• Title/Summary/Keyword: heating characteristics

Search Result 2,433, Processing Time 0.03 seconds

The Experimental Study of Various Salts on the Characteristics of Heat Transfer in Indirect Moxibustion with Salt (염(鹽)의 종류(種類)에 따른 격염구(隔鹽灸)의 열전달(熱傳達) 특성(特性)에 관한 실험적(實驗的) 연구(硏究))

  • Lee, Geon-mok;Lee, Gun-hyee;Seo, Eun-mi
    • Journal of Acupuncture Research
    • /
    • v.21 no.1
    • /
    • pp.119-135
    • /
    • 2004
  • Objective: The purpose of this study is to investigate the mechanism and effect of moxibustion with salt objectively, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxibustion with salt. Methods: We have selected of the moxibustion with salt of indirect moxibustion. We make a comparative study of the thermodynamic characteristics of moxibustion with salt as a kind of the 4 salt. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa. Results: 1. We make out that it is not significantly change the time of thermal conduction of moxibustion with salt as a kind of 4 salt. 2. The heating period of Refined Salt was long and that of Sun-dried Salt was a short time respectively. The heating period of maximum tamperature is high Sun-dried Salt, Mechanical Salt and Refined Salt orderly. Maximun heating speed in the heating period was $0.151{\sim}0.184^{\circ}C/sec$ and at the same tendency of the maximum temperature in the heating period. 3. The retaining period was shorter than the heating period respectively, that is 15~24% of the combustion time of in the heating period. We make out that it is not significantly different the time of the retaining period as a kind of 4 salt. The mean temperature of retaining period was $43.2{\sim}48.1^{\circ}C$, that was extraordinarily high temperature. 4. We make out that it is not significantly different the time of the cooling period as a kind of 4 salt. The cooling period was measured 223~233sec. Beacuse the same density and size of moxa combustion was made an experiment. 5. The effective combustion time of Refined Salt is longer(259sec) than that of Sun-dried Salt(173sec). It is significantly different the time of the combustion time as a kind of 4 salt. 6. It is significantly different the Sample deviation of the combustion time as a kind of 4 salt because of the water content of the 4 salt individually. Conclusions: As the base on this study, we obtained the conclusion as the follows. The salt of moxibustion with salt was fitted for Sun-dried Salt due to making to Mechanical Salt recently. The Refined Salt is composition rate to another and small size comparatively. So It was fitted for the salt of moxibustion with salt. It is necessary to study continuously about the more suitable moxibustion with salt and quantitative analysis about the moxibustion with salt.

  • PDF

Studies on the Characteristics of Rubber Vulcanization Exotherm by Differential Scanning Calorimetry. (Differential Scanning Calorimetry에 의(依)한 고무의 가황발열특성(加黃發熱特性)에 관(關)한 연구(硏究))

  • Choi, Sei-Young;Paik, Nam-Chul
    • Elastomers and Composites
    • /
    • v.19 no.1
    • /
    • pp.13-31
    • /
    • 1984
  • The purposes of this dissertation are to demonstrate that DSC theromoanaytical methods of vulcanization can provide useful informations on the vulcanization characteristics of industrial formulations and also provides the potential basis for a rapid and complete method of sulfur and vulcanizing accelerator analysis for quality control. The influences of those factors such as heating rate, scan temperature, vucanizing accelerator's type and concentration upon vulcanization exotherm in NR and NBR compounds in the presence of vulcanizing accelerators such as TMTD,MBTS,DPG,TMTM,CBS, and MBT were evaluated by means of DSC. In order to examine the credibility in the DSC method, the same samples which were used for DSC method were studied to compare the DSC results with the ODR (Oscillating Disk Rheometer) data. The results obtained were as follows 1. In the DSC dynamic experiments, the observed enthalpy results from vulcanization depends upon the heating rate; In the range of 2 to $20^{\circ}C/min$ of heating rate, as the heating rate was increased the enthalpy change was also increased. However, over the heating rate of $30^{\circ}C/min$ it was observed that the enthalpy change was decreased as the heating rate was further increased. Without regard to the change of enthalpy, tremendous instantaneous heat evolving was observed in the range of high heating rates. 2. For the samples which are added with various vulcanizing accelerators, the activation energies of vulcanization were as follows; 3. Regarding to the influences of vulcanizining accelerator's types upon the characteristics of vulcanization exotherm, NR and NBR compounds in the presence of thiuramsulphide compounds type accelerators such as TMTD, TMTM, were exhibited sharper and higher vulclanization exotherm than others. From the resuts of DSC thermograms which was distributed in even shape in the broad temperature range, it was clearly shown that the guanidine compounds type accelerator such as DPG acts as a delayed acting accelerator. 4. In the comparison of DSC and ODR results, the dependency of temperature in the cure rate and the observed conversions show good agreements between two results. 5. In the same curatives, by the comparison of glass transition temperatures, it was possible to predict relative values of maximum torques. Consequently, from the present studies, it is shown that the DSC thermoanalytical method can provide an alternate new method for rapid and complete quality control analysis of rubber industry.

  • PDF

Quality Characteristics of Mussel Stock with Different Heating Times (가열시간을 달리하여 제조한 홍합육수의 품질특성)

  • You, Soo-Hyun;Shin, Kyung-Eun;Choi, Soo-Keun;Seo, Yoon-Weon
    • Culinary science and hospitality research
    • /
    • v.19 no.3
    • /
    • pp.209-217
    • /
    • 2013
  • This study aims to develop mussel stock, which is the base of sauce, soup, etc., using various nourishing elements in mussels. In mussel stock with different heating times, the moisture content was significantly different according to heating times(p < 0.05). For the color value of mussel stock, L value was highest in MS1(35.48), a value in MS1(-2.39), and b value in MS5(-9.49). pH was lowest as 6.56 in MS5, and with increased heating time, pH decreased significantly (p < 0.001). With increased heating time, the sugar content was highest as $4.03^{\circ}Brix$ in MS3 and lowest as $3.37^{\circ}Brix$ in MS1. The salinity content was lowest as 0.71% in MS1, and with increased heating time, the salinity content increased significantly (p < 0.001). The test for characteristic differences of mussel stock showed that its color intensity, transparency, fish flavor, fish taste, and salty taste increased with increased heating time. Savory taste of mussel stock was highest in MS4 with 4.33% According to the results of acceptance test, taste, and overall acceptance test, MS3 showed the best results. In conclusion, mussel stock showed great preference with increased heating time, and the preference has increased when it was heated for 15 min.

  • PDF

Heating Characteristics of Carbon Fiber Polyimide-Coated by Electrophoretic Deposition (전기영동증착법으로 폴리이미드를 코팅한 탄소섬유의 발열 특성 연구)

  • Geon-Joo Jeong;Tae-Yoo Kim;Seung-Boo Jung;Kwang-Seok Kim
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.30 no.1
    • /
    • pp.90-94
    • /
    • 2023
  • Carbon fiber(CF) with excellent thermal conductivity and electrical conductivity is attracting attention as an alternative material because metal heating elements have problems such as high heat loss and fire risk. However, since CF is oxidized and disconnected at about 200℃ or higher, the application of heating elements is limited, and CF heating elements in the form of vacuum tubes are currently used in some commercial heaters. In this work, polyimide(PI) with high heat resistance was coated on the surface of carbon fiber by electrophoretic deposition to prevent oxidation of CF in the atmosphere without using a vacuum tube, and the coating thickness and heat resistance were investigated according to the applied voltage. The heater made by connecting the PI-coated CF heating elements in series showed stable heating characteristics up to 292℃, which was similar to the heating temperature result of the heat transfer simulation. The PI layer coated by the electrophoretic deposition method is effective in preventing oxidation of CF at 200℃ or higher and is expected to be applicable to various heating components such as secondary batteries, aerospace, and electric vehicles that require heat stability.

Effect of Excess Air and Superficial Air Velocity on Operation Characteristics in a Fluidized Bed Coal Combustor (공탑속도 및 과잉공기비에 따른 석탄유동층연소로의 조업특성)

  • 장현태;차왕석;태범석
    • Journal of the Korean Society of Safety
    • /
    • v.14 no.3
    • /
    • pp.84-92
    • /
    • 1999
  • The effects of air velocity and excess air on combustion characteristics were studied in a fluidized bed combustor. The domestic low-grade anthracite coal with heating value of 2010 kcal/kg and the imported bituminous coal from Australia with heating value of 6520 kcal/kg were used as coal samples. The combustion characteristics of mixed fuels in a fluidized bed combustor could be interpreted by pressure fluctuation properties, ash distribution and gas emission. The properties of the pressure fluctuations, such as the standard deviation, cross-correlation function, dominant frequency and the power spectral density function, were obtained from the statistical analysis. From this study, the combustion region increased with increasing air velocity but decreased with excess air due to combustion characteristics of anthracite and bituminous coal.

  • PDF

A Study on the New Control Scheme of Class-I Inverter for IH-Jar Applications with Clamped Voltage Characteristics Using Pulse frequency Modulation (주파수 변조 기법을 이용한 전압 클램프 특성을 갖는 유도가열용 Class-E 인버터의 새로운 제어에 관한 연구)

  • 이동윤;최영덕;현동석
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.52 no.3
    • /
    • pp.133-139
    • /
    • 2003
  • In this paper, a new control scheme of Class-E inverter for Induction Heating (IH) Jar applications with clamped voltage characteristics using Pulse-Frequency-Modulation (PFM) is introduced. To reduce the voltage stress of switch, the proposed PFM control scheme doesn't need any auxiliary circuit in comparison to a family of Active Clamped Class-E (ACCE) inverter. It can decrease voltage stress of switch through modulation of switching frequency. The Class-E inverter using the proposed control scheme has the advantage of not only the same output power when it is compared with a Hybrid-Active Clamped Class-E (Hybrid-ACCE) inverter but also Zero-Voltage-Switching (ZVS), which are characteristics of conventional Class-E and ACCE inverter. The control principles and analysis of proposed method are explained in detail and its validity is verified through simulation and experimental results.

The characteristics of laminar diffusion flame impinging on the wall (벽면 충돌 층류 확산화염의 특성)

  • Park,Yong-Yeol;Kim, Ho-Yeong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.20 no.3
    • /
    • pp.979-987
    • /
    • 1996
  • A theoretical study for the laminar round jet diffusion flame impinging on the wall was carried out to predict the characteristics and structure of impinging jet flame and heat transfer to the wall. Finite chemistry via Arrhenius equation was adopted as the combustion model. All the transport properties were considered as the variable depending on the temperature and composition. For the parametric study, the distance from nozzle to perpendicular wall and Reynolds number at nozzle exit were chosen as the major parameters. As the results of the present study, the characteristics of flow field and the distributions of temperature, density and each chemical species were obtained. The heat transfer rate from flame to the wall and the effective heating area were calculated to investigate the influence of the major parameters on the heat transfer characteristics.

A Study on the Table Design for Utilization of Cornus controversa Laminated Wood Manufactured by Pressing and Heating (가압.가열 처리한 층층나무 적층재를 활용한 테이블 디자인 연구)

  • Shin, Rang-Ho;Han, Tae-Hyung;Kwon, Jin-Heon
    • Journal of the Korea Furniture Society
    • /
    • v.23 no.1
    • /
    • pp.68-74
    • /
    • 2012
  • In this study domestic thinning and small diameter woods of Giant dogwood (Cornus controversa Hemsl) was used. To increase the utilizability of wood, the utilizability was proposed after manufacturing laminated wood by pressing and heating. The physical and mechanical characteristics of Laminated wood were investigated and the color change was measured, using a Chromaticity coordinates, after being pressed at 10% (45 mm), 20% (40 mm), 30% (35 mm) for 5 minutes, using Stopper, and then heated at $180^{\circ}C$ for 6, 12, 24 and 48 hours. The results were as follows. Wood density, compressive strength, MOR, MOE are increased with increasing pressing rate but decreased as heating time is increased after pressing. However, Color change is clear, dimensional stability is improved after pressing and heating.

  • PDF

Optimum Design of SCR Inverter for High-Frequency Induction Heating (SCR Inverter 고주파유도가열장치의 최적설계에 관한 연구)

  • 박성규;김주홍
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.14 no.1
    • /
    • pp.23-28
    • /
    • 1977
  • This paper describes the practical design of a SCR inverter which is suposed to be very much suitable for high frequency induction heating power source. In this design an optimum control technique was applied to maintain constant output power and constant power factor to various heating load by the use of frequency control. Some appreciable characteristics was obtained for some design guide of large ndstrial heating power sources by the test of the 3KHz, 3KW inverter which was designed in this study.

  • PDF

Performance Analysis of Water Direct Contact Air Conditioning System (물 직접접촉식 공기조화장치의 성능해석)

  • Yoo, S.Y.;Kwon, H.K.;Song, J.;Kim, K.Y.;Park, J.T.
    • Proceedings of the KSME Conference
    • /
    • 2001.06d
    • /
    • pp.158-163
    • /
    • 2001
  • Performance of the water direct contact air conditioning system, in which heat and mass are transferred directly between air and water droplet, is simulated by semi-empirical method. This system improves transport efficiency compared to conventional indirect contact system and cooling, heating, dehumidification and humidification are attained with one unit. In this study, temperature and flowrate for air and water are measured in the various cooling and heating conditions, and correlations for $h_{c}A/c_{pm}$ are derived from these data. Cooling and heating characteristics of the water direct contact air conditioning system are investigated using correlations.

  • PDF