How NASA Reinvented The Wheel - Shape Memory Alloys

Was the Mars Rover really lowered down by flying platform and hooks and winches?

That's kind of awesome!

We get to see the reveal of the memory metal 'tire' at 4:10 in the above video, a mesh tire made of what looks like a chain mail of nitinol. Then there's a great explanation of why nitinol is a super-elastic material (using our old friend, the stress-strain curve) and some nice atomic-level diagrams.

Then we get a bunch of close-up video of the wheel deforming and returning to its original shape.

It's a brilliant idea.

Yemen's Deadly Ghost Ship

I just read an article about the FSO Safer, an oil tanker that has been taken out of service as a ship and converted into floating storage off the coast of Yemen. Apparently, according to OpenDemocracy, anyway, that's a bad thing. (All of the below quotes and the above image are from that article.)

A victim of Yemen’s current civil war, the Safer has fallen in to a dire state of disrepair, with rust spreading around her hull and on-board equipment. She is packed with more than a million barrels of crude oil, which over time is thought to have steadily released flammable gases meaning the Safer could explode if she doesn’t simply begin leaking huge volumes of oil into the sea.

Well, as long as there's a way to avoid an explosion. All we have to do is leak the three MILLION barrels of oil into the ocean.

That's a fair trade, right?

But it gets worse. The 1.15m barrels of oil on board is Marib Light, a type of crude that mixes more easily with water, explains Dr David Soud at IR Consilium, a maritime security consultancy that has been tracking the FSO Safer situation. 

Should that oil begin to flow out of the rusting hull and into the Red Sea, it could form a spill roughly four times as large as the Exxon Valdez spill in 1989 – and with crude that mixes down into the water column. 

... 

That means the Safer presents a significant threat to nearby coral reefs, marine life and also desalination plants in the region that provide drinking water to nearby countries including Saudi Arabia.

Ah, so apparently leaking three million gallons of light crude oil into the ocean would be bad.

But what's the problem with just leaving the tanker in place? It's not like an unmaintained metal tanker in a salty ocean is going to be a problem, is it?

A victim of Yemen’s current civil war, the Safer has fallen in to a dire state of disrepair, with rust spreading around her hull and on-board equipment.

...

Sitting in the sea, it is corroding away rapidly as we speak.

Since civil war broke out, little or no maintenance has been carried out.

...

“Any kind of ship that sits in the sea or moves around in the sea has to be regularly maintained,” says Laleh Khalili, professor of international politics at Queen Mary University London.

...

In the absence of constant sanding and painting of the hull, the Safer has essentially been left to rot.

...

Plus, the Red Sea is a particularly salty body of water, meaning that the Safer’s hull is corroding faster than it would elsewhere in the world.

...

A giant problem begging to be fixed – waiting, rusting, creaking

Oh, that's right. Steel in salt water is going to corrode quickly and disastrously.

Honestly, though, I don't understand the idea that the tanker was simply, "converted into a stationary storage facility for the Safer oil company and brought to an offshore position near the Yemeni coast".

That's weird, but I guess it's not really different from rolling storage.

Mui Ho Fine Arts Library

At first glance, there's not much thrilling about the library - the Mui Ho Fine Arts Library - in the video above.

There are a bunch of bookshelves in open stacks three stories high.  All in all, meh. That's been done before - and much higher, honestly.

But then you get to the moment in the above video - about 0:55 in - where they mention that the books and the floors and shelves supporting them are NOT actually supported by the floor below but rather are hung from the ceiling.

Tension...not compression.

How cool is that?

I mean, as long as you aren't wearing a skirt, a dress, or high heels, anyway.

Corrosionpedia

Corrosionpedia isn't a wiki (that would mean that the website and its information was editable to anyone in the website's community), but it is along the lines of a corrosion encyclopedia - with the words just mushed together.

The site has a huge amount of corrosion-related content, and I've particularly enjoyed the industry news section - a weekly collection of one-paragraph summaries of corrosion in the news with links to more in-depth articles about the story. Some of the stories are in very industry-specific publications, but others are in more popular media. No matter what level your students are, you should be able to find some corrosion-relevant current events with minimal searching.

Much of the rest of the website, however, is internally-written articles on specific corrosion topics. A quick survey of those finds articles on "corrosion control considerations in the equipment design process", "what new materials science studies suggest about corrosion control in the future", and "an intro to pipeline corrosion and coatings". The articles are written on a level that people - students, teachers, even non-education folks - should be able to get much of the content, and the articles have a number of links internal to corrosionpedia if you want to know a little more. The articles are broken up by topic - "cathodic protection", "materials selection", and others.

They also have webinars - some of which are free, all of which require creating an account; downloads - whitepapers, reports, slide presentations; Q&A - single questions with answers from "corrosion experts"; a directory of corrosion-focused companies; and an events calendar of upcoming (and recently past) corrosion industry events.

I've found the articles and news story collections useful. I haven't found the other sections useful...yet.

So, take a look at corrosionpedia and see if you can figure out why a gas station canopy collapsed, why a pedestrian was injured by a streetlight pole, or why a bridge in Mumbai, India collapsed.

You know, in case you couldn't guess from the website's name.

This ain't crazepedia.

A bad corrosion graphic?

In recently searching for sacrificial images online, I came upon the following graphic (at opentextbc.ca)...

...and I think it has a pretty significant error in representing the science of how sacrificial protection from corrosion works.

I'll put my reasoning after the jump...

Sacrificial anode photos and links

I was recently searching online for some better images of sacrificial anodes for our material science slideshow at school, and I thought I might as well put these out there for any other science teachers using the blog.

I will say in advance that I didn't take any of these, and that's why I'll be linking to the source. All were accessed in January and February of 2020. The links may rot, but I'll keep the images up.

What is an anode rod & how does it work?

I know the answer.

Do you?

If you don't, you might want to check out Landmark Home Warranty's great webpage explaining the usefulness of and science behind hot water heater anode rods.

There's even an infographic in case you don't like so many words.