• Carbon letters
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• v.9 no.3
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• pp.195-199
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• 2008

A nanocomposite consisting of $Fe_3O_4$ and MWCNT was produced via sol-gel technique using $FeCl_3$ along with MWCNT by calcination at $300^{\circ}C$. The degradation effect of rhodamine B dye has been investigated under UV illumination in a darkroom. The degradation reaction was studied by monitoring the discoloration of dye as a function of irradiation time using UV-visible spectrophotometeric technique. The $Fe_3O_4$-MWCNT samples have continuous degradation ability under the UV illumination with the first order kinetics and the dye removal was better than in the pristine $Fe_3O_4$. The resultant composite catalyst was found to be efficient for the photo-Fenton reaction of the dye.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.151-158
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• 2015

The aim of this research is to derive an optimum operating condition for the thermal solubilization equipment that is employed to increase concentration of soluble organic materials and to assess whether it would be possible to use the waste sludge generated by thermal solubilization reaction as an external carbon source in biological denitrification process. For the purpose, we have constituted a laboratory-size thermal solubilization equipment and have assessed thermal hydrolysis efficiency based on various reaction temperature and reaction time. We have also derived SDNR using the waste sludge generated by thermal solubilization reaction through a batch experiment. As a result of research, the highest thermal hydrolysis efficiency of about 42.8% was achieved at $190^{\circ}C$ of reaction temperature and at 90 minutes of reaction time. And when SDNR was derived using the waste sludge, the value obtained was $0.080{\sim}0.094\;g\;NO_3{^-}-N/g\;MLVSS{\cdot}day$, showing SDNR that is higher than that obtained by the results of existing researches that used common wastewater as an external carbon source. Accordingly, in view of the fact that food wastes vary quite a bit in characteristics based on the area they are generated from and seasonal change, it seems that a flexible operation of thermal solubilization equipment is required through on-going monitoring of food wastes that are imported to food wastes recycling facilities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.621-623
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• 2017

Mariculture of rainbow trout Onchorhynchus mykiss has been initiated in or around olive flounder Paralichthys olivaceus farms, where viral hemorrhagic septicemia virus (VHSV) is often detected in some fish. In the present study, we investigated VHSV infection in seawater-reared rainbow trout because VHSV has never been detected in salmonids in Korea. A total of 104 adult fish were tested for the presence of VHSV by reverse transcription-polymerase chain reaction, followed by virus isolation with the fathead minnow caudal trunk cell line. Cytopathic effects were observed in two samples but the virus was identified as infectious hematopoietic necrosis virus. Thus, VHSV was not isolated from seawater-reared rainbow trout.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.5
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• pp.383-391
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• 2002

Six types of ozone passive samplers were fabricated with three different filter substrates and two colorants, and tested for their feasibility on atmospheric monitoring. These passive samplers are based on a colorant which fades (indigo carmine and ChromAir (K&M environmental Inc.)) or produces color (mixture of 3-methyl-2-benzothiazolinone acetone azine and 2-phenylphenol colorant) upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Three filters, namely Whatman No.1 paper, SG81 chromatography paper and Silica Gel coated on polyester (TLC Plates), were prepared and coated with two colorants. The response of these passive samplers in ozone chamber were tested and compared with ChromAir (K&M environmental Inc.) passive sampler. The response of Silica Gel filter impregnated with indigo carmine was the best at the constant concentration exposure.

• International Journal of Safety
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• v.9 no.1
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• pp.43-46
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• 2010

In the recycle process of organic solvent, the atmospheric oxygen can cause autoxidation and product peroxide. The time-saving method to evaluate the hazards has been required. In this study, oxygen pressure monitoring experiment was proposed as a new method to evaluate autoxidative resistances of solvents. Some of organic solvents were pressurized by oxygen and kept under isothermal condition. At the same time, the pressure in the vessel tracked. Iodometrical titration, thermal analysis and spectroscopic analysis were performed to measure peroxide concentration, the heat of reaction and chemical bonding change. From the results that THF has larger oxygen consumption rate than CPME, it is considered that autoxidative resistance of THF is lower than that of CPME. This method enables to obtain results in shorter time than other methods. These experimental results were consistent with the previous research with longer test durations [1-2].

• Herbal Formula Science
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• v.19 no.2
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• pp.83-92
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• 2011

Objectives : This study was carried out to moniter microbial flora on freeze-dried herbal powder and identify isolated bacteria. Methods : We measured the total number of bacteria and fungi in 29 herbal powder which had made according to the guideline of KFDA. For the identification, we observed microscopic properties and carried out polymerase chain reaction(PCR). The purified DNA was analyzed by DNA sequencer. Results : Among the 29 herbal powders, the fungi were detected only one sample as unacceptable range of total aerobic bacteria. Isolated bacteria were identified as Bacillus cereus, B. subtilis, B. megaterium, B. licheniformis, Erwinia tasmaniensis, E. amylovora, and Pantoea agglomerans by 16S rDNA analysis. E. tasmaniensis was observed 20 herbal samples. Conclusions : According to above results, further studies for the effective sterilization of low herbal materials should be needed.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.137-137
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• 2010

Copper electroplating is a very popular and important technology for depositing high-quality conductor interconnections, especially in through silicon via (TSV). As this advanced packaging technique developing, a mass of copper and chemical solution are used, so attention to these chemical materials into the utilization and costs can not be ignored. An economical and practical real-time chemical solution monitoring has not been achieved yet. Either Red-green-blue (RGB) or optical emission spectroscopy (OES) color sensor can successfully monitor the color condition of solution during the process. The reaction rate, uniformity and quality can map onto the color changing. Hidden Semi Markov model (HSMM) can establish mapping from the color change to upper indicators, and artificial neural network (ANN) can be integrated to comprehensively determine its targets, whether the solution inside the container can continue to use.

• Proceedings of the KIEE Conference
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• summer
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• pp.622-624
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• 2004

To reduce the effect of fault on power systems, like GIS and transformers, power system authorities are using various technologies to monitor and diagnose there facilities. Developing On-Line monitoring systems by using IT technology is main issue of nowadays for power system authorities. Among various monitoring and diagnosis technologies, gas sensing technologies can be most useful candidate because large power systems are using gas and oils for there insulation and analyzing density of gases that are included in the gas and oils for insulation purpose tell us what kind of reaction were arisen. In this paper, we describe on the gas sensing technology that are used for power systems monitoring and diagnosis.

• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.126-131
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• 2006

The objective of this study was monitoring of genetically modified soybean by PCR and ELISA. We collected 60 soybean samples from the open markets located in Western Gyeongnam (Sacheon, Hamyang, Hadong, Sanchung, Uiryung, Geochang, and Hapcheon). A total of 60 soybeans was examined and 14 genetical modified soybean (GMS) were detected by PCR. The GMS rate of selling soybean in Uiryung, Hadong, Sacheon, and Hapcheon was 50.0%, 37.5%, 33.3% and 25%, respectively. The 7 of 14 GMSs were positive by ELISA and most of positive samples were below 3% GMS but 1 (Uiryung 1) of the positive samples was over the 3% which is maximum permit limit in Korea. These results mean that merchants of open market did not express for selling soybean mixed with GMS, so consumers did not recognize GMO. Therefore, we thought that education of GMO for merchant of open market need to recognize about GMO maximum permit limit.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.2
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• pp.85-92
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• 2003

This paper presents an electric power generating system for stand-alone health monitoring sensor unit of bridge structure based on ambient vibration of bridge. In this paper, a novel electric power generator which has minimum effect of armature reaction is proposed. The related mechanical and electrical design equations are obtained, and a pilot generator has been implemented. In addition, the charging system for extremely low generator current is discussed, and some improvements are identified for the system. This investigation reveals that diode characteristics of rectifier is dominant factor in the charging process. Finally, both the simulation, which uses real measurement data of the Namhae bridge as input of the pilot generator, and indoor test are carried out. The results showed the applicability and effectiveness of the stand-alone vibration powered generator.