)the rectangular steel plate below measures 1 m x 0.5 m x 10 mm. assume that the 1 m dimension is in the x-direction and the 0.5 m dimension is in the y-direction. the plate is made of a material with an elastic modulus of 200 gpa and poisson’s ratio of 0.3. suppose a uniform normal stress, σx, of 125 mpa is applied in the x-direction. a) calculate the stress, σy, required to produce a transverse strain εy = 0 (in mpa). b) compute the normal strains in the x- and z-directions. [ans. to check εx = 0.000569] c) calculate the change in volume the plate will experience in mm3 .

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia