Recent content by chemisthypnos

It should be a reasonably good conductor even at that size as experiments with nano chaff have shown: https://iopscience.iop.org/article/10.1088/1742-6596/1176/6/062002/pdf We assume that the aluminum has not oxidized ( there are very good reasons to make this assumption that I would rather not...

The canister is not assumed to behave like a dipole. I think that 5nm aluminum powder would still be conductive. For the sake of the thought experiment, assume that the aluminum is not oxidized. Paint would be a good analogy.

The pond seawater is opaque to visible light because it is a simplifying assumption of the thought experiment and helps focus attention on the radio aspect of the problem..

The dimensions of the target can be regarded as a 1 meter long glass canister full of aluminum finely cut to a powder for which each particle's diameter is 5 nanometers. Assume that the bottom/sides of the pond are made of a material that is transparent to radio light. The pond is filled with...

The target ( aluminum) should be shiny in the radio spectrum. Visible light cannot be used in this scenario as the pond is opaque to visible light. This is a prototype for a more difficult problem.

We are attempting to image an aluminum target at the base of the pond at 1m depth. The resolution does not particularly matter as we are looking for a binary outcome ( either object is detected or the object cannot be detected). That is a very good point about the 540 kHz antenna length. We were...

It would be used for air to water and it would be for underwater imaging. That graph was very helpful. I think that we are going to try for 540 kHz wavelength. This should minimize the attenuation. We are trying to find out how large of an antenna we would need and how much power that would take...

We are attempting to penetrate 1m of water featuring dissolved ions ( assume salinity of sea water) using radio waves. Aside for using wavelengths of very low frequency radio or below, what would be the best frequency for achieving this task?

The working pressure is going to be 1 ATM ( atmospheric pressure). I am also considering using pressure below ambient if water is the working fluid so it will boil at a lower temperature. The reason for the boiling point range is that 150-180 F will be the relatively constant temperature in the...

I am looking for a good working fluid whose boiling point is in the range of 150-180 F for a waste heat recovery system. The fluid should be minimally flammable, preferably nontoxic, and low in environmental impact. Does anyone know of any working fluids that match this description?

Thank you all for your perspectives. You have all done a great job in helping me to understand this phenomena better.

Those are very good points, everyone. If I may ask another question, does the current quantity of propellant reach the speed of sound of that gas at the elevated temperature of its ignition? If so, then adding additional propellant would be pointless.

Thank you all for bringing your unique perspectives to this discussion. I have found them all to be most informative. Trurle, you are saying that even if more propellant were to be added, it would not benefit the muzzle velocity past a range of 60 km or so?

If the barrel would become too damaged, why don't they just make the walls of the barrel thicker?

I think that the range of a howitzer be increased simply by adding more explosive propellant. Why is this not used? I would think that this would be a straightforward way to increase the gun's effective range. Any ideas?