• Proceedings of the KSME Conference
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• 2000.11a
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• pp.99-104
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• 2000

This paper describes the high temperature creep characteristics for virgin material of 9Cr1MoVNb steel using small punch creep(SP-Creep) test technique which is developing recently. In addition, the several results of SP-Creep test are compared with that of 2.25Cr- 1Mo steel which is widely used as boiler materials and that of conventional uniaxial creep test. The obtained SP-Creep curves show the creep behaviors of three regimes like that obtained from conventional uniaxial creep test, and SP-Creep properties are definitely depended on applied load and test temperature. The correlation of SP-Creep rate and creep rupture life with applied load has been determined like the correlation between creep rate/rupture life and stress in uniaxial creep test, and also is satisfied with Power law. The creep rupture times of newly 9Cr1MoVNb steel are higher than those of 2.25Cr1Mo steel at the same creep temperature and applied loading condition, and the decrease extent of creep rupture life with loads is very lower compared with 2.25Cr1Mo steel.

• Journal of the Korean institute of surface engineering
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• v.43 no.1
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• pp.41-45
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• 2010

The effect of $MoS_2$ and graphite content on wear resistance and mechanical properties of Cu/Sn bonded diamond micro blades was comparatively investigated in terms of volume and weight fraction. For the evaluation of endurance and cutting performance, instantaneous electric power consumption and cumulative wear loss during cutting glass work piece at constant velocity were measured with the micro blades of the wide range of lubricant content. The energy consumption of blades for glass cutting decreased with the content of lubricants. Wear amount of blade in volume increased with the amount of lubricant addition. It was found to be relevant to the decrease in flexural strength and hardness with the amount of lubricants. With the same amount of lubricant content in volume fraction $MoS_2$ showed superiority in mechanical properties and cutting performance than graphite while graphite could result in stronger effect on lowering electric consumption during cutting work piece for the same weight percent fraction than $MoS_2$ because of lower density.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.1
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• pp.78-85
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• 2000

Due to environmental proessures there is increasing use of hydrogen peroxide as a total or partial substitute for chlorine based bleaching agents within ECF or TCF sequences. However, to aceive satifactory brightness using peroxide alone, stages having a combination of high temperature, pressure, pH or residence time are required. It may also have negative impact on fiber quality . Therefore, it would be of advantage if vertain means could be found to make hydrogen peroxide more effective in bleacing , via shortening treaction time and allevaiating the need for such forcing reaction conditions. This can be achieve by converting the peroxide in-situ to stronger oxidant through the use of 손 bleach activator. In this study to investigate the influence of additives, such as tetraacetylethylenediamine (TAED) and Molybdate (MO) . addition on peroxide bleaching were carried out. Under alkaline conditions the bleching additives. TAED and Mo. can react H2O2 to form peracetic acid and peroxomolybdate respectively and these generated activators can improve deliginification,. The activators make it possible to bleach the pulp efficiently at low temperature in the range 50 to 7$0^{\circ}C$. Also, addition of TAED and Mo is an environmentally friendly way of enhancing the performance of peroxide bleaching can be incorporated into TCF and ECF sequences.

• Journal of the Korean institute of surface engineering
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• v.55 no.1
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• pp.18-23
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• 2022

Presence of cracks in electrodeposited hard chromium layer, which provide a path of corrosive media to steel substrate, is a serious issue in metal finishing with chromium electroplating. In this study, we added sodium molybdate in an electrolyte for chromium electroplating bath. 130g/L of sodium molybdate in Sargent bath for chromium electroplating causes a codepostion of molybdenum with chromium in a rage of 0.61 ~ 3.14 wt.%. The co-deposited molybdenum enhances the crystallinity of chromium layer, thus the hardness is slightly decreases by the addition of molybdate in electrolyte. However, due to the co-deposition of molybdenum, a crack-free chromium layer could be electrodeposited. Such crack-free chromium layer shows a significantly improved corrosion resistance.

• Journal of the Korean Chemical Society
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• v.26 no.6
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• pp.383-388
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• 1982

$Mo_2O_4Cl_2$$(X-py)_4{\cdot}2H_2$O and $(X-pyH)_4$[$Mo_2O_4(NCS)_6)$]${\cdot}H_2$O have been prepared. The infrared, electronic and reflectance spectra, molar conductances and magnetic susceptibility data of complexes are reported. $Mo_2O_4Cl_2$$(X-py)_4{\cdot}2H_2$O (X-py were 3-and 4-cyanopyridine, nicotinamide, 3,5-lutidine and 2-amino-4-picoline) were obtained by hydrolysis of the corresponding substituted pyridinium oxopentachloromolybdates(Ⅴ). Addition of water and substituted pyridines to molybdenum(Ⅴ)-thiocyanate ethylacetate extract yielded brown compounds, $(X-pyH)_4$[$Mo_2O_4(NCS)_6)$]${\cdot}H_2$O where X-py were pyridine, ${\alpha}$, 3-bromopyridine 3,5-lutidine, 3-benzoylpyridine and 4-acetylpyridine. Binuclear, $Mo_2O_4Cl_2(X-py)_4{\cdot}2H_2$ prepared from hydrolysis of $(X-pyH)_2[MoOCl_5]{\cdot}H_2O$ were diamagnetic and nonelectrolytes. The anion of $(X-pyH)_4$[$Mo_2O_4(NCS)_6)$]${\cdot}H_2$O was formulated as dimer and electrolyte.

• Korean Journal of Metals and Materials
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• v.56 no.12
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• pp.885-892
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• 2018

Molybdenum disulfide ($MoS_2$) based electrocatalysts have been proposed as substitutes for platinum group metal (PGM) based electrocatalyst to hydrogen evolution reaction (HER) in water electrolysis. Here, we studied $MoS_2/CNFs$ hybrid catalyst prepared by electrospinning method with heat treatment for polymer electrolyte membrane(PEM) water electrolysis to improve the HER activity. The physicochemical and electrochemical properties such as average diameter, crystalline properties, electrocatalitic activity for HER of synthesized $MoS_2/CNFs$ were investigated by the Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), Raman Spectroscopy (Raman) and Linear Sweep Voltammetry (LSV). The as spun ATTM/PVP nanofibers were prepared by sol-gel and electrospinning method. Subsequently, the $MoS_2/CNFs$ was dereived from reduction heat treatment of ATTM at the ATTM/PVP nanofibers and carbonization heat treatment. Synthesized $MoS_2/CNFs$ electrocatalyst had an average diameter of $179{\pm}30nm$. We confirmed that the $MoS_2$ layers in $MoS_2/CNF$ electrocatalyst consist of 3~4 layers from the Raman results. In addition, We confirmed that the $MoS_2$ layers in $MoS_2/CNF$ catalyst consist of 7.47% octahedral 1T phase $MoS_2$, 63.77% trigonal prismatic 2H phase $MoS_2$ with 28.75% $MoO_3$ through the XRD, Raman and XPS results. It was shown that $MoS_2/CNFs$ had the overpotential of 0.278 V at $10mA/cm^2$ and tafel slope of 74.8 mV/dec in 0.5 M sulfuric acid ($H_2SO_4$) electrolyte.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.35-35
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• 2009

• IMMUNE NETWORK
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• v.1 no.1
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• pp.14-25
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• 2001

Background: Bone marrow stromal cells (BMSCs) express many cell surface molecules, which regulate the proliferation and differentiation of immune cells within the bone marrow. Methods: To identify cell surface molecules, which can regulate cell proliferation through cell interaction, monoclonal antibodies (MoAbs) against BMSCs were produced. Among them, 1H8 MoAb, which recognized distinctly an 80 kDa protein, abolished myeloma cell proliferation that was induced by co-culturing with BMSCs. Results: IL-6 gene expression was increased when myeloma or stromal cells were treated with 1H8 MoAb. In addition, the expression of IL-6 receptor and CD40 was up-regulated by 1H8 treatment, suggesting that the molecule recognized by 1H8 MoAb is involved in cell proliferation by modulating the expression of cell growth-related genes. Myeloma cells contain high levels of reactive oxygen species (ROS), which are related to gene expression and tumorigenesis. Treatment with 1H8 decreased the intracellular ROS level and increased PAG antioxidant gene concomitantly. Finally, 1H8 induced the tyrosine phosphorylation of several proteins in U266. Conclusion: Taken together, 1H8 MoAb recognized the cell surface molecule and triggered the intracellular signals, which led to modulate gene expression and cell proliferation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.9
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• pp.701-706
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• 2013

We have focused on the conversion efficiency of CIGS thin film solar cell prepared by co-evaporation method as well as the optimization of process condition. The total thickness of back electrode was fixed at 1 ${\mu}m$ and the structural, electric and optical properties of CIGS thin film were investigated by varying the thickness of Mo:Na bottom layer from 0 to 500 nm. From the experimental results, the content of Na was appeared as 0.28 atomic percent when the thickness of Mo:Na layer was 300 nm with compactly densified plate-shape surface morphology. From the XRD measurements, (112) plane was the strongest preferential orientation together with secondary (220) and (204) planes affecting to the crystallization. The lowest roughness and resistivity were 2.67 nm and 3.9 ${\Omega}{\cdot}cm$, respectively. In addition, very high carrier density and hole mobility were recorded. From the optimization of Mo:Na layer, we have achieved the conversion efficiency of 9.59 percent.

• Journal of the Korean Society for Heat Treatment
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• v.29 no.6
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• pp.284-291
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• 2016

High temperature alloy steel such as Ni-Cr-Mo-V material has excellent properties of high strength and high heating resistance. It has been used for several military weapon components such as gun barrel of a warship, turbine rotor and turbine disk for nuclear power plant. Being curious about this material required excellent wear resistance and durability in extreme environmental conditions. A dry wear test at the ambient air and Ar gas conditions in the room temperature were performed in this study. What's more a lubricant wear test at different temperature was conducted. In addition that DLC was coated on Ni-Cr-Mo-V alloy steel substrate with a thickness of $3{\mu}m$, a property of it was compare with lubricant conditions. All the coefficient of friction and wear volume, comparing with DLC coated specimens. The test parameters were selected as follows: 10 N for normal load; 80 rpm for sliding wear speed; and 300 m for the sliding wear distance.