• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.178-185
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• 1998

To reduce the particulate matter and nitrogen oxides from diesel engine, many studies are proceeding and being accomplished practically. In this situation CNG engine has important meaning both as a clean fuel and an alternative energy. In order to present the direction and application of CNG, we simulated various operating conditions, that is, spark timing, compression ratio and fuel composition etc. Thus we try to understand how those affect performance and exhaust characteristics. The simulation program results found that the optimum combustion start angle was 21$^{\circ}$ at 1800rpm and fuel composition affects performance and emissions, also we could understand the formation of emission as crank angle is changed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.784-787
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• 2006

Even if EGR is known as a technology which dramatically reduces NOx emission, its application is a quite complicate since it affects fuel economy and increase of PM emission. Therefore, it is a very important issue to investigate an optimal EGR rate considering all engine parameters. This research was numerically conducted to predict combustion and emission characteristics with respect to various EGR rates.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.284.1-284.1
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• 2002

In previous studies, we demonstrated that ambient PM collected from urban site of Korea air could induce DNA damage, Various mutagens and carcinogens present in the urban air differ according to the source of the pollutants. Polycyclic aromatic hydrocarbons (PAHs) and their nitrated compound are produced in the combustion of fossil fuels as diesel emission exhausts. In recent, PAH and nitro-PAH have been identified in urban air particulate matter (PM). and some of them were found to be tumorigenic in experimental animals and humans. (omitted)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.8
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• pp.755-760
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• 2010

In this study, we mainly focused on the PM (Particulate Matter) emission characteristics of a diesel engine. To analyze particle behavior in the tail-pipe, particle emission was measured on the engine-out (downstream of turbocharger), each upstream and downstream both of DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter). Moreover, particle emission contours on each sampling point were constructed. The reduction efficiency of particle number concentration and mass through the DOC and DPF was studied. Parameters such as EGR (Exhaust Gas Recirculation) and the main injection timing were varied in part load conditions and evaluated using the engine-out emissions. The DMS500 (Differential Mobility Spectrometer) was used as a particle measurement instrument that can measure particle concentrations from 5 nm to 1000 nm. Nano-particles of sizes less than 30 nm were reduced by oxidation or coagulated with solid particles in the tail-pipe and DOC. The DPF has a very high filtration efficiency over all operating conditions except during natural regeneration of DPF.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.547-553
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• 2016

Black carbon (BC) contained in particulate matter (PM) originating from the exhaust gases of ships' diesel engines has been receiving great attention as a cause of glacial melting and warming in the polar regions. In this study, we took samples from various locations of PM emitted from the training ship (T/S) HANBADA's main engine, in cooperation with the Korea Maritime and Ocean University. We analyzed the structure and characteristics of these samples using high-resolution transmission electron microscopy (HR-TEM) and applied our findings as fundamental research for developing PM reduction technology. We also employed our results to determine appropriate preemptive action to meet upcoming PM/BC regulations. In addition, we confirmed the emission trend of pollutants from exhaust gases under various engine operating conditions using an exhaust gas analyzer. Results obtained from the analysis of HR-TEM images showed that the structure of the PM is chain-like wispy agglomerates consisting of a number of individual spherical particles. As the sampling location was moved away from the turbo charger (T/C) towards the funnel, more condensates were observed at a low temperature and the molecular structure of the PM lost its characteristic BC structure as an amorphous structure gradually appeared. Furthermore, through the analysis of exhaust gases, we predicted a decrease in PM concentration in the exhaust stream as engine rpm increase.

• The Journal of Internal Korean Medicine
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• v.38 no.3
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• pp.353-366
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• 2017

Objective: This study aimed to use a mouse model to evaluate the effects of Gwaruhaengryeon-hwan (GHH) on chronic obstructive pulmonary disease (COPD) and particulate matter induced lung injury. Materials and Methods: The study was carried out in two ways (in vitro, in vivo). In vitro RAW 264.7 cells (mouse macrophage) were used and analyzed by flow cytometry, ELISA. In vivo lipopolysaccharide (LPS) and cigarette smoke solution (CSS), or coal, fly ash, diesel exhaust particle (CFD) challenged mice were used and its BALF was analyzed by ELISA, lung tissue by real-time PCR. Results: In vitro, GHH maintained an 80-100% rate of viability. So cytotoxicity was not shown. In the ELISA analysis with RAW 264.7 cells, GHH significantly decreased NO over $30{\mu}g/ml$. In the ELISA analysis, GHH significantly decreased $TNF-{\alpha}$, IL-6 over $300{\mu}g/ml$. In the COPD model, the GHH 200 mg/kg dosage group, the application of GHH significantly decreased the increasing of neutrophils, $TNF-{\alpha}$, IL-17A, MIP2, CXCL-1 in BALF, $TNF-{\alpha}$, $IL-1{\beta}$ mRNA expression in lung tissue and histological lung injury. In the CFD induced lung injury model, the GHH 200 mg/kg dosage group, the application of GHH significantly decreased the increase of neutrophils, $TNF-{\alpha}$, IL-17A, MIP2, CXCL-1 in BALF, MUC5AC, $TGF-{\beta}$ mRNA expression in lung tissue and histological lung injury. Conclusion: This study suggests the usability of GHH for COPD patients by controlling lung tissue injury.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.898-904
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• 2021

This experimental study aims to investigate the use of a wet electrostatic precipitator as a post-treatment device to satisfy the strict emission regulations for sulfur oxides and particulate matter (PM). The inlet/outlet of a wet electrostatic precipitator was installed in a funnel using a marine four-stroke diesel engine (STX-MAN B&W) consuming marine heavy fuel oil (HFO) with a sulfur content of about 2.1%. Measurements were then obtained at the outlet of the wet electrostatic precipitator; an optical measuring instrument (OPA-102), and the weight concentration measurement method (Method 5 Isokinetic Train) were used for the PM measurements and the Fourier transform infrared (FT-IR; DX-4000) approach was used for the sulfur oxide measurements. The experimenst were conducted by varying the engine load from 50%, to 75% and 100%; it was noted that the PM reduction efficiency was a high at about 94 to 98% under all load conditions. Additionally, during the process of lowering the exhaust gas temperature in the quenching zone of the wet electrostatic precipitator, the sulfur dioxide (SO₂) values reduced because of the cleaning water, and the reduction rate was confirmed to be 55% to 81% depending on the engine load.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.81-88
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• 2023

Background: Air pollution has led to an increased exposure of all living organisms to fine dust. Therefore, research efforts are being made to devise preventive and therapeutic remedies against fine dust-induced chronic diseases. Methods: Research of the respiratory protective effects of KRG extract in a particulate matter (PM; aerodynamic diameter of <4 ㎛) plus diesel exhaust particle (DEP) (PM4+D)-induced airway inflammation model. Nitric oxide production, expression of pro-inflammatory mediators and cytokines, and IRAK-1, TAK-1, and MAPK pathways were examined in PM4-stimulated MH-S cells. BALB/c mice exposed to PM4+D mixture by intranasal tracheal injection three times a day for 12 days at 3 day intervals and KRGE were administered orally for 12 days. Histological of lung and trachea, and immune cell subtype analyses were performed. Expression of pro-inflammatory mediators and cytokines in bronchoalveolar lavage fluid (BALF) and lung were measured. Immunohistofluorescence staining for IRAK-1 localization in lung were also evaluated. Results: KRGE inhibited the production of nitric oxide, the expression of pro-inflammatory mediators and cytokines, and expression and phosphorylation of all downstream factors of NF-κB, including IRAK-1 and MAPK/AP1 pathway in PM4-stimulated MH-S cells. KRGE suppressed inflammatory cell infiltration and number of immune cells, histopathologic damage, and inflammatory symptoms in the BALF and lungs induced by PM4+D; these included increased alveolar wall thickness, accumulation of collagen fibers, and TNF-α, MIP2, CXCL-1, IL-1α, and IL-17 cytokine release. Moreover, PM4 participates induce alveolar macrophage death and interleukin-1α release by associating with IRAK-1 localization was also potently inhibited by KRGE in the lungs of PM4+D-induced airway inflammation model. KRGE suppresses airway inflammatory responses, including granulocyte infiltration into the airway, by regulating the expression of chemokines and inflammatory cytokines via inhibition of IRAK-1 and MAPK pathway. Conclusion: Our results indicate the potential of KRGE to serve as an effective therapeutic agent against airway inflammation and respiratory diseases.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.361-370
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• 2017

Objectives: This study evaluated the diesel engine exhaust (DEE) exposure levels of door-to-door deliverers in Daegu from July to September. Methods: We measured exposure levels of DEE surrogates for the same door-to-door deliverers who joined the particulate matter 2.5 exposure study previously published in this journal. Black carbon(BC) concentrations were measured using real-time BC monitoring devices with 1 minute interval. $NO_2$ concentrations were monitored using passive badges. DEE exposure data were analyzed using the same characteristics and GPS information as the first study. Results: A total of 40 measurements of BC concentrations and $NO_2$ concentrations were collected during delivery of parcels. The average exposure levels to BC, and $NO_2$ were $2.23{\mu}g/m^3$ ($0.001-350.85{\mu}g/m^3$) and 21.26 ppb(3.3-61.37 ppb), respectively. Exposure levels to BC according to the day of a week and coverage areas were not significantly different(p>0.05). Delivery trucks manufactured before 2006 caused significantly higher exposure to BC than the trucks manufactured after 2006(p<0.05). Exposure levels of BC integrated for each time in residential area and roadsides were $1.96{\mu}g/m^3$ and $3.46{\mu}g/m^3$, respectively, and the difference was statistically significant(p<0.001). The Pearson correlation coefficients between the ambient $PM_{2.5}$ and BC was significant, r=0.26(p<0.01); however, the correlations between $PM_{2.5}$ and ambient $PM_{2.5}$, and between BC of DEE and $PM_{2.5}$ of DEE did not show a significant correlation Conclusions: BC and $NO_2$ exposure levels were significantly lower when door-to-door deliverers drove newer trucks. BC exposure levels of deliverers were higher in roadsides than in residential area. DEE from nearby vehicles through open windows might be the main source of BC exposure.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.153-159
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• 2007

Nano-Particles are influenced on the environmental protection and human health. The relationships between transient vehicle operation and nano-particle emissions are not well-known, especially for diesel passenger vehicles with DPF. In this study, a diesel passenger vehicle was measured on condition of DPF regeneration and no regeneration on a chassis dynamometer test bench. The particulate matter (PM) emission from this vehicle was measured by its number, size and mass measurement. The mass of the total PM was evaluated with the standard gravimetric measurement method while the total number and size concentrations were measured on a NEDC driving cycle using Condensation Particle Counter (CPC) and EEPS. Total number concentration by CPC was $1.5{\times}10^{1l}N/km$, which was 20% of result by EEPS. This means about 80% of total particle emission is consist of volatile and small-sized particles(<22nm). During regeneration, particle emission was $6.2{\times}10^{12}N/km$, was emitted 400 times compared with the emission before regeneration. As for the particle size of $22{\sim}100nm$ was emitted mainly, showing peak value of near 40nm in size. This means regeneration decreased the mean size of particles. Regarding regeneration, PM showed no change while the particle number showed about 6 times difference between before and after regeneration. It seems that the regeneration influences on particle number emissions are related to DPF-fill state and filtration efficiency.