Fabrication of Porous Bone Scaffolds Using Alginate and Bioactive Glass

Porous composite scaffold using an alginate and bioactive glass ICIE16M was synthesized by a simple freeze-drying technique. The scaffold was characterized using compression testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), X-ray microtomography (XMT) and scanning electron microscopy (SEM). The bioactivity of the scaffold was evaluated by its ability to form apatite on its surface in simulated body fluid (SBF). The data collected showed evidence that the novel material produced had an appropriate pore size for osteoconduction, with an average pore size of 110 μm and maximum pore size of 309 μm. Statistical analysis confirmed that the glass filler significantly (P < 0.05) increased the collapse yield of the scaffolds compared with pure alginate scaffolds. The ICIE16M glass had an amorphous structure, favorable for bioactivity.The APC was funded by the College of Medicine and Health Sciences, United Arab Emirates University, Grant code G00001885

Effect of cube texture on local softening of friction stir welded joints for nanostructured AA2024 processed by accumulative roll bonding

Copyright © 2023 The Authors. The current research provides an insight into the correlation between the crystallographic textures, microstructure, and hardness of friction stir welded joints in nanostructured AA2024 alloys processed through accumulative roll bonding (ARB). Utilizing varying rotational speeds (250, 500, 750, and 1000 rpm) at a constant traverse tool (150 mm/min) during friction stir welding (FSW), microstructural analyses reveal distinct grain structures and texture components in the nugget zone. The fully recrystallized Cube {001}⟨100⟩ texture-oriented grains appear at the rotational speed of 750 rpm. The hardness profiles of ARB-processed strips after FSW at different rotational speeds show local softening in the nugget zones. There might be a hypothesis concerning the dissolution of stable and metastable precipitates based on generated heat input, providing insights into the mechanisms influencing hardness variations. Notably, the examination of Cube {001}⟨100⟩ texture and its correlation with local softening adds a valuable dimension to the understanding of microstructural changes in FSW of nanostructured AA2024 alloys processed by accumulative roll bonding process

Immersed Fatigue Performance of Glass-Fibre Reinforced Composites for Tidal Turbine Blade Applications

This work presents an experimental study on the fatigue of glass fibre-reinforced polymers (GFRP) for use in ocean energy structures, with particular emphasis on the effects of water saturation. Quasi-isotropic specimens with either epoxy or vinyl-ester matrix were reinforced with E-glass or E-CR glass and immersion-aged for a period of up to two and a half years, using a moderately accelerated ageing technique. A number of the specimens were kept under constant tensile stress while immersed. The water-saturated specimens were fatigue tested while immersed in water. Dry specimens of the same materials were also fatigue tested and comparative results are presented. It was established that moisture saturation has a detrimental stress-dependent effect on the fatigue strength of the epoxy/E-glass composite. The measured evolution of specimen stiffness during the fatigue cycles was similar for both dry and water-saturated coupons