• Title/Summary/Keyword: ultraviolet

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A Study on Ulraviolet-cut Ability of Silk Fabric Dyed with Natural Dyestuffs (천연염재의 자외선 차단성능 연구)

  • 김월순;최인려
    • The Research Journal of the Costume Culture
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    • v.12 no.1
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    • pp.1-11
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    • 2004
  • This study was carried out on the process of natural dye substances which can flock ultraviolet rays without producing harmful substances by pollution, germs, etc. While making human body safe in contact, extracting Gardenia, Sappan wood, Radix scutellariae, Cromwell, Mugwort, Gallnut, Lac. Those are used for curing diseases, dyeing silk cloth with those extracts, and examining the color fastness, Ultraviolet protection. From this study, the following conclusion was produced. Brightness was lower in pre-mordanting than in post. And color difference showed that Radix scutellariae was the highest. Aluminum-mordanting showed a higher color difference than Fe. Colorfastness to washing was high in all samples, and the degree of color-changing by washing was the highest in the sample dyed by gardenia, pre-mordanted gallnut showed the highest degree. Colorfastness to perspiration was the highest in gardenia. UV-A test showed that all samples a high rate of 85% or higher compared with test white cloth. Especially, post-mordanted radix scutellariae, pre-mordanted gallnut and post-mordanted sappanwood showed a superior blocking rate.

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Neurospora의 생육시기에 따른 호흡능의 변화와 자외선 감수성과의 상관관계

  • 이영녹
    • Journal of Plant Biology
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    • v.6 no.4
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    • pp.1-4
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    • 1963
  • Using conidia of Neurospora, changes in respiratory activities and the sensitivity to the ultraviolet light of the cells at different growing stages were measured by manometric methods, and the correlation between them was observed. Efficiency in the utilization of various carbon sources, such as, glucose, sucrose, maltose, starch and sodium acetate, in growth and exogenous respiration of N. crassa was also determined. Growth rate of N. crassa was decreased considerably in the medium containing sodium acetate than in the glucose medium and was almost zero in the lactose medium, whereas the utilization of sucrose, maltose and starch was ve교 high, as that of glucose. Respiratory activities of the cells veried considerably depending upon their different growing stages. Actively growing hyphae exhibited the greatest activity in exogenous glucose respiration, followed by germinating and activated conidia in decreasing order. There was no proportional relationship between the dose of ultraviolet light irradiated and its effect on the respiratory activity of the cells, though the more the dose of ultraviolet light, the more the injury. The sensitivity of the cells to ultraviolet light varied with the different respiratory activities of the cells linked to the developmental stages. In general, the more actively growing cells having high respiratory activities exhibited the more serious injury.

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Effects of Ultraviolet Blood Irradiation in a Type 1 Diabetic Rabbit (제1형 당뇨토끼에서 자외선 혈액 조사 효과)

  • Yang, Yeong-Seok;Kim, Gi-Beum
    • Journal of Biomedical Engineering Research
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    • v.40 no.3
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    • pp.81-96
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    • 2019
  • The purpose of this study is to evaluate the effects of ultraviolet blood irradiation on the blood when a low dose of ultraviolet (UV) C is directly irradiated to the blood in a diabetic rabbit model and to evaluate the effects on treatment for diabetes. This study results indicate that the reduced body weight is increased and blood glucose levels are significantly reduced after the UBI treatment is performed when compared to those prior to the UBI treatment. In addition, $HCO_3{^-}$ levels and blood pH were elevated and lowered, respectively. When the UBI treatment is performed in a diabetic rabbit model, in this result indicate that blood glucose levels are reduced.

Development of the Most Optimized Ionizer for Reduction in the Atmospheric Pressure and Inert Gas Area (감압대기 및 불활성가스 분위기에서 적합한 정전기 제거장치의 개발)

  • Lee, Dong Hoon;Jeong, Phil Hoon;Lee, Su Hwan;Kim, Sanghyo
    • Journal of the Korean Society of Safety
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    • v.31 no.3
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    • pp.42-46
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    • 2016
  • In LCD Display or semiconductor manufacturing processes, the anti-static technology of glass substrates and wafers becomes one of the most difficult issues which influence the yield of the semiconductor manufacturing. In order to overcome the problems of wafer surface contamination various issues such as ionization in decompressed vacuum and inactive gas(i.e. $N_2$ gas, Ar gas, etc.) environment should be considered. Soft X ray radiation is adequate in air and $O_2$ gas at atmospheric pressure while UV radiation is effective in $N_2$ gas Ar gas and at reduced pressure. At this point of view, the "vacuum ultraviolet ray ionization" is one of the most suitable methods for static elimination. The vacuum ultraviolet can be categorized according to a short wavelength whose value is from 100nm to 200nm. this is also called as an Extreme Ultraviolet. Most of these vacuum ultraviolet is absorbed in various substances including the air in the atmosphere. It is absorbed substances become to transit or expose the electrons, then the ionization is initially activated. In this study, static eliminator based on the vacuum ultraviolet ray under the above mentioned environment was tested and the results show how the ionization performance based on vacuum ultraviolet ray can be optimized. These vacuum ultraviolet ray performs better in extreme atmosphere than an ordinary atmospheric environment. Neutralization capability, therefore, shows its maximum value at $10^{-1}{\sim}10^{-3}$ Torr pressure level, and than starts degrading as pressure is gradually reduced. Neutralization capability at this peak point is higher than that at reduced pressure about $10^4$ times on the atmospheric pressure and by about $10^3$ times on the inactive gas. The introductions of these technology make it possible to perfectly overcome problems caused by static electricity and to manufacture ULSI devices and LCD with high reliability.

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.

Characteristics of Environmental Solar Ultraviolet Irradiance

  • Sasaki, Masako;Oyanagi, Takehiko;Takeshita, Shu
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.154-157
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    • 2002
  • Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

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Examination of Color Difference in Elastic Pavement that uses EPDM Chip using Ultraviolet Ray Accelerated Weathering Test (자외선 촉진 내후성 시험에 의한 EPDM Chip을 사용한 탄성포장의 색차분석)

  • Hong, Chang Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1D
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    • pp.91-98
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    • 2011
  • Recently, the usage of elastic paving using EPDM Chip instead of pedestrian sidewalk blocks or permeable concrete used mostly for pedestrian walk, trails and in parks has been increassed as it can absorb impact during walking and produce wide range of colors and designs. However, the properties of EPDM Chip including elasticity and durability are decreased when exposed to ultraviolet ray and scenic paving functions through various colors are lowered due to the yellowing phenomenon. In this study, ultraviolet ray accelerated weathering test has been conducted to analyze the color changes in EPDM Chip and polyurethane resin, which are the main ingredients of elastic paving, when exposed to ultraviolet ray. The color differences are quantitatively analyzed through the color value coordination of the colored space by using the color difference scheme. The experimental results show that the color changes in BL polyurethane resin which is used most frequently at present was larger than that of EPDM Chip. Moreover, the total color difference, ${\Delta}E$, of BC polyurethane resin are 3.162 on the $14^{th}$ day of commencement of acceleration, which is 6 times greater color change resistance against ultraviolet ray than that of BL polyurethane resin with total color difference of 20.639. Therefore, the usage of BC polyurethane resin, which is manufactured to have chain-type molecular structure by using the isocyanate as the HMDI at the time of producing polymer, as binder in elastic paving with EPDM Chip is found to be a highly efficient method of restraining the color changes due to the ultraviolet ray.