The norm for some groups to make direct eye contact when speaking to someone is an example of nonmaterial culture.

Lev Vygotsky developed a sociocultural theory that states knowledge is cultural specific.

In a comparative negligence state, a plaintiff who is partially responsible can still recover from a defendant who is also responsible. 

Professionals at work have a heightened duty of care. 

The acoustic impedance of a plastic matching layer for a transducer should be as close as possible to that of the piezoelectric crystal.

A B-mode ultrasound image of a tissue consists of 256 lines. Assume the ultrasound speed in the tissue is 1540 m/s. What is the maximum tissue thickness that can be imaged with a frame rate at 30 Hz?

In order to increase the ultrasound imaging frame rates, the line density needs to be increased.

Application of a voltage across a piezoelectric crystal causes the crystal either contract or expand depending upon the polarity of the voltage.

A 3D ultrasound image may be formed by moving a sequential linear array in the direction perpendicular to the array.

A single continuous-wave ultrasound transducer can be used for the measurements of blood velocity through Doppler effects, as the same transducer can be used to launch an ultrasound beam and to receive the echo signals.