Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of Fe2O3. It has the same crystal structure as corundum (Al2O3) and ilmenite (FeTiO...

The Fleet Commander is a senior Royal Navy post, responsible for the operation, resourcing and training of the ships, submarines and aircraft, and personnel, of the Naval Service. The Vice-Admiral incumbent is required to provide ships, submarines and aircraft ready for operations, and is based at Navy Command Headquarters. The post was created in April 2012 following a reorganisation of the Royal Navy and a re-designation of the former role of Commander-in-Chief Fleet. Responsibilities The Fleet Commander's purpose is to provide ships, submarines and aircraft ready for any operations that the Government requires.The Fleet Commander's major subordinates included as of September 2020: Commander Operations Commander United Kingdom Strike Force Director Force Generation - Commodore Steve Moorhouse was promoted to Rear Admiral and became Director 14 January 2022 on the promotion of Martin Connell to Vice Admiral and Connell's appointment as Second Sea Lord. Commandant General Royal MarinesThe previous post of Assistant Chief of the Naval Staff (Training)/Flag...

In music, 19 Tone Equal Temperament, called 19 TET, 19 EDO ("Equal Division of the Octave"), 19-ED2 ("Equal Division of 2:1) or 19 ET, is the tempered scale derived by dividing the octave into 19 equal steps (equal frequency ratios). Each step represents a frequency ratio of 19√2, or 63.16 cents (Play ). The fact that traditional western music maps unambiguously onto this scale (unless it presupposes 12-EDO enharmonic equivalences) makes it easier to perform such music in this tuning than in many other tunings. 19 EDO is the tuning of the syntonic temperament in which the tempered perfect fifth is equal to 694.737 cents, as shown in Figure 1 (look for the label "19 TET"). On an isomorphic keyboard, the fingering of music composed in 19 EDO is precisely the same as it is in any other syntonic tuning (such as 12 EDO), so long as the notes are "spelled properly" – that is, with no assumption that the sharp below matches the flat immediately above it (enharmonicity). History and use...