http://hdl.handle.net/2173/1012 Search the Channel search http://www.e-space.mmu.ac.uk/e-space/simple-search http://hdl.handle.net/2173/94454 Title: Influence of substrate conditions on the temporal behaviour of plasma parameters in a pulsed dc magnetron discharge<br/><br/>Authors: Swindells, I.; Kelly, Peter; Bradley, J. W.<br/><br/>Abstract: Using time-resolved optical emission spectroscopy and Langmuir probing, the effect of substrate bias (and the absence of the substrate) on the energetics and concentrations of the plasma species at different phases of the pulse have been investigated in a bi-polar unbalanced pulsed dc magnetron. The discharge was operated in a range of frequencies, 25–100 kHz, and duty cycles, 60–90%, at a constant Ar pressure of 0.66 Pa. In the presence of an electrically grounded substrate at the transition from discharge on to off (when the plasma potential is raised to values over +150 V relative to ground), we have detected a short-lived burst in optical emissions from transitions in Ar and Ti (of duration 200 ns) in the plasma bulk. We also detect an associated elevation in the effective electron temperature measured with the Langmuir probe (Teff> twice that during the rest of the cycle). This phenomenon, we believe, is due to the liberation and increased confinement of electrons emanating from the substrate due to local ion bombardment. With an electrically floating substrate there is a much weaker associated optical flash, and none in the absence of the substrate. The Langmuir probe results also show that in the on phases of the pulse, a general increase in effective electron temperature and density is observed with decreasing frequency and duty cycle, i.e. increased reverse times. The implications of the observed transient bulk heating of electrons on the pulsed sputter deposition process are briefly discussed.<br/><br/>Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in New Journal of Physics, published by and copyright Institute of Physics Publishing. http://hdl.handle.net/2173/94453 Title: Improved durability of dielectric coatings for large-area applications on glass via ion beam pretreatment of the substrate<br/><br/>Authors: West, Glen T.; Kelly, Peter<br/><br/>Abstract: Dielectric coatings are commonly deposited onto large-area glass substrates via the magnetron sputtering process. High refractive index materials such as titania and zinc oxide are employed in a wide range of multilayer coating systems, some of which can experience problems with coating durability. A standard magnetron sputtering system has been enhanced via the inclusion of a Hall-current-type ion source, which has been used for the pretreatment of the glass substrate surfaces prior to deposition. Resulting TiO2 and ZnO films exhibited substantial improvements in mechanical durability (up to 80% increase in critical load and 200% increase in wear resistance, as compared with those grown on untreated glass) with no detrimental effect to their optical performance. These improvements to coating performance, along with the suitability of the ion source to inclusion in commercial coaters, demonstrate a potential for significant benefit to the large-area glass coating industry.<br/><br/>Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in Journal of Vacuum Science & Technology A: Vacuums, Surfaces and Films, published by and copyright American Institute of Physics. http://hdl.handle.net/2173/94438 Title: Ion assisted deposition of titanium chromium nitride<br/><br/>Authors: Vishnyakov, Vladimir M.; Bachurin, V. I.; Minnebaev, K. F.; Valizadeh, R.; Teer, D. G.; Colligon, John; Vishnyakov, V. V.; Yurasova, V. E.<br/><br/>Abstract: Chromium titanium nitride films with different content of Cr and Ti were deposited on a silicon substrate by ion beam assisted deposition and characterised by Rutherford Backscattering Spectroscopy, X-ray Diffraction, X-ray Photoelectron Spectroscopy (XPS), Cross-sectional Transmission Electron Microscopy and nanoindentation testing. All of the samples except for the pure Cr2N coating have a structure similar to the fcc form of TiN (111). XPS data showed that the films contained a small amount of oxygen. The dependence of hardness on film composition was observed. Maximum hardness at about 30 GPa was for coatings containing 15 at.% Ti and 35 at.% Cr. The high hardness in the ternary compound is thought to be attributed to high energy of dislocation propagation. It has been shown that chromium nitride formed in the absence of atomic nitrogen always grows as Cr2N. The addition of atomic nitrogen using an ion assisting beam promotes growth of CrN. The presence of a relatively low amount of Ti in the Ti–Cr–N film was seen to promote a significant increase in the number of Cr–N bonds.Preferential sputtering of nitrogen from the film during Ar ion cleaning for XPS analysis shows that composition analysis by XPS can be unreliable and should be done with great care.<br/><br/>Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in Thin Solid Films, published by and copyright Elsevier. http://hdl.handle.net/2173/94437 Title: A study of diamond synthesis by hot filament chemical vapour deposition on nanocomposite coatings<br/><br/>Authors: Polini, R.; Amar, M.; Ahmed, Waqar; Kumashiro, S.; Sein, H.; Colligon, John<br/><br/>Abstract: Deposition of diamond films onto various substrates can result in significant technological advantages in terms of functionality and improved life and performance of components. Diamond is hard, wear resistant, chemically inert and biocompatible and considered as the ideal material for surfaces of cutting tools and biomedical components. However, it is well known that diamond deposition onto technologically important substrates such as Co-cemented carbides and steels is problematic due to carbon interaction with the substrate, low nucleation densities and poor adhesion. Several papers previously published in the relevant literature have reported the application of interlayer materials such as metal nitrides and carbides to provide bonding between diamond and hostile substrates. In this study, we have investigated for the first time the chemical vapour deposition (CVD) of polycrystalline diamond on TiN/SiNx nanocomposite interlayers deposited at relatively low temperatures. The nanocomposite layers were deposited at 70 °C or 400 °C on silicon substrates by using a dual ion beam deposition system. The results showed that a preliminary seeding pre-treatment with diamond suspension was necessary to achieve large diamond nucleation densities and that diamond nucleation was larger on nanocomposite films than on bare sc-Si submitted to same pre-treatment and CVD process parameters. TiN/SiNx layers synthesized at 70 °C or 400 °C underwent different nanostructure modifications during diamond CVD. The data also showed that TiN/SiNx films obtained at 400 °C are preferable so far as their use as interlayers between hostile substrates and CVD diamond is concerned.<br/><br/>Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in Thin Solid Films, published by and copyright Elseiver. http://hdl.handle.net/2173/94436 Title: Identifying the contribution of different airport related sources to local urban air quality<br/><br/>Authors: Peace, Hazel; Maughan, Janet; Owen, Bethan; Raper, David W.<br/><br/>Abstract: The Air Quality Strategy and part IV of The Environment Act, within the United Kingdom, highlight the need for local authorities to undertake air quality assessments. Many UK local authorities have recently completed a review and assessment of local air quality, which has culminated in the declaration of Air Quality Management Areas (AQMAs) in many urban areas, where air pollution objectives are likely to be exceeded. Those local authorities who declare AQMAs are required to undertake a further stage of assessment, which involves the determination of the contribution of various sources of air pollution, such as airports. Many studies of this nature only consider an airport as one source, however, this study considers the impact of different airport related sources on local air quality from a dispersion modelling study of a large urban area. This paper describes the methodology, results and draws conclusions from a study that assesses the impact of a regional airport's sources (such as it's contribution from road traffic and aircraft). The paper also considers the effect of modelling the above ground aircraft emissions sources (climbout and approach) to different altitude heights. The paper's results highlight the need to investigate the source contributions of an airport, to local air quality, as opposed to considering an airport as just one source.<br/><br/>Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in Environmental Modelling & Software, published by and copyright Elsevier. http://hdl.handle.net/2173/94435 Title: Characteristics of feeding-site selection by breeding Green Woodpeckers Picus viridis in a UK agricultural landscape<br/><br/>Authors: Alder, Danny; Marsden, Stuart<br/><br/>Abstract: Capsule Green Woodpeckers exhibited strong feeding-site preference, choosing areas based on abundance of ants with additional micro-habitat effects. Aims To identify the habitat characteristics influencing feeding-site selection across farmland. Methods A pair of Green Woodpeckers was radiotracked during a breeding season. Habitat and prey abundance variables were compared within the birds' combined home-ranges. canoco was used to identify ecological gradients, and logistic regression used to predict feeding-site use based on ant abundance with resultant residuals correlated to identify habitat features that further influenced site selection. Results Most feeding was done in sheep-grazed pastures and garden lawns with arable and cattle-grazed land avoided. Green Woodpecker feeding sites were associated with areas of short grassland with high plant richness and high densities of ants, especially Lasius flavus. Logistic regression correctly classified 98% of cases from ant abundance. The woodpecker pair had a greater probability of feeding in areas with deep leaf litter, high plant species richness, and lower probability if the site had tall or dense vegetation, or heavily compacted soils. Conclusions Structural habitat characteristics were important, with this woodpecker pair foraging in short grazed and mown grasslands. If these results are replicated elsewhere then appropriate farm management may benefit Green Woodpeckers significantly.<br/><br/>Description: This metadata relates to an electronic version of an article published in Bird Study, Volume 57, Issue 1, February 2010, pages 100-107. Bird Study: The Science and Pure and Applied Ornithology is available online at informaworldTM at http://www.informaworld.com/smpp/content~db=all~content=a919079603 http://hdl.handle.net/2173/94434 Title: Towards the effective use of web notes<br/><br/>Authors: Rowley, Jennifer; Sambrook, Sally<br/><br/>Description: J. Rowley and S. Sambrook. Towards the effective use of web notes. British Journal of Educational Technology, 2010, vol. 41, no. 2, pp. E22-E24. Published by and copyright Wiley-Blackwell Publishing. The definitive version of this article is available from http://www.blackwell-synergy.com/ http://hdl.handle.net/2173/94433 Title: Antimicrobial surfaces: addressing the intended application<br/><br/>Authors: Verran, Joanna<br/><br/>Abstract: The article considers some of the limitations of “hygienic” antimicrobial surfaces used in the environment, particularly in terms of validating their effectiveness at point of use. Although it is often simple to visualise in vitro the diffusion of an antimicrobial from a surface, via the resultant inhibition of target organisms, it is less easy to demonstrate antimicrobial properties of a surface that is exposed to the air.<br/><br/>Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in Chimica Oggi / Chemistry Today, published by and copyright Tekno Scienze. http://hdl.handle.net/2173/94430 Title: Mobility, flexible lifestyles and cosmopolitanism: EU postgraduates in Manchester<br/><br/>Authors: Kennedy, Paul<br/><br/>Abstract: Some commentators on globalisation and migration have suggested that a growing number of young, educated individuals regard moving overseas as a vehicle for pursing their project of self-realisation, whether imagined in terms of promoting careers or of the search for adventure and cultural variety or both. Drawing on the experiences of skilled migrants from EU countries living in Manchester, the paper examines the motives which induced them to migrate and suggests that economic constraints were often equally as or more significant in propelling them overseas and in influencing their choice of destination than their personal preferences. The paper then argues that their actual experiences abroad became much more significant to their life trajectories than earlier decisions. Most were propelled towards cosmopolitanism and greater world openness because of their exposure to, and involvement in, post-national relationships and intercultural encounters. Although these tended to push them even further away from their original national origins, thereby creating more scope for re-constructing a chosen life path, they also left them more exposed to, and dependent upon, these new relationships and cosmopolitan influences.<br/><br/>Description: This metadata relates to an electronic version of an article published in Journal of Ethnic and Migration Studies, Volume 36, Issue 3, March 2010, pages 465-482. Journal of Ethnic and Migration Studies is available online at informaworldTM at http://www.informaworld.com/smpp/content~db=all~content=a917121932 http://hdl.handle.net/2173/94429 Title: Sonoelectroanalysis - application to lead determination<br/><br/>Authors: Šljukić, Biljana R.; Banks, Craig E.; Compton, Richard G.<br/><br/>Abstract: Ultrasound and benefits of its application in electrochemistry and electroanalysis havebeen explained and demonstrated. Lead determination by stripping analysis coupledwith insonation was used to illustrate advantages of employing ultrasound in electroanalysis.Quantitative analysis of lead under insonation was shown to be possible indifferent media, including organic and biological samples where electroanalyticaltechniques often fail to give satisfactory results due to passivation of electrodes inthese complex matrices.<br/><br/>Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in Hemijska Industrija, published by and copyright Savez Hemicara i Tehnologa Srbije.