A rapid, high sensitivity technique for measuring arsenic in skin phantoms using a portable x-ray tube and detector
Bibliographic record
Abstract
Using a portable x-ray tube and silicon PiN diode detector, an improved approach to the measurement of arsenic in skin phantoms was demonstrated. Skin phantoms of 8 mm thickness were made from polyester resin, with arsenic concentrations ranging from 0 to 30 microg g(-1). The excitation of characteristic arsenic x-rays was performed with the x-ray tube and K(alpha) x-rays were used as an indicator of arsenic concentration. From repeated phantom measurements, an instrumental minimum detection limit of 0.446 +/- 0.006 microg g(-1) was found, using an acquisition time of 120 s (real time). This compares with previously reported approaches having instrumental minimum detection limits of 3.5 +/- 0.2 microg g(-1) (1800 s real time), 2.3 +/- 0.1 microg g(-1) (1000 s live time) and 0.40 +/- 0.06 microg g(-1) (1000 s live time).
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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".