Absorption kinetics of oxygen scavengers
Bibliographic record
Abstract
Abstract The oxygen (O2) absorption kinetics of six commercial O2 scavengers were studied. The scavengers were placed in bags which were filled with 240 mL of air, 4.5 L N2 + 15 mL of air, or 3.5 L CO2 + 9 mL of air. The O2 concentration in each bag was measured at hourly intervals for 8 h. The effects of variability among individual scavengers, initial O2 concentrations of 20% or 500 ppm (0.05%), temperatures of 25, 12, 2 or −1.5 °C, and scavenger capacity on the O2 absorption rate were determined. In addition, the effect of placing scavengers within over-wrapped trays within bags, was examined. Rates of O2 absorption varied by factors of up to 2 between individual O2 scavengers of the same type, but rates of absorption by groups of four scavengers of the same type were similar. Low temperatures gave longer O2 half-life when compared with those at higher temperatures, e.g. O2 half-lives of 7.1 and 1.0 h at −1.5 and 25 °C, respectively, were obtained for one scavenger type. Shorter O2 half-lives were obtained in air than in N2 atmospheres at the same temperature, e.g. O2 half-lives of 1.0 and 3.3 h in air and N2 at 25 °C, respectively, were obtained for one scavenger type. The O2 absorption reactions were of first order for both high and low initial O2 concentrations. However, O2 concentration was the primary limiting factor for O2 absorption in atmospheres having O2 concentration of 500 ppm because of the dominance of diffusion. Scavengers, when placed within over-wrapped trays within bags had up to 12 times longer O2 half-lives, indicating that the O2 permeable film acts as an O2 barrier when pack atmosphere has low O2 concentrations. To obtain consistent and reproducible results, it is recommended that multiple scavengers be used in a packaging system. The appropriate number should be based on scavenger type, desired O2 absorption rate, storage temperature, and pack atmosphere (air/N2/CO2).
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.002 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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; a candidate call from one teacher head, 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".