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Use of recycled organic wastes as nutrient sources to aid the growth of energy crops on brownfield sitesPage, Katherine Esther January 2014 (has links)
This thesis presents the results of research into the use of Recycled Organic Wastes (ROWs) as soil amendments to aid the growth of energy crops on brownfield sites in the UK. In order to divert biodegradable waste from landfills, food waste is source segregated by households or is mechanically separated from mixed Municipal Solid Waste (MSW) before being biologically decomposed to form stable ROWs. The source of waste stream influences the future market and use of ROWs. Three different ROWs were characterised to assess the effect of the initial waste stream and the influence of aerobic or anaerobic biodegradation processes on the final organic products. Growth trials were conducted to assess the use of ROWs as nutrient sources for three fast growing tree species, S.viminalis, E. nitens and P. tomentosa. Preliminary growth trials found that high total dissolved solids were associated with some ROWs were detrimental to plant health and survival rates. Further growth trials identified the optimum total nitrogen application rate of ROWs when mixed with Kettering Loam, a clay loam. Analysis of leachate collected from the pot trials identified changes in quantities of heavy metal and nitrogen leaching during the growth trials and allowed comparison to water quality limits for aquatic life to assess the risk to the wider environment. Column growth trials assessed the effect of saturated and unsaturated conditions on a specific ROW known as Compost- Like Output derived from MSW, the impact on plant growth and the effect on leachate composition. Saturated conditions were detrimental to E. nitens, whereas S. viminalis adapted to saturated conditions with greater biomass production compared to the unsaturated columns. A reducing environment resulted in differences in heavy metal leaching and nitrogen forms compared to the unsaturated columns. The use of ROWs on brownfield sites can improve the overall soil quality while providing sufficient nutrients to improve biomass yields of energy crops. However the source of ROWs and biological treatment methods can influence the characteristics and future use of the ROWs. CLO derived from MSW had significantly higher heavy metal concentrations than source segregated material. Higher concentrations of heavy metal, particularly of copper, zinc and lead were identified within the fines (< 1 mm) of MSW derived CLO. Leachate analysis from the optimum and column growth trials identified changes within the pore water chemistry, which also influenced the mobility of heavy metals. The application of ROWs to brownfield sites has the potential to release soluble nitrogen forms and heavy metals into the wider environment; however application to contained sites or lower applications will reduce the risk.
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Investigation into CF3I-CO2 gas mixtures for insulation of gas-insulated distribution equipmentWidger, Phillip January 2014 (has links)
This thesis reviews the use of sulphur hexafluoride (SF6) as an insulating medium in the electrical power industry and quantifies the potential global warming effects associated with its continued use. A mixture of Trifluoroiodomethane (CF3I) and carbon dioxide (CO2) is suggested as a potential alternative to SF6, and its insulation properties are examined. Pressure mixture ratios of 10%:90%, 20%:80% and 30%:70% CF3I-CO2 are used in the laboratory test programme. A test rig has been developed to safely fill and recover gas mixtures of CF3I-CO2 in switchgear. Practical medium voltage (MV) switch disconnectors and ring main units are used to test the insulation properties of CF3I-CO2 gas mixtures and compared with SF6 using standard lightning impulses (1.2/50 μs). The experimental mixture ratios are used to identify how the insulation strength varies depending on the content of CF3I used. The switchgear is filled to its normal and minimum operating pressure to observe the reduction in insulation performance of the gas mixtures when the pressure is reduced. The insulation strength is measured using the 50% breakdown voltages (U50) and withstand strengths of each gas mixture in accordance with international standards. The effective ionisation coefficients of various CF3I-CO2 gas mixtures are calculated. This process identified the estimated critical reduced electric field strengths of several CF3I-CO2 gas mixtures. Furthermore, electric field simulations utilised the effective ionisation coefficient functions and the contact geometry of a switch disconnector to predict the likelihood of a flashover occurring for various CF3I-CO2 gas mixtures. This investigation shows that CF3I-CO2 can successfully be used to insulate practical MV switchgear but is dependent on equipment design and operating pressure. It has previously been indicated that by-products of CF3I make it unsuitable to interrupt high current. Therefore, it is suggested in this study that CF3I-CO2 gas mixtures can be adopted to insulate equipment such as vacuum circuit breakers.
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Establishment of a repeatable test procedure for measuring adhesion strength of particulates in contact with surfacesErmis, Ertan January 2011 (has links)
The firm adhesion of flavouring particles onto snack surfaces during coating processes is a major concern in the snack production industry. Detachment of flavouring powders from products during handling and production stages can lead to poor appearance and reduced taste of the product as well as substantial financial losses for the industry, in terms of variable flavour performance and extended cleaning down time of fugitive particle build-up on process equipment. Understanding the adhesion strength of applied bulk particulates used for flavouring formulations will help analysts to evaluate the efficiency of coating processes and potentially enable them to assess the adhesion strength of newly formulated flavouring powder prior to commitment to full scale plant trials. Meeting this object has required the development of an over-arching review of the adhesion mechanisms as a primary step. Based on this overview to the work of previous researchers, technological gaps and promising techniques have been identified for further research and development. A prototype of a novel adhesion tester called an Impact Adhesion Tester (IAT) has been designed and constructed. The development of the overall tester design is presented, and details of its parts and the resulting tester are discussed. The IAT and its experimental procedure were primarily designed and implemented for use in the snack industry, in particular, for the measurement and evaluation of the key factors affecting the adhesion behaviour of flavour powder onto snack surfaces qualitatively and quantitatively. This measurement can indicate the percent flavour powder loss within production stages (from coating to packing) and in package. The instrument has been evaluated using different materials and substrates subjected to different coating conditions such as rotational speed of the drum, retention time in drum, the amount of surface oil and the amount of powder applied. By plotting the detachment versus impact force, the difference has been obtained between adhesion strength of different flavouring powders (which is a strong function of particle size, particle shape, particle density and surface oil content of the snack). In addition to the above work, ultra-centrifuge method was used as a reference for comparison. The research work conducted using IAT on flavouring powders has proved the importance of particle adhesion strength and that the particle adhesion strength can reflect the changes in particle loss, based on particle characteristics as well as process conditions during snack production. It proved that bench size IAT would be a useful tester to measure adhesion strength of particles. The results obtained from experiments have confirmed that the tester may be able to usefully determine the variations between different powder materials. However the tester needs to be further evaluated by industrialists and researchers before possible use or commercialisation.
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Design and analysis of a biometric access control system using an electronic olfactory device to identify human odour characteristicsMcMillan, Stephen January 2000 (has links)
The use of an electronic olfactory device, termed an electronic 'nose', was investigated for the detection of unique human odour characteristics. The detection of these unique odours was applied to the field of biometrics for access control, where a human's unique characteristics were used to authenticate a user of an access control system. An electronic odour sensing device was designed and constructed using an array of conducting polymer gas sensors in order to facilitate the regular screening of a group of human subjects over a period of six weeks. A static sampling method was used to measure odour levels from human hands, which were found to contain a reliable source of human odour. Human odour levels were low so dynamic sampling proved to be unsuitable for this application due to the dilution of the odour mixture. Feature analysis results revealed that the features of adsorption and desorption gradient contained discriminatory information in addition to the commonly used maximum divergence. Pattern recognition revealed that neural network architectures produced superior results when compared to statistical methods as a result of their ability to model the non-linearities in the data set. The highest recognition rate was 73% which was produced using a Multi-Layer Perceptron (MLP) neural network compared to 63% obtained using the best statistical method of Parzen windows. The majority of the recognition error was caused by a minority of the humans. Analysis of sensor data revealed that only 30% of the sensor array were contributing discriminatory information so it was deduced that performance would undoubtedly improve if a full array of effective sensors were available. Exploratory data analysis revealed that human odour changed from day to day and often an increasing divergence with time was observed. A time-adaptive method was devised which increased the recognition to 89%, but was still too low for use as a biometric recognition device. However, use as a verification device demonstrated acceptable levels of performance but resulted in high levels of user frustration caused by a high proportion of users being falsely rejected. This work demonstrated that an olfactory based biometric access control system could be a realistic proposition but requires further work, especially in the areas of sensor development and unique human odour research, before an operational system could be produced.
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The capacity of ICT to transform teaching and learning : a critical view from within a 'Building Schools for the Future' projectHaw, David January 2015 (has links)
Announced in 2003, Building Schools for the Future (BSF) was New Labour’s attempt to revolutionise secondary education in the UK, both in terms of infrastructure and pedagogy. The country’s school building stock was decades (and in some cases centuries) old and in poor repair, built for a different age with a history of lack of investment in modern technologies. BSF was to change all that with massive investment and plans to transform teaching and learning. The new buildings were to be of contemporary and revolutionary design more akin to modern office spaces than their Victorian predecessors. Each school project had £1,400 per pupil (approximately £1.4m) of its budget ‘ring fenced’ to be spent on Information Communication Technology (ICT), as this was to be a major transformational tool; the key to equipping students with the skills needed for a 21st Century economy. This Doctorate report is written from within one of the first BSF projects in the country, planned from 2005 and opened in 2007, with the ICT contract coming to an end in 2014. The author is the only surviving member of the original BSF planning team still working within the LA as a Deputy Head Teacher. The main research questions ‘To what extent and in what ways has the huge investment in ICT during BSF transformed teaching and learning and what was the perspective of this from the three main stakeholder groups; those leading, those teaching and those learning?’ sets out to investigate the impact of the ICT component of BSF, it does however also reflect on the BSF process as a whole because this set the context in which the ICT systems were deployed; through a Managed Service Provider (MSP) procured from the private sector. This contract cast a long shadow over the prospect of transformation as BSF became largely about procurement, contracts and cost, the ‘B’ prevailed; teaching and learning were marginalized. Another major influence was that the schools in BSF re-opened in the same educational climate of accountability, curriculum, timetables and assessment methodology as they had had in their old accommodation. Conflicting government policy streams only served to make this more evident. Teacher and pupils assimilated their new environments and continued as before. That is not to say the ICT did not have an impact; there were many positive outcomes ranging from a greatly reduced pupil to device ratios and multimedia lesson content readily available to all. Pupils in particular were delighted (initially at least) with their new environments. Communication and the sharing of ideas and resources were the result of modern networks and systems that meant efficiencies for some and up to date information for most. Overall, classroom teachers had little capacity to transform their professional lives with the ICT provision, and there was no real pressure for them to do so given the unchanged nature of the structures of education within which they worked. Although many saw the potential of the new ICT, the opportunities to improve their skills were frustratingly lacking or not suited to their needs, consequently most incorporated the ICT into their classroom practice at a level with which they were comfortable. The cancellation of BSF in 2011 was one of the first acts of the new coalition government, although the schools included in this work had a managed ICT service that ran until August 2014. At the end of this contract schools were left with both expensive change and refresh costs that were likely to be a financial burden many could ill afford and so they were hindered in their ability to embrace newer technologies that might assist transformation.
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British submarine policy, 1853-1918Dash, Michael Wynford January 1990 (has links)
No description available.
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Reductions using Clostridium sporogenesMordaka, Pawel Mateusz January 2014 (has links)
Clostridium sporogenes was previously shown to be an extraordinary source for unusual reductases. It can catalyze reduction of wide a range of substrates such as nitroalkenes, enoates and nitro compounds, and can be used to generate chiral products. In preliminary studies, the ClosTron gene knock-out system for Clostridia was used to inactivate the fldZ gene assumed to encode the enzyme responsible for reduction of cinnamic acid in the reductive branch of L-phenylalanine fermentation via the Stickland reaction. Biotransformations with the fldZ mutant showed that C. sporogenes possesses multiple enzymatic activities, reducing enoates, β,β- and α,β-disubstituted nitroalkenes with different yields and enantioselectivities. The fldZ reductase was found to be responsible for reduction of cinnamic acid, (E)-1-nitro-2-phenylpropene, (E)-2-nitro-1-phenylpropene and β-nitrostyrene. However, the mutant could still reduce (E)-2-nitro-1-phenylpropene, β-nitrostyrene and cinnamic acid confirming the presence of other C=C double bond reductases in C. sporogenes. The analysis of the C. sporogenes genome sequence allowed identification of two hypothetical genes encoding proteins with homology to flavin-containing C=C double bond reductases, fldZ 2-enoate reductase and OYE-like reductase, which were subsequently cloned, overexpressed in E. coli under anaerobic conditions and tested for reduction of unsaturated compounds. The activity tests showed that fldZ possesses a narrow substrate range and can reduce only aromatic enoates such as cinnamic acid or p-coumaric acid. FldZ also reduced (E)-1-nitro-2-phenylpropene and (E)¬-2-nitro-1-phenylpropene with excellent and poor enantioselectivities (>99% and 16% respectively). On the other hand, the OYE-like reductase did not show activity towards unsaturated substrates in the activity assays and the substrate range of this reductase is unknown. Growth experiments comparing wild type C. sporogenes and the mutant in complex and minimal media showed that the fldZ reductase in not involved in the L-phenylalanine fermentation. Further analysis of the C. sporogenes genome resulted in identification of a novel reductase that might be involved in reduction of cinnamoyl-CoA to 3-phenylpropionyl-CoA in the Stickland reaction. Biocatalytic reduction of aromatic nitro compounds to amines can be used as alternative to chemo-reductive routes in preparation of pharmaceutical and agrochemical products. Protein extracts of C. sporogenes were found to reduce aromatic nitro compounds with different yields depending on the substrate structure and electron donor used in the reaction. The genome of C. sporogenes was screened and that allowed identification of six genes encoding hypothetical nitroreductases, which were subsequently overexpressed in E. coli. However, biotransformations using the recombinant nitroreductases did not show amine product formation. A novel Nylon 6 biosynthesis pathway was designed starting from biorenewable feedstocks. The crucial step in this pathway, reductive cleavage of pipecolic acid to 6-aminocaproic acid was proposed to be catalysed by C. sporogenes D-proline reductase. Thus, the activity of this enzyme was tested towards L- and D-pipecolic acid. Biotransformations showed that pipecolic acid was not accepted as a substrate. In the future, the idea of using D-proline reductase for Nylon biosynthesis may be exploited by improving the reductase activity using protein engineering techniques.
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The role of knowledge artefact and agency in IS project escalationBukhary, Wael January 2014 (has links)
This research contributes to current academic thinking by highlighting new perspective to studying the IS Project Escalation phenomenon through the application of Agency Theory. This theory views the customer as the (principal) who needs an IS product, and the IS developer as the (agent) who creates this IS product. According to this viewpoint, examining current IS project escalation literature suggests the majority of previous studies implicitly adopted the assumption that the customer (principal) is entirely capable of identifying the requirements of the proposed IS product, and a project is prone to escalate because of the attitude of the IS developer (agent). This presents a gap in the literature in that the impact of the customer (principal) not been explicitly explored. As such, one critical aim of this research is to investigate IS project escalation by employing an extension of Agency Theory. This extended theory assumes that the customer (principal) suffers challenges of incompetence when it comes to the transfer of knowledge (i.e. requirements) to the IS developer (agent). This leads to a situation of information asymmetry on the principal’s side because of incomplete knowledge transfer. In turn, this situation develops and leads to IS project escalation. Another aim of this research is to investigate the process of requirement elicitation (RE) in IS development practice. This is to identify the role of the incorporated knowledge artefacts within this activity, in terms of how the project manager and developers effectively create and utilise these objects. Thus, this is in order to provide a possible solution with respect to the challenge of incomplete knowledge transfer. To achieve that, this research employed a qualitative methodology and collected data in two stages in Saudi Arabia by using semi-structured interviews. In this respect, in the first stage, a number interviews with 30 IS project manager form five different IS development organisations is conducted. In the second stage, a number of interviews with 10 customers form different organisations is conducted. The findings in general acknowledged and complemented a number of previous studies’ results through the employed perspective of the extended Agency Theory in this research. Considering the identified gap, the empirical evidence supported the assumption of this research, and provided a new explanation for IS project escalation which highlighted the role of the customer (principal) this time. In addition, an influence diagram (i.e. Project Escalation Framework), which clarifies the relationship between the reasons behind incomplete knowledge transfer and IS project escalation, is developed. Also, the empirical evidence identifies a number of incorporated and relevant knowledge artefacts throughout the process of requirement elicitation (RE), namely Initial Request, Features, Process Diagrams, Prototypes, and Requirements. In this respect, the discussion categorised the different roles these artefacts can act out, in terms of being boundary object, epistemic objects, and activity objects. Additionally, a process diagram (i.e. Knowledge Transfer Framework), which clarifies the knowledge process in five main steps during RE phase, is developed. Analysing a number of IS development cases in a various contexts demonstrated multiple practical applications of the Project Escalation Framework with respect to managing issues building up to and leading to several project outcomes (i.e. success, failure, and escalation). Additionally, this analysis presented the artefacts in the Knowledge Transfer Framework as critical linchpins of an otherwise fragmented process when it comes to eliciting customer requirements. These artefacts have much broader implications that go beyond acting as just a procedure to elicit customer requirements. The ‘inclusion’ or ‘omission’ of these artefacts contributes to project success or failure respectively. Consequently, this understanding will result in improvement of IS development investigations, rather than exclusively enhance RE processes between principals and agents. Furthermore, the findings provided a number of highlighted things to be aware of and useful hints which reflect professional experience from real life applications. Thus, considering learning from such rich experience in terms of employing the advantages and avoiding the drawbacks would positively reflect on IS development practice. This includes managing and dealing with challenges of IS development projects, particularly project escalation, in addition to improving RE process and enhancing the process of receiving customer requirements and ideas.
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Continuous flow microwave catalytic chain transfer polymerisation of methyl methacrylate oligomersWalker, Edward January 2014 (has links)
The aim of this project was to develop and compare microwave at 2.45 GHz and conventional heating processes to produce low molecular weight methyl methacrylate oligomers. The required level of conversion for this process to be successful was 40 %. Batch and flow processes were investigated for both heating methods, and conversions of up to 70 % in batch and 55 % in flow were achieved. A large number of publications conclude that microwave heating can lead to significant improvements in conversion, rate and product quality when compared to conventionally heated reactions. In many cases this has been attributed to a non-specific thermal effect due to material interactions with the electric field component of the microwave. In many cases these conclusions stem from inaccurate temperature measurement in a microwave environment, and comparisons with conventional heating being carried out under different conditions. In this work a robust methodology was developed to compare microwave and conventional heating for oligomer production. Initial work was carried out at 30-50 cm³ using a CEM Discover SP (300 W) microwave, a conventionally heated stirred oil bath and a single mode cavity. Investigation into the effects of temperature, heating rate and reaction time on conversion were carried out, and it was found that the target material could be produced to 70% conversion in less than 5 minutes. From the understanding gained using small scale batch reactions a set of design requirements were produced for larger scale flow systems using microwave and conventional heating, and these systems were constructed as part of this project. This apparatus allowed for repeatable production of the target material at flow rates of up to 36 kg/hour when operated using a 2 kW microwave generator with automated tuning. Conventional comparisons were carried out at in flow with the use of apparatus of the same physical geometry under the same conditions. This is the first work published to carry out direct comparisons between conventionally heated and microwave reactions under the same conditions. It was found that at all scales and under all the conditions investigated that there were no quantifiable benefits in conversion or product quality offered by the use of microwave heating. It was concluded that such benefits concluded elsewhere are likely to result from poor control and rigour in experimental comparisons.
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The role of user-producer relations in innovation and diffusion of new technologies : lessons from BrazilCassiolato, Jose Eduardo January 1992 (has links)
No description available.
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