Hard (surname)

Hard is a surname. Notable people with the surname include:

Hardcourt

A hardcourt (or hard court) is a surface or floor on which a sport is played, most usually in reference to tennis courts. They are typically made of rigid materials such as asphalt or concrete, and covered with acrylic material to seal the surface and mark the playing lines, while providing some cushioning. Historically, hardwood surfaces were also in use in indoor settings, similar to an indoor basketball court, but these are now rare.

Tennis

Tennis hard courts are made of synthetic/acrylic layers on top of a concrete or asphalt foundation and can vary in color. These courts tend to play medium-fast to fast because there is little energy absorption by the court, like in grass courts. The ball tends to bounce high and players are able to apply many types of spin during play. Flat balls are favored on hard courts because of the extremely quick play style. Speed of rebound after tennis balls bounce on hard courts is determined by how much sand is in the synthetic/acrylic layer placed on top of the asphalt foundation. More sand will result in a slower bounce due to more friction.

Hard (nautical)

A hard is a firm or paved beach or slope by water that is convenient for hauling boats out of the water. The term is especially used in Hampshire, southern England.

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Orthopedic cast

An orthopedic cast, body cast, plaster cast, or surgical cast, is a shell, frequently made from plaster or fiberglass, encasing a limb (or, in some cases, large portions of the body) to stabilize and hold anatomical structures, most often a broken bone (or bones), in place until healing is confirmed. It is similar in function to a splint.

Plaster bandages consist of a cotton bandage that has been combined with plaster of paris, which hardens after it has been made wet. Plaster of Paris is calcined gypsum (roasted gypsum), ground to a fine powder by milling. When water is added, the more soluble form of calcium sulfate returns to the relatively insoluble form, and heat is produced.

The setting of unmodified plaster starts about 10 minutes after mixing and is complete in about 45 minutes; however, the cast is not fully dry for 72 hours.

Nowadays bandages of synthetic materials are often used, often knitted fiberglass bandages impregnated with polyurethane, sometimes bandages of thermoplastic. These are lighter and dry much faster than plaster bandages. However, plaster can be more easily moulded to make a snug and therefore more comfortable fit. In addition, plaster is much smoother and does not snag clothing or abrade the skin.

Cast (gymnastics)

A cast is a basic skill on uneven bars in artistic gymnastics. From the front hang, a gymnast pikes (allowing the knee to touch the bar) and slides upwards to a handstand. Some gymnasts may perform the move with straddled legs. It is an "A" move in the Code of Points.

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Fossil

Fossils (from Classical Latin fossilis; literally, "obtained by digging") are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record.

The study of fossils across geological time, how they were formed, and the evolutionary relationships between taxa (phylogeny) are some of the most important functions of the science of paleontology. Such a preserved specimen is called a "fossil" if it is older than some minimum age, most often the arbitrary date of 10,000 years. Hence, fossils range in age from the youngest at the start of the Holocene Epoch to the oldest, chemical fossils from the Archaean Eon, up to 3.48 billion years old, or even older, 4.1 billion years old, according to a 2015 study. The observation that certain fossils were associated with certain rock strata led early geologists to recognize a geological timescale in the 19th century. The development of radiometric dating techniques in the early 20th century allowed geologists to determine the numerical or "absolute" age of the various strata and thereby the included fossils.