• Title/Summary/Keyword: temperature effects

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Effects of Hydrogen Passivation on Polycrystalline Silicon Thin Film Transistors (다결정 실리콘 박막 트랜지스터의 수소화 효과)

  • Kim, Yong-Sang
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1239-1241
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    • 1995
  • The different hydrogen passivation effects on low-temperature processed and high-temperature processed poly-Si thin film transistors have been investigated. The hydrogen passivation on low-temperature processed poly-Si TFT results in the increase of the field-effect mobility and the decrease or the threshold voltage, while the hydrogenation increases the field-effect mobility and decreases the leakage current in high-temperature processed poly-Si TFT. The effective trap state densities of low-temperature processed poly-Si TFT before and after 5 hours of hydrogenation are estimated at about $4.0{\times}10^{12}/cm^2$ and $1.5{\times}10^{12}/cm^2$, while those of high-temperature processed poly-Si TFT are about $1.5{\times}10^{12}/cm^2$ and $1.2{\times}10^{12}/cm^2$, respectively.

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EFFECTS OF CAM PHASE AND SPARK RETARD TO INCREASE EXHAUST GAS TEMPERATURE IN THE COLD START PERIOD OF AN SI ENGINE

  • KIM D.-S.;CHO Y.-S.
    • International Journal of Automotive Technology
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    • v.6 no.6
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    • pp.585-590
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    • 2005
  • The effects of spark timing and exhaust valve timing change on exhaust gas temperature during cold start period of an SI engine are studied through engine bench tests. The exhaust gas temperature increases when the spark timing or valve timing are retarded individually, due to late combustion or slow flame speed. Therefore, exhaust gas temperature shows a large increase when the two timings are retarded simultaneously. However, it is considered that combustion stability during cold start deteriorated under these retarded conditions. To increase exhaust gas temperature for fast warmup of catalysts while maintaining combustion stability, an optimal condition for spark and valve timing retard should be applied for the cold start period.

Temperature Dependence of Conductivities of Recyclable Polyethylene and Polypropylene and its Effects on Electric Field Distribution in Power Cable (재활용 가능한 폴리에틸렌과 폴리프로필렌의 전도도 온도의존성과 전력케이블 내의 전계분포에 미치는 영향)

  • Lee, June-Ho;Kong, Tae-Sik;Kim, Seong-Jung;Kwon, Ki-Hyung;Cho, Kyu-Cheol;Hozumi, Naohiro
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.10
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    • pp.1881-1887
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    • 2011
  • In this work the recyclable new polyethylene(PE) and polypropylene(PP), which are thermoplastic, have been investigated as the eco-friendly insulating candidates to replace the cross-linked polyethylene (XLPE). The temperature dependence of conductivities of these materials has been measured and its effects on electric field and space charge distribution in polymeric insulated power cable under temperature gradient have been calculated. It is shown that the sensitivity of conductivity to temperature change has more critical influence to determine the electric field distribution in the power cable than the absolute value of conductivity does and it can be said that the temperature dependence is one of most important factors for the power cable design.

The Experimental Study on the Effects of Temperature and Distance between Injectors on the Spray Characteristics of Duplex Swirl Injector (이중 선회 분무간의 거리와 연료온도 변화에 따른 분무특성에 관한 실험적 연구)

  • Choi, K.S.;Park, B.S.;Kim, H.Y.;Min, S.K.
    • 한국연소학회:학술대회논문집
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    • 2002.06a
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    • pp.11-15
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    • 2002
  • Experimental studies on effects of the interaction of duplex swirl injector and the liquid temperature on the spray characteristics were conducted. Water and fuel were used as a test fluid for the experiments. The drop size distributions of the liquid spray were measured with Malvern particle sizer. The liquid temperature and distance of injectors were adopted as the operating parameter. The results show that SMD decrease as the increases of fuel temperature and pressure. The spray angle increase as fluid temperature increases. For fuel spray, SMD of impacting surface increase as the distance of injectors is lengthened.

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Effects of temperature dependent material properties on mixed mode crack tip parameters of functionally graded materials

  • Rajabi, Mohammad;Soltani, Nasser;Eshraghi, Iman
    • Structural Engineering and Mechanics
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    • v.58 no.2
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    • pp.217-230
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    • 2016
  • Effects of temperature dependent material properties on mixed mode fracture parameters of functionally graded materials subjected to thermal loading are investigated. A domain form of the $J_k$-integral method including temperature-dependent material properties and its numerical implementation using finite element analysis is presented. Temperature and displacement fields are calculated using finite element analysis and are used to compute mixed mode stress intensity factors using the $J_k$-integral. Numerical results indicate that temperature-dependency of material properties has considerable effect on the mixed-mode stress intensity factors of cracked functionally graded structures.

The Analysis of the Temperature Effects on Long-span Strut by Field Monitoring and Numerical Analysis (현장계측 및 수치해석에 의한 장대버팀보의 온도영향 분석)

  • Lee, Moon-Joo;Choi, Sung-Kun;Shin, Se-Young;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1468-1475
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    • 2005
  • In this study, the effects of temperature on loading of long-span strut were studied by using field monitoring and numerical analysis. For the field monitoring, several sensors, such as stain gages, temperature gages and load cells, were installed on the struts. From the monitoring results, the relation between temperature and axial force of the struts was analysed. By numerical analysis, the changes of axial force of strut and lateral displacement of wall due to temperature change were described with the strut length and ground conditions.

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Effect of Temperature and Immersion Time on the Environmental Adhesive Strength of Adhesively Bonded Joints of Rolled Steel Sheet (압연강판 접착제 접합부의 환경 접합강도에 미치는 온도 및 침수시간의 영향)

  • Song, Jun-Hee;Lee, Hee-Jae;Lim, Jae-Kyoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.12
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    • pp.2662-2669
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    • 2002
  • Recently structural applications of adhesive bonding method have been increased extensively in automobile industry. Adhesively-bonded joints which are used in automobile field are exposed to various environmental conditions. In this study, several environmental factors were concerned to evaluate their effects on the adhesive strength such as air temperature, water temperature, exposed time in water. The specimens are exposed for 1, 10 and 100 hours at various air temperatures to evaluate the effects of the air and water temperature on the adhesive strength. It is proved that the adhesive strength decrease with rising the air and water temperature, and the adhesive strength decrease steeply at the higher temperature with increasing the exposure time in water.

Effect of Korean Red Ginseng and Western Ginseng on Body Temperature, Pulse Rate, Clinical Symptoms and the Hematological Changes in Human (고려홍삼과 서양삼이 사람의 체온, 맥박수, 임상증상 및 혈액학적 변화에 미치는 영향)

  • 김성훈;이상룡
    • Journal of Ginseng Research
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    • v.19 no.1
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    • pp.1-16
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    • 1995
  • Effects of Korean red ginseng (KG) and western ginseng (WG) on body temperature, pulse rate, clinical symptoms and hematological changes in human were studied after administration p.o. with Korean red ginseng and western ginseng for 10-days. KG was more effective in keeping homeostsis in than western ginseng in the changes of body temperature and pulse rate. KG was more effective in low body temperature and SOEVMIN (소음인), while inducing tachycardia especially in SOYANGIN (소양인) and TAEEUMIN (태음인). WG tended to drop temperature abruptly and also descended pulse rate with greater range than KG. KG and WG could cause side effects such as headache and gastrointestinal syndromes and induce hypertension or hypotension abruptly in specific constitutions. However, KG and WG did not cause abnormal changes in urinalysis and hematology.

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Effects of Soft Baking Temperature on the Properties of Solution Processed Zn-Sn-O Thin-Film Transistors (소프트 베이킹 온도가 용액기반 Zn-Sn-O 박막 트랜지스터의 전기적 특성에 미치는 영향)

  • Lee, Jae-Won;Cho, Won-Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.1
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    • pp.6-10
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    • 2016
  • In this study, the effects of soft baking temperature on the solution derived ZTO (Zn-Sn-O) TFTs (thin-film transistors) as a In-free oxide semiconductor were investigated. In spite of the same hard baking at high temperature($600^{\circ}C$), the electrical properties of ZTO TFT was greatly changed by a small difference in soft baking temperature($180{\sim}250^{\circ}C$). The performance of TFT was deteriorated as the soft baking temperature increased. Therefore, it is important to remove the water-related defects well as organic impurities from the ZTO films during soft baking for fabrication of solution-derived high performance of TFTs.

A Study on the Room Temperature Control Methods Considering Human Thermal Comfort Under Hot and Humid Condition (인체의 온열환경 적응을 고려한 여름철의 실온 쾌적변동 제어에 관한 연구)

  • Lee, Ju-Youn
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.5
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    • pp.334-341
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    • 2008
  • The purpose of this study is to investigate the effects of changing air temperature and the changing on/off periods of the air-conditioner system. Adding to that, this paper discuss is to consider the effects of air temperature with the air-conditioner system upon the human thermal comfort. The experiment is conducted during the summer. The subjects(6 young females) are exposed to the following conditions: combinations of 2 Swing and 2 Linear air control Conditions. (2 Swing during 40 min, 4 Swing during 40 min, Linear 40 min, Linear 60 min in still air and RH 50%). From the experiment, the following results are obtained; the thermal sensation vote is neutral after 90 minute. The mean skin temperature ranged about $34^{\circ}C$ at all conditions. The skin temperature was greatly affected by 2 Swing big amplitude condition.