• Korean Journal of Materials Research
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• v.19 no.6
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• pp.313-318
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• 2009

Polymer Light Emitting Diodes (PLEDs) with an ITO/PEDOT:PSS/PVK/PFO-poss/LiF/Al structure were prepared on plasma-treated ITO/glass substrates using spin-coating and thermal evaporation methods. The annealing effects of the PFO-poss film when it acts as the emission layer were investigated by using electrical and optical property measurements. The annealing conditions of the PFO-poss emission film were 100 and $200^{\circ}C$ for 1, 2 and 3 hours, respectively. The luminance increased and the turn-on voltage decreased when the annealing temperature and treatment time increased. After examining the Luminance-Voltage (L-V) properties of the PLED, the maximum luminance was found to be 1497 cd/$m^2$ at 11 V for the device when it was annealed at $200^{\circ}C$ for 3 hours. The peak intensity of the PLED emission spectra at approximately 525 nm in wavelength increased when the annealing temperature and time of the PFO-poss film increased. These results suggest that the light emission color shifted from blue to green.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.6
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• pp.305-310
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• 2009

$TiO_2$ thin films consisting of positively charged poly (diallyldimethylammonium chloride) (PDDA) and negatively charged titanium (IV) bis (ammonium lactato) dihydroxide (TALH) were successfully fabricated on a poly (methyl methacrylate) (PMMA) by layer-by-layer (LBL) self-assembly method. By the measurement of quartz crystal microbalance (QCM), it was found that as the solution pH of TALH decreased, the deposition volume of TALH increased and the thickness of (PDDA/TALH) thin film coated on the surface of PMMA particles increased. The PMMA particles coated with the coating sequence of (PDDA/TALH)n showed the variation of color changes as a function of the number of bilayer. The number of bilayer (n) of (PDDA/TALH) thin films was 10 and 20, the values of $a^*$ and $b^*$ decreased from those of PMMA particles without coating films and the color changes was shifted to green and blue direction in the $a^*$, $b^*$ chromaticity diagram. And then, the number of n increased to 30 and 40, the values of $a^*$ and $b^*$ increased and the color changes was shifted to red and yellow direction, respectively. Finally the PMMA particles coated with $(PDDA/TALH)_{50}$ thin film showed a little same value of $a^*$ and $b^*$ with the PMMA particles without (PDDA/TALH) thin film.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.96-104
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• 2008

In this study, the observation of test pieces with an optical microscope was carried out after fabricating 4 groups of standard lacquer, in order to inquire into the ancient lacquering techniques. Group I had transparent reddish brown color, and the part of layer was indefinite, and the layer polished was easily distinguished. Group II had mostly transparent yellowish brown color, and it was possibility distinguished the layers when they were varnished with mixed lacquer after prime coating, and when they were varnished with lacquer as the prime coating. Group III set up membrane in the hardening process of the lacquer, and the lacquer and the unsaturated fatty acid of internal part was dried, so the top layer and the lacquer layer were separated and observed. Group IV: When the lacquer coat film of Group IV test pieces were observed in polarized light, the ferrous components were seen as the black and red color were mixed, and the silica crystals of silty soil were distinguished by reflection of lights. And the colors were distinguished as the lacquer layer of ruddle had red color, and the mixed lacquer of reddish lacquer and ruddle had the deep red color at the top and the bottom, but the middle part had the bright red color.

• Journal of the Korean Wood Science and Technology
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• v.17 no.1
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• pp.12-21
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• 1989

This experiment was executed to investigate the characteristics of gloss and color difference in coated films by N.C. Lacquer, Aminoalkyd, Polyester. and Polyurethan coating after chemical (distilled water, ethyl alcohol. acetic acid, and sodium hydroxide) and heating ($120^{\circ}C$) treatments, cold-check test, and U.V. radiation. The results obtained were summarized as follows 1. The gloss decreasing rate by water resistance test was the least among chemicals treated on coated films. 2. The color difference of coated films chemical treatments highly and similarly increased, except the alkali treatment showing a little increase. 3. In the color difference by U.V. radiation, the polyester coated film showed generally large difference compared with the other coated films.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.1
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• pp.47-58
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• 2000

Transmittances of SiO2 and ZrO2 thin films, made by the electron beam evaporation method, were measured with a spectrophotometer to be used in determining their optical constants and thicknesses in the envelop method. New color glass lenses with high transmittance, which now can be manufactured in the industry, was successfully designed by using these constants. Also the vacuum evaporator could be mechanically corrected with these constants as correction factors.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.1
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• pp.51-56
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• 1999

$TiO_2$ thin films were spin coated on commercial Nickel-Silver with 2%Ti-naphthanate toluene solution by sol-gel process. The thin films were heat-treated at $500^{\circ}C$ for 2min and then decorative-protective coating was obtained. The conditions for gold colored coating, and the morphology, microstructure and color of the coating surface were have been characterized by Optical microscope, Photospectrometer and XRD. The heating temperature of colored-$TiO_2$ coating was $500^{\circ}C$ and was preferable. The average thickness of 1 time coating was $0.24{\mu}m$ and the total thickness increased linearly as a function of the coating time. The color of amorphous colored-$TiO_2$ coating was changed from gold to dark redish gold with coating time. 'L' as lightness and 'b' were decreased to red, but 'a' was decreased to blue after increase with coating time.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.480-486
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• 2008

In this study, Yukwa(YU-G) was prepared by coating in syrup with water-soluble extracts of Gugija(Lycii fructus). The Yukwa samples were stored with PE film packing with air for 12 weeks at room temperature, after which the quality and shelf-life of the Yukwa were assessed. During storage, the moisture contents of YU-G were higher than those of the Yukwa due to being coated in syrup without water-soluble extracts of Gugija(YU-NG), whereas the instrumental textural hardness values of the YU-G were lower than those of the YU-NG. Color determination indicated that YU-NG and YU-G assumed a darker color after storage, becoming both redder and yellower. The peroxide and acid values increased abruptly in the YU-NG during storage, but increased slowly in the YU-G. During the 12 weeks of storage after preparation, the peroxide and acid values of YU-G remained at less than 40 meq/kg and 4 KOH mg/g, respectively. Thus, the experimental method of syrup coating with water-soluble extracts of Gugija rendered the YU-G fairly stable against fat rancidity. The YU-G evidenced generally higher overall acceptability than YU-NG when stored.

• Journal of Mechanical Science and Technology
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• v.17 no.11
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• pp.1704-1713
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• 2003

Point contact film thickness in elastohydrodynamic lubrication (EHL) is analyzed by image processing method for the images from an optical interferometer with monochromatic incident light. Interference between the reflected lights both on half mirror Cr coating of glass disk and on super finished ball makes circular fringes depending on the contact conditions such as sliding velocity, applied load, viscosity-pressure characteristics and viscosity of lubricant under ambient pressure. In this situation the film thickness is regarded as the difference of optical paths between those reflected lights, which make dark and bright fringes with monochromatic incident light. The film thickness is computed by numbering the dark and bright fringe orders and the intensity (gray scale image) in each fringe regime is mapped to the corresponding film thickness. In this work, we developed a measuring technique for EHL film thickness by dividing the image patterns into two typical types under the condition of monochromatic incident light. During the image processing, the captured image is converted into digitally formatted data over the contact area without any loss of the image information of interferogram and it is also interpreted with consistency regardless of the observer's experimental experience. It is expected that the developed image processing method will provide a valuable basis to develop the image processing technique for color fringes, which is generally used for the measurement of relatively thin films in higher resolution.

• Animal Bioscience
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• v.37 no.1
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• pp.123-130
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• 2024

Objective: Beef of Jeju black cattle (JBC) is considered as a healthy meat type due to its significantly higher unsaturated fatty acids (UFA). Lipid (e.g., UFA) is highly susceptible to oxidizing agents, which results in the quality deterioration and economic value loss of meat products. Therefore, development and application of novel preservative techniques is necessary to improve the shelf-life stability of high-UFA beef. The objective of this study was to assess the applicability of chitosan-based coatings in preservation of JBC beef. Methods: Different coating solutions: 2% chitosan alone, and 2% chitosan containing 0.1% or 0.3% gallic acid were prepared to investigate their applicability in preservation of fresh beef during storage. Jeju black cattle beef (2-cm thick steaks) were non-coated (control) or coated with the above coating solutions, placed on trays, over-wrapped with plastic film and stored at 4℃. The microbiological indices, color, total volatile basic nitrogen (TVBN) and lipid oxidation of the beef were investigated after 1, 10, and 21 days of storage. Results: Coating with 2% chitosan alone reduced the spoilage bacteria count, TVBN and thiobarbituric acid reactive substances levels in the beef compared with control during storage (p<0.05). Noticeably, coating with 2% chitosan containing 0.1% or 0.3% gallic acid was more effective on retardation of spoilage bacteria growth, lipid oxidation and discoloration in the beef compared to the chitosan coating alone over the storage period (21 days) (p<0.05). Conclusion: Taken together, the combined chitosan and gallic acid coating could be used as a bio-preservative technique in the meat industry.

• Journal of the Korean institute of surface engineering
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• v.25 no.3
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• pp.133-143
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• 1992

Titanium nitride(TiN) films have been prepared by HCD plasma enhanced reactive ion plating. Density and temperature of the plasma generated by the HCD were investigated. It was shown that parameters such as the substrate bias voltage(0 350V) and N2 flow rate(10 180SCCM) influenced the growth, the growth, the microstructure and the color tone of the film mostly. In order to study the interface region, surface analysis by AES combined with sputter depth profiling was performed. Microhardness of the coated TiN films were measured by micro Vickers hardness tester. Also, the effect of coating parameters on composition, coating surface and fracture morphology, grain size and growth rate were examined.