• 제목/요약/키워드: self-heating

검색결과 272건 처리시간 0.028초

Establishment of calculation methodology and thermal analysis for the development of a water calorimeter

  • Kang, M.Y.;Kim, Junhyuck;Choi, H.D.
    • Nuclear Engineering and Technology
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    • 제52권11호
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    • pp.2620-2629
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    • 2020
  • As an early stage in the development of a water calorimeter, this study established a computer simulation methodology for analyzing the thermal behavior of a water calorimeter based on radiation transport and energy deposition. As a result, this study developed a method wherein the energy deposition distribution, which is obtained by applying Monte Carlo methods in water calorimeters, is directly used as a heat source for the thermal analysis model. Based on the proposed method, heat transfer in a water vessel and the effect of thermistor self-heating were analyzed. Through an analysis of the water velocities with and without a water vessel, it was found that a water vessel can serve as a convection barrier. Furthermore, it was confirmed that when considering thermistor self-heating, the water temperature change at the thermistor location is 0.219 mK higher compared to that when the thermistor was not considered. Therefore, thermistor self-heating must be considered to analyze the thermal behavior of a water calorimeter more accurately.

Pair-Wise Serial ROIC for Uncooled Microbolometer Array

  • Haider, Syed Irtaza;Majzoub, Sohaib;Alturaigi, Mohammed;Abdel-Rahman, Mohamed
    • IEIE Transactions on Smart Processing and Computing
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    • 제4권4호
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    • pp.251-257
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    • 2015
  • This work presents modelling and simulation of a readout integrated circuit (ROIC) design considering pair-wise serial configuration along with thermal modeling of an uncooled microbolometer array. A fully differential approach is used at the input stage in order to reduce fixed pattern noise due to the process variation and self-heating-related issues. Each pair of microbolometers is pulse-biased such that they both fall under the same self-heating point along the self-heating trend line. A ${\pm}10%$ process variation is considered. The proposed design is simulated with a reference input image consisting of an array of $127{\times}92$ pixels. This configuration uses only one unity gain differential amplifier along with a single 14-bit analog-to-digital converter in order to minimize the dynamic range requirement of the ROIC.

Self-Oscillating Switching Technique for Current Source Parallel Resonant Induction Heating Systems

  • Namadmalan, Alireza;Moghani, Javad Shokrollahi
    • Journal of Power Electronics
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    • 제12권6호
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    • pp.851-858
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    • 2012
  • This paper presents resonant inverter tuning for current source parallel resonant induction heating systems based on a new self oscillating switching technique. The phase error is suppressed in a wide range of operating frequencies in comparison with Phase Locked Loop (PLL) techniques. The proposed switching method has the capability of tuning under fast changes in the resonant frequency. According to this switching method, a multi-frequency induction heating (IH) system is proposed by using a single inverter. In comparison with multi-level inverter based IH systems, the advantages of this technique are its simple structure, better transients and wide range of operating frequencies. A laboratory prototype was built with an operating frequency of 35 kHz to 55 kHz and 300 W of output power. The performance of the IH system shows the validity of the new switching technique.

β-Ga2O3/4H-SiC MESFETs에서의 Self-Heating (Self-Heating Effects in β-Ga2O3/4H-SiC MESFETs)

  • 김민영;서현수;서지우;정승우;이희재;변동욱;신명철;;구상모
    • 한국전기전자재료학회논문지
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    • 제35권1호
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    • pp.86-92
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    • 2022
  • Despite otherwise advantageous properties, the performance and reliability of devices manufactured in β-Ga2O3 on semi-insulating Ga2O3 substrates may degrade because of poorly mitigated self-heating, which results from the low thermal conductivity of Ga2O3 substrates. In this work, we investigate and compare self-heating and device performance of β-Ga2O3 MESFETs on substrates of semi-insulating Ga2O3 and 4H-SiC. Electron mobility in β-Ga2O3 is negatively affected by increasing lattice temperature, which consequently also negatively influences device conductance. The superior thermal conductivity of 4H-SiC substrates resulted in reduced β-Ga2O3 lattice temperatures and, thus, mitigates MESFET drain current degradation. This, in turn, allows practically reduced device dimensions without deteriorating the performance and improved device reliability.

Polysilicon Thin Film Transistors on spin-coated Polyimide layer for flexible electronics

  • Pecora, A.;Maiolo, L.;Cuscuna, M.;Simeone, D.;Minotti, A.;Mariucci, L.;Fortunato, G.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.261-264
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    • 2007
  • We developed a non self-aligned poly-silicon TFTs fabrication process at two different temperatures on spin-coated polyimide layer above Si-wafer. After TFTs fabrication, the polyimide layer was mechanically released from the Si-wafer and the devices characteristics were compared. In addition self-heating and hot-carrier induced instabilities were analysed.

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Technical Obstacles to Suftla Flexible Microelectronics

  • Miyasaka, Mitsutoshi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1763-1766
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    • 2007
  • Three technical obstacles must be overcome to build a fruitful business in the nascent industry of flexible microelectronics: the self-heating effect of thin film transistors (TFTs), the thermal and mechanical durability of flexible devices, and the cost issue. The self-heating effect is controlled through TFT shape, TFT electrical performance, dimensional reduction and energy-efficient circuits. Plastic engineering is one of the keys to solving thermal and mechanical durability problems faced by flexible microelectronics devices. For the Suftla flexible microelectronics business to be viable, Suftla transfer yield must be sufficiently high to keep down device cost. Improving the transfer yield is not easy, but it is the same challenge already faced and cleared in the TFT liquid crystal display industry.

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Degradation of High Performance Short Channel N-type Poly-Si TFT under the Electrical Bias Caused by Self-Heating

  • Choi, Sung-Hwan;Song, In-Hyuk;Shin, Hee-Sun;Park, Sang-Geun;Han, Min-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1301-1304
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    • 2007
  • We have investigated degradation of short channel n-type poly-Si TFTs with LDD under high gate and drain voltage stress due to self-heating. We have found that the threshold voltage of short channel TFT is shifted to negative direction on the selfheating stress, whereas the threshold voltage of long channel is moved to positive direction.

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$TiB_2$ SHS 및 직접 접촉가열에 의한 동시 가압법 : 온도분포 모델링 및 공급에너지와 치밀화 관계 (Simultaneous Consolidation of Titanium Diboride with Self-Propagating High-Temperature Synthesis, Direct Contact-Heating, and Pressure: Modeling of Temperature Distribution and the Relationship between Applied Energy and Densification)

  • 정진근;조건;이형복
    • 한국세라믹학회지
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    • 제32권7호
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    • pp.817-824
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    • 1995
  • TiB2 was simultaneously synthesized and densified with concurrent self-propagating high-temperature synthesis and direct contact-heating by electrcial power input and pressure. Density of TiB2 synthesized by self-propagating high-temperature synthesis and consolidated simultaneously by direct contact-heating and pressure was maximum 80% of the theoretical density (4.52g/㎤). Temperature profile was analyzed by solving heat balance equation with numerical method (FTCS method). The temperature of the sample was sufficiently raised to that temperature sufficient to be densified. It was ascertained that the density of the SHS synthesized TiB2 is exponentially proportinal to the input thermal energy per mass.

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