• Journal of Magnetics
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• 제11권2호
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• pp.98-102
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• 2006

It was examined in this study that magnetic beads, which are assumed to be environmentally functional, could be effective in processing heavy metals that are water pollutants. For the purpose, magnetic beads containing carboxyl groups, which has strong binding force with heavy metals, are mixed with each Cd, Pb, Ni, Cu and Cr(III) solution, then stirred in pH 6. As a results of the process, it was proven that heavy metals bind quickly with magnetic beads through the reaction. In order to analyze heavy metal concentration, magnetic beads bind with heavy metal were collected by external magnetic force and dissolved in acid. The graphite furnace AAS was used to get heavy metal concentration melted in the acid solution. The results showed that heavy metal extractions by magnetic beads were influenced by the type and the concentration of a heavy metal, and over 90% of a heavy metal can be extracted in ppm level save for Cr(III). It was also examined in the study whether heavy metal extraction is influenced when other ions exist in each heavy metal solution. According to experiment, adding other heavy metals to a solution did have little influence on extracting an intended heavy metal. But in case salt or heavy metal chelate was added, Ni extraction changed sensitively although extracting other heavy metals were influenced only when the concentration of an added substance is high. In conclusion, it was shown that magnetic beads could be used to treat wastewater with relatively high heavy metal concentration.

• 한국산업융합학회 논문집
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• 제4권1호
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• pp.61-69
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• 2001

Polycarbonate(PC) membranes for oxygen enrichment from air were prepared by the wet phase inversion method. In order to improve oxygen separation performances of the PC membrane, the effect of the added ethanol(nonsolvent) and $CuCl_2$(metal salt) concentration in the casting solution on morphology, oxygen permeability ami $O_2/N_2$ separation factor of the membrane was studied. In addition, tensile strength and elongation at break of the membrane were investigated. An asymmetric membrane with a dense top layer and a porous sublayer was obtained. The thickness of the dense top layer decreased with increasing amount of nonsolvent additive. Compared with pure PC membrane without additive(metal salt), the oxygen permeability and $O_2/N_2$ separation factor of the $PC/CuCl_2$ membrane are significantly improved. The oxygen permeability and $O_2/N_2$ separation factor is $5.25{\times}10^{-9}cm^3(STP){\cdot}cm/cm^2{\cdot}sec{\cdot}cmHg$ and 4.5, respectively. This improvement might be due to good interaction between metal salt and oxygen.

• 한국세라믹학회지
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• 제32권10호
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• pp.1147-1161
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• 1995

When ceramic membrance was made from metal salt solution in place of metal akoxide solution, crack free and good adhesion to supporter was optimized for sol stability and good adhesion force. A starting sol was prepared from aluminum oxychloride aqueous solutjion in order to inhibit the grain growthof Al2O3 during heat treatment. The crack free dip coating can't be achieved in 1mol/ι zirconium oxychloride solution because of the high viscosity which interferes with the hydration copolymerization between Al3+ ion and Zr4+ ion. Thus Al2O3-ZrO2 sol stability and viscosity for dip coating was effective when 0.01 mol/ι zirconium oxychloride was added. The minimizing of crack and achieving better adhesion to the supporter wa obtained by microwave drying, surfactant addition and ultrasonic dip coating in wet atmosphere. The result seems to minimize the capillary force and improve the adhesive ability to supporter during the process. Where the average pore size of Al2O3-ZrO2 ultrafilter ceramic membrane measured 17 Å by the BET method and observed γ-Al2O3 phase with tetragonal zirconia after firing at 700℃.

• 한국분말재료학회지
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• 제19권6호
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• pp.393-397
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• 2012

$AgNO_3$ has the characteristic is controlling the inhibition or promotion of particle growth by adsorbing onto specific facets of platinum nanoparticles. Therefore, in this study, $AgNO_3$ was added to control the shape of platinum nanoparticles during the liquid phase reduction process. Consequently, platinum cubes were synthesized when $AgNO_3$ of 1.1 mol% (with respect to the Pt concentration) was added into the solution. Platinum octahedrons were synthesized when 32 mol% (with respect to the Pt concentration) was added into the solution. These results demonstrate that the metal salt $AgNO_3$, effectively controlled the relative growth rates of each facet of Pt nano particles.

• 공업화학
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• 제10권1호
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• pp.173-176
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• 1999

초임계수를 이용한 금속산화물의 미세입자 제조에 대하여 연구하였다. 금속염 수용액으로는 cobalt nitrate solution과 manganese nitrate solution을 sample solution으로 선택하여 코발트산화물과 망간산화물 입자를 제조하였다. 얻어진 결과로부터 초임계수를 이용한 금속산화물 미세입자의 제조가 가능함을 확인할 수 있었으며, 초임계수 하에서는 매우 빠른 dehydration반응이 일어남을 관찰할 수 있었다. 짧은 반응시간(30~100 초)에도 불구하고 미세입자 ($0.5{\sim}2{\mu}m$)가 생성되었으며, 초임계수 공정에서는 mixer의 온도가 입자의 크기 및 분포에 큰 영향을 미침을 알 수 있었다. 반응온도 조절을 통하여 입자의 크기를 제어할 수 있음을 확인할 수 있었다.

• 한국식품영양학회지
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• 제22권2호
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• pp.238-245
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• 2009

The principal objective of this study was to investigate the association of variable salts with the hardness of cubed white radish. We analyzed the contents of domestic sun-dried salt, Chinese sun-dried salt, domestic refined salt, Australian rock salt and Australian industrial sun-dried salt in the radish samples. Our assessment of the water content of variable salts showed that domestic refined salt was highest(7.27%) and Australian rock salt was lowest(0.16%). The NaCl contents of variable salts were as follows : 93.23% in refined salt, 93.76% in Australian rock salt, 87.85% in domestic Shinan sun-dried salt and 87.98% in Chinese sun-dried salt. The content of insoluble matter in water were $0.03{\sim}0.05%$ in all salts except 0.85% in Australian industrial sun-dried salt. The pH values of salts were as follows : 8.93 in domestic sun-dried salt, 8.62 in Chinese sun-dried salt, 6.69 in refined salt, 5.83 in Australian rock salt and 6.41 in Australian industrial sun-dried salt. Regarding the mineral component content assays, domestic salt was found to harbor lower Na content but far higher Mg, K, Ca contents than other salts. In our evaluation of the hardness of cubed white radish, we detected a continuous increase in the hardness of cubed white radish soaking in a 4% salt solution of domestic Shinan natural salt, but an initial increase followed by a decrease in the hardness of cubed white radish soaking in a 4% solution of the other salts.

• 한국표면공학회지
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• 제25권2호
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• pp.66-72
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• 1992

Magnetite film on iron surface could be coated in strongly alkaline solution (12M NaH\OH) which contained additives such as NaHCO3, KCl and NaNO2, Iron plate was immersed in boiling solution ($130^{\circ}C$) contained above mentioned additives for 1 hour. There are some microcracks and these cracks proved to be the sites for the initiation of corrosion when immersed in 3% NaCl solution. To improve corrosion resistance of the coated steel plate, chromating was done as a post treatment. Chromate film was formed on magnetite oxide film potentiostatically at-918mV/SCE for five minutes at temperature of $70^{\circ}C$ in the alkaline solution containing 5g/l Na2Cr2O7.2H2O.Cr3O4 was electrodeposited on magnetite oxide film and Cr2O3 was electrodeposited on iron surface which was assumed as surface revealed due to microcracks. Increased corrosion resistance of chromated magnetite oxide film was proved in salt spray test & immersion test.

• 약학회지
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• 제47권6호
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• pp.356-360
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• 2003

Nitroso-2-naphthol-3,6-disulfonic acid, disodium salt (NRS) was used as an organic ligand to prepare basic drug-selective polymeric membrane electrode. The sensing membrane of the electrode consited of basic drug-meta1(II)-NRS as an ion-exchanger site in a poly(vinyl chloride) matrix plasticized with 2-nitrophenyl octyl ether (NPOE). The metal ions used were Fe$^{2+}$, Co$^{2+}$, Ni$^{2+}$ and Cu$^{2+}$. The electrodes exhibited fast and wide linear response in the basic drug concentration of 10$^{-5}$ ∼10$^{-3}$ mol/l with a response slope of 50∼60 mV/decade in a buffer solution of pH 4∼8. The electrodes exhibited good selectivity for many basic compounds.mpounds.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권3호
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• pp.23-29
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• 2003

Setschenow constants of six alkali and alkaline earth metal-based electrolytes (i.e., NaCl, KCl, CaCl$_2$, K$_2$SO$_4$, Na$_2$SO$_4$, NaClO$_4$) for three polycyclic aromatic hydrocarbons (PAHs) (i.e., naphthalene, pyrene, and perylene) were investigated to evaluate the influence of a variety of inorganic salts on the aqueous solubility of PAHs. Inorganic salts showed a wide range of K$\_$s/ values (L/mol), ranging from 0.1108 (NaClO$_4$) to 0.6680 (Na$_2$SO$_4$) for naphthalene, 0.1071 (NaClO$_4$) to 0.7355 (Na$_2$SO$_4$) for pyrene, and 0.1526 (NaClO$_4$) to 0.8136 (Na$_2$SO$_4$) for perylene. In general, the salting out effect of metal cations decreased in the order of Ca$\^$2+/>Na$\^$+/>K$\^$+/. The effect of SO$_4$$\^$2-/>Cl$\^$-/>ClO4$\^$-/ was observed for anions of inorganic salts. The K$\_$s/ values decreased in the order of perylene>pyrene>naphthalene for K$_2$SO$_4$. However, the order of decreasing salting out effect for NaCl, KCl, CaCl$_2$, and NaClO$_4$ was perylene>naphthalene>pyrene. Hydration free energy of the 1:1 and 2:1 alkali and alkaline earth metal-based inorganic salts solution was observed to have a meaningful correlation with Setschenow constants. Thermodynamic interactions between PAH molecules and salt solution can be of importance in determining the magnitude of salting out effect for PAHs at a given salt solution.

• Korean Membrane Journal
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• 제5권1호
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• pp.61-67
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• 2003

Various characteristics of ion transport properties of a charged mosaic membrane with a parallel array of positive and negative functional charges were investigated, From the analysis of the volume flux, it was found that the salt flux based on nonequilibrium thermodynamics, preferential salt transport across the charged mosaic membrane. Transport properties of the magnesium sulfate(MgSO$_4$) and sucrose across the charged mosaic membrane were estimated. As a result, metal salts transport depended largely on the charged states and molecular weight otherwise nonelectrolyte solution was rejected under all experimental conditions. On the other hand, the reflection coefficient s indicated the negative value that suggested preferential material transport and was independent of charged mosaic thickness.