Positive pressure enclosure

A positive pressure enclosure, also known as an isolation chamber, is a chamber used to provide a safe work environment for performing hot work in the presence of explosive gases or vapours. They are used most often in conjunction with the need for welding, and are often associated with the offshore oil industry.

A positive pressure enclosure works by providing a constant inflow of breathable atmosphere, which in turn causes gas to continuously leak out of the chamber. This outflow of gases prevents the ingress of explosive gases or vapours which are often present in such work locations. This constant outflow of gases from the chamber also serves to cleanse the air within of the undesirable gaseous by-products of the welding process. Most commercial versions of positive pressure enclosures are referred to by their manufacturers as habitats.

Operating principles

Flammability limits

Flammable gases are not generally explosive under all conditions, and indeed, must be present within specific ranges in order to be explosive, or flammable. Additionally, oxygen must be present. The flammability limits of gases are expressed in proportions to the other gases present. For example, for methane, the lower explosive limit (LEL) is 4.4% and the upper explosive limit (UEL) is 17%. A positive pressure enclosure works by making sure that the methane present in the work area never approaches the 4.4% LEL.

Habitat (horse)

Habitat (1966–1987) was an American-bred British-trained Thoroughbred racehorse and sire. In a racing career which lasted from April until October 1969, the colt ran eight times and won five races. Unraced as a two-year-old, he proved to be the best European miler of 1969, winning the Lockinge Stakes and the Wills Mile in England and travelling to France to win the Prix Quincey and the Prix du Moulin. He was then retired to stud where he became an outstandingly successful sire of racehorses and broodmares.

Background

Habitat was a bay horse standing 16.1 hands high bred in Kentucky by Nuckols Bros. He was sired by Sir Gaylord, a half brother to Secretariat and a successful racehorse and sire in his own right: at the time of Habitat's racing career he was at the height of his reputation as a breeding stallion, having sired the 1968 Epsom Derby winner Sir Ivor. Habitat's dam. Little Hut, won five races and produced several other winners including Northfields (by Northern Dancer) who won the Louisiana Derby and became a successful sire in Europe and South Africa.

Habitat (film)

Habitat is a 1997 science fiction film produced for the direct-to-video market and shown on the Sci Fi Channel. The film's message is largely one of ecological warning, mixed with science fiction elements of genetic engineering, family angst and redemption. It is the only theatrical movie filmed in Sony's early analog High Definition format. Sony donated the equipment and technical support in an attempt to popularize the format. The High Definition video was then transferred to film for release. The film won a Global Film Critics Award for Best Cinematography.

Plot

In a future where the Earth's ozone layer is severely decreased in size, the Symes family is on the run from the father's former employers and the government. Hank Symes (Tchéky Karyo) a molecular biologist, has become so obsessed with saving the world that he has placed his entire family's lives in danger. They stop in a desert community to hide out and continue work when a terrible accident occurs that transforms Hank into a fantastic ethereal lifeform and begins changing the house into a huge botanical biosphere entity which has the ability to threaten all who enter.

Mud

Mud is a mixture of water and any combination of soil, silt, and clay, and usually forms after rainfall or near water sources. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone (generally called lutites). When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds.

Building and construction

Adhesive

In the construction industry, mud is a semi-fluid material that can be used to coat, seal, or adhere materials. Depending on the composition of the mud, it can be referred by many different names, including slurry, mortar, plaster, stucco, and concrete.

Material

Mud, cob, adobe, clay, and many other names are historically used synonymously to mean a mixture of subsoil and water possibly with the addition of stones, gravel, straw, lime, and/or bitumen. This material was used a variety of ways to build walls, roofs and floors.

Mudbrick

Mud can be made into mud bricks,also called adobe, by mixing mud with water, placing the mixture into moulds and then allowing it to dry in open air. Straw is sometimes used as a binder within the bricks, as it adds a support lattice. When the brick would otherwise break, the straw will redistribute the force throughout the brick, decreasing the chance of breakage. Such buildings must be protected from groundwater, usually by building upon a masonry, fired brick, rock or rubble foundation, and also from wind-driven rain in damp climates, usually by deep roof overhangs. In extremely dry climates a well drained flat roof may be protected with a well-prepared (puddled) and properly maintained dried mud coating, viable as the mud will expand when moistened and so become more water resistant. Adobe mudbricks were commonly used by the Pueblo Indians to build their homes and other necessary structures.

Mudá

Mudá is a municipality located in the province of Palencia, Castile and León, Spain. According to the 2004 census (INE), the municipality has a population of 105 inhabitants.

Mudá is first recorded in 1059, under the name Mudave.

Coordinates: 42°53′N 4°24′W / 42.883°N 4.400°W / 42.883; -4.400

Żmudź

Żmudź may refer to: