Group

Group may refer to:

Groups of people

In science and technology

In mathematics

In chemistry

In computing and the internet

Other uses in science and technology

Other uses

Shot grouping

In shooting, a shot grouping, or simply grouping, is the placement of multiple shots on a target, the shots taken in one shooting session. The closeness of the grouping, the nearness of all the shots to each other, is a measure of the accuracy of a weapon, and a measure of the shooter's consistency and skill.

Uses of the term

For firearms that shoot one round at a time, a shot grouping can be used to measure the accuracy of the system comprised out of weapon as well as the precision and uniformity of the ammunition by fixing the weapon into position on a test mount, and aiming it at a target. Multiple shots using rounds from same type and batch are fired to observe how the weapon groups the shots. If a person holds the weapon and shoots it, the grouping measures the combination of the person's skill and the weapon's accuracy.

In shotgun shooting, the grouping is also called the pattern. The pattern is the spread of shot from a single shotgun shell, measured as the smallest circle containing all the shots on the target. The barrel of a shotgun is designed to deliver a wide or narrow grouping, depending on the expected use. Shooting at close range indicates a cylinder bore barrel to deliver a wide grouping, while for hunting at longer distances such as 50 yards or meters, a choke is recommended for a tighter grouping.

Stratigraphic unit

A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features (facies) that characterize it.

Units must be mappable and distinct from one another, but the contact need not be particularly distinct. For instance, a unit may be defined by terms such as "when the sandstone component exceeds 75%".

Lithostratigraphic units

Sequences of sedimentary and volcanic rocks are subdivided on the basis of their lithology. Going from smaller to larger in scale, the main units recognised are Bed, Member, Formation, Group and Supergroup.

Bed

A bed is a lithologically distinct layer within a member or formation and is the smallest recognisable stratigraphic unit. These are not normally named, but may be in the case of a marker horizon.

Member

A member is a named lithologically distinct part of a formation. Not all formations are subdivided in this way and even where they are recognized, they may only form part of the formation.

Hessian (soldier)

Hessians /ˈhɛʃən/ is the term given to the 18th-century German auxiliaries contracted for military service by the British government, which found it easier to borrow money to pay for their service than to recruit its own soldiers. They took their name from the German state of Hesse-Kassel. The British hired Hessian troops for combat duty in several eighteenth century conflicts, but they are most widely associated with combat operations in the American Revolutionary War (1775-1783).

About 30,000 German soldiers fought for the British during the American Revolutionary War, making up a quarter of the soldiers the British sent to America. They entered the British service as entire units, fighting under their own German flags, commanded by their usual officers, and wearing their existing uniforms. The largest contingent came from the state of Hesse, which supplied about 40% of the German troops who fought for the British. The others were rented from other small German states. Several more German units were placed on garrison duty in the British Isles to free up British regulars for service in North America.

Heavy metal subculture

Fans of heavy metal music have created their own subculture which encompasses more than just appreciation of the style of music. Fans affirm their membership in the subculture or scene by attending metal concerts–an activity seen as central to the subculture, buying albums, in some cases growing their hair long, wearing leather jackets and t-shirts with band names and logos and most recently, by contributing to metal websites. Metal fans may also write or take photos for metal zines.

Some critics and musicians have suggested that the subculture is largely intolerant to other musical genres. The metal scene, like the rock scene in general, is associated with alcohol and drug use. While there are songs that celebrate drinking, drug use and partying, there are also many songs that warn about the dangers of alcohol and drug addiction. The metal fanbase was traditionally white and male in the 1970s, but since the 1980s, more women fans have developed an interest in the style, while popularity and interest continue to grow among african-americans and latinos.