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 (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.

Track listing

Personnel

Catalyst (think tank)

Catalyst (later Catalyst Forum) was an independent left wing think tank based in London, United Kingdom, set up in 1998 to promote policies directed to the redistribution of power, wealth and opportunity. Though not aligned to any political party, it was generally sympathetic to the Labour Movement and described itself as "an organisation of the left".

The organisation was founded at the high point of Tony Blair's modernisation of the Labour Party and struggled to attract funding, especially from the trades unions who had originally been expected to be the most sympathetic to its redistributionist platform. Trades unions, concerned at further exclusion from power either by the electorate or the new Labour Party leadership, took a sharp turn away from too deep an association with the Left at this time and only begun in 2005 and 2006 to develop an increased if cautious interest in left-wing thought as a new generation of activist trades union leaders has emerged.

Former right wing but egalitarian Deputy Leader of the Labour Party, Roy Hattersley, was an early supporter, as was John Edmonds, General Secretary of the GMB Union.

Space

Space is the boundless three-dimensional extent in which objects and events have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as spacetime. The concept of space is considered to be of fundamental importance to an understanding of the physical universe. However, disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework.

Space (The Arrogant Worms album)

Space, stylized as SPACE, is the fourteenth album by the Canadian comedy music group, The Arrogant Worms. It was released in March 2014.

Track listing

Space (Modern Jazz Quartet album)

Space is an album by American jazz group the Modern Jazz Quartet featuring performances recorded in 1969 and released on the Apple label.

Reception

The Allmusic review stated "Overall this is an average but worthy outing from a group whose excellence could always be taken for granted".

Track listing

All compositions by John Lewis, except where noted.

Personnel

References