Fluid Embeddable Coupled Coil Sensor for Wireless pH Monitoring in a Bioreactor
Bibliographic record
Abstract
A passive embeddable coupled coil sensor for remote bioprocess pH monitoring is described. The sensor is sterilizable, able to operate in a fluid medium, and small enough to fit inside a small bioreactor or test tube. It consists of a planar spiral inductor connected parallel to a varactor forming an LC resonant circuit. A pH combination electrode made of an iridium/iridium oxide sensing electrode and a silver/silver chloride reference electrode is connected parallel to the varactor. A potential difference change across the electrodes due to pH variation of the medium changes the voltage-dependent capacitance and shifts the resonant frequency of the sensor. An interrogator coil is inductively coupled to the sensor coil and remotely tracks the resonant frequency of the sensor. For in-fluid monitoring, the sensor is encapsulated in a manner that reduces the influence of the permittivity and conductivity of the medium. The sensor, calibrated over 2-12 pH range, exhibits a rapid response with 2.477-MHz/pH sensitivity. The sensor was used for remote pH monitoring of Yarrowia lipolytica and Saccharomyces cerevisiae fermentation in a shake flask over 63 and 25 h, respectively. The experiments demonstrate that the medium pH can be monitored repeatedly with an accuracy of 0.08 pH.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 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".