Hexabenzocoronene Model Compounds for Asphaltene Fractions: Synthesis & Characterization
Bibliographic record
Abstract
Asphaltenes are the fraction of bitumen with the highest molecular weight, containing polyaromatic hydrocarbons rich in heteroatoms and polar groups that result in strong self-association under extraction and upgrading conditions. The synthesis of alkylated hexabenzocoronenes is here reported to provide new insight into the behavior of bitumen residue fractions. The self-association behavior of these polyaromatic model compounds is investigated over a range of temperatures using vapor pressure osmometry (VPO), nuclear magnetic resonance (NMR), optical and electron microscopy, X-ray and small-angle neutron scattering, and calorimetry (DSC/TGA). In addition to these experimental studies, computational studies are used to determine the contribution of alkyl−alkyl and π − π stacking interactions to this association behavior. Experimental and computational results are compared to asphaltene properties under extraction and upgrading conditions, as well as to the archipelago and pericondensed models proposed for asphaltenes.
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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".