Artificial circulation of a mine pit lake
Bibliographic record
Abstract
We describe the artificial circulation (destratification) of a pit lake at the Colomac mine site, 220 km north of Yellowknife, NWT, Canada. The pit lake, with a surface area of 17 ha and depth of 110 m, contained relatively saline water contaminated with the mining-related cyanide by-products, thiocyanate and ammonia. As a result of snow and ice melt, the pit lake was intermittently meromictic and cycling of contaminants through the oxygenated surface layer would have taken many years. To accelerate the oxidation process, the pit was artificially circulated using two air diffusers at a depth of 57 m. The pit lake was circulated during the open-water season, from 12 July 2006 for 57 days, and from 17 June 2007 for 89 days. After the first 12 h of operation of the circulation system, the top 37 m of the pit lake was mixed completely; after 34 h, the pit lake was mixed to the depth of the diffusers (57 m); and after approximately 6.5 days, the pit lake was mixed to the bottom. Upon complete mixing, the temperature and conductivity remained uniform during operation of the circulation system, and the concentration of oxygen in the deep water of the pit lake increased significantly. All thiocyanate was oxidized by the end of the first summer, producing ammonia that was depleted after the second summer of circulation.
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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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 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".