• International Journal of Automotive Technology
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• v.3 no.3
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• pp.111-115
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• 2002

Suddenly increasing numbers of automobiles result in making worse air pollution problems. In particular, the emissions from automobiles affect badly on atmosphere. Nowadays, research on catalyst converter and filter trap as a modem technology is very active because PM is designated as a major cancer material and stringent regulations on this are necessary and required. The ceramic filter is very efficient in reducing particular materials up to 80-90% and is evaluated as a very efficient after-treatment technology. However, it comes with decreased engine performance due to increased back-pressure occurred by thermal crack. In order to solve these problems, several methods are proposed such as fuel additive, electric heater and burner types. This experimental study has been conducted with equipped and unequipped a ceramic filter on a displacement 11,000cc diesel engine and compared in terms of engine performance and emission. To measure the emission, D-13 mode is applied and measured quantities of the exhaust gases, particularly in CO, HC, PM, and NOx. Therefore, this research is focused on the basic mechanism and characteristics on harmful materials generated by ceramic filter.

• Korean Journal of Heritage: History & Science
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• v.56 no.2
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• pp.62-78
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• 2023

The act of burning incense originated from Buddhist rituals and customs, and gradually formed its own culture. In the Goryeo Dynasty, in addition to religious and national rituals, incense came to be enjoyed more generally and widely. In particular, Goryeo literati enjoyed the elegant lifestyle of staying home and burning incense. This was part of a regional culture shared across East Asia. Such incense burning applied the same methods as were used during the same period in China. In collections of writings from the Goryeo Dynasty, it can be seen that incense methods such as gyeok-hwa-hoon-hyang (隔火熏香) and jeon-hyang (篆香) were used. A particular method of incense influenced the size and shape of the incense burner utilized. Small incense burners suitable for simple everyday incense were used, such as the hyangwan (香垸), a cup (wine glass)-shaped burner. White porcelain incense burners from Song were discovered in Gaegyeong, and celadon incense burners from Goryeo were made in the same shape. This phenomenon shows that there was great demand for ceramic incense burners in Goryeo in the 12th and 13th centuries. During this period, incense burners that imitated metalware were produced, and some applied the techniques and patterns of Goryeo celadon. The Goryeo Dynasty-era incense burner was basically a necessity for use in various rituals, but gradually came to be widely used also by individuals.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.395-399
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• 2009

Advanced afterburner used in the most modernized gas turbine has new designing paradigm to cope with reinforced power density. The most distinct change is the designing trend to integrate fuel injectors and flame holder in order to manage higher temperature of inlet air. F414 and F110-GE-132 engine adopted this methodology and installed a variable nozzle utilizing CMC(Ceramic Matric Composite) material and active cooling of nozzle flap with ejector nozzle in order to enhance the life cycle of engine components and an economical aspect. These technological trends can be utilized for an advanced ramjet engine and combined cycle engine like TBCC.

• Composites Research
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• v.27 no.4
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• pp.123-129
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• 2014

Ceramic matrix composites (CMCs) consist of such reinforcements as carbides, nitrides, borides and oxides, which have high melting points, low density, high modulus and high strength, for the purpose of increasing toughness. These materials are used for heat shielding systems for aerospace vehicles, high-temperature gas turbine combustion chambers, turbine blades, stator vane parts, etc. Oxide CMCs are used for the components of burner and flame holder and the high-temperature gas duct. CMCs are also applied to brake disks, which are subjected to severe thermal shock, and slide bearing parts under heavy loads. The research and development of the CMC are progressed for the strategic purpose in defense and energy industry; for instance, for aerospace applications in the U.S., and for hyper-speed aircraft, gas turbines, and atomic fissions in U.S., Japan, and Europe.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.130-141
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• 1997

Work on the reduction of particulate matter(PM) from a diesel vehicl has led to a new trp system and a control method to control the combustion rate of the PM filtrated in the trap, which was named as 'Active Exhaust Feeding Regeneration(AEFR) System' by its operation mechanism. Ceramic cordierite filter is a major component of the trap and susceptible to thermal shock. Therefore the system should be designed to reduce the peak temperature and temperature gradients in the trap ; these have been considered to be the main factors causing thermal shock of the filter during the regeneration. It uses the engine's exhaust gas partially for the regeneration of the ceramic filter. It controlled bypass flow rate of the engine's exhaust gas precisely to control the temperature of the gas entrained into the filter. Gas temperatures were measured inside filter, and the oxygen concentration at the outlet of the filter was also monitored during the regeneration to analyze the combustion process of the PM. The temperature distributions and temperature gradients in the filter during the regeneration varied widely according to the regeneration control schemes. Finally, this system shows relatively low peak temperature and temperature gradients in the filter during its regeneration. It is considered that this system uses a mew method to control the combustion rate of the PM, which is different from the methods used in the previous studies.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.88-94
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• 1997

The oxidation behavior of the NiCrAlY bond coat and thermal fatigue failure in the plasma-sprayed thermal barrier coating system, ZrO2.8wt%Y2O3 top coat/Ni-26Cr-5Al-0.5Y bond coat/Hastelloy X superalloy substrate, in commercial use for finned segment of gas turbine burner were investigated. The main oxides formed in the bond coat were NiO, Cr2O3, and Al2O3. It divided the oxide distribution at this interface into two types whether an Al2O3 thin layer existed beneath ZrO2/bond coat interface before operation at high temperature or not. While a continuous layer of NiO was formed mainly in the region where the Al2O3 thin layer was present, the absence of it resulted in the formation of mixture of Cr2O3 and Al2O3 beneath NiO layer. Analyses on the fracture surface of specimen spalled by thermal cycling showed that spalling occurred mainly along the ceram-ic coat near ZrO2/bond coat oxide layer interface, but slightly in the oxide layer region.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.168-177
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• 1998

The effects of the regeneration parameters such as inlet gas temperature, space velocity, oxygen concentration of the exhaust gas, and initial particulate loading on the oxidation of the particulate inside ceramic cordierite filter have been investigated through an engine experiment. As the inlet gas temperature increases, the remarkable filter temperature occurs owing to the rapid combustion rate. Though the higher space velocity affirms the safe regeneration, it also requires much fuel consumption of the burner. For that reason, the space velocity should be compromised considering the fuel economy. The excessive accumulation of the particulate may cause undesirable regeneration temperatures inside filer even under the optimized regeneration condition. The inlet gas temperature should be selected to overcome the variation of the oxygen concentration which is inherent feature of the diesel engine. It is the most important factor in the regeneration control techniques.