• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.560-563
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• 2008

A modified polyol process is developed to enhance Pt loading during the preparation of Pt/C catalysts. With the help of the zeta potential, the effect of pH on the electrostatic forces between the support and the Pt colloid is investigated. It is shown experimentally that the surface charge on the carbon support becomes more electropositive when the solution pH is changed from alkaline to acidic. However, this change does not affect the electronegative surface charge of Pt colloids already attained and stabilized by glycolate anions. This new behavior caused by the change in the solution pH accounts for the enhanced yield of the process and does not affect the Pt particle size. All our experimental results reveal that this simple modification is a cost effective method for the synthesis of highly Pt loaded Pt/C catalysts for fuel cells.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.60-66
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• 2004

Increased energy costs have placed demands for improved combustion efficiency, high equipment availability, low maintenance and safe operation. Simultaneously low NOx modification, installed due to stricter environmental legislations, require very careful combustion management. The flame diagnostics system has been developed specially to meet these requirements. We aimed at gaining the relationship between burner flame image and emissions such as NOx and unburned carbon in furnace by utilizing the image processing method. For the first step of development, its possibility test was undertaken with bench furnace. The test proceeded to the second step with pilot furnace, the system was observed to be effective for evaluating the combustion conditions.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.12
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• pp.48-55
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• 1997

A useful method to detect tool breakage suing neural network of cutting force signal is porposed and implemented in a basic cutting process. Cutting signal is gathered by tool dynamometer and normalized as a preprocessing. The cutting force signal level is continually monitored and compared with the predefined level. The neural network has been trained normalized sample data of the normal operation and cata-strophic tool failure using backpropagation learning process. The develop[ed system is verified to be very effective in real-time usage with minor modification in conventional cutting processes.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.91-100
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• 2004

This study presents the development of a new aluminum seat frame for the commercial bus. Back moment and seat belt anchorage analysis of the conventional steel seat frame was conducted as a base model. Effective aluminum section dimensions for aluminum pipe were calculated from equivalent stiffness and equivalent weight study. Back moment and seat belt anchorage strength with the developed aluminum seat frame were compared to those of the base model. Additionally, to pass the fatigue test, shape modification of side frame assembly was conducted. From this study we could reduce the weight of seat frame more than 5 kg. And the current analysis model and procedure can provide useful informations in designing a new commercial car seat and can reduce the overall design cost and time.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.95-96
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• 2006

Surface modification of clay minerals has become increasingly important for improving the practical applications of clays such as polymeric nanocomposites. We used the copolymer as modifiers having phenyl components, and successfully developed a route for the preparation of amine functionalized polymer based on oligostyrene and its block copolymers. The oligo(St-co-VBC)s with controlled molecular weight were synthesized via nitroxide mediated polymerization method. We also successfully prepared organophilic layered silicates whose surface is covered with styrenic copolymers. Through the analysis of chemical structure and morphology, we concluded that copolymers were very effective organic modifiers to change the surface characteristics of layered silicates.

• Carbon letters
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• v.25
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• pp.55-59
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• 2018

Carbon chain inserted carbon nanotubes (CNTs) have been experimentally proven having undergone pronounced property change in terms of electrical conductivity compared with pure CNTs. This paper simulates the geometry of carbon chain inserted CNTs and analyzes the mechanism for conductivity change after insertion of carbon chain. The geometric simulation of Pt doped CNT was also implemented for comparison with the inserted one. The results indicate that both modification by Pt atom on the surface of CNT and addition of carbon chain in the channel of the tube are effective methods for transforming the electrical properties of the CNT, leading to the redistribution of electron and thereby causing the conductivity change in obtained configurations. All the calculations were obtained based on density functional theory method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.57-63
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• 2011

Dielectric Barrier Discharge (DBD) reactor with sinsodual AC type of power supply is very widely adopted for its compact size and effective discharging mechanism to generate high density of ozone radicals. However, at the aspect of design on power supply, its optimal switching conditions and topology is achieved by empirical test. Therefore, throughout this paper, it is proposed a design method of DBD power supply to guarantee a maximum ozone yield rate in accordance with DBD reactor modification and impedance variation when rapid gas discharging in the DBD reactor is proceeded.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.499-502
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• 2003

Increase energy costs have placed demands for improved combustion efficiency, high equipment availability, low maintenance and safe operation. Simultaneously low NOx modification, installed due to stricter environmental legislation, require very careful combustion management. We aimed at gaining the relationship between burner flame image and emissions such as NOx and unburned carbon in furnace by utilizing the image processing method. For the first step of development, its possibility test was undertaken with bench furnace. The test proceeded to the second step with pilot furnace, the system was observed to be effective for evaluating the combustion conditions. By using this technology, it is possible to perform continuous monitoring of the combustion conditions and instant detection of individual changes for each burner to prevent future loss of ignition.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.103-110
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• 2000

This study was done in order to increase production speed using coater dryer in maximum capacity without print mottle. The aim of this study was to measure coating color immobilization content(CCIC) and to decrease CCIC through coating color optimization. The final goal of this study was the prevention of print mottle in maximum drying condition by CCIC control. As a result the measuring method of CCIC was set by brightness transition and the effective factors in pigments and binders were defined. With color optimization considered this factors, CCIC was decreased by 4%. Through this CCIC decrease and modification of coater utility, the print mottle was prevented even though using coater dryer in maximum.

• Textile Coloration and Finishing
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• v.21 no.4
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• pp.46-56
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• 2009

In order to establish the standard manufacturing condition of PET flame retardant sheets, physicochetnical properties of the samples made by the conventional flame-retardant finishing were systematically investigated, including compatibility among flame retardant agent and finishing auxiliaries, surface property, and wicking property. From this results, the addition of washing and renapping process after the shearing process was required for the more effective in producing PET flame-retardant sheet by the standard finishing. The effect of the modification of the regular flame retardant finishing process was studied by FTIR, TGA, and flame retardancy test.