Effect of Polarization Treatment Time on Inhibition of Low Temperature Degradation in Y-Doped ZrO2

2012 ◽  
Vol 529-530 ◽  
pp. 601-604
Author(s):  
Yu Tsuchiya ◽  
Naohiro Horiuchi ◽  
Miho Nakamura ◽  
Kosuke Nozaki ◽  
Akiko Nagai ◽  
...  
Keyword(s):  
Low Temperature ◽  
Treatment Time ◽  
Space Charge Polarization ◽  
Surface Charges ◽  
Depolarization Current ◽  
Orientation Polarization ◽  
Polarization Mechanism ◽  
Thermally Stimulated Depolarization ◽  
Effect Of Surface ◽  
Acceleration Test

Effect of surface charges induced by polarization treatment on Low Temperature Degradation (LTD) in 3mol%Y-doped ZrO2 was studied. Samples were polarized by applying voltage (7kV/cm) at 200°C for various time (1~30min). LTD acceleration test was conducted using polarized samples. LTD was inhibited on negatively charged surface in all the polarized samples, which is independent on polarization time. We carried out thermally stimulated depolarization current (TSDC) analysis for investigate polarization mechanism. Two polarization elements were confirmed: orientation polarization and space charge polarization. A comparison of the result of LTD acceleration test and TSDC analysis indicates that orientation polarization is considered superior element in inhibition of LTD.

The Storing Properties of Electric Energy in Bone

2011 ◽  
Vol 493-494 ◽  
pp. 170-174
Author(s):  
Rumi Hiratai ◽  
Miho Nakamura ◽  
Akiko Nagai ◽  
Kimihiro Yamashita
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Electric Fields ◽  
Electric Energy ◽  
Depolarization Current ◽  
Thermally Stimulated Depolarization Current ◽  
High Temperature And Pressure ◽  
Temperature And Pressure ◽  
Thermally Stimulated Depolarization ◽  
Inorganic Components

We have shown that hydroxyapatite (HA), which characteristics were similar to those of bone’s inorganic components, had polarization capability and was possible to accumulate electricity under high temperature and pressure. Then, we presumed that bones had polarization capability which enabled electrical storage and conducted the experiment to measure the polarization capability of bones using rabbit’s femurs. After preparing and polarizing bone samples using KOH treatment (koh), KOH and baking treatment (koh+bake) and decalcification treatment (decalcification) as well as the bone without any treatment (untreat), quantitative amounts of stored charge in samples were determined by thermally stimulated depolarization current (TSDC) measurement of these samples. Under the condition of 400 °C for 1 h with the electric fields of 5kV/cm, samples of koh, koh+bake, and untreat showed polarization capability. In addition, under the polarization condition of 37 °C for 1 hour with the electric fields of 5kV/cm, all samples showed polarization capability. Those findings can be summarized that bones have the polarization capability which enables electrical storage and polarization of bones is possible even under the low temperature condition, which was at 37 °C in our experiment, where polarization is impossible for HA.

Thermally Stimulated Depolarization Current in 3 Mol% Yttria-Doped Zirconia

2013 ◽  
Vol 582 ◽  
pp. 135-138 ◽  
Author(s):  
Naohiro Horiuchi ◽  
Yu Tsuchiya ◽  
Kosuke Nozaki ◽  
Miho Nakamura ◽  
Akiko Nagai ◽  
...  
Keyword(s):  
Room Temperature ◽  
Space Charge Polarization ◽  
Stabilized Zirconia ◽  
Depolarization Current ◽  
Dc Voltage ◽  
Thermally Stimulated Depolarization Current ◽  
Constant Heating ◽  
Two Peaks ◽  
Thermally Stimulated Depolarization ◽  
Dipole Polarization

3 mol% yttria-stabilized zirconia (YSZ) powders were sintered into pellets. The YSZ ceramics were electrically polarized by applying dc voltage at an elevated temperature. After cooling the samples to room temperature, the polarized YSZ ceramics were heated at a constant heating rate. The formed polarizations were relaxed with increase of the increase temperature. The depolarization current was measured as thermally stimulated depolarization current (TSDC). Each of the TSDC spectra had two peaks located at lower and higher temperatures. The lower and higher peaks are attributed to dipole polarization and space charge polarization, respectively.

Dielectric Charging in Low Temperature Silicon Nitride for RF-MEMS Capacitive Switches

2008 ◽  
Vol 1075 ◽  
Author(s):  
Richard Daigler ◽  
George Papaioannou ◽  
Eleni Papandreou ◽  
John Papapolymerou
Keyword(s):  
Silicon Nitride ◽  
Low Temperature ◽  
Film Thickness ◽  
Rf Mems ◽  
Dielectric Film ◽  
Systematic Investigation ◽  
Space Charge Polarization ◽  
Capacitive Switches ◽  
Dielectric Charging ◽  
Polarization Mechanism

ABSTRACTThe paper presents a systematic investigation of dielectric charging in low temperature silicon nitride for RF-MEMS capacitive switches. The investigation takes includes both the effect of dielectric film thickness as well as the effect of metal contacts. The investigation demonstrates that the charging process is asymmetric. It is shown that the amount of stored charge depends significantly on the dielectric film thickness, which is caused from the contribution of the space charge polarization mechanism. Finally, the results are compared with those of higher temperature silicon nitride.

The Influence of Microstructure on the Surface Charge of Sintered Hydroxyapatite Ceramics

2019 ◽  
Vol 800 ◽  
pp. 25-29
Author(s):  
Darta Ubele ◽  
Liene Pluduma ◽  
Karlis Agris Gross
Keyword(s):  
Electric Field ◽  
Charge Density ◽  
Bone Ingrowth ◽  
Surface Charges ◽  
Depolarization Current ◽  
Density Measurements ◽  
Electrical Polarization ◽  
Hydroxyapatite Ceramics ◽  
A Charge ◽  
Thermally Stimulated Depolarization

Hydroxyapatite (HAp) has shown the ability to store a charge induced by electrical polarization a method potential for improved bone ingrowth. In this work electrical polarization was carried out on HAp ceramics with three different microstructures, obtained at three different sintering temperatures. Microstructure of the sintered HAp was evaluated from density measurements and SEM observations. Sintered HAp tablets were electrically polarized in an electric field of 5 kV/cm at 400 °C for 1h. Surface charges investigated by thermally stimulated depolarization current measurements showed 104,8 μC/cm2 for denser tablets, while charge density of 22,8 μC/cm2 was obtained for less dense tablets.

scholarly journals Research on Creeping Flashover Characteristics of Nanofluid-Impregnated Pressboard Modified Based on Fe3O4 Nanoparticles under Lightning Impulse Voltages

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 524 ◽  
Author(s):  
Bingliang Shan ◽  
Meng Huang ◽  
Yupeng Ying ◽  
Mingkang Niu ◽  
Qian Sun ◽  
...  
Keyword(s):  
Electric Field ◽  
Fe3o4 Nanoparticles ◽  
Breakdown Strength ◽  
Transformer Oil ◽  
Uniform Electric Field ◽  
Surface Charges ◽  
Depolarization Current ◽  
Before And After ◽  
Lightning Impulse ◽  
Thermally Stimulated Depolarization

Creeping flashover of mineral-oil-impregnated pressboard under impulse stress is a common insulating failure in oil-immersed transformers, arousing increasing attention. Recent studies have shown that the breakdown strength of transformer oil under positive lightning impulse voltage can be significantly improved through nanoparticles-based modification, and Fe3O4 has shown the best improvement in breakdown strength compared to other nanoparticles that have been used. This paper presents the creeping flashover characteristics of pure oil-impregnated pressboard (OIP) and nanofluid-impregnated pressboard (NIP) based on Fe3O4 nanoparticles under positive and negative lightning impulse voltages, respectively. It was found that NIP possessed higher resistance to creeping flashover than OIP. The relative permittivities of oil and oil-impregnated pressboard before and after nanoparticles-based modification were measured, and the results revealed that the addition of nanoparticles led to a better match in relative permittivity between oil and oil-impregnated pressboard, and a more uniform electric field distribution. Furthermore, the shallow trap density in NIP was obviously increased compared to that of OIP through the thermally stimulated depolarization current (TSDC), which promoted the dissipation of surface charges and weakened the distortion of the electric field. Therefore, the creeping flashover characteristics of oil-impregnated pressboard were greatly improved with Fe3O4 nanoparticles.

Surface Properties of UHMWPE Fiber after Low Temperature Argon-Plasma Treatment

2012 ◽  
Vol 499 ◽  
pp. 90-94 ◽  
Author(s):  
Jin Yun Xu ◽  
Wen Yu Wang ◽  
Xin Jin
Keyword(s):  
Molecular Weight ◽  
Low Temperature ◽  
Plasma Treatment ◽  
Treatment Time ◽  
Argon Plasma ◽  
Uhmwpe Fiber ◽  
Wetting Ability ◽  
Plasma Treatment Time ◽  
Uhmwpe Fibers ◽  
Ultra High Molecular Weight

To improve the adhesion between ultra-high-molecular-weight polyethylene (UHMWPE) fibers and matrix, the UHMWPE fibers were treated by low temperature argon-plasma. The effects of argon-plasma treatment on the properties of UHMWPE have been investigated. The roughness and wetting ability were all found to increase significantly after modifications. The tensile strength of UHMWE fibers were decreased with the plasma treatment time. The optimum plasma treatment is 2min.The increasing of roughness and wetting ability of UHMWPE fiber are beneficial to the improvement the adhesion between UHMWPE fiber and matrix.

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