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Seongnam, South Korea

Lee H.H.,Kyonggi University | Park K.H.,Alantum Corporation | Cha W.S.,Korea University
Applied Chemistry for Engineering | Year: 2013

In this study, Ti added Mn-Cu mixed oxide catalysts were prepared by a co-precipitation method and used for the low temperature (< 200 °C) selective catalytic reduction (SCR) of NOx with NH3. Physicochemical properties of these catalysts were characterized by BET, XRD, XPS, and TPD. Mn-Cu mixed oxide catalysts were found to be amorphous with a large surface and they showed high SCR activity. Experimental results showed that the addition of TiO2 to Mn-Cu oxide enhanced the SCR activity and N2 selectivity. Ti addition led to the chemically adsorbed oxygen species that promoted the oxidation of NO to NO2 and increased the number of NH3 adsorbed-sites such as Mn 3+.

Oh J.-S.,Andong National University | Shim M.-C.,Andong National University | Park M.-H.,Alantum Corporation | Lee K.-A.,Andong National University
Metals and Materials International | Year: 2014

This study investigated the high temperature oxidation behavior of newly developed Ni-Cr-Al powder porous metal. High temperature isothermal oxidation tests were conducted at 900, 1000 and 1100 °C temperatures for 24 h under an atmosphere of 79% N2 + 21% O2 gas. Oxidation weight gain vs. time curves represented typical oxidation behavior of parabolic shape. Weight gain increased with increasing oxidation temperature. Ni-Cr-Al porous metal mainly created oxides such as α-Al203, Cr2O3, NiCr2O4. The α-Al203 oxide could be still maintained up to 1100 °C oxidation temperature as a thick and stable protective layer. It was noted that Ni-Cr-Al porous metal had better high temperature oxidation resistance than those of other Ni-based and Fe-based porous metals. The catastrophic degradation of oxidation resistance especially at very high temperature was not observed up to 1100 °C in this porous metal. The micro-mechanism of high temperature oxidation of Ni-Cr-Al porous metal was also discussed. © 2014, The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht.

Choi K.,Korea University | Kim J.,Korea University | Ko A.,Korea University | Myung C.-L.,Korea University | And 2 more authors.
Journal of Aerosol Science | Year: 2013

The particulate emissions generated from a side-mounted 2.4L gasoline direct injection (GDI) engine were evaluated using a metal foam-type gasoline particulate filter (GPF), placed on the downstream of a three-way catalyst. An ULEV legislation-compliant light-duty vehicle was tested under the new European driving cycle (NEDC) and at constant-speed driving conditions. Particle number (PN) concentrations, particulate size distribution and the filtration efficiency of the GPF were evaluated with the condensation particle counter (CPC) and the differential mobility spectrometer (DMS). The PN emissions for the entire NEDC were 1.17E+12N/km for the base GDI vehicle and 4.99E+11N/km for the GPF-equipped GDI vehicle, and the filtration efficiency of the GPF was 57%. In particular, the number of sub-23nm particles formed in the GDI vehicle was substantially reduced, with 97% efficiency. The pressure drop in the metal foam-type GPF was constrained to be below 1.0kPa at a 120km/h vehicle speed, and as a result, the fuel economy and the CO2 emission for the GPF-applied vehicle were equivalent to those for the base vehicle. © 2012 Elsevier Ltd.

Tewari A.,Indian Institute of Technology Bombay | Vijayalakshmi S.,General Motors | Tiwari S.,General Motors | Biswas P.,General Motors | And 5 more authors.
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2013

The application of lightweight aluminum sheets to fabricate automotive components for vehicle weight reduction continues to be limited due to their low formability and high cost. This report summarizes a metallurgical investigation of the influence of various microstructural attributes on the forming and failure characteristics of aluminum sheets produced by lower cost continuous casting processes. The study has identified the combination of microstructural attributes, such as grain size, texture, and second phase particle distribution, in the sheets which make some sheets more formable than others and has traced the origin of these features to the processing history. The results show that the microstructural features present in the sheets have their origin in the casting, rolling, and recrystallization processes involved in their fabrication. © 2012 The Minerals, Metals & Materials Society and ASM International.

Baek S.,Korea University | Jin D.,Korea University | Jang W.,Korea University | Myung C.-L.,Korea University | And 2 more authors.
Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering | Year: 2015

The nanoparticle emissions from gasoline direct-injection engines are of concern because of the high particle number concentrations compared with those from a gasoline port fuel injection engine. A gasoline particulate filter is a potential solution for reducing the particulate matter emissions. In this study, a 2.0 l turbocharged gasoline direct-injection vehicle with a metal-foam-type gasoline particulate filter was tested using the New European Driving Cycle and steady vehicle operating conditions. The particle number concentration, the particle-size distribution and the filtration efficiency were determined using a condensation particle counter and a fast response differential mobility spectrometer (DMS500). The particle number emissions (particle numbers per vehicle travelling distance (particles/km)) over the New European Driving Cycle were 1.95 × 1012 particles/km for a base vehicle equipped with a three-way catalytic converter and 5.68 × 1011 particles/km for the additional installation of a gasoline particulate filter on the base gasoline direct-injection vehicle. The filtration efficiency of the particle number and the particulate matter mass reached approximately 71% and 67% respectively. The nucleation-mode particles in the size range less than 23 nm for the gasoline direct-injection vehicle equipped with a three-way catalytic converter were further reduced on installation of a gasoline particulate filter at the downstream position of the three-way catalytic converter. A sharp pressure drop between the gasoline particulate filter of 21.0 mbar was obtained at a vehicle speed of 120 km/h in the New European Driving Cycle. The exhaust gas temperature before the gasoline particulate filter reached around 380-610 °C at steady vehicle speeds of 60-120 km/h. The installation of the gasoline particulate filter has the potential to satisfy the Euro 6c particle number emissions regulations for light-duty gasoline direct-injection vehicles. © 2015 Institution of Mechanical Engineers.

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