Why do tubes have a tendency to buckle when bent?

Why do tubes have a tendency to buckle when bent? Experiment with a straight soda straw, and describe your observations. Recall that, in bending of any section, one-half of the cross section is under tensile stresses and the other half under compressive stresses. Also,


compressing a column tends to buckle it, depending on its slenderness. Bending of a tube

subjects it to the same state of stress, and since most tubes have a rather small thickness compared to their diameter, there is a tendency for the compression side of the tube to buckle.

Thus, the higher the diameter-to-thickness ratio, the greater the tendency to buckle during


find the cost of your paper

Explain why attenuation is not a big problem in PET.

Consider a 2-D object consisting of two triangle compartments, as shown in Figure P9.4. Suppose a solution containing a 511 KeV gamma ray emitting radionuclide with concentration f = 0.5….

Give the mean and the variance of the reconstructed image, mean[ˆ f(x, y)] and var[ˆ f(x, y)].

Ignoring the inverse square law and attenuation, an approximate reconstruction for SPECT imaging is given by where c˜() =  {||W()} and W() is a rectangular windowing filter that cuts off at = 0…..

Find the numerical responses in each to an event in crystal C(4, 6).

Suppose a PET detector comprises four square PMTs (arranged as a 2 by 2 matrix) and a single BGO crystal with slits made in such a way that it is….