• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.453-456
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• 2004

This paper surveys the latest findings on vegetable-oil-based dielectric coolants in power systems. In recent years, environmental concerns have been increased on the use of poorly biodegradable mineral oils in distribution and power transformers in regions where spills from leaks and equipment failure could contaminate the surroundings. In addition, there are demands to improve equipment efficiencies in power systems. In this reason, researches were started in the mid 1990s to develop a fully biodegradable dielectric coolants. Vegetable oil was considered the most likely candidate for a fully biodegradable dielectric coolants. Vegetable-oil-based dielectric coolants provide the advantages of high level of biodegradability, renewable natural resource, non-toxic properties, enhanced fire safety, more effective cooling and good dielectric strength for many electrical equipment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.1113-1114
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• 2012

• Transactions on Electrical and Electronic Materials
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• 제18권2호
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• pp.66-69
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• 2017

The internal temperature of human-tissue transfers must be steadily maintained regardless of the external environmental changes. An ice pack and dry ice are the coolants for the transfer containers for which heat-insulating materials such as EPP (expended polypeopylene and EPS (expended polystrene) are used; however, changes of the external temperature/pressure and the melting of the coolants that is due to a long carriage result in changes of the internal temperature, and this makes it difficult to maintain the temperature. Accordingly, the thermoelectric element was used to design/manufacture a transfer container to maintain the internal temperature regardless of the external environmental changes. As a result of the measurement of the changes of the internal temperatures of the manufactured thermoelectric-element container and the EPS container over time, the internal temperature of the EPS container was increased, whereas the internal temperature of the thermoelectric-element container was maintained. The temperature of the distilled water that was poured into the containers indicated a pattern identical to that of the internal temperature.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.169-172
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• 2000

In this paper applicabilities of coolant wastes are an admixture, which are produced from cooling line of the cars and industrial engines, to concrete under cold climate are investigated. According to the test results, as the contents f coolant wastes increase, setting time of cement mortar is shown to be delayed. However, when coolants wastes are overadded, it appears to be fast. In case of compressive strength, It tends to decline as the contents of coolant waste increase. Under low curing temperature, compressive strength of cement mortar containing coolant wasted with the increase of the contents of coolants wastes.

• 한국추진공학회지
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• 제9권2호
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• pp.1-8
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• 2005

가스발생기용 저 연소속도 HTPB/AP계 고체추진제의 조성에서 냉각제인 Oxamide와 Melamine이 추진제의 연소특성에 미치는 효과를 고찰하였다. 냉각제의 함량을 증가시키면 연소속도와 화염온도가 낮아지고, 두 냉각제의 화염온도에 미치는 영향은 유사하였다. 그러나 냉각제의 열분해 특성 차이로 인하여 Melamine 추진제에서는 비정상적으로 $200{\mu}m$ AP의 일부를 $6{\mu}m$ AP로 대체하면 연소속도가 오히려 감소하는 현상을 나타내었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 추계학술발표회요약집
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• pp.57-57
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• 2002

• 설비공학논문집
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• 제11권2호
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• pp.224-235
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• 1999

The present study investigated the effects of the experimental parameters on the cooling characteristics of the multichip module cooled by the indirect liquid cooling method using water, PF-5060, and paraffin slurry. The experimental parameters were coolants including Paraffin slurry with mass fraction of 2.5~7.5%, heat flux of 10~40W/$\textrm{cm}^2$ for the simulated VLSI chips and Reynolds numbers of 3,000~20,000. The size of paraffin slurry was constant as 10~40${\mu}{\textrm}{m}$ before and after the experiment. The chip surface temperatures for paraffin slurry were lower than those for water and PF-5060. The local heat transfer coefficients for the paraffin slurry were larger than those for water and the local heat transfer coefficients reached a row-number-independent and thermally-fully-developed value approximately after the third row. The local Nusselt numbers for paraffin slurry with a mass fraction of 7.5% were larger by 20~38% than those for water. The paraffin slurry with a mass fraction of 5% shelved the best thermal and hydrodynamic characteristics when local heat transfer and pressure drop were considered simultaneously.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1327-1329
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• 1994

In this paper, We treated the electrical characteristic of fluorocarbon. We found that its properties - dielectric properties, resistivities, dielectric characteristics. etc - are sufficient to use as coolants for GAS INSULATED TRANSFORMER.

• 한국정밀공학회지
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• 제21권1호
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• pp.80-86
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• 2004

With the increasing demand of environmentally clean machining in recent years, the use of coolants has been restricted extensively. In this paper, a multiple comparison method(Tukey's HSD method) is proposed to choose the optimum level of coolant necessary for an efficient and environmentally clean machining. The cutting temperature, specific cutting energy, and surface roughness in turning process are analysed by ANOVA(Analysis Of Variance) and Tukey's HSD method. From the experimental results and statistical analysis, it is found that the optimum condition of coolant level is 10 ml/min with 6% mix ratio, which is almost half of the commonly used level.

• Industrial Engineering and Management Systems
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• 제10권2호
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• pp.128-133
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• 2011

This paper presents a study on product design optimization to reduce the environmental impact of machining. The objective is to analyze the effect of changing the product design parameters such as its dimensions, and basic features on the environmental impact of machining process in terms of its energy consumption, waste produced and the chemicals and other consumables used up during the process. To realize this objective, we used a CAD model of a product with different design scenarios, and analyze their energy consumption using an environmental impact calculator method developed. The waste produced, and the consumables used up, such as lubricants and coolants were analyzed using environmental emission factors. Optimization methods using Genetic Algorithm and Goal Programming are applied to the product design parameters in order to get the best possible product dimensions with the least environmental impact of the machining process.