• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.573-578
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• 2003

In this study, new type of induction charging system for electrostatic spraying was manufactured and proposed to improve the electrical safety and charging efficiency. And parameters of proposed system to generate the maximum deposition current with electrical safety were selected and investigated. The selected parameters were frequency of square pulse and thickness of insulation material, outer diameter of device and thickness and positions of electrode. Charging quantity of water drop was measured by deposition current detected from sensing plate indirectly. The maximum deposition current for each parameter were 3.5[uA] at the frequency of 15[kHz] and thickness of 0.25[mm] insulating layer. And maximum deposition currents were 2.8[uA] and 3.0[uA] at 25[mm] outer diameter of charging device and 0.25[mm] thickness of electrode each. Effects of electrode position from spraying nozzle on deposition current was a little.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.205-210
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• 1999

Silk nonwoven fabrics are prepared by needle punching and thermal bonding with silk waste. To enhance the carding efficiency, the degumming rate was controlled with sodium hydrogen sulfite solution. The amount of the remained sericin was 3%(S-3), and 6%(S-6). Mixing wool and LMP(Low melting polyester) with the silk, to improve carding efficiency, was also effective. Following items were tested with prepared silk nonwovon fabrics : weight, thickness, compression, tensile strength, heat insulation, water absorption, and deodorization. The results show that the silk nonwoven fabrics could be used for apparels and new biomaterials.

• Solar Energy
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• v.7 no.1
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• pp.3-13
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• 1987

A batch type passive solar water systems, which perform the dual function of absorbing the solar energy and storing the heated water, have been designed and fabricated for the purpose of side-by-side testing at KIER. The test models included an A, B and C type batch systems which were classified according to the design of box and arrangement of tanks. The year-round performance tests show that B type batch system taken the step-wise tank arrangement indicates 55.7% yearly-average collection efficiency factor and 61% yearly-average maximum collection efficiency factor. Computer-aided-experimental results show that the sufficient hot water can be obtained in the early morning if the glazing is supplemented by a reflector/insulation cover. The thermal performance equation has been developed for the prediction of hourly variation of the water temperature in tank.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1275-1278
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• 2012

Compositional design and optimization of processing parameters are key factors for controlling and improving the properties of electroconductive ceramic composites. Temperature rising time of sheath heater is 1.1 times faster than SiC ceramic heater. Heating insulation of SiC ceramic heater is 2.7 times larger than sheath heater. If SiC ceramic heater is one body type of a product application, contact resistance will decrease. I think that temperature initial rising time is faster than now. The more SiC ceramic heater is used for a long time, the more economic benefit is larger in the view point of heat insulation.

• Journal of Multimedia Information System
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• v.5 no.1
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• pp.47-52
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• 2018

We have developed an electromagnetic generator to bury in subcutaneous area or abdominal cavity of the birds. As we can't use a solar battery, it is extremely difficult to supply a power for subcutaneous implantation such as biosensors under the skin due to the darkness environment. We are aiming to test the antigen-antibody reaction to confirm an avian influenza. One solution is a very small generator with the electromagnetic induction coil. We attached the developed coil to chickens and pheasants and recorded the electric potential generated as the chicken walked and the pheasant flew. The electric potential generated with physical simulator is equal to or exceeds the 7 V peak-to-peak at maximum by 560/min of flapping of wings. Even if we account for the junction voltage of the diode (200 mV), efficient charging of the double-layer capacitor is possible with the voltage doubler rectifier. If we increase the voltage, other problems arise, including the high-voltage insulation of the double-layer capacitor. For this reason, we believe the power generated to be sufficient for subcutaneous area of birds. The efficiency, magnetic 2 mm in length and coil 15mm in length, if axial direction is rectified, the magnetic flux density given to the coil could calculated to 7.1 % and generated power average 0.47mW. The improvements in size and wire insulation are expected in the future.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.10
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• pp.705-710
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• 2012

This study aims to analyse changes of inner temperature of PVS(Passive ventilation skin) and heat recovery when it has ventilation of air through PVS using numerical simulation in the winter condition. Results are as follows. 1) In case of the air inflows through PVS, change of inner temperature of PVS is lower than in case of the air flows inner space to out space, by dynamic insulation. 2) It was identified that the temperature gradient of PVS were bigger by increases of ventilation amount. To reduce ventilation load, heat transfer efficiency at the inner side of PVS is important and what performance of insulation at the inner side of PVS secure helps to improve heat performance of all PVS.

• KIEAE Journal
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• v.13 no.5
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• pp.97-102
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• 2013

Many countries over the world have acknowledged the global warming problem by greenhouse gas emission and tried to solve the problem. The Korean government has also taken many actions such as The Act on Low Carbon, Green Growth and on Promoting Green Building in that architectural building section takes 1/4 of national greenhouse gas emission. Under the situation that buildings constructed 15 years ago when insulation standards were reinforced take about 74%, The Plan on Vitalizing Green Remodeling, finally established on July 2013, will induce energy-efficient remodeling of deteriorated buildings. Using the energy simulation by the Visual DOE 4.0 program, this paper proposed the ways of energy-efficient remodeling of deteriorated high school buildings by measuring energy saving performance of factors that were drawn from the previous study. The factors considered are insulation, window's SHGC, south louver, system efficiency, and indoor setting temperature. Among them, all factors except SHGC proved contribution to reducing energy use at deteriorated high school buildings, compared with the baseline energy consumption.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.45-53
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• 2004

In the summer, the irradiated solar heat gain through the roof has an effect on the thermal environment of the top floor units of apartment houses. This paper investigated the differences of the indoor air temperature and thermal comfort index between the top floor unit and the middle floor unit by measuring them at the sample houses. The purpose of this paper is to provide quantitative data about the irradiated solar heat gain during the summertime through the roof of an apartment house and these data to be the source to reevaluate the appropriate roof insulation efficiency. From this study, we obtained the brief results as follows. Indoor air temperature at the top floor unit is $1.2\sim2.2^{\circ}C$ higher than that of middle floor unit. The evaluation of the indoor thermal comfort index at each sample rooms reveals notable thermal differences between the two units. Top floor units need more cooling load during the summertime compared to middle floor units. Therefore, solutions to reduce solar Heat gain at top floor units to be considered.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.365-370
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• 2005

Infrared (lR) detectors are widely used for such applications as thermoelstic stress analysis, medical diagnostics and temperature measurement. Infrared detectors commonly need to be refrigerated below 80 K, and thus a cooling system should be equipped together with the detector system. The cooling load, which should be removed by the cooling system to maintain the nominal operating temperature of the detector, critically depends on the insulation efficiency of the cryochamber housing the detector. Cryochamber considers the conduction heat transfer through a cold finger, the gases conduction and radiation heat transfer. The thermal loads of an infrared detector Cryochamber with radiation shield are investigated experimentally in present study. Since the effect of radiation heat transfer on thermal loads is significant, radiation shields is installed in the cold finger part to protect heat input through radiation. It is found that the thermal load can be substantially reduced by increasing the number of radiation shield.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.2
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• pp.13-18
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• 2014

This paper proposes an optimum pipe material (PVC vs. PE) design & selection for open loop ground heat exchangers. Heat exchange efficiency and/or workability, and the need for trench insulation were investigated by comparing EWT (cooling mode) of each system. CFD simulations for the PVC and PE pipe with the same inner diameter show similar EWT. This is because the PVC pipe has a small thickness but a low thermal conductivity as compared to the PE pipe, and thus these two properties tend to offset each other. However, a hypothetically insulated pipe led to a meaningful drop of EWT. This means pipe insulation is of importance in performance of ground heat exchangers. From analyzing climate data and system operation, it is not advantageous to insulate trench pipes due to construction difficulties and ground temperature characteristics that are seasonally varied.