• International Journal of Air-Conditioning and Refrigeration
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• v.8 no.2
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• pp.80-88
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• 2000

In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method is to extract the working mixture and then to measure the oil weight. In this study, oil concentration is measured in si.tu way without any extraction of the working fluid. Based on the measurement, a working equation is presented as follows, C=a +b x t +c x $t^2$ +(d + e x t +f x $t^2$) x SG. C is oil concentration, t is temperature($^{\circ}C). SG Is specific gravity of mixture and a~f is coefficients The oil concentration ranges over 0~l2 wt% and the temperature ranges over 20~50$^{\circ}C. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/P0E oil liquid mixtures.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.1
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• pp.20-28
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• 2001

In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method is to extract the working mixture and then to measure the oil weight. In this study, oil concentration is measured in si.tu way without any extraction of the working fluid. Based on the measurement, a working equation is presented as follows, C=a +b x t +c x $t^2$ +(d + e x t +f x $t^2$) x SG. C is oil concentration, t is temperature($^{\circ}C). SG Is specific gravity of mixture and a~f is coefficients The oil concentration ranges over 0~l2 wt% and the temperature ranges over 20~50$^{\circ}C. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/P0E oil liquid mixtures.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.67-72
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• 2010

G8 summit meeting held in July 2008 decided to set up a long-term goal, by 2050, reducing the world greenhouse emissions by half of those emitted in 1990. In November 2009, the Government announced to reduce the national $CO_2$ emission by 30[%] of BAU by 2020. Electric power industries in Korea produce most of their electricity by burning fossil fuels, and emit approximately 28[%] of national $CO_2$ emissions. Monitoring the $CO_2$ emissions. Monitoring the $CO_2$ emission of electric power plants is very important. This paper presents a method to calculate the hourly $CO_2$ emission for a thermal power plant burning mixture of coal and oil using the performance test data and coal-oil mix rate. An example of $CO_2$ emission calculation is also demonstrated.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.845-851
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• 2012

To elucidate the relationship between the arachidonic acid (AA) content and the taste of broiler meat, the effects of AA-enriched oil (AAO) supplements on the fatty acid content and sensory perceptions of thigh meat were evaluated. Four types of oil, including corn oil (CO), a 1:1 mixture of AAO and palm oil (PO) (1/2 AAO), a 1:3 mixture of AAO and PO (1/4 AAO), and a 1:7 mixture of AAO and PO (1/8 AAO) were prepared. Each type of oil was mixed with silicate at a ratio of 7:3, and added to the diet at a final proportion of 5% of fresh matter. Broiler chickens were fed these diets for 1 wk before slaughter. In thigh meat, the AA content of the 1/2 and 1/4 AAO groups was significantly higher than that of the CO group. The AA content in thigh meat (y, mg/g) increased linearly with increasing dietary AAO content (x, g/100 g of diet), according to the equation y = 0.5674+0.4596x ($r^2$ = 0.8454). The content of other fatty acids was not significantly different among the 4 diet groups. Sensory evaluation showed that the flavor intensity, umami (L-glutamate taste), kokumi (continuity, mouthfulness, and thickness), and aftertaste of the 1/2 and 1/4 AAO groups were significantly higher than that of the CO group. There were significant positive correlations between AA content in thigh meat and the flavor intensity, total taste intensity, umami, and aftertaste. These data suggest that the taste of broiler meat can be improved by the amount of dietary AA supplementation.

• Proceedings of the SAREK Conference
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• 2006.11a
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• pp.91-91
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• 2006

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.9-9
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• 2007

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.1
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• pp.73-79
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• 2011

A portion of oil for lubrication of compressor flows together with refrigerant in the refrigeration system. If the oil discharge from a compressor is increased in the refrigeration system, not only pressure drop is increased in other components, such as evaporator and gas cooler, but also heat transfer coefficient in the heat exchangers is decreased. Oil discharge rate from a compressor may strongly depend on operating conditions of a compressor. In this study, one stage single rotary compressor is employed for measuring oil circulation ratio(OCR). Carbon dioxide and PAG oil are used as refrigerant and lubricant. Using a U-tube densimeter, mixture density is measured. Oil circulation ratio(OCR) can be estimated by measured mixture density. The results obtained indicate that the oil circulation ratio(OCR) is increased as the suction temperature or compressor operating frequency is increased. Oil circulation ratio(OCR) correlation of the compressor is also suggested.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.186-192
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• 2017

In this study, water in oil (W/O) emulsion fuel was prepared with surfactant mixture of OIMS90 and NP12 by varying ratio of water to bunker-C oil, surfactant concentration and composition, emulsification time, stirring intensity, temperature and mixing time. Diesel engine performance and exhaust emissions were measured and analyzed with prepared emulsified fuel and compared with those measured using bunker Coil. The results indicated that bunker C emulsion fuel stabilized by surfactant mixture of OIMS90 and NP12 is efficient in reducing emissions of particulate matter, $NO_2$, CO, $CO_2$ and $SO_2$. The biggest reduction in exhaust emission was achieved by using emulsion fuel prepared by OIMS90/NP12 = 4 : 6, 500 ppm of total surfactant concentration and 10% water content at $80^{\circ}C$. Boiler efficiency test measured with emulsion fuel showed excellent energy efficiency compared with bunker C oil.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.893-898
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• 2009

The quantity of discharged oil from a compressor is one of the most important issues for proper operation of refrigeration system. If the oil is increased in the system not only pressure drop is increased in other components, such as evaporator and gas cooler but also heat transfer coefficient in the heat exchangers is decreased. In addition, the lack of oil in the compressor may cause a critical of the system failure. In this study, one stage single rotary compressor is used for measuring oil circulation ratio(OCR). Carbon dioxide and PAG oil are used as refrigerant and lubricant. Using a U-tube densimeter, mixture density is measured. Characteristics of oil circulation ratio have been investigated for $CO_2$ rotary compressor in the range of operation frequency 45 Hz to 63 Hz and the suction temperature range of $0^{\circ}C$ to $15^{\circ}C$. The results obtained indicate that the oil circulation ratio is increased as the suction temperature or compressor operating frequency is increased.

• Research in Plant Disease
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• v.15 no.1
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• pp.23-29
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• 2009

Cooking oil and yolk mixture (COY), a environmentally acceptable plant protection agent, and COY+$CaCO_3$+neem oil mixture were studied to control the powdery mildew occurring on eggplant, paprika, cherry tomato and maturity tomato in glass houses and vinyl houses during 2005 to 2007. The morphological changes of the pathogenic fungi on the leaf surface before and after treatment of COY were observed. COY made of rape seed oil and COY+$CaCO_3$+neem oil mixture were sprayed three times with 5 days interval to foliar parts of eggplant, paprika and tomato and the disease development were examined 5 days after final spray. In eggplant, the control efficacy of COY to powdery mildew was 94.6%. In paprika, the control efficacy of COY to powdery mildew was 91.6% and that of COY+$CaCO_3$+neem oil mixture was 96.2% that revealed little higher than COY itself. In tomatoes(cherry or maturity tomato), the control efficacy of COY were about 91 %, however, when COY mixture were sprayed to tomato leaves and stems the powdery mildew was controlled completely. Typical and healthy mycelia, conidiophores and condia were observed through scanning electron microscope in COY unsprayed leaf surface, on the other hand destroyed and winkled mycelia and conidiophores were observed in COY treated leaves regardless host plants nor taxonomic differences of fungi.