• Title/Summary/Keyword: internal heat generation

Search Result 96, Processing Time 0.028 seconds

A Study on the Disease of Zhongshu of Lidongyuan (이동원의 중서병(中暑病)에 대한 고찰)

  • Yun, Ki-ryoung;Baik, Yousang;Jang, Woo-chang;Jeong, Chang-hyun
    • Journal of Korean Medical classics
    • /
    • v.31 no.4
    • /
    • pp.79-90
    • /
    • 2018
  • Objectives : In present, various definitions of Zhongshu are being used interchangeably in Korea. The paper attempted to discover the disease of Zhongshu as studied by Lidongyuan, who was ahead of his time. Methods : A database of medical books has been studied to find Lidongyuan's writings on the disease of Zhongshu, and mentions about Li's works in past medical books. The paper contemplated the subject by defining the disease of Zhongshu and reviewing the disputes related to the subject. Results & Conclusions : Lidongyuan gave a detailed explanation on the fact that Zhangjiegu distinguished between Zhongshu and Zhongre, and this was influenced by Shangshu as mentioned in Taipinghuiminhejijufang. Therefore, it can be deduced that he was aware of the fact that summerheat-heat as latent summer heat syndrome is lurking inside the body, not being able to be released. According to the disease of Zhongshu by Lidongyuan, yin cold was receieved secondary after first receiving summerheat-heat. It is either summerheat damaged defensive qi, failure in storing the essence made defensive qi weak, or seasonal reasons have caused the defensive qi to be drained and leave the body exposed to damage by summerheat. This is because the fundamental main cause is the hitting of summerheat, since yin cold was received after the presence of summerheat-heat is made first. Many doctors in the following generation criticized that Lidongyuan's disease of Zhongshu cannot be named as a Zhongshu due to its similarity with Shanghan. However, they cannot be viewed as similar since it is a phenomenon where yin cold becomes congested while the body is weak and heat is generated in the body due to summerheat-heat. The doctors who said they were similar only focused on the external cause that was only the superficial issue. According to Lidongyuan's method, the right way to treat a Zhongshu disease is to use the method of tonifying the qi and eliminating the heat in conjunction with eliminating the internal dampness or treat the external syndrome, or to use a formula to tonify the qi and eliminate the fire heat before eliminating the internal dampness or treating the external syndrome.

Design of Optimal Thermal Structure for DUT Shell using Fluid Analysis (유동해석을 활용한 DUT Shell의 최적 방열구조 설계)

  • Jeong-Gu Lee;Byung-jin Jin;Yong-Hyeon Kim;Young-Chul Bae
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.18 no.4
    • /
    • pp.641-648
    • /
    • 2023
  • Recently, the rapid growth of artificial intelligence among the 4th industrial revolution has progressed based on the performance improvement of semiconductor, and circuit integration. According to transistors, which help operation of internal electronic devices and equipment that have been progressed to be more complicated and miniaturized, the control of heat generation and improvement of heat dissipation efficiency have emerged as new performance indicators. The DUT(Device Under Test) Shell is equipment which detects malfunction transistor by evaluating the durability of transistor through heat dissipation in a state where the power is cut off at an arbitrary heating point applying the rating current to inspect the transistor. Since the DUT shell can test more transistor at the same time according to the heat dissipation structure inside the equipment, the heat dissipation efficiency has a direct relationship with the malfunction transistor detection efficiency. Thus, in this paper, we propose various method for PCB configuration structure to optimize heat dissipation of DUT shell and we also propose various transformation and thermal analysis of optimal DUT shell using computational fluid dynamics.

A Study on the Performance Analysis of the High Pressure - Intermediate Pressure Steam Turbine Model for Co-generation Plants using Commercial Programs (상용 프로그램을 이용한 열병합 발전용 고압(HP)-중압(IP) 증기터빈 모델의 성능해석에 대한 연구)

  • Jong Pil Won;Seung Tae Oh;Jungmo Oh
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.29 no.4
    • /
    • pp.395-406
    • /
    • 2023
  • The first technological advance to improve the output and efficiency of the latest steam turbines operating in co-generation plants in Korea can be said to be progress in the field of materials that can use high-temperature, high-pressures steam. As a result of design efforts to improve the internal efficiency of steam turbines along with the development of materials, only a few manufacturers of steam turbine have produced high efficiency steam turbines. The internal efficiency of a steam turbine on the steam path operating for a long period of time is gradually lost owing to the limit of mechanical life, and efficiency and output decrease. Therefore, this study aims to develop a model that can analyze the steam flow path performance of HP (High Pressure) and IP (Intermediate Pressure) steam turbine for a co-generation plant using a commercial program and propose a performance calculation method. Owing to the complex performance calculation method of steam turbines, major variables are presented to serve as practically useful references for steam turbine practitioners. In addition, the thermal dynamic analysis(such as heat balance diagram calculation) and the the thermal dynamic calculation required for steam turbine performance calculation and the suitability of the steam turbine performance calculation results were compared with the performance test results.

Assessment of SCDAP Using the Full-Length High-Temperature FLHT-2 Test (FLHT-2 실험결과를 이용한 SCDAP코드 평가)

  • Park, Choon-Kyung;Park, Jong-Hwa;Yoo, Kun-Jung;Chae, Sung-Ki
    • Nuclear Engineering and Technology
    • /
    • v.20 no.1
    • /
    • pp.54-64
    • /
    • 1988
  • This paper assesses the models in the SCDAP code using the results of the FLHT-2 test. Calculations show that the SCDAP correctly predicts Ire temperatures, oxidation front movement, overall hydrogen generation and peak generation rate, internal fuel rod pressure, and cladding rupture due to ballooning. A comparison of the calculated results with measured data shows that two phase level is underpredicted, and that radiation heat transfer and auto-catalytic reaction temperature of zircaloy are overpredicted. These models are recommended to be modified. The analysis also shows that the simulation of the gap in a fuel rod improves the code prediction on core damage progression.

  • PDF

The Effects of Heat-treatment on Magnetic Properties for Gas-atomized MPP Dust Cores (가스분무법으로 제조한 MPP 분말코어의 자기적 특성에 미치는 열처리 효과)

  • 노태환;김구현;김광윤;정인범;최광보
    • Journal of the Korean Magnetics Society
    • /
    • v.11 no.4
    • /
    • pp.173-178
    • /
    • 2001
  • The effects of heat-treatment with magnetic or non-magnetic field on magnetic properties of gas-atomized MPP dust cores subjected to various cooling processes after annealing were investigated. Upon magnetic-field annealing, ac permeability and core loss decreased with the increase of cooling rate, which were attributed to the generation of inhomogeneous internal stress and anomalous eddy current loss, respectively. It was not observed the formation of ordered phase and the related change in magnetic properties at the cooling stage for MPP dust cores. In MPP alloys, magnetic anisotropy was easily induced through the directional order, and permeability and core loss were changed under the conditions of low cooling rate and magnetic annealing.

  • PDF

A Study on Thermo-flow Characteristics Analysis of Electric Water Pump (전동 워터펌프의 열유동 특성 해석에 관한 연구)

  • Kim, Sung-Chul;Song, Hyeong-Geun
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.20 no.5
    • /
    • pp.95-101
    • /
    • 2012
  • An electric water pump for engine cooling system has an advantage which particularly in the cold start, the use of the electric water pump saves fuel and leads to a corresponding reduction in emissions. The canned type electric water pump without mechanical sealing elements was selected to meet the requirements for operational reliability and life. However, the electric water pump for internal combustion engine generates much more heat loss than for hybrid electric vehicle since it is operated by the electric power of high current and low voltage. In this study, the fluid flow and thermal characteristics of the canned type electric water pump as an inverter integrated water pump has been investigated under the effects of heat generation. The analysis conditions such as outdoor air temperature of $125^{\circ}C$, water pump speed of 6000 rpm, coolant temperature of $106^{\circ}C$ and coolant flow rate of 120 L/min was used as a standard condition. Therefore, flow fields and temperature distribution inside the water pump were obtained. Also, we checked the feasibility of the canned type for the electric water pump in comparison with the mechanical seal type.

Thermal Stress Analysis of the Heat Generation for Mass Concrete Considering Creep Effect (크리이프를 고려한 매스콘크리트의 수화열에 대한 온도응력 해석)

  • Kim, Jin Keun;Lee, Jong Dae
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.14 no.4
    • /
    • pp.771-781
    • /
    • 1994
  • The heat generation of cement causes the internal temperature rise and volume change at early age, particulary in massive concrete structures. As the results of the temperature rise and restraint conditions, the thermal stress may induce cracks in concrete. Therefore, the prediction of the thermal stress is very important in the design and construction in order to control the cracks developed in mass concrete. In case of young concrete, creep effect by the temperature load is larger than that of old concrete. Thus, the effect of creep must be considered for checking the cracks, serviceability, durability and leakage. This paper is concentrated on the development of a finite element program which is capable of simulating the temperature history and the thermal stress considering creep and the modified elastic modulus due to inner temperature change and maturity. The analytical results in the inner parts highest important to control cracks are in good agreement with experimental data. Therefore this study may provide available method to control the cracks.

  • PDF

Estimation of Radio Frequency Electric Field Strength for Dielectric Heating of Phenol-Resorcinol-Formaldehyde Resin Used for Manufacturing Glulam (구조용 집성재 제조용 접착제(Phenol-Resorcinol-Formaldehyde Resin) 유전 가열을 위한 고주파 전기장 세기 추산)

  • Yang, Sang-Yun;Han, Yeonjung;Park, Yonggun;Eom, Chang-Deuk;Kim, Se-Jong;Kim, Kwang-Mo;Park, Moon-Jae;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
    • /
    • v.42 no.3
    • /
    • pp.339-345
    • /
    • 2014
  • For enhancing productivity of glulam, high frequency (HF) curing technique was researched in this study. Heat energy is generated by electromagnetic energy dissipation when HF wave is applied to a dielectric material. Because both lamina and adhesives have dielectric property, internal heat generation would be occurred when HF wave is applied to glulam. Most room temperature setting adhesives such as phenol-resorcinol-formaldehyde (PRF) resin, which is popularly used for manufacturing glulam, can be cured more quickly as temperature of adhesives increases. In this study, dielectric properties of larch wood and PRF adhesives were experimentally evaluated, and the mechanism of HF heating, which induced the fast curing of glue layer in glulam, was theoretically analyzed. Result of our experiments showed relative loss factor of PRF resin, which leads temperature increase, was higher than that of larch wood. Also, it showed density and specific heat of PRF, which are resistance factors of temperature increase, were higher than those of wood. It was expected that the heat generation in PRF resin by HF heating would occur greater than in larch wood, because the ratio of relative loss factor to density and specific heat of PRF resin was greater than that of larch wood. Through theoretical approach with the experimental results, the relative strengths of ISM band HF electric fields to achieve a target heating rate were estimated.

Theraml Analysis of the Heat of Hydration in Concrete with Considering Heat Reduction Techniques (온도저감 공법을 고려한 콘크리트의 수화열 해석기법에 관한 연구)

  • 김진근;김국한;양주경
    • Magazine of the Korea Concrete Institute
    • /
    • v.7 no.6
    • /
    • pp.176-185
    • /
    • 1995
  • The heat generation of hydration of cement causes the internal temperature rise and volum& change at early age, particularly in massive concrete structures. As the results of the temperature rise and external restraint conditions, the thermal stress may induce cracks in concrete. Therefore, various techniques of the thermal stress control of the mass concrete have been wid'dy used. One of them is pipecooling which reduces the temperature of concrete with flowing water. The objective of this paper' is to develop a finite element program which is capable of simulating the temperature history considering pipe-cooling effect. The numerical results in this study are in good agreement with experimental data measured in the footing(l1 x22m). Therefore, this study may provide available method to predict the hydration temperature of concrete with pip:-cooling.

Fast Defect Detection of PCB using Ultrasound Thermography (초음파 서모그라피를 이용한 빠른 PCB 결함 검출)

  • Cho Jai-Wan;Seo Yong-Chil;Jung Seung-Ho;Kim Seungho;Jung Hyun-Kyu
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.55 no.2
    • /
    • pp.68-71
    • /
    • 2006
  • Active thermography has been used for several years in the field of remote non-destructive testing. It provides thermal images for remote detection and imaging of damages. Also, it is based on propagation and reflection of thermal waves which are launched from the surface into the inspected component by absorption of modulated radiation. For energy deposition, it use external heat sources (e.g., halogen lamp or convective heating) or internal heat generation (e.g., microwaves, eddy current, or elastic wave). Among the external heat sources, the ultrasound is generally used for energy deposition because of defect selective heating up. The heat source generating a thermal wave is provided by the defect itself due to the attenuation of amplitude modulated ultrasound. A defect causes locally enhanced losses and consequently selective heating up. Therefore amplitude modulation of the injected ultrasonic wave turns a defect into a thermal wave transmitter whose signal is detected at the surface by thermal infrared camera. This way ultrasound thermography(UT) allows for selective defect detection which enhances the probability of defect detection in the presence of complicated intact structures. In this paper the applicability of UT for fast defect detection is described. Examples are presented showing the detection of defects in PCB material. Measurements are performed on various kinds of typical defects in PCB materials (both Cu metal and non-metal epoxy). The obtained thermal image reveals area of defect in row of thick epoxy material and PCB.