Raman spectral behavior of N<sub>2</sub>, CO<sub>2</sub>, and CH<sub>4</sub> in N<sub>2</sub>–CO<sub>2</sub>–CH<sub>4</sub> gas mixtures from 22°C to 200°C and 10 to 500 bars, with application to other gas mixtures
Bibliographic record
Abstract
Abstract The Raman spectral behavior of N 2 , CO 2 , and CH 4 in ternary N 2 –CO 2 –CH 4 mixtures was studied from 22°C to 200°C and 10 to 500 bars. The peak position of N 2 in all mixtures is located at lower wavenumbers compared with pure N 2 at the same pressure ( P )–temperature ( T ) ( PT ) conditions. The Fermi diad splitting in CO 2 is greater in the pure system than in the mixtures, and the Fermi diad splitting increases in the mixtures as CO 2 concentration increases at constant P and T . The peak position of CH 4 in the mixtures is shifted to higher wavenumbers compared with pure CH 4 at the same PT conditions. However, the relationship between peak position and CH 4 mole fraction is more complicated compared with the trends observed with N 2 and CO 2 . The relative order of the peak position isotherms of CH 4 and N 2 in the mixtures in pressure–peak position space mimics trends in the molar volume of the mixtures in pressure–molar volume space. Relationships between the direction of peak shift of individual components in the mixtures, the relative molar volumes of the mixtures, and the attraction and repulsion forces between molecules are developed. Additionally, the relationship between the peak position of N 2 in ternary N 2 –CO 2 –CH 4 mixtures with pressure is extended to other N 2 ‐bearing systems to assess similarities in the Raman spectral behavior of N 2 in various systems.
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How this classification was reachedexpand
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.003 | 0.003 |
| Meta-epidemiology (broad) | 0.004 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.000 |
| Research integrity | 0.001 | 0.003 |
| 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 itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
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".