Monday, November 17, 2014

Casting in the forge at UC

First, a mention of thanks to Abby Friend, Princeton High School graduate in the class of 2011, and a current student at the University of Cincinnati in their DAAP (Design, Art, Architecture, Planning) school. An additional mention of thanks to Farron Allen, professor in the DAAP school who allowed me to hang out in 'his' forge for an evening class.

The students had previously made their investments out of ludo, plaster, and silica sand, burying wax sculptures and - in some cases - tiny, plastic doll limbs in their investments and ensuring that their hidden treasures had enough sprues attached for the bronze to find their way to every inch of the creations-to-be. I don't have any photos of that investment process, though you can see the final products in the large, white molds into which the bronze you see below is being poured.

Abby explained that much of the investment is reused - mixed with new plaster and sand to be used for the next set of investments.

On to the casting...

Those are the investments to the right. They just came out of the really large kiln. The bricks were on top of the holes to keep any dust out of there. The green flames to the back were coming out of the methane-fired kiln in which a whole bunch of bronze was melting in a ceramic crucible.

Saturday, November 1, 2014

Blogging the Periodic Table: Aluminum - it used to be more precious than gold

Slate has put together a series called Blogging the Periodic Table written by Sam Kean (of the awesome The Disappearing Spoon). They're up to thirty-three articles so far. The last was published in June, 2011, so I'm assuming that thirty-three is where the series is going to end.

Aluminum, as the article relates, is the most common element in the Earth's crust was absolutely useless to us for centuries because it is so reactive. As the article writes...
From a world production total of perhaps a few ounces per month in the decades before, by 1888, the largest U.S. aluminum company (the one that became Alcoa) could produce almost 50 pounds of aluminum each day. Within 20 years, it had to ship out 88,000 pounds per day to meet demand. As production soared, prices plummeted. In the mid-1800s, the first aluminum ingots on the market went for $550 per pound. Fifty years later, not even adjusting for inflation, it cost 25 cents for the same amount.
Check the article out. If you enjoy it, check out Kean's Disappearing Spoon, an absolute masterpiece of chemistry, material science, and story telling.

My Lab Rats: Quick and EZ Defrost Tray Review

I have a MiracleThaw (or a knock-off that Tom picked up for me from a thrift store) that I demonstrate in class. It makes for a cool demonstration to show that the aluminum does a spectacular job of transferring heat to the ice and melting the ice far more quickly than students would expect - especially after they touch the MiracleThaw first and find that it feels absolutely cold in spite of it being firmly at room temperature. I also have a pair of Flinn Scientific's ice melting blocks which make for a nice comparison

Check out another couple of articles about the MiracleThaw that come in pretty digestible, bite-sized servings for you and your students...

UCLA's water main break

So, California is in an historic drought. The water situation there is awful...AWFUL.

Check out this map of the state as of October 28, 2014 (sourced here)...

I mention this only because it makes the following video, of a ruptured, 30-inch water main break on UCLA's campus this past July particularly tragic and ironic.

According to an NPR story, the water main took 30 hours to shut off and lost 20 million gallons of water in the process.

By the way, the main image of the video has absolutely nothing to do with the actual video. The real water main broke in the middle of a busy street on UCLA's campus. That photo is in the middle of greenspace in a residential subdivision. I've no clue why they chose to upload that image as the video's main shot - other than, of course, to draw traffic.

For Gorilla Glass testers, every day is a grind (and scratch and drop...)

Glass isn't supposed to do that, the bending thing that the Gorilla Glass in the photo there is doing.

See, glass shatters.

It's inflexible and rigid.

Yeah, it's tough, but it's not gonna bend like that without a catastrophic failure.

Unless it's Gorilla Glass being bent in Corning Lab's testing lab as chronicled in a cnet article recently. In the article (and included video, check below for the embed) we get to hear why sapphire might not be the material destined to replace Gorilla Glass on all of our smartphone fronts anytime soon.

I particularly enjoy this quote...
We put on safety glasses, walked into a restricted corridor and soon entered one of the main labs, which -- despite all the secretiveness -- looks a lot like shop class. 
I can't tell whether I'm entertained more by the thought that anything that's 'just' a shop class can't do any real science or whether I expect the quote to be followed up with photos of guys with three and a half fingers.

As Infrastructure crumbles, trillions of gallons of water lost

My material science students read (and listened to) this NPR story this week, the day after I heard it on the radio. In her written response to the article, one of the students wrote that she was surprised that two water mains that far apart (I'd also shown video of a water main breaking on UCLA's campus this summer) could coincidentally break at the same time. I explained to her that water mains broke every day all around the country. I typed water main break into Google News and came up with hundreds of hits within the last couple of days.

Water mains break all the time. It's a cost of using metal pipes, that they will eventually corrode and crack and turn into pretty spectacular sinkholes and floods.

My students asked why we didn't just use something that wouldn't corrode, like glass.

Apparently I have some work to do when we get to the ceramics chapter.