• Advances in environmental research
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• v.2 no.4
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• pp.309-321
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• 2013

High AA new high capacity sorbent for preconcentration and determination of nickel in environmental samples was synthesized. The sorbent was synthesized by copolymerization of allyl glaycidyl ether / imminodiacetic acid with N,N-dimethylacrylamide as functional monomers in the presence of N,N-bismethylenacryl amid as cross linker and characterized by Fourier transform infra red spectroscopy, elemental analysis, thermogravimetric analysis and scanning electron microscopy. A recovery of 93.6% was obtained for the metal ion with 0.1 M, sulfuric acid as the eluting agent. The sorption capacity of the functionalized sorbent was 55.9 $mgg^{-1}$. The equilibrium sorption data of Ni(II) on polymeric sorbent were analyzed using Langmuir, Freundlich, Temkin and Redlich.Peterson models. Based on equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined 0.87 (L mg-1), 25.87 ($mgg^{-1}$) $(Lmg^{-1})^{1/n}$ and 171.4 ($Jmol^{-1}$) respectively at pH 4.5 and $20^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1513-1520
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• 2013

Novel chitosan (CS) based membrane networks were developed by solution casting and followed by crosslinking with different crosslinkers such as glutaraldehyde, urea-formaldehyde, and thiourea-formaldehyde. The developed membrane networks were designated as CS-GA, CS-UF and CS-TF. Crosslinking reaction of CS membranes was confirmed by Fourier transform infrared spectroscopy. Membrane rigidity and compactness were studied by the differential scanning calorimetry. The surface morphology of CS membranes was characterized by scanning electron microscopy. The sorption behaviour with respect to contact time, initial pH and initial metal ion concentration were investigated. The maximum adsorption capacity of CS-GA, CS-UF and CS-TF sorbents was found to be 1.03, 1.2 and 1.18 mM/g for $Cu^{2+}$ and 1.48, 1.55 and 2.18 mM/g for $Ni^{2+}$ respectively. Swelling experiments have been performed on the membrane networks at $30^{\circ}C$. Desorption studies were performed in acid media and EDTA and it was found that the membranes are reusable for the metal ion removal for three cycles. The developed membranes could be successfully used for the separation of $Cu^{2+}$ and $Ni^{2+}$ metal ions from aqueous solutions.

• Journal of Hydrogen and New Energy
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• v.27 no.2
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• pp.135-143
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• 2016

Biogas is a renewable fuel from anaerobic digestion of organic matters such as sewage sludge, manure and food waste. Raw biogas consists mainly of methane, carbon dioxide, hydrogen sulfide, and water. Biogas may also contain other impurities such as siloxanes, halogenated hydrocarbons, aromatic hydrocarbons. Efficient power technologies such as fuel cell demand ultra-low concentration of containments in the biogas feed, imposing stringent requirements on fuel purification technology. Biogas is upgraded from pressure swing adsorption after biogas purification process which consists of water, $H_2S$ and siloxane removal. A polymer electrolyte membrane fuel cell power plant is designed to operate on reformate produced from upgraded biogas by steam reformer.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.327-330
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• 2002

A plant growth-promoting substance, FM001, was isolated from the culture broth of Acremonium strictum MJN1. The purification steps included solvent extraction, adsorption chromatography using Diaion HP20, TLC on silica, and HLPC using a C-18 column. The purified FM001 enhanced rice seedling growth by $11.1\%\;and\;34.0\%$ of the dried weight of the shoots and roots, and also radish growth by $26.5\%\;and\;23.7\%$ of the top length and dried weight. FM001 also significantly promoted the growth of red pepper by increasing $32.7\%$ of fruit weight and $11.3\%$ as regards the height. FM001 consisted of C, H, O, N, and S, and its molecular weight was determined to be 537.78 Da. The structure of FM001 resembled brassinosteriods, and it would appear to have great potential as an effective bio-fertilizer.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.47-48
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• 2011

The effect of solution acidity and organic additives, polyethylene glycol (PEG), on the trivalent chromium electroplating was systematically investigated in the view point of solution stability, electroreduction of trivalent chromium ions and characterization of deposition layer. It was found that, the concentration of fraction chromium complexes in the trivalent chromium bath containing formic acid is strongly depended on pH value. PEG molecules were stable in trivalent chromium bath containing formic acid via studies on electrospray ionization mass spectrometry (ESI-MS) and UV-Vis. However, the presence of PEG molecules decreased the reductive current of hydrogen evolution, increasing of current efficiency higher about 10 % compared with solutions without PEG. Moreover, PEG additives developed the nodular morphology during electroreduction of trivalent chromium ions with the increase of solution acidity and enhanced its current efficiency by maintaining the consumption of complexant, formic acid, at a low speed. In this study, the effect of solution acidity was emphasized important, there, it controlled the formation of complexes in the solution, cathodic film (CF) during deposition, and properties of deposited layer. By electrochemical quartz crystal microbalance (EQCM), studies show that chromium electrodeposition occurs via the formation of intermediate complexes and adsorption on the cathode surface, which hinder the penetration of ions from bulk solution to the cathode surface.

• Textile Coloration and Finishing
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• v.12 no.6
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• pp.344-352
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• 2000

Two kinds of nylon 6 fabrics with different fiber denier, such as ultramicro fiber(UMF) nonwoven fabric(monodenier 0.05d) and regular fabric(monodenier 2.92d) are dyed with C.I. Acid Red 18(leveling type) and C.I. Acid Blue 113(milling type). Dyeing rates and adsorption isotherms are measured at $60^\circ{C}$, pH 5.0 and at liquor ratio of 1 : 250. To investigate the effect of fixing agents (Matexil FA-SNX, Monorex-RD and Tinofix-ECO) on UMF nylon 6 nonwoven fabric, dyeing is carried out at 3~10% owf with 1 : 2 metal-complex acid dyes, such as Kayalax Navy R(unsulphonated type), Lanasyn Blue S-BL(monosulphonated type) and Kayakalan Black BGL(disulphonated type). The dyeing rate of UMF nylon 6 is faster than that of regular nylon 6. From the results of absorption isotherms, the regular nylon 6 has higher saturation value of Acid Red 18 compared with UMF nylon 6, whereas UMF nylon 6 has higher saturation value of the acid Blue 113. From the absorption isotherms of both acid dyes, the regular nylon 6 has higher saturation value of Acid Red 18, whereas UMF nylon 6 has higher saturation value of the acid Blue 113. The wash fastnesses of UMF nylon 6 increases in the order of metal-complek dye containing nonsulphonated group > monosulphonated group>disulphonated group. Aftertreatment of UMF nylon 6 dyed with unsulponated and monosulphonated dyes improves wash fastness upto grade 1.5, where as that of UMF nylon 6 dyes with disulphonated dye does not improve wash fastness.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.1
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• pp.71-77
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• 2005

Recycling of reclaimed concrete (RC) is very important in the management of construction and demolition wastes. Most of RC is utilized for land-filling after crushing in this country. In this study, a series of elution experiments were conducted to investigate the type and amount of pollutants released from the crushed RC. Most water quality parameters including heavy metals and some organic compounds were below standards for drinking water. Some of heavy metals such as As, Cd, Pb, Hg were detected in 0.5 N H2S04 solution after 24-hour immersing RC, which was conducted for evaluating a long term release effect. The concentration of the heavy metals were higher than the drinking water standards. The results also showed significant adsorption of heavy metals by crushed Re. Potential risks, based on the result of this study were not high in using crushed RC for land-filling. Appropriate management of RC would reduce the risk, for example the separation of hazardous materials from construction wastes. Long term evaluations for the sites of land filled with RC would be required to assess the environmental impacts.

• Transactions of Materials Processing
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• v.29 no.6
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• pp.323-330
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• 2020

The surface region of a sheet metal may have different characteristics from the inner region because the surface region is less restricted than the interior. In addition, the grains on the free surface are less hardened because of surface adsorption of the dislocations, rather than piling up. In the case of bulk or thick sheet metals, this effect is negligible because the fraction of the surface region is much smaller than that of the inner region. However, this surface effect is important in the case of ultra-thin sheet metals. In order to evaluate the surface effect, tensile and bending tests were performed for the SS304 stainless steel with a thickness of 0.39 mm. The bending force predicted using the tensile behavior is higher than the measurement because of the surface effect. To account for the surface effect, the surface layer model was developed by dividing the sheet section into surface and inner layers. The mechanical behaviors of the two regions were calibrated using the tensile and bending properties. The surface layer model reproduced the bending behavior of the ultra-thin sheet metal.

• Korean Journal of Materials Research
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• v.25 no.3
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• pp.144-148
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• 2015

Cubic mesocrystal $CeO_2$ was synthesized via a hydrothermal method with glutamic acid ($C_5H_9NO_4$) as a template. The XRD pattern of a calcined sample shows the face-centered cubic fluorite structure of ceria. Transmission electron microscopy (TEM) and the selected-area electron diffraction (SAED) pattern revealed that the submicron cubic mesocrystals were composed of many small crystals attached to each other with the same orientation. The UV-visible adsorption spectrum exhibited the red-shift phenomenon of mesocrystal $CeO_2$ compared to commercial $CeO_2$ particles; thus, the prepared materials show tremendous potential to degrade organic dyes under visible light illumination. With a concentration of a rhodamine B solution of 20 mg/L and a catalyst amount of 0.1 g/L, the reaction showed higher photocatalytic performance following irradiation with a xenon lamp (${\geq}380nm$). The decoloring rate can exceed 100% after 300 min.

• Textile Coloration and Finishing
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• v.31 no.3
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• pp.127-134
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• 2019

Cotton fabrics were treated with gelatin to improved their dyeability, color strength toward cochineal dye. Gelatin were used as the protein. Gelatin is containing a large number of hydrophilic groups. Pad-dry-cure method was used for the treatment process(10g/L concentration). The scanning electron micrograph showed the gelatin was deposited on the surface of cotton. Pretreated fabrics were mordanted with 10%(owf) alum. Then the fabrics were dyed with cochineal. Compared with original cotton fabric the K/S value with cochineal dyes was significantly improved on gelatin modified cotton. Treating cotton with 10g/L concentration gelatin offered higher cochineal adsorption. The dyeability of pH 4 yielded the highest color strength. In dyebaths of a ratio of ethanol and water such as; 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9, 0:10, fabrics were dyed. The ratio of ethanol and water had powerful effects on solution polarity. Cochineal dye uptake showed maximum value, when the proportion of ethanol and water was 9:1. Dyeing at increased temperatures and with increased time resulted in higher dye uptake and reddish-purple color(5RP). The washing fastness was 1-2grade, and the fastness to light was 2-3grade.