Polycrystalline diamonds aren't nearly as pretty as monocrystalline ones are, but they seem to be much easier to produce - especially if you're trying to grow them onto a computer chip.
...which I would never have thought to do but which seems to be really desirable because diamond is a phenomenal conductor of heat, seemingly an improvement on aluminum as a heat sink for electronics on a massive scale.
Found on reddit...(my apologies for the subreddit's name)...
Wear your PPE, folks.
I hear people lamenting 'government regulation' all the time, and I recognize that most government regulations were put in place at the cost of somebody's life.
I've seen the reverse spherification technique of using sodium alginate and calcium chloride solutions to produce edible, gelled products (Kool Aid worms, gelled drink spheres, cocktail pods). Sometimes the calcium chloride is swapped out for calcium lactate because it's really the calcium ions that are necessary for the process.
But using that process to make gelled glass which can be shaped in ways that glass normally couldn't be shaped is pretty amazing. All respect to Karen Lise Krabbe for developing this technique. If you want to learn more, you can check out her ebook on the technique.
The materials in our world are rarely pure. Our steels are alloys. Our polymers contain dyes and plasticizers. And apparently our food packaging - like chip bags - are composed of nearly a dozen different polymer and aluminum foil layers glued together.
Trying to get those materials apart again to recycle them is currently all but impossible to recycle.
In our summer camp (more info here, natch) we have an awesome demonstration that heats an iron wire via a variac that demonstrates the solid state phase transition from BCC iron (at room temp) to FCC iron (at higher temperatures).
This video heats wires of various metals at - I think - constant voltages - and observes a few interesting things:
copper wire produces a green flash at the moment of melting
magnesium ribbon rose as it heated and expanded (rather than sagging) at first
molybdenum wire produced a series of evenly spaced 'balls' (unduloids) before melting and breaking
I've seen something somewhat similar to the molybdenum balls when the iron wire melts and fails. Each end of the iron wire creates one single ball of iron on its end where the wire failed. We don't get the repeated drops like molybdenum, but the metal balls are familiar to me.
I appreciate the explanation of the formation of unduloids forming via partial melting and surface tension pulling the molten surface together. Sounds good enough to me.
I do wish they had repeated the 90 degree turned experiment with the molybdenum wire - not just with the copper wires.
We were talking about the expandable, polyurethane foam in class after doing the lab, and I wanted to hunt down some uses of the foams outside the classroom. I figured if I'm looking for them, some of you might be interested in them, too.
If you have any other good videos of uses of expandable foam, please link to them in the comments.
I'm far from an expert when it comes to firing ceramics. I've been using the same programs on the same kilns in my classroom at Princeton HS for almost twenty years now, and as I've learned from the actual ceramics teacher in my school, that likely means my elements and thermocouples aren't anywhere near optimal working condition anymore. She offered to replace the elements for me, and I think I'm going to take her up on that this year.
I've also learned that I should probably be using some pyrometric cones to confirm some of the temperatures that I think we're getting to according to the thermocouples and the digital controllers on the various kilns.
