• Corrosion Science and Technology
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• v.16 no.3
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• pp.128-140
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• 2017

Aluminum alloy matrix may be used for manufacturing lighter automobiles. However, galvanic corrosion may occur between the rivet joint combining aluminum alloy matrix and a CFRP (carbon fiber reinforced plastic) laminate. The possibility of galvanic corrosion may be investigated by measuring galvanic couple currents. Two types of galvanic current measuring methods were used. One method is to use potentiodynamic polarization curves and the other is the ZRA (zero resistance ammeter) method. For galvanic corrosion experiments graphite, a major component of CFRP, was used with carbon steel (rivets) and 6061 aluminum alloys. Regardless of carbon steel, Ni deposited carbon steel, and 316L stainless steels we also investigated the possibility of reduction in galvanic corrosion. Results revealed that even though Ni deposited carbon steel or 316L stainless rivet may slightly increase galvanic current density between those and Al matrix, substitute rivets for carbon steel may be considerably useful for reducing overall galvanic corrosion.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.1
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• pp.53-61
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• 1996

Effects of carbon and Ti on damping capacity are investigated in an Fe-17%Mn alloy. The suppressive force of carbon against ${\gamma}{\rightarrow}{\varepsilon}$ transformation increases linearly with an increase in its content, lowering Ms temperature and volume fraction of ${\varepsilon}$ martensite. Carbon deteriorates damping capacity by reducing the interfacial area of damping sources and mobility of the boundaries contributing to anelastic deformation. The reduction in damping capacity is accelerated when carbon-containing alloy is aged at higher temperatures above room temperature. The effect of Ti on damping capacity is found to be benificial in carbon-containing alloy, which is attributed to the depletion of carbon solute due to the formation of TiC.

• Journal of the Korean Chemical Society
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• v.27 no.5
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• pp.376-381
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• 1983

Dispersed nickel particles on Spherocarb were prepared at 540$^{\circ}C$ in various reaction atmosphere. Magnetic properties of these samples were determined, and results were compared with those of unsupported and MgO supported nickel particles. It was shown that nickel react primarily with carbon regardless of reducing atmosphere. In addition, apparent possibility of nickel-carbon interaction was discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.855-859
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• 2005

Carbon fiber polymeric composites have been widely used in bearing materials under high pressure without oil-lubrication due to their self-lubricating characteristics. However, the severe wear of carbon composite surface occurs due to the generation of wear debris when the pressure applied on the composite surface is higher than the critical value of composite surface. In this work, in order to remove wear debris continuously during sliding operation, composite specimens with many micro-grooves on their sliding surfaces were devised. To investigate the effect of wear debris on the tribological behavior of carbon/epoxy composites, dry sliding tests were performed with respect to applied pressure using the composite specimens with and without micro-grooves. From the measurement of friction coefficients and wear rates, a model for the effect of wear debris on the friction and wear of composites was proposed.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1140-1146
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• 2013

Bioelectrochemical systems (BESs) have been suggested as a new technology for wastewater treatment while accomplishing energy and chemical generation. This study describes the performance of BESs based on mixed culture that are capable of reducing carbon dioxide to acetate. The cathode potential was a critical factor that affected the performance of the BESs. The rate of acetate production increased as the electrode potential became more negative, from 0.38 mM $d^{-1}$ (-900 mV vs. Ag/AgCl) to 2.35 mM $d^{-1}$ (-1,100 mV), while the electron recovery efficiency of carbon dioxide reduction to acetate increased from 53.6% to 89.5%. The microbial population was dominated by relatives of Acetobacterium woodii when a methanogenic inhibitor was added to the BESs initially.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.2
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• pp.83-92
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• 2011

The purpose of this study is to propose strategies for reducing greenhouse gas emissions on urban areas. This study is made up GHG emission estimation and emission prospect methods, setting of GHG reduction target, GHG reduction plan formulation and feasibility assessment. The significance of this study is as follows. First, this study provides the local government for the overall frame of low carbon strategies. Second, this study contribute to establishment of GHG emission reduction strategies in the local autonomy by providing GHG emission estimation and setting reduction target which is essential elements of reduction strategy. Third, we organize a reduction element for low carbon city embodiment and showed the way to assessment the reduction effect of these elements quantitatively.

• Journal of the Korean Professional Engineers Association
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• v.42 no.2
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• pp.41-48
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• 2009

The Government declared 'Low-Carbon Green Growth' as the new national vision for future development to improve economic growth and quality of life through higher energy efficiency, less energy consumption, wider use of renewable energy, etc. Korea can no longer delay participating in international efforts against global warming by reducing carbon dioxide and other greenhouse gas emissions. Thus low-carbon green growth is not a matter of choice, and it becomes indispensible to sustaining the nation's economic development. The Government is determined to take the initiative in speeding up economic recovery by carrying out the large scale investment projects such as the Korean version of a 'Green New Deal. The 49 trillion-won projects include river improvement, eco-friendly transportation networks, advanced information infrastructure, water resources & dam construction, green cars & clean energy development, etc. which will create nearly one million new jobs over the next four years.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.333-338
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• 2002

In this work, the characterization of adsorption of Cu, Zn and Cd on granular activated carbon in water has been studied. The factors that affect adsorption in boundary between activated carbon and wastewater are concentration, temperature, contact time, pH and so on. As the result of this study, the maximum adsorption amount of Cu occurred near pH 7, while that of Zn and Cd was near pH 9.6 and 10, respectively. As contact time and temperature are transformed, such factors as optimum contact time and temperature are taken into consideration in an adsorptive process of heavy metal because an adsorption and a reducing process occur. In isotherm of Freundlich, 1/n values of Cu, Cd capacity were between 0.16 and 0.5.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.199-200
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• 2023

Eco-friendly concrete contains only 5% of cement yet achieves equal or greater strength compared to conventional concrete, reducing salt-attack impact and hydration heat by more than 30% and ensuring higher construction quality for underground structures. Furthermore, eco-friendly concrete can reduce up to 90% of carbon dioxide emissions compared to traditional concrete, enabling a reduction of approximately 6,000 tons of carbon emissions for 1,000 of apartment units construction. This is equivalent to planting around 42,000 trees

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.608-612
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• 2023

Nano-diamond (ND) was added during the carbon block preparation process to increase the thermal conductivity of the carbon block. Added ND controlled the generated pore of carbon block due to the volatilization of the binder pitch during the carbonization process. The ND was added to the kneading process of coke and binder pitch, and carbon blocks were prepared by pressing and carbonization. As the amount of added ND increased, the ND ratio of the carbon block increased. The added ND made a pass-way for generated gas by volatilizing the binder pitch during the carbonization process, increasing the density of the carbon block and reducing the porosity. The thermal conductivity of the carbon block was improved by increased density, lowered porosity, and the high thermal conductivity of added ND.