• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.307-311
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• 2003

The test did for the determine the optimized ratio of cation to anion in mixed ion exchange demineralizers. Binary, ternary, quaternary, and quinary cation and anion adsorption was performed to develop a comprehensive experimental data set from small-volume batch tests to obtain the selectivity coefficients of many cations and anions. The quantitative run time might be estimated by such ion exchange models as semi-empirical mass action and surface complexation models. The demineralizer can be used longer by increasing the ratios of cation to anion exchange resins in the bed.

• Journal of Environmental Science International
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• v.15 no.11
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• pp.1027-1034
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• 2006

Antimicrobial powder was made by exchanging silver ion on calcined oyster shell. On the purpose of application to water clarifier, bail-type media mixed with antimicrobial powder and $0{\sim}30%$ white kaoline were made. The sterilization effect, pore size distribution and zeta potential was tested to indicate the condition for the media of water clarifier. From these tests, it was confirmed that this media have an excellent sterilization power on $G^-\;and\;G^+$ germs. As the concentration of the exchanged silver ion increased, the surface charge density of the anions on the surface of the media also increased. The surface pore size decreased with the concentration of silver ion and 20% more white kaoline ratio. Consequently, mixing ratio of white kaoline would appear to indicate the optimun condition as media have sterilization power.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.373-384
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• 2006

Spent ion-exchanged resin generated from various purification systems in CANDU reactor was contaminated with high activity of $^{14}C$ radionuclide. This paper describes the results of fundamental study to develop the applicable technology for the treatment of this spent resin. Based on the adsorption capacity of inactive $HCO_3$ ion and other anions on IRN-150 mixed resin, the removal characteristics of $HCO_3$ ion adsorbed on to IRN-150 by various stripping solutions were evaluated. Maximum adsorption amount of the $HCO_3$ ion onto IRN-150 raw resin was about 11 mg-C/g-resin which agrees with the theoretical adsorption amount of this resin. Adsorption affinity of various anions such as $CS,\;CO,\;Na\;NH_4$ was analyzed in single and multi-component systems. From the results of removal characteristics of the $HCO_3$ ion adsorbed on IRN-150 by various stripping solutions, $NH_4H_2PO_4$ stripping solution is more effective than $NaNO_3,\;Na_3PO_3$ solutions for the complete removal of $^{14}C$ radionuclide from the IRN-150 spent resin.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.847-856
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• 2014

Spent resin waste containing a high concentration of $^{14}C$ radionuclide cannot be disposed of directly. A fundamental study on selective $^{14}C$ stripping, especially from the IRN-150 mixed bed resin, was carried out. In single ion-exchange equilibrium isotherm experiments, the ion adsorption capacity of the fresh resin for non-radioactive $HCO_3{^-}$ ion, as the chemical form of $^{14}C$, was evaluated as 11mg-C/g-resin. Adsorption affinity of anions to the resin was derived in order of $NO_3{^-}$ > $HCO_3{^-}{\geq}H_2PO_4{^-}$. Thus the competitive adsorption affinity of $NO_3{^-}$ ion in binary systems appeared far higher than that of $HCO_3{^-}$ or $H_2PO_4{^-}$, and the selective desorption of $HCO_3{^-}$ from the resin was very effective. On one hand, the affinity of $Co^{2+}$ and $Cs^+$ for the resin remained relatively higher than that of other cations in the same stripping solution. Desorption of $Cs^+$ was minimized when the summation of the metal ions in the spent resin and the other cations in solution was near saturation and the pH value was maintained above 4.5. Among the various solutions tested, from the view-point of the simple second waste process, $NH_4H_2PO_4$ solution was preferable for the stripping of $^{14}C$ from the spent resin.

• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.13-20
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• 1994

Substituted anthrasemiquinone radical anions, which were formed by laser flash photoreduction of the substituted anthraquinone (1,4-DHAQ, 1,5-DHAQ, 1,8-DHAQ, 1,8-DCAQ), were studied by the electron spin resonance spectroscopy in the mixed solvents of the 2-propanol and the triethylamine. Hyperfine splitting constants (hfsc) were determined by simulating the ESR spectra. Extended Huckel Molecular Orbital (EHMO) calculations were performed to obtain $\pi$ spin densities for these quinones. The hyperfine splitting constants could be assigned to specific protons on the basis of $\pi$ spin densities.

• Herbal Formula Science
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• v.22 no.2
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• pp.87-103
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• 2014

Objectives : Herbal formulas are complicated to analyze and difficult to compose because of its mixed, complex features. So we discussed about how to compose herbal formulas effective and efficient by analyzing various effectiveness of each herbal extracts. Methods : To evaluate the effectiveness of herbal formula, anti-oxidative and anti-inflammatory effectiveness were mathematically analyzed. DPPH, superoxide anions, Nitric Oxide scavenging activity was measured to evaluate the effectiveness of 7 herbal extracts. And next, cytotoxic activity of extracts on RAW 264.7 cells were measured using MTS assay. To asses anti-inflammatory effect, nitric oxide and $PGE_2$ production were measured. Based on these anti-oxidative and anti-inflammatory experiment result, mathematical analyzation were carried out with constOptm function, and determined efficacy-maximizing ratio. Results : This mathematical analysis based formula showed significantly outstanding effectiveness than other formulae. And estimated tendency of anti-inflammatory effectiveness was matched with real effectiveness. Conclusions : So, mathematical analysis can be available to evaluate and estimate the effectiveness of herbal formulae.

• The Korean Journal of Ceramics
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• v.5 no.2
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• pp.142-147
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• 1999

The interaction between commercial $Si_3N_4$ powder and two types of additives (nitrate and oxide additives) during the sintering of $Si_3N_4$ was investigated. The nitrates solution or oxide particles were added as a sintering additives. The surface of mixed powder was observed with FT-IR, TG, and HREM. DTA was used to characterize the reactivity of the powders. The formation of crystalline phases and phase transformation were analyzed by XRD. The adsorption of the additives on the surface of silicon nitride was confirmed in the nitrate salts. It was shown that the adsorption occurred by interaction between the amorphous $SiO_2$ layer on the $Si_3N_4$ surface and metal cations $(Al^{3++\; and \;Y^{3+})$ and anions $(NO_3\;^-\; or\; OH^-)$, resulting in a higher degree of homogeneous distribution of additives.

• Korean Journal of Materials Research
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• v.22 no.12
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• pp.643-649
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• 2012

Coatings composited with alumina and Perfluoro alkoxyalkane (PFA) resin were deposited on stainless steel plate (SUS304) to further improve corrosion resistance. Plate (ca. $10{\mu}m$) and/or nanosize (27~43 nm) alumina used as inorganic additives were mixed in PFA resin to make alumina-fluoro composite coatings. These coatings were deposited on SUS304 plate with wet spray coating and then the film was cured thermally. According to the amount and ratio of the two kinds of alumina having plate morphology and nano size, corrosion resistance of the film was evaluated under strong acids (HF, HCl) and a strong base (NaOH). The film prepared with the addition of 5~10 wt% alumina powders in PFA resin showed corrosion resistance superior to that of pure PFA resin film. However, for the film prepared with alumina content above 10 wt%, the corrosion resistance did not improve with the physical properties, such as surface hardness and adhesion. The film prepared with plate/nanosize (weight ratio = 1/2) alumina especially enhanced the surface hardness and corrosion resistance. This can be explained as showing that the plate and the nanosize alumina dispersed in PFA resin effectively suppressed the penetration of cations and anions due to the long penetration length and fewer defects that accompany the improved surface hardness under a serious environment of 10% HF solution for over 120 hrs.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.5
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• pp.523-533
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• 2011

This study had the aim of characteristics of $PM_{10}$ in subway cabins. $PM_{10}$ was measured by times of day (rush and non rush hours) and seasons with real time $PM_{10}$ sampler on the subway cabins of line 7. Filter samples were collected for evaluation of their elemental composition as well as identification of major sources of $PM_{10}$ using a receptor model, PMF. $PM_{10}$ concentration were the highest in the winter season both in the rush and non rush hours at 152.8 ${\mu}g/m^3$, 90.2 ${\mu}g/m^3$ respectively. The $PM_{10}$ concentrations in rush hour were 30% higher compared to non rush hours. Based on the chemical information, the composition rare of inorganic elements was 52.5%, anions were 10.2% and others were 37.3%. Fe was the most abundant element and significantly correlated (p.0.01) with Mn (r=0.97), Ti (r=0.91), Cr (r=0.88), Ni (r=0.89) and Cu (r=0.88). Characterized $PM_{10}$ sources by PMF in the cabin were soil and road dust related sources (27.2%), railroad related sources (47.5%), secondary nitrate sources (16.2%) and a Cl-factor mixed with a secondary sulfate source (9.1%).

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.3
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• pp.178-187
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• 1982

This pot experiment was undertaken to find out the optimum fertilization ratios of total anions to total cations, ${\Sigma}A/{\Sigma}C$, and the optimum application rates of total macro-nutrients in various soil conditions. Soil samples were collected from uncultivated mountains and hills where grassland development was under consideration. 1. The optimum application ratios of ${\Sigma}A/{\Sigma}C$ and the optimum application rates of total macro-nutrients for the high yields of mixed grass-clover sward in various grassland soils were computed by the Hom$\acute{e}$s systematic variation techniqu.e. 2. With respect to the optimum application ratios of ${\Sigma}A/{\Sigma}C$ in fertilization in a mixed grass-clover sward, the grass yield and botanical composition were distinctly proportional to ${\Sigma}A$ wheras the regume yield and botanical composition were proportional to ${\Sigma}C$. 3. The optimum fertilization rates of total macro-nutrients for the high legume yields were depended upon ${\Sigma}A/{\Sigma}C$ ratios. These optimum rates were in proportional to ${\Sigma}C$ ratios and were inversely proportional to ${\Sigma}A$ ratios. 4. The efficiencies of ${\Sigma}A$ and ${\Sigma}C$ in relation to the grass and grass plus legume yields were highest with the low ratios of each other and the low fertilization rates of total macronutrients. The ${\Sigma}A$ effieiency in the legume yield tended to be similar to that of ${\Sigma}A$ related to the grass yield noted above except Daegu soil. The ${\Sigma}C$ efficiency, however, was proportional to the ${\Sigma}C$ ratio, although that was varied with the fertilization rates of total macro-nutrients and with the kinds of soils. 5. The yield of mixed forages, yield component, and botanical composition in a mixed sward were greatly influenced by the ${\Sigma}A/{\Sigma}C$ ratios, the fertilization rates of total macronutrients, and the interactions of ratio and rate noted above. In addition, these effects were generally different and opposite according to grass and legume.