Electrical Properties of Polyethylene Terephthalate under Hydrothermal Aging
Bibliographic record
Abstract
During the working of rotating machines, dielectric materials are submitted to the action of humidity.At long term, their properties can degrade and the lifetime of devices will be reduced.This paper deals with the influence of hydrothermal aging on the electrical properties of polyethylene terephthalate.The insulation was aged in water at 80℃ and 100℃.The study shows that dielectric loss factor, permittivity, volume resistivity and dielectric strength were affected by aging.The change is attributed to the fact that the aging reduces molecular bonds causing a decrease in the viscosity.Thereby, the free volume and the mean free path raise.This process leads to the raise in the mobility of charge carriers.The evolution of activation energy versus aging time exhibits minimums and maximums resulting to the plasticization and the crosslinking of the material, respectively.The TGA thermograms indicate a variation of onset temperature with aging time.It was highlighted by TGA that the decomposition occurs following one step.The FTIR analysis points out a change in the intensities of the vibrational spectra after aging.The penetration of water within the dielectric induces differential inflations.The physical chemical analysis shows a modification in the molecular conformation of the polymer.The results are analysed and discussed.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".