Using the flowing afterglow of a plasma to inactivate <i>Bacillus subtilis</i> spores: Influence of the operating conditions
Bibliographic record
Abstract
The flowing afterglow of a microwave discharge can be used to efficiently inactivate bacterial spores. We have conducted a parametric study of the operating conditions of such a system, which shows that the species participating in the killing of spores are oxygen atoms and ultraviolet (UV) photons. The oxygen atoms and the excited atoms and molecules emitting the photons being carried by the flowing afterglow can be made available throughout the sterilization chamber. Typical operating conditions are: gas mixture 2%O2/98%N2, pressure range 1–7 Torr and gas flow 0.5–3 slm. Total inactivation of 106 B. subtilis spores is achieved within 40 min with 100 W absorbed microwave power, at afterglow gas temperatures not exceeding 50 °C, a feature of interest for heat sensitive medical devices. The present scheme depends on the gas flow reaching all parts of the objects to be sterilized and on the short-lived active species being transported there sufficiently rapid. Under our operating conditions, it is the UV emission intensity that sets the sterilization time as there are always more than sufficient oxygen atoms available for the process.
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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 | 0.000 |
| 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) | 0.001 | 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".