I'm writing a short report about thermal storage using latent heat and the topic is liquid/solid phase transitions. I would however like to systematize all phase transitions in the intro and I'm curious if gas/gas and/or liquid/liquid phase transitions exist.
For gas-gas I think that the...
Thanks for answer and sorry for not being clear. I mean a gray gas that emits thermal radiation. So the thermal radiation is created inside the cylinder and I need to figure out the irradiation hitting the base of the cylinder. So there is no collimated light and no light entering the cylinder.
Anyone who has an idea for how to calculate the irradition [W/m2] to the base of a cylinder with radius R, height H, absorption coefficient k, and temperature T? I've looked at the approach with mean beam length by Hottel but cannot figure out what to do when it is the base of the cylinder that...
Many thanks for all the answers! I want to perform fire testing without a fire! More specifically I would like to test the fire resistance of a wall, say light concrete. According to the so called standard fire curve (ISO 834) the temperatur on the fire exposed side of the wall should be around...
Hi, I need to heat up a flat surface in a controlled way from room temperature to approximately 950 C. The surface will be some square meters large. Is there any way doing this without combustion, that is using a electric heating blanket? Does anyone know if such blankets exist? (Have already...
I want to measure the emissivity (or more correctly the absorbtivity) in the wavelength range 1 - 10 micrometer of very hot (~1000 degrees Celcius) ceramic materials. At room temperature this is typically done using an FTIR spectrometer with a gold coated integrating sphere. But for very hot...
Say I have two columns containing data in Excel. Column A contains 10 non empty cell and column B contains 12 non empty cells. How can I create a column C with 10 + 12 cells without specifically telling Excel to put cell B1 in cell C11. In other words I would like to concatenate column A and B...
Many thanks!
1) What does "p-hacking" mean?
2) Assume I know K. Could your example with 28/72 and 0/100 balls be expressed so n is given in a mathematical expression in terms of N, c, p, and maximum k, or similar. Or a reference to such an expression.
3) If N=1000 balls in total, I draw 100...
I have a hypergeometric distribution with:
N=total population of red and green balls, I now this
K=total number of red balls, I don't know this
n=sample size (number of investigated balls), I can choose this
k=number of investigated balls that are red, I don't know this
Red balls are a problem...
Ok I see what you mean. But I also sometimes measure on semitransparent polymers which I have now knowledge about, and sometimes I don't know which glass I have either! What I'm looking for is an exact method to use experimental measurements of spectral reflectance and transmittance in order to...
I'm measuring transmittance through and reflectance from thick glass samples, using spectrophotometers. Does anyone know if there's an exact solution for the surface transmittance r, surface reflectance t, and absorption coefficient A (as in Beer-Lamberts law). For a specific wavelength the...
Hi again! Any comments to my questions Q1 and Q2 would be most welcome. (I realized that it was not obvious that I had two questions in my last posting.)
Thanks you Physics Forum!
Many thanks BvU and Buzz Bloom for your help. Thanks to your advices I have now progressed considerably (I think/hope). I now understand that it is more interesting to say that side a comes up 99 times and side b 1 time. The estimation of p is then 99/100=99%. Using the “Normal approximation...