Thrust

Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system. The force applied on a surface in a direction perpendicular or normal to the surface is called thrust. Force, and thus thrust, is measured in the International System of Units (SI) as the newton (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 metre per second squared.

In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as thrust.

Examples

A fixed-wing aircraft generates forward thrust when air is pushed in the direction opposite to flight. This can be done in several ways including by the spinning blades of a propeller, or a rotating fan pushing air out from the back of a jet engine, or by ejecting hot gases from a rocket engine. The forward thrust is proportional to the mass of the airstream multiplied by the difference in velocity of the airstream. Reverse thrust can be generated to aid braking after landing by reversing the pitch of variable-pitch propeller blades, or using a thrust reverser on a jet engine. Rotary wing aircraft and thrust vectoring V/STOL aircraft use engine thrust to support the weight of the aircraft, and vector sum of this thrust fore and aft to control forward speed.

Thrust (rapper)

Chris France (born July 8, 1976), better known by his stage name Thrust, is a Canadian rapper from Toronto, Ontario. He is most known for his appearance on the Rascalz' 1998 single "Northern Touch" which also features Kardinal Offishall, Choclair, and Checkmate. He was also featured on the pop band soulDecision's biggest hit "Faded".

Thrust now teaches "Artist Series" at the Harris Institute in Toronto.

Discography

See also

References

External links

Thrust (science fiction magazine)

Thrust was published from 1973–1991. It started off as a Fanzine by Doug Fratz Steven L. Goldstein at the University of Maryland until 1976. In 1978, Thrust became a trade magazine.

Thrust was a magazine for science fiction fans, offering commentary and criticism of work published within the genre. Nominated for a Hugo Award for Best Fanzine in 1980, it received four other nominations for best semi-prozine in the following years (1988, 1989, 1990, and 1991). As a trade magazine, it expanded rapidly, moving to offset covers. Ultimately the circulation rose to 1,700. Columnists at various times included Ted White, Charles Sheffield, Lou Stathis, John Shirley, Michael Bishop, David Bischoff, Chris Lampton, Darrell Schweitzer and Jeffrey Elliot. Dan Steffan provided art direction for the magazine.

References

Destructor

Destructor may refer to:

Destructor (computer programming)

In object-oriented programming, a destructor (sometimes shortened to dtor) is a method which is automatically invoked when the object is destroyed. It can happen when its lifetime is bound to scope and the execution leaves the scope, when it is embedded into another object whose lifetime ends, or when it was allocated dynamically and is released explicitly. Its main purpose is to free the resources (memory allocations, open files or sockets, database connections, resource locks, etc.) which were acquired by the object along its life cycle and/or deregister from other entities which may keep references to it. The use of destructors is a necessity to the concept of Resource Acquisition Is Initialization (RAII).

In a language with an automatic garbage collection mechanism, it would be difficult to deterministically ensure the invocation of a destructor, and hence these languages are generally considered unsuitable for RAII. In such languages, unlinking an object from existing resources must be done by an explicit call of an appropriate function (usually called Dispose()). This method is also recommended for freeing resources rather than using finalizers for that.

Spanish warship Destructor

Destructor was a 19th-century Spanish warship. She was a fast ocean-going torpedo gunboat and a precursor of the destroyer type of vessel.Destructor was the first warship classified as a "destroyer" at the time of her commissioning. Her designer was a Spanish Navy officer, Fernando Villaamil, commissioned by the Minister of the Navy, Vice-Admiral Manuel Pezuela.

Genesis

During the 1860s, 70s and 80s the rapidly improving, fast and cheap torpedo boats were presenting an escalating threat to major warships. Escort vessels were already in use to provide protection for battleships but it was decided that what was needed was a new type of enlarged torpedo boat, capable of escorting larger ships on long voyages and also able to attack enemy battleships as part of a fleet action.

The Spanish Navy asked several British shipyards to submit proposals capable of fulfilling these specifications. In 1885 it chose the design submitted by the shipyard of James and George Thomson of Clydebank, near the Yarrow shipyards. She was laid down at the end of the year, launched in 1886, and commissioned in 1887.