How the δ<sup>18</sup>O<sub>NO<sub>3</sub></sub> versus δ<sup>15</sup>N<sub>NO<sub>3</sub></sub> Plot Can Be Used to Identify a Typical Expected Isotopic Range of Denitrification for NO<sub>3</sub>-Impacted Groundwaters
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
High Resolution Image Download MS PowerPoint Slide Stable isotope values of δ 15 N NO 3 and δ 18 O NO 3 of dissolved nitrate (NO 3 ) are commonly used to identify the occurrence of denitrification as there is a progressive increase of δ 15 N NO 3 and δ 18 O NO 3 values accompanied by a decrease in NO 3 concentration. Thus, denitrification results in a positive trendline on the dual plot of δ 18 O NO 3 versus δ 15 N NO 3 . The combination of two trendlines with different slopes provides the “typical expected isotopic range of denitrification (TEIRD)” on the δ 18 O NO 3 versus δ 15 N NO 3 plot. Many studies distinguished denitrified groundwaters by applying the TEIRD concept that is incorrectly introduced because it assumes a single NO 3 source even though multiple NO 3 sources exist. Also, most TEIRD applications rely on specific denitrification slopes although these are known to vary owing to the aquifer’s changing biogeochemical conditions. Alternatively, an accurate delineation of the TEIRD requires the identification of all potential NO 3 sources in aquifer with their measured or reconstructed δ 15 N NO 3 and δ 18 O NO 3 values. This allows then for an accurate TEIRD to be traced with two denitrification trendlines having a slope corresponding to that from the correlation of the measured δ 18 O NO 3 and δ 15 N NO 3 values. Ultimately, each NO 3 source can have a specific TEIRD, although denitrification trendlines for multiple NO 3 sources can feature the same slope within a single aquifer.
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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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.003 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.003 |
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