Headlamp

A headlamp is a lamp attached to the front of a vehicle to light the road ahead. While it is common for the term headlight to be used interchangeably in informal discussion, headlamp is the term for the device itself, while headlight properly refers to the beam of light produced and distributed by the device.

Headlamp performance has steadily improved throughout the automobile age, spurred by the great disparity between daytime and nighttime traffic fatalities: the US National Highway Traffic Safety Administration states that nearly half of all traffic-related fatalities occur in the dark, despite only 25% of traffic travelling during darkness.

Other vehicles, such as trains and aircraft, are required to have headlamps. Bicycle headlamps are often used on bicycles, and are required in some jurisdictions. They can be powered by a battery or a small generator.

History of automotive headlamps

Mechanics

The earliest headlamps were fueled by acetylene or oil, and were introduced in the late 1880s. Acetylene lamps were popular because the flame is resistant to wind and rain. The first electric headlamps were introduced in 1898 on the Columbia Electric Car from the Electric Vehicle Company of Hartford, Connecticut, and were optional. Two factors limited the widespread use of electric headlamps: the short life of filaments in the harsh automotive environment, and the difficulty of producing dynamos small enough, yet powerful enough to produce sufficient current.

Beam

Beam may refer to:

BEAM

Beam (music)

In musical notation, a beam is a horizontal or diagonal line used to connect multiple consecutive notes (and occasionally rests) in order to indicate rhythmic grouping. Only eighth notes (quavers) or shorter can be beamed. The number of beams is equal to the number of flags that would be present on an un-beamed note.

Grouping

The span of beams indicates the rhythmic grouping, usually determined by the time signature. Therefore, beams do not usually cross bar lines, or major sub-divisions of bars. If notes extend across these divisions, this is indicated with a tie.

In modern practice beams may span across rests in order to make rhythmic groups clearer.

In vocal music, beams were traditionally used only to connect notes sung to the same syllable. In modern practice it is more common to use standard beaming rules, while indicating multi-note syllables with slurs.

Positioning

Notes joined by a beam usually have all the stems pointing in the same direction (up or down). The average pitch of the notes is used to determine the direction – if the average pitch is below the middle staff-line, the stems and beams usually go above the note head, otherwise they go below.

Beam (structure)

A beam is a structural element that is capable of withstanding load primarily by resisting against bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment. Beams are characterized by their profile (shape of cross-section), their length, and their material.

Beams are traditionally descriptions of building or civil engineering structural elements, but smaller structures such as truck or automobile frames, machine frames, and other mechanical or structural systems contain beam structures that are designed and analyzed in a similar fashion.

Overview

Historically beams were squared timbers but are also metal, stone, or combinations of wood and metal such as a flitch beam. Beams generally carry vertical gravitational forces but can also be used to carry horizontal loads (e.g., loads due to an earthquake or wind or in tension to resist rafter thrust as a tie beam or (usually) compression as a collar beam). The loads carried by a beam are transferred to columns, walls, or girders, which then transfer the force to adjacent structural compression members. In light frame construction joists may rest on beams.

Low

Low or LOW may refer to:

Music

Albums

Songs

Other uses

Low (Flo Rida song)

"Low" is the debut single by American rapper Flo Rida, featured on his debut studio album Mail on Sunday and also featured on the soundtrack to the 2008 film Step Up 2: The Streets. The song features fellow American rapper T-Pain and was co-written with T-Pain. There is also a remix in which the hook is sung by Flo Rida rather than T-Pain. An official remix was made which features Pitbull and T-Pain. With its catchy, up-tempo and club-oriented Southern hip hop rhythms, the song peaked at the summit of the U.S. Billboard Hot 100.

The song was a massive success worldwide and was the longest running number-one single of 2008 in the United States. With over 6 million digital downloads, it has been certified 7× Platinum by the RIAA, and was the most downloaded single of the 2000s decade, measured by paid digital downloads. The song was named 3rd on the Billboard Hot 100 Songs of the Decade. "Low" spent ten consecutive weeks on top of the Billboard Hot 100, the longest-running number-one single of 2008.

Low (Testament album)

Low is the sixth studio album by American heavy metal band Testament. It was released on September 30, 1994. It was the first Testament release not to feature two of its founding members Alex Skolnick (guitar) and Louie Clemente (drums).

Background

Low would be Testament's last album with Atlantic Records, leading group members to create their own label Burnt Offerings Inc. as part of the change.

The record was recorded with original band members Chuck Billy (vocals), Eric Peterson (guitar) and Greg Christian (bass). It also saw the first of two Testament album appearances by artist John Tempesta (drums), and three for artist James Murphy (guitar). Long time Testament collaborator Del James is given composer and vocal credits on the album. Additionally, a music video was filmed for the title track.

Artwork

Album cover artwork for Low was designed by Dave McKean. He would go on to do the next two Testament studio album covers Demonic (1997) and The Gathering (1999).

Reception and legacy