• Journal of Radiation Industry
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• v.5 no.3
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• pp.203-210
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• 2011

To evaluate the ability of Bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BL) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and BL-treated mice exposed chronically to ultraviolet (UV) were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back, increased epidermal thickeness, numerous cell infiltration, and many enlarged keratinizing cysts. BL-treated mice showed a significantly decreased wrinkling score and lack of proliferation of cysts. By the 22nd week, 88.9% (i.p. with saline) or 60.0% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. BL delayed tumor onset significantly. BL (i.p.) was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 37.5% (i.p.) of the mice treated with BL were tumor-free. Tumor multiplicity was reduced by 81.2% (i.p.) in the BL treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and regular use of BL would prevent these photodamaging effects of UV.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.39.2-39.2
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• 2015

The World Space Observatory Ultraviolet (WSO-UV) is the space mission that will grant access to the UV range in the post Hubble epoch. WSO-UV is equipped with instrumentation for imaging and spectroscopy and it is fully devoted to UV astronomy. In this talk, we outline the WSO-UV mission model and present the current status of the project. Also, the NEO observing mission SODA (System of Observation of Day-time Asteroids) is also presented.

• Environmental Mutagens and Carcinogens
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• v.15 no.2
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• pp.94-99
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• 1995

The adaptive response and cross-adaptive response to sister chromatid exchanges (SCEs) and DNA single-strand breaks (SSBs) in Chinese hamster ovary (CHO)-K$_1$ cells treated with ultraviolet radiation (UV), ethyl methanesuffonate (EMS), or bleomycin (BLM) were investigated. Two assays were used in this study; SCEs and alkaline elution. The pretreatment with low conditioning dose of 2 mM EMS or 1 J/m$^2$ UV decreased the yield of SCEs induced by subsequent treatment with 8 mM EMS, 5 J/m$^2$ UV or 5 $\mu$g/ml BLM. And the pretreatment with low conditioning dose of 1 $\mu$g/ml BLM decreased the yield of SCEs induced by subsequent treatment with 5 $\mu$g/ml BLM or 5 J/m$^2$ UV. The rejoining of DNA SSBs in cells subsequently treated with 2 J/m$^2$ UV, 50 mM EMS or 400 $\mu$g/ml BLM is higher than that only treated with 2 J/m$^2$ UV, 50 mM EMS or 400 $\mu$g/ml BLM. These results suggest that there are the adaptive response and cross-adaptive response to SCEs, and is the adaptive response to the rejoining of DNA SSBs in CHO cells.

• Journal of Photoscience
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• v.9 no.2
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• pp.439-441
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• 2002

Cyanobacteria are the dominant micro flora in rice-fields, contributing significantly to fertility as a natural biofertilizer. Recent studies show a continuous depletion of the stratospheric ozone layer, and the consequent increase in solar UV-B (280-315 nm) radiation reaching the Earth's surface. UV-B radiation causes reduction in growth, survival, protein content, heterocyst frequency and fixation of carbon and nitrogen in many cyanobacteria. UV -B induced bleaching of pigments, disassembly of phycobilisomal complexes, thymine dimer formation and alterations in membrane permeability have also been encounterd in a number of cyanobacteria. However, certain cyanobacteria produce photoprotective compounds such as water soluble colorless mycosporine-like amino acids (MAAs) and the lipid soluble yellow-brown colored sheath pigment, scytonemin, to counteract the damaging effects of UV-B. Cyanobacteria, such as Anabaena sp., Nostoc commune, Scytonema sp. and Lyngbya sp. were isolated from rice fields and other habitats in India and screened for the presence of photoprotective compounds. A circadian induction of the synthesis of MAAs by UV -B was noted in a number of cyanobacteria. Polychromatic action spectra for the induction of MAAs in Anabaena sp. and Nostoc commune also show the induction to be UV-B dependent peaking at 290 nm. Another photoprotective compound, scytonemin, with an absorption maximum at 386 nm (also absorbs at 300, 278, 252 and 212 nm), was detected in many cyanobacteria. In conclusion, a particular cyanobacterium having photoprotective compounds may be a potent candidate as biofertilizer for crop plants.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.2
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• pp.109-115
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• 2023

In this paper, we demonstrated the orientation characteristics of liquid crystals using UV-treated FSAM as alignment layer. Moreover we confirmed the FSAM properties before and after UV treatment on indium tin oxide (ITO) glass substrates using physicochemical analysis. The hydrophobic property of the FSAM surface is change to hydrophilic through UV treatment. After UV treatment the LC molecules also were uniformly and horizontally aligned on the FSAM surfaces and the pretilt angle was obviously changed 90° degrees to 0° degrees. EO characteristic of TN cell which was fabricated with UV-treated FSAM was faster response time compare to conventional PI layer. The FSAM before and after UV treatment has a superior application potential as the LC alignment layer for LCD, potentially replacing the conventional polyimide layer.

• Journal of Sensor Science and Technology
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• v.16 no.4
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• pp.307-312
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• 2007

The films of Er-doped ZnO (ZnO:Er) were prepared onto MgO wafers by ultrasonic spray pyrolysis at $550^{\circ}C$. The concentration of Er in the deposition source varied from 0.5 wt% to 3.0 wt%. The crystallographic properties and surface morphologies of the films were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The properties of photoluminescence (PL) for the films were investigated by dependence of PL spectra on the Er concentration in the films. The films were grown as polycrystalline with a dominant direction of [002]. The grain size of the films were reduced by Er-doping. Er-doping enhanced the ultraviolet emission of ZnO:Er films. The ZnO:Er films prepared with the deposition source of 2.0 wt% Er showed the strongest ultraviolet light emission peak among the films in this study.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.1-5
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• 2021

Ultraviolet (UVA)-emissive BaSiO₃:Ce³⁺ phosphor was astonishingly reproducible by vacuum-sintering at a high temperature through a simple solid-state reaction method. It was conveniently formed in BaSiO₃ phases. The compound showed the UVA emission and the UV-VUV excitation due to 5d-4f transitions from Ce³⁺ ions: emission peak at 380 nm with a 56 nm width. Its temperature dependence and vacuum UV excitability were examined for practical application as an excimer discharge lamp, which showed the high thermal stability (80% at 100℃) and the strong VUV excitations at 145 nm and 172 nm.

• Food Engineering Progress
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• v.22 no.4
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• pp.386-391
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• 2018

Effects of a commercial scale intervention system combining ultraviolet (UV)-C and plasma treatments on the microbial decontamination of black pepper powder were investigated. The process parameters include treatment time, time for plasma accumulation before treatment, and water activity of black pepper powder. A significant reduction in the number of indigenous aerobic mesophilic bacteria in black pepper powder was observed after treatments lasted for ${\geq}20min$ (p<0.05) and the reduction was differed by powder manufacturer. The microbial reduction rates obtained by individual UV-C treatment, individual plasma treatment, and UV-C/plasma-combined treatment were 0.2, 0.5, and 1.0 log CFU/g, respectively, suggesting that the efficacy of the microbial inactivation was enhanced by treatment combination. Nonetheless, neither plasma accumulation time nor powder water activity affected the microbial inactivation efficacy of the combined treatment. The UV-C/plasma-combined treatment, however, decreased lightness of black pepper powder, and the decrease generally increased as operation time increased. The plasma accumulation time of 20 min resulted in significant reduction in both lightness and brown color. The results indicate that the commercial-scale intervention system combining treatments of UV-C and plasma has the potential to be applied in the food industry for decontaminating black pepper powder.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.449-455
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• 2005

Electron beam (EB) and ultraviolet (UV) curable monomers (AF-1 with mono functionality and AF-2 with tetra functionality) containing hydroxy and acrylate group for anti-fogging coating were synthesized and applied to EB and UV-curable coating systems. The synthesized reactive AF-1 and AF-2 monomers were first formulated into UV-curable system and the optimization of film properties for anti-fogging coating was investigated. The 5:17.5 ratio for AF-1 and AF-2 was found to be the best optimized formulation for anti-fogging coating without destroying the other essential properties such as hardness, solvent resistance, and adhesion. The optimized formulation was applied to the EB-curable system, and EB and UV-curable systems were compared. The results demonstrated that both EB and UV-cured films coated on PC sheet showed excellent anti-fogging properties; however, the EB-cured film exhibited better hardness, adhesion, and water repellent properties than the UV-cured film.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.143-149
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• 1999

In the tungsten industry as light source material, tungsten filament which used as light source material could form after molybdenumwire which used as the center supporter for coil shape tungsten wire was removed. This process uses hydrogen peroxide, Ozone and UV(Ultraviolet)Lamp, for the quantity of hydrogen peroxide decrease. The results were as follows : 1. An incandescent electric Lamp type : FL(FL-20) type : A standard of commodity (P.W.: $19{\pm}1.0mg$, $C.R:4.5{\pm}0.3{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time : 65Min., P.W.: 18.60mg, $C.R.:4.60{\Omega}$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide; Reaction Time : 64Min., P.W.: 18.61mg, C.R.: $4.61{\Omega}$ 2. A Fluorescent Lamp Type : GLS(GLS-40) Type : A standard of commodity(P.W.: $11.8{\pm}0.2mg$$65{\pm}1.5{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time: 72Min, P.W.:11.88mg, C.R.: $65.62\Omega$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide;Reaction Time:71Min., P.W.:11.88mg, C.R.: $65.63\Omega$