• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.403-409
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• 2005

Methyl tert-butyl ether (MTBE) contamination in groundwater often coexists with benzene, toluene, ethylbenzene, and xylene (BTEX) near the source of the plume. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by BTEX and MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc. In oil-contaminated environments, anaerobic biodegradation of BTEX and MTBE depended on the concentration and distribution of terminal electron acceptor. In this study, effect of electron acceptor on the anaerobic biodegradation for BTEX and MTBE-contaminated soil was investigated. This study showed the anaerobic biodegradation of BTEX and MTBE in two different soils by using nitrate reduction, ferric iron reduction and sulfate reduction. The soil samples from the two fields were enriched for 65 days by providing BTEX and MTBE as a sole carbon source and nitrate, sulfate or iron as a terminal electron acceptor. This study clearly shows that degradation rate of BTEX and MTBE with electron acceptors is higher than that without electron acceptors. Degradation rate of Ethylbenzene and Xylene is higher than that of Benxene, Toluene, and MTBE. In case of Benzene, Ethylbenzene, and MTBE, nitrate has more activation. In case of Toluene and Xylene, sulfate has more activation.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.1
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• pp.55-58
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• 2000

Methyl tertiary butyl ether (MTBE) is a gasoline additive that boosts the oxygen content in fuel (an oxygenate), resulting in less air-polluting carbon monoxide being released from vehicle exhaust systems. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc.. Studies on the chemical and these problems are going on abroad vigorously. These studies should be performed in our country as well more actively. This paper reviews on articles on these studies and focuses on the identification of the chemical as a groundwater contamination source.

• Journal of Drive and Control
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• v.10 no.4
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• pp.1-6
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• 2013

With aggravation of environmental contamination and energy resource exhaustion, Hybrid Electric Vehicles (HEV) that can be economically operated with low fuel consumption are receiving greater attention. For performance improvement of such HEV, the development of efficient transmission can be seen as one of core technologies such as performance of components and driving strategy. Dual clutch transmission (DCT) is actively studied as a transmission type for HEV due to its advantages of having excellent power transmission efficiency based on manual transmission characteristic, resolving the problem of power interruption, and realizing driving convenience of automatic transmission (AT). In this paper, one diesel HEV equipped with 6-Speed DCT, modelled using MATLAB/Simulink, and a performance simulator developed for this vehicle are introduced. Driving simulation with driving cycles such as FTP75 and NYCC was performed using the developed performance simulator, and the simulated results regarding state of charge and fuel economy, when AT and DCT are applied to this diesel hybrid vehicle respectively, are compared. This performance simulator can be utilized to develop a control algorithm for improving the fuel economy of HEV with DCT.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.392-396
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• 2003

Leaking underground storage tanks are a major source of groundwater contamination by petroleum hydrocarbons. Aerobic bioremediation has been highly effective in the remediation of many fuel releases. Bioremediation of aromatic hydrocarbons in groundwater and sediments is ofen limited by the inability to provide sufficient oxygen to the contaminated zones due to the low water solubility of oxygen. Nitrate can also serve as an electron acceptor And nitrate is less expensive and more soluble than oxygen. it may be more economical to restore fuel-contaminated aquifers using nitrate rather than oxygen. And denitrifying bacteria are commonly found in the subsurface and in association with contaminated aquifer materials. These studies have shown that BTEX and MTBE can be degraded by the nitrate-amended microcosms under aerobic and anaerobic conditons. Biodegradation of the toluene and ethylbenzne compounds occurred very quickly under denitrifying conditions. MTBE, benzene and p-xylene were recalcitrant under denitrifying conditions in this study.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.23-26
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• 2004

Methyl Tertiary-Butyl Ether is one of several fuel oxygenates added to gasoline to improve fuel combustion and reduce tile resulting concentration of hydrocarbon. Thus, MTBE transfer readily to groundwater from gasoline leaking from Underground Storage Tank. Therefor, there are significant risks and costs associated with the water contamination. MTBE is far more water soluble than gasoline hydrocarbon. The purpose of the this study is to test the ability of ground tire with facultative bacteria. Bacillus brevis, to sorb MTBE. The process is consisted both batch and column experiment to determine the sorption capacity. And Biofilm is observed by SEM in the column. Finally, it is clear that ground tire represent an attractive and relatively inexpensive sorption medium for a MTBE. The authors can surmise that to determine the economic cost of ground tire utilization, tile cost to sorb a given mass of contaminant by ground tire will have to be compared to currently accepted sorption media. and Bacillus brevis strain was eliminated on MTBE, too. The biobarrier that ground tire with bacteria, has potential for use in the remediation of MTBE-contaminated environments.

• Tribology and Lubricants
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• v.34 no.5
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• pp.191-196
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• 2018

Bunker C is used in heavy-lift ships, furnaces, and boilers for generating heat, and power. Bunker C has only four regulations for quality standards and is rarely inspected in Korea. For these reasons, other oils such as used lubricant oil are commonly blended with Bunker C. This illegal mixture of fuel can damage the boilers, engines and affect the environment adversely. In this study, we investigate the fuel properties and perform atomic analysis of illegal Bunker C blended with used lube oil. The test results show that higher quantities of used lube oil in Bunker C have higher flash points, total acid numbers, copper corruption, solid contamination, and metal components. Further, increasing quantities of used lube oil in Bunker C cause lower viscosity, sulfur, and V content. However, adequate sample (approximately 1 L) is needed to evaluate presence of adulterants in Bunker C, we attempted the SIMDIST analysis. In the SIMDIST chromatogram, the used engine oils are detected for longer retention times than Bunker C owing to the high boiling point. We also quantitatively analyzed the lube oil content using SIMDIST.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.133-133
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• 2013

For both oxygen reduction (ORR) and hydrogen oxidation reactions (HOR) of proton electrolyte membrane fuel cells (PEMFCs), alloying Pt with another transition metal usually results in a higher activity relative to pure Pt, mainly due to electronic modification of Pt and bifunctional behaviour of alloy surface for ORR and HOR, respectively. However, activity and stability are closely related to the preparation of alloy nanoparticles. Preparation conditions of alloy nanoparticles have strong influence on surface composition, oxidation state, nanoparticle size, shape, and contamination, which result from a large difference in redox priority of metal precursors, intrinsic properties of metals, increasedreactivity of nanocrystallites, and interactions with constituents for the synthesis such as solvent, stabilizer, and reducing agent, etc. Carbon-supported Pt-Ni alloy nanoparticles were prepared by the borohydride reduction method in anhydrous solvent. Pt-Ru alloy nanoparticles supported on carbon black were also prepared by the similar synthetic method to that of Pt-Ni. Since electrocatalytic reactions are strongly dependent on the surface structure of metal catalysts, the atom-leveled design of the surface structure plays a significant role in a high catalytic activity and the utilization of electrocatalysts. Therefore, surface-modified electrocatalysts have attracted much attention due to their unique structure and new electronic and electrocatalytic properties. The carbon-supported Au and Pd nanoparticles were adapted as the substrate and the successive reduction process was used for depositing Pt and PtM (M=Ru, Pd, and Rh) bimetallic elements on the surface of Au and Pd nanoparticles. Distinct features of the overlayers for electrocatalytic activities including methanol oxidation, formic acid oxidation, and oxygen reduction were investigated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.368-371
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• 2003

Accidental release of petroleum products from underground storage tank(USTs) is one of the most common causes of groundwater contamination. BTEX is the major components of fuel oils, which are hazardous substances regulated by many nations. In addition to BTEX, other gasoline consituents such as MTBE(methyl-t-buthyl ether), anphthalene are also toxic to humans. Natual attenuation processes include physic, chemical, and biological trasformation. Aerobic and anaerobic biodegradation are believed to be the major processes that account for both containment of the petroleum-hydrocarbon plum and reduction of the contaminant concentrations. Aerobic bioremediation has been highly effective in the remediation of many fuel releases. However, Bioremediation of aromatic hydrocarbons in groundwater and sediments is ofen limited by the inability to provide sufficient oxygen to the contaminated zones due to the low water solubility of oxygen. Anaerobic processes refer to a variety of biodegradation mechanisms that use nitrate, ferric iron, sulfate, and carbon dioxide as terminal electron accepters. The objectives of this study was to conduct laboratory-scale microcosm studies in assessing enhanced bioremediation potential of BTEX and MTBE under various electron accepters(aerobic, nitrate, ferric iron, sulfate) in contaminated Soil. these results suggest that, presents evidence and a variety pattern of the biological removal of aromatic compounds under enhanced nitrate-, Fe(III)-, sulfate-reducing conditions.

• Mycobiology
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• v.37 no.3
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• pp.215-217
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• 2009

Sixty four samples of cocoa beans replicated in quadruplicates were collected from five warehouses from southwest Nigeria and examined for fungal loads, ergosterol and eohratoxin A The levels of all the variables obtained were further used as indices for cocoa grading into food quality, FoQ (erg < 5 mg/kg; OTA < $1{\mu}g$/kg), feed quality, FeQ (erg = $5{\sim}10\;mg$/kg; OTA in the range of $1.1{\sim}3.11{\mu}g$/kg), Screen for mycotoxin, SFM (erg = $10{\sim}20\;mg$/kg; OTA from $3.12{\mu}g$/kg and above) with fuel quality, FuQ having erg > 20 mg/kg and OTA > $6.12{\mu}g$/kg. Using these ergosterol indices, 18.75% of the cocoa beans examined was classified with the FoQ, 18.75% with the FuQ while 31.25% was classified with both the FeQ and the SFM, respectively. In conclusion, ergosterol can be used as a rapid index to grade fermented, dried cocoa beans meant for export.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.310-314
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• 2020

Although waste oil derived fuel (WDF) production technology was developed under a government initiative ~10 years ago, it became stagnant owing to the small size of participating companies, residents' rejection of foul odor, and the nature of the technology for recycling waste that was avoided. However, this subject is under the spotlight again because of recent developments, such as garbage crisis. In particular, plastic is the most difficult waste to dispose of, with more than 4 million tons of plastic waste produced every year according to statistics from the Ministry of Environment. The most effective method for treating plastic waste is to produce WDF through low temperature thermal decomposition. The WDF includes several volatile ingredients that mostly limit the use of fuel for boilers, owing to safety concerns. In particular, flash point is legally stipulated because of secondary contamination in the distribution process and the risk of fire and explosion. It is required that external shipments (distribution) should be maintained in the range of at least 30~60℃ (excluding explosion prevention facilities) for diesel power generation. Therefore, this study seeks to find the flash point that is best suited to WDFs produced from plastic waste.