG) in T1 treatment was higher (p<0.05) than CON, but no improvement in average daily feed intake (ADFI) and feed efficiency (G:F) was noted. During 6 to 16 weeks, no difference (p>0.05) was noted in growth performance. However, ADG was improved (p<0.05) and overall ADFI tended (p = 0.06) to improve in T1 compared with CON. At week 6, the co-efficient of apparent total tract digestibility (CATTD) of dry matter (DM) nitrogen (N) was increased (p<0.05) in T1 compared with CON. Fecal $NH_3$ emission was decreased (p<0.05) in T1 compared with CON, at the end of 6th and 15th weeks. The time and water consumed for washing the pens were decreased (p<0.05) in T1 compared with CON. In conclusion, supplementation with Bacillus-based feed additive could improve the overall growth performances, increase the CATTD of DM and decrease the fecal $NH_3$ content and the time and water consumed in washing the pens for growing-finishing pigs.

• Textile Coloration and Finishing
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• v.35 no.4
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• pp.256-273
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• 2023

Among the dyeing industries, the tenter process is a process that improves the quality of fibers by drying and ironing (heat treatment) dyed fabrics, and drugs such as water repellents, antistatic agents, and fiber softeners are mainly used in these tenter processes. These drugs are vaporized in the process of treatment by high temperatures (180 ~ 230℃), and are observed in a complex form such as white smoke, oil mist, and fine dust, causing odor. To treat the complex exhaust gas at the rear end of the tenter facility, most companies operate by installing a wet scrubber and an adsorption tower alone or in parallel, but there are many problems. In particular, the insoluble oil mist at the rear end of the tenter has significantly low processing efficiency in the cleaning dust collection facility, and there is a problem in the facility by adsorption due to the occlusion phenomenon caused by the oil mist. In addition, the odor gas at the rear end of the tenter contains a lot of aldehydes, and in order to improve these various problems, a complex exhaust purification device using cyclone and electric support collector was developed. This study examined the applicability of economical and efficient technology by removing complex air pollution at the rear end of the tenter and applying improved technology than the existing technology.