An air-to-air missile is a missile fired from an aircraft for the purpose of destroying another aircraft. AAMs are powered by one or more rocket motors solid fueled but sometimes liquid fueled. Ramjet engines, as used on the Meteor are emerging as propulsion that will enable future medium-range missiles to maintain higher average speed across their engagement envelope. Air-to-air missiles are broadly put in two groups; those designed to engage opposing aircraft at ranges of less than 30 km are known as short-range or "within visual range" missiles and are sometimes called "dogfight" missiles because they are designed to optimize their agility rather than range. Most use are called heat-seeking missiles. In contrast, medium- or long-range missiles, which both fall under the category of beyond visual range missiles, tend to rely upon radar guidance, of which there are many forms; some modern ones use inertial guidance and/or "mid-course updates" to get the missile close enough to use an active homing sensor.
The concepts of air-to-air missiles and surface-to-air missiles are closely related, in some cases versions of the same weapon may be used for both roles, such as the ASRAAM and Sea Ceptor. The air-to-air missile grew out of the unguided air-to-air rockets used during the First World War. Le Prieur rockets were sometimes attached to the struts of biplanes and fired electrically against observation balloons, by such early pilots as Albert Ball and A. M. Walters. Facing the Allied air superiority, Germany in World War II invested limited effort into missile research, leading to the deployment of the R4M unguided rocket and the development of various guided missile prototypes such as the Ruhrstahl X-4. Post-war research led the Royal Air Force to introduce Fairey Fireflash into service in 1955 but their results were unsuccessful; the US Navy and US Air Force began equipping guided missiles in 1956, deploying the USAF's AIM-4 Falcon and the USN's AIM-7 Sparrow and AIM-9 Sidewinder. The Soviet Air Force introduced its K-5 into service in 1957.
As missile systems have continued to advance, modern air warfare consists entirely of missile firing. The use of Beyond Visual Range combat became so pervasive in the US that early F-4 variants were armed only with missiles in the 1960s. High casualty rates during the Vietnam War caused the US to reintroduce autocannon and traditional dogfighting tactics but the missile remains the primary weapon in air combat. In the Falklands War British Harriers, using AIM-9L missiles were able to defeat faster Argentinian opponents. Since the late 20th century all-aspect heat-seeking designs can lock-on to a target from various angles, not just from behind, where the heat signature from the engines is strongest. Other types rely on radar guidance. A conventional explosive blast warhead, fragmentation warhead, or continuous rod warhead is used in the attempt to disable or destroy the target aircraft. Warheads are detonated by a proximity fuze or by an impact fuze if it scores a direct hit. Less nuclear warheads have been mounted on a small number of air-to-air missile types although these are not known to have been used in combat.
Guided missiles operate by detecting their target, "homing" in on the target on a collision course. Although the missile may use radar or infra-red guidance to home on the target, the launching aircraft may detect and track the target before launch by other means. Infra-red guided missiles can be "slaved" to an attack radar in order to find the target and radar-guided missiles can be launched at targets detected visually or via an infra-red search and track system, although they may require the attack radar to illuminate the target during part or all of the missile interception itself. Radar guidance is used for medium- or long-range missiles, where the infra-red signature of the target would be too faint for an infra-red detector to track. There are three major types of radar-guided missile – active, semi-active, passive. Radar-guided missiles can be countered by rapid maneuvering, deploying chaff or using electronic counter-measures. Active radar -guided missiles carry their own radar system to detect and track their target.
However, the size of the radar antenna is limited by the small diameter of missiles, limiting its range which means such missiles are launched at a predicted future location of the target relying on separate guidance systems such as Global Positioning System, inertial guidance, or a mid-course update from either the launching aircraft or other system that can communicate with the missile to get the missile close to the target. At a predetermined point the missile's radar system is activated, the missile homes in on the target. If the range from the attacking aircraft to the target is within the range of the missile's radar system, the missile can "go active" upon launch; the great advantage of an active radar homing system is that it enables a "fire-and-forget" mode of attack, where the attacking aircraft is free to pursue other targets or escape the area after launching the missile. Semi-active radar homing guided missiles are more common, they function by detecting radar energy reflected from the target.
David Frederick Skea was a Scottish footballer. He began his career with his hometown club, before joining Aston Villa, where he made just one appearance in The Football League. After a spell back in Scotland with Dundee Thistle, he moved to Darwen, where again he was restricted to a single Football League game before a move to Bury of the Lancashire League. In 1894 he joined Leicester Fosse, where he spent two seasons as a regular in the team, making 45 League appearances and scoring 28 goals. In the 1894–95 season, he was the top scorer in the Football League Second Division. After leaving Filbert Street, he played for Swindon Town and New Brompton of the Southern League
"Nobody Puts Baby in a Corner" is the seventh episode of the second season of the American mystery television series Veronica Mars, the twenty-ninth episode overall. Written by Diane Ruggiero and directed by Nick Marck, the episode premiered on UPN on November 16, 2005; the series depicts the adventures of Veronica Mars as she deals with life as a high school student while moonlighting as a private detective. In this episode, Duncan calls on Veronica to help investigate a subject of child abuse mentioned in his ex-girlfriend, Meg's journal. Meanwhile, the Casablancas family splits up Dick Sr.'s assets. Veronica and Duncan make out before Logan, now living there, walks in the door. Logan invites Kendall into the hotel room, making Veronica uncomfortable. In a Future Business Leaders of America meeting, Cassidy comes out on top of the hypothetical business contest. Keith talks to new mayor Woody Goodman, who states his plan to redesign Neptune, Woody offers to make Keith police chief. Logan meets Veronica in the girls bathroom and asks her to investigate the "witness" to the murder of Felix Toombs, she agrees.
Duncan has searched through Meg's files and finds evidence that she was attempting to help an unknown abused child between 7–10 years old. Meg babysat and Veronica and Duncan will have to break into Meg's house for more evidence; the Casablancas talk to a lawyer. Kendall has received nothing, Dick and Beaver each have a trust fund. Veronica signs up for a babysitting job with one of the people who Meg babysat for, Gia invites Veronica over her house. At the babysitting job, the kid's parents say that they let Meg go because of Duncan. Logan appears at the door of Veronica's babysitting house. Veronica presents information on Logan's accuser; the boy, Edwin's, dad starts acting weirdly towards Veronica and hands her a drawing Edwin made of her, showing her head cut off of her body. Dick and Beaver's biological mother appears at their house. Veronica wins the babysitting job from a high-pressure teacher. However, her son is high-maintenance. Veronica talks to Logan's witness, Dr. Griffith, a plastic surgeon.
Although he seems honest at first, Veronica trails him to a cigar shop. Veronica sees all the signs of emotional abuse. Gia "surprises" Veronica with a girl's night sleepover. Logan ends his friends-with-benefits relationship with Kendall. Kendall tries to seduce Duncan. Veronica meets Gia's little brother, anxious. Veronica overhears Woody telling Rodney that he'll have to tell his mother about him spilling a cup of water on the floor, the mother leads Rodney to an unknown room. Dick and Beaver, raid Gia's sleepover. Veronica learns from Keith. Logan tells Veronica. Veronica and Duncan break into Meg's house. Duncan steals a letter without showing Veronica. Veronica figures out that Meg is covering for the child abuse of her sister. Veronica finds Grace Manning locked in a closet. However, Meg's dad fakes that Veronica and Duncan were just breaking in for no reason. Sheriff Lamb arrests Veronica and Duncan but soon figures out. After driving away with Veronica and Duncan, he soon lets them go and waits menacingly outside of Meg's father's house.
Many cultural references are made in the episode. They include: At the beginning of the episode and Duncan are watching The Big Lebowski. Mr. Pope references "What a Diff'rence a Day Made". Veronica mentions a famous scene from Ferris Bueller's Day Off. One of the teachers quotes the song "The Gambler". In an email to Wallace, Veronica quotes a famous Juliet monologue. In a voiceover, Veronica compares her letters to Wallace to Doogie Howser's journal. Dick and Beaver's biological mother quotes a lyric from "You've Got a Friend". Gia references "I'm So Excited". Veronica says that her "Spidey sense is tingling." Logan quotes part of the iconic line, "Frankly, my dear, I don't give a damn", spoken by Rhett Butler in Gone With the Wind. Madison Sinclair says at the party. Dick and Beaver expect there to be Spin the bottle at the party. Veronica jokingly mentions Goodnight Moon; the newly discovered witness to Felix's murder is a plastic surgeon. Logan says that he wasn't the man on the bridge. Woody Goodman tells Keith of his plan for Neptune, which involves incorporating the wealthy part of the town.
Dick and Beaver's real mother shows up to unlock their trust funds. Duncan pockets it. Sheriff Lamb hints; this marks one of the few times that he takes Veronica when she reports a crime. When cuffing her, he leans forward, she tells him where to look for the secret room. The following songs are heard in the episode: "Pon de Replay" by Rihanna "The Nth Degree" by Morningwood "Run" by Air The episode was written by Diane Ruggiero and directed by Nick Marck, marking Ruggiero's ninth writing credit for Veronica Mars and Marck's sixth directing credit for the show. Despite being credited, Weevil and Jackie do not appear in "Nobod
TEDx Tarfaya is a TED conference organized locally by the city of Tarfaya, Morocco. It's the first of its kind in the Sahara; the inaugural TEDx Tarfaya conference was held on May 4, 2013 at the Antoine de Saint-Exupery Museum. TED is an acronym for "Technology and Design," and TED conferences are sponsored by the Sapling Foundation, an American non-profit organization whose motto is "ideas worth sharing." In 2009, TED started granting licenses to independent third-party organizations to organize TED conferences worldwide under the name "TEDx." These are programs consisting of organized local events in which people gather to share an experience similar to the TED in that they are led by the principle of "ideas worth sharing." In TEDx events, televised conversations are combined with speeches in front of live audiences, with the purpose of generating profound discussion and connection within a small group. The x in TEDx represents the fact, it is forbidden for TEDx conference organizers to profit financially from running the events, though they are allowed to charge entrance fees to cover the operational costs of the conference.
The licenses are free, but TED runs inspections before granting them, as there are conditions that must be met. TEDx does not pay speakers, it must consent to releasing the right to edit and present materials from the conference according to Creative Commons licensing. By late 2012, more than 16,000 "TED Talks" had been presented in over 5,000 TEDx conferences in 1,200 cities in 133 countries. In June of 2012, TEDx conferences are organized by volunteers divided into specific teams: Board Logistics Team Sponsoring team Registration Team Speakers Organizing Team Entertainment Team Media Team Social Media Team Stage Preparation Team Designing Team Photographers Team Web Developing Team The TEDx Tarfaya conference was held on May 4, 2013 in the hall of the Antoine de Saint-Exupery Museum. There were 6 speakers: Julio Barbosa. Sabine Blan Ghizlan Ishodar Murabihi Rab Shiba As-Salek Ayusa François Bastide The first edition of the TEDx Tarfaya conference was overseen by a group of volunteers divided into the following teams: Logistics Team led by Muhammad Saalem El Wali El Alaoui Speakers Organizing Team led by El Wali El Alaoui Social Media Team led by Asselik Ad-Daoudi Stage Preparation Team led by Mustafa Ad-Demnati Photographers Team led by Hassan Affan Sapling Foundation
Cyclopropanation refers to any chemical process which generates cyclopropane rings. It is an important process in modern chemistry; however the high ring strain present in cyclopropanes makes them challenging to produce and requires the use of reactive species, such as carbenes and carbanions. Many of the reactions proceed in a cheletropic manner. Several methods exist for converting alkenes to cyclopropane rings using carbene type reagents; as carbenes themselves are reactive it is common for them to be used in a stabilised form, referred to as a carbenoid. In the Simmons–Smith reaction the reactive carbenoid is iodomethylzinc iodide, formed by a reaction between diiodomethane and a zinc-copper couple. Modifications involving cheaper alternatives have been developed, such as dibromomethane or diazomethane and zinc iodide; the reactivity of the system can be increased by exchanging the zinc‑copper couple for diethylzinc. Asymmetric versions are known. Certain diazo compounds, such as diazomethane, can react with olefins to produce cyclopropanes in a 2 step manner.
The first step involves a 1,3-dipolar cycloaddition to form a pyrazoline which undergoes denitrogenation, either photochemically or by thermal decomposition, to give cyclopropane. The thermal route, which uses KOH and platinum as catalysts, is known as the Kishner cyclopropane synthesis after the Russian chemist Nikolai Kischner and can be performed using hydrazine and α,β-unsaturated carbonyl compounds; the mechanism of decomposition has been the subject of several studies and remains somewhat controversial, although it is broadly thought to proceed via a diradical species. In terms of green chemistry this method is superior to other carbene based cyclopropanations; however the reaction can be dangerous as trace amounts of unreacted diazo compounds may explode during the thermal rearrangement of the pyrazoline. Methyl phenyldiazoacetate and many related diazo derivatives are precursors to donor-acceptor carbenes, which can be used for cyclopropanation or to insert into C-H bonds of organic substrates.
These reactions are catalyzed by dirhodium tetraacetate or, more spectacularly, related chiral derivatives. Free carbenes can be employed for cyclopropanation reactions, however there is limited scope for this as few can be produced conveniently and nearly all are unstable. An exception are dihalocarbenes such as dichlorocarbene or difluorocarbene, which are reasonably stable and will react to form geminal dihalo-cyclopropanes; these compounds can be used to form allenes via the Skattebøl rearrangement. The Buchner ring expansion reaction involves the formation of a stabilised carbene. Cyclopropanation is stereospecific as the addition of carbene and carbenoids to alkenes is a form of a cheletropic reaction, with the addition taking place in a syn manner. For example and cis-2-butene yield cis-2,3-dimethyl-1,1-dibromocyclopropane, whereas the trans isomer yields the trans cyclopropane. Cyclopropanes can be generated using a sulphur ylide in the Johnson–Corey–Chaykovsky reaction, however this process is limited to use on electron-poor olefines α,β-unsaturated carbonyl compounds.
Cyclopropanes can be obtained by a variety of intramolecular cyclisation reactions. A simple method is to use primary haloalkanes bearing appropriately placed electron withdrawing groups. Treatment with a strong base will generate a carbanion which will cyclise in a 3-exo-trig manner, with displacement of the halide. Examples include the formation of cyclopropyl cyanide and cyclopropylacetylene This mechanism forms the basis of the Favorskii rearrangement. A related process is the cyclisation of 1,3-dibromopropane via a Wurtz coupling; this was used for the first synthesis of cyclopropane by August Freund in 1881. This reaction was performed using sodium, however the yield can be improved by exchanging this for zinc. BrCH2CH2CH2Br + 2 Na → 3 + 2 NaBr The Kulinkovich reaction form cyclopropanols via a reaction between esters and Grignard reagents in presence of a titanium alkoxide; the Bingel reaction is a specialised cyclopropanation reaction used to functionalise a fullerene. In the di-pi-methane rearrangement photochemical stimulation causes 1,4-dienes to rearrange to form vinylcyclopropanes.
These can undergo vinylcyclopropane rearrangements Cyclopropane-fatty-acyl-phospholipid synthase performs cyclopropanation is biological systems Although cyclopropanes are rare in biochemistry, many cyclopropanation pathways have been identified in nature. The most common pathways involve ring closure reactions of carbocations in terpenoids. Cyclopropane fatty acids are derived from the attack of S-adenosylmethionine on unsaturated fatty acids; the precursor to the hormone ethylene, 1-aminocyclopropane-1-carboxylic acid is derived directly from SMM via intramolecular nucleophilic displacement of the SMe2 group subsequent to condensation with pyridoxal phosphate. Direct carbene transfer from diazoesters to olefins has been achieved through in vitro biocatalysis using engineered variants of the cytochrome P450 enzyme from Bacillus megaterium that were optimized by directed evolution
Athlético Marseille is a French amateur football club founded in 1964 and based in the Bouches-du-Rhone department of Marseille. The club was named until 2018 after Consolat, a neighborhood located in La Calade, in the 15th arrondissement, north of Marseille. Founded in 1964 by the residents of Consolat, the club has been run by current club president Jean-Luc Mingallon since 1983. Mingallon pushed the team to success which has led to their promotion from the Division d’Honneur in 1999. In 2006, the club reached the national amateur level of football with its promotion to CFA2; this promotion sparked new derbies with the reserve team of Olympique de US Endoume. The desire to become “the second club of Marseille” was one step closer with the promotion to the CFA in 2011. Consolat won the CFA title in 2014, earning promotion to the Championnat National, the third tier of French football, they nearly were promoted to Ligue 2 during the 2015-2016 season, falling short only by a single point behind Amiens SC.
They again missed out on possible promotion in the following season, finishing behind division rivals Paris FC due only to goal differential. In the summer of 2018, Consolat underwent a re-branding process and changed their name to Athlético Marseille. Despite finishing 5th in the league, Athlético Marseille were relegated to Championnat National 3 in 2019, due to financial issues; as of 14 February 2019Note: Flags indicate national team. Players may hold more than one non-FIFA nationality. Gaetan Hardouin Nordine Essemeri Stéphane Haro Club information at FFF