• Journal of Life Science
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• v.5 no.4
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• pp.203-210
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• 1995

Fibrinolytic activity of fermented kimchi and ingredients used for the preparation were assayed by measuring the lysis area on plasminogen-rich fibrin plate. Fermented kimchi and picked fish sauces from changlan, prwan, and anchovy showed the activity, and the activity of pickled fish sauces were high in the order of pickled changlan, picked anchovy(pickled mulchi), and pickled prawn. However, the activity of kimchi may not be attributed to pickled fish sauce because kimchi containing fish sauce did not possess activities were determined from the samples heated for 30min at 100$\circ$C. There was no changes in activities before and after heat treatment indicating the agents may be components other than protein. Since major changes occur during kimchi fermentation were increased sour taste due to production of organic acids such as lactic, citric, oxalic, and succinic acids, the authentic organic acids present were examined for fibrinolytic activities. The results indicates that the major component posses the activity is lactic acid.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.53-53
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• 2003

There has been increasing interest in the fabrication of nano-sized structures because of their various advantages and applications. Anodic Aluminum Oxide (AAO) is one of the most successful methods to obtain highly ordered nano pores and channels. Also It can be obtained diverse pore diameter, density and depth through the control of anodization condition. The three types of substrates were used for anodization; sheets of Aluminum on Si wafer and Aluminum on Mo-coated Si wafer. In Aluminum sheet, a highly ordered array of nanoholes was formed by the two step anodization in 0.3M oxalic acid solutions at 10$^{\circ}C$ After the anodization, the remained aluminum was removed in a saturated HgCl$_2$ solution. Subsequently, the barrier layer at the pore bottom was opened by chemical etching in phosphoric acid. Finally, we can obtain the through-channel membrane. In these processes, the effect of various parameters such as anodizing voltage, anodizing time, pore widening time and pre-heat treatment are characterized by FE-SEM (HITACH-4700). The pore size. density and growth rate of membrane are depended on the anodizing voltage and temperature respectively. The pore size is proportional to applied voltage and pore widening time The pore density can be controlled by anodizing temperature and voltage.

• Journal of the Korean institute of surface engineering
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• v.13 no.4
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• pp.221-227
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• 1980

When anodizing the Al in the acid electrolyte, it is well known that the parallel pores grow continuously perpendicular to the surface. This fact can be used for the manufacturing of the porous membrane, if thc pores pass through the anodized foil. Anodizing both surfaces of the Al-foil spontaneously in 20$^{\circ}C$, 2% oxalic acid under tile potentiostatic condition, it is found that the harrier layer remaining in the midst of the foil finally disappears and thc pores pass through the foil. And examined the porous structure change when the voltage is changed during the anodizing treatment. From the result, it is revealed that the new pores and cell grow, adjusting themselves to the final voltage. The characteristic of the porous membrane is greatly dependent upon the diameter of the pore and the cell. So studied the relationship between the voltage and the diameter of the pore and the cell quantitatively with the aid of field-assisted dissolution concept. And derived the following two equation, Pi = 8.32Vi, Ci = 26.80Vi. These equations are in good accord with the experimental data above 30V, but do not accord nuder 30V.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.429-436
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• 2008

Membrane system has been increasingly considered as a safe and cost-effective water treatment process especially in case of small scale water works. This research is a basis of membrane application in water works through a long period test with obtaining operation skills and evaluation of water quality and cost competitiveness. For the research, the UF membrane system was installed in small water treatment plant that uses river-bed water as raw water. The system was consisted of 2 stage membrane and operated in constant flow mode (Flux: 1.5, 1.0, 0.9, 0.6). In each different flux condition, TMP trends were showed better results at lower flux condition. And through the high flux condition test, it is certified that membrane system could deal with breakdown of one stage. Water quality of permeate was satisfied the water quality standards especially turbidity. To know what mainly causes fouling on membrane, the test by membrane with several cleaning agents and EDX analysis have done in lab. Through the tests, ferrous concentration in raw water, backwashing water and membrane surface etc. was high and it causes fouling inside and outside of membrane. So acid cleaning using organic acid such as oxalic acid is necessary in Chemical in Place (CIP). At the economical aspect the electrical cost of membrane system is higher than that of slow sand filtration but labor cost can be reduced by automation. However, the use of labor should be determined considering effectiveness and stability of operation. Because during the operation, there are several breakdown such as electrical shock by lightning, water drop in summer, etc.

• Analytical Science and Technology
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• v.24 no.2
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• pp.69-77
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• 2011

Ethylene glycol (EG) is produced commercially in large amounts and is widely used as antifreeze or deicing solution for cars, boats, and aircraft. EG poisoning occurs in suicide attempts and infrequently, either intentionally through misuse or accidental as EG has a sweet taste. EG has in itself a low toxicity, but is in vivo broken down to higher toxic organic acids which are responsible for extensive cellular damage in various tissues caused principally by the metabolites glycolic acid and oxalic acid. The most conclusive analytical method of diagnosing EG poisoning is determination of EG concentration. However, victims are sometimes admitted at a late stage to hospitals or died during emergency treatment like a gastric lavage or found rotten dead, when blood EG concentrations are low or not detected. Therefore, in this study, the identification of EG was not only performed by gas chromatograpyc-mass spectrometry (GC-MS) following derivatization but also further toxicological analyses of metabolites, glycolic acid (GA) and oxalic acid (OA), were performed by ion chromatography in various biological specimens. A ranges of blood concentrations (3 cases) was $10\sim2,400\;{\mu}g/mL$ for EG, $224\sim1,164\;{\mu}g/mL$ for GA and ND $\sim40\;{\mu}g/mL$ for OA, respectively, In other biological specimens (liver, kidney, bile and pleural fluid), a range of concentrations (3 cases) was ND $\sim55,000\;{\mu}g/mL$ for EG, ND $\sim1,124\;{\mu}g/mL$ for GA and ND $\sim60\;{\mu}g/mL$ for OA, respectively. Liver and kidney tissues were recommended specimens including blood because OA, a final metabolite of EG, was identified large amounts in these despite no detectable EG caused by some therapy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.600-607
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• 2017

The total acidity (TA) of Makgeolli was affected by suspended solids and $CO_2$ produced during the fermentation process. Nine Makgeollis (four sterilized and five unsterilized Makgeollis) were collected in the market, and their TAs were compared before and after filtration and $CO_2$ removal. TAs of sterilized Makgeollis were 0.379~0.477%, which significantly decreased to 0.167~0.225% after filtration and 0.132~0.170% after $CO_2$ removal (P<0.05). TAs of unsterilized Makgeollis were 0.412~0.467% and decreased to 0.157~0.365% after filtration and 0.143~0.280% after $CO_2$ removal (P<0.05). TAs of Makgeollis were compared by three methods using different indicators. The TAs of sterilized and unsterilized Makgeollis were 0.105~0.123% and 0.105~0.200%, respectively, by bromthymol blue+neutral red (light green), 0.129~0.154% and 0.130~0.255%, respectively, by phenolphthalein (faint pink), and 0.120~0.146% and 0.130~0.232%, respectively, by bromthymol (blue). Nowadays, Makgeolli is commercialized with various distinct colors, and thus it is important to select appropriate indicators for proper titration endpoint identification for TA measurement. The compositions of organic acids profiles varied depending on sterilized or unsterilized Makgeollis, in which oxalic acid (0.108~0.329 mg/mL), malic acid (ND to 0.134 mg/mL), lactic acid (0.127~0.776 mg/mL), and citric acid (ND to 1.159 mg/mL) were found, and lactic acid was in unsterilized more than sterilized Makgeollis.

• Microbiology and Biotechnology Letters
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• v.2 no.1
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• pp.13-17
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• 1974

A strain of Streptomyces sp. which producing a metal containing proteolytic enzyme was isolated from soil and some properties of this enzyme were investigated. The following results were obtained. 1. Optimal pH and temperature of this enzyme were pH7.0 and 37$^{\circ}C$ 2. This enzyme was easily inactivated with heat treatment: for example, by the treatmentat 37$^{\circ}C$ for 100 minutes the activity of the enzyme was decreased to about 50 per cent of intial actively but this enzyme was stable at neutral pH. 3. The activity of this enzyme was not inhibited by $Mg^{＋＋}$, $_Mn^{＋＋}$, $Ca^{＋＋}$, Pb$^{＋＋}$, or $Ba^{＋＋}$ ect. but strongly inhibited by Hg$^{＋＋}$, Co$^{＋＋}$, Ag$^{＋}$, Cu$^{＋＋}$, or Cd$^{＋＋}$. 4. This enzyme was strongly inhibited by EDTA but was not inhibited by oxalic acid, citric acid, 2, 4-dinitrophenol, $\varepsilon$-aminocaproic acid, cysteine, or thiourea.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.401-410
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• 2005

A series of studies involving formulation processes, bubbling activity test, diffusibility test and biological efficacy test was undertaken to develop Jumbo herbicide formulations in paddy rice field. Gas evolution speed from the tablets prepared by different organic acids was in the order of oxalic acid, malonic acid, citric acid, and tartaric acid. The total volume of evolved gas from the tablet and diffusibility of the active ingredient in the submerged water were increased with increase of water temperature; the volume from 1 g of tablet at 10, 15, 25 and $30^{\circ}C$ for 5 minutes after immersion into water was 20, 25, 28, 45, 57 mL, respectively. The concentration of halosulfuron-methyl and pyriminobac-methyl in submerged water at 5, 15, 20 and $30^{\circ}C$ at the 2.4 m distance from the applied spot of the tablet was 20, 48, 85, and 97% of the concentration of treated spot, respectively. The evolved gas volume from the tablets was not affected by pH of submerged water. The concentration of halosulfuron-methyl in different sizes of submerged water within 24 hours after treatment of the tablet was maintained 0.16 ppm, which is ideal concentration at standard dosage regardless of the submerged water area. The concentration of pyriminobac-methyl was also uniformly dispersed in the water within 24 hours after applying it into the submerged water. The wind velocity of 5 m $sec^{-1}$ on concentration distribution of halosulfuron-methyl and pyriminobac-methyl in the submerged water 24 hours after treatment was not influenced; an equal concentration in the up the wind and down the wind from the applied spot was maintained. Spot treatments of one tablet formulations(5 g) including 4 times higher dosage at 4 different spots resulted in even concentration distribution of active ingredient in the water 24 hours after applying it into the submerged water.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.69-74
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• 2012

This study investigated the TNT decomposition by the treatment of alkaline hydrolysis. To obtain this objecitive, spectrum shift characteristics, pH effect, kinetics, and product analysis were examined during the alkaline hydrolysis by means of hydroxide ions. At pH = 12, an aqueous solution of TNT was changed into yellow-brown coloring, in which its absorbances were newly increased in a range of wavelength 400-600 nm. From the kinetic data, pseudo-first-order rate constant in a excess of hydroxide ion, in contrast to TNT concentration, was $0.0022min^{-1}$, which means that the reaction rate between TNT and hydroxide ion can be very slow, and that 1,047 min is necessary to achieve a 90% reduction of the initial TNT. In products analyses, nitrite ions and formic acid were mainly produced by the alkaline hydrolysis, nitrate ions and oxalic acid as minor products were generated.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.2
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• pp.167-177
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• 2016

This work investigated the decomposition of aqueous anatoxin-a originated from cyanobacteria using an underwater dielectric barrier discharge plasma system based on a porous ceramic tube and an alternating current (AC) high voltage. Plasmatic gas generated inside the porous ceramic tube was uniformly dispersed in the form of numerous bubbles into the aqueous solution through the micro-pores of the ceramic tube, which allowed an effective contact between the plasmatic gas and the aqueous anatoxin-a solution. Effect of applied voltage, treatment time and the coexistence of nutrients such as $NO_3{^-}$, $H_2PO_4{^-}$ and glucose on the decomposition of anatoxin-a was examined. Chemical analyses of the plasma-treated anatoxin-a solution using liquid chromatography-mass spectrometry (LC-MS) and ion chromatography (IC) were performed to elucidate the mineralization mechanisms. Increasing the voltage improved the anatoxin-a decomposition efficiency due to the increased discharge power, but the energy required to remove a given amount of anatoxin-a was similar, regardless of the voltage. At an applied voltage of 17.2 kV (oxygen flow rate: $1.0L\;min^{-1}$), anatoxin-a at an initial concentration of $1mg\;L^{-1}$ (volume: 0.5 L) was successfully treated within 3 min. The chemical analyses using LC-MS and IC suggested that the intermediates with molecular weights of 123~161 produced by the attack of plasma-induced reactive species on anatoxin-a molecule were further oxidized to stable compounds such as acetic acid, formic acid and oxalic acid.