• Corrosion Science and Technology
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• 제16권4호
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• pp.187-193
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• 2017

Polymer amines are found to show distinct corrosion inhibition effects in acidic media. The functional groups of organic compounds have a wide role in the physical and chemical properties, for the inhibition efficiency with respect to steric factors, aromaticity, and electron density. The influence of $H^+$ ions and $Cl^-$ ions on the corrosion inhibitive effect of poly(p-aminophenol) for iron in hydrochloric acid was studied using electrochemical methods such as impedance, linear polarization, and Tafel polarization techniques. The experiments were conducted with and without the inhibitor, poly(p-aminophenol). The concentration range of $H^+$ ions and $Cl^-$ ions are from 1 M to 0.05 M and 1 M to 0.1 M, respectively. With the inhibitor poly(p-aminophenol), this study shows that inhibition efficiency decreases with the reduction of $H^+$ ion and $Cl^-$ ion concentrations in aqueous solution. Further, it reveals that the adsorption of an inhibitor on the surface of iron is dependent on the concentrations of $H^+$ and $Cl^-$ ions in the solution and the adsorption of inhibitor on the iron surface through the cationic form of amine.

• Advances in materials Research
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• 제6권4호
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• pp.329-341
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• 2017

The challenge of replacing conventional plastics with biodegradable composite materials has attracted much attention in product design, particularly in the tensile-related areas of application. In this study, fibres extracted from oil palm empty fruit bunch (EFB) were treated and utilized in reinforcing polyester matrix by hand lay-up technique. The effect of fibre loading and combined influence of alkali and silane treatments on porosity and water absorption parameters, and its correlation with the tensile behaviour of composites was analyzed. The results showed that tensile strength decreased whilst modulus of elasticity, water absorption and porosity parameters increased with increasing fibre loading. The composites of treated oil palm EFB fibre exhibited improved values of 2.47 MPa to 3.78 MPa for tensile strength; 1.75 MPa to 2.04 MPa for modulus of elasticity; 3.43% to 1.68% for porosity and 3.51% to 3.12% for water absorption at respective 10 wt.% fibre loadings. A correlation between porosity and water absorption with tensile behavior of composites of oil palm EFB fibre and positive effect of fibre treatment was established, which clearly demonstrate a connection between processing and physical properties with tensile behavior of fibre composites. Accordingly, a further exploitation of economic significance of oil palm EFB fibres composites in areas of low-to-medium tensile strength application is inferred.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.657-662
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• 2012

Mercaptoacetic acid (MAA) and mercaptopropionic acid (MPA) capped ZnS:Mn nanocrystals were synthesized and their physical characteristics were examined by XRD, HR-TEM, EDXS, and FT-IR spectroscopy. The optical properties of the MPA capped ZnS:Mn nanocrystals dispersed in aqueous solution were also measured by UV/Vis and solution photoluminescence (PL) spectra, which showed a broad emission peak around 598 nm (orange light emissions) with calculated relative PL efficiency of 5.2%. Comparative toxicity evaluation of the uncoordinated ligands, MAA and MPA, with the corresponding ZnS:Mn nanocrystals revealed that the original ligands significantly suppressed the growth of wild type E. coli whereas the ligandcapped nanocrystals did not show significant toxic effects. The reduced cytotoxicity of the conjugated ZnS:Mn nanocrystals was also observed in NIH/3T3 mouse embryonic fibroblasts. These results imply that potential toxicities of the capping ligands can be neutralized on ZnS:Mn surface.

• 분석과학
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• 제12권2호
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• pp.166-170
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• 1999

A ceramic floor with improved thermal conductivity and efficiency has been developed in this study. The new ceramic floor minimizes the shrinkage rate to below 0.07% and shows almost no cleavage. There is no need to repaire the ceramic floor because its bottom surface is flat. It especially shows an excellent perfomance in the test of a compressive strength ($300kg/cm^2$ based on 28 days), a flexural strength ($64kg/cm^2$ based on 28 days), and a convenient pressing. It is lighter than the present floor and it is expected to be applicable for a self-leveling ceramic motar in the residences and apartments. It shows an excellent character in the thermal conductivity and other physical properties compare to the present cement mortar.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권3호
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• pp.58-64
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• 2013

This study proposed a low temperature hydrothermal carbonization to treat and recycle sewage sludge and determined the optimal conditions for the biochar production. The physical and chemical properties of biochar were analyzed and its sorption capacity for heavy metals was evaluated. To produce biochar, 50 g of sewage sludge was heated at 220, 230, and $240^{\circ}C$ for 1, 2, 3, 5, 8, and 10 hours in a reactor. The optimal conditions to produce biochar was $230^{\circ}C$ and 8 hours. Sorption capacity tests were conducted for arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn) and nickel (Ni). Among them, lead was shown the highest heavy metal adsorption efficiency of biochar, followed by copper, cadmium, zinc, and nickel, but arsenic was hardly adsorbed overall.

• Membrane and Water Treatment
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• 제8권5호
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• pp.483-498
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• 2017

Novel mixed matrix membranes of Sodium Alginate (NaAlg) were developed by the incorporation ofunmodified, modified Phosphomolybdic acid (PMA) then cross-linked with glutaraldehyde externally. These membranes were prepared by the solution casting technique. Pervaporation (PV) experiments have been performed with pure NaAlg, unmodified NaAlg-PMA5, NaAlg-PMA10, modified NaAlg-mPMA5, and NaAlg-mPMA10 (wt. % of PMA 5 and 10) at 30, 40 and $50^{\circ}C$, to separate water-isopropanol feed mixtures containing 10-30 wt. % of water. Pervaporation results of NaAlg-mPMA10 produced a highest separation factor of 9028 with a flux of $0.269kg/m^2.h$ for 10 wt. % of water containing feed mixture. Both separation factor and flux for water increased significantly with increasing content of mPMA into NaAlg; a significant improvement in PV performance was observed for NaAlg-mPMA5 and NaAlg-mPMA10 membranes when compared to pure NaAlg& PMA-5, PMA-10 membrane.

• Food Science and Biotechnology
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• 제18권2호
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• pp.374-378
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• 2009

Three physical methods, photostimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance (ESR), have been applied to detect the irradiation treatment for the non- and steamed sesame seed samples. PSL successfully screened the irradiated samples from the non-irradiated control by comparing their photon counts (PCs) with the lower (less than 700 count/60 sec) and upper threshold values (higher than 5,000 count/60 sec). TL signals were still detected in all irradiated samples even after steaming, which was reconfirmed with TL ratios [integrated area of $TL_1$ (the first glow)/$TL_2$ (the second glow)] through re-irradiation step. ESR spectrometry showed that radiation-induced cellulose radicals were detected in all the irradiated samples irrespective of steaming treatment. Identification of the irradiated sesame seeds was possible even after steaming by analyzing PSL, TL, and ESR.

• 한국응용과학기술학회지
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• 제14권3호
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• pp.71-77
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• 1997

Low foaming acidic degreasing agent(LFADAs) were prepared by blending sorbitol, n-octanoic acid, MJU-100A, Tetronix T-701, Na-dioctyl sulfosuccinate, Demol C, and phosphoric acid. The physical properties of LFADAs tested with aluminum specimen showed the following results ; when 3wt% LFADA-6 was performed at $70^{\circ}C$, the degreasing rate was 95% which is comparitively good, and the percentage of etching was 0.275% which was found to be less than that of commercialized product. When 20wt% of LFADA-6 was added at $65^{\circ}C$, the percentage of derusting was 92% and the good defoaming effect proved by following low foaming power tests respectively : Ross and Miles, and Ross and Clark methods.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.415-423
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• 2011

HI decomposition step certainly demand catalytic reaction for efficient production of hydrogen in SI process. Platinum catalyst can apply to HI decomposition reaction as well as hydrogenation or dehydrogenation. Generally, noble metal is used as catalyst which is loaded form for getting high dispersion and wide active area. In this study, Pt was loaded onto zirconia, ceria, alumina, and silica by impregnation method. HI decomposition reaction was carried out under the condition of $450^{\circ}C$, 1atm, and $167.76h^{-1}$ (WHSV) in a fixed bed reactor for measuring catalytic activity. And property of a catalyst was observed by BET, TEM, XRD and chemisoption analysis. On the basis of experimental results, we discussed about conversion of HI according to physical properties of the loaded Pt catalyst onto each support.

• 한국응용과학기술학회지
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• 제12권2호
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• pp.51-58
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• 1995

To prepare a durable softening water repellent, quaternized octadecyl methacrylate-2-diethyl-aminoethyl methacrylate as a mother resin and quaternized 1, 3-dioctadecyl-2, 7-dioxy-6, 8-di(2-hydroxyethyl)-1, 3, 6, 8-tetraazacyclodecane which increase the softening effect and the hydrostatic pressure blended with waxes and their emulsifier in various proportions to give water repellent PADWC. As the results of the measurement of water repellency, washable, tear strength and crease recovery to polyestercotton(P/C) blended fabrics treated with PADWC only or addition of textile finishing resin, the physical properties were increased. There was no significant lowering effect in water repellency when PADWC was treated the antistatic agent by the one-bath method, and the effect of water repellency by the adding the catalyst was studied. PADWC was confirmed as durable water repellent with the results of making little difference of water repellency as ${\pm}5$ point after and before washing.