• Water quality and water-rock interaction in the Harz Mountains (Germany)

      Bozau, Elke; Staerk, Hans-Joachim; Strauch, Gerhard; Swanson, Claudia H.; Technische Universitaet Clausthal, University of Chester (European Federation of Geologists, 2015-11-01)
      The Harz Mountains, known for ancient silver and base metal mining, are an important drinking water supply region for northern Germany today. The water quality of the Harz Mountains is mainly influenced by atmospheric depositions, water-rock inter- actions and biological activities. Anthropogenic influences are minor. Springs, creeks, lakes and reservoirs have relatively low mineralisation. Measured as specific electrical conductivity, the mineralisation of the different water bodies ranges from about 15 to 650 µS/cm. Only deep springs and mine waters reach higher values. Despite dilution effects due to different rainwater amounts, water-rock interaction can be retraced by the chemical water composition, especially by trace metals and rare earth element concentrations. Examples of water-rock interaction are discussed for granite, greywacke and limestone.
    • Wheelchair-MR: A Mixed Reality Wheelchair Training Environment

      Day, Thomas W.; University of Chester (IEEE, 2017-09-20)
      In previous work we have demonstrated that Virtual Reality can be used to help train driving skills for users of a powered wheelchair. However, cybersickness was a particular problem. This work-in-progress paper presents a Mixed Reality alternative to our wheelchair training software, which overcomes this problem. The design and implementation of this application is discussed. Early results shows some promise and overcomes the cybersickness issue. More work is needed before a larger scale study can be undertaken.
    • Will Future Resource Demand Cause Significant and Unpredictable Dislocations for the UK Ministry of Defence?

      Antill, Peter; Powell-Turner, Julieanna; Cranfield University
      This paper focuses on the drivers which may affect future trends in material availability for defence, in particular, the availability of rare earth elements (REE). These drivers include resource concentration, tighter regulatory policy and its enforcement, export policies, their use in economic statecraft, increases in domestic demand, promoting greater efficiency in resource use, efforts to mitigate resource depletion and more efficient resource extraction while reducing its associated environmental impact. It looks at the effect these factors might have on global systems and supply chains, the impact on material insecurity and how this may exacerbate the issue of their use in UK military equipment. It finds that these drivers are likely to have an increasing impact on material availability (if measures are not taken to mitigate them), which will have consequences for the provision of military capability by the UK.
    • X-ray Photoelectron Spectroscopy Analysis of Biochar

      Smith, Graham C.; University of Chester (CSIRO Publishing, 2017-03-01)
      The chapter describes the application of the XPS technique to the analysis of biochar.
    • The X-ray photoelectron spectroscopy of surface films formed during the ASTM D-130/ISO 2160 copper corrosion test

      Reid, David G.; Smith, Graham C.; University of Chester (Taylor & Francis, 2014-01)
      The surfaces of ISO 2160 copper strips tested in iso-octane with elemental sulfur, aliphatic, cyclic and aromatic thiols, diphenyl sulfide, and diphenyl disulfide individually or in combination were studied using XPS. Aliphatic thiols bonded through the sulfur, whereas elemental sulfur formed a cuprous sulfide layer. Aromatics bonded partially through the sulfur with the rings oriented horizontally due to π orbital interactions, accounting in part for their inhibitory effects in the test. The test rating was not directly related to the sulfur concentration in solution or on the surface, and certain combinations of species resulted in higher levels of sulfur at the surface than found individually.
    • XPS Analysis of the chemical degradation of PTB7 polymers for organic photovoltaics

      Kettle, Jeff; Ding, Ziqian; Smith, Graham C.; Horie, Masaki; Bangor University, National Tsing Hua University, Taiwan, University of Chester (Elsevier, 2016-10-14)
      The chemical degradation of the Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] or ‘ PTB7’ has been studied using X-ray Photoelectron Spectroscopy (XPS). This material system appears to be intrinsically unstable especially when illuminated in air and XPS studies confirm the rapid photo-degradation is related to changes in chemical structure of the polymer. In particular, XPS spectra show an initial reduction in relative C-C intensity, suggests loss of the alkoxy side chains. This is followed by a dramatic increase in the level of oxygen-bonded species, especially C-O at ~286.5 eV and C(=O)O at 289.2 eV, indicative of COOH and OH group formation, and oxidation of S. The XPS results support the view that using processing additives reduces the chemical stability of the polymer and provides insight into strategies to improve molecular design to ensure higher chemical stability.