• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.51-51
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• 2003

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.17-23
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• 2009

Interest in application of ultraviolet light technology for primary disinfection of potable water in drinking water treatment plants has increased significantly in recent years. The efficacy of disinfection processes in water purification systems is governed by several key factors, including reactor hydraulics, disinfectant chemistry, and microbial inactivation kinetics. The objective of this work was to develop a computational fluid dynamics(CFD) model to predict velocity fields, mass transport, chlorine decay, and microbial inactivation in a continuous flow reactor. The CFD model was also used to evaluate disinfection efficiency in alternative reactor designs. In a typical operation, water enters the inlet of a UV lamp and flows through the annular space between the quartz sleeve and the outside chamber wall. The irradiated water leaves through the outlet nozzle. In this paper, it describe the how to design optimal ultraviolet disinfection device for ground water and rainwater. To search the optimal design method, it was performed computer simulation with 3D-CFD discrete ordinates model and manufactured prototype. Using proposed design method, performed simulation and proved satisfied performance.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.713-719
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• 2009

In this paper, we develope a water demand forecasting algorithm using AR(Auto-regressive) and MLP(Multi-layer perceptron). To show effectiveness of the proposed method, we analyzed characteristics of time-series data collected in "A" purification plant at Jeon-Buk province during 2007-2008, and then performed the proposed method with various input factors selected through various analyses. As noted in experimental results, the performance of three types model such as multi-regressive, AR(Auto-regressive), and AR+MLP(Auto-regressive + Multi-layer perceptron) show 5.1%, 3.8%, and 3.6% with respect to MAPE(Mean Absolute Percentage Error), respectively. Thus, it is noted that the proposed method can be used to predict short-term water demand for the efficient operation of a water purification plant.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1799-1804
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• 2019

The concept of a new method, the CARBEX (CARBonate EXtraction) process, was proposed for reprocessing of spent uranium oxide fuel. The proposed process is based on use of water solutions of $Na_2CO_3$ or $(NH_4)_2CO_3$ and solvent extraction (SE) by the quaternary ammonium compounds for selective recovery and purification of U from the fission products (FPs). Applying of SE allows to reach high degree of purification of U from FPs. Carrying out the processes in poorly aggressive alkaline carbonate media leads to increasing safety of SNF's reprocessing and better selectivity of separation of lanthanides and actinides. Moreover carbonate reprocessing media allows to carry out a recycling and regeneration of reagents. We have been done laboratory scale experiments on the extraction components of simulated voloxidated spent fuel in the solutions of NaOH or $Na_2CO_3-H_2O_2$ and recovery of U from carbonate solutions by SE method using carbonate of methyltrioctylammonium in toluene. It was shown that the purification factors of U from impurities of simulated FPs reached values $10^3-10^5$. The received results support our opinion that CARBEX after the further development can become more safe, simple and profitable method of spent fuel reprocessing.

• Advances in environmental research
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• v.9 no.3
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• pp.215-232
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• 2020

Crude oils are essential source of energy. It is majorly found in geographical locations beneath the earth's surface and crude oil is the main factor for the economic developments in the world. Natural crude oil contains unrefined petroleum composed of hydrocarbons of various molecular weights and it contains other organic materials like aromatic compounds, sulphur compounds, and many other organic compounds. These hydrocarbons are rapidly getting degraded by biosurfactant producing microorganisms. The present study deals with the isolation, purification, and characterization of biosurfactant producing microorganism from oil-contaminated soil. The ability of the microorganism producing biosurfactant was investigated by well diffusion method, drop collapse test, emulsification test, oil displacement activity, and blue agar plate method. The isolate obtained from the oil contaminated soil was identified as Bacillus subtilis. The identification was done by microscopic examinations and further characterization was done by Biochemical tests and 16SrRNA gene sequencing. Purification of the biosurfactant was performed by simple liquid-liquid extraction, and characterization of extracted biosurfactants was done using Fourier transform infrared spectroscopy (FTIR). The degradation of crude oil upon treatment with the partially purified biosurfactant was analyzed by FTIR spectroscopy and Gas-chromatography mass spectroscopy (GC-MS).

• YAKHAK HOEJI
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• v.54 no.4
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• pp.316-321
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• 2010

Adefovir dipivoxil which was originally developed by Gilead Sciences has been used as treatments of HIV and HBV, especially a therapeutics for HBeAg positive and negative chronic patients. We developed highly efficient purification method using reverse phase column chromatography for mass production and a stable amorphous Adefovir dipivoxil using solid dispersion method. Reverse phase column chromatography led to highly pure product, more than 99.7% by HPLC and can be used for mass production compared with normal column chromatography. Solid dispersion method containing watersoluble polymer and Isomalt showed improved stability of amorphous Adefovir dipivoxil against heat and moisture.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1470-1474
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• 2009

This paper describes the development a of direct multiplex reverse transcription-nested polymerase chain reaction (PCR) method, devised for simultaneous detection and typing of influenza viruses. This method combines the direct reverse transcription reaction without RNA purification with the enhancement of sensitivity and specificity of nested PCR. The method successfully detected three major human influenza viruses: influenza virus A subtype 1 (H1N1) and subtype 3 (H3N2), and influenza B virus (B). The minimum number of virus particles (pfu/ml) necessary for detection in spiked saliva samples was 200 (H1N1), 140 (H3N2), and 4.5 (B). The method's sensitivity and simplicity will be convenient for use in clinical laboratories for the detection and subtyping of influenza and possibly other RNA viruses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.9-17
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• 2016

A purification method was established for high-purity chondroitin sulfate from skate cartilage. Hydrolytic extraction of skate backbone cartilage was investigated with the proteases alcalase and protamex, and the extraction contents of chondroitin sulfate were measured with several physicochemical processes. The yield of extract from skate cartilage with $40^{\circ}Brix$ concentration was 23.3% with 2% alcalase hydrolysis, which was decreased to 8.47% and 3.37% with the first and second additional ethanol purifications, respectively. The yield was 16.62% with one ethanol purification after hydrolysis with a mixture of 1% alcalase and 1% protamex. The content of chondroitin sulfate was measured as 39.88-45.08% with different ratios of ethanol solvent. The content was 42.92% at a solvent ratio of 1:1 with alcalase protease and 45.08% with a ratio of 1:2 using a protease mixture of alcalase and protamex. The molecular weight range of chondroitin sulfate was about 110-310 thousand Da, and the purity of chondroitin sulfate was 24.87-49.92% with a mixture of alcalase and protamex in GPC analysis. The maximum purity of chondroitin sulfate was 53.93% after ultrafiltration. The odor strength of chondroitin sulfate was decreased by 33% and 38% after ethanol purification and additional filtration with activated carbon, respectively. The odor concentration of ammonia and TMA from chondroitin sulfate was decreased by 52.1% and 37.89% with activated carbon filtration and two ethanol purifications, respectively, but it was necessary to eliminate the odor components efficiently using additional physicochemical processes.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.465-468
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• 2000

Methyl mercaptan oxidase was successfully induced from Rhodococcus rhodochrous IGTS8 using methyl mercaptan gas and purified to homogeneity for the detection of mercaptans. The purification procedure involved DEAE-Sephacel and Superose 12 column chromatography with recovery yields of 85.8 and 83.3%, and a specific activity of 92.7 and 303.4 units/mg-protein, respectively. The molecular weight of purified methyl mercaptan oxidase was determined to be 64.5 kDa by SDS-PAGE. The extract from gel filtration chromatography oxidizes methyl mercaptan to produce formaldehyde, which can be easily detected by the purpald-coloring method. Optimum temperature for activity was achieved at 60$^{\circ}C$. This enzyme was inhibited by both K$_2$SO$_4$and NaCl at concentration of less than 100mM and recovered to original activity at concentration of 200mM. In the presence of methanol, the activity decreased by 33%.

• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.43-49
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• 2011

As a rare sugar alcohol, L-arabitol can be used in food and can prevent extra fat deposits in the intestinal tract. Commercially, L-arabitol is prepared from pure L-arabinose by hydrogenation, which needs a high temperature and high pressure, leading to a high production cost for Larabitol. Therefore, this study describes a novel L-arabitol production method based on biological purification from the xylitol mother liquor, a cheap and readily available raw material that contains a high concentration of Larabitol. First, a novel Bacillus megaterium strain was screened that can utilize xylitol, sorbitol, and mannitol, yet not L-arabitol. The isolated strain was inoculated into a medium containing the xylitol mother liquor under formulated culture conditions, where a high L-arabitol yield (95%) and high purity (80%) were obtained when the medium was supplemented with 50 g/l of xylitol mother liquor. Upon further purification of the fermentation broth by ion exchange and decolorization, L-arabitol was crystallized with a purity of 98.5%.