• Title/Summary/Keyword: CHANGE OF TEMPERATURE

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The Effects of Storage Temperature and pH on Color Change in Garlic Puree (마늘 퓨레의 변색에 관여하는 저장온도와 pH의 영향)

  • 장현세;홍경훈
    • Food Science and Preservation
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    • v.5 no.3
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    • pp.211-216
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    • 1998
  • This study was carried out to how the effects of storage temperature of garlic bulbs, pH and temperature of garlic puree on its color change. Color change was severely appeared in puree made of garlics stored at pH 4.0, 2$^{\circ}C$ and pH 4.0, 25$^{\circ}C$. The color of garlic puree was changed from green to blue during storage. The yellowing occured by the oxidation at high temperature of puree. Garlic puree absorbed the wavelengths of 486nm. 580nm, and 656nm. The precursors of pigments produced by enzymatic reaction were seemed to be the reasons of color change because there was no my change of color in puree when the enzymes including alliinase were inactivated. However, the color changes of puree at low storage temperature should be studied further in the future.

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A Study on the Temperature Change of Braking Disc and Thermal Conductivity during the Service (철도차량용 제동디스크의 운행중 온도 변화 및 열전도도 측정 연구)

  • Kim, Jae-Hoon;Goo, Byeong-Choon;Suk, Chang-Sung
    • Journal of the Korean Society for Railway
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    • v.10 no.6
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    • pp.665-669
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    • 2007
  • This study investigates the temperature change and thermal conductivity for the braking disc of the railway vehicle due to the types of train and service conditions. The temperature change was measured by non-contact Infrared thermometers. Average temperature was measured between $79.32^{\circ}C$ and $104.46^{\circ}C$ due to types of train and service section. In the same service section, the surface temperatures of Saemaul train were higher than Mugungwha train; the reason might have been the average service speed of Saemaul train (83km/h) was higher than Mugungwha train (107km/h), and the weight was similar 39t (Mugungwha) and 39.3t (Saemaul). But the maximum surface temperature was measured on the Mugungwha train; however the difference was not too big with the maximum temperature of Saemaul train. Also, the disc surface temperatures were changed due to the material of lining; metal and non-asbestos, on the same train and the same service section. In addition. the thermal conductivity was tested the thermal conductivities were increased by the increasing of the temperature. The change is too big between $100^{\circ}C$ and $200^{\circ}C$. But each average value is small. and the mechanical property change is very low. As a result, we conclude that this disc is suitable for usage between $100^{\circ}C$ and $300^{\circ}C$.

The Impact of Climate Change on Fire

  • Eun-Hee JEON;Eun-Gu, HAM
    • Journal of Wellbeing Management and Applied Psychology
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    • v.7 no.4
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    • pp.15-20
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    • 2024
  • Purpose: Climate change is greatly affecting the frequency and intensity of fires around the world. The main effects of climate change on fires are rising temperatures, dry seasons and extreme droughts, changes in precipitation, increased strong winds, extended fire danger periods, and changes in natural ecosystems. Several factors due to climate change are increasing the risk of large-scale fires, such as wildfires. Research design, data and methodology: Rising temperatures caused by climate change will make forests and grasslands drier, make it easier for wildfires to occur in drier environments and spread quickly to wider areas, and the generated wildfires will release large amounts of greenhouse gases into the atmosphere, such as carbon dioxide (CO2), and the released greenhouse gases will strengthen the global greenhouse effect, further raising the temperature. As temperatures rise, the risk of wildfires increases in drier environments, and this process is repeated, leading to a vicious cycle of intensifying climate change as more fires occur and more greenhouse gases are released. Results: In conclusion, climate change is increasing the risk of fire occurrence and this phenomenon is expected to become more frequent and severe in the future. Conclusions: In order to cope with the increasing fire risk caused by climate change, fire prevention and management. Fire detection and response systems need to be strengthened, supportive policies and international cooperation are needed to restore ecosystems, and these measures, along with fire prevention, management and countermeasures, should take into account long-term climate change and adaptation as well as short-term responses.

Simulation of Temperature Behavior in Hydrogen Tank During Refueling Using Cubic Equations of State (3차 상태방정식을 이용한 수소 충전 온도 거동 모사)

  • PARK, BYUNG HEUNG
    • Journal of Hydrogen and New Energy
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    • v.30 no.5
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    • pp.385-394
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    • 2019
  • The analysis of temperature behavior of a hydrogen tank during refueling is of significance to clarify the safety of the compressed hydrogen storage in vehicles since the temperature at a tank rises with inflow of hydrogen. A mass balance and an energy balance were combined to obtain analytical model for temperature change during the hydrogen refueling. The equation was coupled to Peng-Robinson-Gasem (PRG) equation of state (EOS) for hydrogen. The PRG EOS was adopted after comparison with other four different cubic EOSs. A parameter of the model was determined to fit data from experiments of various inlet flow rates and temperatures. The temperature and pressure change with refueling time were obtained by the developed model. The calculation results revealed that the extent of precooling was more effective than the flow rate control.

Surface Acoustic Waves Sensors for Wireless Measurement of Temperature (Surface Acoustic Wave를 이용한 무선 온도 센서 설계 및 구현)

  • Kim, Jaek-Won;Park, Joo-Yong;Kim, Kyung-Hwan;Yeo, Joon-Ho;Burm, Jin-Wook
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.469-470
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    • 2006
  • Surface Acoustic Wave(SAW) devices can be used to as wireless sensor elements, called SAW transponders, for measuring shysical quantities such as temperature that do not need any power supply and may be accessed wirelessly. SAW devices were fabricated on Y-Z $LiNbO_3$ piezoelectric substrate with a good temperature coefficient property. The signal response of SAW sensor on the temperature change were compared. To measure the change of SAW velocity. Temperature changed form $20^{\circ}C$ to $400^{\circ}C$ was linearly changed, the SAW sensor is application to the temperature sensor.

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Analysis of IPMSM Temperature Characteristics based on Stator Design Parameters (600W급 IPMSM의 고정자 설계 변수 변화에 따른 온도 특성 분석 및 고찰)

  • Go, Duk-Hwa;Kim, Yong-Tae;Kim, Gyu-Tak
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.8
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    • pp.1201-1206
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    • 2017
  • In this paper, the temperature characteristics by change the width of teeth and yoke in the stat or parameters were analyzed. An initial model of fill factor 45 [%] was produced. Through the experiment, the validity of the temperature analysis using the thermal equivalent circuit method was verified. So, initial model was selected as basic model. Also, temperature characteristic analysis was performed for each width change of the stator teeth and yoke, and the effects of the width of stator teeth and yoke on the temperature characteristics were analyzed.

An Experimental Study on the Freezing Protection Valve Using Phase Change Material(PCM) for the Heat Exchanger (상변화물질(PCM)을 이용한 열교환기용 동파방지밸브에 관한 실험적 연구)

  • Yun, Jea-Ho;Kim, Joung-Ha;Jeong, Soon-Young;Yang, Yoon-Sub;Kim, Seong-Hyun;Song, Duk-Yong
    • Journal of the Korean Solar Energy Society
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    • v.32 no.6
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    • pp.127-133
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    • 2012
  • This paper is an experimental study on the freezing protection valve used for solar water heating, air-conditioning systems, and plumbing systems. When the phase change occurs from liquid to solid, most of the substances except water volumetrically shrink. And referred to as PCM(Phase Change Material) a substance with such properties, the phase change temperature varies depending on the material. To prevent the freezing of the plumbing system, such as air-conditioning system in the winter season, we developed a several types of freezing protection valve using PCM whose freezing temperature are $2-4^{\circ}C$. The working principle of the freezing protection valve is that the fluid inside the pipe is released to prevent the system-collapse when fluid temperature reaches the freezing temperature of the PCM. And then the valve is closed and returned to the original position automatically when the temperature of the operating fluid rises. In this paper, the operating temperatures, discharge flow rate and the response characteristics of the valve during the operation are tested and investigated. From the results of this research the freezing protection valves employing PCM are expected to be commercialized in the near future.

A study on thermal properties of concrete using gang form coated with polyurethane (폴리우레탄 폼을 도포한 갱폼사용에 따른 콘크리트 온도이력특성)

  • Nam, Kyung-Yong;Won, Joon-Yuen;Kang, In-Seon;Jeon, Pan-Keun;Lee, Young-Do;Jung, Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.11-12
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    • 2011
  • This study examine Effect of Change of Compressive Strength of Concrete Members with Insulating Gang form on Temperature History of Concrete Positions. Test show, insulating gang forms differences and gang forms have 10℃ on peak point temperature of surface and Center if temperature history have 24Mpa by change of compressive strength. In addition, there have 14℃(16℃) on peak point temperature of surface and Center if temperature history have 40(60)Mpa. Therefore, insulating gang forms have an effect insulating performance.

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Effects of Curing Temperature on Early Strength of Polymer Concrete (폴리머 콘크리트의 초기강도에 미치는 양생온도의 영향)

  • 연규석;김광우;이봉학
    • Proceedings of the Korea Concrete Institute Conference
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    • 1990.10a
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    • pp.151-156
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    • 1990
  • This is an experimental study to investigate chante of early strength of polymer concrete due to curing temperature change. Polymer binders that were used in the experiment include 2 types of epoxy system and 4 types of polyester system which are commercially producer in Korea. The study result showed that there was a difference in early strength by curing temperature. At $35^{\circ}C$ which is a higher than normal curing temperature, higher strengths were developed in polymer concretes prepared with KB-Clear and YD-128 of epoxy system, and G-550 and H-660 of polyester system. However, at the same temperature, reduced strengths were obtained for FH-103 and TR-132 of polyester system. Further study under various curing conditions with humidity and temperature change will warrant more generalized result.

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A Study about Change in the Temperature by Each Region and Time After Hot & Cold Application (온.냉적용시 신체부위별 및 시간에 따른 체온변화에 대한 연구)

  • Kim, Keun-Jo;Lee, Cu-Ri
    • Journal of Korean Physical Therapy Science
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    • v.2 no.3
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    • pp.577-586
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    • 1995
  • This paper was the study of a change in the body temperature of each region(Oral cavity, Axillary, Cubital, Popliteal, Inguinal region)and by time after appling hot(Hot Pack, Infra Red) and cold (Ice Pack, Cooling Pack) to lumbar region. The statistical measures were sampled through 16 senior students in dept. of Physiothrapy, Kim Cheun College and the period for this was from July 13, 1995 to July 20, 1995. There was an increse in the temperature of distal portion besides application area after hot application. The increse in the body temperature according to applied agents and time showed significance statistically(p<0.01, p<0.05). There was just a decrease in the temperature of distal portions besides application area after appling Ice Pack. Furthermore there was an increase in the body temperature after appling Cooling Towel. Therefore, during cold application the appling agents and time did not showed any significance statistically.

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