Bibliographic record
Abstract
Polar compounds as found in oils are hydrocarbon compounds containing nitrogen, sulphur or oxygen. Measurement of the presence of these compounds in oils can be carried out using sophisticated analysis techniques, however quantification and separation of compounds is very difficult and will remain a problem for many years to come. Characterization of polar compounds in oils is at a state of infancy and little polar analysis for many oils has been carried out to date. In order to measure the toxicity of a specific compound or class of compounds, separation is needed. Separation is very difficult and in many cases, beyond the scope of today's technology. An alternative has been to synthesize the compound of concern and then test its toxicity. This approach ignores the matrix in which the compound is usually present and the compound of interest may be not bioavailable when present in the actual oil, due to its solubility in oil. Highly polar compounds are likely not present in produced oils due to the polar compound's high water solubility. Compounds with moderate or less polarity are typically more soluble in oil than water. Similarly, highly polar compounds produced by biodegradation or photo oxidation would be diluted in water during a spill. The aquatic toxicity of polar compounds compared to aromatic compounds has been tested by using evaporative weathering. Aromatic compounds, particularly that of the 2 to 5 ring polyaromatic hydrocarbons (PAHs), are fairly well-established as the primary toxic component of oils. Polar compounds are soluble in water and thus may pose another source of toxicity. Evaporative weathering tests where photo oxidation is not involved, in which some of the low molecular weight compounds and PAHs are lost from the oil, are thought to be one test of the comparison of polar compound toxicity compared to that of the PAHs. These tests show that polar compounds are generally less-aquatically-toxic than the 2 to 5-ring PAHs. Another test that has been performed is that of physical separation of oil components. In these type of tests, polar compounds have again been shown to have less aquatic toxicity that the PAHs in the same oil. Both tests have obvious limitations in that there are many compounds involved.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".