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Model-free non-invasive health assessment for battery energy storage assets
Full text linkIncreasing penetration of renewable energy generation in the modern power network introduces uncertainty about the energy available to maintain a balance between generation and demand due to its time-fluctuating output that is strongly dependent on the weather. With the development of energy storage technology, there is the potential for this technology to become a key element to help overcome this intermittency in a generation. However, the increasing penetration of battery energy storage within the power network introduces an additional challenge to asset owners on how to monitor and manage battery health. The accurate estimation of the health of this device is crucial in determining its reliability, power-delivering capability and ability to contribute to the operation of the whole power system. Generally, doing this requires invasive measurements or computationally expensive physics-based models, which do not scale up cost-effectively to a fleet of assets.As storage aggregation becomes more commonplace, there is a need for a health metric that will be able to predict battery health based only on the limited information available, eliminating the necessity of installation of extensive telemetry in the system. This work develops a solution to battery health prognostics by providing an alternative, a non-invasive approach to the estimation of battery health that estimates the extent to which a battery asset has been maloperated based only on the battery-operating regime imposed on the device. The model introduced in this work is based on the Hidden Markov Model, which stochastically models the battery limitations imposed by its chemistry as a combination of present and previous sequential charging actions, and articulates the preferred operating regime as a measure of health consequence.The resulting methodology is demonstrated on distribution network level electrical demand and generation data, accurately predicting maloperation under a number of battery technology scenarios. The effectiveness of the proposed battery maloperation model as a proxy for actual battery degradation for lithium-ion technology was also tested against lab tested battery degradation data, showing that the proposed health measure in terms of maloperation level reflected that measured in terms of capacity fade. The developed model can support condition monitoring and remaining useful life estimates, but in the wider context could also be used as the policy function in an automated scheduler to utilise assets while optimising their health.Increasing penetration of renewable energy generation in the modern power network introduces uncertainty about the energy available to maintain a balance between generation and demand due to its time-fluctuating output that is strongly dependent on the weather. With the development of energy storage technology, there is the potential for this technology to become a key element to help overcome this intermittency in a generation. However, the increasing penetration of battery energy storage within the power network introduces an additional challenge to asset owners on how to monitor and manage battery health. The accurate estimation of the health of this device is crucial in determining its reliability, power-delivering capability and ability to contribute to the operation of the whole power system. Generally, doing this requires invasive measurements or computationally expensive physics-based models, which do not scale up cost-effectively to a fleet of assets.As storage aggregation becomes more commonplace, there is a need for a health metric that will be able to predict battery health based only on the limited information available, eliminating the necessity of installation of extensive telemetry in the system. This work develops a solution to battery health prognostics by providing an alternative, a non-invasive approach to the estimation of battery health that estimates the extent to which a battery asset has been maloperated based only on the battery-operating regime imposed on the device. The model introduced in this work is based on the Hidden Markov Model, which stochastically models the battery limitations imposed by its chemistry as a combination of present and previous sequential charging actions, and articulates the preferred operating regime as a measure of health consequence.The resulting methodology is demonstrated on distribution network level electrical demand and generation data, accurately predicting maloperation under a number of battery technology scenarios. The effectiveness of the proposed battery maloperation model as a proxy for actual battery degradation for lithium-ion technology was also tested against lab tested battery degradation data, showing that the proposed health measure in terms of maloperation level reflected that measured in terms of capacity fade. The developed model can support condition monitoring and remaining useful life estimates, but in the wider context could also be used as the policy function in an automated scheduler to utilise assets while optimising their health
Self-organising multi-agent control for distribution networks with distributed energy resources
Full text linkRecent years have seen an increase in the connection of dispersed distributed energy resources (DERs) and advanced control and operational components to the distribution network. These DERs can come in various forms, including distributed generation (DG), electric vehicles (EV), energy storage, etc. The conditions of these DERs can be varying and unpredictably intermittent. The integration of these distributed components adds more complexity and uncertainty to the operation of future power networks, such as voltage, frequency, and active/reactive power control. The stochastic and distributed nature of DGs and the difficulty in predicting EV charging patterns presents problems to the control and management of the distribution network. This adds more challenges to the planning and operation of such systems. Traditional methods for dealing with network problems such as voltage and power control could therefore be inadequate. In addition, conventional optimisation techniques will be difficult to apply successfully and will be accompanied with a large computational load. There is therefore a need for new control techniques that break the problem into smaller subsets and one that uses a multi-agent system (MAS) to implement distributed solutions. These groups of agents would coordinate amongst themselves, to regulate local resources and voltage levels in a distributed and adaptive manner considering varying conditions of the network.This thesis investigates the use of self-organising systems, presenting suitable approaches and identifying the challenges of implementing such techniques. It presents the development of fully functioning self-organising multi-agent control algorithms that can perform as effectively as full optimization techniques. It also demonstrates these new control algorithms on models of large and complex networks with DERs. Simulation results validate the autonomy of the system to control the voltage independently using only local DERs and proves the robustness and adaptability of the system by maintaining stable voltage control in response to network conditions over time.Recent years have seen an increase in the connection of dispersed distributed energy resources (DERs) and advanced control and operational components to the distribution network. These DERs can come in various forms, including distributed generation (DG), electric vehicles (EV), energy storage, etc. The conditions of these DERs can be varying and unpredictably intermittent. The integration of these distributed components adds more complexity and uncertainty to the operation of future power networks, such as voltage, frequency, and active/reactive power control. The stochastic and distributed nature of DGs and the difficulty in predicting EV charging patterns presents problems to the control and management of the distribution network. This adds more challenges to the planning and operation of such systems. Traditional methods for dealing with network problems such as voltage and power control could therefore be inadequate. In addition, conventional optimisation techniques will be difficult to apply successfully and will be accompanied with a large computational load. There is therefore a need for new control techniques that break the problem into smaller subsets and one that uses a multi-agent system (MAS) to implement distributed solutions. These groups of agents would coordinate amongst themselves, to regulate local resources and voltage levels in a distributed and adaptive manner considering varying conditions of the network.This thesis investigates the use of self-organising systems, presenting suitable approaches and identifying the challenges of implementing such techniques. It presents the development of fully functioning self-organising multi-agent control algorithms that can perform as effectively as full optimization techniques. It also demonstrates these new control algorithms on models of large and complex networks with DERs. Simulation results validate the autonomy of the system to control the voltage independently using only local DERs and proves the robustness and adaptability of the system by maintaining stable voltage control in response to network conditions over time
Development of alternative thermomechanical processing techniques to improve forging outcomes of cast peritectic TiAl alloys
Full text linkThe aim of this research was to investigate and develop alternative thermomechanical processingtechniques to improve the forging outcomes, at industrially viable temperatures, of two cast,peritectic solidifying, consolidated titanium aluminide alloys; 45XD (Ti-45Al-2Nb-2Mn-1B at.%) and4822 (Ti-48Al-2Nb-2Cr at.%).This study differed from existing work on TiAl alloy composition-processing-microstructurerelationships with an emphasis on controlling the initial microstructure to optimise primary processing(i.e., ingot breakdown) efficiency and produce a microstructure that improves the outcome ofsecondary processing (i.e., isothermal closed die forging, or hot rolling), ideally approaching a strainrate sensitivity of ≥0.3. For these alloys, consolidation by hot isostatic pressing (HIP) followed byprimary compression alone does not remove the casting segregation or the anisotropic behavinglamellar content that hinders secondary processing; alternative processes are required.For 45XD, this study found that integrating HIP and homogenisation stages into one step, using HIPequipment, proved beneficial to the forging outcome in comparison to the traditional two stepapproach. Achieving an elementally homogeneous and refined fully lamellar microstructure enabledhigh levels of globularisation, and dynamic recrystallised material from 50 % primary compression at1100 °C and 0.001 s-1. This aided secondary compression, returning the highest strain rate sensitivityof 0.32.For 4822, this study investigated the impact of cyclic heat treatment (CHT) and cooling rate on HIPand homogenised material, as well as its subsequent effect on forging outcomes. For the first time,industrially relevant induction heating equipment was applied to conduct the five cycles to the singleα phase temperatures (1370 °C) necessary for lamellar grain refinement. The compression resultsshowed that CHT, irrespective of cooling, proved successful with uniform 50 % primary compressionat 1100 °C and 0.001 s-1, compared to the shearing instability of HH material. This led to secondarycompression of CHT material returning material high in dynamic recrystallised content and free oflamellar morphologies, with a strain rate sensitivity of 0.25.The aim of this research was to investigate and develop alternative thermomechanical processingtechniques to improve the forging outcomes, at industrially viable temperatures, of two cast,peritectic solidifying, consolidated titanium aluminide alloys; 45XD (Ti-45Al-2Nb-2Mn-1B at.%) and4822 (Ti-48Al-2Nb-2Cr at.%).This study differed from existing work on TiAl alloy composition-processing-microstructurerelationships with an emphasis on controlling the initial microstructure to optimise primary processing(i.e., ingot breakdown) efficiency and produce a microstructure that improves the outcome ofsecondary processing (i.e., isothermal closed die forging, or hot rolling), ideally approaching a strainrate sensitivity of ≥0.3. For these alloys, consolidation by hot isostatic pressing (HIP) followed byprimary compression alone does not remove the casting segregation or the anisotropic behavinglamellar content that hinders secondary processing; alternative processes are required.For 45XD, this study found that integrating HIP and homogenisation stages into one step, using HIPequipment, proved beneficial to the forging outcome in comparison to the traditional two stepapproach. Achieving an elementally homogeneous and refined fully lamellar microstructure enabledhigh levels of globularisation, and dynamic recrystallised material from 50 % primary compression at1100 °C and 0.001 s-1. This aided secondary compression, returning the highest strain rate sensitivityof 0.32.For 4822, this study investigated the impact of cyclic heat treatment (CHT) and cooling rate on HIPand homogenised material, as well as its subsequent effect on forging outcomes. For the first time,industrially relevant induction heating equipment was applied to conduct the five cycles to the singleα phase temperatures (1370 °C) necessary for lamellar grain refinement. The compression resultsshowed that CHT, irrespective of cooling, proved successful with uniform 50 % primary compressionat 1100 °C and 0.001 s-1, compared to the shearing instability of HH material. This led to secondarycompression of CHT material returning material high in dynamic recrystallised content and free oflamellar morphologies, with a strain rate sensitivity of 0.25
Towards an endoscopic capsule for the detection of gastrointestinal bleeding: spectroscopic sensing and optical data communications
Full text linkIntroduction: Gastrointestinal (GI) bleeding is a common and potentially life-threatening condition that necessitates prompt diagnosis and intervention. While endoscopy remains the gold standard for detecting GI bleeding, it has limitations, notably its inability to reach the small intestine, where critical bleeding may be missed. In 1981, Gavriel Iddan’s introduction of the wireless camera pill revolutionized gastroenterology by enabling comprehensive imaging of the entire GI tract. Despite advancements, existing wireless capsules primarily rely on optical sensors limited to two wavelengths, restricting their ability to detect various substances. Furthermore, the communication system using radio frequency (RF) faces bandwidth constraints, hindering data transfer capabilities. Methods: This PhD thesis aimed to enhance both the sensing and communication systems of wireless capsule endoscopes. The first objective was the development of an optical sensor with a higher optical channel count than existing capsule-based devices. This is a necessary step for detecting a broader range of substances within the GI tract. The second objective was the development of an optical communication link with high bandwidth. To assess the feasibility of the proposed optical communication system, theoretical simulations were performed to estimate the data transmission rates achievable through biological tissue. Additionally, practical bench tests were conducted using phantoms and biological tissue to evaluate the performance of the new optical communication system. Results: The multi-wavelength optical sensor was successfully developed, offering the ability to sense a wider spectrum of wavelengths compared to traditional systems. In addition to the spectrometer’s capabilities, separate theoretical simulations indicated that optical communication could support higher data transmission rates than RF communication. Experimental testing further demonstrated that the optical system was capable of transmitting data through biological tissue at a data rate of up to 12 Mbps. Furthermore, the optical communication system successfully transmitted an uncompressed colour image with a data rate of up to 1 Mbps, demonstrating its potential for high-quality image transmission from the capsule to external receivers. Discussion: The results indicate that the number of channels and bandwidth of a multiwavelength optical sensor can indeed be improved. This shows promise to enhance the diagnostic capabilities of wireless capsule endoscopes. By expanding the range of detectable wavelengths, the new system provides detection with higher specificity. Moreover, the successful implementation of optical communication addresses the limitations of RF communication, enabling faster data transmission and the possibility of real-time high resolution image delivery. The main limitation of the thesis is that the work is only qualitative, and no reference tests exist to demonstrate the capabilities quantitatively. Future work will need to define reference tasks, test the system under these tasks, and under clinical conditions.Introduction: Gastrointestinal (GI) bleeding is a common and potentially life-threatening condition that necessitates prompt diagnosis and intervention. While endoscopy remains the gold standard for detecting GI bleeding, it has limitations, notably its inability to reach the small intestine, where critical bleeding may be missed. In 1981, Gavriel Iddan’s introduction of the wireless camera pill revolutionized gastroenterology by enabling comprehensive imaging of the entire GI tract. Despite advancements, existing wireless capsules primarily rely on optical sensors limited to two wavelengths, restricting their ability to detect various substances. Furthermore, the communication system using radio frequency (RF) faces bandwidth constraints, hindering data transfer capabilities. Methods: This PhD thesis aimed to enhance both the sensing and communication systems of wireless capsule endoscopes. The first objective was the development of an optical sensor with a higher optical channel count than existing capsule-based devices. This is a necessary step for detecting a broader range of substances within the GI tract. The second objective was the development of an optical communication link with high bandwidth. To assess the feasibility of the proposed optical communication system, theoretical simulations were performed to estimate the data transmission rates achievable through biological tissue. Additionally, practical bench tests were conducted using phantoms and biological tissue to evaluate the performance of the new optical communication system. Results: The multi-wavelength optical sensor was successfully developed, offering the ability to sense a wider spectrum of wavelengths compared to traditional systems. In addition to the spectrometer’s capabilities, separate theoretical simulations indicated that optical communication could support higher data transmission rates than RF communication. Experimental testing further demonstrated that the optical system was capable of transmitting data through biological tissue at a data rate of up to 12 Mbps. Furthermore, the optical communication system successfully transmitted an uncompressed colour image with a data rate of up to 1 Mbps, demonstrating its potential for high-quality image transmission from the capsule to external receivers. Discussion: The results indicate that the number of channels and bandwidth of a multiwavelength optical sensor can indeed be improved. This shows promise to enhance the diagnostic capabilities of wireless capsule endoscopes. By expanding the range of detectable wavelengths, the new system provides detection with higher specificity. Moreover, the successful implementation of optical communication addresses the limitations of RF communication, enabling faster data transmission and the possibility of real-time high resolution image delivery. The main limitation of the thesis is that the work is only qualitative, and no reference tests exist to demonstrate the capabilities quantitatively. Future work will need to define reference tasks, test the system under these tasks, and under clinical conditions
Essays on financial constraints : text analysis and social network analysis
Full text linkThis thesis delves into the relationship between financial constraints and board characteristics, including board interlocks, board expertise, and CEO overconfidence. Based on assumption that firms disclose information about incapability of raising capital in the financial statement, I adopt an innovative measure of financial constraints using textual analysis of firms’ annual reports, which indeed captures typical characteristics of firms that are conventionally perceived financially constrained. For example, constrained firms pay less dividend, are smaller, showing higher R&D intensity, holding higher cash holding, having higher Tobin’s Q. Chapter 2 focuses on the effect of board interlocks on financial constraints. It is assumed that with more board interlocks, firms tend to have better information environment and thus mitigate information asymmetry, leading to
lower financial constraints. Consistent with this assumption, I find that firms with well-connected directors face less risk of financial constraints. Two tests are conducted to mitigate the endogeneity concerns, including instrumental variable approach, and a difference-in-difference test based on propensity score matching process using directors’ death as external shock. Chapter 3 investigates the relationship between board expertise and financial constraints. Although previous literature highlights the merits of board expertise, I find that board experience in the focal industry indeed increases the risk of financial constraints. The proportion and number of independent directors who have industry experience are positively related to financial constraints. The results are robust
to fixed effects, inverse causality test, and alternative measures of financial constraints. Chapter 4 deals with the effects of CEO overconfidence on financial constraints. The results indicate that firms run by CEOs having low level of overconfidence faces more risk of financial constraints. However, the effect of high level of overconfidence is insignificant. The results are validated through robustness tests of alternative measure of financial constraints. Additionally, a quasi-experimental test based on propensity score matching also confirms the results.This thesis delves into the relationship between financial constraints and board characteristics, including board interlocks, board expertise, and CEO overconfidence. Based on assumption that firms disclose information about incapability of raising capital in the financial statement, I adopt an innovative measure of financial constraints using textual analysis of firms’ annual reports, which indeed captures typical characteristics of firms that are conventionally perceived financially constrained. For example, constrained firms pay less dividend, are smaller, showing higher R&D intensity, holding higher cash holding, having higher Tobin’s Q. Chapter 2 focuses on the effect of board interlocks on financial constraints. It is assumed that with more board interlocks, firms tend to have better information environment and thus mitigate information asymmetry, leading to
lower financial constraints. Consistent with this assumption, I find that firms with well-connected directors face less risk of financial constraints. Two tests are conducted to mitigate the endogeneity concerns, including instrumental variable approach, and a difference-in-difference test based on propensity score matching process using directors’ death as external shock. Chapter 3 investigates the relationship between board expertise and financial constraints. Although previous literature highlights the merits of board expertise, I find that board experience in the focal industry indeed increases the risk of financial constraints. The proportion and number of independent directors who have industry experience are positively related to financial constraints. The results are robust
to fixed effects, inverse causality test, and alternative measures of financial constraints. Chapter 4 deals with the effects of CEO overconfidence on financial constraints. The results indicate that firms run by CEOs having low level of overconfidence faces more risk of financial constraints. However, the effect of high level of overconfidence is insignificant. The results are validated through robustness tests of alternative measure of financial constraints. Additionally, a quasi-experimental test based on propensity score matching also confirms the results
An investigation of influential factors of leaders and followers trust relationships in UK SMEs: studies in assistive technology industry and mental health sector
Full text linkThis thesis combines four aspects, individual characteristics, leadership and followership, exchanges and interaction, and external factors, to illustrate what factors could influence the trust relationships between leaders and followers in small and medium-sized enterprises (SMEs) in Assistive Technology (AT) and mental health industries in the UK. The combination of these four aspects provides a comprehensive view to depict trust relationship influential factors between leaders and followers in the workplace. Furthermore, this thesis considers both leaders’ and followers’ opinions on building workplace trust relationships in order to describe trust on a dyadic level. Understanding dyadic trust in the workplace enables leaders and followers to recognise each other’s different demands and antecedents for establishing trust relationships. This thesis also sheds light on how to build trust in virtual teams. With the advent of the coronavirus pandemic (COVID-19), the development of trust in virtual teams between leaders and followers could underpin effective leadership and assist successful online teamwork. Individual and focus group interviews were conducted with 22 SMEs, and 40 participants contributed valuable perspectives on building trust with their leader or followers.
The first contribution of this thesis is a conceptual framework which enhances comprehension regarding the various elements that may influence trust relationships between leaders and followers in SMEs. This research finds several influential factors in trust relationships, which are summarised into four aspects: individual characteristics, leadership/followership styles, exchanges and interactions, and external factors. The second contribution is that findings reveal that leaders and followers place different weight on trust relationship influential factors, which develops organisational trust theory on a dyadic level. In terms of individual characteristics, leaders claim that integrity is necessary for a trustworthy follower, whereas followers believe that benevolence and integrity are characteristics of a trustworthy leader. In terms of exchanges and interactions, leaders propose that team diversity could facilitate trust relationships, whereas followers suggest that friendship could increase their trust in their leaders. The different attitudes of leaders and followers toward developing workplace trust relationships suggest that studies of trust require perspectives from both parties in a trust relationship. Therefore, the findings theoretically develop the trust research field on a dyadic level, meanwhile, this thesis provide suggestions for leaders and followers to practically establish trust relationships in the workplace in SMEs.This thesis combines four aspects, individual characteristics, leadership and followership, exchanges and interaction, and external factors, to illustrate what factors could influence the trust relationships between leaders and followers in small and medium-sized enterprises (SMEs) in Assistive Technology (AT) and mental health industries in the UK. The combination of these four aspects provides a comprehensive view to depict trust relationship influential factors between leaders and followers in the workplace. Furthermore, this thesis considers both leaders’ and followers’ opinions on building workplace trust relationships in order to describe trust on a dyadic level. Understanding dyadic trust in the workplace enables leaders and followers to recognise each other’s different demands and antecedents for establishing trust relationships. This thesis also sheds light on how to build trust in virtual teams. With the advent of the coronavirus pandemic (COVID-19), the development of trust in virtual teams between leaders and followers could underpin effective leadership and assist successful online teamwork. Individual and focus group interviews were conducted with 22 SMEs, and 40 participants contributed valuable perspectives on building trust with their leader or followers.
The first contribution of this thesis is a conceptual framework which enhances comprehension regarding the various elements that may influence trust relationships between leaders and followers in SMEs. This research finds several influential factors in trust relationships, which are summarised into four aspects: individual characteristics, leadership/followership styles, exchanges and interactions, and external factors. The second contribution is that findings reveal that leaders and followers place different weight on trust relationship influential factors, which develops organisational trust theory on a dyadic level. In terms of individual characteristics, leaders claim that integrity is necessary for a trustworthy follower, whereas followers believe that benevolence and integrity are characteristics of a trustworthy leader. In terms of exchanges and interactions, leaders propose that team diversity could facilitate trust relationships, whereas followers suggest that friendship could increase their trust in their leaders. The different attitudes of leaders and followers toward developing workplace trust relationships suggest that studies of trust require perspectives from both parties in a trust relationship. Therefore, the findings theoretically develop the trust research field on a dyadic level, meanwhile, this thesis provide suggestions for leaders and followers to practically establish trust relationships in the workplace in SMEs
Imaging and quantification of nutrient-transporting channels in Escherichia coli biofilms
No full textLandscapes of ‘Civilisation’ and ‘Barbarity’ in the 1641 Irish Rebellion
Full text linkThe present research is comprised of an investigation into the organisation, execution, and reportage of the 1641 Irish rebellion in relation to the early modern Anglo-Irish struggle over ‘civility’ and ‘civilisation’, specifically by examining Irish and English perspectives of the ownership, use, and representation of the physical landscape throughout the sixteenth andseventeenth centuries. In doing so, this investigation has contributed towards a greater understanding of the complexity of the Irish rebellion beyond its confessional scope, and has emphasised the significance of the landed dimension in relation to the continuation and endurance of Anglo-Irish conflict, from the Desmond Rebellions, to the Nine Years’ War, up until the outbreak of the Irish rebellion in 1641. By sampling individual testimonies of the Irish insurrection alongside larger contemporary accounts of the conflict, the English concern with the conquest and ‘civilisation’ of the physical Irish landscape and its inhabitants has been proven to extend across time, and was as much of a concern for average English and Protestant settlers seeking to ‘improve’ upon the land as for the colonial authorities of thecrown, even after the onset of the conflict. As for the non-elite Irish population, who became the driving force behind the insurrection, given the scale of the displacement, dispossession, and devastation associated with the English conquest of Ireland, the rebellion was fought in order to reclaim their ancestral landscape, and was executed in order to restore the landscape to its former condition, use, and ownership, thus reinforcing Gaelic ties to the landscapeitself. The rebellion constituted a battleground, not simply for the English conquest of the Irish landscape and its inhabitants, or even for religious denomination, but for the defence and advancement of English ‘civilisation’, or, from the perspective of the Irish, the restoration of Irish Gaeldom.The present research is comprised of an investigation into the organisation, execution, and reportage of the 1641 Irish rebellion in relation to the early modern Anglo-Irish struggle over ‘civility’ and ‘civilisation’, specifically by examining Irish and English perspectives of the ownership, use, and representation of the physical landscape throughout the sixteenth andseventeenth centuries. In doing so, this investigation has contributed towards a greater understanding of the complexity of the Irish rebellion beyond its confessional scope, and has emphasised the significance of the landed dimension in relation to the continuation and endurance of Anglo-Irish conflict, from the Desmond Rebellions, to the Nine Years’ War, up until the outbreak of the Irish rebellion in 1641. By sampling individual testimonies of the Irish insurrection alongside larger contemporary accounts of the conflict, the English concern with the conquest and ‘civilisation’ of the physical Irish landscape and its inhabitants has been proven to extend across time, and was as much of a concern for average English and Protestant settlers seeking to ‘improve’ upon the land as for the colonial authorities of thecrown, even after the onset of the conflict. As for the non-elite Irish population, who became the driving force behind the insurrection, given the scale of the displacement, dispossession, and devastation associated with the English conquest of Ireland, the rebellion was fought in order to reclaim their ancestral landscape, and was executed in order to restore the landscape to its former condition, use, and ownership, thus reinforcing Gaelic ties to the landscapeitself. The rebellion constituted a battleground, not simply for the English conquest of the Irish landscape and its inhabitants, or even for religious denomination, but for the defence and advancement of English ‘civilisation’, or, from the perspective of the Irish, the restoration of Irish Gaeldom
The development of novel combinations therapies for the treatment of triple negative breast cancer
Full text linkIntroduction: Cancer has one of the highest mortality rates in humans, second only to heart disease. In 2018 there was an estimated 9.6 million deaths due to cancer. Cancer survival rates vary according to malignancy type, however modern medicine has improved cancer survival rates globally. Despite recent advancements, certain hard to treat cancers such as brain, pancreatic and triple negative breast cancer still have a poor prognosis. Therapy resistance is one of the major contributing factors to the failure of cancer therapy, leading to relapse, metastasis, and mortality. Radio- and chemoresistance can occur for a variety of reasons. One of the major contributing factors to therapy resistance is tumour heterogeneity, related to epigenetics, genomic instability, and therapy related mutagenesis. Thus, during treatment, cancer cells continue to evolve and mutate often to therapy resistant phenotypes. Over the course of the disease and its treatment, cancers therefore become more heterogeneous and are composed of pockets of tumour cells which are molecularly distinct from others and possess differential levels of sensitivity to therapies. As a result of this, many current cancer therapies have limited success and more optimal combination chemoradiotherapies are therefore required. Materials and methods; Triple negative breast cancer cells were cultured in 2D and 3D models to investigate the efficacy of combination therapies designed from eitherchemotherapy or irradiation and a pre-approved fumaric acids dimethyl fumarate and monomethyl fumarate. Dimethyl fumarate and monomethyl fumarate have been shown to inhibit the NRF2 activation via the DJ-1 stabiliser which induces oxidative stress and promoted cancer cell death, dimethyl fumarate is currently used as a treatment for several autoimmune diseases. Triple negative breast cancer cells resistant to Radiation and Chemotherapy were developed in house by serial culture and used to investigate novel combination therapies to overcome resistance. Clonogenic Assays and Spheroid analysis was used to investigate toxicity and mechanistic studies such as Comet Assay, Cell Cycle analysis, Annexin V, Glutathione Assay and Autophagy Assay were carried out to understand the mechanisms underpinning observed effects. The chick embryo model, a promising method of in vivo analysis was also investigated for its potential as a model to be used in the development of novel therapies. Results and Discussion; Specifically scheduled combination therapies using Chemotherapy and Radiation with monomethyl fumarate in toxicity studies, showed a statistically significantly reduction in cell survival when compared with the control and the individual treatments alone. Mechanistic studies suggest an increase in DNA damage, depletion in glutathione levels and cell cycle arrest between combination therapy, control, and single treatments. These findings in triple negative breast cancer cells were mirrored in the resistant cells, providing a possible combination therapy that can be used to overcome resistance in triple negative breast cancer patients. Conclusion: Our research focuses on utilising medicines already approved for other conditions and using them in combination with current therapies to improve the efficacy of the treatment and potentially reduce the amount of chemotherapy/radiotherapy required. The results found provide a promising potential treatment option for TNBC patients with recurring cancer. In addition, it was determined that the chick embryo model could be used as an in vivo model to investigate novel therapies to treat cancer.Introduction: Cancer has one of the highest mortality rates in humans, second only to heart disease. In 2018 there was an estimated 9.6 million deaths due to cancer. Cancer survival rates vary according to malignancy type, however modern medicine has improved cancer survival rates globally. Despite recent advancements, certain hard to treat cancers such as brain, pancreatic and triple negative breast cancer still have a poor prognosis. Therapy resistance is one of the major contributing factors to the failure of cancer therapy, leading to relapse, metastasis, and mortality. Radio- and chemoresistance can occur for a variety of reasons. One of the major contributing factors to therapy resistance is tumour heterogeneity, related to epigenetics, genomic instability, and therapy related mutagenesis. Thus, during treatment, cancer cells continue to evolve and mutate often to therapy resistant phenotypes. Over the course of the disease and its treatment, cancers therefore become more heterogeneous and are composed of pockets of tumour cells which are molecularly distinct from others and possess differential levels of sensitivity to therapies. As a result of this, many current cancer therapies have limited success and more optimal combination chemoradiotherapies are therefore required. Materials and methods; Triple negative breast cancer cells were cultured in 2D and 3D models to investigate the efficacy of combination therapies designed from eitherchemotherapy or irradiation and a pre-approved fumaric acids dimethyl fumarate and monomethyl fumarate. Dimethyl fumarate and monomethyl fumarate have been shown to inhibit the NRF2 activation via the DJ-1 stabiliser which induces oxidative stress and promoted cancer cell death, dimethyl fumarate is currently used as a treatment for several autoimmune diseases. Triple negative breast cancer cells resistant to Radiation and Chemotherapy were developed in house by serial culture and used to investigate novel combination therapies to overcome resistance. Clonogenic Assays and Spheroid analysis was used to investigate toxicity and mechanistic studies such as Comet Assay, Cell Cycle analysis, Annexin V, Glutathione Assay and Autophagy Assay were carried out to understand the mechanisms underpinning observed effects. The chick embryo model, a promising method of in vivo analysis was also investigated for its potential as a model to be used in the development of novel therapies. Results and Discussion; Specifically scheduled combination therapies using Chemotherapy and Radiation with monomethyl fumarate in toxicity studies, showed a statistically significantly reduction in cell survival when compared with the control and the individual treatments alone. Mechanistic studies suggest an increase in DNA damage, depletion in glutathione levels and cell cycle arrest between combination therapy, control, and single treatments. These findings in triple negative breast cancer cells were mirrored in the resistant cells, providing a possible combination therapy that can be used to overcome resistance in triple negative breast cancer patients. Conclusion: Our research focuses on utilising medicines already approved for other conditions and using them in combination with current therapies to improve the efficacy of the treatment and potentially reduce the amount of chemotherapy/radiotherapy required. The results found provide a promising potential treatment option for TNBC patients with recurring cancer. In addition, it was determined that the chick embryo model could be used as an in vivo model to investigate novel therapies to treat cancer
Development of HTS trapped field magnet using 2G HTS coated conductors
Full text linkCompact High-Temperature Superconducting (HTS) trapped field magnets stand at the frontier of breakthroughs for advanced industrial equipment, medical devices, and transportation electrification, offering capabilities that conventional permanent magnets and electromagnets cannot achieve. While superconductors capitalize on zero resistance to uphold high currents, thus generating substantial fields, traditional HTS bulks and stacks have been limited by constraints such as geometry size and mechanical robustness. As second-generation (2G) commercial HTS coated conductors advance, there's a growing emphasis on utilizing these tapes to attain expansive and stable trapped field profiles. This thesis explores the innovative magnetization mechanisms and design optimizations of HTS trapped field magnets fabricated with 2G HTS tapes through a comprehensive analysis of HTS-stacked ring magnets, hybrid HTS-stacked ring design, their mechanical stress responses, and trapped field closed-loop HTS coil under field cooling magnetization. The research primarily investigated a novel hybrid HTS trapped field magnet, integrating HTS-stacked ring magnets with HTS bulks to surpass traditional size limitations and achieve a significant trapped field of 7.35 T. It further predicted their capability to generate a trapped field exceeding the applied field due to unique induced current distributions and flux redistribution. Additionally, the study addressed the mechanical challenges posed by Lorentz forces during magnetization, presenting 3D numerical models to analyze stress and strain in HTS-stacked ring magnets. A 90 % stress reduction was seen by proper impregnation and fixation methods. Lastly, a novel closed-loop HTS coil approach was introduced, achieving a compact high-field superconducting magnet that trapped a central field 4.59 T which was higher than the 4.5 T applied field, showcasing potential for diverse high-field applications. Above the inner edge of the HTS coil, the trapped field exceeded the applied field by 1.5 T. This thesis combines experimental findings and numerical modelling to advance the understanding of HTS magnetization processes, offering insights into designing more efficient and durable compact and portable HTS magnets for applications in nuclear magnetic resonance, Maglev transportation, and HTS machineryCompact High-Temperature Superconducting (HTS) trapped field magnets stand at the frontier of breakthroughs for advanced industrial equipment, medical devices, and transportation electrification, offering capabilities that conventional permanent magnets and electromagnets cannot achieve. While superconductors capitalize on zero resistance to uphold high currents, thus generating substantial fields, traditional HTS bulks and stacks have been limited by constraints such as geometry size and mechanical robustness. As second-generation (2G) commercial HTS coated conductors advance, there's a growing emphasis on utilizing these tapes to attain expansive and stable trapped field profiles. This thesis explores the innovative magnetization mechanisms and design optimizations of HTS trapped field magnets fabricated with 2G HTS tapes through a comprehensive analysis of HTS-stacked ring magnets, hybrid HTS-stacked ring design, their mechanical stress responses, and trapped field closed-loop HTS coil under field cooling magnetization. The research primarily investigated a novel hybrid HTS trapped field magnet, integrating HTS-stacked ring magnets with HTS bulks to surpass traditional size limitations and achieve a significant trapped field of 7.35 T. It further predicted their capability to generate a trapped field exceeding the applied field due to unique induced current distributions and flux redistribution. Additionally, the study addressed the mechanical challenges posed by Lorentz forces during magnetization, presenting 3D numerical models to analyze stress and strain in HTS-stacked ring magnets. A 90 % stress reduction was seen by proper impregnation and fixation methods. Lastly, a novel closed-loop HTS coil approach was introduced, achieving a compact high-field superconducting magnet that trapped a central field 4.59 T which was higher than the 4.5 T applied field, showcasing potential for diverse high-field applications. Above the inner edge of the HTS coil, the trapped field exceeded the applied field by 1.5 T. This thesis combines experimental findings and numerical modelling to advance the understanding of HTS magnetization processes, offering insights into designing more efficient and durable compact and portable HTS magnets for applications in nuclear magnetic resonance, Maglev transportation, and HTS machiner
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