• Proceedings of the KSME Conference
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• 2001.11a
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• pp.258-265
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• 2001

Turbine blade is subject to force of three type ; torsional force by torsion-mount, centrifugal force by rotation of rotor and cyclic bending force by steam pressure. Cyclic bending force of them is main factor on fatigue fracture. In the X-ray diffraction method, the change in the values related to plastic deformation and residual stress near the fracture surface mat be determined, and information of internal structure of material can be obtained. Therefore, to find a fracture mechanism of torsion-mounted blade in nuclear plant, based on the information from the fracture surface obtained by fatigue test, the correlation of X-ray parameter and fracture mechanics parameter was determined, and then the load applied to actual broken turbine blade parts was predicted. Failure analysis is performed by finite element method and Goodman diagram on torsion-mounted blade.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.6 s.249
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• pp.560-567
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• 2006

Although various conjectures have been proposed to explain abnormal increase in thermal conductivity of nanofluids, the detailed mechanism could not be understood and explained yet. The main reason is primarily due to the lack of knowledge on the most fundamental factor governing the mechanisms such as Brownian motion, liquid layering, phonon transport, surface chemical effects and agglomeration. By applying surface complexation model for the measurement data of hydrodynamic size, zeta potential, and thermal conductivity, we have shown that sulfate charge state is mainly responsible for the increase in the present condition and may be the factor incorporating all the mechanisms as well. Moreover, we propose a new model including concepts of fractal and interfacial layer. The properties such as thickness and thermal conductivity of the layer are estimated from the surface charge states and the concept of electrical double layer. With this, we could demonstrate the pH dependences of the layer properties and eventually of the effective thermal conductivity of the nanofluid.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.37-41
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• 2001

HPLC separation of ionic samples tends to be more complicated and difficult to understand than that of non-ionic compounds. On the other hand, band spacing is much more easily manipulated for ionic than for neutral samples. Ion-suppression RP-HPLC method was used with organic modifier and aqueous buffer solution. In this work, five mononucleotides of cytidine-5-monophosphate (5-CMP) disodium salt, uridine-5-monophosphate disodium salt (5-UMP), guanosine-5-monophosphate disodium salt (5-GMP), inosine-5-monophosphate disodium salt (5-IMP), and adenosine-5-monophosphate disodium salt (5-AMP) were examined. Acetic acid and sodium phosphate were used as buffers, and methanol as an organic modifier. A new relationship between the retention factor and the buffer concentration at a fixed modifier content (5% of methanol) could be expressed by following: K = (k(sub)-1 + k(sub)0 (k(sub)B/k(sub)S)/(1 + (k(sub)B/k(sub)S) C(sub)B(sup)a), where C(sub)B was the concentration of buffer. Using this relationship, the calculated values closely matched the experimental data. The derived relationship showed that as the buffer concentration increased, the retention factor approached a certain value, and this was buffer dependent.

• 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.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.224-230
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• 2006

Escherichia coli transcription termination factor Rho catalyzes the unwinding of RNA/DNA duplex in reactions that are coupled to ATP binding and hydrolysis. We report here the kinetic mechanism of presteady state ATP binding and hydrolysis by the Rho-RNA complex. Presteady state chemical quenched-flow technique under multiple turnover condition was used to probe the kinetics of ATP binding and hydrolysis by the Rho-RNA complex. The quenched-flow presteady state kinetics of ATP hydrolysis studies show that three ATPs are bound to the Rho-RNA complex with a rate of $4.4\;{\times}\;10^5M^{-1}s^{-1}$, which are subsequently hydrolyzed at a rate of $88s^{-1}$ and released during the initiation process. Global fit of the presteady state ATP hydrolysis kinetic data suggests that a rapid-equilibrium binding of ATP to Rho-RNA complex occurs prior to the first turnover and the chemistry step is not reversible. The initial burst of three ATPs hydrolysis was proposed to be involved in the initialization step that accompanies proper complex formation of Rho-RNA. Based on these results a kinetic model for initiation process for Rho-RNA complex was proposed relating the mechanism of ATP binding and hydrolysis by Rho to the structural transitions of Rho-RNA complex to reach the steady state phase, which is implicated during translocation along the RNA.

• 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.

• Journal of the Korean earth science society
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• v.28 no.5
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• pp.613-619
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• 2007

Mesoscale low is often observed over the downstream region of the East Sea (or, northwest coast off the Japan Islands) during East-Asia winter monsoon. The low system causes a heavy snowfall at the region. A series of numerical experiments were conducted with the aid of a regional model (MM5 ver. 3.5) to examine the formation mechanism of the mesoscale low. The following results were obtained: 1) A well-developed mesoscale low was simulated by the regional model under real topography, NCEP reanalysis, and OISST; 2) The mesoscale low was simulated under a zonally averaged SST without topography. This implies that the meridional gradient of SST is the main factor in the formation of a mesoscale low; 3) A thermal contrast ($>10^{\circ}C$) of land-sea and topography-induced disturbance served as the second important factor for the formation; 4) Paektu Mountain caused the surface wind to decelerate downstream, which created a more favorable environment for thermodynamic modification than that was found in a flat topography; and 5) The types of cumulus parameterizations did not affect the development of the mesoscale low.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2429-2432
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• 2000

Adaptive filter algorithm has been used for plant identifier and noise cancellation. This algorithm has been researched for performance enhancement of filtering. The design and development of a reliable system has been becoming a key issue in industry field because the reliability of a system is considered as an important factor to perform the system's function successfully. And the computing with reliability and fault tolerance is a important factor in the case of aviation and nuclear plant. This paper presents design of reliable adaptive filter with fault tolerance. Generally, redundancy is used for reliability. In this case it needs computing or circuit for voting mechanism or computing for fault detection or switching part. But this presented Filter is not in need of computing for voting mechanism, or fault detection. Therefore it has simple computing, and practicality for application. And in this paper, reliability of adaptive filter is analyzed. The effectiveness of the proposed adaptive filter is demonstrated to the case studies of plant identifier and noise cancellation by using DSP.

• 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.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.555-562
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• 2006

Recently, liquid chromatography (LC) has been used more frequently to separate drugs and natural substances. Especially, to selection of the solutes from the products, the operation condition of analytical chromatography should be necessarily determined. So accurate computer modeling and simulation of chromatographic performances has become a necessary part of the development and design of processes. High-Purity Separation Lab. Inha University developed the resulting HCI software for the purpose of the optimization of chromatographic performances. The HCI program was utilized to find the optimum operating condition more accurately and rapidly, reducing the number of many possible experiments. The elution profiles were calculated by the plate theory based on the three retention mechanism of capacity factor.