Microbiologically Influenced Corrosion Capability of Bacteria Isolated from Yucca Mountain
Bibliographic record
Abstract
Microorganisms, implicated in microbiologically influenced corrosion, were isolated from the deep subsurface at Yucca Mountain. Corrosion rates of iron-oxidizing, sulfate-reducing, and exopolysaccharide (EPS)-producing bacteria were examined in constructed electrochemical corrosion cells for periods up to 109 days. The test system consisted of a 1020 carbon steel (CS) coupon immersed in soft R2A agar prepared with simulated groundwater. A 1% potassium chloride (KCl) bridge was used to connect the test to a reference calomel electrode and a potential was applied with a platinum counter electrode. The corrosion process was measured by polarization resistance methodology. Average corrosion rates were measured in milli-inches per year (mpy) against time. Purified cultures of EPS-producing bacteria and enrichment cultures of iron-oxidizing and sulfate-reducing bacteria were tested separately and in various combinations. An uninoculated control cell was prepared to assess abiotic corrosion. The corrosion rates peaked at 35 days at 1.2 mpy (control), 2.3 mpy (iron-oxidizing bacteria), 3.30 mpy (sulfate-reducing bacteria), and 2.8 mpy (EPS-producing bacteria) before stabilizing. Various microbial combinations demonstrated higher corrosion rates (3.1 mpy to 4.8 mpy) than single groups and peaked at 30 days. The results indicate that Yucca Mountain microorganisms, alone and in combination, are capable of causing corrosion of 1020 CS. Upon completion of these experiments, phospholipid fatty acid analysis detected all of the bacterial groups inoculated into the individual test systems, suggesting that biofilm development had occurred. The examination of mineralized biofilms on the CS surface with light microscopy and scanning electron microscopy/energy-dispersive x-ray analysis (SEM/EDXA) demonstrated that all of the bacterial groups promoted a generalized corrosion process; however, the corrosion experiments containing SRB were particularly effective in biofilm development and pitting.
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 | 0.000 |
| 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 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".