Using numerical simulations we study the slow dynamics of a colloidal hard-sphere fluid adsorbed in a matrix of disordered hard-sphere obstacles. We calculate separately the contributions to the single-particle dynamic correlation functions due to free and trapped particles. The separation is based on a Delaunay tessellation to partition the space accessible to the centres of fluid particles in...

There are several issues related to the mechanical and electrical wirebond failure during wirebonding process. Major factors are associated with AuAl intermetallic system. AuAl intermetallic compounds (IMC) can easily form at room temperature and can be accelerated with the elevated temperature. In this paper, pattern of intermetallic compounds growth and potential degradation due to voids in t...

Interconnects are susceptible to solid diffusion under residual stress, electric current, and elevated temperature. As atoms diffuse, voids nucleate, drift, and enlarge. At some point, the voids of rounded shape can collapse to narrow slits and sever the interconnects. The fatal slits are often found to be transgranular, i.e., each slit cuts across a single grain. They have raised many concerns...

Here, we combine experiments with Langmuir trough and atomic force microscopy (AFM) to investigate the reasons for the special properties of layers from the protein HFBII hydrophobin spread on the air-water interface. The hydrophobin interfacial layers possess the highest surface dilatational and shear elastic moduli among all investigated proteins. The AFM images show that the spread HFBII lay...

In many applications, Cu base Shape Memory Alloys (SMA S) are a more economical alternative to other systems showing Shape Memory Effect (SME). However, bearing in mind the potential use of these SMA it is becoming increasingly important to develop suitable techniques to join them satisfactorily to themselves and to another material. In that sense, a liquid phase diffusion bonding process with ...

This paper explores the usage of microfocus X-ray computed tomography (CT) for visualization and quantification of diffusion phenomena in cracked concrete. Mortar specimens of varying shapes (prismatic and cylindrical), crack types (artificial and splitting tensile), and binder compositions (OPC and fly ash) were prepared. Cesium carbonate (Cs2CO3) was used as a tracer in the diffusion test bec...

In work reported at last year’s QNDE meeting, a first step towards the development of a model for the Scanning Laser Source (SLS) technique was presented, which provides an analytical formulation for the transient response of an isotropic, homogeneous, linearly elastic half-space submitted to a pulsed laser line source operating in the thermoelastic regime. The formulation takes into account op...

Diffusion bonds offer several advantages over alternative welding methods, including the ability to produce near-net shapes and achieve almost parent metal strength. However, voids remnant from the joining process can be tens of microns in their lateral dimension, making them difficult to detect with conventional pulse-echo immersion inspection at any significant metal depth. In titanium the in...

A theory is developed for the attenuation and dispersion of compressional waves in inhomogeneous fluid-saturated materials. These effects are caused by material inhomogeneity on length scales of the order of centimeters and may be most significant at seismic wave frequencies, i.e., on the order of 100 Hz. The micromechanism involves diffusion of pore fluid between different regions, and is most...