Molecular and Isotopic Study of Bitumens from the Alberta Oil Sands
Bibliographic record
Abstract
Summary Molecular and isotopic analyses of oil samples from Athabasca, Peace River and Cold Lake oil sands reservoirs in Alberta, Canada, were conducted to evaluate the effect of biodegradation processes on the molecular and isotopic compositions of these oils. The results indicate that all studied samples are affected by biodegradation to different degrees. Based on the molecular composition, the levels of biodegradation range from at least PM5 to PM8 in Athabasca, PM5 to PM6 in Peace River and PM4 or lower at Cold Lake. Increasing levels of oil biodegradation from top to bottom of the oil columns was observed everywhere. Biodegradation does not cause observable systematic carbon, nitrogen or sulfur isotope changes vertically in whole bitumen columns; however, some 32 S-enriched oils found locally may reflect secondary sulphur incorporation related to local microbial activity. Major differences in the sulfur and nitrogen isotopic composition of oils across the province are suggested to be source rock related.
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 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".