• 한국건설순환자원학회논문집
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• 제7권4호
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• pp.423-430
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• 2019

본 연구에서는 콘크리트 보도블록의 표층에 광촉매를 적용하여 광촉매 혼입률 및 블록 표면워싱 유무 등에 따른 휨강도, 흡수율, 메틸렌블루 광촉매 분해 성능 및 방오성능을 평가하였다. 실험결과, 콘크리트 블록 표면층에만 광촉매를 혼입한 블록의 휨강도는 광촉매 무혼입인 기준콘크리트 블록의 휨강도 5.46MPa과 비교하여 광촉매 5% 혼입 일반블록(SNW) 5.32MPa로 나타났으며, 표면워싱블록(SW) 5.26MPa, 광촉매 10%혼입 일반블록(SNW) 5.26MPa, 표면워싱블록(SW) 5.15MPa로 나타나 콘크리트 블록의 표면 워싱 유무 및 광촉매 혼입율이 휨강도에 미치는 영향은 없는 것으로 나타났다. 또한 콘크리트 보도블록의 광촉매 분해성능은 이산화티타늄이 5% 혼합된 시편의 메틸렌블루 제거율은 34.2%, 이산화티타늄이 10% 혼합된 시편의 메틸렌블루 제거율은 37.1%, 세척을 실시한 경우 이산화티타늄이 5% 혼합된 시편의 경우 제거율은 약 37.9%, 10% 혼합된 시편의 메틸렌블루 제거율은 약 37.6%로 나타났다.

• 한국세라믹학회지
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• 제43권10호
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• pp.613-618
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• 2006

Graphite is suitable materials as a moderator, reflector, and supporter of a nuclear reactor because of high tolerance to the high temperature and neutron irradiations. Because graphite is so weak to the oxidation, its oxidation study is essentially demanded for the operation and design of the nuclear reactor. This work focuses on the effect of the surface oxidation of graphite according to the surface treatment. With thermogravimeter (TG), oxidation characteristics of the isotropic graphite are measured at the three temperature areas, and oxidation ratio and amounts are estimated as changing the surface roughness. Furthermore, the polished graphite surface produced fom the surface treatment is investigated with the Raman spectroscopic study. Oxidation behaviors of the surface are also evaluated as elimination the polished layer by washing with strong sonication.

• 한국치위생학회지
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• 제9권2호
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• pp.73-88
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• 2009

The purpose of the study was to provide the basic for the prevention of infection control by analyzing the level of recognition and practice of dental hygiene students. It is important for dental clinic staffs to know and practice infection control measures in favor of effective infection control. Thus, this study conducted an one-month questionnaire survey (during October 2008) for dental hygiene students who ever experienced in 16-week clinical practice, and analyzed total 206 questionnaire forms as collected from them, so that it could determine potential associations between their recognition and practice of infection control and thereby suggest an efficient solution for infection control in dental hygiene. 1. It was found that our students' recognition about infection control averaged $4.49{\pm}.58$ points on the whole, and they were best aware of instrumental disinfection and sterilization among other measures, which was followed by hand washing, extirpation control, post-sterilization management, personal protective outfit and instrumental surface maintenance respectively. 2. It was found that our students' practice of infection control averaged $3.85{\pm}.57$ points on the whole, and they practiced hand washing most actively among other measures, which was followed by extirpation control, post-sterilization management, instrumental disinfection and sterilization, personal protective outfit and instrumental surface maintenance respectively. 3. It was found that our students scored higher mean points in recognition about every measure of infection control than those in practice (t=15.676, p=0.000). Particularly, it was notable that there were significant differences between their mean points in recognition and practice of some infection control measures, such as instrumental surface maintenance (t=15.361, p=0.000), personal protective outfit (t=15.245, p=0.000) and instrumental disinfection and sterilization (t=11.169, p=0.000). But there was least significant difference between mean points in recognition and practice of hand washing (t=5.460, p=0.000). 4. For potential associations between recognition and practice of infection control, it was found that higher recognition was in significantly positive associations with higher practice in every measure of infection control (r=.478, p=.000), such as extirpation control (r=.630, p=.000), instrumental disinfection and sterilization (r=.477, p=.000) and post-sterilization management (r=.433, p=.000). 5. It was found that there were differences in our students' recognition depending upon availability of infection control guideline (t=4.587, p=.011), and there were significant differences in practice depending on necessity of infection control education on a statistical basis (t=2.229, p=.027). Overall, it is found that our dental hygiene students are very likely to practice hand washing and extirpation control, because both of these measures are relatively easy to practice or are considered legally binding.

• 한국염색가공학회지
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• 제17권1호
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• pp.1-6
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• 2005

This study were carried out to investigate the effects of mordants and mordanting methods under the various dyeing conditions such as temperature, time, pH, repetition of dyeing in the silk fabrics with Petasites japonicus leaf. It was the most high K/S values of the silk fabrics dyed with Petasites japonicus leaf according to co mordanting and used cupric sulfate, ferric sulfate as mordanting agents. K/S values of the silk fabrics dyed with Petasites japonicus leaf were increased gradually with dyeing temperature, dyeing time, repetition of dyeing was higher and the optimum pH was pH 7. Silk fabrics were colored yellowish orange and surface color(munsell value) was changed from 8.3YR to 2.0Y by using mordanting agents and those of the silk showed high tone when mordanting with cupric sulfate but decolored and darked when mordanting with ferric sulfate. Washing fastness of silk fabrics were good in 4 ～ 5 grade, so washing fastness of the silk fabrics was significantly improved when washed with the neutral detergent.

• The Korean Journal of Ceramics
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• 제7권1호
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• pp.16-19
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• 2001

For the fast dry of the aqueous tape, the process which water was reaplaced by organic solvent was proposed. Socalled, it was the solvent washing dry. Three organic solvents (methanol, ethanol and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol and acetone were available organic solvents for this method. The tapes washed in methanol, ethanol and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not found any more, The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated.

• 한국분말재료학회지
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• 제19권6호
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• pp.398-404
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• 2012

This paper describes the spherical ammonium diuranate gel particles which are the intermediated material of the $UO_2$ microsphere for an VHTR(very high temperature reactor) nuclear fuel. The characteristics of the intermediate-ADU gel particles prepared by AWD(ageing, washing, and drying) and FB(fluidized-bed) apparatus were examined and compared in a sol-gel fabrication process. The electrical conductivity of washing filtrate from the FB treating and the surface area of dried-ADU gel particles were higher than those of AWD treating. Also, an internal pore volume in dried-ADU gel particles showed a more decrease in AWD treatment than FB treatment because of decomposition of PVA affected by the washing time. However, the internal microstructures of ADU gel particles were similar regardless of the process variation.

• 복식문화연구
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• 제16권1호
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• pp.158-165
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• 2008

The purpose of this study was to investigate the dyeing property and ultraviolet-cut ability on silk 100% and nylon 100% fabrics dyed with Rhus verniciflua extracts. This study was investigated K/S values, surface color, washing fastness, dry cleaning fastness and ultraviolet-cut ability of the silk and nylon fabrics dyed with Rhus verniciflua extracts under the various dyeing conditions. As mordanting were used Tin(II) Chloride dihydrate $(SnCl_2{\cdot}2H_2O)$, Copper(II) sulfate pentahydrate$(CuSO_5{\cdot}5H_2O)$, Iron(II)Chloride$(FeC_2{\cdot}4H_2O)$. pH was adjusted by sodium carbonate$(Na_2CO_3)$ and formic acid(HCOOH). The optimum dyeing temperature, dyeing time, and pH of the silk fabrics dyed with Rhus verniciflua extracts were $90^{\circ}C$, 100min, and in the nylon fabrics were $90^{\circ}C$, 45min. It were colored(munsell value) 6.4Y 7.5/4.1 in the silk fabrics and colored 4.3Y 6.6/5.9 in the nylon fabrics dyed with Rhus verniciflua extracts. Washing fastness and dry-cleaning fastness in the silk and nylon fabrics dyed with mordanting agent improved in $4{\sim}5$ grade. UV-A test showed that nylon fabrics a high rate of 92% with Rhus verniciflua extracts.

• 한국분무공학회지
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• 제16권2호
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• pp.90-96
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• 2011

Atomized liquid jets from the washing nozzle which configured with recirculation chamber for cleaning hot-zone area are accelerated and impinged on the head lamp surface. Cleaning efficiency of head lamp can be increased with injecting washing fluids into the hot-zone area. Experimental and numerical studies with various design parameters were executed to reveal the relations between internal geometry and internal flow in the washing nozzle. Spray structures were fitted with each of the head lamp surfaces and spray nozzles were optimized to the spray pattern. The recirculation chamber induces a recirculation flow and can be decreased the pressures perturbation inside the chamber. Orifice determines the mass flow rate. When the diameter of orifice is excessively large, it showed an unstable spray pattern. As a nozzle exit angle increases, density distributions are separated with two section. Also, as a protrusion length of nozzle exit increases, spray patterns are spread into a large area and density distributions showed unstable trend.

• Agricultural and Biosystems Engineering
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• 제5권2호
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• pp.60-63
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• 2004

Demand for development of processing systems for pre-washed rice and propagation of the systems has recently been on the rise, because rice-cooking requires watering 15 times the rice quantity to cook, as in case of the regular rice currently being circulated in Korean market, in addition to paying the trouble of washing it for cooking, and besides the milky turbid water coming from the rice-washing contributes to water contamination. In this study, therefore, a processing system for pre-washed rice was designed and built with rice surface polishing devices that adopted abrading and airing methods, an electrostatic method and a method using a fine watering, to conduct its performance test. The result showed that turbidity of the wash water, which is the base to determine the pre-washed rice standard, turned out 47.33 ppm and 48.00 ppm respectively for 800 kg/hr and 1,000 kg/hr supplies, which meets the standard for the processing system free from rice-washing for cooking. The quantity of watering at this experiment was only 0.43 times the rice, thus resulting in curtailment of process-watering by approximately $69\%$ compared with the existing wet-type pre-washed rice processing system popular in Korean market.

• 한국염색가공학회지
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• 제29권2호
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• pp.62-68
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• 2017

Coffee sludge and onion shells are known typically as waste resources as well as simultaneously being the raw material for dye having a golden brown color. This research studies the dyeability, functionality, and colors of woolen fabric after being dyed by different dyeing method using coffee sludge and onion shells extract. The woolen fabric was refined and pre-mordanted with tannin. The dyeing process conducted was single-dye, using coffee sludge and onion shells extract, sequential multi-dye, consecutively dyeing with coffee sludge and onion shells, and mixed-dye, blending coffee sludge extract and onion shells extract to dye. The dyeing was measured on the surface color, color fastness, and UV-protection ability. As a result, the expression of various hues of tan using coffee sludge and onion shells extract were shown to be possible. Additionally, single-dye, sequential multi-dye, mixed-dye had generally superiority in color fastness to light, all rating 3 and color fastness to washing, rating 3 or 4, showing relatively stable color fastness to washing. The UV protection ability was shown to be better, especially appearing satisfactory in the UV-B protection, all measured to be over 90%.