• Safety and Health at Work
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• v.11 no.1
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• pp.80-87
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• 2020

Background: Residential and commercial cleaning is a part of our daily routine to maintain sanitation around the environment. Health care of professionals involved in such cleaning activities has become a major concern all over the world. The present study investigates the risk of musculoskeletal disorders in professional cleaners involved in floor mopping tasks. Methods: A cross-sectional study was performed on 132 mopping professionals using a modified Nordic questionnaire. The Pearson correlation test was implemented to study the association of perceived pain with work experience. The muscle strain and postural risk were evaluated by means of three-channel electromyography and real-time motion capture respectively of 15 professionals during floor mopping. Results: Regarding musculoskeletal injuries, risk was reported majorly in the right hand, lower back, left wrist, right shoulder, left biceps, and right wrist of the workers. Work experience had a low negative association with MSDs in the left wrist, right wrist, right elbow, lower back, and right lower arm (p < 0.01). Surface EMG showed occurrence of higher muscle activity in upper trapezius and biceps brachii (BB) muscles of the dominant hand and flexor carpi radialis and BB muscles of the nondominant hand positioned at the upper and lower portion of the mop rod, respectively. Conclusion: Ergonomic mediations should be executed to lessen the observed risk of musculoskeletal injuries in this professional group of workers.

• Korean Journal of Veterinary Research
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• v.14 no.2
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• pp.273-279
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• 1974

Studies were made on the relation of mastitis infection rate to the management and sanitations of dairy farms by examining 46 dairy herds. The results obtained were as follows: 1. The higher infection rate was observed in farms managed by employees than by owners, and in impoprted cattle than cattle horn in Korea. 2. Type of education and the period of experience of management were not correlated to the infection rate. 3. The infection rate was the highest in Summer and in cattle of 5~8 lactating age group. 4. It was observed that the amount of water supply, time of cleaning stall, frequency of disinfection, the method of using cleaning towel and the method of milking were correlated to the infection rate.

• Journal of Ocean Engineering and Technology
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• v.17 no.3 s.52
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• pp.52-56
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• 2003

This study investigates the photoelectrochemical behavior of STS304 steel with TiO2 thin films coating, applied by sol-gel mehod, for the purpose of cathodic photoprotection of the steel corrosion. One time TiO2-coated STS304 steel, adapted with two kinds of TiO2 sol solution, has the most dominant photopotential abilities, which was -200mV vs. SCE and -500mV vs. SCE under illumination with 40 W fluorescent lamp, respectively. That had yielded more negative values than the corrosion potential of the bare metal(-130mv vs.SCE). The bleaching of TCE was confirmed on TiO2-coated STS304 steel under UV-illumination with 20W Black-light. This Study concluded that Ti02-coated STS304 exhibited both a cathodic photoprotection effect against corrosion and a photocatalytic self-cleaning effect.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.7 no.2
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• pp.59-65
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• 1982

In this paper, the CdS single crystal, which was grown as piper-polish method, was Ion-bombarded with Sb and In, and the thermally stimulated current of the spot that was Ionbombarded was measured. In the sample which was individually bombarded by Sb and In, the over-lapping peak was found, this over lapping peak was separated, by the method of thermal cleaning, showing the trap levels of 0.25(eV) and 0.31(eV) at the temperature of 147(K) and 181(K). While the spot is being cooled down and excited with photolight at the same time, the trap level 0.25(eV) disappeared and the new trap level of 0.85(eV) appeared. It can be said that the better photo-conductive crystals, the T.S.C is better measured.

• Journal of Microbiology
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• v.38 no.2
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• pp.99-104
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• 2000

Hydrogen peroxide has been used in cleaning the piping of an advanced high-purity water system that supplies ultra-high purity water (UHPW) for 16 megabyte DRAM semiconductor manufacturing. The level of hydrogen peroxide-resistant bacteria in UHPW water was monitored prior to and after disinfecting the piping with hydrogen peroxide. Most of the bacteria isolated after hydrogen peroxide disinfection were highly resistant to hydrogen peroxide. However, the percentage of resistant bacteria decreased with time. The hydrogen peroxide-resistant bacteria were identified as Micrococcus luteus, Bacillus cereus, Alcaligenes latus, Xanthomonas sp. and Flavobacterium indologenes. The susceptibility of the bacteria to hydrogen peroxide was tested as either planktonic cells or attached cells on glass. Attached bacteria as the biofilm on glass exhibited increased hydrogen peroxide resistnace, with the resistance increasing with respect to the age of the biofilm regrowth on piping after hydrogen peroxide treatment. In order to optimize the cleaning strategy for piping of the high-purity water system, the disinfecting effect of hydrogen preoxide and peracetic acid on the bacteria was evaluated. The combined use of hydrogen peroxide and peracetic acid was very effective in killing attached bacteria as well as planktonic bacteria.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.307-311
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• 2002

This study was investigated the photoelectrochemical behavior of STS304 steel with $TiO_2$ thin films coating, applied by sol-gel method, for the purpose of cathodic photoprotection of the steel corrosion. One time $TiO_2$-coated STS304 steel adopted two kinds of $TiO_2$ sol solution has the most dominant photopotential abilities, which was -200mV vs. SCE and -500mV vs. SCE under illumination with 40W fluorescent lamp, respectively. That was more negative than the corrosion potential of the bare metal(-150 mV). The bleaching of TCE was confirmed on $TiO_2$-coated STS304 under UV-illumination with 20 W Black-light. This Study was concluded that $TiO_2$-coated STS304 exhibited both a cathodic photoprotection effect against corrosion and photocatalytic self-cleaning effect.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3279-3281
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• 1999

This paper describes a method of direct wafer bonding using surfaces activated by a radio-frequency hydrogen plasma. The hydrogen plasma cleaning of silicon in the RIE mode was investigated as a pretreatment for silicon direct bonding. The cleaned silicon surface was successfully terminated by hydrogen, The hydrogen-terminated surfaces were rendered hydrophilic, which could be wetted by Dl water rinse. Two wafers of silicon and silicon dioxide were contacted to each other at room temperature and postannealed at $300{\sim}1100^{\circ}C$ in an $N_2$ atmosphere for 2 h. From the AFM results, it was revealed that the surface became rougher with the increased plasma exposure time and power. The effect of the plasma treatment on the surface chemistry was investigated by the AES analysis. It was shown that the carbon contamination at the surface could be reduced below 5 at %. The interfacial energy measured by the crack propagation method was 122 $mJ/m^2$ and 384 $mJ/m^2$ for RCA cleaning and hydrogen plasm, respectively.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.1
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• pp.19-25
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• 2021

Purpose: This study seeks to develop behavior-induced automatic separation X-Bin for disposable cup speculators. Some students throw away the contents. Research design, data and methodology: Therefore, environmental beautification workers spend a lot of time sorting disposable cups at school garbage collection sites. Disposable cups that have been thrown away like this are bad in terms of appearance and smell. In addition, cleaning inside garbage affects recycling rates and is closely related to environmental problems. Results: Clean cleaning reduces the amount of garbage incinerated without being recycled and reduces the cost of recycling. According to Korean Social Trends 2020, COVID-19 began to spread, and recycling of disposable items such as disposable cups increased by about 15 percent from the same period last year. Conclusions: These are classified for recycling, and the amount of garbage thrown on the streets is estimated to be larger. In order to prevent COVID-19s, the use of disposable goods is inevitable, but facilities are needed to dispose of them properly.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.407-410
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• 2003

We will introduce our new concept deposition system for SMOLED manufacturing in this conference. This system is designed to deposit organic and metal material to downward to overcome the limit of substrate size and process tact time hurdle for OLED mass production, and is organized with organic deposition chamber, substrate pre-cleaning chamber, metal deposition chamber and encapsulation system. These entire process chambers are integrated with linear type substrate transfer system. We also compare our new SMOLED manufacturing system with conventional vacuum deposition systems, and show basic organic thin film property data, organic material deposition property data, and basic device property.

• Textile Coloration and Finishing
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• v.12 no.3
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• pp.183-191
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• 2000

The dyeing of silk fabric with chinese scholar tree extract was investigated. The colorant was extracted with distilled water, and concentrated under reduced pressure, and, finally spray-dried. The optimum temperature and dyeing time for the dyeing of silk with the scholar tree extract was $60^\circ{C}$ and 60 minutes respectively. In mordant dyeing, pre-mordanting method was most effective for color yield, and 1~2 % of mordant concentration was acceptable. Fastness of the dyed silk fabric to laundering and rubbing was shown to be good, but fastness to light, dry cleaning, and perspiration were varied with used mordants.