• Resources Recycling
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• v.11 no.6
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• pp.18-23
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• 2002

A study on the solvent extraction of hexavalent chromium from aqueous solutions has been investigated. The results showed that the extraction efficiency of chromium increased in proportion to extractant concentration. Aliquat 336 of quarternary amine effectively extracted hexavalent chromium and was superior to Alamine 336. And the stabilizers like polyhydric alcohols of octanol, decanol and dodecanol showed the similar effect fur prevention of third phase and a little promotion of extraction efficiency in comparison with non-use of polyhydric alcohols. On the other hand, in solvent extraction of hexavalent chromium from aqueous solutions, the hexavalent chromium was completely extracted at pH range lower than 7 with 1% Aliquat 336 as extractant and 5% decanol as stabilizer and the hexavalent chromium in extractant was completely stripped with 1M sodium hydroxide solution in the stripping step.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.507-512
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• 2005

When carbon electrode is used as an anode in Li ion battery, passivation film forms on the electrode surface during the initial charge process due to so called Solid-Electrolyte Interphase (SEI). The passivation film formed by solvent decomposition during the initial charge process affects charge/discharge capacity. In this paper, 1 M $LiPF_6,EC:DEC$ (1 : 1, volume ratio) electrolyte with $Li_2CO_3$, at various temperatures, the electrochemical characteristics of passivation film formed on Kawasaki Mesophase Fine Carbon electrode surface were investigated by using chronopotentiometry, cyclic voltammetry, and impedance spectroscopy. Experimental observations indicated that as solvent decomposition occurred, the decomposition voltage was strongly dependent on ionic conductivity, which was low in the process at low temperature. The impedance of passivation film formed during the initial charge process, were dependent on the temperature.

• Membrane Journal
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• v.33 no.6
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• pp.279-304
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• 2023

Polybenzimidazole (PBI) based membranes have evolved in literature as a popular membrane material for various applications in the past two decades because of their high temperature thermal durability, strong mechanical and tensile properties, high glass transition temperature (T_g), ion conduction ability at elevated temperature (up to 200℃), oxidative or chemical durability along with robust network like structural rigidity, which make PBI membranes suitable for various potential applications in chemically challenging environments. Ion conducting PBI based membranes have been extensively utilized in high temperature proton exchange membrane fuel cells (HT-PEMFC). In addition, PBI based membranes have been vastly utilized for the development of gas separation membranes and organic solvent nanofiltration (OSN) membranes for their unique characteristics. This review will cover the recent progress and application of various types of flat sheet PBI based membranes for HT-PEMFC, gas separation and OSN application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s01
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• pp.26-32
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• 1989

The analytic principles of GC and MS were explained in relation to plant hormone analyses and the characteristics of two instruments were compared. The selection of column, condition of measurement and the method of ionization to get a good spectrum were also briefly described. Finally, the pre-treatment of sample by solvent extraction method to remove the unnecessary part of sample and the synthetic method, especially reagents and reaction condition, for the preparation of ether or ester derivative which can be easily vaporized in GC were explained.

• Journal of Magnetics
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• v.6 no.1
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• pp.13-18
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• 2001

Permalloy soft magnets have been produced by the powder injection molding process. Rheological characteristics of mixtures, debinding conditions, and the magnetic properties of permalloy after sintering have been investigated. A permalloy soft magnet with a permeability of 14200 could be obtained by preparing a mixture with a powder loading of 65.4 vol % and a PP/PEG binder systems solvent extraction, thermal debinding, and subsequent sintering at 1350$\^{C}$ in hydrogen. The permalloy soft magnet sintered in hydrogen had 95% of theoretical density and a magnetic induction of 13.2 kG in an applied magnetic field of 50 Oe.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.217-227
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• 2000

The permalloy soft magnet was produced by powder injection molding process. Rheological characteristics of mixtures, debinding conditions and the magnetic properties of permalloy after sintering ware investigated. The permalloy soft magnet with a permeability of 14200 could be obtained by preparing a mixture with a powder loading of 65.4 vol.% and PP/PEG binder system, solvent extraction, thermal debinding and subsequent sintering at 1350 $^{\circ}C$ in hydrogen. The permalloy soft magnet sintered in hydrogen showed a 95 % of theoretical density and a magnetic induction of 13.2 kG at the applied magnetic field of 50 Oe

• KSBB Journal
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• v.8 no.1
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• pp.1-9
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• 1993

The acetone-butanol fermentation by C. acetobutylicum has gained increasing attention for the following reasons. First, the finite supply of petrochemical resources, combined with increasing concern over global environmental effects and the unstable nature of the price of petroleum has renewed interest in the development of fermentation technology that allows utilzation of biomass wastes for the production of alcohol. Second, it serves as excellent model system for understading the regulation and molecular biology of tightly regulated complex primary metabolism, and for applications of metabolic engineering. In this review various aspects of acetone-butanol fermentation by C. acetobutylicm including strain and fermentation characteristics, enzyme regulation, and solvent formation mechanism, and product recovery and summarized.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.09a
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• pp.65-70
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• 1998

Fine powders of $\alpha$-Fe2O3 were prepared by precipitation method using iron (III) nitrate in ethanol solvent and the thick film using this powder was made by the screen printing technology. Effects of the reaction temperature and concentration of the iron (III) nitrate on the particle size and specific surface area were studied. Also, the relationship between the powder size and properties of the thick film was discussed.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.169-172
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• 2002

Silver pastes for inner conductor in the Low Temperature Co-fired Ceramics (LTCC) are composed of silver powder, binder, solvent and additives. The composition of the chemicals have influence on rheology, printability, shrinkage rate, etc. In this study, commercial Ag pastes and Ag pastes made in KETI were investigated to find the relationship between characteristics of Ag paste and solid contents. Ag pastes with 68~90 wt% Solid Contents were tested. Substrate/paste matching property and conductivity of the conductor lines showed large dependence on solid contents of Ag paste.

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.269-277
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• 1995

A topological theory has been introduced to extend the theory of Balsara and Nauman to evaluate the entropy of in homogeneous polymer solutions. Previous theories have considered only the terms about the displacement of junction points, while the present theory has obtained a more complete expression for the entropy by adding the topological interaction terms between strands. There have been predicted the characteristics of the spinodal decomposition and the interfacial tension of polymer solutions from the resultant expression. It is exposed that the theoretically predictive values show good agreement with the experimental data for polymer solutions.