An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or holes. In an electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons.
Fleetwood Mac are a British-American rock band, formed in London in 1967. Fleetwood Mac was founded by guitarists and vocalists Peter Green and Jeremy Spencer and drummer Mick Fleetwood. Bob Brunning was hired as a temporary bass guitarist before John McVie joined the line-up in time for their eponymous debut album. Danny Kirwan joined as a third guitarist and vocalist in 1968. Keyboardist and vocalist Christine Perfect, who contributed as a session musician starting with the band's second album, married McVie and joined Fleetwood Mac as a full member in 1970, becoming known as Christine McVie.
Metallica is an American heavy metal band. The band was formed in 1981 in Los Angeles by vocalist and guitarist James Hetfield and drummer Lars Ulrich, and has been based in San Francisco for most of its career. The band's fast tempos, instrumentals and aggressive musicianship made them one of the founding "big four" bands of thrash metal, alongside Megadeth, Anthrax and Slayer. Metallica's current lineup comprises founding members and primary songwriters Hetfield and Ulrich, longtime lead guitarist Kirk Hammett, and bassist Robert Trujillo. Guitarist Dave Mustaine, who formed Megadeth after being fired from Metallica, and bassists Ron McGovney, Cliff Burton and Jason Newsted are former members of the band.
Rock music is a broad genre of popular music that originated as "rock and roll" in the United States in the late 1940s and early 1950s, developing into a range of different styles from the mid-1960s, particularly in the United States and United Kingdom. It has its roots in 1940s and 1950s rock and roll, a style that drew directly from the blues and rhythm and blues genres of African-American music and from country music. Rock also drew strongly from genres such as electric blues and folk, and incorporated influences from jazz, classical, and other musical styles. For instrumentation, rock has centered on the electric guitar, usually as part of a rock group with electric bass guitar, drums, and one or more singers. Usually, rock is song-based music with a 4
4 time signature using a verse–chorus form, but the genre has become extremely diverse. Like pop music, lyrics often stress romantic love but also address a wide variety of other themes that are frequently social or political. Rock was the most popular genre of music in the United States and much of the Western world from the 1950s to the 2000s.
Bruce Frederick Joseph Springsteen is an American singer and songwriter. He has released 21 studio albums during a career spanning six decades, most of which feature his backing band, the E Street Band. He is an originator of heartland rock, a genre combining mainstream rock music with poetic and socially conscious lyrics that tell a narrative about working-class American life. Nicknamed "The Boss", he is known for his lyrics and energetic concerts, with performances that can last more than four hours.
In solid-state physics, a band gap, also called a bandgap or energy gap, is an energy range in a solid where no electronic states exist. In graphs of the electronic band structure of solids, the band gap refers to the energy difference between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. It is the energy required to promote an electron from the valence band to the conduction band. The resulting conduction-band electron are free to move within the crystal lattice and serve as charge carriers to conduct electric current. It is closely related to the HOMO/LUMO gap in chemistry. If the valence band is completely full and the conduction band is completely empty, then electrons cannot move within the solid because there are no available states. If the electrons are not free to move within the crystal lattice, then there is no generated current due to no net charge carrier mobility. However, if some electrons transfer from the valence band to the conduction band, then current can flow. Therefore, the band gap is a major factor determining the electrical conductivity of a solid. Substances having large band gaps are generally insulators, those with small band gaps are semiconductor, and conductors either have very small band gaps or none, because the valence and conduction bands overlap to form a continuous band.
Hard rock or heavy rock is a loosely defined subgenre of rock music typified by aggressive vocals and distorted electric guitars. Hard rock began in the mid-1960s with the garage, psychedelic and blues rock movements. Some of the earliest hard rock music was produced by the Kinks, the Who, the Rolling Stones, Cream, Vanilla Fudge, and the Jimi Hendrix Experience. In the late 1960s, bands such as Blue Cheer, the Jeff Beck Group, Iron Butterfly, Led Zeppelin, Golden Earring, Steppenwolf and Deep Purple also produced hard rock.
Indie rock is a subgenre of rock music that originated in the United States, United Kingdom and New Zealand from the 1970s to the 1980s. Originally used to describe independent record labels, the term became associated with the music they produced and was initially used interchangeably with alternative rock or "guitar pop rock".
Alternative rock is a category of rock music that emerged from the independent music underground of the 1970s and became widely popular in the 1990s. "Alternative" refers to the genre's distinction from mainstream or commercial rock or pop music. The term's original meaning was broader, referring to musicians influenced by the musical style or independent, DIY ethos of late-1970s punk rock.
Glam metal is a subgenre of heavy metal that features pop-influenced hooks and guitar riffs, upbeat rock anthems, and slow power ballads. It borrows heavily from the fashion and image of 1970s glam rock.
Cheap Trick is an American rock band from Rockford, Illinois, formed in 1973 by guitarist Rick Nielsen, bassist Tom Petersson, lead vocalist Robin Zander and drummer Bun E. Carlos. The current lineup of the band consists of Zander, Nielsen and Petersson. Their work bridged elements of '60s guitar pop, hard rock, and punk rock, and would help set the template for subsequent power pop artists.
Maroon 5 is an American pop rock band from Los Angeles, California. It consists of lead vocalist Adam Levine, keyboardist and rhythm guitarist Jesse Carmichael, lead guitarist James Valentine, drummer Matt Flynn, keyboardist PJ Morton and multi-instrumentalist and bassist Sam Farrar. Original members Levine, Carmichael, bassist Mickey Madden, and drummer Ryan Dusick first came together as Kara's Flowers in 1994, while they were in high school.
In solid-state physics, the electronic band structure of a solid describes the range of energy levels that electrons may have within it, as well as the ranges of energy that they may not have.
In semiconductor production, doping is the intentional introduction of impurities into an intrinsic semiconductor for the purpose of modulating its electrical, optical and structural properties. The doped material is referred to as an extrinsic semiconductor.
In the Royal Navy and other navies of Europe and the Commonwealth of Nations, ships are identified by pennant number. Historically, naval ships flew a flag that identified a flotilla or type of vessel. For example, the Royal Navy used a red burgee for torpedo boats and a pennant with an H for torpedo boat destroyers. Adding a number to the type-identifying flag uniquely identified each ship.
Blink-182 is an American rock band formed in Poway, California, in 1992. Their current lineup consists of bassist/vocalist Mark Hoppus, guitarist/vocalist Tom DeLonge, and drummer Travis Barker. Though their sound has diversified throughout their career, their musical style, described as pop-punk, blends catchy pop melodies with fast-paced punk rock. Their lyrics center on relationships, adolescent frustration, and maturity—or lack thereof. The group emerged from a suburban, Southern California skate-punk scene and gained notoriety for high-energy live shows and irreverent humor.
R.E.M. was an American rock band from Athens, Georgia, formed in 1980 by drummer Bill Berry, guitarist Peter Buck, bassist Mike Mills, and lead vocalist Michael Stipe, who were students at the University of Georgia. One of the first alternative rock bands, R.E.M. was noted for Buck's ringing, arpeggiated guitar style; Stipe's distinctive vocal quality, unique stage presence, and obscure lyrics; Mills's melodic bass lines and backing vocals; and Berry's tight, economical drumming style. In the early 1990s, other alternative rock acts such as Nirvana and Pavement viewed R.E.M. as a pioneer of the genre. After Berry left the band in 1997, the band continued its career in the 2000s with mixed critical and commercial success. The band broke up amicably in 2011 with members devoting time to solo projects after having sold more than 90 million albums worldwide and becoming one of the world's best-selling music acts.
Band Jub-e Do is a village in Beyranvand-e Jonubi Rural District, Bayravand District, Khorramabad County, Lorestan Province, Iran. At the 2006 census, its population was 49, in 10 families.
Milan Dufek was a Czech singer, composer, guitarist and flautist. He was a co-founder of the Czech pop folk band Rangers.
