Experimental and Theoretical Modeling of Expansion in Pyritic Shale
Bibliographic record
Abstract
Abstract Expansive pyritic shales are found in black carbonaceous shales throughout the United States as well as in other countries, including Ireland, England, Norway, Canada, and Sweden. Expansion occurs when the pyrite, which occurs either as finely disseminated syngenetic framboids, macroscopic crystals, or diagenetic replacement fossils, oxidizes to form sulfuric acid. Various hydrous sulfates could precipitate in the complex geochemical environment; however, gypsum typically precipitates as the sulfuric acid reacts with the calcareous (calcium carbonate) component of the shale. This paper explores kinetic and passive attempts at measuring the expansion of the shale and introduces a hybrid experimental testing procedure that uses hydrogen peroxide to initiate the expansion process. The normalized expansion (h/H) for the non-intact shale and intact shale core were 0.0008 and 0.0033, respectively, after 84 days. Expansion rates of 3.5 mm/year/m and 1.43 mm/year/m were calculated for the non-intact shale and intact shale core samples, respectively. A theoretical expansion model is developed that uses stoichiometric calculations to determine gypsum volume and discontinuity infilling theory to determine maximum total expansion. Input variables include shale type (intact bedrock, poorly-graded fragments, well-graded fragments), % pyritic shale (%S2), height of the expansion zone, and surcharge pressure. The theoretical model is used to predict maximum height of expansion and time to maximum expansion for the experiments studied and developed.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.000 | 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".