• Title/Summary/Keyword: Junction

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Analysis of Lattice Temperature in Super Junction Trench Gate Power MOSFET as Changing Degree of Trench Etching

  • Lee, Byeong-Il;Geum, Jong Min;Jung, Eun Sik;Kang, Ey Goo;Kim, Yong-Tae;Sung, Man Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.3
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    • pp.263-267
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    • 2014
  • Super junction trench gate power MOSFETs have been receiving attention in terms of the trade-off between breakdown voltage and on-resistance. The vertical structure of super junction trench gate power MOSFETs allows the on-resistance to be reduced compared with conventional Trench Gate Power MOSFETs. The heat release of devices is also decreased with the reduction of on-resistance. In this paper, Lattice Temperature of two devices, Trench Gate Power MOSFET and Super junction trench gate power MOSFET, are compared in several temperature circumstance with the same Breakdown Voltage and Cell-pitch. The devices were designed by 100V Breakdown voltage and measured from 250K Lattice Temperature. We have tried to investigate how much temperature rise in the same condition. According as temperature gap between top of devices and bottom of devices, Super junction trench gate power MOSFET has a tendency to generate lower heat release than Trench Gate Power MOSFET. This means that Super junction trench gate power MOSFET is superior for wide-temperature range operation. When trench etching process is applied for making P-pillar region, trench angle factor is also important component. Depending on trench angle, characteristics of Super junction device are changed. In this paper, we focus temperature characteristic as changing trench angle factor. Consequently, Trench angle factor don't have a great effect on temperature change.

Investigation of the effect of Hibiscus sabdariffa L. extracts on tight-junction related genes in human keratinocyte HaCaT cells (히비스커스 추출물이 인간 각질 형성 세포의 밀착 연접 관련 유전자 발현에 미치는 영향 연구)

  • Jung, Haesoo;Kim, Eunmi;Han, Hyosang;Kim, Keekwang
    • The Korea Journal of Herbology
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    • v.36 no.5
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    • pp.59-67
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    • 2021
  • Objectives : Hibiscus (Hibiscus sabdariffa L.) is rich in antioxidants such as flavonoids and anthocyanins and is known to have anti-inflammatory activity and anti-aging function of the skin, but there is no study on its effect on the skin barrier. This study aim to investigate the positive effect on the skin barrier by confirming the effect of water extracts of Hibiscus sabdariffa L. (WEHS) on the tight junction-related gene expression. Methods : The antioxidant efficacy of WEHS was investigated through ABTS and DPPH assays, and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium was performed to examine the effect on cell viability. quantitative Reverse transcription polymerase chain reaction and immunoblot analysis were performed to confirm the effect of WEHS on the expression of tight junction-related genes, and immunofluorescence microscopy was used to confirm the movement of Claudin 1 protein into tight junctions. Results : WEHS showed strong antioxidant activity and induced an increase in both mRNA and protein expression levels of Claudin 1 among tight junction-related genes. The strong localization of Claudine 1 protein increased by WEHS to the tight junction was confirmed by immunofluorescence microscopy. Conclusions : Hibiscus was confirmed through this study to show antioxidant activity and the function of promoting the expression of the tight junction Claudin 1 gene, suggesting that Hibiscus can be used as a material for the prevention and treatment of skin moisturizing and atopy, which have an important influence on tight junction.

Macro-Modeling for Magnetic Tunnel Junction (Magnetic Tunnel Junction 의 Macro-Modeling)

  • 홍승균;송상헌;김수원
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.943-946
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    • 2003
  • This paper proposes new SPICE Macro-Model of MTJ(Magnetic Tunnel Junction). This Macro-Model has five I/O terminals, reproduces MR characteristics including hysteresis and behaves correctly to time varying input signals. Furthermore, this Model can be easily modified to various MTJs with different characteristics by simply varying internal parameters.

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Effect of temperature gradient on junction magnetoresistance of magnetic tunnel junction devices

  • No, Seong-Cheol;Park, Min-Gyu;Lee, Yeo-Reum
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.495-497
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    • 2014
  • Combining the quantum transport theory with new field of Spin Caloritronics, we investigate on the influence of thermal gradient on the magneto tunnel junction structure under various circumstances. The results indicate enhancement in performance of spintronic device is possible using thermal energy.

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Realistic Simulations on Reverse Junction Characteristics of SiC and GaN Power Semiconductor Devices

  • Wei, Guannan;Liang, Yung C.;Samudra, Ganesh S.
    • Journal of Power Electronics
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    • v.12 no.1
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    • pp.19-23
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    • 2012
  • This paper presents a practical methodology for realistic simulation on reverse characteristics of Wide Bandgap (WBG) SiC and GaN p-n junctions. The adjustment on certain physic-based model parameters, such as the trap density and photo-generation for SiC junction, and impact ionization coefficients and critical field for GaN junction are described. The adjusted parameters were used in Synopsys Medici simulation to obtain a realistic p-n junction avalanche breakdown voltage. The simulation results were verified through benchmarking against independent data reported by others.

Formation of Chimeric Gap Junction Channels in Mammalian Ovarian Follicle

  • Oh Seunghoon
    • Reproductive and Developmental Biology
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    • v.28 no.3
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    • pp.147-153
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    • 2004
  • The oocyte and its surrounding granulosa cells co-exist in a closed compartment called a follicle, although they receive many signals from other parts of the body. It is well established that the intercellular communications between the oocyte and granulosa cells are required for normal oocyte development and ovulation during folliculogenesis. Gap junctions are intercellular channels allowing the direct transmission of ions and small molecules between coupled cells. Several lines of studies have shown that multiple connexins (Cx, subunits of gap junction) are expressed in mammalian ovarian follicles. Among them, two major connexins Cx37 and Cx43 are expressed in different manner. While the gap junction channels formed by Cx37 are localized between the oocyte and encompassing granulosa cells, the intercellular channels by Cx43 are located between granulosa cells. In this review, I will summarize the general properties of gap junction channels and discuss their possible formation (or compatibility) of intercellular channels formed by the oocyte and granulosa cells.

A Study on the Hydraulic Characteristics of River Junctions Using FLDWAV Model (FLDWAV 모형을 이용한 하천합류부에서의 수리학적 특성 연구)

  • Cho, Hyeon-Kyeong
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.4
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    • pp.275-283
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    • 2007
  • This study aims at the calculation of a variation of flow characteristics of main channel for tributary inflow in river junction. So this study was analyzed the variation of flow depth and velocity in main channel for a change of inflow degree. For this purpose, FLDWAV model are carried out for variations of $30^{\circ}$, $60^{\circ}$ and $90^{\circ}$ tributary inflow at junction. Results show that velocity ratio(V1/V3) increases and flow depth ratio(H1/H3) decreases for discharge ratio(Q1/Q3) of upstream and downstream when degree increases in junction. And FLDWAV model was applied at a real river junctions. Selected area is a junction of Gumho river and Sin stream. Results show that pattern is similar to a virtual channel.

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