• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.243-247
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• 2009

This study is purposed to analyze thermodynamic properties on the hydrogen production by ethylene glycol steam reforming. Various reaction conditions of temperatures(300~1,600 K), feed compositions(steam/carbon= 0.5~4.5), and pressures(1~30 atm) were applied to investigate the effects of the reaction conditions on the thermodynamic properties of dimethyl ether steam reforming. An endothermic steam reforming competed with an exothermic water gas shift reaction and an exothermic methanation within the applied reaction condition. Hydrogen production was initiated at the temperature of 400 K and the production rate was promoted at temperatures exceeding 500 K. An increase of steam to carbon ratio(S/C) in feed mixture over 1.0 resulted in the increase of the water gas shift reaction, which lowered the formation of carbon monoxide. The maximum hydrogen yield with minimizing loss of thermodynamic conversion efficiency was achieved at the reaction conditions of a temperature of 900 K and a steam to carbon ratio of 3.0.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.76-82
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• 2006

Fenton's reaction are difficult to apply in the field due to the low pH requirements for the reaction and the loss of reactivity caused by the precipitation of iron (II) at neutral pH. Moreover, Fenton-like reactions using iron mineral instead of injection of iron ion as a catalyst are operated to get high removal result at low pH. Because hydroxyl radical can generate at the surface of iron mineral, there are competition with a lot of hydroxide at around neutral pH. On the other side, to operate Fenton's reaction series at neutral pH, modified Fenton reaction is suggested. The complexes, composed by iron ions (ferrous ion or ferric ion)-chelating agent, could be acted as a catalyst and presented in the solution at neutral pH. However, modified Fenton reaction requires a lot of hydrogen peroxide. Accordingly, the purpose of this experiment was to effectively combine Fenton-like reaction and modified Fenton reaction for extending application of Fenton's reaction. i.e., injecting chelating agents in Fenton-like reaction at around neutral pH is increasing the concentration of dissolved iron ion and highly promoting the oxidation effect. 2,4,6-trinitrotoluene (TNT) was used as a probe compound for comparing reaction efficiencies in this study. If the concentration of dissolved iron ion in combined Fenton process were existed more than 0.1 mM, the total TNT removal were increased. Magnetite-NTA system showed the best TNT removal (76%) and Magnetite-EDTA system indicated about 56% of TNT removal. The results of these experiments proved more promoted 40-60% of TNT removal than Fenton-like reaction's.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.239-247
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• 1990

The gas-phase S_N2$ reactions can be classified into neutral bimolecular, solvated, and ionic reactions; the neutral bimolecular reaction proceeds via retention mechanism whereas the ionic reaction produces inversion products. In the reaction of solvated nucleophile with one solvent molecule, a six-center transition state (TS) is formed and the two processes i.e., retention and inversion, are found to compete with a favored path depending on the electronic effect of the nucleophile and substituents in the substrate and on the steric requirement. In the ionic reaction, the difference in the energy barrier between the two processes reduces to a small value when the substrate methyl group is made bulky, leaving ability of the leaving group is improved and at the same time the negative charge of the nucleophile is dispersed. When the reaction center atom in the $S_N2$ reaction is changed to a larger sized second row elements, the activation barrier decreases since the steric crowding in the penta-coordinated TS is relieved. However within the same row, the barrier was found to increase as the atomic size decreased. For the boron, B, the barrier height was the least since in addition to the relatively large atomic size compared to C and N, it forms tetra-coordinated TS so that the steric crowding becomes nearly negligible.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.455-462
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• 1995

The new six herbicidal N-[(pyrimidin-2-yl)aminocarbonyl]-2-substituted-6-(1-hydroxy-2-fluoroethyl)benzenesulfonamide derivatives(S) were synthesized and rate constants for the hydrolysis of thier in the range of pH $1.0{\sim}10.0$ have been studied in 15%(v/v) aqueous acetonitrile solution at $45^{\circ}C$. From the basis of the results, pH-effect, solvent effect, ortho-substituent effect, thermodynamic parameters(${\Delta}H^{\neq}$ & ${\Delta}S^{\neq}$), pKa constant(4.80), rate equation, analysis of hydrolysis products(2-(1-hydroxy-2-fluoroethyl)benzenesulfonamide & 4,6-dimethoxyaminopyrimidine), it may be concluded that the general acid catalyzed hydrolysis through $A-S_E2$ mechanism and specific acid catalyzed hydrolysis through A-2 type(or $A_{AC}2$) mechanism proceeds via conjugate acid($SH^+$) and tetrahedral intermediate(I) below pH 8.0, whereas, above pH 9.0, the general base catalyzed hydrolysis by water molecules(B) through $(E_1)_{anion}$ mechanism proceeds via conjugate base(CB). In the range between $pH\;7.0{\sim}pH\;9.0$, these two reactions occur competitively.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.181-192
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• 2019

The purpose of this study is to look at the fun that high school students from blind schools feel in sports programs. A questionnaire was used to collect data from 10 out of 12 blind schools nationwide, including 122 male and 102 female students. Research tools are open questionnaires and questions are as follows. - Questionnaire: "Write down three of the most interesting things about sports programs." The data analysis was done with frequency analysis and the following conclusions were drawn. First, male high school students at blind schools are able to build up their physical strength in the area of competent factors (control-self) (23, 21.5%), in the area of competent factors (7, 77.8%) and in the area of motion-related factors (competition) (24, 15.1%), and in the area of non-execution factors (26, 37.7%), Second, high school girls with visual impairments did not respond in the areas of proficiency (control-self) because of stress release (25, 26.6%), in the areas of control-tain), in the areas of movement (competition) because they were able to do various exercises (22, 15.7%), and in the areas of non-watering (environmental) (18, 37.5%). Third, in the sports program comparative analysis of high school students between genders of blind schools, boys are interested in health and physical fitness in the field of competent factors (control-self) and girls are considered to be a means of relieving stress. In the field of competent factors (control-others), boys and girls can react to a variety of sports opportunities. In the future, by studying the fun of students in the physical education program through research to find out more fun in the school physical education program, we will explore practical ways to maximize student participation and increase motivation level The educational aspect of the process, that is, the educational value provided by the physical education, should be composed of content that can change the thinking and behavior of the teacher and the student so that the program contents and operation method.

• Journal of Korea Port Economic Association
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• v.30 no.4
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• pp.255-273
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• 2014

The purpose of this paper is to examine the causal relationship among the trading volume of Pyeongtaek port, Incheon Inner Harbor, Incheon North Harbor. Methodologically, Granger causality, impulse response function, and variance decomposition based on VAR are used. The results indicate that Pyeongtaek port trading volume positive shock has positive effects on Incheon North Harbor. In addition, Incheon Inner Harbor trading volumes positive shock has negative effects on Pyeongtaek port. The results also suggest that the volume of Pyeongtaek port Granger-causes the volume of Incheon North Harbor, but not vice versa. The volume of Incheon Inner Harbor Granger-causes the volume of Pyeongtaek port. Based on these results, we suggest that port authorities have to focus on policies that would promote copetition between port of Pyeongtaek and Incheon in the world harbor industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.574-581
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• 2016

Exports of Korean non-timber forest products to the Japanese market decreased 46.3% from 17.54 million dollars in 2010 to 9.42 million dollars in 2014. This research aims to find the appropriate strategies for exporting Korean non-timber products, such as chestnut, shitake, persimmon, and wild ginseng. We applied conjoint analysis to investigate the preferences of Japanese homemakers for Korean non-timber products. The results are as follows: (1) There is a clear distinction in the preference for the attributes and levels of products; (2).Korean products are preferred to Chinese products, but have lower competitiveness than Japanese products; (3) Japanese homemakers responded sensitively, not to the forest product prices, but to changes in their specific attributes. These results can be used to promote the export of Korean non-timber products to the Japanese market.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.395-400
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• 2019

The Web environment of the frontend domain is increasingly competitive to preempt the new standard of presentation layer. N-Screen, a service that enables users to seamlessly use one content in various devices in Korea, is competing for market preemption by recognizing it as a core service of the future. In the cloud computing, N-screen is a typical service type. However, most of the frontend research required for groupware in enterprise environments has been limited to responsive web design for the web and native apps for mobile. Gradually, the need for MVC design patterns is increasingly widening in enterprise environments to overcome the cultural differences of companies and to support one source multi-use strategy supporting multiple devices and development productivity. Therefore, in this study, we will analyze and design JPetStore with hybrid application design based on Spring MVC, e-government standard framework environment of next generation web standard, and provide reference model of frontend hybrid apps design in future enterprise environment.

• Journal of Radiation Protection and Research
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• v.22 no.2
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• pp.103-109
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• 1997

Adult male rats were exposed to a whole body with a single dose of 1.0, 2.0, 3.0, 5.0, and 7.0 Gy. The animals were sacrificed 48, 72, 96 and 216 hours following exposure. A competitive enzyme linked immunosorbent assay(ELISA) with antigen immobilized on the solid phase has been developed to measure ceruloplasmin in rat serum and complete dose response curves. Ceruloplasmin was purified from the plasma of turpentine treated male rats. Coating of ceruloplasmin had more effectiveness in 10 mM Tris-HCI, 150 mM sodium chloride, pH 7.4 than in 50 mM carbonate/bicarbonate buffer, pH 9.6. The coating range for ceruloplasmin was $70{\sim}140ng$/well. Levels of ceruloplasmin increased to maximum on the $72{\sim}96$ hours after irradiation. Slope of between response and dose was greatest value 96 hours following irradiation. Normal ceruloplasmin levels were not recorded 216 hours following exposure. In 0.1 Gy irradiated group, levels of ceruloplasmin also increased to maximum on the $72{\sim}96$ hours following irradiation. The concentration of this protein remained significantly different from control value, 196 hours after exposure. Ceruloplasmin was identified as one of the major acute phase protein following irradiation and further studies about gene expression and regulation would be necessary for radiation protection.

• Clean Technology
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• v.17 no.1
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• pp.41-47
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• 2011

[ $MnO_2$ ]catalysts were prepared by precipitation method using potassium manganate and manganese acetate. The effect of calcination temperatures of $MnO_2$ catalysts for CO oxidation has been studied and their physicochemical properties were studied by X-ray diffraction (XRD), $N_2$ sorption, temperature programmed reduction of $H_2$ ($H_2-TPR$), and temperature programmed desorption of CO (CO-TPD) techniques. $MnO_2$ calcined at $300^{\circ}C$ catalyst has a large surface area $181m^2/g$ having a narrow pore size distribution at 9 nm. The results of XRD and $H_2-TPR$ showed that the catalysts calcined at different temperatures showed mixed oxidation states of Mn such as $Mn^{4+}$ and $Mn^{3+}$. CO-TPD showed that the quantity of $CO_2$ desorbed was decreased with increasing the calcination temperatures. The catalytic activity over the catalyst calcined at $300^{\circ}C$ exhibited the highest conversion reaching to 100% at $200^{\circ}C$. $H_2O$ vapor showed an inhibiting effect on the efficiency of the catalyst because of co-adsorption with CO on the active sites of manganese oxide catalysts and the initial catalytic activity of CO oxidation could be regenerated by removing $H_2O$ vapor in the reactants.