Doppler ultrasound is a type of ultrasound that depends on the Doppler Effect, a change in the wave's frequency, which can occur from the motion of a reflector, such a red blood cell. We experience the Doppler Effect when, for example, an ambulance approaches us, passes and then drives away.
Definition of PLACODERM. : any of a class (Placodermi) of extinct chiefly Devonian fishes with an armor of bony plates and primitive jaw structures.ADVERTISEMENT. New Latin Placodermi, ultimately from GK plak-, plax + derma skin â more at derm-. any of a class (Placodermi) of extinct chiefly Devonian fishes with an armor of bony plates and primitive jaw structures. ADVERTISEMENT.
Not to be confused with Neoplasm. Pleonasm (/ËpliËÉnÃ¦zÉm/; from Greek ÏÎ»ÎµÎ¿Î½Î±ÏÎ¼ÏÏ (pleonasmos), from ÏÎ»Î­Î¿Î½ (pleon), meaning more, too much) is the use of more words or parts of words than is necessary or sufficient for clear expression: examples are black darkness, burning fire, or people's democracy.