• Journal of the Speleological Society of Korea
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• v.20 no.21
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• pp.34-43
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• 1989

Cheju island is situated at about 60km south of southern most tip of the Korean peninsula. Its shape is an ellips with size of 80*40$\textrm{km}^2$, and it is characterized by a symmetrical form whose peak is Mt. Halla(1950m). Major chemical composition of the rock samples from Manjang gul cave is determined by XRF using the fundamental parameter method consisting of fully auto quantitative analysis, semi quantitative analysis (order estimation) and group quantitative analysis. Judging from chemical composition (SiO$_2$ = 53.07Wt％, Fe$_2$O$_3$ = 11.34Wt％, MgO=6.48Wt％, Na$_2$O=3.07Wt％, $K_2$O=1.05Wt％), this rocks from the Manjang gul cave are also determined. The discrepancy of K-Ar ages is found. They are 0.03 Ma and 0.42Ma, respectively. This paper describes some problems experienced in dating young volcanic rocks and then discusses chemical composition, X-ray fluorescence analysis and the age of the formation of a lava tunnel such as Manjang gul cave in cheju Island.

• Journal of the Korean Wood Science and Technology
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• v.18 no.2
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• pp.3-7
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• 1990

The chemical Composition of Chinese red pine (Pinus massoniana) submerged in the Yellow Sea for more than 700 years has been examined. When compared to the recent wood, the marked chemical changes in the waterlogged wood is the higher amount of lignin with lesser amount of holocellulose and abnormally high ash content. In the heavily degraded samples, the degradation of cellulose is more severe than that of hemicellulose. However, hemicellulose is much more attacked than the cellulose at the initial stage of deterioration in the sea water. Chemical analysis suggests that the cellulolytic marine microorganisms, whether they are fungi or bacteria. can be regarded as the primary agents for the destruction of the archaeological woods submerged in the sea water.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6257-6260
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• 2013

Gallstone disease is a major surgical problem in many populations; it is probably related to diet, especially excessive consumption of meat. The objective of this study was to determine the chemical composition of gallstones and their association with neoplastic changes including cholangiocarcinomas in cholecystectomised patients. The chemical composition of gallstones from 40 patients (8 males and 32 females) was analyzed. This is a prospective study performed in Baquba teaching hospital in the period from 1/10/2012 to 1/1/2013 in which we collected the gallstones for the patients who underwent cholecystectomy, whether open or laparoscopic. The stones were classified according to their chemical composition as a mixed stones (MS), and examined using a stone analysis set (chemical qualitative method) for calcium, magnesium, phosphate, uric acid and oxalate which was used reagent for qualitative determination of main individual components of stones. The results of this study showed the highest incidence of gallstones in the age group 40-49 was 13 cases followed by 11, 8 and 4 cases for age groups 30-39, 50-59, 20-29 and 60 and above, respectively. The chemical analysis showed the majority of gallstones were mixed, 38 containing calcium followed by 37 cases with uric acid, 28 with magnesium, and 25 and 22 stones with oxalate and phosphate, respectively. Microscopically, we confirmed neoplastic changes (17.5%) as cholangiocarcinomas (CCCs) (7.55%) and dysplastic cells of carcinoma in situ in 4 (10%), 31 (77.5%) cases were chronic cholecystitis and 2 (5%) cases were acute cholecystitis with empyema out of bile duct disorders patients. In conclusion, majority of cases had mixed gallstones that involved five and four of inorganic chemicals of calcium, magnesium and phosphate, the highest incidence of gallstones in age group 40-49 years old was 13 cases, and neoplastic changes were confirmed (17.5%) including CCCs, (7.5%) and dysplastic cells of carcinoma in situ (10%), while 31 (77.5%) cases were chronic cholecystitis.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.79-89
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• 1998

In determining optimal cutting condition for face milling operation, tool wear is an important factor. For the purpose of establishing the relationship between various machining factors and tool wear, cutting tests have been performed. As a result, hardness and chemical composition of workpiece material, chemical composition and grain size of cutting tool and cutting speed have been selected as machining factors. In addition, relationship between feed rate and workpiece hardness has been observed. Prior to utilizing cutting conditions recommended by ‘Machining Data Handbook(MDH)’ as a knowledge base, an analysis for the validity of the MDH has been provided. Based on this analysis, tool life criteria applied by MDH has been modified. Finally, using MDH recommended data for neural network trainning, the results from the trained neural network for optimal cutting condition for some given workpiece and cutting tool can be used as reference cutting conditions.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.12
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• pp.1718-1723
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• 2017

Objective: The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo. Methods: The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. Results: The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Conclusion: Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

• Journal of Environmental Science International
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• v.26 no.12
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• pp.1333-1339
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• 2017

Coal-fired power plants emit various Particulate Matter(PM) at coal storage pile and ash landfill as well as the stack, and affect the surrounding environment. Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analyzer(FE-SEM/EDX) were used to develop identification factor and the physico-chemical analysis of PM emitted from a power plant. In this study, three samples of pulverized coal, bottom ash, and fly ash were analyzed. The pulverized coal was spherical particles in shape and the chemical composition of C-O-Si-Al and C/Si and C/Al ratios were 200~300 on average. The bottom ash was spherical or non-spherical particles in shape, chemical composition was O-C-Si-Al-Fe-Ca and C/Si and C/Al ratios were $4.3{\pm}4.6$ and $8.8{\pm}10.0$. The fly ash was spherical particles in shape, chemical composition was O-Si-Ai-C-Fe-Ca and C/Si and C/Al ratios were $0.5{\pm}0.2$ and $0.8{\pm}0.5$.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.382-387
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• 2011

The chemical composition of essential oils obtained from aerial parts in spearmint, apple mint and chocolate mint, was investigated by gas chromatography/mass spectrometry analyses. (-)-Carvone (33.0%) was quantitatively major compound in spearmint, followed by R-(+)-limonene (11.7%) and ${\beta}$-phellandrene (9.7%); (-)-carvone (37.4%) and germacrene D (11.9%) in apple mint; and (-)-menthol (34.3%), p-menthone (18.4%) and menthofuran (9.8%) in chocolate mint. Hierarchical cluster analysis and principle components analysis showed the clear difference in chemical composition of the three mint oils.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.2
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• pp.101-111
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• 1999

In previous study, the local trends in dustfall chemistry and deposition were determined and the characteristics of chemical compositions among dustfall, TSP and rainwater were also compared. Based on the previous results, in this study, the effects of sea salts and soil and soil on the chemical composition of dustfall were studied and then the sources of dustfall in Cheju area were tentatively identified by principal component analysis(PCA)

• Bulletin of the Korean Chemical Society
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• v.20 no.2
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• pp.159-162
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• 1999

Three different chemical compositions of total paraffin, total naphthene, total aromatic content in naphtha have been successfully analyzed using FT-Raman spectroscopy. Partial least squares (PLS) regression has been utilized to develop calibration models for each composition from Raman spectral bands. The PLS calibration results showed Blood correlation with those of gas chromatography (GC). Using PLS regression, the spectral information related to each composition has been successfully extracted from highly overlapped Raman spectra of naphtha.

• Mycobiology
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• v.36 no.1
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• pp.50-54
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• 2008

This study examined the chemical composition of A. blasiliensis and the chemical structural properties of an immuno-stimulating polysaccharide. The amino acids, free sugars, and organic acids by HPLC and fatty acids by GC were analyzed. The immuno-stimulating substance from A. blasiliensis was extracted with hot water and purified by ethanol precipitation. It underwent ion exchange chromatography on DEAE-cellulose and gel filtration on Toyopearl HW 65F. Through GP-HPLC, the substance was found to be homogeneous. Its chemical structure was determined by $^{13}C-NMR$. Fatty acids, organic acids, and sugar alcohol composition consisted exclusively of linoleic acid, fumaric acid and mannitol, respectively. The amino acids were mainly glutamic acid, glycine, and arginine. By $^{13}C-NMR$ analysis, the immuno-stimulating substance was identified as ${\beta}-(1{\rightarrow}3)\;(1{\rightarrow}6)$-glucan, composed of a backbone with $(1{\rightarrow}3)$-linked D-glucopyranosyl residues branching a $(1{\rightarrow}6)$-linked D-glucopyranosyl residue. The ${\beta}$-glucan from A. blasiliensis showed pronounced immuno-stimulating activity on the antibody-production ability of B-lymphocytes by the hemolytic suspension assay. In these results, A. blasiliensis was estimated to have potent pharmacological properties and potential nutritional values.