• 대한화장품학회지
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• 제34권4호
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• pp.311-316
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• 2008

본 연구에서는 모발의 내부 및 외부구조에 자외선이 미치는 영향에 관하여 조사를 수행하였다. 자외선이 조사된 모발의 형태학적 및 화학적 구조의 변화를 알아보기 위해 주사전자현미경(SEM), 투과전자현미경(TEM), 공초점레이져주사현미경(CLSM) 등을 사용하였다. SEM상에서 자외선이 조사된 모발은 자외선에 의한 화학적 산화반응에 의한 표면이 거칠고 부풀어진 형태를 보였다. 이황화결합(disulfide bond)의 산화에 의한 시스테인산(cysteic acid)의 분해로 팽윤부위가 관찰되었다. 또한 자외선 조사에 의해 표면색의 변화를 나타내었다. TEM 분석결과 버진헤어(virgin hair)의 경우에는 매끄러운 표면구조를 나타내었지만, 자외선 조사모발에 있어서는 거칠고 모수질층이 갈라진 형태를 보여주었다. 모피질층에 존재하는 멜라닌 입자의 크기가 감소하고 소실되는 것이 관찰 되었다. CLSM에 의해 3차원적 구조의 입체영상을 얻을 수 있었으며, 광학분할에 의한 버진헤어는 강한 형광을 나타내었지만, 자외선 조사모발은 낮은 형광을 보여주었다. 이는 버진헤어의 경우 자동형광을 나타낼 수 있는 방향족 아미노산이 많이 존재하는데 비해 자외선 조사모발은 방향족 아미노산이 파괴되어 낮게 나온 것으로 여겨진다.

• 한국전기전자재료학회논문지
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• 제25권2호
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• pp.153-158
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• 2012

We use UV(ultraviolet)-$O_3$ treatment to increase the surface area and porosity of $TiO_2$ films in dye-sensitized solar cells (DSSCs). After the UV-$O_3$ treatment, surface area and porosity of the $TiO_2$ films were increased, the increased porosity lead to amount of dye loading and solar conversion efficiency was improved. Field emission scanning electron microscopy images clearly showed that the nanocrystalline porosity of films were increased by UV-$O_3$ treatment. The Brunauer, Emmett, and Teller surface area of the $TiO_2$ films were increased from $0.71cm^2/g$ to $1.31cm^2/g$ by using UV-$O_3$ treatment for 20 min. Also, UV-$O_3$ treatment of $TiO_2$ films significantly enhanced their solar conversion efficiency. The efficiency of the films without treatment was 4.9%, and was increased to 5.6% by UV-$O_3$ treatment for 20 min. Therefore the process enhanced the solar conversion efficiency of DSSCs, and can be used to develop high sensitivity DSSCs.

• 한국염색가공학회지
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• 제19권5호
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• pp.1-7
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• 2007

A new UV-curable coating was carried out to impart the flame-retardant property to cotton fabric using Bis[2-(methacryloyloxy)ehtyl]phosphate(DMEP) and 2-hydroxy-2-methyl-1-phenyl-propan-l-one(HMPP) as a UV-curable monomer and a photoinitiator, respectively. The cotton fabrics were applied with various amounts of DMEP and HMPP via padding and UV irradiation, and the optimal concentrations of DMEP and HMPP in the formulation were 40%(w/w) and 7%omp respectively. A limiteed oxygen index(LOI) up to 28.9 was obtained for the UV-cured fabric, which may occur through a condensed phase mechanism as verified by the increased residue number with increased application level. The characterization of the UV-cured coating was made by IR analysis, thermo-gravimetric analysis, LOI test, and scanning electron microscopy.

• Korea Journal of Cosmetic Science
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• 제2권1호
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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.

• 한국레이저가공학회지
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• 제6권1호
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• pp.9-16
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• 2003

Micromachining using the DPSS 3rd Harmonic Laser (355nm) has outstanding advantages as a UV source in comparison with Excimer lasers in various aspects such as maintenance cost, maskless machining, high repetition rate and so on. It also has the greater absorptivity of many materials in contrast to other IR sources. In this paper, the process for micro-drilling of blind hole in Cu/PI/Cu substrate with the DPSS UV laser and the scanning device is investigated by the experimental methods. It is known that there is a large gap between the ablation threshold of copper and that of PI. We use the Archimedes spiral path for the blind hole with different energy densities to ablate the different material. Finally, the blind via hole of diameter 100$\mu\textrm{m}$ and 50$\mu\textrm{m}$ was drilled.

• 한국레이저가공학회지
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• 제13권3호
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• pp.13-18
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• 2010

In this paper, polyimide (PI) surface was modified by UV Laser with a low laser fluence and investigated changes of surface geometry and chemical characteristics by SEM (scanning electron microscope), X-ray diffraction (XRD), XPS (x-ray photoelectron spectroscopy) and the measurements of contact angle of water. PI surface was peeled off and modified with microstructure fabrications by photochemical ablation over the laser fluence of 50 mJ/cm2. As laser fluence increased, delamination of PI surface was occurred largely and strongly. In chemical characteristics, the O/C and N/C atomic ratios increased and contact angle decreased from $80^{\circ}$ to $40^{\circ}$.

• 한국기계가공학회지
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• 제13권2호
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• pp.15-20
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• 2014

The stereolithography(SL) process is a type of fabrication technology which relies on photopolymerization. It has a relatively simple fabrication process and a resolution of several tens of ${\mu}m$. Recently, SL technology has been applied to various areas, such as bioengineering and MEMS devices, due to the development of advanced materials. This technologycan be divided intothe scanning(SSL) and projection (PSL) types. In this paper, in stereolithography, parts are fabricated by curing photopolymeric resins with light. The application of stereolithography can now include fabricated parts. This process, called stereolithography, can fabricate parts by taking into account theirdegrees of geometry complexity. In particular, UV-LED stereolithography can perform quite rapid fabrication in which specific cross-sections are cured upon exposure to light.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.47-50
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• 2005

In this study, micro mirror array for small form factor optical pick-up was replicated by micro UV-molding. First, mold for micro mirror array was fabricated using micromachining. Also, to analyze the characteristics of the surface quality, flatness of replicated mirror surface were measured by white light scanning inteferometry system. The results show that the micro mirror array with a sufficient surface quality can be obtained by polymer replication process.

• 대한화장품학회지
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• 제41권3호
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• pp.279-285
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• 2015

여성의 얼굴에 과색소침착이 발생하는 것은 불안감, 특히 미적인 요소에 있어서 많은 고민을 유발한다. 피부의 흑화는 자외선(UV)에 대하여 이를 방어하기 위한 기작으로 멜라닌의 양과 밀접한 관계가 있다. 이러한 피부의 구성성분을 관찰하기 위해, confocal scanning laser microscope (CSLM)은 피부에 직접 현미경 검사를 실시하여 어떠한 조직의 변화 없이 피부를 실시간으로 관찰할 수 있는 비침습적 이미지 장치이다. 본 연구에서는 자외선 조사를 통해 유도된 하박 내측 피부의 과색소침착을 유도하여, 다른 피부색을 평가하는 측정기기와 상관성을 분석하여, CSLM을 이용한 새로운 미백 평가방법을 제시하였다. CSLM을 활용한 미백 효능 평가법은 소비자가 보다 이해하기 쉽도록 미백 제품을 평가하는데 유용할 것으로 생각된다.

• 한방안이비인후피부과학회지
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• 제16권2호
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• pp.57-77
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• 2003

Objectives: The aim of this study was to investigate the depigmentation effects of Barley, Unpolished rice, Job's-tear. Metbods: We investigated that the extracts of Barley, Unpolished rice, Job's-tear inhibit activity of tyrosinase, the enzyme which convert ts 3-(3,4-dihydroxyphenyl) alanine to dopachrom in the biosynthetic process of melanin, the UV absorbance of the extracts in the UV-A region and UV-B region was measured by UV scanning, the effect of extracts on cell viability and melanin production in cultured B16 mouse melanoma cells were measured, and cytoprotective effects of extracts on PC12 cells injured by hydrogen peroxide measured by MTT assay. Results: The extracts of Barley, Unpolished rice, Job's-tear inhibited activity of tyrosinase in low density. The Barley, Job's-tear extracts not only showed inhibitory effects on melanin production in cultured B16 mouse melanoma cells, but also exhibited cytoprotective effects on PC12 cells injured by hydrogen peroxide in low density. Unpolished rice extract showed inhibitory effect on melanin production in cultured B16 mouse melanoma cells, but did not showed cytoprotective effect Barley, Unpolished rice, Job's-tear extracts did not showed an absorbance effect in the UV-A region and UV-8 region. Conclusions: These results suggest that Barley, Unpolished rice, Job's-tear inhibit melanin biosynthesis which is involved in hyperpigmentation and could be used as a whitening agent.