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This run features an aqueous solution that is approximately 15.5 wt.% Na2SO4. Initially, the pressure was about 100 MPa. 05/10/11 12:10:03: The run starts with a liquid sample at 295 K ad p = 100 MPa. The light was originally dim, but was increased. As the sample is cooled, the volume decreases due to thermal contraction. 05/10/12 00:07:44: After supercooling to 265.5 K, mirabilite crystals begin to grow and the volume increases slightly. 05/10/12 06:08:44: Upon further cooling, not much happens until suddently the system freezes. Since this is in the Ice Ih regime, the volume increases significatnly upon freezing and the pressure inside the cell rises significantly. Since the fluid in the connecting tubing is frozen solid, the pressure and volume transducers do not fully reflect those conditions inside the pressure cell. 05/10/12 21:41:44: Upon warming, some material begins to melt, but the volume transducer still is not moving freely, so it is not clear what the corresponding pressure is. 05/10/13 10:45:44: After additional warming, the connecting tube fluid is soft enough that the volume and pressure transducers again are connected to the fluid in the pressure chamber. Upon warming, the material melts rapidly, but it is reversible and starts freezing upon small amounts of cooling. This reversible loop indicates eutectic melting. 05/10/13 20:12:44: Once all the ice has melted, the remaining mirabilite crystals begin dissolving on continued warming up until the liquidus point is reached.
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