• KSBB Journal
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• v.10 no.5
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• pp.491-498
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• 1995

In order to fraclionate ${\alpha}$-, ${\beta}$- and ${\gamma}$-cyclodextrins(CDs) from CD reaction mixture, various CD adsorbents were manufactured using fatty acids as the ligand molecules and anion exchange resins as matrix. Among several anion exchange resins, DEAE Cellulose was found to be the most suitable matrix for binding fatty acid. The binding stability between DEAE Cellulose and capric acid was tested under the various operation conditions, such as temperature, ethanol concentration, and ionic strength. Specific CD adsorbents manufactured with different chain-length fatty acids, saturated and unsaturated, were compared in terms of the recovery yield and selectivity of ${\alpha}$-, ${\beta}$- and ${\gamma}$-CDs. Stearic acid (C18, saturated) was identified as the most effective ligand for fractionation of ${\alpha}$-CD, and linoleic acid ((C18, unsaturated ) for ${\beta}$-CD. The spacer length between the matrix and ligand was required for effective adsorption of CDs, and the double bond in fatty acid molecules was also acted as an important factor determining recovery yield and selectivity. The elusion patterns of ${\alpha}$- and ${\alpha}$-, ${\beta}$-CD from column packed with stearic acid and linoleic acid CD adsorbents were also investigated at the various elusion conditions for fractionation of ${\alpha}$- and ${\beta}$-CD.

• Resources Recycling
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• v.27 no.4
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• pp.29-35
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• 2018

In this study, the electrochemical redox behavior of neodymium in non-aqueous electrolytes was investigated to confirm the possibility of neodymium metallurgy at room temperature. The non-aqueous electrolytes include ionic liquids such as $[C_4mim]PF_6$, $[C_4mim]Cl$, and $[P_{66614}]PF_6$, ethanol which are highly soluble in neodymium salts, and mixed electrolytes based on carbonate with highly electrochemical stability. The electrochemical redox properties of neodymium were better than those of other electrolytes in the case of the mixed electrolyte based on ethylene carbonate (EC)/di-ethylene carbonate (DEC). Ethanol was added to improve the physical properties of the mixed electrolyte. Thorough the analysis about ionic conductivity of EC/DEC ratio, ethanol content and $NdCl_3$ concentration, the best electrolyte composition was 50 vol% content of ethanol and 0.5 M of $NdCl_3$. Using cyclic voltametry and linear sweep voltametry, a current peak estimated at -3.8 V (vs. Pt-QRE) was observed as a limiting current of neodymium reduction. Potentiostatic electrolysis for 18 hours at room temperature at -6 V (vs. Pt-QRE) confirmed that metallic neodymium was electrodeposited.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.223-229
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• 1986

These studies were investigated ionic balance of leaves from different stalk positions of tobacco plant (cv. NC82) grown on pots supplied with nitrate salts solution in the phytotrone. The results of studies are summerized as follows: 1. In comparision with the leaves along the stalk positions, lower position contained higher proportion of total cation and total anion including organic acid, but their concentration lessened gradually at the upper stalk. The ratio in amounts of inorganic cations and anions in leaf laminae depended on their stalk positon, being more than three times in the fifth, but becoming about 1.3 in the tenth. 2. Inorganic cations in the laminae were mostly $K^+$, $Ca^{{+}{+}}$, and $Mg^{{+}{+}}$, comprising about 80% of total with the first two regardless of their stalk positions. Among these two ions $Ca^{{+}{+}}$ tended to become higher at lower stalks, while $K^+$ was higher in younger and became lower when leaves got older and/or more number of leaves were emerged. 3. Total cations were balanced with inorganic and organic acid anions. Composition of inorganic and organic anions were different along stalk positions, ionic balance was governed by organic acid anions dominantly in older leaves, but by inorganic anions in the younger leaves. 4. The discrepancy in the balance between total cations and anions was more pronounced in the older leaves containing higher amount of cations and organic acids. It was suggested that discrepancy was due to precipitation of oxalate as Ca-salt which was not dissolved in the methylation solution of measurement employed.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.236-247
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• 1996

The main objective of this study was to evaluate the effectiveness of nutrient solutions, substrates, and nutrient solution concentrations in substrate culture of radish(Raphanus sativus L. var. sativus). Cooper's, Hoagland ＆ Arnon' 5, and Yamazaki's solution were used to determine the most suitable nutrient solution in deep flow culture(DFC). In result, Yamazaki's solution treatment showed better results than Hoagland's and Cooper's solution treatments in leaf length, leaf number, shoot and root fresh weights. Cooper's solution was much worse than others. Root shape index were low as 0.6 in all treatments. The selection of suitable was conducted among 14 kinds of substrates which were used commercially, such as sand, perlite and peatmoss, in substrates culture. Sand was the most proper in radish growth and shortened the growth periods. Sand also showed better results then others in leaf length, leaf number, shoot and root fresh weight. On the contrary, radish growth in peatmoss was the worst. Generally, root shape index was higher in substrate than in DFC. In order to investigate the suitable ionic strength in radish, Yamazaki's solution was treated with EC of 0.5, 1.0, 1.5, and 2.0 mS/cm. Generally radish growth above 1.0 mS/cm concentration was good, and the best result was shown in 1.5 mS/cm. Vitamin C contents were not significantly different in the roots of radish grown under 1.0 mS/cm or more. The highest vitamin C content was shown in 0.5 mS/cm, and so was thiocyanate content. Anthocyanin contents increased with the increase of the ionic strength in nutrient solution. Mineral nutrient contents had no significant statistical differences between the treatments, but potassium content was remarkably high in 1.5 mS/cm.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.94-101
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• 2023

Zinc oxide(ZnO) is a semiconductor material with a bandgap of 3.37 eV and an exciton binding energy of 60 meV for various applications. Recently ZnO has been proven to enhance its electrical properties for utilization as an alternative for transparent conducting oxide (TCO) materials. In this study, cation(Al, Ga)-anion(F) single and double doped ZnO thin films were grown by atomic layer deposition (ALD) to enhance the electrical properties. The structural and optical properties of doped ZnO thin films were analyzed, and doping effects were confirmed to electrical characteristics. In single doped ZnO, it was observed that the carrier concentration was increased after doping, acting as a donor to ZnO. Among the single doping elements, F doped ZnO(FZO) showed the highest mobility and conductivity due to the passivation effect of oxygen vacancies. In the case of double doping, higher electrical characteristics were observed compared to single doping. Among the samples, Al-F doped ZnO(AFZO) exhibited the lowest resistance value. This results can be attributed to an increase in delocalized electron states and a decrease in lattice distortion resulting from the differences in ionic radius. The partial density of states(PDOS) was also analyzed and observed to be consistent with the experimental results.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.839-846
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• 2006

This study was conducted to evaluate the effects of dietary addition of sucrose, propylene glycol and Tween 80 (Polysorbate 80 : Non-ionic Surfactants) on pre-partum (21 d) and post-partum (21 d) nutrients intake, blood metabolites, occurrence of metabolic disorders, milk yield and its composition in Holstein cows. Two basal diets were formulated each for pre- and post-partum period. The diets were mixed daily and fed at ad libitum to transitional cows. Forty cows of similar parity and milk yield were randomly divided into four groups (ten animals in each). The cows in three groups were supplemented either with 280g of sucrose/day (SU), SU+64g propylene glycol/day (SUP) or SUP+50g Tween80/day (SUPT). The feed for the fourth group was not supplemented and this group served as control (C). Pre-partum DM, total digestible nutrients (TDN), and crude protein (CP) intake was similar in cows fed C, SU, SUP, and SUPT diets. Post-partum DM, TDN, and CP intakes were the highest with SUPT diet followed by SU, SUP and control diets. Pre-partum blood non-esterified fatty acids (NEFA) concentration was noticed significantly higher in cows fed control diet compared to those fed SU, SUP and SUPT diets. The concentration of NEFA was similar at calving and during post-partum period across cows fed different experimental diets. Blood glucose and Ca concentration during pre- and post-partum periods were not significantly different in cows fed C, SU, SUP and SUPT diets. Milk yield (kg/day) was similar in cows fed different experimental diets. However, milk fat percent and 4% fat corrected milk yield were higher in cows fed SU diet (p<0.05) followed by SUP, SUPT and C diets. One case of ketosis was recorded in cows fed control diet however its occurrence was not observed in cows fed other diets. Occurrence of retained placenta and mastitis was numerically higher in cows fed control diet compared with those fed SU, SUP and SUPT diets. In conclusion, the NIS and propylene glycol feeding along with sucrose could improve the 4% fat corrected milk and fat yield in early lactating cows with significant reduction in NEFA and metabolic disorders during transitional period.

• Journal of Life Science
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• v.24 no.11
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• pp.1252-1257
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• 2014

While dimethyl sulfoxide (DMSO) is the most commonly used cryoprotectant agent in the cryopreservation of cultured mammalian cells, it has been reported to cause differentiation of some cell lines by DNA methylation and associated histone modifications. To avoid the side effects of DMSO in cryopreservation, other agents might be more appropriate for maintaining the stable differentiation of cultured cell phenotypes through cryopreservation. All cryoprotectants should be highly soluble in water and display low cell toxicity. Cryoprotective agents have been shown to be effective in animal sperm preservation, and eight types of amides were examined in the cryopreservation of cultured mouse endothelial cells. Among the amides examined, acetamide and lactamide were effective cryoprotectants for cultured mammalian cells. The most effective concentration of lactamide, 1.5 M, had an even lower cryoprotective ability than 1M DMSO. Because successful cryopreservation of cultured cells is hampered by osmotic stress, the adequate ionic concentration was determined by diluting phosphate-buffered saline (PBS) in the 1.5M lactamide solution. The most effective concentration was $0.4{\times}PBS$, which minimized osmotic stress during the cryopreservation of cultured cells. As the addition of high molecular weight materials in cryopreservation media improves the viability of cells, the effects of bovine serum albumin (BSA), hydroxyethyl-starch (HES), and dextran were examined. The best combination of lactamide-based media for cryopreservation was found to be 1.5 M lactamide in $0.4{\times}PBS$ with 1% BSA.

• Clean Technology
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• v.11 no.1
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• pp.1-12
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• 2005

In these studies, semibatch emulsion copolymerization of n-butyl acrylate (n-BA) as adhesive component and methyl metacrylate (MMA) as coagulant component was carried out in order to investigate the role of surfactant in aqueous phase for polymer cement. It was found that the particle size and concentration of final polymer are affected by surfactant type used. The effect of nonionic surfactants was shown in the decrease of polymer emulsion concentration and small emulsion particle in order of LE-50, NP-50 > CE-50, Tween 20 > TX-405 > Brij 35. In LE and NP (n=7-50) as nonionic surfactant, it could be obtained the stable polymer emulsion of 40% in aqueous phase with average particle size of 250-320 nm using over n=30. On the other hand, the effect of surfactant type in initial reactor charge was shown that when SDS as ionic surfactant was used, the polymer emulsion concentration was constant irrespective of the amount used, whereas CTAB as cationic surfactant and HN-100 as reactive surfactant were shown a tendency to the decrease of that. The effect surfactant type on final polymer particle size was shown in decrease by the order of SDS > CTAB > HN-100.

• KSBB Journal
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• v.11 no.5
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• pp.606-612
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• 1996

A specific ammino auid in a mixture can be crystallized inside an ion exchange column when displacer concentration is high enough to concentrate the amino acid in a pure band beyond its solubility limit. Glutamic acid formpd a discrete crystal layer in a cation exchanger column by operating displacement development mode and using a high concentration of displacer NaOH. The glutamic acid crystal formed was eluded from the column with the effluent stream and collected in a fraction collector. When 1.0 M of NaOH was used as a displacer, more than 60% of the loaded glutamic acid was recovered as crystal. The continuous crystallization and dissolution of crystal occurred, resulting in apparent movement of the crystal along the column without clogging or pressure increase. NaOH was proved a better displacer than NaCl because hydroxide ions neutralized hydrogen ions released from the resin and thus reduced the number of hydrogen ion competing with sodium ion for re-adsorption. The displacement development process coupled with crystallization provided higher concentration and recovery of glutamic acrid than conventional chromatography.

• Membrane Journal
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• v.18 no.3
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• pp.234-240
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• 2008

This work demonstrates the preparation of proton conducting crosslinked polymer electrolyte membranes by blending polystrene-b-poly(hydroxyethyl acrylate) (PS-b-PHEA) and poly(vinyl alcohol) (PVA) at 1 : 1 wt ratio. The PHEA block of the diblock copolymer was crosslinked with PVA using sulfosuccinic acid (SA) via the esterification reaction between -OH of membrane and -COOH of SA, as confirmed by FT-IR spectroscopy. Ion exchange capacity (IEC) continuously increased from 0.14 to 0.91 meq/g with increasing concentrations of SA, due to the increasing portion of charged groups in the membrane. In contrast, the water uptake increased up to 20.0 wt% of SA concentration above which it decreased monotonically. The membrane also exhibited a maximum proton conductivity of 0.024 S/cm at 20.0 wt% of SA concentration. The maximum behavior of water uptake and proton conductivity is considered to be due to competitive effect between the increase of ionic sites and the crosslinking reaction according to the SA concentration.