http://hdl.handle.net/2173/31374 Wed, 19 Jun 2013 17:12:58 GMT 2013-06-19T17:12:58Z http://hdl.handle.net/2173/108711 Title: Effect of hindered piperidine light stabilizer molecular structure and UV-absorber addition on the oxidation of HDPE. Part 1: Long-term thermal and photo-oxidation studies Authors: Liauw, Chris; Quadir, Angela; Allen, Norman S.; Edge, Michele; Wagner, Alan Abstract: This series of papers explores the effect of structural characteristics of 2,2,6,6-tetramethylpiperidine-based hindered amine light stabilizers (HALS) on the long-term (40 months) thermal (110°C in air) and photo-stabilization (Microscal unit wavelength >300 nm) performance characteristics of high-density polyethylene formulations. Possible synergism with a triazine functional UV absorber is also explored. Under thermal degradation (measured by carbonyl index) the polymeric HALS performed best, mainly because of reduced volatilization. Additionally, >N-methyl HALS generally showed superior performance under thermal degradation. There was no synergism between an N-CH3 polymeric HALS and the UV1164 triazine additive. However, the equivalent N-H polymeric HALS interacted in a complex manner with UV1164, giving synergism and antagonism, depending on HALS/UV1164 ratio. Strong synergism was evident with the monomeric HALS when the total stabilizer level was 0.2% w/w. Reduction in the overall stabilizer level to 0.05% w/w eliminated the synergism. The UV1164 alone led to rapid and intense yellowing; however, the rate and intensity of yellowing reduced dramatically upon combination with HALS, particularly when the UV1164 level was above 0.1% w/w. When the formulation was under UV attack, the molar mass and the type of N-substitution had no influence on stabilization performance because of the relatively low temperature of testing (leading to reduced volatilization), and the similarly effective UV-stabilization routes for N-methyl HALS and N-H HALS. Under UV attack, yellowing reached a maximum and then decreased to approximately the initial level, while HALS/UV1164 combinations generally showed weak antagonism. 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 Vinyl & Additive Technology, published by and copyright John Wiley and Sons. Tue, 01 Jun 2004 00:00:00 GMT http://hdl.handle.net/2173/108711 2004-06-01T00:00:00Z http://hdl.handle.net/2173/107442 Title: Surface topography and physicochemistry of silver containing titanium nitride nanocomposite coatings Authors: Whitehead, Kathryn A.; Kelly, Peter; Li, Heqing; Verran, Joanna 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 and Technology. Part B. Microelectronics and Nanometer Structures, published by and copyright American Institute of Physics. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/2173/107442 2010-01-01T00:00:00Z http://hdl.handle.net/2173/94420 Title: Investigation of food and environmental exposures relating to the epidemiology of Campylobacter coli in humans in Northwest England Authors: Sopwith, Will; Birtles, Andrew; Matthews, Margaret; Fox, Andrew J.; Gee, Steven; James, Sam; Kempster, Jeanette; Painter, Michael; Edwards-Jones, Valerie; Osborn, Keith; Regan, Martyn; Syed, Qutub; Bolton, Eric Abstract: This study uses multilocus sequence typing (MLST) to investigate the epidemiology of Campylobacter coli in a continuous study of a population in Northwest England. All cases of Campylobacter identified in four Local Authorities (government administrative boundaries) between 2003 and 2006 were identified to species level and then typed, using MLST. Epidemiological information was collected for each of these cases, including food and recreational exposure variables, and the epidemiologies of C. jejuni and C. coli were compared using case-case methodology. Samples of surface water thought to represent possible points of exposure to the populations under study were also sampled, and campylobacters were typed with multilocus sequence typing. Patients with C. coli were more likely to be older and female than patients with C. jejuni. In logistic regression, C. coli infection was positively associated with patients eating undercooked eggs, eating out, and reporting problems with their water supply prior to illness. C. coli was less associated with consuming pork products. Most of the cases of C. coli yielded sequence types described elsewhere in both livestock and poultry, but several new sequence types were also identified in human cases and water samples. There was no overlap between types identified in humans and surface waters, and genetic analysis suggested three distinct clades but with several "intermediate" types from water that were convergent with the human clade. There is little evidence to suggest that epidemiological differences between human cases of C. coli and C. jejuni are a result of different food or behavioral exposures alone. Description: Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in Applied and Environmental Microbiology, published by and copyright American Society for Microbiology. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/2173/94420 2010-01-01T00:00:00Z http://hdl.handle.net/2173/90569 Title: Campylobacter jejuni multilocus sequence types in humans, northwest England, 2003-2004 Authors: Fox, Andrew J.; Sopwith, Will; Birtles, Andrew; Matthews, Margaret Abstract: Detailed understanding of the epidemiology of Campylobacter is increasingly facilitated through use of universal and reproducible techniques for accurate strain differentiation and subtyping. Multilocus sequence typing (MLST) enables discriminatory subtyping and grouping of isolate types into genetically related clonal complexes; it also has the advantage of ease of application and repeatability. Recent studies suggest that a measure of host association may be distinguishable with this system. We describe the first continuous population-based survey to investigate the potential of MLST to resolve questions of campylobacteriosis epidemiology. We demonstrate the ability of MLST to identify variations in the epidemiology of campylobacteriosis between distinct populations and describe the distribution of key subtypes of interest. Description: Full-text of this article is not available in this e-prints service. This article was originally published [following peer-review] in Emerging Infectious Diseases, published by and copyright U.S. Department of Health and Human Services. Sun, 01 Oct 2006 00:00:00 GMT http://hdl.handle.net/2173/90569 2006-10-01T00:00:00Z