TPT July 2020

data. “It is difficult to predict borehole degradation trajectory with the sparse data generated by traditional methods. Having higher frequency datasets covering the entire borehole is key to provide an early warning of potential borehole failures,” Wu said. In the new CEC-funded project, Berkeley Lab will work with UC Berkeley, PG&E, Schlumberger, and C-FER Technologies. The teams will test a new suite of technologies for autonomous real-time monitoring using two methods, one based on distributed strain, vibration and temperature sensing in fibre optic cables and the other using electromagnetic wave reflectometry. Wu believes that the scientific challenges for both the offshore wind and natural gas projects are in optimising the technology design and sensitivity, and developing real-time edge computing technologies. He added: “In addition to using commercial systems, our team is developing new fibre interrogators that will allow us to not only get to the original raw data, but also play with the physics to better design a system that can give us the most sensitive signal we want.” Versatile graphene causes more excitement for the materials research community; a new, and timely, application. Mining News magazine reported in early May that Illinois-based Graphene Solutions is collaborating with the UK’s Graphene Composites (GC), and Canada’s ZEN Graphene Solutions, to work on a graphene ink that could be applied to textiles. As soon as the development, testing, and confirmation of the graphene ink’s properties are complete, the ink will be incorporated into fabrics used in personal protection equipment, such as masks and filters. For its part, ZEN’s Guelph, Ontario laboratory has synthesised a silver nanoparticle functionalised graphene oxide ink that previous researchers documented as capable of destroying earlier versions of coronavirus. COVID-19 testing of the ZEN/GC ink will be carried out at Western University’s ImPaKT facility biosafety level 3 laboratory in Ontario, and tested to kill influenza A and B viruses at biosafety level 2 laboratories in Britain and the US.

transparent polyethylene terephthalate film. Experiments have demonstrated that the device is sensitive to where the electrodes sit, in relation to the shadow edge and the transparency of the metal film. In 50 per cent shadow it can generate a power density of 0.14μW/cm 2 under indoor conditions (0.0001 sun illumination) – roughly twice that of a commercial silicon solar cell in the same situation. However, Anita Ho-Baillie, an Adjunct Professor at the School of Photovoltaic and Renewable Energy Engineering at Australia’s University of Sydney, has her doubts: “Commercial silicon cells are designed for respectable power generation and deliver a reasonable amount of current. The efficiency [of the shadow effect generator] is actually really low – 0.14μW/cm 2 under 0.0001 sun corresponds to a 0.000014 per cent power conversion efficiency.” Mr Tan’s aim is to make the device cheaper by using a tungsten film and plans surface modifications to boost performance. Admittedly the generated power will not be as high as that of solar cells under full illumination, but Mr Tan wants to inspire others to think about shadows as “an untapped energy source” rather than a problem. Monitoring for greater reliability in natural gas storage and offshore wind The California Energy Commission (CEC) has awarded $3.5mn in funding to the Lawrence Berkeley National Laboratory to develop fibre optic cables that can monitor offshore wind operations and underground natural gas storage. Mr Yuxin Wu, head of Berkeley Lab’s geophysics department, said: “One of the most expensive components of a wind turbine is the gearbox; they also tend to be the part that’s most vulnerable to failure. Often, before they fail, they produce abnormal vibrations or excessive heat due to increased or irregular friction. We intend to use fibre optic cables to monitor the vibrational, strain, and temperature signal of the gearbox in order to pinpoint where problems are happening.” The Berkeley researchers believe that fibre optic cables, wrapped around the entire gearbox, could provide a 3D map of changes. Dr Wu continued: “It could help identify problems with the gearbox at an early stage, which would trigger emergency management before a catastrophic failure [causes the] loss of the whole turbine.” The project will also examine ways of using fibre optic cables to monitor boreholes, used in underground natural gas storage reservoirs, for corrosion and degradation. Borehole integrity is currently monitored using tools that are intrusive, expensive, and incapable of providing frequent, real-time

Industr y New copper find has raised hopes of reviving the Cornish mining industry

The discovery of copper has raised the possibility of a revival for an historic UK industry. Engineers from Cornish Lithium were exploring hot underground springs for lithium at

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JULY 2020