Kinetics of Surface-Bound Benzo[<i>a</i>]pyrene and Ozone on Solid Organic and Salt Aerosols
Bibliographic record
Abstract
An aerosol flow tube apparatus was developed to perform the first kinetic study of the oxidation of particulate-bound BaP on solid organic and salt aerosols by gas-phase ozone. The studies on azelaic acid aerosols were performed with submonolayer coatings of BaP under both dry (RH < 1%) and high relative humidity (RH ∼ 72%) conditions. The reaction exhibited pseudo-first-order kinetics for BaP loss and the pseudo-first-order rate coefficients displayed a Langmuir−Hinshelwood dependence on gas-phase ozone concentration. Under high relative humidity conditions the kinetics were faster but also displayed a similar functional dependence on the gas-phase ozone concentration. By assuming Langmuir−Hinshelwood behavior, the following parameters were obtained: ozone-surface equilibrium constant K O3 (< 1% RH) = (1.2 ± 0.4) × 10 -15 cm -3, K O3 (72% RH) = (2.8 ± 1.4) × 10 -15 cm -3, the maximum pseudo-first-order rate coefficient (< 1% RH) = (0.048 ± 0.008) s -1, (72% RH) = (0.060 ± 0.018) s -1 . Uptake coefficients were extracted from the pseudo-first-order rate coefficients and a slight trend of decreasing uptake coefficients with increasing ozone concentration was observed. In contrast to the behavior on azelaic acid aerosols, no reaction was observed between ozone and BaP adsorbed to solid NaCl particles. These results are compared to previous studies, which have been performed on different substrates, and their atmospheric implications are discussed. We conclude that a strong substrate effect prevails in this reaction with the kinetics proceeding faster on surfaces best able to adsorb ozone.
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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".