• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.77-86
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• 2020

Persulfate-based advanced oxidation processes (AOPs) can oxidize various organic pollutants. In this study, persulfate/Fe(II) system was utilized in phenol removal, and the effect of various organic and inorganic chelators on Fe(II)-medicated persulfate activation was investigated. The feasibility of persulfate/Fe(II)/chelator in cleanup of phenol-contaminated sediment was confirmed through toxicity assessment. In persulfate/Fe(II) conditions, the rate and extent of phenol removal increased in proportion to persulfate concentration. In chelator injection condition, the rate of phenol removal was inversely proportional to chelator concentration when it was injected above optimum ratio. Thiosulfate showed greater chelation tendency with persulfate than citrate and interfered with persulfate access to Fe(II), making the latter a more suitable chelator for enhancing persulfate activation. In contaminated clay sediment condition, 100% phenol removal was obtained within an hour without chelator, with the removal rate increased up to four times as compared to the rate with chelator addition. A clay sediment toxicity assessment at persulfate:Fe(II):phenol 20:10:1 ratio indicated 71.3% toxicity reduction with 100% phenol removal efficiency. Therefore, persulfate/Fe(II) system demonstrated its potential utility in toxicity reduction and cleanup of organic contaminants in sediments.

• Journal of the Korean Home Economics Association
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• v.36 no.5
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• pp.137-150
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• 1998

The purpose of this study was to examine the effect of sex role orientation on the amount of household work time by husbands and wives in Seoul and Taejon. The data were collected from 100 couples in Seoul and 142 in Tadjon. The Major finding were as follows: 1. Taejon did not differed from Seoul in sex role orientation of the couples. 2. Sex role orientation of wife was related to the amount of time that husband spent on meal preparation and cleanup, clothing care, and child care. 3. Total household work time by husbands in Taejon was affected by the sex role orientation of himself, but the couples in Seoul and the wife in Taejon was not.

• The KSFM Journal of Fluid Machinery
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• v.12 no.1
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• pp.43-50
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• 2009

Waste heat recovery process designs and performance analyses are conducted on the IGCC(Integrated Gasification Combined Cycle) power plants integrated with two different coal gasification and gas cleanup processes by Shell and GE/Texaco. Through the analysis results, the present study provides the steam integration concept between the HRSG and the chemical processes of IGCC power plant, and investigates the effect of steam integration on the power generation of IGCC power plant. The present simulation results show less steam power output and higher overall IGCC efficiency of the Shell-based power plant than the GE/Texaco.

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.288-293
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• 1997

Analytical method using capillary GC/ECD was developed to determine trace residues of chlofluazuron, 1-[3, 5-dichloro-5-trifluoromethyl-2-pyridyloxy)phenyl]-3-(2, 6-difiuorobenzoyl), in meat, and applied to analyze the residues in domestic and imported meats. The analytical scheme developed does not require column chromatographic cleanup; chlorfiuazuron was extracted with diethyl ether and petroleum ether (50: 50), partitioned against acetonitrile, cleaned up with silica Sep-Pak cartridge, identified GC/ECD, and comfirmed by GC/MS. The mean recoveries of the pesticide in meat fortified with standard solution 0.1, 0.5, 0.1 mg/kg were ranged from 82 to 95%. The limit of detection and limit of quantitation were 0.001 and 0.005 mg/kg, respectively. Chlorfluazuron residues were not found in domestic samples, but found in imported Australian beef ranging from 0.02 to 0.17 mg/kg, detected by 18% among the samples.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.2 s.30
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• pp.166-179
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• 1989

This study was undertaken to discuss the frameworks of the gorgeous and magnificent royal procession ceremonies in the Yi Dynasty, thereby exploring the classification systems of 'three stages and five segments' on the basis of cultural anthropology and Korean traditional shamanism of ancestral sacrifices. The ceremonies were classified into three phases of (1) cleanup stage, (2) primary objective attendance stage, and (3) completing stage. Among these phases, p. :mary objective attendance stage was further distributed into five segments of (1) road guide, (2) dressing, (3) royal procession, (4) attendants' procession, and (5) back row procession. The isolates and functions of the royal procession ceremonies in the Yi Dynasty were studied through the application of Levi Strauss's structural methodology.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.341-344
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• 2008

Computational studies have been performed to analyze the particle loadings onto the filters according to the different inflow pattern of dusty gas and the flow uniformities on the filter surface of back-blown gas at different permeability of porous media setup at the filter outlet. This is preliminary study to find how we can reduce the regeneration time and improve the regeneration efficiency of filters with dust layer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.39-43
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• 2001

This paper aims to manufacturing of connecting rod die using CAD/CAM systems. CAD/CAM systems are consist of CAD(MDT4.0), CAM(Z-MASTER) software and CNC milling machine. CAM software is purpose to G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for data network.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.812-815
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• 2007

Computational simulation has been performed to design the filtration system for Korea model IGCC demonstration plant. The filtration system for optimal design has four effective filters corresponding to the clusters composed of a group of ceramic candle filters. It was analyzed how the different entrance geometry influences the flow field and the particle behavior in the filtration system. The particle loading is minimum when the gas mixed with particles flows into the filter vessel with a shroud tube through a tangential inlet. However, the particle loading is maximum when the gas with particles enters the filter vessel through a normal inlet which a entrance tube extended from. By controling adequately both conditions of inflow, the filtration system can be operated optimally to prolong the filter life-time and to save the energy for cleaning filters.

• Asian Journal of Atmospheric Environment
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• v.5 no.3
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• pp.181-188
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• 2011

Photocatalysis is a photochemical catalytic reaction which is a highly promising tool for the environmental cleanup process. It is very effective in treatment of environmental pollutants by its unique redox property. It has wide applications in the treatment of atmospheric pollutants (e.g., nitrogen dioxide, trichloroethylene, volatile organics, hydrogen sulfide, benzene, etc) through oxidative removal and by disinfection (aeromicro flora). In this research, the fundamental aspects of photocatalysis are described with respect to the composition of catalysts, experimental conditions (e.g., temperature, duration, etc), and interfering factors (e.g., catalyst deactivation).

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.5
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• pp.455-464
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• 1998

Removal teals of Soxmox were performed using low density ceramic filters doped with various catalysts. Disc type (50 mmO.Dx10 mmt) low density ceramic filters were doped with three different catalysts such as Cu to remove SOx and NOx, and Mn and Co to remove NOx. The air permeabilities and specific surface areas were 40~50cc/min.cm2.cmH2O and 4.1~8.88 m2/g, respectively. Also, the peak pore sizes of catalyst support were 3~5nm. Tests were focused to search optimum operating temperatures for different catalysts. It was found that as the CuO content increases, SOx removal efficiency was increased. NOx removal efficiencies for Mn, Cu and Co, were 85% at 30$0^{\circ}C$, 90% at 40$0^{\circ}C$ and 90% at 45$0^{\circ}C$, respectively.