• Title/Summary/Keyword: Microwave

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A Study of Microwave Waste Tire Pyrolysis in a Batch Reactor (회분식 반응기에서의 마이크로파 폐타이어 열분해 연구)

  • KIM, SEONG-SOO
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.5
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    • pp.577-583
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    • 2017
  • A series of microwave waste tire pyrolysis experiments were conducted using a lab-scale batch reactor to delineate the effects of microwave ouput power on the pyrolysis behavior of waste tire. As results of experiments, it was found that as the microwave output power was increased from 1.22 kW/kg to 2.26 kW/kg, the reaction temperature and oil yield increased significantly and the required time and microwave power consumption decreased remarkably, respectively. With increased power consumption, the content of the fixed carbon of pyrolysis residue increased.

The Analysis of the Related Variables Affecting the Use of the Microwave oven (전자레인지 이용율에 영향을 미치는 관련변인에 대한 분석)

  • 조혜정
    • Journal of the Korean Home Economics Association
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    • v.24 no.4
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    • pp.93-104
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    • 1986
  • The purpose of this study was to see that how about the related variables influence on the use of the microwave oven and how about the use of the microwave oven influence on the time spent in meal preparation and meal management. Questionaires were give to randomly selected homaker's, in kwangju in August, 1986. Data from the 149 response were analyzed according to multiple regression. The results were as follows; 1. The variables affecting the use of the microwave oven were family income, homaker's employed hours, homakers' education level, a period of use a microwave oven, congnition of a special character in a microwave oven, family style of participation in meal preparation, frequency in use of instant food. 2. The variables of the use the microwave oven was significantly influence on the time spent in meal preparation. 3. The variables of the use the microwave oven was not significantly influence on meal management.

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Oxidative Stability of Fatty Acids and Tocopherols in the Fats and Oils during Microwave Heating (Microwave 오븐 가열에 의한 유지의 지방산과 토코페롤의 안정성)

  • 주광지;김은미
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.2
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    • pp.234-241
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    • 1995
  • Effect of microwave heating on the oxidative stability of the soybean oil, sesame oil, butter and margarine were investigated by mearsuring fatty acids amout and tocopherol losses. The index for chemical properteis, free fatty acid, peroxide value, anisidine value, carbonyl value, conjugated diene and triene levels were also mearsured in the oil samples for 5, 10, 15 and 20 min of heating in a microwave oven. No significant difference was observed on the fatty acids composition in the fats and oils before and after microwave heating. During microwave treatment, the oxidative degradation of the tocopherols in the samples became greater with increasing heating time. The amount of tocopherols in the soild fats, butter and margarine, dropped drastically after 5 min of heating and reduced to 95% of their original levels after 20min heating ${\gamma}$-tocopherol in butter showed the most unstable states and completely destroyed during microwave treatment for 20min. On the other hand, 80% of tocopherols in the liquid oils were still remained after 5min of heating except $\delta$-tocopherol in sesame oil.

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Characteristics of Linear Microwave Plasma Using the Fluid Simulation and Langmuir Probe Diagnostics

  • Seo, Gwon-Sang;Han, Mun-Gi;Yun, Yong-Su;Kim, Dong-Hyeon;Lee, Hae-Jun;Lee, Ho-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.158.1-158.1
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    • 2013
  • Microwave는 일반적으로 300 [MHz]~30 [GHz] 사이의 주파수를 가지는 전파로 1 [m] 이하의 파장을 가진다. Microwave를 이용한 플라즈마의 경우 낮은 이온 에너지, 효율적인 전자 가열, 넓은 동작압력 범위, 높은 밀도 등의 장점을 가지고 있어 PECVD(Plasma Enhanced Chemical Vapor Deposition)에 적합한 플라즈마 소스라고 할 수 있다. 또한 Microwave는 파장의 길이가 증착이 이루어지는 진공 챔버의 길이보다 매우 작기 때문에 대면적 적용성이 용이하므로 현재 많은 연구가 이루어지고 있다. 본 연구에서는 Fluid Simulation을 통해 Maxwell's equation, continuity equation, electromagnetic wave equation 등을 이용하여 Microwave의 파워 및 압력에 따른 플라즈마 parameter를 계산하고, 자체 제작한 Linear microwave plasma 장치에서 정전 탐침(Langmuir Probe)을 이용하여 플라즈마 Parameter를 측정하였다. 또한 Simulation 결과와 실험결과를 비교 분석하였다.

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Extraction of pesticide residues in medical herbs by microwave (Microwave를 이용한 한약재 중의 잔류농약 추출)

  • Kim, Taek-Kyum;Kim, Tang-Eok
    • The Korean Journal of Pesticide Science
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    • v.4 no.3
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    • pp.60-67
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    • 2000
  • This study was conducted to elucidate extraction efficiency by microwave in comparison with Soxhlet for extraction of pesticide residues in dried medical herbs; red-ginseng, white-ginseng, Bupleuri Radix, Angelica gigas Nakai, Rehmannia glutinosa. The acetone extraction by microwave of tolclofos-methyl and quintozene in medical herbs was efficient. The extraction efficiency by microwave with power 45 to 150 watts, extraction time 1 to 5 minutes and solvent volume 30 ml was compared with that of Soxhlet with extraction time 7 hours and solvent volume 150 ml. The extraction efficiency by microwave with extraction time 3 to 5 minutes was similar with extraction time of 7 hours by Soxhlet. When medical herbs spiked with tolclofos-methyl and quintozene was analyzed to how the extraction efficiency of microwave by kind of medical herbs, the extraction efficiency by microwave with extraction time of 3 to 5 minutes was the same as Soxhlet extraction. The optimal condition for extraction of tolclofos-methyl and quintozene in medical herbs by microwave was 45 to 90 watts of power supply, 3 to 5 minutes of extraction time and acetone 30 ml of solvent volume.

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Microwave-assisted Photocatalytic Degradation of Methylene Blue (마이크로웨이브가 부가된 광촉매에 의한 메틸렌블루의 분해)

  • Kim, Yu-Bong;Jo, A-Ra;Ra, Deog-Gwan;Park, Jae-Hyeon;Kim, Sun-Jae;Jung, Sang-Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.8
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    • pp.817-822
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    • 2008
  • In this study, the photocatalytic degradation of methylene blue in TiO$_2$ particles-dispersed water solution was carried out by irradiating microwave and UV light simultaneously. A microwave-discharged electrodeless UV lamp was developed to use microwave and UV simultaneously for photocatalytic reactions. The results of photocatalytic degradation of methylene blue showed that the decomposition rate increased with the microwave intensity, the circulating fluid velocity, and the amount of TiO$_2$ particles and auxiliary oxidizing agents added. Especially, the rate constant of H$_2$O$_2$-added photocatalytic reaction increased about three times from 0.0075 min$^{-1}$ to 0.0250 min$^{-1}$ when microwave was additionally irradiated. This study demonstrates that the microwave irradiation can play a very important role in photocatalytic degradation using peroxides although it is not easy to quantitatively assess the effect of microwave on photocatalytic reactions from the experimental data of this study.

Comparison of Microwave and Conventional Cooking Methods on the Nutritional Composition of Potatoes -(1) Changes of Proximate Composition, Minerals and Water-soluble Vitamins- (감자의 몇가지 영양성분(營養成分)에 대한 마이크로파(波)와 재래적(在來的) 조리방법(調理方法)의 비교(比較) -1. 일반성분(一般成分), 무기질(無機質) 및 수용성(水溶性) 비타민의 변화에 대하여-)

  • Yoo, Yang-Ja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.2
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    • pp.171-176
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    • 1985
  • The effects of cooking methods by boiling, electric oven and microwave on the proximate composition, minerals and water-soluble vitamins of two major Korean potato varieties (Soomi and Namjac) were studied. The dry matter content was increased after the cooking by the methods of electric oven and microwave, however, the crude fiber content was highly decreased by both methods. The crude ash content was not affected by the cooking methods used. The potassium content was increased by electric oven and microwave methods, and iron content was increased by electric oven baking, however, the copper content was significantly decreased by the electric oven and microwave cooking methods. The macrominerals (phosphorus, magnesium, calcium) and microminerals (zinc, manganese, nickel, lead, cadmium) content present initially in potatoes have not been changed by the cooking methods employed in this study. Relative retention value of ascorbic acid was the lowest and the value of thiamin was the highest in the potatoes cooked by microwave. The retention values of riboflavin and folic acid obtained. after boiling were similar to those after microwave cooking, and both of these treatments were superior to the electric oven baking. The retention values of niacin and vitamin $B_6$ varied between 93 and 100% depending on the cooking methods used. Overall, with a few exceptions, the retention values of water-soluble vitamins in boiled and microwave cooked potatoes were superior to those of the electric oven baked.

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Effect of Microwave Treatment on Chemical Composition and In sacco Digestibility of Wheat Straw in Yak Cow

  • Dong, Shikui;Long, Ruijun;Zhang, Degang;Hu, Zizhi;Pu, Xiaopeng
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.1
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    • pp.27-31
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    • 2005
  • Wheat straw was treated with microwave for 4 min and 8 min at a power of 750 W and frequency of 2,450 MHz. Chemical compositions of untreated, 4 min treated and 8 min treated straws were analyzed and in sacco degradabilities of all these straws in yak rumens were measured. Microwave treatment didn't significantly (p>0.05) affect the chemical composition of the straw. In sacco dry matter (DM) degradability of the straw after 18 h incubation in rumen was significantly (p<0.01) improved by microwave treatment. In sacco crude protein (CP) degradability of the straw was not (p>0.05) affected by microwave treatment. In sacco organic matter (OM) degradability of the straw was increased (p<0.01) by around 20% for both the 4 min and 8 min microwave treatment, that of acid detergent fibre (ADF) was increased (p<0.01) by 61.6% and 62.8%, and that of ash free ADF was enhanced by 72.1% and 69.6% for the 4 min and 8 min microwave treatment respectively. No significant difference was observed between the 4 min and 8 min microwave treatment on the degradability of DM, OM, CP, ADF and ash-free ADF of the straw.

Microwave Cure of Rubber Compound for Tire Tread (타이어 트레드용 고무배합물의 마이크로파 가황)

  • Han, Shin;Kang, Yong-Gu;Sohn, Bong-Young;Oh, Sei-Chul;Park, Chan-Young
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.1
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    • pp.69-75
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    • 1999
  • Intending to develop a new rubber curing process using only microwave, the both the characteristics of cure and the mechanical properties of rubbers for the tire tread, for which a green styrene-butadiene compounds had been cured with 2.45 GHz microwave, have been compared with those of the custom thermal cured rubber. The unintentional hot spot formation in the compound during the microwave curing has not found where the compound has a microwave absorbing ceramic powders in 4.18 weight percents and the supplying voltage has been adjusted to 90 volts. The new microwave process accomplished preheating to 418K in a quarter of the thermal cure time. The average tensile strength of the microwave-cured rubber indicating $190kg/cm^3$ was compatible to that of the thermal cure. In conclusion, the new microwave cure had approved to be applicable in a commercial plant.

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