Catalysis

Catalysis (/kəˈtælᵻsᵻs/) is the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalyst (/ˈkætəlᵻst/). With a catalyst, reactions occur faster and require less activation energy. Because catalysts are not consumed in the catalyzed reaction, they can continue to catalyze the reaction of further quantities of reactant. Often only tiny amounts are required.

Technical perspective

In the presence of a catalyst, less free energy is required to reach the transition state, but the total free energy from reactants to products does not change. A catalyst may participate in multiple chemical transformations. The effect of a catalyst may vary due to the presence of other substances known as inhibitors or poisons (which reduce the catalytic activity) or promoters (which increase the activity). The opposite of a catalyst, a substance that reduces the rate of a reaction, is an inhibitor.

Catalyzed reactions have a lower activation energy (rate-limiting free energy of activation) than the corresponding uncatalyzed reaction, resulting in a higher reaction rate at the same temperature and for the same reactant concentrations. However, the detailed mechanics of catalysis is complex. Catalysts may affect the reaction environment favorably, or bind to the reagents to polarize bonds, e.g. acid catalysts for reactions of carbonyl compounds, or form specific intermediates that are not produced naturally, such as osmate esters in osmium tetroxide-catalyzed dihydroxylation of alkenes, or cause dissociation of reagents to reactive forms, such as chemisorbed hydrogen in catalytic hydrogenation.

Catalyst (TV program)

Catalyst is the ABC's primary science journalism television series and the only science show on primetime television in Australia. Launched in 2001, it replaced Quantum, which had ceased the previous year. Catalyst is regularly broadcast on ABC 1 at 8:00 pm on Tuesdays and at 11:30 am Saturdays. Also repeated on ABC News 24 on Saturdays at 4:30 pm.

Catalyst celebrated its tenth year of production in 2010.

Description

The show broadcasts stories on scientific themes, and in particular significant recent developments and discoveries. It focuses primarily on stories relevant to Australia, but the series covers international developments as well. It attempts to convey information in a way that is not only accurate but also interesting and informative to the general population, often discussing the ethical, political, and other implications of scientific discoveries and research as well as the discoveries themselves.

The show's website describes it as follows:

Each week Catalyst brings you stories from Australia and around the world.

Catalyst (Prototype album)

Catalyst is the third studio album by heavy metal band Prototype. The album was released on September 11, 2012 by Nightmare Records, following up from their 2006 album Continuum.

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Shit (song)

"Shit" (stylized as "Sh!t", edited for radio as "Shhh...") is a song by American hip hop recording artist Future. It was released on September 24, 2013, as the third single from his second studio album, Honest (2014). The song has since peaked at number 45 on the US Billboard Hot R&B/Hip-Hop Songs.

Remixes

On December 14, 2013, it was announced Canadian rapper Drake, would appear on the song's remix. On December 15, 2013, it was revealed fellow American rappers Schoolboy Q, Jeezy, Pastor Troy, T.I. and Juicy J, were also added to the remix. On December 17, 2013, a remix featuring Drake and Juicy J was released, which appears on DJ Esco's No Sleep mixtape. On December 19, 2013, the "ATL remix" was released which features Pastor Troy, Jeezy and T.I.. On December 20, 2013, a remix featuring West Coast rapper Schoolboy Q and hip hop mogul Sean "Diddy" Combs, was released. On December 23, 2013, the song's producer Mike Will Made It, released a mixtape titled #MikeWillBeenTrill, which was hosted by Future. The mixtape includes a "Megamix" of the song, featuring verses from rappers Drake, Jeezy, T.I., Juicy J, Schoolboy Q, Diddy and Pastor Troy.

Shit (disambiguation)

Shit is an English-language vulgarism, literally referring to feces, but having many metaphoric uses.

Shit or The shit may also refer to:

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See also

Triangular prism

In geometry, a triangular prism is a three-sided prism; it is a polyhedron made of a triangular base, a translated copy, and 3 faces joining corresponding sides. A right triangular prism has rectangular sides, otherwise it is oblique. A uniform triagular prism is a right triangular prism with equilateral bases, and square sides.

Equivalently, it is a pentahedron of which two faces are parallel, while the surface normals of the other three are in the same plane (which is not necessarily parallel to the base planes). These three faces are parallelograms. All cross-sections parallel to the base faces are the same triangle.

As a semiregular (or uniform) polyhedron

A right triangular prism is semiregular or, more generally, a uniform polyhedron if the base faces are equilateral triangles, and the other three faces are squares. It can be seen as a truncated trigonal hosohedron, represented by Schläfli symbol t{2,3}. Alternately it can be seen as the Cartesian product of a triangle and a line segment, and represented by the product {3}x{}. The dual of a triangular prism is a triangular bipyramid.

Trip (Cause and Effect album)

Trip is the second album from the synthpop act Cause and Effect. It is dedicated to the memory of Sean Rowley. The album includes the song "It's Over Now," which climbed to the #7 spot on Billboard's modern rock charts. It was released in 1994 under the BMG label.

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