The Transbay Tube carrying BART across the bay is immersed tube. The sections were welded together by divers. The sections were filled with water and then pumped out.
Fehmarnbelt tunnel sections are concrete. I couldn't find how they are connected by concrete would make sense.
A video posted in another thread says the segments are sealed with bulkheads, floated into position, submerged by allowing water into a ballast section, dropped into place , aligned with pins, drawn to the next segment with hydraulic jacks, and sealed to it with rubber gaskets. Then the bulkheads can be removed. The gaskets also allow for some thermal expansion.
I'm curious what the lifetime of those gaskets might be and how you might maintain them.
They are GINA gaskets[0], they were supposed to last 120 years[1], but it has recently been shown that they may deteriorate faster than previously expected due to being under constant compression[2][3]
The "ballast sections" may act as bilges, so that any leaks will accumulate there and can be pumped out. 100% water-tightness is not essential. Occasional re-grouting/caulking of the joints may be good enough.
Sealing is really not that difficult if you have access to the high pressure side. The hard part is identifying the location of the leak. In sum, this means that they have to absolutely nail it, on the first attempt, for the bottom part that is resting on the sea floor. If they can to that, the rest of the circumference will also be so good they don't have to even think about fixability.
You can get plastic NFC cards. I bet there are companies that will print and program them.
It must be possible to have flexible paper-like cards because my city has one-time tickets with NFC. Game would be nicer with card stock and not rigid plastic.
Joule is a derived unit, it is kg*m^2/s^2. There are lots of derived units, like hertz and newton, because they useful than writing out the whole thing. Electronics would be really annoying if had to write out volt, ohm, and watts (ampere is base unit, coulomb is derived).
Don’t put words in my mouth. I only said that power should be J/s instead of watts. The “per second” part of that is what is most important thing about power. It’s the rate at which energy is accumulating or being used up.
You can't split a quark, partial quarks doesn't exist. In fact, singular quarks can't exist, if you try to pull quark out of nucleus, it produces another quark to pair with. Quarks can be destroyed in particle accelerators collisions but those aren't components.
Also, all of the components of an atom, electrons and nucleus, have mass.
Around here, it isn't possible to do native lawn. The grasses are too tall and the low groundcovers can't be walked on. I'm trying to plant wildflower meadow but it will be a couple of feet high.
My idea is that there are two types of lawns. There are the lawn you use, and it is fine to be grass. But there is a lot of lawn that is landscaping and that can be native plants.
Cars don't follow traffic laws. Cars roll through stop signs and run red lights. Cars speed and weave through traffic. They go the wrong way down one-way streets. Since cars are much bigger, this is much more dangerous.
What happens when your new version is broken? Kubernetes would rollback to old version. You have to rerun the deployment script and hope you have the old version available. Kubernetes will even deploy new version to some copies, test it, and then roll out the whole thing when it works.
Also, Kubernetes uses immutable images and containers so you don't have to worry about dependencies or partial deploys.
Citrus isn't one species but hybrids of citrons, mandarins, pomelos in Citrus genus. It isn't like cabbage that produces multiple cultivars. Citrus genus is supposed to be diverse cause they do hybridization in wild.
My understanding is that the water farther east is shallower which makes bridge cheaper. But not enough to be chosen.
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