• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.156-161
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• 1982

Three plastic film solar dryers covered with different film layer were constructed by modifying farm vinyl house and studied their performance. The collection efficiency and temperature raising of type C which was covered with double layers of transparent PE and black PVC film was most efficient, followed after B covered with double layer of transparent PE film and type A covered with single layer transparent PE film. The inside temperature of type C was average $18^{\circ}C$ higher than ambient temperature and its collection efficiency showed 31.5% with air flow rate of $3.8m^3/min$. The solar energy collection efficiency of type C was increased in proportion to air flow rate up to 60.2% at $11.3m^3/min$. In demonstration drying test of red pepper in type C, drying capacity per unit area was 2.5 times higher than that of conventional solar drying on straw mat and drying time shortened to about half.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.365-370
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• 2009

For the production of diglyceride (DG) containing medium chain fatty acid, which could be utilized as a substrate to structured lipid production, monoglyceride (MG) and caprylic acid were reacted in the presence of lipase. The reaction system was well mixed homogeneously without using any organic solvent. Among the lipases investigated, Lipozyme RM IM and Novozym 435 were selected on the basis of equilibrium DG yields from the medium chain fatty acid and MG. And reaction conditions such as addition of molecular sieve, water content of immobilized lipase, reaction temperature, and mole ratio of MG/caprylic acid are optimized to increase DG production by using Lipozyme RM IM. DG content of reaction mixture showed 8% increase by adding molecular sieve to reaction mixture. Removal of water from the immobilized lipase could affect seriously equilibrium content of DG. More than 2.8%(w/w) removal of water from the support could make 44% of DG. Optimum temperature was found to $60^{\circ}C$. Temperature shift from $60^{\circ}C$ to $25^{\circ}C$ resulted in increase of free fatty acid (FFA) content. The equilibrium DG yield was not seriously affected by on MG/caprylic acid molar ratio. However, at the stoichiometric ratio of 1:1 the highest DG yield was obtained. Increasing MG/caprylic acid ratio from 0.3 to 1.8 decreased FFA content from 34% to 13%, while MG content increased from 27% to 50%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.271-276
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• 1997

The study was attempted to detemine the ratio of stomach and intestine to viscera gathered on catching vessels, the critical level of VBN content as a freshness quality of viscera of Alaska pollack for raw materials of Changran-jeotgal. It also examined the changes of VBN values, pH and viable tell counts during the fermentation. Then sensory evaluation of the fermented products, Changran-jeotgal, was done according to the freshness of raw materials used. The ratio of stomach and intestine to the gathered viscera on the vessel was about $72\%$, while that of round state of Alaska pollack was about $18\%$. There was no significant relationship in VBN content between fish muscle and viscera. It suggests that VBN content is not a reasonable freshness criteria in viscera but in fish muscle. However, if we use the VBN content as a freshness criteria of viscera for raw materials of Changran-jeotgal, less than $70mg\%$ of VBN value could be recommended. According to the experimental results, the product yields and sensory evaluation scores were no good not only for economical evaluation but also for consumption.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.42-49
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• 2018

In steel industries, cold-rolled sheet manufacturing is one of the links between the front and rear important industries for national competitiveness and high value-added production. In particular, in small and medium-sized enterprises, one of the major problems is the carbonization phenomenon of the steel sheet during the annealing process. Carbonization occurring on the surface of the coil help reduce steel production. After conducting various experiments to identify the cause of carbonization on the surface of a cold-rolled steel, the following results were obtained: (1) An analysis of the rolling oil, which is used in the field, revealed it to contain approximately 40 ppm carbonized material. (2) A comparison of the thermal denaturation characteristics of the fresh rolling oil and using rolling oil by FT-IR analysis showed that thermal denaturation had occurred, as shown by the significant decrease in the relative intensity of the 2900 and $1750cm^{-1}$ peaks. (3) The thermal decomposition of the rolling oil took place for the rolling oil at approximately $220^{\circ}C$. Furthermore, annealing experiments at $200^{\circ}C$ showed that the carbonization phenomenon of the sample was not observed. On the other hand, carbonization was observed at temperatures higher than $240^{\circ}C$.

• Journal of Sericultural and Entomological Science
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• v.6
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• pp.34-38
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• 1966

This experiment was to find out the exact amount of iron component in filature water affecting or the coloring and iron component content in the raw silk after the quantitative analysis of iron component in the filature water, cocoon bave and raw silk. 1. In Korea the extent of iron component in filature water is 0.01-0.77 PPM, and the average amount is 0.23 PPM. 2. The sample water from wells contains more than twice as much iron component as the river water. 3. The iron component content in the cocoon bave (Fe$_2$O$_3$ 0.0096%) and that in the raw silk (Fe$_2$O$_3$ 0.0084%) are similar. But it should be noticed that while the ash content in cocoon bave is twice as much as raw silk, the same amount of ash in raw silk has twice as much iron component as the cocoon bave. 4. The amount of iron component in filature water has great effect on the resolution and absorption of iron component contained in the raw silk during cooking and reeling. That is, when the amount of iron component is small, the rate of iron component resolution from the cocoon bave increases and finally the raw silk comes to contain much less iron component than the cocoon bave, but when the iron component amount is over 0.40 PPM, the raw silk happens to contain more iron component than the cocoon bave. 5. The iron component in filature water makes the raw silk grayish and the more the iron component, the grayer the raw silk. 6. While even very small amount of iron component can affect the depth of raw silk, relatively large amount of Mn component does not have so much influence on the coloring.

• Food Science and Preservation
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• v.12 no.5
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• pp.442-448
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• 2005

To develop efficient drying method, one of important process in manufacturing of Saengsik, uncooked food, the change of physicochemical characteristics and functional component contents of cereals dried by various drying methods was investigated. The proximate composition and dietary fiber content of rice, brown rice, glutinous rice and barley showed little changes during hot-air drying (50$\circC$, 55$\circC$, 60$\circC$) and freeze-drying. Yellowness(b) value of hot-air dried products was higher than one of freeze-dried products. The content of niacin was 0.77 mg% in milled rice, 1.84 mg% in brown rice, 0.68 mg% in glutinous rice, 1.00 mg% in barely dried by hot-air at 60$\circC$ and was lower than those of other samples. $\beta$-glucan content in barely was not changed by hot-air drying and freeze-drying method. In conclusion, hot-air drying would be recommended for barley having $\beta$-glucan, a kind of functional components and freeze-drying should be used for raw materials having heat-labile components such as niacin.

• Journal of Korea Soil Environment Society
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• v.3 no.3
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• pp.21-31
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• 1998

A study on the acid leaching and precipitation has been conducted to remove arsenic from the closed-mine tailings. HCI and H$_2$SO$_4$were used as the leach liquor of arsenic and the tailing obtained from the Da-Duck Mine, which was already closed several decades ago, was also used as the source of arsenic. The effect of the concentration of acid, leaching time and the slurry density on the leaching efficiency of arsenic has been examined. In addition, pH controls and the addition of sodium sulfide were also attempted to remove the arsenic compound as the precipitation from the leachate. After 1 hr leaching by HCI, 40 to 86% of arsenic was leached out depending on the concentration of acid or the slurry density while 47 to 77% of it was leached out by $H_2$$SO_4$. The leaching of arsenic by both acids was almost accomplished within 10 min. and after that only a slight increase in leaching efficiency was observed with leaching time. When the leach liquor was used repeatedly for the leaching of arsenic, the concentration of arsenic in the leach liquor was found to increase continuously although the leaching efficiency was diminished. As far as the precipitation of arsenic in the leachate was concerned, more than 99% of arsenic could be precipitated through the addition of sodium sulfide as the precipitator while the pH controls resulted in the precipitation of up to 84%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.7-12
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• 2004

탄화규소 전력반도체 소자는 실리콘 전력반도체 소자에 비해 우수한 물질특성을 갖고 있어 성능 측면에서 뿐 만 아니라 전력변환장비의 크기를 획기적으로 줄일 수 있는 새로운 반도체 소자이다. 특히 unipolar 계열의 소자에서 괄목할 만한 특성을 보이고 있다. 현재 쇼트키 장벽 다이오드의 경우 5kV급, UMOSFET의 경우 3kV급의 소자까지 보고되고 있으며 반도체 물질 중에서 가장 활발히 연구가 진행되고 있는 분야 중의 하나이다. 단결정성장 분야에서도 3인치 급이 상용화 되었으며 4인치 크기의 웨이퍼의 상용화가 조만간 실현될 것으로 기대되고 있다. 이러한 기술적 발전을 토대로 600V, 1200V급 쇼트키 다이오드가 PFC boost 용으로 시판되고 있으나 아직은 다른 반도체 소자에 비해 미미한 실정이다. 현재에는 $250^{\circ}C$까지의 온도영역에서 실리콘 SOI(Silicon on Insulator) 소자가 주로 사용되고 있다. 그러나 $300^{\circ}C$를 넘는 온도 영역에서는 실리콘으로는 한계가 있고, 특히 SOI는 전력소자에 적용하기는 한계가 있어 주로 저전력 고온소자가 필요한 부분에 적용이 되고 있다. 따라서 전력용에 적합한 고온소자로 탄화규소 소자의 연구가 활발히 진행되고 있다. 현재의 추세로 보아 $200-300^{\circ}C$ 영역의 응용분야에서는 SOI와 탄화규소가 함께 적용될 것으로 예상되며, $300^{\circ}C$를 넘는 온도영역에서는 탄화규소 소자의 우월적 지위가 예상된다. 이러한 이유로 탄화규소 반도체소자의 응용 분야는 크게 확대될 것으로 예상되며 국가적 차원의 지원 및 육성이 요구되는 분야 중의 하나이다.t로 사용한 소자보다 발광 소광 현상이 적게 일어난 것에 기인하였다고 생각된다. 두 소자 모두 $40mA/cm^2$ 에서 이상적인 화이트 발란스와 같은(0.33,0.33)의 색좌표를 보였다.epsilon}_0=1345$의 빼어난 압전 및 유전특성과 $330^{\circ}C$의 높은 $T_c$를 보였고 그 조성의 vibration velocity는 약4.5 m/s로 나타났다.한 관심이 높아지고 있다. 그러나 고 자장 영상에서의 rf field 에 의한 SAR 증가는 중요한 제한 요소로 부각되고 있다. 나선주사영상은 SAR 문제가 근원적으로 발생하지 않고, EPI에 비하여 하드웨어 요구 조건이 낮아 고 자장에서의 고속영상방법으로 적합하다. 본 논문에서는 고차 shimming 을 통하여 불균일도를 개선하고, single shot 과 interleaving 을 적용한 multi-shot 나선주사영상 기법으로 $100{\times}100$에서 $256{\times}256$의 고해상도 영상을 얻어 고 자장에서 초고속영상기법으로 다양한 적용 가능성을 보였다. 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.1
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• pp.37-45
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• 1975

The present study was ,conducted to evaluate the effects of condensed phosphates on the refeezing damage of Alaska pollack muscle. The fillets were dipped in such solution as 5 and $10\%$ sodium polyphosphate, 1 and $5\%$ mixture of sodium polyphosphate and sodium pyrophosphate (1:1, w/w) for 1 and 5 minutes, respectively, before refreezing. And fillets were frozen at $27^{\circ}C\~28^{\circ}C$ and stored for 15 days at $-18^{\circ}\~-20^{\circ}$. The degree of denaturation was estimated by determining amounts of drip relased, content of total solids, nitrogen, and DNA in the drip an cooking-weight-loss. Phosphorus absorbed in the muscle was also determined. Phosphorus absorbed in the fillets treated with loft solution of sodium polyphosphate for 5 minutes amounted to 101 mg/100g muscle as $P_2O_5$. The absorption was dependent on tile concentration of treating solution rather than on the dipping time. The increase of phosphorus absorption seemed to affect to reduction of drip. Among the treating conditions, $10\%$, 5 minutes and $10\%$ 1 minute with sodium polyphosphate appeared most effective ones on drip reduction. The effect of $5\%$, minutes with the mixture of sodium polyphosphate and sodium pyrophosphate did not show so benefitable effect in refrozen fillets. As a tendency total solids, nitrogen, and DNA in tile drip varied proportionally to the amount of drip released. And the content of DNA was lower than the amount. Treatment, at higher the concentration and longer the dipping time, resulted in the lower cooking-weight-loss and the better quality on organoleptic test of thawed fillets.

• Journal of Dairy Science and Biotechnology
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• v.15 no.1
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• pp.33-44
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• 1997

We investigated the immunological function of cheese whey protein concentrate (CWPC), which is a by-product of cheese production, using mitogenic activity in murine splenocytes as an index. A fraction isolated by gel filtration and anion exchange chromatography of CWPC showed high mitogenic activity, comparable to the activity of lipopolysaccharide (LPS). The fraction was detected as a single band on SDS-PAGE. It contained calcium, inorganic phosphorus, and carbo-hydrate, indicating the active component to be a glycophosphopeptide (GPP) Since pronase digestion of GPP did not reduce its mitogenic activity, carbohydrate rather than peptide may be important in the activity, When applied on an anti-${\beta}$-caseinophosphopeptide (${\beta}$-CPP ) antibody affinity column, the GPP was separated into two components, one with affinity to ${\beta}$-CPP and the other without such affinity. Both the components contained N-linked oligosaccharide chains and had the mitogenic activity. These results demonstrate that cheese whey contains a GPP having strong mitogenic activity