• Title/Summary/Keyword: microwave method

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Studies on the Extraction Method and Polysaccharide of Tricholoma matsutake using the Supersonic wave and Microwave (초음파와 극초단파를 이용한 송이버섯의 추출법과 다당체에 관한 연구)

  • Yu, Seung-Hyun;Chong, Myong-Soo;Kim, Hae-Ja;Lee, Ki-Nam
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.6
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    • pp.1431-1436
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    • 2007
  • In order to optimize the extract condition and improve physiological activity of the extract form Tricholoma matsutake, experiments related to extraction methods, totale yield, content of total soluble polysaccharide, SOD-like activity, total polyphenol amount, and volatile flavor compound and the others were carried out, results were obtained as following: Compare with traditional hydrothermal extraction method (Hot water extraction : HWEW), it illustrates that the low temperature extraction method which combines a supersonic waves and microwave (Supersonic microwave extraction : SMEW) causes of increasing the total yield, total soluble polysaccharide. As to the anti-oxident effect, SMEW method leds to increasing of the SOD-like activity, total polyphenol amount as well. Also, cytotoxic effect and growth inhibitory effect against cancer cell line are much higher in SMEW method than HWEW method, especially SMEW5 extracts treated by supersonic 15 min. and microwave 120W, 3 min. and 2 times. The main volatile flavor compound and infinitesimal volatile flavor compound both increase significantly by SMEW method. It is concluded the main components of the volatile flavor compounds extracted from Tricholoma matsutake are 1-octen-3-0l, Methyl cinnamate, 2-octeno1 et al. alcohol typies. Consequently, SMEW5 method is considered as the most effective one for anti-oxidant and is prior to any other methods. And the optimun conditions of this method are : supersonic waves (supersonic, 25KHz, 50W) 15 minutes, microwave spectroscopy (microwave, 2,450MHz, 120W) 3 minutes, and every treatment is performed once followed twice repeats.

Measurement of High Temperature Dielectric Property at Microwave Frequency Using Cavity Perturbation Method (Cavity Perturbation Method를 이용한 마이크로파 주파수대의 고온 유전특성 측정 연구)

  • Kim, Dong-Eun;Jung, Jin-Ho;Lee, Sung-Min;Kim, Hyung-Tae
    • Journal of Powder Materials
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    • v.13 no.6 s.59
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    • pp.455-461
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    • 2006
  • High temperature dielectric constants of the various ceramic materials have been measured using cavity perturbation method. The measurements were applied to refractory, traditional and fine ceramic powder compacts from room temperature to $1200^{\circ}C$. Calibration constant in the equation suggested by Hutcheon et al., was determined from the dielectric constants of reference specimen (teflon and alumina) at room temperature. From these results, informations on the refectory materials were obtained for the microwave kiln design and understanding of the microwave heating effects of ceramics have been improved.

The Effect of Microwave Diathermy against the Body Composition of Obese Women (비만 여성들의 체성분에 대한 극초단파 심부투열치료의 효과)

  • Kang, Jeong-Il;Park, Seung-Kyu;Lee, Joon-Hee
    • The Journal of Korean Physical Therapy
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    • v.20 no.4
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    • pp.29-34
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    • 2008
  • Purpose: This study investigated the effect of microwave diathermy against the body composition of obese women with protein content, muscle quantity, and the change of body weight for three weeks by microwave diathermy. Methods: we performed the change of body weight for three weeks using the method of 100,000 Hz microwave diathermy against obese women. The obese women were examined the change of body weight by pre-test using microwave diathermy. Results: The effect of microwave diathermy in protein content, muscle quantity, and body weight did not show any statistically significant in an experimental group of eight female university students for three weeks, but the change of body weight was statistically significant (p>0.05) for three weeks to eight students who were examined by microwave diathermy. The control group did not show any statistically significant in protein content, muscle quantity, body fat, and the change of body weight for three weeks.s). Conclusion: These results suggest that microwave diathermy may be an effective method for the management of the body and the diet in obese women.

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The Study on Pre-treatment Method of Filter for Analysing the Heavy Metals in Air Quality (대기중의 중금속 분석을 위한 여지의 전처리 방법에 관한 연구)

  • 김광래;이상칠;어수미;김민영;신재영;이재영
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2002.04a
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    • pp.16-19
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    • 2002
  • This study was carried out to establish the standardized analysis method in order to decide accurate concentrations of hazardous metals in the air. Acid decomposition method used usually was compared to microwave digestion method. Comparing results of tested background concentration in blank filter, we found that the magnitude of element concentration was Na, Ca, K, Mg, Al and Ba by order. The element concentrations of Glass fiber filter were higher than those of Quartz fiber filter, and the number of undetected components in Glass fiber filter was lower than that in Quartz fiber filter. Thus it is supposed that the concentration of background elements in Glass fiber filter was higher than those in Quartz fiber filter The extraction rate of microwave digestion method was superior to those of acid decomposition method during the test of blank filter as well as SRM of NIST. In case of the SRM of NIST, the average extraction efficiency of acid decomposition Method and microwave pretreatment is 53.8∼82.7%, 81.3∼97.1%, respectively. This result might be caused by the closed system of Microwave, which make outflow and loss of components less. Also microwave digestion method has other merits such as the minimization of time, reagents, and contamination. Furthermore, if the extraction condition, extraction time and used acids are optimized, the better results will be represented.

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Improvement of Histopathological Sample Preparation by Employing Microwave Heating Method on Frozen Section Specimens

  • Ahn, Seung-Ju
    • Biomedical Science Letters
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    • v.13 no.4
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    • pp.361-368
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    • 2007
  • Biological samples can be fixed either by chemical method by using chemical solution or physical methods by using heat treatment. The problem in traditional heat fixation is unsatisfactory quality due to uneven heat conduction in specimen and loss of inner cell contents. Chemical fixation method also bears several intrinsic problems like the limit in specimen size, time consumption in fixative impregnation, and loss of low molecular weight cell components. These factors deteriorate the quality of fixed specimen, thus limit the magnification and contrast of tissue pictures. Microwave heat has been reported to be a good alternative to current chemical methods to overcome these problem. In this study, we tried to introduce the microwave energy method to routine fixation work in hospital. We replaced chemical fixative with saline to provide moderate reaction condition, and used frozen section to reduce time for sample preparation. Temperature was measured at each experiment. The fixation of rat kidney tissue with 2.45 GHz electromagnetic wave and saline showed similar result to the control group fixed with traditional chemical method. Human tumor tissue fixed with 2.45 GHz electromagnetic in frozen section was improved in terms of histochemistry of PAS and immunohistochemistry of tumor marker like cytokeratin. Total turnaround time was reduced from $24\sim38$ h to to $2\sim4$ h. In conclusion, the quality of samples prepared by microwave heating method was at least as good as that of traditional method. If the condition for the fixation of different specimens is standardized, this new method could be applied to routine work in hospital, and could save working time as well.

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Microwave characteristics of traveling-wave modulator considering the microwave feed-line (마이크로파 feed line을 고려한 진행파형 광 변조기의 특성 분석)

  • Gu Min-Ju;Ok Seong-Hae;Cho Yeong-Wan
    • 한국정보통신설비학회:학술대회논문집
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    • 2003.08a
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    • pp.172-174
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    • 2003
  • In this paper, we analyze the traveling-wave electro-absorption modulator (TW-EAM) in consideration of the microwave feed-line. The TW-EAM is analyzed by using the equivalent circuit model. The microwave feed-line isanalyzed by momentum method. In a view point of microwave characteristics, we present the effect of the structure and the length of microwave feed-line.

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A Preliminary Study of Patchouli Oil Extraction by Microwave Air-Hydrodistillation Method

  • Kusuma, Heri Septya;Altway, Ali;Mahfud, Mahfud
    • Korean Chemical Engineering Research
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    • v.55 no.4
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    • pp.510-513
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    • 2017
  • Patchouli oil extraction in general is still using conventional methods that require a long time of extraction. It is therefore necessary to develop extraction methods to obtain patchouli oil with optimum yield and quality. One of the new methods, which has been successfully developed, is microwave hydrodistillation (MHD). In addition to optimizing the extraction process of patchouli oil, this study also used microwave air-hydrodistillation (MAHD). Based on the research results, extraction using MAHD method can produce higher yield of patchouli oil when compared using MHD method. Also, based on the results of the analysis by GC-MS, extraction using MAHD method can produce quality of patchouli oil that is almost the same when compared using MHD method. This is supported by the results of the analysis by GC-MS, which showed that the content of patchouli alcohol is the main component of patchouli oil, and is almost the same for patchouli oil extracted using MHD method (26.32%) and MAHD method (25.23%).

A Study on Measuring Technique of Characteristics for Electromagnetic Wave of Microwave Absorbers (전파흡수체의 전자파적 특성측정기법 연구)

  • Kim, Dong-Il;Chung, Se-Mo;Ahn, Young-Sup
    • Journal of the Korean Institute of Navigation
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    • v.16 no.4
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    • pp.25-34
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    • 1992
  • As a method of measure the absorbing characteristics of microwave absorber, the various microwave measuring method can be used fundamentally. There is, however, a big problem in measuring errors, since the wavelength of microwave such as used for radar is very short. Therefore, this research aimed to design and fabricate a converting adaptor of $20mm^{\phi}$ coaxial tube from a Type-N connector to $20mm^{\phi}$ coaxial tube and to use it for evaluating absorption characteristics of microwave absorber. Furthermore, the measurements of absorbing characteristics and material constants have been performed and review, which were carried out by using the coaxial tube and by using rectangular waveguide, respective. As a result, the validity of the proposed measuring method has been confirmed.

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COMPUTATIONAL ANALYSIS ON DRYING OF POROUS MEDIA (다공성 매질의 건조 해석)

  • Lee, Ju-Seok;Lee, Chang-Hwan;Bae, Young-Min;Moon, Young-J.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.145-150
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    • 2009
  • In this study, characteristics of microwave and convective drying are studied by using a multiphase porous media model. Temperature and moisture profiles for hot-air convective heating and microwave heating of 1-D porous media with varying time and space are numerically investigated. This result shows the microwave drying method is more effective than the convective drying method. Comparing to convective drying, microwave drying can increase temperature and evaporation rate significantly since microwave generates internal heat and increases internal pressure, which results in moisture movement toward the surface on which moisture is vaporized.

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A Study on Development of High Performance Microwave Absorbers in Wide-Band Type for RADAR (레이다용 광대력형 고성능 전파흡수체의 개발에 관한 연구)

  • 김동일;안영섭;정세모
    • Journal of the Korean Institute of Navigation
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    • v.15 no.1
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    • pp.1-9
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    • 1991
  • The coaxial sample holder with 20mm in diameter and the adaptor from type N connector-to-20mm${\phi}$ coaxial tube are designed and manufactured which have been used for designing and measuring the fabricated microwave absorber. In addition, the measure in method of material constants of the microwave absorbers is described, which is focused on minimizing the error due to the sample's shapes, the fitting conditions, etc. After describing the design method of a single-layed microwave absorber, the microwave absorbers for X-band, C-band and S-band RADARs are designed and fabricated, respectively, which are composed of ferrite, carborn, and binder and have good performance. Futhermore, we develop the high performance microwave absorber in extremely wide-band type for RADAR, which is composed of different material and its mixing ratio and which could cover nearly from 4 to 10 GHz.

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