• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.199-205
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• 2002

The scale of repair parts market reached 0.1 billion won. Above all, it is remarkable that the automotive insurance business world is paying f3r 40 ~5o% of the whole repair cost. The repair parts consist of a genuine parts, non-genuine parts, recycling used parts. It is the recent trend that recycled parts are more popular than the genuine parts f3r repairing crashed cars due to the cost. Performance of recycled continuous velocity(CV) joints and power steering(PS) gear box as replacement parts was tested and analysed in this study. To examine the durability of the recycled parts, the replaced CV joints and PS gear box after repair were tested and analysed periodically. The results were showed that basic performance of the recycled parts was normal. However the ball cage of CV joints was more frequently damaged than genuine parts. We concluded that a test standard and amendment of related laws for recycled parts is required to get a safe and durable parts.

• Journal of Environmental Science International
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• v.19 no.3
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• pp.365-370
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• 2010

In this study, we carried out the evaluation of EPDM(Ethylene Propylene Diene Monomer) reclaimed rubber mixing with natural rubber at various mixing ratio to reuse as rubber filler. The scorch time and moony viscosity was analyzed to evaluate the effect of cure behavior. And also, we analyzed the tensile strength, the elongation at break and cure time to evaluate the variation of cure behavior. As the results, the scorch time and optimal cure time was decreased according to the increasing of EPDM reclaimed rubber. However, the moony viscosity was increased at each mixing ratio. In case of the added EPDM reclaimed rubber was 20 phr(parts by weight per 100 parts by weight of rubber), the hardness and specific gravity was increased a little. The hardness and specific gravity was increased in rapidly under 40 phr of the added EPEM reclaimed rubber. The tensile strength and elongation at break of the compound of natural and EPDM reclaimed rubber was rapidly decreased compared with its natural rubber when the ratio of adding EPDM reclaimed rubber was over 40 phr.

• Journal of the Korean institute of surface engineering
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• v.55 no.4
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• pp.231-235
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• 2022

As environmental pollution becomes more serious, the demand for electric vehicles (EVs) and lithium-ion batteries for electric vehicles is rapidly increasing worldwide. Accordingly, the amount of waste batteries is also increasing, and a technology for recycling and reusing them is required. In order to reuse a used battery, it is necessary to non-destructively diagnose the deterioration condition of the battery. Therefore, in this study, we investigate the diagnosis of degradation for parallel-connected lithium-ion battery cells through non-constructive electrochemical approach. As the number of parallel-connected cells increased, in addition to linear degradation, abrupt step-like degradation occurred, which is attributed to the predominant degradation of specific cells. In addition, it is confirmed that deteriorated cells among multiple cells can be distinguished through a simple measurement of open circuit voltage (OCV).

• Magazine of the Korea Concrete Institute
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• v.6 no.5
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• pp.123-130
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• 1994

In this paper, a development of composite bridge decks was proposed for design of civil and architectural structures to reuse the empty cans and plastics etc. The experimental specimens were made of rigid foamed urethane taking advantage of corrosionlessness in steel bridge decks, and simplicity in the field construction. 'Therefore, introducing the empty cans into the rigid foamed urethane, this experimentation have been carried out to demonstrate and evaluate the structural behavior by means of loading and vibration tests in composite bridge decks. Consequently, it was possible that had a good effect on the structural behavior by absorbing the strain due to the low elasticity of rigid foamed urethane, and not influence to cans in composite bridges.

• Korean Business Review
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• v.20 no.2
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• pp.87-104
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• 2007

With the effectuation of Kyoto Protocol, one of the important movement throughout the world is reducing the emission of greenhouse gas which is the main reason of making global warming. The actual factor of greenhouse gas is CO2, and in year of 2002 20% of total CO2 emission was produced only through transportation throughout the South Korea. In the contrary, the recycling of municipal wastes in South Korea was 44.0% in 2002, but it will be targeted upto 53.5% in 2011. This study applied survey research for the activities affecting to the emission of CO2 and packaging wastes produced from transportation and packaging stages in logistics area. For this, survey questionary was constructed with five specific areas - strategy, transportation & distribution, custody, packaging, and information. Based on the 144 returned survey questionaries, this study analyzed 54 categories and finally suggests necessary four alternative in Korea.

• Clean Technology
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• v.6 no.1
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• pp.39-49
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• 2000

Ultra Rapid Coagulation (URC) can dramatically remove pollutants loaded in wastewater by adding weighted coagulation additives (WCA) and recycling sludge into the coagulation basin to increase settling velocity and surface adsorption ability of floc. Also settling chamber together with lamella plates offers the high rate settling velocity, which can economically treat a considerable amount of pollutants like as combined sewage overflow (CSO) during the heavy rainfall and reduce the pollutants load into the receiving water for securing water source. It was estimated optimal configuration of settling chamber by using fluent model and the possibilities of reusing the sludge generated in this system.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.25-30
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• 2003

Owing to the deterioration of reconstruction and the construction, much of the construction waste is discharged in our construction field. By supplementing aggregate resources that are insufficient by recycling waste concrete, it is considered that the resource-preserving effect according to the saving and reuse of resource as well as eco-friendly effect that is regarded as important in recent industrial society may be expected. In this study conducted an experiment by setting up 15 levels according to the variations in the rate of substitution of recycled coarse aggregate by the water cement ratio(40, 50, 60%). As the result of it, the slump and air contents was increased by ratio of coarse aggregate, and the elapsed characteristics by the ratio of recycled coarse aggregate showed that there is no clear difference in slump and the air contents. Further, in the characteristics of strength development, the lower the water cement ratio, the higher the compressive strength at early ages, compared with crushed stone, while the compression declined according to the increase of substitution rate of recycled gravel as it was tending upward long-term ages.

• Membrane and Water Treatment
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• v.3 no.2
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• pp.133-140
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• 2012

The overall performance of BNR-MBR, so-called Anoxic-Anaerobic-Aerobic Membrane Bioreactor ($A^3$-MBR), developed for nutrient removal was studied to determine the efficiencies and mechanisms under different solid retention time (SRT). The reactor was fed by synthetic high-rise building wastewater with a COD:N:P ratio of 100:10:2.5. The results showed that TKN, TN and phosphorus removal by the system was higher than 95%, 93% and 80%, respectively. Nitrogen removal in the system was related to the simultaneous nitrification-denitrification (SND) reaction which removed all nitrogen forms in aerobic condition. SND reaction in the system occurred because of the large floc size formation. Phosphorus removal in the system related to the high phosphorus content in bacterial cells and the little effects of nitrate nitrogen on phosphorus release in the anaerobic condition. Therefore, high quality of treated effluent could be achieved with the $A^3$-MBR system for various water reuse purposes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.603-609
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• 2008

The recycled aggregates which were produced from the waste concretes have the disadvantages of inferior properties for natural aggregate. Therefore, in order to reuse the recycled aggregate it must be solved to improve the quality of recycled aggregate. In this study, the quality of recycled aggregate was improved by the surface treatment method using the colloidal silica solution. And, in order to examine the possibility of reusing the surface coated recycled aggregate in constructing concrete structures, we studied the mechanical properties and durability of the concrete using the surface coated recycled aggregates and the other concrete.

• Journal of Environmental Science International
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• v.14 no.3
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• pp.335-343
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• 2005

The objective of this research is to evaluate a feasibility of wastewater reuse by membrane treatment with vibrating membrane separation equipment. Molecular weight of compounds in wastewater, permeability of membrane and retentate characterization after membrane filtration were investigated in order to determine appropriate membrane pore size and materials for wastewater treatment. Selected membrane was evaluated with vibration membrane separation equipment to optimize operating conditions. The following conclusion are drawn. 1. We got as following test results after the distribution of particles in the semiconductor wastewater, are made up of $1\~20{\mu}m$. Si, gold and Al in turn are contained in semiconductor wastewater. 2. Recovery rate is changeless under increasing recovery rate in operation. Though a value can be if pressure can be changed, the highest value of permeate rate is presented in 150 psi. 3. The AS-100(polysulpone) was selected as the most appropriate membranes for the treatment of semi-conductor wastewater to VSEP system. The fouling almost did not occur during this experiments. The analyses of treated water with VSEP system showed conductivity: 0.059,us/cm, TDS: 40mg/l, COD: 20mg/l, SS : 5mg/l, n-Hexane: 8.3mg/l. Comparing previous systems, operating expenses is decreased by more $50\%$.