• 한국유체기계학회 논문집
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• 제11권2호
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• pp.29-37
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• 2008

Air supply is required to the cathode of fuel cells for the provision of oxygen to produce electricity through chemical reaction with hydrogen in the cell, and supplied air should be free of impurities such as oil mist and tiny particles separated from sliding surfaces. Hence, air compressor for fuel cell air supply must be oil-less type and have no severe sliding surfaces inside. This paper introduces the concept of single-vane type rotary air compressor whose structure is particularly suitable for the fuel cell application: sliding action of the vane against the cylinder wall, which causes severe friction in the conventional vane rotary compressors, is made to be prevented by attaching the vane to the driving shaft with the compliant device between the vane and the rotor in this new design. For 2 kW fuel cell application, preliminary design has been carried out, and its performance has been estimated by using computer simulation program: for discharge pressure of 2 bar, the volumetric, adiabatic, and mechanical efficiencies are calculated to be 82.5%, 92.5%, and 96.3%, respectively.

• Preventive Nutrition and Food Science
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• 제18권2호
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• pp.111-116
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• 2013

Chrysanthemum indicum is widely used to treat immune-related and infectious disorders in East Asia. C. indicum flower oil contains 1,8-cineole, germacrene D, camphor, ${\alpha}$-cadinol, camphene, pinocarvone, ${\beta}$-caryophyllene, 3-cyclohexen- 1-ol, and ${\gamma}$-curcumene. We evaluated the safety of C. indicum flower oil by conducting acute oral toxicity, bone marrow micronucleus, and bacterial reverse mutation tests. Mortality, clinical signs and gross findings of mice were measured for 15 days after the oral single gavage administration of C. indicum flower oil. There were no mortality and clinical signs of toxicity at 2,000 mg/kg body weight/day of C. indicum flower oil throughout the 15 day period. Micronucleated erythrocyte cell counts for all treated groups were not significantly different between test and control groups. Levels of 15.63~500 ${\mu}g$ C. indicum flower oil/plate did not induce mutagenicity in S. Typhimurium and E. coli, with or without the introduction of a metabolic activation system. These results indicate that ingesting C. indicum flower oil produces no acute oral toxicity, bone marrow micronucleus, and bacterial reverse mutation.

• Plant Resources
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• 제3권3호
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• pp.163-172
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• 2000

We compared microstructural features of the ordered cell and disordered leaves in Citrus junos Sieb. by electron microscopy. In the cell of the ordered leaves, many chloroplasts and large vacuoles were particularly observed. Also a lot of vessel, companion cell and big nucleus were presented in vascular bundle regions. The mitochondria and the other organelles were interspersed among the chloroplasts in a thin, peripheral layer of cytoplasm. The chloroplast possessed typical grana and intergranal lamellae, numerous starch grains and a few small osmophilic globules. Besides, microbodies were closely associated with the mitochondria and the chloroplast. The process of the formation of the secondary cell wall from primary cell wall was observed the vessel elements, the tonoplast wall and the secondary cell wall. It was observed that the oil sac with the unique perfume distributed the adjacent cell wall. In the cell of disordered leaves, the all of the organelles were thrust toward the cell wall due to the fusion of vacuoles in the cells. It was observed that a lot of the very small particles spreaded in the cytoplasm. The loss of unique perfume of the leaves was resulted in the destruction of the oil sac. Also, there was not observed grana, lamellae, starch and osmophillic globules in the chloroplast. The small distributed organelles was not observed but the elongation of the cell wall was proceed no longer. Therefore, the plasma membrane diverged from the cell wall. All of organelles in the cell had poor function and deformation. A massive vacuole was fulfilled in single cell and the vacuole contains a lot of large and small particles. The organelles were presented on the side of the cell wall according to the enlargement of vacuole and they were observed to be breakdown.

• 한국식품과학회지
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• 제4권3호
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• pp.200-205
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• 1972

Candida tropicalis KIST 351을 $2.5{\ell}$ 및 $28{\ell}$ 발효조에시 배양하여 석유 유분별자화능, 석유탄화수소기질의 즉차적 유가배양(流加培養), 폐배지(spent medium)의 재사용 및 연속배양 등 배양기술적인 기초문제를 검토한 바 그 개요는 다음과 같다. (1) 각종 경유유분(LGO, HGO, VGO, Diesel oil, SP(E), HGO-wax, L/M-wax)에 있어저 균체농도는 $11{\sim}15g/{\ell}$, 경유에 대한 수율은 $10{\sim}12%$, 소비된 n-paraffin에 대한 수율은 $77{\sim}82%$였다. (2) 동 균주를 유가배양 함으로써 균체들 배지에 대하여 $18.9g/{\ell}$, 경유에 대한 수율을 13%로 향상시킬 수 있었다. (3) 폐배지는 탄화수소를 유화시키고 증식을 촉친하는 효과를 가지고 있었으며 $Mg^{++}$를 보충하지 않었을 때는 20%, 보충하였을 때는 50%까지 회수 재 사용 할 수 있었다. (4) 균체생산을 위한 연속배양의 최적희석율은 $D=0.1{\sim}0.125\;hr^{-1}$의 범위내에 있으며, 이때의 균체농도는 약 $8g/{\ell}$였고, $D=0.125\;hr^{-1}$에서의 균체생산속도는 $1.0\;g/{\ell}/hr$로써 최대치에 달하였다. 소비된 경유 중의 n-paraffin에 대한 균체수율은 $D=0.1\;hr^{-1}$에서 0.94로써 최대치를 보였다. 그러나 희석율 $0.1\;hr^{-1}$에서 공급된 n-paraffin의 약 24%가 기질로써 소비 되지 않었으므로 이에 대한 적절한 대책이 요구된다.

• Applied Biological Chemistry
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• 제14권1호
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• pp.9-18
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• 1971

석유에 효모를 길러 식량 내지 사료로 이용할것을 목적으로 전국 각지의 100여점의 토양시료로부터 400여주의 탄화수소이용 효모균주를 분리하고 그 중 가장 균체수율이 좋은 균주를 선정하여 동정 하였다. 그 균주의 석유탄화수소 배지에서의 배양최적조건, 생육경과 및 균체조성을 조사하여 다음과 같은 결과를 얻었다. 1. 우수균주로 신정된 효모는 Candida curvata-SNU 70으로 동정되었다. 2. 선정호모의 적정 증식배지조성은 다음과같다 Light Gas Oil 30ml, $(NH_2)_2CO$ 400mg, $(NH_4)_2\;SO_4$ 100mg, $KH_2PO_4$ 670mg, $Na_2HPO_4{\cdot} 12H_2O$ 330mg. $MgSO_4{\cdot}7H_2O$ 500mg, $CaCO_3$ 3g, Yeast Extract 50mg, Tween 20 0.05ml, Tap Water 1000ml. 3. 선정효모의 배양조건은 pH $5.5{\sim}7.0,\;30^{\circ}C$, 및 충분한 통기조건이 적당함을 알았다. 4. 유가법은 특히 10% 이상의 고농도배양에서 효과를 보였다. 5. 선정효모, Candida curvata-SNU 70는 lag phase가 16시간 까지이고 다음 28시간까지가 대수기임을 알 수 있었으며, 대수기에서 비증식율, ${\mu}x$는 $0.22hr^{-1}$이고 doubling time은 3.2시간이었다. 6. 얻어진 최적조건에서 2일간 배양시켜 Light Gas Oil에 대한 균체수율 16.1%를 얻었으며 건조세포의 단백질함량은 48.4%였다.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.195-199
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• 2003

Extracts of Escherichia coli as a elicit were treated to suspension cultures of Streptanthus tostus in order to observe the effect on the pholem development. By the elicit treatment, cell wall, sieve endoplasmic reticulum (SER) and p-protein were normally synthesized, but the structure of amyloplast was changed from a round form to irregular and swollen unhalthy form with a tiny starch granular. Oil drops were new synthesized and accumulated in a large oleoplast and proteins were also accumulated in a single membrane. The concentration of sucrose in the phloem, which was induced during the elicit treatment, was higher than normally developed phloem cells. These results suggest that phloem cells might be changed in the normal cycles of metabolism of lipids, carbohydrates and proteins to overcome during the eilicit stress.

• Applied Biological Chemistry
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• 제13권1호
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• pp.43-50
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• 1970

석유탄화수소 이용미생물연구의 일환으로서 미생물에 의한 세포단백질생산의 목적으로 전국각지 135 개지역에서 주유소 세차장의 유침(油浸)토양을 비롯 석탄, 논밭, 하천토양등 242종을 수집하고 이시료로부터 석유탄화수소를 유일한 유기탄소원으로 이용하는 효모 468균주를 분리하였고 분리된 효모균주의 증식율(增殖率)을 screening 하여 우수균주를 선정하였다. 선정된 효모에 대하여 동정(同定) 및 배양 최적 조건의 검토 그리고 효모균체의 성분분석을 한 결과 다음과 같다. 1) 석유탄화수소 이용효모중 90.8%가 주유소및 세차장등 유침토양에서 나머지 10%가 석탄, 작토(作土) 하천토양에서 분리되였다. 2) 분리선정된 가장 우수한 효모균주는 주유소의 유침토양에서 분리됐고 Candida curvata HY-69-19로 동정되었다. 3) 분리선정된 Candida curvata HY-69-19는 optimum pH 5.0, optimum temperature $28^{\circ}C$, aerobic condition에서 균증식율이 컸다. 4) Candida curvata HY-66-19는 유기탄소원으로 petroleum fraction 중 비중이 0.8654이고 비점이 $268.9^{\circ}C$ 이상의 fraction인 heavy gas oil을 잘이용하며 무기질소원으로$(NH_2)_2CO$가 증식율과균체세포생산에 최적임을 알었다. 5) 분리선정된 이효모는 heavy gas oil 배지에서 lag phase 18시간, logarithmic growth phase 24시간${\sim}$42시간 사이며 이 때의 generation time은 3.8${\sim}4.5$시간이었다. 6) 분리선정된 이 효모는 heavy gas oil 및 $(NH_2)_2CO$ 배지로 54시간 pH 를 6시간마다 조정하면서 진탕배양하여 300mg/ml. H.G,0.의 건조균체를 생산하였다. 7) Candida curvata HY-69-19의 균체성분은 조단백질 40.25%, 조지방 14.81%,탄수화물 24.32% 회분 10.63%이었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1668-1670
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• 2002

Since more than two decades, the conventional PD detecting systems have been employed in order to detect the partial discharges occurring inside the HV power apparatus for their diagnosis by use of different type of detection such as acoustic and UHF detection method. Regardless of their wide on-site application, a certain number of technical inconveniences have been disclosed as follows : multistage amplification. large volume, susceptible to external noise and high price. In this respect, the optical measurement techniques are widely proposed in these days in this concerned field ascribed to the following advantages : immune to external EMI noise and broad band response of the Pockels cell covering from DC to GHz. However, the reliability of several proposed techniques enabling to measure the electric field inside the large high power apparatus has not yet been well approved In this work, an optical measuring system, based on the Pockels effect, has been developed for measuring the field variation due to the corona discharges occurring in air and in oil. This system consists of He-Ne laser, single mode optical fiber, multi mode optical fiber, polarizing film, Y-cut LiNbO3 cell, photo detector, digital oscilloscope and personal computer with GPIB. For this purpose, optical probe has been specially designed and realized and put into the needle-plane electrode. Afterward, same measurement is carried out in oil. We demonstrate the characteristic of the optical measuring system and the measurement results.

• 한국식품과학회지
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• 제47권3호
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• pp.281-285
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• 2015

아라키돈산(AA)은 포유동물에 식품을 통해 섭취되는 필수지방산으로써 동물조직에서 추출되어 이용되어 왔다. 경제적으로 AA를 생산하기 위하여 토양으로부터 AA를 다량으로 생산하는 모르티에렐라 종으로 확인된 M-12균주를 선발하였다. 균체로부터 지방질과 AA를 효율적으로 추출하기 위하여 전처리 공정, 공정 순서, 추출 용매, 추출 방식, 입자 크기 등을 달리하여 추출 효율을 분석하였다. M-12를 GY배지로 $25^{\circ}C$에서 7일 배양하여 동결건조한 시료를 사용하였을 때 지질방 중 47% 이상의 AA를 함유하고 있었다. 지방질 추출 효율은 균체의 젖은 상태와 건조 상태로 나눈 전처리 공정에 따라 큰 차이를 보이지 않았다. 클로로폼과 메탄올(2:1) 용액을 추출 용매로 사용하였을 때 가장 높은 추출율을 보였으며 헥세인이나 아이소헥세인도 우수한 추출 효율을 나타내었다. 균체를 분쇄하기 위하여 blending, ultrasonication, Ultra-turrex homogenization 등 기계적 분쇄방법을 사용하였으나 추출 효율은 큰 차이를 보이지 않았다. 균체 입자가 고울수록 유지의 추출 효율은 높게 나타났고 추출 시간보다는 추출 시 입자 크기가 추출 효율에 더 큰 영향을 주는 것으로 나타났다. 그러나 추출된 유지를 분획하여 지방산 조성을 분석한 결과 neutral lipids 내에 AA의 함량이 65.3-68.9%로 가장 높게 나타났다.

• 한국식품위생안전성학회지
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• 제14권1호
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• pp.60-66
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• 1999

Diethylnitrosamine (DEN) is known as a potential hepatic carcinogen by single administration. This study was designed to measure the effects of DEN-induced cell damage on the triglyceride and cholesterol concentration in the liver, excluding dietary effects. Fertilized chicken eggs, 10 days before hatching, were randomly divided into three groups (n=20) and each egg was injected 10 ${mu}ell$ of corn oil (vehicle control), 5 $\mu\textrm{g}$ of DEN/10 ${mu}ell$ of DEN/10 ${mu}ell$ into yolk via air sac. After 48 hr and 96 hr incubation, the damage of the chick-embryo liver cell was investigated by electron microscopy and by measuring the concentration of lipid components (total cholesterol, free cholesterol, phospholipid and triglyceride). For eggs administered 10 $\mu\textrm{g}$ of DEN and incuvated 96 hr, in hepatocyte, the nucleus membrane was roughed, the size of nucleolus was apparently increased and euchromatin was accumulated. Mitochondria were condensed and cristae, located mitochondiral inner membrane, were obscured. Additionally, the leaves of triglyceride and cholesterol classes were significantly increased depend on the amount treated with 10 $\mu\textrm{g}$ DEN at 96 hr, but phospholipids component of cell membrane, were decreased with significance. As a conclusion, carcinogen induced hepatic lesion was correlated with the changes in lipid component of liver.