Its sunday night and a bunch of hackers are sitting at the door of the cube fixing bugs and figuring out the last few hick-ups for the cube to conclude a phenomenal week of cube building. This is day 8 of the installation and things went a lot faster then we first anticipated. The main structure was done after 300 man hours of work. The new frame worked out great and despite somewhat larger flexibility then we thought its doing its job perfectly. The new weight estimate for the cube is in the 1700 pound range which is *a lot* lighter then the 4500 or so pound weight on the playa (we know this accurately since the crane operator told us). The new cube has a nearly 2/3rd weight reduction. 1150lbs coming from the new aluminum frame.
Installation time is also significantly down (about 40-50% less) but i think there’s a lot of mileage here still. Many things were learned and figured out during this isntallation, especially about the new frame and I firmly believe installation time could be reduced to 200 or even 150 man hours with an experienced team and a number of possible and easy hardware upgrades. Watch this space.
We lift it into place tomorrow.
Below: The Software team engrossed in the code next to the finished cube ont he floor.
Today we started our installation of the Groovik’s cube at the Pacific Science Center. After a smooth load and unload session we finished 2 hours early and started assembly. Unfortunately I managed to overlook one box containing all of the bolts and nuts needed for the frame assembly so there was some hectic running around trying to scavenge, buy and retrieve bolts in order not stall the build. Once we figured that out though everything went very quickly and we erected the entire frame. After putting in the internal cable bracing we test lifted the cube by two opposite corners and found that the structure is actually fairly elastic and will flex somewhat under this unnatural load vector. Tomorrow morning we plan to do another full test lift hanging the cube from all three corners and seeing if the problem persists in the hanging orientation it was actually designed for. My guess is that once under the right load direction things will look a lot better but who knows. Alternatively we will be figuring out how to stiffen out the frame while we press forward with the installation of the top layers of fabric, lights and reflectors. I’m sure many unknowns stil lay ahead but for now things are going forward ok. Right now we’re ironing out the last few bugs in the software at ALTSpace and hopefully we’ll have a fully running, mappable and color calibratable interface in the next few days. Just in time to be tested on the whole object – i expect instllation will go smoothly and quickly.
Ubiquitin is a small regulatory protein found in almost all tissues of eukaryotic organisms. The cell attaches short chains of Ubiquitin molecules to proteins, which labels them for destruction and subsequent recycling. The Ubiquitin tag directs proteins to the proteasome, which is a large protein complex in the cell that degrades unneeded proteins back into their amino acid constituents. These are then reused to synthesize new proteins. The constant recycling of proteins not only ensures damaged proteins are removed quickly but also allows rapid regulation of enzyme levels in the cell.
Structurally, Ubiquitin features all of the major structural features of typical proteins including two a-helices a curved b-sheet. Its small size (76 amino acids) makes it one of the most studied proteins for protein folding and dynamics.
Potassium channels form potassium-selective pores that span cell membranes. They are the most widely distributed type of ion channel found in virtually all living organisms. The four identical subunits are situated in a four-fold symmetrical manner around a central pore, which allows potassium ions to pass freely. At the top of the structure, formed by four loops lining the pore, a selectivity filter is situated which prevents other ions (such as sodium ions) from passing. The correct ions are detected by their size and charge. Note that that no active pumping of ions occurs; it merely allows passive conductance of ions down the con-centration gradient between the two sides of the membrane.
The KcsA is an archetypal membrane protein with eight tightly packed membrane-spanning a-helices. The four short helices in the center where the chain crosses half the membrane and then returns to the top are a more unusual feature.
Today I swapped my MIG Welder for Kevin’s TIG welder (temporarily) and experimented with TIGing copper together. Turns out its not that hard except that the copper i’m welding is so thin that its really easy to just blow a hole in it or turn it all into a molten puddle with just a little bit too much heat. I found in the end that keeping the electrode tip fairly close but giving lots of power gives a small controllable puddle as opposed to less power and larger distance which gives a much wider puddle. We’ll see if the joints are any good once i start bending and “folding” the whole thing into shape. If they crack then i have screwed it up. I realized after welding all the parts to gether that I should have ground down the excess weld each time piece by piece rather then ding it now with all pieces attached to eachother which is much more unwieldy. And bending the loop regions into their approximate shapes is totally pointless. Might as well leave them straight (just cut to the right length at 1″/aa and bend them later in the context of the secondary structure elements. Steep learning curve but super fun. WIth the TIG too – it’s really fun and clearly a lot more practice needed but it feels really satisfying. MIGing is just metal hot glue. TIGing is so much more precise. And its lovely and quiet and looks gorgeous under the helmet – you can literally see the stream of electrons flying into the base metal like a glowing shower – not like tig where its all splatter and noise and smoke. TIG is clearly the high-class of welding .