• Title/Summary/Keyword: temperature variation

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A study on the thermal characteristics of MOSS type LNG carrier (MOSS형 LNG 선박의 열공학적 특성에 관한 연구)

  • 이세동;송성옥;이종원;김춘식;최두열
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.1
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    • pp.28-34
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    • 1998
  • This paper introduced the thermal characteristics of Moss Rosenberg Verft spherical tank type LNG Carrier. Especially described the temperature variation during cooling down condition. It is not easy task to calculate the temperature variation because of unsteady state condition. In this paper, computer simulation program is developed by using a Tomas Algorithm on unsteady state condition and compared with calculation results and experimental results on existing LNG Carrier voyage.

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Influence of Temperature and Relative Humidity in Infection of Nosema bombycis (Microsporidia: Nosematidae) and Cross-infection of N. mylitta on Growth and Development of Mulberry Silkworm, Bombyx mori

  • Chakrabarti, Satadal;Manna, Buddhadeb
    • International Journal of Industrial Entomology and Biomaterials
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    • v.17 no.2
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    • pp.173-180
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    • 2008
  • The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

Estimation of Performance Variation of ER Clutch due to Temperature Increase of ER Fluid (ER 유체의 온도상승에 의한 ER 클러치의 성능변화 예측)

  • 이규한;심현해;김창호;임윤철
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1997.04a
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    • pp.151-166
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    • 1997
  • ER clutch is a device using ER fluid, so called "intelligent material" and is a controlled system with electric field strength. Current problem of this device is that the temperature of ER fluid increases when ER clutch is operating and affects the performance of ER clutch. This study was undertaken to estimate this performance variation due to temperature increase of ER fluid. Analytic power transmission relationships and the temperature increase model using the rheological model of ER fluid were developed and the dynamic model of proposed ER clutch system was constructed, also. With this relationships, effects of changing geometric, kinetic parameters of ER clutch and ER fluid properties were described and performance variations due to temperature increases of ER fluid were estimated. In conclusion, compared with neglecting temperature increase effects, a performance of ER clutch was very differential. Therefore, to achieve uniform performance of ER clutch, we have to improve thermal stability of ER fluid with a view point of material development and design carefully ER clutch considering temperature increase effects with a view point of mechanical design skill.ign skill.

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Correlation between the temperature and elastic properties of the light guide plate in edge-lit light-emitting-diode backlights

  • Kim, Jae-Hyun;Kim, Tae-Hyun;Lee, Byung-Woo;Seo, Jae-Seok;Ko, Jae-Hyeon
    • Journal of Information Display
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    • v.12 no.1
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    • pp.23-27
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    • 2011
  • The correlation between the temporal and spatial variations of the elastic constant and temperature change was examined for a light guide plate (LGP) adopted in the edge-lit light-emitting-diode backlight for mobile applications, using the micro- Brillouin light scattering method. The velocity of sound and the elastic constant $C_{11}$ of an LGP made from bisphenol-A polycarbonate (PC) were investigated as functions of temperature, time, and position on the LGP. The temporal variation of $C_{11}$ exhibited an exponential decay, while the spatial variation of $C_{11}$ reflected the temperature distribution on the LGP. The glass transition temperature of the PC LGP was found to be located at $155^{\circ}C$. The result showed that systematic transformation between the elastic property and the temperature is possible and that the temperature distribution on the bulk LGP can be accurately probed via the present experiment method, without using any special temperature measurement equipment.

Design of Temperature Compensation Circuit to Compensate Temperature Characteristics of VCO (VCO의 온도 특성 보상을 위한 온도 보상 회로의 설계)

  • Kim, Byung-Chul;Huang, Gui-Hua;Cho, Kyung-Rae;Lee, Jae-Buom
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.3
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    • pp.223-228
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    • 2010
  • In this paper, temperature compensation circuit for the X-band voltage controlled oscillator(VCO) is presented by using the temperature sensor with the OP-AMP circuit. The frequency drifting by the temperature could be compensated by applying the tuning voltage which include the linearly changing output voltage of the temperature sensor. As a result, the frequency variation is reduced to 6.6~4.4 MHzfrom the 71~73 MHz variation with the compensation circuit over -30~+$60^{\circ}C$ range, when VCO is operated in the frequency range of 9.95~10.05 GHz.

Temperature characteristics of condenser and evaporator of Air-conditioner applying variable capacity compressor under cooling condition (가변용량 압축기를 적용한 에어컨의 냉방운전 시 응축 및 증발온도 특성)

  • Kwon, Young-Chul;Chun, Chong-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.6
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    • pp.1325-1331
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    • 2007
  • In order to investigate the cooling capacity of an air-conditioner applying a variable capacity compressor and the temperature characteristics on a condenser and an evaporator, the experiment on the operation characteristics of the air-conditioner was performed along a compressor operation ratio and an indoor/outdoor temperatures, under a cooling operation mode. The system characteristics were measured by the psychrometric calorimeter. The cooling capacity increased with decreasing the outdoor temperature and increasing the indoor temperature. Also, it increased with increasing the compressor operation ratio. The temperature of the condenser was more sensitive for the variation of the outdoor temperature and the temperature of the evaporator was more sensitive for the variation of the indoor temperature. The operation characteristics of the cycle used in this present were also analyzed by a pressure-enthalpy chart.

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A Study on the Characteristics of (Na,K)$NbO_3$-system Pb-free Piezoelectric Ceramics with Calcination Temperature (하소온도 변화에 따른 (Na,K)$NbO_3$계 무연 압전세라믹스의 특성에 관한 연구)

  • Ryu, Sung-Lim;Chung, Kwang-Hyun;Lee, Sang-Ho;Yoo, Ju-Hyun;Park, Chang-Yub;Hong, Jae-Il;Lee, Duck-Chool
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.305-306
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    • 2005
  • In this paper, in order to develop Pb-free piezoelectric ceramics, $(Li_{0.04}Na_{0.44}K_{0.52})(Nb_{0.86}Ta_{0.10}Sb_{0.04})O_3$ ceramics were fabricated with the variation of calcination temperature and sintering temperature. Specimens couldn't be sintered below $111^{\circ}C$ and showed the largest density at calcination temperature of $800^{\circ}C$. Specimens manufactured with the variation of calcination temperature showed pseudo-tetragonal phase, and showed the optimal values of kp=0.45, ${\varepsilon}r$=1336 and $d_{33}$=254 at calcination temperature of $800^{\circ}C$ and sintering temperature of $1110^{\circ}C$.

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