Comparison of seasonality of urban grime in three southern Ontario cities
Bibliographic record
Abstract
Urban grime refers to films made of a complex chemical mixture of organics and inorganics deposited on outdoor surfaces. The specific chemical composition of such films can vary considerably due to geographic and seasonal influences. We compared the seasonal change of grime’s water-soluble inorganic ion content in a rural (Thamesford), suburban (Oshawa), and urban city (Toronto) in southern Ontario, Canada. Sodium, calcium, chloride, nitrate, and sulfate amounts in grime were collected and quantified over four seasons in Oshawa, ON and Thamesford, ON and compared with results from a previous study in Toronto to elucidate differences. We found that all three regions displayed a clear seasonality in sodium and chloride consistent with winter road salt inputs and chloride loss in summer. Mole fractions of sulfate were consistently the lowest of the measured ions, and NO3 −/SO4 2− ratios showed a winter–spring minimum and summer–fall maximum. Urban–rural differences in the seasonal changes of ionic mole ratios suggest that additional chloride displacement by nitrate occurs within grime in Toronto that is not present in the two other rural/suburban cities in the same region.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".