• Nuclear Engineering and Technology
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• v.44 no.1
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• pp.21-32
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• 2012

Fluorinated compounds mainly used in the semiconductor industry are potent greenhouse gases. Recently, thermal plasma gas scrubbers have been gradually replacing conventional burn-wet type gas scrubbers which are based on the combustion of fossil fuels because high conversion efficiency and control of byproduct generation are achievable in chemically reactive high temperature thermal plasma. Chemical equilibrium composition at high temperature and numerical analysis on a complex thermal flow in the thermal plasma decomposition system are used to predict the process of thermal decomposition of fluorinated gas. In order to increase economic feasibility of the thermal plasma decomposition process, increase of thermal efficiency of the plasma torch and enhancement of gas mixing between the thermal plasma jet and waste gas are discussed. In addition, noble thermal plasma systems to be applied in the thermal plasma gas treatment are introduced in the present paper.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.101-103
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• 2004

To investigate the evidence for the influence of sea water on Pohang geothermal groundwater, the chemical data for geothermal groundwaters from which are pumped during 48 hours and other hot groundwaters, another groundwater on the well for the purpose of agriculture, were considered. And to predict possible the secondary mineral which are easily to make the clogging, geochemical modeling was carried out using EQ3NR equilibrium solubility code. The results are that 1.4%～3.3%(bulk composition) of sea water were mixed with geothermal groundwater. From the well logging data, when the level of groundwater is drow down, the conductivity is increased in the geothermal groundwater, the existence of transition zone are recognized in the well. The predicted possible secondary minerals are Antigorite [Mg48Si24O85(OH)62], Chrysolite [Mg3Si2O5(OH)4] , Cristobalite, Dolomite, Talc, Tremolite. The recommended cooling temperature of best condition to minimize the production of secondary minerals is same as temperature of geothermal water pumped from the well.

• Journal of the Korea Institute of Building Construction
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• v.4 no.3
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• pp.101-108
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• 2004

The physical factor having a great influence among components of making values of profit model in apartment houses is equilibrium change of house and this study suggests an alternative of remodelling. It sets profit models including model dividing household of large scale into that of small scale using value making factor of apartment house and spatial composition techniques and model integrating households of small scale and converting them into those of large scale and finds that its economy is good as over 'average', evaluative value of economy is reduced as discount rate increases and economy of remodelling is superior.

• Journal of the Korean Institute of Gas
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• v.4 no.4 s.12
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• pp.1-5
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• 2000

Cubic and non-cubic equations of state are used to calculate the vapor-liquid equilibrium(VLE) compositions for liquified natural gas(LNG) containing hydrogen sulfide. Modified Benedict-Web-Robin EOS is chosen as a non-cubic equation of state while Peng-Robinson, Soave-Redlich-Kwong EOS are used for a cubic EOS. Modified Benedict-Web-Robin EOS. showed better predictability than the cubic EOS used for the systems $H_2S/CH_4,\;H_2S/iC_4H_{10},\;H_2S/N_2$. specially for liquid composition.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.2
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• pp.31-42
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• 1986

The prediction of performance, exhaust emissions and EGR effect is made by the SI engine cycle simulation. In this simulation several models are employed - two zome, thermodynamic combustion, mass fraction burned, heat transfer, chemical equilibrium, chemical kinetics for NOx, laminar flame speed for ignition delay. The chemical species in burned gas considered are 13 species-CO$_{2}$, CO, $O_{2}$, H$_{2}$O, H$_{2}$,OH, H, O, N$_{2}$, NO$_{2}$, N, Ar - and the cylinder pressure, burned and unburned zone temperature and composition of gas are calculated at each crank angle through the compression, ignition delay, combustion and expansion process. To check the validity of the model, experimental study is done for measuring emissions, combustion pressure and engine output. The predicted values for pressure and emissions show qualitative agreement with the measured data and the EGR effect also shows similar tendency.

• Laser Solutions
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• v.5 no.3
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• pp.15-20
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• 2002

The principal obstacle to selection of a laser processing method in production is its relatively high equipment cost and the natural unwillingness of production supervision to try something new until it is thoroughly proven. The major objective of this work is focused on the combined features of gas tungsten arc and a low-power cold laser beam. In this work, the laser beam from a 7 watts carbon monoxide laser was combined with electrical discharges from a short-pulsed capacitive discharge GTA welding power supply. When the low power CO laser beam passes through a special composition shielding gas, the CO molecules in the gas absorbs the radiation, and ionizes through a process blown as non-equilibrium, vibration-vibration pumping. The resulting laser-induced plasma(LIP) was positioned between various configurations of electrodes. The high-voltage impulse applied to the electrodes forced rapid electrical breakdown between the electrodes. Electrical discharges between tungsten electrodes and aluminum sheet specimens followed the ionized path provided by LIP. The result was well-focused melted spots.

• Transactions on Electrical and Electronic Materials
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• v.7 no.3
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• pp.108-111
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• 2006

The oxidizer-induced corrosion state and microstructure of surface passive metal-oxide layer greatly influenced on the removal rate of tungsten film according to the slurry chemical composition of different mixed oxidizers. In this paper, the actual polishing mechanism and pH-potential equilibrium diagram obtained from potentiodynamic polarization curve were electrochemically compared. An electrochemical corrosion effect implies that slurries with the highest removal rate (RR) have the high dissolution rate.

• Elastomers and Composites
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• v.28 no.3
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• pp.183-190
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• 1993

The radical copolymerization with propagation and depropagation is presented in order to estimate reactivity rate of monomers and $K_{11}$(the equilibrium constant for propagation and depropagation) in the copolymerization of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-acrylonitrile$. The value of ${\alpha}-methylstyrene$ and methylmethacrylate and $K_{11}$ are found to be 0.48, 0.47 and 5.0 respectively. The value of ${\alpha}-methylstyrene$ and acrylonitrile and the $K_{11}$ are found to be 0.1251, 0.0577 and 23.8 respectively. The treatment rate constant of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-co-acrylonitrile$ in the copolymerization is estimated to be 2.5, 80.72 regardless of monomer feed composition.

• Journal of the Semiconductor & Display Technology
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• v.7 no.2
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• pp.1-5
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• 2008

Silicide formation process and the formation sequence were investigated in this study. It was postulated that the formation of the second silicide phase involves glass formation between the first silicide phase and Si given that a thin metal film is deposited on a Si substrate. The concentration of glass was assumed to be located where the free energy of the liquid alloy with respect to the first nucleated compound and solid Si (${\Delta}$G') is most negative. It was also mentioned that the glass concentration is close to the composition of the second phase in order to achieve the maximum energy degradation. It was shown that the minimum ${\Delta}$G' concentration can be estimated by interpolating the portion of the liquidus where the liquid alloy is in equilibrium with the two solid constituents, namely the first compound phase and Si, thereby forming a hypothetical eutectic.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.206-212
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• 2016

Experimental data are reported on the phase equilibrium of propoxylated neopentyl glycol diacrylate in supercritical carbon dioxide. Phase equilibria data were measured in static method at a temperature of (313.2, 333.2, 353.2, 373.2 and 393.2) K and at pressures up to 27.82 MPa. At a constant pressure, the solubility of propoxylated neopentyl glycol diacrylate for the (carbon dioxide + propoxylated neopentyl glycol diacrylate) system increases as temperature increases. The (carbon dioxide + propoxylated neopentyl glycol diacrylate) system exhibits type-I phase behavior. The experimental result for the (carbon dioxide + propoxylated neopentyl glycol diacrylate) system is correlated with Peng-Robinson equation of state using mixing rule. The critical property of propoxylated neopentyl glycol diacrylate is predicted with Joback and Lyderson method.