• Tribology and Lubricants
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• 제1권1호
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• pp.80-87
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• 1985

고온에서 화학적역안정성 및 기계적안정성의 섬유구조를 갖기 위해 lithim complex gellant로 정한 지방산과 $LiOH\cdot H_2O$ 및 boric acid의 이차연속검화반응으로 lithium dual complex 그리이스를 합성하였다. complex gellant의 양은 14%(NLGI 2호)가 적정량이었으며, 특히 castor wax를 1.5% 첨가했을때 이상적인 성능을 나타냈다. 이렇게 합성한 그리이스의 유분리성, 산화안정성, 내수성, 혼화안정성, 극압 및 내마모성은 ASTM 및 KS 방법에 준해 시험하였으며, 매우 우수한 특성을 지녔음을 알았다.

• Tribology and Lubricants
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• 제5권2호
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• pp.55-59
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• 1989

Measurement of the friction force of vane tip have been made to provide essential information for the study of the pump dynamics, the pump design and the analysis of triboligical problems in the sliding components. The influences of the radial load, rotating speed and frequency of vane on the friction forces of vane tip have been investigated. The results indicated that the friction coefficient of vane tip are affected by the rotating speed remarkably but the effect of acting load on the vane tip and frequency of load are very small. The stribecks diagram shows that the lubrication regime of the sliding point of vane tip is mixing lubrication.

• Natural Product Sciences
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• 제26권2호
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• pp.132-135
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• 2020

Volatile constituents obtained by water distillation from the aerial parts and root of Onosma dichroanthum Boiss (Boraginaceae) native to the north of Iran were investigated by GC and GC/MS for the first time. Palmitic acid (39.61%) and decane (31.39%) were the major components in the root while decane (26.26%) and phytol (25.52%) were the predominant constituents in the aerial parts. Ketones, aldehydes, alkanes, fatty acids, oxygenated diterpenes and sesquiterpenes were characterized as the most phytochemicals in the aerial parts. Alkanes and fatty acids were identified as the main groups in the root volatile substances. There were two ketone derivatives, belong to apocarotenoids, in the aerial parts; β-ionone and hexahydrofarnesyl acetone.

• 한국연초학회지
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• 제21권2호
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• pp.182-187
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• 1999

A bulk curing experiment was carried out to evaluate the effect of air flow reduction in the bulk barn from color fixing stage in the chemical properties of cured leaves, The air flow was controlled by reducing air velocity of a blower from 0.3m/sec to 0.2m/sec using a boltage regulator(Slidac). The bulk curing before color fixing stage was processed in the conventional curing method. Reduction of air circulation in bulk barn did not affected so much on change of the contents of the main chemical components in cured leaved, such as nicotine, total sugar, total nitrogen, petroleum ether extract, and organic acids. Only a slight increase in essential oil contents, such as solanone, damascenone, damascone, $\beta$-ionone, and megastigmatrienone isomer, could be observed in leaves cured in the reduced air flow.

• 한국연초학회지
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• 제6권2호
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• pp.147-153
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• 1984

During curing of aromatic tobacco leaves, coloring temperatures were set at 26, 30, 34, 38 and $42^{\circ}C$, and also leaf drying temperatures were established at 35, 40, 45, 50, 55 and $60^{\circ}C$, respectively, to investigate the thermal effect on characteristics of cured leaves. Appearance of yellow color from green was accelerated, the contents of non-volatile organic and higher fatty acids in leaves tended to increase with the higher yellowing temperature. Quality by price per kg was best at 45-$50^{\circ}C$ and score of smoking test was highest at 40-$50^{\circ}C$ during leaf drying stage. The concentrations of non-volatile organic acids and volatile essential oil inclined to decrease, but a reverse in this trend with higher fatty acids as temperature increased during leaf drying stage. The difference of other components was discussed.

• 한국염색가공학회지
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• 제29권4호
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• pp.256-267
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• 2017

The purpose of this study was to analyze the functional ingredients of Perilla Frutescens L. Britt extracts and to confirm the possibility of producing PVA nanofibers using extracts. Distilled water, 3% aqueous sodium hydroxide solution and ethanol were used as extraction solvents. The electrospinning was carried out at a PVA concentration of 12%, an applied voltage of 10 kV and a tip to collector distance of 15cm. The contents of volatile substances, essential oils, total polyphenols and flavonoids of the extracts were measured to examine the constituents of functional materials. Flavor components and esters were identified in 3% sodium hydroxide and ethanol extracts. The content of polyphenols and flavonoids in ethanol extracts was higher than that of medicinal plants. 1wt.% of Tween 20 was added to disperse the essential oil components of the ethanol extract. Addition of a dispersant made it possible to produce a homogeneous mixture by having some compatibility with the ethanol extracts and the PVA molecule. When the concentration of the ethanol extract was 0.25 and 0.5wt%, relatively uniform PVA nanofiber having an average diameter of 350 to 365nm could be produced. The results of FT-IR, XRD and DSC analysis confirmed that Perilla Frutescens L. Britt ethanol extract was well mixed with PVA molecules and was electrospun.

• KSBB Journal
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• 제8권5호
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• pp.495-503
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• 1993

페퍼민트 세포의 회분배양에 의한 monoterpenoid 풍미성분의 생산 가능성과 세포의 생육 및 정유생산 특성을 알아보기 위해 캘러스로부터 얻은 모배양액 을 기포반응기 형태의 생물반응기에 접종하여 배양 하였다. 회분배양 중 접종량, abiotic stress, yeast elicitor, 그리고 2단 배양 등의 배양조건이 세포생육 과 박하정유 생성 빛 조성에 마치는 영향을 조사하 였으며 배지의 sucrose 농도와 세포생육의 kinetics 를 분석하였다. 접종량을 탈리하여 배양한 결과 2.0 %(PCV)를 접종한 경우가 반응기에서 배양이 가장 적당하였는데 배양 10일 만에 5.8g/P 의 세포생육을 얻었으며 0.109g/P 의 박하정유가 생성되였다. Abi-otic stress의 영향을 보기 위해 16시간은 $27^{\circ}C$ 에서 명상태로,8시간은 암상태로 하고 10'C로 온도를 낮추어 배양한 결과 세포의 생육은 떨어졌으나 박하정유 생성량은 0.546g/P 로 높은 수율을 보여 주었다. 사용한 Lin-Staba 배 지 에 100mg/P 의 yeast extract를 elicitor로 첨가했을 때 세포의 생육과 정유 의 생성량이 높았으며 유일하게 menthol이 정유 중 22.5%의 높은 농도로 생성되었다. 배지의 당농도를 1/2로 줄이고 $27^{\circ}C$ , 명조건으로 6일간 배양한 후 1OOmg/P 의 yeast elicitor를 첨가하여 8시간을 암 상태와 lOoe로 저온처리를 실시하여 6일간 배양한 결과 8일 이후에는 세포의 생육이 감소하였고 정유 생성량은 증가하지 않았으며 menthol도 생생되지 않았다. Dry cell yield는 O.38g dry cell/g sugar이 였으며 specific growth rate은 O.25day-1 이었다. 회분배양에 의해 박하정유가 생성됨을 알 수 있었으 냐 menthol이 생성되지 않고 전구체인 pulegone과 p piperitone이 축적되였다. 그러나 특이하게도 yeast elicitor를 첨가한 경우 menthol이 22.5%로 생성되 었는데 이제까지 박하세포 배양에 의해 생성된 men­t thol 함량으로는 최대치를 보여주는 결과이였다.

• 한국식품과학회지
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• 제28권5호
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• pp.827-833
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• 1996

연속증류추출(SDE) 장치를 이용하여 냉이로부터 휘발성 향기성분을 추출할 때 분산매의 조성(pH, 당 및 염)에 따른 향기성분의 강도 및 회수율을 조사하였다. 분산매의 pH를 3, 5, 7및 9로 하여, 각 pH에 따른 휘발성 향기성분의 변화 패턴 및 냉이로부터의 휘발성 향기성분 추출에 가장 적합한 pH를 조사한 결과 분산매의 pH가 7일 때 총 51종의 가장 다양한 휘발성 성분이 확인되었으며 냉이로부터 휘발성 향기성분을 추출할 때 중성 pH 부근에서 수증기 증류하는 것이 향기성분의 구성 및 회수율 측면에서 가장 바람직함을 알 수 있었다. 냉이를 수증기 증류할 때 분산매의 sucrose 농도가 10%, 20% 및 40%로 증가함에 따라 획득된 정유량은 각각 18.1 mg, 29.0 mg 및 33.4 mg으로 40% sucrose용액에 의하여 증류할 때 정유 회수율이 가장 높게 나타났다. 또한 sucrose 농도가 증가할수록 확인된 휘발성 향기성분의 종류가 다양하였으며 10%, 20% 및 40% socrose 용액으로 증류할 때 각각 27종, 32종 및 38종이 확인되었다. 냉이의 수증기 증류시 분산매의 surcrose 농도가 증가함에 따라 향기를 구성하는 휘발성 성분의 수는 더욱 다양하였으나 양적인 측면에서는 각 성분마다 다른 양상을 보였다. 2%, 8% 및 15% NaCl용액으로 냉이를 수증기 증류하여 얻어진 정유의 함량은 각각 33.0 mg, 12.5 mg 및 22.4 mg으로 2% NaCl용액을 사용하였을 때 정유의 회수율이 가장 좋았으나 15% NaCl용액으로 증류할 때 가장 많은 수인 22종의 휘발성 성분이 검출 및 확인되었다.

• 한국정밀공학회지
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• 제24권3호
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• pp.100-107
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• 2007

A internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobes with circular shape, while the inner rotor profile is determined as conjugate to the other. The topic of this paper is the design of a new rotor, which is based on specific performance as different types depending on the shape of the lobe of the outer rotor. First, the design of internal lobe pumps with circular, elliptical, and their combined lobe profiles is considered. The latter is a new type of lobe profile with special shape whose curvature follows a definite function. Then we introduce the performance indexes used for the comparison. Some of these indexes, such as flow rate and flow rate irregularity, are commonly used for the comparison, while specific slipping is particularly suitable in this case. It is possible to notice that the circular and elliptical type is comparable to the circular one or the elliptical one in terms of flow rate irregularity, but has improved performance in terms of specific slipping. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

• 한국정밀공학회지
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• 제27권9호
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• pp.67-77
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• 2010

An internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobe with elliptical and involute shapes, while the inner rotor profile is determined as conjugate to the other. And the integrated design system which is composed of three main modules has been developed through AutoLISP under AutoCAD circumstance plus CFD-ACE+. It generates new lobe profile and calculates automatically the flow rate and flow rate irregularity according to the lobe profile generated. CFD simulation results show trends similar to those carried out in experiments, and a quantitative comparison is presented. Results obtained from the automotive integrated design system enable the designer and manufacturer of oil pump to be more efficient in this field.