Research Picks Extra – July 2017

Smoke and fires

New research into smoke and fire detection published this month in the International Journal of Signal and Imaging Systems Engineering suggests that a fire can be detected earlier and with fewer false alarms if the various detection technologies utilize image processing as well as sensor technology. Malik Mohamed Umar and colleagues at the Universiti Brunei Darussalam explain that smoke is a good indicator of conditions in a building or other environment that might ultimately develop into a potentially lethal fire. As such smoke detectors are key to warning occupants of a fire having started. There are several devices that can detect smoke for disaster prevention. However, the team suggests that image processing is far more effective especially in terms of avoid false alarms triggered by bathroom steam, cigarette smoke, burnt toast or other common false alarms.

Malik, M., De Silva, L.C., Saifullah Abu Bakar, M. and Iskandar Petra, M. (2017) ‘State of the art of smoke and fire detection using image processing‘, Int. J. Signal and Imaging Systems Engineering, Vol. 10, Nos. 1/2, pp.22-30.

Supercritical drying of carbon dioxide

As atmospheric carbon dioxide levels continue to rise through human activities, specifically the burning of fossil fuels – coal, oil and natural gas – it is unlikely that the future climate will be as comfortable as it is today. As such, there are many efforts to find alternative energy sources that are close to carbon neutral, wind, solar, tidal, to name a few. However, there is also a need to remediate the damage already done as we attempt to head towards a sustainable future. Technologies that extract carbon dioxide from the atmosphere would have to be carried out on a geological scale and would only be truly beneficial if the energy and resources they needed were themselves carbon neutral. Steps towards such a system is being developed by researchers from China and the US. They are developing an aerogel sorbent, amine hybrid silica aerogel, that can absorb the greenhouse gas. Moreover, the material is more effective with higher humidity.

Kong, Y., Shen, X., Cui, S. and Fan, M. (2017) ‘Supercritical drying: a promising technique on synthesis of sorbent for CO2 capture‘, Int. J. Global Warming, Vol. 12, No. 2, pp.228-241.

Recycling rechargeable batteries

Rechargeable lithium batteries have a limited lifespan as drivers of electric vehicles and anyone who uses a modern portable electronic device knows only too well. Moreover, the cobalt and lithium metals, which are essential components of these batteries, need to be reclaimed from expired batteries. Researchers in Malaysia have taken steps towards and efficient and effective way to retrieve the cobalt from such batteries. Once processed to calcinate the material and remove any organic compounds, the team was able to extra 90-99% of the cobalt from a used battery using their high-temperature technique. Of course, such recycling must itself be carried out using sustainable energy and resources otherwise some of the benefit will be negated.

Rahman, A. and Afroz, R. (2017) ‘Lithium battery recycling management and policy‘, Int. J. Energy Technology and Policy, Vol. 13, No. 3, pp.278-291.

The entropy of walking

Human gait is a fascinating area of biometrics and pedestrian dynamics. Individuals can be recognized from the way they walk even if we cannot see their face while understanding the movements of a crowd or group of people as they walk can tell us a lot about social activity. Researchers in Portugal are taking a thermodynamic approach to understanding human gait in terms of the disorder, or entropy, that arises as a crowd moves around. Self-selected gait speed, and gait transitions from walking to running, can be linked to, and understood based on the quantification of entropy generation, Antonio Miguel of the University of Evora, Portugal reports. Moreover, he has demonstrated through this analytical approach that there exist repulsive forces between pedestrians that ensure interpersonal distances are moderated by the energy of the crowd and dissipation of energy.

Miguel, A.F. (2017) ‘Entropy generation: a path for understanding human gait patterns and crowd dynamics‘, Int. J. Exergy, Vol. 23, No. 1, pp.18-30.

Author: David Bradley

Award-winning, freelance science writer based in Cambridge, England.