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Rhythmic gymnastics

Rhythmic gymnastics is a sport in which gymnasts perform on a floor with an apparatus: hoop, clubs, ribbon or rope. The sport combines elements of gymnastics and calisthenics. Rhythmic gymnastics is governed by the International Gymnastics Federation, which first recognized it as a sport in 1963, it became an Olympic sport with an individual all-around event. The group all-around competition was added to the Olympics in 1996. At the international level, rhythmic gymnastics is a women-only sport; the most prestigious competitions, besides the Olympic Games, are the World Championships, World Games, European Championships, European Games, the World Cup Series and the Grand Prix Series. Gymnasts are judged on their artistry, execution of skills, difficulty of skills, for which they gain points, they perform leaps, balances and flexibility movements, along with tossing, catching and otherwise manipulating the apparatus. Rhythmic gymnastics grew out of the ideas of Jean-Georges Noverre, François Delsarte, Rudolf Bode, who all believed in movement expression, where one used dance to express oneself and exercise various body parts.

Peter Henry Ling further developed this idea in his 19th-century Swedish system of free exercise, which promoted "aesthetic gymnastics", in which students expressed their feelings and emotions through body movement. This idea was extended by Catharine Beecher, who founded the Western Female Institute in Ohio, United States, in 1837. In Beecher's gymnastics program, called dance without dancing", the young women exercised to music, moving from simple calisthenics to more strenuous activities. During the 1880s, Émile Jaques-Dalcroze of Switzerland developed eurhythmics, a form of physical training for musicians and dancers. George Demeny of France created exercises to music that were designed to promote grace of movement, muscular flexibility, good posture. All of these styles were combined around 1900 into the Swedish school of rhythmic gymnastics, which would add dance elements from Finland. Around this time, Ernst Idla of Estonia established a degree of difficulty for each movement. In 1929, Hinrich Medau founded The Medau School in Berlin to train gymnasts in "modern gymnastics", to develop the use of the apparatus.

Competitive rhythmic gymnastics began in the 1940s in the Soviet Union. The FIG formally recognized this discipline in 1961, first as modern gymnastics as rhythmic sportive gymnastics, as rhythmic gymnastics; the first World Championships for individual rhythmic gymnasts was held in 1963 in Budapest. Groups were introduced at the same level in 1967 in Denmark. Rhythmic gymnastics was added to the 1984 Summer Olympics in Los Angeles, with an individual all-around competition. However, many federations from the Eastern European countries were forced to boycott by the Soviet Union. Canadian Lori Fung was the first rhythmic gymnast to earn an Olympic gold medal; the group competition was added to the 1996 Summer Olympics in Atlanta. The Spanish team won the first gold medal of the new competition with a team formed by Estela Giménez, Marta Baldó, Nuria Cabanillas, Lorena Guréndez, Estíbaliz Martínez and Tania Lamarca. Olympic rhythmic gymnastics is only for female participants. Japan has begun developing programs.

In Spain, men are allowed to participate in the women's competition. The men's program has yet to be formally recognized by the FIG, men cannot compete in the Olympics as a rhythmic gymnast. Gymnasts start at a young age and become age-eligible to compete in the Olympic Games and other major international competitions on January 1 of their 16th year. Gymnasts in Russia and Europe start training at a young age and those at their peak are in their late teens or early twenties, but since 2004 it is common to see gymnasts achieving their peak after reaching their twenties. Top rhythmic gymnasts must have many qualities, they must possess psychological attributes such as the ability to compete under intense pressure, in which one mistake can cost them the title, the discipline and work ethic to practice the same skills over and over again. A gymnast can perform in the individual event or in the group event, they perform routines in 12 x 12 meter areas, accompanied by music. Since 1995, groups are consisted of 5 gymnasts, but six gymnasts composed a group, although around the 1980s this could be eight.

The duration of a group exercise should be two and a half minutes, one minute more than the individual one, one minute and a half. The FIG selects which apparatus will be used in competitions, only four out of the five possible apparatuses are sanctioned. Hoop and rope were the first apparatus used at World Championships, followed by ball and clubs. For 2011, rope was dropped for senior national group competition. In 2011, it was to be dropped for junior national individual competition but returned again in 2015. Rope appeared in junior national group competition in 2011–2012. In 2017, rope appeared in senior group competition. Freehand was an event for the four first World Championships before being dropped and only used in local competitions for the youngest levels. Since 2011, senior individual gymnasts perform four different routines with hoop, ball and ribbon. Senior group performed two different routines, one with a single apparatus and one with mixed apparatus (for example, a routine w

Bradbury–Nielsen shutter

A Bradbury–Nielsen shutter is a type of electrical ion gate, first proposed in an article by Norris Bradbury and Russel A. Nielsen, where they used it as an electron filter. Today they are used in the field of mass spectrometry where they are used in both TOF mass spectrometers and in ion mobility spectrometers, as well as Hadamard transform mass spectrometers; the Bradbury–Nielsen shutter is ideal for injecting short pulses of ions and can be used to improve the mass resolution of TOF instruments by reducing the initial pulse size as compared to other methods of ion injection. The concept behind the Bradbury–Nielsen shutter is to apply a high frequency voltage in a 180° out-of-phase manner to alternate wires in a grid, orthogonal to the path of the ion beam; this results in charged particles only passing directly through the shutter at certain times in the voltage phase, when the potential difference between the grid wires is zero. At other times the ion beam is deflected to some angle by the potential difference between the neighboring wires.

This deflection is divergent with ions that pass through alternate slits being deflected in opposite directions. The maximum deflection angle can be calculated by tan α = k Vp / V0where α is the deflection angle, k is a deflection constant, Vp is the wire voltage, V0 is the ion acceleration voltage in eV; the deflection constant k can be calculated by k = π / 2ln where R is the wire radius and d is the wire spacing. A Bradbury-Nielsen Gate micromachined from a silicon on insulator wafer has been reported. Ion mobility spectrometer Time-of-flight

Latin Emperor

The Latin Emperor was the ruler of the Latin Empire, the historiographical convention for the Crusader realm, established in Constantinople after the Fourth Crusade and lasting until the city was recovered by the Byzantine Greeks in 1261. Its name derives from its Western European nature; the empire, whose official name was Imperium Romaniae, claimed the direct heritage of the Eastern Roman Empire, which had most of its lands taken and partitioned by the crusaders. This claim however was disputed by the Byzantine Greek successor states, the Empire of Nicaea, the Empire of Trebizond and the Despotate of Epirus. Out of these three, the Nicaeans succeeded in displacing the Latin emperors in 1261 and restored the Byzantine Empire. Baldwin II, in exile from Constantinople Philip I, his son Catherine I, his daughter, with... Charles, her husband Catherine II, their daughter, with... Philip II, her husband Robert II, their son Philip III, his brother James, his nephewJames of Baux willed his titular claims to Duke Louis I of Anjou claimant to the throne of Naples, but Louis and his descendants never used the title.

List of Latin empresses List of Roman emperors List of Byzantine emperors