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Characteristics of the Metal–Metal Oxide Reaction Matrix
Published in Anthony Peter Gordon Shaw, Thermitic Thermodynamics, 2020
Thermitic reactions are not constrained by our preconceptions regarding the products that “should” be formed. Realistic simulations can generate complex product distributions or unanticipated products for several reasons. One is that certain suboxides containing metals in unusual oxidation states become increasingly stable at higher temperatures. Examples include AlO and Al2O, which exist as gases. These suboxides and others are predicted to occur as minor products at the maximum adiabatic equilibrium temperature of the Al/MoO3 system. The stoichiometry of point D corresponds to the simple reaction of equation 2.17.
Analysis of Crystallization Fouling Durability of Novel Heating Elements for Electric Water Heating
Published in Heat Transfer Engineering, 2022
Alexander Janzen, Eugeny Y. Kenig
All metals and special ceramic types (e.g., titanium suboxide (TiOx), nickel-chromium (NiCr), tin oxide (SnO)) conduct electricity. When an electrical current flows through such a material having a certain resistance, it generates heat. The power generated by the resistance can be determined with the following equation:where Pel is the power in watts, Uel is the voltage across the element, Iel is the current through the element, and Rel is the electrical resistance of the element. The resistance of a given element is directly proportional to its length l and inversely proportional to its cross-sectional area A. The resistivity ρel depends on the material of the element, rather than its geometry. The following equation expresses this relationship:
Algebraic discrete variable representation approaches: application to interatomic effective potentials
Published in Molecular Physics, 2021
M. Rodríguez-Arcos, M. Bermúdez-Montaña, J. M. Arias, J. Gómez-Camacho, E. Orgaz, R. Lemus
The algebraic DVR approaches presented in Section 2 are characterised by being embraced in a 1D framework. This makes possible to propose different routes to establish algebraic DVR methods based on the possibility to obtain ladder operators for analytic solutions for particular potentials. The generalisation, however, is far from being obvious, except for the HO-DVR method and the UGA cases. In this section, we first extend the HO-DVR approach to the 2D case. On the other hand, the -UGA for 2D systems has already been presented with particular attention to a quartic potential applied to describe the bending modes of the non-rigid linear molecule of carbon suboxide [52,53]. In this section, we shall present the salient features of the model to latter on show the application of both methods to the 2D Coulomb potential, which displays an unexpected convergence results.
Transition of deformation mechanisms in nanotwinned single crystalline SiC
Published in Philosophical Magazine, 2019
Saeed Z. Chavoshi, Mark A. Tschopp, Paulo S. Branicio
The influence of nanoscale twins on the mechanical response and deformation mechanisms in engineering ceramics and semiconductors is poorly understood [12–15]. Density functional theory (DFT) calculations show that the ideal shear strength of boron carbide (B4C) is improved by 11% by embedding nanoscale thin twins [16] whilst nanotwins in single crystalline boron-rich boron carbide (B13C2) lower the shear strength, making it softer than single crystalline B4C [17]. In the same way, a critical twin spacing of 0.89 nm is predicted for boron suboxide (B6O) to achieve higher shear strength [18,19]. DFT calculations also reveal that by introducing nanoscale CTBs in thermoelectric semiconductor bismuth telluride (Bi2Te3) and indium antimonide (InSb), the shear strength is improved by 215% and 11%, respectively [20,21]. However, nanotwins drastically soften the thermoelectric semiconductor Mg2Si [22]. From these studies, it is evident that how nanoscale twins affect the mechanical properties of ceramics and semiconductors is very material-dependent. Thus, nanotwins play diverse roles in strengthening or weakening of such materials.