• 한국재료학회지
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• 제11권4호
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• pp.251-257
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• 2001

반도체 소자의 고집적화에 따른 세정공정 수는 점점 증가하고 있는 추세에 있다 현재 사용되는 세정은 다량의 화학약품 및 초순수를 소비하며, 고온에서 행하여지고 있는 RCA세정을 근간으로 하고 있다. 세정공정수의 증가는 바로 화학약품의 사용량 증가를 초래하게 되며, 이에 따른 환경문제가 심각하게 대두되고 있는 실정에 이르렀다. 따라서 이러한 화학약품 및 초순수 사용을 절감하고, 저온에서 세정공정이 이뤄지는 기술이 향후 요구되어 지고 있다. 이번 연구는 이러한 관점에서 화학약품 및 초순수 사용량을 줄이며, 상온 공정이 이뤄지는 전리수를 이용하여 실리콘 웨이퍼 세정을 하였다. 제조된 전리수는 산화성 성질을 지닌 양극수와 환원성 성질인 음극수로 이루어지고, 각각 pH 및 ORP는 4.7/+1050mV, 9.8/-750mV를 30분 이상 유지하고 있었다 전리수의 양극수에 의한 금속제거 효과가 음극수의 효과보다 우수함을 확인할 수 있었으며, 다양한 입자제거 실험에도 불구하고, 동일한 분포도를 나타내고 있었다.

• Agribusiness and Information Management
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• 제9권1호
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• pp.18-22
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• 2017

It takes lots of time and labor if a worker have to measure the water quality at a certain but designated time every day in an un-automated aqua farm. In addition, if the equipment is soaked in the sea water consistently, it will be contaminated by diverse floating matters and barnacles, and it often becomes mal-functional within 2~3 months. Therefore, we need to develop a system with which the sensed data could be checked in real time and operated automatically, while preventing the contamination of the sensor, a crucial component for water quality measuring equipment, as much as possible, and increasing the replacement cycle. We have developed a non-cleaning water quality measuring equipment and its software which are used in the fishery household of offshore aqua farms. By providing the workers with a mobile application which has a function of monitoring the water quality in real time, they can check the situation directly without going to the fishery household.

• Journal of Advanced Marine Engineering and Technology
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• 제36권7호
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• pp.894-901
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• 2012

For more efficient use of the high pressure water-jet in rehabilitation of the water pipes, we have studied the water-jet cleaning motion of the in-pipe robot with screw drive. The mathematical models of the water-jet in the straight and the curved pipe (90 degrees elbow), representative features of the water mains, were designed to understand the water-jet motion and simulations have been performed. Furthermore the experiments has been conducted to validate the simulations by using the prototype in-pipe robot in the 3-D pipeline. The simulation results show that the water-jet motion in the straight pipe has a constant water-jet interval, whereas the motion in the curved pipe is changed by its position. By the comparison of the simulation and the experimental results, we have demonstrated that the simulations successfully estimate the water-jet motion inside the water pipes. Therefore in-pipe robot operators can predict a water-jet motion for a target water pipe through the simulation and flexibly make a proper water-jet motion by changing the robot configurations before a cleaning work.

• 기본간호학회지
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• 제18권4호
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• pp.472-479
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• 2011

Purpose: The purpose of this study was to develop guidelines for cleaning of enteral nutrition bags by comparing the level of equipment contamination according to cleaning and disinfection methods. Method: This study was a true-experimental study, with 60 cases in total. Twenty cases each were randomly assigned to tepid water, detergent and brush, and disinfectant groups. The period of the experiment was March to April 2010, and enteral nutrition was given for 1 houre, 3 times a day at 7AM, noon, and 7PM for seven days. Enteral nutrition bags were cleaned after each feeding according to assigned cleaning and disinfection method followed by microbial cultures on 4th and 8th day before the 7AM feeding. Results: After 3 days of feeding and cleaning, the level of contamination of bags was not significantly different among the three groups. After seven days, the level of contamination was significantly lower when bags were cleaned with detergent and brush or with disinfectant compared to cleaning with tepid water. Conclusion: In cases where enteral nutrition bags are reused for example, in home care settings, studying findings indicate that cleaning bags using detergent and brush or disinfectant is an effective way to prevent contamination of bags.

• 대한치과의사협회지
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• 제12권1호
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• pp.37-42
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• 1974

To ascertain if the ultrasonic cleaning technique caused any dimensional changes in heat and cold curing and fluid resin denture bases and in addition to evaluate the dimensional changes of the resin denture bases stored in water and air, the author measured the distance between the outsides of two pins embedded in methyl methacrylate test denture bases by mean of 12 inch vernier caliper, accurate to 0.02mm. The results were as follows; (1) Ultrasonic cleaning didn't cause any permanent dimensional changes, but only affected temporary dimensional expansion in 16 test denture bases. (2) Temporary expansion rate caused by 10 minutes' ultrasonic cleaning was 0.29% and at the maximal temperature of the cleaning solution it was 0.64%. (3) The half of the denture bases stored in water showed the dimensional expansion rate of 0.47% while the others stored in air showed the dimensional shrinkage rate of 0.15% after 4 months.

• 한국보건간호학회지
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• 제10권1호
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• pp.31-38
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• 1996

Disinfection is a very important process in water plant on account of our surface water usage. Particularly. the rainfall of Korea is concentrated in summer time. it is almost carried away to ocean before our utilization as water resource. To overcome the unbalance of water resource, artificial dams and reservoirs are constructed. According to such storage of water to aggravate water pollution and make the increase of water cleaning chemicals. Chlorine, as a main traditional chemical for water treatment. is focused on account of THMS formation in recent days. In this paper. the data of a water plant located in Seoul is adopted as the foundation of water quality analysis and introduce the substitute chemicals to supplement the harmful formation. additionally. Conclusions are summarized as follows: 1. The water quality of water resource is the worst in summer time and the supply of cleaning chemical is inevitably increased on account of general bacteria increase. 2. Chlorine, as a main chemical for water cleaning, formed the cancer-causing organic THMS with water molecules. 3. One of substitute chemical. chlorine dioxids suppress the formation of THMS comparing with the case of chlorine only. Therefore. the continuous research of substitute chemicals should be activated. 4. As the supply of disinfected clean water concerned with the citizen sanitary, the cultivation of professionals and academic conference must be needed on the basis of nation

• 한국수처리학회지
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• 제26권6호
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• pp.99-107
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• 2018

This research has developed a high temperature steam cleaning technology using a ceramic membrane with durability against temperature and pressure conditions. In steam cleaning, steam of $120^{\circ}C$ is injected into the ceramic membrane to induce pyrolysis by the endothermic reaction to remove fouling from the membrane. The water quality of raw water was adjusted to turbidity 10, 25 NTU and DOC 2.5 mg/L, and the membrane was uniformly fouled by constant pressure operation at 100, 200, and 300 kPa. Physical backwashing was performed with water and air at a pressure of 500 kPa and steam at $120^{\circ}C$ was injected for 0 to 5 minutes. As the turbidity concentration and the operating pressure increased, the flux decreased by 0.7 to 14.4%. It is confirmed that 10.7 to 53.8% recovery is possible than physical cleaning at the injection of steam for 3 minutes, so it is considered that the steam cleaning of the ceramic membrane is effective. Compared with CEB after NaOCl (300 mg/L) filtration at 25 NTU and 300 kPa of turbidity, the steam cleaning result for 3 minutes was similar to 46.7% of CEB for 3 hours. It has been confirmed that steam cleaning is suitable for a ceramic membrane having excellent heat resistance against high temperature. It was considered to have better cleaning efficiency as compared with general physical backwashing.

• 멤브레인
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• 제27권6호
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• pp.519-527
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• 2017

멤브레인 파울링은 지표수를 처리하는 저압 멤브레인 기술 적용의 확장에 있어 큰 장애가 된다. 따라서 파울링 제어를 위한 주기적인 수리학적 세정기술의 최적화는 매우 중요하다. 주기적인 수리학적 세정과 이와 연관된 파울링 현상에 관한 올바른 이해는 멤브레인 세정 전략을 최적화하기 위해 매우 유용할 수 있다. 실험적으로 측정한 투과도와 전통적인 Hermia 파울링 모델 예측 치의 비교를 통해, 본 연구에서는 합성 탁도유발 시료를 처리하는 가압식 멤브레인 공정에서 30분 여과와 정세정/역세정이 포함된 1분 세정조건을 바탕으로 6번의 운전사이클을 통해 발생하는 파울링 현상을 분석하고 이를 통해 지배적인 파울링 기작을 정량적으로 이해하고자 하였다. 단독 세정에서, 첫 번째 운전사이클에서 발생하는 파울링은 완전공극막힘 현상에 의해 주로 지배되었고 마지막 운전 사이클에서는 케이크 형성이 지배적인 파울링 기작으로 관찰되었다. 정세정과 역세정이 혼합된 경우, 파울링 속도는 감소하였으나 전반적으로 케이크 형성이 주 파울링 기작으로 관찰되었다.

• 설비공학논문집
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• 제23권10호
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• pp.656-661
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• 2011

The amount of water resources that can be used tend to be decreased gradually. In contrast, the rapidly increasing water consumption is a problem that need to be addressed. Renovation and equipment replacement to improve energy efficiency and to reduce expenditure for building usage is required. But the excessive initial investment cost and the prolonged of pay back period may be uneconomical choice. Water usage for cleaning the toilet bowl accounts for 27%of the total water usage. Water-saving valve that can select the amount of water for cleaning toilet bowl can be reduced expenditure. After installing water-saving valve, analysed the economic effects. Water-saving valves compared with flush valves, and researched the amount of water usage. Then analyzed for the economic effects. Water-saving valve was used 5.6 ${\ell}$/time for cleaning toilet bowl. In contrast, flush valve was consumed 8.4 ${\ell}$/time. Water-saving valve's water-saving rate was 33.3%. The initial payback period for Water-saving valve was 459.5 days. By a small investment in water saving valve, the economic benefits can be obtained.

• 청정기술
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• 제9권1호
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• pp.9-21
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• 2003

CFC-113, 1,1,1-TCE는 오존파괴물질로 선진국에서는 이미 사용이 전면 규제되고 있고 MC, TCE는 유해성 또는 발암성물질로 판명되어 일부사업장에서 제한적으로 사용되고 있다. 그러므로 세정성이 좋고 환경/안전성이 우수한 대체세정제를 개발하여 사용하거나 기존 개발된 세정제 중에서 우수한 세정제를 선정하여 사용하는 것이 필요한 실정이다. 대체세정제로는 수계세정제가 환경성과 경제적면에서 유망한 것으로 평가받고 있어 많은 사업장에서 사용될 전망이다. 본 연구에서는 환경친화적인 수계세정제를 개발하기 위하여 수계세정제의 주요성분인 여러 형태의 계면활성제를 선정하여 이들의 물성, 거품성, 오염물 종류에 따른 세정성, 유수분리성을 평가하여 비교하였다.