Physics General Subjects Thread

Nuclear Reactions At Chernobyl "Cause For Concern"

nomadski wrote:
Yes it seems the best short term solution, before more Nuclear power plants are built. Iran's needs right now about 20 Megawatt to avert problems. This is around 1000 medium size generators. I think Iran manufactures own diesel marine Engines. So they could make savings there. Can Russian company provide 1000 generators?  Or provide complete units on lend / lease basis? Or even Russian military provide some emergency  mobile generators?

https://www.tss.ru/eng_about/

limb wrote:Can anyone explain to me if the tesla cybertruck's aerodynamics are any good. According to common sense, theres a reason all cars have curve, but the cybertruck is very blocky and edgy.

All the articles touching upon the drag claim its actually very good but that seems a bit fishy

lancelot wrote:I enjoy watching Thunderf00t's videos but in this one like quite often he uses some misdirection in parts of the video.
He is correct to lambast the Youtube channels pushing this drivel message out and making all sorts of erroneous statements.

But metal hydride hydrogen storage is a real technology which has been worked on for decades. He is correct that the main issue with it has always been that it weighs a lot more than just storing the hydrogen because of the matrix you use to store the hydrogen gas into. But the whole point of the matrix is to be a more compact way to store the hydrogen volumetrically. He himself points out how CH4 is more dense as an hydrogen storage method than H2 because of the molecular configuration of it. The matrix is a cage to force the hydrogen molecules to be stored more compactly than they would otherwise. Hydrides enable more compact storage, and no it is not on the level of compressed hydrogen in terms of volumetric density, it can be better and often is. Hydrides also have the advantage they are a lot safer as a hydrogen storage medium than other alternatives in terms of shock resistance for example. He is also correct that it usually requires a lot of heating energy to release the hydrogen gas from the hydride and that has always been a stumbling block. So the conclusion is this technology is likely a long way from being marketable, if ever, I personally think hydrogen cars are a complete non starter given electric cars have much more superior characteristics. You waste a lot less energy with electrics. Even if for whatever reason you want to eliminate gasoline, it makes a lot more sense to just use CH4 directly. It is readily available and is a lot more dense than hydrogen.

One example of what the people in the Youtube channels he's quoting get wrong is the quotes the company which develops this product make about using sewage and other "greenhouse" waste gases as an hydrogen source. He claims CO2 has no hydrogen in it. Well duh. The company isn't talking about CO2. They are talking about METHANE GAS (CH4) which you can get from sewage and landfills. But like I said, I would just burn it directly. But for whatever reason people seem to believe the AGW agenda and that's the excuse companies like these use to push things like hydrogen storage on us.