Systems Containing Additional Elements

The so-called superalloys are based on the ternary system M-Cr-Al and they contain additional elements in minor quantity Y, Ce, Zr, W, C, Ti, Mo. Some of these... 

If the system contains symmetry, there are additional Cl matrix elements which become zero. The symmetry of a determinant is given as the direct product of the symmetries of the MOs. The Hamilton operator always belongs to the totally symmetric representation, thus if two determinants belong to different irreducible representations, the Cl matrix element is zero. This is again fairly obvious if the interest is in a state of a specific symmetry, only those determinants which have the correct symmetry can contribute. 

The addition of elemental sulfur to systems containing 82 or 83 results in the formation of more sulfur-rich species [89] ... 

Leucophane is a relatively rare berylhum silicate. Of interest are the trace amounts of rare earth elements in its chemistry, especially cerium which substitutes for some calcium. Its true symmetry is triclinic, pedion class which is the lowest symmetry possible in a three dimensional system. The only symmetry element is translational shift as it lacks any mirrors, rotations, or even a center. The symmetry is noted by a 1. Ce ", Eu +, Sm +, Dy +, Tb ", Nd " " and Mn " centers characterize steady-state luminescence spectra of leucophane (Gorobets and Rogojine 2001). Time-resolved luminescence spectra contain additionally Eu and Tm " " centers (Fig. 4.25). 

If deposits found on filters, pump parts, and engine systems contain high levels of zinc, calcium, phosphorus, and sulfur, the possible source of the contamination is lubricating oil. These elements are part of the composition of the engine oil additive package. The elements and the compounds in which they can be found are listed in TABLE 4-11. 

A solar photovoltaic system contains, in addition to solar cells and module(s), an array structure to support the modules, power-conditioning circuitry for control and modification of the output, and a means of storing energy if required. All elements beyond the module are referred to as balance-of-system (BOS) components. The cost of BOS items is nominally about equal to the cost of the PV module. However, the BOS fractional cost contribution can vary from one- to two-thirds of the total installed cost of a system, depending on application. 

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