• Journal of Environmental Science International
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• v.21 no.10
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• pp.1181-1186
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• 2012

We studied the ozone concentrations generated by low-temperature dielectric barrier discharge plasma reactor after adding air and phytoplankton to control the ozone concentrations in seawater. We also examined the numbers of bacteria and Vibrio spp. after treatment using the plasma reactor. As the airflow rate was increased, more ozone was removed. Although marked variation in the ozone decrease was observed with and without airflow, the rate of ozone removal did not increase proportionately with the airflow rates. The ozone concentration decreased with increasing organic matter and time. The amount of organic matter seems to be an important factor decreasing the dissolved ozone concentration in liquid. The ozone concentration was 0.07, 0.32, 1.28, and 2.3 mg/L when operating the plasma reactor for 30, 60, 180, and 300 s, respectively; i.e., the ozone concentration increased with the reactor operating time. The initial numbers of bacteria and Vibrio spp. were 800 and 480 CFU/mL, respectively. After operating the plasma reactor at a flow rate of 6 L/min for 30 s, no bacteria or Vibrio spp. were detected. The disinfection effect of this plasma reactor seems to be superior to that of a conventional ozone generator.

• Korean Journal of Oriental Medicine
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• v.15 no.2
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• pp.119-124
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• 2009

The purpose of this study was investigation of quantitative analysis of marker substances in Paeonia lactiflora extracts by solid fermentation. High performance liquid chromatography (HPLC) for the determination of albiflorin and paeoniflorin in P. lactiflora extracts by solid fermentation, the separation method was performed on C18 column ($250\;mm\;{\times}\;4.6\;mm$, $5\;{\mu}m$, RS tech) using gradient solvent mixtures of water-acetonitrile with photodiode array detector (230nm). The flow rate was 1.0 ml/min. Retention time of albiflorin and paeoniflorin was about 28.88, 31.92 min and linearity of calibration was showed good result(r2 = 0.9998, 0.9996), respectively. Content of albiflorin was $0.090\;{\pm}\;0.03%$ in P. lactiflora extract(control), $0.102\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Paecilomyces japonica, $0.056\;{\pm}\;0.01%$ in P. lactiflora extract fermented with Ganoderma lucidum, $0.093\;{\pm}\;0.00%$ in P. lactiflora extract fermented with honey and $0.046\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Nuruk. Content of paeoniflorin was $4.506\;{\pm}\;0.13%$ in control, $2.599\;{\pm}\;0.04%$ in P. lactiflora extract fermented with Paecilomyces japonica, $1.222\;{\pm}\;0.03%$ in P. lactiflora extract fermented with Ganoderma lucidum, $2.750\;{\pm}\;0.05%$ in P. lactiflora extract fermented with honey and $0.847\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Nuruk, respectively. Content of the marker substances did not increase in all fermentation experiment group.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.798-803
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• 2011

IgY(Immunoglobulin Yolk) is a specific antibody in egg yolk, and it protects human body from virus and antigen. There are a lot of egg yolk components such as lipoprotein and protein. To separate IgY, HPLC(High Performance Liquid Chromatography) and precipitation were used in a batch mode and SMB(Simulated Moving Bed) was adopted for continuous purification of yolk proteins. IgY and other proteins in yolk were separated by using three-zone SMB chromatography. Before performing SMB experiments, batch chromatography and PIM(pulse input method) were performed to find operation parameters and adsorption isotherms. The results of batch chromatography were compared with simulated results using Aspen chromatography. To find the most suitable separation condition in SMB chromatography, simulations in $m_2$-$m_3$ plane on the triangle theory were carried out. $m_2$ = 0.18, $m_3$ = 1.0 and ${\Delta}$t = 419 s are the best conditions for the highest purity of IgY. With this operating parameters(flow rate in three zone and switching time), the purity of raffinate results in 98.39% from Aspen chromatography simulation. Most of the simulation reached steadystate within second recycle.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.328-333
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• 2012

In this study, CFD simulation was performed with commercial CFD code FLUENT for the 3D mixing tank model (1 m in a diameter and 2.5 m in a height) of DME-Propane liquified fuels. Initial condition set-up with existence of DME 146 l at the upper side of mixing tank and Propane 770 l at the lower side of mixing tank. Characteristics of mixture and fluid flow were observed for 34 hours simulation. Two liquid fuel were uniformly mixed within range of 3 mol% after 24 hours, and range of 1 mol% after 34 hours. The simulation result following 4 hours was verified with KOGAS experimental data.

• Clean Technology
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• v.2 no.2
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• pp.100-125
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• 1996

After recycle of spent materials has been optimised, there remains a proportion of waste which must be dealt with in the most environmentally friendly manner available. For materials such as municipal waste, clinical waste, toxic waste and special wastes such as tyres, incineration is often the most appropriate technology. The study of incineration must take a process system approach covering the following aspects: ${\bullet}$ Collection and blending of waste, ${\bullet}$ The two stage combustion process, ${\bullet}$ Quenching, scrubbing and polishing of the flue gases, ${\bullet}$ Dispersion of the flue gases and disposal of any solid or liquid effluent. The design of furnaces for the burning of a bed of material is being hampered by lack of an accurate mathematical model of the process and some semi-empirical correlations have to be used at present. The prediction of the incinerator gas phase flow is in a more advanced stage of development using computational fluid dynamics (CFD) analysis, although further validation data is still required. Unfortunately, it is not possible to scale down many aspects of waste incineration and tests on full scale incinerators are essencial. Thanks to a close relationship between SUWIC and Sheffield Heat&Power Ltd., an extended research programme has been carried out ar the Bernard Road Incinerator plant in Sheffield. This plant consists of two Municipal(35 MW) and two Clinical (5MW) Waste Incinerators which provide district heating for a large part of city. The heat is distributed as hot water to commercial, domestic ( >5000 dwelling) and industrial buildings through 30km of 14" pipes plus a smaller pipe distribution system. To improve the economics, a 6 MW generator is now being added to the system.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.133-138
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• 2002

A 3-D axisymmetric computer program is developed to predict the NO behavior in SNCR system for the stoker incinerator with the waste treatment capacity, 200ton/day. To this end a turbulent reacting flow field calculation is made using proper assumption and empiricism. The stoker bed is assumed to be a homogeneous waste-volatilized gaseous state. The initial composition or reactants are assumed based on the data of the ultimate analysis. Turbulent is resolved by k-e model and turbulent reaction is handled by eddy-breakup model harmonized with empirical chemistry data for gaseous combustion, NO and urea reaction. The liquid droplet is traced by Lagrangian method incorporated by aerodynamic drag, Coriolis and crntrifugal forces. Radiation is treated by sensible heat loss model. Calculation results are in good agreement with experimental data at the outlet of post combustion chamber in Daejon 4th industrial complex. The flue gas shows the temperature range of $900\sim1000^{\circ}C$, velocity of 5m/s and NO concentration of 140ppm at the exit while the measured temperature, flue gas velocity and NO concentration are $967^{\circ}C$, $3\sim4m/s$ and $100\sim200ppm$respectively. Using the developed computer program a parametric study has been made with the variation of heat content of waste, castable length and SNCR variables for the determination of proper injector location. In general, the calculated results are consistent and physically acceptable.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.795-796
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• 2010

Interest has been increasing worldwide in Fischer-Tropsch synthesis (F-T) as a method of producing synthetic liquid fuels from biomass. Hydroisomerization of $C_7-C_{15}$ paraffins applies to production of diesel fuel with high cetane number and improved cold flow properties, such as viscosity, pour point and freezing point. The commercial products such as fuel jet produced from F-T synthesis should have low freezing and pour points. In this study, our major aim is to develop a catalyst for hydroisomerization of synthesis-oil for bio-jet fuel. Effects of zeolites and platinum loading on hydroisomerization of dodecane were investigated as a model reaction in a batch reactor.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.729-732
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• 2010

The present study has been motivated by the development of a reliable numerical methodology for simulation of kerosene/LOx coaxial swirl injectors. To deal with thermodynamic non-ideality and anomalies of transport properties pronounced at supercritical pressures, a set of subroutine libraries has been constructed based on the cubic equations of state, and applied to an existing flamelet analysis code. For computational efficiency, two-dimensional axisymmetric RANS formulation with swirl was adopted and validated successfully against an isothermal coaxial swirling jet. For the actual problem with high pressure combustion, however, numerical results show that the RANS models yield excessive production of turbulence probably due to high density gradient magnitude in the vicinity of mixing layer of swirling film flow, and imply strongly further improvement of the turbulence models.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.5
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• pp.37-46
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• 2013

The gas jet from a coaxial porous injector for two-phase flows is discharged radially from the porous surface, which encloses the center liquid jet. Several hot-firing test using ethanol/nitrous oxide propellants was conducted to analyze the effect of oxidizer/fuel ratio on the combustion performance, and the uncertainty analysis was performed for the results. The characteristic velocity was affected by oxidizer/fuel ratio similarly with the results of CEA calculation except that the maximum characteristic velocity was appeared in the stoichiometric ratio. The characteristic velocity efficiency was increased as the oxidizer/fuel ratio increases.

• YAKHAK HOEJI
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• v.56 no.5
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• pp.280-287
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• 2012

A high-performance liquid chromatography (HPLC) combined with ultraviolet (UV) method for the simultaneous determination of ${\alpha}$-cyperone and nootkatone was developed for the quality control of Cyperus rotundus Linne. The separation was performed on a KR100-$5C_{18}$ ($4.6{\times}250mm$) column, and an elution gradient composed of methanol and water with a flow-rate of 1.0 ml/min. Detection wavelength was set at 254 nm. The optimum extraction for the detection of the ${\alpha}$-cyperone and nookatone was achieved by ultrasonic with methanol for an hour. Two marker compounds ${\alpha}$-cyperone and nootkatone in Cyperi Rhizoma showed good linearity ($R^2$ >0.999) in the concentration range of $12.5{\mu}g/ml$ to $200{\mu}g/ml$. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.04~1.23% and 0.08~0.68%, respectively, and the overall recoveries of 97.45~105.58% for the two compounds analyzed. Additionally, a difference was observed in the cluster analysis and principal component analysis between Cyperi Rhizoma in Korea and China. The result demonstrated that the principal component analysis is useful to distinguish between Cyperi Rhizoma in Korea and China.