• 복식문화연구
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• 제23권6호
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• pp.1082-1096
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• 2015

The purpose of this study was to examine laundry behavior according to the number of households and the type of washing machine that each household used. The data was obtained from questionnaires filled out by 417 households, which included college students living in Seoul and Gyeonggi province. The results of this study are as follows: first, according to the results of survey about the number of household members and type of washing machine that household had, one or two-person households accounted for 24.0%. Regarding the type of washing machine that each household used, there were more drum washers. In households comprised of three or more persons, a higher percentage had a machine with a pulsator. Second, with regard to the method of classifying the wash in doing the laundry, all families classified the wash according to color and textile material. Third, with regard to the amount of detergent in doing the laundry, 63.5% of households used the recommended amount of detergent while 28.3% of households used more detergent than the recommended amount. Fourth, with regard to the set temperature of water in doing the laundry, 36.2% of households used cold water; this was the highest percentage. Fifth, with regard to input sequence in doing the laundry, most households put the wash in the machine in advance, and then filled the washer with water; 56.1% of households added a rinsing process for all washing processes.

• 한국전산유체공학회지
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• 제18권3호
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• pp.8-13
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• 2013

Drag reduction of a running vehicle is very important issue for the energy savings and emission reduction of its power train. Especially for a solar powered electric vehicle, the drag reduction and weight lightening are two serious problems to be solved to extend its driving distance under the given energy condition. In this study, the ground effect of an airfoil shaped road vehicle was studied for an optimum body design of an ultra-light solar powered electric vehicle. Clark-Y airfoil type was adopted to the body shape of the model vehicle to reduce aerodynamic drag. From the study, it was found that the drag of the model vehicle was reduced as the height(h) between ground and the lower surface of the model vehicle was decreased. It is due to the reduction of the down-wash decreasing the induced drag of the vehicle. The lift was also decreased as the height decreased. It is due to the turbulent boundary layer developed beneath the vehicle body. The drag is classified into two types; the form and friction drag. The fraction of form drag to friction one is 76 to 24 on the model vehicle. As the height(h) of the model vehicle from the ground surface increases the form drag also increases but the friction drag is in reverse.

• 한국물환경학회지
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• 제20권5호
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• pp.494-499
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• 2004

Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Therefore, it is necessary to manage both point and non-point sources contaminations for protecting water environment and improving water quality. This study investigated the characteristics of pollutant release over a wide range of rainfall intensities as a requisite to control road runoff that accounts for the largest portion of non-point source contamination in urban areas. Samples of runoff rainwater collected from real road surfaces were analyzed for physicochemical parameters such as pH, suspended solids, and heavy metals. A experimental model road ($30cm{\times}30cm$) was also used to evaluate wash-off properties of pollutants deposited on the surface as functions of time and rainfall intensity. Analysis of runoff samples on rain events showed that the pollutant wash-off patterns for heavy metal and suspended solids were similar. This implies that the particles in rainwater adsorb heavy metals. Experiments using the model road made of impervious asphalt demonstrate a strong first flush phenomenon. At high rainfall intensity, approximately 80% of total pollutants were released within 15 min. The pollutant wash-off rates rapidly increase from 9 mm/hr to 12 mm/hr of rainfall intensity and decrease over 12 mm/hr of rainfall intensity.

• 보존과학연구
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• 통권24호
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• pp.81-98
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• 2003

The biodeterioration on Iksan Mireuksaji pagoda has been studied with fucus on application of K201 as a chemical treatment. Total of 39species, including 10 algae, 16 lichens, 6 mosses and 7 unidentified bacteria and fungi, were collected and identified on the surface of the pagoda. Most of them caused serious discoloration on the surface. The effectiveness and stability of K201 was examined by applying it on some part of the pagoda. A mild spraying of solution diluted to half of original reagent was good enough to eliminate all the deteriorating species on the surface. Most of discoloration disappeared after the treatment except the red color caused by iron substance. The effectiveness of the regent was compared with water wash. The stone was first washed with water and the dirt on the surface was scrubbed off from the surface. The initial surface of the stone was clearer in water wash. However, many of the deteriorating species reappear in 4 weeks after water wash. Although spraying of the reagent K201 could noteliminate all the remnant of dead organisms as good as scrubbing the surface, no deteriorating algae or lichen was observed until two month after treatment. Therefore, spraying method with chemicals seems more stable and reliable way to remove the biodeterioration than physical scrubbing of the surface.

• 멤브레인
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• 제27권1호
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• pp.104-107
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• 2017

역삼투막 운영에 있어서 유기물 오염에 대한 문제들을 해결하기 위해 많은 연구를 하고 있다. 현재 가성소다(NaOH)를 사용하여 유기물 오염 제거를 하고 있다. 본 연구는 지속적인 막오염 증가 문제를 해결하기 위한 물리/화학적 세정 기법으로서 기존에 사용하던 가성소다와 Micro-bubble를 이용하여 유기물 오염 제거 실험을 수행되었다. 멤브레인 강제 오염을 위해 Humic acid sodium, Bovine serum albumin, Sodium alginate 약품을 사용하여 유기물 오염을 시켰다. 유기물 오염에 따른 Flux를 관찰하였고, 가성소다와 Micro-bubble를 이용한 유기물 오염 제거 실험은 가성소다로만 사용했을 때보다 향상된 것을 관찰했다.

• 한국의류산업학회지
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• 제13권3호
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• pp.438-444
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• 2011

Bamboo leaves, as natural dye provide unartificial fresh green, are known for expert property at anti-bacterial, anti-aging, anti-oxidation, skin whitening, moisturizing, peeling of horny, deodorizing and some skin disease like as eczema and inflammation without any allergic response. Also, It is quite common to obtain bamboo leaves from our surrounding but most of them were not in use. On purpose of development the way of recycle with common material to dye, bamboo leaves were used to dye on ramie fiber which is valuable for both of apparel and industrial field and investigated their dyeing property. Using extract from bamboo leaves, dyeing property was examined with dyeability, colorimetric property, light fastness and wash fastness under different conditions by extract density, dyeing time, dyeing method and mordants. As results, dyeing was generally colored in yellowish, K/S Value was shown more higher on hemp fiber than ramie. The most optimum dyeing condition was investigated on pre-mordant treatment, dyeing temperature $60^{\circ}C$, dyeing time 30min and extract density 400%. On the treatment with mordant(Al, Fe, Cu), dyebility on both of hemp and ramie fiber were increased by mordant. Especially with Copper(Cu) as mordant, dyebility was highly increased than any other mordants and dyeings showed in deep color. Also on the fastness test which is the most important to natural dyeing, wash-fastness showed good performance with 4-5 grade but light-fastness was above 4 grade on both of hemp and ramie fiber, lower than wash-fastness overall.

• The Journal of Advanced Prosthodontics
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• 제11권3호
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• pp.155-161
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• 2019

PURPOSE. Although dental impression disinfection is determinant to reduce the cross-infection risk, some studies have shown that, in real practice, the disinfection procedures vary considerably. Thus, the aim of this study was to evaluate the antimicrobial effectiveness and the impact on the dimensional stability of addition silicone' impressions of water wash and the most clinically used disinfection solutions: 3% hydrogen peroxide, commercial disinfectant MD520 (Durr) and 1% and 5.25% sodium hypochlorite. MATERIALS AND METHODS. For this investigation, dental impressions were taken on 16 volunteer dental students. The antimicrobial effectiveness of each procedure was evaluated by pour plate method. The dimensional stability was evaluated using a standardized stainless-steel model, according to ANSI/ADA nº19 specification. RESULTS. The study results showed that water wash does not alter the dimensional stability of addition silicone impressions but doesn't reduce the microbial load of the material (P>.05). On the other hand, addition silicone disinfection by immersion with 3% hydrogen peroxide, MD520 (Durr), or sodium hypochlorite at 1% and 5.25% does not alter the dimensional stability significantly but reduces > 99.9% of the microbial load of the impressions (P<.001). CONCLUSION. Addition silicone impressions should always be disinfected after water wash in order to reduce effectively the cross-infection risk. All disinfectants tested showed high antimicrobial efficiency without significant changes in three-dimensional shape of impressions. Hydrogen peroxide and sodium hypochlorite are of particular importance because are easily accessible in dental setting. The less explored hydrogen peroxide could be a valuable alternative for silicone impressions disinfection.

• Korean Chemical Engineering Research
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• 제59권3호
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• pp.435-442
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• 2021

요소를 이용한 균일용액침전법으로 망간이 첨가된 바륨 헥사알루미네이트를 제조하였다. 합성 후 수세 여부와 건조온도에 따른 영향을 열중량분석, X선 회절분석과 장방출 주사현미경으로 분석하였다. 수세하지 않은 여과단계만 거친 소성촉매가 수세단계를 거친 소성촉매보다 순수한 헥사알루미네이트 상을 얻을 수 있었다. 건조과정 동안 합성 후 잔존한 요소가 전구체에 탈수과정을 도와 주요 금속종인 깁사이트를 순수한 헥사알루미네이트로 변환되기 쉬운 보에마이트로 상변이에 영향을 주었다. 제조된 촉매의 메탄 연소성능 평가는 WO200이 가장 우수하였으며, 모든 촉매연소반응에서 NOx가 배출되지 않았다. 헥사알루미네이트는 최고 CO 배출량을 감소시키는데 영향을 주는 것으로 확인되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권4호
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• pp.1-9
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• 2022

This study was conducted to supplement new-normal strategies on management plans of rural groundwater resources in the era of Post COVID-19. Global outbreak of COVID-19 has damaged across all areas including public policy, economics, industrial services, and others without exception, which has resulted in establishing new-normal strategies in order to restore balance and functions as for these areas. The new-normal ones were represented as enhancing preventative management on infectious diseases, expanding non face-to-face services, enhancing protective trades and food securities, and preparing growth policies on public services using the 4^th industrial revolution techniques. In this study, G-WASH_AD (Groundwater supply, sanitation, and hygiene with attraction and digitization) was suggested to be new-normal strategies on rural groundwater resources. The G-WASH_AD was consisted of three detailed action plans: a preventative plan on waterborne-diseases of groundwater (PP), a groundwater-tourism plan with rural heritage (GP), and an application plan of the 4^th industrial revolution techniques to groundwater facilities and its data (P4). The PP can contribute to protect human health from waterborne-diseases and minimize hazardous effects on crop cultivation. The GP accompanied with high-quality groundwater resources is able to strengthen rural tourism, to promote marketing activities on local agricultural products, and to increase household incomes of rural communities. The P4 can reinforce fast, comfortable, and scientific management on groundwater facilities and its data, creating a virtuous cycle between innovative management on groundwater and growth of technology related to it. Results of the G-WASH_AD strategies can encourage a green growth engine in field of rural groundwater management keeping up with Post COVID-19.

• 치위생과학회지
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• 제23권2호
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• pp.132-141
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• 2023

Background: The purpose of this study was to identify the connection between handwashing and toothbrushing, focusing on eating habits, and to verify whether eating habits can be used as an action cue for forming health habits. Methods: This was a cross-sectional study using secondary data from the 2019 community health survey. The participants included 229,099 adults aged 19 years or older, representative of the South Korean people. We employed two dependent variables: one was washing hands, and the other was brushing teeth. Eating habits was a major independent variable. Socioeconomic variables, such as age, gender, income, occupation, economic activity, education, and residence were adjusted as confounders. Multivariate logistic regression was performed to calculate adjusted odds ratio and 95% confidence intervals. Results: Most of the participants had good health behaviors: those who wash their hands and brush their teeth were each approximately 80%. Our finding indicated that brushing teeth and washing hands can be connected with eating habits. After adjusting for confounders, it was found that people who wash their hands before meals (compared to those who did not wash their hands before meals) had a higher toothbrushing rate after meals (i.e., socioeconomic status) (Adjusted Odds Ratio: 2.0, Confidence Intervals: 1.9 to 2.1). Conclusion: Those who practice either washing hands before meals or brushing teeth after meals were found to have a connection between washing hands and brushing teeth based on the results of practicing other health behaviors. This implies that eating habits can be connected as a behavior cue to promote health habits, such as washing hands before meals and brushing teeth after meals.