Operation Sigma Sigma

The Sigma is an experimental glider developed in Britain from 1966 by a team led by Nicholas Goodhart. After disappointing performance during flight testing the Sigma was passed on to a Canadian group which carried out modifications, making the Sigma more competitive.

Design and development

Designed to compete in the 1970 World Championships, the team aimed to develop a wing that would climb well through a high lift coefficient and a large wing area, but equally had the "maximum possible reduction of area for cruise at low lift coefficients". At the same time for the minimum possible drag they aimed for "extensive" laminar flow. To achieve this they employed flaps that would alter both wing area and wing camber. Based on analysis of the nature of thermals encountered in cross-country flying, they reasoned that by having a slow turning circle, their sailplane could stay close to the central (and strongest) part of the thermal and gain maximum benefit.

Its unusual feature is its ability to vary its wing area using Fowler flaps. It had been tried before by the Hannover Akaflieg in 1938 with their AFH-4, the South African Beatty-Johl BJ-2 Assegai and the SZD Zefir gliders.

Sigma (cosmology)

Sigma in cosmology was a property of galaxies used when trying to work out the mystery of galaxies and their supermassive black holes.

History

In the late 1990s the NUKER experts had made observations with a spectroscope of two galaxies, one of an active galaxy with an active galactic nucleus called NGC10-68 and a dormant galaxy next door to us named Andromeda.

The observations are shown. The light from the centre in Andromeda galaxy was distorted proving the existence of super-massive black holes.

Other observations proved most galaxies had a similar centre whether it be active or dormant.

They then realised that the black holes must have something to do with a galaxy's formation, so they turned to something they thought was useless: the speed of the stars around the edge of the galaxy. This was Sigma, the speed of the stars at the edge of the galaxy supposedly unaffected by the mass of the black hole at the centre.

Usage In Cosmology

The NUKER team calculated the sigma of several stars in different galaxies and the mass of the black hole at the (nucleus) centre. They expected no correlation what so ever. But when plotting their results on a Scatter diagram and drawing a line of best fit they ended up with a positive correlation. It appeared that the heavier the black hole at the centre was the faster the stars within the galaxy travelled.

Sigma (duo)

Sigma is an English drum and bass duo consisting of Cameron Edwards and Joe Lenzie. They met at Leeds University at drum and bass nights. Their 2010 collaboration with DJ Fresh, "Lassitude", peaked at number 98 on the UK Singles Chart. Their single "Nobody to Love" topped the UK Singles Chart, becoming their first UK number one. Follow-up single "Changing", featuring Paloma Faith, also got to number one.

Career

Formation

Lenzie and Edwards met in 2006 at Leeds University; Cameron was working in local record store Tribe Records and with Echo Location's Obi running local night Event Horizon, while Lenzie was DJing hip-hop and warming up Event Horizon for such acts as Rahzel and Grandmaster Flash. Once they had finished in Leeds, they relocated to London and became a three-piece with Edwards' school friend Ben Mauerhoff, being signed under DJ Fresh's Breakbeat Kaos. After a while, long distances took their toll – Edwards and Mauerhoff were based in Surrey, whereas Lenzie was based in Harpenden, Hertfordshire and they couldn't get three people into the Harpenden studio – and Mauerhoff left. In December 2008 they formed their own record label, Life Recordings (so called because, according to Lenzie, the industry demanded that it be their life). Its inaugural release was a VIP mix of their early Bingo Beats single "El Presidente".

Testimony (August Alsina album)

Testimony is the debut studio album by American R&B recording artist August Alsina. It was released on April 15, 2014, by Def Jam Recordings. The album was supported by six singles; "I Luv This Shit" featuring Trinidad James, "Ghetto", "Numb" featuring B.o.B and Yo Gotti, "Make It Home" featuring Jeezy, "Kissin' on My Tattoos" and "No Love (Remix)" featuring Nicki Minaj; along with the promotional single, "Benediction" featuring Rick Ross.

Upon its release, Testimony was met with generally positive reviews from music critics, who praised the whole creativity of the album. The album debuted at number 2 on the Billboard 200, with first-week sales of 67,000 copies in the United States.

Singles

On February 14, 2013, the music video was released for the lead single, "I Luv This Shit" featuring Trinidad James. The song was produced by Knucklehead. It was officially released for digital download on February 19, 2013. The song peaking at number 48 on the US Billboard Hot 100, while peaking at number 13 on the Billboard's Hot R&B/Hip-Hop Songs charts.

Ghetts

Justin Clarke (born 9 October 1984), better known by his stage name Ghetts (formerly Ghetto) is an English Grime MC, from Plaistow, Newham, East London with Caribbean roots from Jamaica and Grenada. His music has been played on national radio stations such as BBC Radio 1,Kiss 100,BBC Asian Network and BBC Radio 1Xtra. Currently, Ghetts is signed to independent record label Disrupt, and released his debut studio album, Rebel with a Cause, on 9 March 2014. Known for his hard hitting lyrics and intricate rhyme schemes, he is associated and has toured internationally with such acts as Kano and was a member of NASTY Crew.

Musical career

Ghetto was a member of grime collective NASTY Crew, however he left, saying that things had gone "pear shaped" due to the number of people in the group. He later went on to create the grime collective The Movement, including Devlin, Wretch 32, Scorcher, Mercston, Lightning and DJ Unique. Ghetts is a very enthusiastic UK artist who has made a number of well-known songs within the UK Grime scene. In 2008 Ghetts was nominated for a BET award for Best UK Act along with Chipmunk, Giggs and Skepta, in the end Giggs took home the award.

Ghetto (Kelly Rowland song)

"Ghetto" is a song by American recording artist Kelly Rowland, featuring vocals by rapper Snoop Dogg. It was written by Durrell "Tank" Babbs, Calvin Broadus, Lonny Bereal and Rowland, and produced by the former for Rowland's second solo album Ms. Kelly (2007). A mid-paced R&B ballad which was originally recorded for her shelved My Story album, "Ghetto" is influenced by the Crunk&B subgrene in the early to mid-2000s. Its instrumentation consists essentially of synthesizers and a drum machine rhythm and lyrically, finds Rowland, as the protagonist, singing sensually about becoming attracted to dangerous men.

One of Rowland's favorites on Ms. Kelly, "Ghetto" was released as the album's second single to US radios on August 7, 2007, while "Work" was serviced as the album's second international single. The song performed weakly on the Billboard charts, reaching reaching number nine on the Bubbling Under R&B/Hip-Hop Singles chart only, ranking it among Rowland's lowest-selling single to date. An accompanying music video was directed by Andrew Gura and shot in Los Angeles, California in August 2007.