• Title/Summary/Keyword: Thermal Stabilizer

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Behavior of Intrinsic Viscosity and Moisture Content of Antistatic Polyethyleneterephthalate by Thermal Stabilizer (열안정제에 의한 제전성 폴리에틸렌테레프탈레이트의 고유점도 및 수분율의 거동 변화)

  • Kim, Moon-Chan;Lee, Cheal-Gyu
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.707-710
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    • 1999
  • Moisture content and intrinsic viscosity of antistatic polyethyleneterephthalate(PET) depending on the thermal stabilizer content was studied. The terminal moisture content of antistatic PET was a function of drying temperature rather than drying time. Intrinsic viscosity drop of antistatic PET after melt spinning increased with increasing moisture content of it. After melt spinning, intrinsic viscosity of antistatic PET was decreased due to the thermal degradation of polyoxyalkyleneglycol(POAG) component of antistatic agent. Triphenylphosphate(TPP) was more effective as a thermal stabilizer than trimethylphosphate(TMP). A little intrinsic viscosity drop after melt spinning was found in PET containing 300 ppm of TPP as a thermal stabilizer.

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Investigation on stability characteristics of 2G HTS coated conductor tapes with various stabilizer thickness

  • Quach, Huu Luong;Kim, Ji Hyung;Hyeon, Chang Ju;Chae, Yoon Seok;Moon, Jae Hyung;Kim, Ho Min
    • Progress in Superconductivity and Cryogenics
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    • v.20 no.1
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    • pp.19-22
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    • 2018
  • The thermal and electrical properties of the conductor are critical parametersfor the design and optimization of the superconducting magnet. This paper presents simulation code to analyze electrical and thermal stability characteristics of the second generation (2G) high-temperature superconductor (HTS) by varying copper stabilizer thickness. Two types of commercial 2G HTS coated conductor tapes, YBCO and GdBCO were used in this study. These samples were cooled by Liquid Nitrogen ($LN_2$) having boiling at 77.3 K and an equivalent electrical circuit model for them is choosen and analysed in details. Also, an over-current pulse test in which a current exceeding a critical current was performed. From the simulation results, the influences of the copper stabilizer thickness on the stability characteristics of these samples are presented.

Phase Transition and Thermal Expansion Behavior of Zirconia Setter Fabricated from Fused CaO Stabilized Zirconia

  • Park, Ji-Hoon;Bang, Il-Hwan;Lee, Sang-Jin
    • Journal of the Korean Ceramic Society
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    • v.56 no.2
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    • pp.184-190
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    • 2019
  • To improve resistance in thermal shock of zirconia setter which is frequently and repeatedly exposed to high temperature, high degree of porosity and control of thermal expansion are needed for which the fused CSZ (CaO stabilized zirconia) is used to produce the zirconia setter. In the present study, the effects of sintering temperature, cool down condition, addition of CaO stabilizer, and addition of other additives on phase transition and thermal expansion behavior of the fabrication process of zirconia setter, were examined. The zirconia setter, fabricated with fused CSZ at 1550℃, exhibited 20.4 MPa of flexural strength, 6.8% of absorbance, and 27.9% of apparent porosity. The rapid change in thermal expansion of zirconia setter is observed at temperature around 800℃, and it was reduced by low firing temperature, slowed cooled down, and addition of CaO.

Thermal Stability Improvement of Liquid Fuel by Using Some Additives (첨가제를 이용한 액체연료의 열안정성 향상)

  • Park, Sun-Hee;Kim, Joong-Yeon;Chun, Byung-Hee;Han, Jeong-Sik;Jeong, Byung-Hun;Kim, Sung-Hyun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.294-299
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    • 2010
  • Thermal stability of exo-tetrahydrodicyclopentadiene (exo-THDCP) were investigated in a batch-type reactor perfectly coated with quartz. The 1 ml liquid product, which was a sufficiently small amount so as not to affect the reaction pressure, was sampled at 90 min intervals during the reaction and determined by gas chromatography-mass spectrometry (GC-MS) to measure thermal decomposition products of exo-THDCP and specify mechanism for additives (thermal stabilizer). Hydrogen donors (thermal stabilizer) such as 1,2,3,4-tetrahydroquinoline (THQ), benzyl alcohol (BnOH) increased thermal stability of exo-THDCP. These materials donated hydrogen to radical of exo-THDCP produced after initiation of exo-THDCP to decrease activity of primary products of exo-THDCP.

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A study on the bonding properties of YBCO coated conductors with stainless steel stabilizer (스테인레스 강 안정화 YBCO 초전도선재의 접합 특성에 관한 연구)

  • Kim, Tae-Hyung;Oh, Sang-Soo;Song, Kyu-Jeong;Kim, Ho-Sup;Ko, Rock-Kil;Shin, Hyung-Seop
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.262-263
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    • 2005
  • For mechanical and electrical stability and environment protection, Cu and stainless steel stabilizer is laminated to Ag layer to produce a composite neutral-axis(N-A) architecture in which the YBCO layer is centered between the oxide buffered metallic substrate and stabilizer strip lamination. this architecture allows the wire to meet operational requirements including stresses at cryogenic temperature, winding tensions, mechanical bending requirements thermal and electrical stability under fault conditions. we have experimentally studied mechanical properties of laminated stainless steel stabilizer on YBCO coated conductors. we have laminated YBCO coated conductors by continuous dipping soldering process. we have investigated lamination interface between solder and stabilizer, YBCO coated conductor. we evaluated bonding properties tensile / shear bonding strength, peeling strength laminated YBCO coated conductors.

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A study on the properties of SmBCO coated conductors with stabilizer tape (SmBCO 고온 초전도 선재의 안정화재 특성)

  • Kim, Tae-Hyung;Oh, Sang-Soo;Kim, Ho-Sup;Ko, Rock-Kil;Song, Kyu-Jeong;Ha, Hong-Soo;Lee, Nam-Jin;Park, Kyung-Chae;Ha, Dong-Woo
    • Progress in Superconductivity and Cryogenics
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    • v.9 no.3
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    • pp.9-12
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    • 2007
  • In this study. we searched for the mechanical and electrical properties of laminated coated conductors with stabilizer tape. Stabilizer tape plays a role for mechanical and electrical stability and environmental protection. Cu material stabilizer was laminated to Ag capping layer on SmBCO conductor layer. This architecture allows the wire to meet operational requirements including the stressless at cryogenic temperature and winding tension as well as mechanical bending requirements including thermal and electrical stability under fault current conditions. First, we have experimentally studied mechanical bonding properties of the laminated Cu stabilizers on SmBCO coated conductors. We have laminated SmBCO coated conductors by continuous dipping soldering process, Second, we have investigated electrical properties of the SmBCO coated conductors with stabilizer lamination. We evaluated bonding properties, peeling strength and critical current for laminated SmBCO coated conductors with Cu stabilizers.

Droplet Size and Thermal conductivity Measurements of Binary Nanoemulsion (이성분 나노에멀전의 입도 및 열전도도 측정)

  • Cho, Chang-Hwan;Sul, Hea-Youn;Jung, Jung-Yeul;Kang, Yong-Tae
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.815-820
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    • 2009
  • Binary nanoemulsions which are defined as the, oil-droplet suspensions in binary solution ($H_2O$/LiBr), are developed to enhance the heat and mass transfer performance of absorption refrigeration systems. In this study, a novel two-step method is proposed to prepare the stable oil-in-binary solution (O/S) emulsion. Polymer is used as a steric stabilizer to stabilize the oil-droplets in a strong electrolyte ($H_2O$/LiBr). It is found that the thermal conductivity of the binary nanoemulsion is inversely proportional to the emulsion size while the concentrations of oil and $H_2O$/LiBr are less dominant for the thermal conductivity of binary nanoemulsions.

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Studies on Recycling Technology Wasted Plastic (폐플라스틱의 재활용에 관한 연구)

  • Lee, Soo-Keun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.11 no.1
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    • pp.47-52
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    • 2005
  • The wasted plastic PC/ABS retainer, polyurethane foam (PUF) and vinyl (PVC) skin. In order to investigate the recycling process, the multi-layered instrument panel Each of materials separated was shredded and crushed to create many small particles respectively. The separation of the foam and skin and retainer of zigzagged air blower. Pilot tests performed at the equipment yielded 98.8% by weight of the available PVC and 99.3% by weight of the available PC/ABS respectively. Secondly, the thermal stabilizer and the compatabilizer have been used to improve the physical propertied of recycled materials.. The properties of recycled PVC materials resulted in about 50% compared to that of virgin materials after treatment by Pb-St thermal stabilizer. In addition, the properties of recycled PC/ABS materials was also obtained about 80% compared to that of virgn materials after treatment by PMMA compatabilizer.

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A Practical Power System Stabilizer Tuning Method and its Verification in Field Test

  • Shin, Jeong-Hoon;Nam, Su-Chul;Lee, Jae-Gul;Baek, Seung-Mook;Choy, Young-Do;Kim, Tae-Kyun
    • Journal of Electrical Engineering and Technology
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    • v.5 no.3
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    • pp.400-406
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    • 2010
  • This paper deals with parameter tuning of the Power System Stabilizer (PSS) for 612 MVA thermal power plants in the KEPCO system and its validation in a field test. In this paper, the selection of parameters, such as lead-lag time constants for phase compensation and system gain, is optimized using linear and eigenvalue analyses. This is then verified through the time-domain transient stability analysis. In the next step, the performance of PSS is finally verified by the generator's on-line field test. After the field test, measured and simulated data are also compared to prove the effectiveness of the models used in the simulations.

A study on the bonding properties of YBCO coated conductors with stabilizer tape (안정화 선재의 YBCO 초전도 접합 특성)

  • Kim Tae-Hyung;Oh Sang-Soo;Ha Dong-Woo;Kim Ho-Sup;Ko Rock-Kil;Shin Hyung-Seop;Park Kyung-Chae
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.3
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    • pp.23-26
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    • 2006
  • For mechanical and electrical stability and environment protection. Cu and stainless steel stabilizers are laminated to a Ag layer to produce a composite neutral-axis(N-A) architecture in which the YBCO layer is centered between the oxide buffered metallic substrate and stabilizer strip lamination. This architecture allows the wire to meet operational requirements including stresses at cryogenic temperature. winding tensions as well as mechanical bending requirements including thermal and electrical stability under fault current conditions. We have experimentally studied mechanical properties of the laminated stainless steel and Cu stabilizers on YBCO coated conductors. We have laminated YBCO coated conductors by continuous dipping soldering process. We have investigated lamination interface between solder and stabilizer of the YBCO coated conductor. We evaluated bonding properties. tensile / shear bonding strength. and peeling strength laminated YBCO coated conductors.