Experimental determination of concentration‐dependent carbon dioxide diffusivity in LDPE
Bibliographic record
Abstract
Abstract In this work, we experimentally determine the concentration‐dependent diffusivity of carbon dioxide in low‐density poly(ethylene) (LDPE). For this purpose, experiments are carried out to obtain pressure‐decay data for isothermal diffusion of the gas in the polymer. Based on a detailed mass transfer model, variational calculus is used to establish the conditions necessary to yield the concentration‐dependent diffusivity that enables the model‐predicted mass of absorbed gas in polymer to match with the experimental counterpart. A computational algorithm is implemented to solve the model and the conditions and obtain the diffusivities. Determined at 120 and 130°C for four different pressures in the range 0.352 to 1.232 MPa, the diffusivities are strong unimodal functions of gas concentration in polymer and of the order 10 −9 m 2 s −1 . Mathematical correlations are developed to calculate the diffusivity at a given temperature, pressure, and gas concentration. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
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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 | 0.001 | 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 | 0.001 |
| 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".