Macroscopic removal cross section

Shielding Material Macroscopic Removal Cross Section (cm )... 

Symbols Oj, = microscopic removal cross section, barns/atom Ej) = macroscopic removal cross section per cm... 

For X rays ft is analogous to the macroscopic absorption cross section 2a for neutrons. The only difference is that ft represents the fraction of energy removed from the beam of X rays per cm length, whereas 2. represents the fraction of neutrons absorbed per unit length. 

The use of tubes of rectangular cross section provides a maximum amount of wall area and so facilitates the removal of heat to the surroundings, and the maintenance of the apparatus at somewhat below 4 , where the variation of the density of the liquid with temperature is very small, greatly diminishes convection effects. With these improvements, and a device for obtaining initially sharp boundaries, the macroscopic method has proved a valuable means for the study of electrophoresis, and for its utilization to separate particles moving with different speeds. 

The nominal or macroscopic stress on the section (here, uniaxial) is o = P/BW, where P is the load applied to the component, and B and W are shown in Fig. 7.98. In the limit of distances sufficiently removed from a notch or crack to no longer be influenced by it, a is the uniform cross-section stress in the material. However, in the vicinity of the... 

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