The experiment was done at the Advanced Photon Source, the synchrotron at Argonne National Lab in Chicago. What was being done was 3d x-ray microtomography. Below the waterblock assembly are very precise motors that are computer controlled. One of the motors rotates the sample 180 degrees in very small increments (0.25 degree). The other motors are used prior to the experiment to adjust the sample so that it is in the exact center of the frame of view over all angles.
Behind the sample is a camera with CCD that takes an etremely high resolution 13,000 picture of the x-ray absorbance of a sample. These images are collected for every angle from 0 to 180, and the x-ray absorbance over all angles is used to reconstruct a 3d image of what is inside the sample. This is similar to a CAT scan at the doctor, but at a much smaller scale and at a much higher resolution.
Very computational intensive to convert the data. Pretty amazing technique. Once it is complete, you get images of slices of the inside of your sample. In the old days, this info would come from making tons of thin sections of sample with a knife and resins and then analyzing them with electron microscopy. This is a non-destructive alternative.
The peltier was needed to freeze water inside of a soil sample. The small aggregate was first analyzed dry, then after satuation with water, and then after freezing. How these conditions change the porosity and average pore size will be modelled once I get the software all in place. Currently, the chemical transport guys use empirical equations that could use a bit of revision.
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