• Analytical Science and Technology
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• v.16 no.1
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• pp.82-89
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• 2003

Isotope dilution mass spectrometry (IDMS) was applied to the determination of Ni, Cr, Mo in low alloy steel reference materials. The Mo isotope ratio measurement was performed by dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP/MS) using ammonia as a reaction cell gas. In the case of Ni and Cr measurement, all data were obtained at medium resolution mode (m/${\Delta}m=3000$) of double focusing sector field high resolution inductively coupled plasma mass spectrometry (HR-ICP/MS). For the method validation of the technique was assessed using the certified reference materials such as NIST SRM 361, NIST SRM 362, NIST SRM 363, NIST SRM 364, NIST SRM 36b. This method was applied to the determination of Ni, Cr and Mo in low alloy steel sample (CCQM-P25) provided by NMIJ for international comparison study.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.135-140
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• 2020

Since the process gas that is essential in the semiconductor process is a harmful gas, it is an essential task to solve it in an environmentally friendly manner. Currently, the cleaning technology used in the semiconductor process is mostly a wet cleaning based on hydrogen peroxide developed in the 1970s, and the SC-1 cleaning liquid for removing particles on the surface uses a mixture of ammonia and hydrogen peroxide. Therefore, environmental problems are caused, and economic problems caused by excessive water use are also serious. For this reason, the products developed through this study are used to decompose the process harmful gas from the chamber outlet into a harmless gas before entering the vacuum pump, or by incineration and the gaseous components are deposited on the pump. I want to solve the problem. In this paper, CPS (Confined Plasma Source) is proposed to save environment and improve productivity by replacing harmful gases (N2, CF4, SF6⋯., Etc) which are indispensable in semi-contamination process with innocuous gases or incineration with plasma, to study.

• Journal of the Korean Vacuum Society
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• v.15 no.6
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• pp.576-580
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• 2006

Mercury-free lamp, external electrode fluorescent lamp (EEFL) which includes the xenon gas, is now going on the research for the replacement of mercury lamp. The densities of excited xenon atom in the $1s_4$ resonance state and the $1s_5$ metastable state are investigated in the EEFL by a laser absorption spectroscopy under various gas pressures. We have measured the absorption signals for both $1s_4$ resonance and the $1s_5$ metastable state in the EEFL by varying the discharge currents for a given pressure. This basic absorption characteristic is very important for improvement of the VUV luminous efficiency of the EEFL as well as plasma display panel.

• Polymer(Korea)
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• v.38 no.2
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• pp.205-212
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• 2014

Polyethersulfone (PES) membranes were modified by various physico-chemical modification methods to enhance the surface hydrophilicity for application as a separation membrane to separate and collect water vapor from the flue gas. Homogeneous PES flat-sheet membranes were prepared and modified by acid treatment, blending and plasma treatment for hydrophilic surface modification. The surface characteristics of the modified PES membranes were evaluated by ATR-FTIR, XPS, SEM and contact angle measurements. No significant change in hydrophilicity was observed for the PES membranes modified by acid treatment with sulfuric acid or blending with various compositions of poloxamer as an amphiphilic PEO-PPO-PEO tri-block copolymer. On the other hand, Ar plasma treatment led to a significant increase in the hydrophilicity of the surface, depending on the plasma treatment time. As a result, the PES membrane could be the most efficiently surface-treated by applying the plasma treatment for enhancing their surface hydrophilicity.

• Analytical Science and Technology
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• v.13 no.5
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• pp.601-607
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• 2000

Lanthanum has been used as one of the burnup monitor in spent nuclear fuel. $U_3Si/Al$ spent nuclear fuel contains small amount of La in high concentration of U and Al. Therefore, chemical separation of La is required to remove matrix elements. At first, ion chromatography (IC) and inductively coupled plasma systems were installed in radiation shielded glove box to handle the radioactive samples. Retention behavior of uranium, aluminum, lanthanum and some interesting fission products (Sr, Zr, Y, Mo, Ru, Pd, Rh, Cs, Ba, Ce, Pr, Nd, Sm, Eu and Cd) was investigated using the CG10 column and ${\alpha}$-HiBA eluent. As all elements were eluted earlier than lanthanum in 0.2 M ${\alpha}$-HiBA eluent, a portion of U and Al was directly passed to waste using a three way valve between the column and the nebulizer. Thus it was possible to determine the lanthanum in a high concentration of U and Al matrix. Retention time of La was about 12 minutes in this separation condition. Optimum range for the determination of La in $U_3Si/Al$ spent nuclear fuel was $1-10{\mu}g/L$ (ppb) with this system and detection limit was $0.25{\mu}g/L$ in case of $200{\mu}L$ of sample volume.

• Analytical Science and Technology
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• v.17 no.5
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• pp.438-442
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• 2004

To determine the contents of $^{99}Tc$ in the spent PWR (pressurized water reactor) nuclear fuels by ICP-MS (inductively coupled plasma-mass spectrometry), a technetium separation method using an extraction chromatographic resin (TEVA Spec resin) has been established. $^{99}Tc$ was separated from a spent PWR nuclear fuel solution by this separation procedure and its concentration was determined by ICP-MS. The result agrees well with the value calculated by the program ORIGEN 2 and also the value measured by AG MP-1 resin/ICP-MS method described in our previous paper. It can be concluded that the present separation procedure is superior to the AG MP-1 resin procedure with respect to the time required for technetium separation as well as the efficiency of decontamination from other radioactive nuclides.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.1-8
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• 1998

The a-C:H films have been grown on the glass substrate by PECVD mathod, where plasma was generated with a 60Hz line power source. The carbonization is checked from peak intensities of D($sp^3$) and G($sp^2$) peaks in Raman spectra. The hydronization and C-H bonding status in films can also be determined from FTIR results. Both the bonding strength of C-H and the ratio of $sp^3$ to $sp^2$ in bonding are found to be slightly dependent of partial pressure of $C_2H_2$. Judging from above results, we can conclude that the best value for partial pressure of $C_2H_2$ in growing process of thick films is about 15%.

• Transactions of The Korea Fluid Power Systems Society
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• v.1 no.3
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• pp.7-13
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• 2004

The hydraulic pump for a Electro-hydrostatic Actuator for aircrafts should be able to quickly feed large volume of oil into hydraulic cylinder in order to reduce the response time. On the other hand, it should be also able to precisely dispense small amount of oil by low-speed operation so that the steady state position control error of the EHA can be accurately compensated. This paper is focused on the investigation how the plasma coating surface treatment of cylinder barrel with CrSiN can contribute to the reduction of low-speed friction torque of a bent-axis type piston pump. The results showed that the reduction of the friction torque was not remarkable, but that the anti-wear characteristics of the CrSiN-coated cylinder barrel were much better that those of the original one.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.259-265
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• 2006

We measured sputtering yield of RF $O_2-plasma$ treated MgO protective layer for AC-PDP(plasma display panel) using a Focused ion Beam System(FIB). A 10 kV acceleration voltage was applied. The sputtering yield of the untreated sample and the treated sample were 0.33 atoms/ion and 0.20 atoms/ion, respectively. The influence of the plasma-treatment of MgO thin film was characterized by XPS and AFM analysis. We observed that the binding energy of the O 1s spectra, the FWHM of O 1s spectra and the RMS(root-mean-square) of surface roughness decreased to 2.36 eV, 0.6167 eV and 0.32 nm, respectively.

• Korean Journal of Materials Research
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• v.28 no.9
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• pp.511-515
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• 2018

W-10 wt% Ti alloys that have a homogeneous microstructure are prepared by thermal decomposition of $WO_3-TiH_2$ powder mixtures and spark plasma sintering. The reduction and dehydrogenation behavior of $WO_3$ and $TiH_2$ are analyzed by temperature programmed reduction and a thermogravimetric method, respectively. The X-ray diffraction analysis of the powder mixture, heat-treated in an argon atmosphere, shows W- oxides and $TiO_2$ peaks. Conversely, the powder mixtures heated in a hydrogen atmosphere are composed of W, $WO_2$ and $TiO_2$ phases at $600^{\circ}C$ and W and W-rich ${\beta}$ phases at $800^{\circ}C$. The densified specimen by spark plasma sintering at $1500^{\circ}C$ in a vacuum using hydrogen-reduced $WO_3-TiH_2$ powder mixtures shows a Vickers hardness value of 4.6 GPa and a homogeneous microstructure with pure W, ${\beta}$ and Ti phases. The phase evolution dependent on the atmosphere and temperature is explained by the thermal decomposition and reaction behavior of $WO_3$ and $TiH_2$.