Work, Health, and Wellbeing WE908 Exam papers

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Internal load modelling of tapered-roller main bearings in wind turbines

The replacement of double-row spherical roller bearings with double-row tapered roller bearings as the main shaft support in wind turbines has been proposed as one of the solutions to the premature failures affecting the industry. In order to improve our scientific knowledge of tapered roller bearing loading in wind turbine main shafts, this thesis sets out to explore how these components may be modelled, how such models can be utilised to improve the understanding of their operational characteristics in relation to the inflow wind, and to compare their behaviour with that of spherical roller bearings. Novel drivetrain models with tapered roller main bearings are developed in this thesis with capabilities of evaluating internal component loading while accounting for variations in system sti↵ness at different operating points. The findings demonstrate that modelling the moment reaction behaviour of tapered-roller bearings is crucial for even simplistic representations, since moment loads at the wind turbine hub are key drivers of bearing displacement. The models developed here are used in an extensive analysis to determine characteristics and sensitivities regarding operational conditions experienced by double-row tapered roller bearings under realistic turbulent inflow conditions, while properly accounting for the system load-response behaviour, roller load distributions and impacts on bearing fatigue life ratings. The presence of “looped” loading structures and evidence of consistent roller edge-loading throughout normal operation is demonstrated, and load response was also found to be largely shared between the two roller rows, this contrasts strongly with the conditions known to hold for spherical-roller main bearings. High levels of fatigue life sensitivity to both operational and lubrication conditions are documented, and shear effects in the wind were found to have opposite effects depending on the bearing type in use, with increased shear exponents drastically reducing the fatigue life rating of the tapered roller bearing. Crucially, this work demonstrates the uniqueness of load conditions experienced by tapered roller bearings in wind turbines, indicating that experience developed in more conventional rolling bearing applications should not be reapplied blindly without first determining its validity in this application space.The replacement of double-row spherical roller bearings with double-row tapered roller bearings as the main shaft support in wind turbines has been proposed as one of the solutions to the premature failures affecting the industry. In order to improve our scientific knowledge of tapered roller bearing loading in wind turbine main shafts, this thesis sets out to explore how these components may be modelled, how such models can be utilised to improve the understanding of their operational characteristics in relation to the inflow wind, and to compare their behaviour with that of spherical roller bearings. Novel drivetrain models with tapered roller main bearings are developed in this thesis with capabilities of evaluating internal component loading while accounting for variations in system sti↵ness at different operating points. The findings demonstrate that modelling the moment reaction behaviour of tapered-roller bearings is crucial for even simplistic representations, since moment loads at the wind turbine hub are key drivers of bearing displacement. The models developed here are used in an extensive analysis to determine characteristics and sensitivities regarding operational conditions experienced by double-row tapered roller bearings under realistic turbulent inflow conditions, while properly accounting for the system load-response behaviour, roller load distributions and impacts on bearing fatigue life ratings. The presence of “looped” loading structures and evidence of consistent roller edge-loading throughout normal operation is demonstrated, and load response was also found to be largely shared between the two roller rows, this contrasts strongly with the conditions known to hold for spherical-roller main bearings. High levels of fatigue life sensitivity to both operational and lubrication conditions are documented, and shear effects in the wind were found to have opposite effects depending on the bearing type in use, with increased shear exponents drastically reducing the fatigue life rating of the tapered roller bearing. Crucially, this work demonstrates the uniqueness of load conditions experienced by tapered roller bearings in wind turbines, indicating that experience developed in more conventional rolling bearing applications should not be reapplied blindly without first determining its validity in this application space

People, Technology and Work WE907 Exam papers

Access available to staff and registered students of the University of Strathclyde only

Application of pharmacoepidemiological approaches to generate real-world evidence on the use and impact of metastatic colorectal cancer medicines

Introduction: Metastatic colorectal cancer (mCRC) is characterised by multiple treatment strategies. Randomised clinical trials are not always aligned with clinical practice, and greater use of real-world (RW) studies has been suggested to inform health care decisions by providing results that reflect RW practice. Methods: This thesis utilised multiple methods. First, a systematic review and meta-analyses (SRMA) of RW studies including mCRC patients treated with first-line (1L) systemic anti-cancer therapy (SACT) was conducted to explore the comparative safety and effectiveness, including overall survival (OS), progression free survival (PFS) and objective response of 1L mCRC SACTs. Second, a retrospective observational cohort study using linkage of routinely collected data of mCRC patients treated with 1L SACT in NHS GGC from 01/01/2015 to 31/12/2016 was performed to investigate the factors influencing selection of 1L mCRC SACTs, treatment pathways, and treatment outcomes including median OS (mOS) and time-to-next-treatment (TTNT) of mCRC patients. Results: Between 2015 and 2016, A total of 220 new mCRC SACT users were identified in NHS GGC, with 52.3% (N=115) of the patients treated with a doublet of FOLFOX or FOLFIRI, 22.3% (N=49) with 5FU, 19.5% (N=43) with cetuximab+FOLFIRI, and 5% (N=11) of patients treated initially with aflibercept+FOLFIRI. Treatment choices for 1L mCRC were made based on patients’ age and gender, tumour RAS status, and previous treatment response. The median overall survival (mOS) for these patients was statistically influenced by the initial mCRC SACT and the performance status. The combination of cetuximab+FOLFIRI demonstrated a statistically significant prolonged mOS compared to 5FU (HR 0.4 (95% CI 0.24-0.85) and the longest time to next treatment (TTNT (12.93 months (95%CI 5.85-15.25)). The SRMA also indicated an OS, PFS, and overall response rate benefit for bevacizumab+chemotherapy over chemotherapy alone with a statistically increased risk of non-haematological toxicities and a non-statistically significant increased risk for haematological toxicity. Conclusions: Real-world evidence can help understand the impact of mCRC SACT on evidence-based practice.Introduction: Metastatic colorectal cancer (mCRC) is characterised by multiple treatment strategies. Randomised clinical trials are not always aligned with clinical practice, and greater use of real-world (RW) studies has been suggested to inform health care decisions by providing results that reflect RW practice. Methods: This thesis utilised multiple methods. First, a systematic review and meta-analyses (SRMA) of RW studies including mCRC patients treated with first-line (1L) systemic anti-cancer therapy (SACT) was conducted to explore the comparative safety and effectiveness, including overall survival (OS), progression free survival (PFS) and objective response of 1L mCRC SACTs. Second, a retrospective observational cohort study using linkage of routinely collected data of mCRC patients treated with 1L SACT in NHS GGC from 01/01/2015 to 31/12/2016 was performed to investigate the factors influencing selection of 1L mCRC SACTs, treatment pathways, and treatment outcomes including median OS (mOS) and time-to-next-treatment (TTNT) of mCRC patients. Results: Between 2015 and 2016, A total of 220 new mCRC SACT users were identified in NHS GGC, with 52.3% (N=115) of the patients treated with a doublet of FOLFOX or FOLFIRI, 22.3% (N=49) with 5FU, 19.5% (N=43) with cetuximab+FOLFIRI, and 5% (N=11) of patients treated initially with aflibercept+FOLFIRI. Treatment choices for 1L mCRC were made based on patients’ age and gender, tumour RAS status, and previous treatment response. The median overall survival (mOS) for these patients was statistically influenced by the initial mCRC SACT and the performance status. The combination of cetuximab+FOLFIRI demonstrated a statistically significant prolonged mOS compared to 5FU (HR 0.4 (95% CI 0.24-0.85) and the longest time to next treatment (TTNT (12.93 months (95%CI 5.85-15.25)). The SRMA also indicated an OS, PFS, and overall response rate benefit for bevacizumab+chemotherapy over chemotherapy alone with a statistically increased risk of non-haematological toxicities and a non-statistically significant increased risk for haematological toxicity. Conclusions: Real-world evidence can help understand the impact of mCRC SACT on evidence-based practice

Investigation into maximizing component availability for superconducting cables in turbo-electric distributed propulsion aircraft

The commercial aviation industry is growing at a substantial rate, with demand doubling every 15 years and this trend is set to continue well into the 21st Century. At the same time regulatory pressures are being exerted on the industry as governments around the world seek to reduce their greenhouse gas emissions in an effort to contain global temperature rise to 2°C . Combined with existing infrastructure challenges, these issues are forcing air-framers to develop new, novel designs that support sustainable approaches to future aviation to meet environmental, social and economic demands. The pathway to decarbonisation of aviation will involve a combination of fuel, technology and operational measures. Many of the proposed technologies, such as electrical propulsion, are inherently disruptive and require changes to supply-chains,ground operations, maintenance standards and procedures, and pilot training. Such disruption is unavoidable given the scale of the challenge of electrical propulsion: a typical widebody jet engine for passenger aircraft can output over 22 MW fully loaded; an equivalent electrical system must be able to generate, distribute, and produce same amount of thrust with equal or greater reliability than the existing drivetrain that has been perfected over the course of the last century. Turbo-electric Distributed Propulsion (TeDP) is an approach for the electrification of propulsion systems on aircraft that aims to do this. Instead of large turbofan engines used to generate thrust, power in the engines is converted to electricity using electrical generators, and then distributed electrically through a network to propulsion motors placed in aerodynamically advantageous locations, significant fuel savings and performance benefits may be realised. Electrification of the propulsion system comes with large weight penalties. It is critical that the weight of the electrical power system does not mitigate the benefits of electrification. Superconducting electrical machines have been proposed as a route to lightweighting the electrical power system due to their promising high power densities compared to conventional electrical machines. It is proposed that the rest of the electrical power system be superconducting as far as technically possible to minimise heat sinks within the system. Integration of superconducting materials into the most safety critical aspects of commercial aviation raises multiple research questions regarding the design of resilient systems and how appropriate electrical protection strategies can be designed given the strict electric, magnetic, and thermal operating requirements that these components have. All electrical systems experience faults. This Thesis investigates how these faults manifest within a compact, power-electronically interfaced, superconducting network. The research presented in this thesis captures electrical protection requirements through modelling, simulation, and experimentation to develop requirements for TeDP feeder cables. By building on these requirements this thesis will then show how cable design can be optimised to withstand faults and present a control method which enables maximising throughput of cables during temperature rise events. This knowledge aims to improve availability, in terms of reducing the amount of superconducting network de-rating required, and power provision of superconducting feeder cables during adverse conditions encountered by superconducting TeDP aircraft.The commercial aviation industry is growing at a substantial rate, with demand doubling every 15 years and this trend is set to continue well into the 21st Century. At the same time regulatory pressures are being exerted on the industry as governments around the world seek to reduce their greenhouse gas emissions in an effort to contain global temperature rise to 2°C . Combined with existing infrastructure challenges, these issues are forcing air-framers to develop new, novel designs that support sustainable approaches to future aviation to meet environmental, social and economic demands. The pathway to decarbonisation of aviation will involve a combination of fuel, technology and operational measures. Many of the proposed technologies, such as electrical propulsion, are inherently disruptive and require changes to supply-chains,ground operations, maintenance standards and procedures, and pilot training. Such disruption is unavoidable given the scale of the challenge of electrical propulsion: a typical widebody jet engine for passenger aircraft can output over 22 MW fully loaded; an equivalent electrical system must be able to generate, distribute, and produce same amount of thrust with equal or greater reliability than the existing drivetrain that has been perfected over the course of the last century. Turbo-electric Distributed Propulsion (TeDP) is an approach for the electrification of propulsion systems on aircraft that aims to do this. Instead of large turbofan engines used to generate thrust, power in the engines is converted to electricity using electrical generators, and then distributed electrically through a network to propulsion motors placed in aerodynamically advantageous locations, significant fuel savings and performance benefits may be realised. Electrification of the propulsion system comes with large weight penalties. It is critical that the weight of the electrical power system does not mitigate the benefits of electrification. Superconducting electrical machines have been proposed as a route to lightweighting the electrical power system due to their promising high power densities compared to conventional electrical machines. It is proposed that the rest of the electrical power system be superconducting as far as technically possible to minimise heat sinks within the system. Integration of superconducting materials into the most safety critical aspects of commercial aviation raises multiple research questions regarding the design of resilient systems and how appropriate electrical protection strategies can be designed given the strict electric, magnetic, and thermal operating requirements that these components have. All electrical systems experience faults. This Thesis investigates how these faults manifest within a compact, power-electronically interfaced, superconducting network. The research presented in this thesis captures electrical protection requirements through modelling, simulation, and experimentation to develop requirements for TeDP feeder cables. By building on these requirements this thesis will then show how cable design can be optimised to withstand faults and present a control method which enables maximising throughput of cables during temperature rise events. This knowledge aims to improve availability, in terms of reducing the amount of superconducting network de-rating required, and power provision of superconducting feeder cables during adverse conditions encountered by superconducting TeDP aircraft

The sustainable livelihoods of informal artisan entrepreneurs in tourism : a case of Kenya

The tourism industry is a source of livelihood for many people as it creates employment and business opportunities. Nonetheless, the industry experiences many fluctuations and instabilities that threaten the livelihoods of those who depend on it. These threats are more intense for informal artisan entrepreneurs in tourism, who also grapple with enormous challenges in the informal sector despite their persistent work in the context. Thus, this exploratory research aims to understand how informal artisan entrepreneurs sustain their livelihoods while facing challenges in the informal sector and the tourism industry. The study uses the conceptual lens of the Sustainable Livelihoods Approach (SLA) and framework alongside the concepts of resilience, vulnerability and culture. It incorporates 51 telephone interviews with 32 artisans and 5 institutions in Kenya, conducted over two phases, and includes document analysis, field notes and researcher diaries. In doing so, the study draws key methodological considerations for conducting remote qualitative data collection and engaging with marginalised participants in Sub-Saharan Africa. The findings show that artisans experience constant challenges such as poverty, an indecent work environment, and inadequate institutional support. Nevertheless, their exposure to vulnerable conditions is paradoxically matched with resilience. The artisans’ resilience stems from their agency and socio-cultural structures, which have allowed them to combine different resources to sustain their livelihoods, cope with challenges, and persist in making handicrafts. Theoretically, the study creates a modified framework for sustainable livelihood analysis. It also challenges how resilience is conceptualised in sustainable livelihoods and entrepreneurship and suggests how it should be conceptualised. Relatedly, it draws insights into the paradoxical relationship between resilience and vulnerability. Hence, it contributes to the understanding of resilience in sustainable livelihoods. Notably, the study extends the body of knowledge on informal artisan entrepreneurs in tourism, who have proven unique in their characteristics and how they sustain their livelihoods.The tourism industry is a source of livelihood for many people as it creates employment and business opportunities. Nonetheless, the industry experiences many fluctuations and instabilities that threaten the livelihoods of those who depend on it. These threats are more intense for informal artisan entrepreneurs in tourism, who also grapple with enormous challenges in the informal sector despite their persistent work in the context. Thus, this exploratory research aims to understand how informal artisan entrepreneurs sustain their livelihoods while facing challenges in the informal sector and the tourism industry. The study uses the conceptual lens of the Sustainable Livelihoods Approach (SLA) and framework alongside the concepts of resilience, vulnerability and culture. It incorporates 51 telephone interviews with 32 artisans and 5 institutions in Kenya, conducted over two phases, and includes document analysis, field notes and researcher diaries. In doing so, the study draws key methodological considerations for conducting remote qualitative data collection and engaging with marginalised participants in Sub-Saharan Africa. The findings show that artisans experience constant challenges such as poverty, an indecent work environment, and inadequate institutional support. Nevertheless, their exposure to vulnerable conditions is paradoxically matched with resilience. The artisans’ resilience stems from their agency and socio-cultural structures, which have allowed them to combine different resources to sustain their livelihoods, cope with challenges, and persist in making handicrafts. Theoretically, the study creates a modified framework for sustainable livelihood analysis. It also challenges how resilience is conceptualised in sustainable livelihoods and entrepreneurship and suggests how it should be conceptualised. Relatedly, it draws insights into the paradoxical relationship between resilience and vulnerability. Hence, it contributes to the understanding of resilience in sustainable livelihoods. Notably, the study extends the body of knowledge on informal artisan entrepreneurs in tourism, who have proven unique in their characteristics and how they sustain their livelihoods

Truncated Euler Maruyama numerical method for stochastic differential (delay) equations models

In this thesis, our focus has been on enhancing the applicability and reliability of the truncated Euler-Maruyama (EM) numerical method for stochastic differential equations (SDEs) and stochastic delay differential equations (SDDEs), initially introduced by Mao [21]. Building upon this method, our contributions span several chapters. In Chapter 3, we pointed out its limitations in determining the convergence rate over a finite time interval and established a new result for SDEs whose diffusion coefficients may not satisfy the global Lipschitz condition. We extended our exploration to include time delays in Chapter 4, allowing for varying delays over time. The chapter also introduces additional lemmas to ensure the convergence rates of the method to the solution at specific time points and over finite intervals. However, the global Lipschitz condition on the diffusion coefficient is currently required. In Chapter 5, we focused on the Lotka-Volterra model, introducing modifications such as the Positive Preserving Truncated EM (PPTEM) and Nonnegative Preserving Truncated EM (NPTEM) methods to handle instances where the truncated EM method generated nonsensical negative solutions. The proposed adjustments, guided by Assumption 5.1.1, ensure that the numerical solutions remain meaningful and interpretable. Chapter 6 extends these concepts to the stochastic delay Lotka-Volterra model with a variable time delay, demonstrating the adaptability and applicability of our methods. Despite we also assume the stronger condition 6.1.1 to prove the convergence of numerical solutions, future research aims to explore relaxed conditions, broadening the applicability of these numerical methods. Overall, this thesis contributes to establishing convergence rates for SDEs under local Lipschitz diffusion coefficients, extending the methodology to address time delays and modifying the truncated EM method to ensure positive and nonnegative numerical solutions. These advancements are demonstrated through applications to the stochastic variable time delay Lotka-Volterra model, emphasizing the meaningfulness and interpretability of the solutions.In this thesis, our focus has been on enhancing the applicability and reliability of the truncated Euler-Maruyama (EM) numerical method for stochastic differential equations (SDEs) and stochastic delay differential equations (SDDEs), initially introduced by Mao [21]. Building upon this method, our contributions span several chapters. In Chapter 3, we pointed out its limitations in determining the convergence rate over a finite time interval and established a new result for SDEs whose diffusion coefficients may not satisfy the global Lipschitz condition. We extended our exploration to include time delays in Chapter 4, allowing for varying delays over time. The chapter also introduces additional lemmas to ensure the convergence rates of the method to the solution at specific time points and over finite intervals. However, the global Lipschitz condition on the diffusion coefficient is currently required. In Chapter 5, we focused on the Lotka-Volterra model, introducing modifications such as the Positive Preserving Truncated EM (PPTEM) and Nonnegative Preserving Truncated EM (NPTEM) methods to handle instances where the truncated EM method generated nonsensical negative solutions. The proposed adjustments, guided by Assumption 5.1.1, ensure that the numerical solutions remain meaningful and interpretable. Chapter 6 extends these concepts to the stochastic delay Lotka-Volterra model with a variable time delay, demonstrating the adaptability and applicability of our methods. Despite we also assume the stronger condition 6.1.1 to prove the convergence of numerical solutions, future research aims to explore relaxed conditions, broadening the applicability of these numerical methods. Overall, this thesis contributes to establishing convergence rates for SDEs under local Lipschitz diffusion coefficients, extending the methodology to address time delays and modifying the truncated EM method to ensure positive and nonnegative numerical solutions. These advancements are demonstrated through applications to the stochastic variable time delay Lotka-Volterra model, emphasizing the meaningfulness and interpretability of the solutions

Unsteady hydrodynamics of ships moving in confined waterways

When a ship is navigating on water surface, its resistance can be divided into three components: frictional resistance, eddy resistance, and wave-making resistance (Havelock, 1909). While in many cases, the steady component dominates the wave-making resistance, there are still certain instances where unsteady effects cannot be ignored. For example: • Sudden changes of boundaries, such as the width and depth of the waterway. This may occur when ships navigate in port, harbor or lock environments. It will potentially increase the risk of collisions or grounding incidents. • When a ship is overtaking (or being overtaken) or passing other vessels in busy waterways, the unsteady effects of the free surface can generate horizontal unsteady forces between the two ships. This can result in collisions between the vessels and lead to the blockage of the waterway. • Another typical scenario is when a ship keeps accelerating in open area, particularly in extremely shallow depths. In this case, the unsteady effects will significantly increase after the ship’s velocity exceeds the critical speed. At this point, the unsteady effects alter the flow field around the ship, resulting in changes in wave-making resistance. This thesis posits that the aforementioned unsteady effects are closely correlated with unsteady waves on the free surface. Hence, the primary objectives of this research are two-fold: 1) To develop a linear unsteady numerical program which is capable of simulating the unsteady free surface effects. This program will accurately capture the formation and evolution of unsteady waves. 2) To devise a real-time updating mesh method that handles changes in waterway boundaries and depths encountered during the simulation process. Additionally, it ensures temporal continuity for all cells on the free surface. In this thesis, Chapter 1 will be an introduction and literature review of the research topic. Chapter 2 introduces the methodology used in this research. Chapters 3 to 5 constitute the main body of this thesis. Specifically, Chapter 3 presents the simulation of unsteady waves generated by a single object, with particular focus on the simulation of the previously mentioned scenario of a ship accelerating in shallow water. Chapter 4 aims to simulate multiple objects. In this chapter, the ship-to-ship problem and the unsteady bank effect within a confined waterway will be investigated. Due to the presence of interacting objects, the grid is required to be updated in real-time to accommodate changes in the boundary conditions. The simulation results will be compared with experimental data to validate their accuracy. Chapter 5 will build upon the foundation established in Chapter 3 by extending the grid handling techniques to account for unsteady banks. Additionally, the unsteady hydrodynamic model developed in Chapter 2 will also be incorporated. This integration will enable the simulation of the intricate wave phenomena that occurs during the process of a vessel entering a lock. The simulation results will be compared against experimental data as well as computational fluid dynamics (CFD) results to validate their accuracy. This comparative analysis serves to ensure the reliability and fidelity of the simulation outcomes. By undertaking these efforts, Chapter 4 aims to provide a comprehensive understanding of the wave behaviour within the lock chamber during vessel entry, contributing to the advancement of knowledge in the field of unsteady water dynamics. Finally, Chapter 6 serves as the conclusion which summarizing all the achievements of this thesis and also proposing future directions for research.When a ship is navigating on water surface, its resistance can be divided into three components: frictional resistance, eddy resistance, and wave-making resistance (Havelock, 1909). While in many cases, the steady component dominates the wave-making resistance, there are still certain instances where unsteady effects cannot be ignored. For example: • Sudden changes of boundaries, such as the width and depth of the waterway. This may occur when ships navigate in port, harbor or lock environments. It will potentially increase the risk of collisions or grounding incidents. • When a ship is overtaking (or being overtaken) or passing other vessels in busy waterways, the unsteady effects of the free surface can generate horizontal unsteady forces between the two ships. This can result in collisions between the vessels and lead to the blockage of the waterway. • Another typical scenario is when a ship keeps accelerating in open area, particularly in extremely shallow depths. In this case, the unsteady effects will significantly increase after the ship’s velocity exceeds the critical speed. At this point, the unsteady effects alter the flow field around the ship, resulting in changes in wave-making resistance. This thesis posits that the aforementioned unsteady effects are closely correlated with unsteady waves on the free surface. Hence, the primary objectives of this research are two-fold: 1) To develop a linear unsteady numerical program which is capable of simulating the unsteady free surface effects. This program will accurately capture the formation and evolution of unsteady waves. 2) To devise a real-time updating mesh method that handles changes in waterway boundaries and depths encountered during the simulation process. Additionally, it ensures temporal continuity for all cells on the free surface. In this thesis, Chapter 1 will be an introduction and literature review of the research topic. Chapter 2 introduces the methodology used in this research. Chapters 3 to 5 constitute the main body of this thesis. Specifically, Chapter 3 presents the simulation of unsteady waves generated by a single object, with particular focus on the simulation of the previously mentioned scenario of a ship accelerating in shallow water. Chapter 4 aims to simulate multiple objects. In this chapter, the ship-to-ship problem and the unsteady bank effect within a confined waterway will be investigated. Due to the presence of interacting objects, the grid is required to be updated in real-time to accommodate changes in the boundary conditions. The simulation results will be compared with experimental data to validate their accuracy. Chapter 5 will build upon the foundation established in Chapter 3 by extending the grid handling techniques to account for unsteady banks. Additionally, the unsteady hydrodynamic model developed in Chapter 2 will also be incorporated. This integration will enable the simulation of the intricate wave phenomena that occurs during the process of a vessel entering a lock. The simulation results will be compared against experimental data as well as computational fluid dynamics (CFD) results to validate their accuracy. This comparative analysis serves to ensure the reliability and fidelity of the simulation outcomes. By undertaking these efforts, Chapter 4 aims to provide a comprehensive understanding of the wave behaviour within the lock chamber during vessel entry, contributing to the advancement of knowledge in the field of unsteady water dynamics. Finally, Chapter 6 serves as the conclusion which summarizing all the achievements of this thesis and also proposing future directions for research

An investigation of the interventional role of perceived norms on greener choice

Encouraging green consumption is a key goal of green marketing. However, the practice of green consumption often deviates from green attitudes. The approach of behavioural interventions can help reduce the deviation, i.e., the green attitude-behaviour gap, by influencing consumers’ decision-making. Nevertheless, this approach lacks a coherent theory underlying the promotion of green consumption behaviour, neglects the influence of self-consciousness on decision-making and intervention effectiveness, and has little recognition of its potential side effects on consumers’ well-being. To address this, this research, using a combined lens of decision-making and behavioural intervention, aims to investigate the impact of normative mechanisms as informational interventions on encouraging consumers to make greener choice and how selfconsciousness affects these interventional impacts. Three experimental studies in hotel towel reuse scenarios were conducted to achieve the aim. The findings reveal that both personal and social normative interventions are effective in promoting green consumption, and self-consciousness affects consumer responses to these interventions. The negative influence of private (public) selfconsciousness on the impact of personal (social) normative interventions provides insight into why some studies failed to produce intervention effects. In addition, the research suggests that the impact of intervention on self-concept clarity could reflect its effect on consumers’ well-being. By revealing the mediating role of green preference in normative interventions, this research bridges the causal process among personal norms, green preference, and greener choice. These findings have important implications for marketers and policymakers seeking to promote green consumption while ensuring the well-being of consumers. Focusing on personal norms can encourage sustained greener choice, as it relates strongly to green preference and further activates one’s private self-consciousness, providing well-being benefits due to increased self-concept clarity. Effective normative prompts for different marketing communication purposes can be crafted using the research's findings.Encouraging green consumption is a key goal of green marketing. However, the practice of green consumption often deviates from green attitudes. The approach of behavioural interventions can help reduce the deviation, i.e., the green attitude-behaviour gap, by influencing consumers’ decision-making. Nevertheless, this approach lacks a coherent theory underlying the promotion of green consumption behaviour, neglects the influence of self-consciousness on decision-making and intervention effectiveness, and has little recognition of its potential side effects on consumers’ well-being. To address this, this research, using a combined lens of decision-making and behavioural intervention, aims to investigate the impact of normative mechanisms as informational interventions on encouraging consumers to make greener choice and how selfconsciousness affects these interventional impacts. Three experimental studies in hotel towel reuse scenarios were conducted to achieve the aim. The findings reveal that both personal and social normative interventions are effective in promoting green consumption, and self-consciousness affects consumer responses to these interventions. The negative influence of private (public) selfconsciousness on the impact of personal (social) normative interventions provides insight into why some studies failed to produce intervention effects. In addition, the research suggests that the impact of intervention on self-concept clarity could reflect its effect on consumers’ well-being. By revealing the mediating role of green preference in normative interventions, this research bridges the causal process among personal norms, green preference, and greener choice. These findings have important implications for marketers and policymakers seeking to promote green consumption while ensuring the well-being of consumers. Focusing on personal norms can encourage sustained greener choice, as it relates strongly to green preference and further activates one’s private self-consciousness, providing well-being benefits due to increased self-concept clarity. Effective normative prompts for different marketing communication purposes can be crafted using the research's findings

Investigation and assessment of the benefits for power systems from wind farm control

As wind turbines are increasingly situated in large arrays offshore, connected to power grids by a single long cable, it is necessary to consider the operation of the whole wind farm as a single plant rather than as a series of individual units. To achieve this, the development of advanced wind farm modelling software is required to test and evaluate new control strategies for wind farm operation. This thesis considers the use of Strathfarm, The University of Strathclyde’s in-house wind farm modelling software, presenting novel wind farm control algorithms which significantly reduce the fatigue of wind turbine towers and wind turbine blades. The thesis also further develops Strathfarm in two key areas, presenting improvements to the modelled wakes and also details the development of a novel power system model. The power system model can be used to show the efficacy of previously developed dispatch algorithms for wind farms to support power grids.As wind turbines are increasingly situated in large arrays offshore, connected to power grids by a single long cable, it is necessary to consider the operation of the whole wind farm as a single plant rather than as a series of individual units. To achieve this, the development of advanced wind farm modelling software is required to test and evaluate new control strategies for wind farm operation. This thesis considers the use of Strathfarm, The University of Strathclyde’s in-house wind farm modelling software, presenting novel wind farm control algorithms which significantly reduce the fatigue of wind turbine towers and wind turbine blades. The thesis also further develops Strathfarm in two key areas, presenting improvements to the modelled wakes and also details the development of a novel power system model. The power system model can be used to show the efficacy of previously developed dispatch algorithms for wind farms to support power grids