• Corrosion Science and Technology
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• 제6권4호
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• pp.211-218
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• 2007

In this paper, evaluation and development of corrosion resistant materials for smokestacks is summarized mainly on the basis of the author's experimental results. Operating environments of smokestacks and the problems of conventional lining materials for smokestacks are described briefly. The emphasis is focused upon the evaluation and development of recently developed corrosion resistant steels such as YUS260 for heavy oil fired smokestacks, WELACC5 for LNG fired smokestacks and NSL310MoCu Clad steel for coal fired smokestacks. Corrosion resistance of these steels under laboratory corrosion testing environments and actual environments are evaluated. Finally future problems of corrosion resistant materials for smokestacks are touched on briefly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.84-86
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• 2001

Acrylonitrile Butadiene Rubber (NBR) has been used as a transformer gasket material because the transformer gaskets should have high resistivity to oil and should not swell and deform when it contact to insulating oils. Serious cracks were observed in the gaskets being used and ozone test was performed on new, specimens. Cracks were also observed on specimens. So we have performed the following tests on the anti-oxidants containing new gaskets according in accordance with KEPCO purchase specifications; ozone resistance, oil resistance, mechanical properties before and after aging.

• 동력기계공학회지
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• 제22권6호
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• pp.44-50
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• 2018

As a type of bolt with a spherical head, the ball stud is widely used as a part of a ball joint in steering or suspension systems in automobiles. Balls and studs are subjected to heat treatment suitable for each material; in particular, the shear strength of the ball stud must meet the specifications of the production company. This study evaluated the shear strength of joints according to the cooling method of ball studs subject to resistance welding. The shear stress of water cooling was higher than that of air cooling (as-received material). Note, however, th at oil cooling showed lower stress than that of as-received. When judged by standard deviation, mean, and coefficient of variation according to the arithmetic statistics and shape parameter as well as scale parameter, oil cooling is suitable.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제31회 춘계학술대회
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• pp.126-133
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• 2000

A computer program for the analysis of engine lubrication systems has been developed. And a case study of a four cylinders gasoline engine is illustrated. This paper gives the mathematical models for oil flow through hydraulic tappet as well as the ones of oil jet and plain journal bearings. And the new from an oil pump and the flow resistance through an oil filter is considered at various temperatures. In the analysis, the various design guidelines are applied. The distribution of flow and pressure of an engine lubrication system are calculated, and the pressure data compared with the experimental data at a few points in the engine lubrication system. This method is helpful to design of engine lubrication system efficiently.

• 한국전기전자재료학회논문지
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• 제19권1호
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• pp.46-51
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• 2006

This paper reports on the effects of silicone oils, used as processing agents, on the recovery of hydrophobicity of silicone rubber. The recovery of hydrophobicity was evaluated by the measuring the contact angle, the surface electrical resistance and SEM. Here, we formed artificial contamination on the surface of samples, which scratched by sand papers and alumina powders. There was small recovery of hydrophobicity on the surface of SIR-A that silicone oil was not added. In both oil-added samples, SIR-B and SIR-C, recovery of hydrophobicity was achieved greatly. The surface of SIR-C showed that a lot of silicone oil was observed due to migration of oil, relatively in comparison with SIR-B. The tendency of recovery of hydrophobicity expressed by contact angle was in a good agreement with electrical property as determined by surface resistivity.

• KSTLE International Journal
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• 제1권1호
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• pp.21-28
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• 2000

A computer program fur the analysis of engine lubrication systems has been developed. And a case study of a four cylinders gasoline engine is illustrated. This paper gives the mathematical models far oil flow through hydraulic tappet as well as those of oil jet and plain journal bearings. And the flow from an oil pump and the flow resistance through an oil filter is considered at various temperatures. In the analysis, the various design guidelines are applied. The distribution of flow and pressure of an engine lubrication system are calculated, and the pressure data compared with the experimental data at a few points in the engine lubrication system. This method is helpful to design of engine lubrication system efficiently.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.35-36
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• 2022

In order to supplement the flame-retardant performance of oil stain, which can prevent wooden buildings from contamination, (NH4)2HPO4, a phosphorus flame-retardant, was added to oil stain and applied for each type of plywood, and an experiment was conducted. The addition rate was set to 0-60%, but white powder appeared on the surface of plywood from 40% and thus it was impossible to experiment, so the maximum addition rate was selected as 30%. As a result of the experiment, acacia plywood had the best performance. As the rate of addition of the flame retardant increased, the remaining time and carbonization length of all plywood decreased, but the carbonization length of the MDF plywood was not met with the standards.

• 수산해양교육연구
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• 제25권3호
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• pp.705-715
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• 2013

This Paper presented the reduction methods of $CO_2$ emission from ships during voyage. In order to decrease $CO_2$ emission during voyage the equation was established and conducted the study about the relationship between ship speed, the propulsive efficiency and its $CO_2$ production. The results obtained from the examinations are as follows : 1. $CO_2$ emission from sailing ships can be decreased by reducing specific fuel oil consumption of main diesel engine, coefficient of total resistance and ship speed and also by increasing propeller efficiency. 2. Diesel-electric propulsion system is more effective than diesel-mechanical system to decrease the level of $CO_2$ emission during long voyage. 3. Good condition of ship's hull surface, rudder and propeller's surface can decrease the quantity of fuel oil and $CO_2$ emission by reducing the resistance of ship that can rise the propeller efficiency 4. $CO_2$ emitted from ships can be decreased in a global scale by giving attention to the synthetic transport efficiency.

• Journal of Korean Biological Nursing Science
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• 제6권2호
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• pp.5-17
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• 2004

Purpose: The purpose of this study is to determine effects of aromatherapy on the activity and balance of autonomic nervous system and on physical resistance to stress. Methods: This research is a primitive experimental design which attempts to analyze aromatherapy EKG monitoring on real-time basis. Lavender & Chamomile, each 30 drops, were blended with 100ml Sweet Almond oil. Subjects was laid relaxed, and had insides of his wrists and ankles attached with electrodes for EKG. Right after applied with essential oil onto his philtrum and parotid, started on EKG monitoring. Results: The activities of parasympathetic and sympathetic nerve were changed as time elapsed, with significant differences(p=.000). In multiple comparison, the value was significantly different(p<.05).The balance of autonomic nerve was changed, becoming close to the normal level in accord with applicable international standards(1.5)(p=.011). In multiple comparison, the value showed a significant difference(p<.05). Physical resistance to stress increased with the passage of time, but not statistically significant. Conclusions: This suggests that aromatherapy can be used as a nursing intervention which aims at alleviating symptoms related to the imbalance of autonomic nerve system such as headache, hot flashes, irregular heartbeat, nervousness, depression and anxiety.

• Tribology and Lubricants
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• 제11권5호
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• pp.162-171
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• 1995

The application of reciprocating engine crankshaft bearings is of particular importance and interest among the plain bearing, not only because the sheer volume of intemal combustion engines now produced, but because the severe operating conditions they are subjected to. Demands for better performances of crankshaft bearings have provide an important impetus in the development of bearings and bearing materials. As engine design progresses toward higher outpt and higher efficiency, crankshaft bearings must perform under more seveve operating conditions. Higher load, temperature, and speed as well as lower viscosity oil are applied to the bearing sysem, resulting in a smaller minimum oil film thickness. This means more solid-solid contact between the shaft and bearing, and the bearing is exposed to more danger of seizure. Some engines may experience bearing seizure problems. However, understanding about the seizure behavior and mechanism is far from being enough. Seizure resistance of a bearing-shaft system will be affected by the properties of the shaft and bearing, especially their materials and surface texture. Commonly used engine bearing materials include Al-Pb-Si, Al-Sn-Si, Al-Sn, and Cu-Pb with Pb-Sn-Cu overlay. These materials have very different properties. They showed different behaviors dering seizure tests and seizure may occur with different mechanism for different bearing material. Shaft materials also affect the seizure resistance of the system. Surface texture of the bearing and shaft have apparent effects on the lubrication and solid-solid contact pattern, and therefore will affect the seizure behavior of the system. Bearings and shafts which are made of different materials and have different surface textures have been tested and analyzed. Their effects on seizure resistance are discussed and possible seizure mechanisms for different beatings are presented in this paper.