• Journal of the Korean Graphic Arts Communication Society
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• v.15 no.2
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• pp.107-115
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• 1997

The ultraviolet(UV)-curable materials are widely used in inks and coatings. In this paper is designed to develop materials having flexibility and functionality with UV-curable acrylate monomer and alkyd resin. At first, phase diagram is prepared for miscibility of UV -curable acrylate monomer with alkyd resin. Also the gel fraction and dynamic viscosity are measured to curing speed of mixing system. In results, it has been demonstrated that miscibility and curing speed are greatly influenced by alkyd resin content.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.253-259
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• 2000

The purpose of this study is to investigate the physicochemical characteristics of salinization of groundwater at the estern area of Cheju island. For this purpose, the major ions of groundwater, spring water are analyzed. The concentration of $Cl^-$ and Na^++K^+$/ contained in the groundwater at near the coastline are higher than those at inland area away from the coastline. The water quality components of groundwater observed at this area can be classified into 4 types such as Na-Cl, $HCO_3, Na-Cl-HCO_3$ and Ca-HCO$_3$. The concentration ratio of $SO_4^1 to Cl^- is 0.1354(R^2=0.972)$ at this area. This value is very similar with Dittomer's ratio of 0.13. For Na^+, K^+, and Mg^{2+}/ versus Cl^-$, their ratios also show a significant relationship between sea water and groundwater in this area. From the chloride-bicarbonate ratio, it can be estimated that the intrusion distance of seawater from coastline to inland area is 2.8km at Onpyung-Nansan, Sangdo and Pyungdae areas, and 5.4km at Kosung-Susan area. The mixing ratio between seawater and fresh water by the intrusion of seawater is decreased with the distance toward inland from coastline. This ratio(fresh water : seawater) is 80:20 in spring water adjacent the coastlines, Onpyung area and 99.8:0.2 in the well at No.3 of Susan located at inland away from the coastline. The concentration of $Na^+$ observed at field is 25~45% lower than that theoretically calculated by this mixing ratio. Based on the data of EC, the equipotential line of 500$\mu$mhos/cm is located at 4~5km poing at Kosung-Susan area and 2.5km point at the other area. The equation of correlation between $Cl^-$ concentration and EC values is $Cl^-$=0.1927EC-16.683 for the area lower than 500 $\mu$mhos/cm and $Cl^-$=0.2773EC for the area beyond 500 $\mu$mhos/cm.

• 한국해양학회지
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• v.27 no.2
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• pp.154-163
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• 1992

Bacterial abundance, production, and environmental parameters were investigated three times to study distribution of bacterial variables and to examine how estuarine mixing would influence the distribution of bacterial variables in the euphotic zone of the estuarine system of the Mankyung river and Dongjin river during a period of October, 1990-August, 1991. Although a limited number of investigations were made, bacterial abundance and production showed large variations from 0.4 to 5.8${\times}$10/SUP 9/ 1/SUP -1/ and from 0.1 to 22.2 ug C 1/SUP -1/ d/SUP -1/, respectively. The wide ranges of bacterial variables indicated very dynamic changes in conditions of bacterial growth in the estuary. Interestingly, bacterial abundance substantially increased with depth in most stations f shallow depth. but bacterial production remarkably decreased with depth. We propose that the observed distribution of bacterial abundance and production would be explained by estuarine mixing in the estuary. Analyses of mixing diagrams showed that estuarine mixing would mix conservatively bacteria and bacterial production. Further, estuarine mixing often seemed to cause an increase in bacterial abundance and reduction of bacterial production presumably due to resuspension of sediment. This suggests that roles of estuarine mixing would be significant in the distribution of bacterial abundance and production, and thus in biogeochemical cycles in the estuary.

• Journal of Power System Engineering
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• v.18 no.1
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• pp.69-75
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• 2014

The pressure and temperature characteristics of mixed refrigerant gases in bulb for thermostatic expansion valve were studied using R22 refrigerant and $N_2$ gases. The characteristics of mixed refrigerant gases were investigated according to pressure variation and the variation of composition ratio of R22 refrigerant and $N_2$ gases in the temperature range of -$15^{\circ}C$~$15^{\circ}C$. The Maximum operating pressure(MOP) of mixed refrigerant gases were showed a tendency to decrease with decreasing the mixing ratio of $N_2$ gas. The characteristics in the case of the mixing ratio of 90:1 for R22 refrigerant and $N_2$ gases were the same result as Reference refrigerant. In addition, the characteristics of the mixed refrigerant gases in the mixing ratio of 90:1 for R22 refrigerant and $N_2$ gases were showed almost linear in the measurement range of pressure-temperature, and the physical properties also were showed similar results with Reference refrigerant. It was able to confirm that a MOP on the thermostatic expansion valve for sensing bulb can be maintained by adjusting the mixing ratio of R22 refrigerant and $N_2$ gases.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.126-132
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• 2014

The P-T characteristics of mixed refrigerant in thermostatic expansion valve sensing bulb were studied using R-134a and R-410A refrigerant. The characteristics of mixed refrigerant were investigated according to pressure variation and the variation of composition ratio of R-134A and R-410A in the temperature range of $-15^{\circ}C{\sim}15^{\circ}C$. The Thermodynamic characteristic values of the mixed refrigerants were identified using the characteristic value analysis program of mixed refrigerant(Refrop v9.0, NIST). The P-T characteristics in the case of the mixing ratio of 90:10 for R-410A and R-134A were the same result as R-22. And the physical properties showed similar results with R-22. The Maximum operating pressure(MOP) of mixed refrigerant showed a tendency to decrease with decreasing the mixing ratio of additive gases($N_2$ or He) gases. The characteristics in the case of the mixing ratio of 80:1 for mixed refrigerant and additive gases were the similar result as Reference refrigerant.(R-22 MOP, Sporlan company) In addition $N_2$ and He, both showed the same results. It was able to confirm that a MOP on the thermostatic expansion valve sensing bulb can be maintained by adjusting the mixing ratio of mixed refrigerant gases and additive gases.

• Journal of the Korean Chemical Society
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• v.60 no.2
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• pp.111-117
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• 2016

In this article, new Gibbs free energy of mixing is derived when there are specific interactions between solvent-solute molecules and between solute-solute molecules in binary solutions. It is asssumed that a probability of specific interactions satisfies a binomial distribution. Using this Gibbs free energy of mixing, we investigate possible types of partial miscibilities and show that Ω-shaped temperature-composition phase diagrams can exist. We calculate Ω-shaped temperature-composition phase diagram of water-2-butanol system and compare that with result calculated by the method of Hino⁵ et al. and the experimental data.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.42.1-42.1
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• 2017

We investigate the evolutionary properties of red supergiant stars (RSGs), using stellar evolution model of Modules for Experiments in Stellar Astrophysics (MESA). In this study, we calculate models with mass range of 9-39M_sun and several different convection parameters (e.g. mixing length, overshooting, and semiconvection) at SMC, LMC, Milky Way, and M31 metallicities. We compare the calculated evolutionary tracks with observed RSGs in SMC, LMC, Milky Way and M31, and discuss appropriate input physical parameters in model calculation. We find that a larger mixing length parameter is necessary for M31 metallicity to fit the positions of RSGs in H-R diagram, compared to lower metallicity environments. Theoretically predicted numbers of yellow supergiant stars (YSGs) are also compared with the observed population. We find that Ledoux models with semiconvection can better explain the number of YSGs. Finally, we investigate the final radius, final star mass, and final hydrogen envelope mass of RSGs and discussed the their properties as type II-P supernova progenitors.

• Journal of the Korean Society of Combustion
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• v.6 no.1
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• pp.1-6
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• 2001

To evaluate the effect of lobed structure on pollutant emission, an experimental study examines NOx and CO emissions associated with four burner geometries, such as a conventional circular burner and three lobed ones. Rapid mixing allowed by the lobed burner to produce lean premixed flames, with narrower flame stability diagram than for the conventional circular one. Conventional circular burner of wide and uniform burner rim has an advantage of flame stabilization. Correlation on fuel discharge velocity for flame blowout should be included a variable related to the wall effect of the burner. NOx emission reduces by about 5% at the burner with lobed structure in fuel discharge side compared to conventional circular one. This is due to lower flame temperatures through flame elongation and increased radiative heat losses, caused by partially luminous flame in flame front. Meanwhile, at the burner with lobed structure in air discharge side and both fuel and air discharge sides, NOx emission somewhat increases with reduced radiative heat losses in spite of flame elongation. Therefore, the rapid mixing by lobed structure does not always have an advantage on NOx reduction.

• Journal of Environmental Science International
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• v.3 no.3
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• pp.229-239
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• 1994

By laying emphasis on the intermediate layer, water property distribution in the Northwest Pacific is studied using the hydrographic data obtained by Japan Meteorologica] Agency in the period from 1960 to 1986. The scattering of water type in T-S diagram is relatively small in the Kuroshio Region. Both the envelopes of saline side and of fresh side of the scattered data points shifts gradually from saline side to fresh side as the observation line moves from southwest to northeast. In the Mixed Water Region, the scattering of water type increases rapidly as the observation line moves north; The envelope of fresh cold side moves towards fresh cold side much faster than that of same side. The thermosteric anomaly value at the salinity minimum decreases as the observation line moves from north to south or southwest. This suggests that the water does not advect along the salinity minimum layer, but that the salinity minimun layer is understood as a boundary of two different waters aligned vertically. We defined the typical water masses for the Oyashio Water and the Kuroshio Water. The water mass below the salinity minimum layer may be created by isopycnal mixing of these two water masses with a fixed mixing rate. While, the water mass above the salinity minimum cannot be created simply by isopycnal mixing. The salinity minimum layer may be eroded from upper side due to active mixing processes in the surface layer, while the water of the salinity minimum layer moves gradually southward. This appears to give an explanation why the thermosteric anomaly value at salinity minimum decreases towards south.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.383-392
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• 2013

In this research, mixing behavior of the floating pollutant such as oil spill accidents was analyzed by studying the advection-diffusion of GPS floaters at water surface. The LPT (Lagrangian Particle Tracking) model of EFDC (Environmental Fluid Dynamics Computer Code) was used to simulate the motion of the GPS floater tracer. In the field experiment, 35 GPS floaters were injected at the Samun Bridge of Nakdong River. GPS floaters traveled to downstream about 700 m for 90 minutes. The field data by the GPS floater experiments were compared with the simulation in order to calibrate the parameter of LPT model. The turbulent diffusion coefficient of LPT model was determined as $K_H/hu^*$ = 0.17 from the scatter diagram. The arrival time of peak concentration and transverse diffusion from the simulation results were similar with the experiments from the concentration curves. Numerical experiments for anticipation of damage from floating pollutant were conducted in the same reach of the Nakdong River and the results show that the pollutant cloud transported to the left bank where the Hwawon pumping station is located. For this reason, it is suggested that the proper action should be needed to maintain the safety of the water withdrawal at the Hwawon pumping station.