300 bar<i>in situ</i>gas pressure cell for powder diffractometers
Bibliographic record
Abstract
A new in-situ cell has been designed and constructed to simulate the temperature, pressure and chemical conditions present in deep saline aquifers.The cell has been built to study reactions at the CO 2brine-solid interfaces produced during injection of supercritical CO 2 (sc-CO 2 ) for storage and sequestration purposes.Much of the data relating to CO 2 storage relates to oil and gas wells.However, by far the largest potential reservoirs are deep saline aquifers where the chemistry has little in common with oil wells.Little experimental data exists on the behavior of various rocks and engineering materials under these conditions, particularly with injection of impure CO 2 streams, and some of the existing data give significant cause for concern.The cell has been designed for both reflection and transmission geometries so may be used both in laboratory and synchrotron environments.Although sc-CO 2 /water often reacts slowly under equilibrium, concerns have been raised about impurities such as SO 2 and H 2 S that will inevitably be present in industrial streams.These gases can react rapidly, so the slower laboratory and more rapid synchrotron measurements are highly complementary.Flow-through experiments may also be possible but haven't been specifically targeted.The cell has maximum working conditions of 300 bar pressure and 300 °C in pH3 brine conditions.These conditions are extremely demanding for any metals, sealing and window materials, and the restrictions imposed by the ASME Pressure Vessel and Boiler Code [1] and Process Piping Code [2] posed additional challenges.The materials certification requirements in the ASME code forced us into using structural grade beryllium windows as in our first generation cell [3].Beryllium is highly susceptible to chloride corrosion so a thin coating of tantalum is used to protect the windows under these conditions.Requirements of the pressure vessel certification process meant the cell was successfully tested hydrostatically to 450 bar pressure before delivery.Some of the theoretical and practical considerations for the design and construction of the cell will be described.Although the cell may be used with a laboratory diffractometer, the silver X-ray tube source and high-energy optimized PSD detector needed to gain sufficient penetration and signal are not standard components.Such a cell needs to be operated as part of an overall 'system' and is of limited use in isolation.
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 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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.004 | 0.001 |
| Research integrity | 0.001 | 0.003 |
| Insufficient payload (model declined to judge) | 0.021 | 0.006 |
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".