• Journal of the Korean Society of Combustion
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• v.15 no.3
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• pp.57-66
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• 2010

The purpose of this paper is to investigate the effects of fuel injection strategy and engine load on the structure and emissions characteristics of a DI diesel engine with 1.6L of piston displacement. In order to analyze the particulate matter (PM) and exhaust emissions characteristics in a direct injection diesel engine, the quantity of PM and exhaust emissions (including HC, CO and $NO_X$) were investigated under various injection strategies and engine loads. Two different injection strategies (one pilot/main injection and two pilots/main injection) was investigated under the various engine loads. A thermophoretic sampling method with a scanning electron microscope (SEM) were used to obtain the PM morphology (including primary particles, the size of the agglomerates, the number of agglomerates, the fractal dimension). The quantity of soot gradually increased with increasing engine load at both injection strategies. The primary particles in the PM agglomerates indicate that the average of the primary particle and radius of gyration increased as the engine load increased.

• Journal of the Korean Society of Combustion
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• v.12 no.3
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• pp.16-23
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• 2007

Employing an after-treatment system has almost become a mandatory requirement for Diesel vehicles, which results from a reinforced exhaust regulations as the number of vehicles powered by a Diesel engine increases. The Diesel Particulate Filter (DPF) system is considered as one of the most efficient method to reduce particulate matter (PM); however, the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Temperature, gas composition and flow rate of exhaust gas are important parameters in DPF evaluation processes, especially during a regeneration process. Engine dynamometer and segment tester are generally used in DPF evaluation so far. These test methods, however, could not completely evaluate the effect of various parameters on real DPF, such as oxygen concentration, amount of soot and exhaust gas temperatures. The evaluation of DPF systems using a dump combustor has been verified experimentally and this dump combustor system is likely to be appropriate for the DOC (Diesel Oxidation Catalyst) and SCR (Selective Catalytic Reduction) assessments test, too.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.10-16
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• 2011

Diesel particulate filter is being recognized that it is the most effective technologies to reduce particulate matter. In this study, to determine the characteristics of the cell-open-type pDPF, we employed p-DPF to exhaust gas tunnel of diesel engine and surveyed filtration efficiency and BPT on the basis of PM which is exhausted from engine. In this paper the soot loading mass in DPF can be predicted from increase of differential pressure of DPF so that we can measure filtration efficiency and Balance Point Temperature (BPT) by soot loading mass. The result of the research showed that the filtration efficiency is 65% in ESC mode with 0.7mm hole diameter. For the results of the characteristics of filtration efficiency and BPT according to mass_exh, we found that if mass_exh increases, filtration efficiency increases and BPT decreases.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.78-84
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• 1996

In order to eliminate TPM(Total Particulate Matter) from a diesel engine, we designed and developed a particulate trap system using a burner, which was named as AEFR(Active Exhaust Feeding Regeneration) system. We have considered the temperature distributions and gradients in the filter being regenerated according to regeneration control schemes Ⅰ, Ⅱ and Ⅲ. Schemes Ⅲ has shown the most desirable peak temperature and temperature gradients in AFER system. Finally, it was concluded that much lower peak temperature and temperature gradients in the filter could be obtained than that of other advanced research results by our AEFR system.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.179-189
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• 1997

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now studied actively. In this study, a transient one-dimensional model developed to simulate the thermal and conversion characteristics of adiabatic monolithic converters operating under warm up conditions is presented. This model takes into account the gas solid heat and mass transfer, axial heat conduction, chemical reactions and the related heat release. The model has been used to analyze the transient response of an axisymmetric catalytic converter during a warm-up as a function of catalyst design parameters and operation conditions in order to observe their effects on the lightoff behaviour. The experimental test was carried out 2400 cc light diesel engine with DOC.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.99-104
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• 2003

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.176-183
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• 2008

Performance of electrostatic diesel PM filtration systems (E-DPS) with different types has been tested using the carbon particles generated by spark discharge in laboratory. Among the five electrostatic precipitators, the multiple wires cylindrical E-DPS with the highest collection efficiency and relatively lower differential pressure at the flow rate of $1\;m^3$/min, as an applicable device to diesel engine as an after treatment system, has been combined with another collection cylinder to improve the collection efficiency of diesel particulate matters generated from diesel engines. The multiple wires cylindrical E-DPS combined with the cylindrical collector showed the collection efficiency of more than 60% at the engine speed of 2,000 rpm with the engine loads of 25 and 50%.

• Journal of Environmental Science International
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• v.26 no.9
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• pp.1013-1021
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• 2017

Exposure to Diesel Particulate Matter (DPM) potentially causes adverse health effects (e.g. respiratory symptoms, lung cancer). Due to a lack of data on Elemental Carbon (EC) exposure levels in underground copper ore mining (unlike other underground mining industries such as non-metallic and coal mining), this case study aims to provide individual miners' EC exposure levels, and information on their work practices including use of personal protective equipment. EC measurement was carried out during different work activities (i.e. drilling, driving a loader, plant fitting, plant operation, driving a Specialized Mining Vehicle (SMV)) as per NIOSH Method 5040. The copper miners were working 10 h/day and 5 days/week. This study found that the most significant exposures to EC were reported from driving a loader (range $0.02-0.42mg/m^3$). Even though there were control systems (i.e. water tanks and DPM filters) on the diesel vehicles, around 49.5% of the results were over the adjusted recommendable exposure limit ($0.078mg/m^3$). This was probably due to: (1) driver's frequently getting in and out of the diesel vehicles and opening the windows of the diesel vehicles, and (2) inappropriate maintenance of the diesel vehicles and the DPM control systems. The use of the P2 type respirator provided was less than 19.2%. However, there was no significant difference between the day shift results and the night shift results. In order to prevent or minimize exposure to EC in the copper ore mine, it is recommended that the miners are educated in the need to wear the appropriate respirator provided during their work shifts, and to maintain the diesel engine and emission control systems on a regular basis. Consideration should be given to a specific examination of the diesel vehicles' air-conditioning filters and the air ventilation system to control excessive airborne contaminants in the underground copper mine.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.117-121
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• 2006

Non-thermal plasma technology has many applications in various areas. One of the applications is regenerating diesel particulate filter (DPF). DPF is a widely applied device to control the particulate emission of diesel engines. But it needs periodic removal of clogged soot for the smooth running of engine. Conventional high-temperature removal processes easily leads to the breakage of DPF. Herein, low-temperature plasma formed in a dielectric barrier discharge (DBD) reactor was used to form active oxidants such as ozone and nitrogen dioxide. Experimentally, the effects of discharge power and frequency on the performance of DBD reactor were studied. Two oxidants, $O_3$ and $NO_2$, were synthesized and used for incinerating soot in the used DPF. Performances of the two oxidants on the reduction of soot were compared, and it was found that $NO_2$ is more effective than $O_3$ for getting rid of soot

• Asian Journal of Atmospheric Environment
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• v.1 no.1
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• pp.28-35
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• 2007

Accumulated epidemiological and animal studies have suggested that prolonged exposure to ambient particulate matter (PM) is associated with an increased risk of cardiovascular disease and pulmonary dysfunction. While diesel exhaust particles (DEP) contain large variety of compounds, polycyclic aromatic hydrocarbons (PAHs) are a dominant component contaminated in DEP. This article reviews effects of two PAH quinones, 9,10-phenanthraquinone (9,10-PQ) and l,2-naphthoquinone (l,2-NQ), on vascular and respiratory systems.