Explain why of length-of-bend to sheet thickness increases.

As noted in Fig. 7.16, the state of stress shifts from plane stress to plane strain as the ratio

 

of length-of-bend to sheet thickness increases.

Explain why. This situation is somewhat similar to rolling

of sheet metal where the wider the sheet, the

closer it becomes to the plane-strain condition.

In bending, a short length in the bend area

has very little constraint from the unbent regions,

hence the situation is one of basically

plane stress. On the other hand, the greater

the length, the more the constraint, thus event

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….