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Updated: Jun 17, 2026
08:55
Translaminar Autonomous System Model for the Modulation of Intraocular and Intracranial Pressure in Human Donor Posterior Segments
Published on: April 24, 2020
Summary
High-pressure studies reveal reversible phase transitions in calcite at 14 and 17 kbar. Researchers also observed a solid-solid transition in nitric acid (HNO3) at 8 kbar.
Area of Science:
- Mineral Physics
- High-Pressure Chemistry
Background:
- Understanding material behavior under extreme conditions is crucial for geology and materials science.
- Phase transitions in minerals and chemical compounds provide insights into Earth's interior and novel material properties.
Purpose of the Study:
- To investigate and document pressure-induced phase transitions in calcite and nitric acid.
- To characterize the nature and reversibility of these transitions using high-pressure techniques.
Main Methods:
- Utilized a diamond anvil cell to subject single crystals of calcite to hydrostatic pressures up to 17 kbar.
- Observed and photographed transition planes in calcite under pressure.
- Grew a single crystal of nitric acid (HNO3) in equilibrium with its liquid at approximately 4 kbar.
- Monitored nitric acid for solid-solid transitions at room temperature and 8 kbar.
Main Results:
- Successfully observed and photographed two reversible phase transitions in calcite at 14 kbar and 17 kbar.
- Characterized the transition planes associated with these calcite phase changes.
- Achieved crystal growth of HNO3 at 4 kbar and identified a solid-solid transition at 8 kbar.
Conclusions:
- Calcite exhibits distinct reversible phase transitions at specific high-pressure points.
- Nitric acid undergoes a solid-solid phase transition at 8 kbar, indicating complex pressure-dependent behavior.
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