• Journal of the Korean Society for Precision Engineering
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• v.23 no.10
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• pp.60-67
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• 2006

This paper presents the temperature control in aluminum plate with Peltier module. From the experimental work, Peltier module is used to control the temperature of small aluminum plate for both heating and cooling with the control of current and fan ON/OFF. And current control of Peltier module was accomplished by PWM method. As a result of experiments, it is proper that operate cooling fan only while cooling duration and there exist a proper cooling current to drop temperature rapidly. It takes about 125sec to control temperature of aluminium plate between $30^{\circ}C$ and $70^{\circ}C$ and about 70sec between $40^{\circ}C$ and $60^{\circ}C$, in ambient temperature $28^{\circ}C{\sim}29^{\circ}C$ while cooling fan is operated only cooling duration. With the cooling current, temperature control of aluminum plate was accomplished more rapidly in comparison without cooling current. Future aim is to realize more rapid temperature control and develop SMHA(special metal hydride actuator) by using Peltier module as a heating and cooling source.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.767-768
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• 2006

In this study, copper vapor chambers with built-in cooling fins, which eliminated the soldered or brazed joints in the conventional vapor chamber, were fabricated using the metal injection molding process. The results show that with optimized molding parameters, fins with an aspect ratio up to 18 could be produced. After sintering, the densities of the fin and chamber reached 96%. With only 32 cooling fins and a small fan installed, the thermal resistance of the heat sink was $1.156^{\circ}C/W$, and the power dissipation was 40W when the junction temperature was $70^{\circ}C$. When copper powder was sintered onto the chamber to make a vapor chamber, the thermal resistance decreased to $1.046^{\circ}C/W$.

• The International Journal of Costume Culture
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• v.8 no.2
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• pp.71-84
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• 2005

Fibulae have been used as clothing fasteners throughout history. They were especially popular with the Celts, but were also used by the Greeks, Romans, Saxons, and Vikings, to name a few. The earliest examples are found in the Mediterranean and Middle East, and date from 800 B. C. and earlier. Their use continues today, in the form of the modern safety pin. The first fibulae of the Bronze Age were very simple, much like modern safety pins. The form of this small functional object varies from simple to extravagant since it is also seen as a piece of jewelry, and is thus subject to the evolution of style. Its size depends on the thick/Jess of the clothing to be attached. Its fabrication demonstrates a great mastery of metal work. Fibulae would vary with the taste and wealth of the wearer. The Fibulae were divided into 10 styles according to the shape, Fibulae with Safety pin shaped style, Penannular shaped style, Animal shaped style, Diamond shaped style, Radiated head shaped style, Horsefly shaped style, Arched bow shaped style, Fan-shaped style, Trumpet shaped style, Arched-fan shaped style.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.395-403
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• 2013

Fishing efficiency of the squid jigging vessel using the LED and metal halide fishing lamp combination was analyzed to reduce the cost for fishing operation utilizing the fishing light system for high degree of efficiency in the squid jigging fishery (one of the representative coastal and offshore fisheries in Korea). This study aims to improve the nature of existing LED lamps and to develop fan-shaped LED lights having 180W of power and ${\pm}45^{\circ}$ angle of light intensity distribution. The marine experiment for making a comparison of their fishing efficiency was tested by a 9.77 tons fishing vessel from Oct. through Dec. 2012. As a result, experimental fishing vessel showed slightly higher fishing efficiency than the average of metal halide lamp-equipped vessel and 20% energy savings. This means that the combination of LED and metal halide lamps would provide an efficient way to lower energy consumption while maintaining fishing efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.474-479
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• 2016

As the Eco-energy is recently required, electrical energy is fast increased. Several induction heating methods are attractive for Eco-energy and energy saving. In this paper, electrical fan heater was designed and developed with new concept for energy saving by electromagnetic induction heating. Proposed system was composed of three module, blast part, induction heating part and power transformation part. Induction heating method was adapted for heating and the resonant inverter was used for increasing of the power transformation efficiency. Full-bridge resonant inverter was adopted to resonant inverter. This system was composed of induction heating part made with metal(SUS 40 series), and power transformation part made with rectifier module, filter module and resonant inverter. From these results, the proposed new electric heater could be saved the energy from faster increasing the temperature compared to commercial gas and other electric heater. This electrical fan heater is possible to be used in field of home, commercial and agricultural area for eco-energy saving heater.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.274-276
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• 2006

This study was researched by measuring the amount how much a welder inhaled the major harmful metals such as Fe, Mn, Cu, Zn and so on which occurred at the welding site during welding work and also by measuring the heavy metal concentration in a welder's blood after the welding. By using the mobile fan, the measure of welding fume and the result were taken.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.897-900
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• 2005

This paper presents temperature control of aluminum plate using Peltier module. As one of the thermoelectric effect, Peltier effect is heat pumping phenomena by electric energy. So if current is charged to Peltier module, it absorbs heat from low temperature side and emits heat to high temperature side. In this experiment, Peltier module is used to control the temperature of small aluminum plate with heating and cooling ability of Peltier module with current control and fan On/OFF control. And current control of Peltier module was accomplished by PWM method. As a results of experiments, it takes about 125sec to control temperature of aluminium plate between $30^{\circ}C\;and\;70^{\circ}C$ and about 70sec between $40^{\circ}C\;and\;60^{\circ}C$, in ambient temperature $29^{\circ}C$ while operating cooling fan only while cooling duration. Future aim is to realize more rapid temperature control and develop SMHA(special metal hydride actuator) by using Peltier module as a heating and cooling source.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1802-1813
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• 2023

Conjugate heat transfer between liquid metal and solid is a common phenomenon in a liquid-metal-cooled fast reactor's fuel assembly and heat exchanger, dramatically affecting the reactor's safety and economy. Therefore, comprehensively studying the sophisticated conjugate heat transfer in a liquid-metal-cooled fast reactor is profound. However, it has been evidenced that the traditional Simple Gradient Diffusion Hypothesis (SGDH), assuming a constant turbulent Prandtl number (Pr_t,, usually 0.85 - 1.0), is inappropriate in the Computational Fluid Dynamics (CFD) simulations of liquid metal. In recent decades, numerous studies have been performed on the four-equation model, which is expected to improve the precision of liquid metal's CFD simulations but has not been introduced into the conjugate heat transfer calculation between liquid metal and solid. Consequently, a four-equation model, consisting of the Abe k - ε turbulence model and the Manservisi k_𝜃 - ε_𝜃 heat transfer model, is applied to study the conjugate heat transfer concerning liquid metal in the present work. To verify the numerical validity of the four-equation model used in the conjugate heat transfer simulations, we reproduce Johnson's experiments of the liquid lead-bismuth-cooled turbulent pipe flow using the four-equation model and the traditional SGDH model. The simulation results obtained with different models are compared with the available experimental data, revealing that the relative errors of the local Nusselt number and mean heat transfer coefficient obtained with the four-equation model are considerably reduced compared with the SGDH model. Then, the thermal-hydraulic characteristics of liquid metal turbulent pipe flow obtained with the four-equation model are analyzed. Moreover, the impact of the turbulence model used in the four-equation model on overall simulation performance is investigated. At last, the effectiveness of the four-equation model in the CFD simulations of liquid sodium conjugate heat transfer is assessed. This paper mainly proves that it is feasible to use the four-equation model in the study of liquid metal conjugate heat transfer and provides a reference for the research of conjugate heat transfer in a liquid-metal-cooled fast reactor.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3749-3754
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• 2013

Two 3D isomorphous and isostructural complexes, namely, $[Zn(BDOA)(bpy)(H_2O)_2]_n$ (1) and $[Cd(BDOA)-(bpy)(H_2O)_2]_n$ (2); (BDOA = Benzene-1,4-dioxyacetic acid, bpy = 4,4'-bipyridine) were synthesized under hydrothermal conditions and characterized by means of elemental analyses, thermogravimetric (TG), infrared spectrometry, and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the triclinic system, space group P-1 and each metal ion in the complexes are six-coordinated with the same coordination environment. In the as-synthesized complexes, $BDOA^{2-}$ anions link central metal ions to form a 1D zigzag chain $[-BDOA^{2-}-Zn(Cd)-BDOA^{2-}-Zn(Cd)-]_{\infty}$, whereas bpy pillars connect metal ions to generate a 1D linear chain $[-bpy-Zn(Cd)-bpy-Zn(Cd)-]_{\infty}$. Both infinite chains are interweaved into 2D grid-like layers which are further constructed into a 3D open framework, where hydrogen bonds play as the bridges between the adjacent 2D layers. Luminescent properties of complex 1 showed selectivity for $Hg^{2+}$ ion.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.143-148
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• 2014

Conventional wireless power transfer methods based on coupled magnetic fields need a complex winding structure on the surface of the energy transfer and shows poor efficiency near metal objects due to the eddy current effect. In this study, to mitigate these problems, we investigate an electric field-coupled power transmission system, which is less prone to metal object problems and EMI. Because of the fundamental physical limit in the size of link capacitances, a half-bridge converter with an impedance matching transformer is proposed and the design procedure is derived to provide a soft-switching scheme. Hardware implementation shows that the proposed scheme with a pair of 10cm by 10cm copper plate can power a 1.4W USB FAN in a separation of 0.2mm by using insulating paper when driven by 227 kHz gate pulse.