• 대한치과보철학회:학술대회논문집
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• 1999.04a
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• pp.97-97
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• 1999

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.93-98
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• 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.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.189-199
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• 2015

In this study, we have investigated the stability of sunscreens based on the solubility of organic UV absorbers in the oil and sun protection efficacy of the products composed of a combination of organic UV absorbers to develop more stable and efficient sunscreen products. Results showed that the solubility of the organic UV absorber and stability were varied depending on the type, storage conditions and concentration of oil. It was also observed from the products in the emulsion type. Various UV absorbances were determined to the products composed of the combination of organic UV absorbers. In some combinations, a synergistic effect was observed to make an increase in absorbance compared to a single component. In other cases, specific synergistic effect was displayed only when combined with the particular component. In addition, the storage condition also affected the sunscreen efficacy. In conclusion, this study confirmed that there are various factors which could affect the UV-blocking efficiency of sunscreen products.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.392-396
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• 2014

New organic-inorganic composite of 2,4-dihydroxybenzophenone (BP-1) encapsulation into dodecylbenzenesulfonate (DBS) modified layered double hydroxide (LDH) was successfully prepared. The surface, structural, thermal and absorption properties of the BP-1/DBS-LDH nanohybrid was characterized by BET analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and diffuse reflectance UV-Vis absorbance spectra (DRUV-vis). The interlayer configuration of composite and the adsorption mechanism of BP-1 on MgAl-DBS-LDH were discussed. It was suspected that DBS anions located in the form of monolayer arrangement with a $75^{\circ}$ anti parallel angle between dodecylbenzenesulfonate chain axis. The diffuse reflectance UV-Vis absorbance results revealed that the UV absorbing wavelength of BP-1/DBS-LDH evidently extends to about 400 nm, which shows that the BP-1/DBS-LDH has the potential application as a UV absorber.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.237-244
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• 2005

Sunscreens have been in use for about 70years and 'tanning without burning' was propagated as their major advantage. The objective changed from 'getting a tanned skin' to 'getting skin protection' since UV have been proposed to a major risk of skin cancer and the risk of developing skin cancer related also to non-burning UVA. The new expectation from consumers has triggered the development of new UV absorbers and led to the approval of 7 new, organic UV absorbers in Europe over the last few years. The significant progress due to these new UV absorbers will be discussed in this report. These UV absorbers provide an efficient absorption of UV radiation (UVB and/or UVA) and easily incorporate in any kind of formulation. These are also safe, i.e. devoid of adverse effects. These new filters give the formulators new possibilities to cover the whole UV range iron 290 to 400 nm, and also to use less filter due to the boosting effect of the new UVA and broadband fitters.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.23-27
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• 1995

Several characteristic results of physical and optical properties of paper treated by UV light were obtained in the previous papers(Kim et al. 1988). In this paper, folding endurance and brightness of paper prepared by spraying photostabilizer were examined in order to elucidate photodegradation phenomena, UV light absorber and radical scavenger were most effective in preventing of folding endurance decrease. These results may be indicated that depolymerization of cellulose and hemicellulose chains leading to degradation of paper mechanical properties mainly caused by radical reaction. Ineffective hydroperoxide decomposer may be explained because of auto-oxidation reactions before forming stable compound from hydroperoxide.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1314-1319
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• 2006

This paper describes the novel fabrication method of the high-aspect-ratio nano structure which is impossible by conventional method using a shadow mask and a Deep X-ray Lithography (DXRL). The shadow mask with $1{\mu}m-sized$ apertures is fabricated on the silicon membrane using a conventional UV-lithography. The size of aperture is reduced to 200nm by accumulated low stress silicon nitride using a LPCVD (low pressure chemical vapor deposition) process. The X-ray mask is fabricated by depositing absorber layer (Au, $3{\mu}m$) on the back side of nano shadow mask. The thickness of an absorber layer must deposit dozens micrometers to obtain contrast more than 100 for a conventional DXRL process. The thickness of $3{\mu}m-absorber$ layer can get sufficient contrast using a central beam stop method, blocking high energy X-rays. The nano circle and nano line, 200nm in diameter in width, respectively, were demonstrated 700nm in height with a negative photoresist of SU-8.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.267-267
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• 2009

Solar cells with CIGS absorber layers have proven their suitability for high efficiency and stable low cost solar cells. We prepared and characterized particle based CIGS thin film using a non-vacuum processing. CIGS powder were obtained at $240^{\circ}C$ for 6 hours from the reaction of $CuCl_2$, $InCl_3$, $GaCl_3$, Se powder in solvent. The nanoparticle precursors were mixed with binder material. The CIGS thin film deposited on a sodalime glass. The CIGS thin film were identified to have a typical chalcopyrite tetragonal structure by using UV/Visible-spectroscopy, X-ray diffraction(XRD), Auger Electron Spectroscopy(AES), Scanning Electron Microscopy(SEM).

• Laser Solutions
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• v.6 no.1
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• pp.33-40
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• 2003

The ablative decomposition mechanism of PMMA(polymethyl methacrylate) and PET(polyethylene terephthalate) with KrF excimer laser(λ : 248nm, pulse duration: 5㎱) is investigated. The UV/Vis spectrometer analysis showed that PMMA is a weak absorber and PET is a strong absorber at the wavelength of 248nm. The results(surface debris, melt, etch depth, etching shape) from drilling and direct writing experiments imply that ablation mechanism of PMMA is dominated by photothermal process, while that of PET is dominated by photochemical process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1857-1860
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• 2003

The ablative decomposition mechanism of PMMA(polymethyt methacrylate), PET(polyethylene terephthalate) and PC(polycarbonate) with KrF excimer laser(λ: 248nm, pulse duration: 5ns) is investigated. The UV/Vis spectrometer analysis showed that PMMA is a weak absorber and PET, PC are a strong absorber at the wavelength of 248nm. The results(surface debris, melt, etch depth, etching shape) from drilling and direct writing experiments imply that ablation mechanism of PMMA is dominated by photothermal process, while that of PET, PC are dominated by photochemical process.