• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.361-367
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• 2004

In this study, a different UV (ultra-violet) ray absorption system is presented in which butyl methoxydiben-zoylmethane (BMDM, a model UV-A absorbent, 320$\~$400 nm) is stabilized in phase-controlled poly(methyl methacrylate) (PMMA) microspheres. The photochemistry of BMDM in the microspheres was investigated considering its phase characteristics therein. The analysis of a differential scanning calorimeter and X-ray diffractometer showed that the BMDM in the microspheres was present with a non-crystalline state. The phase control of BMDM in the polymer microsphere has an excellent ability to protect UV-A with maintaining its photo- and thermal stability. The results obtained in this study illustrate well that the phase control of the UV absorbents in the polymer microspheres is another key factor that de-termines its photochemistry and photostability in the final formulations.

• Journal of the Korean Society of Earth Science Education
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• v.8 no.3
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• pp.267-280
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• 2015

The purpose of this study is to identify the conceptions of middle school students and teachers about Visible-Light, Ultra-Violet(UV) and Infrared-Ray(IR). We administered questionnaire 3 teacher and 102 students(48 people of middle school 2nd students and 54 people of middle school 3rd students) who learned by 3 teachers in seoul. From the analysis, it was found that many students and teachers didn't understand the basic principle of UV and IR. Significant number of students belive that it is possible to see objects the absence of visible light. Most students belive that they can see objects in the presence of UV light alone. They think that "Light" is single concept. Teachers were generally more aware of the origin and explanation of UV. But teachers expressed some uncertainties. They tend to think negative effect for UV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1104-1108
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• 2004

A Study has been made of surface modification of various polymers by ion implantation to change the optical transmittance property at ultraviolet ray (UV, $200\sim400nm$). The substrates were PC (Polycarbonate), PET(Polyethyleneteraphtalate) and PP (Polypropylene). The effects of ion implantation on the change of optical transmittance were investigated in relation to ion species, implantation energies and ion fluences. The N, Ar, Kr, Xe ion implantation performed at ion energies from 20 to 50keV. The fluences ranged from $5\times10^{15}$ to $7\times10^{16}ions/cm^2$. UV/Vis transmittance spectroscopy, FT-IR and XPS were used to investigate optical transmittance, chemical structure and surface chemical state of irradiated polymer. Surface color was changed from the yellow to the dark brown and the transmittance of UV ray in the range UV-A($320\sim400nm$) decreased more than 80% after ion implantation.

• Analytical Science and Technology
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• v.21 no.6
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• pp.553-561
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• 2008

$CNT/TiO_2$ composites were prepared by using multiwall carbon nanotubes (MWCNT) and various titanium alkoxide precursors. The composites were comprehensively characterized by scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and UV-vis absorption spectroscopy. The photoactivity of the prepared materials under UV irradiation, was tested using the conversion of MB from model aqueous solution. Finally, according to the results of methylene blue (MB) removal experiment, we could see that sample CTOS have better MB removal effect than samples CTIP and CTPP.

• Proceedings of the SCSK Conference
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• 1994.07a
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• pp.26-53
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• 1994

• Journal of Korean Society of Water and Wastewater
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• v.26 no.3
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• pp.373-381
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• 2012

Antibiotics have been issued recently in water environments because of potential impacts on ecosystem and public health. This study was aimed to investigating the degradation of antibiotics such as tetracycline, lincomycin, sulfamethazine and cephradine using gamma ray irradiation. And the toxicity before and after irradiation on antibiotics was tested in order to examine the aquatic eco-risk assessment by aquatic organisms. In addition, comparing tests on toxicity for gamma ray and UV irradiated antibiotics was conducted. Four different antibiotics were prepared by concentration of 30 mg/L with demi-water respectively. The absorption dose of gamma ray was ranged from 0.2 to 2 kGy. The concentration of four antibiotics was gradually decreased corresponding to the increase of the absorption dose. A method for toxicity assessment using Pseudokirchneriella subcapitata was evaluated to the most acceptable compared with methods by Daphnia magna and Microtox$^{(R)}$ in terms of sensibility. It showed that the reduction of toxicity on antibiotics treated by gamma ray was superior comparing to the test results obtained from UV treatment. By-products from antibiotics treated by gamma ray were easily decomposed by microorganism and their toxicity was also evaluated to low.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.36.1-36.1
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• 2016

The physical scenario describing the origin of quasar winds remains largely unsettled due to our failure to account for X-ray weak BAL quasars. We approach this problem by studying the relation between the inner part of the outflow which is likely to be shielding the X-ray emission and thereby helping to drive the UV winds characterised by broad absorption lines (BALs). In particular, we aim to probe the wind-shield connection in the highly X-ray variable BAL quasar PG 2112+059, which has exhibited periods of X-ray weakness and X-ray normality in the past. A set of two 20 ks Chandra observations and two contemporaneous HST observations, separated by at least eight months, combined with a nearly simultaneous archival Chandra-HST observation from 2002, afford us a unique opportunity to study the connection between the shield (which is thought to be responsible for the X-ray absorption) and the ionisation state of the wind (observed as UV BAL features; e.g., C IV and O VI lines) over various timescales.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.4
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• pp.16-20
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• 2014

To prevent any accident in electric power utilities, many researches for inspection and diagnosis deteriorations occurring by corona discharges have been continuously studying. Inspection and diagnosis of electric power utility is very important to prevent an accident. This paper studies a measurement of ultra-violet(UV) ray of corona discharges on polymer insulators using an UV sensor array with an optic lens. The detection of an UV signal begins at 60kV, which is about 37.5% of the breakdown voltage of the polymer insulator and the stronger the high voltage increased to the polymer insulator was. It can be determined that the polymer insulator mounted on a live part must be examined when the discharge risk exceeds approximately 40%. In conclusion, the status of power utilities can be checked using an UV sensor.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.15-19
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• 2002

In this work, the surface modification of carbon/epoxy composites was investigated using UV (ultraviolet ray) surface treatment to increase adhesion strength between the carbon/epoxy composites and adhesives. After UV surface treatment, XPS (X-ray photoelectron spectroscopy) tests were performed to analyze the surface characteristics of the carbon/epoxy composites. Comparing adhesion strengths with the surface characteristics, the effects of the surface modification of carbon/epoxy composites by UV surface treatments on the adhesion strengths were investigated.

• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.316-321
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• 2009

Er-doped ZnO(ZnO:Er) films were deposited onto MgO wafers by ultrasonic spray pyrolysis at 550 $^{\circ}C$ varying the concentration of Er in the deposition source from 0.5 wt% to 3.0 wt%. Annealing of the films in a vacuum was carried out to increase the intensity of ultraviolet(UV) emission from the films. The annealing temperature was between 600$^{\circ}C$ and 800$^{\circ}C$. The crystallographic properties and surface morphology 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 the dependence of PL spectra on the annealing temperature. X-ray photoelectron spectroscopy(XPS) was conducted to find the composition change in the films by the annealing.