Tech Tuesday 06/11/19 – Back in WA Edition
It is so good to be back in WA, where the sun does not assault your skin!
TT01 – We should do this with every major bridge. Not just the installation of sensors, but making the sensor data public.
TT02 – I love it when we can manage some bio-mimicry. Even more so when we can get close to the performance nature manages. But doing it better? I’m always a little skeptical when it comes to claims made by Chinese teams. I am certain they’ve got something interesting, I’m just not sure if it really is better than polar bear fur.
TT03 – Given the means by which the data was collected, I’m sure there are some pretty healthy error bars involved. That said, this does warrant a more rigorous inspection.
TT04 – I have been talking about Tweels (now,Uptis) for years now. Too many damn years. It’s good to see them putting these things on the road (they’ve been on construction vehicles for a while now), but they took an awful long time to work out the lateral stability issues. Of course, that might be because they wanted them to be printable, and fully recyclable, and that is going to limit the materials you can use.
TT05 – Making the MRI scan quicker is good, but can’t they do something about the hammer noise?
TT06 – I love this idea, but the name… Space Rider sounds like the name of my 70’s Prog Rock Tribute Band.
TT07 – My guess is that the random nature of the metal foam creates so many pathways for energy to travel along that the kinetic energy just dissipates as it shatters those pathways.
TT08 – I could also see this as a kind of reactive armor, if it can respond to the applied magnetic field fast enough. Think about something like motorcycle armor that is soft like leather unless it detects a crash, then it hardens into plates to protect the rider.
TT09 – And here you thought Tesla was introducing a hazard to navigation. Cornell has handed someone their beer.
TT10 – I’ve seen similar designs at the Lazy B, but they were often set aside as just requiring too much work to make feasible, especially given the difficulties had with the Blended Wing Body (BWB) design. There is nothing terrible wrong with the design itself, but it is not aerodynamically stable in the same way that tube and wing aircraft are, which means figuring out new calculations for how to determine the stability. Although I do have to wonder why the model shown has crazy long landing gear, when there is nothing under the wing or body? About the best I can think of is that they expect a high angle of attack at take off and landing and want to avoid a tail strike.
TT11 – It’s a proof of concept, but this tower is built with engineered wood that is programmed to bend and twist into a final shape as the wood dries out.
TT12 – So about those Paleo diets, you may want a genetic test done before you start along that fad.
TT13 – Editing stem cells in situ. Better for the cells, and it ensures that a gene therapy doesn’t get overwritten by stem cells that retain the original error.
TT14 – I don’t want to say it’s aliens, but given all the Sci-Fi I’ve read concerning giant ships being hidden under the surface of the moon…
TT15 – If it is as efficient as they claim, it’s an interesting way to recycle certain plastics. I question the carbon balance on this, though.
TT16 – Gold could be the new green in the world of synthetic photosynthesis, especially as it could enable the generation of liquid hydrocarbons.
TT17 – Another day, another story about how little we understand the impacts of gut flora on our health. In this case, how gut flora can metabolize ingested medicine, making said medicine more, or less, effective.
TT18 – If we had a way of protecting people living near nuclear reactors, would they feel better about it?
TT19 – If a robot can pick a raspberry, back breaking Ag harvesting may soon be at an end.
TT20 – I foresee a future where the Black Rose is synonymous with pure water…
Photo by Kaspar C 
TT03: Every time new tech for remote methane sensing is deployed, it turns out that some industry or another is leaking methane at an order of magnitude higher rate than previously assumed.Report
Is that an indictment of how we officially asses methane discharge, or of how remote sensing tech tends to overblow the leakage?Report
More the former then the latter, as methane discharge in regulated industries is significantly self-reported.Report
What Philip said, at least in the oil and gas industry. The EPA’s official methodology is bottom-up, and makes assumptions about best practices, equipment failure rates, etc. A few years back Colorado toughened its standards and the companies were required to do a lot more measurements. What they found was more leaks, and bigger leaks, than anticipated. All of that lost gas was money flying away — the industry has improved its practices considerably. Even though drilling and production activity is up quite a lot since the new regs were put into effect, the number of reported leaks and their size are down significantly.
My son-in-law supervises the fabrication shop for a company that builds custom manifolds and such for oil and gas producers. The company’s forte has always been quality — better welding, zero corner-cutting on testing, etc. Starting a couple of years after the new regulations were in place, their business has been growing quite a bit.Report
I double checked the article’s numbers, and sure enough, they fail the metric system.
Given their finding that 0.34% of the natural gas used by fertilizer plants is leaking, they correctly extrapolated to an estimate of 28 gigagrams of leakage, which is 28,000 tonnes. That would mean the fertilizer plants consuming 8.2 million metric tonnes of natural gas, whereas based on CO2 emissions (including re-use), I’d calculated a usage of 8.6 million metric tons, with the difference probably due to using a slightly different year’s data.
Where they screwed up was with the EPA emissions figures. The EPA and everyone else said that industry leaks 8,000,000 tonnes of methane, which was updated by a surprising finding that the actual leakage rate was 60% higher than assumed, at 13 million tonnes.
Google thought that 8 million tonnes, which is eight billion kilograms, is a gigagram, but it’s actually a teragram. They then used the erroneous eight gigagrams figure to find that the fertilizer plants emit 3.5 times more than everything else in the US, when the actual number would be 0.35% as much as all the other emission sources.
Now they’ll get laughed at by everyone in industry for not knowing how to shift units between tera and giga.Report
TT03, the story about Google researchers finding that fertilizer plants are emitting three times more methane than the rest of the US, is probably a reflection of garbage data. Natural gas isn’t pure methane, and I suspect some other component of it that isn’t used in the Haber process might be going through the high-temperature, high-pressure process and producing a compound that pegs the needle on Google’s remote sensors, even at trace amounts.
The US fertilizer industry only consumes 8.6 million metric tons of methane, based on how much CO2 they produce. The hydrogen is stripped to combine with 9.6 million tons of nitrogen, resulting in 31 million tons of CO2, of which 24% is recycled to make urea and other products. The reaction produces the same waste heat as burning 4 million tons of the methane input, and 51% of that waste heat is recovered.
The EPA’s estimate of methane leaks from just the production side is 2.3%, or 13 million tonnes. Just using that figure would mean that the fertilizer industry is emitting 4.5 times more methane then they’re buying from the gas companies.
So if Google’s data was accurate, the oil companies should just run pipes from the fertilizer plants to their other customers and quit drilling holes in the ground.
Fertilizer production is a very expensive undertaking in a highly competitive world market, and the chemical engineers optimize it every way they can because they have to buy all the natural gas and other inputs, unlike an oil company that can just vent the gas because it’s an unwanted byproduct of drilling holes in the ground.Report
The article says:
Actually, just from leakage on the production side, the number is 13 million metric tons, which is 13,000,000 tonnes, 13,000,000,000 kg, or 13,000,000,000,000 grams. The older EPA number would have been about 8 instead of 13. But that’s a teragram, not a gigagram.
What they’ve probably done is assume that a gigagram is a billion kilograms, which is off by a factor of a thousand.Report
A former co-worker left to start a company doing that kind of survey from the air, and it took three PhD’s and several experts in optical sensors to develop the kind of equipment needed and turn the measurements into actual data. This isn’t something you can do with a gas detector that you bought at Lowe’s duct-taped to the roof of your car.
That said, the company was hired by industrial gas providers and producers, and they weren’t allowed to republish the data on leakage afterwards. He did let on that what they was a lot higher than anyone was really willing to talk about.Report
I pulled up the original paper and their science and technique section looked really thorough. I suspect that when they reached their erroneous conclusion caused by screwing up the metric system on the EPA’s emission figures, they went over their methods really carefully because they thought they had a truly shocking result and wanted to be absolutely sure their data would hold up. Unfortunately, they apparently never double checked their conversion of the EPA figure from tonnes to grams. Peer review didn’t catch it either.
I left a short little comment on the paper pointing out the mistake.Report
TT04: So Michelin has managed to use a complex shape made out of advanced polymers to replicate what everyone else can do with compressed air, which is virtually free, and which results in a tire whose innards don’t get filled up with gravel when you zip down a rural road.
If we had been using the Michelin tires all along, and some garage mechanic in Alabama came up with a way to make a tire using just compressed air, we’d have hailed him as the genius of the age.
Yeah, I’m probably in a bit of a skeptical mood after TT03.Report
Modern tires are an exercise in complex composite materials, and when you get a hole in them, you run a very good chance you will have to throw them out, and maybe the rim too.Report
Well, given how those tires flex, gravel that lands in the open area, where it will likely be held by centrifugal forces until the car stops, is probably going to chew them up. They might want to consider a fabric sidewall made out of something like Kevlar, just to keep out debris, and especially mud.Report
Google images of airless tires mounted on construction vehicles, see how they deal with it.
Alternatively, we can assume that there will be different variations on the theme, so if you frequent gravel roads, you get a different kind of wheel.Report
TT03 – the Google Car is a driven vehicle that does all the Street View imaging. SO its not a hazard to navigation. Yet. The Methane sensor is just a small add-on that puts additional data into the cars memory bank. Interestingly, NOAA has similar under reporting of methane emissions from fracking out west.Report
Did I say the Google Car is a hazard to navigation?Report
[TT10] oh hey there extreme-aft CG, how are you today? still flipping the aircraft over? cool, cool, catch ya later!
I mean, it’s at least an interesting approach to solving the problem of “elliptical cross-sections are not as efficient as round tubes”, but I that looks like the aerodynamic center is going to be *way* too close to the center of gravity. The thing’ll flip like a coin! I kinda feel like the solution would be to fill in the opening of that V-split, but that adds weight, and eventually your design isn’t any better than the way we’ve been building airplanes since forever. Ye canna change the laws’o physics, cap’n!Report
That’s where I was going with my comment. Can you make it work? Yeah, sure. Is it worth the effort? Boeing kept looking at it, and kept saying ‘no’.
Maybe now it is worth the effort, if part of the effort is on someone else’s budget. Perhaps TU Delft got themselves a fancy new computing cluster and is itching for something they can use it for.Report
[TT19] the shocking secret here is that we’ve had the capability to do this since the 1970s, we just didn’t, because it was cheaper to hire migrant workers and pay them cash. It wasn’t just a California and Texas thing, it was all over; retirees or Okie pickers driving from state to state, and up north it was Canadian families who’d move across the border for a season and pick blueberries and apples. As the illegality of hiring migrant pickers is being increasingly enforced, the cost of work increases, and it becomes worth it to buy machines to do the job.
I mean, that’s the thing; as with coal mining, ag-labor jobs are gone and aren’t going to come back. If we make the cheap labor illegal people will just mechanise, and then you’ll need skilled labor to operate and maintain the machinery.Report
[TT07] I’d say it’s probably the number of thin membranes undergoing buckling as the load hits them. Buckling and crippling cause a great deal of plastic (that is, permanent) deformation in a material, and plastic deformation is very dissipative of energy (this is why cars have crumple zones.) Foam, by its nature, has plenty of thin membranes, which means it’s very dissipative of energy.
You could probably get a similar effect by using honeycomb, but the honeycomb is directional–if you don’t line up the axis of the honeycomb holes with the bullet, then it’s just punching through the sides of the foil walls and that hardly does anything. The foam’s advantage is that the bubbles result in “walls” oriented in every direction.Report
This. Sorry, I was knocking this out in a hurry.Report
Due to what you mention, the area or volume undergoing deformation is probably much larger, a bit like a foam mattress, instead of the thin cone of deformation around the projectile’s path that you get with homogeneous armor.
And each bubble in the direct path might be acting like a saw tooth to shred the surface of the projectile, as opposed to a solid cylinder (with a cone in front) applying uniform pressure that helps maintain the projectile’s shape. A foam has places for the shavings to go.
If that is part of what’s going on, it would be interesting to see how foams do against shaped charge projectiles, where they might be better at turning the uniform stream of molten copper into more of a spray pattern you’d get from your faucet’s aerator.Report
I have concerns about the rates of ablation of that foam. It appears to be ejecting considerable volume per impact.Report
That’s not the foam ablating, it’s a ceramic cover plate.Report
Ah, so that brings up the next question on how it performs after the ceramic is ablated?Report
Good question. One thing to note is that the researchers admit that they were using what was basically COTS facing and backing material, and the bonding agents employed were not ideal for mating that material to the foam, so a lot of what you see may be the result of ‘cobbled together’ armor, rather than something that had been designed with purpose.
Which means, once they begin optimizing for the foam, it could be scary good.Report
I was thinking the next jump in bullets will be a ceramic clearing tip with a dart thing behind it, (if it hasn’t been done already).Report
The thing about arms and armor is that each advance* makes it more expensive for someone else to wage war against you. An anti-material round that can penetrate foam armor will probably be expensive to buy, and difficult for companies to make, so you won’t have them readily showing up in Khyber Pass workshops.
*Hopefully. Sometimes the other side gets clever and finds cheap and easy ways to defeat your expensive new toys.Report
Just dump a bucket of black paint or tar on a modern tank and they’ll be blind as a bat. Even fancy active countermeasures to remotely strike an incoming projectile would just give the bucket of goo a better spray pattern.Report
Here you go.Report
Ha.Report
The sun doesn’t assault your skin in WA, but for four months it doesn’t register in your brain as “daylight”.Report
Here’s another piece of tech/defense news.
Defense News: Supersonic speeds a problem for F-35 stealth coating
The stealth coating isn’t compatible with the heat at the back end of the plane.
And this potential happens at Mach 1.3, which is just peachy.Report
So many asterisks in that statement that appear when you read the actual article and actually know something about how this works.
“The F-35 stealth coating melts when the airplane flies!*”
*at the maximum speed possible**
**with full afterburner***
***which it ordinarily will never do, even in combat****
****and this is the old coating anyway, and we’re about three iterations beyond that*****
*****and it only happened once******
******and the “structural damage” they talked about was superficial scarring on the surface*******
*******which has to be reported because the terms of the contract demand it, not because anyone thinks it’s actually going to be a problem********
********which they know because this will, like, reduce the structural performance margin for FS 2.5 from 3.0 to 2.8, which means you’re still 280% stronger than you need to be for the a load state that’s 2.5 times worse than the absolute highest loads the jet would ever experience in its design life
So, does it need to be addressed? Sure, these planes will presumably be flying for the next 50 years and we don’t really want them to be degrading just from flying around. But is this a worse problem than, say, compressor stalls or inertial coupling? No, nowhere near, and we fielded operational systems with those problems.Report
Yes, a whole lot of caveats in that article.
That such a low Mach number can be considered the edge of the envelope caught my eye. They went to a whole lot of trouble to a make a jet that’s only somewhat faster than a Harrier?
In any event, my first guess is radiative heating from the glowing afterburner exhaust and its pretty Mach diamonds. If that is the case, and given that they couldn’t replicate the conditions, I’d ask what might have been different that would make the exhaust brighter than normal in the IR spectrum, such as more soot or water vapor in the exhaust stream, or some type of aerosol or particulate matter in the atmosphere when the incident occurred.Report
Or it’s a different surface material, or a different application method. Pretty early on they switched from hand-trimmed and -applied decals to robot-sprayed treatments, with machine-cut decals applied by hand only in areas like door edges where treatments get ripped off through the operation of the system. It could be that the tech putting those treatments on just didn’t work out the air bubbles well enough, and that’s why the treatment bubbled in a way that they couldn’t reproduce in testing.Report
That’s probably more likely, especially early in the production run. A lot of low-rate aircraft production is essentially craft work, and that can vary quite a bit as they try to figure out a good process.
One time I was in a bar outside a Grumman plant and one of the workers told me how they did they carbon fiber layup for the tail cone of some military transport. The cone was made pointy end down, and they couldn’t figure out a good way to lay plies in near the inside tip of it. So they had a big guy hold a small ex-cheerleader upside down by her ankles so she could reach down in there.
There’s a video of wartime B-24 production that shows how they used midgets inside the wing to bolt the outer section to the inner section.Report