• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.603-603
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• 2007

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• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.495-501
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• 2016

Mineral oil has been widely used as an insulating oil for electrical transformers for a long time, but the necessity of employing new insulation oil such as vegetable oil has been increased due to urgent needs for the biodegradability when it leaks and also for the thermal stability at a higher operation temperature. Although specific periods are required between the production and consumption, there are still short of the data to prove the insulation oils' storage stability depending upon various circumstances and their resources. Thus, this paper demonstrates the insulation oils' oxidation characteristics of both mineral and vegetable oils when each was exposed to different environments for 12 weeks. From this test, some properties including total acid number, water content and dielectric breakdown were changed under specific conditions and resources. Vegetable oils showed higher hydrophilicity and water saturation than those of mineral oils due to their molecular compositions. Under sunlight exposure condition, all insulation oils oxidized and changed their properties when exposing to the direct light, regardless of the resource used.

• Economic and Environmental Geology
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• v.41 no.5
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• pp.609-615
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• 2008

Peru is located on Andean Range and faced Pacific Ocean and one of the important oil and gas production countries in the South America. Peru's oil business have been invested by foreign oil companies due to the good investment environment, even though the Peru could not be self-sufficiency in oil. Increase in oil price of the world has contributed to the oil and gas developments and productions in the last few years in many oil and gas blocks, such as in the 1-AB blocks and Camisea gas field within the Amazon jungles. Korean oil companies also have obtained several oil and gas blocks in the Peru in last few year, corresponding with the resources diplomacy of Korean government. Investment is strongly expected to be increased in the Peru's oil business due to positive investment environment, such as low royalty rate, tax avoidance, and the favourable terms of the contract to foreign companies etc.

• Economic and Environmental Geology
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• v.41 no.5
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• pp.617-624
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• 2008

Azerbaijan, located on western part of Caspian Sea, has been developed oil and gas exploration and production business from about 200 years ago and once charged of 50% of world oil production in the early 20th century. After Azerbaijan was independent of Soviet Union in 1991, foreign oil companies, including Korean oil companies, have been investing in Azerbaijan oil business on offshore blocks. Productive capacity of downstream in the Azerbaijan is lower than productive capacity of upstream, whereas there are important pipelines, such as BTC, SCP, NREP, and WREP, provide opportunities of the oil and gas exporting to the world. Oil fields in onshore blocks in the Azerbaijan are almost mature oil fields, caused by high recovery rate. Offshore oil blocks are still high potential in oil exploration with high risk.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1672-1677
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• 2003

Carbon dioxide($CO_2$, R-744) has become a very popular issue in application to refrigeration and air conditioning systems as a natural refrigerant. An experimental study has been carried out to investigate the vapor pressure and miscibility of refrigerant R-744 in the presence of lubricant oil. This is of particular interest in the selection of the lubricant oil for the compressor of a refrigeration system or an air conditioning system using the refrigerant R-744. This apparatus consists of the test section, measuring devices, the vacuum pump, the constant temperature bath and relevant connecting pipes made of stainless steel. Two lubricant oils, such as mineral oil(Naphthenic) and polyol ester(POE) oil, are considered in the present study. For this purpose, test runs were conducted with the oil concentration range from 5 to 50 wt%, and the temperature range from -10 to $10^{\circ}C$ with $2^{\circ}C$ intervals. The results are correlated with the vapor pressure. and showed with the miscibility as visualization for the individual text components.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.916-921
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• 2009

In this study, lubrication characteristics of sliding members were compared with the change of the hardness of friction surfaces and the application of nano-oil. The materials of the specimens were gray cast iron (AISI 35, AISI 60) and nickel chromium molybdenum steel (AISI 4320). The Friction coefficients and the temperature variations of on the frictional surfaces were measured by disk-on-disk tribotester under the condition of fixed rotating speed. The friction surfaces were observed by scanning electron microscope (SEM). In the results, the friction coefficients of the disk surface were increased as hardness difference was increased. The friction coefficient lubricated in nano-oil was less than mineral oil. This is because a spherical nano particle plays a tiny ball bearing between the frictional surfaces, improved the lubrication characteristics.

• 월간산업보건
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• s.231
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• pp.15-18
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• 2007

• 월간산업보건
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• s.229
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• pp.14-16
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• 2007

• 월간산업보건
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• s.230
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• pp.18-21
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• 2007

• Clinical and Experimental Reproductive Medicine
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• v.50 no.4
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• pp.244-252
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• 2023

Objective: We evaluated the efficacy of the newly developed optimized in vitro culture (OIVC) dish for cultivating preimplantation mouse embryos. This dish minimizes the need for mineral oil and incorporates microwells, providing a stable culture environment and enabling independent monitoring of individual embryos. Methods: Mouse pronuclear (PN) zygotes and two-cell-stage embryos were collected at 18 and 46 hours after human chorionic gonadotropin injection, respectively. These were cultured for 120 hours using potassium simplex optimized medium (KSOM) to reach the blastocyst stage. The embryos were randomly allocated into three groups, each cultured in one of three dishes: a 60-mm culture dish, a microdrop dish, and an OIVC dish that we developed. Results: The OIVC dish effectively maintained the osmolarity of the KSOM culture medium over a 5-day period using only 2 mL of mineral oil. This contrasts with the significant osmolarity increase observed in the 60-mm culture dish. Additionally, the OIVC dish exhibited higher blastulation rates from two-cell embryos (100%) relative to the other dish types. Moreover, blastocysts derived from both PN zygotes and two-cell embryos in the OIVC dish group demonstrated significantly elevated mean cell numbers. Conclusion: Use of the OIVC dish markedly increased the number of cells in blastocysts derived from the in vitro culture of preimplantation mouse embryos. The capacity of this dish to maintain medium osmolarity with minimal mineral oil usage represents a breakthrough that may advance embryo culture techniques for various mammals, including human in vitro fertilization and embryo transfer programs.