Determination of paper degradation by-products by direct injection on an HPLC column
Bibliographic record
Abstract
The by-products of the thermal degradation of insulating paper include 2-furfural, 2-acetylfuran and 5-methyl-2-furfural. These furanic compounds are usually isolated by subjecting the insulating oil to a pretreatment stage on a silica solid-phase cartridge, or liquid-liquid extraction (IEC 1198) before analyzing them by high-performance liquid chromatography (HPLC). However, these procedures are time-consuming and not very practical. This paper describes an alternative analytical method, also based on HPLC, but not requiring pretreatment. The insulating oil is injected directly on a PRP-1 column. The furanic by-products are eluted in less than 20 min when a mixture of water and acetonitrile (75:25, v/v) is used as the mobile phase with a flow rate of 0.5 cm/sup 3//min. The by-products are detected by ultraviolet. In-service transformer oils have been analyzed by the new method and the results compared to those obtained using the IEC method as well as others obtained by a private laboratory. The paper stresses the simplicity and, in particular, the increase in productivity offered by the proposed method.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".