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Multi-objective network planning for the integration of electric vehicles as responsive demands
Get PDFThe integration of electric vehicles (EVs) into distribution networks presents substantial challenges to Distribution Network Operators (DNOs) internationally. In the 12 months from November 2017, EV registrations in Great Britain have increased by ~22% [A.1], though it is noted that EVs account for only 6% of all UK vehicle registrations [A.1] in 2018. With the UK Government announcement in 2017 [A.2] that "by 2040 there will be an end to the sale of all conventional petrol and diesel cars and vans", the penetration of EVs will require to - unless a new technology emerges - grow exponentially over the next 10 to 20 years towards 100% penetration by 2050. However, the increasing penetration of EVs can provide to the system multiple benefits and assist in mitigating issues; if EV integration is optimally planned using a suitable method. The managed charging of multiple EVs can assist in better utilising power generated by intermittent renewables, which will provide substantial benefits such as peak shifting, deferred reinforcement costs and the reduced requirement for imported energy to support the network at times of need.;Accurately assessing the impact that EVs will have on distribution networks is critical to DNOs [A.3]. In particular, the aim of this thesis is to identify the optimal location, battery size, charger power output and operational envelope for multiple EVs when used as responsive demands in high voltage/low voltage (HV/LV) distribution networks. Societal benefits can include reduced or deferred asset investment costs; reduced technical losses and increasing the utilisation of renewable generation [A.3]. System benefits must be accounted for and can support and inform planning and operational decisions - such as asset investment and network reinforcement. Coordinated smart charging of multiple EVs can assist in managing peaks in the demand curve and increase the utilisation of intermittent renewables. Unmanaged EV charging at times of peak demand would require the DNO to invest in reinforcement solutions to ensure the required additional capacity is made available. However, one approach is to cluster EV charging in periods when the base load would otherwise be low, to lessen the need for asset reinforcement as EV charging during the period of peak demand would be avoided.;Time periods for charging EVs (dependent on the chosen objectives) will be identified and then correlated to times when renewable generation availability is high and when base demand is low. The use of the presented network planning tool will identify EV charging strategies that can be applied to multiple EVs (based on the chosen objectives and with respect to constraints) whilst optimising the type, number and location on a specific modelled network. The planning framework utilises the Strength Pareto Evolutionary Algorithm 2 (SPEA2); the use of this algorithm will ensure that the network constraints are not breached and that multiple objectives are included in the analyses. This thesis investigates the impact that the inclusion of multiple EVs (when used as responsive demands); will have on the HV distribution network when the additional EV load is smartly scheduled to meet specific objectives and to correspond with the availability of intermittent renewables. The ultimate aim of this planning approach is to offer DNOs low cost solutions to multiobjective problems relating to EV integration and operation. [References A1-A3 for Abstract available p. XV of thesis.]The integration of electric vehicles (EVs) into distribution networks presents substantial challenges to Distribution Network Operators (DNOs) internationally. In the 12 months from November 2017, EV registrations in Great Britain have increased by ~22% [A.1], though it is noted that EVs account for only 6% of all UK vehicle registrations [A.1] in 2018. With the UK Government announcement in 2017 [A.2] that "by 2040 there will be an end to the sale of all conventional petrol and diesel cars and vans", the penetration of EVs will require to - unless a new technology emerges - grow exponentially over the next 10 to 20 years towards 100% penetration by 2050. However, the increasing penetration of EVs can provide to the system multiple benefits and assist in mitigating issues; if EV integration is optimally planned using a suitable method. The managed charging of multiple EVs can assist in better utilising power generated by intermittent renewables, which will provide substantial benefits such as peak shifting, deferred reinforcement costs and the reduced requirement for imported energy to support the network at times of need.;Accurately assessing the impact that EVs will have on distribution networks is critical to DNOs [A.3]. In particular, the aim of this thesis is to identify the optimal location, battery size, charger power output and operational envelope for multiple EVs when used as responsive demands in high voltage/low voltage (HV/LV) distribution networks. Societal benefits can include reduced or deferred asset investment costs; reduced technical losses and increasing the utilisation of renewable generation [A.3]. System benefits must be accounted for and can support and inform planning and operational decisions - such as asset investment and network reinforcement. Coordinated smart charging of multiple EVs can assist in managing peaks in the demand curve and increase the utilisation of intermittent renewables. Unmanaged EV charging at times of peak demand would require the DNO to invest in reinforcement solutions to ensure the required additional capacity is made available. However, one approach is to cluster EV charging in periods when the base load would otherwise be low, to lessen the need for asset reinforcement as EV charging during the period of peak demand would be avoided.;Time periods for charging EVs (dependent on the chosen objectives) will be identified and then correlated to times when renewable generation availability is high and when base demand is low. The use of the presented network planning tool will identify EV charging strategies that can be applied to multiple EVs (based on the chosen objectives and with respect to constraints) whilst optimising the type, number and location on a specific modelled network. The planning framework utilises the Strength Pareto Evolutionary Algorithm 2 (SPEA2); the use of this algorithm will ensure that the network constraints are not breached and that multiple objectives are included in the analyses. This thesis investigates the impact that the inclusion of multiple EVs (when used as responsive demands); will have on the HV distribution network when the additional EV load is smartly scheduled to meet specific objectives and to correspond with the availability of intermittent renewables. The ultimate aim of this planning approach is to offer DNOs low cost solutions to multiobjective problems relating to EV integration and operation. [References A1-A3 for Abstract available p. XV of thesis.
Prediction and control of organic xerogel microstructure : experiments and modelling
Get PDFResorcinol-formaldehyde (RF) gels are a fairly new addition to the variety of porous materials used by current industry. However, a better understanding of their formation processes is crucial for efficient structure tailoring, leading to high-performance materials for a range of applications. The usual RF gel manufacture process involves gelation of an RF sol at elevated temperatures, followed by exchanging water within the structure for another liquid, in order to limit shrinkage during the final drying step. Yet, despite significant research efforts, the RF growth processes are still not fully understood and there is no accepted model describing these processes. Therefore, this study combines experimental and simulation approaches to better understand the gel growth process, and how the resulting structure depends on the growth conditions. The experimentally investigated areas include the influence of sodium carbonate catalyst concentration, processing temperature, solvent exchange and drying methods, as well as the presence of different anions within the reaction solution. Discussion on optimal processing parametersis included, in order to preserve the majority of the porous structure of RF xerogel materials, taking process economics into account, and the diversity of textural properties for obtained materials is examined. In order to model the growth processes in RF gels, and investigate how they impact the structural properties of final materials, a two-dimensional lattice-based computational model, using kinetic Monte Carlo, was developed in this work. The presented model is developed to capture growth from monomeric species present in the initial stages of the gelation composition. Experimentally, gel growth is primarily controlled through catalyst concentration, which determines the density of species that are activated for rapid growth, and solids concentration; the model captures both of these dependencies.;Generated cluster structures were analysed for textural properties, such as accessible porosity and accessible surface area, as well as fractal properties, in the form of the correlation dimension and the Hurst exponent. Increasing both solids content and percentage of activated monomers led to an observed increase in complexity of cluster arrangement and tortuosity of pore structure, both reflected in the values of evaluated fractal properties. In order to allow comparison of generated cluster structures with trends observed for experimental samples, gas sorption was modelled here using a lattice gas in a mean field approximation. The observations for model pores with varying dimensions agree with the background theory and the trends observed for the cluster structures were in line with those obtained experimentally. This helps to close the loop from growth processes to textural properties, providing the possibility to tailor materials for specific application.Resorcinol-formaldehyde (RF) gels are a fairly new addition to the variety of porous materials used by current industry. However, a better understanding of their formation processes is crucial for efficient structure tailoring, leading to high-performance materials for a range of applications. The usual RF gel manufacture process involves gelation of an RF sol at elevated temperatures, followed by exchanging water within the structure for another liquid, in order to limit shrinkage during the final drying step. Yet, despite significant research efforts, the RF growth processes are still not fully understood and there is no accepted model describing these processes. Therefore, this study combines experimental and simulation approaches to better understand the gel growth process, and how the resulting structure depends on the growth conditions. The experimentally investigated areas include the influence of sodium carbonate catalyst concentration, processing temperature, solvent exchange and drying methods, as well as the presence of different anions within the reaction solution. Discussion on optimal processing parametersis included, in order to preserve the majority of the porous structure of RF xerogel materials, taking process economics into account, and the diversity of textural properties for obtained materials is examined. In order to model the growth processes in RF gels, and investigate how they impact the structural properties of final materials, a two-dimensional lattice-based computational model, using kinetic Monte Carlo, was developed in this work. The presented model is developed to capture growth from monomeric species present in the initial stages of the gelation composition. Experimentally, gel growth is primarily controlled through catalyst concentration, which determines the density of species that are activated for rapid growth, and solids concentration; the model captures both of these dependencies.;Generated cluster structures were analysed for textural properties, such as accessible porosity and accessible surface area, as well as fractal properties, in the form of the correlation dimension and the Hurst exponent. Increasing both solids content and percentage of activated monomers led to an observed increase in complexity of cluster arrangement and tortuosity of pore structure, both reflected in the values of evaluated fractal properties. In order to allow comparison of generated cluster structures with trends observed for experimental samples, gas sorption was modelled here using a lattice gas in a mean field approximation. The observations for model pores with varying dimensions agree with the background theory and the trends observed for the cluster structures were in line with those obtained experimentally. This helps to close the loop from growth processes to textural properties, providing the possibility to tailor materials for specific application
Entrepreneurial orientation and marketing capabilities : a study on the performance of small and medium enterprises in the United Kingdom
Get PDFOrganisational performance has been the focal point of research for many years. Throughout the development of business studies, marketing has been suggested to play a key role in improving business performance. However, previous studies are inconclusive about the impact of specific organisational phenomena on company's performance. Moreover, some complexities should be considered, like the interrelationships between orientations, marketing capabilities, and competitive positioning.;Building upon the resource-based view of the firm, this study employed a survey to investigate the relationships among entrepreneurial orientation, marketing capabilities (specifically marker sensing capabilities, customer linking capabilities and adaptive marketing capabilities), competitive positioning and organisational performance. A scale was developed regarding a new set of marketing capabilities, namely adaptive marketing capabilities, while 221 completed questionnaires from small and medium UK manufacturing companies were utilised. Further information from secondary sources was collected to complement questionnaire responses regarding objective performance indicators. Eventually the theoretical model was estimated using structural equation modelling.;By explicating the concepts of marketing capabilities and focusing on their explorative and exploitative nature, the study contributes to the theories which support the important role of those outside-in capabilities. Another contribution is the suggestion that an entrepreneurial orientation will create an environment for the development of such capabilities. Out of the three marketing capabilities studied, adaptive marketing capabilities are found to be most important, considering that they affect most performance indicators directly, and indirectly by mediating other relationships.;In this vein, another contribution is the development of a construct to measure them. Meanwhile, analysing the moderating role of the external environment on the relationships between entrepreneurial orientation and performance, and between marketing capabilities and performance, the study contributes to the literature that supports contingency approaches. Finally, the present study employs different performance indicators for assessing marketing functions, which provide more clarity about their role and effects.Organisational performance has been the focal point of research for many years. Throughout the development of business studies, marketing has been suggested to play a key role in improving business performance. However, previous studies are inconclusive about the impact of specific organisational phenomena on company's performance. Moreover, some complexities should be considered, like the interrelationships between orientations, marketing capabilities, and competitive positioning.;Building upon the resource-based view of the firm, this study employed a survey to investigate the relationships among entrepreneurial orientation, marketing capabilities (specifically marker sensing capabilities, customer linking capabilities and adaptive marketing capabilities), competitive positioning and organisational performance. A scale was developed regarding a new set of marketing capabilities, namely adaptive marketing capabilities, while 221 completed questionnaires from small and medium UK manufacturing companies were utilised. Further information from secondary sources was collected to complement questionnaire responses regarding objective performance indicators. Eventually the theoretical model was estimated using structural equation modelling.;By explicating the concepts of marketing capabilities and focusing on their explorative and exploitative nature, the study contributes to the theories which support the important role of those outside-in capabilities. Another contribution is the suggestion that an entrepreneurial orientation will create an environment for the development of such capabilities. Out of the three marketing capabilities studied, adaptive marketing capabilities are found to be most important, considering that they affect most performance indicators directly, and indirectly by mediating other relationships.;In this vein, another contribution is the development of a construct to measure them. Meanwhile, analysing the moderating role of the external environment on the relationships between entrepreneurial orientation and performance, and between marketing capabilities and performance, the study contributes to the literature that supports contingency approaches. Finally, the present study employs different performance indicators for assessing marketing functions, which provide more clarity about their role and effects
A systems approach to determine how Toxoplasma gondii Infection causes neuropsychiatric disease
Get PDFThis thesis was previously held under moratorium from 16/03/2020 to 16/03/2022T. gondii infection acquired during life has been associated with psychoneurological disease in humans and behavioural changes in mice. However, less is known about the potential of congenitally acquired T. gondii infection, or for maternal T. gondii infection induced immune activation, to cause psychoneurological disease. The studies described herein, using LCMS (Liquid chromatography–mass spectrometry) demonstrate that adult acquired infection alters the neurochemistry and transcriptome of the brains of BALB/c mice. Notable changes to tryptophan, purine, arginine and carnitine metabolism were observed in infected mice.Congenitally infected and mice exposed to the maternal immune response to T. gondii, but not congenitally infected were found to have decreased mobility compared with control mice. Congenital T. gondii infection resulted in similar alterations in the neurochemistry of mice as seen in adult acquired infections. Some of these changes were observed, including tryptophan metabolism in mice exposed to the maternal immune response to T. gondii, but not congenitally infected.Both adult acquired T. gondii and congenital infection altered the brain transcriptome of mice relative to control uninfected mice with notable changes seen to transcripts of many immunologically important genes and enzymes in some of the metabolic pathways identified by LCMS. In addition, both adult acquired T. gondii infection, congenital infection and maternal exposure to different degrees were found to induce changes in a number of additional transcripts previously associated with psychoneurological diseases.These results demonstrate that maternal exposure to T. gondii infection during pregnancy induces a subset of neurochemical and transcriptomic changes found in mice with adult acquired and congenital T. gondii infection. The results therefore reinforce the potential of maternal immune activation to affect psychoneurological diseases and implicate T. gondii as a potential aetiological agent of this process.T. gondii infection acquired during life has been associated with psychoneurological disease in humans and behavioural changes in mice. However, less is known about the potential of congenitally acquired T. gondii infection, or for maternal T. gondii infection induced immune activation, to cause psychoneurological disease. The studies described herein, using LCMS (Liquid chromatography–mass spectrometry) demonstrate that adult acquired infection alters the neurochemistry and transcriptome of the brains of BALB/c mice. Notable changes to tryptophan, purine, arginine and carnitine metabolism were observed in infected mice.Congenitally infected and mice exposed to the maternal immune response to T. gondii, but not congenitally infected were found to have decreased mobility compared with control mice. Congenital T. gondii infection resulted in similar alterations in the neurochemistry of mice as seen in adult acquired infections. Some of these changes were observed, including tryptophan metabolism in mice exposed to the maternal immune response to T. gondii, but not congenitally infected.Both adult acquired T. gondii and congenital infection altered the brain transcriptome of mice relative to control uninfected mice with notable changes seen to transcripts of many immunologically important genes and enzymes in some of the metabolic pathways identified by LCMS. In addition, both adult acquired T. gondii infection, congenital infection and maternal exposure to different degrees were found to induce changes in a number of additional transcripts previously associated with psychoneurological diseases.These results demonstrate that maternal exposure to T. gondii infection during pregnancy induces a subset of neurochemical and transcriptomic changes found in mice with adult acquired and congenital T. gondii infection. The results therefore reinforce the potential of maternal immune activation to affect psychoneurological diseases and implicate T. gondii as a potential aetiological agent of this process
Surface enhanced spatially offset raman spectroscopy (SESORS) imaging of bacterial biofilms
No full textThis thesis was previously held under moratorium until 19th October 2022.Bacterial biofilm formation is crucial to establishing chronic infections including respiratory infection, orthopaedic infection and medical device infection et.al. Many antibiotics are unable to eradicate dense biofilms since extracellular polymeric substances (EPS) make up the matrix of the biofilm which retard the diffusion penetration of antibiotics. Current methods of bacteria detection rely upon laboratory-based techniques that are time-consuming and costly and require specialist trained users. Hence, there is an urgent need for in-situ methodologies to detect and prevent the formation of bacterial biofilms. Raman spectroscopy (RS) is based on the inelastic scattering of photons following monochromatic laser excitation. This powerful technique has the advantages of being non-destructive, non-invasive and label-free. However, the main disadvantage is that spontaneous Raman spectroscopy has low signal levels and long acquisition time. To address these issues, surface-enhanced Ramanscattering (SERS) has been used to enhance the Raman signal up to 1013 - 1015 orders of magnitudes and can increase acquisition speeds as well as improving the accuracy of detection. Therefore, the focus of this research is to use specially designed bionanosensors (lectin and DNA aptamer) with resonant nanotag chalcogenpyrylium dyes and low-pH sensing probes PhagoGreen as optical imaging tools showing spectral change in response tothe interaction with defined target molecules via enhanced SERRS signals to detect biofilm. This research focuses on developing new biomolecular sensing Raman-active nanotags as highly sensitive surface enhanced Raman probes. The specific nanosnesor was designed such that they will detect bacterial biofilms in vitro. This approach involves using galactophilic lectin PA-IL functionalised silver nanoparticles as a molecular recognition agent to detect the carbohydrates on the surface of bacteria using SERS. This research demonstrated this lectin biosensor is not only capable of detecting bacteria but also providing a rapid, sensitive discrimination between Gram-negative and Gram-positive bacteria, offering opportunities for future SERS biosensing in biomedical applications. None of current biofilm models can mimic the complexity of the 3D microenvironment and host defence mechanisms. In this study, clinically relevant bacterial species including Escherichia coli (E.coli), methicillinsensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa were 3D bioprinted using a double-crosslinked alginate bioink to form mature bacteria biofilms, characterized by confocal laser scanning microscopy (CLSM) and fluorescent staining. Importantly, we observed the complete five-step biofilm life cycle in vitro following 3D bioprinting for the first time, suggesting the formation of mature 3D bioprinted biofilms. 3D biofilm constructs produce a model with much greater clinical relevance compared to 2D culture models and we have demonstrated their use in antimicrobial testing. The advantage of using Raman rather than fluorescence as the optical imaging technique is the molecular specificity of the optical response, however more importantly in this case, is the combination of surface enhanced spectroscopy and spatially offset Raman (SESORS) which allows detection of Raman signals at depth. Herein, we have developed a novel approach for the detection of bacterial biofilms at depth using a 3D bioprinted biofilm model combined with gold nanoparticles functionalised with resonant Raman reporters and bacteria specific DNA aptamers. Detection was carried out using surface enhanced spatially offset resonant Raman spectroscopy (SESORRS) allowing detection of the bacterial biofilms to be achieved at penetration depths up to 2.1 cm through tissue for single bacteria and 1.5 cm for multiple bacteria. This work uses a low-pH sensing fluorescent probe, PhagoGreen, as a Raman reporter attached to a silver nanoparticle, to detect phagosome acidification in Gram-negative bacteria strain Escherichia coli activated macrophages by surface enhanced Raman spectroscopy (SERS). The SERS intensity of PhagoGreen conjugates at peak 759 cm-1 was shown to be highly responsive at a lower pH range (pH5-pH3).Bacterial biofilm formation is crucial to establishing chronic infections including respiratory infection, orthopaedic infection and medical device infection et.al. Many antibiotics are unable to eradicate dense biofilms since extracellular polymeric substances (EPS) make up the matrix of the biofilm which retard the diffusion penetration of antibiotics. Current methods of bacteria detection rely upon laboratory-based techniques that are time-consuming and costly and require specialist trained users. Hence, there is an urgent need for in-situ methodologies to detect and prevent the formation of bacterial biofilms. Raman spectroscopy (RS) is based on the inelastic scattering of photons following monochromatic laser excitation. This powerful technique has the advantages of being non-destructive, non-invasive and label-free. However, the main disadvantage is that spontaneous Raman spectroscopy has low signal levels and long acquisition time. To address these issues, surface-enhanced Ramanscattering (SERS) has been used to enhance the Raman signal up to 1013 - 1015 orders of magnitudes and can increase acquisition speeds as well as improving the accuracy of detection. Therefore, the focus of this research is to use specially designed bionanosensors (lectin and DNA aptamer) with resonant nanotag chalcogenpyrylium dyes and low-pH sensing probes PhagoGreen as optical imaging tools showing spectral change in response tothe interaction with defined target molecules via enhanced SERRS signals to detect biofilm. This research focuses on developing new biomolecular sensing Raman-active nanotags as highly sensitive surface enhanced Raman probes. The specific nanosnesor was designed such that they will detect bacterial biofilms in vitro. This approach involves using galactophilic lectin PA-IL functionalised silver nanoparticles as a molecular recognition agent to detect the carbohydrates on the surface of bacteria using SERS. This research demonstrated this lectin biosensor is not only capable of detecting bacteria but also providing a rapid, sensitive discrimination between Gram-negative and Gram-positive bacteria, offering opportunities for future SERS biosensing in biomedical applications. None of current biofilm models can mimic the complexity of the 3D microenvironment and host defence mechanisms. In this study, clinically relevant bacterial species including Escherichia coli (E.coli), methicillinsensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa were 3D bioprinted using a double-crosslinked alginate bioink to form mature bacteria biofilms, characterized by confocal laser scanning microscopy (CLSM) and fluorescent staining. Importantly, we observed the complete five-step biofilm life cycle in vitro following 3D bioprinting for the first time, suggesting the formation of mature 3D bioprinted biofilms. 3D biofilm constructs produce a model with much greater clinical relevance compared to 2D culture models and we have demonstrated their use in antimicrobial testing. The advantage of using Raman rather than fluorescence as the optical imaging technique is the molecular specificity of the optical response, however more importantly in this case, is the combination of surface enhanced spectroscopy and spatially offset Raman (SESORS) which allows detection of Raman signals at depth. Herein, we have developed a novel approach for the detection of bacterial biofilms at depth using a 3D bioprinted biofilm model combined with gold nanoparticles functionalised with resonant Raman reporters and bacteria specific DNA aptamers. Detection was carried out using surface enhanced spatially offset resonant Raman spectroscopy (SESORRS) allowing detection of the bacterial biofilms to be achieved at penetration depths up to 2.1 cm through tissue for single bacteria and 1.5 cm for multiple bacteria. This work uses a low-pH sensing fluorescent probe, PhagoGreen, as a Raman reporter attached to a silver nanoparticle, to detect phagosome acidification in Gram-negative bacteria strain Escherichia coli activated macrophages by surface enhanced Raman spectroscopy (SERS). The SERS intensity of PhagoGreen conjugates at peak 759 cm-1 was shown to be highly responsive at a lower pH range (pH5-pH3)
Searching for mechanistic insights in complex reaction pathways
Get PDFIn order to further advance chemical reactions, understanding the mechanism underpinning complex reaction pathways is key. This is the overarching aim of the work contained in this thesis, and through the application of density functional theory calculations four different systems are studied.Investigation of the mechanism of 1,2,4-triarylbenzene formation from 1,3-diaryl-2-propen-1-ols as proposed by Ghorai et al.1 demonstrates that the phenyl anion can be a competent leaving group. The implications of this study are that simply considering the pKa of the leaving group's conjugate acid does not afford a reliable prediction, for when the choice of leaving group is hydride or phenyl anion - the phenyl anion wins. Such a leaving group would not be predicted to be competent by the simple consultation of a pKa table, and this opens further possibilities of bad leaving groups made good.Competing reaction pathways are an inherent part of complex reaction systems; as such it is no surprise that in order to gain mechanistic insights into the reducing abilities of the Stoltz-Grubbs reducing system two competing reduction mechanisms were investigated. Through calculations it was possible to determine that the hydride and single electron transfer mechanisms were indeed not competing but were individually active for different types of substrate. Hydride reduction was applicable to the polyaromatic hydrocarbons naphthalene, phenanthrene and anthracene, whilst single electron transfer was deemed responsible for the reduction of N-benzylindole and N-phenyl-N-methylaniline.;Time is often key in achieving mechanistic insights for some complex reactions, one such reaction has been shown to be the reduction of benzophenone by KOtBu. Studied initially by Ashby et al.2 in the 1980s this reduction was predicted to occur by electron transfer from KOtBu to benzophenone resulting in the blue coloured benzophenone ketyl. The mechanism behind this reaction has now been uncovered and shown to involve the visible light excitation of a complex between KOtBu and benzophenone resulting in a charge transfer from KOtBu to benzophenone.The homocoupling of benzene under the action of potassium metal and an alkali metal salt was recently disclosed by experimental colleagues in the Murphy Group. A preliminary study of this complex reaction has shown that a further understanding of the composite structures formed upon mixing potassium metal and alkali metal salt is required in order to facilitate meaningful computational studies.In order to further advance chemical reactions, understanding the mechanism underpinning complex reaction pathways is key. This is the overarching aim of the work contained in this thesis, and through the application of density functional theory calculations four different systems are studied.Investigation of the mechanism of 1,2,4-triarylbenzene formation from 1,3-diaryl-2-propen-1-ols as proposed by Ghorai et al.1 demonstrates that the phenyl anion can be a competent leaving group. The implications of this study are that simply considering the pKa of the leaving group's conjugate acid does not afford a reliable prediction, for when the choice of leaving group is hydride or phenyl anion - the phenyl anion wins. Such a leaving group would not be predicted to be competent by the simple consultation of a pKa table, and this opens further possibilities of bad leaving groups made good.Competing reaction pathways are an inherent part of complex reaction systems; as such it is no surprise that in order to gain mechanistic insights into the reducing abilities of the Stoltz-Grubbs reducing system two competing reduction mechanisms were investigated. Through calculations it was possible to determine that the hydride and single electron transfer mechanisms were indeed not competing but were individually active for different types of substrate. Hydride reduction was applicable to the polyaromatic hydrocarbons naphthalene, phenanthrene and anthracene, whilst single electron transfer was deemed responsible for the reduction of N-benzylindole and N-phenyl-N-methylaniline.;Time is often key in achieving mechanistic insights for some complex reactions, one such reaction has been shown to be the reduction of benzophenone by KOtBu. Studied initially by Ashby et al.2 in the 1980s this reduction was predicted to occur by electron transfer from KOtBu to benzophenone resulting in the blue coloured benzophenone ketyl. The mechanism behind this reaction has now been uncovered and shown to involve the visible light excitation of a complex between KOtBu and benzophenone resulting in a charge transfer from KOtBu to benzophenone.The homocoupling of benzene under the action of potassium metal and an alkali metal salt was recently disclosed by experimental colleagues in the Murphy Group. A preliminary study of this complex reaction has shown that a further understanding of the composite structures formed upon mixing potassium metal and alkali metal salt is required in order to facilitate meaningful computational studies
Prison staff perceptions of their role in the rehabilitation & desistance support of prisoners
Get PDFThe principle objective of my ethnographical investigation was to interrogate prison staff perceptions in a Scottish prison to their role in affecting positive change, how this integrates into regular regimes of security and care and how they are trained to be positive agents of change. Research literature concludes that prison officers are the mainstay of the prison system, but rehabilitation and desistance support for prisoners is secondary to their primary role of security and care. In response to the Scottish Government's expectation that prisons reduce recidivism, the Scottish Prison Service introduced two strategies: (i) to positively transform the provision for prisoners internally and with community reintegration externally; (ii) to professionalise prison officer's service to transform how they facilitate positive change and desistance support for prisoners. I believe my empirical research has added to the knowledge of rehabilitation and desistance support in a penal environment through the lens of prison officers using a unique combination of video recordings of training and focus groups and audio recordings of one-to-one interviews which augment my observations, notes and interview responses, and provide an ontological perspective of a prison officer's occupation. My findings identify perspectival dichotomies and suggest that: training only provides new recruits with the bare essentials to undertake their primary function of security and care, positively conditions them to violence, but also conditions them to view prisoners negatively; poor intra- and inter-communication between different teams and groups of prison officers limits and impedes support of a prisoner's desistance journey; the architectural design of the prison has created a divide metaphorically and physically, so much so that rehabilitative support is seen as a formal process operating in specific areas of the prison away from the residential wings where a prisoner is likely to spend the majority of time incarcerated. What is claimed to be an holistic approach across the whole of the prison is unattainable due to the centralisation and concentration of 'support' in areas separated from the residential wings, and where prison staff have to make stark choices on who they can protect and support. Thus, strategies for the facilitation of rehabilitation, I contend, are not fundamentally meeting the needs of prisoners but the strategic goals of the Government, courts and prison service, where what is processed can be tangibly accountable through KPIs, contractual obligations and be fiscally affordable.The principle objective of my ethnographical investigation was to interrogate prison staff perceptions in a Scottish prison to their role in affecting positive change, how this integrates into regular regimes of security and care and how they are trained to be positive agents of change. Research literature concludes that prison officers are the mainstay of the prison system, but rehabilitation and desistance support for prisoners is secondary to their primary role of security and care. In response to the Scottish Government's expectation that prisons reduce recidivism, the Scottish Prison Service introduced two strategies: (i) to positively transform the provision for prisoners internally and with community reintegration externally; (ii) to professionalise prison officer's service to transform how they facilitate positive change and desistance support for prisoners. I believe my empirical research has added to the knowledge of rehabilitation and desistance support in a penal environment through the lens of prison officers using a unique combination of video recordings of training and focus groups and audio recordings of one-to-one interviews which augment my observations, notes and interview responses, and provide an ontological perspective of a prison officer's occupation. My findings identify perspectival dichotomies and suggest that: training only provides new recruits with the bare essentials to undertake their primary function of security and care, positively conditions them to violence, but also conditions them to view prisoners negatively; poor intra- and inter-communication between different teams and groups of prison officers limits and impedes support of a prisoner's desistance journey; the architectural design of the prison has created a divide metaphorically and physically, so much so that rehabilitative support is seen as a formal process operating in specific areas of the prison away from the residential wings where a prisoner is likely to spend the majority of time incarcerated. What is claimed to be an holistic approach across the whole of the prison is unattainable due to the centralisation and concentration of 'support' in areas separated from the residential wings, and where prison staff have to make stark choices on who they can protect and support. Thus, strategies for the facilitation of rehabilitation, I contend, are not fundamentally meeting the needs of prisoners but the strategic goals of the Government, courts and prison service, where what is processed can be tangibly accountable through KPIs, contractual obligations and be fiscally affordable
An examination of the role of self-regulatory fatigue in adaption to chronic pain
Get PDFObjectives: The prevalence of chronic pain and disability will continue to increase due to an aging population and lifestyle factors. Identifying factors which facilitate self-management is essential. Managing chronic pain requires the self-regulation of many factors that affect self-management, for example, to manage activity levels, mood, motivation, self-discipline, self-efficacy and inner conflicts. It has been proposed that difficulties in self-management in people with chronic pain arise from deficits in self-regulation, or a reduced capacity for self-regulation.;It would be useful, therefore, to understand the factors that impact on self-regulatory processes in chronic pain as a possible means by which self-management might be optimised. This thesis applied the Strength Model to understand self-regulation in people with chronic pain.;Methods: Six studies were conducted. In the first study, people with chronic pain and controls participated in tasks of self-regulation to examine the role of self-regulatory fatigue and self-efficacy on performance. In the second study, a cross-sectional design was employed where participants completed questionnaires to assess the relationship between self-regulatory fatigue, pain self-efficacy and mood. In the third study, two short forms of the Self-regulatory Fatigue Scale (SRFS) were developed and an initial validation was conducted. A discriminant content validity study of the SRFS was conducted in study 4.;A series of N-of-1 studies formed studies 5 and 6, which employed diary methods to examine the role of pain, self-regulatory fatigue, self-efficacy, motivation, goal striving and demands on goal pursuit. Results: The findings did not support Strength Model assumptions due to conceptual and methodological limitations of the Strength Model. At between-person and within-person levels, self-regulatory fatigue did not reliably predict self-regulation performance or goal pursuit. The findings suggest that self-regulatory fatigue and self-efficacy influence allocation of resources during self-regulation.;Higher self-efficacy may be adaptive at the group level, but not at the within-person level when self-regulatory capacity is reduced. Discussion: The evidence did not support the Strength Model but pointed to a motivated resource allocation explanation of self-regulation in people with chronic pain. The findings have implications from both a theoretical and clinical perspective.Objectives: The prevalence of chronic pain and disability will continue to increase due to an aging population and lifestyle factors. Identifying factors which facilitate self-management is essential. Managing chronic pain requires the self-regulation of many factors that affect self-management, for example, to manage activity levels, mood, motivation, self-discipline, self-efficacy and inner conflicts. It has been proposed that difficulties in self-management in people with chronic pain arise from deficits in self-regulation, or a reduced capacity for self-regulation.;It would be useful, therefore, to understand the factors that impact on self-regulatory processes in chronic pain as a possible means by which self-management might be optimised. This thesis applied the Strength Model to understand self-regulation in people with chronic pain.;Methods: Six studies were conducted. In the first study, people with chronic pain and controls participated in tasks of self-regulation to examine the role of self-regulatory fatigue and self-efficacy on performance. In the second study, a cross-sectional design was employed where participants completed questionnaires to assess the relationship between self-regulatory fatigue, pain self-efficacy and mood. In the third study, two short forms of the Self-regulatory Fatigue Scale (SRFS) were developed and an initial validation was conducted. A discriminant content validity study of the SRFS was conducted in study 4.;A series of N-of-1 studies formed studies 5 and 6, which employed diary methods to examine the role of pain, self-regulatory fatigue, self-efficacy, motivation, goal striving and demands on goal pursuit. Results: The findings did not support Strength Model assumptions due to conceptual and methodological limitations of the Strength Model. At between-person and within-person levels, self-regulatory fatigue did not reliably predict self-regulation performance or goal pursuit. The findings suggest that self-regulatory fatigue and self-efficacy influence allocation of resources during self-regulation.;Higher self-efficacy may be adaptive at the group level, but not at the within-person level when self-regulatory capacity is reduced. Discussion: The evidence did not support the Strength Model but pointed to a motivated resource allocation explanation of self-regulation in people with chronic pain. The findings have implications from both a theoretical and clinical perspective
The assessment of mooring line damping for offshore structures
Get PDFWith increasing water depth of oil and gas exploration, greater importance has been attached to the damping force from mooring systems. The effect is significantly important to slow drift motion of the floating structure, and it is also coupled with its motions. Coupled analysis is thus preferred to be applied to estimate the floating structure motions and to calculate the mooring system response, especially for offshore structures in deep-water.;In this study, the aim is to achieve a better understanding of mooring line induced damping estimation. Drag forces normal to the mooring line due to the motion of the mooring line through the water, are the main source of hydrodynamic damping of the mooring line. A method of energy dissipation based on the mooring line dynamic response obtained by Orcaflex is developed. The validation is established through two types of mooring lines in shallow water and deep water.;The present approach shows a good agreement with the published results, but with two exceptions. One is for the mooring line oscillated by a very slow LF motion in shallow water, when the hydrodynamic damping is very small. Another one is for the wire mooring line oscillated by WF motion in deep water, the result shows significant discrepancy with that from the quasi-static method.;Then a non-dimensional analysis is completed, due to the strong complexity of the mooring line induced damping. The effects of the factors can be divided into three groups: first, the effects from pretension and scope are related to the geometry changes of the mooring line; second, the oscillation, current velocity and drag coefficient make contributions to the drag forces of mooring line directly; and the last, the effects of stiffness and seabed friction which, it was found, can be neglected.;In order to experimentally investigate the chain behaviour moving in water, a series model tests for the damping characteristics of a single chain line is implemented through oscillation tests of various parameters. The drag coefficient ( C D ) variations with different Reynold ( Rn ) and KC numbers are investigated. The drag coefficients in this study range from 1.5 to 4.0, which is case-dependent, because both Reynold ( Rn ) and KC number affect them.;With the increase of KC number, the drag coefficient shows a decrease with exceptions occurring in low KC cases. In addition, it is shown that the chain segments near the fairlead and touch down area are most sensitive to the drag coefficient, which is consistent with the velocity distribution along the mooring line.;Finally, the validation is established by comparing the results of experimental tests and numerical simulations. Based on the assessment of drag coefficient from the scaled experimental investigation, numerical simulations of estimated drag coefficient are carried out within Orcaflex. A good agreement is achieved between the numerical calculations and experimental measurements, which illustrates that the present method can be applied for mooring line damping estimation. Meanwhile, the effects of the amplitude and frequency of the oscillation are studied.With increasing water depth of oil and gas exploration, greater importance has been attached to the damping force from mooring systems. The effect is significantly important to slow drift motion of the floating structure, and it is also coupled with its motions. Coupled analysis is thus preferred to be applied to estimate the floating structure motions and to calculate the mooring system response, especially for offshore structures in deep-water.;In this study, the aim is to achieve a better understanding of mooring line induced damping estimation. Drag forces normal to the mooring line due to the motion of the mooring line through the water, are the main source of hydrodynamic damping of the mooring line. A method of energy dissipation based on the mooring line dynamic response obtained by Orcaflex is developed. The validation is established through two types of mooring lines in shallow water and deep water.;The present approach shows a good agreement with the published results, but with two exceptions. One is for the mooring line oscillated by a very slow LF motion in shallow water, when the hydrodynamic damping is very small. Another one is for the wire mooring line oscillated by WF motion in deep water, the result shows significant discrepancy with that from the quasi-static method.;Then a non-dimensional analysis is completed, due to the strong complexity of the mooring line induced damping. The effects of the factors can be divided into three groups: first, the effects from pretension and scope are related to the geometry changes of the mooring line; second, the oscillation, current velocity and drag coefficient make contributions to the drag forces of mooring line directly; and the last, the effects of stiffness and seabed friction which, it was found, can be neglected.;In order to experimentally investigate the chain behaviour moving in water, a series model tests for the damping characteristics of a single chain line is implemented through oscillation tests of various parameters. The drag coefficient ( C D ) variations with different Reynold ( Rn ) and KC numbers are investigated. The drag coefficients in this study range from 1.5 to 4.0, which is case-dependent, because both Reynold ( Rn ) and KC number affect them.;With the increase of KC number, the drag coefficient shows a decrease with exceptions occurring in low KC cases. In addition, it is shown that the chain segments near the fairlead and touch down area are most sensitive to the drag coefficient, which is consistent with the velocity distribution along the mooring line.;Finally, the validation is established by comparing the results of experimental tests and numerical simulations. Based on the assessment of drag coefficient from the scaled experimental investigation, numerical simulations of estimated drag coefficient are carried out within Orcaflex. A good agreement is achieved between the numerical calculations and experimental measurements, which illustrates that the present method can be applied for mooring line damping estimation. Meanwhile, the effects of the amplitude and frequency of the oscillation are studied
Integrated bioprocessing for the sustainable manufacture of poly (methyl methacrylate) precursors
Get PDFThis thesis was previously held under moratorium from 23/08/2019 to 23/08/2024Industrial focus is shifting from the utilisation of petrochemicals and is moving towards the utilisation of biomass for the production of platform chemicals. The finite lifespan of petrochemicals, the dramatic fluctuation in the price of oil and environmental concerns are all significant drivers for this change. Polymers such as poly (methyl methacrylate), a mass market polymer, can be sustainably produced using platform chemicals derived from biomass. This study investigates the production of two platform chemicals, mesaconate and butyl-methacrylate, from biomass which would allow the sustainable production of poly (methyl methacrylate). Mesaconate was initially targeted with butyl methacrylate later identified as a potential target with envisaged reduced downstream processing required for integration onto poly (methyl methacrylate) production.
Initially a mesaconate production pathway was incorporated into Corynebacterium glutamicum selected due to the inherent ability of C. glutamicum to produce large quantities of glutamate. Mesaconate production was demonstrated through bioprocesses containing the constructed Escherichia coli strains with improvement in the analysis method providing accurate quantification. Adaption of the bioprocess in particular through alteration of the dissolved oxygen improved the mesaconate titre further.
Secondly a novel pathway for the production of a poly (methyl methacrylate) precursor butyl methacrylate was constructed within E. coli. Strains containing this pathway demonstrated production of butyl methacrylate within biotransformations. Adaptation of the biotransformation method and strain development produced an increase in the butyl methacrylate titre. Further engineering allowed the elimination of by-products from the bioprocess and improved the tolerance of the host to the toxicity of butyl methacrylate. Production of butyl methacrylate directly from glucose was attempted although this was not
successful.Industrial focus is shifting from the utilisation of petrochemicals and is moving towards the utilisation of biomass for the production of platform chemicals. The finite lifespan of petrochemicals, the dramatic fluctuation in the price of oil and environmental concerns are all significant drivers for this change. Polymers such as poly (methyl methacrylate), a mass market polymer, can be sustainably produced using platform chemicals derived from biomass. This study investigates the production of two platform chemicals, mesaconate and butyl-methacrylate, from biomass which would allow the sustainable production of poly (methyl methacrylate). Mesaconate was initially targeted with butyl methacrylate later identified as a potential target with envisaged reduced downstream processing required for integration onto poly (methyl methacrylate) production.
Initially a mesaconate production pathway was incorporated into Corynebacterium glutamicum selected due to the inherent ability of C. glutamicum to produce large quantities of glutamate. Mesaconate production was demonstrated through bioprocesses containing the constructed Escherichia coli strains with improvement in the analysis method providing accurate quantification. Adaption of the bioprocess in particular through alteration of the dissolved oxygen improved the mesaconate titre further.
Secondly a novel pathway for the production of a poly (methyl methacrylate) precursor butyl methacrylate was constructed within E. coli. Strains containing this pathway demonstrated production of butyl methacrylate within biotransformations. Adaptation of the biotransformation method and strain development produced an increase in the butyl methacrylate titre. Further engineering allowed the elimination of by-products from the bioprocess and improved the tolerance of the host to the toxicity of butyl methacrylate. Production of butyl methacrylate directly from glucose was attempted although this was not
successful
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