• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.37-44
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• 2013

Generally, a reduced chemical mechanism of n-heptane is used as chemical fuel of a 3-D diesel engine simulation because diesel fuel consists of hundreds of chemical components and various chemical classes so that it is very complex and large to use for the calculation. However, the importance of fuel in a 3-D simulation increases because detailed fuel characteristics are the key factor in the recent engine research such as homogeneous charged compression ignition engine. In this study, normal paraffin, iso paraffin and aromatics were selected to represent diesel characteristics and n-dodecane was used as a representative normal paraffin to describe the heavy molecular weight of diesel oil (C10~C20). Reduced kinetics of iso-octane and toluene which are representative species of iso paraffin and aromatics respectively were developed in the previous study. Some species were selected based on the sensitivity analysis and a mechanism was developed based on the general oxidation scheme. The ignition delay times, maximum pressure and temperature of the new reduced n-dodecane chemical mechanisms were well matched to the detailed mechanism data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.449-456
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• 2018

In this study, a soil nail design method for a stability analysis of local instability with nail reinforced slope was proposed. The failure mechanism of a local instability of slope was studied and a theoretical equation to estimate the stability of slope was developed. Using the developed equation, the stability analysis was performed according to installation conditions of soil nail such as a slope inclination, a thickness of soil layer, a nail inclination, and a nail spacing. Considering those design factors, a sensitivity analysis for each influence factors was conducted. Analysis results showed that the safety factor of reinforced slope with nail was higher than the slope without nail. In addition, the safety factor of slope according to ground condition was increased in the order of dry, saturated, and seepage condition.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.46-53
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• 2014

An automatic grease lubricator provides an adequate amount of fresh grease constantly to any type of rotating machine to minimize friction heat and reduce friction loss. This study seeks to develop an automatic grease lubricator by means of rapid prototyping with a gear-driven mechanism and a controlled operation time. The ultimate design is to lubricate an adequate amount of grease by a simple dip-switch clicking mechanism according to an advanced set cycle. The backlash of the gear was minimized to increase the power, and to increase the power of the mechanism, the binding frequency and the thickness of the coil were changed. To control the rotation cycles of the main shaft according to certain set numbers, different resistances and chips were used in the design of the circuit which controls the electrical signals via a pulse. A digital mock-up was analyzed and the rapid prototyping (RP) trial products were tested with a PCB circuit and grease. An evaluation of the outlet capacity of RP trial products was conducted, as the friction caused by the outlet on the wall surface was an important factor in the operation of the equipment. Finally, a finishing process was applied to decrease the roughness of a surface to a comparable level to test the performance of the product.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.143-143
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• 2005

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.239-245
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• 1983

Electrochemical adsorption always was accompanied with solvent displacement and relative size factor(x) of adsorbate and solvent and hydrogen coverage(${\theta}$) on the lead anodic film electrode formed in phosphoric acid in NaCl solution and the sea water at $15{\sim}35^{\circ}C$ were studied by means of constant current-potential method and potentiodynamic cathodic polarization method. In this experiment, various constants and thermodynamic quantities calculated from the hydrogen coverage were also described to explain the reactivities of di-iso-butylnitrosoamine(DBNA) and proton ($H^+$) according to the changes of interactions between solute and solvent in the bulk phase and interphase. It was investigated that the average values of relative size factor and the coverage of hydrogen atoms studied with the electrode of lead anodic film formed in phosphoric acid solution in 60mM DBNA+0.5M NaCl and in 60mM DBNA+$6\%0$ sea water were about 11.0 and 0.2 respectively. Hydrogen evolution was electrochemical mechanism because of substitutional adsorption of aromatic substance with their delocalization of electrons, but in the case of non-charge transfer adsorption of aliphatic substance(DBNA) interacting relatively little with the electrode, it was combination mechanism.

• Archives of Pharmacal Research
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• v.29 no.1
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• pp.67-72
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• 2006

The abnormal proliferation of aortic vascular smooth muscle cells (VSMCs) plays a central role in the pathogenesis of atherosclerosis and restenosis after angioplasty and possibly also in the development of hypertension. The present study was designed to examine the inhibitory effects and the mechanism of luteolin 7-glucoside (L7G) on the platelet-derived growth factor (PDGF)-BB-induced proliferation of VSMCs. L7G significantly inhibited the PDGF-BB-induced proliferation and the DNA synthesis of the VSMCs in a concentration-dependent manner. Pre-incubation of the VSMCs with L7G significantly inhibited the PDGF-BB-induced extracellular signal-regulated kinase 1/2 (ERK1/2), Akt and the phospholipase C $(PLC)-{\gamma}1$ activation. However, L7G had almost no affect on the phosphorylation of $PDGF-{\beta}$ receptor tyrosine kinase, which was induced by PDGF-BB. These results suggest that L7G inhibits the PDGF-BB-induced proliferation of VSMCs via the blocking of $(PLC)-{\gamma}1$, Akt, and ERK1/2 phosphorylation.

• Geomechanics and Engineering
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• v.23 no.1
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• pp.1-13
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• 2020

To give a solution for seismic stability of tunnel faces subjected to earthquake ground shakings, the pseudo-dynamic approach is originally introduced to analyze tunnel face stability in this study. In the light of the upper-bound theorem of limit analysis, an advanced three-dimensional mechanism combined with pseudo-dynamic approach is proposed. Based on this mechanism, the required support pressure on tunnel face can be obtained by equaling external work rates to the internal energy dissipation and implementing an optimization searching procedure related to time. Both time and space feature of seismic waves are properly accounted for in the proposed mechanism. For this reason, the proposed mechanism can better represent the actual influence of seismic motion and has a remarkable advantage in evaluating the effects of vertical seismic acceleration, soil amplification factor, seismic wave period and initial phase difference on tunnel face stability. Furthermore, the pseudo-dynamic approach is compared with the pseudo-static approach. The difference between them is illustrated from a new but understandable perspective. The comparison demonstrates that the pseudo-static approach is a conservative method but still could provide precise enough results as the pseudo-dynamic approach if the value of seismic wavelengths is large or the height of soil structures is small.

• Journal of Pharmacopuncture
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• v.23 no.2
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• pp.54-61
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• 2020

Inflammation is an immune response of the human body but excessive inflammation is taken as a major factor in the development of many diseases including autoimmune disorders, cancer and nerve disorders etc. In this regards the need is to suppress the inflammatory response. Suppression of extra or imperfect inflammatory response is not a big deal provided there is an exact knowledge of particular target in the body. Recent advancements in Pharmacological aspect made the therapy with improved outcomes in number of patients. Anticytokine therapy might be one of the important and novel approaches for inflammation and Arthritis. This can be achieved only when we go through the pathophysiology of expression and identification of mediators. Let's take an example of cytokine like interleukins (IL), chemokines, interferons (INF), tumor necrosis factors (TNF-α), growth factors, and colony stimulating factors) release pathway which is a major signalling protein in inflammatory response. In the present study we have reviewed the recent pharmacological therapeutic advancement, inflammatory mediators, receptors, and major signalling pathways. Such information will not only provide the idea about the mechanism of action of Pharmaceuticals and molecular targets but also it provides a new aspect for drug designing and new corrective approaches in existing clinical medicines. This study will be a source of good information for the researchers working in the area of drug designing and molecular Pharmacology especially in anti-inflammatory and anti arthritic medicines for target based therapy.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.11-19
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• 2011

A new PCD (Pitch Circle Diameter) adjustment system has been designed in this study. Traditional system requires repetitive same works in changing automobile tires. The system proposed in this study requires just one simultaneous work to finish the job. We designed the system using Solidworks CAD software. We further investigate the jobs for both cases through work factor method. Based on careful clarification of the job, work factor units were assigned to each work factor. Even if further analysis should be processed for actual field application, the mechanism proposed in this study may provide good reference for practical usage.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.669-676
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• 2019

Zanthoxylum piperitum D.C. (ZP) peels has been used as a natural spice and herb medicine for hypertension reduction, for strokes, and for its anti-bacterial and anti-oxidant activity. However, the anti-inflammatory mechanisms employed by ZP have yet to be completely understood. In this study, we elucidate the anti-inflammatory mechanism of ZP in lipopolysaccharide (LPS)-induced RAW264.7 cells. We evaluated the effects of ZP in LPS-induced levels of inflammatory cytokines, prostaglandin E₂ (PGE₂), and caspase-1 using ELISA. The expression levels of inflammatory-related genes, including cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), were assayed by Western blot analysis. We elucidated the effect of ZP on nuclear factor (NF)-κB activation by means of a luciferase activity assay. The findings of this study demonstrated that ZP inhibited the production of inflammatory cytokine and PGE₂ and inhibited the increased levels of COX-2 and iNOS caused by LPS. Additionally, we showed that the anti-inflammatory effect of ZP arises by suppressing the activation of NF-κB and caspase-1 in LPS- induced RAW264.7 cells. These results provide novel insights into the pharmacological actions of ZP as a potential candidate for development of new drugs to treat inflammatory diseases.