• Title/Summary/Keyword: 유리구

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The Study of annealing condition and press method of glass for making glasses lens (안경렌즈 제작을 위한 유리의 열처리조건과 성형방법에 관한 연구)

  • Cha, Jung Won;Ha, Tae Wook
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.1
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    • pp.133-137
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    • 2001
  • The method to make glass is tried first thing in domestic study for glasses lens. Tg of glass KzFSl was measured by DSC experiment and press method of glass of meniscus shape was studied for minimize the cost. Tg was increased $483^{\circ}C$ to $501^{\circ}C$ with increasing heating rate $2^{\circ}C/min$ to $20^{\circ}C/min$. It shows Arrhenius temperature dependence and the activation energy of Tg is ${\Delta}E$=409 kJ/mole(4.25eV) by using Ozawa method and Tg is near $480^{\circ}C$. The melt of KzFSl powder was poured to concave cast stainless and pressed convex cast stainless. The quenched glass was slow cooled with cooling rate $0.25^{\circ}C/min$ in temperature range $520{\sim}430^{\circ}C$. The glass was made without strain. It has meniscus shape and same size to commercial glasses lens.

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Antioxidative Activity and Quality Characteristics of Kochujang Amended with Different Ratios of Deodeok (Condonopsis lanceolata) Root Powder (더덕분말을 첨가한 고추장의 품질 특성 및 항산화 활성)

  • Kim, Ok-Sun;Sung, Jung-Min;Ryu, Hye-Sook
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.5
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    • pp.667-676
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    • 2012
  • This study was conducted to investigate the quality characteristics and antioxidant activity of Kochujang following the addition of deodeok (Condonopsis lanceolata) powder. To accomplish this, 1%, 3% and 5% deodeok powder was added to Kochujang and the samples were then incubated at $30^{\circ}C$. during which time the general ingredients, water content, acidity, salinity, reducing sugar content, amino-nitrogen content and DPPH were analyzed at intervals of about two weeks. The water crude protein, crude fat and ash content were 3.61%, 8.44%, 4.62% and 8.85%, respectively. The initial acidity was 3.23~3.97%, and this increased to 4.39~44.86%. highlight please clarify this, I cannot infer your intended meaning; however, this can likely be deleted. The salinity was 7.42~7.73%, and 5% with deodeok powder producing the lowest content and showing a tendency to decrease during the storage period. The early amino-nitrogen content was 274.0~333.1%, with higher nitrogen contents being associated with large amounts of deodeok powder. The amino-nitrogen content during the storage period increased to the 4th week, then decreased. Additionally, the a value decreased sharply during the 4-week storage period. Addition of large amount of deodeok powder significantly improved the free radical scavenging activity. The free radical scavenging activity of 1%, 3% and 5% deodeok powder was higher than that of Kochujang throughout the maturation period. Overall, the results of this study indicate that there is the potential to develop functional foods by the addition of deodeok.

Changes in Physicochemical Characteristics of Kochujang Prepared with Different Koji during Fermentation (고오지 종류에 따른 식혜 고추장의 숙성 중 이화학적 특성 변화)

  • Shin, Dong-Hwa;Ahn, Eun-Young;Kim, Yong-Suk;Oh, Ji-Young
    • Korean Journal of Food Science and Technology
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    • v.33 no.2
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    • pp.256-263
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    • 2001
  • Physicochemical characteristics of kochujang prepared with meju, koji and mixture of meju and koji were analyzed during fermentation in order to improve quality of traditional sikhe kochujang. Amino nitrogen content, an index of kochujang quality, was remarkably higher in kochujang prepared with p-2 koji, p-1 koji, mixture of p-2 koji and meju. Titratible acidity of kochujang slightly increased and pH of kochujang increased until 40 days of fermentation and then decreased there after. Citric acid was found as a major organic acid followed in decreasing order by malic, oxalic, succinic, acetic and lactic acids. As a free sugar, maltose, glucose and fructose were detected. Free sugar content was higher in kochujang prepared with p-1 koji than the others. The major free amino acids were aspartic acid, glutamic acid, alanine, phenylalanine and arginine, and total free amino acid content was higher in kochujang prepared with koji, and mixture of meju and koji than the one with traditional meju only. In sensory evaluation, all tested groups did not show a significant difference. This result indicates that addition of koji to sikhe kochujang influences on taste components like free sugars and free amino acids, but decisively not on the sensory properties.

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Changes in Quality Characteristics of Traditional Kochujang Prepared with a Meju of Different Fermentation Period during Aging (메주의 발효기간에 따른 재래식 고추장 숙성 중 품질 특성의 변화)

  • Oh, Hoon-Il;Park, Jong-Myon
    • Korean Journal of Food Science and Technology
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    • v.29 no.6
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    • pp.1166-1174
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    • 1997
  • This study was designed to investigate the changes in physicochemical and sensory characteristics of traditional kochujang during aging, which was prepared with a different meju fermented for various periods of time. The non-volatile organic acid contents in all samples gradually increased up to 90 days of fermentation. Kochujang prepared with a 40-day-fermented meju had $1.14{\sim}2.54$ times highter organic acid content after 90 days of aging as compared to other kochujang preparations. The most abundant free sugars were found to be glucose and fructose representing $82.27{\sim}100%$ of total free sugar contents in kochujang. 17 kinds of free amino acid including Glu, Asp and Met were found in traditional kochujang aged for 90 days. Glu was noted as the most contributing amino acid to the brothy taste of kochujang in the light of increasing ratio and content of Glu among free amino acids during aging. The total free amino acid contents of kochujang increased with an Increase in fermentation time of meju. Results of sensory evaluation revealed that kochujang prepared with a 40-day-fermented meju was best in terms of flavor and taste. These results suggest that kochujang prepared with a 40-day-fermented meju had the highest quality in terms of physicochemical and sensory characteristics of kochujang.

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Changes in The Chemical Composition of Apple Slices Pretreated with Supercritical Carbon Dioxide (건조 전처리 방법으로써 초임계 이산화탄소가 사과절편의 화학적 성분에 미치는 영향)

  • Lee, Bo-Su;Lee, Won-Young
    • Food Science and Preservation
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    • v.17 no.2
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    • pp.256-260
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    • 2010
  • We investigated changes in the chemical composition of apple slices after pretreatment with supercritical $CO_2$. Total phenolic levels increased with increasing temperature, although the concentrations were lower in pretreated material than in fresh or untreated slices. The levels of vitamin C and malic acid in pretreated slices were also lower than in untreated or fresh apple slices. Little difference was evident among various pretreatmentconditions. It was found that supercritical $CO_2$ served not as a solvent but rather as a means of tissue compression. Supercritical $CO_2$ compressed the apple slices, causing juice to be extruded. The juice disappeared when the supercritical $CO_2$ pressure was released.