• Title/Summary/Keyword: RF Heating

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Effect of heat treatment of digestion-resistant fraction from soybean on retarding of bile acid transport in vitro

  • Han, Sung-Hee;Lee, Seog-Won;Rhee, Chul
    • Nutrition Research and Practice
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    • v.3 no.2
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    • pp.149-155
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    • 2009
  • In this study, we investigated the heat effect of digestion-resistant fraction (RF) from soybean on retarding bile acid transport in vitro. The RFs from soybean retarded bile acid transport. A raw, unheated RF of soybean (RRF-SOY) was significantly more effective than the heated RF of soybean (HRF-SOY). The RS1 which physically trapped in milled grains and inaccessible to digestive enzyme after 18 hrs incubation level of content in RRF-SOY was found to be as high as 24.1% and after heating the RS1 of HRF-SOY was significantly reduced to 16.8%. The X-ray diffraction pattern of RF from soybean was altered after heat treatment. The RFs from soybean were characterized by peak at diffraction angles of $12.0^{\circ}$ and $20.0^{\circ}$ corresponding to RS content. Cellulose contents of RRF-SOY was 5% higher than that of HRF-SOY and pentosan contents of RRF-SOY was 5% higher than that of HRF-SOY, too. Whereas the hemicellulose content of RRF-SOY was 13% lower than HRF-SOY.

Preparation of p-type transparent semiconductor $SrCu_2O_2$ thin film by RF magnetron sputtering (RF 마그네트론 스퍼터링에 의한 p형 투명 반도체 $SrCu_2O_2$ 박막의 제조)

  • Kim, Sei-Ki;Seok, Hye-Won;Lee, Mi-Jae;Choi, Byung-Hyun;Jeong, Won-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.47-47
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    • 2008
  • P-type transparent semiconductor $SrCu_2O_2$ thin films have been prepared by RF sputtering using low-alkali glass for LCD and quartz as substrates. Single phase of $SrCu_2O_2$ powder was obtained by heating a stoichiometric mixture of CuO and $SrCO_3$ at 1223K for 96h under N2 gas flow, and target was fabricated at 1243K for 24h. Room temperature conductivity of the sintered body was about 0.02S/cm, and the activation energy in the temperature range of $-50^{\circ}C$~RT and RT~$150^{\circ}C$ were 0.18eV, 0.07eV, respectively. Effects of deposition pressure and post-annealing temperature on the electrical and optical properties of the obtained thin film have been investigated.

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Influence of Magnetic Field Near the Substrate on Characteristics of ITO Film Deposited by RF Sputtering Method (기판 부근의 자기장이 RF 스퍼터링법으로 증착된 ITO 박막의 특성에 미치는 영향)

  • Kim, Hyun-Soo;Jang, Ho-Won;Kang, Jong-Yoon;Kim, Jin-Sang;Yoon, Suk-Jin;Kim, Chang-Kyo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.7
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    • pp.563-568
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    • 2012
  • Indium tin oxide (ITO) films were prepared using radio frequency (RF) magnetron sputtering method, magnets were equipped near the target in the sputter to bring the plasma near the target. The effect of magnetic field that brings the plasma near the substrate was compared with that of substrate heating. The effect of substrate heating on the grain size of the ITO thin film was larger than that of the magnetic field. However, the grain size of the ITO thin film was larger when the magnetic field was applied near the substrate during the sputtering process than when the substrate was not heated and the magnetic field was not applied. If stronger magnetic field is applied near the substrate during sputtering, it can be expected that the ITO thin film with good electrical conductivity and high transparency is obtained at low substrate temperature. When magnetic field of 90 Gauss was applied near the substrate during sputtering, the mobility of the ITO thin film increased from 15.2 $cm^2/V.s$ to 23.3 $cm^2/V.s$, whereas the sheet resistivity decreased from 7.68 ${\Omega}{\cdot}cm$ to 5.11 ${\Omega}{\cdot}cm$.

Active control of amplitude and phase of high-power RF systems in EAST ICRF heating experiments

  • Guanghui Zhu;Lunan Liu;Yuzhou Mao;Xinjun Zhang;Yaoyao Guo;Lin Ai;Runhao Jiang;Chengming Qin;Wei Zhang;Hua Yang;Shuai Yuan;Lei Wang;Songqing Ju;Yongsheng Wang;Xuan Sun;Zhida Yang;Jinxin Wang;Yan Cheng;Hang Li;Jingting Luo
    • Nuclear Engineering and Technology
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    • v.55 no.2
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    • pp.595-602
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    • 2023
  • The EAST ICRF system operating space has been extended in power and phase control with a low-level RF system for the new double-strap antenna. Then the multi-step power and periodic phase scanning experiment were conducted in L-mode plasma, respectively. In the power scanning experiment, the stored energy, radiation power, plasma impedance and the antenna's temperature all have positive responses during the short ramp-ups of PL;ICRF. The core ion temperature increased from 1 keV to 1.5 keV and the core heating area expanded from |Z| ≤ 5 cm to |Z| ≤ 10 cm during the injection of ICRF waves. In the phasing scanning experiment, in addition to the same conclusions as the previous relatively phasing scanning experiment, the superposition effect of the fluctuation of stored energy, radiation power and neutron yield caused by phasing change with dual antenna, resulting in the amplitude and phase shift, was also observed. The active control of RF output facilitates the precise control of plasma profiles and greatly benefits future experimental exploration.

Isolation and Identification of Cholesterol Oxidation products in heated tallow by TLC (TLC를 이용한 가열우지중 콜레스테롤 산화생성물의 분리 및 확인)

  • 장영상;양주홍
    • Food Science and Preservation
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    • v.8 no.3
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    • pp.338-344
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    • 2001
  • The oxidative stability of cholesterol in tallow heated at different frying temperatures (130$\^{C}$, 150$\^{C}$, and 180$\^{C}$) was studied by identifying cholesterol oxides by thin layer chromatography(TLC). And fatty acid compositions in tallow heated were also measured and compared with cholesterol oxides. Unsaturated fatty acid contents slightly decreased as the heating time increased, whereas saturated fatty acid contents increased This phenomenon became excessive especially by heating to higher temperature. It was found that RF value and spot color of the nonsaponifiable lipids from tallow heated on TLC analysis accorded with the synthetic cholesterol oxides in this experiment. Four kinds of cholesterol oxides were detected in tallow heated for 24 hours at three different temperatures. The oxides were identified as 7-$\alpha$-hydroxycholesterol, 7-$\beta$-hydroxycholesterol, 7-ketocholesterol and cholesterol epoxide. It was found that there was a little difference in oxidative pattern of cholesterol between several heating temperatures.

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Component analysis of cultivated ginseng and mountain ginseng to the change of ginsenoside components in the process of heating and fermentation. (열처리 및 발효과정이 인삼 및 산양삼의 ginsenoside 함량에 미치는 영향)

  • Cha, Bae-Cheon;Yoon, Hye-Chul;Lee, Dae-Ho;Park, Jae-Seuk;Kwon, Ki-Rok
    • Journal of Pharmacopuncture
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    • v.13 no.2
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    • pp.33-49
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    • 2010
  • Objectives: The aim of this experiment is to provide an objective differentiation of cultivated ginseng, mountain ginseng through component analysis, and to know the change of gin senoside components in the process of heating and fermentation Methods: Comparative analyses of ginsenoside $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf, $Rg_1$, $Rg_3$, $Rh_1$, and $Rh_2$, from the cultivated ginseng 4 and 6 years, and mountain cultivated ginseng were conducted using HPLC (High Performance Liquid Chromatography, hereafter HPLC). And the same analyses were conducted in the process of heating and fermentation using mixed Lactobacillus rhamnosus, Lactobacillus plantarum, Bifidobacterium lactis for 7 days. Results: The change of ginsenosides to the process of red ginseng and fermentation, cultivated ginseng and mountain cultivated ginseng were showed another results. Mountain ginseng showed a lot of change compared with cultivated ginsengs. In the 7 days of fermentation, mountain ginseng showed that ginsenoside $Rg_1$, $Rb_1$, $Rb_2$, Rc, and Rd were decreased and increased ginsenoside Re, Rf, $Rg_3$ and $Rh_1$ were increased compared with cultivated ginseng Conclusions: It seemed that ginsenosides of mountain cultivated ginseng was better resolved than cultivated ginseng because the difference of structure or distribution of ginsenosides in the condition of fermentation.

Variations in Ginsenosides of Raw Ginseng According to Heating Temperature and Time

  • Kim, Chan Joong;Kim, Bo Mi;Kim, Cheon Suk;Baek, Jung Yeon;Jung, In Chan
    • Journal of Pharmacopuncture
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    • v.23 no.2
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    • pp.79-87
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    • 2020
  • Objectives: Ginsenosides found in ginseng, and the hydrolysates derived from their conversion, exhibit diverse pharmacological characteristics [1]. These have been shown to include anti-cancer, anti-angiogenic, and anti-metastatic effects, as well as being able to provide hepatic and neuroprotective effects, immunomodulation, vasodilation, promotion of insulin secretion, and antioxidant activity. Therefore, the purpose of this study was to examine how quickly the ginsenosides decompose and what kinds of degradation products are created under physicochemical processing conditions that don't involve toxic chemicals or other treatments that may be harmful. Methods: The formation of ginsenoside-Rg2 and ginsenoside-Rg3 was examined. These demonstrated diverse pharmacological effects. Results: We also investigated physicochemical factors affecting their conversion. The heating temperatures and times yielding the highest concentration of ginsenosides (-Rb1, -Rb2, -Rc, -Rd, -Rf, -Rg1, and -Re) were examined. Additionally, the heating temperatures and rates of conversion of these ginsenosides into new 'ginseng saponins', were examined. Conclusion: In conclusion, obtained provide us with effective technology to control the concentration of both ginsenosides and the downstream converted saponins (ginsenoside-Rg2, Rg3, Rg5, and Rk1 etc.), as well as identifying the processing conditions which enable an enrichment in concentration of these compounds.

A study on SiC crystal growth by sublimation process using resistance heating method (저항가열 방식을 적용한 승화법에 의한 SiC 결정 성장에 대한 연구)

  • Kang, Seung Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.25 no.3
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    • pp.85-92
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    • 2015
  • SiC crystals are well known for their true potential as high power devices and their crystal growth activity is actively carried out in domestic as well as in abroad. Until now the process to grow this crystal has been done by sublimation technique using radio frequency induction heating method. However in order to get better quality of SiC crystals, the stability of temperature is needed because SiC crystal tends to transform to other polytypes. So, the possibility of SiC crytals growth was evaluated by different heating method. This study aimed to observe whether the resistant heating method would show stable growth and better quality of SiC single crystal than that of RF induction heating. As a result, polycrystalline SiC crystals were grown by the growth rate of 0.02~0.5 mm/hr under the condition of $2100{\sim}2300^{\circ}C$ at the bottom side of the crucible and 10~760 torr. The polycrystalline SiC crystals with 0.25 and 0.5 mm in thickness were grown successfully without seed and characterized by optical stereo microscopic observation.

Dielectric Properties of Agricultural Properties and Their Use in Moisture Sensing and Other Applications

  • Nelson, Stuart O.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.293-304
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    • 1996
  • Historical interest in dielectric properties of agricultural products and definitions of dielectric terms and basic principles governing their influence on elelctromagnetic energy are presented briefly . The nature of dielectric properties variation with frequency, temperature , and product density is discussed, Graphical data on the dielectric properties of products are presented that illustrate the dependence of these properties on moisture content, frequency, temperature, and density. Applications microwave dielectric properties of agricultural products are cited that include radio-frequency (RF) and microwave heating for seed treatment, improvement of nutritional and keeping qualities of some products, and controlling insects in grain. Uses of dielectric properties for product quality measurement and the rapid determination of moisture content are described. Principle of moisture determination in bulk grain by RF and microwave measurements are briefly presented.

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Preparation of Bismuth Thin Films by RF Magnetron Sputtering and Study on Their Electrical Transport Properties (RF 마그네트론 스퍼터링을 이용한 Bismuth 박막의 제조와 그 전기적 특성 연구)

  • Kim Dong-Ho;Lee Gun-Hwan
    • Journal of the Korean institute of surface engineering
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    • v.38 no.1
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    • pp.7-13
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    • 2005
  • Bismuth thin films were prepared on glass substrate with RF magnetron sputtering and effects of substrate temperature on surface morphology and their electrical transport properties were investigated. Grain growth of bismuth after nucleation and the onset of coalescense of grains at 393 K were observed with field emission secondary electron microscopy. Continuous thin films could not be obtained above 473 K because of grain segregation and island formation. Hall effect measurements showed that substrate heating yields the decrease of carrier density and the increase of mobility. Resistivity of bismuth film has its minimum (about 0.7 x 10/sup -3/ Ωcm) in range of 403~433 K. Annealing of bismuth films deposited at room temperature was carried out in a radiation furnace with flowing hydrogen gas. The change of resistivity was not significant due to cancellation of the decrease of carrier density and the increase of mobility. The abrupt change of electrical properties of film annealed above 523 K was found to be caused by partial oxidation of bismuth layer in x-ray diffraction analysis.