• Journal of Institute of Convergence Technology
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• v.1 no.1
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• pp.41-47
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• 2011

With the world-wide demand on the emission minimization, the needs on the diesel aftertreatment devices with high efficiency are also increasing. In order to effectively develop or design a high-performance diesel particulate filter, a clear understanding on the deposition and regeneration mechanism is required. In the present study, a theory on the lumped parameter model for wall-flow type diesel particulate filters is described focusing on the deposition efficiency, pressure drop inside the filter. The fourth order explicit Runge-Kutta method is utilized for the mass flow rate computation. Engine operation modes with controlled and uncontrolled regeneration options are selected. The computational lumped parameter model is validated by comparing the computed results with the measured data.

• Journal of the Semiconductor & Display Technology
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• v.16 no.4
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• pp.1-4
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• 2017

Encapsulation of organic based devices is essential issue due to easy deterioration of organic material by water vapor. Atomic layer deposition (ALD) is a promising solution because of its low temperature deposition and quality of the deposited film. Moisture permeation has a mechanism to pass through defects, Thin Film Encapsulation using inorganic / organic / inorganic hybrid film has been used as promising technology. $Al_2O_3$ / Polymer / $Al_2O_3$ multilayer film has shown excellent environmental protection characteristics despite of thin thicknesses of the films.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.154-159
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• 1997

The crystal structure properties of TiN thin films deposited on SKD61 steel and Si(100) substrates by Ion Beam Assisted Deposition have been studied to clarify the thin film growth mechanism by using XRD, RBS, SEM, and AFM. The preferred orientation of TiN thin films changes from (111) to (100) as increasing the assisted energy. This tendency is independent of the substrate structure. The TiN thin film grow with (100) direction having surface free energy minimum as the assisted energy increases.

• Progress in Superconductivity and Cryogenics
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• v.17 no.2
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• pp.1-17
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• 2015

$MgB_2$ thin films with superior superconducting properties are very promising for superconducting magnets, electronic devices and coated conductor electric power applications. A clear understanding of flux pinning mechanism in $MgB_2$ films could be a big aid in improving the performance of $MgB_2$ by the enhancement of $J_c$. The fabrication advancement and the understanding of flux pinning mechanism of $MgB_2$ thin and thick films fabricated by using hybrid physical-chemical vapor deposition (HPCVD) are reviewed. The distinct kind of $MgB_2$ films, such as single-crystal like $MgB_2$ thin films, $MgB_2$ epitaxial columnar thick films, and a-axis-oriented $MgB_2$ films are included for flux pinning mechanism investigation. Various attempts made by researchers to improve further the flux pinning property and $J_c$ performance by means of doping in $MgB_2$ thin films by using HPCVD are also summarized.

• Journal of the Korean Vacuum Society
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• v.9 no.3
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• pp.197-206
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• 2000

The deposition characteristics of MOCVD Cu using the (hfac)Cu(1,1-COD)(1,1,1,5,5,5-hexafluoro-2,4-pentadionato Cu(I) 1,5-cyclooctadine) have been investigated in terms of the effects of carrier gas such as hydrogen and argon as well as the effects of H(hfac) ligand addition. MOCVD Cu using a hydrogen carrier gas led to a higher deposition rate and lower resistivity than an argon carrier gas system. The improvement in the surface roughness of the MOCVD Cu films and the (111) preferred orientation texture was obtained by using a hydrogen carrier gas. However, the adhesion characteristics of the films showed relatively weaker compared to the Ar carrier gas system, probably due to the larger amount of F content in the films, which was confirmed by the AES analyses. When an additional H(hfac) ligand was added, the deposition rate was significantly enhanced in the case of an argon + H(hfac) carrier gas system while significant change in the deposition rate of MOCVD Cu was not observed in the case of the hydrogen carrier gas system. However, the addition of H(hfac) in both carrier gases led to lowering the resistivity of the MOCVD Cu films. In conclusion, this paper suggests the deposition mechanism of MOCVD Cu and is expected to contribute to the enhancement of smooth Cu films with a low resistivity by manipulating the deposition conditions such as the carrier gas and addition of H(hfac) ligand.

• Korean Journal of Environment and Ecology
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• v.15 no.3
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• pp.230-236
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• 2001

The fluxes of wet deposition(WD), throughfall(TF), stemflow(SF) and soil leachates were measured to understand base cation budgets on deciduous ecosystem impacted by acidic deposition in the north-western part of Tomakomai in Hokkaido, Japan. The flux of $H^{+}$ for wet deposition was $0.34kmo1_{c}$ $ha^{2+}$ and the flux of base cation, $K^{+}$ /, Na$^{ + }$, $Ca^{2+}$ and $Mg^{2+}$ far throughfall plus stemflow wart 1.6 kmolc $ha^{-1}$ , 3 times higher level than that for wet deposition. The flux of base cation for canopy leaching(LI) was 0.95 kmolc ha$^{-1}$ , 2.8 times higher level than $H^{+}$ sources in wet deposition. The major mechanism of $^{+}$ consumption closely related to acidic neutralizing capacity of canopy. The ionic flux for soil leachates from Boil reservoir and proton consumption in soil was dependent on soil chemical states and exchangeable Ca in soil had a major factor of H$^{+ }$ consumption. The base cation budgets on deciduous ecosystem showed positive balance fur Na, Ca and Mg, while K was the negative value.

• Journal of Ginseng Research
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• v.47 no.6
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• pp.743-754
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• 2023

Background: Myocardial fibrosis post-myocardial infarction (MI) can induce maladaptive cardiac remodeling as well as heart failure. Although 20(S)-ginsenoside Rg3 (Rg3) has been applied to cardiovascular diseases, its efficacy and specific molecular mechanism in myocardial fibrosis are largely unknown. Herein, we aimed to explore whether TGFBR1 signaling was involved in Rg3's anti-fibrotic effect post-MI. Methods: Left anterior descending (LAD) coronary artery ligation-induced MI mice and TGF-β1-stimulated primary cardiac fibroblasts (CFs) were adopted. Echocardiography, hematoxlin-eosin and Masson staining, Western-blot and immunohistochemistry, CCK8 and Edu were used to study the effects of Rg3 on myocardial fibrosis and TGFBR1 signaling. The combination mechanism of Rg3 and TGFBR1 was explored by surface plasmon resonance imaging (SPRi). Moreover, myocardial Tgfbr1-deficient mice and TGFBR1 adenovirus were adopted to confirm the pharmacological mechanism of Rg3. Results: In vivo experiments, Rg3 ameliorated myocardial fibrosis and hypertrophy and enhanced cardiac function. Rg3-TGFBR1 had the 1.78×10^-7 M equilibrium dissociation constant based on SPRi analysis, and Rg3 inhibited the activation of TGFBR1/Smads signaling dose-dependently. Cardiac-specific Tgfbr1 knockdown abolished Rg3's protection against myocardial fibrosis post-MI. In addition, Rg3 downregulated the TGF-β1-mediated CFs growth together with collagen production in vitro through TGFBR1 signaling. Moreover, TGFBR1 adenovirus partially blocked the inhibitory effect of Rg3. Conclusion: Rg3 improves myocardial fibrosis and cardiac function through suppressing CFs proliferation along with collagen deposition by inactivation of TGFBR1 pathway.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.34-34
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• 2012

Heavy storms rainfall has caused many landslides and slope failures especially in the mountainous area of the world. Landslides and slope failures are common geologic hazards and posed serious threats and globally cause billions in monetary losses and thousands of casualies each year so that studies on slope stability and its failure mechanism under rainfall are being increasing attention of these days. Rainfall-induced slope failures are generally caused by the rise in ground water level, and increase in pore water pressures and seepage forces during periods of intense rainfall. The effective stress in the soil will be decreased due to the increased pore pressure, which thus reduces the soil shear strength, eventually resulting in slope failure. During the rainfall, a wetting front goes downward into the slope, resulting in a gradual increase of the water content and a decrease of the negative pore-water pressure. This negative pore-water pressure is referred to as matric suction when referenced to the pore air pressure that contributes to the stability of unsaturated soil slopes. Therefore, the importance is the study of saturated unsaturated soil behaviors in evaluation of slope stability under heavy rainfall condition. In an actual field, a series of failures may occur in a slope due to a rainfall event. So, this study attempts to develop a numerical model to investigate this failure mechanism. A two-dimensional seepage flow model coupled with a one-dimensional surface flow and erosion/deposition model is used for seepage analysis. It is necessary to identify either there is surface runoff produced or not in a soil slope during a rainfall event, while analyzing the seepage and stability of such slopes. Runoff produced by rainfall may result erosion/deposition process on the surface of the slope. The depth of runoff has vital role in the seepage process within the soil domain so that surface flow and erosion/deposition model computes the surface water head of the runoff produced by the rainfall, and erosion/deposition on the surface of the model slope. Pore water pressure and moisture content data obtained by the seepage flow model are then used to analyze the stability of the slope. Spencer method of slope stability analysis is incorporated into dynamic programming to locate the critical slip surface of a general slope.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.55.1-55.1
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• 2010

Cost efficient and large area deposition of superior quality $Al_2O_3$ doped zinc oxide (AZO) films is instrumental in many of its applications including solar cell fabrication due to its numerous advantages over ITO films. In this study, AZO films were prepared by a highly efficient rotating cylindrical dc magnetron sputtering system using AZO target, which has a target material utilization above 80%, on glass substrates in argon ambient. A detailed analysis on the electrical, optical and structural characteristics of AZO thin films was carried out for solar cell application. The properties of films were found to critically depend on deposition parameters such as sputtering power, substrate temperature, working pressure, and thickness of the films. A low resistivity of ${\sim}5.5{\times}10-4{\Omega}-cm$ was obtained for films deposited at 2kW, keeping the pressure and substrate temperature constant at 3 mtorr and $230^{\circ}C$ respectively, mainly due to an increase in carrier mobility and large grain size which would reduce the grain boundary scattering. The increase in carrier mobility with power can be attributed to the columnar growth of AZO film with (002) preferred orientation as revealed by XRD analysis. The AZO films showed a high transparency of>87% in the visible wavelength region irrespective of deposition conditions. Our results offers a cost-efficient AZO film deposition method which can fabricate films with significant low resistivity and high transmittance that can find application in thin-film solar cells.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.1
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• pp.114-123
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• 2017

The global small and mid-sized display market is changing from thin film transistor-liquid crystal display to organic light emitting diode (OLED). Reflecting these market conditions, the domestic and overseas display panel industry is making great effort to innovate OLED technology and incease productivity. However, current OLED production technology has not been able to satisfy the quality requirement levels by customers, as the market demand for OLED is becoming more and more diversified. In addition, as OLED panel production technology levels to satisfy customers' requirement become higher, product quality problems are persistently generated in OLED deposition process. These problems not only decrease the production yield but also cause a second problem of deteriorating productivity. Based on these observations, in this study, we suggest TRIZ-based improvement of defects caused by glass pixel position deformation, which is one of quality deterioration problems in small and medium OLED deposition process. Specifically, we derive various factors affecting the glass pixel position shift by using cause and effect diagram and identify radical reasons by using XY-matrix. As a result, it is confirmed that glass heat distortion due to the high temperature of the OLED deposition process is the most influential factor in the glass pixel position shift. In order to solve the identified factors, we analyzed the cause and mechanism of glass thermal deformation. We suggest an efficient method to minimize glass thermal deformation by applying the improvement plan of facilities using contradiction matrix in TRIZ. We show that the suggested method can decrease the glass temperature change by about 23% through an experiment.