Online Optical Monitoring of Asphaltene Aggregation
Bibliographic record
Abstract
An optical method is employed to investigate asphaltene aggregation kinetics in real time using a photometric dispersion analyzer (PDA). The size of the aggregates is obtained by coupling photographic technique and image analysis with the online output of the PDA. The aggregation and breakup of the flocs are studied in a stirred tank for various volume fractions of particle (φ), stirring speed, and solvent composition (i.e., ratio of toluene-to-heptane in the solution, T:H). Initially, the average aggregate size increases and eventually reaches a steady-state value that reflects a balance between aggregation and fragmentation. Increasing the stirring speed reduces the steady-state size. At a certain stirring speed, when either φ is increased or T:H is decreased, the steady-state floc size increases. The presence of maltenes in the bitumen greatly retards the aggregation kinetics of asphaltenes. A cyclic- and tapered-shear schedule decreases the average floc size. The steady-state size attained at a certain stirring speed depends on the shear history of the flocs.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".