• Ceramist
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• v.22 no.2
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• pp.133-145
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• 2019

Thermoelectric energy conversion has attracted much attention because it can convert heat into electric power directly through solid state device and vice versa. Current research is aimed at increasing the thermoelectric figure of merit (ZT ) by improving the power factor and reducing the thermal conductivity. Although there have been significant progresses in increasing ZT of material systems composed of Bi, Te, Ge, Pb, and etc. over the last few decades, their relatively high cost, toxicity, and the scarcity have hindered further development of thermoelectrics to expand practical applications. In this paper, we review the current status of research in the fields of nanostructured thermoelectric materials with eco-friendly and low cost elements, such as skutterudites and oxides, for mid-high temperature applications, highlighting the strategies to improve thermoelectric performance.

• Journal of Internet Computing and Services
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• v.20 no.2
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• pp.1-7
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• 2019

The latest mobile applications such as augmented reality, virtual reality, and deep learning can be used efficiently in various fields such as emergency management and game. Accordingly the corresponding applications have been developed for these purposes. However modern mobile applications such as augmented reality and virtual reality increase the energy burden on mobile devices. In order for mobile devices to focus their energy on the latest mobile applications, energy consumption should be minimized for communication and networking, such as cognitive radio. In this paper, we propose a method to reduce the energy consumption of Centralized Cooperative Spectrum Sensing (CCSS) scheme in cognitive radio by devising Stop Reporting Algorithm (SRA). Simulation results show that SRA can reduce energy consumption of mobile devices using cognitive radio.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1573-1579
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• 2013

To test the performance of nuclear fuels, coolant needs to be circulated through the test rig installed in the test loop. Because the pressure and temperature of the coolant is 15.5 MPa and $300^{\circ}C$ respectively, coolant sealing is one of the most important processes in fabricating a nuclear fuel test rig. In particular, 15 instrumentation cables installed in a test rig pass through the pressure boundary, and brazing is generally applied as a sealing method. In this study, an induction brazing system has been developed using a high frequency induction heater including a vacuum chamber. For application in the nuclear field, BNi2 should be used as a paste, and optimal process variables for Ni brazing have been found by several case studies. The performance and soundness of the brazed components has been verified by a tensile test, cross section test, and sealing performance test.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1701-1705
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• 2005

We have established an efficient method for the synthesis of the arylpiperazine derivatives in which the acylation of 2-aminopyridine, the coupling reaction of the acyl compound with piperazines, and reduction of the arylpiperazines were performed under a microwave irradiation (300 W) to afford the corresponding target compounds in quantitative yields. In all cases, the reaction times were remarkably reduced when compared with those of the conventional method.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.84.2-84.2
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• 2015

Growing market of electric vehicles such as hybrid, plug-in hybrid, and bare electric vehicles in the world is accelerating the significance of Li-ion batteries as a renewable green energy. According to such market flow, the developing components such as cathode, anode, electrolyte, and separator, composing the Li-ion batteries, is significantly important tasks for the commercialization. In particular, development of the cathode material having high capacity and stable thermal stability is essential for long-distance electric vehicle in the near future. Herein we introduce various applications of Li-ion batteries such as portable electronics, electric vehicles, and energy storage system, and also its research trend, in particular on the cathode materials.

• Solar Energy
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• v.17 no.2
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• pp.43-53
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• 1997

Characteristics and properties of batteries applicable to the photovoltaic system are described in this paper. The use of a number of different types of batteries and designs depends on the many and varied requirements for battery power and the different environmental and electrical conditions under which they must operate. Most of the batteries used in PV systems are lead/acid batteries, though nickel/cadmium batteries are used for small applications in locations with extreme climates or where high reliability is essential such as spacecraft. The vanadium redox battery has been acknowledged as a promising energy storage system for a wide range of applications.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.165-167
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• 2006

On our return to India from Germany, we have worked on the development of parabolic solar concentrators with input and collaboration of German and Austrian inventors. We have gradually improved the solar technologies to include food processing based on inputs and feedback from users to fulfill their specific requirements. We will discuss the acceptability and commercialisation of various systems that we have successfully developed, their implications and their benefit. These success stories can work as multipliers. These concentrators can have various other applications. The Global Treaty Kyoto Protocol's CDM (Clean Development Mechanism) can result in a win-win situation for both developing and developed nations and the world environment at large - whereby developed nations get carbon credits by supporting renewable energy projects in developing nations. North-South dialogue and South-South dialogue can effectively foster global co-operation meaningfully to benefit People and environments ensuring sustainable development and protection of Our planet Earth, our only HOME!!!

• Nuclear Engineering and Technology
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• v.43 no.3
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• pp.217-242
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• 2011

A variety of Generation III/III+ water-cooled reactor designs featuring enhanced safety and improved economics are being proposed by nuclear power industries around the world in efforts to solve the future energy supply shortfall. Thermal-hydraulics is recognized as a key scientific subject in the development of innovative reactor systems. Phase change by boiling and condensation in the reverse process is a highly efficient heat transport mechanism that accommodates large heat fluxes with relatively small driving temperature differences. This mode of heat transfer is encountered in a wide spectrum of nuclear systems,and thus it is necessary to determine the thermal limit of water-cooled nuclear energy conversion in terms of economic and safety. Such applications are being advanced with the introduction of new technologies such as nanotechnology. Here, we investigated newly-introduced nanotechnologies relevant to boiling and condensation in general engineering applications. We also evaluated the potential linkage between such new advancements and nuclear applications in terms of advanced nuclear thermal-hydraulics.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1125-1128
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• 2009

Conversion of light energy to electrical energy by using a solar cell has long been considered as one of the option for an electrical energy supply in the future. In the past, commercial use was restricted largely to remote area applications where conventional electricity is expensive. Recently, the major application of the solar cells changed to become generation of residential electricity in urban areas where the electricity is already supplied by the conventional grid. This paper covers the current market and technology status of the solar cells and future prospect of their terrestrial applications. Reviewing market trend, this paper discusses high efficiency approach in silicon solar cells, low cost approach in silicon solar cells and finally covers future prospects of silicon solar cells.

• Journal of Electrochemical Science and Technology
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• v.13 no.2
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• pp.167-176
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• 2022

Electrochemical impedance spectroscopy (EIS) is a unique non-destructive technique employed to analyze various devices in different energy storage applications. It characterizes materials and interfaces for their properties in heterogeneous systems employing equivalent circuits as models. So far, it has been used to analyze the performance of various photovoltaic cells, fuel cells, batteries, and other energy storage devices, through equivalent circuit designing. This review highlights the diverse applications of EIS in fuel cells and specific parameters affecting its performance. A particular emphasis has been laid on the challenges faced by this technique and their possible solutions.