During the flood development in an oil field, the creep characteristic of mudstone is one of the important factors causing casing damage. In this study, based on the theory of fractional order differential and taking into account the creep damage evolution rules, a fractional nonlinear creep-damage model is proposed to reflect the instantaneous deformation in loading processes and the accelerat...

The rock salt (B1) structure of binary oxides or chalcogenides transforms to the CsCl (B2) structure under high pressure, with critical pressures P(s) depending on the cation to anion size ratio (R(c)/R(a)). We investigated structural changes of A(2)MO(3) (A = Sr, Ca; M = Cu, Pd) comprising alternate 7-fold B1 AO blocks and corner-shared MO(2) square-planar chains under pressure. All of the exa...

The present paper studies MX crystals in rock-salt structure (M: Li, Na, K; X: F, Cl, Br, I). They are often described as being formed by ions. Pictures based on quantum mechanical calculations sustain and quantify it. The tools used are (i) the Quantum Theory of Atoms in Molecules, (ii) the Electron Localization Function, and (iii) the maximization of the probability to find in a spatial domai...

The tensile creep and creep-recovery behavior of a unidirectional Sic-fiher/Si,N,-matrix composite was investigated at 1200°C in air. A primary objective of the study was to determine how various sustained and cyclic creep loading histories would influence the creep rate, accumulated creep strain, and the amount of strain recovered upon specimen unloading. The key results obtained from the inve...

Synthesis parameters, storage conditions, and electrolyte chemistry are all critical parameters limiting the cycling performances of disordered rock salt cathodes.

Some exploratory work on creep and inverse creep in nylon 6 monofilament, polyester multifilament yarn and wool and cotton spun yarns has been presented. It is observed that the extent of creep and inverse creep differs from material to material and depends on the initial stress. Cotton shows minimum inverse creep while nylon shows maximum inverse creep. Wool and polyester have intermediate inv...

[1] We present a new statistical framework to analyze rock deformation data and determine a corresponding flow law and its uncertainty. All experimental uncertainties, including inter-run bias, are taken into account in the new formalism. Our approach is based on Bayesian statistics and is implemented by a Markov chain Monte Carlo method. We apply this approach to published data on the subsolid...

A new structure motif in nitridometalate chemistry is the tetracatena-nitridotantalate anion [Ta4N13]19-. It occurs in the crystal structure of the triple salt Sr14[Ta4N13][TaN4]O (monoclinic, space group P21/c with a = 15.062(2) Å, b = 7.2484(6) Å, c = 24.266(3) Å, and β = 97.280(10)o) together with ortho-tantalate and isolated oxide anions. Synthesis followed a new approach with employment of...

The 60 min creep data from National Type Evaluation Procedure (NTEP) tests performed at the National Institute of Standards and Technology (NIST) on 65 load cells have been analyzed in order to compare their creep and creep recovery responses, and to compare the 60 min creep with creep over shorter time periods. To facilitate this comparison the data were fitted to a multiple-term exponential e...

Carefully designed indentation creep experiments and detailed finite-element computations were carried out in order to establish a robust and systematic method to extract creep properties accurately during indentation creep tests. Samples made from an Al–5.3mol%Mg solid-solution alloy were tested at temperatures ranging from 573 to 773K. Finite-element simulations confirmed that, for a power-la...