• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.320-320
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• 2016

Nanocrystalline Carbon thin films have numerous applications in different areas such as mechanical, biotechnology and optoelectronic devices due to attractive properties like high excellent hardness, low friction coefficient, good chemical inertness, low surface roughness, non-toxic and biocompatibility. In this work, we studied the comparison of pure DC power and pulsed DC power in plasma sputtering process of carbon thin films synthesis. Using a close field unbalanced magnetron sputtering system, films were deposited on glass and Si wafer substrates by varying the power density and pulsed DC frequency variations. The plasma characteristics has been studied using the I-V discharge characteristics and optical emission spectroscopy. The films properties were studied using Raman spectroscopy, Hall effect measurement, contact angle measurement. Through the Raman results, ID/IG ratio was found to be increased by increasing either of DC power density and pulsed DC frequency. Film deposition rate, measured by Alpha step measurement, increased with increasing DC power density and decreased with pulsed DC frequency. The electrical resistivity results show that the resistivity increased with increasing DC power density and pulsed DC frequency. The film surface energy was estimated using the calculated values of contact angle of DI water and di-iodo-methane. Our results exhibit a tailoring of surface energies from 52.69 to $55.42mJ/m^2$ by controlling the plasma parameters.

• Culinary science and hospitality research
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• v.19 no.1
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• pp.151-163
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• 2013

The purpose of this study was to examine the optimization and quality characteristics of balsamic vinegar jelly by the addition of various gelling agents: agar, gelatin, arrowroot starch, potato starch. For this purpose, mechanical tests(moisture content, color value, pH, sugar content, texture) and sensory tests(quantitative descriptive analysis & acceptance test) were conducted, showing the following results. The moisture content of balsamic jelly was the highest in the gelatin addition group, the color intensity of the L value in the potato starch addition group, redness a value in the gelatin addition group, and the b value(yellowness) in the agar addition group. The pH of balsamic jelly was the highest values in the gelatin addition group while its sugar content was the highest values in the arrowroot starch addition group. As a result of measuring balsamic jelly texture, there were significant differences in hardness, chewiness and gumminess by gelling agents. In the quantitative descriptive analysis of sensory test, the gelatin addition group showed the most high level in purple color intensity, glossiness, transparency, and chewiness. As for the acceptance in the sensory test, the gelatin addition group showed the most high level in appearance, taste, texture, and overall acceptance, which also had a significant difference. In case of balsamic flavor, Arr added arrowroot starch showed the highest values, which also had a significant difference. The result of this study showed that the gelatin addition group made a positive acceptance and improvement of sensory and machinery quality characteristics.

• Culinary science and hospitality research
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• v.15 no.2
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• pp.84-92
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• 2009

Fish patty is a product spotlighted recently in the application area of functional food because its main ingredients are soybean and fish with various functions which make it highly digestible, tasty, rich with protein and calcium, and with low fat. Thus, in order to optimize fish patties, this study analyzed their water content, colors, texture and sensory characteristics according to the addition of soybean powder. As a result, water content and lightness decreased with the increase of the addition of soybean powder while hardness, elasticity, chewiness, and gumminess increased with the increase of the addition of soybean powder. Among sensory characteristics, taste, chewiness and texture were highest in S2, and in general evaluation, S2 received the highest score. Thus, S2 was found the most appropriate addition of soybean powder in making fish patties. Based on the results of this study, if fish patties to which soybean powder is added can be used in hamburgers and other food products for the diversity, functionality, and high quality of processed food products using soybean and fish, people's appreciation of hamburgers will be changed, and this will bring a new turning point to the consumption of hamburgers. Furthermore, it is believed that the development of healthy patty-type soybean powder products may resolve worries about fast food and quality-related and health-related problems in hamburger patties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.926-934
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• 2009

The study investigated the quality of pound cake prepared with various concentrations of cherry powder (obtained from ground fruit of Prunus serrulata L. var. spontanea Max. wils.). Pound cake was evaluated for their sensory property and physical quality stored for 10 days at $25^{\circ}C$. The pH of the batter decreased with rising cherry powder concentration. The specific loaf volume and height decreased (from 2.95 to $2.60\;cm^3/g$) with increasing in cherry powder. The baking loss rate of the pound cake tended to increased by $11.47{\sim}12.67%$, but with no significant differences. The lightness, redness, and yellowness values were significantly decreased with increases in cherry powder except for redness of pound cake crumb. As the concentration of cherry powder increased, the mechanical characteristics of the pound cake did not differ significantly. The hardness tended to increase, while adhesiveness and springiness decreased with increases in powder. The retrogradation degree of pound cake prepared with cherry powder was higher than the control but there were no significant differences. For the antioxidative activity measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, pound cake prepared with 10% and 15% added cherry powder showed high antioxidant activities. The pound cakes containing 10 and 15% cherry powder had acceptable sensory properties, such as flavor, taste, softness, moisture, and overall acceptability. The results exhibited that adding the cherry powder into the pound cake increased antioxidant activity with the highest quality improvement obtained by incorporating 10% (w/w) of cherry powder into the pound cake formula.

• Korean Journal of Poultry Science
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• v.30 no.3
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• pp.211-217
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• 2003

A study was conducted to investigate the fattening performance, physico-chemical properties of breast meat, vaccine titers in cross bred meat type hybrid chicks fed organic sulfur. Total three hundred and sixty chicks of eight weeks old were replaced in individual cage from 8 to 10 weeks old. Four levels of organic sulfur (0, 1.0, 2.0, 4.0%) containing 45% sulfur were added into basal diet containing CP 19% and ME 2,950 kcal/kg. Weight gain, feed intake, fred conversion were weekly measured. The proximate composition, physico-chemical properties of breast meat, vaccine titer and sensory characteristics were examined at the end of experiment. Weight gain, feed intake and feed conversion of birds fed organic sulfur were not statistically different with control. There were no significant difference in feed intake and feed conversion. However, abdominal fat(%) of birds fed organic sulfur tended to increase compared with control. Crude fat of breast meat decreased significantly in organic sulfur treatments(P<0.05). The red color of breast meat seemed to increase but was not statistically different among the treatments. Cooking loss showed decrements significantly in organic sulfur treatments(P<0.05). Mechanical Hardness, cohesiveness and springiness were prone to be high and gumminess greatly high in breast meat of birds fed organic sulfur addition compared with control. Juiciness tended to increase and greasiness decreased(P<0.05) in organic sulfur treatments by the sensory evaluation. The overall acceptability of the breast meat was the highest at 2.0% organic sulfur added chicks(P<0.01). There were no different blood cholesterol, AST, ALT and BUN.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1685-1688
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• 2004

This study mechanically measured physical properties of jelly made by adding kappa carrageenan and agar-agar to the sipjeondaebo extract, varying the addition ratio. The sipjeondaebo extract used in the study showed 4.95 pH, 7.0 Brix$^{\circ}$, and high turbidity of more than 3.0 NTU. The sugar content was fixed at 25.2 Brix$^{\circ}$ when isomaltooligosaccharide was added in a 25-percent concentration. When the jelly was mechanically measured after it became hard in the refrigerator, the measurement results did not show any significant difference in cohesiveness between different addition ratios of agar-agar to kappa carrageenan. In the measurement of chewiness and gumminess, the jelly show a significantly decreasing tendency in both the two properties as the increase in the addition rate of agar-agar was made. Hardness was also measured lower as the more addition of agar-agar was made, and its the highest level was shown when there was the addition of kappa carrageenan only. Springiness was the highest when the ratio of kappa carrageenan to agar-agar was 0.7%:0.3%, while it was measured the lowest when agar-agar was added in a 1.0% concentration. In the measurement of the jelly's physical properties, the results showed the highest level of appearance when the ratio of kappa carrageenan to agar-agar was 0.7% but indicated that there was no significant difference in flavor. The overall Quality was evaluated to maintain the highest level at the kappa carrageenan to agar-agar ratio of 0.7%:0.3%, followed by a 0.5%:0.5% addition ratio.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2015-2022
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• 2008

The effect of content of $Al_2O_3+Y_2O_3$ sintering additives on the densification behavior, mechanical and electrical properties of the pressureless-sintered $SiC-ZrB_2$ electroconductive ceramic composites was investigated. The $SiC-ZrB_2$ electroconductive ceramic composites were pressurless-sintered for 2 hours at 1,700[$^{\circ}C$] temperatures with an addition of $Al_2O_3+Y_2O_3$(6 : 4 mixture of $Al_2O_3$ and $Y_2O_3$) as a sintering aid in the range of $8\;{\sim}\;20$[wt%]. Phase analysis of $SiC-ZrB_2$ composites by XRD revealed mostly of $\alpha$-SiC(6H), $ZrB_2$ and In Situ YAG($Al_5Y_3O_{12}$). The relative density, flexural strength, Young's modulus and vicker's hardness showed the highest value of 89.02[%], 81.58[MPa], 31.44[GPa] and 1.34[GPa] for $SiC-ZrB_2$ composites added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at room temperature respectively. Abnormal grain growth takes place during phase transformation from $\beta$-SiC into $\alpha$-SiC was correlated with In Situ YAG phase by reaction between $Al_2O_3$ and $Y_2O_3$ additive during sintering. The electrical resistivity showed the lowest value of $3.l4{\times}10^{-2}{\Omega}{\cdot}cm$ for $SiC-ZrB_2$ composite added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at 700[$^{\circ}C$]. The electrical resistivity of the $SiC-TiB_2$ and $SiC-ZrB_2$ composite was all negative temperature coefficient resistance (NTCR) in the temperature ranges from room temperature to 700[$^{\circ}C$]. Compositional design and optimization of processing parameters are key factors for controlling and improving the properties of SiC-based electroconductive ceramic composites.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.2
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• pp.276-285
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• 2012

The objective of this research is to develop the coating technique by a porous self-fluxing alloy for improving the mechanical properties of run-out table roller surface with the hot rolling. To enhance the durability of run-out table roller with the hot rolling, the high hardness of roller surface should be maintained at high temperatures, and the improvement of wear resistance, corrosion resistance, heat resistance, burn resistance and adhesion resistance should be maintained. In order to be able to transport reliably a hot rolled steel sheet, also, the appropriate friction coefficient on the roller surface should be maintained and the slip between roller and steel should not occur. In this study, the wear resistance of roller increases after the self-fluxing alloy is changed to a cermet by adding the tungsten carbide(WC), and the coefficient of friction increases and the ability of grip is improved because the porosities are made by coating with fine iron powder on the roller surface. As a result, it is found that the ability of grip between the steel and the roller coated by a porous self-fluxing alloy contained to 5 ~ 10 wt% of Fe in the coating layer is improved compared to the roller coated by Ni-Cr. This is because the porosities are made after Fe contained in the roller is partially alloyed by heating with a furnace in the fusing process and the rest is eliminated by oxidation and dissolution.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.595-605
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• 2018

In recent years, researches on organic-inorganic coating films have conducted a nanocomposite system composed of organic resin matrices having excellent flexibility and chemical stability and inorganic materials having excellent mechanical properties. The o-phenylphenoxyethyl acrylate (OPPEA) used as the acrylate monomer has a high refractive index of 1.58, and the bisphenol A ethoxylate diacrylate (BAEDA) has a low refractive index but improves the chemical stability of the organic resin. In addition, zirconia used as an inorganic material exhibits excellent durability and optical properties. In this study, the BAEDA contents in acrylate monomer were controlled to produce a film with suitable optical transparency. And optimum conditions were established by comparing the changes in surface properties of PET films detected with pencil hardness tester, Abbe's refractometer, and UV-vis spectrophotometer. The hydrophobicity and the dispersibility of zirconia in acrylate monomer were much improved after modification with ${\gamma}$-methacryloxypropyltrimethoxysilane (MPS), which is a silane coupling agent. And the existence of ester C=O bond peak at $1716cm^{-1}$ introduced by MPS through FT-IR ATR spectrophotometer confirmed the completion of surface modification of zirconia with MPS. In addition, the presence of silicon atom on the surface modified zirconia was also proved using X-ray fluorescence spectrometer. When the photocurable hybrid coating was prepared by introducing chemically modified zirconia into acrylate monomer, the refractive index of this coated PET film was improved by 1.2%, compared to the only acrylate coated PET film. The homogeneous distribution of zirconia in acrylate coating layer on PET film was also identified through SEM/EDS mapping analysis technique.

• Korean Journal of Materials Research
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• v.21 no.1
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• pp.8-14
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• 2011

To improve the chemical stability of metal, the ceramic coatings on metallic materials have attracted interest from many researchers due to the chemical inertness of ceramic materials. To endure strong acids, SiOC coating on metal substrate was carried out by dip coating method using 20wt% polyphenylcarbosilane solution; SiC powder was added to the solution at 10wt% and 15wt% to improve the mechanical properties and to prevent cracks of the film. Thermal oxidation as a curing step was carried out at $200^{\circ}C$ for crosslinking of the polyphenylcarbosilane, and the coating samples were pyrolysized at $800^{\circ}C$ under argon to convert the polyphenylcarbosilane to SiOC film. The thicknesses of the SiOC coating films were $2.36{\mu}m$ and $3.16{\mu}m$. The quantities of each element were measured as $SiO_{1.07}C_{6.33}$ by EPMA, and it can be confirmed that the SiOC film from polyphenylcarbosilane was formed in a manner that was carbon rich. The hardness of the SiOC film was found to be 3.2Gpa through nanoindentor measurement. No defect including cracks appeared in the SiOC film. The weight loss of the SiOC coated stainless steel was within 2% after soaking in 10% HCl solution at $80^{\circ}C$ for one week. From these results, SiOC coating shows good potential for application to protect against severe chemical corrosion of stainless steel.