Del

Del, or nabla, is an operator used in mathematics, in particular, in vector calculus, as a vector differential operator, usually represented by the nabla symbol ∇. When applied to a function defined on a one-dimensional domain, it denotes its standard derivative as defined in calculus. When applied to a field (a function defined on a multi-dimensional domain), del may denote the gradient (locally steepest slope) of a scalar field (or sometimes of a vector field, as in the Navier–Stokes equations), the divergence of a vector field, or the curl (rotation) of a vector field, depending on the way it is applied.

Strictly speaking, del is not a specific operator, but rather a convenient mathematical notation for those three operators, that makes many equations easier to write and remember. The del symbol can be interpreted as a vector of partial derivative operators, and its three possible meanings—gradient, divergence, and curl—can be formally viewed as the product with a scalar, dot product, and cross product, respectively, of the del "operator" with the field. These formal products do not necessarily commute with other operators or products.

Deel (clothing)

A deel (Mongolian: дээл [teːɮ]; Buryat: дэгэл) is an item of traditional clothing commonly worn since centuries ago among the Mongols and other nomadic tribes of Central Asia, including various Turkic peoples, and can be made from cotton, silk, wool, or brocade. The deel is still commonly worn by both men and women outside major towns, especially by herders. In urban areas, deels are mostly only worn by elderly people, or on festive occasions. The deel appears similar to a caftan or an old European folded tunic. Deels typically reach to below the wearer's knees and fan out at the bottom and are commonly blue, olive, or burgundy, though there are deels in a variety of other colors.

Description

The deel looks like a large overcoat when not worn. Instead of buttoning together in the middle, the sides are pulled against the wearers body, the right flap close to the body with the left covering. On the right side of the wearer are typically 5 or 6 clasps to hold the top flap in place. There is one clasp below the armpit, three at the shoulder, and either one or two at the neckline.

Del (disambiguation)

Del or DEL may refer to:

In computing:

Outburst

Outburst may refer to:

See also

Outburst (mining)

An outburst is the sudden and violent ejection of coal, gas and rock from a coal face and surrounding strata in an underground coal mine. When outbursts occur, they can be very serious events, possibly even resulting in multiple fatalities.

Effects of outbursts

Outbursts may range in severity from being barely noticeable, to causing the destruction of an entire mining panel, and throwing pieces of machinery weighing tens of tonnes several metres. An outburst at Tahmoor Colliery, in NSW, Australia in June 1985 involved the ejection of 350 tonnes of coal and rock and over 3000 cubic metres of gas, resulting in one fatality. Another outburst at the nearby South Bulli Colliery in 1991 resulted in three fatalities, and yet another outburst at Westcliff Colliery in January 1994 involved 300 tonnes of coal and rock and resulted in one fatality.

Predisposing factors

Several factors predispose certain coal seams to being outburst-prone. These include:

Supermen of America

The Supermen of America is the name of two fictional superhero teams published by DC Comics. The original group first appeared in a special written by Stuart Immonen published in 1999, and a later mini-series written by Fabian Nicieza, which was published in 2000. The second group debuted in Superman #714 in 2011.

Historical Supermen

The original Supermen of America was an official Superman fan club from the 1940s. Comic readers could send away for and receive special membership cards that also doubled as decoders. Members also received buttons and special certificates.

Fictional history

Original Team

The young members of the superhero team Supermen of America are all young metahumans gathered by Outburst after the shooting death of singer Junior K-D from the boy band Crossfire. Outburst and his family had been saved from death at Doomsday's hands by Superman. The young naive meta is willing to accept Lex Luthor's funding for a team of superheroes to protect the city in Superman's absence. Although Luthor volunteered money, Outburst is tasked with recruiting the members.