• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.81-81
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• 2010

This paper presents results of experimental investigations on natural ester regarding the breakdown strength. Aging of insulating material in a pole transformer has been studied by performing accelerated thermal aging test. Sealed aging test vessels containing copper, laminated core, Krapt paper and insulating oil(Natural oil and Mineral oil) were aged at $140^{\circ}C$ for 30days. Compared to the conventional transformer oil, electric property of the natural ester fluid is excellent.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.167-168
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• 2003

The Upo wetland, the largest natural wetland in Korea, is located in Changnyeong-gun, Gyeongsannam Province ($35^{\circ}33'$ N, $128^{\circ}25'$ E), and 70 km upstream from the Nakdong River estuary. Unlike most other Korean wetlands that have been destroyed under the name of economic development, the Upo wetland has been able to preserve its precious ecosystem throughout the years. Thanks to increased public awareness about natural wetlands and environmental conservation, the Korean Ministry of Environment designated the Upo wetland an 'Ecological Conservation Area' on July 26th, 1997. On March 2nd of the following year, the Upo wetland (8.54 $\textrm{km}^2$) was designated a 'Protected Wetland' in accordance with the international Ramsar Treaty. A 4.49m long (from 9.73 to 5.24 m in altitude) UP-1 core ($35^{\circ}33'05"N$, $128^{\circ}25'17"E$), recovered in the marginal part of the Upo wetland, is divided into eight buried paleosol units of different ages on the basis of the abundance of color mottles and vertical color variations (Aslan et al., 1998). Radiocarbon datings suggested that the paleosol profile represent the last 5700 years. The entire section of the core was more or less subjected to pedogenetic processes, and shows very weak to moderate soil profile development. These Holocene paleosols are therefore regarded as synsedimentary soils of deluvium (deposits formed by floods) origin (Sycheva et al., 2003). Unit 1 to 5 paleosols are generally silt-rich and exhibit moderate profile development. The boundaries between the units are somewhat distinguishable, but not so clear cut. This is due to variable repeated combination of accumulation, denudation and soil forming processes within various periods. Mottle textures gradually decrease in abundance with increasing clay content in Unit 6, which results in weak profile development. The lower boundary of Unit 6 lies around about 2000 yrBP, the beginning of Subatlantic in Korea (Kim et al., 2001). Abrupt sediment textural change is detected in Unit 7, which is interpreted to indicate the human activities on the Upo wetland. Unit 8 represents the recent soil forming processes. The preliminary results of this ongoing study imply the primary factor for pedogenetic processes is the water table fluctuations related to the sedimentary textures like grain size distributions, and the geomorphological stability of the Upo wetland.o wetland.

• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.49-61
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• 2009

We studied the mineral composition and mineral distribution pattern of 131 surface sediments collected at the cruise in 2000 and 2007 from Southeastern Yellow Sea, South Sea of Korea and Southern part of Jeju Island. Mineral compositions of surface sediments were determined using the quantitative X-ray diffraction analysis. Surface sediments were composed of rock forming minerals (quartz 37.4%, plagioclase 11.7%, alkali feldspar 5.5%, hornblende 3.1%), clay minerals (illite 19.2%, chlorite 4.7%, kaolinite 1.8%) and carbonate minerals (calcite 10.7%, aragonite 3.4%). Distribution of clay minerals is very similar with fine-grained sediments, and especially same as the distribution of HSMD (Hucksan Mudbelt Deposit), SSKMD (South Sea of Korea Mudbelt Deposit) and JJMD (Jeju Mudbelt Deposit). The coarse sediment seemed to be relic sediment during the last glacial maximum and mainly consisted of rock forming minerals. Whereas the fine sediments mainly composed of clay minerals. Based on the clay mineral composition, main ocean current and geographical factor, HSMD and SSKMD might have derived from the rivers around the Korean Peninsula. However, JJMD is complex mudbelt deposit, which formed by Korean rivers and oceanic sediments.

• Journal of the Mineralogical Society of Korea
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• v.24 no.3
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• pp.205-216
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• 2011

Mineral compositions of 69 southeastern Yellow Sea surface sediments collected at the Korea Ocean Research and Development Institute (KORDI) cruise in 2010, were determined using the quantitative X-ray diffraction analysis. Southeastern Yellow Sea surface sediments are composed of major minerals (quartz 49.1%, plagioclase 13.0% and alkali feldspar 9.3%), clay minerals, calcite, and aragonite. Illite (9.4%) is the most abundant clay mineral, chlorite (4.6%) is the second, and kaolinite (0.8%) is few. Quartz and alkali feldspar contents are high in coarse-grained sediments, whereas amphibole and clay mineral contents are high in fine-grained sediments. Quartz, plagioclase, alkali feldspar, chlorite, and kaolinite contents are higher, and illite content is lower in mud zone 1 corresponding to south margin of Central Yellow Sea Mud than in mud zone 2, a part of Southeastern Yellow Sea Mud. Difference of mineral composition between two mud zone suggests that source of fine sediment may be different in two mud zone and Southeastern Yellow Sea Mud might be largely supplied from the Keum and Youngsan rivers in southern part of the west coast in the Korean Peninsula.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.10a
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• pp.53-67
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• 2002

As in the past, we are concerned today with the magnitudes of mineral resources and the adequacy of these resources to meet future needs. In looking at global resource issues, we should consider the need for the resource, its supply, and the environmental consequences of using it. The need for a resource can become a resource dependency, especially as the global population expands and each of us becomes increasingly dependent upon hundreds of natural materials. Therefore, our great mineral consumption makes the human population a true 'Geologic Force', which will be even more significant in the future when the global population is projected to reach alarming proportions. Although our supplies of mineral resources probably will be sufficient for the 21s1 century, the uneven distribution of minerals in the Earth's crust almost certainly will continue to be a major problem The most likely result will be major shifts in both prices and sources of supply of many mineral resources. As for energy resources, we must avoid an obsessive dependency on one fuel and expand instead to thor energy resources. Finally, because the use of resources affects the environment, we need to focus on resource exploitation and global pollution, particularly in regard to ground water and arable land. We must manage our resources so as to be in balance with our environment. And the accelerated industrialization of South Korean economy over the last three decades has resulted in the mass consumption of nuneral commodities. South Korea has around 50 useful mineral commodities for the mineral industry, among 330 kinds of minerals described. The component ratio of the mining industry sector of the gross national production(GNP) in South Korea dropped from $1.2\%\;in\;1971\;to\;0.34\%$ in 1997 due to the rapid growth of other industries In the countxy. During the period from 1971 to 1997, the average growth rate of mineral consumption in South Korea was $9.13\%$ yearly and that of GNP per capita was $14.97\%$. The mineral consumptions per capita showed a continual Increase during the last 30 years as follows(parenthesis. GNP per capita): 0.99 metric tons in 1971($\$289$), 3.83 metric tons in 1989($\$5,210$), 6.11 metric tons in 1995 ($\$10,037$), and 6.66 metric tons in 1997($9,511). The total amount of mineral consumption in South Korea was 33 million tons of 32 mineral commodities in 1971, and 306 million metric tons of 47 mineral commodities In 1997.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.57-63
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• 2020

In this paper, we reported that the global trend of cement production and utilization as raw materials and as a fuel. As we know, cement is one of the significant materials required for the construction industry. The recent trend of rising urbanization, both the cement and construction industry played a vital role. The cement industry is a major sustainable infrastructure for the countries. Currently, China producing cement half of the world's cement production. During the year 2018, Korea producing cements nearly 57.5 million metric tons. Waste materials are used as circular resources and also having tremendous benefits for cement production. Another important use of these circular resources is fuel for the cement industry. There is a large potential benefit of the cement industry, but it's creating a severe environmental threat. The cement industry contributes to the major emissions of CO2. This leads the global warming. As per the Paris agreement, the Korean government initiated the recycling policy of waste materials and also the utilization of circular resources for the prevention of limited natural resources and also the global warming effect.

• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.1-7
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• 1997

This study was performed to find out the mineral cycles of manganese and zinc in dynamic grassland ecosystems in a steady state condition at the northwest side on Mt. Kwanak. The experimental results may be summarized on the communities of a Zoysia japonica and a Miscanthus sincnsis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, manganese and zinc was greater quantity in a Miscanthus sincnsis than in a Zoysia japonica on Mt. Kwana For the case of steady procluction and release, the ratio of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants of Mn and Zn of the litter were 0.19 and 0. 14 in the Zoysia japon- ica grassland, and were 0.44 and 0.41 in a Miscanthus sincnsis grassland, respectively. The halftimes of Mn and Zn required for the release or accumulation of the litter on the grassland were 3. 65 and 4.95 years in the Zoysia japonica, and were 1.57 and 1.69 years in the Miscanthus sincnsis, respectively. The amounts of annual cycles for Mn and Zn in the grassland ecosystem under the steady-state conditions were 58.60 and 21.46 mg /$m^2$ in a Zoysia japonica, and were 372.12 and 321.49 ing /m$^2$ in a Miscanthus sincnsis grassland. Key words: Zoysia japonica. Miscanthus sincnsis, Mt. Kwanak, Manganese, Zinc, Mineral cycles.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.4
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• pp.227-239
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• 2021

A practical and effective method of X-ray powder diffraction analysis was investigated for quantitative analysis of the mineral content of natural samples. Sample mounting experiments were conducted to select the best randomly oriented powder sample mount. A comparative experiment was also made between a reference intensity ratio (RIR) method, which compares a single peak intensity with standard material, and the Rietveld method, which calculates a full X-ray diffraction pattern, to search for the effective method of mineral quantification. In addition, samples containing amorphous minerals were quantitatively analyzed by the Rietveld method and the efficiency was reviewed. As a result of the study, the optimal random orientation could be reached by the side mounting method. The Rietveld method using the full pattern of X-ray diffraction was more suitable for mineral quantitative analysis, rather than the RIR method using a specific peak. However, either method could depend on the analyst's experience in addition to analytical technique. Moreover, amorphous minerals can be quantitatively analyzed by the Rietveld method, and the analysis results make the geological analysis possible.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.245-246
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• 2005

• 대한예방의학회:학술대회논문집
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• 2002.05a
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• pp.86-86
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• 2002