• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.248-261
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• 2021

The purpose of this study is that the blood nutrient indicator in adult women, is the depressive indicator. This study recruited 77 pre-menopausal women, and excluding missing values, 53 (mean age 44.2±6.5 years) blood indexes were statistically confirmed and then analyzed the effect of indexes on the Beck Depression Inventory. The Beck's Depression Inventory(BDI)'s average of the study subjects was 7.6±7.2, and most of the depression symptoms were within the normal range. Only two women were very serious and other two women were serious state. As a result of this study, 21 questions of BDI was classified into 5 sub-factors. Of these, 2 factors were considered physical depression, 1 factor was mood depression, 1 factor was cognitive depression, and 1 factor undecided. As a result of the correlation analysis, triglyceride, LDL(low density lipoprotein) cholesterol and potassium showed statistically significant positive relationship with depressive factors. On the other hand, HDL(high density lipoprotein) cholesterol, sodium and chloride ions showed negative relationship with depressive factors. When multiple regression analysis was performed. Considering the depression factors was dependent variable, and triglyceride, cholesterol, blood sugar, and ketone bodies was considered as independent variables. HDL(high density lipoprotein) cholesterol had a statistically significant negative effect on the depression factor 3. Considering the depression factors was dependent variable, and minerals were considered as independent variables. Potassium had a positive effect, and chloride ions had a negative effect on the depressive factor 3. This study was limited to 77 pre-menopausal women. In the future, post-menopausal women, men, and clinical neurological disorders group will be possible.

• Resources Recycling
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• v.32 no.1
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• pp.21-32
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• 2023

Because the application of lithium has gradually increased for the production of lithium ion batteries (LIBs), more research studies about recycling using solvent extraction (SX) should focus on Li⁺ recovery from the waste solution obtained after the removal of the valuable metals nickel, cobalt and manganese (NCM). The raffinate obtained after the removal of NCM metal contains lithium ions and other impurities such as Na ions. In this study, we optimized a selective SX system using di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant and tri-n-butyl phosphate (TBP) as a modifier in kerosene for the recovery of lithium from a waste solution containing lithium and a high concentration of sodium (Li⁺ = 0.5 ~ 1 wt%, Na⁺ = 3 ~6.5 wt%). The extraction of lithium was tested in different solvent compositions and the most effective extraction occurred in the solution composed of 20% D2EHPA + 20% TBP + and 60% kerosene. In this SX system with added NaOH for saponification, more than 95% lithium was selectively extracted in four extraction steps using an organic to aqueous ratio of 5:1 and an equilibrium pH of 4 ~ 4.5. Additionally, most of the Na⁺ (92% by weight) remained in the raffinate. The extracted lithium is stripped using 8 wt% HCl to yield pure lithium chloride with negligible Na content. The lithium chloride is subsequently treated with high purity ammonium bicarbonate to afford lithium carbonate powder. Finally the lithium carbonate is washed with an adequate amount of water to remove trace amounts of sodium resulting in highly pure lithium carbonate powder (purity > 99.2%).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.2
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• pp.63-71
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• 2011

A large volume of uranium electrokinetic leachate has been generated during the electrokinetic decontamination to remove uranium from contaminated soil. The treatment technology for the reuse of the uranium leachate was developed. The concentration of uranium in the generated uranium leachate was 180 ppm and concentrations of Mg(II), K(I), Fe(II), and Al(III) ions ranged from 20 ppm to 1,210 ppm. The treatment process for uranium leachate consisted mainly of mixing and cohesion, precipitation, concentration, and filtration. In order to obtain the pH=11 of a precipitate solution, the calcium hydroxide needs to be 3.0g/100ml and the sodium hydroxide needed to be 2.7g/100ml. The results of several precipitation experiments showed that a mixture of NaOH+0.2g alum+0.15g magnetite was an optimal precipitant for filtration. The average particle size of precipitate with NaOH+alum+0.15g magnetite was $600\;{\mu}m$. Because the total value of metal concentrations in supernatant at pH=9 was the smallest, sodium hydroxide should be added with 0.2g alum and 0.15g magnetite for pH=9 of leachate.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.15-19
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• 1973

A method was developed for the separation of titanium, niobium and zirconium together in a group from the coexisting ions of various metals such as iron, cobalt, nickel, yttrium and rare earths by means of the cation exchange column using ${\alpha}$-hydroxyisobutyric acid as the eluent. In the course of the present investigation, it was found that the tailing phenomena of zirconium were attributable to the hydroxide precipitation which was made prior to the elution. For example, if zirconium was precipitated by sodium hydroxide, the tailing of zirconium became very serious in contrast to the results reported by others. This paper describes how these tailing phenomena of zirconium were prevented and how a practical procedure for the separation of these ions was, achieved using ion-exchange method. Using the present method the nuclides of $^{90m}Y$ and $^{90}Y$ were separated with radiochemical purity from the irradiated zirconium.

• Journal of the Korean Ceramic Society
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• v.53 no.3
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• pp.282-287
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• 2016

This study involves enhancing the performance of the $Na(Li,Ti)O_2$ system as an Na-ion battery anode with the addition of Mg, which partially replaces Li ions. We perform both computational and experimental approaches to achieve a higher reversible capacity and a faster transport of Na ions for the devised system. Computational results indicate that the $Na(Li,Mg,Ti)O_2$ system can provide a lower-barrier path for Na-ion diffusion than can a system without the addition of Mg. Experimentally, we synthesize various $Na_z(Li_y,Mg_x,Ti)O_2$ systems and evaluate their electrochemical characteristics. In agreement with the theoretical study, Mg addition to such systems improves general cell performance. For example, the prepared $Na_{0.646}(Li_{0.207}Mg_{0.013}Ti_{0.78})O_2$ system displays an increase in reversible capacity of 8.5% and in rate performance of 13.5%, compared to those characteristics of a system without the addition of Mg. Computational results indicate that these improvements can be attributed to the slight widening of the Na-$O_6$ layer in the presence of Mg in the $(Li,Ti)O_6$ layer.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.3
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• pp.75-86
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• 1991

Ion exchange strengthening is a chemical process whereby large alkali ions(such as potassium) are substituted for smaller ions(sodium) within the surfaces of glasses and ceramics, thereby reducing the thermal expansion coefficient of this surface region, and creating beneficial state of compressive stress within the near surface region. The purpose of this study was to determine the effects of ion exchange and etching treatments on the strength of some dental porcelains. Two feldspathic dental porcelains(Vitadur-N, G-Cera) were used in this study. A commercial ion exchange paste and etching gel containing 8% hydrofluoric acid were used for surface conditioning. Transverse strength was measured using a universal testing machine and the technique of EPMA(electron probe micro analysis) was used to access the potassium contents. The results were as follows: 1. Improvement in strength was only obtained by treating the surface placed in tension. 2. No changes in the dimensions of the treated specimens were detected when samples were measured with a micrometer. 3. There was significant increase in transverse strength of G-Cera IV group treated with etching and ion exchange, compared with G-Cera II group only treated with ion exchange. 4. From the results of EPMA test, increase in potassium contents was observed on the surface treated with ion exchange paste.

• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.35-41
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• 2006

This paper analyzed elution and ingredients of soil components which consist of soil and rocks in 6 regions in Yeongyang and Cheongsong to identify substantial matters that cause muddy water in Imha reservoir. We identified that more than 80% of major ingredients in collected soil and rocks are vermiculite(V), illite(I), kaolinite(Ka), quartz(Q), feldspar(F). Sodium and calcium are eluted in large quantities from soil of Sanseong and Cheongki. When calcium is in contact with water, much ions are eluted rapidly. We confirmed these ions are alkali minerals rising pH. We consider clay components distributed in Yeongyang as major cause of muddy water and rising pH of Imha reservoir because its ingredient calcite easily is dissolved in rainwater and splits other mineral particles into ${\mu}m$ sized particles.

• Microbiology and Biotechnology Letters
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• v.10 no.1
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• pp.1-7
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• 1982

A Rhizopus sp. was selected for its strong cellulolytic activity among various strains of molds found in rotting ginseng roots. Studies were made on some properties of the cellyloiytic enzyme produced by the strain. The results obtained were summarized as follows: The optimum pH of the enzyme was 4.5 and the range of its stability to the pH was 3.0 to 7.0. The optimum temperature was 5$0^{\circ}C$, while the enzyme was instantly inactivated above 6$0^{\circ}C$. Mn$^{＋＋}$ and Co$^{＋＋}$ ions increased enzyme activity and the metal ions were found to increased the ther-mostability of the enzyme. This enzyme was inhibited by sodium dodecyl sulfate and 2,4-dinitrophenol. This enzyme had a strong cellulolytic enzyme activity on various native cellulose given a sufficient reaction time. The addition of 0.5% saponin solution into reaction mixture increased the enzyme activity.

• Journal of Microbiology and Biotechnology
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• v.20 no.7
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• pp.1069-1076
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• 2010

A novel laccase from Tricholoma mongolicum was purified by using a procedure that entailed ion-exchange chromatographies on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and FPLC-gel filtration on Superdex 75. The purified enzyme was obtained with a specific activity of 1,480 U/mg-protein and a final yield of 15%. It was found to be a monomeric protein with a molecular mass of 66 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its N-terminal amino acid sequence was GIGPVADLYVGNRIL, similar to some but also different to other mushroom laccases. The optimum pH and temperature for the purified enzyme were pH 2 to pH 3 and $30^{\circ}C$, respectively. It displayed a low $K_m$ toward 2,7-azinobis (3-ethylbenzothiazolone-6-sulfonic acid) diammonium salt (ABTS) and high $k_{cat}/K_m$ values. The purified laccase oxidized a wide range of lignin-related phenols, but exerted maximal activity on ABTS. It was significantly inhibited by $Hg^{2+}$ ions, and remarkably stimulated by $Cu^{2+}$ ions. It inhibited HIV-1 reverse transcriptase and proliferation of hepatoma HepG2 cells and breast cancer MCF7 cells with an $IC_{50}$ of 0.65 ${\mu}M$, 1.4 ${\mu}M$, and 4.2 ${\mu}M$, respectively, indicating that it is also an antipathogenic protein.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.14-19
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• 2009

To obtain the basic data on reclaimed tideland soils, 90 soil samples were collected from 9 tideland reclamation project areas in Korea. The soils consisted of clay (2.0 to 35.0 percents), silt (2.0 to 80.0 percents), and sand (8.0 to 95.0 percents), and were dominantly classified sandy loam and silty loam. The soils had pH of 4.5 to 9.1, organic matter of 0.50 to $19.20g\;kg^{-1}$, total nitrogen of 4 to $1,159mg\;kg^{-1}$, and avaliable phosphorus (as $P2_O_5$) of 3.5 to $147.7mg\;kg^{-1}$. The electrical conductivity in soil saturation-paste extracts (ECe) ranged between $0.62dS\;m^{-1}$ and $31.60dS\;m^{-1}$ and the concentrations of sodium and magnesium ions were higher than those of potassium and calcium ions. The magnitude of the ECe was as low as that of normal level in Nam-Po, Pu-Sa, and Kye-Hwa reclamation project areas having sandy loam texture, but was as high as that of normal level saline-sodic level in Nam-Yang and So-Po reclamation project areas having silty loam texture even though the soils were cultivated more than 10 years as a paddy. Some part of Saemangeum area was surveyed and soil textures were various; some were silt loam and some were sandy loam. The ECe values were very high in topsoil and subsoil.