• The Korean Journal of Pesticide Science
• /
• v.14 no.1
• /
• pp.54-64
• /
• 2010

Effects of thirteen essential oils (anise oil, clove oil, marigold, mustard oil, neem oil, quassia, quilaja, rosemary oil, rotenone, tea tree extract, thyme oil, wintergreen oil, and yucca) and caffeine on typical industrial insect, silkworm (Bombyx mori) and two entomopathogenic nematodes, Steinernema carpocapsae GSN-1 strain (Sc) and Heterorhabditis sp. Gyeongsan strain (Hg) were investigated in the laboratory. When 1,000 ppm of each essential oils was treated, neem oil showed the highest insecticidal activity against silkworm. Mortality of silkworm fed on neem oil treated mulberry leaf was 55.3 and 100% 5 and 10 days after treatment, respectively. The silkworm fed on neem oil treated mulberry leaf did not make cocoon and pupa. Weight of cocoon and pupa was low in rotenone treatment showing 0.27 g and 1.01 g, respectively. Mustard oil had the highest nematicidal activity against entomopathogenic nematodes. 20 ppm of mustard oil resulted in 69.0% and 100% mortality of Sc and Hg 3 days after treatment, but 4% and 36% at 5 ppm in X-plate, respectively. Mortality of baited Galleria mellonella larva by Sc was not different from control at the concentration of 100 ppm of mustard oil while 30% lower in Hg in sand barrier. Mean numbers of established infective juveniles of Hg in Galleria larva were lower than Sc in sand barrier. Survival rate of Sc was similar to control at the concentration of <200 ppm of mustard oil in sand barrier.

• KSTLE International Journal
• /
• v.2 no.2
• /
• pp.103-113
• /
• 2001

The influence of aerated oil on high-speed journal bearing is examined by classical thermohydrodynamic lubrication theory coupled with analytical models for viscosity and density of air-oil mixture in fluid-film bearing. Convection to the walls and mixing with supply oil and re-circulating oil are considered. The live oil surface tension is considered as functions of temperature, API gravity and air volume ratio. With changing eccentricity ratio, it is investigated the effects of air bubbles on the performance of a high-speed plain journal bearing. Just at the moderate eccentricity ratios, even if the involved aeration levels are not so severe and the entrained air bubble sizes are not so small, it is found that the bearing load and friction farce may be changed so visibly for the high speed bearing operation.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.3 s.192
• /
• pp.61-66
• /
• 2007

This work is aimed to measure the deterioration in oil sensor. For the study, the circuit of a coil-type oil sensor packaged was developed and applied to the automobile engine for monitoring the deterioration of engine oil in driving conditions. From the principle which the deterioration of automobile engine oil can be expressed to the dielectric constant, the capacitance bridge circuit and the integrator circuit were designed. As results, the range of operating temperature of engine oil was experimentally recommended within $55^{\circ}C$ for the stability of a sensor designed. It was also concluded that the characteristics of output voltage converted from the dielectric constant were linearly distributed and predicted the optimized time for the exchange of engine oil.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.10b
• /
• pp.423-424
• /
• 2002

Amount of regulated emissions (CO, $NO_x$, HC), and emissions of some groups of organic substances (volatile hydrocarbons, polyaromatics, and aldehydes) were measured in the standard ECE 83 test on spark ignition engine of a passenger car. The influence of the engine oil composition (mineral or fully synthetic) was examined. For both engine oils, exhaust emissions were measured with fresh oil as well as used oil at the end of the oil drain interval. Unleaded petrol and CNG were used as fuels in all experiments performed. The main conclusion made from the tests is that polyaromatics is the only part of th ε exhaust emissions that was influenced with the nature of the engine oil. Effect on the other components of emissions (aldehydes and VOC) was negligible. Emissions of polyaromatics were almost twice higher for fresh mineral as for fresh fully synthetic oil. The amount of polyaromatics in the exhaust emissions increased slightly with mileage for fully synthetic and substantially more for mineral engine oil.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.12 no.9
• /
• pp.791-801
• /
• 2000

An experimental study was conducted to analyze the effects of oil on refrigerant flow through adiabatic capillary tubes, and to develop a model for mass flow rates of refrigerant/oil mixture at various capillary tubes and flow conditions. Mass flow rates and the profiles of the pressures and temperatures along the capillary tubes was obtained with the oil concentration of R-22/SUNISO 4GS oil mixture at various test conditions. The flow trends as a function of geometry and flow conditions for pure refrigerant and refrigerant/oil mixture were similar in adiabatic capillary tubes. Mass flow rate of the refrigerant/oil mixture was less than that of pure refrigerant at the same test conditions.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.2
• /
• pp.108-112
• /
• 2011

When oil spills occur in the ocean because of a ship collision or grounding, the oil in the sea will spread to the coastline. To effectively and promptly prevent such an oil spread, the prediction of the direction and speed of the spreading oil must be made. By applying the coastal wave diffusion theory with a consideration of the effects of wind and current, the oil spreading direction and speed can be predicted promptly so that the National Disaster Prevention System can effectively and promptly take countermeasures against the attack and contamination of the coastline by such oil bands.

• Journal of Sensor Science and Technology
• /
• v.21 no.6
• /
• pp.434-439
• /
• 2012

In this study, the oil degradation measuring for integrated sensor of drain valve was fabricated. A sensor used in the experiments was integrated with drain valves and installed in oil pan without requiring additional space. As a result of the experiments, the capacitances changed with two inflection points in accordance with an after in mileage. The first inflection point indicated the exhaustion of oil additives, and after the second inflection point, the oil degradation was completed, which increased the viscosity and disabled the functions of oil. Thus, this section was determined as the time of oil exchange.

• Tribology and Lubricants
• /
• v.7 no.1
• /
• pp.46-54
• /
• 1991

As the additives of engine oil, Mo-DTP and Zn-DTP were studied by experimental works. These additives were added to the engine oil with various ratios, which was an attempt to find out the best ratio at which the wear and friction can be reduced effectively; Mo-DTP is belived to be able to decrease the frictioh of the sliding metal, while Zn-DTP is known as a very stable additive for oxidation at high temperature in addition to the good antiwear property. This study showed that the optimum addition ratio of Mo-DTP and Zn-DTP is 3:2. This oil made it possible to slide steel with minimum wear and low friction over various lovels of load at moderate temperature. But as the oil temperature increased, the wear slid with Mo-DTP oil was increased more. The reason of this result was that Mo-DTP deteriorated the property of oil at high temperature by the higher oxidation and viscosity of Mo-DTP oil than that of Zn-DTP oil.

• Journal of Power System Engineering
• /
• v.19 no.2
• /
• pp.90-95
• /
• 2015

Recently worldwide concern and research is being actively conducted on green energy which can reduce environmental pollution. A plant such as the natural rapeseed oil, soybean oil, palm, etc. is used as a bio source in home and industry. Biofuels is a sustainable fuel having economically benefits and decreasing environmental pollution problems caused due to fossil fuel, and it can be applied to the conventional diesel engine without changing the existing institutional structure. Waste vegetable oil contains a high cetane number and viscosity component, the low carbon and oxygen content. A lot of research is progressing about the conversion of waste vegetable oil as renewable clean energy. In this study, waste oil was prepared to waste cooking oil generated from the living environment, and applied to diesel engine to confirm the possibility and cost-effectiveness of biodiesel blend waste oil. As a result, brake specific fuel consumption and NOx was increased, carbon monoxide and soot was decreased.

• Tribology and Lubricants
• /
• v.14 no.3
• /
• pp.51-58
• /
• 1998

This paper considers analysis of the lubrication between the piston ring and the cylinder liner. Piston ring lubrication analysis considering oil transport is important because oil consumption is an essential factor to design the piston assembly. To develop the lubrication analysis program for the piston ring, oil continuity condition and open-end boundary assumption are used for computational boundaries. Results show that oil continuity can be almost satisfied at any crank angle in and out of the piston ring clearance. Therefore the amount of oil consumption and the dynamic behavior of ring pack can be estimated using this algorithm. And it can be known that the effective width may be smaller than the full width of the piston ring, so oil starvation condition should be considered for the lubrication analysis of the piston ring.