• Title/Summary/Keyword: Heating methods

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A Study on the Dyeing of Polyester Fabric by Microwave Heating(I) (Microwave 가열에 의한 Polyester직물의 염색에 관한 연구(I))

  • 서수정;임수경;김삼수
    • Textile Coloration and Finishing
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    • v.10 no.4
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    • pp.7-14
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    • 1998
  • Microwaves are high frequency radiation capable of generating very rapid, uniform and efficient heating of textile material. Microwave heated dyeing of polyester fabric was tried with different solvent systems, irradiation time and dye concentration. Microwave fixation methods were used with 100% water,30% urea, EG and DMF, respectively, pad-baths in which the padded fabrics were exposed over a heated or boiling water bath to maintain sufficient moisture content during irradiation. In order to ascertain the relation between the dyeing property of polyester fabric and the microwave irradiation condition caused by microwave heating, the K/S values and fastness properties of dyed fabrics such as light, washing and sublimation fastness were measured.

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A Method to Simulate Frictional Heating at Defects in Ultrasonic Infrared Thermography

  • Choi, Wonjae;Choi, Manyong;Park, Jeonghak
    • Journal of the Korean Society for Nondestructive Testing
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    • v.35 no.6
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    • pp.407-413
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    • 2015
  • Ultrasonic infrared thermography is an active thermography methods. In this method, mechanical energy is introduced to a structure, it is converted into heat energy at the defects, and an infrared camera detects the heat for inspection. The heat generation mechanisms are dependent on many factors such as structure characteristics, defect type, excitation method and contact condition, which make it difficult to predict heat distribution in ultrasonic infrared thermography. In this paper, a method to simulate frictional heating, known to be one of the main heat generation mechanisms at the closed defects in metal structures, is proposed for ultrasonic infrared thermography. This method uses linear vibration analysis results without considering the contact boundary condition at the defect so that it is intuitive and simple to implement. Its advantages and disadvantages are also discussed. The simulation results show good agreement with the modal analysis and experiment result.

A method for Thermal Control of Nano Injection Molding using the Peltier Devices (펠티어 소자를 이용한 나노 사출 금형의 능동형 온도 제어)

  • Shin, H.;Kwon, J.;Hong, N.;Seo, Y.;Kim, B.
    • Transactions of Materials Processing
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    • v.17 no.5
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    • pp.337-342
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    • 2008
  • The injection molding process has high accuracy and good reproducibility that are essential for mass production at low cost. Conventional molding processes typically use the water-based mold heating and air cooling methods. However, in the nano injection molding processes, this semi-active mold temperature control results in the several defects such as air-flow mark, non-fill, sticking and tearing, etc. In order to actively control temperature of the molds and effectively improve the quality of the molded products, the novel nano injection molding system, which uses active heating and cooling method, has been introduced. By using the Peltier devices, the temperature of locally adiabatic molds can be controlled dramatically and the quality of the molded patterns can be improved.

The Effects of Prediction and Reset Control of Outdoor Air Temperature on Energy Consumption for Central Heating System (외기온도 예측 및 보상제어가 난방시스템의 에너지 소비량에 미치는 영향)

  • Ahn, Byung-Cheon;Hong, Sung-Suk
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.12 no.4
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    • pp.8-14
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    • 2016
  • In this study, the effects of prediction and reset control of outdoor air temperature on energy consumption for central heating system are researched by using TRNSYS program package, and the control performances with the suggested methods of prediction and reset control of outdoor air temperature are compared with the existing ones. As a result, the value of coefficient of determination $R^2$ for the predicted outdoor temperatures is improved and the suggested control method shows maximum 21.8% energy saving in comparison with existing control ones.

Effects of Heat Therapy Using a Far Infrared Rays Heating Element for Dysmenorrhea in High School Girls (원적외선 방사체를 이용한 온열요법이 여고생의 월경곤란증에 미치는 효과)

  • Hong, Yeon-Ran
    • Journal of Korean Academy of Nursing
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    • v.41 no.1
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    • pp.142-149
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    • 2011
  • Purpose: The purpose of this study was designed to identify the effects of heat therapy on dysmenorrhea, heat being provided using a far infrared rays heating element. Methods: The research design for the study was a non-equivalent control group quasi- experimental design. Participants were 22 students for the experimental group, and 26 students for the control group. Data were analyzed using SAS WIN 9.1 program. Results: The experimental group had significantly lower mean scores for menstrual pain, dysmenorrhea, and blood pressure than those in the control group. However, no significant differences were found between two groups for pulse, respiration, and temperature. Conclusion: These findings show that thermotherapy was effective for reduction of menstrual pain, dysmenorrhea, and B/P. Therefore, this therapy could be used as a nursing intervention for students with dysmenorrhea.

Non-destructive evaluation technology using infrared thermography and near infrared heating for detecting inside-defects of concrete structures (근적외선과 열화상 기법을 이용한 콘크리트 내부 공극 검출)

  • Sim, Jun-Gi;Zi, Goang-Seup;Lee, Jong-Seh
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.1021-1024
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    • 2008
  • Near infrared heating as an alternative to the conventional heating techniques for thermography -NDT is tried in this paper. A concrete specimen containing a defect was heated by the near infrared ray and the thermography-NDT technique was applied. Using a dimensinless temperature, the defects were detected. It was found that the near infrared ray could efficiently heat up the concrete specimen compared to others conventional methods like lamps, heat flow, etc.

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Effect of System Configuration on Design Performance of Atmospheric Pressure MCFC/Gas Turbine Hybrid Systems (상압형 MCFC/가스터빈 하이브리드 시스템의 구성방법에 따른 설계성능 분석)

  • Oh Kyong Sok;Kim Tong Seop
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.11
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    • pp.1021-1027
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    • 2004
  • Design performances of various configurations of hybrid systems combining an atmospheric pressure molten carbonate fuel cell and a gas turbine have been analyzed. Two different fuel reforming methods (internal and external reforming) were considered. Influences of turbine inflow heating method, location of fuel combustor and associated component arrangements were investigated. In general, internal reforming leads to higher system efficiencies. The optimum design pressure ratio varies among different system configurations. In particular, the design point selection is closely related to the allowable turbine inlet temperature. Configurations with direct heating of turbine inlet flow may realize both higher efficiency and higher specific power than those with indirect heating.

Analysis of Life Cycle Cost for Heat Source Equipments in Buildings for Adolescent Trainees (청소년 수련관의 열원설비 대안별 생애주기 비용에 관한 연구)

  • Ahn, Chang-hwan;Pang, Seung-ki;Baik, Yong-gyu
    • KIEAE Journal
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    • v.5 no.3
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    • pp.25-31
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    • 2005
  • Computer simulations were performed for Heating Ventilating and Air-Conditioning (HVAC) systems to figure out more efficient maintenance methods for the building used for adolescent trainees. This study aims at suggesting design alternatives for optimum operation and performing life cycle cost (LCC) for each alternative. First, the capacity of the heat source equipment was determined using annual maximum heating and cooling loads. Annual loads were calculated and applied to the alternative for the purpose of calculating annual energy cost. Second, several types of data were collected to predict energy cost. Finally, the pay back period for each alternative was calculated using total cost estimation during standard duration period. This study indicates that the absorption chiller that does not occupy most part of a mechanical room, and does not need much operation cost was most economical.

Steady and Transient Solution of heat Conduction from hurried Pipes of panel heating Slab (상-파넬 히-팅의 해석법)

  • Lee Kun
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.3 no.3
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    • pp.185-190
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    • 1974
  • Floor panel heating system is popular in Korea as dwelling house heating system. There are two methods for keeping floor surface warm. One method is delivering warm air under the floor such as Roman Hypocaust and Korean traditional Ondol. The other method is imbedding hot water pipes into the concrete floor slab. This paper gives basic equations for steady and transient solutions of heat conduction from hurried pipes. For steady-state solution, fin Efficiency Method and Sink and Source Method were introduced. Sink and Source Method is applied to transient state and basic solution is given in the form of Exponential Integral Function. Numerical solutions can be solved easily by digital computer from these equations.

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Confirmation of Applicability of Heating and Curing Method of Concrete in Winter Using Electric Heating System (전기열풍기를 이용한 동절기 콘크리트 가열양생공법 적용 및 적정성 효과 검증)

  • Kim, Se-Jong;Park, Jong-Hoon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.04a
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    • pp.131-132
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    • 2022
  • Looking at recent construction cases at winter construction sites, there is a risk that heat sources such as kerosene fans and fossil fuels (brown coal, molded carbon) used in concrete will cure rapidly, so in situations where further curing is impossible after formwork removal, the outer wall and the entire slab are exposed to rapid external deterioration, resulting in delays in concrete strength expression and until collapse accidents. In this study, we applied kerosene fans and tropical circulating electric heat fans mainly used as curing heat sources at construction sites, comparative analysis. also verified the performance of structures during concrete curing due to thermal convention / circulation performance, concrete demand strength expression, and implementation of electric heat fans by heavy disaster methods.

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