• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.14-19
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• 1997

Laboratory experiments were conducted to study the effects of pH and salt level on the soil sorption equilibrium of pentachlorophenol (PCP) which is hydrophobic and ionogenic. Experimental results indicated that the sorption equilibrium constant (Kp) of PCP increased with decreasing pH. A quantitative sorption model involving linear isotherms was estabilished to predict the pH effect on the PCP sorption equilibrium over the pH range from 3 to 8. The model prediction was in good agreement with the experimental data. Also, the Kp increased with salt concentration over the entire pH range. At added salt levels less than 0.1M, increase in Kp was larger than when the added levels were higher than 0.1M. Salt might increase the PCP sorption by inducing 'salting out-effect' or by forming deprotonated PCP-cation ion pairs such as PCP$\^$-/K$\^$＋/. Taking the pH range (5-8) and the salt content (up to 50 g/L) in the groundwater of Metropolitan landfill sites into consideration, the results indicated that the retardation factor of PCP in this area might range from 3 to 550 depending upon pH and salt content.

• Korean Management Science Review
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• v.32 no.1
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• pp.83-100
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• 2015

We analyze a duopoly competition when two firms face input cost increases. The objective of this study is to determine the firms' optimal strategy between a price increase and downsizing under conditions of a spatially differentiated market and consumers' diminishing utility on the product size. We develop a theoretical model of two competing firms offering homogenous products using the standard Hotelling model to determine how firms' optimal strategies change when facing input cost increases. In this paper, there are two types of duopoly competitions: symmetric and asymmetric. In the symmetric case, the two firms have the same marginal cost and are producing and selling identical products. In the asymmetric case, the two firms have different marginal costs. The results show that the optimal strategy decision depends on the size of the input cost increase and the cost differences between the two firms. We find that when two firms are asymmetric (i.e., they have different marginal costs), the two firms might choose asymmetric pairs of strategies in equilibrium under certain conditions. When the cost differences between the two firms are sufficiently large and the cost increase is sufficiently small, the cost leader chooses price increase, and the cost-disadvantaged firm chooses downsizing in equilibrium. This asymmetric strategy reduces price competition between two firms, and consumers are better off. When the cost differences between the two firms are sufficiently large, downsizing is the dominant strategy for the cost-disadvantaged firm. The cost-disadvantaged firm finds it more profitable to reduce the product size than to increase its price to reduce price competition, because consumers prefer downsizing to price increases. This paper might be a good starting point for further analytical research in this area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.30-33
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• 2004

Shallow p+-n junctions were formed by low-energy ion implantation and dual-step annealing processes The dopant implantation was performed into the crystalline substrates using $BF_2$ ions. The annealing was performed with a rapid thermal processor and a furnace. FA+RTA annealing sequence exhibited better junction characteristics than RTA+FA thermal cycle from the viewpoint of junction depth. A new simulator is designed to model boron diffusion in silicon, which is especially useful for analyzing the annealing process subsequent to ion implantation. The model which is used in this simulator takes into account nonequilibrium diffusion, reactions of point defects, and defect-dopant pairs considering their charge states, and the dopant inactivation by introducing a boron clustering reaction. Using a resonable parameter values, the simulator covers not only the equilibrium diffusion conditions but also the nonequilibrium post-implantation diffusion. Using initial conditions and boundary conditions, coupled diffusion equation is solved successfully. The simulator reproduced experimental data successfully.

• Journal of the Mineralogical Society of Korea
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• v.4 no.2
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• pp.119-128
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• 1991

In the southern limb of the Hambaek geosyncline belt, large-scaled skarn deposits are developed in the Cambro-Ordovician sedimentary rocks of the Chosun Supergroup. They are the Sangdong tungsten deposit, Geodo iron-copper deposit, Yeonhwa I and II lead-zinc deposits, and Ulchin zinc-lead deposit, all of which are associated with various skarn minerals. Though different occurrences and paragenesis are found in different deposits, most skarn deposits always have skarns of garnet (andradite-grossular series) and clinopyroxene(heden-bergite-diopside series). Andradite and hedenbergite are Fe-dominant members, but show different oxidation states, that is, Fe3+ for andradite and Fe2+ for hedenbergite. According to iron chemistry and log([Fe/Al]gd/[Fe/Mg]cpx) derived from equilibrium reactions, the diopside-andradite and hedenbergite-grossular pairs suggest the oxidized state (dian type) and reduced state (hegro type), respectively. Among skarn deposits developed in the Hambaek geosynline, it can be classified that the Geodo and Yeonhwa I skarns are of dian type, while the Sangdong, Yeonhwa II, and Ulchin deposits are of hegro type. This classification is not applicable to all kinds of skarn deposits, but may be applicable to such deposits as are more controlled by oxygen fugacity than composition of skarn fluid.

• Journal of Powder Materials
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• v.20 no.2
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• pp.114-119
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• 2013

In the DBC (direct bonding of copper) process the oxygen partial pressure surrounding the AlN/Cu bonding pairs has been controlled by Ar gas mixed with oxygen. However, the direct bonding of Cu with sound interface and good adhesion strength is complicated process due to the difficulty in the exact control of oxygen partial pressure by using Ar gas. In this study, we have utilized the in-situ equilibrium established during the reaction of $2CuO{\rightarrow}Cu_2O$ + 1/2 $O_2$ by placing powder bed of CuO or $Cu_2O$ around the Cu/AlN bonding pair at $1065{\sim}1085^{\circ}C$. The adhesion strength was relatively better in case of using CuO powder than when $Cu_2O$ powder was used. Microstructural analysis by optical microscopy and XRD revealed that the interface of bonding pair was composed of $Cu_2O$, Cu and small amount of CuO phase. Thus, it is explained that the good adhesion between Cu and AlN is attributed to the wetting of eutectic liquid formed by reaction of Cu and $Cu_2O$.

• Analytical Science and Technology
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• v.7 no.1
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• pp.25-31
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• 1994

As for analytes which did not represent the differences of the selectivity on the stationary and mobile phase, secondary chemical equilibrium theory was applied to study pH effects on the separation of alkylphenols. Mobile phase was consisted of an aqueous sodium carbonate-bicarbonate buffer and acetonitrile. The maximum selectivity for adjacent peak pairs was predicted from those values of $k^{\prime}_{HA}/k^{\prime}_{A-}$ and ${\Delta}pK$. The optimum pH determined by this method was 11.18 pH and solvent selectivity were considered at the same time to invoke the full range of selectivity effects possible for separations. Quaternary mixture composed of methanol, acetonitrile, tetrahydrofuran and water was adjusted to optimum pH 11.18. As the statistical simplex technique of an overlapping resolution map (ORM) was used to predict the optimized solvent system. The optimum solvent, which gives complete separation of alkylphenols, was determined as follws MeOH : ACN : THF = 14.4 : 81.8 : 2.8.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.851-857
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• 2009

We developed and characterized 36 polymorphic microsatellite markers for the oyster mushroom (Pleurotus ostreatus). In total, 169 alleles were identified with an average of 4.7 alleles per locus. Values for observed ($H_o$) and expected ($H_E$) heterozygosities ranged from 0.027 to 0.946 and from 0.027 to 0.810, respectively. Nineteen loci deviated from Hardy-Weinberg equilibrium. Significant (P<0.05) excess heterozygosity was observed at nine loci. Linkage disequilibrium (LD) was significant (P<0.05) between pairs of locus alleles. Cluster analysis revealed that five species of genus Pleurotus made a distinct group, and the individual cultivars were grouped into major five groups from G-1 to G-5. The diverse cultivars of P. ostreatus were discriminated and the other four species revealed a different section in the UPGMA tree. These microsatellite markers proved to be very useful tools for genetic studies, including assessment of the diversity and population structure of P. ostreatus.

• Analytical Science and Technology
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• v.8 no.1
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• pp.33-40
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• 1995

Only trace amounts of hydroxide ion can be extracted from aqueous phase into organic phase by Tetra-n-Butyl Ammonium Chloride(TBAC). Addition of small amounts of primary alcohols, particularly certain dials, dramatically changes the behavior of Phase Transfer Catalysis systems, and surprising amounts of base can be found in the organic phase. Quantitative measurements were carried out for the extraction amounts of primary alkoxides, secondary alkoxides, and diol anions into organic phase. On the other hand, the selectivity constants for extraction of primary alcohols and benzylalcohol could be separated to the equilibrium constants of the ion pairs such as $Q^+RO^-$ and $Q^+Cl^-$ in the aqueous and organic phases and this distribution coefficients between phases on anions respectively. In a word, the colligated property for the selectivity of $Q^+RO^-$ in which $Q^+$ is quaternary cation and $RO^-$ alkoxide ion could be discussed in more detail by using of the corresponding free energies to the various constants mentioned.

• YAKHAK HOEJI
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• v.32 no.2
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• pp.101-111
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• 1988

$[^3H]$ Quinuclidinyl benzilate(QNB) binding assays were performed in the dog ventricular sarcolemma fraction enriched approx. 32-fold in sarcolemma compared to the starting homogenate to elucidate the effect of antihistaminics on cardiac muscarinic receptor. Chlorpheniramine(CHP) inhibited specific binding of $[^3H]$QNB and delayed the equilibrium binding. The rate constants at $37^{\circ}C$ for formation and dissociation of the QNB receptor complex were $0.38{\times}10^9\;M^{-1}$ and $1.6{\times}10^{-2}\;min^{-1}$, respectively. The mean value for the dissociation constant from the pairs of the rate constants was 43. 2 pM and this value was similar to the value(44.8pM) determined from Scatchard analysis. CHP decreased association rate constant, indicating increase in $K_D$ value. Decrease in affinity without affecting the binding site concentration$(B_{max})$ for $[^3H]$QNB binding by CHP was also demonstrated by Scatchard analysis. $K_i$ values for $H_i$-blockers that inhibited specific $[^3H]$QNB binding were $0.02{\sim}4.8{\mu}M$. Cimetidine with $K_i$ value of $230{\mu}M$, however, was ineffective in displacing $[^3H]$QNB binding at concentration of $50{\mu}M$. The Hill coefficient for $H_1$-blockers were about one. The results indicate that $H_1$-antihistaminics inhibit $[^3H]$ QNB binding by interaction with myocardiac muscarinic cholinergic receptor and anticholinergic side effects of these drugs are mainly due to this receptor blocking mechanism.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.110.2-110.2
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• 2012

We investigate a cool loop and a dark lane over a limb active region on 2007 March 14 by the Hinode/EUV Imaging Spectrometer (EIS). The cool loop is clearly seen in the EIS spectral lines formed at the transition region temperature (log T = 5.8). The dark lane is characterized by an elongated faint structure in coronal spectral lines (log T = 5.8 - 6.1) and rooted on a bright point. We examine their electron densities, Doppler velocities, and non-thermal velocities as a function of distance from the limb using the spectral lines formed at different temperatures (log T = 5.4 - 6.4). The electron densities of the cool loop and the dark lane are derived from the density sensitive line pairs of Mg VII, Fe XII, and Fe XIV spectra. Under the hydrostatic equilibrium and isothermal assumption, we determine their temperatures from the density scale height. Comparing the scale height temperatures to the peak formation temperatures of the spectral lines, we note that the scale height temperature of the cool loop is consistent with a peak formation temperature of the Mg VII (log T = 5.8) and the scale height temperature of the dark lane is close to a peak formation temperature of the Fe XII and Fe XIII (log T = 6.1 - 6.2). It is interesting to note that the structures of the cool loop and the dark lane are most visible in these temperature lines. While the non-thermal velocity in the cool loop slightly decreases (less than 7 km $s^{-1}$) along the loop, that in the dark lane sharply falls off with height. The variation of non-thermal velocity with height in the cool loop and the dark lane is contrast to that in off-limb polar coronal holes which are considered as source of the fast solar wind. Such a decrease in the non-thermal velocity may be explained by wave damping near the solar surface or turbulence due to magnetic reconnection near the bright point.