The mechanisms of forensic vacuum metal deposition (fVMD): A literature review
Bibliographic record
Abstract
Since the early 1970s, forensic vacuum metal deposition (fVMD) has been used in operational casework. It is renowned for its sensitivity and ability to work on aged impressions and difficult substrates. However, the precise mechanism by which this development occurs remains unclear. This article examines the current literature on fVMD to see what is known about the technique, what is unclear, and what are the next steps that should be taken. This review shows that, while the operational utility of the technique is not in question, none of the currently posited theories can explain all the observed phenomena. They are therefore, at best, incomplete, and further research is required. • Literature review of the mechanism of forensic vacuum metal deposition (fVMD). • Summary of current fVMD literature, both theory and operation. • Presents the current mechanisms per the literature: Absorption theory, condensation theory, and morphology theory. • Current literature theories can’t explain several observed scenarios. • Current literature theories are therefore likely incorrect, or incomplete.
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 | 0.003 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.006 | 0.004 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.003 | 0.005 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.006 | 0.002 |
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".