Defects in the in situ synthesized TiB2/Fe composite coatings during PTA process

The in situ synthesized TiB₂/Fe composite coatings were deposited by the plasma transferred-arc (PTA) powder surfacing process. The macro and micro defects in the TiB₂/Fe composite coatings were investigated in this paper. It is found that heat input plays an important role in macro defects in the coatings. Only when the energy density and total heat input are appropriate will nice forming with few macro defects be obtained. As micro defects in the coatings, slag inclusions (C, Al₂O₃) and cracks often appear together. And it is found that slag inclusions and cracks tend to appear with a low dilution rate of the coatings, and their tendency decreases as the dilution rate increases.     

Existence Results on Semi-Infinite Intervals for Nonlocal Evolutions Equations and Inclusions via Semigroup Theory

In this paper, we prove existence and controllability results on semi-infinite intervals for first- and second-order evolutions equations and inclusions in Banach spaces with nonlocal conditions. Our theory makes use of semigroups, cosine families, nonlinear alternative of Leray–Schauder, and a diagonalization argument.     

Existence of Solutions for Impulsive Neutral Integro-Differential Inclusions with Nonlocal Initial Conditions via Fractional Operators

This paper is mainly concerned with existence of mild solutions for first-order impulsive neutral integro-differential inclusions with nonlocal initial conditions in α-norm. We assume that the undelayed part generates an analytic resolvent operator and transforms it into an integral equation. By using a fixed point theorem for condensing multivalued maps, a main existence theorem is established. As an application of this main theorem, a practical consequence is derived for the sublinear growth case. Finally, we present an application to a neutral partial integro-differential equation with Dirichlet and nonlocal initial conditions.     

Quasilinear elliptic inclusions of Clarke's gradient type under local growth conditions

We consider a class of elliptic inclusions under Dirichlet boundary conditions involving multifunctions of Clarke's generalized gradient that satisfies only a one-sided local growth condition. An appropriate modification of the associated potential function along with truncation techniques will allow us to apply the theory of multivalued pseudomonotone operators for obtaining existence and comparison results under only one-sided local growth conditions on Clarke's generalized gradient.     

A Proof of the Relaxation Theorem for Differential Inclusions Based on Euler Approximations

In this note, an alternative proof of the relaxation theorem is presented that is based on a two-level Euler approximation.     

‘Star‐like’ defects in Cd‐annealed CdZnTe crystals—an experimental study of their origin and formation mechanism

We conducted low‐temperature annealing experiments at temperatures slightly above and below the melting point of Te to clarify the effects of the state of Te inclusions (solid or liquid) upon the formation of ‘star‐like’ defects in Cd‐annealed CdZnTe (CZT). We also carried out post‐growth annealing experiments with and without using Cd vapor to clarify the mechanism of formation of such defects. We demonstrated that these ‘star‐like’ defects are due to the reaction between in‐diffused Cd atoms and the molten Te inclusions, but we found no observable ‘one‐to‐one’ correlation between ‘star‐like’ defects and Te inclusions. The non‐uniform distribution of Te inclusions in the CZT matrix could account for this phenomenon since the punching distance of the dislocations depends on the volume fraction of inclusions within the matrix.     

In situ study of magmatic processes: a new experimental approach

We present an internally heated autoclave, modified in order to permit in situ studies at pressure up to 0.5 GPa and temperature up to 1000 °C. It is equipped with transparent sapphire windows, allowing the observation of the whole experiment along the horizontal axis. In the experimental cell, the sample is held between two thick transparent plates of sapphire or diamond, placed in the furnace cylinder. The experimental volume is about 0.01 cm³. Video records are made during the whole experiment. This tool is developed mainly to study the magmatic processes, as the working pressures and temperatures are appropriate for subvolcanic magma reservoirs. However, other applications are possible, such as the study of subsolidus phase equilibria as we have used well-known phase transitions, such as the system of AgI, to calibrate the apparatus with respect to pressure and temperature. The principle of the apparatus is detailed. Applications are presented, such as studies of melt inclusions at pressure and temperature and an in situ study of magma degassing through the investigation of nucleation and growth processes of gas bubbles in a silicate melt during decompression.     

Dielectric elastomer composites: small-deformation theory and applications

Abstract

We provide estimates for the effective response of Electro-Active Polymer Composites (EAPCs) consisting of aligned ellipsoidal inclusions of a stiff dielectric material which are distributed randomly in an soft elastomeric matrix with “ellipsoidal” two-point statistics. The derivation of the results for the electro-mechanical response assumes linearized deformations, but includes non-linear (quadratic) terms in the electric fields. We investigate three different physical mechanisms contributing to the macroscopic electro-mechanical response of the composite: the intrinsic effect of the particles on the Maxwell stress, the inter-particle (dipole) interactions which are accounted for by evaluating the effect of changes in the “shape” of the two-point probability functions with the deformation, and the effect of particle rotations and torques when the geometric and/or anisotropy axis of the particles are not aligned with the applied electric field. Several illustrative examples are provided to emphasize the relative importance of the different effects on the overall electrostriction of the composites. In particular, for the “compliant electrode” boundary conditions that are widely used in applications, it is shown that inter-particle interactions are synergistic with the intrinsic effect of the particles on the Maxwell stress, leading to significant enhancements in the electro-mechanical coupling of the EAPCs, especially at high particle concentrations. On the other hand, the effect of electric torques on non-aligned particles is generally deleterious for electrostriction.