• Title/Summary/Keyword: microwave

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Use of uniform distribution for generating synthetic brightness temperature in passive microwave soil moisture retrieval

  • Lee Khil-Ha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.19-28
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    • 2005
  • Passive microwave remote sensing technique have shown great potential for mon monitoring regional/global surface soil moisture. Given a single measurement at dual polarization/single frequency/single view angle, a strategic approach to artificially generating multiple microwave brightness temperatures is presented. And then the statistically generated microwave brightness temperature data are applied to the inverse algorithm, which mainly relies on a physically based microwave emission model and an advanced single-criterion multi-parameter optimization technique, to simultaneously retrieve soil moisture and vegetation characteristics. . The procedure is tested with dual polarized Tropical Rainfall Measurement Mission Microwave Imager (TRMM/TMI) over two different cover sites in Oklahoma and Beltsville field experimental data. The retrieval results are analyzed and show excellent performance.

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The Synthesis of Crystalline-Size Controlled Organic Pigment by Microwave Energy (마이크로파 에너지에 의해 결정 크기가 조절된 유기 안료의 합성)

  • 정기석;고진필;박상보;박찬영;민성기;권종호;오인환;박성수
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.609-616
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    • 2001
  • The application of microwave technology to synthesis of polymer in solvent media has been shown by the synthesis of copper phthalocyanine (CUPc). The increase of synthetic yield-was demonstrated successfully in this study. A power variable microwave synthetic system has been developed with modifying cavity of domestic microwave oven and attaching microwave power controller. The properties of the specimen synthesized at various condition under the conventional thermal processing and microwave processing has been characterized by the means of chemical analysis, X-ray diffractometry (XRD), scanning electron microscopy (SEM), and particle size analysis (PSA).

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Desorption Characteristics of Volatile Organics Compounds in Soil by Microwave Heating (마이크로파 가열에 의한 토양 유기오염물질 탈착특성)

  • 문경환;김덕찬
    • Journal of environmental and Sanitary engineering
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    • v.11 no.2
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    • pp.65-73
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    • 1996
  • The objective of this study is to investigate the removal efficiency of volitile organic compounds in soil, and the mechanism of desorption by bench scale microwave heating, Silt soil used for experiment and was impregnated with toluene, tetrachloroethylene, o-xylene and p-dichlorobenzene and the microwave treatment was conducted in a modified domestic microwave oven : 2450MHz, 700W. According to the results of the research the removal efficiency was improved with increasing water contents and the soil temperature appeared to plateau period extending to 2-3minutes corresponds to the temperature a which steam distillation was expected. The value of removal rate constant (k) were calculated on dry and moisty silt soil, respectively, which showed linear with increasing microwave heating time. Therefore, addition of a certain amount of water to the contaminated soil can efficiently enhance the ability of the soil to absorb microwave energy and promote the evaporation of the volitile contaminants.

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Subcutaneous Temperature Estimation By Microwave Radiometry (Microwave Radiometry 원리를 이용한 생체 내부 온도 추정)

  • Kim, Kyeong-Seop;Lee, Jeong-Whan
    • Journal of Biomedical Engineering Research
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    • v.27 no.6
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    • pp.357-364
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    • 2006
  • Microwave Radiometry is the spectral measurement of eleclromagnetic radiation at frequency bands in the microwave region. One particular application of Microwave Radiometry is for analyzing temperature difffrentials of inside of human body to detect and diagnose pathologic conditions in which the temperature differentials are related with the symptoms of certain diseases. To accomplish this aim, we propose a new calibration method for estimating subcutaneous temperature by Microwave Radiometer and we also suggest a tumor-imitator phantom structure for simulating heat diffusion propagated by tissues around tumors to evaluate the discernment of brighuless temperature difffrentials.

Effects of Ceramic Coating for Microwave Blanching on Vegetables (전자레인지의 Ceramic Coating이 채소류의 마이크로파 데치기에 미치는 영향)

  • Kum, Jun-Seok;Han, Ouk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.6
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    • pp.951-957
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    • 1996
  • Changes in quality of blanched vegetables(carrot, green onion, spinach) by microwave heating were evaluated. Ceramic coating treatment(CCT) within microwave oven caused the reduction of blanching time and Hunter's L, a, b values of vegetables. Also, CCT showed the higher cutting force compared to NCCT after microwave heating. Photomicrographs of cross-section of blanched vegetables after heating in ceramic coated microwave oven showed better appearance than those in nonceramic coated microwave oven. CCT process improved retention of vitamin C.

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Manufacture of Composite Electromagnetic Absorber using Natural Lacquer Binder (옻을 지지재로 이용한 복합형 전자파 흡수체의 제작)

  • 김동일;최동한;김수정;박우근;송재만;김민정
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.7
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    • pp.756-761
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    • 2003
  • The microwave absorption properties of silicone, chloride polyethylene(CPE), and natural lacquer which is newly suggested in this study as a binder for composite microwave absorber were investigated to develop a superior microwave absorber. MnZn ferrite composite microwave absorbers mixed with them were prepared and their absorption property was investigated. A MnZn ferrite microwave absorber mixed with natural lacquer showed an excellent microwave absorption property in expanded frequency band.

Microwave characteristics of traveling-wave modulator considering the microwave feedline (마이크로파 feedline을 고려한 진행파형 광변조기의 특성 분석)

  • 구민주;옥성해;윤영설;문연태;김도균;최영완
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.4
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    • pp.41-47
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    • 2004
  • In this paper, we analyze the microwave characteristics of traveling-wave electro-absorption modulator (TW-EAM) considering the microwave feedline and the impedance mismatch. The TW-EAM is analyzed by using the equivalent circuit model. The capacitance and the inductance of the equivalent circuit are evaluated by using 3-dimensional finite difference time domain (FDTD) method, while the microwave feedline is analyzed by momentum method. In a viewpoint of microwave characteristics, we present the effect of the structure and the length of microwave feedline.

A Case of the Laryngopharyngeal Burn Caused by A Microwave-Heated Egg Bite

  • Won, Seong Jun;Woo, Seung Hoon
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.24 no.2
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    • pp.122-124
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    • 2013
  • Nowadays, microwave ovens are commonly used for cooking. However, the cooking certain food in microwave ovens can be hazardous. It has been reported that the heating eggs in a microwave oven can cause an explosion and injuries. The exploding eggs can cause burn injury of face, neck, eyelid, pharynx and larynx. Direct thermal damage to the larynx after swallowing microwave-heated eggs is rare. The authors report a larynx thermal injury due to microwave-heated eggs and review the cause and the prevention methods of exploding eggs.

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Solubilization of Sewage Sludge by Microwave Pretreatment and Elutriated Acid Fermentation (Microwave를 이용한 하수슬러지의 전처리 특성 및 회분식 세정산발효를 이용한 슬러지 가용화)

  • Lee, Won-Sic;Hong, Seung-Mo;Min, Kyung-Sok
    • Journal of Korean Society on Water Environment
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    • v.22 no.6
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    • pp.1130-1136
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    • 2006
  • This work elucidates the effects of pretreatment of the sewage sludge from wastewater treatment plant by microwave irradiation on elutriated acid fermentation. These experiments typically fell into two process; pretreatment as microwave irradiation and elutriated acid fermentation for hydrolysis and acidification as main process of primary sludge. The results of maximum solubilization rate of B, D primary and secondary sludge were 0.042, 0.086 and 0.15 gSCODprod./gICODin and the optimum irradiation time of microwave on 2,450 MHz and 900 W were 5 min. for primary sludge and 7 min. for secondary sludge. From batch tests on elutriated acid fermentation that was used the pretreated primary sludge as microwave, the optimum pH and HRT (hydraulic retention time) were 7 and 5 days at $35^{\circ}C$ condition.

Electron Spin Resonance (ESR) and Microwave Absorption Studies of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) for Hyperthermia Applications

  • Choi, Yong-Ho;Yi, Terry;Kim, Do-Kyung
    • Journal of the Korean Ceramic Society
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    • v.48 no.6
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    • pp.577-583
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    • 2011
  • Stabilized biocompatible superparamagnetic iron oxide nanoparticles (SPIONs) were prepared by controlled coprecipitation method for hyperthermia application. ESR measurements determined that all of the interactions in the individual SPIONs (1 nm and 11 nm) were antiferromagnetic in nature because the ions contributed to the magnetization with a range of magnetic moments. In-situ monitoring of the temperature increment was performed, showing that the microwave absorption rate of the SPIONs was dispersed in an appropriate host media (polar or non-polar solvents) during microwave irradiation. Microwave absorption energy rates and heat loss of SPIONs in solvent were calculated by non-linear data fitting with an energy balance equation. The microwave absorption rates of SPIONs dispersed in solvent linearly increases when the concentration of SPIONs increases, implying that the microwave absorption rate can be tunable by changing the concentration of SPIONs.