• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.437-441
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• 2017

This study was carried out to investigate the volumetric expansion ratio and hardness of expanded graphite after coating with various resins which were used as an additive of fireproof sealant. The coating thickness of the resin, which represents the coating rate, was dependent of the drying speed of the resin and the viscosity of the resin. Therefore the coating thickness was shown as follows: polyvinyl acetate > acrylic resin > urethane resin > water soluble latex. Furthermore, the volumetric expansion ratio was as follows: urethane resin > water soluble latex > acrylic resin > polyinyl acetate and the hardness was as follows: polyvinyl acetate resin > acrylic resin > water soluble latex > urethane resin. This showed that the volume of expansion was reduced by expansion, which was not covered by coating, but significantly increased by increasing hardness and allowed it to be used as a refractory addition. According to the response surface methodology, the optimized addition amount and stirring speed of acrylic resin were 37.6 wt% and 441.4 rpm, respectively.

• Food Engineering Progress
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• v.15 no.3
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• pp.235-242
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• 2011

This study was conducted to investigate the quality characteristics of cookies added with different levels of flaxseed powder. Cookies were prepared with four different levels (0%, 6%, 12% and 18%) of flaxseed powder and the physicochemical properties were examined. The pH of cookie dough was higher in cookies containing flaxseed powder. The spread factor of control cookie was lower than that of cookies containing 6%, 12% and 18% of flaxseed powder. The incorporation of flaxseed powder in cookies lowered lightness and yellowness but increased redness values. Rheology testing showed that cookies with 6%, 12% and 18% flaxseed powder had significantly lower hardness value than control cookies (p < 0.05). Consumer acceptance test revealed that overall preference score was the highest in cookies containing 12% flaxseed powder. During storage at $55^{\circ}C$ for 60 days, peroxide value increased until 30 days of storage and decreased thereafter, while acid value steadily increased and there was no significant difference in peroxide value and acid value between control cookies and flaxseed added cookies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1340-1347
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• 2002

Finite element simulations are being widely used to increase the efficiency and effectiveness of design of bulk metal forming processes. In such simulations, proper consideration of friction condition is crucial in obtaining reliable results. For this purpose, tip test based on backward extrusion was proposed recently. In this lest, a cylindrical billet is positioned in a shallow groove of a counter punch for centering purpose and formation of a radial tip is induced on the extruded end of the workpiece. In this study, the effect of centering groove on tip test was investigated. The quantitative ratio of the shear friction factors between the punch and die was numerically determined depending on the shape of centering groove. Also, surface expansion and pressure distribution along the punch and die were considered in order to better understand the reason that friction condition at the punch compared to the one of die was more severe.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.105-108
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• 2012

포소화약제는 물과 혼합시, 물의 표면장력을 저하시켜 공기와 혼합 교반을 통하여 거품을 발생시키는 약제로 소화에 이용되는 소화용수의 효율적 이용을 위하여 이용된다. 특히, 유류화재에 사용시 유면을 거품으로 덮어 질식소화에 적합한 특성을 가지고 있다. 포소화약제는 발포 방식에 따라 저발포, 중발포, 고발포로 나누어지는데 국내의 포소화약제 기준에는 저발포와 고발포의 2가지만을 규정하고 있어, 소화에 더욱 효과적이라 평가되는 중발포 소화기의 이용이 어렵다. 본 연구에서는 휴대용 중발포 소화기를 이용하여 발포실험과 소화실험을 실시하고, 저발포, 중발포, 고발포의 특성을 분석하였다. 결과로 3% 농도로 중발포 소화기 이용시 26.1배의 팽창률을 보였으며, 20단위 화재모형을 32초에 소화시킴으로써 중발포 소화기의 발포, 소화능력을 검증하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1813-1820
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• 2013

This study is conducted to investigate the quality characteristics of cookies containing different levels (0%, 20%, 40%, 60%) of brown rice powder with enhanced levels of GABA (${\gamma}$-amino butyric acid). The pH of cookie dough was higher in cookies containing brown rice powder. A proximate composition analysis showed that the moisture content was increased with the addition of the brown rice powder, yet there was no significant difference in the crude protein and crude fat contents among the added groups. The ash content was the highest in the 60% added group. The spread factor of the control cookie was higher than that of cookies containing 40% and 60% brown rice powder. The incorporation of brown rice powder in cookies lowered the lightness and yellowness values, but increased the redness value. The hardness of the cookies was lower in 40% and 60% added groups than that of the controls. The GABA content in the brown rice added groups was higher than that of the control cookie, and increased as brown rice powder increased. A consumer acceptance test revealed that there was no significant difference in the overall preference scores among the cookies. From these findings, it is suggested that the cookies with brown rice powder up to 60% added can be developed as goods.

• Journal of Adhesion and Interface
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• v.13 no.4
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• pp.171-181
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• 2012

The demand characteristics of the conventional 12 kinds of epoxy resins which have been used for restoration of the ceramic relics were investigated to provide standards of the effective materials in this study. The result of durability analysis showed that a liquid type is more effective in ceramic relics (low damage, high strength), and a paste type is more effective in earthenware relics (high damage, low strength). The result of workability analysis appears that the liquid type is higher than the paste type, and a slow curing type is higher than a fast curing type in surface hardness. Therefore, in the case of the liquid type which is hard to reprocess due to high surface hardness, it is necessary to conduct a study on improving physical properties by adding filler. The result of the gloss analysis on epoxy resins showed that the liquid type (colorless) has higher gloss than the paste type, and the slow curing type has higher gloss than the fast curing type in liquid types. CDK-520A/520B and Araldite SV 427-2/HV 427-1 showed the most similar gloss to $700^{\circ}C$ earthenware, Devcon 5 minute, EPO-TEK 301-2, and Quik Wood showed the most similar gloss to celadon and whiteware, Quik Wood, EPO-TEK 301-2, and Devcon 5 minute showed the most similar gloss to buncheongware. It is necessary for conservator to decide the range of the restoration surface by predicting the increase and decrease of the restoration surface because most of the epoxy resins caused the volume change in curing process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7773-7780
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• 2015

Analysis of existing kettle and its heating system has been the topic for localization technology development. Test pieces are made, polished and etched for existing kettle analysis. Surface of test pieces is observed using SEM, the kettle is verified to be made by deep drawing process from Ferrite-Perlite material. The kettle is also identified to be plated $16{\sim}49{\mu}m$ of thickness with Nickel(16%). Also heat transfer characteristics based on hot wire arrangement is investigated and optimal hot wire system is developed. Developed control system detects overheating and stops the whole system on the long operating time. Developed kettle takes the performance evaluation test for volume expansion and satisfied for standard 'KS G3602'.

• Food Science and Preservation
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• v.18 no.2
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• pp.178-183
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• 2011

The consumer awareness concerning coffee beverages has increased in Korea. The objective of this study was to optimize the roasting conditions of coffee bean for consumer's attribute. The optimal roasting conditions for Colombian coffee beans were analyzed by using a central composite design with a quadratic polynomial model by response surface methodology (RSM). The experimental conditions for coffee bean roasting were $194.82^{\circ}C{\sim}250.00^{\circ}C$ and 7.93~22.07 minutes. The responses of sensory attributes. physicochemical and physical properties were analyzed with RSM. The width. length and height of green beans increased when the beans were roasted. The higher degree of roasting gave the higher pH and solid contents but the lower total acidity and total phenolic compounds. In sensory tests, the roasting temperature and time had a significant effect on the flavor score. The optimum roasting condition of Colombian coffee bean predicted for maximizing the length, width, solid contents, total phenolic compounds and flavor score were 20 minutes at $225^{\circ}C$ by RSM.

• Food Science and Preservation
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• v.24 no.3
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• pp.421-430
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• 2017

This study was conducted to investigate the effect of Lentinus edodes powder on the quality characteristics and antioxidant of rice cookies. The cookies for this experiment was made by 3 main ingredients including rice powder, flour, Lentinus edodes powder. The proportion of rice powder was fixed to 50% for the total amount of ingredients. The amount of reminded 2 ingredients (flour and Lentinus edodes powder) were varied. The amount of flour was decreased up to 38%, and the addition of Lentinus edodes powder was increased to 4%, 8% and 12%. Density of the dough, hardness, total polyphenol content, DPPH free radical scavenging activity, and reducing power increased with increasing Lentinus edodes powder content. Moisture content, pH of the dough, spread factor, loss rate, leavening rate, and L values of the cookies were decreased with increasing Lentinus edodes powder content. The result of consumer acceptance test revealed that there were no significant differences in smell, taste and overall acceptability, while the preference of color decreased as the amount of Lentinus edodes powder increased. To sum up, the cookies with 12% Lentinus edodes powder can produced the best results in terms of quality and antioxidant potential.

• Journal of Conservation Science
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• v.32 no.2
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• pp.167-178
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• 2016

Despite the size layer is an important part for conserving the artworks in the configuration of oil painting, the conservation scientific approaches of that have not been made yet. Therefore, this study produced standard samples on the basis of the analysis results of oil painting works, and carried out the evaluation of functions of the size layer materials. As a result of literature material, traditionally, animal glue was used for the size layer, whereas synthetic resin have been used in combination with animal glue since the modern age, in particular, it was identified that Polyvinyl Acetate(PVAc) was in general use. As a result of analysis of oil painting works, size layer was detected on the support and it was identified as animal glue. As a result of analysis based on Funaoka canvas for ground, it showed that the lead oxide and the titanium dioxide were the main constituents. On the basis of these results, standard samples were produced. As a result of evaluation on the functions of the size layer materials, in the case of the animal glue, stable result was observed in the shrinkag expansion rate, whereas slight weakness was observed in moisture proofing, color, and tensile strength, and dense cracks were found on surface. As for PVAc(A), moisture proofing, color, and the tensile strength exhibited stable results. Higher shrinkage rate was observed and the cracks with wide gaps were found on surface. As for PVAc(B), tensile strength, shrinkage expansion rate, and surface observation showed stable results, whereas moisture proofing property showed poor results. Different aspects were observed in each experiment, and this phenomena were considered to be due to the density and the adhesion properties between the hydrophilic and hydrophobic molecules in the size layer materials. The results are expected to be used as materials for the oil painting work conservation henceforth.