• Journal of Korean Society on Water Environment
• /
• v.20 no.5
• /
• pp.391-396
• /
• 2004

• Proceedings of the Korean Nuclear Society Conference
• /
• 2002.05a
• /
• pp.321.1-321
• /
• 2002

• Proceedings of the Korean Nuclear Society Conference
• /
• 2002.05a
• /
• pp.321.2-321
• /
• 2002

• Journal of the Korean Society of Clothing and Textiles
• /
• v.36 no.2
• /
• pp.127-137
• /
• 2012

This study focuses on the optimal washing conditions for dry cleaning recommended fabrics to minimize dimensional changes using wet cleaning. We suggest water-based alternatives to a perchloroethylene based cleaning process. Wool and rayon fabrics were laundered under various washing conditions and then air-dried for 24hrs. All specimens were extended after spinning and shrunk after drying. This is probably because the fibers were swollen and extended by wetting. The wool fabrics were shown to be acutely influenced by washing temperature and mechanical force. The optimal washing conditions for wool fabric to minimize the dimensional change implied a normal washing temperature and minimized mechanical force. For rayon specimens, dimensional change by a hand wash showed a remarkable decrease compared with a machine wash. Rayon fabric seemed to be influenced by the quantity of water contained in the fabric after spinning and washing time. Therefore, the desirable washing conditions for rayon fabric are to reduce the time required for washing and to increase the spin speed.

• Korean Journal of Occupational Health Nursing
• /
• v.24 no.3
• /
• pp.183-193
• /
• 2015

Purpose: The purpose of this study was to describe cleaning workers' working experiences in Korea. Methods: The data were collected in two focus-group interviews with 9 cleaning workers. The phenomenological analytic method suggested by Colaizzi was used to analyze the data. Results: Five theme clusters and thirteen themes emerged from the analysis. The first theme clusters, 'Dead-end choice' included Limits of elderly women workers, Financial difficulties, Lowered self-esteem. The second theme clusters, 'Facing with discriminatory working environments' included Fear and unfair working conditions. The third theme clusters, 'Potential health problems' included Physical overload, Repeated exposure to hazardous substances and Emotional labor. The fourth theme clusters, 'Excluded from protection of the law' included Gloomy reality and Sexual harassment. The fifth theme clusters, 'Desire to get out of social isolation' included Efforts to maintain the status, Desire to live confidently and Desire to change social recognition. Conclusion: The findings of the study provide understanding on cleaning workers' working experiences to explain by their vision and language and should ensure proper working conditions and environment to live a better life.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.40-40
• /
• 1999

가속기나 토카막과 같은 거대한 진공 장치의 용기 내벽을 청정화 하기 위해서는 용기 전체의 열처리(굽기, Baking)와 글로우 방전(Glow discharge) 법을 병행하여 사용한다. Baking은 일반 기체(N2, O2, 그리고 CO2)와 물(H2O)의 탈착에 효과적이고, Glow discharge cleaning은 탄소(Carbon-based)와 산소(Oxygen-based) 화합물의 탈착에 효과적이다. 특히 Glow discharge cleaning의 경우에는 전극의 모양, 진공 용기의 재질과 모양, 전극간의 거리, 사용되는 반응 기체의 압력 등에 따라 그 효과에 큰 차이가 있으므로 다각적인 연구가 필요하다. 본 연구에서는 그림 1과 같이 시험용 스테인레스(AISI 304와 AISI 316LN) 진공 용기를 설치하고, 시험 용기의 한쪽은 배기 용기와 oriffice로, 다른 편은 불순물의 정성.정량 분석을 위해 RGA(Residual gas analyser) 용기와 oriffice로 연결하였다. 전체 시스템 중에서 배기 부분과 분석 부분은 15$0^{\circ}C$에서 24시간 가열하여 전체의 기저 진공도를 1$\times$10-8Torr로 하였다. 기저 진공도의 용기에 고순도의 반응기체 (He, Ar, Ar+He, Ar+H2, Ar+N2 등)를 주입한후, DC 전압(0.8~1.5kV)을 변화하며 글로우 방전의 최적조건을 찾았다. 방전 동안 시험용 용기에서 방출되는 반응 기체 이외의 기체를 RGA로 측정하였고 외부에 Thermocouple을 여러곳에 장착하여 온도 변화를 측정하였다. 이상의 결과로부터 진공 용기 표면적으로부터의 불순물 탈착(desorption)과 불순물 분석, 플라즈마와 내벽의 상호작용등에 대한 결론을 얻을 수 있었다. 또한 Baking과 Glow discharge cleaning을 동시에 수행하여 Baking 온도의 낮춤에 따른 영향 평가도 수행하였다.

• Korean Journal of Materials Research
• /
• v.28 no.11
• /
• pp.620-626
• /
• 2018

Highly self-cleaning thin films of $TiO_2-SiO_2$ co-doped with Ag and F are prepared by the sol-gel method. The asprepared thin films consist of bottom $SiO_2$ and top $TiO_2$ layers which are modified by doping with F, Ag and F-Ag elements. XRD analysis confirms that the prepared thin film is a crystalline anatase phase. UV-vis spectra show that the light absorption of $Ag-F-TiO_2/SiO_2$ thin films is tuned in the visible region. The self-cleaning properties of the prepared films are evaluated by a water contact angle measurement under UV light irradiation. The photocatalytic performances of the thin films are studied using methylene blue dye under both UV and visible light irradiation. The $Ag-F-TiO_2/SiO_2$ thin films exhibit higher photocatalytic activity under both UV and visible light compared with other samples of pure $TiO_2$, Ag-doped $TiO_2$, and F-doped $TiO_2$ films.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.36 no.4
• /
• pp.163-172
• /
• 2020

In this study, the effect of window opening, which is a control mechanism for air control in winter high school classrooms, on the change in air and indoor environment of the classroom was analyzed and physical conditions of indoor and air environment were observed during the classroom course, and satisfaction of the students and teachers was assessed with questionnaires. And the changes in air environment were assessed by the performance of the duster cleaning work in the classroom. It was found that 84.6% of the students surveyed said the air was stuffy. And among the alternatives, opening windows all times during class was most effective in reducing CO₂ concentration and PM concentration was measured within classroom's standard. In addition, the concentration change rate of duster cleaning work was reduced by 74.4% and 65.4% of PM10 compared to broom cleaning work.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.10
• /
• pp.710-715
• /
• 1999

The purpose of this work is to develop a high-efficiency air cleaning system for air pollutants such as particulate and gaseous state in indoor environments. In order to enhance a removal efficiency of gaseous state pollutants, we suggested that pulsed discharge plasma be combined with $TiO_2$ photocatalyst (photocatalytic plasma air cleaning unit). We investigated experimentally the basic characteristics of photocatalytic plasma air cleaning unit and measured air pollutants removal efficiency. The wavelength of light radiated from pulsed discharge plasma under the atmospheric condition was 310~380nm. Its energy is enough to excite the $TiO_2$ photocatalyst and it makes a photochemical reaction in the surface of $TiO_2$ photocatalyst. The removal quantity of trimethylamine$((CH_3)_3N)\; was\; 130mg/m^34 which is twice quantity of pulsed discharge plasma without $TiO_2$ phtocatalyst unit. From the result of gas analysis using FT-IR, nitric oxide was not detected and trimethylamine was decomposed to $H_2O\; and \;CO_2$. And trimethylamine removal efficiency was 95%. These experimental results indicate that photocatalytic plasma air cleaning unit is a potential method in removing the pollutants.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.5
• /
• pp.575-582
• /
• 2011

A cleaning blade is an attachment installed in the toner cartridge of a laser printer for removing the residual toner from an organic photo-conductive drum. There have been many studies on the performance and life of the rubber blade. We focus on optimally designing the blade shape parameters to minimize the maximum stress of the blade while satisfying design constraints on the cleaning performance and part interference. The blade is optimally designed using a design of experiments, meta-models and an optimization algorithm implemented in PIAnO (process integration, automation, and optimization), a commercial PIDO (process integration and design optimization) tool. We integrate the CAE tools necessary for the structural analysis of the cleaning blade, automate the analysis procedure, and optimize the solution using PIAnO. We decreased the maximum stress by 32.6% in comparison with that of the initial design.