• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.17-26
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• 1996

This research was accomplished to evaluate possibility of using paper sludge for the raw materials of wood based panel products. The experimental panels were manufactured by four mixed ratios, the proportion of paper sludge to wood particle: 20:80, 30:70, 40:60, 50:50% (oven dry weight basis) and by three composition types, sludge-particle mixed board, three layered sludge-particle board and three layered particle board. They were tested mechanical (bending strength and internal bond) and physical properties (water absorption, thickness swelling and linear expansion). From the results they were shown that bending strength of mixed and three layered sludge-particle board were decreased with increasing of composition ratios of sludge. And the mechanical and physical properties of the boards of three layered composition types have superior to those of mixed composition type. Although composition ratios of sludge increased, the internal bond strength and dimensional stability of sludge-particle board not decreased quantitatively. We concluded that the mechanical and physical properties of three layered sludge-particle board were similar w those of three layered particle-board (control) made by our laboratory design. Therefore, it was recognized that paper sludge can be used as potential raw material in particle-board manufacturing industry.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.84-89
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• 1995

The growth and the film characteristics of heteroepitaxial $Si_{1-x}Ge_x$ films growth by the Rapid Thermal Chemical Vapor Deposition(RTCVD)method are described. For the growth of $Si_{1-x}Ge_x$ heteroepitaxial layers, $SiH_4/GeH_4/H_2$gas mixtures are used. The growth conditions are varied to investigate their effects on the Si/Ge composition ratios, the interface abruptness and crystalline properties. The Si/Ge composition ratios are analyzed with the RBS and the SIMS techniques, and the interface abruptness are deduced from these data. The crystalline properties are analyzed from TEM pictures. The experimental data shows that the crystalline perfection is excellent at the growth temperature of as low as $650^{\circ}C$, and the composition ratios change linearly with $SiH_4/GeT_$$ gas mixing ratios in our experimental ranges. Boron doping experiments are also performed using 200 ppm $B_2H_6$ source gas. The doping profiles are measured with SIMS technique. The SIMS data shows that the doping abruptness can be controlled within about 200$\AA$/decade.

• Journal of Ginseng Research
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• v.21 no.3
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• pp.196-200
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• 1997

The headspace volatiles of the Korean ginseng and the Chinese ginseng were extracted using the SepPak Cl8 cartridge (Wasters Co.) and were analyzed using GC/MSD. The overall GC pattern of the headspace volatiles of the Chinese ginseng was similar to that of the Korean ginseng, but the composition ratios of the two major components, $\beta$-panasinsene to $\beta$-muurolene, were quite different between them. The composition ratios of $\beta$-panasinsene to $\beta$-muurolene of the Korean red and white ginseng were 1.02$\pm$0.28 (n=19) and 1.49$\pm$0.55 (n=14) , respectively. However the com- position ratios of the Chinese red and dried ginseng were 0.58$\pm$0.19 (n=41) and 0.57$\pm$0.17 (n=28), repetitively, which were significantly lower than those of the Korean ginseng at I% level. The composition ratio of the two major headspace volatile components, $\beta$-panasinsene to ${\gamma}$-muurolene, is thought to be as a useful indicator for differentiating the Chinese ginseng with the Korean ginseng.

• YAKHAK HOEJI
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• v.8 no.4
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• pp.96-99
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• 1964

In the previous study, the composition ratios of the Cu-sulfa drugs complexes determined by gravimetric and solvent extraction method reported. In this paper, the continuous variations method has been used to know whether the complexes are simple complexes or chelates, and to recertify the composition ratios of the complexes at pH 7-8. It has been certified that the ratio of $Cu^{+2}$ ion to sulfa drugs in 1:2 from the result of this experiment.

• Journal of Nutrition and Health
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• v.38 no.7
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• pp.521-532
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• 2005

The prevalence of atopic dermatitis (AD) continues to rise in industrialized countries related to Western lifestyle, including dietary habits, especially imbalance of intake of dietary fatty acids. The purpose of this study was to evaluate the dietary fatty acids and the assess the blood fatty acid composition and immune parameters in AD patients. AD (n = 50) patients and gender ${\cdot}$ age matched healthy controls (HC) were studied in case-control clinical trail. Current fatty acids intake status was determined by 3-day food record method. Blood sample were collected from 30 subjects in each group and blood fatty acid composition and immune parameters were analysed. AD patients consumed less PUFA and their n-6/n-3 PUFA ratio was higher than that of HC. Both the ratios of PUFA and MUFA were positively correlated with SCORAD in AD patients (p < 0.05). In the AD patients, there were abnormalities in the fatty acid composition of the RBC and WBC, SFA being significantly high and most n-3 PUFA being significantly low. Moreover, both the ratios of EPA and DHA in WBC were negatively correlated with dietary n-6/n-3 PUFA ratio in AD patients (p < 0.05). Serum total IgE and IL-4 levels of AD patients increased significantly compared with the levels of HC (p < 0.01). Ratios of monocyte and eosinophil in WBC of AD patients increased significantly compared with the levels of HC including total WBC count (p < 0.01), and ratios of Iymphocyte and basophil in WBC of AD patients decreased significantly compared with the levels of HC (p < 0.05). Moreover, the ratios of eosinophil in WBC were positively correlated with dietary P/M ratio (p < 0.05), and the ratios of monocyte in WBC were positively correlated with n-6/n-3 PUFA ratio (p < 0.05) in AD patients. This results indicated that AD patients had significantly high intake of dietary n-6/n-3 PUFA compared with HC. Imbalance of intake of dietary fatty acids affected fatty acid compositions in the RBC and WBC, and these lead to immune imbalance and grow worse of AD.

• Korea journal of population studies
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• v.24 no.2
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• pp.117-147
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• 2001

The main purpose of this paper is to analyze sex and age composition of the 1994 North Korean census data. First this paper describes the background information concerning the first population census ever taken in North Korea since the separation of the North and South. It utilizes the available data to explain the trend and current population status of North Korea. The focus of this research is to point out and analyze the problems in the sex and age composition of the North Korean census data. One of the most striking characteristics of the census data is that an enormous portion of the young male population was excluded from the census counts. Such omissions are strongly suggested by a incredible drop in sex ratios for the age groups of 16 to 25. In addition, the total sum of the population by age groups turns out to be substantially smaller than the total sum of the population by geographical regions. The total discrepancy amounts to 691 thousand. Along with sex ratios and age ratios, Myers indices, UN age-sex accuracy indices, indices of relative difference, and indices of dissimilarity are calculated to analyze the characteristics and accuracy of sex and age composition in the North Korean census data. Finally, this paper readjusts the sex and age composition of the 1994 census data, and attempts to produce a more accurate population of North Korea.

• 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 $0.8{\pm}0.5$.

• Journal of Korea Foundry Society
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• v.29 no.6
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• pp.270-276
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• 2009

After casting button-type small ingots of ternary Fe-Mn-S alloys which had three different Mn/S ratios (1, 5 and 70) in a vacuum arc furnace, the effect of the ratio on the sulfide formation was investigated. In case of the Mn/S ratio of 1, if alloy composition was located in an iron-rich corner on a Fe-Mn-S ternary phase diagram, only duplex MnS-FeS sulfide films were observed in the grain boundary. If the alloy composition was located in the miscibility gap area of the phase diagram, primary globular dendritic sulfides and dendritic sulfide slags were generated within the grain and tubular monotectic sulfides were also detected in the grain boundary. When the Mn/S ratio was 5, if the alloy composition was in the iron-rich corner, only bead-like sulfides were generated. On the other hand, if the composition was in the miscibility gap area, globular dendritic sulfides and dendritic sulfide slags were generated in the form of primary sulfide inclusions and rod-like eutectic sulfides were observed in the grain boundary. Especially, if the contents of Mn and S increased more in the miscibility gap area of the phase diagram, primary globular sulfides containing iron intrusions were observed. In case of Mn/S ratio of 70, if the contents of Mn and S was decreased in the Fe corner of the phase diagram, only bead-like sulfides were observed in the grain boundary. Despite the composition was outside the miscibility gap area of the phase diagram, if the contents of Mn and S increased, clusters of fine sulfide particles as well as fine spherical primary monophase sulfides were observed in the grain boundary.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.32-41
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• 1999

Natural gas is an attractive fuel in view of environment benefits due to its flow carbon-to-hydrogen ratio. However, its compositions and properties are varied depending upon production regional groups. Therefore, study on the combustion characteristics of natural gas engines with a variety of compositions has been demanded for the efficient application of gas engines. This study aims to investigate the effects of gas composition on engine combustion characteristics. It was found that , by controlling an engine with fixed fuel nozzle area, power and heat release were subject to Wobbe Index. And at fixed excess air ratios, power and heat release were subject to low heating value of unit mixture . In addition, in case of constant nozzle area, combustion duration was found to be inversely proportional to CP(Combustion Potential), and the condition of fixed excess air ratios showed no change in combustion duration, regardless of CP.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.493-502
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• 2012

Syngas laminar burning velocity measurements were carried out at atmospheric pressure and ambient temperature using the Bunsen flame configuration with nozzle burner as a fundamental study on flame stability of syngas fuel. Representative syngas mixture compositions ($H_2$:CO) such as 25:75%, 50:50% and 75:25% and equivalence ratios from 0.5 to 1.4 have been conducted. Average laminar burning velocities have been determined by the stabilized nozzle burner flames using the angle method, radical surface area method and compared with the data obtained from the other literatures. And the results of each experimental methodologies in the various composition ratios and equivalence ratios were coincided with the result of numerical simulation. Especially, it was confirmed that there was necessary to choice a more accurate measurement methodology even the same static flame method for the various composition ratios of syngas fuel including hydrogen. Also, it was reconfirmed that the laminar burning velocities gradually increased with the increasing of hydrogen content in a fuel mixture.