Browsing by Author "Wilson, A."

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    Disruption of cells in biosolids affects E. coli dynamics in storage
    (IWA Publishing, 2019-05-22) Fane, Sarah Elizabeth; Madureira, D.; Nocker, Andreas; Vale, Peter C. J.; Rivas Casado, Monica; Wilson, A.; Bajón Fernández, Yadira; Harris, Jim A.; Cartmell, Elise; Tyrrel, Sean
    Achieving microbial compliance during biosolids storage can be complicated by the unpredictable increase of Escherichia coli. Thermal treatment during anaerobic digestion (AD) and the effects of dewatering may be a significant factor contributing to indicator survival. Shear forces present during dewatering may promote cell damage, releasing nutrient for E. coli growth. The effect of cell damage on E. coli survival was assessed in laboratory-scale thermal and physical disruption experiments. E. coli growth curves for disrupted treatments were compared with control conditions and quantified using flow cytometry and membrane filtration techniques. A significant difference (p < 0.05) in the level of damaged cells between control and disrupted conditions was observed. For thermal and physical disruption treatments, the peak of E. coli concentration increased significantly by 1.8 Log and 2.4 Log (CFU (colony forming units) g−1 DS), respectively, compared with control treatments. Research findings contribute to the understanding of bacterial growth and death dynamics in biosolids
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    Flatness optimization of micro-injection moulded parts: the case of a PMMA microfluidic component
    (Institute of Physics Publishing; 1999, 2011-10-20T00:00:00Z) Marson, Silvia; Attia, Usama M.; Lucchetta, G.; Wilson, A.; Alcock, Jeffrey R.; Allen, David M.
    Micro-injection moulding (µ-IM) has attracted a lot of interest because of its potential for the production of low-cost, miniaturized parts in high-volume. Applications of this technology are, amongst others, microfluidic components for lab-on-a-chip devices and micro-optical components. In both cases, the control of the part flatness is a key aspect to maintaining the component's functionality. The objective of this work is to determine the factors affecting the flatness of a polymer part manufactured by µ-IM and to control the manufacturing process with the aim of minimizing the in-process part deformation. As a case study, a PMMA microfluidic substrate with overall dimensions of 10 mm diameter and 1 mm thickness was investigated by designing a µ-IM experiment having flatness as the experimental response. The part flatness was measured using a micro-coordinate measuring machine. Finite elements analysis was also carried out to study the optimal ejection pin configuration. The results of this work show that the control of the µ-IM process conditions can improve the flatness of the polymer part up to about 15 µm. Part flatness as low as 4 µm can be achieved by modifying the design of the ejection system according to suggested guidelines
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    Time-division-multiplexed interrogation of fibre Bragg grating sensors using laser diodes
    (Iop Publishing Ltd, 2001-02-28T00:00:00Z) Wilson, A.; James, Stephen W.; Tatam, Ralph P.
    An intensity-based technique for the interrogation of fibre Bragg grating sensors is described. The technique utilizes two longitudinal modes of a single, pulsed laser diode as a dual-wavelength source for grating illumination. Time-division-multiplexed addressing of sensor arrays in serial and tree topologies is also demonstrated.