Paramount Poster

4/26/13

The day flew by today in the lab. All four of the capsules had been taken out of the furnace from last week and I quickly jumped to work cleaning them out. After breaking the capsules open and trying not to breathe in too many of the less than pleasant sulfur fumes, I scraped the sulfur-34 from the glass and extracted the four crystals. I then let them soak in 4 different beakers of ethanol and put them in the ultrasonic. The ultrasonic however had too much water in it, and with the vibrations of the ultrasonic, my four little beakers almost started floating away. After dumping out a little of the water, my beakers were now comfortably resting on the bottom and I was able to turn on the ultrasonic without fear of my beakers tipping over, losing the recycled sulfur-34 in the process.

After I was done with the crystals Heather was nice enough to suggest that we could work on my poster. We downloaded everything on the lab computer and began looking at graphs. I found the linear fit using excel of a sphalerite crystal that had been scanned by the ion beam in a process called Rutherford backscattering spectrometry or RBS. This is where a burst of Helium ions are shot at the sample and a detector analyzes the backscattered electrons. Daniele then showed me a detector she would use. It was a shiny gold colored cylinder with a smaller mirror-like cylinder at its core. Daniele told me the outside was usually made of gold or platinum to help contain the particles. The mirror-like cylinder was made of silicon. The very top layer of the cylinder was doped silicon that was silicon and a lot of other elements about the width of a hair thick. The rest of the cylinder was simply pure silicon. It is the silicon that does the analyzing and measures the electron pairs that exit the sample. Using this RBS graph, I used the linear fit to calculate the activation energy of this sphalerite sample. Heather showed me the formula:
D = D₀ exp (–Q/RT)
where D is the diffusivity
D₀ is a constant
Q is the activation energy
R is the gas constant
and T is the temperature in Kelvins
After taking the natural log of both sides and doing other math, I found the activation energy to be 131 which Daniele said was a reasonable number. I had finally gotten a number from my data!

Next week, Daniele and Heather are taking me to see the ion beam at SUNY Albany. I am super excited to see the facility and finally see the behind-the-scenes analyzing that happens after I extract my crystals. It should be lots of fun even though I sadly only have one week left after the ion beam before my internship draws to a close.

Clashing Conflicts

4/5/13

Did not meet with Daniele today due to the Open House where I was asked to speak on a panel :)

Bandaging Blanks

4/19/13

Today I had a little trouble finding Daniele as I wander the catacombs of the RPI basement. After I finally stumbled upon Daniele, she showed me a list she had made planning out the experiments we should do in order to fill in the gaps in our data. We decided to plan to do three sphalerite experiments at 650, 750 and 850 degrees Celsius to get some data of sulfur diffusion at higher temperatures. We also planned on doing another experiment with celestite and barite at a higher temperature of 600 degrees Celsius because the diffusion did not occus at a perceptible rate in our previous experiment. With this busy to-do list ahead of  us, I quickly set to work making the first sphalerite capsule. It took me no time at all with the finished result on the left. Daniele already had a furnace set at the correct temperature, so we walked to the furnace room to put in our first sphalerite experiment at a steamy 850 degrees Celsius. I had to be very careful putting in the experiment, because just because the thermocouple didn't look hot, it had just been in an 850 degree furnace and could cause quite a burn. My favorite part of this day in the lab had to be looking in the furnace after I had put in my capsule. This was the hottest I had seen a furnace and when I looked inside, I could see the ceramic pipe glowing a burning hot red.

After I had finished the first sphalerite capsule I proceeded to begin work on another sphalerite capsule. I quickly cranked out another one, but not before noticing something near the Bunsen burner before I finished sealing my sphalerite capsule. I had stumbled upon capsuleception. The person who had been working in the lab before me had made a capsule, within a capsule, within a capsule! Daniele explained how this technique created ideal atmospheric conditions for the capsule containing the intended reaction. After finally sealing my sphalerite capsule, Daniele, Heather and I went to check if there were any furnaces available near one of the temperatures we were aiming to test. Since none of the furnaces were going to reach 650 degrees anytime soon, I headed back to the lab to work on making some more capsules. I had just enough time to find a really nice barite and celestite crystal to put in a capsule and quickly seal two capsules in record time.  After being complimented on my capsule-making finesse I ran out to the van just in time for my shuttle. Next week, Daniele and I are going to work on setting up a few more experiments and looking at data. More excitingly, I have planned a trip with Daniele for May 3rd to go and see the ion beam in SUNY Albany that Daniele uses to analyze our crystals to see the results of sulfur diffusion. Hopefully I'll have some exciting pictures in two weeks and I'll collect my data in no time!

Gallant Graphing

4/12/13

Today I worked with Daniele at cleaning out two capsules that I had put in before break. Our capsules weren't labeled and Daniele couldn't find her notes from before the experiments were put in. After getting a little concerned, we looked more closely at the crystals within the capsules. Daniele reminded me how the barite and celestite crystals had different shapes even though they had similar clear coloring. I identified the more prism-shaped crystal as the celestite and Daniele agreed with me. We quickly cleaned out the two capsules and since Heather was going to be late, Daniele set me up on a computer in the lab. She had some barite results and she wanted me to make a curve to try and match the data.

The pink line is the line I eventually got to fit the results by manipulating data on excel. The y-values represent the counts a receptor received after an ion beam hit our sample to analyze it. The x-values represent the distance within the crystal, which as you can see from the data, the data the receptor receives decreases the deeper into the crystal you go. After I manipulated a few graphs to find the line of best fit, Heather showed up and we decided to run another sphalerite crystal at around 750 degrees Celsius to fill some holes in our data. My internship literally flew by today as the furnaces take forever to heat up to the correct temperature because they overshoot and then turn off, undershooting before turning back on. These fluctuations take a long time to regulate so sadly we ran out of time before we could put another experiment into the furnace. Hopefully next week I'll have some more data and can potentially work with manipulating more graphs.