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Fundamentals of Macroeconomics EC948 Exam Papers
No full textAccess restricted to staff and registered students of the University of Strathclyde.PAST EXAM PAPERS ARE NO LONGER BEING ADDED TO STAX. PLEASE VISIT SUPRIMO TO ACCESS AN UP-TO-DATE COLLECTION OF PAST EXAM PAPERS: https://suprimo.lib.strath.ac.uk
Numerical modelling of blood fluid dynamics in patient-specific paediatric and adult aortae
No full textIn the human body, the aorta is the largest artery and is responsible for distributing oxygenated blood from the heart to the surrounding organs and tissues. However, the aorta is vulnerable to a number of disorders, many of which are life-threatening. The root cause of aortic disease is unknown, but we do know that some individuals are more prone than others. In some cases, individuals with a genetic abnormality are predisposed to an increased risk of aortic disease. This is true for females with Turner syndrome (TS), a rare genetic disorder, who have a higher prevalence of cardiovascular disease than the general population. While there are established clinical practice guidelines for cardiovascular risk assessment in TS, evaluation using the current guidelines have seen life-threatening aortic events occurring out with measurements classified within the normal threshold. This is largely due to a lack of clinical data and understanding of the developmental origins of the cardiovascular manifestations seen specifically in TS. Thoracic Endovascular Aortic Repair (TEVAR) is an established treatment for a range of aortic diseases, including aortic aneurysm and dissection, and is favored in acutely unstable patients or individuals with a high operative risk (inclusive of Turner syndrome). In this work, three-dimensional geometries of the diseased aorta from two patient groups were studied: the first being children with a genetic abnormality (Turner syndrome) and the second being adult patients without a genetic abnormality who underwent TEVAR for aortic aneurysm repair. Our aims were to: (1) characterise the aortic geometries and evaluate various morphological parameters, such as diameter, curvature, and torsion; (2) compute the flow field in these geometries using computational fluid dynamics (CFD); and (3) compare the morphological and haemodynamic results between TS children and their age-matched healthy counterparts, and Post- and Pre-TEVAR adults. CFD was chosen as it enables detailed, non-invasive characterisation of complex physiological pressure and flow fields, thus improving our understanding of haemodynamics in specific groups of patients. In recent years, CFD models have driven clinical decisionmaking, surgical planning, and the evaluation of innovative surgical techniques. In the child aorta, healthy-to-Turner syndrome differences were observed, with Turner syndrome children presenting a greater variance in aortic arch morphology than their healthy counterparts. The visualisation of multidirectional blood flow revealed an increase in vortical flow in the arch, supra-aortic vessels, and descending aorta, and a correlation between the presence of aortic abnormalities and disturbed flow. Additionally, markers of abnormal aortic morphology were significantly associated with markers of obesity, which is believed to accelerate the initiation and progression of endothelial dysfunction. Given the young age of our study group, these findings may be an indication of atherosclerotic disease manifesting earlier in life in these patients. Clinically, age, obesity and aortic morphology may, therefore, play a key role in assessing cardiovascular risk in TS children. In the adult aorta, pre- and post-TEVAR differences were observed, with significant remodeling of the aortic vessel wall post-TEVAR. The radius at the aneurysm site, aortic curvature, torsion, and the combined curvature-torsion score were all reduced in the postTEVAR geometries. A favourable return to more physiological flow structures and a decrease in overall aortic time-averaged wall shear stress was observed post-TEVAR. For these patients who underwent elective TEVAR for thoracic aortic aneurysm repair, the numerical simulations revealed a positive return to a more physiologically normal aorta within two years. Future work in this field would be to assess the aorta of Turner syndrome patients pre- and post-TEVAR and compare these results to those presented in this thesis.In the human body, the aorta is the largest artery and is responsible for distributing oxygenated blood from the heart to the surrounding organs and tissues. However, the aorta is vulnerable to a number of disorders, many of which are life-threatening. The root cause of aortic disease is unknown, but we do know that some individuals are more prone than others. In some cases, individuals with a genetic abnormality are predisposed to an increased risk of aortic disease. This is true for females with Turner syndrome (TS), a rare genetic disorder, who have a higher prevalence of cardiovascular disease than the general population. While there are established clinical practice guidelines for cardiovascular risk assessment in TS, evaluation using the current guidelines have seen life-threatening aortic events occurring out with measurements classified within the normal threshold. This is largely due to a lack of clinical data and understanding of the developmental origins of the cardiovascular manifestations seen specifically in TS. Thoracic Endovascular Aortic Repair (TEVAR) is an established treatment for a range of aortic diseases, including aortic aneurysm and dissection, and is favored in acutely unstable patients or individuals with a high operative risk (inclusive of Turner syndrome). In this work, three-dimensional geometries of the diseased aorta from two patient groups were studied: the first being children with a genetic abnormality (Turner syndrome) and the second being adult patients without a genetic abnormality who underwent TEVAR for aortic aneurysm repair. Our aims were to: (1) characterise the aortic geometries and evaluate various morphological parameters, such as diameter, curvature, and torsion; (2) compute the flow field in these geometries using computational fluid dynamics (CFD); and (3) compare the morphological and haemodynamic results between TS children and their age-matched healthy counterparts, and Post- and Pre-TEVAR adults. CFD was chosen as it enables detailed, non-invasive characterisation of complex physiological pressure and flow fields, thus improving our understanding of haemodynamics in specific groups of patients. In recent years, CFD models have driven clinical decisionmaking, surgical planning, and the evaluation of innovative surgical techniques. In the child aorta, healthy-to-Turner syndrome differences were observed, with Turner syndrome children presenting a greater variance in aortic arch morphology than their healthy counterparts. The visualisation of multidirectional blood flow revealed an increase in vortical flow in the arch, supra-aortic vessels, and descending aorta, and a correlation between the presence of aortic abnormalities and disturbed flow. Additionally, markers of abnormal aortic morphology were significantly associated with markers of obesity, which is believed to accelerate the initiation and progression of endothelial dysfunction. Given the young age of our study group, these findings may be an indication of atherosclerotic disease manifesting earlier in life in these patients. Clinically, age, obesity and aortic morphology may, therefore, play a key role in assessing cardiovascular risk in TS children. In the adult aorta, pre- and post-TEVAR differences were observed, with significant remodeling of the aortic vessel wall post-TEVAR. The radius at the aneurysm site, aortic curvature, torsion, and the combined curvature-torsion score were all reduced in the postTEVAR geometries. A favourable return to more physiological flow structures and a decrease in overall aortic time-averaged wall shear stress was observed post-TEVAR. For these patients who underwent elective TEVAR for thoracic aortic aneurysm repair, the numerical simulations revealed a positive return to a more physiologically normal aorta within two years. Future work in this field would be to assess the aorta of Turner syndrome patients pre- and post-TEVAR and compare these results to those presented in this thesis
Essays on family, education, and public health policies
Full text linkThis thesis consists of three self-contained essays in applied microeconomics. Chapter two investigates the effects of UK austerity measures on individuals and families using data from the UK Household Longitudinal Study. By applying difference-in-differences and event study models, I find that austerity significantly increased parental employment and reduced unemployment. However, we present suggestive evidence showing that mothers may have experienced a 20 percentage point drop in income, amounting to £182 per month, while fathers’ incomes were unaffected. These gendered income changes shaped relationship dynamics, with mothers showing a decline in divorce rates and an increase in new cohabitations, patterns not observed among fathers. Austerity also reduced parent-child interaction, as time was reallocated to meet rising labor demands. By examining the effects of benefit reduction policies, this paper adds to the literature by demonstrating their far-reaching implications for labor markets, family relationships, and inner household relationships. Chapter three examines the 2016 school reform policies implemented by the Oklahoma City School District, which sought to replace exclusionary discipline practices with more inclusive approaches. Using a Synthetic Difference-in-Differences model, I analyse school administrative records alongside FBI crime data. The reforms resulted in a 50 percent drop in school suspensions, improvements in math and science scores, mixed effects on reading performance, and a 22.8 percent reduction in youth arrests. These findings highlight the trade-offs between academic outcomes and broader youth impacts, showing how inclusive policies can shape both classroom and community dynamics. This study contributes to the literature by providing evidence on the short term effects of discipline reforms on student achievement and juvenile justice outcomes. Chapter four estimates the impact of supervised consumption sites (SCS) on opioid related emergency callouts, crime, and mental health incidents, using neighborhood-level data from the Toronto Police. By a difference-in-differences approach, I analyse the staggered implementation of 10 Health Canada-approved SCS in Toronto between 2017 and 2021. The results show no significant changes in overdose callouts, assault rates, or mental health apprehensions, though a rise in break-ins near SCS locations is observed. These findings suggest that SCS do not substantially reduce emergency service demands or mental health issues but may bring localised property crime concerns. This study contributes to understanding the trade-offs of SCS and emphasizes the importance of embedding them in broader public health strategies that address community-level impacts.This thesis consists of three self-contained essays in applied microeconomics. Chapter two investigates the effects of UK austerity measures on individuals and families using data from the UK Household Longitudinal Study. By applying difference-in-differences and event study models, I find that austerity significantly increased parental employment and reduced unemployment. However, we present suggestive evidence showing that mothers may have experienced a 20 percentage point drop in income, amounting to £182 per month, while fathers’ incomes were unaffected. These gendered income changes shaped relationship dynamics, with mothers showing a decline in divorce rates and an increase in new cohabitations, patterns not observed among fathers. Austerity also reduced parent-child interaction, as time was reallocated to meet rising labor demands. By examining the effects of benefit reduction policies, this paper adds to the literature by demonstrating their far-reaching implications for labor markets, family relationships, and inner household relationships. Chapter three examines the 2016 school reform policies implemented by the Oklahoma City School District, which sought to replace exclusionary discipline practices with more inclusive approaches. Using a Synthetic Difference-in-Differences model, I analyse school administrative records alongside FBI crime data. The reforms resulted in a 50 percent drop in school suspensions, improvements in math and science scores, mixed effects on reading performance, and a 22.8 percent reduction in youth arrests. These findings highlight the trade-offs between academic outcomes and broader youth impacts, showing how inclusive policies can shape both classroom and community dynamics. This study contributes to the literature by providing evidence on the short term effects of discipline reforms on student achievement and juvenile justice outcomes. Chapter four estimates the impact of supervised consumption sites (SCS) on opioid related emergency callouts, crime, and mental health incidents, using neighborhood-level data from the Toronto Police. By a difference-in-differences approach, I analyse the staggered implementation of 10 Health Canada-approved SCS in Toronto between 2017 and 2021. The results show no significant changes in overdose callouts, assault rates, or mental health apprehensions, though a rise in break-ins near SCS locations is observed. These findings suggest that SCS do not substantially reduce emergency service demands or mental health issues but may bring localised property crime concerns. This study contributes to understanding the trade-offs of SCS and emphasizes the importance of embedding them in broader public health strategies that address community-level impacts
The effect of internal market orientation and family-work balance actions on salespeople’s perception of family-work balance and their performance
Full text linkThe thesis explores the impact of investing resources in creating a family–work balanced (FWB) working environment and adopting internal market orientation (IMO) on the wellbeing of employees and the organization. The aim is twofold: to understand what drives employees’ perception of FWB within the organization and to explore the impact of employees’ perceived FWB on their job satisfaction and performance. The objectives of this study include an examination how employees’ workplace expectations, individual differences, and competencies affect their perception of FWB and its impact on their performance and exploring how the adoption of IMO and FWB policies jointly influence employees’ perception of balance between work and family/personal life. The research involved the sales departments of 166 commercial companies in Greece and considered two levels: the managerial (corporate) level and the employee level. This thesis makes several contributions to literature. It presents a new perspective by jointly examining FWB and IMO, which have previously been researched separately. It also makes a methodological contribution by integrating multiple levels of analysis in IMO and FWB research using structural equation modelling for multilevel analysis. Additionally, it offers practical proposals for effectively managing IMO adoption and FWB actions. Overall, this thesis bridges the two highly related research streams of IMO and FWB and attempts to answer some of the questions the extant literature has not addressed.The thesis explores the impact of investing resources in creating a family–work balanced (FWB) working environment and adopting internal market orientation (IMO) on the wellbeing of employees and the organization. The aim is twofold: to understand what drives employees’ perception of FWB within the organization and to explore the impact of employees’ perceived FWB on their job satisfaction and performance. The objectives of this study include an examination how employees’ workplace expectations, individual differences, and competencies affect their perception of FWB and its impact on their performance and exploring how the adoption of IMO and FWB policies jointly influence employees’ perception of balance between work and family/personal life. The research involved the sales departments of 166 commercial companies in Greece and considered two levels: the managerial (corporate) level and the employee level. This thesis makes several contributions to literature. It presents a new perspective by jointly examining FWB and IMO, which have previously been researched separately. It also makes a methodological contribution by integrating multiple levels of analysis in IMO and FWB research using structural equation modelling for multilevel analysis. Additionally, it offers practical proposals for effectively managing IMO adoption and FWB actions. Overall, this thesis bridges the two highly related research streams of IMO and FWB and attempts to answer some of the questions the extant literature has not addressed
Understanding the components of consumer assemblages, within the context of food-insecurity in Royston, Glasgow
Full text linkThis thesis examines food-insecurity within an urban demographic of Glasgow,
which is recognised within public, private, and government sectors, as a substantial
societal concern. The overall aim of this research is to provide a thorough
understanding of food-insecurity, by exploring the lived experience of those involved
within the receipt and delivery of supplementary food provision. With consumer
research as its core, this study considers literature from the aspect of consumption,
vulnerability, poverty, food-insecurity, and assemblages. The contextual underpinning contained within this ethnographic work, is the urban demographic of Royston, Glasgow, which despite aspects of community regeneration and transformation, has remained within the most deprived areas across Scotland. The thesis considers three key research objectives within the investigation: to understand heterogenous cultural phenomena, to investigate relations between those phenomena, and to identify what relations impact upon the stability of the food insecurity landscape. The findings contribute to consumer research assemblages by making three contributions to knowledge: firstly, it highlights distinct conditions that impede access to supplementary food provision through the role of boundary making and levels of vulnerability. Secondly, it provides empirical evidence of how people experience socio-spatial disadvantage, which increases aspects of vulnerability. Thirdly, through examining the food-insecurity landscape, this work identifies socially created marketplace tensions which occur between people and resources. The work concludes by emphasising the importance for subsequent marketing research, to duly explore, innovate, and respond to entangled social issues.This thesis examines food-insecurity within an urban demographic of Glasgow,
which is recognised within public, private, and government sectors, as a substantial
societal concern. The overall aim of this research is to provide a thorough
understanding of food-insecurity, by exploring the lived experience of those involved
within the receipt and delivery of supplementary food provision. With consumer
research as its core, this study considers literature from the aspect of consumption,
vulnerability, poverty, food-insecurity, and assemblages. The contextual underpinning contained within this ethnographic work, is the urban demographic of Royston, Glasgow, which despite aspects of community regeneration and transformation, has remained within the most deprived areas across Scotland. The thesis considers three key research objectives within the investigation: to understand heterogenous cultural phenomena, to investigate relations between those phenomena, and to identify what relations impact upon the stability of the food insecurity landscape. The findings contribute to consumer research assemblages by making three contributions to knowledge: firstly, it highlights distinct conditions that impede access to supplementary food provision through the role of boundary making and levels of vulnerability. Secondly, it provides empirical evidence of how people experience socio-spatial disadvantage, which increases aspects of vulnerability. Thirdly, through examining the food-insecurity landscape, this work identifies socially created marketplace tensions which occur between people and resources. The work concludes by emphasising the importance for subsequent marketing research, to duly explore, innovate, and respond to entangled social issues
Innovative 8D problem-solving framework to reduce lifecycle management and warranty costs in the maritime sector
Full text linkRemanufacturing is the process of returning used products (or core) to a condition like that of
a new product with a matching warranty. Remanufacturing is the most effective process among
other recovery options because it can bring cost-effective benefitsfor companies with a positive
impact environment. Decision-making in the remanufacturing industry is more complicated
than in conventional manufacturing due to uncertainties in design cost estimation, product
quality issues, and the return time of used components. Estimating cost has become a
significant business driver in many industries. It is the key to the success of all strategic
decisions that allow a company to remain competitive globally. However, there needs to be
more research on cost estimations and quality issues of multiple radar system product
remanufacturing tasks, which are under-studied factors. A cost estimation decision made at one
remanufacturing activity would significantly impact the decisions made in subsequent
activities, which will affect remanufacturing outcomes.
Customer satisfaction is critical for the success of any organisation. This research aims to
identify the root cause of the issue and implement a solution to prevent its recurrence using the
Lean Eight Disciplines methodology. This includes (1) a 5 Whys analysis by a cross-functional
team, (2) confirmation of the problem description, (3) containment actions, (4) root cause
analysis of the occurrence, (5) permanent corrective actions, (6) implementation of the
permanent corrective action, (7) actions to prevent a recurrence, and (8) closure with an 8D
report and congratulations to the cross-functional team template for the design, engineering,
and supplier production sites. Therefore, this study developed a systematic and holistic way of
producing radar system design costing strategies for maritime products with improved quality
for remanufacturing value-added benefits for the organisation and a longer life cycle of
remanufactured units.
This research studied radar systems remanufacturing suppliers’ cost estimation issues using the
costing requirement questionnaire and benchmarking analysis of manufacturing processes to
develop a parametric cost trade-off tool for the remanufacturing activities. The research used
case studies to present the development and implementation of the Eight Disciplines (8D)
investigation tool for addressing product design and development issues for remanufacturing.
The novelty in case studies is the development of an 8D analytics template for product
managers and practitioners in the remanufacturing and production companies to improve the
quality and reliability of the radar systems. This study used mathematical costing modelling to
enhance the ability to research various cost estimation models. This leads to higher quality cost
estimation using a comparison between an analogy, parametric, and detailed cost drivers of the
radar systems, which is the research output. This thesis introduces the 8D Template, a tailored
8D problem-solving framework integrated with 5 Whys specifically for maritime radar
systems. By applying this framework across four case studies, the research achieved a
substantial £603,198 reduction in warranty costs. Additionally, analysing radar design
configurations and life cycle costs led to a high-level breakdown structure, revealing cost tradeoffs and enabling an estimated 15% reduction in Non-Recurring Costs (NRC) and 12% in Unit
Through-life Costs (UTC). Establishing a design costing knowledge hub facilitated accurate
cost estimates through identified parametric equations, while targeted design improvements on
high-failure components further reinforced cost and quality efficiencies.
The remanufacturing of radar systems for the maritime sector has garnered increasing interest
in recent years due to the need to address the end-of-life stages for high-value products. This
study reviewed design costing frameworks, cost trade-off techniques, and cost estimation
methods which can be used in the maritime sector to develop cost estimation tools for radar
systems. This study used benchmarking analysis of maritime best practices to identify how product life cycle costing solutions can be used to reduce design, operational, remanufacturing,
and production costs to improve profit, minimise downtime of radar systems and maximise the
reliability of the radar system components. This research finding will help remanufacturers in
the maritime sector to find new growth and business opportunities by increasing the cost and
improving quality using templates to resolve design or product issues, such as gearbox triple
seal, pulley and improved photodiode for remanufacturing units.Remanufacturing is the process of returning used products (or core) to a condition like that of
a new product with a matching warranty. Remanufacturing is the most effective process among
other recovery options because it can bring cost-effective benefitsfor companies with a positive
impact environment. Decision-making in the remanufacturing industry is more complicated
than in conventional manufacturing due to uncertainties in design cost estimation, product
quality issues, and the return time of used components. Estimating cost has become a
significant business driver in many industries. It is the key to the success of all strategic
decisions that allow a company to remain competitive globally. However, there needs to be
more research on cost estimations and quality issues of multiple radar system product
remanufacturing tasks, which are under-studied factors. A cost estimation decision made at one
remanufacturing activity would significantly impact the decisions made in subsequent
activities, which will affect remanufacturing outcomes.
Customer satisfaction is critical for the success of any organisation. This research aims to
identify the root cause of the issue and implement a solution to prevent its recurrence using the
Lean Eight Disciplines methodology. This includes (1) a 5 Whys analysis by a cross-functional
team, (2) confirmation of the problem description, (3) containment actions, (4) root cause
analysis of the occurrence, (5) permanent corrective actions, (6) implementation of the
permanent corrective action, (7) actions to prevent a recurrence, and (8) closure with an 8D
report and congratulations to the cross-functional team template for the design, engineering,
and supplier production sites. Therefore, this study developed a systematic and holistic way of
producing radar system design costing strategies for maritime products with improved quality
for remanufacturing value-added benefits for the organisation and a longer life cycle of
remanufactured units.
This research studied radar systems remanufacturing suppliers’ cost estimation issues using the
costing requirement questionnaire and benchmarking analysis of manufacturing processes to
develop a parametric cost trade-off tool for the remanufacturing activities. The research used
case studies to present the development and implementation of the Eight Disciplines (8D)
investigation tool for addressing product design and development issues for remanufacturing.
The novelty in case studies is the development of an 8D analytics template for product
managers and practitioners in the remanufacturing and production companies to improve the
quality and reliability of the radar systems. This study used mathematical costing modelling to
enhance the ability to research various cost estimation models. This leads to higher quality cost
estimation using a comparison between an analogy, parametric, and detailed cost drivers of the
radar systems, which is the research output. This thesis introduces the 8D Template, a tailored
8D problem-solving framework integrated with 5 Whys specifically for maritime radar
systems. By applying this framework across four case studies, the research achieved a
substantial £603,198 reduction in warranty costs. Additionally, analysing radar design
configurations and life cycle costs led to a high-level breakdown structure, revealing cost tradeoffs and enabling an estimated 15% reduction in Non-Recurring Costs (NRC) and 12% in Unit
Through-life Costs (UTC). Establishing a design costing knowledge hub facilitated accurate
cost estimates through identified parametric equations, while targeted design improvements on
high-failure components further reinforced cost and quality efficiencies.
The remanufacturing of radar systems for the maritime sector has garnered increasing interest
in recent years due to the need to address the end-of-life stages for high-value products. This
study reviewed design costing frameworks, cost trade-off techniques, and cost estimation
methods which can be used in the maritime sector to develop cost estimation tools for radar
systems. This study used benchmarking analysis of maritime best practices to identify how product life cycle costing solutions can be used to reduce design, operational, remanufacturing,
and production costs to improve profit, minimise downtime of radar systems and maximise the
reliability of the radar system components. This research finding will help remanufacturers in
the maritime sector to find new growth and business opportunities by increasing the cost and
improving quality using templates to resolve design or product issues, such as gearbox triple
seal, pulley and improved photodiode for remanufacturing units
Optimisation and measurement of bremsstrahlung and synchrotron radiation in ultra-intense laser-solid interactions
Full text linkThis thesis reports on experimental and numerical investigations to optimise and measure bremsstrahlung and synchrotron x-ray production in ultra-intense lasersolid interactions. The aim of the work is to better understand the processes behind the generation of synchrotron and bremsstrahlung x-rays within laser-solid interactions and to be able to resolve and differentiate between x-ray distributions from such interactions. This study also significantly advances understanding of a key diagnostic for measuring x-ray emission in these interactions. First, a numerical investigation of the influence of laser focal spot size, focusing geometry, and pulse energy on bremsstrahlung and synchrotron x-ray production is presented. PIC simulations indicate that bremsstrahlung emission is highly dependent on pulse energy, whereas synchrotron production is highly spot-size and intensity dependent. An increase in synchrotron photon numbers with small spot size is attributed to greater holeboring for higher laser intensities, as there is a larger volume within which electrons can interact directly with the laser fields Building on this, an experimental investigation of the influence of laser focal spot size, focusing geometry, and pulse energy on electron and bremsstrahlung x-ray production is reported. While the data do not strongly indicate a focusing geometry effect, electron and bremsstrahlung production is found to be highly dependent on pulse energy. This is consistent with the previous numerical results. Finally, the focus moves to the development of x-ray diagnostics which would enable improved measurements of the x-ray spectrum. Measurements of bremsstrahlung x-rays for laser intensities up to 3 × 1021 Wcm−2 were analysed. Such laser intensities were achieved through the use of F/1 focusing plasma optics which enabled higher intensities to be reached than otherwise achievable with the Vulcan laser. Through analysis of these measurements and extensive PIC and Monte Carlo modelling, an existing absorption-based x-ray spectrometer is characterised. It is found that there is a high degree of uncertainty in spectral deconvolution with the current spectrometer design, and several improvements are designed and numerically tested. Additionally, through analysis of the total x-ray spectrometer signal and analytical modelling, with comparison to Cu Kα x-ray measurements, our results suggest the presence of lower fast electron temperatures than many published electron temperature scalings predict. This highlights a critical challenge: the combined effects of low-resolution detector design and unexpected physical behavior complicates x-ray measurements in the high-energy part of the spectrum. Consequently, this thesis work underscores the need for more focused efforts on improving signal-to-noise ratios in this region, for example, through dual-spectrometer designs, to better measure high-energy x-rays.This thesis reports on experimental and numerical investigations to optimise and measure bremsstrahlung and synchrotron x-ray production in ultra-intense lasersolid interactions. The aim of the work is to better understand the processes behind the generation of synchrotron and bremsstrahlung x-rays within laser-solid interactions and to be able to resolve and differentiate between x-ray distributions from such interactions. This study also significantly advances understanding of a key diagnostic for measuring x-ray emission in these interactions. First, a numerical investigation of the influence of laser focal spot size, focusing geometry, and pulse energy on bremsstrahlung and synchrotron x-ray production is presented. PIC simulations indicate that bremsstrahlung emission is highly dependent on pulse energy, whereas synchrotron production is highly spot-size and intensity dependent. An increase in synchrotron photon numbers with small spot size is attributed to greater holeboring for higher laser intensities, as there is a larger volume within which electrons can interact directly with the laser fields Building on this, an experimental investigation of the influence of laser focal spot size, focusing geometry, and pulse energy on electron and bremsstrahlung x-ray production is reported. While the data do not strongly indicate a focusing geometry effect, electron and bremsstrahlung production is found to be highly dependent on pulse energy. This is consistent with the previous numerical results. Finally, the focus moves to the development of x-ray diagnostics which would enable improved measurements of the x-ray spectrum. Measurements of bremsstrahlung x-rays for laser intensities up to 3 × 1021 Wcm−2 were analysed. Such laser intensities were achieved through the use of F/1 focusing plasma optics which enabled higher intensities to be reached than otherwise achievable with the Vulcan laser. Through analysis of these measurements and extensive PIC and Monte Carlo modelling, an existing absorption-based x-ray spectrometer is characterised. It is found that there is a high degree of uncertainty in spectral deconvolution with the current spectrometer design, and several improvements are designed and numerically tested. Additionally, through analysis of the total x-ray spectrometer signal and analytical modelling, with comparison to Cu Kα x-ray measurements, our results suggest the presence of lower fast electron temperatures than many published electron temperature scalings predict. This highlights a critical challenge: the combined effects of low-resolution detector design and unexpected physical behavior complicates x-ray measurements in the high-energy part of the spectrum. Consequently, this thesis work underscores the need for more focused efforts on improving signal-to-noise ratios in this region, for example, through dual-spectrometer designs, to better measure high-energy x-rays
The industrial microbiome as a resource for biotechnology : identification and isolation of butyl methacrylate tolerant pseudomonas species for enhanced sustainable bio-production of methacrylate esters
No full textThe increased demand for sustainable acrylic plastic has led to interest in developing a fermentation process to produce the monomers used to make this versatile compound. This would provide an alternative to the current finite and environmentally damaging petrochemical processes. Butyl Methacrylate (BMA) is an appealing precursor to these monomers. The current bottleneck for the fermentation of BMA is toxicity; its hydrophobic properties, which make it ideal for extraction from a bioreactor, are toxic to microorganisms interfering with cell membranes. Pseudomonas species, known for thriving in industrially contaminated sites, provide a potential solution to this bottleneck. By targeting industrial environments heavily contaminated with hydrophobic solvents, we isolated Pseudomonas species with tolerance to BMA. The most tolerant isolate, P. putida, held a plasmid, which significantly contributed to conferring tolerance to BMA. The primary tolerance mechanism was an RND(resistance-nodulation-division) eQlux pump, which when transferred to P. putida KT2440, significantly increased its tolerance to BMA. Features of this RND eQlux pump were used to identify other eQlux pumps which may also confer tolerance to hydrophobic compounds. To oQer additional tolerance and intracellular protection from BMA, we also used unsupervised machine learning to sort compounds produced by biosynthetic gene clusters (BGC) and BMA. The natural compound FR900098 an antimalarial candidate with a similar electrostatic profile to BMA was identified, and the corresponding resistance gene frbF associated with the BGC was cloned into a high-copy plasmid with a constitutive promotor. When transformed into P. putida KT2440, this resulted in a significant increase in BMA tolerance. In summary, the newly isolated P. putida strain (RCS09A) may be advantaged as an BMA production strain, due to its intrinsic tolerance to this hydrophobic molecule and a candidate for engineering for production. Alternatively, the identified RND eQlux pump and the resistance protein may be used to ‘upgrade’ the tolerance of other potential BMA production strains. Improved BMA tolerance could lead to increased product titres and lower the costs of the sustainable fermentation process.The increased demand for sustainable acrylic plastic has led to interest in developing a fermentation process to produce the monomers used to make this versatile compound. This would provide an alternative to the current finite and environmentally damaging petrochemical processes. Butyl Methacrylate (BMA) is an appealing precursor to these monomers. The current bottleneck for the fermentation of BMA is toxicity; its hydrophobic properties, which make it ideal for extraction from a bioreactor, are toxic to microorganisms interfering with cell membranes. Pseudomonas species, known for thriving in industrially contaminated sites, provide a potential solution to this bottleneck. By targeting industrial environments heavily contaminated with hydrophobic solvents, we isolated Pseudomonas species with tolerance to BMA. The most tolerant isolate, P. putida, held a plasmid, which significantly contributed to conferring tolerance to BMA. The primary tolerance mechanism was an RND(resistance-nodulation-division) eQlux pump, which when transferred to P. putida KT2440, significantly increased its tolerance to BMA. Features of this RND eQlux pump were used to identify other eQlux pumps which may also confer tolerance to hydrophobic compounds. To oQer additional tolerance and intracellular protection from BMA, we also used unsupervised machine learning to sort compounds produced by biosynthetic gene clusters (BGC) and BMA. The natural compound FR900098 an antimalarial candidate with a similar electrostatic profile to BMA was identified, and the corresponding resistance gene frbF associated with the BGC was cloned into a high-copy plasmid with a constitutive promotor. When transformed into P. putida KT2440, this resulted in a significant increase in BMA tolerance. In summary, the newly isolated P. putida strain (RCS09A) may be advantaged as an BMA production strain, due to its intrinsic tolerance to this hydrophobic molecule and a candidate for engineering for production. Alternatively, the identified RND eQlux pump and the resistance protein may be used to ‘upgrade’ the tolerance of other potential BMA production strains. Improved BMA tolerance could lead to increased product titres and lower the costs of the sustainable fermentation process
A text mining approach to performance enhancement in BIM pervasive major project delivery
Full text linkPurpose: This research aims to rigorously develop and implement a specialized TM technique to significantly enhance performance in BIM pervasive major project delivery. By addressing challenges related to errors, uncertainties, and expectations within this context, the study endeavours to offer substantial contributions to construction management knowledge. The research introduces the “BIM Text Analysis and Performance Enhancement” (BIMTAPE) framework, which synergizes the TM methodology with BIM to optimize project execution within the BIM pervasive major project delivery. Methodology: A holistic systematic literature review enabled by the Nine-Square Process (NSP) was conducted, entailing a thorough search of relevant literature from academic databases and other relevant sources, identifying current knowledge and the research gap on delivery. Additionally, the research process adhered to a sequenced approach, where the development of the BIMTAPE Framework took precedence before conducting specific experimental case studies. This structured framework provided a systematic and comprehensive approach to analyse diverse BIM-related texts. Findings: This research validates experimental findings and provides insights into the relationship between text analysis and performance enhancement in major project delivery, using Social Network Analysis. The study comprehensively understands the role of text analysis in major project performance, emphasizing BIM alignment with industry standards for value realization in contracts. Notably, the BIMTAPE Framework’s potential impact in addressing challenges, exemplified by the High Speed Two (HS2) project’s initiatives, enhances major project execution within the BIM pervasive major project delivery. Implications: The integration of BIM technology with TM within the BIMTAPE Framework excludes structured data standards like Industry Foundation Classes (IFC) and building SMART Data Dictionary (bSDD). In academic settings, the framework introduces a new approach for investigating unstructured textual data in BIM, encouraging further exploration. Limitations: This research’s applicability is constrained by the limited sample size. Expanding the scope to encompass larger studies will be crucial for generalisability. Further exploration across various contexts will provide a more comprehensive understanding of the framework’s implications.Purpose: This research aims to rigorously develop and implement a specialized TM technique to significantly enhance performance in BIM pervasive major project delivery. By addressing challenges related to errors, uncertainties, and expectations within this context, the study endeavours to offer substantial contributions to construction management knowledge. The research introduces the “BIM Text Analysis and Performance Enhancement” (BIMTAPE) framework, which synergizes the TM methodology with BIM to optimize project execution within the BIM pervasive major project delivery. Methodology: A holistic systematic literature review enabled by the Nine-Square Process (NSP) was conducted, entailing a thorough search of relevant literature from academic databases and other relevant sources, identifying current knowledge and the research gap on delivery. Additionally, the research process adhered to a sequenced approach, where the development of the BIMTAPE Framework took precedence before conducting specific experimental case studies. This structured framework provided a systematic and comprehensive approach to analyse diverse BIM-related texts. Findings: This research validates experimental findings and provides insights into the relationship between text analysis and performance enhancement in major project delivery, using Social Network Analysis. The study comprehensively understands the role of text analysis in major project performance, emphasizing BIM alignment with industry standards for value realization in contracts. Notably, the BIMTAPE Framework’s potential impact in addressing challenges, exemplified by the High Speed Two (HS2) project’s initiatives, enhances major project execution within the BIM pervasive major project delivery. Implications: The integration of BIM technology with TM within the BIMTAPE Framework excludes structured data standards like Industry Foundation Classes (IFC) and building SMART Data Dictionary (bSDD). In academic settings, the framework introduces a new approach for investigating unstructured textual data in BIM, encouraging further exploration. Limitations: This research’s applicability is constrained by the limited sample size. Expanding the scope to encompass larger studies will be crucial for generalisability. Further exploration across various contexts will provide a more comprehensive understanding of the framework’s implications
Cost-effective energy transfer for offshore wind
Full text linkOffshore wind and green hydrogen have the potential to help address the energy trilemma
of sustainability, security, and affordability. However, their high cost remains one of the
main barriers to their rapid development. Using DC collection systems in offshore
wind farms has the potential to make the transfer of electrical energy to shore more
cost-effective by reducing the size of offshore platforms or by removing them entirely.
Similarly, co-locating electrolysers and wind turbines without a grid connection can
make the transfer of chemical energy more cost-effective by removing the need for the
offshore platform, export cables, and collector cables.
The first part of this thesis identifies the most promising DC wind farm configurations
and carries out a cost-benefit analysis. The results show that all-DC wind farms can
lower the levelised cost of electricity, depending on factors such as the DC/DC converter
costs, platform costs, and collector voltage. A multi-objective optimisation is then
carried out for four promising DC/DC converter topologies, and their performance is
compared in terms of reliability, volume, weight, and losses. The optimal operating
frequency for each of the selected topologies is also determined. The results show that
the single-phase single active bridge operating at 2.5 kHz or the three-phase dual active
bridge operating at 1 kHz are optimal.
The second part of the thesis investigates the technical challenges associated with a standalone wind turbine and electrolyser system. A complete control system is developed to
allow off-grid operation, and three strategies are proposed to balance the power between
the wind turbine and electrolyser. The levelised cost of hydrogen is then investigated
for each power balancing strategy, as well as for three alternative DC-based drivetrains
to improve the system efficiency. The results show that using supercapacitor energy
storage and the standard AC-based drivetrain is the most realistic and cost-effective
option.Offshore wind and green hydrogen have the potential to help address the energy trilemma
of sustainability, security, and affordability. However, their high cost remains one of the
main barriers to their rapid development. Using DC collection systems in offshore
wind farms has the potential to make the transfer of electrical energy to shore more
cost-effective by reducing the size of offshore platforms or by removing them entirely.
Similarly, co-locating electrolysers and wind turbines without a grid connection can
make the transfer of chemical energy more cost-effective by removing the need for the
offshore platform, export cables, and collector cables.
The first part of this thesis identifies the most promising DC wind farm configurations
and carries out a cost-benefit analysis. The results show that all-DC wind farms can
lower the levelised cost of electricity, depending on factors such as the DC/DC converter
costs, platform costs, and collector voltage. A multi-objective optimisation is then
carried out for four promising DC/DC converter topologies, and their performance is
compared in terms of reliability, volume, weight, and losses. The optimal operating
frequency for each of the selected topologies is also determined. The results show that
the single-phase single active bridge operating at 2.5 kHz or the three-phase dual active
bridge operating at 1 kHz are optimal.
The second part of the thesis investigates the technical challenges associated with a standalone wind turbine and electrolyser system. A complete control system is developed to
allow off-grid operation, and three strategies are proposed to balance the power between
the wind turbine and electrolyser. The levelised cost of hydrogen is then investigated
for each power balancing strategy, as well as for three alternative DC-based drivetrains
to improve the system efficiency. The results show that using supercapacitor energy
storage and the standard AC-based drivetrain is the most realistic and cost-effective
option
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