• Tribology and Lubricants
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• 제10권1호
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• pp.78-88
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• 1994

For the study of chemical and mechanical properties of the synthetic and mineral oil added with two different Zn-DTPs, base and formulated oils were analyzed and compared. Kinematic viscosity and total acid number (TAN) were tested at high temperature for formulated oils. Also the oils added with different alkyl groups of Zn-DTP were tested for thermal stability and TAN changes. The 4-ball machine was used to test for the mechanical properties, such as the coefficient of friction and wear. The worn areas after sliding test were analyzed with microscope and EDX, too. From the study, mineral and synthetic oil have different effects according to the various added ratio of the primary and secondary alkyl groups of Zn-DTP. Also the temperature of test oil affected the anti-wear and friction property of the formulated oils. For synthetic oil, the primery alkyl group of Zn-DTP made better friction properties than that of secondary, while, for mineral oil, secondary alkyt group was better only at low temperature for mineral oil.

• 패션비즈니스
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• 제13권6호
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• pp.45-60
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• 2009

This study examined the efficacy of restraining the increase of the bacteria colony of scalp according to the application of the Ayurvedic base oils and essential oils to scalp and hair. The result is as follows. The experiment illustrated that as the result of doing the paired sample t-test of a treated group and a control group according to constitutional oiling, the efficacy of the statistically significant decrease of the colony manifested in six tested groups except the group of Pitta constitution to which sesame and lavender were applied. Also, in a group that sesame was applied to Vata constitution and a group that coconut and lavender were applied to Pitta constitution, according to the passage of time, the result of being reduced the number of the colony was obtained and it showed that the oiling suitable for each constitution has the efficacy to decrease the colony of scalp. At the same time, regardless of the constitutions, the application of oils also showed the efficacy of restraining the increase of the bacteria colony of scalp. As the result of performing Paired Sample t-test for the subjective evaluation of the subjects in pre and post clinical testing, In the analysis of questionnaire that were obtained before and after the clinical testing, the results of all of the items except the item questioning a degree of inflammation appeared to be significant. That is to say, the subjects answered that a degree of keratin or a pain in scalp, an amount of sebum and a degree of hair damage were decreased after the application of oil more than before it. And in the question of a degree of hair damage, the application of oils were proved as having the efficacy to improve the hair damage.

• 청정기술
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• 제12권3호
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• pp.113-127
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• 2006

폐윤활유는 세멘트 킬른과 화력발전소의 직접 연료로 사용하여 에너지원으로 재활용하거나 정제 과정을 거쳐 연료유 또는 재생 윤활기유로 재활용 되고 있다. 우리나라는 주로 이온처리 공정을 활용하여 폐윤활유를 저급 연료유로 재활용하고 있고 2003년도 예치금제에서 생산자 책임재활용제도를 도입하여 폐윤활유의 재활용을 촉진하고 있다. 그러나 지난 5년간 재활용율은 70% 이내로 정체되고 있고 아직까지 선진국에서 추구하고 있는 재생 윤활기유로의 재활용기술 개발연구도 전혀 없는 실정이다. 이에 비하여 일부 선진 국가에서는 근래에 폐윤활유의 열분해 생성유 중의 타르 및 악취의 발생을 대폭 감소시키고 색도를 향상시켜 고급연료유를 생산하는 안정화 기술과 폐윤활유로부터 고급 재생 윤활기유를 생산하는 새로운 공정을 개발하여 상용화하였다. 또한 호주, 이태리, 독일, 미국 등 몇몇 국가에서는 폐윤활유를 재생윤활기유로 재활용하였을 경우 훨씬 많은 보조금을 지급하거나 국가나 지방 정부에서 재생 윤활유를 우선적으로 구매하도록 하고 소비자로 하여금 재생 윤활유를 사용하도록 권장하는 정책을 채택하고 있다. 이렇게 선진국에서는 점차적으로 고갈되는 석유자원의 절약과 환경오염을 저감시키는 폐윤활유를 윤활기유로 재활용하는 정책을 채택하고 있어 우리나라에서도 지속가능한 개발을 위한 새로운 윤활유 재활용정책을 수립하여야할 시점에 있다고 판단된다.

• 한국표면공학회지
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• 제40권1호
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• pp.11-15
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• 2007

Stable metallic Cu/Zn nanoparticles were prepared in the base oil phase by hydrothermal method. The physical properties, such as crystal structure, crystallite size and crystallinity according to synthesis conditions have been investigated by XRD, FT-IR and TEM. In addition, 4-ball test has been performed in order to investigate the frictional wear properties of prepared nanosized Cu/Zn particles. The peaks of the X-ray diffraction pattern indicate that the particle size was very small and crystallinity of Cu/Zn particles was good. The micrographs of TEM showed that nanosized Cu/Zn particles possessed a spherical morphology with a narrow size distribution. The crystallite size of the Cu/Zn particles synthesized in base oils was 23-30 nm. It was found that the antiwear capacity increases with increasing Cu/Zn concentration. When the concentration of Cu/Zn was 5.0 wt%, the wear scar diameters was 0.38 mm.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.165-172
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• 2014

The distribution of basic nitrogen-containing compounds in three vacuum gas oils (VGOs) with different boiling ranges and their dewaxed oils from the lube base oil refining unit of a refinery were characterized by positive-ion electrospray ionization (ESI) Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). It turned out that the composition of basic nitrogen compounds in the samples varied significantly in DBE and carbon number, and the dominant basic N-containing compounds in these oil samples were N1 class species. $N_1O_1$, $N_1O_2$, and $N_2$ class species with much lower relative abundance were also identified. The composition of basic nitrogen compounds in VGOs and dewaxed VGOs were correlated with increased boiling point and varied in DBE and carbon numbers. The comparison of the analytical results between VGOs and dewaxed VGOs indicated that more basic N-containing compounds in VGO with low carbon number and small molecular weight tend to be removed by solvent refining in lube base oil processing.

• Journal of Mechanical Science and Technology
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• 제17권9호
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• pp.1276-1286
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• 2003

The performance of porous bearing under different lubricants and lubricating conditions was experimentally investigated in this study. In order to carry out the experiments, a new test rig was designed to determine the tribological properties of based sintered bronze journal bearings that were manufactured by powder metallurgy (P/M) techniques. To determine the effects of lubricating conditions with and without oil supplement (OS) on the tribological characteristics of these bearings under static loading and periodic loadings, some experiments were carried out using different lubricants. In the tests, pure base oil (SAE 20W50), two fully formulated commercial engine oils (SAE20W50) and lubricating oils with commercial additive concentration ratio of 3％ were used. The worn surfaces of test bearings were examined using optical microscopy. Experimental results showed that the change in friction coefficient was more stable and in smaller magnitude under static loading than that of periodic loading. In addition, the friction coefficient and the wear rate conducted with base oil resulted in higher values than those of fully formulated oils with and without OS lubricating conditions. The experimental results obtained in this study indicated that the correct selection of lubricant and suitable running conditions were very important on the tribological characteristics of porous bearings.

• 한국응용과학기술학회지
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• 제30권4호
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• pp.715-725
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• 2013

바이오디젤은 세계 화석연료의 흐름을 변화시킬 수 있는 환경 친화적 대체물질로 관심의 대상이 되고 있으며 대체연료 외에도 다양한 분야에서 수많은 응용 연구가 진행되고 있다. 최근에는 원유의 정제로부터 얻어진 석유제품을 대체하려는 다양한 움직임이 활발하게 진행되고 있다. 그 중 윤활기유로서의 식물성 오일은 급속도로 발전된 석유산업으로 인해 상용화 되지 못했던 오일로 관심의 대상이 되고 있으며 자연친화적 생분해성과 무독성, 윤활유로서의 낮은 휘발성과 우수한 계면윤활 등 대체 오일로써 충분한 가능성을 지니고 있다. 하지만 우수한 윤활 및 마모성능에도 불구하고 윤활연구에 넓게 활용되지 못했던 이유 중에는 지방산메틸에스테르가 갖는 열악한 산화안정성(oxidation stability) 및 열화안정도(thermal stability) 때문으로 보고되고 있다. 따라서 바이오디젤을 윤활기유 내 일정비율로 혼합하여 윤활성능 및 산화안정성의 변화를 확인하였으며 사구식 내마모 성능시험 후 발생되는 산화 및 열화현상을 알아보았다. 또한 산화에 따른 혼합 오일의 윤활특성 변화를 분석하였으며 이러한 결과를 바탕으로 윤활유 또는 윤활 향상제로서의 가능성을 살펴보았다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.263-264
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• 2002

The tribological characteristic of several environmentally friendly lubricating base stocks was examined, and the effect of some commonly used additives on th tribological behavior of the lubricating oils was comparatively investigated on a four-ball machine. It has been found that the commercial additives including butene sulfide, wax chloride, zinc dialkyldithiophosphate and ashless P-N type agent helped to improve the friction-reducing and antiwear properties as well as the extreme pressure behavior. Non-toxic nanoscale $(CF)_x$ showed the best friction-reducing ability, though it registered relatively poor extreme pressure properties. The mechanism on friction of nano-scale material is discussed.

• 분석과학
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• 제10권2호
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• pp.139-145
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• 1997

합성 윤활기유로 사용되고 있는 알킬벤젠들 중에 단일, 그리고 이중치환된 알킬벤젠의 양과 알킬사슬에 존재하는 탄소원자의 수를 $^{13}C$-NMR, 근적외선 및 UV-Vis 분광법으로 분석하였다. 또한 엔진윤활유에 포함되어 있는 직선형 긴 사슬 알킬벤젠을 적외선분광법으로 분석하였다.

• Tribology and Lubricants
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• 제25권2호
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• pp.125-131
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• 2009

Biodiesel produced from triglyceride which is main component of animal fats and vegetable oils by methanolysis was known for excellent lubricity. In this study, the lubricity of 12 kinds of biodiesel come from vegetable oils were analyzed using HFRR(High frequency reciprocating rig). The biodiesel synthesized from soybean oil has best lubricity by $153{\mu}m$ of wear scar in HFRR and used fried oil's biodiesel has slightly low lubricity by $299{\mu}m$. Also we have found that the lubricity of diesel was improved when mixing ratio of soybean biodiesel was increased in base diesel.