Chemical characterization of microtexture transformation during plastic layer formation via synchrotron macro ATR-FTIR microspectroscopy
Bibliographic record
Abstract
This study investigates the mechanisms of microtexture development during coking and the influence of chemical structure transitions during plastic layer formation, using anisotropy quotient (AQ) colour-coded bireflectance mapping and synchrotron macro attenuated total reflectance Fourier transform infrared (macro ATR-FTIR) microspectroscopy. Plastic layer samples, including the plastic layer, resolidified layer, and semi coke regions, were produced from three Australian coking coals of varying rank via interrupted coking tests in a lab scale double wall heated coke oven designed to simulate practical coking conditions. AQ mapping revealed changes in microtexture components such as isotropic inert, incipient vitrinite, and lenticular and ribbon structures across the plastic layer samples. These microtextural transitions were correlated with spatial distributions of aromaticity, degree of aromatic ring condensation (DOC), and CH 2 /CH 3 , derived from macro ATR-FTIR mapping. During the transformation from the plastic layer to early semi coke, anisotropic content, particularly longer carbon structures such as ribbon and lenticular forms, increased more significantly in higher rank coals. For higher rank coals, incipient and circular structures formed during early resolidification exhibited low DOC and aromaticity but high CH 2 /CH 3 , suggesting extensive CH 2 crosslinking that may have facilitated subsequent carbon structure growth. With further coking toward the early semi coke stage, these structures evolved into more anisotropic microtextures, particularly ribbons and lenticular forms, accompanied by synchronised increases in aromaticity and DOC. In contrast, the lowest rank coal exhibited low CH 2 /CH 3 and DOC within circular and lenticular structures at the early resolidification stage, indicative of a higher content of residual methyl groups. These aliphatic residues likely acted as barriers to aromatic stacking and condensation, thereby constraining the development of ribbon and lenticular structures.
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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 | 0.000 |
| 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) | 0.001 | 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".