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        검색결과 196

        82.
        2009.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The coffee has been used as drink in the world and it has been using not only food but also dyeing. It can be used for four seasons in our normal living and it can be taken friendly everywhere. The coffee consists of about 8~10% phenol(chlorogenic acid) that related to antioxidant and antimicrobial activity. However, its exact components and the dyeing property effects has not been well known yet. Therefore, the purpose of this study was to investigate the dyeing property and ultraviolet-cut ability of silk and nylon fabrics that was dyed variously with coffee extracts. Coffee extracts were done by boiling coffee with distilled water at 100℃ for 2 hours. As mordanting agent, we used AlK(SO4)2․12H2O, CuSO4․5H2O, FeCl2․4H2O. As the result of the dyeing properties and ultraviolet-cut ability of fabrics dyed with coffee bean extracts, we can find that the optimum dyeing temperature and dyeing time of the silk and nylon fabrics dyed with coffee bean extracts was 90℃, 60 min. and the colorfastness of washing and dry-cleaning was improved by using mordanting agent(4~5 grade). Ultraviolet-cut ability was showed more 90% in dyed nylon fabrics.
        4,000원
        83.
        2009.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        자외선 살균소독기의 유효성을 검정하기 위하여 스테인리스스틸 컵 바닥에서 E. coli를 대상으로 살균력을 측정하고 살균패턴을 조사하였다. 스테인리스스틸 컵 바닥의 자외선 강도는 컵의 위치에 따라 큰 차이를 보였다. 중앙부에 놓인 컵의 바닥에서는 높은 자외선 강도를 보인 반면 외곽으로 갈수록 자외선 강도는 급격하게 약화되었으며, 이러한 편차는 상단 선반에서 가장 심하였고 중단 및 하단 선반으로 갈수록 완화되었다. E. coli를 대상으로 한 스테인리스스틸 컵 바닥에서 살균효과는 컵 바닥의 자외선 강도와 살균시간에 비례하였다. 자외선에 의한 E. coli 살균패턴은 tailing을 수반하는 의사 1차반응으로 나타났으며 각 구간의 살균속도상수를 산출한 결과 초기 살균속도상수(K1)는 위치에 따라 큰 차이를 보인 반면 후기 살균속도상수(K2)는 위치에 따른 차이가 크지 않았다. 현장에서 자외선 살균소독기를 용이하게 사용할 수 있도록 일정 살균치를 얻는데 필요한 자외선 조사시간을 산출하는 방정식을 제시하였다.
        4,000원
        84.
        2008.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        ZnO/ZnS core/shell nanocrystals (~5-7 nm in diameter) with a size close to the quantum confinement regime were successfully synthesized using polyol and thermolysis. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) analyses reveal that they exist in a highly crystalline wurtzite structure. The ZnO/ZnS nanocrystals show significantly enhanced UV-light emission (~384 nm) due to effective surface passivation of the ZnO core, whereas the emission of green light (~550 nm) was almost negligible. They also showed slight photoluminescence (PL) red-shift, which is possibly due to further growth of the ZnO core and/or the extension of the electron wave function to the shell. The ZnO/ZnS core/shell nanocrystals demonstrate strong potential for use as low-cost UV-light emitting devices.
        4,000원
        85.
        2008.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        For possible applications as luminescent materials for white-light emission using UV-LEDs, Ba2Mg(PO4)2:Eu2+ phosphors were prepared by a solid state reaction. The photoluminescence properties of the phosphor were investigated under ultraviolet ray (UV) excitation. The prepared phosphor powders were characterized to from a single phase of a monoclinic crystalline structure by a powder X-ray diffraction analysis. In the photoluminescence spectra, the Ba2Mg(PO4)2:Eu2+ phosphor showed an intense emission band centered at the 584 nm wavelength due to the f-d transition of the Eu2+ activator. The optimum concentration of Eu2+ activator in the Ba2Mg(PO4)2 host, indicating the maximum emission intensity under the excitation of a 395 nm wavelength, was 5 at%. In addition, it was confirmed that the Eu2+ ions are substituted at both Ba2+ sites in the Ba2Mg(PO4)2 crystal. On the other hand, the critical distance of energy transfer between Eu2+ ions in the Ba2Mg(PO4)2 host was evaluated to be approximately 19.3 A. With increasing temperature, the emission intensity of the Ba2Mg(PO4)2:Eu phosphor was considerably decreased and the central wavelength of the emission peak was shifted toward a short wavelength.
        4,000원
        86.
        2008.09 구독 인증기관 무료, 개인회원 유료
        Anti-wrinkle effect of herbal extracts was investigated on the skin of in a model of animal irradiated by ultraviolet rey B (UVB). The female albino hairless mice (HR/ICR) were randomly allocated to the normal control group (NC-non irradiated-vechicle), positive control group (PC, UVB irradiated vehicle) and herbal extract (HE) group. The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunbert, Phellinus linteus, and Phaseolus radiatus. The herbal extract was treated dorsally with 0.2 ml per mouse five times a week for 12 weeks. At fifth week of the treatment, the animals were exposed to UVB irradiation for subsequent eight weeks three times a week. The intensity of irradiation was gradually increased from 30 mJ/㎠ to 240 mJ/㎠ (1MED: 60 mJ/㎠). Dorsal skins were obtained and stained with H&E to examine histological changes and epidermal/dermal thckness. The collagen fiber was also observed in Masson-Trichrome staining. Hydroxyproline assay and western blot analysis were also carried out to detect the change of collagen amount and to investigate MMP-1 expression, respectively. The HE group showed a better appearance and weak wrinkling, compared to PC group, The treatment of herbal extract significantly increased the thickness of dermis and the amount of collagen fibers compared to PC group (p<0.05). The treatment of HE significantly increased the hydroxyproline amount compared to PC group (p<0.05). The chronic UVB irradiation to hairless mice skin increased expression of MMP-1 but the treatment of HE decreased the expression of MMP-1. These results indicate that the herbal extract used in this study have a preventive effect on the UVB-induced wrinkle in a hairless mice model, partly due to the reduction of MMP-1 expression and increment of collagen amount.
        4,000원
        89.
        2008.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Green-emitting Ba1.468Sr0.5SiO4 : Eu0.012, Y0.02 phosphor powders under long-wavelength ultraviolet light were prepared via high-temperature flame spray pyrolysis from spray solutions with and without NH4Cl flux. The effects of the temperature of the diffusion flame and the NH4Cl flux on the morphologies, crystal structures and photoluminescence intensities of the Ba1.468Sr0.5SiO4 : Eu0.012, Y0.02 phosphor powders were investigated. The phosphor powders obtained from the spray solution with the NH4Cl flux had higher photoluminescence intensities compared to phosphor powders obtained from the spray solution without the flux. The photoluminescence intensity of the phosphor powders obtained from the spray solution without the flux decreased as the flow rate of the fuel gas increased. On the other hand, the photoluminescence intensity of the phosphor powders obtained from the spray solution with the flux increased as the flow rate of the fuel gas increased. The difference of in the phase purity and morphology of the powders affected the photoluminescence intensities of the phosphor powders.
        4,000원
        91.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 Bulk형 플라스틱과 유리 조광렌즈, 박막형 플라스틱 조광렌즈를 이 용하여 온도를 6 0C 에 서 UVA, UVB, UVC을 각각 조사하여 자외 선 파장에 따라 조 광렌즈의 변색전을 기준으로 조광렌즈의 색차에 대한 분석을 위하여 lN꺼Tis Spectrophometer로 조사시간을 다양하게 하여 측정하였다. Bulk형 플라스틱 조광렌 즈의 경우 6 0C 의 UVA에서 색상변화가 가장 크고, UVC 에서 가장 작았다. 유리조광 렌즈인 SINbr는 온도의 변화에 무관하게 색상변화가 거의 없었다. Bulk형 유리조광 렌즈의 눈에 띄는 감각정도는 광원과 온도에 관계없이 Slight에 해당하였다. Brown 색상이 Smoke 색상보다 온도와 광원에 무관하게 색상변화가 더 컸다. 광원에 따른 색상변화는 UVC에서 가장 작았다.
        4,000원
        95.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to estimate the UV-A ray line 's cut rate and sensitivity in color lens, it was measured the light transmittance in the 320-700 nm wavelength regions. W e obtained the area to integrate the light transmittance of standard lens and sample in the 320-400 nm wavelength regions and established a, ~ of UV-A line' s cut efficiency by contrast its area. The Eye sensitivity in the difference conditions of a light source intensity consists of two functions by the receptor of cone and rod according to a wavelength. Transmission light which permeate depends on absorption wavelength, and relationship of final luminous efficiency' s estimation method is expressed by multiplication of luminous efficiency and transmittance intensity of lens. P/ = T(A) · P(A) About R · Y · G · B color, applied photopic and scotopic that is luminous efficiency
        4,000원
        96.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
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