• Title/Summary/Keyword: Heating effect

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The Impact of Interaction between Cloud and Longwave Radiation on the Asian Monsoon Circulation (구름-장파복사 상호작용이 아시아 몬순에 미치는 영향)

  • Ryu, Geun-Hyeok;Sohn, Byung-Ju
    • Journal of the Korean earth science society
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    • v.30 no.1
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    • pp.58-68
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    • 2009
  • Three-dimensional distributions of longwave radiation flux for the April-September 1998 period are generated from radiative transfer calculations using the GEWEX Asian Monsoon Experiment (GAME) reanalysis temperature and humidity profiles and International Satellite Cloud Climatology Project (ISCCP) cloudiness as inputs to understand the effect of cloud radiative forcing in the monsoon season. By subtracting the heating of the clear atmosphere from the cloudy radiative heating, cloud-induced atmospheric radiative heating has been obtained. Emphasis is placed on the impact of horizontal gradients of the cloud-generated radiative heating on the Asian monsoon. Cloud-induced heating exhibits its maximum heating areas within the Indian Ocean and minimum heating over the Tibetan Plateau, which establishes the north-south oriented differential heating gradient. Considering that the differential heating is a ultimate source generating the atmospheric circulation, the cloud-induced heating gradient established between the Indian Ocean and the Plateau can enhance the strength of the north-south Hadley-type monsoon circulation. Cooling at cloud top and warming at cloud bottom, which are the vertical distributions of cloud-induced heating, can exert on the monsoon circulation by altering the atmospheric stability.

A Study on the Greenhouse Heating of Solar Energy - Latent Heat Storage System - (태양열-잠열축열시스템의 온실보온특성)

  • 송현갑;류영선
    • Journal of Bio-Environment Control
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    • v.1 no.1
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    • pp.14-20
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    • 1992
  • For the high quality and low cost agricultural crops in greenhouse cultivation, it is necessary to use natural energy as much as possible. In order to reduce the fossil fuel consumption and maximize the solar energy utilization in greenhouse heating, a latent heat storage material was developed as a relatively highly concentrative solar energy storage medium. And a solar energy-latent heat storage system was designed and constructed. The experimental research on greenhouse heating effect of the system was performed.

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Effect of Pretreatments on Reducing Surface Cracks of Heat-treated Western Hemlock Roundwoods

  • Kim, Chung-Ho;Kang, Chun-Won;Kang, Seog-Goo;Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.40 no.5
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    • pp.343-351
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    • 2012
  • A large diameter roundwood is an important element of Korean traditional buildings, Hanok, and is hard to be dried without surface cracks. Four different pretreatments, such as pre-cracking, oil heating, kerfing-oil heating and PEG impregnation, were investigated for reducing the surface cracks of large-diameter roundwood specimens during heat treatment. The roundwood specimens of pre-cracking, oil heating and kerfing-oil heating showed surface cracks during pretreatment, but that of PEG impregnation did not. It was confirmed that kerfing reduced the total crack width. Among the four pretreatments and control only the PEG impregnation roundwood specimen had no crack on both outer and inner surfaces after heat treatment. The PEG impregnation specimen shrank only 1.6% in the tangential direction while the pre-cracking did 8.0%.

Effect of Heating Height within Microwave Oven on Microwave Heating of Food (전자레인지 내부에서 가열높이 변화가 품질 특성에 미치는 영향)

  • Kum, Jun-Seok;Ha, Tae-Youl;Han, Ouk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.3
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    • pp.489-494
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    • 1998
  • For the purpose of improving the qualities of popcorn, potato, frozen hotdog and steamed egg, the effects of food height(0mm: HO, 5mm: H5, 10mm, 15mm: H15) for microwave cooking on physicochemical properties were investigated. In popcorn, weight loss was decreased as height increased while volume of popcorn was increased, which indicated that popcorn was poped very well as height increased. H10 showed the highest taste score in sensory evaluation. In potato, degree of gelatinization was increased as hight increased. H10 showed the highest overall acceptance score. In frozen hotdog, hardness of hotdog was decreased as hight increased and H15 showed the lowest hardness score (408.8g). In steamed egg, H5 showed the highest temperature and H10 showed the highest overall acceptance score. Physicochemical properties of food were changed by heating height of microwave heating.

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Joule Heating of Metallic Nanowire Random Network for Transparent Heater Applications

  • Pichitpajongkit, Aekachan;Eom, Hyeonjin;Park, Inkyu
    • Journal of Sensor Science and Technology
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    • v.29 no.4
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    • pp.227-231
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    • 2020
  • Silver nanowire random networks are promising candidates for replacing indium tin oxide (ITO) as transparent and conductive electrodes. They can also be used as transparent heating films with self-cleaning and defogging properties. By virtue of the Joule heating effect, silver nanowire random networks can be heated when voltage bias is applied; however, they are unsuitable for long-term use. In this work, we study the Joule heating of silver nanowire random networks embedded in polymers. Silver nanowire random networks embedded in polymers exhibit breakdown under the application of electric current. Their surface morphological changes indicate that nanoparticle formation may be the main cause of this electrical breakdown. Numerical analyses are used to investigate the temperatures of the silver nanowire and substrate.

Optimum Design of the Heating Equipment by Influence of Wind Speed at Cryogenic Temperature (극저온에서 풍속의 영향에 따른 발열기자재의 최적설계)

  • Cho, Hyun Jun;Yun, Won Young
    • Journal of Korean Society for Quality Management
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    • v.48 no.3
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    • pp.463-479
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    • 2020
  • Purpose: The purpose of this study is to evaluate the performance of heating equipments by implementing the extreme environment in which ships navigating the ice zone are exposed and to study and apply the experimental method to infer the optimized design for each factors. Methods: It is required to verify by analysis and experiment how the environment with low temperature and wind speed implemented through the test facility affects the heating walk-way and The optimum design of the heating walk-way in that extreme environment is derived using the Taguchi technique. Results: The results of this study are as follows; It was found the effect on the condition of each factor and derive optimized conditions that satisfy the performance condition of the heating walk-way in extreme use environment. Conclusion: Ships operating in Polar waters require reliable and durable facilities for all environments during sailing.

Finite Element Analysis for Forming Process of Semi-Solid Material Considering Induction Heating (유도가열을 고려한 반용융 재료의 성형공정에 관한 유한요소 해석)

  • Park, W.D.;Ko, D.C.;Kim, B.M.;Park, J.C.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.8
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    • pp.82-91
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    • 1997
  • The major objective of this study is to establish analytical technique in order to analyze the behaviour of semi-solid material considering induction heating of the billet. Induction heating process is analyzed by using commerical finite element software. ANSYS. The finite element program, SFAC2D, for the simulation of deformation in semi-solid state is developed in the present study. The semi-solid behaviour is described by a viscoplastic model for the solid phase, and by the Darcy's law for the liquid flow. Simple compression and closed-die compression process considering induction heating are analyzed, and also it is found that the distribution of initial solid fraction of the billet has an important effect on deformation behaviour of semi-solid material. In order to verify the effectiveness of proposed analytical technique the simulation result is compared with experimental result.

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Temperature Uniformity of the Glass Panel Heated in the Infrared Heating Chamber

  • Lee, Kong-Hoon;Kim, Ook-Joong
    • Journal of Mechanical Science and Technology
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    • v.19 no.10
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    • pp.1950-1956
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    • 2005
  • An analysis has been carried out to investigate the effect of the reflectivity on the temperature distribution of a glass panel by infrared radiant heating. Halogen lamps are used to heat the panel, located near the top and bottom of the rectangular chamber. The thermal energy is transferred from the lamps to the panel only by radiation and it is considered by using view factor. The conductive transfer is limited inside the panel. The results show that the uniformity of the temperature distribution of the panel is improved and, at the same time, the time for heating increases as the wall reflectivity increases. The temperature difference between the center and the corner reaches a maximum in the early stage of the heating process and then decreases until it reaches a uniform steady-state value.