Friday, 17 September 2021 12:00


Professor Ursel Bangert and Dr Shahrzad Daghighi

Bernal Institute


Professor Ursel Bangert

Atomic Scale Imaging and Spectroscopy:  Revelation of Atom Configuration, Dynamics and Collective Electron Motion

By using atomic resolution transmission electron microscopy supported by image simulation and atomic-scale spectroscopy, sites and behaviour of single atoms as well as collective electron motion around these, can be revealed. This hugely helps the development of novel devices, e.g., for quantum technologies. For example, controlled introduction of dopants into nano- and especially 2-D materials in order to tailor their work function and bandgap, is a big goal. Ion-implantation at ultra-low energies for electronic doping of these materials was explored, enabling their inclusion in scalable manufacture processes, integratable with semiconductor technologies. The success of these undertakings depended crucially on direct proof, by sub-atomic scale revelation, of the precise sites, chemical nature and electronic structure of individual implants/dopants/ defects/impurities in these nano-materials. Another area of increasing interest involves ferro-electric materials with domain walls therein, the latter constituting, in themselves, 2-D entities, which, if conducting and moveable, can act as novel mobile electronic switches for nano-electronic devices. The properties of domain walls are proven/revealed by assessment of the constellations of atoms, i.e., their sub-Å shifts, leading to the formation of electric dipoles.

Dr Shahrzad Daghighi

On the Potential of Non-circular Pressure Vessels for Hydrogen Storage

Pressure vessels are widely used in many industries for storing liquids and gases and for transportation in often harsh environments. The design of pressure vessels is deep-rooted in history, and it was first referred to by Leonardo da Vinci in 1495 in Madrid, where he described how to use containers of pressurised air to lift heavy weights. Recent strategies in the transition to hydrogen as a primary power source, together with moving to a zero-carbon economy by 2050, have led to a renewed interest in designing pressure vessels. Hydrogen has the potential to be stored in large quantities for a long time; however, it has low energy per volume, which indicates the need for pressure vessels that withstand high amounts of pressures with a large packing efficiency. Currently, lightweight composite pressure vessels are desirable, especially in transportation industry applications, because of their subsequent benefits in fuel consumption, cost and environmental issues. Using composite materials for pressure vessels along with advanced manufacturing technologies such as automated fibre placement provides excellent scope to tailor stiffness through the structural surface using fibre steering to achieve desirable structural performance. In this presentation, the use of variable angle tow (VAT) technology to suppress bending in non-circular composite pressure vessels will be described. The results of ongoing research into their advantages will also be presented. Finally, the potential of using the bend-free super ellipsoids of revolution composite pressure vessels for the next generation of pressure vessels and specifically for hydrogen storage will be discussed.



Ursel Bangert is Bernal Chair in Microscopy and Imaging at the University of Limerick, following positions of Reader and Lecturer at the University of Manchester, and of Research Fellow at Surrey University. The major pursuits of her research career are in Solid State Physics and Materials Science, especially geared toward 2-D materials (e.g., having pioneered graphene research with the Geim group in Manchester), with emphasis on materials characterisation via Advanced Electron Microscopy and Spectroscopy.

Shahrzad Daghighi completed a Bachelor’s in Mechanical Engineering with a specialism in solid design (2013), followed by a Master’s in Automotive Engineering (2016). In 2017, Shahrzad joined the University of Limerick as a PhD student in Composite Structures within the VariComp project under the supervision of Professor Paul M. Weaver. Recently, she has graduated. Shahrzad’s PhD thesis “Structurally Efficient Composite Super Ellipsoidal Shells” proposes a novel design methodology that exploits variable angle tow technique to suppress bending stresses in non-circular shell structures. Currently, Shahrzad is a postdoctoral researcher at the School of Engineering and Bernal Institute and continues her research under the supervision of Professor Paul M. Weaver.

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