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Electropositivity is a measure of an element's ability to donate electrons, and therefore form positive ions; thus, it is antipode to electronegativity. Mainly, this is an attribute of metals , meaning that, in general, the greater the metallic character of an element the greater the electropositivity.
Electron-beam machining is a process in which high-velocity electrons are concentrated into a narrow beam with a very high planar power density. The beam cross-section is then focused and directed toward the work piece, creating heat and vaporizing the material. Electron-beam machining can be used to accurately cut or bore a wide variety of metals.
Electronegativity is not a uniquely defined property and may depend on the definition. The suggested values are all taken from WebElements as a consistent set. Many of the highly radioactive elements have values that must be predictions or extrapolations, but are unfortunately not marked as such.
The results of the beam application depend on several factors: Beam power – The power of the beam [W] is the product of the accelerating voltage [kV] and beam current [mA], which are easily measured and must be precisely controlled. The power is controlled by the beam current at constant voltage, usually the highest accessible.
The basic components of a typical electron-beam processing device include: [1] an electron gun (consisting of a cathode, grid, and anode), used to generate and accelerate the primary beam; and, a magnetic optical (focusing and deflection) system, used for controlling the way in which the electron beam impinges on the material being processed ...
Historically a beam is a squared timber, but may also be made of metal, stone, or a combination of wood and metal [1] such as a flitch beam.Beams primarily carry vertical gravitational forces, but they are also used to carry horizontal loads such as those due to earthquake or wind, or in tension to resist rafter thrust or compression (collar beam).
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Zn has three excited metastable states and 73 Zn has two. [47] The isotopes 65 Zn, 71 Zn, 77 Zn and 78 Zn each have only one excited metastable state. [45] The most common decay mode of a radioisotope of zinc with a mass number lower than 66 is electron capture. The decay product resulting from electron capture is an isotope of copper. [45] n ...