• 제목/요약/키워드: Ultra-violet light

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가시광선, 자외선과 적외선에 대한 학생들의 개념 (Korean Secondary Students' Conceptions about Visible light, Ultra Violet and Infrared Ray)

  • 한신;박태윤
    • 대한지구과학교육학회지
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    • 제8권1호
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    • pp.35-44
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    • 2015
  • The purpose of this paper is to identify the conceptions of middle school and high school students about visible light, Ultra violet(UV) and Infrared ray(IR). We administered questionnaire 40 people of middle school 3rd students and 43 people of high school 2nd students in Gyeonggi-do. Misconceptions about visible light, UV and Ir were observed in many students. The results of study are as follows: Firstly, Many students think that it is possible to see objects without visible light. The explanations given by students for the visiblity of objects in darkness indicates a heavy reliance on personal experiences. Secondly, we have confirmed that high school students well understand the fact that the object reflects the light. However, a significant number of students exhibited an eye-centered perspective of vision. Thirdly, students had a variety of ideas about the meaning of the term UV and IR. Analysis of questionnaire data indicates that many students believe that it is possible to see objects in the presence of UV light alone.

순수 폴리올레핀(PP/UHMWPE) 소재용 초소수성 보라색 염료의 합성 (Synthesis of a Super Hydrophobic Violet Dye for Pure Polyolefin(PP/UHMWPE) Fibers)

  • 김태경;이창환
    • 한국염색가공학회지
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    • 제25권3호
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    • pp.165-171
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    • 2013
  • A new monoazo violet dye optimized for polyolefin fibers such as polypropylene and ultra high molecular weight polyethylene fibers was synthesized and its dyeability was investigated. Two hexyl groups were introduced to coupler, 2,5-dimethoxyaniline, in order to increase hydrophobicity of the dye. The maximum absorption wavelength was appeared at 580nm, which meant that the dye showed violet color. From the dyeing results at various conditions, the optimum dyeing was determined as $130^{\circ}C$ for 1 hour with 5% owf of dyes. The good fastness ratings to washing, rubbing were obtained showing at least 4 for both fibers. Light fastness was acceptable for polypropylene fibers giving ratings 3~4. However, relatively poor light fastness was obtained in case of ultra high molecular weight polyethylene fibers showing ratings 2.

라면 유지(油脂)의 안전성(安定性)에 관한 연구(硏究) -(I) 시험저장중(試驗貯藏中) 라면유지(油脂)의 산패(酸敗)에 대(對)하여- (Stability of Lipids in Ramyon (deep fat fried instant noodle) -I. Oxidative Changes in the Ramyon Lipids during Storage-)

  • 최홍식;권태완
    • 한국식품과학회지
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    • 제4권4호
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    • pp.259-264
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    • 1972
  • 국산(國産) 라면제품을 형광등조사구(螢光燈照射區) 고온암소구(高溫暗所區) 자외선조사구(紫外線照射區) 등의 처리구(處理區)로 나누어 20주(週)동안 저장하고, 경시적(經時的)으로 산가(酸價) 과산화물가(過酸化物價) carbonyl가(價) TBA가(價) 지방산조성(脂肪酸組成) 옥도가(沃度價) 등의 지방산화현상(脂肪酸化現象)을 살펴 본 바 다음과 같은 결과를 얻었다. 전반적으로 형광등조사구(螢光燈照射區) 및 고온암소구(高溫暗所區)의 라면은 완만한 산화현상(酸化現象)을 보였으며, 저장 16주(週)에 변패취(變敗臭)를 확인하였고, 자외선조사구(紫外線照射區)의 라면은 저장초(初)부터 급격한 산화(酸化)가 일어났으며, 저장 4주(週)에 변패취(變敗臭)를 확인하였다. 2) 산가(酸價) 과산화물가(過酸化物價) TBA가(價)등은 각처리구(名處理區) 공(共)히 전실험기간동안 증가하였으며 자외선조사구(紫外線照射區)에서 그 증가현상(增加現象)은 현저하였다. 특히 TBA가(價)는 자외선조사구(紫外線照射區)에서 저장 4주(週)이후 급격히 증가하여 10주(週)에 그 정점(頂點)을 이루고 다시 감소하였다. 이 때의 bound malonaldehyde는 14주(週)까지 증가하다가 그 이후 완만히 변화하였다. 3) 저장초(貯藏初) 그리고 저장(貯藏) 12주(週)의 고온암소구(高溫暗所區) 및 자외선조사구(紫外線照射區)의 라면유지(油脂)에 대한 지방산조성(脂肪酸組成)을 살펴 본 결과 고온암소구(高溫暗所區)에선 큰 변화가 없었으며, 자외선조사구(紫外線照射區)에선 저장초(貯藏初)의 지방산조성(脂肪酸組成)에 비(比)하여 linoleic acid 등 불포화 지방산의 상대적(相對的)인 감소현상을 볼 수 있었으며 저장 중 옥도가(沃度價)의 감소(減少)가 이러한 사실(事實)을 뒷받침하고 있다.

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중학교 과학 교사와 학생들의 빛에 대한 인식과 이해 정도 분석 (A Research on Middle School Teachers and Students Awareness and Understanding of Analysis for the Light)

  • 김민영;한신;박태윤
    • 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.

Xenon flashlamp와 광촉매를 이용한 타원형 반응기의 살균 특성에 관한 연구 (A Study on Sterilization Characteristics of Elliptical Reactor by Using Xenon Flashlamp and Photocatalyst)

  • 이동길;홍지태;최경화;차재호;김홍주;김희제
    • 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.

반사방지 코팅기술 기반 자외선 차단 기능의 고굴절률 안경렌즈 (Anti-Reflection Coating Technology Based High Refractive Index Lens with Ultra-Violet Rays Blocking Function)

  • 김기출
    • 한국산학기술학회논문지
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    • 제17권12호
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    • pp.482-487
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    • 2016
  • 파장 400 nm 이하의 자외선은 눈 건강에 매우 해롭다. 특히 UVA (315 nm ~ 400 nm)는 백내장, 설안염, 초자체경화 등을 유발할 수 있고, UVB (280 nm ~ 315 nm)는 결막염, 각막염 및 설안염 등을 일으킬 수 있다. 따라서 폴리머 안경렌즈를 사용함에 있어서 자외선의 차단 기능과 가시광선 영역에서 투과되는 빛을 증가시키고, 안경렌즈 표면에서 형성되는 허상을 방지하는 반사방지 기능은 매우 중요하다. 본 연구에서는 m-자일릴렌 디이소시아네이트 모노머와 2,3-Bis-1-propanethiol 모노머 및 벤조트리아졸 UV 흡수제 (SEESORB 709), 안료 혼합물, 이염화 이부틸 주석 촉매제, 알킬인산 에스터 이형제 등의 혼합물을 인젝션 몰드 방법으로 열중합 공정을 적용하여, 굴절률 1.67의 고굴절률 폴리머 안경렌즈를 제조하였다. 폴리머 안경렌즈 표면에서의 반사를 줄이기 위하여 렌즈 양면에 다층박막 반사방지 코팅을 E-beam 증착 시스템으로 코팅하였다. 자외선 차단 폴리머 안경렌즈의 광학적 특성을 UV-visible spectrometer로 분석하였고, 반사방지층을 구성하는 박막의 굴절률, 표면거칠기 등과 같은 박막소재 특성을 각각 Ellipsometry 및 원자힘 현미경으로 분석하였다. 분석 결과 제조된 안경렌즈는 395 nm 파장 이하의 자외선을 99% 이상 완벽하게 차단하였다.

극자외선 리소그래피용 마스크의 결함 검출 (Defect Inspection of Extreme Ultra-Violet Lithography Mask)

  • 이문석
    • 대한전자공학회논문지SD
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    • 제43권8호
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    • pp.1-5
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    • 2006
  • 본 논문은 극자외선 리소그래피용 마스크의 결함을 극자외선을 이용하여 검출하는 방법과 기존의 가시광선을 이용하여 결함을 검출해 내는 시스템과 비교하고, 인위적으로 만들어진 결함을 이용하여 극자외선이 결함에 조사되었을 때의 반사되는 패턴을 분석하였다. 포커스된 극자외선을 래스터 스캔 방식으로 조사하면서 반사되는 극자외선의 세기를 비교함으로서 결함을 발견해 내는 시스템을 구축하였고, 이를 이용하여 기존의 가시광선을 이용하는 결함 검출 장비와 상관 실험을 진행하여 반사된 빛의 세기로 예측한 결함의 크기가 두 검출 방법 사이에 강한 상관관계를 가짐을 확인하였다. 또한, 인광판을 이용하여 극자외선이 결함에 조사되어 반사되는 패턴을 영상화하여 크기별, 결함의 종류별로 다른 프린지 패턴을 가지는 것을 확인하였다.

Strong Carrier Localization and Diminished Quantum-confined Stark Effect in Ultra-thin High-Indium-content InGaN Quantum Wells with Violet Light Emission

  • Ko, Suk-Min;Kwack, Ho-Sang;Park, Chunghyun;Yoo, Yang-Seok;Yoon, Euijoon;Cho, Yong-Hoon
    • 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.

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Dimerization Behavior of Cinnamate Group attached to Flexible Polymer Backbone and Its Application to Liquid Crystal Alignment

  • Sung, Shi-Joon;Cho, Ki-Yun;Hah, Hyun-Dae;Kim, Won-Sun;Jeong, Yong-Cheol;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.1163-1166
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    • 2004
  • Cinnamate group is well-known for the dimerization reaction by ultra-violet irradiation and cinnamate polymers are studied for photo-alignment materials. The cinnamate groups of flexible polymer are found to produce LC alignment parallel to polarization direction of ultra-violet light, which is contrary to the LC orientation on conventional cinnamate polymers. The un-reacted cinnamate groups in the flexible polymer are also found to participate in cycloadducts formation by additional thermal reaction that preserves the orientation of cycloadducts, leading to the enhancement of thermal stability of LC alignment.

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