jabl

> eventually larger ocean going vessels, which I predict will go diesel-electric before they go all electric.

Diesel-electric, particularly when using Azipods, is great when you need to do a lot of maneuvering in narrow spaces like ports. But for long-haul it's hard to beat the economics of a two-stroke direct drive diesel.

Maybe a hybrid concept for a long-haul ship would be using a direct drive two-stroke main engine, but the auxiliary diesels replaced by batteries?

Other companies saw that IBM effectively lost control over their platform (and thus lost a large revenue stream), and are determined to not make the same mistake.

That's a long running effort, going all the way from lobbying (DMCA and their ilk), to all kinds of hardware root-of-trust, encrypted and signed firmware, OS kernels and drivers etc etc. And yes, today we have the transistor budgets to spend on things like this, which wasn't an option back when the PC architecture was devised.

> As a lifelong Toyota fan, I agree they are miserable to work on, especially the electronics.

I had a Toyota Yaris a couple of decades ago. Very reliable, very few issues. But some routine things like replacing headlights were completely bonkers. You had to wiggle your hand between some sharp metal parts to unscrew the back end of the armature. Sheesh, would it have been that prohibitive to add a few cm of extra space there?

At least over here where we have mandatory inspections you can find statistics on percentage of cars which fail the inspections, broken down by brand and model. Toyota seems to consistently place in the top.

I coworker of my mother some 20-25 years ago bought a new car. Drove it until it stopped and refused to go further. Called some road service who upon inspecting it announced that she had run out of gas. She was surprised, "Cars still need to be refueled??!!".

Not in 1905, no. I believe water-glycol mixes became widely used in the 1920'ies. But without glycol, water is an even better heat transfer agent. Shame about the freezing thing, though.

Well, it gets really complex. Yes, specific heat matters, but as you say so does the heat transfer coefficient. And the viscosity. And is the flow laminar or turbulent? Etc.

There are various figures of merit, such as the Mouromtseff number https://doi.org/10.1109/JRPROC.1942.234654 or https://www.electronics-cooling.com/2006/05/comparing-heat-t... for a quick overview.

Some tables of heat transfer coefficients: https://www.engineersedge.com/heat_transfer/convective_heat_...

But, turns out water is just very very good also when you take these other factors into account. Compared to oil, it has, as mentioned, much higher specific heat, it has higher heat conductivity, it has lower viscosity which means less pumping power and more likely to see turbulent flow which helps with mixing.

It's of course possible to design engines to be oil cooled, though water-glycol tends to be preferred due to about twice the specific heat capacity, meaning smaller coolant channels, radiators, and fans are required.

Just pour coolant in via the oil cap. It'll be fine. /s

Yeah, but that's because general aviation engines are stuck in a time capsule from the 1940'ies, not because they are particularly good engines by today's standards. Exception being Rotax on the low end.

I think they lost it when they started dictating what kind of engines teams can use. Just limit the max fuel flow, and then let the teams go wild. Want to use a gas turbine? Go for it!

I once got free tickets to a race (DTM, German touring cars), and to be honest I don't know why people go to them. You saw a small section of the track, and occasionally cars whizzed by. No idea who was in the lead, who was behind, or what was happening in the race in general. Much better to watch on TV.

Shame they're getting rid of the MGU-H just when it's starting to roll out in production road cars (the latest 911, specifically).

> Although EVs now have to pay 3p per mile from 2028, which is a big change.

This is interesting, how is this accomplished?

Over here there was some proposal some years ago to move to a per-mile taxation, with higher tax in congested areas. All managed by some kind of GPS device in each car. There was much opposition as people didn't want the government spying on them via this GPS device, so the plan was eventually dropped.

A simpler approach would be to just record the mileage during annual inspections, but hey why make it simple when you can have some public-private grift making zillions on selling these GPS devices and running the infrastructure for them..

From your past posting history, I presume that you're implying this makes RISC-V better?

Do we have any data showing that having a dedicated zero register is better than a short and canonical instruction for zeroing an arbitrary register?

> I've also know some trucks used in mines that don't even need charging. The electricity generated when descending with a full load is enough to power the empty truck back uphill.

Mines tend to be underground, or then a big hole in the ground, so the truck would be going uphill when fully loaded and down empty, no?

Unless we're talking about a mine up on a mountain?

There's pipework for circulating air inside it when they want to charge/discharge it, but yes, essentially it's mostly tons of sand.

They have resistors for charging it with electricity (resistors heat the air, air is circulated in the pipes which heats the sand) when the electricity price is cheap, and then for discharging they have a air-water heat exchanger so they can pump the heat energy into the district heating network.

They tried in southern Finland not long ago. At great expense and spending a lot of time they managed to drill down 6-7 km until they figured out that the porosity of the rock down there was so poor that it was impossible to make the project economical, so it was cancelled. The idea was to pump this heat directly into the district heating grid.

> And even with perfect insulation, you will loose approximately 30 to 40% of heat in your piping.

At least here in Finland the norm is losses in the range of 5-20%, with the upper end of the scale for smaller scale networks with smaller diameter piping and low flow rate. In the larger cities losses are closer to the low end of that scale.

In the summer when the consumption is very low (essentially only hot tap water production) losses can rise up to 50%.

This was AFAIU a 'dry annealing' on a full scale power reactor: https://inis.iaea.org/records/505bf-gcq02 and https://inis.iaea.org/records/a42j1-np856

Not the whole reactor vessel though, just one critical circumferential weld seam.

(As mentioned in the second link, other VVER-440 reactors had previously been annealed, I'm sure one could find information about them as well.)

> The only way to make a cheap synthetic fuel is from a nuclear reactor that produces heat in the 900C range (could be 700C or 1100C, but near there). You can't do that with solid fuel reactors, you need a liquid fueled reactor for that

Some of the highest temperature reactor concepts use solid fuel (see e.g. various VHTR gen4 concepts).

As an aside, some nuclear proponents claiming synthetic fuel production as some unique selling point of advanced nuclear sounds more like wishful thinking combined with admitting being unable to produce electricity at competitive price. With the 'electrotech revolution', most things will switch to being powered by electricity, leaving a relatively modest market for synthetic fuels (long range aviation and shipping, mainly, and some chemicals production), assuming regulation prevents usage of fossil fuels.

> And you need Thorium for a liquid fueled reactor.

No, why would you? You can use U235 in a non-breeding thermal reactor (Terrestrial being an example design), or you can run the U-Pu breeding cycle in a liquid fueled fast reactor (such designs use chloride salts as the fuel carrier rather than FLiBe).

> That's why this design is so popular.

So popular that despite being invented in the 1960'ies, it hasn't yet progressed beyond the prototype stage?

Many old LWR's have had their reactor vessels heat treated during a maintenance break to undo some of that neutron radiation damage and extend the life of the reactor.

Not sure whether it would be possible to do something similar to a liquid fueled reactor, including all the hot pipework. Maybe, but yet another cost. Notably some of the recent MSR projects propose replacing the entire reactor every now and then (Terrestrial or whatever they were called, not sure if they are still around).

You need to go tell the French that what they've been doing for decades isn't possible, then.

I found a brief from a research project that studied blends of silicone and butyl rubber for Mars applications at https://science.nasa.gov/wp-content/uploads/2023/11/r.anyszk...

Also a more detailed version https://ris.utwente.nl/ws/portalfiles/portal/459340626/Rubbe...

But this seems to be rubber for gaskets, hoses, tires etc. and not fiber reinforced stuff for construction applications.

I can understand basalt, as that is abundant on Mars. But butyl rubber, from where do you get that? Synthetize from CO2 in the atmosphere might work on Mars but on an Asteroid? But if you go through the route of synthetizing from CO2, why butyl rubber and not some other hydrocarbon?

All over the world really, AFAIU. And why not, it's non-flammable, rot-resistant, affordable and made from abundant raw materials.

And yes, you should probably use gloves and a mask when working with it, but it's not carcinogenic like asbestos.

In addition to what sibling posts say, basalt is certainly abundant. Per Wikipedia, 90% of volcanic rock on earth is basalt. We're not going to run out of it.

Maybe, but in that case maybe have some special casing logic to detect that yes indeed we're under a massive DDOS at this very moment, do a rapid rollout of this thing that will mitigate said DDOS. Otherwise use the default slower one?

Of course, this is all so easy to say after the fact..

Radiation detectors can detect very low levels of radiation (far below any measurable health effects, for instance), so claiming we can still detect fallout from Chernobyl doesn't really say anything.

I have to say I hate ansible too (and puppet and cfengine that I have previously used). But it's unclear to me how containers fix the problems ansible solves.

So instead of an ansible playbook/role that installs, say, nginx from the distro package repository, and then pushes some specific configuration, I have a dockerfile that does the same thing? Woohoo?