Radiation chemistry of the branched-chain monoamide di-ethylhexyl-isobutyramide
Bibliographic record
Abstract
The radiolytic degradation rate of DEHiBA is similar to that of TBP and malonamides, and slow compared to the DGAs, and is unaffected by contact with an aqueous phase or aeration. However, product distributions vary with irradiation conditions. Based on these results, DEHiBA apparently undergoes degradation via two pathways: an acid promoted pathway, Scheme 1, and an acid independent pathway, Scheme 2. It is clear that the monoamide degrades when irradiated in the presence of an aqueous phase to form a series of lower molecular weight species generated from the cleavage of the C-N amide bond or C-N amine bond. As this is the active site during synthesis, it is not surprising that this is the weak point in the ligand structure. The main degradation products appear to be DEHA and EHiBA. These species, and the smaller fragments produced by their radioysis have increased solubility in the aqueous phase. Another product common to all irradiation conditions was the species at m/z 310.2, which is identified as an unsaturated derivative of DEHiBA, resulting from the loss of two H-atoms. In contrast, when an aqueous phase is not present, higher molecular weight products are generated via carbon radical addition reactions under the more reducing conditions. These products have maximum abundance at 750 kGy, and then decrease with increasing absorbed dose. Their significance to a biphasic solvent extraction process is probably inconsequential. Solvent extraction results show that DEHiBA radiolytic degradation had little effect on uranium distribution ratios even at absorbed doses as high as 1 MGy. The build-up of degradation products in the aqueous phase apparently decreased stripping distribution ratios, which is not adverse to a process application. Thus, these findings for DEHiBA are in agreement with previous work that claimed good radiation stability and generation of inoffensive radiolysis products for the monoamides. This, in addition to their CHON nature suggests that they will be good candidates for the development of advanced fuel cycles. Interesting future work would include a comparison study on the n-alkane monoamide DEHBA.
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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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".