• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.58-59
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• 2004

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.64-65
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• 2005

• Journal of the korean veterinary medical association
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• v.18 no.5
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• pp.54-59
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• 1982

Now in Korea Brucellosis was diagnosed by individual periodic blood tests. Author hope that individual periodic blood tests was performed after Milk Ring Test, because if Cattles show negative reaction to Milk Ring Test, Periodic blood tests are needless.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.821-825
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• 2014

Steam gasification of sawdust char was performed in a thermobalance reactor at high temperature. Gasification temperature was changed from $850^{\circ}C$ to $1400^{\circ}C$ and steam partial pressure was 0.3, 0.5 and 0.7 atm. Three models of gas-solid reaction were applied to the reaction kinetics analysis and modified volumetric model was an appropriate model. Reaction control regime and diffusion control regime were distinct depending on the temperature. Apparent activation energy and pre-exponential factors for both of the regimes were evaluated and the effects of steam partial pressure were examined. $H_2$ concentration in the produced gas was two times higher than that of CO due to the gasification accompanying by the water gas shift reaction.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.293-300
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• 2020

Eucheuma spinosum, red macro-algae, contains carrageenan as the major polysaccharide and is commercially produced in Indonesia, Malaysia, Philippines, China and Tanzania. In this study, E. spinosum was converted to sugar and platform chemicals (5-HMF, levulinic acid, formic acid) via FeCl₃-catalytic hydrothermal reaction. In addition, statistical methodology (3-level 3-factor Box-Behnken design) was applied to optimize and evaluate the effects of reaction factors (reaction temperature, catalyst concentration and reaction time). As a result of optimization, the concentration of 5-HMF was obtained to be 2.96 g/L at 160 ℃, 0.4 M FeCl₃ and 10 min. Optimal conditions of levulinic and formic acids were determined at 200 ℃, 0.6 M FeCl₃ and 30 min, and the concentrations were obtained to be 4.26 g/L and 3.77 g/L, respectively.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.650-655
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• 2013

In this study, the synthesis of succinic acid from hydrogenation of maleic anhydride over Pd/C were performed in aqueous solution at various reaction conditions. We confirmed that the distribution of product was different according to process parameters. When increasing the reaction pressure and agitation speed, the by-product decreased and the purity of succinic acid increased. From the result, we may conclude that the reaction pressure and agitation speed are important factors for promoting the mass transfer rate of gas-liquid interface by increasing gas-liquid solubility in liquid hydrogenation. When the reaction pressure increased from 5 bar to 10 bar, the reaction rate increased 2.14 times. When the agitation speed increased from 300 rpm to 700 rpm, the reaction rate increased 2.75 times.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.635-645
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• 2017

The purpose of this study was to examine the moderating effect of perceived parental empathy in the relationship between adolescent depression and eat problem. For this purpose, we conducted a hierarchical regression analysis for 246 middle and high school boys in the K region. As a result, the relationship between eating problem and depression was controlled by parental sympathy. As a result of analyzing the moderating effects of sub- factors of parental sympathy, in the case of the father, awareness of emotion, cold emotional reaction, and excessive emotional reaction showed moderating effects. And in mothers, awareness of emotion, perspective taking, cold emotional reaction, and excessive emotional reaction moderated the relationship between eating problem and depression. It is significant that this study confirmed that the empathy of parents perceived by adolescents is a control variable to mitigate the adverse effects of depression on eating problems.

• Journal of Preventive Medicine and Public Health
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• v.7 no.1
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• pp.107-113
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• 1974

Many factors exert an influence on enzyme activity and thus on the rate of reactions that they catalyse. The most important of these factors are pH, temperature, substrate concentration, and the concentration of some inhibitors present. A solution of the enzyme diastase, which breaks down molecules of the polysaccharide starch to the disaccharide maltose by hydrolysis, was provided. Activity of this enzyme was measured by the rate at which starch was removed from the reaction mixture. These experiments were designed to study this reaction rate under varying conditions and the following results were obtained. 1. The range of optimum pH for this enzyme at room temperature was 4.0-7.0 and the optimum pH was 5.0. 2. The range of optimum temperatures for this enzyme at pH 7.0 was $30^{\circ}C-50^{\circ}C$ and the optimum temperature was $40^{\circ}C$. 3. The relationship between the enzyme activity and substrate concentration could be expressed by the Michaelis-Menten equation. The limiting velocity of this enzyme at room temperature and pH 7.0 was $415{\mu}g$ starch removed/ml of reaction mixture/min and $K_m$, Michaelis constant, was $343{\mu}g/ml$. 4. Inhibitors NaCl and $HgCl_2$ blocked this enzyme activity completely at 1% and 0.01% respectively.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.8-23
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• 1981

Color is one of the most important quality factors of red ginseng (Hong-sam) which is processed from fresh ginseng (Panax ginseng C. A. Meyer). Therefore, a study of characteristics of browning mixtures of aqueous fresh ginseng extracts, factors which accelerate the browning of the aqueous extracts, and the antioxidant activity of the browning mixtures may contribute to the improvement of the color and other quality of red ginseng and other ginseng products such as ginseng extracts. In the present study, factors which affect the Maillard-type browning reaction of aqueous extracts of fresh ginseng roots were investigated firstly by adding various concentrations (0.001-0.5M) of arginine or glucose solutions, by varying the browning reaction temperatures and durations. Secondly, some characteristics such as brown color intensity, amounts of water-soluble and ether-soluble extracts, amounts of non-dialyzable materials, pH, viscosity, and reactivity with 2,2'- diphenyl -1 - picrylhydrazyl and antioxidant activity of the browning mixtures of the aqueous fresh ginseng extracts with small amounts of 0.1 M arginine, 0.1 M glucose, and distilled water at various browning temperatures and reaction time were studied. The results of the present study are as follows. 1. Color intensity (absorbance at 470 nm) of the browning mixtures was increased by adding various concentrations of arginine solution to the fresh ginseng extract, but the addition of the same amount of glucose solution did not increase the color intensity. 2 The amounts of water- or ether-soluble extracts, amounts of non-dialyzable materials were slightly greater in case of the browning mixtures of the fresh ginseng extract with 0.1M arginine solution than in case of the browning mixtures of the fresh ginseng extract with the same amount of 0.1 M glucose solution. In the process of the browning reaction, the pH of the browning mixtures of the fresh ginseng extract with 0.1 M arginine solution decreased slightly, while that of the browning mixtures with 0. 1 M glucose solution was almost constant. 3. The color intensity (absorbance at 470 nm) of the browning mixtures of the fresh ginseng extract with 0.1 M arginine or 0.1 M glucose solutions did not correlate well with the reducing power or the antioxidant power of the browning mixtures. The antioxidant activity of 90% ethanol extracts from the earlier stages of the browning mixtures of the fresh ginseng extract with the arginine solution was almost comparable to that of the 90% ethanol extracts from the later stages of the corresponding browning mixtures. The browning mixtures of only the fresh ginseng extract or of the fresh ginseng extract with the glucose solution showed considerable antioxidant activity, although both showed less brown color intensity than the fresh ginseng extract with he arginine solution.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.439-448
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• 2016

The population over 65 years old is 12.7% of total population in 2014 and Korea is going to be an aged society in the near future. The transportation vulnerable including the aged should be guaranteed in walking mobility under safe and comfortable environment for their socio-economic activities. For the era of fusion and convergence this paper investigated the characteristics of walking accidents related to the aged pedestrians and analyzed the aged-oriented walking factors with a reaction time and a walking speed at crosswalks in Yeosu. In the results, the crashes for the aged occur at 9.9% of total crashes and the fatalities of the aged are 40.3% of total fatalities in 2014. The 47.4% of the aged fatalities is also attributed to vehicle-to-pedestrian accidents. The 49.3% of all pedestrian fatalities occurs at the aged pedestrians with a very high proportion. The reaction time and walking speed for the aged were determined as the values located at the lower 15%-tile of the elderly physical ability. It is shown that the reaction time is 4.56 seconds and the walking speed is 0.76 m/s in the case of Yeosu. From two factors' standpoint, the walking environment at crosswalks in Yeosu is inappropriate for the aged.