3D Printing Extremely Viscous Materials

I'm guessing that Bonnie Raitt could've helped solve this long ago if anybody had just asked her.

Seriously, though, I love that song. Take a few minutes to give it a listen if you haven't before.

More to the topic, though, the idea of 3d printing highly viscous materials would open up a whole lot more possibilities. Heating any polymer filament up to force the polymer through the nozzle leads to complications that could be mitigated apparently with a little shaking.

Plus we get increased opportunities to precisely print with ceramics, cement, even - as the video above mentions - icing.

I wish we'd gotten more of the icing shown.

As always, check out the ASM video of the week.

Making aluminum without making CO2

At this point, jainism is starting to look pretty good to me.

The basic summary - if I'm in a charitable mood - that I've come to about our environmental impact is that everything we do changes the environment. If I'm feeling a little less neutral, it's more that everything we do harms the environment.

Yes, the aluminum industry's carbon dioxide emissions are - from the graphic above (source) - far less than those of the iron & steel industry, cement manufacturing, or - by leaps, bounds, and a broken scale - our consumption of fossil fuels. And, according to the Aluminum Association's website, "Energy demand to produce new (primary) aluminum is down more than a quarter since 1995 and the industry's carbon footprint is down nearly 40 percent." That doesn't, however, remotely mean that the carbon dioxide released by the aluminum industry is negligible.

A recent article from C&EN, highlighted one of the industry's further efforts to reduce CO2 emission by developing more and more inert anodes instead of the current, carbon-rich anodes which produce CO2 - and CF4 and C2H6 gases, also potent greenhouse gases - throughout the aluminum production. In fact, Alcoa and Rio Tinto have formed a new venture, Elysis, to develop and market these anodes.

For two years, Alcoa has been offering a premium, sustainable aluminum line guaranteeing that the aluminum produced creates 75% fewer CO2 emission than the industry average.

All of these are among many industry efforts to reduce CO2 emissions and environmental impact - within all industries, honestly, not just aluminum. As a presentation titled "Can the global aluminum industry achieve carbon neutrality" writes, "we didn't inherit aluminum from our parents. We are borrowing aluminum from our children."

Source - link

How tough is the new Gorilla Glass 6?

Wait, Gorilla Glass 5 has been improved upon?

Fine, but I'm sure nothing will ever surpass Gorilla Glass 6.

In all honesty, I did like seeing the various tests that the glass designers undertake when they're developing a new glass. I haven't had the issues described with the purse, but I'm assuming those are real issues.

In the video below, we get a brief glimpse into the manufacturing and prototyping of the various glass compositions on the way toward a final product.

Plastic Injection Molding

Well, if they're going to talk about - and briefly focus on - how Lego bricks are made (not Legos, ya savages), then I'm going to post the video.

Our material science class at Princeton High School doesn't get anywhere near practicing injection molding. One of our dreams out in the distance is to sometime get to lost wax casting, but that's about as close as we've considered. In this video, however, The Engineer Guy does a great job explaining the process of injection molding and a bit of the history of celluloid because one of the claimants for the invention of celluloid is the inventor of the injection molding process.

Plus there's the Lego connection...more of which after the break...

MAKING A BOWIE KNIFE WITH REAL ENGINEERING!!! PART 2 - WHY we heat treat steel!

Finally, the testing...

The first part of the video is more making a knife - grinding the blade, drilling to attach the handle.

Then, at 5:50, the actual materials testing comes in. Alec Steele takes a steel bar and heat treats it different ways (not on camera, sadly) and gives each piece a few solid wacks with a sledge hammer.

These two videos (Alec's and Real Engineering - whatever that guy's name is) really balance the two sides of material science. Alec shows a lot of a practical knowledge. Real Engineering shows a lot of academic knowledge. Together they're pretty awesome.

Oh, and the testing wraps up around 12:25. Then it's back to finishing off the handle of the Bowie knife.

MAKING A BOWIE KNIFE WITH REAL ENGINEERING!!! PART 1

I get that much of your personal taste in enjoying YouTube videos (or not) comes down to the personality of the presenter. That's why I'm going to refrain from commenting on Alec Steele's videos.

I won't mention the overly-enthusiastic schtick.

Honestly, I won't.

I'm a little disappointed that this isn't the video I was really looking for. I was looking for the video showing the testing of the various heat treatments of the steel.

I guess that's on part 2. Arrgghh...I guess that's next week then.

Heat Treatment -The Science of Forging (feat. Alec Steele)

There is something weird happening with the Real Engineering guy's accent. I'm struggling to place it exactly. There's a sing-song lilt to it that's screaming, "Irish" to me. Then, at 1:50, there's a weird ll-th thing going on with the 'through the heat treatment process' phrase that makes me think he's almost got Welsh in there. His patreon page says Galway, Ireland, but I've not heard that ll-th thing anywhere but from Wales.

Can anybody definitely say where he's from?

I'm going to have to check out the testing video from Alec Steele (an aptronym). Maybe that'll be next week's post.

So much great metallurgical explanation here...BCC, FCC, ferrite vs austenite vs pearlite, phase diagrams, quenching vs tempering vs annealing (normalising - British spelling, natch).

Aluminum recycling - How it works by Norsk Hydro

We have to recycle more.

There are many countries that are far, far better at recycling than is the US, but we (the US) have to get better.

I hadn't thought about the challenge of not just sorting the majority metals (steel from aluminum from copper from etc) but rather sorting the various similar metal alloys out from each other. The use of x-ray spectroscopy to do that is an application that I would never have considered, and the puff of air used to fire away the unacceptable aluminum alloy chips is amazingly fast.

It's amazing to me how technologically advanced the recycling industry is becoming.

Smart Materials of the Future - with Anna Ploszajski

"Rock-paper-scissors is a game that you use to compare materials' properties. The rock blunts the scissors because rock is harder than stainless steel."

C'mon, nerd, rock-paper-scissors is just a game like mumbledepeg or roshambo.

The simplicity of showing a smart material via pine cones is brilliant.

Oh, I found a definition of smart materials that I very much like (via BBC): "[s]mart materials have properties that react to changes in their environment. This means that one of their properties can be changed by an external condition, such as temperature, light, pressure or electricity. This change is reversible and can be repeated many times."

Other smart materials mentioned in the video are lime mortar from the Egyptian pyramids, piezoelectric quartz crystals, thermochromic pigments (on a mug), NiTiNOL, and ferrofluids. Most of the latter materials are applied to the future of airplane design.

Why graphene hasn't taken over the world...yet

As long as they don't make ropes of graphene and have a 200,000-person tug of war, I'm all good with most uses of graphene.

The idea of mixing graphene in with ink and printing circuits on fabric seems pretty outstanding to me. I love the image of clothing that could include its own circuitry and would be fully durable no matter how we treat it.

What is the NEW Silver Play Button REALLY made of?!

The video description doesn't remotely need that ?! at the end.

That being said, the process that the youtubers here go through to find out what specific elements are in the 'silver' play button is fascinating. The (?) Energy Dispersive X-ray Spectrometer is something that's new to me.

I'm particularly fascinated by the results at 5:39 showing the elemental makeup at various depths of the 'button.'

Yeah, all that's interesting, but what's the 'gold' play button award made of? And what's beyond the gold button?

Your old phone is a veritable gold mine

Honest question - how do I make sure my data is cleared from the electronics before I let them be recycled?

The most stunning fact in this video - recovering metals like gold from e-waste is now more efficient than digging it up from the Earth.

But it makes sense if the facts (1:40) are true. If a typical gold mine has 5-6 grams of gold per ton of Earth and a ton of mobile phones (typical e-waste) contains 350 grams, that's a brilliant source of gold.

Now we just have to find ways to get to the gold.

Notice the 'nothing you do to gold does anything to it (I'm paraphrasing, admittedly)' fact? That's because it's really low on the activity series. It's a noble metal.

Oh, and the fact that we haven't ratified the Basel Convention reminds us that the US is an awful global citizen. From wikipedia, "The 10 UN member states that are not party to the treaty are East Timor, Fiji, Grenada, Haiti, San Marino, Solomon Islands, South Sudan, Tuvalu, United States, and Vanuatu."

Quenching Steel: Understanding The Why's and Wherefore's

(Edit: 6/28/21 I can't find another upload of this video. The channel that hosted it is still there, but this video seems to have disappeared. I'll check again and hope that Trent brings the video back.)

Trent's back!

Honestly he never left, but I didn't look any further into his videos than his "Moronic Jet Fuel 9/11 argument" video.

Turns out he has more to tell us...

This video goes through differences of oil versus water quenching...what quenching does to the steel of the blade (with an interesting to a latex glove as an analogy to the quenched steel)...and comes to the final lesson, "if you do not know what steel you are dealing with, you will not know how to properly quench it or harden it or temper it"...

He does, I warn you, use the word 'retard' again at about 0:28 - the "new samurai retard squad". C'mon, Trent, spread the word to end the word.

What quenching and tempering does to SWORDS

Trigger warning: Aussie accent...keep hacky comedians and actors away lest they start doing the Philosophers song.

There's a whole bunch of high-quality explanation in this one...

• 1:19 - percentage breakdown of carbon in various steels (low carbon, medium carbon, high carbon)
• 1:49 - "When the iron is hot...reaches the austenite phase...lost magnetic interaction...body centered cubic or face centered..." Honestly, he screws up the crystals verbally (though the graphics are correct) but does nicely say that "there's more room in between the iron atoms when it's this hot which means carbon atoms can all fit around evenly wherever they want" and that "when iron is cool...they try and squeeze out the carbon in between these iron atoms" and shows ferrite in the graphic
• 2:56 - micrograph of ferrite and cementite as the carbon in squeezed out from between the iron atoms, making pearlite
• 4:16 - Say "crystals" not "structure", man...c'mon
• 4:44 - discussion of work hardening and how that's lost once the metal is reheated, "it loosens the insides. It basically gives the opportunity for the stresses to be released and moved around and become uniform...as soon as you heat it up, you're losing whatever benefits - but also detriments - you might've put into the steel"
• 8:16 - "When heated up to where austenite is formed in the steel, the carbon is not forced into these veins/pocket/lines...and if you were to cool it down rapidly, you can actually give those iron atoms not enough time to force [carbon] out into these more condensed pockets...and a different, amazing crystalline structure is formed within the steel called martensite"
• 9:40 - "[Martensite] can be very useful to swords because you want swords to have a very hard edge, but you don't want them to be too brittle"...Goldilocks of metals, eh
• 10:05 - how the Japanese solved the problem, great diagram of the anatomy of a samurai sword (ion core, pearlite jacket, martensite edge) created via clay control of cooling rate
• 11:50 - tempering makes its appearance...we've been waiting, Shad
• 12:30 - showing quench of a katana with differential cooling causing bending in both directions (flubbed vocals but corrected captions)
• 13:10 - "[tempering] releases stress between these dislocations creating a much greater level of ductility and flex in between the crystal structure that's being formed within it" - nice micrographs of martensite and tempered martensite
• 15:00 onward...what makes for a good sword, particularly its sharpness...not so much material science 

Crystal Birth

Well, those are just gorgeous.

The video is nothing but close up, sped up growth of reduced metal crystals from metallic ion solutions. There's no mention of what the anions are, but we do know that the crystals were grown via "electrocrystallization - Metal deposition actuated via electrodic reduction on the electrode surface. An electric current operates a metal deposition reaction."

But they're just pretty to watch...

Ecovative's Mushroom Tiny House

Edit: 12/20/24 - updated links to buy Ecovative kits.

How's your little mushroom house going to stand up to that kind of an attack?

From their MushroomTinyHouse.com website

Ecovative uses mycelium (mushroom “roots”) to bond together agricultural byproducts like corn stalks into a material that can replace plastic foam. We’ve been selling it for a few years as protective packaging, helping big companies replace thousands of Styrofoam (EPS), and other plastic foam packaging parts. We’re now working to develop new products for building materials.

Here’s how it works. Mushroom Insulation grows into wood forms over the course of a few days, forming an airtight seal. It dries over the next month (kind of like how concrete cures) and you are left with an airtight wall that is extremely strong. Best yet, it saves on material costs, as you don’t need any studs in the wall, and it gives you great thermal performance since it’s one continuous insulated wall assembly. The finished Mushroom® Insulation is also fire resistant and very environmentally friendly.

In all honesty, that's a pretty exciting swap - fiberglass insulation or styrofoam packaging material for mycelium. That's going to be a heck of a lot easier to dispose of at the end of the material's life.



This is the part that excites me most for a material science classroom. They offer grow-it-yourself kits to make the ecovative material at home.


The giy.ecovative.com link doesn't work anymore. Instead, try these links. Yes, but what if somebody comes at your house with a pizza oven and some pepperoni?

You Won[']t Believe What Super Glue Does in Borax

If you're going to try this yourself, make sure to do this in a well ventilated area. As you can see at 4:58 (and onward), the fume that come off of any large amount of super glue require a lot of ventilation.

That being said, I have absolutely no idea why you would want to recreate this experiment at home.

I can't personally come up with any way to turn the immediate, catalytic solidification of cyanoacrylate glue in borax into something useful for class.

Does anybody out there in the blogosphere have any ideas about how to turn this into something useful?

From DNA to Silly Putty, the diverse world of polymers - Jan Mattingly

I don't really appreciate the cartoon graphics of chemists adding one drop of a reactant (2:25 and 3:15) to an Erlenmeyer flask resulting in an instantaneous explosion.

But that's a pretty good summary of just about everything we teach in our polymer chapter. The video introduces monomers and polymers, natural and synthetic polymers, addition and condensation polymerization, some history of man-made polymers (bakelite, Silly Putty), drawbacks of synthetic polymer use.

Maybe this will be an end of the chapter review next year.

Tyvek round-up

I've been searching for a video showing the production of Tyvek, and I haven't had any luck. I've found a bunch of videos (not those shown below) that show the manufacturing of products made of Tyvek (disposable hazmat suits, festival bracelets, a whole bunch of wallets and tents and bivies), but I haven't found anything that will show me how the original 'fabric' is made.

Along the way of my searches, though, I came upon a number of interesting Tyvek videos...

From what I can tell, DuPont (Tyvek's manufacturer) seems most concerned about distinguishing their product from SMS (spunbond-meltblown-spunbond) and MPF (microporous film).



The further data on the DuPont website isn't terrifically detailed, admittedly, but I very much like the simple method they set up to test the permeability of the different materials.



The Professor Tytonius (?) video is hoaky, but the tests are the sorts of things my students could probably reproduce in the classroom to gauge the permeability of the various underlayments.



That's just gross. However, if I were doing work like they show at the end, I think a Tyvek suit would be appreciated.



Again, a straightforward test that my students would reproduce...




I appreciate that they do end by saying that Tyvek isn't really meant for paintballing.



Simple test...I like it...



So, Tyvek isn't bulletproof? Good to know...

Piezoelectricity round-up

Clearly piezoelectricity is way more common than I knew.

Sugar crystals? DNA? Bones? All are piezoelectric?

And if piezoelectric crystals lack a center of symmetry (2:20), how the heck is quartz piezoelectric? It looks awfully symmetrical to me.

Apparently, though, the quartz crystal is absolutely piezoelectric, as shown by Bill Hammack, the Engineer Guy...



Theoretically, it's possible to make and test your own piezoelectric crystal at home...(though sadly he uses a commercial piezoelectric crystal to make his guitar pickup)



As to how we can make use to piezoelectrcitiy...

• Top uses of piezoelectricity in everyday applications (inkjet printers, earbuds, tennis racquets, course-changing bullets, humidifiers, sonar, pressure sensors)
• Applications of piezoelectricity (from wikipedia)
• Piezoelectricity and its uses (even explaining how some tennis racquets use piezoelectrcity)

Summer camp map 2018

Have you ever had déjà vu?

Or maybe déjà map?

This year's map of the ASM material science summer camps is now available (just in time for the first camp to start in a week and a few days (not Memorial Day week but the week after that).

We progress, as we have the past few years, from red during the early summer through to purple in mid-August. There is one black pin because the dates of the Knoxville camp hadn't been finalized when the list I was working from was published.

If you have any questions about the camps - and I think the vast majority of folks who frequent this blog do so because they've attended a camp - ask 'em in the comments or to me via email (phschemguy at gmail.com).

If you happen to go through the maps from the past five years (linked above), you can also see how Google maps has changed the appearance of its pins. For a more detailed look at the changes, check out Justin O'Beirne's fascinating series of posts.

Matter, Energy, and the Material Scientist

I'm hopeful that there are more creative uses for the formcards that are demonstrated above than just making toothbrush holders.

I do appreciate the demonstration of the formcards' glass transition from solid to flexible solid. I'm curious to see some data as to at what specific temperature that happens for this specific polymer (check the MSDS, and you still won't know).

How It's Made - 1372 Ultra Thin Glass

Standard materials such as lime, sand, soda, and pot ash...plus "smaller, secret ingredients...[to] enhance optical clarity and electrical conductivity"

There's a lot that's not being said there in those quotes.

The real payoff of this video is - to me, anyway - the thin, sagging ribbon of glass at 2:49 through 2:58 then the rolled-up glass at 3:25.

That's stunning.

Computer Plastics Recycled Into Toys

Source

As Thomas Thwaites mentioned in his Toaster Project TED talk (and as did one of last month's videos at about 5:35), we have plastics within us.

Well, as reported in Chemistry World, "[r]esearchers in Europe have narrowed the search for bad recycling practices that are to blame for some toys and food packaging inadvertently containing banned pollutants." And they've found ways to check this using handheld x-ray fluorescence spectrometers rather than the much larger gas chromatography method.

"The team found evidence for brominated flame retardants in 61% of 26 samples of toys and cup lids. Rare earth element concentrations in the positive samples correlated to a particular waste stream – plastics used in copier, laptop and computer casings – for the first time providing evidence on the source of the problem. "

Stupid copiers...

A potential solution to the sand crisis - FINITE

Actually 'melted down' to be reused? A different resource I read said, [t]he recycling process is a secret but talking over email,  Oza described the gist: “We use a non-toxic solution that allows the material to enter a more liquid state that can be recast or reapplied” in new Finite-based constructions.

That reads to me a lot more like either dissolving or de-polymerizing rather than 'melting'.

The actual information about Infinite comes at 4:30 in the above video: the reasoning, the general method of binding the desert sand, their testing, the project's future.

Sadly they are very tight-lipped about the method of binding the desert sand together. I'm really curious about it.

More reading about Finite...

• The Next Great Building Material? It Could be Sand from Deserts
• Finite's website

Sand shortage - update

I've mentioned the world's growing sand shortage before and thought I'd take a moment or two to update you with a few more articles.

• NPR - 7/21/17 - "World Faces Global Sand Shortage"
• Pulitzer Center - 7/28/16 - "The Global Sand Shortage"
• NY Times - 6/23/16 - "The World's Disappearing Sand"
• Independent - 12/6/17 - "Sand mafias and vanishing islands"
• South China Morning Post - 12/31/17 - "The world is running out of a resource, and it's not oil"
• Noccolls & Dimes - 4/23/18 - "Written in Sand"
• Wired - 3/26/15 - "The Deadly Global War for Sand"
• Dezeen - 10/11/17 - "Sand becomes 'increasingly scarce and expensive,' threatening glassmaking and construction"
• Dezeen - 7/18/17 - "Atelier NL calls for sand samples from all over the world to make region-specific glass"

Some folks are working on solutions, however, but I'll save that link for next week...

(Ooh, a teaser...)

CarbonCure Technologies - Simply better concrete.

When the claim is that spectacular...

CarbonCure works with existing concrete factories to simply add CO2 without changing the concrete recipe or machines. CO2 is collected from smokestacks of large polluters like coal power or cement plants and brought to the concrete factory for recycling. Our proprietary technology injects the CO2 gas into the concrete where it is converted into more stone within the concrete...

The best part is that it costs about the same and it keeps the same good looks and durability that you're used to with regular concrete.

It's green concrete without the trade-offs.

...I find myself skeptical as to just how we get benefits without any downsides at all.

Ok, I don't get it. My understanding is that cement is produced by heating calcium carbonate to decompose it into calcium oxide and carbon dioxide. Why, then, can we just add the carbon dioxide back into the concrete to produce calcium carbonate later in the process? And if that's the case, why did we both to take the carbon dioxide out of the calcium carbonate in the first place?

I'm confused.



How does the CO2 get trapped?

According to a CNN article,

CarbonCure's system takes captured CO2 and injects it into concrete as it's being mixed. Once the concrete hardens, that carbon is sequestered forever. Even if the building is torn down, the carbon stays put. That's because it reacts with the concrete and becomes a mineral.

...

"The best thing about it is the mineral itself improves the compressive strength of the concrete," Christie Gamble, the director of sustainability at CarbonCure, told CNNMoney."

Again with the extraordinary claims. I'm going to need a little more detail.

From the CarbonCure website...

The technology may be used to increase the compressive strength performance of a concrete mix. The strength improvement can then be leveraged in the optimization of the mix design for a specific end goal[.] (source)

...

Once injected into the wet concrete mix, the CO2 reacts with calcium ions from cement to form a nano-sized calcium carbonate mineral that becomes permanently embedded in the concrete. (source)

I hope that this technology is as perfect as is suggested, but I'm not holding my breath.

Plastic Pollution: How Humans are Turning the World into Plastic

I am wildly unhappy with the results of the survey quoted at 6:25: "making a single-use plastic bag requires so little energy and produces far lower carbon dioxide emissions compared to a reusable cotton bag, that you need to use your cotton bag 7100 times before it would have a lower impact on the environment than the plastic bag."

Seriously?

That's kind of depressing.

The video actually does a great job presenting a very balanced view of plastics, presenting facts that show that just not using plastics isn't as easy as it looks at first blush.

Expanding Foam For Filling Post Holes

So, the reason I'm posting these is that there's apparently a new-to-me use for the expanding polymer foam that we use in our polymers labs: filling post holes.

I've always heard of using cement - or quickcrete - for setting fence (or mailbox or basketball goal) posts, but I guess expandable foam could be strong enough to work.

There are multiple options, however, not just Sika's product.



The above video - made by Secure Set - demonstrates that their product is far superior to Sika's and that Sika's product container while convenient can be explosively dangerous (2:54).



Admittedly, the Secure Set videos just might be a little biased toward their product.

Then again, so is the Rainbow Foam video. Though I like their clinical narration and reasonably consistent tests.



I do with they would name what product P and product B are. I have to assume those initials were chosen because they fit the product names that I just don't know.

Oh, and there is a bit of blood in this video as the mute demonstrator cuts himself in the video cut between 9:10 and 9:14. It's not spurting blood or anything, but I thought I'd warn you.

And I am kinda glad we get to finally see the demonstrator's face at 16:35.

Admittedly, that last video is way too long, but I appreciate that they show that the tests have to be performed on each of the products with reasonably repeatable precision.

Updated cKit manual!!!!!

We've been giving out cKits from the National Association of Corrosion Engineers (actually, they're just NACE now) at our ASM summer teachers camps for quite a few years now. The Kit is outstanding, and contains a lab manual, a comic book of Inspector Protector, a set of electrodes, a multimeter, a booklet about NACE, and a CD of the lab manual.

All of which is great...

...except the lab manual.

Which was great once but has been recently showing its age. The labs were developed by some of our ASM master teachers for NACE, and you can see their students in the lab photos. Since the labs were developed nearly twenty years ago now, however, our procedures have been refined and adjusted to be more successful, more portable, and often less wasteful. During the summer camps, then, we've been sharing the adjusted procedures and telling our campers to make those adjustments in spite of what the lab manual says.

But now we won't have to do that anymore because the lab manual has been updated.

I'll admit that I'm going to miss the iPhone-commercial-like graphics, but I'm thrilled that the manual now includes our procedure for brassing a penny.

In case you've taken our camp already and have the old version, a pdf version of the new manual has been posted by NACE on their website.

Material Science Girl's website

Material Science Girl is one of our ASM, summer camp, master teachers. She's at Tolles High School on the far west side of Columbus, a vocational high school that teaches two years of material science.

Her curriculum - created and taught along with another master teacher at Tolles - started out being pretty similar to our summer camps but has grown and evolved from there.

As a way to share documents and videos with her students - and with you and us - she made a website (matscigirl.weebly.com).

On the site, she has absolutely no personal information about herself, but she's pretty awesome. She does have individual sections about...

• ASM summer camps
• Solids
• Metals
• Ceramics & glass
• Polymers
• Composites

Sadly she doesn't have photos of the outstanding projects that her students made, but she does have a whole bunch of articles, worksheets, and lab instructions that she uses in class.

Plus she's used only her own in-class photos to mark the website sections.

How is plastic recylced?

The short answer to Andy Brunning's question, of course, is that it's recycled badly and far too infrequently.

I'm typing this up on Earth Day - though it won't post for a month or so now - and am just torn up that less than 20% of the PETE is being recycled, but I watch my students through water bottles away all the time even though the recycling bin in two inches to the left of the trash can.

I don't have any idea why recycling is so infrequent because it just seems like an automatic thing to me at this point. I'm the one carrying cans away from meetings because there aren't recycling bins in our meeting rooms.

Why Concrete Needs Reinforcement

It's the jorts (2:39), the New Balance shoes, and the pasty, white legs of one Grady Hillhouse that really endear this video to me.

Yes, Grady's style is a little dry, but he does a marvelous job showing very basic concepts of engineering as they apply to our everyday world and not just talking about the concepts but rather by building and showing small, graspable demonstrations.

In this video, Grady shows...

• how much force it takes to break two 'identical' concrete cylinders - one under tension, one under compression
• concrete beams (fairly thick beams) tested to failure with a four-point break test - a beam with no reinforcement, with 'rebar' reinforcement, and with pre-stressed 'rebar' 

Dissimilar metals and Galvanic Action - Acorn to Arabella

A little background first, the YouTube channel Acorn to Arabella...

We are building a 38’ wooden sailboat designed in 1934 by William Atkin. Atkin calls this particular boat “Ingrid” but our vessel will be named “Arabella”, once built we intend to take her to the most far flung corners of the world. We are documenting every aspect of the build as we go, we hope to inspire and educate people along the way and to experience as much of this wonderful world as possible in the process.

In this week's episode (or rather the episode from April 13, 2018), Steve (the guy with the awesome beard) is looking at using various metals as fasteners on the boat. Apparently it matters whether the metal is very reactive (less noble) or not very reactive (more noble).

Specifically, Steve puts various metal samples in salt water alone and in various combinations to see which metals should and should not share fasteners in the boat.

I haven't yet checked out the follow-up where Steve looks at the effects of the metal corrosion on various woods.

You Can Hear The Difference Between Hot and Cold Water

The title of the video, "You Can Hear The Difference Between Hot and Cold Water," is clearly wrong and stupid.

There's no way that you can hear the difference between hot and cold water at all.

Except that the video makes clear that you can...because of viscosity.

Red Hot JACKHAMMER Vs. Frozen Lake

While standing on a frozen lake and trying to jackhammer through said lake with a red-hot jackhammer tip seem like a real, "hold my beer" kind of moment, that's not why I posted this video.

Instead, it's because of the utterly surprising but in retrospect kind of obvious results from the red hot jachammer tip.

See, the first four minutes are the guy (host of the Hydraulic Press Channel) just digging his way through half a meter of ice with a non-red-hot jackhammer. Meh...

It's at 4:19, though, that the material science gets real.

(Spoiler...watch the video first, at least the part from 4:00 through 4:30 before you highlight the text below)

At 4:19 the red-hot jackhammer tip meets the ice, and the jackhammerer learns a little bit about the effects of phase changes on steel. The tip - now properly softened via BCC to FCC phase change, curls right in on itself like it was made of soft butter.

He and his wife laugh like loons as the tip curls into nearly full U-shape.

Brilliant...

To quote at 4:49, "I think this is bad idea."

Then we're treated to an up-close replay at 5:03.

After about 5:40, then, there's nothing much to see here. Just a guy hammering away at blocks of ice he's cut from the lake's surface.

The money shots are all between 4:00 through 4:30 - or maybe through 5:30 if you really want to fill a little more class time.

The Disaster That Changed Engineering: The Hyatt Regency Collapse

The initial design was good.

The engineer signed off on the design change.

He shouldn't have.

I'm always appreciative of someone who can explain complex ideas in such a simple fashion, and Grady from Practical Engineering is such a someone, using a simple model to show the differences in forces in the original and revised design for the walkways.

The Physics of Slingshots 2 | Smarter Every Day 57

I keep wanting to tell Destin that he's gonna shoot his eye out.

But it looks like he still has his predator vision at the end of this video, so that's his business as to whether he wears goggles or not.

At 2:13, Destin shows a graph of the potential and kinetic energy of the ball/band system as the band stretches and releases.

At 4:39, he then uses actual data/video to show that a tapered slingshot band accelerates the bullet faster than does an un-tapered band.

Then, at 5:00, our favorite - the stress-strain curve - shows up.

Sadly, some of the links in the video description to learn more about hysteresis, for example, are dead.

Destin got two videos out of his visit with Jorg (check the slingshot channel for even more). The other video doesn't have as much material science content, but it's still fun, and it shows some momentum and energy calculation with a gigantic slingshot.

COLD HARD SCIENCE: SLAPSHOT Physics in Slow Motion - SmarterEveryDay

Yes, a hockey player with a missing tooth is frighteningly stereotypical.

The sight of the hockey stick at full flex - in motion at about 2:35 - is outstanding...as is the idea that the player likes his stick 'whippier'.

I'm not a hockey player, but I was a tennis player, and I understand the same idea in a different application. Players can choose how much tension they want in their strings when the tennis racket is strung. Stringing at a lower tension allows the ball to deflect the strings more, creating more of a trampoline effect and generating more power. The cost to that is a decrease in control - worse aim - because of that increased power.

Here's a second video going through the same physics - for the first seven minutes anyway. After the first seven, we get a look at the physics of a wrist shot and a hockey player's workout.

Personally, I prefer Destin's enthusiasm.

Modified sponge mops up oil but not water

"Due to the nature of the industry, cost-effective high absorbents are needed...Any advancement to have high spill sorbent is of use." ~ Seshadri Ramkumar

See, what he's saying is that the oil industry (and the shipping industry and pretty much everybody else) spills oil in the ocean...and lakes...and rivers...and fields...so we need to be ready to soak up the oil.

The environmental impact and morals of our modern dependence on fossil fuels aside, the chemistry here is pretty cool.

Though the name of 'compound 1' seems a little odd to me because I can't imagine that the first compound they tried was their successful attempt. There's a reason why we have Formula 409.

Watch glass objects disappear and learn about the index of refraction

Has anybody out there actually been to the Exploratorium out in San Francisco? I assume it's a great science museum, but I've never actually been to San Francisco.

The video above shows an experiment comparing the index of refraction of pyrex (borosilicate glass - the rods that disappear) to that of, I assume, soda lime glass (the rod that stays visible). Pyrex has a nearly identical index of refraction as does corn or vegetable oil (and mineral oil, too). Because of that, Pyrex 'disappears' when soaked in corn oil.

For a slightly more theatrical presentation, check out Steve Spangler's take on the same experiment.



The demo also works with ghost crystals...


I've also heard that it works with colorless gelatin, but I haven't found a video of that, and I haven't tried it at home...yet...

Watch NASA Plane Fold Its Wings Mid-Flight

We've been hearing for a few years that plane designers are trying to use NiTiNOL to change the angle of the wings or of the fins (my terms, probably not the term of the designers) behind the jet engines.

Now, it looks like NASA might've been successful in adjusting the wing angle using a memory alloy.

And, if you were curious about the size of the plan we see above, here's a longer video with a little more context and without the voice-over.

Scrub Daddy Science

I bought a Scrub Daddy a couple of years ago and have been using it to demonstrate glass transition in polymers since then. It's good, however, to know a little more science than what I've been explaining ("it's a polymer, and they have phase transitions from rigid to flexible").

The above video shows the phase transition and the 2012 patent (linked here) for the Scrub Daddy. The blog entry associated with the video has more information as well as data from a few experiments (FTIR, for example) done with the Scrub Daddy.

In a semi-exciting detail, the video also shows that the thermoplastic polymer from Education Innovations is the same polymer as the Scrub Daddy. Conveniently, I already have that product in my storage room.

How cool is that?

But wait, there's more...





And also a video that I don't understand in the least. It's a wordless video of somebody pouring slime on a Scrub Daddy and squishing it with what I believe to be added sound effects. Clearly the internet it the realm of the long tail.

Why Bridges Move... (and more thermal expansion demos)

I wouldn't want to get my hands caught between those jaws on a hot day.

I don't know that I would actually show this video in class. The demonstrations of thermal expansion aren't all that impressive. The explanation and theory is solid, but the demos could be a little more impressive.

Like these, for example...

TRANSPARENT Solar Panels?!

We can maybe back off with the question mark-exclamation point ending on the title, folks.

I'll take 'not 100% transparent' any day of the week if it means that we can turn our windows into solar panels. That would be outstanding.

I am a little curious, though, about just how 'not 100% transparent' they would be. The whole <640 nm thing would be around red/orange, and their explanation that longer wavelengths would travel right on through seems odd. Longer than red/orange doesn't leave a whole lot of colors because the rest of the colors are shorter wavelengths than red/orange.

Turning air into plastic?

I remember the 'Anything Into Oil' claims. The article was first posted in 2006, and I thought our environmental concerns were solved.

It has, of course, been eleven years now since that first article, and we're still throwing away trash and pumping oil out of the ground - at increasingly desperate cost to our environment.

So, in the spirit of  'extraordinary claims require extraordinary evidence', I'm not going to hold my breath until the airplastic comes to a store near me and gets the full scientific exploration that it deserves.

And as much as the science of this video from Thuderf00t seems sound, I don't know his bonafides either.

All that being said, the concept of sequestering carbon from the air to make the plastics that we're already using is pretty outstanding. I'm skeptically hopeful.

Why Roman Concrete Still Stands Strong While Modern Version Decays

Concrete, strong stuff...

But apparently Roman concrete is among the strongest stuff, and it just got stronger while it was under seawater.

Previous work had revealed lime particles within the cores that surprisingly contained the mineral aluminous tobermorite – a rare substance that is hard to make.

The mineral, said Jackson, formed early in the history of the concrete, as the lime, seawater and volcanic ash of the mortar reacted together in a way that generated heat.

But now Jackson and the team have made another discovery. “I went back to the concrete and found abundant tobermorite growing through the fabric of the concrete, often in association with phillipsite [another mineral],” she said.

She said this revealed another process that was also at play. Over time, seawater that seeped through the concrete dissolved the volcanic crystals and glasses, with aluminous tobermorite and phillipsite crystallising in their place.

These minerals, say the authors, helped to reinforce the concrete, preventing cracks from growing, with structures becoming stronger over time as the minerals grew.

And it looks like the Romans knew what they were doing.

As the authors note, the Romans were aware of the virtues of their concrete, with Pliny the Elder waxing lyrical in his Natural History that it is “impregnable to the waves and every day stronger”.

If you want to read more, check out the original research article...or the Guardian article that's way more readable and that I quoted up above.

Update: ...or check out a CNN article about the same research.