• Journal of Korean Society for Atmospheric Environment
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• v.13 no.1
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• pp.9-18
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• 1997

Precipitation samples were collected by the wet- only event sampling method from Seoul during September 1991 to April 1995. These samples were analyzed for the concentrations of the major ionic components (N $O_3$$^{[-10]}$ , N $O_2$$^{[-10]}$ , S $O_4$$^{2-}$, C $l^{[-10]}$ , $F^{[-10]}$ , N $a^{＋}$, $K^{+}$, $Ca^{2＋}$, $Mg^{2＋}$, and N $H_4$$^{＋}$), pH, and electric conductivity. During the study period, a total of 182 samples were collected, but only 163 samples were used for the data analysis via quality assurance of precipitation chemistry data. The volume-weighted pH was found to be 4.7. The major acidifying species from our precipitation studies were identified to be non-seasalt sulfate (84$\pm$9 $\mu$eq/L) and nitrate (24$\pm$2 $\mu$eq/L) except for chloride. Because the Cl/Na ratio in the precipitation was close to the ratio in seawater. If all of the non-seasalt sulfate and nitrate were in the form of sulfuric and nitric acids, the mean pH in the precipitation could have been as low as 3.7 lower than the computed value. Consequently, the difference between two pH values indicate that the acidity of precipitation was neutralized by alkaline species. The equivalent concentration ratio of sulfate to nitrate was 3.5, indicating that sulfuric and nitric acids can comprise 78％ and 22％ of the precipitation acidity, respectively. Analysis of temporal trend in the measured acidity and ionic components were also performed using the linear regression method. The precipitation acidity generally showed a significantly decreasing trend, which was compatible with the pattern of the ratio (N $H_4$$^{＋}$＋C $a^{2＋}$)/ (nss-S $O_4$$^{2-}$＋N $O_3$$^{[-10]}$ ).).

• Journal of Environmental Science International
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• v.25 no.5
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• pp.737-744
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• 2016

For electrolysis process using an insoluble electrode, electrochemical performance was greatly affected by the manufacturing method and procedure, such as the firing temperature, pre-treatment, type of precursor solution, coating method, electrode material, etc. Components of the electrode therein is one of the most important factors in electrochemical reaction. To achieve such characteristics, a appropriate ratio of the electrode material should be carefully chosen. The aim of this research was to apply experimental design method in the optimization of electrode component for the maximum generation of oxidants in electrochemical oxidation process. Mixture design, especially expanded simplex lattice design, in DOME (design of mixture experiments) with Design Expert - commercial software - was used to analyze the data. Analysis of variance (ANOVA) showed a high coefficient of determination ($R^2$) value of 0.9470, thus ensuring a satisfactory adjustment of the $3^{rd}$ order special cubic regression model with the experimental data. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the TRO generation concentration and independent variables(mol ratio of 3 electrode components) in a real unit: TRO generation concentration $(mg/L)=TRO\;conc.=98.25{\times}[Ir]+49.71{\times}[Sn]+95.29{\times}[Sb]-16.91{\times}[Ir]{\times}[Sn]-29.47{\times}[Ir]{\times}[Sb]-22.65{\times}[Sn]{\times}[Sb]+703.19{\times}[Ir]{\times}[Sn]{\times}[Sb]$. The optimized formulation of the 3 component electrode for an high TRO (total residual oxidants) generation was acquired at mol ratio of Ir 0.406, Sn 0.210, Sb 0.384 (desirability d value, 1).

• 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.

• Journal of Astronomy and Space Sciences
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• v.22 no.3
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• pp.233-242
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• 2005

The absolute dimensions and orbital elements of 66 near contact binaries, collected from literatures, have been analyzed to investigate the physical characteristics of the near contact binaries as well as co-relations among physical parameters. The relationship between the mass ratio and luminosity ratio of the near contact binary systems have been obtained as a $L_2/L_1{\approx}(M_2/M_1)^{1.45}$, which is similar to that of the early type contact binary system. The physical parameters of the new contact binaries show that the difference in mass, radius, luminosity and temperature between the primary and the secondary components for the F type NCBs are smaller than those for the A type NCBs. In H-R diagram, the components of the A types are located closer to the terminal age main sequence than those of the F types.

• Journal of the Korean Society of Food Culture
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• v.18 no.6
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• pp.584-591
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• 2003

The objective of this study is to develope natural and economical Naengmyun broth using stock prepared with chicken heads. Proper mixing ratio of chicken head stock and chicken breast broth was determined through the sensory evaluation. In order to find out the attributes of chicken head-chicken breast broth(CH-CB broth), chicken breast broth and beef brisket(BB) broth were mixed to the chicken head stock and compared the preference and chemical elements between the broths were compared. The appropriate mixing ratio for reinforcing the meat broth and savory flavor, of was determined to 3:7(w:w). The comparison of CH-CB broth's and CH-BB broth's elements showed that the amount of crude protein and ash was the same and, in the case of crude lipid, CH-BB broth had 0.01% more than CH-CB broth. In the case of the total amount of free amino acids, CH-CB broth had 1.6 times more than CH-BB broth. A survey with 50 consumers showed that was prefered between CH-CB broth and CH-BB broth. CH-CB broth with significance.

• Journal of Food Hygiene and Safety
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• v.11 no.3
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• pp.215-220
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• 1996

Korean and Chinese sesames were subjected to microscopic observation and instrumental determination of fatty acid composition and sesamolin/sesamin ratio to obtain basic data for discriminating each other. The overall appearance of both samples was differently observed by stereo microscope (X8). Fatty acid composition of sesame oils, extracted from both samples with different roasting degrees, showed a similar pattern although Chinese samples cointained about 6% higher content of stearic acid and 47% lower content of linolenic acid then Korean ones. The sesamolin/sesamin ratio was remarkably lower(.039) in Chinese samples than Korean (0.67∼0.72). showing a variation depending on producing districts. Roasting degrees of raw sesames little influenced their composition of fatty acid and sesamolin/sesamin ratio. Based on the above results, it is considered that the comparison between domestic and Chinese sesames in view of their stearic and linolenic acid contents and sesamolin/sesamin ratio might be one of the potential criteria in discriminating their production origins.

• Journal of the Korean Ceramic Society
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• v.39 no.3
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• pp.222-225
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• 2002

Microwave dielectric properties of the layered and functionally graded materials (FGMs) of $Mg_{0.93}Ca_{0.07}TiO_3$ (MCT) and $(Ca_{0.3}Li_{0.14}Sm_{0.42})TiO_3$(CLST) were investigated as a function of the volume ratio of two components. Dielectric constant was decreased with an increase of the volume ratio of MCT which had a lower dielectric constant thant CLST. For the layered FGMs specimens, the difference of thermal expansion coefficients between two components induced thermal strain to dielectric layers, which was confirmed by the plot of ${\Delta}$k (X-ray diffraction peak width0 versus k (scattering vector) using the double-peak Lorentzian function, f(x). Quality factor of the specimens was affected by the thermal strain of dielectric layer, especially MCT layer. For the specimen with the volume ratio of MCT/CLST = 2, the qulaity factor of the specimen showed a minimum value due to the maximum thermal strain fo MCT layer.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.38-42
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• 2006

When whole cells are subjected to pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) analysis, it provides biochemical profiles containing overlapping signals of the majority of compounds. To determine marker compounds that discriminate embryogenic calluses from nonembryogenic calluses, samples of embryogenic and nonembryogenic calluses of five higher plant species were subjected to Py-GC/MS. Genetic programming of Py-GC/MS data was able to discriminate embryogenic calluses from nonembryogenic calluses. The content ratio of 5-meyhyl-2-furancarboxaldehyde and 5-(hydroxymethyl)-2-furancarboxaldehyde was greater in nonembryogenic calluses than in embryogenic calluses. However, the content ratio of phenol, p-cresol, and $^1H-indole$ in embryogenic calluses was 1.2 to 2.4 times greater than the ratio in nonembryogenic calluses. These pyrolysates seem to be derived from the components of the cell walls, which suggests that differences in cell wall components or changes in the architecture of the cell wall playa crucial role in determining the embryogenic competence of calluses.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1776-1785
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• 2004

In this research, the relationships between static bimaterial constant and dynamic oscillation index are studied. It was certified that static bimaterial constant has the same form equation as the dynamic oscillation index. Bimaterial constant and oscillation index are increased with the increment of Young's modulus ratio and approached to the some value. Isochromatic fringe patterns are slanted to the left side with increment of bimaterial constants and oscillation index. Though patterns of stress components in above the crack surface are similar to each other, their magnitudes are different a little. In the ahead of crack tip, there are big differences in the isochromatic fringe patterns and their magnitudes. The influence of bimaterial with Young's modulus ratio is bigger in the propagation crack than in the stationary crack.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.62-68
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• 1996

Precipitation samples were collected by the wet-only event sampling method at Seoul from September 1991 to April 1995. Concentrations of samples for the ion components($NO_3^-, NO_2^-, SO_4^{2-}, Cl^-, F^-, Na^+, K^+, Ca^{2+}, Mg^{2+}$ and $NH_4^+$) were measured in addition to pH and electric conductivity. During the sampling period, 182 samples were collected, but only 163 samples were identified as valid. The pH, calculated from the volume-weighted $H^+$ concentration, was found to be 4.7, indicating a relatively intensive acidity compared with data from other regions of the world, where acid deposition was known to be a problem. Above all, the concentration of non-seasalt sulfate was $84 \mu eq/L$, which was the highest compared to that measured in other regions of the world. The major acidifying ions in the precipitation at Seoul were identified as sulfate and nitrate except for chloride, because the Cl/Na ratio in the precipitation was close to the ratio in seawater. If all of the non-seasalt sulfate and nitrate existed in the form of sulfuric and nitric acids, respectively, the average pH in the precipitation was calculated as 3.7, lower than the measured value. Consequently, the difference between the calculated and measured pH suggest that the acidity of precipitation was neutralized by alkaline species, not due to the low contribution of an anthropogenic air pollutants to the precipitation. The equivalent concentration ratio of sulfate to nitrate was 3.5, which indicated that the contributions of sulfuric and nitric acids to the precipitation acidity were 78% and 22%, respectively.