• Bulletin of the Korean Chemical Society
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• v.21 no.2
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• pp.157-158
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• 2000

• The Korean Journal of Quaternary Research
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• v.9 no.1
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• pp.1-18
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• 1995

The intent of this study is to suppose the time of engraving of Bangudae-rockgraving-picture and the change of the ancient soci-ety related to the Postglacial transgression and regression in the Ulsan Bay. Main results can be summed up as follows; 1. It is supposed that the shoreline in the maximum Postglacial transgression of the Ulsan bay has arrived to Gulhwa-Ri about 14km upstream from the present Taehwa River mouth. 2,.This transgression has occurred about 6,000-5,000 years ago. The prehistoric men around the Bangudae had hunted the whale near the inner bay From this time the people had begun to engrave pictures on the Rock of Bangudae for the ceremony and instruction of the whale hunting,. 3. Since then the shoreline had regressed and the whale hunting area had moved to distant area from the residence and the number of the captured whales had diminished. The whale hunting society had been transformed to the overland animals on the Bangudae-rockgraving- pictures had gradually increased.

• Polymer(Korea)
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• v.39 no.2
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• pp.268-274
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• 2015

In this paper, the isothermal crystallization kinetics of a functional PP (FPP) with different grafting yields (GY)-methacryloxyethyltrimethyl ammonium chloride (DMC) grafted PP were investigated by differential scanning calorimetry (DSC). The results showed that the crystallization rate of FPP (GY=4.83%) was the highest for all of the studied samples. Furthermore, for the FPP with different GY, the value of $t_{1/2}$ became longer with increasing the grafting yield (GY). The possible explanation was that the quaternary ammonium groups introduced affected the crystallization process of the FPP in two opposite directions, i.e. promoting the nucleation and hindering the transport of the chain molecules towards the growing nuclei. Polarized optical micrographs showed that the DMC chains acted as nucleating agents, which accelerated the nucleation. In addition, the results showed the FPP had lower nucleation free energy than the PP. This study would be useful for designing the processing parameters of the grafted samples.

• The Korean Journal of Quaternary Research
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• v.16 no.2
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• pp.39-56
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• 2002

The results of geoarchaeological studies of the prehistoric cultural complexes on the Russian Far East (Primorye, or Maritime Province; the Amur River basin; and Sakhalin Island) are presented. Upper Palaeolithic sites are dated to ca. 40,000-10,500 B.P. They existed during the mild climate of the Chernoruchie interstadial (ca. 40,000-21,000 B.P.); during harsh climate at the Last Glacial Maximum, ca. 20,000-18,000 B.P., in several places on the Russian Far East (Primorye, Amur River basin, and Sakhalin); and during climatic amelioration in the Late Glacial time, ca. 16,000-10,500 B.P. The earliest Neolithic sites, represented by Osipovka and Gromatukha cultures, existed at ca. 13,000-10,000 B.P. in the environment of coniferous forests with admixture of broadleaved taxa. Since ca. 8000 B.P., Neolithic cultures appeared in all of the Russian Far East. They existed until ca. 3000 B.P., first during the Holocene Climatic Optimum, ca. 8000-5000 B.P., in the environment of coniferous-broadleaved forests, and later, at ca. 5000-3000 B.P., in the environment of birch-oak and coniferous forests.

• The Korean Journal of Quaternary Research
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• v.8 no.1
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• pp.33-42
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• 1994

The study area is filled up by alluvium which can be classified into lower and upper beds by the facies of deposits and their degree of weathering. The lower bed is not of marine but of fluvial. The upper bed is mainly composed of clay and silt or fine sand beds col-ored dark or dark gray which are of neritic or brackish yielding mollusca fossils. The oyster(Crassostrea ariakensis) obstained from the depth of 3m below the present sea level in the upper bed was dated at 4,100 110Y.B.P. and the veneridae(Meretrix lamarck) 1m height above the present delta plain in the old sand bar was dated at 1,700 85Y,B,P. It is therfore concluded that the study area a small kern col of terrestri-al basin prior to postglacial age had experienced the Holocene transgression. Consequently the study area is considered to have been progressively formed under neritic or brackish circumstance before 1,700Y.B.P.

• The Korean Journal of Quaternary Research
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• v.19 no.2
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• pp.40-43
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• 2005

The island alpine biogeography of Mt. Halla (Hallasan), Jeju Island (Jejudo), Korea is discussed. The presence of numerous species of alpine flora on Mt. Halla, the southernmost distributional limit for certain species, may primarily be attributed to palaeo-environmental factors, since it can not be wholly explained by reference to current environmental conditions. The alpine flora on the peak of Mt. Halla, mainly above 1,500m a.s.l, is evidently descended from immigrants from NE Asia via the Korean Peninsula during the epochs of the Ice Age. These plants, which are very intolerant of competition with temperate vegetation, have been able to persist in alpine belts thanks to their harsh climatic conditions, sterile soil, rugged topography and cryoturbation. The alpine plants on Hallasan are in a stage or process of retreat toward the mountaintop, most likely due to recent climatic amelioration. The lower limit of some species seems to coincide with maximum summer isotherms. The continued survival of arctic-alpine and alpine plants on the summit of Hallasan, Jejudo, the Korean Peninsula, however, is in danger, if global warming associated with the greenhouse effect continues.

• Proceedings of the Korean Quaternary Association Conference
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• 2002.12a
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• pp.94-95
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• 2002

South Korea is divided into five ecoprovinces and sixteen ecoregions. The criteria for ecoprovince classification are ecosystem connectivity and cultural homogeneity. Ecoregions are classified by cluster analysis. The variables used in the analysis are latitude, longitude, seasonal mean temperature, and seasonal precipitation. The large forest fires occurred in the specific ecoregions including Kangwon coastal ecoregion, WoolYoung coastal ecoregion, Hyungsan Taehwa coastal ecoregion, Upper Nagdong river basin ecoregion and Southeastern inland ecoregion. The largest forest fire in the korean history occurred in Kangwon coastal ecoregion in the year 2000. The fire devastated the forestland over 25,000ha. Korea Forest Service, Ministry of Environment, Province Kangwon and NGO organized an investigation committee for the restoration of the burnt area. The committee suggested restoration principles and also forged a restoration strategy of the Kangwon burnt area.

• The Korean Journal of Quaternary Research
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• v.21 no.2
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• pp.77-79
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• 2007

The source regions of Asian Dusts (Yellow Sands) in the western part of China are investigated, and the soil samples are collected samples for approximately 15 days during the spring of 2005. Particle sizes of sediments are analyzed and compared with each other. These grain-size analyses from the source areas can be compared Particle sizes between loess deposits and desert sands in western part of China and desert areas show distinctive differences. Loess deposits are predominantly composed of fine sands and silts. The distinction between the final characteristics of Asian Dust particles arrived in Korea and characteristics during transportation can be recognized comparison with the Asian Dust particles collected where the dust particles settled down. The characteristics of Asian Dust particle sizes can provide the basic information regarding the transportation history from the source region.

• The Korean Journal of Quaternary Research
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• v.22 no.2
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• pp.6-11
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• 2008

Vegetation change reconstructed by pollen analysis is effective to clarify natural conditions such as climate and soil as well as intensity of human activity. Pollen analysis in Korea is difficult to obtain peaty soil sedimented by low relief geomorphollogically and formation age is usually confined to obtain information during young Holocene as well as little absolute age data. Isopollen map was constructed in order to analyze the change of vegetation environment time-spatially during Holocene based on the 30 data with age dated from 78 results from pollen analysis in Korea. The indicatives for vegetation environment were the main trees in Korea such as Alnus, Pinus, Quercus and AP/NAP during the periods of 6,000 y.BP, 4,000 y.BP, 3,000 y.BP, 2,000 y.BP, 1,000 y.BP. As a result, the regional time-spatial patterns of vegetation distribution appeared clearly on the isopollen map. The dominant vegetation stage was repeated in the different pattern e.g. the dominance between Alnus and Quercus at West Coast and between Pinus and Quercus at East Coast competitively.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.45-51
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• 1987

Methyl orange(MO) and cetyltrimethylammonium bromide(CTA) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 419nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the CTA-MO calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of CTA concentration of $1.5\times$$10^{-5}$~1.0$\times$$10^{-4}M$ by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparations.