Application of the ATR-IR Spectroscopic Technique to the Characterization of Hydrates Formed by CO<sub>2</sub>, CO<sub>2</sub>/H<sub>2</sub> and CO<sub>2</sub>/H<sub>2</sub>/C<sub>3</sub>H<sub>8</sub>
Bibliographic record
Abstract
The spectroscopic investigation of CO(2)-containing clathrate hydrates is complicated because techniques such as Raman spectroscopy cannot distinguish cage populations. (13)C NMR spectroscopy also has some complications as the isotropic chemical shifts do not change for the different CO(2) cage populations. It is known that CO(2) molecules in the different phases relevant to hydrates give unique infrared vibrational frequencies; however, so far only thin cryogenic films prepared at low pressure have been studied with IR transmission spectroscopy. In this study, hydrates from CO(2), CO(2)/H(2), and CO(2)/H(2)/C(3)H(8) mixtures were synthesized in a high-pressure attenuated total reflection (ATR) cell and in situ infrared spectroscopy was performed at -50 degrees C to distinguish the vibrational frequencies from CO(2) in small and large cages in the resultant hydrate and in the other CO(2)-containing phases. Quantitative estimates of cage occupancies and hydration numbers are provided as based on the analysis of the IR spectra and knowledge of hydrate gas composition from gas chromatography.
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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 | 0.001 |
| 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".