• 한국자동차공학회논문집
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• 제19권2호
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• pp.66-71
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• 2011

This study analyzed the mechanical characteristics and evaluated their subsequent performance for two types of seals which reinforced characteristics with lower friction and anti-wear functions among the foremost important features in the automotive engine seals; one with the addition of glass fiber to PTFE(Polytetrafluoro ethylene); the other with the addition of self-lubricant molybdenumin addition to the glass fiber. Based on the configuration design of seal installed to the front part in the automotive engine, this study carried out interpretations on the stress and reaction for those two types of oil seals to compare the maximum stress and contact load generated from the seal steel, rubber and PTFE lip. This study also verified the stress concentration and anti-wear performance through the coefficient of friction, torque and durability test by producing two types of PTFE seals actually.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.122-129
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• 2011

Biodiesel produced from triglyceride which is main component of animal fats and vegetable oils by methanolysis was known for remarkable cetane number. In this study, the derived cetane number of 3 kinds of biodiesel came from vegetable oils such as soybean oil, palm oil, and perilla oil and 2 kind of biodiesel which were produced from beef tallow and pork lard were analyzed using IQT (Ignition quality tester). In IQT test result, the derived cetane number of palm- , beef tallow- and pork lard's biodiesel were more excellent than other biodiesels. After analysis of biodiesel composed molecular by gas chromatography-mass and determination of the derived cetane number of pure biodiesel components using IQT, we have found that the low olefin contented and long alkyl chained biodiesel have excellent derived cetane number.

• International Journal of Automotive Technology
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• 제7권3호
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• pp.245-249
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• 2006

Accelerated aging of engine exhaust system components such as catalytic converters are traditionally performed using an engine/dynamometer test stand. $SwRI^{(R)}'s\;FOCAS^{(R)}$ system reduces or eliminates many of the engine based aging limitations. This paper will describe several studies. These include: 1) replication of engine based catalyst aging cycles with added precision and dependability; 2) catalyst aging with and without lubricating oil effects; 3) effects of lubricant phosphorus on catalyst performance; and 4) the potential to thermally age components beyond the capabilities of engine based systems. The first study includes the development of the SwRI FOCAS system to run programmed aging conditions with or without lubricating oil. A description of the subsystems is given. The second two studies used the SwRI FOCAS system to age catalysts. One study compared thermal-only aging using of the SwRI FOCAS system with equivalent aging on a traditional engine/dynamometer test stand. The other study examined the effect on catalyst performance of two lubricating oils containing different levels of phosphorus, and compared the results to field data generated using the same oils in a fleet of vehicles.

• Coupled systems mechanics
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• 제8권2호
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• pp.129-146
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• 2019

The main goal of this work is to develop a numerical simulator to study an isothermal single-phase two-component flow in a naturally fractured oil reservoir, taking into account advection and diffusion effects. We use the Peng-Robinson equation of state with a volume translation to evaluate the properties of the components, and the discretization of the governing partial differential equations is carried out using the Finite Difference Method, along with implicit and first-order upwind schemes. This process leads to a coupled non-linear algebraic system for the unknowns pressure and molar fractions. After a linearization and the use of an operator splitting, the Conjugate Gradient and Bi-conjugated Gradient Stabilized methods are then used to solve two algebraic subsystems, one for the pressure and another for the molar fraction. We studied the effects of fractures in both the flow field and mass transport, as well as in computing time, and the results show that the fractures affect, as expected, the flow creating a thin preferential path for the mass transport.

• Applied Biological Chemistry
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• 제45권2호
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• pp.101-107
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• 2002

순비기나무의 잎, 꽃, 줄기 및 열매로부터 수증기 증류법으로 정유를 분리한 다음 GC-MS 및 GC를 이용한 표준품과 머무름 시간의 비교에 의해 76종의 성분을 동정하였다. 동정된 성분은 monoterpene hydrocarbons 16종, oxygenated monoterpenes 30종, sesquiterpene hydrocarbons 10종, oxygenated sesquiterpenes 8종, diterpenes 3종, 기타 성분 9종으로서, 특히 ${\alpha}-pinene$, ${\beta}-pinene$, sabinene, 1,8-cineole, terpinen-4-ol, ${\alpha}-terpineol$등의 monoterpene류가 주요 구성성분들이었다. 부위별 주요 구성성분으로서 잎에서는 ${\alpha}-pinene$ (30.25%) > 1,8-cineole (19.89%) > sabinene (9.56%) > ${\alpha}-ternineol$ (7.94%) > ${\beta}-pinene$ (5.69%) > terpinen-4-ol (2.37%), 꽃에서는 ${\alpha}-pinene$ (25.47%) > 1,8-cineole (7.69%) > manoyl oxide(6.21%) > ${\beta}-pinene$ (4.20%) > ${\alpha}-terpineol$ (3.76%) >sabinene (2.78%), 줄기에서는 ${\alpha}-pinene$ (13.24%)>${\alpha}-terpineol$ (10.64%)>1,8-cineole (4.40%)>manoyl oxide (4.02%) > ${\beta}-pinene$ (2.39%) > terninen-4-ol (2.21%), 그리고 열매에서는 ${\alpha}-pinene$ (20.24%) > 1,8-cineole (11.47%) > ${\beta}-pinene$ (9.79%) > u-terpineol (7.08%) > sabinene (3.68%) limonene (2.77%)의 순서로 조성비율이 높았다. 전반적으로 순비기나무의 잎과 열매에서 분리한 정유에서는 monoterpene류의 조성비율이 높았으나 꽃과 줄기에서는 잎이나 열매에 비해 sesquitepene류, diterpene류 이외에도 구조를 동정하지 못하였으나 diterpene류 일 것으로 예상되는 분자량이 비교적 큰 성분들의 조성비율이 높았다.

• 한국식품저장유통학회지
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• 제14권4호
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• pp.351-355
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• 2007

감귤 부위별 및 감귤 주스 가공 후 폐기되는 착즙박을 배지로 하여 재배된 간, 표고, 새송이, 산호침, 참부채 및 영지 버섯) 균사체의 GC/MS에 의한 휘발성 물질을 분석하였다. 감귤 분말에서 휘발성 물질은 29종류이었는데, ${\delta}-elemene$, ${\beta}-elemene$, ${\beta}-caryophyllene$, caryophyllene, ${\gamma}-elemene$, germacrene-D 및 ${\delta}-cadinene$은 감귤류의 essential oil 중의 성분들이었으나 8-hydroxy-linalool, ${\beta}-selinene$, tetradecanoic acid 및 pentadecanal은 essential oil 중의 성분들이 변화한 것이었다. 이외에도 tangeretin, nobiletin, 및 stigmasterol이 검출되었다. 버섯 균사체 분말에서 검출된 휘발성 성분들은 18종이었으며, ${\beta}-elemene$, germacrene-D 및 ${\delta}-cadinene$은 버섯이나 균사체에서 보고되지 않은 것으로 보아 균사체 배지로 사용한 착즙박에서 유래한 것으로 생각된다. caryophyllene, hexadecanoic acid, decanoic acid 및 tetradecanoic acid는 기 보고된 버섯이나 균사체의 성분들이었으며, Limonene-1,2-epoxide, ethyllinoleate, 1,2-benzenedicarboxylic acid, dicyclohexyl ester 및 ($3{\beta}$,24S)-stigmast-5-en-3-ol (${\gamma}-sitosterol$)은 감귤이나 버섯 균사체에서 보고되지 않은 성분들이 검출되었다.

• Preventive Nutrition and Food Science
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• 제17권3호
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• pp.234-238
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• 2012

The volatile aroma constituents of Chrysanthemum zawadskii var. latilobum K. were separated by hydro distillation extraction (HDE) method using a Clevenger-type apparatus, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of C. zawadskii var. latilobum K. flower essential oil (FEO) was 0.12% (w/w) and the color was light green. Fifty-five volatile chemical components, which make up 88.38% of the total aroma composition, were tentatively characterized. C. zawadskii var. latilobum K. FEOs contained 27 hydrocarbons, 12 alcohols, 7 ketones, 4 esters, 1 aldehyde, 1 amine, and 3 miscellaneous components. The major functional groups were terpene alcohol and ketone. Borneol (12.96), (${\pm}$)-7-epi-amiteol (12.60), and camphor (10.54%) were the predominant volatiles. These compounds can be used in food and pharmaceutical industries due to their active bio-functional properties.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1288-1292
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• 2009

Volatile flavor compounds were isolated from the flowers of Chrysanthemum indicum L. (gamguk) produced in Korea and China by the hydro distillation, and were analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of oils from Korean and Chinese gamguk were 2.0 and 0.5%(v/w), respectively. Sixty-three volatile compounds of Korean gamguk representing 89.28% of the total peak area were tentatively identified, including 35 hydrocarbons, 12 alcohols, 6 ketones, 3 esters, 5 aldehydes, 1 oxide, and 1 miscellaneous component. Thirty-six volatile components of Chinese gamguk constituted 58.15% of the total volatile composition were tentatively characterized, consisting of 19 hydrocarbons, 7 alcohols, 2 ketones, 2 esters, 4 aldehydes, 1 oxide, and 1 miscellaneous component. The predominant components of Korean oil were ${\alpha}$-pinene, 1,8-cineol, and chrysanthenone. Whereas, camphor, ${\alpha}$-curcumene, and ${\beta}$-sesquiphellandrene were the main aroma compounds of Chinese gamguk.

• 한국정밀공학회지
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• 제31권5호
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• pp.451-457
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• 2014

Surface roughness of mechanical components is an important factor which affects the tribological phenomena. Various surface patterns have been applied to surfaces to improve the tribological characteristics of mechanical components. In this work, the friction reduction effect of micropatterns on silicon was investigated. For this purpose, micro-dimple patterns were fabricated on silicon wafer by DRIE process. In the friction experiments silicone oil was used as lubricant. Also, the lubricant was cleaned to simulate a lubricant depleted condition. In depleted lubricated condition, friction coefficient of micro-pattern specimens was lower than specimens without micro-patterns. It was found that friction reduction effect of micro-pattern could be successfully maintained even after cleaning the lubricant on the surface.

• 유공압시스템학회논문집
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• 제6권1호
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• pp.25-31
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• 2009

This study presents an analytical model of hydraulic clutch system of a power shift transmission to analyze pressure modulation characteristics. A typical hydraulic clutch system was modeled by using AMESim in which the parameters of major components were measured for simulation. Test apparatus was established using the components of power shift and power shuttle clutches with instrumental equipment. The results of simulation and experiment were so close that the proposed analytical model in this study was validated. However the cylinder model analogized clutch dynamics need to be improved in future study. The effects of parameters of orifice diameter, accumulator stroke and oil temperature on pressure modulation were analyzed respectively. The results of parameter sensitivity analysis show that modulation time and set pressure can be easily adjusted by changing parameter values. It is also found that the hydraulic clutch system used in this study is so susceptible to oil temperature that cooling equipment is necessary.