• Title/Summary/Keyword: Short-wavelength ultraviolet

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Effect of forensic short wavelength UV on DNA (법과학 단파자외선이 DNA에 미치는 영향)

  • Kim, A-Ram;Kim, Woo-Joong;Park, Hee-Yeon;Lim, Si-Keun
    • Analytical Science and Technology
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    • v.27 no.3
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    • pp.147-152
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    • 2014
  • RUVIS(Reflective Ultraviolet Imaging System) is an effective equipment that detects the location of latent fingerprint at crime scene using short wavelength ultraviolet of 254 nm. In this study, the degree of DNA damage in biological samples was compared depending on the distance and time of processing using four commonly used RUVIS. 50% of DNA was damaged by treating 10 seconds at 10 cm distance in 3 types of RUVIS such as Police RUVIS, SIRCHIE mini light and SIRCHIE RUVIS. In addition, the degree of DNA damage was increased as the distance was closer and the treatment time was longer. It showed that short wavelength UV could cause DNA damage when used close to the samples at crime scene. Therefore, it was suggested to use RUVIS at a distance of at least 1 m. The degree of DNA damage was not significant by Polilight which used long wavelength ultraviolet of 350 nm. As a result, the choice and usage of which UV light and RUVIS were critical for detection of fingerprint and successful DNA typing.

UV ultra-short laser pulse generation and amplification (UV 극초단 레이저 펄스의 발생과 증폭)

  • 이영우
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.324-326
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    • 2004
  • We have obtained ultra-short pulses with a wavelength of 616 nm from a Distributed Feedback Dye Laser pumped by excimer laser. Using the second harmonic generation, we obtained ultra-short pulse at 308nm in ultraviolet region and also performed amplification in 3 stages of XeCl amplifiers.

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Estimation of Application of Artificially Deteriorated Silk by Ultraviolets for Conservation of Paintings on the Silk (견본 회화보존처리에 자외선 인공열화견의 적용성 평가)

  • Oh, Joon-Suk;Chun, Ji-Youn;Lim, In-Kyung
    • Journal of Conservation Science
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    • v.27 no.2
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    • pp.191-199
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    • 2011
  • A study was done to compare the properties of artificially deteriorated silk with ultraviolets for reinforcing of loss area of paintings on silk. Deteriorated surface of raw silk irradiated by long-wavelength ultraviolet(UV-A) than short-wavelength ultraviolet(UV-C) was similar to naturally aged raw silk. UV-A irradiation raw silk was slowly decreased in tensile tenacity and elongation and lowered in yellowness index than that of UV-C. Water content of UV-A irradiation raw silk than that of UV-C was higher. UV-A irradiation raw silk had no problem in dyeing and inpainting for conservation because of low yellowness index. UV-C irradiation raw silk was brittle, but UV-A irradiation raw silk was seemed to tough and similar to naturally aged raw silk. Korean painting conservator estimated that UV-A irradiation raw silk was more proper for reinforcing of loss area of paintings on silk than that of UV-C.

A Study on the Effect on UV Exposure in Coastal Buildings (연안건축물의 자외선 노출에 따른 안전성 연구)

  • Kim, Taehwan;Uh, Jesun
    • Journal of the Society of Disaster Information
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    • v.17 no.2
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    • pp.195-205
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    • 2021
  • Purpose: The ultraviolet reflectance and transmittance of coastal building materials are one of the important factors of ultraviolet radiation in and out of coastal building. In this research, the ultraviolet spectral reflectance of many kinds of building materials was measured. Also, the relationships with the lightness, roughness, and chromaticity, which are surface characteristics, were reviewed and suggested. Method: In this study, according to the CIE classification, the ultraviolet region was defined as short-wavelength region UV-C(10nm~280nm), medium-wavelength region UV-B (280-315 nm), and long-wavelength region UV-A (315-400nm), and the visible light region was defined as (400nm~780nm). Spectrophotometer was used to continuously measure the reflectance from the ultraviolet region to the visible light region. Results: From the measurement results, the ultraviolet reflectance on Wood was shown to be about Visible 55-68%, UV-A* 7-12%, and UV-B 4-5%. Wall tiles are about Visible18-40%, UV-A* 8-20%, and UV-B* 7-8%. That on concrete was shown to be about Visible 37%, UV-A* 28%, and UV-B*19%. Conclusion: The ultraviolet reflectance can be estimated by visible reflectance. Also, it is important to select a variety of materials according to the application when blocking UV.

A Study on the Relationship of Change of Mechanical Properties and Carbonyl Index Induced through Short-wavelength Ultraviolet Radiation (254 nm) for High Density Polyethylene (단파장 자외선(254 nm)에 노출된 고밀도 폴리에틸렌 수지의 카르보닐 지수(CI)와 기계적 물성 변화의 관계에 관한 연구)

  • Kim, Chang-Hwan;Shin, Jin-Yong
    • Applied Chemistry for Engineering
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    • v.24 no.2
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    • pp.138-143
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    • 2013
  • This paper studied the possibility to predict a mechanical property variation from changes in created carbonyl bands by irradiating the surface of high-density polyethylene with short-wavelength ultraviolet radiation of 254 nm to induce a fast chemical degradation. The meaning of this study lies in checking whether a mechanical property change with the same chemical property as the induced optical deterioration is caused by using a UVC lamp with high photon energy instead of optical deterioration via xenon arc light source and outdoor exposure test via natural sunlight requiring a long time. The mechanical strength of high-density polyethylene checked by a tensile test and a creep destruction test showed a similar tendency with CI changes. In particular, the yield strength and elongation had a close relationship with the exposure time to ultraviolet radiation. Accordingly, this paper presented a method to grasp the mechanical property change outdoors requiring a long time more fast through the relationship between the mechanical property change and the carbonyl index using a UVC lamp causing the fast surface degradation.

UV ENERGY DISTRIBUTION OF AZ CASSIOPEIAE

  • Kang, Young-Woon
    • Journal of Astronomy and Space Sciences
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    • v.11 no.1
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    • pp.31-40
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    • 1994
  • The IUE low dispersion spectra of AZ Cas have been analyzed for line identifications and energy distribution in ultraviolet region. Highly ionized atoms, SiIV and CIV are identified. We could infer a temperature range of the B star between 15,000K and 20,000K. The energy density distribution shows a hump between IUE short wavelength and long wavelength regions. Photometric and spectroscopic elements were revised based on the Florkowisk photeelectric observations and collected radial velocities. The temperature of both stars were reduced as 16,000K and 3,800K. The radii of both stars are $10 R_{\odot}\;and\;320R_{\odot}$. The eccentricity and longitude of periastron are 0.61 and $10.5^{\circ}$, respectively.

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Test Result of Off-axis Parabolic Cylinder Mirror for FIMS (FIMS에 사용되는 비축 포물 원통 반사경의 간섭계 측정)

  • ;;Jerry Edelstein
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.86-87
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    • 2001
  • Far-ultraviolet IMaging Spectrograph(이하 FIMS)는 2002년에 발사 예정인 과학위성 1호의 주 탑재체이며, 은하 주변에 분포한 고온의 가스에서 방출되는 자외선 영역 (short wavelength band : 900-1150 $\AA$, long wavelength band : 1335-1750$\AA$)의 방출선을 약 2$\AA$의 분광 분해능으로 관측하는 천문학적 목표를 가지고 있다 일반적인 망원경을 사용하는 대신 제한된 위성의 크기 내에서, 넓은 지역에 퍼져 있는 가스의 분포와 특성을 관측하는데 적합하도록, 그림 1과 같이 비축 포물 원통 반사경과 타원형의 substrate를 가진 회절 에돌이발 (grating)의 사용을 고안하였다. (중략)

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Visible-light photo-reduction of reduced graphene oxide by lanthanoid ion

  • Kim, Jinok;Yoo, Gwangwe;Park, Jin-Hong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.290.1-290.1
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    • 2016
  • Grapehen, a single atomic layer of graphite, has been in the spotlight and researched in vaious fields, because its fine mechanical, electrical properties, flexibility and transparence. Synthesis methods for large-area graphene such as chemical vaper deposition (CVD) and mechanical, chemical exfoliation have been reported. In particular, chemical exfoliation method receive attention due to low cost process. Chemical exfoliation method require reduction of graphene oxide in the process of exfoliation such as chemical reduction by strong reductant, thermal reduction on high temperature, and optical reduction via ultraviolet light exposure. Among these reduction methods, optical reduction is free from damage by strong reductant and high temperature. However, optical reduction is economically infeasible because the high cost of short-wavelength ultraviolet light sorce. In this paper, we make graphene-oxide and lanthanoid ion mixture aqueous solution which has highly optical absorbency in selective wevelength region. Sequentially, we synthesize reduced graphene oxide (RGO) using the solution and visible laser beam. Concretely, graphene oxide is made by modified hummer's method and mix with 1 ml each ultraviolet ray absorbent Gd3+ ion, Green laser absorbent Tb3+ ion, Red laser absorbent Eu3+ ion. After that, we revivify graphene oxide by laser exposure of 300 ~ 800 nm layser 1mW/cm2 +. We demonstrate reproducibility and repeatability of RGO through FT-IR, UV-VIS, Low temperature PL, SEM, XPS and electrical measurement.

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A Study of Characteristic of Oriental Herbal Medicine Storage System using Ozone Lamp (오존램프를 이용한 한약재 저장 장치의 특성 연구)

  • Woo, Sung-Hun;Lee, Kwang-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.1
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    • pp.98-103
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    • 2007
  • We made a oriental herbal medicine storage system and studied a preservation characteristic of oriental herbal medicine in this research. The lamp(OZ-Lamp) in a storage system is the low pressure ultraviolet lamp which radiates the sterilizing and ozonic rays. We made research ozone generation and electric discharge characteristic of a oriental herbal medicine storage system, which have radiation feature of ultraviolet rays of a short wavelength to be happened in the electric discharge. Also, we made research an ingredient and quality characteristic of oriental herbal medicine according to ozone treatment storage.

Observation and Analysis of Radiation Characteristics According to the Type of City During the Summer Season - Focus on the Daegu Metropolitan City and the Surrounding Four Regions - (하절기 도시 유형별 복사특성 관측과 분석 -대구광역시와 인근 4개 지역을 중심으로-)

  • Choi, Dong-Ho;Lee, Bu-Yong;Jeong, Hyeong-Se
    • Journal of the Korean Solar Energy Society
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    • v.35 no.2
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    • pp.21-31
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    • 2015
  • The purpose of this study is to understand the characteristics of urban climate in several cities, from observing radiation according to wavelength band(UV, short and long wave radiation). Observation start from 5 May to 31 August 2013. The followings are the main results from this study. 1) In every observation area, greater amounts of short-wave radiation have been recorded in May compared to June. Even though the highest solar elevation occurs in June, May sees clearer days, which has attributed to the outcome. 2) The analysis concerning the correlation between ultraviolet radiation and shortwave radiation have revealed that regions closer to the Daegu area have stronger correspondence. 3) The time series of daily long-wave radiation shares a similar tendency with the time series of air temperature, and the maximum value was recorded at 14:00 and 15:00.