Multiscale approach for determining hydrogen diffusivity in zirconium
Bibliographic record
Abstract
Abstract The current research presents an approach which is used to determine the diffusivity of hydrogen in the hexagonal close packed (hcp) zirconium crystal, using a combination of first principles calculations and kinetic Monte Carlo (KMC) simulations. Rate constants found through the energy landscapes of hydrogen motion between different interstitial sites in the zirconium lattice were used in KMC to determine the values of bulk diffusivity. We simulated a stress-free environment to eliminate the effect of stress. It is hypothesized that stress could act as a driving forces for diffusion. We found that hydrogen diffusivity in hcp Zr is closely isotropic, with a slightly higher diffusivity in the axis direction. The individual diffusion jumps were closely investigated to identify the reasons for the isotropic nature of the diffusivity in the anisotropic hcp Zr lattice. We also use this study to validate the modeling approach followed to extend it to other diffusion studies of similar nature, which comprises of clearly understood diffusion steps.
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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 | 0.001 |
| 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 | 0.000 | 0.000 |
| 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".