Week 8
About the model
I finish this model this week, and it turned out to be decent. Like I mentioned in last week's blog, I reglued the tube to the box and leave it to dry over the weekend. I turned out to look fine on Monday. I added the silicone on Monday and leave it to dry for 48 hours before my next step.
You can see the bubble inside the silicone after I mix them. That is why putting the silicone in the vacuum chamber is necessary.
There is a leak at the edge of the model. I try to fix it with hot glue but it is still not completely sealed.
Liquid silicone inside the box.
After leaving the silicone sitting for two days, I came back and take apart the box and put the entire model in water to dissolve PVA. This process is faster than I expected although I accidentally got water all over me.
Silicone with PVA tube inside
Detaching PVA from the silicone
Getting PVA out of silicone
Completed model
About PIV
I spend most of my time this week helping Rafael with the PIV experiment. We first transported the pump from WIMR to ME in the morning, and then we did the set up of the experiment in the afternoon. Unlike last time, this time's set up include testing the experiment with the model in its place.
After placing everything in its place, we put the model at where it should be and change the camera setting to make it focus on the part of the model that we want the image from. Because the image we get from every camera is 2D, we need to do calibration to tell the computer where each camera is thus the computer can create a 3D image. The calibration plate has two surfaces and there are dots on each of the surfaces. We place the calibration plate at where we want the model to be without changing the setting of the camera. Then we take a picture of the calibration plate with all three cameras. The software then will know the distance between the two plates thus create a 3D image when scanning the model.
The set up for the experiment
The calibration plate
Processing image of the calibration plate on the computer
The computer recognize where each camera is in space.
On the second day, we did the actual PIV experiment. We did have some problem with the glucose and water mixture first. The index of refraction of the liquid is not the same as silicone, we thus have to add more glycerol to make it fit better. Other than that, the experiment went pretty well.
You can see the aneurysm inside the silicone because the index of refraction doesn't match up.
You cannot see the aneurism after the index of refraction matches up with the silicone.
The image taken by the camera.