Recent content by rwooduk

Hello, I am currently trying to determine the method to calculate the heat absorbed / released when a gas and liquid mix. I believe that this is known as the heat/enthalpy of mixing (or excess molar enthalpy). I also believe, that if this value is negative it means an exothermic reaction (heat...

I don't know what this is but will look into it, many thanks.

Hello, I have recently started collecting photomultiplier tube (PMT) tube data, and I'm curious how best to analyse it (attached right). I also have a background capture (attached left). I am looking to get the relative total intensity and any other statistical analysis I could make. Is anyone...

Appreciated!

Just one, last thing please. I am reading a paper that uses 100 Hz PRF so 10 ms Burst. This with 30% duty cycle (30% on, 70% off). 30% of 10ms is 3 ms. It's at 1.1 MHz so ~909.1 ns per cycle. So in the paper they must have used 3ms/909.1ns ~ 3300 cycles. Does this look like a correct...

Many thanks!

Thank you very much Klystron, I really wasn't so sure.

Hi, I am having to refresh my oscilloscope knowledge and am confused about one last function generator setting... Burst period. If I have 1 cycle at say 700 kHz it is 1.43us. If I set number of cycles to 10 then that is 10 * 1.43us = 14.3us time. This is my ON burst. So what is the burst...

Thank you very much nasu, I had completely messed up my calculation. Extremely helpful!

Thanks, I did see that paper but it seems they do not factor in the attenuation due to tissue / depth at all. I should have probably put this in the physics sections above as I think I'm having a calculation problem, rather than a definition problem. But I really appreciate the reply, thanks...

On the surface, the equation is simply the peak rarefractional pressure divided by the root of the applied frequency: ##MI = \frac{P_{ra}}{\sqrt{f}}## But the pressure is reduced/derated by an attenuation factor/coefficient that is dependent on depth and frequency e.g. ##0.3 \ dB / (cm \cdot...

Ohh, I was going at this completely the wrong way, then went around in circles trying to convert the different units. Very helpful, thanks!

Agree, but other than SWR ratio how is it a function of distance? Especially for lower frequencies? This is actually really useful, thanks! At the end point the cable would be similar to used in oil / gas wells. Let's just call it a transmitter operating at depth. I also need to factor in...

Thanks for the reply. I just used coax as an example, at present using coax for only 50 W devices. Are the voltages / currents needed to determine attenuation of the signal? I thought it could be done using just the power used? My problem is the dB to Watts conversion which seems off for such...

The above is just an example question to describe the situation. I am doing some simple calculations, but I think I am missing something. Is anyone here familiar with decibels? It is a coax cable and I'm working at ~20 kHz where attenutation isn't listed on the data sheet -...