• Journal of Environmental Health Sciences
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• v.14 no.1
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• pp.63-71
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• 1988

This study is an experimental research on the anaerobic digestion of pig manure and night soil mixed waste at room temperature (25$\circ$C), and the results are shown below: 1. The steady-state condition based on gas production as digestion temperature dropped to 25$\circ$C from 35$\circ$C was achieved at around 28, 47, 56, 64 days respectively when its hydraulic retention time(HRT) are 10, 20, 30, 40 days. 2, Alkalinity and volatile acid(VA) was increased as increasing the organic loading. 3. Removal efficiency of chemical oxygen demand(COD) and biochemical oxygen demand (BOD) was improved as longer HRT, and generally COD value is lower and BOD value is higher relatively. 4. Overall treatment efficiencies of mixed waste are higher than of pig manure and of night soft. 5. Organic removal efficiency at room temperature (25$\circ$C) is 20-25% lower at medium temperature (35$\circ$C) in a same VS loading condition. 6. Refractory fraction of the infiuent VS and organic removal rate constant(K) estimated at around 37% and 0.107/day respectively.

• Computers and Concrete
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• v.19 no.5
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• pp.515-526
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• 2017

Recent trend is to use the lightweight concrete in the construction industry because it has several advantages over normal weight concrete. The Lightweight concrete can be produced from the industrial waste materials. In South East Asian region, researchers are very keen to use the waste materials such as oil palm shell (OPS) and palm oil clinker (POC) from the palm oil producing industries. Extensive research has been done on lightweight concrete using OPS or POC over the last three decades. In this paper the aggregate properties of OPS and POC are plotted in conjunction with mechanical and structural behavior of OPS concrete (OPSC) and POC concrete (POCC). Recent investigation on the use of crushed OPS shows that OPSC can be produced to medium and high strength concrete. The density of OPSC and POCC is around 20-25% lower than normal weight concrete. Generally, mechanical properties of OPSC and POCC are comparable with other types of lightweight aggregate concrete. It can be concluded from the previous study that OPSC and POCC have the noteworthy potential as a structural lightweight concrete.

• Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.349-357
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• 2015

To reutilize fisheries waste, we isolated a bacterial strain from a coastal area located in Busan. It was identified as Bacillus licheniformis TK3-Y. Using plate assay and 500-mL flask experiments, we found that the isolate simultaneously possessed cellulolytic, proteolytic, and lipolytic activities with salt tolerance. 10% (v/v) inoculums, were used to examine the biodegradation characteristics of the TK3-Y strain on carboxymethylcellulose, skim milk, and olive oil media. The optimum conditions for pH, temperature, agitation speed, and NaCl concentration on each 1% substrate were 6, $50^{\circ}C$, 180 rpm, and 17.5%, respectively. Under optimal conditions, the TK3-Y strain showed 1.07 U/mL cellulolytic, 1,426 U/mL proteolytic, and 6.45 U/mL lipolytic activities. Each enzyme was stable within a range of 17.5-35% NaCl. Therefore, the salt tolerance ability of strain TK3-Y was superior to other related strains. In degradation of a mixed medium containing all three substrates, both the cellulolytic and proteolytic activities were somewhat lower than those on each single substrate, while the lipolytic activity was somewhat higher. From the above results, the TK3-Y strain appears to be a good candidate for use in the efficient treatment of fisheries waste in which components are not collected separately.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.140-145
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• 2010

The simultaneous detection of Cd (II), Pb (II), Cu (II), and Hg (II) ions in aqueous medium using a BDD electrode with DPASV is described. XPS was used to characterize the chemical states of trace metal ions deposited on the BDD electrode surface. Experimental parameters that affect response, such as pH, deposition time, deposition potential, and pulse amplitude were carefully optimized. The detection limits for Cd (II), Pb (II), Cu (II), and Hg (II) ions were 3.5 ppb, 2.0 ppb, 0.1 ppb and 0.7 ppb, respectively. The application of the BDD electrode on the electrochemical pretreatment for the simultaneous metal detection in the dye waste water was also investigated.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.100-110
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• 2022

Corrosion of steel reinforcement is the most important mode of concrete structures damages. It strongly depends on the composition and physicochemical properties of the cementitious medium. The use of waste materials as lightweight aggregates in concrete is environmentally recommended in polluted environments such as marine and/or industrial atmospheres in order to reduce its porosity and ensure the requested protection of reinforcing steel. The present study investigated the effect of waste cork addition on corrosion resistance of steel rebar in mortar specimen prepared in the laboratory. The main objective of this study was to improve the corrosion resistance of reinforcing steel. Another objective of this study was to valorize this ecological product and preserve the environment. Results obtained from various electrochemical tests indicated that the presence of a fine cork powder substantially improved the corrosion resistance of steel in the mortar contaminated by chloride ions. This improvement was reflected by a notable decrease in corrosion current density and a shift of corrosion potential of the steel towards more noble values. Moreover, the presence of a fine cork powder in the mortar had no adverse effect on its mechanical properties.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.182-190
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• 2004

An unique extraction chromatographic column (TOA: Tri-n-octylamine on Teflon powder) with a two-stage sample loading was prepared to separate Np and Pu from the environmental matrix. Np and Pu were efficiently retained in 4 M $HNO_3$ medium on the column and easily eluted with 0.02 M oxalic acid in 0.16 M HNO$_3$at $95^{\circ}C$. The separated solutions were free from most of the matrix elements and were aspirated into the ICP-MS directly. The decontamination factor for 238U is more than 104. The instrumental detection limit for 237Np was 0.46 pg mL-l ($1.2{\times}10_{-5}$Bq mL-l), and for 239Pu was 0.48 pg mL-l ($1.1{\times}10_{-3}$ Bq mL-l). The feasibility for the determination of both elements was proved by analysing IAEA-135 reference samples, the measured values agreed with the recommended reference value.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.106-113
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• 2004

A major problem of nuclear energy is the production of radioactive wastes. Needs for more environmentally favorable method to decontaminate radioactive contaminants make the use of liquid/Supercritical $CO_2$ as a solvent medium. In removing radioactive metallic contaminants under $CO_2$ solvent, two methods - use of chelating ligands and that of water in $CO_2$ emulsion - are possible. In the chelating ligand method, a combination of ligands that can make synergistic effects seems important. We discuss about the properties of microemulsion formed by F-AOT. By adding acid in water core, decontamination of metallic parts, soils were possible.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.133-134
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• 2009

조사 핵연료 및 구조재료의 핫셀시험을 위한 조사재시험시설은 고방사능물질의 시험 및 취급과정에서 발생한 각종 방사성 물질에 오염된 공기를 정회하기 위한 특수 공기조화설비를 운영하고 있다. 시설의 배기 계통은 핫셀 계통 및 핫셀 이외의 계통으로 니눠지고 있다. 그 중 핫셀 구역 이외의 공기는 1차적으로 프리필터와 HEPA 필터로 구성된 AFU(Air Filtering Unit)로 정화하여 외부에 방출하는 MUP(Medium Under Pressure) 시스템을 채용하고 있다. 외부에 방출하는 배기의 오염을 최소화하기 위하여 설치된 AFU에 대한 풍량 측정 및 HEPA필터의 성능시험을 실시하였으며, 그 결과에 대하여 고찰하였다.

• 연구논문집
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• s.32
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• pp.5-13
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• 2002

This paper deals with the result of an analysis on the effect of the power generation by municipal solid waste(MSW)-refuse derived fuel(RDF) and the introduction of tipping fee sharing between RDF manufacturing and power generation project. As a model case for the MSW generated at small and medium cities in our country, an analysis of the RDF power generation and Tipping fee sharing shows that 1) MSW amount of 7,800* $10^3 $t/y could produce 1,950*$10^3$t/y of RDF 2) Electric power generated by MSW-RDF could supply 290,000 households/year and 98,548 C-t/y of $CO_2$ could be reduced. 3) Tipping Fee should be shared by the considering of the contents of project of both side between RDF Production and power generation.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.09a
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• pp.3-12
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• 2006

The main feature of these total technologies is that we can constitute the optimum treatment scheme fitting to the property of wastes, amount of wastes and energy requirement. For high moisture content wastes or biomass resources, high pressure steam process (MMCS) for crush, dry and deodorize wastes to produce high quality fertilizer of fuel is most appropriate. For dry or semi-dry solid wastes, the STAR-MEET system can be applied to produce low-BTU gases for power generation using duel fueled diesel engines of Stirling engines, and the REPRES and HyPR-MEET systems can be applied to produce hydrogen rich medium-BTU gas. For waste plastics and oils, liquefaction technology is best fit to produce light oil or kerosene equivalent fuel oils. These total technologies are completely different from the existent waste treatment technologies based on land-filling or incineration, and are expected to disseminate all over the world in the near future.