• Title/Summary/Keyword: High frequency heat treatment

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Childhood Obesity Patients treated by Korean Medicine Treatment: A Case Series (한의 치료로 호전된 소아비만 환자 9례에 대한 임상증례군 보고)

  • Choi Eun Young;Lee Hyun Hee;Lee Hye Lim
    • The Journal of Pediatrics of Korean Medicine
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    • v.37 no.3
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    • pp.101-110
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    • 2023
  • Objectives This study was written to report Korean medicine treatment for obese children. Methods This study included obese children who visited the Department of Korean Pediatrics at the Daejeon Korean Medicine Hospital of Daejeon University from September 18, 2020 to March 30, 2023. Height and weight at the first visit and on the day of the last herbal medicine termination were measured, and changes before and after treatment were observed. Liver function tests were performed before and after the treatment. Results Of the nine obese children who received Korean medicine treatment, five were male (55.6%) and four, female (44.4%). In term of age, there were five 8-year-olds (55.6%), two 6-year-olds, and two 10-year-olds (22.2%); the patients' mean age was 8.00 ± 1.414 years. The treatment period was more than three months, and the average treatment period was 177.11 ± 106.013 days. After treatment with Korean medicine, the patients' heights increased, and the body mass index (BMI) percentile and obesity decreased. Liver levels were maintained within the normal range without abnormal liver function after herbal medicine treatment, and no adverse reactions were observed during Korean medicine treatment. As a result of the pattern identification analysis, gastrointestinal damp-heat type and yin deficiency with internal heat were reported at a high frequency. Conclusions Korean medical treatment can reduce the degree of obesity without hindering the growth of childhood obesity.

Analysis of Frequency Response Curve for Conduction-Cooled Power Capacitors (전도 냉각 파워 커패시터의 주파수 응답 곡선 분석)

  • An, Gyeong Moon;Kim, Hiesik
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.10
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    • pp.123-130
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    • 2016
  • High-frequency induction heating equipment can heat the metal by applying a High-Frequency power to the resonant circuit. The resonance circuit is composed of the work coil and the conduction-cooled power capacitor, it influences the performance of the heat treatment equipment according to the characteristics of the capacitor. However, dependence on conduction-cooled power capacitor's import is high due to lack of core technology research and development. Minimizing the generation of internal heat transmitted inside during LC resonance, reduce the reactive power loss, there is a need for a capacitor within the voltage characteristic outstanding. To implement localization it is vital that prior study of the analysis on the frequency response characteristic for the finished capacitor advanced manufacturer be implemented. Studying the interpolation method to read the value at any point of the characteristic curve for a given log-log scale was applied to the analysis tool of the capacitor by my proposed algorithm. The simulation for reproducing frequency response curves was attempted by assuming a capacitor in a simplified series equivalent RC circuit to obtain the equivalent series resistance value. It was confirmed that the reproduction rate was the result value above 83% as compared to the simulation of the properties and characteristics on the actual reactive power for Peak value, and that the algorithm can be applicable when analyzing and predicting the characteristic curves of a simpled model capacitor.

An efficient strategy for blocking the 1st mitotic cleavage of fish zygote using combined thermal treatment, exemplified by mud loach (Misgurnus mizolepis)

  • Nam, Yoon-Kwon;Park, Geyong-Cheol;Kim, Dong-Soo
    • Proceedings of the Korean Aquaculture Society Conference
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    • 2003.10a
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    • pp.38-38
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    • 2003
  • Blocking the first mitotic cleavage of the zygote is a key tool for chromosome-set manipulations in fish. We developed an improved method for inducing tetraploidy by blocking the mitosis with a combination of heat shock at 40.5$^{\circ}C$ for 1, 2 or 3 min followed by cold shock at $1.5^{\circ}C$ for 30, 45 or 60 min. When applied during the first cleavage metaphase of mud loach (Misgurnus mizolepis) zygotes, the optimal combination was heat for 2 min followed by cold for 45 min. At 1 month, the frequency of 4N survivors and the yield from total eggs fertilized was 55.7% and 14.4%, respectively, compared to heat shock alone with 20.0% efficiency and 3.6% yield. The effectiveness of the procedure was confirmed by diploid mitotic gynogenesis using transgenic markers. The overall yield of homozygous diploids, 34.0%, was better than that for single heat shock, 17.3%. The tetraploids and homozygous diploids had higher early mortality than normal diploid controls. However at 1 month, the viability of the tetraploids was the same as normal diploids. For gynogenetic diploids, the survival was similar to normal diploids after 3 months. The high efficiency of this new protocol extends the opportunity to study polyploidy in basic and applied research.

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Nano-scale Inter-lamellar Structure of Metal Powder Composites for High Performance Power Inductor and Motor Applications

  • Kim, Hakkwan;An, Sung Yong
    • Journal of Magnetics
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    • v.20 no.2
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    • pp.138-147
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    • 2015
  • The unique nano-scale inter-lamellar microstructure and unparalleled heat treatment process give our developed metal powder composite its outstanding magnetic property for power inductor & motor applications. Compared to the conventional polycrystalline Fe or amorphous Fe-Cr-Si-B alloys, our unique designed inter-lamellar microstructure strongly decreases the intra-particle eddy current loss at high frequencies by blocking the mutual eddy currents. The combination of optimum permeability, magnetic flux and extremely low core loss makes this powder composite suitable for high frequency applications well above 10 MHz. Moreover, it can be also possible to SMC core for high speed motor applications in order to increase the motor efficiency by decreasing the core loss.

Comparative Study on Numerical Analysis using Co-simulation and Experimental Results for High Frequency Induction Heating on SCM440 Round Bar (연동해석을 통한 SCM440 환봉의 고주파 유도가열 해석 및 실험 비교분석에 관한 연구)

  • Lee, Inyoung;Tak, Seungmin;Pack, Inseok;Lee, Seoksoon
    • Journal of Aerospace System Engineering
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    • v.11 no.3
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    • pp.1-7
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    • 2017
  • The applications of high-frequency induction heating has recently been studied in various industrial fields. In this study, induction heating is applied to a SCM440 specimen that is widely used in industry. The specimen was made up of a cylinder 20 mm in diameter and 160 mm long. An induction heating power supply module was used to generate heat in the cylinder at a high frequency (approximately 85 kHz) for 50 seconds. The temperature of the specimen was measured at the 150 mm length in 5 second intervals. Results such as joule heat and temperature are compared with the numerical model analysis using an electromagnetic-thermal co-simulation technique. The analytical model of the cylinder was modeled by considering the skin effect. The median measured temperature after induction heating was conducted for 50 seconds was $57.65^{\circ}C$, compared to a predicted analytical value of $57.27^{\circ}C$. Thus, the analytical results are in good agreement with the experimental results, and this model can predict the induction heating phenomenon numerically.

A Study on the Phase Bandwidth Frequency of a Directional Control Valve Based on the Hydraulic Line Pressure (배관 압력을 이용한 방향제어밸브 위상각 대역폭 주파수 측정에 관한 연구)

  • Kim, Sungdong;Lee, Jung-eun;Shin, Daeyoung
    • Journal of Drive and Control
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    • v.15 no.4
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    • pp.1-10
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    • 2018
  • Spool displacement of a direction control valve is the standard signal to measure the bandwidth frequency of the direction control valve. When the spool displacement signal is not available, it is suggested in this study to use the metering hydraulic line as an alternative way to measure - 90 degree phase bandwidth frequency of the hydraulic direction control valve. Dynamics of the hydraulic line is composed of inertia, capacitance, and friction effects. The effect of oil inertia is dominant in common hydraulic line dynamics and the line dynamics is close to a derivative action in a range of high frequency; such as a range of bandwidth frequency of common directional control valves. Phase difference between spool displacement and line load pressure is nearly constant as a valve close to 90 degree. If phase difference is compensated from the phase between valve input and pressure, compensated phase may be almost same as the phase of spool displacement that is a standard signal to measure phase bandwidth frequency of the directional control valve. A series of experiments were conducted to examine the possibility of using line pressure in to measure phase bandwidth frequency of a directional control valve. Phase bandwidth frequency could be measured with relatively high precision based on metering hydraulic line technique and it reveals consistent results even when valve input, oil temperature, and supply pressure change.

USING LOW-VOLTAGE-HIGH-FREQUENCY ELECTRIC FIELD TO MITIGATE MINERAL FOULING IN A HEAT EXCHANGER

  • Tijing, Leonard D.;Pak, Bock-Choon;Baek, Byung-Joon;Lee, Dong-Hwan;Cho, Young-I.
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2315-2320
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    • 2007
  • This paper presents an investigative study on the efficacy of a new physical water treatment (PWT) technology using an oscillating electric field to mitigate mineral fouling in heat exchangers. Parallel graphite electrode plates immersed in water were used to generate the electric field directly in water. Artificial hard water at 500 ppm hardness was used in all fouling tests. The inlet temperatures were maintained at 23.5${\pm}$0.5$^{\circ}C$ and 85${\pm}$0.5$^{\circ}C$ for cold and hot water sides, respectively. The results at a cold water-side velocity of 0.3 m/s showed a 16-60% drop in fouling resistances from the baseline test depending on the frequency of the electric field for the PWT-treated cases.

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Surface characteristics and stability of implants treated with alkali and heat (알칼리와 열처리에 의한 임플란트의 표면 특성 및 골유착 안정성에 관한 연구)

  • Song, Yun-Seok;Cho, In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.5
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    • pp.490-499
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    • 2008
  • Statement of problem: Bioactive materials must have the ability to spontaneously form a bone like apatite layer on their surface and induce direct biochemical bonding to bone. A simple chemical treatment via alkali and heat has been revealed to induce bioactivity in titanium. Purpose: The purpose of this study was to evaluate the surface characteristics and stability of alkali and heat treated implants. Material and methods: Specimens were divided into three groups; group 1 was the control group with machined surface implants, groups 2 and 3 were treated with alkali solutions and heat treated in the atmosphere and vacuum conditions respectively. The surface characteristics were observed with FESEM, XPS, TF-XRD and AFM. Stability was evaluated with the resonance frequency analysis, periotest and removal torque values. One-way ANOVA and Duncan test were used for statistical analysis. Results: 1. Groups treated with alkali and heat showed similar characteristics. Groups 2 and 3 showed high compositions of Na ions on the surface with sub-micron sized pores compared to group 1. Group 2 showed mixed compositions of anatase and rutile with superior contents of rutile. 2. Resonance frequency analysis : The ISQ of group 2 showed significantly higher values than that of groups 1 and 3 at 12 weeks. The ISQ of groups 1 and 2 showed significant increase after 4 weeks, and the ISQ of group 3 increased significantly after 2 and 4 weeks respectively (P < .05). 3. Periotest: The PTV of groups 1 and 2 showed significant decrease after 4 weeks, and the PTV of group 3 showed significant decrease after 2 and 4 weeks respectively (P < .05). 4. Removal torque analysis: The removal torque value of group 2 was significantly higher than those of groups 1 and 3 at 2, 4 and 8 weeks. The removal torque values of groups 1 and 3 showed increase at 4 and 12 weeks, but the removal torque value of group 2 showed increase after 4 weeks (P < .05). Conclusion: An oxide layer with appropriate crystal structure and amorphous sodium titanate layer can be obtained on titanium implants through alkali and heat treatment in the atmosphere, and even alkali and heat treatment in vacuum conditions, provided a bioactive surface containing sodium. These surface layers can be considered to be effective for enhancement of osseointegration and reduction of healing period for implant treatment.

Effect of Coating Thickness on Rolling Contact Fatigue of CNx Coated Steel (CNx코팅된 강의 회전접촉피로에 미치는 코팅두께의 영향)

  • Choi, Byung Young;Umehara, Noritsugu
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.5
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    • pp.355-359
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    • 2000
  • Ion beam assisted deposition system was used to deposit CNx coatings with various thickness on the substrates of high-frequency induction hardened steels. Rolling contact fatigue tests were performed using Polymet RCF-1 machine with a constant supply of lubricant. Rolling contact fatigue life was substantially different in the steels with various thickness of CNx coatings. The optimum thickness of CNx coating was found to be $8.9{\mu}m$, showing the longest fatigue life, mainly caused by higher resistance to initiation of cracks and protective overcoat remaining to the surface failure during rolling contact fatigue. Cracks were initiated in the substrates under the surface of wear track and propagated to the surface, which eventually resulted in the failure. The reduction of fatigue life observed in the specimen with elimination of CNx coating during rolling contact fatigue was explained by the substrates deformation.

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Effect of Post Deposition Annealing Temperature on the Hydrogen Gas Sensitivity of SnO2 Thin Films (증착 후 열처리온도에 따른 SnO2 박막의 수소 검출 민감도 변화)

  • You, Y.Z.;Kim, S.K.;Lee, Y.J.;Heo, S.B.;Lee, H.M.;Kim, Daeil
    • Journal of the Korean Society for Heat Treatment
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    • v.25 no.5
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    • pp.239-243
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    • 2012
  • $SnO_2$ thin films were prepared on the Si substrate by radio frequency (RF) magnetron sputtering and then post deposition vacuum annealed to investigate the effect of annealing temperature on the structural properties and hydrogen gas sensitivity of the films. The films that annealed at $300^{\circ}C$ show the higher sensitivity than the other films annealed at $150^{\circ}C$. From atomic force microscope observation, it is supposed that post deposition annealing promotes the rough surface and also, increase gas sensitivity of $SnO_2$ films for hydrogen gas. These results suggest that the vacuum annealed $SnO_2$ thin films at optimized temperatures are promising for practical high-performance hydrogen gas sensors.