Spin-echo measurements for capillary rheometry at low field
Bibliographic record
Abstract
A single spin-echo, acquired in the presence of a constant magnetic field gradient, has a phase proportional to the average velocity of the sample and an amplitude determined by the distribution of velocities for laminar flow in a pipe. If we make assumptions about symmetry, it is therefore possible to reconstruct a velocity profile from a series of spin echoes acquired with different echo times, . The velocity profile encompasses a range of shear stresses and so describes the shear-rate dependence of the fluid viscosity, making this a rapid, non-invasive rheometric measurement. The appeal of this approach lies in its simplicity: a constant, uniform magnetic field gradient can be readily constructed using low-field permanent magnets and the resulting magnetic resonance instrument is relatively cheap and easily sited. In order to extend the range of fluids to which such a rheometer can be applied, we have designed a pre-measurement polarization unit to maximize the polarization of fluids with a long , such as aqueous solutions.
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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 | 0.000 | 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) | 0.000 | 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".