• Environmental Engineering Research
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• v.10 no.1
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• pp.22-30
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• 2005

Nitrite accumulation is not unusual in batch processes such as sequencing batch reactor (SBR) with high-strength of ammonium or nitrate wastewaters. A possible mechanism of nitrite inhibition on Acinetobacter was depicted in a biochemical model, which the protonated species, nitrous acid form of nitrite, affects proton relating transport at the proton-pumping site crossing the cell membrane under unlimited carbon and phosphorus conditions. This effect exerts inhibition of phosphorylation under aerobic condition and yields low APT/ADP ratio, consequently decrease poly-P synthesis and phosphorus uptake from outside the cell in the model.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.784-793
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• 2010

The Bimodal Tram is expected to take an important role of transit system in Korea under the national strategy of transportation system such as 'Low Carbon and Green Growth' for the next generation. Recently, many cities are thinking of Bimodal Tram as an alternative transit mode that comes up with the policy of 'Low Carbon and Green Growth'. But, there is no specific manual for introducing Bimodal Tram with various requirement of facility and operation regarding the service level of Bimodal Tram system. This study considered the Bimodal Tram system with three different service level- high, mid, and low- and defined the service elements by facility and operational perspectives. This study is expected to help any cities where transport agencies are trying to introduce the Bimodal Tram with different level of service as a new transit system.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.137-140
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• 1997

A cathodic arc with beam filter is employed for the deposition of metallic and hydrogen-free amorphous carbon films. A solenoid filter is used to prevent macropaticles and nonionized atoms from reaching the substrate. The detail transport characters of the filter are presented in the paper. With an optmum filter arrangement we are able to obtain a filter output of 18.4% of the total number of ions produced by the vacuum arc discharge. The deposited amorphous cabon thin film contains no hydrogen and a high fraction of $sp^3$ is determined by XPS. A dense Ti film deposited on H13 steel improves the corrosion resistance of the H13 steel and significant improvements of corrosion resistance were observed by implanting Ti, C in the film.

• Nuclear Engineering and Technology
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• v.30 no.1
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• pp.17-25
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• 1998

Transport of carbon and boron impurity ions parallel to magnetic field lines in the tokamak SOL (scrape-off layer) is numerically investigated for a one-dimensional steady state. The spatial distributions of density and velocity of the impurity ions in a steady state are calculated by finite difference method for a single-fluid model. The calculated results show that among forces acting on SOL particles thermal force produced tv plasma temperature gradient is a principal force determining the feature of impurity distribution profiles in the tokamak edge. However, strong collisional friction forces appearing dominant in front of the diverter plate restrain impurity ion flows due to temperature gradients from moving toward the midplane. Consequently, the stagnation point develops in the impurity flow by these two forces near the diverter region, in which ion flows change their directions. Impurity ions turn out to be accumulated at the stagnation points, where peaked profiles of highly-ionized state ions are relatively predominant over those of low-ionized state ions.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.695-697
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• 2008

Reduction of $CO_2$ emission is one of major issues in the whole industries, especially transport system. Railroad companies in the advanced countries such as EU, Japan, etc. have made great efforts on the improvement of their systems including energy sources, operational efficiency and PR of achievement resulted. Recently, to emphasize the environment-friendly characteristics of the railroad as public transport, the importance of PR is emerging. The achievements were listed in annual, sustainability and corporate responsibility reports. And the superiority of railroad in $CO_2$ emission can be confirmed in web sites and simple advertizing materials. In this study, we proposed the PR programs of achievement and ongoing works in Korean railroad through the case studies on web-based and off-line programs of railroad companies in EU and Japan.

• Ecology and Resilient Infrastructure
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• v.3 no.3
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• pp.156-161
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• 2016

An R&D project, 'Carbon Neutral Road Technologies Development', sponsored by the Korean Ministry of Land, Infrastructure, and Transport was performed and sustainable development is being discussed in relation to global climate change. A draft of the green highway certification system, the green highway design and construction technologies for making low carbon eco-friendly roads, and Green Highway Technology Investment Evaluation System (GTIES) for estimating and managing carbon emissions from roads have been developed from the results of the R&D project. A scheme for expanding the application of these technologies and building sustainable road systems by considering the concept of sustainability was proposed in this research.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.549-552
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• 2009

Methane hydrate is crystalline ice-like compounds which formed methane gas enters within water molecules composed cavity at specially temperature and pressure condition, and water molecule and each other from physically-bond. $1m^3$ hydrate of pure methane can be decomposed to the maximum of $172m^3$ at standard condition. If these characteristics of hydrate are reversely utilized, natural gas is fixed into water in the form of hydrate solid. Therefore the hydrate is considered to be a great way to transport and store natural gas in large quantity. Especially the transportation cost is known to be 18~24% less than the liquefied transportation. However, when methane hydrate is formed artificially, the amount of consumed gas is relatively low due to a slow reaction rate between water and methane gas. In this study, for the better hydrate reaction rate, there is make nano fluid using ultrasonic dispersion of carbon nano tube. and then, Experiment with hydrate formation by nano fluid and methane gas reaction. The results show that when the carbon nano tubes of 0.004 wt% was added to pure water, the amount of consumed gas was about 300% higher than that in pure water and the hydrate formation time decreased.

• Korean Journal of Materials Research
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• v.33 no.10
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• pp.430-438
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• 2023

In this study, we synthesized pH-controlled resorcinol-formaldehyde (RF) gels through the polymerization of two starting materials: resorcinol and formaldehyde. The prepared RF gels were dried using an acetone substitution method, and they were subsequently carbonized under nitrogen atmosphere to obtain carbon xerogels (CX_Y) prepared at different pH (Y). The carbon xerogels were utilized as active materials for coin-type organic supercapacitor electrodes to investigate the influence of pH on the electrochemical properties of the carbon xerogels. The carbon xerogels prepared at lower pH (CX_9.5 and CX_10) exhibited sufficient particle growth, with a three-dimensional network of particles during the RF gel formation, resulting in the development of abundant mesopores. Conversely, the carbon xerogels prepared at higher pH (CX_11 and CX_12) retained densely packed structures of small particles, leading to pore collapse and low specific surface areas. Consequently, CX_9.5 and CX_10 showed high specific surface areas, and provided ample adsorption sites for the formation of electric double layers with electrolyte ions. Moreover, the three-dimensional particle network in CX_9.5 and CX_10 significantly enhanced electrical conductivity. The presence of well-developed mesopores in these materials further facilitated the effective transport of electrolyte ions, contributing to their superior performance as organic supercapacitor electrodes. This study confirmed that pH-controlled carbon xerogels are one of the promising active materials for organic supercapacitor electrodes. Furthermore, we concluded that pH during RF gel formation is a crucial factor determining the electrode performance of the carbon xerogels, highlighting the need for precise pH control to obtain high-performance carbon xerogel electrodes.

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.471-480
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• 2015

Reliance on road transport in domestic logistics can lead to intensified congestion and greenhouse gas emissions due to the rise in oil prices, any increase in logistics costs can have a high social cost. The government policy on Low Carbon Green Growth is seeking to take advantage of the railway system. However, existing railway transport logistics systems, for reasons such as low speed, low track capacity constraints, and the impossibility of implementing a Door to Door system, make it difficult to activate a railway logistics program. As a result of this study, a national R&D project to develop a High-Speed Passenger/Baggage Mixed Train(Hy-SoBex) utilizing the rail capacity constraints to overcome the difficulties of linking an air cargo and freight railway logistics system, we propose a variety of service models and select the optimal service model.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.712-720
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• 2015

The cabotage rule has been protecting the domestic industry from foreign competitions as a kind of trade barrier. In the United States, the shipbuilding industry has been maintained with the help of to the strict cabotage operations by reinforcing advantages for domestic crews and ships which are built in the U.S. For most countries, cabotage has been granted legitimacy in their coastal shipping by Low Carbon Transport in terms of economic and emergency reasons. The cabotage rule is required in the stable supply of the seafarers which rely on the legitimate maritime education. This study analyzes Korean cabotage system and the problems with regard to seafarers education. It is found that the resolution is set up the cabotage act such as Jones Act, U.S.