• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1218-1223
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• 2021

A hydrophobic ionic liquid including an amino moiety ([DiOcAPmim][NTf₂]) was synthesized. Its extraction behaviors towards Pd(II), Ru(III), Rh(III) were investigated in nitric acid aqueous solution as a function of contact time, effect of concentration of nitric acid, effect of temperature, and effect of co-existing metal ions. The extraction kinetics of Pd(II) was fairly fast and extraction equilibrium can be attained within only 5 min under the [HNO₃] = 2.05 M. When [HNO₃]< 1 M, the extraction percentage of Pd(II), Ru(III), Rh(III) were all above 80%. When [HNO₃] reached 2 M, all of the extraction percentage decreased and in an order of Pd(II)>Ru(III)>Rh(III). When [HNO₃]> 2 M, the extraction performance gradually recovered. The effect of temperature can slightly affect the extraction performance of Pd(II). Furthermore, in simulated high-level liquid waste, [DiOcAPmim][NTf₂] showed a better preference towards Pd(II) under the interference of various other co-existing metal ions.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1787-1791
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• 2007

Several hydroxylated cinnamic acid derivatives were prepared from the corresponding acids and amino acid residues, and their hypocholesterolemic activities were evaluated in high cholesterol-fed mice. The presence of the double bond in hydroxylated cinnamide derivatives decreases cholesterol-lowering activities and the number of free phenolic hydroxy groups affect greatly the activities. 3,4-Dihydroxy hydrocinnamides obtained from amino acid derivatives containing a hydrophobic side chain such as alanine, valine, phenylalanine, and isoleucine exhibited potent cholesterol-lowering activities.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.315-318
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• 1995

Sulfanilic acid (4-aminobenzenesulfonic acid) alone is normally not permeant in bacteria but can be readily delivered via the microbial dipeptide transport system. A dipeptidyl derivative of this compound, L-phenylalanyl-L-2-sulfanilylglycine (PSG), prepared by attachment of its primary amino group to the phenylalanyl $\alpha$-glycine moiety, appeared to have a Km of 0.125 mM and a Vmax of 1.9 nmoles/ml/min ($A_{660}$, 1.0) in Escherichia coli. From competitive spectrophotometric analysis, it was found that the type of amino acids in both of the N- and C-terminals affected the kinetic power of dipeptides. The growth inhibitory effect of PSG was over 7 times more potent than that of the sulfanilic acid against E. coli, suggesting that this potential inhibition was presumably due to the increased hydrophobic nature of the sulfanilyl dipeptide.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.215-217
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• 1996

We have examined the electrical properties of arachidic acid Langmuir(L)films by using a displacement-current-measuring technique with pressure stimulation, displacement current peak appeared at a area per molecule around $90{\AA}^2$, possibly due to the orientational change in hydrophobic part of arachidic acid molecules. The displacement current is the transient current, it is generated when charged particles existing in single monolayers are displaced with the external stimulation. In this report, we mainly describe the displacement current generation from arichidic acid monolayers with pressure stimulation.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.316-325
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• 2018

Aluminum based metal-organic framework using a di-carboxylate linker succinic acid (Al-SA MOF), are synthesized in water with minimal generation of secondary pollutants. The physicochemical properties of Al-SA MOF were examined, followed by its utility for the adsorption of Acid Black 1 (AB1) in aqueous media. Influences of key parameters such as pH, contact time, initial AB1 concentration,temperature, and selectivity on the adsorption process were assessed. A series of adsorption mechanisms are proposed, which involve electrostatic, hydrogen bonding, and hydrophobic interactions. These findings suggest that Al-SA MOF is a potent candidate in removing complex azo dyes molecules from aqueous media.

• Journal of Life Science
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• v.24 no.2
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• pp.161-166
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• 2014

We screened Paenibacillus sp. strains from Jeotgal, a Korean salted and fermented fish product, for use as a novel probiotic. Among these Paenibacillus sp. isolates, BCNU 5016 was a typical Paenibacillus sp. strain that showed gram-positive, gelatinase-negative, and urease negative activity. On the basis of 16S rDNA sequence comparisons, BCNU 5016 was most closely related phylogenetically to P. polymyxa. When Paenibacillus sp. BCNU 5016 was subjected to the acid tolerance test, this strain showed 91.89% survival after 3 h culture at pH 2.5. Paenibacillus sp. BCNU 5016 also showed excellent bile acid tolerance. Furthermore, its auto-aggregation, coaggregation, and hydrophobic capacities suggest that BCNU 5016 had the capacity to adhere well to the intestinal tract. We conclude that Paenibacillus sp. BCNU 5016 has excellent potential as a probiotic.

• Polymer(Korea)
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• v.35 no.5
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• pp.438-443
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• 2011

In order to enhance water permeability through the improvement of fouling phenomena and wettability of hydrophobic porous membranes, various adsorption materials, i.e., poly(vinyl amine), poly (styrene sulfonic acid), poly(vinyl sulfonic acid), and poly(acrylamide-co-acrylic acid) were adsorbed onto the surface of polyethylene (PE) porous membrane. The concentration of adsorption solutions, adsorption time, the sort of salts and their ionic strength were varied, and the pure water permeability of their resulting adsorbed membranes was measured. In general, water permeability increased with an initial increase in the concentration of adsorption solution, adsorption time, and ionic strength and then decreased with a further increase. The pure water permeability of 375 $L/m^2h$(LMH), 35% enhancement, was obtained at a condition of poly(vinyl sulfonic acid) 1000 ppm, $Mg(NO_3)_2$ ionic strength(IS) 0.1, and adsorption time 150 sec, while the 50% (411 LMH) and 35% (374 LMH) enhancements were obtained at conditions of poly(styrene sulfonic acid) 1000 ppm, adsorption time 60 sec, and NaCl IS 0.1 and 0.2, respectively.

• Rubber Technology
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• v.9 no.1
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• pp.25-28
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• 2008

By combining the multi-faceted environmental responsiveness of polymer hydrogels with photonically active structures, there has been a significant effort to create color-tunable photonic crystal sensors by changing either the periodic spacing of the structure or the dielectric constants of the materials. Here, we show that reversible spiral and helical opal switches with both dimensional and optical functionalities that respond to environmental chemistry can be constructed. When the transparent opal switch is swollen in hydrophilic acetic acid, right-handed spirals and helices that exhibit angularly dependent colors from Bragg diffraction are formed. When the transparent opal switch is swollen in hydrophobic hexane, left-handed spirals which exhibit angularly dependent colors from Bragg diffraction are formed. When the transparent opal switch is swollen in hydrophobic hexane solvent, a left-handed spiral and helix with an angularly independent bluish color is formed. After deswelling, all switches returned back to the transparent planar state. These color-tunable, reversible spiral and helical opal switches can be useful as mechanical actuators, and electrical devices as well as optical components.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.129-132
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• 2000

In this research, we proposed the immobilization zone where the organic contaminant would be fixed, so that ground water could be prevented from the organic contaminants. The surfactant was adsorbed on the soil particles and the organic contaminants were partitioned into the hydrophobic tails of the surfactant in the immobilization zone. Surfactants with different molecular structures-SDDBS (sodium dodecylbenzenesulfonic acid), MADS (monoalkylated disulfonated diphenyl oxide), DADS (dialkylated disulfonated diphenyl oxide) - were used in this study. Up to the present, the research on the immolization simulated the saturated condition. But many site contaminated with organic contaminants and the zones where immobilization would be applied are unsaturated. In this research, in order to investigate the behaviors of surfactants and organic contaminants in unsaturated condition, the unsaturated columns were experimented, and their results were compared with the saturated case.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.647-650
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• 2003

In anhydrous organic solvents, the complexes formed between AOT (dodecylbenzene sulfuric acid sodium salt) and hemoproteins, such as hemoglobin, myoglobin, or cytochrome c, displayed remarkably higher activity than the hemoprotein powders to oxidize dibenzothiophene, a model compound of organic sulfurs contained in fossil fuels. In slightly hydrophobic organic solvents, such as ethyl acetate and butyl acetate, dibenzothiophene was completely oxidized catalytically by the cytochrome c-AOT complex with cumene hydroperoxide (${\alpha},{\alpha}-dimethylbenzyl$ hydroperoxide) as an oxidant. In highly hydrophobic organic solvents, such as decane and hexadecane, however, the activity of the cytochrome c-AOT complex decreased, presumably due to the aggregation of the hemoprotein-AOT complex in these solvents.