• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.1
• /
• pp.20-27
• /
• 2012

The $NH_3$-SCR characteristics of $NO_X$ over a V-based catalyst are experimentally examined over a wide range of operating conditions, i.e., $170-590^{\circ}C$ and $30,000-50,000h^{-1}$, with a simulated diesel exhaust containing $NH_3$, NO, $NO_2$, $O_2$, $H_2O$, and $N_2$. The influences of the space velocity and oxygen concentration on the standard-SCR reaction are analyzed, and it is shown that the low space velocity and high oxygen concentration promote the SCR activity by ammonia. The best $deNO_X$ efficiency is obtained with a $NO_2/NO_X$ ratio of 0.5 because of an enhanced chemical activity induced by the fast-SCR reaction, while at the $NO_2/NO_X$ ratios above 0.5 the $deNO_x$ activity decreases due to the slow-SCR reaction. The oxidation of ammonia begins to take place at about $300^{\circ}C$ and the reaction products, such as $N_2$, NO, $NO_2$, $N_2O$, and $H_2O$, are produced by the undesirable oxidation reactions of ammonia, particularly at high temperatures above $450^{\circ}C$. Also, $NO_2$ decomposes to NO and $O_2$ at temperatures above $240^{\circ}C$. Therefore, $NO_2$ decomposition and ammonia oxidation reactions deteriorate significantly the SCR catalytic activity at high temperatures.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.251-251
• /
• 2016

For several decades, industrial processes consume a huge amount of raw water for various objects that consequently results in the generation of large amounts of wastewater. Wastewaters are consisting of complex mixture of different inorganic and organic compounds and some of them can be toxic, hazardous and hard to degrade. These effluents are mainly treated by conventional technologies such are aerobic and anaerobic treatment and chemical coagulation. But, these processes are not suitable for eliminating all hazardous chemical compounds form wastewater and generate a large amount of toxic sludge. Therefore, other processes have been studied and applied together with these techniques to enhance purification results. These include photocatalysis, absorption, advanced oxidation processes, and ozonation, but also have their own drawbacks. In recent years, electrochemical techniques have received attention as wastewater treatment process that could be show higher purification results. Among them, boron doped diamond (BDD) attract attention as electrochemical electrode due to good chemical and electrochemical stability, long lifetime and wide potential window that necessary properties for anode electrode. So, there are many researches about high quality BDD on Nb, Ta, W and Si substrates, but, their application in effluents treatment is not suitable due to high cost of metal and low conductivity of Si. To solve these problems, Ti has been candidate as substrate in consideration of cost and property. But there are adhesion issues that must be overcome to apply Ti as BDD substrate. Al, Cu, Ti and Nb thin films were deposited on Ti substrate to improve adhesion between substrate and BDD thin film. In this paper, BDD films were deposited by hot filament chemical vapor deposition (HF-CVD) method. Prior to deposition, cleaning processes were conducted in acetone, ethanol, and isopropyl alcohol (IPA) using sonification machine for 7 min, respectively. And metal layer with the thickness of 200 nm were deposited by DC magnetron sputtering (DCMS). To analyze microstructure X-ray diffraction (XRD, Bruker gads) and field emission scanning electron microscopy (FE-SEM, Hitachi) were used. It is confirmed that metal layer was effective to adhesion property and improved electrode property. Electrochemical measurements were carried out in a three electrode electrochemical cell containing a 0.5 % H2SO4 in deionized water. As a result, it is confirmed that metal inter layer heavily effect on BDD property by improving adhesion property due to suppressing formation of titanium carbide.

• Journal of the Korea Institute of Building Construction
• /
• v.21 no.6
• /
• pp.689-700
• /
• 2021

Due to the COVID-19 pandemic, higher education in South Korea has rapidly shifted online. In addition, the advent of the Fourth Industrial Revolution has highlighted the need to introduce innovation teaching methods. To cope with these changes and demands, the learning management system used by domestic universities must therefore be improved. This study developed a learning management system for the application of team-based learning to improve and develop the learning management system of domestic universities. The major research findings are as follows. The analysis results showed that there is not sufficient function to apply new innovation teaching methods, such as team-based learning, in the current learning management system of domestic universities. Therefore, a learning management system capable of supporting team-based learning courses was developed in this study. The system consisted of 'pre-class learning,' 'team activities' and 'participation learning,' which were further classified into nine sub-items. In the future, a survey of system users is planned in order to further improve the system. It is believed that if the proposed learning management system were introduced to domestic universities, it would improve the educational environment and contribute to the spread and use of innovative teaching methods.

• Atmosphere
• /
• v.31 no.2
• /
• pp.241-249
• /
• 2021

A smart city utilizes data collected from various sensors through the internet of things (IoT) and improves city operations across the urban area. Recently substantial research is underway to examine all aspects of data that requires for the smart city operation. Atmospheric data are an essential component for successful smart city implementation, including Urban Air Mobility (UAM), infrastructure planning, safety and convenience, and traffic management. Unfortunately, the current level of conventional atmospheric data does not meet the needs of the new city concept. New and innovative approaches to developing high spatiotemporal resolution of observational and modeling data, resolving the complex urban structure, are expected to support the future needs. The geographic information system (GIS) integrates the atmospheric data with the urban structure and offers information system enhancement. In this study we proposed the necessity and applicability of the high resolution urban meteorological dataset based on heavy fog cases in the smart city region (e.g., Sejong and Pusan) in Korea.

• The Journal of Korean Institute for Practical Engineering Education
• /
• v.2 no.2
• /
• pp.120-136
• /
• 2010

As there has recently been a rapid increase in importance of lifelong study, the number of learners participating in lifelong educational programs is increasing geometrically and lifelong educational institutions turned out to be the best one where everyone wants to study. Hereupon, aimed at team leaders managing the whole nation lifelong institutions and teachers interacting briskly with learners, we tried to research and analyze main cause affecting performances of lifelong educational institutions of university in this study based on Resource Based View and Dynamic Capability Theory for continuous development of lifelong educational institutions and securement of the competition. The contents and results of this study run as follows First, We tried to investigate the relation between resources and performances of lifelong educational institutions of university as contents and results of this study. The results were analyzed that material resources like an easy accessibility, superiority of facilities and teachers' excellence of lifelong educational institutions have an beneficial influence. Second, We tried to understand a leading cause affecting Dynamic Capabilities of lifelong educational institutions. The analyzed results were that material and human resources like easy accessibility, superiority of facilities, superiorities of teachers and director's empowering readership as a superior and organizational culture(autonomy, interaction) affect Dynamic Capabilities. These results could be understood that lifelong educational institution characteristics of university are well reflected. Third, We tried to find that even though elements of Resource Based view are surely important, Dynamic Capabilities of the organization are more important for continuous development and growth of lifelong educational institutions. Upon investigation, we found that there were mediating effectiveness in relations between Absorptive Capability and Innovative Capability which are Dynamic Capabilities and performances. Like preceding, there wes also mediating effectiveness in relations between empowering and organizational culture(autonomy, interaction) of a superior. And to conclude, superiority of resources could contribute to developing lifelong educational institutions to some degree but considering features of lifelong educational markets rapidly changed, Dynamic Capabilities of organization are more important for continuous growth and expensive preferability.