• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.526-532
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• 2000

Cation exchange separation and inductively coupled plasma atomic emission spectrometric(ICP-AES) determination of ruthenium in HCl solutions were studied to quantitatively determine ruthenium in spent nuclear fuels. Ruthenium-bearing samples were dissolved with the mixed acid solution(9 : 1 mole ratio, HCl-HNO$_3$) using an acid digestion bomb. Based on the absorption spectra and ion exchange behaviour of ruthenium in hydrochloric acid media, its possible chemical species were discussed. On a cation exchange column (0.7 ${\times}$ 8.0 cm) packed with AG 50W ${\times}$ 8(100~200 mesh) and equilibrated with 0.5 M HCl, ruthenium was eluated with 0.5 M HCl while uranium was retained on the column. The established separation method was applied to a simulated spent nuclear fuel and resulted in the recovery of 98.5% with a relative standard deviation of 0.7%.

• Polymer(Korea)
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• v.32 no.6
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• pp.509-515
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• 2008

The aminated polypropylene melt blown ion exchange fibers were synthesized with acrylic acid monomer onto polypropylene melt blown fibers by radiation-induced polymerization and subsequent amination. Degree of grafting was increased with increasing the acrylic acid monomer concentration and total dose. The highest degree of grafting was obtained 140% at a monomer concentration of 20 v/v% acrylic acid and total dose of 4 kGy. Optimum condition of Mohr's salt was 5.0 $\times10^{-3}$ M. Degree of amination was increased with increasing degree of grafting. Water content was about 1.5 times higher than that of trunk polymer. The maximum ion-exchange capacity was 7.3 meq/g which was 2$\sim$3 times higher than a commercial ion exchange fiber. The average pore size was decreased and BET surface area was increased in order of PPmb, PPmb- g- AAc and APPmb- g- AAc. The average pore size and BET surface area of synthesised fibers were $366.1\;{\AA},\;3.71m^2/g,\;143.3\;{\AA},\;4.94m^2/g,\;40.97\;{\AA},\;8.98m^2/g$, respectively.

• Ocean and Polar Research
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• v.31 no.2
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• pp.189-198
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• 2009

Passive air samplers with polyurethane foam (PUF) disks were employed to determine seasonal gas phase variation of polycyclic aromatic hydrocarbons (PAHs) in ambient air on Anmyeon island from March 2007 to January 2008. Sum of 13 PAHs ranged between $3.5\;ng/m^3$ and $27.6\;ng/m^3$. Total PAHs during the heating season was 6.2 times higher than non-heating season. The dominant PAHs components during sampling periods were low and middle molecular weight PAHs including phenanthrene, fluoranthene, pyrene and chrysene. Gas exchange fluxes of PAHs across the air-water interface of the Yellow Sea were calculated using a modified two-film exchange model. PAHs fluxes ranged from $196\;ng/m^2/d$ net volatilization during summer to $3830\;ng/m^2/d$ net absorption during winter. Passive air sampler provides a convenient and cost-effective tool for measuring averaged gas phase PAHs, which was successfully used for calculation of gas exchange flux of PAHs in the Yellow Sea.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.407-416
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• 1996

${\ulcorner}$Ilbonseogi${\lrcorner}$(edited A.D. 720) )was studied to investagate the medical and pharmaceutical exchange among ancient Korea, China and Japan. It seemed that Korean and Chinese traditional medicine was introduced to Japan through Korea. It was also shown in ${\ulcorner}$Ilbonseogi${\lrcorner}$ that Koreans who lived in china and Japan during that time seemed to hove active medical idea exchange. From various facts indicated in ${\ulcorner}$Ilbonseogi${\lrcorner}$, it was believed that Korean and Chinese traditional medicine was the basis for the foundation of Japanese traditional medicine.

• Korean Journal of Materials Research
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• v.27 no.3
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• pp.161-165
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• 2017

In this paper, synthesis of terephthalate intercalated Zn-Al: Layered double hydroxides (LDHs) was studied. We designed freestanding Zn-Al: carbonate LDH nanosheets for a facile exchange technique. The as-prepared Zn-Al carbonate LDHs were converted to terephthalate intercalated Zn-Al:LDHs by ion exchange method. Initially, Al-doped ZnO (AZO) thin films were deposited on p-Si (001) by facing target sputtering. For synthesis of free standing carbonate Zn-Al:LDH, we dipped the AZO thin film in naturally carbonated water for 3 hours. Further, Zn-Al: carbonate LDH nanosheets were immersed in terepthalic acid (TA) solution. The ion exchange phenomena in the terephthalate assisted Zn-Al:LDH were confirmed using FT-IR analysis. The crystal structure of terephthalate intercalated Zn-Al:LDH was investigated by XRD pattern analysis with different mole concentrations of TA solution and reaction times. The optimal conditions for intercalation of terephthalate from carbonated Zn-Al LDH were established using 0.3 M aqueous solution of TA for 24 hours.

• Membrane Journal
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• v.31 no.4
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• pp.275-281
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• 2021

To evaluate the possibility as a separator in alkaline water electrolysis, the thermal stability, ion conductivity and durability of 5 commercially available anion exchange membranes were tested. The thermal stability of FAAM-PK-75 and FAAM-40 membrane analyzed by thermo-gravimetric analysis (TGA) showed good performance compared to the other three types of AEM, AHO, and AHA membrane. The ion conductivity of AEM membrane measured in 7 M KOH solution at 25℃ and 80℃ had a higher value of about 4~17 times compared to the other membranes. The durability of FAAM-PK-75 tested in 7 M KOH solution at 25℃ was high compared to the other membranes.

• Journal of Hydrogen and New Energy
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• v.33 no.4
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• pp.330-336
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• 2022

In order to evaluate the possibility as a separator in alkaline water electrolysis, the high temperature characteristics were evaluated by measuring the membrane resistance and durability of 5 types of commercial anion exchange membranes in 7 M KOH solution and at 80℃. The membrane resistance of AEM membrane measured in 7 M KOH solution and at 80℃ had a lower value of about 8-24 times compared to the other membranes. The durability of AEM membrane tested with the soaking time in 7 M KOH solution and at 80℃ showed a very good stability and that of FAAM40 and FAAM75-PK showed secondly a good stability. The thermal stability with the soaking time in 7 M KOH solution and at 80℃ of FAAM40 and FAAM75-PK membrane analyzed by thermo-gravimetric analysis showed a good stability compared to the other membranes.

• Korean Journal of Community Nutrition
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• v.17 no.6
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• pp.689-706
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• 2012

The purpose of this study was to evaluate effects of a nutrition education focused on Food Exchange System for the higher grades elementary children. Nutrition education lessons (40 min/lesson, 4 times), '5 major nutrients and functions', '6 food groups', 'daily needed energy and food exchange units', 'good choice of snacks and balanced exercise' were provided to elementary students (5th grade students). This research was based on the data from two groups of elementary school children in the 'education' group (n = 31) and 'non-education' group (n = 31). We assessed the changes in dietary attitude, food habit and nutrition knowledge using questionnaire and nutrient intake using 24hr recall method by nutrition education using the developed pamphlet. After education, there was a significant difference in the dietary attitude score only in attitude of 'balanced meal' (p < 0.001) in the education group compared to the non-education group. In food habit, there were significant positive changes in the type of breakfast and in the priority of choosing snack in the educated group. In nutrition knowledge, there were significant increases in scores of 'function of carbohydrate' (p < 0.05), 'function of fat' (p < 0.01), 'function of vitamin' (p < 0.01), 'foods of carbohydrate' (p < 0.01), and 'foods of vitamin' (p < 0.01) in the educated group. After education, carbohydrate: protein: fat (CPF) ratio was significantly different between the two groups (education group, 59 : 16 : 26 vs. non-education group, 63 : 15 : 23). In evaluation of nutrient intake by Dietary Reference Intakes for Koreans (KDRIs), there were significant positive effects in energy (p < 0.05), thiamin (p < 0.05), riboflavin (p < 0.05), vitamin C (p < 0.05), phosphorus (p < 0.01), Fe (p < 0.01) and zinc (p < 0.01) in the education group compared to the non-education group. In conclusion, the developed 4 times' nutritional education pamphlet focused on individual daily energy requirements and food exchange units using food exchange system for higher grades' elementary student may positively change nutrition knowledge and dietary intakes.

• Korean Journal of Community Nutrition
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• v.13 no.6
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• pp.922-933
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• 2008

The purpose of this study was to investigate the effects of nutrition education using Food Exchange System on elementary students' nutrition knowledge, dietary attitude and nutrients intake. Nutrition education lessons (40 min /lesson, 4 times), '5 major nutrients and functions', '6 food groups and sources of 6 food groups', 'good choice of snacks and eating out' as class lesson, 'daily needed energy and food exchange units' as individual lesson, were provided to 70 elementary students (4th grade 33 students, 5th grade 37 students) in Jeonbuk Province. We assessed the changes in nutrition knowledge, dietary attitude, food habit using a questionnaire and nutrient intake using 24 hr recall method by nutrition education. In nutrition knowledge, there were significant increases in scores of 'functions of carbohydrate', 'functions of protein', 'functions of lipid', 'foods of carbohydrate', and 'foods of lipid'. In dietary attitude, there were significant increases in scores of 'taking a meal with joy', 'taking a meal at ease', 'taking a meal with sufficient protein intake' and 'taking a meal without spicy foods' by nutrition education. There were significant changes in the type of breakfast and in the frequency of snacks. After education, in type of breakfast, it showed higher number of students ate rice oriented meal than they did before education. and in frequency of snacks, it showed lower number of students ate snacks 'over 3 times' than they did before education. In Carbohydrate : Protein : Fat (CPF) ratio (%), it was significantly changed from 55.8 : 17.7 : 26.6 to 63.6 : 15.3 : 21.1. In evaluation of nutrient intake by Dietary Reference Intakes for Koreans (KDRIs), vitamin A, thiamin, niacin, vitamin $B_6$, calcium, phosphate, iron and zinc showed positive changes in distribution of number of children by intake level. That is, there were significant improvements in intakes of vitamin A, thiamin, niacin, vitamin $B_6$, calcium, phosphate, iron and zinc. These results showed that nutrition education using Food Exchange System for elementary students improved nutrition knowledge, dietary attitude and nutrients intake. It suggest that nutrition education using Food Exchange System may improve dietary behaviors and reduce an incidence of obesity in elementary students.

• Journal of Adhesion and Interface
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• v.15 no.1
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• pp.1-8
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• 2014

Ion exchange membrane is widely used in various fields such as electro dialysis, diffusion dialysis, redox flow battery, fuel cell. PVC cation exchange membrane using ultrasonic modification was prepared by sulfonation reaction in various sulfonation times. Sulfuric acid was used as a sulfonating agent with ultrasonic condition. We've characterized basic structure of sulfonated PVC cation exchange membrane by FT-IR, EDX, water uptake, ion exchange capacity (IEC), electrical resistance (ER), conductivity, ion transport number and surface morphology (SEM). The presence of sulfonic groups in the sulfonated PVC cation exchange membrane was confirmed by FT-IR. The maximum values of water uptake, IEC, electrical resistance and ion transport number were 40.2%, 0.87 meq/g, $35.2{\Omega}{\cdot}cm^2$ and 0.88, respectively.