• Tribology and Lubricants
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• 제18권4호
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• pp.273-278
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• 2002

Grease deterioration of mineral oil type grease was investigated using sealed deep groove ball bearings (6203) and bearing life test rig. The bearing test was performed under 3,000 rpm and 245 N radial load at 120。C. Grease taken ken tested bearings was checked in using certain evaluation methods, for example, oxidation induction time (OIT), FT-IR peak intensity, leakage .ate, bleeding .ate, total acid number. (TAN) and bearing noise increase. Within these test conditions, OIT, TAN, bleeding rate were changed gradually in accordance with bearing operating time and showed useful indices for deterioration of grease.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.338-341
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• 2007

본 논문에서는 공동주택에서 운전되고 있는 승강기의 노후화 현상에 대한 현장 조사를 실시하였다. 조사대상 승강기는 1990년도부터 시설된 교류제어방식 승강기와 1995년부터 설치된 인버터 승강기이다. 현장 조사 결과 승강기의 주요 노후화 현상은 누유, 마모, 부식 등인 것으로 조사되었다. 또한 승강기가 시설되고 8년이 되는 시점부터 고장 횟수가 크게 증가하는 것으로 분석되었다.

• 오토저널
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• 제13권4호
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• pp.85-93
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• 1991

Engine oil of the vehicle is very important to reduce friction and wear of the moving parts as long as possible without deterioration. As the technique of engine design and manufacturing improves, the performance of engine was increased greatly with the improvement of the quality of engine oil. All the additives and formulations skill of engine oil produced in our country are imported from foreign country. So it is necessary to study the basic knowledge of the mechanism of friction and wear of engine oil for the development of our own formula and additives. From this research, the basic mechanism of tribology and the change of oil properties were studied with a home made oil and two foreign oils by bench and engine test and laboratory works.

• 한국해양환경ㆍ에너지학회지
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• 제15권1호
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• pp.22-24
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• 2012

엔진오일 상태에 따라서 엔진 오일의 유전율이 변화하게 된다. 오일의 유전율은 프로브의 특성 임피던스와 관계가 있으며, 프로브의 특성 임피던스는 프로브 입력단의 반사 신호를 결정한다. 본 논문에서는 프로브의 등가회로를 유도하고 정전용량 측정에 의해서 구한 유전율의 변화에 따른 프로브의 반사 계수를 이론적으로 계산 하였다. 결과로 오일의 상태가 열화 되면 반사 계수가 증가 되는 것을 알 수 있다.

• 한국안전학회지
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• 제21권1호
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• pp.86-91
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• 2006

Oil spills caused by the accidents have been occurred from house and factory waste, grounded tanker, the rupture of storage tank and oil pipelines, the deterioration of various industrial facilities, etc. Many oil spills result in contamination of shorelines and workplace. Fire and explosion may happen from these spills. There are several technologies used for clean-up application, which include use of oil dispersing agents, absorbents, solidifiers, booms and skimmers by physical, chemical, and biological methods. Methods for oil spill clean-up operation are classified into the absorption type, gel type and self-swelling type. Porous materials with oil absorptive properties are classified into micropore, mesopore, and macropore depending on their pore sizes. Recently, new porous materials with smaller size have been developed, but the selective oil absorption in water-in-oil interface demonstrates the macro pore size. In this study oil absorption effects were evaluated using the organic porous materials with a complex function of gel type and swelling type. Samples were subjected to analysis by FT-IR spectroscopy and were characterized in terms of gel formation and morphologies. Oil sorption capacity, pressure retention force and gel strength were also measured. From these results, the physicochemical reactivity before and after gelation was verified and the industrial applications of clean-up operation were suggested.

• Advances in nano research
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• 제15권6호
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• pp.541-550
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• 2023

The escalating growth of industrial sectors has led to a pervasive global problem—oil pollution, particularly in industrial areas. The release of substantial volumes of oil and its by-products into the environment has resulted in extensive contamination. Multiple factors contribute to the entry of these substances into water bodies and soils, thereby inflicting irreparable consequences on ecosystems, natural resources, and human health. Consequently, it becomes imperative to comprehend the characteristics and behavior of oil pollution, anticipate its impacts, and develop effective mitigation strategies. Understanding this intricate issue requires considering the physicochemical properties of the environment, the interactions between oil and sediments, and biological factors such as evaporation and dissolution. Although the oil industry has brought about remarkable advancements, its activities have raised significant concerns regarding pollution from extraction and production processes. Oil-rich nations face a particularly challenging predicament of soil pollution caused by petroleum compounds. The areas surrounding oil exploration mines and refineries often endure contamination due to oil leakages from storage tanks and transmission lines resulting from deterioration and damage. Investigating the dispersion of such pollutants and devising methods to remediate petroleum-contaminated soil represent crucial and intricate issues within the realm of environmental geotechnics.

• 한국해양환경ㆍ에너지학회지
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• 제15권1호
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• pp.25-29
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• 2012

본 논문은 프로브의 반사계수를 이용하여 엔진오일의 열화정도를 측정하기 위해 반사 계수를 측정하는 회로를 설계한다. 프로브에 펄스를 인가하고 반사 신호를 측정할 수 있는 회로를 구현 하였다. 엔진오일의 상태가 열화 될 수록 반사 신호는 증가하는 것을 알 수 있었고, 엔진오일의 온도가 상승함에 따라 열화된 엔진오일의 유전율이 감소하는 현상을 측정하였다. 결론적으로, 프로브의 반사 계수를 이론치와 측정치를 비교 분석하였다.

• 전기의세계
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• 제25권2호
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• pp.87-91
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• 1976

Experimentally to investigate the conductive characteristic of oil-immersed paper, we observed the leakage current-voltage characteristic of oil-immersed paper, the temperature dependence of ionization rate and the effect of metal electrode on the leakage current. The results showed that the leakage current-voltage characteristic generally followed the experimental equation i=i$_{0}$ exp (K.root.E) and the slope K did not change by the temperature and electric strength, but only when the direct voltage was applied. And also the leakage current seemed to depend on the work function of metal electrode. From the above results we concluded that the deterioration of oil-immersed paper was not only caused by the thermionic emission from the cathode but also by the conductive property of oil-immersed paper in itself and the work function of metal electrode.e.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.130-136
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• 2004

Presence of water in the lubricating oils could be one of the first indicators of potentially expensive and possibly catastrophic failure of the machine as it may cause displace the oil films to prevent the lubrication function of the oil or chemically react with many oil additives resulting in the oil degradation. In order to detect water content quantitatively in lubricating oils many methods and sensors has been developed. Among these, capacitive sensors including sensitive layer, whose dielectric factor changes according to the water content absorbed in the layer, are proposed mainly in the market. But these sensors are not sensitive to a high water content. Besides, the absorbing layer soils in time. In this work, an evaporation of water moisture from oil into air volume above lubricant surface and condensation of water vapor at a cooling surface was used to measure water content quantitatively in an lubricating oil. Laboratory test results of a prototype sensor were presented. Test results showed that the proposed method could be avaliable to measure a low levels of oil moisture.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1036-1038
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• 1998

The while, PD source detection in the oil TR was the level of the planar source detection. and it is to respected scientific research. The planar source detection technique had limits which have difficulties finding out the point of deterioration generation. In this study, our purpose is a development of PD source detection technique with Three-Dimensional using a principle and a technique of the planar source location.