active power filter
51Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
52Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …
53Photoconductive atomic force microscopy — (pc AFM) is a scientific technique.. Multi layer photovoltaic cells have gained popularity since mid 1980s.[1] At the time, research was primarily focused on single layer photovoltaic (PV) devices between two electrodes, in which PV properties… …
54Amiga — This article is about the family of home computers. For other uses, see Amiga (disambiguation). The former Amiga logo, as used by Commodore Amiga Inc …
55Loudspeaker — For other uses, see Loudspeaker (disambiguation). An inexpensive, low fidelity 3½ inch speaker, typically found in small radios …
56Passive radar — systems (also referred to as passive coherent location and passive covert radar) encompass a class of radar systems that detect and track objects by processing reflections from non cooperative sources of illumination in the environment, such as… …
57List of Doctor Who items — This is a list of items from the BBC television series Doctor Who. Contents: Top · 0–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0–9 …
58Operational amplifier — A Signetics μa741 operational amplifier, one of the most successful op amps. An operational amplifier ( op amp ) is a DC coupled high gain electronic voltage amplifier with a differential input and, usually, a single ended output.[1] An op amp… …
59Sun — This article is about the star. For other uses, see Sun (disambiguation). The Sun …
60Microphone — For the indie film, see Microphone (film). Microphones redirects here. For the indie band, see The Microphones. A …
