• Magazine of the Korea Concrete Institute
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• v.3 no.3
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• pp.101-110
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• 1991

Results of an experimental study on the manufacture, the mechanical properties and watertightness of pitch - based carbon fiber reinforced fly ash. cement composites are presented in this paper. The carbon fiber reinforced fly ash. cement composites using early strength cement silica powder and a small amount of stylene butadiene rubber latex are prepared with carbon fiber, foaming agents and mixing conditions. As a result, the mechanical and physical properties such as compressive , tensile and flexural strengths, watertightness and drying shrinkage of lightweight carbon fiber reinforced fly ash cement composites are Improved by using a samll amount of stylene butadiene rubber latex. Also, the manufacturing pnx:ess technology of carbon fiber reinforced fly ash . cement composItes is developed. The development and applications of precast products of lightweight carbon fiber remforced cement composites are expected in the near future.

• Polymer(Korea)
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• v.39 no.1
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• pp.64-70
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• 2015

Thermally expandable microcapsules (TEMs) can be expanded upon heating since the activation energy of liquid hydrocarbon at the core of the TEMs increased at high temperature. Due to this property, TEMs are widely used in the industry as blowing agents or light-weight fillers. In this article, chemical blowing agent and TEM were used for making polypropylene (PP) foams, and their mechanical properties were compared. Physical properties (tensile strength, impact strength etc.) of PP foams decreased with increasing the amount of blowing agents while weight of specimen decreased. However, PP foam produced with TEMs showed higher impact strength than the one with a chemical blowing agent. In order to figure out the difference of impact strength, the morphology of PP foamed was investigated. Expanding properties of TEM can be controlled by changing core back distance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.447-451
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• 1998

Functional properties such as anti-blood coagulation, angiotensin converting enzyme (ACE) inhibitory activity, fat binding capacity, foaming properties, emulsifying properties and chemical components of sulfated polysaccharides isolated from ascidian tunics were investigated. The sulfated polysaccharide mainly consisted of sulfate, uronic acid, protein, and chondroitin sulfate, among which chondroitin sulfate showed higher concentration while sulfate and uronic acid did lower. Compositional menosaccharides were arabinose, xylose, glucose, galactose, glucuronic acid, N-acetylgalactosamine and N-acetyglucosamine. Especially, galactose content was dominant among them. And emulsifiability and foaminess of the sulfated polysaccharide was higher than the control group. Anti-blood coagulation of sulfated polysaccharide showed with respect to APTT (Activated partial thromboplastin time). ACE inhibitory activity showed about $16.7\%$.

• Applied Biological Chemistry
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• v.37 no.2
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• pp.85-93
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• 1994

The fish skin gelatin hydrolysates were produced using a continuous two-stage membrane (MWCO 10,000, MWCO 5,000) reactor, and molecular weights, amino acids and functional properties of the hydrolysates were investigated. The major molecular weights distribution of the major fractions were $8{\sim}10\;KDa$ and $4.5{\sim}6.5\;KDa$ in the 1st-step hydrolysates, $2{\sim}6\;KDa$ and $0.5{\sim}2\;KDa$ in the 2nd-step hydrolysates. Among the amino acids in the hydrolysates, glycine, proline, serine, alanine, hydroxyproline, glutamic acid and aspartic acid having sweet taste were responsible for $68{\sim}72%$ of the total amino acids. But valine, methionine, isoleucine, leucine, phenylalanine and histidine having a bitter taste were only $23{\sim}25%$ Taste evaluations show that the gelatin hydrolysates have a brothy and sweet taste, 2nd-step hydrolysate have more a favorable taste than 1st-step hydrolysate. The hydrolysates were completely soluble and clear over the entire pH range. Moisture sorption at intermediate water activities of the 2nd-step hydrolysate was much higher than the unmodified fish skin gelatin, but foaming and emulsification properties were poor. Buffer capacity of the 2nd-step hydrolysate was higher than the fish skin gelatin and 1st-step hydrolysate, while viscosities of the hydrolysates were lower than the fish skin gelatin.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.516-523
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• 2020

Supercritical carbon dioxide (_SCO2) extraction was applied for the defatting of mealworm to prepare defatted powder (DP) and protein isolate (PI) and compare the process to press and hexane extraction, with respect to DP and PI physicochemical properties. _SCO2 DP was obtained by extracting 34.40% oil at 41.37 MPa, 40℃ for 180 min, and the product contained 71.66% crude protein, which is similar to that of hexane DP and higher than that of press DP. In using alkali protein extraction to prepare PI from DP, _SCO2 was as effective as hexane and better than press. _SCO2 produced brighter DP and PI than press, but not as much as hexane. Protein solubility was similar in all DP, with minimum values at pH 5. The highest water adsorption capacity was noticeable for _SCO2 PI, and _SCO2 DP showed an oil adsorption capacity comparable to that of hexane DP. _SCO2 DP and PI had better foaming capacity than press DP and PI and showed superior emulsion activity compared to others.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.50-54
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• 2007

In this study, the physicochemical properties of cheese whey protein isolate (WPI) were measured. The total amount of amino acids in WPI was 89.5% and the proportion of essential amino acids was 44.6%. Among these, leucine, lysine, isoleucine, and valine were shown in large amounts. At various pHs, the solubility of WPI (82-88%) was higher than that of sodium caseinate, (5-79%). The solubility of WPI was not affected by variation of pH. It was shown that the emulsifying capacity of WPI was higher than that of egg yolk by 1.6 times, but the stabilities of emulsions made with WPI and egg yolk was almost same each other at 65-97% and 60-89%, respectively. The foaming capacity of WPI was higher than that of egg white, at 323.3% and 186.6%, respectively, but the foam stability of WPI was similar to that of egg white.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.345-355
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• 1991

In order to effectively utilize the by-products of sea-food, the utilization of enzyme-modified flounder(Limanda aspera) skin gelatin as an emulsifier was investigated. In the experiment, the gelatin was extracted from the flounder skin with the heat-treatment at $60^{\circ}C$ and in pH 5.0 for 3 hrs with four volumes of distilled water and emulsifiers were enzymatically modified L-leucine alkyl esters$(L-leucine-OC_n$ : n= 2, 4, 6, 8 and 10) to the gelatin$(EMFSG-C_2,\;EMFSG-C_4,\;EMFSG-C_6,\;EMFSG-C_8,\;EMFSG-C_{10})$ for improving the functional properties such as emulsifying activity, emulsifying viscosity, whippability, electric conductivity, critical micelle concentration and interface tension, etc. Also, the functional properties of the L-leucine alkyl ester modified gelatins were compared with those of Tween-60 as reference. Molecular weights of the enzymatically modified flounder skin gelatin(EMFSG) were 20.5kDa. in $EMFSG-C_2.\;19.5 kDa.\;in\;EMFSG-C_4\;and\;16.5kDa.\;in\;EMFSG-C_6,\;EMFSG-C_8$ and $EMFSG-C_{10}$. respectively. Emulsifying activity and emulsifying viscosity in the modified gelatins were risen with increase of carbon number of the introduced L-leucine alkyl esters. Among the modified gelatins, $EMFSG-C_6$ exhibited the highest emulsifying stability and foaming stability, whereas $EMFSG-C_8$ showed the highest whippability. The electric conductivities of the all $EMFSG-C_n$ were linearly risen to critical micelle concentration(CMC) , therefore $EMFSG-C_{10}$ exhibited the lowest CMC value and interface tension, and dense particles in the microscopic observation. In conclusion, the best quality in functional properties was assured on $EMFSG-C_{10}$.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.4
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• pp.435-441
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• 1999

This study was designed to investigate the effects of roasting temperatures on the antinutritional factors and functional properties of sesame protein isolates. The protein contents a sesame protein isolates (SPI) prepared at roasting temperatures of 5$0^{\circ}C$, 10$0^{\circ}C$, 15$0^{\circ}C$ and 20$0^{\circ}C$ were 65.5%, 66.6%. 68.9% and 64.1%, respectively. Total phenolic compounds, condensed tannin and phytate contents of SPI was increased from 5$0^{\circ}C$ to 20$0^{\circ}C$. From color measurements, higher roasting temperature decreased 'L' and 'b' values significantly, but 'a' value was increased. The bulk density, fat absorption and water absorption of SPI was increased as the temperature of roasting was increased. Sesame protein isolates prepared by roasting at 5$0^{\circ}C$, 10$0^{\circ}C$ and 15$0^{\circ}C$ had higher emulsifying activity than those prepared by roasting at 20$0^{\circ}C$. Foaming capacity of SPI was not changed by roasting up to 10$0^{\circ}C$, but this property was reduced dramatically when roasted at 20$0^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.17 no.4
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• pp.450-457
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• 2004

In wine making, to perform yeast culture effectively, which is the most important factor, 5 strains of representative active dry yeasts were selected : Montrachet, Pasteur Champagne, Epernay II, Prise do Mousse, Lalvin W15. The results about fermentation properties were as follows. After 1 day of fermentation, the ethanol contents of Lalvin W15 wine and Montrachet wine were 5.4% and 4.0%. After 2 days of fermentation, the ethanol content of Lalvin W15 wine was 9.2%, which is the highest degree among all experimental groups. As for the content of sugar solution, the wine fermented by Lalvin W15 was the highest one. In acidic solution, fermentation activity of Prise de Mousse, Lalvin W15, Montrachet were highest degrees and Red wine fermentation activity of Prise de Mousse has shown the highest degree in its fermentation activity, if only initial SO$_2$ amounts were 200 ppm. In regard to the foaming tendency during fermentation, the size of foams in Montrachet was big and the amount of foams was a lot. The change in Brix during the fermentation became evident after two days. The Brix of Montrachet wine and Lalvin W15 wine was 3.0, a high initial fermentation speed. After 10 days of fermentation, total acidity of Lalvin W15 wine was 0.99g/100m1, the highest degree. After 3 days of fermentation, the ethanol content of Lalvin W15 wine was 7.4%, the highest degree. But after 9 days of fermentation Epernay II showed the higher ethanol concentration to 13.8%.

• Journal of the Korea Institute of Building Construction
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• v.18 no.2
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• pp.117-123
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• 2018

The increase in energy efficiency has became a significantly important issue for building construction and maintenance. The energy efficiency is known to be achieved by using a material with lower thermal conductivity, and the best method is to increase the internal porosity of the material. Typical ways to increase internal porosity within cementitious composite are to use foaming agents or to use reactive powder such as aluminum. However, in this work, hydrogen peroxide was chosen as an alternative material to make lightweight cement mortar. The volume expansion of fresh cement mortar and unit weight, compressive strength and thermal conductivity of 28 day old cement mortar were measured. According to the experimental results, the incorporation of hydrogen peroxide increased internal porosity, and thereby reducing the compressive strength and thermal conductivities of cement mortar. It was found that hydrogen peroxide can be successfully used to produce lightweight mortar for thermal insulation purposes of buildings.