Clay mineral characterization through the methylene blue test: comparison with other experimental techniques and applications of the method
Bibliographic record
Abstract
This article illustrates an experimental study of clay mineral characterization conducted with the aid of the methylene blue "stain" test, which yields a semiquantitative evaluation of the activity of a geomaterial based on the type and quantity of clay minerals contained in it. The properties of clay minerals are described briefly, with special regard to their swelling behaviour in the presence of water. The testing method is described with reference to the procedures and interpretation criteria specified in the Association française de Normalization (AFNOR) and American Society for Testing and Materials (ASTM) standards. The results are then presented of a testing campaign conducted to assess the applicability of the methylene blue test for the characterization of geomaterials through a comparison with other testing methods. Additional tests were performed on stratigraphic sequences to identify the levels containing higher proportions of active clay minerals, based on their tendency to swell on coming into contact with water. This characterization technique was applied to marlyarenaceous formations of the Langhe region (Piedmont, Italy), where planar sliding instability phenomena have often been observed following abundant rainfall, and marlyarenaceous formations of Monferrato (another region in southeast Piedmont, Italy), where studies of a geologicalstructural nature have often revealed traces of postsedimentary tectonic phenomena.Key words: methylene blue stain test, marl, clay mineral, swelling phenomenon, planar sliding instability.
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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 | 0.003 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".