• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.331-334
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• 2009

Currently, the bipolar plates are fabricated mainly from graphite materials. However, metal bipolar plate are getting most attractive due to their good feasibility of mass production and low cost. In this study, metal bipolar plates for fuel cell Vehicles were developed with a concept based on the straight flow patterns to minimize the pressure drop and spring back. And molded gasket apply to the bipolar plate for improve sealing performance. Results show that the metal bipolar plate have a high potential to replace for graphite materials in fuel cell application.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.150-156
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• 1986

A Rankine cycle including heat exchange processes in the steam generator has been analyzed by the concept of available energy. The operation condition of the cycle can be expressed with the evaporation temperature, and there exists an optimum power condition at which the thermal efficiency of the cycle is almost the same as that of the Carnot cycle at the maximum power condition. The mass flow rate of the working fluid increases sharply as the evaporation temperature approaches to the critical point, and the regenerative system is needed to operate the cycle at the maximum power condition.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.534-535
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• 2006

This study attempts to develope the micro-turbine generators which is expected to run efficiently even in very low head and small flow rate, so that the limitations on the conventional small scale hydropower could be alleviated and competition with other alternative energy sources in the changable design conditions could be attained. The micro turbine generator of a new concept was designed based on changable design conditions, hydrodynamics and theory of power transmission.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1779-1792
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• 2009

Now, the goal of the third generation KTX project is to create a new species of high speed train in order to open a new era of high speed railway system in history by authentic Korean technology and innovative design. Now the third generation KTX, must go beyond the original stagnant paradigm and be positioned as an emotional resource which is creating a shift in the public's perspective of transportation and expanding the idea that transportation intersects the two distinct realms of culture and environment as well. In addition, the overall design should reflect the Korean culture and characteristics, simple yet resonant, both the interior space and the exterior fuselage should portray the dynamic heritage of Korea such as the powerful yet subdued energy of Jung Joong Dong. In short, through the symbolic key words in Korean, Dong(Dynamics), Mek(Pulse), Ryu(Flow), Gam(Sensibility), the third generation KTX design project aims to create an new identity of Korean high speed railway which can stand globally.

• Journal of Institute of Convergence Technology
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• v.6 no.1
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• pp.37-41
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• 2016

The serpentine internal passage is located in turbine blade and it shows the variety heat transfer distribution. Especially, the Coriolis force, which is induced by blade rotation, makes different heat transfer distribution of the leading and trailing surfaces of serpentine internal passage. The different heat transfer is one of the reasons why the serpentine cooling passage shows low cooling performance in the rotating condition. So, this study tried to design the advanced the serpentine passage to consideration of the Coriolis force. The design concept of advanced serpentine cooling is maximizing cooling performance using the Coriolis force. So, the flow turns from leading surface to trailing surface in advanced serpentine passage to match the direction of Coriolis force and rotating force. We performed numerical analysis using CFX and compared the existing and advanced serpentine internal passage. This design change is induced the high heat transfer distribution of whole advanced serpentine internal passage surfaces.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.295-308
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• 2009

Now, the goal of the third generation KTX project is to create a new species of high speed train in order to open a new era of high speed railway system in history by authentic Korean technology and innovative design. Now the third generation KTX, must go beyond the original stagnant paradigm and be positioned as an emotional resource which is creating a shift in the public's perspective of transportation and expanding the idea that transportation intersects the two distinct realms of culture and environment as well. In addition, the overall design should reflect the Korean culture and characteristics, simple yet resonant, both the interior space and the exterior fuselage should portray the dynamic heritage of Korea such as the powerful yet subdued energy of Jung Joong Dong. In short, through the symbolic in Korean, Dong(Dynamics), Mek(Pulse), Ryu(Flow), Gam(Sensibility), the third generation KTX design project aims to create an new identity of Korean high speed railway which can stand globally.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.5
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• pp.1319-1332
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• 1995

Numerical analysis was performed to characterize the particle deposition behavior on a horizontal free-standing wafer with thermophoretic effect under the turbulent flow field. A low Reynolds number k-.epsilon. turbulence model was used to analyze the turbulent flow field around the wafer, and the temperature field for the calculation of the thermophoretic effect was predicted from the energy equation introducing the eddy diffusivity concept. The deposition mechanisms considered were convection, diffusion, sedimentation, turbulence and thermophoresis. For both the upper and lower surfaces of the wafer, the averaged particle deposition velocities and their radial distributions were calculated and compared with the laminar flow results and available experimental data. It was shown by the calculated averaged particle deposition velocities on the upper surface of the wafer that the deposition-free zone, where the deposition velocite is lower than 10$^{-5}$ cm/s, exists between 0.096 .mu.m and 1.6 .mu.m through the influence of thermophoresis with positive temperature difference of 10 K between the wafer and the ambient air. As for the calsulated local deposition velocities, for small particle sizes d$_{p}$<0.05 .mu.m, the deposition velocity is higher at the center of the wafer than at the wafer edge, whereas for particle size of d$_{p}$ = 2.0 .mu.m the deposition takes place mainly on the inside area of the wafer. Finally, an approximate model for calculating the deposition velocities was recommended and the calculated deposition velocity results were compared with the present numerical solutions, those of Schmidt et al.'s model and the experimental data of Opiolka et al.. It is shown by the comparison that the results of the recommended model agree better with the numerical solutions and Opiolka et al.'s data than those of Schmidt's simple model.

• Economic and Environmental Geology
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• v.45 no.5
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• pp.579-587
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• 2012

The purpose of this study is to emphasize the necessity of extention of a government R&D planning scope. Presently, government R&D planning is focused on the selecting a R&D project. There is no R&D strategy for R&D conducting such as the composition of R&D team, collaboration and knowledge flow. Ordinarily these strategies are established by research director. This study analyzed the determinants of excellent R&D performance and proposed R&D strategy for R&D conducting using the patent bibliograpy information in energy resources production technology field. On the other hand, this study introduced the concept of technology lifecycle and showed that R&D strategy should be differentiated by technology lifecycle.

• Journal of Energy Engineering
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• v.12 no.2
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• pp.74-83
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• 2003

In the advanced nuclear power plants including APR1400, the SDVS (Safety Depressurization and Vent System) is adopted to increase the plant safety using the concept of feed-and-bleed operation. In the case of the TLOFW (Total Loss of Feedwater), the POSRV (Power Operated Safety Relief Value) located at the top of the pressurizer is expected to open due to the pressurization of the reactor coolant system and discharges steam and/or water mixture into the water pool, where the mixture is condensed. During the condensation of the mixture, thermal-hydraulic loads such as pressure and temperature variations are induced to the pool structure. For the pool structure design, such thermal-hydraulic aspects should be considered. Understanding the phenomena of the submerged steam jet condensation in a water pool is helpful for system designers to design proper pool structure, sparger, and supports etc. This paper reviews and evaluates the steam jet condensation in a water pool on the physical phenomena of the steam condensation including condensation regime map, heat transfer coefficient, steam plume, steam jet condensation load, and steam jet induced flow.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.3
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• pp.363-372
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• 2020

Anionic radionuclides pose one of the highest risks to the long-term safety assessments of disposal repositories. Therefore, techniques to immobilize and separate such anionic radionuclides are of crucial importance from the viewpoints of safety and waste volume reduction. The main objective of this study is to design a separator with minimum pressure disturbance, based on the concept of a conventional cyclone separator. We hypothesize that the anionic radionuclides can be immobilized onto a nanomaterial-based substrate and that the particles generated in the process can flow via water. These particles are denser than water; hence, they can be trapped within the cyclone-type separator because of its design. We conducted particle tracking analysis using computational fluid dynamics (CFD) for the conventional cyclone separator and studied the effects due to the morphology of the separator. The proposed sandglass-like design of the separator shows promising results (i.e., only one out of 10,000 particles escaped to the outlet from the separation zone). To validate the design, we manufactured a laboratory-scale prototype separator and tested it for iron particles; the efficiency was ca. 99%. Furthermore, using an additional magnetic effect with the separator, we could effectively separate particles with ~100% efficiency. The proposed sandglass-like separator can thus be used for effective separation and recovery of immobilized anionic radionuclides.