• Journal of Adhesion and Interface
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• v.15 no.3
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• pp.116-122
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• 2014

This work deals with the effects of different oligomers, monomers, photoinitiators, and steel plates on the variation of gloss for UV coated steel plates at $20^{\circ}$ and $60^{\circ}$ (ASTM D523). The gloss value was more significantly varied with $20^{\circ}$ angle as compared with $60^{\circ}$. No substantial change in gloss was observed for the type of single oligomer; however, the gloss varied with the mixing ratios of oligomers, type and mixing ratio of monomers, type and concentration of photoinitiator, and type of steel plate. The maximum gloss value was observed when the mixing ratio of polyurethane acrylate (UA) to epoxy acrylate (EA) was 70 : 30, the mixing ratio of trimethylolpropantriacrylate (TMPTA) to tetrahydrofurfurylacrylate (THFA) was 5 : 5, the content of the mixed oligomer (UA : EA = 70 : 30) was 90 wt%, respectively. Darocur MBF of liquid type showed better gloss property than the solid type of Irgacure 184, and the gloss was decreased as the concentration of Darocur MBF increased from 1 to 4 wt%. Regarding the type of steel plate, GI steel plate showed better gloss property as compared with EG and primer-coated steel plates. The maximum gloss values of 95 GU and 120 GU, respectively, at $20^{\circ}$ and $60^{\circ}$ angles throughout the parametric study in the absence of leveling agents enhancing the gloss.

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.155-160
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• 2013

Research on mutant generation and isolation for microalgae yielding enhanced lipid accumulation is an important issue for the production of economic biodiesel. In the present study, ultraviolet (UV-B type) ray induced mutant generation was tried using a photosynthetic microalgae, Nannochloropsis oculata (N. oculata), for the production of biodiesel. The resulting colonies were isolated and further cultured with both liquid and solid state f/2 media. After a few week cultivation, changes of cell growth rate, dry cell weight, and several important intracellular components (chlorophyll, carotenoid, and lipid) were investigated. Two mutants among thousands colonies showed an increased cell growth and high lipid accumulation as compared to those of wild type. It was also observed that the increased cell growth rate is associated with the overexpressed intracellular proteins. However, the mutants showed a decrease in the chlorophyll biosynthesis.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.108-108
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• 2011

공동주택에서 2025년 정부가 추진하고 있는 Zero Energy 건축물 구현과 친환경에 대한 탄소배출 저감 문제로 재생에너지 생산시스템의 추가 적용은 반드시 필요하다. 따라서 공동주택 적용 및 활용성을 높일 수 있는 BIPV시스템 개발을 통하여 설치면적 확보와 세대 활용성을 높일 수 있도록 하는 것이 필요하다. 특히 거실 창호의 경우 주방향이 남향, 남동 또는 남서향으로 배치되어 태양광을 적용하기에 적합한 특성을 가지고 있다. 그러나 창호는 건물외피의 역할과 재실자가 조망과 정보취득을 얻을 수 있는 중요한 통로가 되기 때문에 단열 문제나 시야 차폐의 문제는 발생하지는 않도록 하는 것이 필요하다. 본 연구에서는 a-si타입 모듈 2개를 10% 투과율로 Bsck Coating 색상을 달리한 모듈과 c-si BIPV 모듈을 커튼월 창호시스템으로 개발, 일반 2중 창호시스템과 비교 평가를 위해 실제 Test bed 건물에 시공하여 시환경 및 실내 창측면 온도변화 측정 분석을 진행하였다. 현재 국내외 출시되고 있는 a-si see through 모듈은 10~30%의 투과율로 창 마감재로 대체가 가능하나 건축 환경(시환경,열환경)에 대한 분석은 전무한 상태이다. 본 연구에서는 시환경과 창유리면의 열 부하, 자외선, 적외선 차폐 및 가시광선의 투과율에 대한 평가와 Back Coating에 따른 색온도 평가를 통해서 a-si BIPV의 공동주택 세대 발코니 창호 적합성에 대한 검토를 진행하였다. 연구결과는 아래와 같다. ${\bullet}$ 실내조도는 청천공 정오기준 가시성 확보 모듈의 경우 2,300 ~ 3,500lx를 나타내고 있어 대비 현상이나 창측의 급격한 조도 변화가 적은 시환경 구축이 가능 ${\bullet}$ 12시경 휘도는 창측면, 실내 벽체, 코너 바닥면을 대상으로 a-si BIPV 모듈을 적용한 경우 휘도비가 12:1로 KS나 IESNA의 광원과 근접면의 비 20:1 범위에 모두 존재, 적합한 것으로 분석되었으나 c-si의 경우는 그림자로 인한 대비 현상이 발생, 작업 시환경 문제 발생. ${\bullet}$ 이중시스템 창호와 비교하여 단열 성능 떨어짐. 발전시간대 창유리 면 온도 상승 으로 하절기 냉방부하 증가. ${\bullet}$ 자외선은 100% 가까이 차단, 적외선은 13~42%만 투과되고 가시광선은 13% 투과율을 나타내어 일반 창에 칼라 코팅을 적용하는 것과 유사한 경향을 나타냄.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.3
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• pp.45-50
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• 2005

A UV camera is being used in various application regions such as industry, medical science, military, and environment monitoring. A ROIC(ReadOut IC) is developed and can read the responses from UV photodiode sensors which are made with III-V nitride semiconductors of GaN series haying high resolution and high efficiency. To design FPA(Focal Plane Array) UV $8{\times}8$ ROIC, the photodiode type sensor devices are modeled as the capacitor type ones. The ROIC reads out signals from the detector at)d outputs sequentially pixel signals after amplifying and noise filtering of them. The ROIC is fabricated using the $0.5{\mu}m$ 2Poly 3Metal N-well CMOS process. And then, it and photodiode array are hybrid bonded by gold stud bumping process using ACP(Anisotropic Conductive Paste). After the packaging, UV images appearing on PC verified the operations of the ROIC.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.199-208
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• 2019

This study reports water-resistant oil-in-water (O/W) emulsion-based sunscreening formulations prepared using a poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG) triblock polymeric surfactant. As a result of a variety of outdoor recreational activities such as swimming and hiking, consumer needs for development of advanced water-resistant sunscreen formulations are increasing. Water-resistant sunscreens are mostly based on water-in-oil (W/O) emulsions, because they should not be wiped off by water or sweat. However, the W/O emulsion formulations have a disadvantage in that the feeling of use is oily and difficult to remove. On the other hand, the O/W emulsion formulations are excellent in achieving the better skin feel as well as the easier removal. However, it is difficult to provide the O/W emulsion formulations with the water-repelling performance, since re-emulsification likely occurs upon getting touch with water. To solve this problem, this study proposes a O/W emulsion-based sunscreen formulation, a triblock polymeric surfactant having relatively high interfacial tension HLB value (~ 10). This allows the sunscreen formulations to exhibit the improved water repellence function by preventing their re-emulsification. The sunscreen formation system prepared in this study would be useful for diversification of functional sunscreen products, taking advantages of its excellent emulsion stability, UV protection performance, long lasting water-resistant function and selective cleansing effect with only foam cleanser.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.5
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• pp.395-406
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• 2015

The Ballast Water Treatment System was developed to prevent the unintended transport of unwanted organisms from one region to another as demanded by the IMO (International Maritime Organization). Although various types of BWTS in the world have been developed until now and applied to various ships, there has been no systematic basis for its selection and installation. Currently, the system selection and installation are as per ship owner’s suggestion or by easy installation point of view by the shipyard. In order to organize, systemize and solve problems related to the selection and installation of BWTS, a definitive study has been performed to come up with the best alternative to derive value and criteria which were to be met for vessels which are to be equipped with BWTS. Multiple criteria were compared alongside each other during the course of this study. Accordingly an AHP (Analytic Hierarchy Process) analysis method for A, B and C companies were done for container ships with size 10,000 TEU and above. Equipment type for “A” company is “Filter, UV & TiO2” combined type. For “B” company it is “Filter & UV” combined type. Finally for “C” company it is “Electrolysis” type. Henceforth, the results of this study aims to come up with the optimum way to select the best and the most suitable BWTS for a certain vessel.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.317-323
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• 2009

Chronic exposure of solar ultraviolet (UV) light to human skin results in photoaging with wrinkle formation. This study was performed to investigate anti-wrinkle effects of Lindera obtusiloba extract (LO) on UVB-induced wrinkle formation. We first measured cell proliferation and type I pN collagen synthesis activities in normal human dermal fibroblasts. Cell proliferation and type I pN collagen synthesis were increased by 33.8 % and 91.8 %, respectively, compared with no treatment control. SKH-1 hairless mice were topically applied 5 % LO solution for 10 weeks with UVB irradiation three times a week. After 10 weeks, a visual assessment and replica assay were performed on each mouse. According to visual assessment of close-up photos and skin replica, application of 5 % LO solution inhibited UV-induced wrinkle formation in mouse skin as compared to the vehicle-applied control mice. These results indicated that LO could protect skin wrinkle formation caused by chronic photo-irradiation in hairless mice.

• Journal of Life Science
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• v.28 no.5
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• pp.524-531
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• 2018

The essential oil from Abies koreana E.H. Wilson had been developed, however, its efficacy has not yet been studied especially in terms of skin care research. The aim of this study is to investigate the effects of Abies koreana extracts (AKE) on melanogenesis and wrinkle formation in B16F10 melanoma cells (B16F10) and human dermal fibroblast cell line (HDF). The essential oil was extracted by hydrodistillation method and purified by anhydrous sodium sulfate. At a concentration of $10^{-5}$-fold, viability in these cells had been defined by cytotoxicity assays. Anti-melanogenic effects on B16F10 were evaluated using tyrosinase inhibition assay, and real-time PCR for verifying gene expression of tyrosinase, tyrosinase related protein-1 and -2 (TRP-1 and -2). AKEs reduced about 5-fold of tyrosinase inhibitory activity compared to ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH)-induced group and about 30% reduction compared to Arbutin induced group. The mRNA levels of three melanin-related factors were increased, separately. To investigate the effects of anti-wrinkle, procollagen type I c peptide synthesis assay (PIP) and Western blot were performed. At AKE-treated group, PIP was up-regulated and the expression of collagen type 1 and matrix metalloproteinase (MMP)-1 were improved. Furthermore, AKE presented anti-wrinkle effects by increasing UVB-inhibited collagen type 1 expression, and reducing UVB-induced MMP-1 production at $60mJ/cm^2$ of UVB radiation. Therefore, Abies koreana extracts has potentials as a safe and an effective skin ingredient for whitening and anti-wrinkle.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.279-287
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• 2014

Estrogen deficiency results in a reduction of skin quality and function in postmenopausal women. Over the past decade, many studies have supported that estrogen provides anti-aging effects as a result of the ability of estrogen to prevent skin collagen decline, restore skin elasticity, and increase skin hydration in postmenopausal women skin. Due to their structural similarity with estrogen, isoflavones have been called phytoestrogens. Photoprotective effects of isoflavones are well established while their estrogenic-like activities are not fully understood in human skin. In this study, we investigated whether daidzein, an effective isoflavone, has phytoestrogenic activity and induces transcriptional change of extracellular matrix components in dermal fibroblasts. We examined the luciferase activity of daidzein and ${\beta}$-estradiol using transiently transfected NIH3T3-ERE cells. The estrogenic receptor-dependent transcriptional activity was increased in a dose-dependent manner when treated with daidzein, with a maximum of 2.5-fold induction at $10{\mu}g/mL$ of daidzein compared with non-treated control. In addition, daidzein significantly in creased the expressions of collagen type I, collagen type IV, elastin, and fibrillin-1 in human dermal fibroblasts. By comparing with the effects of ${\beta}$-estradiol through out all the experiments, we confirmed that daidzein had estrogenic activity and function in fibroblasts. These results suggest that daidzein-based application, having both photoprotective and phytoestrogenic effects, may be a powerful approach for skin anti-aging of postmenopausal women.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.694-696
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• 2010

We have synthesized boron (or phosphorous) doped silicon nanoparticles (Si-NPs) by a solution process. The surfaces of the Si-NPs were terminated with various alkyl groups to form a protecting layer. The Si-NPs were characterized by UV-Vis, PL, FTIR, and NMR. Through a microwave sintering process, the crystalline thin films of the Si-NPs were prepared by removing the surface alkyl groups. The TEM and SEM images reveal that contiguous films as large as $200{\mu}m$ in diameter were formed with a cubic structure. The electrical conductivity of the Si film was controlled by a doping type.