• Membrane Journal
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• v.30 no.5
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• pp.307-318
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• 2020

Conventional perfluorinated sulfonic acid membrane, Nafion is widely used for vanadium redox flow battery (VRFB). It is desired to prevent vanadium ion permeation through a membrane to retain the capacity, and to keep the cell efficiency of a VRFB. Highly proton conductive and chemically stable Nafion membranes, however, suffer from high vanadium permeation, which induce the reduction in charge and discharge capacity by side reactions of vanadium ions. In this study, to resolve the issue, silica nanoparticles, which are functionalized with 3-aminopropyl group (fS) are introduced to enhance the long-term performance of a VRFB by lowering vanadium permeation. It is expected that amine groups on silica nanoparticles are converted to positive ammonium ion, which could deteriorate positively charged vanadium ions' crossover by Gibbs-Donnan effect. There is reduction in proton conductivity may due to acid-base complexation between fS and Nafion side chains, but ion selectivity of proton to vanadium ion is enhanced by introducing fS to Nafion membranes. With the composite membranes of Nafion and fS, VRFBs maintain their discharge capacity up to 80% at a high current density of 150 mA/㎠ during 200 cycles.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.261-266
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• 1979

This experiment was carried out to evaluate the sanitary quality of cultured vegetables and to check the removing rate of bacteria by treating methods such as washing with tap water or commercial detergent, or blanching. Samples collected from farm land located at Busan suburbs and markets were Fragaria chiloensis var. ananasa, Lycopersicum esculentum, Capsium longum, Cucumis sativus, Lactuca scariola var. sativa leaf of Perilla frutescens var, japonica, Oananthe stolonifera and Allium odoium. Fecal coliform MPN was ra god from less than 30 to 430,000 per 100 grams of samples examined while plate count was $7.2\times10^3\;to\;2.2\times10^7$ per gram. Usually contamination rate of fecal coliform of leaf vegetal)les was much higher than that of fruit vegetables. Removing rate of bacterial density of vegetables by washing three times with tap water was about $70\%$ in fruit vegetables, about $20\%$ in leaf vegetables but it was about $80\%$ in leaf vegetables by washing with a commercial detergent. Sirvival rate of viable cell count of leaf vegetables was less than $0.1\%$ after blanching for one minutes in boiling tap water, Composition of coliform was $18\%$ Escherichia coli group, $22\%$ Citrobacter freundii group and $60\%$ Klebsiella aerogenes group, among Escherichia coli, type I being $16\%$ in total. The coliform detection from BGLB gas positive tubes being planted with various vegetables was about $80\%$ in the result of IMViC reaction.

• Development and Reproduction
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• v.13 no.4
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• pp.249-256
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• 2009

The estrogen receptor-related receptors (ERRs) are a group of nuclear receptor superfamily of transcription factors. ERRs and estrogen receptors (ERs) have overlapping affinities for coactivators and DNA binding sites, but differ markedly in ligand binding and activation. The three mammalian ERR genes have been implicated in diverse physiological processes ranging from placental development to maintenance of bone density, whereas the molecular diversity, function, and regulation of ERRs in non-mammalian species are not well understood. In the present study, to investigate the involvement of ERR in transcription and embryogenesis in marine invertebrates, a cDNA encoding ERR (SnERR) was cloned from the gonad in Strongylocentrotus nudus, by polymerase chain reaction (PCR). The amino acid sequence of SnERR showed high homology with that of S. purpuratus (91%). A phylogenetic tree clearly showed that SnERR is a member of the ERR family and clustered in echinodermata group as supported by a high bootstrap value. We examined gene expression of SnERR during embryonic development of S. nudus using real-time PCR. During the embryonic development, the mRNA of ERR was significantly high levels in early development stages (4~64 cell) and larval stages. The SnERR slightly activated transcription through the classical estrogen response elements (EREs) in the presence of genistein. In addition, peroxisome proliferator-activated receptor $\gamma$ coactivator (PGC)-$1\alpha$ knwon as a coactivator of ERR enhanced the snERR-mediated transactivation, suggesting that the PGC-$1\alpha$ is a coactivator of SnERR.

• Korean Journal of Environmental Biology
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• v.28 no.3
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• pp.172-178
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• 2010

The bloom of the genus Stephanodiscus was gradually extinguished after 18 April. Counts of bacterial population were increased as the diatom bloom was disappeared. Numbers of the heterotrophic nanoflagellates and ciliates were also increased during the disappearance of the bloom. The densities of the mesozooplankton, the major predator of the diatoms, started to increase in April. However, their growth was suppressed during the bloom period of the diatoms (from January to March). During the bloom period of the diatoms, the monthly average value of the basic productivity amounted up to 11,765.7 mgC $m^{-2}day^{-1}$, which is relatively high value considering the low temperature and light during that period. The growth rate of phytoplankton in March, when the bloom was beginning to be supressed was 0.007. The growth rate of phytoplankton was negative value in April when the decreasing of the algal density was started.

• Applied Microscopy
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• v.33 no.1
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• pp.59-78
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• 2003

This research was conducted to determine the effects of chitosanoligosaccharide on liver poisoning induced by cadmium (Cd). Three groups of mice were used in this research. The first group was only injected with cadmium (5.0 mg/kg; i.p.) (group Cd) and the second one with cadmium and chitosanoligosaccharide (0.5% solution) at the same time (group Cd+Chi). The third one which had already been injeted with chitosanoligosaccharide (0.5% Solution) aweek before (group Ch7+Cd) was used. In order to investigate the inhibitory action of chitosanoligosaccharide on liver damage, enzyme activity in serum, glutathione peroxidase (GSHPx) activity and glutathione reductase (GR) activity were relatively measured. In addition, histological observations were made to determine the morphologic injury of liver tissues. As the result of enzyme activity in serum, the activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in chitosanoligosaccharide-injected groups Cd+Chi and Chi7+Cd was lower than in group Cd. GSH-Px activity was sharply increased in groups Cd+Chi and Chi7+Cd compared to group Cd. GR activity was conspicuously decreased in groups Cd+Chi and Chi7+Cd compared to group Cd. As the result of light microscopic observation, liver cell necrosis caused by cadmium poisoning was obseved in liver cells. The finding of group Cd+Chi and Chi7+Cd was similar total on of normal groups. As the result of electron microscopic observation, mitochondria in group Cd showed a severe swelling phenomenon, RER fragment and ribosome dropout. However, in groups Cd+Chi and Chi7+Cd, mitochondria wiht high electron density were distributed and RER forming a typical lamellae with ribosome was observed. From these results, cadmium toxicity on rat liver tissues could be lessened by chitosanoligosaccharide.

• Journal of Chest Surgery
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• v.36 no.4
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• pp.219-228
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• 2003

Background:Liquid nitrogen freezing techniques have already met with widespread success in biology and medicine as a means of long-term storage for cells and tissues. The use of cryoprotectants such as glycerol and dimethylsulphoxide to prevent ice crystal formation, with carefully controlled rates of freezing and thawing, allows both structure and viability to be retained almost indefinitely. Cryopreservation of various tissues has various con-trolled rates of freezing. Material and Method: To find the optimal freezing curve and the chamber temperature, we approached the thermodynamic calculation of tissues in two ways. One is the direct calculation method. We should know the thermophysical characteristics of all components, latent heat of fusion, area, density and volume, etc. This kind of calculation is so sophisticated and some variables may not be determined. The other is the indirect calculation method. We performed the tissue freezing with already used freezing curve and we observed the actual freezing curve of that tissue. And we modified the freezing curve with several steps of calculation, polynomial regression analysis, time constant calculation, thermal response calculation and inverse calculation of chamber temperature. Result: We applied that freezing program on mesenchymal stem cell, chondrocyte, and osteoblast. The tissue temperature decreased according to the ideal freezing curve without temperature rising. We did not find any differences in survival. The reason is postulated to be that freezing material is too small and contains cellular components. We expect the significant difference in cellular viability if the freezing curve is applied on a large scale of tissues. Conclusion: This program would be helpful in finding the chamber temperature for the ideal freezing curie easily.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.393-402
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• 1993

Redox flow secondary battery have been studied actively as one of the most promising electrochemical energy storage devices for a wide range of applications, such as electric vehicles, photovoltaic arrays, and excess power generated by electric power plants. In all-vanadium redox flow battery using solution of vanadium-sulfuric acid as a active material, the difficulty in developing an efficient ion selective membrane can still be identified. The asymmetric cation exchange membrane(M-30) as a separator of all-vanadium redox flow battery which were obtained by the reaction of chlorosulfonation for 30 minutes under the irradiation of UV, showed its superiority in the transport number of 0.94 and electrical resistivity of $0.5{\Omega}{\cdot}cm^2$. The base membrane were prepared by lamination a low density polyethlene film of $10{\mu}m$ thickness on polyolefin membrane(HIPORE 120). The electrical resistivity of M-30 membrane in real solution of vanadium-sulfuric acid was $3.79{\Omega}{\cdot}cm^2$ and it was similar to that of Nafion 117 membrane. Also the cell resistivity was $6.6{\Omega}{\cdot}cm^2$and lower than that of Nafion 117. In considertion of electrochemical properties and costs of membranes, M-30 membrane was better than that of Nafion 117 and CMV of Asahi glass Co. as a separator of all-vanadium redox flow battery.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.136-144
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• 2000

M. aeruginosa isolated from Lake Paldang was cultured in CB medium, and then each wet plants put into the cultured medium at a rate of 0.5 g and 2.5 g wet wt/l. There was slight inhibition by the input of cattail and iris of each 0.5 g wet wt/l cultured medium, but showed no reduction in algal growth in other flasks. Among the applied plants, ginkgo, pine needles, big cone pine, waterreed and water chestnut had an effect on inhibition of algal growth at the input of 2.5 g wet wt/l. Plants which were dried for 3 days at $50^{\circ}C$ introduced into the testing flask for 10days cultured at dose rates of 2.5 g/l. When chlorophyll a concentration was remarkably high as $802.6\;{\mu}g/l$ after five days, there was noticeably less chlorophyll compared with control at a rate of 98% by big cone pine, 96% by ginkgo, 95% by pine needles and 86% by rice straw, respectively. To examine the effect of plant extracts on algal growth, big cone pine and water chestnut were put to the amount of 1.25 g liquid extracts/l. Chlorophyll a concentration and cell density decreased to the extent of average 43% as compared with the beginning of experiment, but when concentration of chlorophyll a increased a most high, the inhibition of algal growth by liquid extracts did not affect at all. When a quantity of plant equivalent to 2.5 g liquid extracts/l inhibited the growth of algae by 95% after nine days.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.251-256
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• 1995

Sucrose is added to feed materials to alter the taste and texture of extruded products. Emulsifier can affect extrudate properties by forming complexes with amylose during extrusion-cooking. These ingredients may improve the cell structure and texture of cornmeal extrudates obtained by using $CO_{2}$ as a bubble forming agent. The objective of this study was to evaluate effects of sucrose (5% and 10%) and glyceryl monostearate (GMS) (0.75% and 1%) on properties of cornmeal extrudates produced with $CO_{2}$ at injection pressures from 1.04 to 2.07 MPa. Dough temperature increased and die pressure decreased when $CO_{2}$ was injected into barrel. The addition of sucrose to cornmeal resulted in decreasing dough temperature, specific mechanical energy (SME) input, and die pressure. SME input was not significantly influenced by GMS addition but die pressure was decreased when GMS was added. Extrudate density was decreased over observed $CO_{2}$ injection compared to GMS. WSI was significantly decreased with the addition of GMS. Paste viscosity was also decreased with addition of sucrose or GMS, but significant differences of paste viscosity among $CO_{2}$ injection pressures were not found. Stucture forming and texture of cornmeal extrudates by $CO_{2}$ injection was improved by adding GMS.

• Research in Plant Disease
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• v.11 no.2
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• pp.158-161
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• 2005

Stenotrophomonas maltophilia BW-13 is a potent biocontrol agent to control crisphead lettuce bottom rot caused by Rhizoctonia solani. To define the optimum conditions for the mass production of the S. maltophilia BW-13, we have investigated optimum culture conditions and effects of various carbon sources on the bacterial growth. The optimum initial pH and temperature were determined as pH $6.0\~7.0 and $35^{\circ}C$, respectively. For the selection of effective carbon source for the mass production, we tested the low molecular carbon sources such as sucrose, glucose, lactose, maltose, manose and the high molecular carbon source such as dough conditioner, rice bran, corn starch, sweet potato starch. As the results, the addition of dough conditioner in a basal medium ($1.25\%\;K_{2}HPO_4,\;0.38\%\;KH_{2}PO_4,\;0.01\%\;MgSO_4{\cdot}7H_{2}O,\;0.5\%\;Yeast extract$) was able to achieve higher cell density and the antifungal activity than others. Therefore, the basal medium containing $3\%$ dough conditioner (named as dough conditioner medium) was finally selected the optimized media for the mass production of BW-13 strain.