• Resources Recycling
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• v.20 no.6
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• pp.56-62
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• 2011

Zirconium is used in nuclear reactors as a structural material due to its excellent corrosion resistance and to low neutron crosssection. Variation in the distribution and solubility of Zr(IV) with solution pH was obtained. Distribution of Zr(IV) containing species in HCl and $HNO_3$ solution was analyzed by considering the complex formation of Zr(IV) species with the anion of the inorganic acid. Bromley interaction parameter between $ZrO^{2+}$ and nitrate ion was estimated by using the reported data on the solvent extraction of Zr(IV) by Cyanex272 from $HNO_3$ solution. This Bromley parameter can be utilized in calculating extraction isotherm of Zr(IV) and in predicting the separation factor between Zr(IV) and Hf(IV).

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.575-579
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• 2002

Two-dimensionally cross-linked ultrathin films of poly(maleic acid-alt-methyl vinyl ether) (MA-MVE) and poly(allylamine) (PAA) were produced by using sodium dioctadecyl sulfate (2C18S) as the monolayer template for Langmuir-Blodgett (LB) depositio n. The template molecules were subsequently removed by thermal treatment followed by extraction. The polyion-complexed monolayers of three components, i.e., template 2C18S, co-spread PAA, and subphase MA-MVE, were formed at the air-water interface. Their monolayer properties were studied by the surface pressure-area isotherm. The monolayers were transferred on solid substrates as Y type. The polyion-complexed LB films and the resulting network films were characterized by FT-IR spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The cross-linking to form a polymer network was achieved by amide or imide formation through heat treatment under a vacuum. SEM observation of the film on a porous fluorocarbon membrane filter (pore diameter 0.1 ㎛) showed covering of the pores by four layers in the polyion complex state. Extraction by chloroform followed by heat treatment produced hole defects in the film.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.493-498
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• 1995

Ultrathin networks of itaconic acid copolymers and poly(allylamine) were produced by a Langmuir-Blodgett (LB) technique employing a double-chain amine as a monolayer template which was subsequently removed by extraction after thermal crosslinking. Itaconic acid copolymers used were copoly (itaconic acid-ethyl vinyl ether) and copoly (itaconic acid-n-butyl vinyl ether). The polyion-complexed monolayers of three components consisting of template amine, itaconic acid copolymer and poly (allylamine) were formed at the air-water interface. The Langmuir film properties have been studied by the surface pressure-area isotherm and fluorescence microscopy. The monolayers were transferred on solid substrates and were characterized by FT-IR spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). Two-dimensional polymer networks were formed through imide or amide linkages by heat treatment under vacuum. The heat-treated films were extracted with chloroform after immersion in aq. sodium chloride to remove the template amines. SEM observation of a LB film on a porous fluorocarbon membrane filter with pore diameter of 0.1 μm showed covering of the pores by six layers in the polyion complex state.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.133-142
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• 2008

This paper studies the early-aged chloride binding capacity of various blended concretes including OPC(ordinary Portland cement), PFA(pulversied fly ash), GGBFS(ground granulated blast furnace slag) and SF(silica fume) cement paste. Cement pastes with 0.4 of a free water/binder ratio were cast with chloride admixed in mixing water, which ranged from 0.1 to 3.0% by weight of cement and different replacement ratios for the PFA, GGBFS and SF were used. The content of chloride in each paste was measured using water extraction method after 7 days curing. It was found that the chloride binding capacity strongly depends on binder type, replacement ratio and total chloride content. An increase in total chloride results in a decrease in the chloride binding, because of the restriction of the binding capacity of cement matrix. For the pastes containing maximum level of PFA(30%) and GGBFS(60%) replacement in this study, the chloride binding capacity was lower than those of OPC paste, and an increase in SF resulted in decreased chloride binding, which are ascribed to a latent hydration of pozzolanic materials and a fall in the pH of the pore solution, respectively. The chloride binding capacity at 7 days shows that the order of the resistance to chloride-induced corrosion is 30%PFA > 10%SF > 60%GGBFS > OPC, when chlorides are internally intruded in concrete. In addition, it is found that the binding behaviour of all binders are well described by both the Langmuir and Freundlich isotherms.

• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.476-484
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• 2014

The purpose of this study was to investigate the dyeing properties and anti-microbial ability of silk and wool fabrics dyed with Terminalia chebula Retzius(TCR) extract using two extraction solvent, hot water and methanol. Dyeing properties of fabrics were studied by investigating the characteristics of colorant, changes in dye uptake under different dyeing conditions, and by investigating color change when mordants were applied. Also, color fastness, and antimicrobial activity of dyed fabrics were estimated. Regardless of extraction solvent type, colorant showed maximum absorption wavelength at 280 nm and 578 nm, which implied that tannin was the major pigment component of TCR. Also, through FT-IR spectrum result, it was confirmed that tannin of TCR methanol extract was hydrolysable tannin. But for the hot water extract, it was only assumed that its tannin was condenced tannin. Fabric dyed with hot water solvent extract showed higher dye uptake than fabric dyed with methanol solvent extract, dye uptake increasing by higher concentration of the dye, longer dyeing time and higher dyeing temperature. And the absorption curve between TCR extract and protein fiber was shaped in the form of Langmuir adsorption isotherm. Fabric dyed without mordant was yellow in color, and when dyed with mordant, fabric showed various colors depending on mordant types except Sn. Color fastness to washing was generally fine and color fastness to light was moderate. But color fastness to rubbing and dry cleaning was outstanding. Lastly, dyed fabrics showed very good antimicrobial activity of 99.9% against Staphylococcus aureus and Kiebsiella pneumoniae.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.23-28
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• 2007

A number of batch isotherm and electrokinetic experiments were conducted in order to investigate the migration of zinc and its removal efficiency during electrokinetic soil processing. Sorption and desorption characteristics of zinc spiked kaolin clay have been examined by comparison with electrically induced desorption and precipitation occurring in the anode and cathode regions, respectively. The removal efficiency of zinc under the applied voltage gradient of 300 V/m was found to be up to approximately 80 % within 4 hours of the electrokinetic treatment. The study is significant with respect to the remediation of contaminated areas.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.57-62
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• 2000

This experiment was done to investigate the leaching and adsorption properties of heavy metals on porphyry. The comparison with respect to the leachability of heavy metals from porphyry between the Korea Standard Leaching Test (KSLT) and the Toxicity Characteristic Leaching Procedure (TCLP) was carried out. The fractional composition of leachate and the total concentration of heavy metal of porphyry were studied through Sequential Extraction Procedure (SEP) and EPA Method 3050. Adsorption experiment of porphyry has pointed out that the optimum dosage of porphyry for 50ppm Pb was over 10g/L, the effective particle size for absorption was below 200 mesh and the optimum pH was about 7. From the Freundlich' adsorption equation, 1/n was 1.0722, and k was 0.0041. After adsorption, the fractional composition of Pb was changed. The exchangeable, carbonate, reducible fractions were increased, and the organic fraction was not changed, and the residual fraction was decreased.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1583-1591
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• 2014

PVA-D2EHPA/TOPO beads containing two extractants, di-(2-ethylhexyl) phosphoric acid (D2EHPA) and trioctylphoshine oxide (TOPO) were prepared for the removal of copper ions from aqueous solution. The prepared PVA-D2EHPA/TOPO beads were characterized by SEM and FT-IR. The removal characteristics of copper ions by PVA-D2EHPA/TOPO beads was investigated using batch and continuous systems. In batch experiments, the maximum removal capacity calculated from Langmuir isotherm model was 18.6 mg/g and the optimal pH was in the range of 4.5~6. The continuous experiments showed that the removal capacity of copper ions increased with increasing inlet copper ion concentrations and bed heights, but decreased with increasing inlet flow rates.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1157-1163
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• 2014

The solid phase extractant (PVC-D2EHPA bead) was prepared by immobilizing di-2-ethylhexyl-phosphoric acid (D2EHPA) with polyvinyl chloride (PVC). The prepared PVC-D2EHPA beads were characterized by using fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The removal experiments of Cu(II) by PVC-D2EHPA beads conducted batchwise. The removal kinetics of Cu(II) was found to follow the pseudo-second-order model. The equilibrium data fitted well with Langmuir isotherm model and the maximum removal capacity was 2.6 mg/g at $20^{\circ}C$. The optimum pH region was in the range of 3.5 to 6. and the standard free energy (${\Delta}G^{\circ}$) was between -4.67~-4.98 kJ/mol, indicating the spontaneous nature of Cu(II) removal by PVC-D2EHPA beads.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.407-410
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• 2006

Studies were performed on evaluating the applicability of activated carbon bugs on dye tracer tests as tracer detectors by using its adsorption isotherm of the grained activated carbon. We preliminary conducted several standard adsorption and extraction tests and obtained the relationship between standard dye solution and detected concentrations from activated carbon samples in dry and wet conditions. the slopes of the regression line were 0.71 for wet condition and 0.74 for dried one. Field dye tracer tests were performed in a karst area, where several faults occur along a stream and pass the test area. We sampled water samples and activated carbon samples at three points in Hwangji Pond, where groundwater outflows from the karst conduit. According to the results of breakthrough curve analysis, the regional flow along the conduit, which is assumed to cause a karst conduit, was estimated as 0.18 m/day. The relationship between the concentrations of water sample and extracted activated carbon bugs shows the similar slopes with those from standard solution tests. This suggests that activated carbon could be useful as a dye tracer detector because the extraced concentration can be quantified.