The investigation of mechanical properties in molecular crystals is emerging as a novel area of interest in crystal engineering. Indeed, good mechanical properties are required to manufacture pharmaceutical and technologically relevant substances into usable products. In such endeavour, bendable single crystals help to correlate microscopic structure to macroscopic properties for potential design. The hydrate forms of two anticonvulsant zwitterionic drugs, Pregabalin and Gabapentin, are two examples of crystalline materials that show macroscopic plasticity. The direct comparison of these structures with those of their anhydrous counterparts, which are brittle, suggests that the presence of water is critical for plasticity. In contrast, structural features such as molecular packing and anisotropic distribution of strong and weak interactions seem less important.
20 May 2009 in International Journal of Computational Fluid Dynamics
Solid particle erosion is a major concern in the engineering industry, particularly where transport of slurry flow is involved. Such flow regimes are characteristic of those in alumina refinement plants. The entrainment of particulate matter, for example sand, in the Bayer liquor can cause severe erosion in pipe fittings, especially in those which redirect the flow. The considerable costs involved in the maintenance and replacement of these eroded components led to an interest in research into erosion prediction by numerical methods at Rusal Aughinish alumina refinery, Limerick, Ireland, and the University of Limerick. The first stage of this study focused on the use of computational fluid dynamics (CFD) to simulate solid particle erosion in elbows. Subsequently an analysis of the factors that affect erosion of elbows was performed using design of experiments (DOE) techniques. Combining CFD with DOE harnesses the computational power of CFD in the most efficient manner for prediction of elbow erosion. An analysis of the factors that affect the erosion of elbows was undertaken with the intention of producing an erosion prediction model.