PEX and PP Water Pipes: Assimilable Carbon, Chemicals, and Odors
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Eleven brands of plastic drinking water pipe were evaluated for assimilable organic carbon (AOC) release at 23°C for 28 days: polyvinyl chloride, high‐density polyethylene, polypropylene (PP), and cross‐linked polyethylene (PEX) pipes. Three of eight PEX pipe brands exceeded a 100 µg/L AOC microbial regrowth threshold for the first exposure period, and no brands exceeded this value on day 28. No AOC increase was found for PP or PEX‐a1 pipes; the remaining pipe brands contributed marginal AOC levels. Pipe water quality impacts were more fully evaluated for two PEX‐b brands and one PP brand. PEX pipes caused greater odor than the PP pipe and released more organic carbon as well as volatile and semi‐volatile organic compounds. Water quality impacts were less after 30 days. Regulated and unregulated contaminants were found in three PEX plumbing systems. Drinking water odors were attributed to toluene, ethyl‐ tert ‐butyl ether, and unidentified contaminants.
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.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 it