Neutron Profiles

Some more flux profiles of the irridator.  I think the energy deposition is the coolest; you can see how much energy the cadmium (high neutron absorbance) adsorbs, compared to the air and the Li-6 glass.  You can also clearly see the reduction in the neutron flux as well. Still confused why the neutron flux over the two wells are equivalent when the alpha fluxes are not; the alpha's are produced in (n,alpha) reactions so I would expect there to be a one to one correspondence.

Gamma Flux Profile

You might think that the lead cylinder would attenuate photons more than the cadmium, but this is not so since the attenuation coeffients are about the same:

Source

The sudden changes in the spectrum are from the orbital levels of the electrons - they are label in the original data set.  (Pretty Nifty, huh?).  Note that gamma's follow an exponential decay $$I/I_0 = e^{-(\mu/\rho)x}$$, and I have already multiplied by the density, so it makes sense that there would be a large attenuation for low energy gammas.

Swill in the 'Ville: Voodoo (SO)

Voodoo (SO) played their first tournament this weekend, Swill in the 'Ville, in Louisville, Kentucky.  I am a little disappointed in how well we did, but it was our first tournament.  It was very hot.  We need to do a lot of work in taking care of the disc / cleaning up the cutting on offense if we plan on beating some the Atlanta based teams.

Highlights: 

• Seeing Jeremy, Ben Clark, Andrew Bunn, and getting a CMU bumber sticker from Ashimey
• Beating the Missouri team twice
• Voodoo's initial D line had 5 previous farmers on it
• Getting beaten up line by a girl.  There was some fantastic heckling afterwards

Lowlights:

• Getting beaten up line by a girl for a score. 
• My lefty backing going about 20 feet.  Probably should have tried that out in summer league first.
• Almost losing to the Missouri team in the Ninals.

I still need to work on calling the trap soon enough in a zone, and a little bit of holding the force.  There were two points where I shifted to a straight up close to the endzone near the sideline on 3 on 3 situations when I though the other two O players where farther from the break side than they were, and I ended up being broken for the on the cone shot - I think we just need more communication there. 

Thesis Decision

I finally had to pick a thesis topic and I went with: "Scintillating Crystals in Scintillating and Non-scintillating Matrices".

The general idea is to embed crystals (micron sized, 6Li or 10B based (currently looking at LYB)) into polymers designed to support Pulse Shape Discrimination (the pulse can be molded by a double exponential, the first constant is PMT / electronic dependent and the second is the decay time of the material; crystals are usually 50 ns or so while polymers are in the 5 ns range).  Modeling will be done in Geant4 / MCNPX / MCNP6.

Kinda scared about having to actually pick a topic - and that I have been getting a lot of hints to stay on the project for a PhD, but I don't know how interested I am.  Staying on would provide a safe career choice and assure me of a well paid job afterwards, though . . .

I leave you with profiles of the neutron flux (a mesh tally) plotted over the geometry of the irridator.  Notice how much smaller the flux is in the Cadmium shielded well; that is because cadmium has a high absorbance cross section for thermal neutrons.

Finally, I think I would have more dating success if I went away from cheesy pick up lines. There so go though! What women could resist a man with a perchance for bad science puns?  None worth having, I tell you.

Cold Water Glass

I am a pro at become distracted by side projects.  In any case it is very similar to the coffee cup model, expect that the temperatures will switch.  Each simulation just brings more questions, namely:

• What happens if their is condensation of the outside?  How much energy does it take to for the condensation?  Is the convection more efficient for a film of water compared to silica glass?
• Can I add ice cubes?
• How does this compare to experimental data?
• What are the effects of different geometries?  Would the cup that we (Zilla, Nate, plus other) actually be more effective?

Check out the results for a rather simple cup:

Linear Heat Loss - Convection is proportional to the temperature difference

All of the heat flux is through the top of the glass

I see an ear.

Ultimate Update

I made Voodoo!  Evidently it's cool to have the same name as another team in ultimate. . . though when I asked about this I was told that Knoxville played Voodoo NW for it at one time and won.  Not sure if this is a good decision or a bad one.  I don't like the idea of playing on a team with tryouts but still being bad, and the current talent is looking only slightly better than Steel Reserve.  Tryout teams just make it seem more important, but Knoxville doesn't have the personal - all of the good players are willing to drive the 3 hrs to Atlanta for Chain or are playing with Tanasi (Nashville based).

I am finding Summer League frustrating.  The worst is the miscommunication throw aways - I expect a certian cut to be made and throw it to that space, but the cutter decides that he didn't want to make that cut after all.  Our team has even developed our own Jeremiah, (old guy who plays bad ultimate), and I find it really frustrating.  We also have two other people that like to pretend they know strategy and keep trying to impart their wisdom upon me.  Just become hard to have fun when you have to deal with personnel gibberish. 

Coffee Cup Model - Combined Fluid Dynamics and Heat Transfer

Turns out through a bit of research COMSOL already published a simulation similar to mine - a cold glass cooling down, complete with a nice animation.  I can't quite figure out how they did theirs, but the model I have currently cannot be correct - it simply takes way to long to converge.  Below is the initial profile and the profile at 65s; the well developed temperature contours present in the model without fluid dynamics are gone and we have the cooler liquid sinking to the bottom.

Coffee Cup Model - Cardboard Holder

What is the effect of having the little cardboard thing around a coffee cup?  Do they serve as an applicable amount of insulation, or just keep your hand from being too hot?  What about the effects of a cap?








First Model

• Heat Transfer in Solid's physics - the water (coffee) was assumed to be a solid; it couldn't move due to density differences.  I assumed the cup was antisymmetric, so you only get a slice.  
•  Natural Convection from air on the boundaries.  The top boundary was from modeled as a plate above, the bottom of the cup was modeled as a horizontal plate below (these are actually quite different - when the heat comes from the top it can raise away, but on the bottom it cannot), and from a vertical plate on the side.
• The fluid was assumed to be water with an initial temperature of 212 F, and the cup was assumed to be paper with an initial temperature of 50F.  The ambient temperature was also assumed to be 50 F.
• Density, heat capacity, and thermal conductivity values from library materials or the internet. 
• (Pro tip - creating both sides of the geometry with antisymmetric settings causes terrible convergence to non-physical values.)

Initial Temperature Profile

Temperature Profile of a point Halfway up the r=0 axis of the cup.  x-axis is time in seconds, y-axis is temperature in F.

What we observe is that the temperature at the center of the coffee changes 14 F in 30 min, while huge temperature gradients appear in the fluid.  Temperature gradients would then effect the density, so some sort of circulation would result.

What's the effect of a 3% change in density?  Source Data

Anywhos, using coupled fluid dynamics with heat transfer has already taken 2 hours to simulate 28.9s; so I think I just should have borrowed a thermal camera from Dr. Hiato and done the experiment.  To do the effects of the cardboard holder (which this entire shinding is about) I will need to find a better method.

The solver crashed sometime during the night; something about an illegal mathematical expression, so I don't have the correct physics / model because it I get an illegal mathematical expression that probably means I am not converging (I could simply be taking too large of a step size initially).  I did get the velocity profile of the first two time steps, 0 and 10s.  Initially it looks like that I am getting small currents (10 microns/s) near the top of the cup (these have to circulate, I think that is why the velocity is highest in the middle), and at 10s they are much larger.

 The interesting thing from these results is why the velocity current of the top extend all the way to the symmetry axis?

Presenation Boots

At the ANS conference there were a lot of people rocking the cowboy boot look.  I liked it, but I think that theirs was too subtly done.  You couldn't really tell that they were wearing them until close up.  So, for my next presentation I want to wear a pair of black cowboy boots with silver spurs (like the image on the left) with a strap across the foot like the next image.   The spurs need to jingle as I walk.  I'd still wear a suit.  I think that would be awesome and provide mad street cred.

Summer League

Yesterday's summer league games was one of the worst for our team.  The team we played was better than most (top 3 I would say), and I tried to be aggressive up-field when I handled.  At points less than 50% of my throws were caught.  It was frustrating because they weren't bad decisions, just bad decisions for that particular cutter.  And then the old person on our team berated me for not looking at him as a dump and throwing too much away when he is never in position for a dump - evidently I am supposed to make eye contact with him about stall 3, give him until stall 7 to try and get open; but why not take the first shot down-field?

There were lots of situations where I caught a deep ball and threw it away near the goal line.  I would normally look back for the dump, but I wanted to see what would happen.  It seems dumb to waste the one on one match up, but I think in those cases where you can float the throw anywhere I needed to have a receiver who would read the throw.  A lot of my receievers tried to catch my loop around to the back come on the front cone and couldn't come up with the height; but I thought they would have lost the foot race to the front cone.

In any case I am trying out for Voodoo (Knoxville's Open Team) where I will get to be a cutter with handlers that I can rely on.   I still want to work on upfield handling at summer league though.

Everglades

The everglades are very different than anything I have ever been to.  I don't think that I would go back there again, at least not during the summer.  The bugs were terrible:



Or presented in terms of my favorite type of chart:

I'm kinda confused how I got so many bites on my legs when I wore pants the entire time. I also wore a long sleeved shirt, but at times I had the sleeves rolled up.

You try navigating off this map.  How do you tell the blobs apart?

I started at the Rangers Station in Chokoloskee Bay, and followed the outgoing tide to the Sandfly pass, camping on the little Island to the Southwest of Jack Daniel's key.  I think the navigation was the most frustrating part of it; everything looks the same.  It was the only time camping where I really used my compass.

 

Pretty Seashell

Smug Bird

Pretty sweet campsite.  Shame that it was below the tide line.