• Elastomers and Composites
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• v.50 no.2
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• pp.81-86
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• 2015

In this study, natural rubber latex foam was prepared in order to replace commercialized polyurethane foams as a car seat material. Physical properties of the latex foam were investigated and the light stability was improved. The latex foam was mixed in an aqueous solution state, and the degree of foaming and the accelerator ratios were appropriately controlled. Tensile properties, hysteresis and dynamic mechanical properties of the latex foam were measured to compare with those of polyurethane foams. UV light absorbers and radical scavengers were added for improving light stability of the latex foam. Xenon lamp test was conducted to investigate the effects of the reagents on light stability. Our results revealed that the prepared latex foam including a light absorber with an antioxidant showed excellent light stable performances.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.506-512
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• 1998

In order to replance systhetic colors by natural colors as food additive, properties of Gardenia yellow color and Gardenia blue color were compared with Food yellow No. 4 and Food blue No. 1. Color differeance between Food yellow No. 4 and Gardenia yellow color was 7.55. Thermal stability of Food yellow No. 4 was above 99%. On the other hand, in case of Gardenia yellow color, showed adove 90% of residual color units in 8$0^{\circ}C$$\times$30min and 10$0^{\circ}C$$\times$30min at pH 7.0 but 75% in 121$^{\circ}C$$\times$15min. Difference of light stability between Food yellow No. 4 and gardenia yellow color was about 18%. Addition of ascorbic acid was increased about 6% in light stability. Color difference between Food blue No. 2 and Gardenia blue color was 107. Thermal stability of Food blue No. 2 was above 99%. But Gardenia blue color showed 92% of residual color units in 8$0^{\circ}C$$\times$30min and 10$0^{\circ}C$$\times$30min at pH 7.0 but 90% in 121$^{\circ}C$$\times$15min. Difference of light stability between Food blue No. 4 and Gardenia blue color was about 8%. Addition of -tocopherol was increased about 4% in light stability of Gardenia blue color.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.441-452
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• 1996

The effects of chlorophyll, tocopherols($\alpha$-tocopherol, ${\gamma}$-tocopherol and $\delta$-tocopherol), carotenoids ($\beta$-carotene and lutein), light sources, light intensities and strage temperatures on the photooxidative stability of soymilk were studied by measuring TBA value and depleted headspace oxygen(DHO) of soymilk. The samples were stored in the light storage box for 6 days and evaluated for the photooxidative stabilities. As the concentrations of chlorophyll increased, TBA value and DHO of the sample increased significantly(p<0.05), indicating chlorophyll acting as a photosensitizer. However, as the concentrations of tocopherols ($\alpha$-tocopherol, ${\gamma}$-tocopherol and $\delta$-tocopherol) and carotenoids ($\beta$-carotene and lutein) increased, TBA values and DHO of the samples decreased significantly(p<0.05). The light screening effects of carotenoids on DHO in the samples were not significantly different from the control at p>0.05. Therefore, there was no light screening effects of carotenoids on the oxidative stability of soymilk. The results indicate that tocopherols and carotenoids reduce the photooxidative stability of soymilk. $\delta$-Tocopherol was the most effective in photosensitized oxidation followed by ${\gamma}$-and $\alpha$-tocopherols in the order of increasing stability. $\beta$-Carotene was significantly(p<0.05) more effective than lutein in minimizing the chlorophyll-sensitized photooxidation of soymilk. Visible light was more effective than UV light in decreasing the photooxidative stability of soymilk. Therefore, photooxidation of soymilk containing chlorophyll is mainly due to photosensitized oxidation rather than photolysis reaction. As the intensities of fluorescence light increased, TBA values and DHO of the samples increased significantly at P<0.05. However, as the storage temperatures increased, TBA values and DHO of soymilk did not change significantly at p>0.05.

• ETRI Journal
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• v.31 no.1
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• pp.62-64
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• 2009

We report on the bias stability characteristics of transparent ZnO thin film transistors (TFTs) under visible light illumination. The transfer curve shows virtually no change under positive gate bias stress with light illumination, while it shows dramatic negative shifts under negative gate bias stress. The major mechanism of the bias stability under visible illumination of our ZnO TFTs is thought to be the charge trapping of photo-generated holes at the gate insulator and/or insulator/channel interface.

• Journal of Environmental Science International
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• v.1 no.2
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• pp.69-80
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• 1992

Effects of light on leaf senescence of Phseolus vulgaris were investigated by measuring the disassembly of chlorophyll-protein complexes in detached leaves which had been kept in the dark or under light. The loss of chlorophyll accompanied by degradation of chlorophyll- protein complexes. PSI (photosystem I) complex containing LHCI (light harvesting complex of PSI) apoproteins was rapidly decreased after the early stage of dark-induced senescence. RC(reaction center)-Cores was slightly increased until 4 d and slowly decreased thereafter. As disassembly of LHCII trimer progressed after the late stage of senescence, there was a steady increase in the relative amount of SC(small complex)-2 containing LHCII monomer. On the other hand, white and red light adaptation caused the structural stability of chlorophyll-protein complexes during dark-induced senescence. Particularly, red light was more effective in the retardation of LHCII breakdown than white light, whereas white light was slightly effect in protecting the disassembly of PSI complex compared to red light. These results suggest, therefore, that light may be a regulatory factor for stability of chlorophyll-protein complexes in the senescent leaves.

• Journal of the Korean Applied Science and Technology
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• v.26 no.2
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• pp.191-198
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• 2009

We have tested the stability of paeoniflorin, a new cosmetic ingredient, extracted from the roots of Paeoniae lactiflora. The stability of aqueous paeoniflorin solution at pH 3, 5 and 7 varied by adding buffer solution was tested at $0^{\circ}C,\;25^{\circ}C,\;40^{\circ}C,\;and\;65^{\circ}C$. The test was performed with or without UV light. The solution of paeoniflorin was stable at pH 3.0, however, the recovery rate of paeoniflorin was 40% at pH 7.0. The stability of paeoniflorin solution was decreased as the pH of paeoniflorin solution was increased by pH 7.0. The effect of storage temperature of paeoniflorin solution shows that the stability of paeoniflorin solution was decreased as the temperature was increased. The stability of paeoniflorin was rather good under UV light than the condition given above $40^{\circ}C$. The stability of paeoniflorin in W/O emulsions shows similar pattern to that of aqueous solution.

• Journal of the Optical Society of Korea
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• v.4 no.2
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• pp.89-93
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• 2000

Recently a new signal processing algorithm for white light interferometry was presented. In this paper, the proposed signal processing algorithm was applied for absolute temperature measurement using white light interferometry. Stability testing and absolute temperature measurement were demonstrated. Stability test demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe. The test also showed that the absolute temperature measurement system using white light interferometry is capable of obtaining the theoretical minimum detectable change (0.0005 fringe), which is consistent with the performance predicted by the proposed signal processing algorithm.

• Current Photovoltaic Research
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• v.9 no.4
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• pp.145-159
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• 2021

Light soaking (LS) stability in polymer solar cells (PSCs) has always been a challenge to achieve due to unstable photoactive layer-electrode interface. Especially, the electron transport layer (ETL) and photoactive layer interface limits the LS stability of PSCs. Herein, we have modified the most commonly used and robust zinc oxide (ZnO) ETL-interface using an organic dye molecule and a co-adsorbent. Power conversion efficiencies have been slightly improved but when these PSCs were subjected to long term LS stability chamber, equipped with heat and humidity (45℃ and 85% relative humidity), an outstanding stability in the case of ZnO/dye+co-adsorbent ETL containing devices have been achieved. The enhanced LS stability occurred due to the suppressed interfacial defects and robust contact between the ZnO and photoactive layer. Current density as well as fill factors have been retained after LS with the modified ETL as compared to un-modified ETL, owing to their higher charge collection efficiencies which originated from higher electron mobilities. Moreover, the existence of less traps (as observed from light intensity-open circuit voltage measurements and dark currents at -2V) are also found to be one of the reasons for enhanced LS stability in the current study. We conclude that the mitigation ETL-surface traps using an organic dye with a co-adsorbent is an effective and robust approach to enhance the LS stability in PSCs.

• Journal of the Korean Professional Engineers Association
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• v.9 no.1
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• pp.35-39
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• 1976

Possible methods of protection of non cellulosic fibers, particularly nylon filament yarn, from the damaging effects of light are discussed. Manganese acetate, cupricacetate, G1-06-196 and sodium phosphate are used as a light stabilizer for nylon filament yarn. The light stability of filament containing different weight of TiO$_2$ is increased as the following order: Bright>Semi-Dull>Full-Dull The protection effect against light according to the present of the light stabilizer in filament increased in the following order: Manganese acetate> Cupric acid> G1-06-196> Sodium phosphate Manganese acetate is shown to be the most effecting salt for protecting nylon against light. 15 ppm of the salt is shown to be effective enough for protecting nylon filament yarn against light.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1269-1274
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• 2012

A visible light responsive N, Mo co-doped $TiO_2$ were prepared by sol-gel method. X-ray diffraction, TEM, $N_2$ adsorption, UV-vis spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy were used to characterize the prepared $TiO_2$ samples. Doping restrained the phase transformation from anatase to rutile and reduced the particle sizes. The band gap was much narrowed after N, Mo co-doping. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under visible light. The photocatalytic activities of doped $TiO_2$ were much higher than that of neat $TiO_2$. The photocatalytic stability of N, Mo co-doped $TiO_2$ was much better than that of N doped $TiO_2$.