• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.266-271
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• 2005

This paper studied succinic acid recovery from organic acid mixture by using mono-polar membrane electrodialysis. Current efficiency, solute recovery efficiency, energy consumption, and separation factor were measured at various pHs and concentration ratios. The separation factor of succinic acid could be interpreted in terms of ionization degree, molecular weight, ionic conductance, average charge, and initial feed composition.

• Animal cells and systems
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• v.2 no.4
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• pp.455-462
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• 1998

A survey was conducted on the inorganic and organic solute patterns of plants in connection with nitrate metabolism according to different light regimes (1.9, 16.0, 91.5 $Wm^{-2}$). Besides measuring in vivo NRA, we also quantitatively analyzed ater-soluble inorganic ions, organic acids, low molecular weight carbohydrates, amino aciss and total N (% DW). Among 4 Carex species, C. pilosa is known as shade-adapted species and the others as half (C. gracilis) to full (C. rostrata & C. distans) light-adapted species. Compared to species adapted to high light intensity, shade-adapted C. pilosa showed reduced productivity under the highest light intensity. In general, nitrate and amino acid levels decreased at higher light intensity, while sugar and organic acid concentrations increased. In C. pilosa osmolality tended to rise with increasing light intensity, while in the other species it tended to fall. Under low light intensity, the drop in soluble carbohydrate contents is osmotically compensated for by an enhanced nitrate concentration. It is concluded that competition between nitrate and $CO_2$reduction for reductants and ATP from photosynthesis may have important ecological consequences for the adaptation of plants to low or high light conditions. Additionally, the patterns of ionic changes due to increased light intensities were essentially the same in all selected species, indicating similar characteristics of heir mineral ion and organic acid metabolism as well as in field-grown Carex species.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.96-101
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• 2005

A theory for the material transports through ion exchange membrane has been developed on the basis of nonequilibrium thermodynamics by removing the assumption of solvent flow in the previous paper and applied to a detailed study of the ionic transport properties of new charged mosaic membrane(CMM) system. The CMM having two different fixed charges in the polymer membrane indicated unique selective transport behavior then ion-exchange membrane. The separation behavior of ion transport across the CMM with a parallel array of positive and negative functional charges were investigated. It was well-known the analysis of the volume flux and solute flux based on nonequilibrium thermodynamics. Our suggests preferential salt transport across the charged mosaic membranes. Transport properties of heavy metal ions, $Mg^{2+}$, $Mn^{2+}$and sucrose system across the charged mosaic membrane were estimated. As a result, we were known metal salts transport depended largely on the CMM. The reflection coefficient indicated the negative value that suggested preferential material transport and was independent of charged mosaic membrane thickness.

• Journal of the Korean Chemical Society
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• v.18 no.1
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• pp.58-65
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• 1974

The relation between the concentration of concentrated solution, the quantity of electromigrated solute/electricity and the increasing volume of concentrated solution/the quantity of electromigrated ion to the concentration of solution and the applied current density in the electrodyalisis using ion exchange membranes are studied. It is found that the experimental results on the above mentioned quantities can be understood by the ionic concentration in the membrane phase, the mobility of electrolytes and the flux of electro-osmosis.

• Journal of Ecology and Environment
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• v.30 no.2
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• pp.187-193
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• 2007

Higher plants can be categorized as C3, C4 or CAM according to their photosynthetic pathways, and some succulent plants are known to shift their patterns of photosynthesis from C3 to CAM in response to environmental stresses such as salt treatment or water deficiency. To investigate fundamental photosynthetic patterns and the induction of pattern shifts (C3, CAM, C3-CAM etc.) as a result of environmental stresses, we measured the water content, diurnal changes in pH, net $CO_2$ exchange, transpiration rate, total ionic contents, and osmolality of Kalancoe daigremontiana, Sedum kamschaticum and Sedum sarmentosum which belong to Crassulaceae known as representative CAM plant, after 10 days of drought treatment. S. kamschaticum and S. sarmentosum did not show a significant difference in diurnal pH variation in the treatment and control conditions. However, the pH of drought-treated Kalancoe was low at night and high in the daytime, with a pH value between 4 and 5. Typical CAM plants display a net $CO_2$ exchange that increases at night and decreases in the daytime. Kalancoe displayed the predicted pattern. However, S. kamschaticum and S. sarmentosum showed a photosynthetic pattern more typical of C3 plants, and did not show changes in photosynthetic pattern under drought stress. Kalancoe also showed a transpiration rate typical for CAM pho-tosynthesis, whereas the transpiration rates of S. kamschaticum and S. sarmentosum were in the typical range for C3 photosynthesis. Kalancoe had high total ionic contents during the night, which decreased somewhat during the daytime, whereas S. kamschaticum and S. sarmentosum displayed the opposite pattern. This result is similar to the diurnal patterns of changes in pH in the three plant species, which suggests a relationship between pH and ionic contents. S. sarmentosum showed lower osmolality under drought stress than in the control condition, whereas the osmolality of Kalancoe and S. kamschaticum did not differ between conditions. S. sarmentosum may have maintained internal water content by lowering its osmolality and raising its total ionic contents. In conclusion, Kalancoe displayed the characteristic responses of a typical CAM plant, whereas S. kamschaticum and S. sarmentosum displayed aspects of the C3 photosynthetic pattern under drought conditions. These results suggest that S. kamschaticum and S. sarmentosum (Crassulacea) in Korea overcome drought stress by increasing solute and ionic contents internally rather than changing their photosynthetic pattern from C3 to CAM under drought stress.

• Journal of Ecology and Environment
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• v.37 no.3
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• pp.131-137
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• 2014

To investigate the solute pattern of salt marsh plants in Suncheon Bay in Korea, plants and soil samples were collected at three sites from July to September 2011. The soil pH around the investigated species was weakly alkaline, 6.9-8.1. The total ion and Cl- content of site 1 gradually increased, while those of site 2 and site 3 were lowest in August and highest in September. The exchangeable $Ca^{2+}$, $Mg^{2+}$ and $K^+$ in the soil were relatively constant during the study period, but the soil exchangeable $Na^+$ content was variable. Carex scabrifolia and Phragmites communis had constant leaf water content and very high concentrations of soluble carbohydrates during the study period. However, Suaeda malacosperma and S. japonica had high leaf water content and constant very low soluble carbohydrate concentrations. Carex scabrifolia accumulated similar amounts of $Na^+$ and $K^+$ ions in its leaves. Phragmites communis contained a high concentration of $K^+$ ions. Suada japonica and S. malacosperma had more $Na^+$ and $Cl^-$ ions than $K^+$ ions in their leaves. Suaeda japonica had higher levels of glycine betaine in its leaves under saline conditions than C. scabrifolia and P. communis. Consequently, the physiological characteristics of salt marsh chenopodiaceous plants (S. japonica and S. malacosperma) were the high storage capacity for inorganic ions (especially alkali cations and chloride) and accumulation of glycine betaine, but monocotyledonous plant species (C. scabrifolia and P. communis) showed high $K^+$concentrations, efficient regulation of ionic uptake, and accumulation of soluble carbohydrates. These characteristics might enable salt marsh plants to grow in saline habitats.

• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.483-494
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• 1988

The adsorption behavior of aromatic acids on Amberlite XAD-4 resin was investigated by measuring the distribution coefficient by batch method. The adsorption of solutes on XAD-4 was affected by the several factors such as, analyte concentration, the pH of solution and concentration of pairing ion. The enhanced adsorption of solutes on XAD-4 in the presence of tetraalkylammonium salt as an ion pairing reagent, referred to as ion interaction, was suggested to follow a double layer model where the pairing ion occupies a primary layer at the adsorbent while the solute anion and other anions in the system comlpete for the secondary layer. Therefore, the ability of an ion pairing reagent to enhance solute adsorption depended significantly on the type and concentration of counter-ion and co-anion accompanying the ion pairing reagent or salt used for ionic strength control. In addition, a good linear relationship between the logarithm of capacity factors measured by batch and elution method as a function of the concentration of ion pairing reagent and methanol can be used to predict the retention in elution method on the basis of capacity factors measured by batch method.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.351-358
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• 2012

To investigate the environmental adaptation and ecophysiological characteristics of Suaeda maritima and S. asparagoides under saline conditions, plant growth and density were analyzed according to environmental changes of habitats. The total ion content of soil decreased with time, which was caused by the predominance of exchangeable $Na^+$ and $Cl^-$ in the upper layers. The population of S. maritima was more densely distributed in the region with higher ion contents of $Cl^-$, $Mg^{2+}$, $K^+$ and $Na^+$ than the population of S. asparagoides. Both species were showed a decreased population density according to increases in plant growth. Under the conditions of a salt field, S. maritima and S. asparagoides contained high inorganic ions to maintain low water potential, but low water soluble carbohydrate contents. In the case of free amino acid, S. maritima showed an especially high proline content, and contained rather large amounts of free amino acids, whereas S. asparagoides did not. Both species showed high inorganic ion contents in the leaves, which might be a mechanism of avoiding the ionic toxicity by diluting the accumulated ionic concentration with a high ratio of water content to dry weight. This result suggests that S. maritima seems to adapt to saline conditions by accumulating proline in addition to inorganic ions. S. asparagoides seems to adapt by osmoregulation processes, using inorganic ions rather than free amino acids.

• The Plant Pathology Journal
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• v.16 no.1
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• pp.25-28
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• 2000

The effect of ionic osmotic potential (Ψ$\pi$), and matric potential (Ψm) in the range of -0.2 to -4.0 Mpa on mycelial growth of three species of Pleurotus (P.florida, P.ostrenatus and P.safor-caju) were determined over a range of temperature (15-3$0^{\circ}C$) on a 2% malt extract agar medium and compared with the Ψ$\pi$ effect on growth of two strains of Trichoderma green mould. With the ionic solute KCl, optimun Ψ$\pi$for growth was -0.2 MPa for P.floreda and in the range of -0.2 to -0.5 MPa, with slight growth at -3.0 MPa and with nogrowth at -4.0 MPa. Of the species of Pleurotus, P.florida grew signigicantly slower than the other two species. Growt of the species of Pleurocus was significantly slower when water potential (Ψ$\omega$) was modified matrically with polyethylene glycol (PEG) 8000 then osmotically with KCl. They were also more sensitive to changes in Ψm than Ψ$\pi$The optimum Ψm of the Pleurotus was -0.5 Ψm, with no growth below -3.0 MPa. Of the species of Pleurotus, P.florida was most sensitive and P.sajor-caju was more tolerent to lowered Ψ$\pi$,but P.sajor-caju was most sensitive to lowered Ψm. The growth rate of the Trichoderma green mould strains was much faster than that observed for the Pleurotus spp. Optimum growth for bot strains of Trichoderma was in the range of -0.2 to -0.5 MPa. Strain CNU 503 was more tolerant to water stress than strain CNU 501. Both strains were able to grow up to 30% of optimum growth at -4.0 MPa at 25-3$0^{\circ}C$.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.349-357
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• 2007

Reports of endocrine disrupting compounds (EDCs), pharmaceutically active compounds (PhACs), and personal care products (PCPs) have raised substantial concern in important potable drinking water quality issues. Our study investigates the removal of EDCs, PhACs, and PCPs of 10 compounds having different physico-chemical properties (e.g., molecular weight, and octanol-water partition coefficient ($K_{OW}$)) by nanofiltration (NF) membranes. The rejection of micropollutants by NF membranes ranged from 93.9% to 99.9% depending on solute characteristics. A batch adsorption experiments indicated that adsorption is an important mechanism for transport/removal of relatively hydrophobic compounds, and is related to the octanol-water partition coefficient values. The transport phenomenon associated with adsorption may also depend on solution water chemistry such as pH and ionic strength influencing the pKa value of compounds. In addition, it was visually seen that the retention was somewhat higher for the larger compounds based on their molecular weight. These results suggest that the NF membrane retains many organic compounds due to both hydrophobic adsorption and size exclusion mechanisms.