MetalA metal (from Ancient Greek μέταλλον métallon 'mine, quarry, metal') is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the metallic bond between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.
Extreme metalExtreme metal is a loosely defined umbrella term for a number of related heavy metal music subgenres that have developed since the early 1980s. It has been defined as a "cluster of metal subgenres characterized by sonic, verbal, and visual transgression". The term usually refers to a more abrasive, harsher, underground, non-commercialized style associated with the speed metal, thrash metal, black metal, death metal, and doom metal genres.
Doom metalDoom metal is an extreme subgenre of heavy metal music that typically uses slower tempos, low-tuned guitars and a much "thicker" or "heavier" sound than other heavy metal genres. Both the music and the lyrics are intended to evoke a sense of despair, dread, and impending doom. The genre is strongly influenced by the early work of Black Sabbath, who formed a prototype for doom metal.
Black metalBlack metal is an extreme subgenre of heavy metal music. Common traits include fast tempos, a shrieking vocal style, heavily distorted guitars played with tremolo picking, raw (lo-fi) recording, unconventional song structures, and an emphasis on atmosphere. Artists often appear in corpse paint and adopt pseudonyms. During the 1980s, several thrash metal and death metal bands formed a prototype for black metal. This "first wave" included bands such as Venom, Bathory, Mercyful Fate, Hellhammer and Celtic Frost.
Heat transferHeat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes. Engineers also consider the transfer of mass of differing chemical species (mass transfer in the form of advection), either cold or hot, to achieve heat transfer.
User interfaceIn the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from the human end, while the machine simultaneously feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls and process controls.
Heat exchangerA heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact. They are widely used in space heating, refrigeration, air conditioning, power stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing, and sewage treatment.
Post-transition metalThe metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals and chemically weak metals. The most common name, post-transition metals, is generally used in this article. Physically, these metals are soft (or brittle), have poor mechanical strength, and usually have melting points lower than those of the transition metals.
Christian metalChristian metal, also known as white metal, Jesus metal or heavenly metal, is heavy metal music distinguished by its Christian themed song lyrics and the dedication of the band members to Christianity. Christian metal is typically performed by professed Christians, principally for Christians and is often produced and distributed through various Christian networks. Christian metal bands exist in most of the subgenres of heavy metal music, and the only common link among most Christian metal bands are the lyrics.
Heavy metalsHeavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers. The criteria used, and whether metalloids are included, vary depending on the author and context. In metallurgy, for example, a heavy metal may be defined on the basis of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist would likely be more concerned with chemical behaviour. More specific definitions have been published, none of which have been widely accepted.
Convection (heat transfer)Convection (or convective heat transfer) is the transfer of heat from one place to another due to the movement of fluid. Although often discussed as a distinct method of heat transfer, convective heat transfer involves the combined processes of conduction (heat diffusion) and advection (heat transfer by bulk fluid flow). Convection is usually the dominant form of heat transfer in liquids and gases. Note that this definition of convection is only applicable in Heat transfer and thermodynamic contexts.
Death metalDeath metal is an extreme subgenre of heavy metal music. It typically employs heavily distorted and low-tuned guitars, played with techniques such as palm muting and tremolo picking; deep growling vocals; aggressive, powerful drumming, featuring double kick and blast beat techniques; minor keys or atonality; abrupt tempo, key, and time signature changes; and chromatic chord progressions. The lyrical themes of death metal may include slasher film-style violence, political conflict, religion, nature, philosophy, true crime and science fiction.
Nu metalNu metal (sometimes stylized as nü-metal) is a subgenre of alternative metal that combines elements of heavy metal music with elements of other music genres such as hip hop, alternative rock, funk, industrial, and grunge. Nu metal bands have drawn elements and influences from a variety of musical styles, including multiple genres of heavy metal. Nu metal rarely features guitar solos or other displays of musical technique; the genre is heavily syncopated and based on guitar riffs.
Graphical user interfaceThe graphical user interface, or GUI (ˌdʒi:juːˈaɪ or ˈɡu:i ), is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicators such as primary notation, instead of text-based UIs, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces (CLIs), which require commands to be typed on a computer keyboard. The actions in a GUI are usually performed through direct manipulation of the graphical elements.
Transport phenomenaIn engineering, physics, and chemistry, the study of transport phenomena concerns the exchange of mass, energy, charge, momentum and angular momentum between observed and studied systems. While it draws from fields as diverse as continuum mechanics and thermodynamics, it places a heavy emphasis on the commonalities between the topics covered. Mass, momentum, and heat transport all share a very similar mathematical framework, and the parallels between them are exploited in the study of transport phenomena to draw deep mathematical connections that often provide very useful tools in the analysis of one field that are directly derived from the others.
Coinage metalsThe coinage metals comprise, at a minimum, those metallic chemical elements which have historically been used as components in alloys used to mint coins. The term is not perfectly defined, however, since a number of metals have been used to make "demonstration coins" which have never been used to make monetized coins for any nation-state, but could be. Some of these elements would make excellent coins in theory (for example, zirconium), but their status as coin metals is not clear.
OreOre is natural rock or sediment that contains one or more valuable minerals concentrated above background levels, typically containing metals, that can be mined, treated and sold at a profit. The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining, and is therefore considered an ore.
DiamondDiamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools.
Folk metalFolk metal is a fusion genre of heavy metal music and traditional folk music that developed in Europe during the 1990s. It is characterised by the widespread use of folk instruments and, to a lesser extent, traditional singing styles (for example, Dutch Heidevolk, Danish Sylvatica and Spanish Stone of Erech). It also sometimes features soft instrumentation influenced by folk rock. The earliest folk metal bands were Skyclad from England and Cruachan from Ireland.
Viking metalViking metal is a subgenre of heavy metal music characterized by a lyrical and thematic focus on Norse mythology, Norse paganism, and the Viking Age. Viking metal is quite diverse as a musical style, to the point where some consider it more a cross-genre term than a genre, but it is typically seen as black metal with influences from Nordic folk music. Common traits include a slow-paced and heavy riffing style, anthemic choruses, use of both sung and harsh vocals, a reliance on folk instrumentation, and often the use of keyboards for atmospheric effect.
