• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.2
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• pp.73-79
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• 2004

For the global microwave market, high RF power or deluxe model is applying for inverter gradually. In this paper, 120[V]/1200[W] high power inverter is proposed and verified by an optimized design of PFM type. Especially the steady power output control was fulfilling at ＋/－ 10[％] input voltage variation.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.176-176
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• 2007

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.243-250
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• 2020

The purpose of this study is to find out the possibility of applying microwave-hypochlorous acid leaching to effectively leaching Au in hydrothermal minerals on board. The comparative leaching experiment were confirmed that the leaching rate of Au with(T1)/with out(T2) of microwave nitric acid leaching. In addition, the leaching rate of Au on the conventional leaching by mechanical agitation(T3) and microwave leaching was compared. The result of microwave nitric acid leaching(solid-liquid ratio; 10%, leaching temperature; 90 ℃, leaching time; 20 min) confined that the metal leaching rate was high in the order of As>Pb>Cu>Fe>Zn, and the content of Au in the leaching residue was increased from 33.77 g/ton to 60.02 g/ton. As a result of the comparative leaching experiment using a chloride solvent, the dissolution rate of Au was high in the order of T1(61.10%)>T3(53.30%)>T2(17.30%). Therefore, chloride, which can be manufactured using seawater and that can be recycled by collecting chlorine gas generated in the leaching process, is expected to be an optimal solvent for Au leaching. In addition, the application of microwaves is believed to be effective in terms of time, efficiency and energy.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.31.4-32
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• 2008

The microwave instruments are used many areas of the space remote sensing and space science applications. The imaging radar of synthetic aperture radar (SAR) is well known microwave radar sensor for earth surface and ocean research. Unlike radar, microwave radiometer is passive instrument and it measures the emission energy of target, i.e. brightness temperature BT, from earth surface and atmosphere. From measured BT, the geophysical data like cloud liquid water, water vapor, sea surface temperature, surface permittivity can be retrieved. In this paper, the radiometer characteristics, system configuration and principle of BT measurement are described. Also the radiometer instruments TRMM, GPM, SMOS for earth climate, and ocean salinity research are introduce. As first korean microwave payload on STSAT-2, the DREAM (Dual-channels Radiometer for Earth and Atmosphere Monitoring) is described the mission, system configuration and operation plan for life time of two years. The main issues of DREAM unlike other spaceborne radiometers, will be addressed. The calibration is the one of main issues of DREAM mission and how it contribute on the space borne radiometer. In conclusion, the radiometer instrument to space science application will be considered.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.1-6
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• 1997

In home-style microwave oven, silica-Al powder mixture was ignited among pellets and combustion wave-front propagated to produce Si+AIN+Al2O3 as resultant phases under N2 atmosphere. Without cooling pro-cedure the resultant phases of Si+AIN+Al2O3 continously absorbed microwave and were heated to be syn-thesized into sialon phases. This synthesis rate of sialon phases from silica-Al powder mixture in home-style microwave oven was higher than that in conventional furnace, and total processing time was around 1 hour, which could save energy and cost.

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.44-47
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• 1998

A reduction/oxidation reaction between A1 metal powder and SiO2 powder was performed by Self-propagating High-temperature Synthesis (SHS) reaction induced by microwave energy to produce a composite of Al2O3 and Si powders by using a 2.45 GHz kitchen model microwave oven. A Microwave Hybrid Heating(MHH) method was applied by using SiC powders as a suscepting material to raise the temperature of the disk samples and the heat increase rate of over 100℃/min were obtained before the reaction. The reaction started around 850℃ and the heat increase rate jumped to over 200℃/min after the reaction took place.

• Korean Journal of Materials Research
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• v.6 no.6
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• pp.576-584
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• 1996

The zirconia-alumina composite, a low loss material, was sucessfully sintered using a 2.45 GHz microwave radiation. The dense zirconia was used as a microware coupling aid. The effect of microwave power level on the heating rates of samples and the feasibility of microwave energy use in processign ceramec materials were obtained. It was also obtained how to accurately measure the temperature. According to the microwave heating theory, heating mechanisms were discussed.

• International Journal of Korean Welding Society
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• v.2 no.1
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• pp.57-61
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• 2002

This paper presents development of a SEC(Solar Energy Concentration) utilizing the concentrated solar beam radiation for joining engineering thermoplastics such as Acrylonitrile/Butadiene/Styrene(ABS), Polycarbonate(PC) and Polymethylmethacrylate (PMMA). In addition, to study the joining of the materials, necessary experimentation with applying primer was performed. Tensile tests were conducted to determine the bond strength achieved at the specimen Joint interface. Microscopic examinations of the fractured joints were performed in order to analyze the overall bond quality. Finally, the results in terms of bond strength achieved at the joint interface and energy consumed in the process was compared with those obtained with similar thermoplastic joining technique utilizing microwave energy.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.287-288
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• 2018

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.125-133
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• 2009

Wastewater sludge had normally filled up in land before revising the law of waste material management in 2003, which does not permit landfill of organic sludge in Korea. After the law, most sludge has been littered in the ocean up to now. However, due to the London Convention 96 Protocol, littering sludge in the ocean will also be prohibited after 2011. This Protocol makes countries find out new methods to treat wastewater sludge. There is no exception in Korea too. Many researchers have urgently try to find out better ways to treat sludge. One of ways is to make sludge recycle energy and the success of it depends on drying method. Specifically, it really depends how to make sludge dry ecologic friendly and economic efficiently. Therefore, wastewater sludge produced in Youngdong was analyzed to make it energy resources in this study. The sludge was tested to analyze the drying and chemical characteristics of it by irradiating microwave. In the result, it is sure that the sludge has little heavy metals as like as others in country side. High calories, 3370 Kcal, shows that it has good potential to be recycle energy. Moreover, weight deduction of the sludge vs. time shows long S-curve and has same deduction ratio. Specifically, S-curve can be divided by three sections based on the curvature points. There are steady state reduction ratio of weight and approximately 80% of weight duction in the second section. This results can be used to estimate the amount of sludge reduction in the full-scale microwave dryer. Drying capacity of microwave shows approximately 1.0 kg/kw/hr. It makes sure that sludge recycle energy has the potential of economic efficiency too.