• 제목/요약/키워드: UV-A

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A Study on the Ultraviolet(UV)-Cut Fiber (자외선 차단 직물에 환한 연구)

  • 최인려
    • The Research Journal of the Costume Culture
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    • v.11 no.6
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    • pp.967-971
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    • 2003
  • As the concerns over health increased in 1990's, research and development on the health material were also activated. The development of UV-cut textile became the hot issue, because the damage of W irradiation due to ozone depletion has become widely known. UV-cut effect is determined by the material, the color, the organization and the density of UV-cut fibers. UV-cut effect is very different according to the fibers. Polyester is known to have a better effect. Even in the same textile material, staple fiber has more effect than filament fiber. Different colors have different offsets. Although textiles have the same color, the effects can be different according to the depth of color. PET, PET/cotton blend, nylon and cotton fabrics were ultraviolet cutting finished with padding method using several absorbers. These UV-cut effect can be improved through the processing. Safety of UV-cut textile for the body must be considered future, Until now the figure of the UV-cut effects has been emphasized. There has been no experiment on the human body, although the textiles are directly on the human body. Futhermore there os no safety standard of UV-cut textiles. Therefore every effort will be made to set the standard UV-cut processing is established. The need of UV-cut products will be known to the consumers.

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Kinetic analysis of E. coli disinfection using UV-LED (LED 광원 UV에 의한 대장균(E. coli) 소독의 속도론 해석)

  • Kim, Kyeong-Rae;Chang, In-Soung
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.489-496
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    • 2021
  • Water disinfection using UV-LED(Light emitting diode) has many advantages, such as smaller footprint and power consumption as well as relatively longer lifespan than those of conventional mercury-UV lamps. Moreover, UV-LED disinfection is considered an environmentally benign process due to its mercury-free nature. In this study, disinfection using an LED module emitting 275nm UV was carried out. 384 UV-LEDs were put into a cylinder tube with a capacity of 1.7 liters. The UV intensity of the UV-LED module was controlled from 1.7 to 8.4 mW/cm2. The disinfection efficiency for the model microorganism solutions(E. coli ) was monitored. As the UV intensity(I) and contact time(t) varied, inactivation of the microorganisms from 2 to 4-log-removals(i.e., 99 to 99.99% of disinfection efficiency) was achieved. Disinfection using UV-LED was followed to 1st order reaction and the reaction rate constant, k was determined. In addition, the relationship between UV intensity(I) and contact time(t) in order to obtain 99.99% of disinfection efficiency was modeled: I1.2·t= 460, which indicates that the product of UV intensity and contact time requiring 4-log-removals is always constant.

전해질 무첨가 전기/UV 공정을 이용한 염료의 제거

  • Park, Yeong-Sik;Kim, Dong-Seok
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2008.11a
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    • pp.350-354
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    • 2008
  • 전기/UV 공정에 사용하기 위해 일반적인 살균 램프인 UV-C 램프와 오존도 같이 발생하는 오존 등의 RhB 분해능을 고찰한 결과 오존 램프의 RhB 제거율이 UV-C램프보다 높은 것으로 나타났다. 전해질을 첨가하지 않은 전기/UV 공정에서 최적 전류는 1 A로 나타났다. 전기/UV 공정에서 RhB 제거의 경우 전기분해 공정과 UV 공정의 단일 공정의 RhB 농도감소와 전기/UV 복합 공정의 RhB 제거는 같아 공정의 시너지 효과는 관찰되지 않았다. 그러나 COD의 경우 전기분해 공정과 오존 램프에 의한 단일 공정의 COD 제거보다는 전기/UV 공정의 COD 제거농도가 높아 시너지 효과가 나타나는 것으로 사료되었다.

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Enhanced Lycopene Production by UV-C Irradiation in Radiation-Resistant Deinococcus radiodurans R1

  • Kang, Chang Keun;Yang, Jung Eun;Park, Hae Woong;Choi, Yong Jun
    • Journal of Microbiology and Biotechnology
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    • v.30 no.12
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    • pp.1937-1943
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    • 2020
  • Although classical metabolic engineering strategies have succeeded in developing microbial strains capable of producing desired bioproducts, metabolic imbalance resulting from extensive genetic manipulation often leads to decreased productivity. Thus, abiotic strategies for improving microbial production performance can be an alternative to overcome drawbacks arising from intensive metabolic engineering. Herein, we report a promising abiotic method for enhancing lycopene production by UV-C irradiation using a radiation-resistant ΔcrtLm/crtB+dxs+ Deinococcus radiodurans R1 strain. First, the onset of UV irradiation was determined through analysis of the expression of 11 genes mainly involved in the carotenoid biosynthetic pathway in the ΔcrtLm/crtB+dxs+ D. radiodurans R1 strain. Second, the effects of different UV wavelengths (UV-A, UV-B, and UV-C) on lycopene production were investigated. UV-C irradiation induced the highest production, resulting in a 69.9% increase in lycopene content [64.2 ± 3.2 mg/g dry cell weight (DCW)]. Extended UV-C irradiation further enhanced lycopene content up to 73.9 ± 2.3 mg/g DCW, a 95.5% increase compared to production without UV-C irradiation (37.8 ± 0.7 mg/g DCW).

Improvement of the Accuracy of Optical Simulation Using by the Multi-cube UV Source in PDP Cells (Multi-cube UV source 이용한 PDP에서 광학시뮬레이션의 정확성 개선에 관한 연구)

  • Kang, Jung-Won;Eom, Chul-Whan
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.2 s.19
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    • pp.41-44
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    • 2007
  • Optical simulation of the rear and front panel geometries were needed to improve the luminance and efficiency in PDP cells. The 3-dimensional optical code can be used to analyze the variation of geometries and changing of optical properties. In order to improve the accuracy of simulated results, a new UV source, called a multi-cubes UV source, was designed. To design the source, at first UV distribution was calculated with the plasma fluid code and then the UV distribution was transformed to the multi-cube structures in the optical code. Compared to the results from existing UV source, called a planar UV source, could be improved the accuracy of visible light distribution. Simulated results were also compared to the visible distribution measured with the ICCD in a real PDP cell.

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Degradation of Triclosan by the Photolysis, the Fenton, and the Hybrid Reaction with Fe$^{2+}$ and UV : A Comparative Study (광반응, 펜톤, 그리고 Fe$^{2+}$와 UV의 조합반응을 이용한 Triclosan의 분해 : 공정 비교 연구)

  • Son, Hyun-Seok;Zoh, Kyung-Duk
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.5
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    • pp.517-523
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    • 2008
  • The degradation mechanism of Triclosan(TCS), which is a potent broad-spectrum antimicrobial agent and has been considered as an emerging pollutant, was investigated in the Fenton and the hybrid reaction with Fe$^{2+}$ and UV-C. The results show that the Fe$^{2+}$ is oxidized to 30% by $H_2O_2$, 28% by UV-C, and 15% by UV-A for 10 min. The degradation rate of TCS for beginning time(10 min) was higher in UV-C only reaction than that in hybrid reaction, which of the order was inverted according to the lapse of reaction time. The effect of methanol was the greatest in Fenton reaction, in which the degradation rate of TCS decreased from 90% to 5% by the addition of methanol. Chloride, ionic intermediate, was produced to 77% for 150 min of hybrid reaction(Fe$^{2+}$ + UV-C), which was the greatest. In case with methanol, the generation rate of chloride for 15 min was ignorable in all reactions($\leq$2%) but the hybrid reaction with Fe$^{2+}$ and UV-C(12%). Additionally, the removal rate of TOC in each reaction was estimated as the followed orders; Fe$^{2+}$ + UV-C > Fe$^{2+}$ + $H_2O_2$ > Fe$^{2+}$ + UV-A > UV-C > UV-A. However, the Fenton reaction was almost stopped after 90 min because the reaction between Fe$^{2+}$ and $H_2O_2$ cannot be kept on without adding the oxidant. The phenomena was not observed in the hybrid reaction. In view of generating chloride, the reductive degradation of TCS may be in the hybrid reaction with Fe$^{2+}$ and UV-C, which is favorable to mineralize halogenated organic compounds such as TCS. Consequently, the hybrid process with Fe$^{2+}$ and UV-C may be considered as the alternative treatment method for TCS.

Characterization of Expression of UV-Inducible Gene (UV100 and UV150) in Caenorhabditis elegans (Caenorhabditis elegans에서 분리한 자외선 유도유전자 (UV100과 UV150)의 발현 및 특성에 관한 연구)

  • Shin, Sue-Hwa;Choi, Eun-Young;Choi, In-Soon
    • Journal of Life Science
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    • v.16 no.4
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    • pp.704-709
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    • 2006
  • The present study intends to characterize the DNA damage-inducible responses in Caenorhabditis elegans. To study UV-inducible responses in C. elegans, two UV-inducible cDNA clones were isolated from C. elegans by using subtration hybridization method. To investigate the expression of isolated genes, UV100 and UV150, the cellular levels of the transcript were determined by Northern blot analysis after UV-irradiation. The transcripts of isolated gene increased rapidly and reached maximum accumulation after UV-irradiation. Compared to the message levels of control, the levels of maximal increase were approximately 2 folds to UV-irradiation. These results implied that the effects of damaging agents are complex and different regulatory pathways exist for the induction of these genes. To study the function of UV100 and UV150 gene in response to UV irradiation, we carried out a RNAi experiment and investigated the UV sensivity. This result indicated that UV100 gene involved in stage-specific repair pathway or regulated by development.

Removal and Decomposition of Organochlorine Compounds in Water Using UV Irradiation (자외선에너지를 이용하여 물속에 함유된 유기염소계 화합물의 분해 및 제거)

  • Kim, Jong Hyang
    • Applied Chemistry for Engineering
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    • v.10 no.1
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    • pp.30-34
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    • 1999
  • Photolysis behavoirs of pesticides(Chlorothalonil and Endosulfan) over UV irradiation UV irradiation with pH 3.0 and irradiation with 3.5% salt were studied. The analyses of pesticides were carried out using gas chromatograph with an electron-capture detector, total organic carbon, and Ion chromatograph, respectively. The reactions were conducted in a alumium annular reactor equipped with a low pressure mercury multilamp ($8W{\times}6$) and initial concentration was 10 ppm. Chlorothalonil was almost photodegraded by UV irradiation, UV irradiation with pH 3.0 and 3.5% salt within 30 min of reaction time. Endosulfan-${\alpha}$,${\beta}$(100%) were photodegraded to 38% of Endosulfan-${\alpha}$ and 25% of Endisulfan-${\beta}$ by UV irradiation. Endosulfan-${\alpha}$(83%) was photodegraded to 66% by UV irradiation, 70% by UV irradiation and pH 3.0 and 75% by UV irradiation and 3.5% salt. Endosulfan-${\beta}$(16%) was photodegraded to 80% by UV irradiation, 98% by UV irradiation and pH 3.0 and 90% by UV irradiation and 3.5% salt.

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A Comprehensive Study for Two Damage Sites of Human Hair upon UV-B Damage

  • Song, Sang-Hun;Son, Seongkil;Kang, Nae Gyu
    • Korea Journal of Cosmetic Science
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    • v.2 no.1
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    • pp.1-10
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    • 2020
  • Protection mechanisms for skin damage of ultraviolet (UV) absorbers in personal care products for protection against UV are well studied, but not for hair protection. The purpose of this study is to describe and compare the changes of physical property produced in human hair by doses of the UV-B exposure causing protein degradation. To observe the change of physical properties in hair, the experimental intensity of UV-B exposure has been established on the basis of statistical data from official meterological administration as daily one hour sunlight exposure for two weeks. Polysilicone-15, ethylhexyl methoxycinnamate (OMC), and octocrylene were employed for UV-B absorber, and those were treated to hair swatch by rubbing wash through shampoo and conditioner. Bending rigidity displayed kinetically successive reduction at high doses of UV exposure up to the 8,000 s, and exhibited different level at each sample of UV-B absorber. However, the values of Bossa Nova Technologies (BNT) for shinning factor were already saturable at the 2,000 s exposure except that treated with polysilicone-15. The differential scanning calorimetry (DSC) to measure a strength of inner protein produces a successive reduction of enthalpy as like a reduction of bending rigidity upon UV exposure. Surface roughness from lateral force microscope (LFM) acquired immediately after UV exposure show a saturable frictional voltage which has been also found in a saturable BNT data as the time of UV exposure increases. Through researching the DSC and the LFM, shinning of hair was much correlated to the protein damage at the surface, and bending rigidity could be regulated by the protein structural damage inside hair. Therefore, the optimization of efficient strategy for simultaneous prevention of hair protein on the surface and internal hair was required to maintain physical properties against UV.

Electro-Optical Characteristics of TN Cell using UV Alignment Method on the a-C:H Thin Film (a-C:H 박막표면에 UV 배향법을 이용한 TN 셀의 전기광학특성)

  • Park, Chang-Joon;Hwang, Jeoung-Yeon;Kim, Jong-Hwan;Seo, Dae-Shik;Ahn, Han-Jin;Baik, Hong-Koo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.1043-1046
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    • 2003
  • We investigated the EO performances of the UV aligned twisted nematic liquid crystal display (TN-LCD) with the UV exposure on a-C:H thin film surface. LC alignment using UV exposure on the a-C:H thin film surface was achieved. Monodomain alignment of the UV aligned TN-LCD can be observed. An good EO characteristics of the UV aligned TN-LCD was observed with oblique ion beam exposure on the a-C:H thin film surface. Therefore, the EO property of the UV-aligned TN-LCD with UV exposure on the a-C:H thin film surface is almost the same as that of the rubbing-aligned TN-LCD on a polyimide (PI) surface.

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