Triboelectric Charging Between Polytetrafluoroethylene and Metals
Bibliographic record
Abstract
Measurements were obtained on charge exchange processes occurring between small metal ballistic pellets and a polytetrafluoroethylene (PTFE) tube. Lead pellets of 5.5-mm diameter were propelled at a range of speeds through PTFE tubes of different lengths by compressed carbon dioxide. The charge incurred by the pellets and the tube was compared with the charge observed on copper and lead spheres rolled through the tube, driven by gravity. In all experiments, the charge on the moving pellet was measured with a Faraday cup. The experiments determined the effect of pellet speed on the magnitude of the charge accumulated on the pellet and on the PTFE tube. Sectioned shielding on the PTFE tube allowed the determination of surface charge distribution along its length by means of an electrometer. It was observed that the charge also depended on the work functions of the materials involved (lead, copper, PTFE). The charge on the pellets was found to range from +0.5/spl times/10/sup -8/ to +3.0/spl times/10/sup -8/ C, for pellet speeds from 10 to 80 m/spl middot/s/sup -1/. The reproducibility of results is discussed and comment provided on the degree of charge imbalance observed.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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) | 0.000 | 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 teacher head, 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".