Chamber pressure of the F-1 engine was 70 bar. The helium bottles used to pressurize the fuel tank of the first stage of the Saturn V used a much higher pressue of 213 bar.
Construction materials used to built the rocket were selected for high strength at low weight. Al used materials were carefully tested for maximum acceptable loads.
All forces working ...
It's because the ambient atmospheric pressure affects the thrust generated by the engine.
An engine nozzle has a "design altitude" at which the pressure of the exhaust at the exit plane matches the ambient pressure.
It isn't just the Ariane but all engines with fixed-geometry nozzles. Here is a graph showing the change in performance for ...
I've not heard it called that, it is normally called an 'aspirator'. And yet there it is on your drawing :) Perhaps they crunched up 'exhaust aspirator' into one word?
As quoted in this answer
The aspirator prevented the fuel-rich exhaust gases of the gas
generator from recirculating into the missile boat tail during flight.
Instead, the gases merged ...