• Title/Summary/Keyword: Microwave treatment

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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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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.

Improvement of Device Characteristic on Solution-Processed InGaZnO Thin-Film-Transistor (TFTs) using Microwave Irradiation

  • Moon, Sung-Wan;Cho, Won-Ju
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.2
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    • pp.249-254
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    • 2015
  • Solution-derived amorphous indium-gallium-zinc oxide (a-IGZO) thin-film-transistor (TFTs) were developed using a microwave irradiation treatment at low process temperature below $300^{\circ}C$. Compared to conventional furnace-annealing, the a-IGZO TFTs annealed by microwave irradiation exhibited better electrical characteristics in terms of field effect mobility, SS, and on/off current ratio, although the annealing temperature of microwave irradiation is much lower than that of furnace annealing. The microwave irradiated TFTs showed a smaller $V_{th}$ shift under the positive gate bias stress (PGBS) and negative gate bias stress (NGBS) tests owing to a lower ratio of oxygen vacancies, surface absorbed oxygen molecules, and reduced interface trapping in a-IGZO. Therefore, microwave irradiation is very promising to low-temperature process.

Microwave heating of carbon-based solid materials

  • Kim, Teawon;Lee, Jaegeun;Lee, Kun-Hong
    • Carbon letters
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    • v.15 no.1
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    • pp.15-24
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    • 2014
  • As a part of the electromagnetic spectrum, microwaves heat materials fast and efficiently via direct energy transfer, while conventional heating methods rely on conduction and convection. To date, the use of microwave heating in the research of carbon-based materials has been mainly limited to liquid solutions. However, more rapid and efficient heating is possible in electron-rich solid materials, because the target materials absorb the energy of microwaves effectively and exclusively. Carbon-based solid materials are suitable for microwave-heating due to the delocalized pi electrons from sp2-hybridized carbon networks. In this perspective review, research on the microwave heating of carbon-based solid materials is extensively investigated. This review includes basic theories of microwave heating, and applications in carbon nanotubes, graphite and other carbon-based materials. Finally, priority issues are discussed for the advanced use of microwave heating, which have been poorly understood so far: heating mechanism, temperature control, and penetration depth.

Stabilization of Rice Bran by Microwave Energy (마이크로파 에너지에 의한 쌀겨의 안정화)

  • Rhee, Joon-S.;Yoon, Heeny H.N.
    • Korean Journal of Food Science and Technology
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    • v.16 no.1
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    • pp.113-119
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    • 1984
  • Initial moisture content and weight of the rice bran and treatment time were identified as important variables for the inactivation of lipase and peroxidase present in rice bran. Multiple regression analysis was used to obtain a prediction equation to measure the effects of moisture content and weight of the sample and microwave treatment time on the residual lipase activity and loss in weight. It was found that the microwave treatment did not affect acid value and extractability of the rice bran oil.

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Effects of massage and microwave diathermy therapy on eccentric exercise-induced DOMS and indices of muscle damage (마사지 및 극초단파 치료가 원심성 운동으로 유발된 지연성 근육통과 근 손상 지표에 미치는 영향)

  • Yoon, Bum-Chul;Ham, Young-Woon;Lee, Myung-Hwa;Hong, Hye-Jung;Lee, Jae-Hak
    • The Journal of Korean Physical Therapy
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    • v.13 no.2
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    • pp.293-303
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    • 2001
  • The purpose of this study was to determine if there were any beneficial effects of massage or microwave diathermy regarding delayed onset muscle soreness (DOMS) and indices of muscle damage. Twenty-one adult women, randomly divided in two treatment groups and a control group, performed eccentric stepping exercise with the quadriceps until exhaustion. The treatment groups additionally performed massage or microwave diathermy after the stepping exercise. Pressure pain threshold measure for DOMS and muscle enzymes in the blood were obtained before, and 0, 24, 48 and 72 hours after exercise. The results were as follows; 1. Eccentric exercise caused DOMS and elevations of muscle enzymes in the blood, with peak values exercise levels by 24 hours after exercise and GOT and CRP by 72 hours after exercise. DOMS and CK activity remained elevated 72 hours after exercise. 2. DOMS and blood muscle enzymes response to eccentric exercise were reduces by massage or micro diathermy therapy. DOMS was significantly decreased at 72 hours after exercise by massage and microwave diathermy. CK activity was significantly decreased at 72 hours after exercise by microwave diathermy. There was the significant reduction in LDH at 48 hours, GOT at 24, 48, 72 hours. and CRP at 24, 48 hours after exercise by massage and microwave diathermy. These results indicate that massage or microwave diathermy is had effect on recovery from exercise-induced muscle damage. In our's suggestion. microwave diathermy is particularly more appropriate therapeutic modality because it is more simple and economic than massage.

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Studies on Dismantlement Property of Dismantlable Polyurethane Adhesive (우레탄계 해체성 접착제의 해체특성에 관한 연구)

  • Kim, Dong Ho;Chung, Ildoo;Kim, Gu Ni
    • Journal of Adhesion and Interface
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    • v.11 no.1
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    • pp.26-34
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    • 2010
  • We synthesized polyurethane adhesive having thermal characteristic could be debonded by heat treatment and made a dismantlable polyurethane adhesive including thermally expansive bead. We used dynamic mechanical thermal analyzer (DMA) to confirm thermal characteristic and investigated bond strength, dismantlement property of dismantlable polyurethane adhesive by content of thermally expansive bead, heating trigger and treatment conditions. The dismantlable polyurethane adhesive could be expanded by hot-air or microwave treatment and the dismantlement of the specimens became easier as the weight fraction of the thermally expansive bead increased. At the dismantlable polyurethane adhesive, the content of thermally expansive bead 40% was suitable for both bond strength and dismantlement, in case of using hot-air treatment as trigger for dismantlement, bonded joints were separated easily at $160^{\circ}C$ for 30 min and in case of using microwave as trigger, bonded joints were separated easily by irradiating microwave for 4 min.

Synthesisand Electrochemical Behaviors of Hybrid Carbon (ACF/Graphene) as Supports by Microwaves-irradiation Method for Polymer Exchange Membrane Fuel Cells (PEMFC) (마이크로웨이브를 이용한 고분자 전해질 연료전지용 복합 탄소 촉매 지지체 (ACF/Graphene)의 합성과 전기화학적 거동)

  • Cho, Yongil;Jeon, Yukwon;Park, Dae-Hwan;Juon, So-Me;Kim, Tae-Eon;Oh, Kyeongseok;Shul, Yong-Gun
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.2
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    • pp.142-149
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    • 2013
  • Carbon materials are mainly used as catalyst supports for polymer exchange membrane fuel cell (PEMFC). Catalyst supports are required specific characteristics of the carbon materials, such as large surface area and high electrical conductivity. Attempted were to improve electrical conductivity and to maintain high surface area of carbon materials using a microwave treatment. Microwave treatment, as a relatively new technique, takes short reaction time and reduce the consumption of the gases used for carbon treatment compared to a traditional heat treatment. Hybrid carbon (ACF/Graphene) as catalyst supports by microwave-irradiation method for PEMFC increase the cell performance because of increased electrical conductivity resulting in triple-phase contact and reduced the interfacial resistance. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-Ray Diffraction (XRD) were employed to analyze carbon materials. The performance of microwave-treated carbon materials was evaluated by measuring current-voltage (I-V) characteristics and electrode impedance.

Microwave Cavity with Controllable Temperature for In Vitro Hyperthermia Investigations

  • Kiourti, Asimina;Sun, Mingrui;He, Xiaoming;Volakis, John L.
    • Journal of electromagnetic engineering and science
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    • v.14 no.3
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    • pp.267-272
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    • 2014
  • Hyperthermia is a form of cancer treatment in which affected human tissue is exposed to $>40^{\circ}C$ temperature. In this paper, our goal is to assess the efficacy of fullerene agents to reduce heating time for cancer treatment. Such agents can accelerate heating of cancer cells and improve hyperthermia treatment efficacy. Typically, in vitro testing involves cancer cell culturing, heating cell cultures in accordance to specifications, and recording cancer cell viability after hyperthermia. To heat cell cultures, we design and evaluate a 2.4-GHz microwave cavity with controllable temperature. The cavity is comprised of a polystyrene cell culture dish (diameter = 54 mm, height = 13.5 mm) and a printed monopole antenna placed within the cavity for microwave heating. The culture temperature can be controlled through the intensity and duration of the antenna's microwave radiation. Heating experiments were carried out to validate the cavity's performance for F-12K culture medium (Kaighn's F-12K medium, ATCC). Importantly, fullerene agents were shown to reduce heating time and improve hyperthermia treatment efficacy. The culture medium temperature increased, on average, from $24.0^{\circ}C$ to $50.9^{\circ}C$ (without fullerene) and from $24.0^{\circ}C$ to $56.8^{\circ}C$ (with 3 mg/mL fullerene) within 15 minutes.

Effect of Heat Treatment on Some Qualities of Korean Pickled Cucumbers during Fermentation (열처리가 오이지의 발효에 미치는 영향)

  • Choi, Hee-Sook;Kim, Jong-Goon;Kim, Woo-Jung
    • Korean Journal of Food Science and Technology
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    • v.21 no.6
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    • pp.845-850
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    • 1989
  • Effect of high temperature soaking in salt solution and short time microwave heat treatment on quality of Korean pickled cucumbers during fermentation was investigated. The Korean pickled cucumbers were fermented at $25^{\circ}C$ for 10 days in 10% salt solution. The physicochemical properties measured were pH, the total acidity, hardness and the sensory properties of odor, taste and texture were also evaluated. The result showed that the effect of soaking cucumber in $80-90^{\circ}C$ hot salt solution significantly reduced the fermentation rate and softening rate of texture while a rather rapid fermentation was found for those soaked in $60-70^{\circ}C$. The effect of microwave treatment inhenced fermentation a little for short treatment but it was significantly reduced softening rate of texture by 3 minutes heating. The sensory evaluation of Korean pickled cucumber was found that heat treatments with hot solution and microwave heating had a possitive effect for reduction of softening of cucumber tissue, however odor and taste were not significantly affected.

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