The step size of random walks is shown to exhibit an important role in controlling the structure of clusters produced ,by the diffusion-limited aggregation (DLA) processes. In this study, the structural compactness is found to increase significantly as the random-walk size is increased. The step-size effects are precisely quantified by the radius of gyration evaluated during the cluster growth ...

This paper presents a comparison between a number of different failure prediction methods forsuperplastic forming processes. Attention is limited here to superplastic forming of Ti-6Al-4V at 927C. Thefailure prediction methods considered include the flow localisation factor approach, forming limit curvesbased on void growth models, such as the Rice and Tracey model and the Cocks and...

This paper presents a comparison between a number of different failure prediction methods for superplastic forming processes. Attention is limited here to superplastic forming of Ti-6Al-4V at 927C. The failure prediction methods considered include the flow localisation factor approach, forming limit curves based on void growth models, such as the Rice and Tracey model and the Cocks and Ashby mo...

A new model for bubbly, cavitating flow is validated and used to study the shock-induced oscillations of bubble clouds arising in shockwave lithotripsy and other applications. Compared to previous models based on volume and phase averaging, the new model extends the range of void fractions that can be reliably simulated and, for appropriately low void fractions, reproduces the results of the po...

The pressure variations associated with a filling undulating pipeline containing an entrapped air pocket are investigated both experimentally and numerically. The influence of entrapped air on abnormal transient pressures is often ambiguous because the compressibility of the air pocket permits the liquid flow to accelerate but also partly cushions the system, with the balance of these tendencie...

The effects of tight junction structure on water and solute fluxes across proximal tubular epithelium were examined with fiber-matrix equations previously derived by Curry and Michel (1980. Microvascular Research. 20:96-99). Using plausible estimates of tight junction fiber length and width the model predicts solute (Ps) and water permeability (Lp) coefficients that agree with the measured valu...

Abstract Ductile metals undergo a considerable amount of plastic deformation before failure. Void nucleation, growth and coalescence is the mechanism failure in such metals. ? – ? titanium alloys are ductile nature widely used for their unique set properties as specific strength, fracture toughness, corrosion resistance to fatigue failures. Voids these have been reported nucleate on phase bound...

Through cyclic regeneration, feather stem cells are molded into different shapes under different physiological states. With its distinct morphology, context-dependent growth, and experimental manipulability, the feather provides a rich model to study growth control, regeneration, and morphogenesis in vivo. Recent examples include novel insights revealed by transient perturbation with chemothera...

We present a model for the distribution of void sizes and its evolution within the context of hierarchical scenarios of gravitational structure formation. For a proper description of the hierarchical buildup of the system of voids in the matter distribution, not only the voidin-void problem should be taken into account, but also that of the void-in-cloud issue. Within the context of the excursi...