scholarly journals Breakdown Mechanism of Different Sulphur Hexafluoride Gas Mixtures

2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
E. Onal
Keyword(s):  
High Pressure ◽  
Thermal Properties ◽  
Electric Fields ◽  
Alternating Current ◽  
Gas Mixtures ◽  
Sulphur Hexafluoride ◽  
Circuit Breakers ◽  
Breakdown Mechanism ◽  
Liquefaction Temperature ◽  
Dielectric And Thermal Properties

Sulphur hexafluoride (SF6) gas and SF6 gas mixtures are widely used in gas-insulated systems (GIS) because they have good dielectric and thermal properties. Among the various gas mixtures investigated so far, SF6-air, SF6-CO2, and SF6-N2 are most used gas mixtures. Also, these mixtures have much technical superiority in GIS. These are nontoxic and nonflammable gases, and they have less sensitivity to nonuniformities and higher liquefaction temperature at high pressure. GIS, switchgears, circuit breakers, and substations are systems that work with alternating current and have nonuniform electric fields. For this reason, in this study the breakdown mechanisms of 0.125, 0.5, 1, and 20% SF6 gas mixtures with rod-plane configuration under AC voltage are investigated and explained breakdown mechanism.

Electrcn Trapping/Detrapping in Thin SiO2 Under High Fields

1985 ◽  
Vol 47 ◽  
Author(s):  
N. R. Wu ◽  
S. Chiao ◽  
C. Wang ◽  
B. Bhushan ◽  
C. Y. Yang
Keyword(s):  
Silicon Dioxide ◽  
Electric Fields ◽  
Local Field ◽  
Alternating Current ◽  
Electron Trapping ◽  
Oxide Breakdown ◽  
Breakdown Mechanism ◽  
Current Stressing ◽  
High Fields ◽  
High Electric Fields

ABSTRACTA constant alternating current stressing technique is employed to study the electron trapping and detrapping cha~acteristics within a layer of thin silicon dioxide (˜.100 Å). A two-charge centroid model is proposed to explain the trapping/detrapping phenomena under high electric fields. The oxide breakdown mechanism induced by the local field of trapped electrons is also discussed.

Mutagenic Potential of Alternating Current Electric Fields.

1997 ◽  
Author(s):  
John Obringer ◽  
Brandon Horne ◽  
Brian Kelchner
Keyword(s):  
Electric Fields ◽  
Alternating Current ◽  
Mutagenic Potential

scholarly journals Impact of Innovative Technologies on the Content of Vitamin C and Its Bioavailability from Processed Fruit and Vegetable Products

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Monika Mieszczakowska-Frąc ◽  
Karolina Celejewska ◽  
Witold Płocharski
Keyword(s):  
High Pressure ◽  
Vitamin C ◽  
Electric Fields ◽  
New Technologies ◽  
High Pressure Processing ◽  
Food Preservation ◽  
Fruit And Vegetable ◽  
Negative Effects ◽  
Minimal Processing ◽  
Processing Technologies

Nowadays, thermal treatments are used for extending the shelf-life of vegetable and fruit products by inactivating microorganisms and enzymes. On the other hand, heat treatments often induce undesirable changes in the quality of the final product, e.g., losses of nutrients, color alterations, changes in flavor, and smell. Therefore, the food industry is opening up to new technologies that are less aggressive than thermal treatment to avoid the negative effects of thermal pasteurization. Non-thermal processing technologies have been developed during the last decades as an alternative to thermal food preservation. Processing changes the structure of fruit and vegetables, and hence the bioavailability of the nutrients contained in them. In this review, special attention has been devoted to the effects of modern technologies of fruit and vegetable processing, such as minimal processing (MPFV), high-pressure processing (HPP), high-pressure homogenization (HPH), ultrasounds (US), pulsed electric fields (PEF), on the stability and bioavailability of vitamin C.

scholarly journals Clarifications on the Behavior of Alternative Gases to SF6 in Divergent Electric Field Distributions under AC Voltage

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1065
Author(s):  
Houssem Eddine Nechmi ◽  
Michail Michelarakis ◽  
Abderrahmane (Manu) Haddad ◽  
Gordon Wilson
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Partial Discharge ◽  
Mean Value ◽  
Electrode System ◽  
Polarity Reversal ◽  
Buffer Gas ◽  
Co2 Gas ◽  
Breakdown Mechanism ◽  
Positive Cycle

Negative and positive partial discharge inception voltages and breakdown measurements are reported in a needle-plane electrode system as a function of pressure under AC voltage for natural gases (N2, CO2, and O2/CO2), pure NovecTM gases (C4F7N and C5F10O) and NovecTM in different natural gas admixtures. For compressed 4% C4F7N–96% CO2 and 6% C5F10O–12% O2–82% CO2 gas mixtures, the positive-streamer mode is identified as the breakdown mechanism. Breakdown and negative partial discharge inception voltages of 6% C5F10O–12% O2–82% CO2 are higher than those of 4% C4F7N–96% CO2. At 8.8 bar abs, the breakdown voltage of 6% C5F10O–12% O2–82% CO2 is equal to that of 12.77% O2–87.23% CO2 (buffer gas). Synergism in negative partial discharge inception voltage/electric field fits with the mean value and the sum of each partial pressure individually component for a 20% C4F7N–80% CO2 and 6% C5F10O–12% O2–82% CO2, respectively. In 9% C4F7N–91% CO2, the comparison of partial discharge inception electric fields is Emax (CO2) = Emax(C4F7N), and Emax (12.77% O2–87.23% CO2) = Emax(C5F10O) in 19% C5F10O–81%(12.77% O2–87.23% CO2). Polarity reversal occurs under AC voltage when the breakdown polarity changes from negative to positive cycle. Polarity reversal electric field EPR was quantified. Fitting results show that EPR (CO2) = EPR(9% C4F7N–91% CO2) and EPR(SF6) = EPR (22% C4F7N–78% CO2). EPR (4% C4F7N–96% CO2) = EPR (12.77% O2–87.23% CO2) and EPR (6% C5F10O–12% O2–82% CO2) < EPR (4% C4F7N–96% CO2) < EPR (CO2).

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