Hello, I'm Brian Power and in this video I will be showing you some examples of scattering patterns. For this purpose I have written a small program which you will be seeing in this talk. As you may know what we see on the detector of a small angle scattering machine is mathematically identical to observing the intensity of the Fourier transform of the real space electron density It sounds complicated but it's just a way of saying that we take whatever sample we want to look at put it through a mathematical operator and we end up with our scattering pattern. This is fairly easy to do on a computer so this is what you are seeing here. This display here shows you the output of my lapse of camera on which I will show some examples of structures you will find in this samples. On this display to my left over here you are right. You see the intensity of the Fourier transform for the camera image. In other words you can see what we will see on the detector of a small angle scattering machine for the sample. Starting with a simple sphere you see that the detector shows us some repeating rings for a smaller sphere. The period of the rings becomes larger. Due to the bobbin A's principle the inverted image gives us exactly the same scattering pattern. Different shapes show different scattering patterns such as cubes, squares which can be rotated and ellipsoids which can be also rotated. You will see here that the oscillation frequency for the ellipsoid is highest in the long dimension and lowest along the short dimension. For dense but monodispir systems we still see these oscillations like this. But when we introduce polydispiracy the oscillations of the spheres of different sizes, different frequencies and overlap and therefore we cannot distinguish the individual oscillations anymore. For the crystallographers among you regular structures such as this lattice will give you your diffraction spots. So that's it. If you have a MacBook and a MATLAB download a copy of this program and start playing around. Feel free to ask me if you have any question and let me know if you use this in any presentation. Good luck. Bye bye. Bye.