• 제목/요약/키워드: Microwave heating

검색결과 395건 처리시간 0.028초

전형적인 열처리와 마이크로웨이브 열처리에 따른 PDP용 전극과 투명 유전체의 동시 소성 (Co-firing of Dielectric and Electrode with Conventional and Microwave Heating in Plasma Display Panel)

  • 황성진;;;김형순
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.463-463
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    • 2008
  • The glass frit has been used in transparent dielectric, barrier rib and electrode of PDP (Plasma display panel). In PDP fabrication, the firing temperature of glass frit is normally 550~$580^{\circ}C$ with conventional heating. However, there are a problem that silver in electrode is diffused throughout the transparent dielectric. For inhibiting the Ag diffusion we considered use of the microwave heating. We investigated firing of glass frit compared between conventional and microwave heating. After firing by two types of heating, the diffusion of silver is determined using a optical microscope and UV-spectrometer. Based on the our results, the microwave heating should be a candidate to heating source for high efficacy in PDP.

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Microwave 조사에 의한 Listeria monocytogenes의 불활성에 관한 연구 (Thermal Inactivation of Listeria monocytogenes in Liquid Cultures during Microwave Radiation)

  • 이조윤;김종우;이강욱;배형철
    • 농업과학연구
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    • 제26권1호
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    • pp.50-57
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    • 1999
  • 본 시험은 L. monocytogenes KCTC 3443을 액체 배양한 후, 일반적인 열처리 및 마이크로파를 조사함으로써 가열효과에 의한 균의 불활성효과를 파악하는데 그 목적을 두었다. 2,450MHz, microwave oven을 통한 마이크로파의 온도 제어는 시료가 각각의 시험 설정 온도에 도달한 후 30분간 온도를 유지할 수 있도록 컴퓨터에 의해 제어되었으며, 온도의 편차는 ${\pm}1^{\circ}C$ 정도로 비교적 안정된 제어 효과를 보여주었다. 마이크로파 조사와 일반 가열처리 간의 균의 불활성효과를 비교한 시험에서는 55, 65, $75^{\circ}C$$85^{\circ}C$의 제어온도에서 거의 유사한 불활성도를 보여주었으며 이와같은 결과로 미루어 L. monocytogenes KCTC3443의 경우, 마이크로파 조사에 의한 비가 열 효과는 없는 것으로 보여진다. 아울러 공시균주인 L. monocytogenes KCTC3443는 $85^{\circ}C$의 30분간 가열에서도 약 $10^2{\sim}10^3cells/ml$의 균체가 생존하는 것으로 나타나 식품의 조리나 가열 후에도 2차 오염의 위험이 있는 병원성 균주로 주위가 요구된다.

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급속 microwave 열처리 방법으로 합성한 $YVO_4$: $Eu^{3+}$, $Bi^{3+}$ 적색 형광체의 발광 특성 (Luminescence characterization of $YVO_4$: $Eu^{3+}$, $Bi^{3+}$ red phosphor by rapid microwave heating synthesis)

  • 박우정;송영현;문지욱;윤대호
    • 한국결정성장학회지
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    • 제18권4호
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    • pp.169-173
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    • 2008
  • 본 연구에서는 자외선 영역에서 우수한 발광강도를 가지는 적색 형광체를 얻기 위하여 microwave 급속 열처리법으로 합성하여 $Eu^{3+}$$Bi^{3+}$가 도핑된 $YVO_4$의 발광특성을 관찰하였다. Microwave 급속 열처리시 입자의 크기는 매우 미세하며, 응집이 매우 심하였으나 열처리 유지시간이 증가할수록 입자 크기는 증가하고 응집현상은 개선되는 경향을 나타내었다. $YVO_4$: $Eu^{3+}$, $Bi^{3+}$ 적색 형광체의 발광 peak는 $Eu^{3+}$ ion의 영향에 의해 594.9 nm와 602.3 nm에서 $^5D_0{\longrightarrow}^7F_1$ 전자 천이에 의한 약한 발광 peak와 616.7 nm와 620.0 nm에서 $^5D_0{\longrightarrow}^7F_2$ 전자 천이에 의한 강한 발광 peak이 관찰 되었다. Microwave 급속 열처리법을 형광체 합성시 장시간 열처리 시간이 필요하지 않으면서 균일한 activator의 확산으로 인하여 발광특성을 향상시키는 것을 확인 할 수 있었다.

Microwave 가열이 밤 당침제품의 물성에 미치는 영향 (The Effects of Microwave Heating on the Texture of Sugared Chestnuts)

  • 황태영;김준한;김종국;문광덕
    • 한국식품과학회지
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    • 제30권3호
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    • pp.569-573
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    • 1998
  • Microwave를 이용하여 밤 당침제품을 제조하고, microwave가 당침제품의 물성 및 조직구조에 미치는 영향에 대하여 조사하였다. 박피한 생율을 각각 일반가열방법으로 자숙한 후 당침을 행한 당침밤과, 일반가열방법으로 자숙하고 microwave로 당침한 밤, 자숙 및 당침 전과정에 microwave를 이용한 밤의 세 구로 제조하였다. 당침제품의 수분함량은 microwave를 이용하여 당침한 경우 가장 높게 나타났으며 조지방의 함량은 microwave를 이용하여 자숙 및 당침을 행한 당침제품에서 가장 낮았다. 총펙틴 및 HSP (hydrochloric acid soluble pectin)함량은 microwave로 처리한 제품에서 가장 낮게 나타났다. 당침밤제품의 물성 측정 결과 당침시에만 microwave처리를 행한 당침밤이 springiness를 제외한 fracturability, hardness, gumminess, chewiness에서 가장 낮은 값을 나타내었으며, microwave 처리를 행하여 자숙 및 당침을 행한 당침밤 간에는 유의차가 인정되지 않았다. 처리방법에 따른 당침밤의 조직을 주사전자현미경으로 관찰했을 때 당침을 행한 밤의 세포벽이 당침투에 따라 점성을 띠는 것을 볼 수 있으며 microwave 처리가 행해진 경우 세포벽이 심하게 파괴되었음을 관찰할 수 있었다.

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마이크로파 가열방법에 따른 감자전분의 호화특성 변화 (Changes in Gelatinization Properties of Potato Starch by Microwave Heating Methods)

  • 최옥자;고무석;신말식
    • 한국식품과학회지
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    • 제26권6호
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    • pp.696-703
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    • 1994
  • The purpose of this study was to investigate the gelatinization properties of potato starch heated with microwave. Two types of potato starches were prepared; In group A raw potato starch was heated with microwave and in group B potato starch was isolated from potato heated with microwave. Both groups were exposed to the microwave energy in a 560W, 2,450 MHz oven for 60, 120, 180 and 300 seconds. Gelatinization behaviour by DSC made a few differences according to the ratio of starch to water. As the microwave heating time took longer, gelatinization temperature and gelatinization $enthalpy({\bigtriangleup}H_1)$ were decreased in and melting $enthalpy({\bigtriangleup}H_2)$ was increased in group A. Whereas they were increased in group B. In both groups, maximum viscosity in gelatinization by Brabender amylogram was decreased by microwave heating. Then the peak of the maximum viscosity was shifted to higher temperature and cold viscosity was slightly increased. In group A, viscosity in gelatinization and light transmittance by NaOH was increased in initial stage and gel volume in gelatinization by KSCN was decreased. On the other hand, in group B, viscosity by alkali was slightly decreased, but light transmittance by NaOH was almost never changed. Gel volume is decreased like group A.

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

  • 문경환;김덕찬
    • 환경위생공학
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    • 제11권2호
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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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Microwave가열에 의한 Polyester직물의 염색성에 관한 연구(II) (A Study on the Dyeing of Polyester Fabric by Microwave Heating(II))

  • 임수경;김삼수;허만우
    • 한국염색가공학회지
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    • 제11권3호
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    • pp.49-57
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    • 1999
  • The effect of padding solution for the microwave heat dyeing of polyester fabric was studied variously. The dyeing property of polyester fabric varied with the kinds of added chemicals in the padding solution. Polyester fabrics impregnated in aqueous urea solution and aqueous sodium chloride solution for 10 minutes and then dyed for 7 minutes by microwave apparatus(2450 MHz, 700 W) under optimum conditions give good exhaustion. An aqueous solution of urea and a sodium chloride solution was more effective than water as padding solution for microwave heating dyeing. The K/S values of dyed polyester fabric by microwave were significantly affected by the type of solvent added in padding media and its concentration. Added solvents, n-hexane, acetone and dimethyl formamide were also more effective than water as padding media for the microwave heating dyeing. It is assumed that the effect of used solvents on dyeing property of polyester fabrics depends on the solubility parameter difference between solvent and polyester fabric.

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마이크로파 가열에 의한 스테인레스강 분진의 환원 (Reduction of Stainless Steelmaking Dust by Microwave Heating)

  • 반봉찬;조환종
    • 자원리싸이클링
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    • 제2권4호
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    • pp.10-16
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    • 1993
  • 마이크로파 가열 공정에 의하여 스테인레스강 제조시의 발생하는 분진의 환원거동올 환원제로서 코크스와 목탄을 이용하여 조사하였다. 원래 상태의 펠릿 분진과 환원제로서, 펠릿을 만든 분진을 마이크로파 가열오븐 내에서 $1000^{\circ}C$까지 가열하여 환원시켰다. 코크스에 비하여 목탄의 경우가 더 높은 환원율율을 나타내었다. 마이크로파 오븐에서 500W와 700W의 사용한 경우 유사한 환원율을 나타냈으며 200분 이내에 급속하게 환원되였다. 환원정도는 Fe>Ni>Cr로 감소되었다.

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당의 종류 및 가열방법에 따른 당침밤 제품의 품질 변화 (The Changes in Quality of Sugars Chestnuts by Sugars and Heating Methods)

  • 홍순갑;황태영
    • 한국식품저장유통학회지
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    • 제4권2호
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    • pp.173-180
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    • 1997
  • The effects of sugars and heating methods on the sugar infilteration, hardness, color and organoleptic characteristics were investigated for quality improvement of sugared chestnuts. Among the tested sugars, isomaltooligosugar was the most effective on the rate of sugar infilteration. High temperature increased the rate of sugar infilteration during sugaring process, but color and flavor were deteriorated at 9$0^{\circ}C$. The most suitable temperature for sugaring process was 7$0^{\circ}C$. The product sugared with fructooligosugar recoreded the highest score in hardness, odor and preference than any other sugars tested and increased the rate of sugar infilteration when mixed with sugar at same amount. The changes of soluble solids in chestnuts boiled with microwave oven were ranged from 18。Brix to 32。Brix, while chestnuts heated in general were from 18。Brix to 28。Brix. Chestnuts boiled with microwave heating were sugared rapidly. The hardness of boiled and sugared chestnuts was lower when treated with microwave than with general heating. Hunter's L and b value of sugared chestnut treated with microwave decreased during processing but a value somewhat increased.

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Microwave Application in the Heating of Low-Loss Ceranmic Materials

  • Park, Seong-S.;Lee, Yoon-B.;Ryu, Su-C.;Jang, Youn-S.;Park, Hong-C.
    • 한국재료학회지
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    • 제6권6호
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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.

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