• Title/Summary/Keyword: Ultraviolets

Search Result 4, Processing Time 0.032 seconds

Extreme Ultraviolet Plasma and its Emission Characteristics Generated from the Plasma Focus in Accordance with Gas Pressure for Biological Applications

  • Kim, Jin Han;Lee, Jin Young;Kim, Sung Hee;Choi, Eun Ha
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.178.2-178.2
    • /
    • 2013
  • Conventional ultraviolets A,B,C are known to be very important factor of killing, changing surface properties of biological cells and materials. It is of great importance to investigate the influence of extreme ultraviolet (EUV) exposure on the biological cell. Here we have studied high density EUV plasma and its emission characteristics, which have been generated by plasma focus device with hypercycloidal pinch (HCP) electrode under various Ar gas pressures ranged from 30~500 mTorr in this experiment. We have also measured the plasma characteristics generated from the HCP plasma focus device such as electron temperature by the Boltzman plot, plasma density by the Stark broading method, discharge images by open-shuttered pin hole camera, and EUV emission signals by using the photodiode AXUV-100 Zr/C.

  • PDF

Hydroxyl Radical Species Generated by Non-thermal Direct Plasma Jet and Their Qualitative Evaluation

  • Ghimire, B.;Hong, S.I.;Hong, Y.J.;Choi, E.H.
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.198.2-198.2
    • /
    • 2016
  • Reactive oxygen and nitrogen species (RONS) can be generated by using non-thermal atmospheric pressure plasma jet which have profound biomedical applications [1, 2]. In this work, reactive oxygen species like hydroxyl radical (OH) are generated by using non-thermal direct plasma jet above water surface using Ar gas and their properties have been studied using ultraviolet absorption spectroscopy. OH radicals are found to be generated simultaneously with the discharge current with concentration of $2.7{\times}1015/cm3$ at 7mm above water surface while their persistence time have been measured to be $2.8{\mu}S$. In addition, it has been shown that plasma initiated ultraviolets play a major role to generate RONS inside water. Further works are going on to measure the temporal behavior of OH and $O2^*-$.

  • PDF

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
    • /
    • v.27 no.2
    • /
    • pp.191-199
    • /
    • 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.

Assessment of UV Blocking Performance for Development of Converged Technologies of Vision Correcting Spectacle Lenses (시력교정용 안경렌즈의 융복합적 기술개발을 위한 UV차단 성능 평가)

  • Kim, Heung-Soo
    • Journal of the Korea Convergence Society
    • /
    • v.9 no.4
    • /
    • pp.93-98
    • /
    • 2018
  • This study was wanted to confirm ability for UV blocking according to its material. The lenses materials were Acryl, CR-39, NK-55, and MR-8. It was grouped: Group A consisting of anti-scratch hard coated lenses and anti-refractive multi coated lenses, Group B added UV blocking coating on the group A, and Group C consisting of only UV blocking lenses. The results measured UV transmittance, On the UV-A wavelength, Group A showed the UV transmittance of 7.726%, 0.043%, 0.007%, and 0.007% respectively. Group B showed 0.038%, 0.037%, 0.007%, and 0.007%, respectively. The UV-blocking performance of CR-39 has been greatly improved. Group C has shown the best UV blocking function; only 0.005% and 0.004% of UV transmittances.(1.60 and 1.67 index of refraction respectively). For the low power of lenses and sunglasses, the CR-39 lens is the most used. Therefore, to UV blocking from the lens, new materials or UV absorbers or UV coating technology and development of Converged Technologies are required.