• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.541-548
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• 2014

The pickling brine generated from the salting process of kimchi production is difficult to treat biologically due to very high content of salt. When pickling brine is treated and discharged, it cannot satisfy the criteria for effluent water quality in clean areas, while resources such as the salt to be recycled and the industrial water are wasted. However, sterilization by ozone, UV and photocatalyst is expensive installation costs and operating costs when considering the small kimchi manufacturers. Therefore there is a need to develop economical process. The study was conducted on the sterilization efficiency of the pickling brine using electrochemical processing. The electrochemical treatment of organic matters has advantages over conventional methods such as active carbon absorption process, chemical oxidation, and biological treatment because the response speed is faster and it does not require expensive, harmful oxidizing agents. This study were performed to examine the possibility of electrochemical treatment for the efficient processing of pickling brine and evaluated the performance of residual chlorine for the microbial sterilization.

• Journal of Life Science
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• v.11 no.3
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• pp.259-265
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• 2001

Mercury vapor inhalation-induced acute respiratory failure(ARF) has been reported to be fatal. This study was designed to observe the possible mechanism of inhaled mercury vapor poisoning in the respiratory system. Sixty percent of rats(12/20) exposed to mercury vapor were dead within 72 hours of exposure whereas all the rats(20/20) exposed to mercury vapor combined with dithiothreitol(DTT) vapor survived. The histological observation showed that ARF was a direct cause of the death induced by mercury vapor inhalation, which was significantly circumvented by DTT vapor. Cyclic AMP mediated chloride secretion was inhibited by luminal side but not serosal side sulfhydryl blocking agents (Hf$^{2+}$ $\rho$-chloromercuribenzoic acid or $\rho$-chloromercuriphenyl sulfonic acid) in a dose-dependent manner in a primary cultured rat airway monolayer. The inhibitory component of cAMP induced chloride secretion was completely restored by luminal side DTT(0.5mM). these results suggest that the oxidized form(Hg$^{2+}$) of mercury vapor(Hg0) contribute to ARF and subsequent death. The finding is important as it can provide important information regarding emergency manipulation of ARF patients suffering from by mercury vapor poisoning.ing.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.57-62
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• 2006

Six organophosphorus, one organochlorine, and three synthetic pyrethroid pesticides were analyzed for their residues during washing and hot-air drying of red peppers conducted in the production of powder. The residue ratio in organophosphorus pesticides was 33% in chlorpyrifos, 31 % in diazinon, 50% in methidathion, 80% in EPN, 28% in fenitrothion, and 60% in profenofos. The ratio in pyrethroids was 109% in cypermethrin, 102% in deltamethrin, and 106% in fenvalerate. That in organochlorine was 56% in ${\alpha}$-endosulfan and 90% in ${\beta}$-endosulfan. The results were greatly different between organophosphorus and pyrethroid pesticides. UV irradiation along with hot-air drying brought about a remarkable reduction of the residues, up to 70% as compared with hot-air drying only. The removal effect was most remarkable in pyrethroids, which are hardly removed by hot-air drying. The color of the pepper was not changed during UV irradiation. The use of oxidizing agents such as hydrogen peroxide or chlorine dioxide during washing did not show a remarkable removal of residues. The residue ratio was not affected whether the pesticide is contaminated artificially or naturally.

• Proceedings of the KIEE Conference
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• summer
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• pp.1193-1195
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• 2004

Ozone gas is one of the strongest oxidizing and bleaching agents which leave no residues harmful to the global environment. In recent years, the ozone generator has been widely utilized, However, it has been known that a broader application of ozone is hindered primarily because of its low efficiency of generation. Thus, it is more indispensable to improve actual system efficiency of the silent discharge type ozonizer using high frequency inverter. This paper presents a multi level resonant ozone power regulation by association of high frequency transformers and full bridge invert. And proposed resonant inverter system can generate continuous output voltage. can control linearly quantity of ozone gas. This invert that add PWM forms within square forms of output voltage about one level range. The power regulation characteristics and operating performances of silent discharge (SD)type ozone generating tube load driven by this load proposed inverter using FET modules are illustrated from a practical point of view, which can operate under stable conditions of basic level and PWM hybrid control strategy implemented DSP(2406). The effectoveness of propsed invert type ozonizer is proved by experiment results.

• Resources Recycling
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• v.26 no.1
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• pp.3-10
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• 2017

The special properties of silver are often indispensable in the manufacture of advanced materials. Therefore, it is of importance to develop a process to recover silver which is necessary for the production of advanced materials from diverse resources. In this manuscript, the developed processes for the leaching of silver from diverse resources are reviewed. For this purpose, the advantages and disadvantages of using some inorganic acids (nitric and sulfuric acid) and their mixture with other oxidizing agents (ozone, oxygen, hydrogen peroxide and ferric ion) were investigated. Moreover, the leaching of silver with thiourea and thiosulfate was compared over those by inorganic acids in terms of environmental effect.

• Journal of agriculture & life science
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• v.44 no.1
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• pp.9-15
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• 2010

Barley, a monocotyledonous plant, is relatively recalcitrant to the process of Agrobacterium-mediated genetic transformation. In this study, seedlings of six barley cultivars (Keunal-1-Ho, Saessal, Ol, Saechalssal, Seodunchal and Pungsanchalssal) were injured using alkali, oxidizing or reducing agents. They were then transformed using Agrobacterium via vacuum infiltration for the analysis of comparative GUS gene expression. It was determined that chemical injuries causing a slight growth retardation could overall enhance the GUS transformation rate. Hydrogen peroxide was determined to be the most effective.

• Journal of Medicine and Life Science
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• v.18 no.1
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• pp.20-23
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• 2021

Methemoglobin is generated by the oxidation of ferrous iron to ferric iron within a hemoglobin molecule. Methemoglobin is unable to bind and transport oxygen, resulting in methemoglobinemia, which can lead to fatal tissue hypoxia. The most common cause of methemoglobinemia is poisoning by oxidizing agents such as dapsone, benzocaine, and primaquine. However, methemoglobinemia can also be caused by normal dietary sources. We present two cases of methemoglobinemia that developed after a normal diet in two male patients. In this case report, the patients suddenly developed dyspnea and cyanosis after eating the same meal. They had no history of suspected poisoning, such as the use of drugs, exposure to chemicals, or gas inhalation. Their symptoms did not improve even after a high dose of oxygen was administered; further, an abnormal 'oxygen saturation gap' was observed. Because of CO-oximetry, the methemoglobin levels of the patients were 50.0% and 46.6%, respectively. We administered methylene blue (1 mg/kg), and the patients recovered completely without any complications. Emergency physicians should, therefore, be aware that methemoglobinemia can also be caused by normal dietary sources. In addition, if the source and route of contamination are unclear, an epidemiological investigation should be conducted.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1005-1014
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• 2021

Organic contaminants can be released into water environments due to chemical accidents and exist as dissolved and non-aqueous phase liquids (NAPL). Fenton oxidation was tested for bisphenol A and nitrobenzene as model organic contaminants in dissolved and NAPL states. Fenton oxidation was successfully applied for both of the dissolved and NAPL states of the two pollutants and the results indicated that a quick treatment was needed to reduce the risk from a chemical accidents instead of carrying out oxidation after the contaminants dissolve in water. A set of Fenton reactions were tested under seawater conditions because chemical accidents often occurs in the ocean. Chloride ions act as radical scavengers and inhibit Fenton oxidation. The reaction rate is inversely proportional to salt contents and the reduced reaction rate can be compensated by increasing the quantity of the oxidizing agents. The current study showes that Fenton oxidation could be applied as a quick treatments for organic contaminant in dissolved and NAPL state organic contaminants released as a result of leaks or chemical accidents.

• Membrane Journal
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• v.10 no.2
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• pp.75-82
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• 2000

This study, which was tarried out to investigate the characteristics of permeation rates and fouling phenomena in drinking-water treating processes with MF membrane, showed that pressure drop was dependent on the length of membrane module and operating pressure; the pressure drop increased with the length of membrane module and operating pressure, operation at a relatively low pressure(0.5kg/$cm^2$) is better than that at a relatively (2.0kg/$cm^2$), since high operating pressure accelerates the clogging. In case of out-in permeation type, almost same flux was obtained after a certain operating time regardless of membrane length and operating pressure. In order to understand, the microbial fouling, chemical cleaning was carried out to the forced contaminated hollow-fiber membrane with chemicals($H_2O_2$, NaOCl, and NaOH). Chemical cleanings with $H_2O_2$and NaOCl, which are oxidizing agents, are better for sterilizing and desorbing the microbes than those with NaOH.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.476-482
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• 2002

Methanol dehydrogenase (MDH) and c-type cytochromes from marine methanol-oxidizing bacterium, Methylophaga sp. MP, were purified and characterized. The native MDH had a molecular mass of 148 kDa and its isoelectric point was 5.5. Two c-type cytochromes, $c_L\;and\;c_H$, were found, and their isoelectric points were 3.4 and 8.0, respectively. The purified MDH had higher thermal stability than that of the other soil methylotrophic bacteria. The electron flow rate from MDH to cytochrome $c_L$was higher than that from MDH to cytochrome $c_H$, indicating that the physiological primary electron acceptor for MDH is cytochrome $c_L$. The electron transfer from MDH to phenazine ethosulfate (PES, artificial electron acceptor) in the two dye (PES/DCPIP)-linked assay system was not inhibited by NaCl, whereas the electron flow from MDH to cytochrome $c_L$ in the cytochrome/DCPIP-linked assay system was suppressed significantly by NaCl. Metal chelating agents such as EDTA showed the same effects on the MDH activity.