Vapor

In physics a vapor (American English spelling) or vapour (British) is a substance in the gas phase at a temperature lower than its critical point, which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature. A vapor is a different substance than an aerosol. An aerosol is a suspension of tiny particles of liquid, solid or both within a gas.

For example, water has a critical temperature of 374 °C (647 K), which is the highest temperature at which liquid water can exist. In the atmosphere at ordinary temperatures, therefore, gaseous water (known as water vapor) will condense into a liquid if its partial pressure is increased sufficiently.

A vapor may co-exist with a liquid (or a solid). When this is true, the two phases will be in equilibrium, and the gas-partial pressure will be equal to the equilibrium vapor pressure of the liquid (or solid).

Properties

Vapor refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance. (For example, water has a critical temperature of 374 °C (647 K), which is the highest temperature at which liquid water can exist.) If the vapor is in contact with a liquid or solid phase, the two phases will be in a state of equilibrium. The term gas refers to a compressible fluid phase. Fixed gases are gases for which no liquid or solid can form at the temperature of the gas, such as air at typical ambient temperatures. A liquid or solid does not have to boil to release a vapor.

Vapor (disambiguation)

A vapor is a substance in the gas phase below its boiling point.

Vapor or vapour may also refer to:

See also

U-Foes

The U-Foes are a fictional supervillain team appearing in American comic books published by Marvel Comics. The group consists of four members: Vector, the group's leader who can repel matter telekinetically; Vapor, who can transform into any form of gaseous matter; X-Ray, who can generate and project radiation and fly; and Ironclad, who can transform into any metal form and control his density. They first appeared in The Incredible Hulk vol. 2 #254 (December 1980). As noted on the first page of that issue, the group's name was inspired by the 1979 Graham Parker song "Waiting for the UFOs".

Fictional team biography

Simon Utrecht, a former politician and multi-millionaire, funds an operation to gain superpowers the same way the Fantastic Four had, by flying into space and being exposed to cosmic rays. He chooses three other members to join him: Ann Darnell, Jimmy Darnell, and Mike Steel. What the group did not know was that they would be exposed to much higher amount than the Fantastic Four and that it would most likely kill them. The Hulk, in his Bruce Banner form, brings the ship down by reprogramming their computer before the group was exposed to the terminal levels of cosmic rays. The group did manage to gain powers and the newly christened U-Foes attacked Banner for interfering, convinced they could have become even more powerful without his intervention. Banner transforms into the Hulk and a fight ensues, but the U-Foes lose due to their inexperience with their newly gained powers and inability to fight as a team. Sometime later they escape from jail, and X-ray discoveres a way to keep Bruce Banner in his human form by generating 'anti-gamma rays'. Hulk is freed by his allies and defeats the team.

Exposure

Exposure may refer to:

Law and finance

Photography

Science and medicine

Exposure (heights)

Exposure is a climbing and hiking term. Sections of a hiking path or climbing route are described as "exposed" if there is a high risk of injury in the event of a fall because of the steepness of the terrain. If such routes are negotiated without any protection, a false step can result in a serious fall. The negotiation of such routes can cause fear of falling because of the potential danger.

Definitions

What constitutes exposure on a path is fairly obvious, however, an "exposed" location or section of a climbing route is not uniformly or clearly defined in the literature. There are no threshold values, for example, based on the gradient of the terrain, the height of rock faces or the character of an ridge or arête. Authors tend to use their own definition of the terms "exposure" or "exposed" when describing routes, for example:

Exposure

Exposure (photography)

In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance in a specified region.

In photographic jargon, an exposure generally refers to a single shutter cycle. For example: a long exposure refers to a single, protracted shutter cycle to capture enough low-intensity light, whereas a multiple exposure involves a series of relatively brief shutter cycles; effectively layering a series of photographs in one image. For the same film speed, the accumulated photometric exposure (H_v) should be similar in both cases.

Definitions

Underexposure and overexposure

A photograph may be described as overexposed when it has a loss of highlight detail, that is, when important bright parts of an image are "washed out" or effectively all white, known as "blown-out highlights" or "clipped whites". A photograph may be described as underexposed when it has a loss of shadow detail, that is, when important dark areas are "muddy" or indistinguishable from black, known as "blocked-up shadows" (or sometimes "crushed shadows", "crushed blacks", or "clipped blacks", especially in video). As the image to the right shows, these terms are technical ones. There are three types of settings they are manual, automatic and exposure compensation.