An extract on #livetravelchannels
Transition metal compounds are paramagnetic when they have one or more unpaired d electrons. In octahedral complexes with between four and seven d electrons both high spin and low spin states are possible. Tetrahedral transition metal complexes such as [FeCl
4]2 are high spin because the crystal field splitting is small so that the energy to be gained by virtue of the electrons being in lower energy orbitals is always less than the energy needed to pair up the spins. Some compounds are diamagnetic. These include octahedral, low-spin, d6 and square-planar d8 complexes. In these cases, crystal field splitting is such that all the electrons are paired up.
Ferromagnetism occurs when individual atoms are paramagnetic and the spin vectors are aligned parallel to each other in a crystalline material. Metallic iron and the alloy alnico are examples of ferromagnetic materials involving transition metals. Anti-ferromagnetism is another example of a magnetic property arising from a particular alignment of individual spins in the solid state.
The London Eye was formally opened by then Prime Minister Tony Blair on 31 December 1999, but did not open to the paying public until 9 March 2000 because of a capsule clutch problem.
On 5 June 2008 it was announced that 30 million people had ridden the London Eye since it opened.
A taekwondo student typically wears a uniform (dobok ), often white but sometimes black (or other colors), with a belt tied around the waist. White uniforms are considered the traditional color and are encouraged for use at formal ceremonies such as belt tests and promotions. Colored uniforms are often reserved for special teams (such as demonstration teams or leadership teams) or higher-level instructors. There are at least two major styles of dobok, with the most obvious differences being in the style of jacket: (1) the cross-over front jacket (ITF style), (2) the V-neck or Y-neck jackets (no cross-over) typically worn by Kukkiwon/WT practitioners. White uniforms in the Kukkiwon/WT tradition will typically be white throughout the jacket (black along the collars for dan grades), while ITF-style uniforms are trimmed with a black border along the bottom of the jacket (for dan grades).
The belt color and any insignia thereon indicate the student's rank. Different clubs and schools use different color schemes for belts. In general, the darker the color, the higher the rank. Taekwondo is traditionally performed in bare feet, although martial arts training shoes may sometimes be worn.
When sparring, padded equipment is worn. In the ITF tradition, typically only the hands and feet are padded. For this reason, ITF sparring often employs only light-contact sparring. In the Kukkiwon/WT tradition, full-contact sparring is facilitated by the employment of more extensive equipment: padded helmets called homyun are always worn, as are padded torso protectors called hogu; feet, shins, groins, hands, and forearms protectors are also worn.
The school or place where instruction is given is called the dojang (). Specifically, the term dojang refers to the area within the school in which martial arts instruction takes place; the word dojang is sometimes translated as gymnasium. In common usage the term dojang is often used to refer to the school as a whole. Modern dojangs often incorporate padded flooring, often incorporating red-and-blue patterns in the flooring to reflect the colors of the taegeuk symbol. Some dojangs have wooden flooring instead. The dojang is usually decorated with items such as flags, banners, belts, instructional materials, and traditional Korean calligraphy.
The grandmaster of the dojang is called a gwanjangnim (); the master (senior instructor or head of dojang) is called sabeomnim (); the instructor is called gyosannim (); and the assistant instructor is called jogyonim ().