• 생명과학회지
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• 제7권3호
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• pp.212-218
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• 1997

The studies were conducted to explore the dffects of growth or survival against various factors and plasmid profiles of 49 Y. enterocolitica isolated from springs water. In the presence of calcium hypochlorite, y. enterocolitica was entirely extinguished by exposure for 33 hours at 0.8 ppm concentration, and was grown up to 7% NaCl, but not at 95 NaCI. Y. enterocolitica was presented optimal growth at pH 7.0 anad 9.0, and not allowth the growth at pH3.0, 5.0 and 11.0. The optimal temperature for growth of Y. enterocolitica was 25$\circ$C and 35$\circ$C, and allowed the growth at refrigerant temperature, 5$\circ$C. Y. enterocolitica was remarkably decreased by exposure for 30 seconds under UV light, and entirely extinguished by exposure for 90 seconds. Therefore, UV light was effective for sterilization of Y. enterocolitica. Fourty-nine strains of Y. enterocolitica were harbor plasmid DNA of approximately 46 Kb molecular weight.

• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.193-195
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• 1989

A simple fabrication technique of diffraction gratings with short periods is presented. We can see that the monitoring of diffracted light from photoresist gratings during the development process provides optimum conditions for exposure and development processes. With this technique reproducibility and high quality of diffraction gratings is expected.

• 자연과학논문집
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• 제11권1호
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• pp.41-44
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• 1999

가정용 칫솔 UV 멸균기의 성능을 개선 할 목적으로, 먼저 UV 처리에 따른 칫솔의 멸균효과를 알아보기 위한 실험을 하였다. UV를 5분, 15분, 30분, 60분의 여러 시간동안 처리하여 실험한 결과, 유의성 있는 효과는 15분 후에 나타났으며, 그 때 80% 이상의 세균 치사율이 됨을 알 수 있었다. UV에 장시간 노출될 경우 나타나는 플라스틱의 탈색을 예방하기 위하여 15분 UV 처리 후 2시간의 무처리 시간을 주고, 다시 3분을 처리한 결과, 97%의 치사율을 보임을 알 수 있었다. 한편, 멸균기에서 칫솔 위치에 따른 멸균효과는 UV light를 직접적으로 받는 위치의 칫솔에만 국한되어 멸균이 되어 이의 개선점이 제시되었다.

• Restorative Dentistry and Endodontics
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• 제11권1호
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• pp.43-52
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• 1985

The purpose of this study was to measure the Micro-Knoop Hardness of three commercial visible light-cured composite resins (Plurafil-super, He1iosit and Durafi) according to the difference of depth and shade. Specimens of the resin were prepapared in plastic tubes 5mm in diameter with height of 5mm, and the tubes were put into the columned holes in stone molds. The molds were exposed to the visible light through the hole 5mm in diameter in metal plate. Specimens were sectioned (longitudinally) with disk. Knoop Hardness measurements were made at the depth of surface, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0mm from the surface to the deep portion. Knoop Hardness numbers were taken on each depth under 20gm load for 10 seconds with Shimadzu Tester. The following results were: 1. The highest hardness value was measured at 0.5mm depth. Then the deeper the depth, the lesser the hardness was observed. 2. The value of hardness was directly propotional to the time of exposure to the light. 3. The hardness of light shade resin was higher than the that of the dark shade. 4. The pattern of hardness change at varying depth is similar to all the experimental materials with no relation to the shade nor exposure time.

• 한국염색가공학회지
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• 제27권4호
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• pp.288-300
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• 2015

This study was executed to substitute Carbon-arc method, which is a method currently used for testing light-fastness of military textile products, with Xenon arc method. Specimens used in the study were classified according to the fabric material and color of military textile products and were composed of 11 items of 42 kinds with different colors. Light-fatness test was done by comparing the result of Carbon-arc(KS K 0700) and Xenon arc(KS K ISO 105-B02) method. In Xenon arc method, blue wool reference materials of 1~8 was used, and exposure condition preferred in American continent and light exposure method 3 were applied. After testing with both methods, grade of light-fastness, color difference, reflectance and color were examined. Even though there was a slight difference among 42 specimens used in the test, results exceeded the quality standard both in Carbon-arc-lamp and Xenon arc-lamp. Therefore, it was confirmed that applying KS K ISO 105-B02 together in the KS K 0700-regulated Ministry of National Defense standard and purchase order would also fit.

• 치과방사선
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• 제17권1호
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• pp.7-20
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• 1987

The author studied the acute reaction of cobalt-60 irradiation to buccal mucosa in rats and difference of the effects of single versus fractionated exposure. 195 Sprague Dowley strain rats, weighing about 120gm, were used in this experiment. 3 rats served as controls and the remaining 192 rats were divided into six groups of 32 rats each. Experimental group Ⅰ, Ⅱ, Ⅲ were received a single dose of 15Gy, 16.5Gy, 18Gy and group Ⅳ, Ⅴ, Ⅵ were received two equal sized fractionated dose of 9Gy, 9.75Gy, 10.5Gy at 4 hour intervals, respectively. The experimental groups were irradiated with cobalt-60 teletherapy unit, Picker model 4M 60 (Field size, 12x5 cm, SSD, 50㎝, Dose rate, 222cGy/min, Depth, 1㎝). The animals were sacrificed at 1, 2, 3, 6, 12 hours, 1, 3, 7 days after irradiation and the changes of the irradiated buccal mucosa were observed by electron and light microscopy. The results were as follows: 1. A single exposure was more damaging than fractionated exposure, and as the radiation dose increased, the changes of cell organelles became faster, but the healing of radiation-induced damage in fractionated exposure was faster than in single exposure. 2. The radiation-induced changes of the basal cells were the most prominent in 18Gy-single exposure group, and the least in 18Gy-fractionated exposure group. 3. Electron-microscopically, there appeared nuclear changes, swelling of mitochondria and rough endoplasmic reticulum, decrease of free ribosome, presence of vesicles, widening of intercellular space, and loss of basal lamina. The early remarkable changes were partly loss of nuclear membrane and swelling of mitochondria. 4. Light-microscopically, derangement and pyknosis of basal cells, hydropic changes of spinous cells, enlargement of granular cells, indistinctness of basement membrane, and proliferation of epithelium were observed.

• 대한가정학회지
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• 제46권9호
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• pp.1-6
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• 2008

홍화 황색소와 홍색소로 염색을 한 나일론 직물에 자외선을 조사 한 후 시료들의 염착량과 색채변화, 표면 특성 변화와 인장 강도 변화를 측정한 결과는 다음과 같다. 1. 색소의 종류에 상관없이 자외선 조사시간 증가에 따라 염착량이 감소되었다 그러나 홍색 소보다는 황색소로 염색한 시료들의 자외선 조사 28일 후의 염착량 보유율이 더욱 낮았다. 2. 색채변화의 경우, 황색소로 염색한 시료들은 $L^*$은 증가하고 $a^*$와 $b^*$는 감소하였으며, H/VC, ${\Delta}E$등 색채 전반에 퇴색이 나타났다. 홍색소로 염색한 시료들 도 자외선 조사 시간 증가에 따라 $L^*$은 증가하고 $a^*$는 감소하였으며, $b^*$는 증가하였고, H/VC, ${\Delta}E$등 색채 전반에 퇴색이 나타났다. 그러나 홍색소와 황색 소로 염색한 나일론 직물 시료의 조사 28일 후의 색차는 황색소가 더욱 낮아 나일론 직물에는 황색소가 자외선에 대한 견뢰도가 더욱 높은 것으로 보인다. 3. 자외선 조사 시간에 따른 표면 특성 변화의 결과, 색소의 종류와 상관없이 조사 28일 후 모든 시료들에서 심한 손상을 관찰할 수 있었다. 4. 자외선 조사 시간에 따른 인장 강도 변화 결과, 모든 종류의 시료에서 자외선 조사 시간 증가에 따른 강도의 손실을 알 수 있었다. 그러나 홍색소보다는 황 색소로 염색한 나일론 직물 시료들의 인장 강도 보유율이 상대적으로 높은 것으로 나타났다.

• 한국세라믹학회지
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• 제45권6호
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• pp.345-349
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• 2008

$TiO_2$ coating ceramic tile for self-cleaning purpose was prepared by the precipitant dropping method using $TiCl_4$ as a precursor. $TiO_2$ film was formed on the ceramic tile by spray-coating technique and heat-treated at $500^{\circ}C$ for 1 h. The size and crystalline structure of $TiO_2$ particles were 15.3 nm and anatase phase. The outdoor exposure tests were conducted and the effects of outdoor exposure test conditions, such as exhaust concentration of contamination materials (test places), the UV light intensity (irradiation direction) and coating amounts of $TiO_2$ on the self-cleaning properties were investigated by the brightness measurements. As a results, self-cleaning property of $TiO_2$ coating tile was affected by the coating amount of $TiO_2$ however, not affected by the UV light intensity included in sun's ray (irradiation direction). $TiO_2$ coating ceramic tile can be utilized for exterior finishing materials because of self-cleaning property of $TiO_2$ coating tile.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권1호
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• pp.47-52
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• 2004

3D microstructures with different side-wall angles and different scales are fabricated by both methods of inclined exposure and rear-side exposure at each of selected areas on a same substrate. Conventional methods of inclined exposure are used to make side-walls with a same inclined angle on one substrate and to get a scale error due to front-side exposure through thick photoresist layer, But, by using the proposed method, we are able to fabricate 3D microstructures on a same substrate with various side-wall angles and accurate dimensions as the original design. In the rear-side exposure, UV exposure light reflects from the chromium mask pattern after passing through the thick photoresist layer, resulting in fabrication of well-defined, inclined 3D structures inside the thick photoresist layer.

• Fisheries and Aquatic Sciences
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• 제19권6호
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• pp.28.1-28.7
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• 2016

Background: Significant increases in the bacterial resistance to various antibiotics have been found in fish farms. Non-antibiotic therapies for infectious diseases in aquaculture are needed. In recent years, light-emitting diode technology has been applied to the inactivation of pathogens, especially those affecting humans. The purpose of this study was to assess the effect of blue light (wavelengths 405 and 465 nm) on seven major bacterial pathogens that affect fish and shellfish important in aquaculture. Results: We successfully demonstrate inactivation activity of a 405/465-nm LED on selected bacterial pathogens. Although some bacteria were not fully inactivated by the 465-nm light, the 405-nm light had a bactericidal effect against all seven pathogens, indicating that blue light can be effective without the addition of a photosensitizer. Photobacterium damselae, Vibrio anguillarum, and Edwardsiella tarda were the most susceptible to the 405-nm light (36.1, 41.2, and $68.4J\;cm^{-2}$, respectively, produced one log reduction in the bacterial populations), whereas Streptococcus parauberis was the least susceptible ($153.8J\;cm^{-2}$ per one log reduction). In general, optical density (OD) values indicated that higher bacterial densities were associated with lower inactivating efficacy, with the exception of P. damselae and Vibrio harveyi. In conclusion, growth of the bacterial fish and shellfish pathogens evaluated in this study was inactivated by exposure to either the 405- or 465-nm light. In addition, inactivation was dependent on exposure time. Conclusions: This study presents that blue LED has potentially alternative therapy for treating fish and shellfish bacterial pathogens. It has great advantages in aspect of eco-friendly treating methods differed from antimicrobial methods.