• 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.

• 대한공업교육학회지
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• v.33 no.1
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• pp.249-264
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• 2008

In this dissertation, shallow $p^+-n$ junctions were formed by ion implantation and dual-step annealing processes and a new simulator is designed to model boron diffusion in silicon. This simulator predicts the boron distribution after ion implantation and annealing. The dopant implantation was performed into the crystalline substrates using $BF_2$ ions. The annealing was performed with a RTA(Rapid Thermal Annealing) and a FA(Furnace Annealing) process. 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. FA+RTA annealing sequence exhibited better junction characteristics than RTA+FA thermal cycle from the viewpoint of sheet resistance and the simulator reproduced experimental data successfully. Therefore, proposed diffusion simulator and FA+RTA annealing method was able to applied to shallow junction formation for thermal budget. process.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.1-5
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• 1998

A spectrophotometric method was developed for the acidic solution stripped after an extraction of 0.5 to 2.5 ppm of Lead(II) from 50 mL of $Na_2S_2O_3$ solution into chloroform as the ion-pairs formed between their thiosulfate complexes and alkylamine, Aliquat336. Pb(II) in the stripped solution forms an complex with DDTC in pH 7.3 buffer solution, and was developed in yellow by copper replacement. The ydlow-colored solution have the maximum absorbance at 435 nm in the measurement of absorbance by UV-Visible spectrophotometer. The interference ions such as Fe(III), Hg (II), Al(III), Co, Cu, Ni, Zn, Ca, Sn, have great effects on the extraction, but they were overcomed by the usage of adequate masking agents before an extraction. At last, a good result was obtained in applying this method to synthetic water.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.380-380
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• 2006

Styrene-Butadiene diblock or styrene-butadiene-styrene triblock copolymers are industrially important materials for asphalt modification and adhesives. A kinetic modeling study on non-isothermal anionic styrene-butadiene diblock copolymerization system is presented. The model deals with the association/dissociation reaction of initiator and propagating ion pairs in its kinetic scheme. By comparing model calculation results with real plant data, it is possible to obtain useful ideas for more efficient plant operation. For example, the model clearly provides important relation between the reaction temperature profile and the conversion of monomers.

• 한국가시화정보학회:학술대회논문집
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• 2001.12a
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• pp.6-13
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• 2001

A new GA-3D-PTV technique has been constructed to measure an impinging jet. The measurement system consists of three CCD cameras, Ar-ion laser, an image grabber and a host computer. GA (Genetic Algorithm) was used based on one-to-one correspondences in order to take advantage of the combinatorial optimization in tracking the pairs of the whole particles of the two images having a time interval. Two fitness functions were introduced in order to enhance the correspondences of the particles. One was based on a concept of the continuum theory and the other one was based on a minimum distance error. The constructed GA-3D-PTV system was applied in success to the measurement of flow characteristics of the impinging jet.

• Journal of the Korean Magnetics Society
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• v.10 no.1
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• pp.7-10
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• 2000

The soft magnetic properties of Co-based amorphous alloy have been studied as a function of cooling condition after annealing. The F&W treatment (furnace cooling to 25$0^{\circ}C$ then water quenching) could increase 60~10$0^{\circ}C$ more the initial permeability than those of furnace cooled or water quenched alloys. These results are investigated in terms of thermal stress and ordering of magnetic ion pairs.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.948-952
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• 2008

The molecular association of acceptors with electron donors is studied in the highly-polar solvent $CH_3CN$. Tetracyanoquinodimethane (TCNQ) forms a stable charge-transfer complex with donor molecules such as 4- aminobiphenyl (4-AB), benzidine (BD) and 2-aminobiphenyl (2-AB) with high association constants. The complexes of TCNQ with 4-AB or BD show new absorption bands at around 800 and 500 nm, which can be identified as reduced $TCNQ^{{\bullet}-}$ and $TCNQ^{2-}$ species, respectively. These bands grow quickly upon photoirradiation, implying that the charge-transfer complexes are easily formed in an excited state. Conversely, a small spectral manifestation of the charge transfer was observed in the case of 2-AB complex. It is demonstrated that the structural orientation between the geminate ion pairs could play an important role in building a stable complex.

• Journal of Integrative Natural Science
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• v.5 no.2
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• pp.135-138
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• 2012

The reduction of efficiency of missing observations on complete diallel cross designs are examined. we studies robustness of optimal block designs for estimating general combining ability against loss of missing observations in diallel cross. A-efficiencies suggest that these designs are fairly robust. Simple g-inverses may be found for the information matrices of the line effects which allow evaluation of expressions for the variances of the differences between the pairs of line effects with missing observations. we numerically calculate the reduction of efficiency for estimating general combining ability against loss of missing observations in diallel cross.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.566-568
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• 2003

The phosphor $CaTiO_3:Pr^{3+}$ attracts much attention as a low-voltage red phosphor because of its good chromaticity and intrinsic conductivity. The addition of Ga into this CaTiO₃:Pr led the luminance intensity to greatly enhance without the change of the wavelength for the electronic transition and the peak shape of it. The increase of the recombination rate of electron-hole pairs through the Ga ion doping, which was expected to play a role of a hole-trap center, is proposed to be one of the reasons for the enhancement of the cathodoluminescence intensity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.7
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• pp.708-712
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• 2004

Shallow $p^+-n$ junctions were formed by 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 and sheet resistance. A new simulator is designed to model boron diffusion in silicon. 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 initial conditions and boundary conditions, coupled diffusion equations are solved successfully. The simulator reproduced experimental data successfully.