Cam

A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice versa. It is often a part of a rotating wheel (e.g. an eccentric wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes a lever at one or more points on its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to a steam hammer, for example, or an eccentric disc or other shape that produces a smooth reciprocating (back and forth) motion in the follower, which is a lever making contact with the cam.

Overview

The cam can be seen as a device that rotates from circular to reciprocating (or sometimes oscillating) motion. A common example is the camshaft of an automobile, which takes the rotary motion of the engine and translates it into the reciprocating motion necessary to operate the intake and exhaust valves of the cylinders.

Displacement diagram

Certain cams can be characterized by their displacement diagrams, which reflect the changing position a roller follower (a shaft with a rotating wheel at the end) would make as the cam rotates about an axis. These diagrams relate angular position, usually in degrees, to the radial displacement experienced at that position. Displacement diagrams are traditionally presented as graphs with non-negative values. A simple displacement diagram illustrates the follower motion at a constant velocity rise followed by a similar return with a dwell in between as depicted in figure 2. The rise is the motion of the follower away from the cam center, dwell is the motion where the follower is at rest, and return is the motion of the follower toward the cam center.

Space station

A space station, also known as an orbital station or an orbital space station, is a spacecraft capable of supporting a crew, which is designed to remain in space (most commonly as an artificial satellite in low Earth orbit) for an extended period of time and for other spacecraft to dock. A space station is distinguished from other spacecraft used for human spaceflight by lack of major propulsion or landing systems. Instead, other vehicles transport people and cargo to and from the station. As of September 2014 two space stations are in orbit: the International Space Station, which is permanently manned, and China's Tiangong-1 (which successfully launched on September 29, 2011), which is unmanned most of the time. Previous stations include the Almaz and Salyut series, Skylab and most recently Mir.

Today's space stations are research platforms, used to study the effects of long-term space flight on the human body as well as to provide platforms for greater number and length of scientific studies than available on other space vehicles. Each crew member staying aboard the station for weeks or months, but rarely more than a year. Most of the time crew remain at station but its not necessary that crew should have to be stay at station. Since the ill-fated flight of Soyuz 11 to Salyut 1, all manned spaceflight duration records have been set aboard space stations. The duration record for a single spaceflight is 437.7 days, set by Valeriy Polyakov aboard Mir from 1994 to 1995. As of 2013, three astronauts have completed single missions of over a year, all aboard Mir.

International Space Station

The International Space Station (ISS) is a space station, or a habitable artificial satellite, in low Earth orbit. Its first component launched into orbit in 1998, and the ISS is now the largest artificial body in orbit and can often be seen with the naked eye from Earth. The ISS consists of pressurised modules, external trusses, solar arrays, and other components. ISS components have been launched by Russian Proton and Soyuz rockets as well as American Space Shuttles.

The ISS serves as a microgravity and space environment research laboratory in which crew members conduct experiments in biology, human biology, physics, astronomy, meteorology, and other fields. The station is suited for the testing of spacecraft systems and equipment required for missions to the Moon and Mars. The ISS maintains an orbit with an altitude of between 330 and 435 km (205 and 270 mi) by means of reboost manoeuvres using the engines of the Zvezda module or visiting spacecraft. It completes 15.54 orbits per day.

The Herd

The Herd may refer to:

See also

Colin Cowherd

Colin Murray Cowherd (born January 6, 1964) is an American sports media personality. Born in Bay Center, Washington, Cowherd began his broadcasting career as sports director of Las Vegas television station KVBC, and as a sports anchor on several other stations before joining ESPN in 2003, where he hosted a radio show on the ESPN Radio network, and also became one of the original hosts of ESPN's television program SportsNation, as well as Colin's New Football Show. Colin is currently the host of The Herd with Colin Cowherd on Fox Sports Radio and Fox Sports 1.

In July 2015, it was announced that Cowherd would leave ESPN following the conclusion of his contract with the company, and in turn announced in August 2015 that he would join Fox Sports beginning in September—a deal which includes his radio show moving to Fox Sports Radio and Fox Sports 1, and other appearances as a contributor; while he was to leave at the end of the month, Cowherd was suspended from ESPN on July 24, 2015 following controversial remarks he made on The Herd the previous day.