• Title/Summary/Keyword: material stability

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Stability enhancement of armorphous znic oxide thin film transistors fabricated by pulsed laser deposition with DBD (PLD-DBD 공정으로 제작된 비정질 Zn 산화물 박막트랜지스터의 안정성 향상)

  • Chun, Yoon-Soo;Chong, Eu-Gene;Jo, Kyoung-Chol;Kim, Seung-Han;Jung, Da-Woon;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.391-391
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    • 2010
  • The stability enhancement of Znic oxide thin film transistor deposited by PLD-DBD has been reported here using the bias temperature stress test. Znic oxide (ZnO) thin films were deposited on $SiO_2$/Si (100) by pulsed laser deposition method with and without dielectric barrier discharge (DBD) method. The DBD is the efficient method to adopt the nitrogen ions into the thin films. The TFT characteristics of ZnO TFTs with and without Nirogen (N) doping show similar results with $I_{on/off}$ of $10^5{\sim}10^6$. However. the bias temperature stress (BTS) test of N-doped ZnO TFT with DBD shows higher stability than that of ZnO TFT.

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Liquid Crystal orientation on the NDLC Thin Film Deposited using physical deposition method (PVD방식을 이용한 NDLC 박막에서의 액정 배향 효과)

  • Lee, Won-Kyu;Oh, Byoung-Yun;Lim, Ji-Hun;Na, Hyun-Jae;Lee, Kang-Min;Park, Hong-Gyu;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.301-301
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    • 2008
  • Ion beam (IB)-induced alignment of inorganic materials has been investigated intensively as it provides controllability in a nonstop process for producing high-resolution displays[1][2]. LC orientation via ion-beam (IB) irradiation on the nitrogen doped diamond like carbon (NDLC) thin film deposited by physical deposition method-sputtering was embodied. The NDLC thin film that was deposited by sputter showed uniform LC alignment at the 1200eV of the ion beam intensity. The pretilt angle of LC on NDLC thin films was measured with various IB exposure time and angle. The maximum pretilt angle were showed with IB irradiation angle of $45^{\circ}$ and exposure time of 62.5 sec, respectively. To show NDLC thin film stability in high temperature, thermal stability test was proceeded. The uppermost of the thermal stability of NDLC thin film was $200^{\circ}C$. In this investigation, the electro-optical (EO) characteristics of LC on NDLC thin film were measured.

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Thermal Stability Improvement of Ni-germanide using Ni-Co alloy for Ge-MOSFETs Technology (Ge-MOSFETs을 위한 Ni-Co 합금을 이용한 Ni-germanide의 열안정성 개선)

  • Park, Kee-Young;Jung, Soon-Yen;Zhang, Ying-Ying;Han, In-Shik;Li, Shi-Guang;Zhong, Zhun;Shin, Hong-Sik;Kim, Yeong-Cheol;Kim, Jae-Jun;Lee, Ga-Won;Wang, Jin-Suk;Lee, Hi-Deok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.8
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    • pp.733-737
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    • 2008
  • In this paper, Ni-Co alloy was used to improve thermal stability of Ni Germanide. It was found that uniform germanide is obtained on epitaxial Ge-on-Si substrate by employing Ni-Co alloy. Moreover, neither agglomeration nor penetration is observed during post-germanidation annealing process. The thermal stability of Ni germanide using Ni-Co alloy is improved due to the less agglomeration of Germanide. Therefore, the proposed Ni-Co alloy is promising for highly thermal immune Ni germanide for nano scale Ge-MOSFETs technology.

Finite element analyses of the stability of a soil block reinforced by shear pins

  • Ouch, Rithy;Ukritchon, Boonchai;Pipatpongsa, Thirapong;Khosravi, Mohammad Hossein
    • Geomechanics and Engineering
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    • v.12 no.6
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    • pp.1021-1046
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    • 2017
  • The assessment of slope stability is an essential task in geotechnical engineering. In this paper, a three-dimensional (3D) finite element analysis (FEA) was employed to investigate the performance of different shear pin arrangements to increase the stability of a soil block resting on an inclined plane with a low-interface friction plane. In the numerical models, the soil block was modeled by volume elements with linear elastic perfectly plastic material in a drained condition, while the shear pins were modeled by volume elements with linear elastic material. Interface elements were used along the bedding plane (bedding interface element) and around the shear pins (shear pin interface element) to simulate the soil-structure interaction. Bedding interface elements were used to capture the shear sliding of the soil on the low-interface friction plane while shear pin interface elements were used to model the shear bonding of the soil around the pins. A failure analysis was performed by means of the gravity loading method. The results of the 3D FEA with the numerical models were compared to those with the physical models for all cases. The effects of the number of shear pins, the shear pin locations, the different shear pin arrangements, the thickness and the width of the soil block and the associated failure mechanisms were discussed.

Conformational Switch and Functional Regulation of Proteins (단백질의 구조 전환과 기능 조절)

  • Yu, Myeong-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.3-6
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    • 2001
  • In common globular proteins, the native form is in its most stable state. However, the native form of inhibitory serpins (serine protease inhibitors) and some viral membrane fusion proteins is in a metastable state. Metastability in these proteins is critical to their biological functions. Our previous studies revealed that unusual interactions, such as side-chain overpacking, buried polar groups, surface hydrophobic pockets, and internal cavities are the structural basis of the native metastability. To understand the mechanism by which these structural defects regulate protein functions, cavity-filling mutations of a 1-antitrypsin, a prototype serpin, were characterized. Increasing conformational stability is correlated with decreasing inhibitory activity. Moreover, the activity loss appears to correlate with the decrease in the rate of the conformational switch during complex formation with a target protease. We also increased the stability of a 1-antitrypsin greatly via combining various stabilizing single amino acid substitutions that were distributed throughout the molecule. The results showed that a substantial increase of stability, over 13 kcal/mol, affected the inhibitory activity with a correlation of 11% activity loss per kcal/mol. The results strongly suggest that the native metastability of proteins is indeed a structural design that regulates protein functions and that the native strain of a 1-antitrypsin distributed throughout the molecule regulates the inhibitory function in a concerted manner.

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Degradation Properties in the QCM Gas Sensors Coated with the PEG Materials (PEG 물질을 도포한 QCM 가스센서의 열화특성)

  • Jang, Kyung-Uk;Kim, Myung-Ho;Lee, Won-Jae;Kim, Sang-Keol;Jung, Dong-Hoe;Lee, Joon-Ung;Lee, Ho-Sik;Kim, Tae-Wan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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    • pp.218-222
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    • 2002
  • In the recognition of the gases using the quartz crystal microbalance (QCM) coated with the PEG film materials, it is important to obtain the recognition ability of gases, and the stability of PEG film coated above the QCM. Especially, the thickness of PEG film coated above the QCM is decreased according with the using circumstance and time of QCM gas sensor. Therefore, the sensing characteristics of PEG film is changed with these. In this paper, we coated the PEG materials varing with the blended amount of PVC(Poly Vinyl Chloride) and chloroform above QCM to obtain the sensitive and the stability of PEG film. We measured the degradation characteristics of QCM gas sensor in the ethyle acetate 50[%] concentration to show the properties of stability.

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Electrical Properies, Clamping Voltage Characteristics, and Stability of Dysprosia-doped ZnO-Pr6O11Based Varistors (디스프로시아가 첨가된 ZnO-Pr6O11계 바리스터 전기적 성질, 제한전압특성 및 안정성)

  • Nahm, Choon-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.1
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    • pp.50-56
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    • 2005
  • The electrical properties, clamping voltage characteristics, and stability of dysprosia-doped ZnO-P $r_{6}$ $O_{11}$-based varistors were investigated with different dysprosia contents from 0 to 2.0 mol%. The incorporation of dysprosia in varistor ceramics greatly increased the varistor voltage from 50 to 481.0 V/mm. It was found that the dysprosia is good additive improving a nonlinearity, in which the nonlinear exponent is above or near 50, and the leakage current is below 1.0 $\mu$A. The dysprosia-doped varistors exhibited superior clamping voltage characetristics, in which clamping voltage ratio is above or neat 2 at surge current of 50 A. The 0.5 mol% dysprosia-doped varistors only exhibited high stability, with the rate of varistor voltage of -0.9%, under DC acceleraetd aging stress, 0.95 $V_{lmA}$/15$0^{\circ}C$/24 h.h.h.h.

Thermal Stability of the Mechanical and Thermal Conductive Properties on Cu-STS-Cu Clad Metal for LED Package Lead Frame (LED 리드프레임 패키징용 Cu/STS/Cu 클래드 메탈의 기계 및 열전도 특성의 온도 안정성 연구)

  • Kim, Young-Sung;Kim, Il-Gwon
    • Journal of Welding and Joining
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    • v.31 no.5
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    • pp.77-81
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    • 2013
  • We have investigated thermal stability of the mechanical and thermal conductive properties of Cu/STS/Cu 3 layered clad metal lead frame material for a LED device package at different temperatures ranging from RT to $200^{\circ}C$. The fabricated Cu/STS/Cu clad metal has a good thermal stability for the mechanical tensile strength and thermal conductivity of the over 50 $Kg/mm^2$ to the $150^{\circ}C$ and 270 $W/m{\cdot}K$ to the $200^{\circ}C$, respectively. This clad metal lead frame material at a high temperature of $150^{\circ}C$ shows a reinforced mechanical tensile strength by 1.5 times to conventional pure copper lead frame materials and also a comparable thermal conductivity to typical copper alloy lead frame materials.

Manufacture Technology Development of Paper Mending Tape for Conservation of Archive Document (종이 기록물 보수용 안전 테이프 시제품 제조 기술 연구)

  • Shin, Joung-Soon;Yoo, Sun-Kyun
    • Journal of the Korean Graphic Arts Communication Society
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    • v.29 no.3
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    • pp.41-53
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    • 2011
  • For manufacturing the tape for repairing archival documents, we tested ten carrier candidates for selecting best material. The tensile strength, transmissivity, stability of deterioration, and processability were determined. Physical-chemical characteristics and stability of deterioration was best to the Hanji. Tensile strength and transmissivity was best in tracing paper, but was low in oil paper, white sketch paper, lyon coat paper. Synthetic carrier to tensile strength showed higher than paper carrier and to the transmissivity showed 2-8 times higher than paper carriers. The tracing paper to the transmissivity was 10 times higher than others. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $90^{\circ}C$ for 15 days. Oil paper and white sketch paper turned strongly yellowish. Cellulopane, Felt, and Cpp film showed stable stability of deterioration, but deformation like wrinkles. PET film and Syntheletic film showed excellent conservation characteristics without any change of exterior. Test of adhesive uniform between carriers and adhesive processability was performed. PET film > Syntheletic film > Tracing Paper in order were determined. Ununiformal adhesive characteristics appeared to Hangi. Accordingly, we thought that Hanji as carrier material might be unsuitable because of low adhesive processability.

DC Accelerated Aging Characteristics of $ZnO-Pr_{6}O_{11}$ Based Varistor Ceramics ($ZnO-Pr_{6}O_{11}$계 바리스터 세라믹스의 직류가속열화 특성)

  • Kim, Hyang-Suk;Nahm, Choon-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.330-333
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    • 2002
  • The stability against DC accelerated aging stress of $Dy_{2}O_{3}-doped$ $ZnO-Pr_{6}O_{11}-based$ varistor ceramics was investigated. The calculated nonlinear exponent$(\alpha)$ in varistor ceramics without $Dy_{2}O_{3}$ was only 4.9, whereas the $\alpha$ value of the varistors with $Dy_{2}O_{3}$ was abruptly increased in the range of 48.8 to 58.6. The varistor ceramics with $Dy_{2}O_{3}$ content of 1.0 mol% exhibited maximum ${\alpha}$, reaching 58.6, whereas they exhibited very poor stability. While, The varistor ceramics doped with 0.5 mol% $Dy_{2}O_{3}$ exhibited not only the high nonlinearity, which the ${\alpha}$ is 55.3 and the leakage current is $0.1{\mu}A$, but also the highest stability, which the variation rates of varistor voltage and nonlinear exponent are -0.8% and -14.3%, respectively, under DC accelerated aging stress, $0.95 V_{1mA}/150^{\circ}C/24h$.

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