• Journal of Astronomy and Space Sciences
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• 제20권4호
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• pp.327-338
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• 2003

본 논문은 인공위성에 탑재될 것을 감안한 극자외선 태양망원경의 제작을 통한 연구 결과를 기술한다. 극자외선은 지상에서는 관측되지 않는 영역으로 인공위성이나 로켓 등에 탑재되어 관측하게 된다. 본 연구의 극자외선 태양망원경(EUVT; Extreme-Ultra-Violet solar Telescope)의 설계는 '인공위성 탑재용 극자외선 태양망원경 공학모형 설계'(한정훈 등 2001)를 기반으로 인공위성에 탑재할 만한 크기와 위성 입력전압에 따른 전자부 설계 등 기본적인 요구사항에 맞추었으며, 특히 EVUT의 관측 파장대인 58.4㎚에서 62.9㎚의 검출 가능성에 중점을 두었다. 본 논문에서는 부경으로 인한 차폐율을 줄이기 위한 광학계 설계 변경과 공학모형(Engineering Model)을 제작하는데 사용된 검출기와 광학 기술에 대해 논의한다. 또한, EUVT의 검출기가 받는 태양 복사량을 산출하기 위한 검출효율 프로그램과 차후 관측 자료 처리에 대해 기술한다.

• 한국진공학회지
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• 제18권1호
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• pp.60-65
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• 2009

본 연구에서는 분광타원분석법을 이용하여 최근 주목 받고 있는 microwave dielectric materials 인 $BaSm_2Ti_4O_{12}$ 박막의 광 특성을 $0.92{\sim}8.6\;eV$ 에너지 영역에서 분석하였다. 광역 에너지영역에서 측정이 가능한 Vacuum Ultra Violet spectroscopic ellipsometer를 사용하여 시료의 광 스펙트럼을 측정 하였으며, 측정된 스펙트럼으로부터 $BaSm_2Ti_4O_{12}$ 박막의 광 특성을 얻기 위하여 Tauc-Lorentz 분산 함수를 이용하였고, 고 에너지 영역대의 새로운 피크구조 (structure) 를 최초로 발견하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.293-293
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• 2014

Over last decade InGaN alloy structures have become the one of the most promising materials among the numerous compound semiconductors for high efficiency light sources because of their direct band-gap and a wide spectral region (ultraviolet to infrared). The primary cause for the high quantum efficiency of the InGaN alloy in spite of high threading dislocation density caused by lattice misfit between GaN and sapphire substrate and severe built-in electric field of a few MV/cm due to the spontaneous and piezoelectric polarizations is generally known as the strong exciton localization trapped by lattice-parameter-scale In-N clusters in the random InGaN alloy. Nonetheless, violet-emitting (390 nm) conventional low-In-content InGaN/GaN multi-quantum wells (MQWs) show the degradation in internal quantum efficiency compared to blue-emitting (450 nm) MQWs owing higher In-content due to the less localization of carrier and the smaller band offset. We expected that an improvement of internal quantum efficiency in the violet region can be achieved by replacing the conventional low-In-content InGaN/GaN MQWs with ultra-thin, high-In-content (UTHI) InGaN/GaN MQWs because of better localization of carriers and smaller quantum-confined Stark effect (QCSE). We successfully obtain the UTHI InGaN/GaN MQWs grown via employing the GI technique by using the metal-organic chemical vapor deposition. In this work, 1 the optical and structural properties of the violet-light-emitting UTHI InGaN/GaN MQWs grown by employing the GI technique in comparison with conventional low-In-content InGaN/GaN MQWs were investigated. Stronger localization of carriers and smaller QCSE were observed in UTHI MQWs as a result of enlarged potential fluctuation and thinner QW thickness compared to those in conventional low-In-content MQWs. We hope that these strong carrier localization and reduced QCSE can turn the UTHI InGaN/GaN MQWs into an attractive candidate for high efficient violet emitter. Detailed structural and optical characteristics of UTHI InGaN/GaN MQWs compared to the conventional InGaN/GaN MQWs will be given.

• 환경위생공학
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• 제12권2호
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• pp.65-74
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• 1997

The purpose of this study was to investigate the removal effect and variation of contaminated water by various water treatment processes using sediment filter, activated carbon, photocatalysis, reverse osmosis, ultra violet sterilizer and ultra filtration. The removal effect of chloride and trace metal was low by activated carbon and ultra filter but high in reverse osmosis. The removal effect of bacteria and E. coli was low by activated carbon and membrane filter system using activated carbon but high in impregnated activated carbon. The removal effect of TCE was low in sand and ultra filter system as compared with activated carbon. Ultra filtration process was effective for purify agricultural water without E.coli. Reverse osmosis was effective to remove heavy metal and activated carbon was effective to remove halogenated organic chemical compound. The flux and the removal effect of COD in spiral wound ultrafilter were higher than the hollow fiber ultrafilter.

• 한국광학회:학술대회논문집
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• 한국광학회 1996년도 Advance Program of 13th optics andquantum Electronics conference, 1996제13 회 광학 및 양자전자 학술 발표회 논문 요약집
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• pp.5-5
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• 1996

• 한국의류학회지
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• 제29권3_4호
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• pp.561-568
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• 2005

The irradiation of Ultra-Violet (UV) is an efficient treatment for polymer to improve hydrophilic properties. 4-Channel PET knit fabrics were treated with UVA and UVC to develop functional and environment-friendly fabric. The fabric was treated with various treatment times and distances from UV lamps having different wavelength. FT-IR and XPS investigated the chemical changes. To confirm the change of surface properties, contact angle, surface energy and SEM were examined. The study of UV as a treatment for PET knit fabric shows significant changes in chemical and surface properties, which is proved by analyses. FT-IR and XPS analyses prove the augmentation of carboxylic, Hydrophilic groups on the surfaces treated by UV. The increase of water contact angle and surface energy means more water wettable and surface energy of PET film was substantially increased by UV irradiation time. The ageing after surface treatment had little influence on the surface energy of the irradiated PET film. SEM proves the surface modification of PET such as etching, bubble and crack. The negative effects are increased in accordance with increasing treatment time.

• 한국의류학회지
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• 제29권5호
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• pp.617-625
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• 2005

The purpose of this study was to develop functional and environment-friendly polyester fabric by irradiating Ultra-Violet, which was produced by the low-pressure mercury lamp. UV irradiation was conducted with various treatment times and distances. Also, pretreatments of solvents and photoinitiator were used to improve the surface modification effects. The effects of UV irradiation on the moisture regain were found to increase gradually with increase of UV treatment time and decrease of treatment distance. Compared the effects of UVC and UVA, UVC was more effective than UVA. Moisture regain and wicking of PET was increased after UV treatment in our experimental condition. And owing to increasing of moisture regain, static charge was decreased. Pretreatment of solvents such as methanol, ethyl ether and addition of photoinitiator such as Benzophenone accelerated surface modification. The moisture regain was increased but wicking was decreased with pretreatment and addition of photoinitiatior. Therefore it is considered as inappropriate f3r clothing because of wicking effects. Yellowness, tensile strength and elasticity slightly decreased after UV irradiation.

• 대한지구과학교육학회지
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• 제8권3호
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• pp.267-280
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• 2015

The purpose of this study is to identify the conceptions of middle school students and teachers about Visible-Light, Ultra-Violet(UV) and Infrared-Ray(IR). We administered questionnaire 3 teacher and 102 students(48 people of middle school 2nd students and 54 people of middle school 3rd students) who learned by 3 teachers in seoul. From the analysis, it was found that many students and teachers didn't understand the basic principle of UV and IR. Significant number of students belive that it is possible to see objects the absence of visible light. Most students belive that they can see objects in the presence of UV light alone. They think that "Light" is single concept. Teachers were generally more aware of the origin and explanation of UV. But teachers expressed some uncertainties. They tend to think negative effect for UV.

• 한국진공학회지
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• 제16권1호
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• pp.40-45
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• 2007

본 연구에서는 광전자 소자에 폭넓게 사용되는 ZnCdSe 화합물 반도체의 end-point인 CdSe의 유전함수 spectrum을 Vacuum Ultra Violet spectroscopic ellipsometry(타원편광분석법) 측정하여 분석하였다. 측정 결과는 변수화 모델을 이용하여 분석하였으며 그 결과 6 eV 이상에 존재하는 전자전이점들을 확인할 수 있었고 CdSe의 Critical Point(CP) 구조를 수치화 함으로써 온도나 화합물 함량에 따른 광특성 의존성 연구 등에 활용될 수 있는 database를 확보하였다.

• 전기학회논문지
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• 제58권3호
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• pp.559-565
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• 2009

In this paper, we invented a new and unique technique for the sterilization of Escherichia coli(E. coli) in polluted water. We applied a rich ultra-violet(UV) light from pulsed xenon flashlamp and photocatalyst(TiO2) to sterilize E. coli in polluted water. This method based on the use of UV light and photocatalyst is eco-friendly and does not cause secondary pollution. The proposed elliptical reactor is able to concentrate on quartz sleeve coated TiO2 or general quartz sleeve. The primary objective of our research was to determine the important parameters such as pulse repetition rate and input voltage and to know on the sterilizing efficiency of quartz sleeve coated TiO2 and general quartz sleeve. We obtained to achieve 99.999% sterilization in as little as 6 pulses at 800V in case of quartz sleeve coated Ti02, and 10 pulses at 800V in case of general quartz sleeve for 5 minutes. Although transmitted light of quartz sleeve coated TiO2 is deceased, the sterilizing efficiency is increased by 40% than general quartz sleeve. The reason of high sterilizing efficiency is that generated hydroxyl radical(OH) by photocatalyst and is able to concentrate light at a focus by using elliptical reactor.