Browsing by Author "Cook, M."

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    The effect of ionising radiation on the explosives: TATB, HMX and PETN
    (Cranfield University, 2019) Lewis, D. A.; Akhavan, Jacqueline; Cook, M.; Wilson, I; Stennett, C.
    The effect ionizing radiation, specifically gamma, has on three of the most well known explosive materials; HMX, PETN and TATB, has been studied experimentally and computationally. Samples of these explosives that had been irradiated in vacuum to a total dose (equivalent to water) of 200 kGy by an average incident energy of 1.25 MeV, showed changes to their explosive and physical properties to varying degrees, with sensitivity to impact being most notably changed for PETN and HMX. Changes to the thermal properties of HMX and TATB, alongside the detection of long lived radicals for TATB and PETN, suggests alterations to each material’s chemistry. Changes were only detectable in solid state analytical methods, indicating that alterations to these materials are isolated within this state. Through comparison with other data, these changes appear to be highly dependant on the gaseous environment in which they are irradiated, with vacuum having the most significant effect. The widely reported greening of TATB under the influence of gamma (and ultraviolet and x-Ray) irradiation was found to be reversible upon re-crystallisation, with the process also appearing to remove the long lived radical that had existed in the material for over eight years. Radical concentration appears to correlate with total absorbed dose along with the level of green within the material. Computational investigation attributes the discolouration of TATB to the cationic radical derivative of TATB, which is stabilised by de-localised pi-bonding resonance of the constitutive aromatic ring, it is also suggested that this is the source of the radical signal observed in ESR analysis.Further computational investigation suggests that purported decomposition products of TATB such as the mono-furazan, mono-nitroso and phenoxyl radical are not the source of the discolouration and are also not thermodynamically favourable, unless the monofurazan or phenoxyl derivatives are in a cationic form. Thermodynamic evaluation of potential decomposition pathways for PETN and HMX yield a selection of energetically favourable products, however the significant majority are, like TATB, in the cationic radical form. Simulated ESR spectra for purported HMX decomposition products did not agree with those observed in literature, attributed to their short lived nature. However a measured long lived radical in TATB is attributed to the cationic radical form of TATB, the purported source of the discolouration. A long lived radical in PETN was also measured and assigned to the cation derivative of PETN by comparison with computational predictions.
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    Promoting sustainable resource use through product service systems.
    (2007-06-01T00:00:00Z) Cook, M.; Angus, Andrew; Gottberg, Annika; Smith, Richard; Longhurst, Philip J.
    In a world of declining prices for manufactured goods and increased global competition, many manufacturers have developed a range of services that complement and in certain instances replace traditional products, in an attempt to maintain or boost profitability. Resultant products have been classified as Product Service Systems (PSS) and comprise both an tangible artefact and intangible service, which are conflated through business processes to deliver value to customers. Research suggests that the environmental performance of PSS may be significantly better than that of traditional products. Theoretically, improvements in resource productivity that might be gained from use of PSS as opposed to traditional products are potentially enormous: somewhere between a factor of 10 and 20. To realise these environmental benefits, there is a need to identify instances where conventional material products can be substituted by PSS. This will depend on the criteria upon which consumers’ decisions are made. One prominent theory of decision-making assumes that a decision to buy is based on the performance of product or service against well-defined criteria, such as price and quality. An analytical technique is required to enable consideration of multi-criteria and provide information regarding the relative importance of each criterion. A review of the literature was undertaken to identify suitable methodologies for this study. Three techniques were identified as being appropriate, namely: Choice Experiments (CE); Multi-Attribute Utility Theory (MAUT); and the Analytical Hierarchy Process (AHP). AHP was seen to be a suitable tool to enable consumers to compare product service systems with traditional products and identify substitutions, as it is a robust method that is particularly suited to decisions made with limited informatio
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    Receptivity to the production of product service systems in the UK construction and manufacturing sectors: A comparative analysis
    (Elsevier Science B.V., Amsterdam., 2012-09-30T00:00:00Z) Cook, M.; Gottberg, Annika; Angus, Andrew; Longhurst, Philip J.
    Trajectories of service innovations emanating from manufacturing sectors have been of particular interest to those wishing to improve resource productivity and promote sustainable development. Research has focused on product service systems (PSSs), which are a category of service innovations deliberately designed to offer superior environmental performance. This paper draws on research which explored whether trajectories of PSS can be induced on new UK housing developments to satisfy household demand and prevent household waste. The research was undertaken with a UK speculative house-builder and facilities management service providers from its supplier network. Qualitative data were collected via interviews and focus groups to enable rich accounts of the range of factors in these firms' selection environments which affect receptivity to PSS production to be developed. These were compared with factors affecting receptivity to PSS production identified in a study of UK manufacturers. The results show that in contrast to the manufacturing study, clear drivers for PSS delivery on new housing developments are absent in external selection environments of participating firms and uncertainty associated with the potential of PSS concepts to satisfy household demand inhibits development of requisite competence for PSS delivery within these. Thus further research is needed to explore new PSS supply arrangements involving a range of household service providers.