Oxidation/alteration of pentlandite and pyrrhotite surfaces at pH 9.3: Part 1. Assignment of XPS spectra and chemical trends
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Using X-ray photoelectron spectroscopy, the oxidation/alteration of massive coexisting pentlandite [(Fe,Ni)9S] and pyrrhotite (Fe1-xS) from Voiseys Bay has been studied in aqueous solution at pH 9.3. The Fe 2p, Ni 2p, S 2p, and O1s spectra were obtained for each mineral from polished surfaces, and from surfaces reacted with the solutions for up to 180 minutes. Both minerals oxidize rapidly to give mostly a relatively thin layer (tens of angstroms) of Fe(III) oxyhydroxide (probably FeOOH). In addition, violarite (FeNi2S4), Ni(OH)2, and NiSO4 are found in the pentlandite oxidized overlayer, and Fe(III)-S and polysulfide species are found in the overlayers of both minerals. A protocol was developed to fit quantitatively all spectra in a consistent fashion. Fe 2p3/2 spectra were fitted with two Fe(II)-S peaks depending upon Fe coordination (four and six) in pentlandite, pyrrhotite, and violarite. An Fe(III)-S multiplet, an Fe(III) oxyhydroxide multiplet, as well as Ni Auger peaks, were also required to fit the Fe 2p spectra. The Ni 2p3/2 spectra for pentlandite were fit with two Ni(II)-S peaks from the original pentlandite or violarite (four and six coordination), as well as Ni(OH)2 and NiSO4 peaks. The S 2p spectra for both minerals were fit with four and five coordinate S peaks from the original minerals and violarite, as well as polysulfides and sulfate. Finally, the O 1s spectra of both minerals were fit with peaks from oxide, hydroxide, and adsorbed water.
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.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 it