• Journal of Conservation Science
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• v.25 no.2
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• pp.155-160
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• 2009

This study is designed to optimize the method of using SE-101 for strengthening the durability and the stabilization of moving historical site. The permeability and the shear strength of The epoxy SE-101 with low viscosity were measured on different particle sizes and moisture content of soil. Like it can be expected from the data of viscosity, as the soil particle size was increased, the permeability was also increased, while the shear strength was decreased. And especially, it is noted that the deviation of permeability can be more extreme according to the different hardening speed of macromolecule and mineral additives. As the rate of moisture content in soil sample is increased, the deviation between permeability and shear strength is also increased. Even though among the same soil sample, some parts of it can be weaker than others, which cause the breakages of epoxy products. Thus, it is necessary that the soil should be dried over 50% of permeation depth of SE-101 before use.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.791-795
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• 1996

Toha-jeot(salt-fermented Toha shrimp) is a traditional fermented food in Korea. Toha-jeot is fermented for 90 days at $4\pm1^{\circ}C$ with 20%(w/w) salt per live Toha shrimp. We expect that the high polymer chitin of Toha shell will be hydrolyzed by chitinase during the fermentation of Toha-jeot and that the low molecular weight of chitin oligosaccharides will be produced. We experimented 7 samples which were taken at the interval of 15 days during the total 90 days of fermentation. We also measured molecular weight of Toha-chitin, viscosity and molecular weight distribution of chitin during fermentation of Toha-jeot, The decrease of viscosity and average molecular weight of chitin were observed as fermentation proceeds. Chitin oligosaccharide with $10^3molecular$ weight was low until 60 days fer-mentation. However, chitin oligosaccharide with $10^3molecular$ weight was high after 75 days fer-mentation. And chitin oligosaccharide with $10^2molecular$ weight were observed after fermenting Toha for 75 days and 90 days, but chitin oligosaccharide with 10'molecular weight did not appear up to 60 days of fermentation.ation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3627-3632
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• 2015

We investigated mechanical, rheological and electrical properties of graphite/PP/LCP composites for a bipolar plate of the polymer electrolyte membrane fuel cell. The composites containing very low molecular weighted PP showed much higher electrical conductivity compared with other thermoplastics. This was attributed to the enhanced dispersion of graphite particles due to the low viscosity of the PP. The conductivity of the composites was increased in a great extent by incorporation of small amount of carbon nano tube (CNT). However, the acid treated CNT which contains oxygen atoms did not increase the conductivity of the composite. From this result, it is concluded that the CNT has higher affinity with non polar polymer. The composite with low molecular weighted PP provided good processability so that the composites can be processed by an injection molding while the mechanical strength is deficient compared to other polymers. In order to reinforce the low mechanical property, LCP/PP was used as a binder and the graphite/PP/LCP composite showed the higher conductivity and moderate mechanical strength maintaining suitable processability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.664-668
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• 1999

The extracting conditions of alginates from sea tangle were evaluated by measuring water vapor permeability (WVP) and tensile properties of alginate film to obtain basic data of making an edible and biodegradable film. The alginates were extracted with $1\%,\;3\%$ and $5\%$ sodium carbonate ($Na_2CO_3$) for 1, 3, 5 and 10 hours, and the alginate film was made with various plasticizers. The higher concentration of $Na_2CO_3$ solution showed the lower viscosity and polymerization degree of alginate and the film prepared with alginates having low viscosity showed the higher WVP. The extracting hours had little effect on the WVP and the elongation of alginate film, but the polymerization degree of alginates directly affected the tensile strength of the film. The addition of sorbitol and polyethylene glycol as a plasticizer lowered the WVPs and the elongation of alginate film.

• Journal of the Korean Institute of Gas
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• v.11 no.4
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• pp.29-34
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• 2007

In recent years, the need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as LPG(Liquefied Petroleum Gas) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a hish vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to directly apply the conventional gasoline or diesel fuel pump. In this study, experiments are performed to get performance and efficiency of the fuel pump under different condition of the temperature, rotating speeds, and composition of fuel. The characteristics of fuel pump were affected by cavitation occurred from the variation of temperature and composition.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.111-115
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• 2007

To modify the physical properties of alginate film, the gamma ray irradiation was performed, and alginate film properties such as elongation strength (ES), elongation rate (ER), water vapor permeability(WVP), and water solubility (WS) were measured. The film made from 1.75% alginate solution (w/w) with the addition of 2% CaCl$_2$ solution suggested a good application for a film preparation in that elongation strength(ES) increased 5 fold by CaCl$_2$ treatment and water vapor permeability was decreased by 17${\sim}$22%. A solid form of alginates were irradiated with Co$^{60}$ gamma rays in the dose range of 2 to 10 kGy to make a low molecular weight alginate film, and then the intrinsic viscosity and the molecular weight of alginates were measured. Increasing the dose range of 2 to 10 kGy produced lower intrinsic viscosity and lower molecular weight, causing the decrease in the ES and WS. However, ER increased four times compared to that of without gamma ray dose, which is an indication of the different properties of algiante film. WVP of the films did not show any significant change at different doses.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.65-65
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• 2011

천연염색에 대한 관심이 높아지고 있지만 색상의 재현성, 견뢰도의 취약성, 디자인의 제한성의 문제로 실용화의 한계에 부딪히고 있다. 이를 극복하기 위하여 본 연구는 침염 위주의 천연 염색에서 벗어나 키토산을 바인더로 이용하는 날염의 유효성을 검토하고자 한다. 본 연구에서는 키토산을 바인더로 이용한 방법을 제시하고자 키토산과 광물성, 동 식물성 안료를 혼합하여 날염호를 조제하여 날염하였다. 키토산의 점도와 농도, 키토산을 이용한 바인더와 안료의 비율 등을 변화시키고 날염직물의 색상과 염착량, 세탁 일광 마찰 견뢰도를 측정하여 적정조건을 도출하였다. 기존의 합성바인더와 구아검을 사용한 경우의 색상, 염착량, 견뢰도와 비교하여 키토산 날염 바인더로서의 유효성을 검토하였다. 키토산을 바인더로 이용한 날염방법에서 적정 점도는 저 중점도, 농도는 1.7%정도가 적절한 것으로 판단하였다. 날염호 제조시 안료의 비율을 증가시켜 진한 색상을 얻을 수 있었으며, 그 비율은 광물성 안료의 경우 1:4, 동 식물성 안료의 경우 1:10까지 변화시켜 명도의 차이를 나타낼 수 있다. 실험결과를 바탕으로 적정조건에서 날염한 직물의 견뢰도를 평가한 결과, 광물성 안료의 경우 4등급 이상, 동 식물성 안료의 경우 3등급 이상으로 우수하게 평가되었다. 안료의 비율이 높아지면 마찰 견뢰도는 감소하였다. 키토산, 구아검, 합성바인더의 색상과 견뢰도를 비교해 본 결과 색상은 동일한 계열로 나타났으며, 키토산을 바인더로 이용한 경우 세탁, 일광, 마찰 견뢰도는 구아검보다 우수하게 평가되었다. 합성바인더의 경우 세탁, 마찰 견뢰도는 비슷하게 나타났으며, 일광견뢰도의 경우 키토산이 더 우수하게 평가되었다.

• Korean journal of food and cookery science
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• v.17 no.4
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• pp.367-372
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• 2001

This study was conducted to investigate the effect of rheological and sensory characteristics of the low-calorie layer cake made by adding different levels of polydextrose as a fat substitute for shortening. As the substitution level of polydextrose increased, the specific gravity of the cake batter increased and the viscosity decreased. The microstructures of cake crumb observed by a scanning electron microscope showed the decreased number and size of air cells and fat particles by increasing fat substitution level. The texture profile analysis using rheometer showed significant differences among the samples according to the levels of polydextrose for shortening. The hardness. gumminess, cohesiveness and chewiness of the cake declined gradually by increasing polydextrose level, while the springiness increased. There were no significant differences in resilience. Among various sensory properties, the appearance, flavor, crumb texture and overall acceptance of the layer cake decreased by increasing polydextrose level, although the taste score increased by adding 25% of polydextrose for shortening. Taking these results together, adding 25% polydextrose for shortening suggested to be a good substitution level for the low-calorie layer cake.

• Bulletin of Food Technology
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• v.15 no.2
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• pp.93-99
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• 2002

고압처리로 멸균된(high-pressure- sterilized) 저산성 식품은 아직 본격적으로 시장에 나오지는 않고 있다. 그러나 고압처리로 살균시켜(high-pressure-pasteurized) 제품의 부가가치를 높인 상품들은 일부 시판되고 있다. 미국시장에는 구아카몰(guacamole),굴 등이 있고, 일본과 유럽에는 잼, 젤리, 생선제품, 육제품, 슬라이스 햄, 샐러드 드레싱, 쌀떡, 주스, 요구르트 등이 판매되고 있다. 기술이 발전되어 처리비용이 떨어짐에따라 우유나 오렌지 주스 같은 저부가가치의 제품(high-volume commodity products)에도 고압처리 기술이 적용되는 예를 보게 될 것이다.미국 FDA의 "열처리된 저산성식품은 용접밀봉된 용기(캔, hermetically sealed container)에 포장되어야 한다." 는 규정(Title 21, Part 113 of the Code Federal Regulations)은 고압처리 식품을 염두에 두고 만들어진 규정은 아니지만, 저산성식품의 고압처리 공정(high-pressure processing)은 강력한 살균력을 제공하고 있다. 따라서 위의 FDA 규정(21 CFR 113)의 모든 조항은 고압처리 저산성 식품이 상업적인 생산에 들어가기 전에 시행되어야만 하는 것이다. 그 규정의 주요 조항중의 하나는 고압처리 공정에 대한 전문적인 지식을 가진 전문가나 위원회 등에 의하여 세부적인 고압처리공정 절차를 확립하는 것이다. 공정의 전문가들은 안전성을 증명하기 위해서 적합한 과학적인 방법을 사용하여 고압처리 공정을 확립해야만 한다. 저산성 식품에 대한 고압처리 공정은 주의깊게 설정된 공정조건하에서 재현성 있게 안전한 식품을 생산할 수 있어야 한다. 살균에 대한 안전성과 재현성이 입증되면 고압에 의한 살균처리공정 설계는 일반적인 대량생산 공정으로 활용될 수 있게 된다. PP(고압처리공정)의 유효성이 보다 확실하게 입증되고 널리 활용되려면, 공정의 살균력과 일관성(uniformity)을 증명하는 미생물적, 물리적, 화학적, 공학적인 여러 분야가 통합된 검증방법이 필요하다. 전통적인 열처리 공정은 스팀열의 가열시간으로 설명이 충분하다. 물론 HPP살균에서도 시간과 온도는 주요 변수이지만, 압력에 의한 미생물살균도 고려되어야만 한다. 또한 점도, 밀도, 구성성분, pH, 수분활성도 같은 해당제품의 특성도 제품의 고압처리 살균공정, 특히 미생물의 사멸에 영향을 미칠 수도 있다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.588-593
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• 2006

This study was intended to observe possibility of which radiation technique can be used for oligopeptide production from pigskin collagen to reduce environmental pollution in processing and simplify the processing steps. Raw pigskin was ground using chopper, and then defatted in acetone cooled at $-20^{\circ}C$ freezer. Defatted dried pigskin was irradiated at 20, 40, 60, 100, 150, 200, 250, and 300 kGy using Co-60 gamma rays irradiator. With irradiation doses, the amount of soluble proteins increased, and the viscosity and turbidity of soluble proteins decreased, which could be clue of that irradiation degrade high molecular proteins directly. pH of soluble proteins from defatted pigskin increased in the sample above 150 kGy, and low molecular weight components (below 24 kDa) in SDS-PAGE increased. From gel permeation chromatography of the hydrolysates of pigskin irradiated at 300 kGy showed the major peak of 9,000, 8,200, 860, and 170 Da.