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Internationalising teacher education in China and Scotland
Get PDFThis study is an exploration of the internationalisation of teacher education at two case-study universities, one located in China and the other in Scotland. It explores how different approaches to internationalisation affect student teachers' learning, as well as how teacher educators understand the concept of internationalisation in teacher education. The study, drawing on postcolonial theory, adopts a qualitative approach within a constructivist paradigm. Data collection comprises semi-structured interviews with 34 students and teacher educators across two universities.;Findings suggest that all the teacher educators interviewed view internationalisation as a broad concept that includes different approaches. However, they differ in their understandings of the rationale for internationalisation, which fall into three discourses: neocolonialism, neoimperialism and decolonisation. The teacher educators' different understandings are translated into their practices, and ultimately reflected in student teachers' learning experiences.;Another key finding is that student teachers, who are encouraged to engage in transformative learning through programmes, modules or other learning activities which have an intercultural, international or global dimension, show more readiness to become globally competent teachers. Further to this, influential factors such as financial issues, language barriers, narrow mind-sets and an overcrowded curriculum, prevent many student teachers from participating in internationalisation initiatives, which, however, can be addressed by ensuring that teacher educators have rich expertise in internationalisation.;Recommendations are for more international collaboration and communication between universities from different parts of the world, in order that internationalisation can be promoted as a two-way learning process. Moreover, communication among different stakeholders is also needed in order to ensure the success of internationalisation in teacher education within each institutional context.;Additionally, nuanced understandings of student teachers' transformative learning experiences through internationalisation initiatives suggest that, in order to prepare all student teachers to become globally competent teachers, it is essential to incorporate multicultural education, the pedagogy of discomfort and critical pedagogy into teacher education.This study is an exploration of the internationalisation of teacher education at two case-study universities, one located in China and the other in Scotland. It explores how different approaches to internationalisation affect student teachers' learning, as well as how teacher educators understand the concept of internationalisation in teacher education. The study, drawing on postcolonial theory, adopts a qualitative approach within a constructivist paradigm. Data collection comprises semi-structured interviews with 34 students and teacher educators across two universities.;Findings suggest that all the teacher educators interviewed view internationalisation as a broad concept that includes different approaches. However, they differ in their understandings of the rationale for internationalisation, which fall into three discourses: neocolonialism, neoimperialism and decolonisation. The teacher educators' different understandings are translated into their practices, and ultimately reflected in student teachers' learning experiences.;Another key finding is that student teachers, who are encouraged to engage in transformative learning through programmes, modules or other learning activities which have an intercultural, international or global dimension, show more readiness to become globally competent teachers. Further to this, influential factors such as financial issues, language barriers, narrow mind-sets and an overcrowded curriculum, prevent many student teachers from participating in internationalisation initiatives, which, however, can be addressed by ensuring that teacher educators have rich expertise in internationalisation.;Recommendations are for more international collaboration and communication between universities from different parts of the world, in order that internationalisation can be promoted as a two-way learning process. Moreover, communication among different stakeholders is also needed in order to ensure the success of internationalisation in teacher education within each institutional context.;Additionally, nuanced understandings of student teachers' transformative learning experiences through internationalisation initiatives suggest that, in order to prepare all student teachers to become globally competent teachers, it is essential to incorporate multicultural education, the pedagogy of discomfort and critical pedagogy into teacher education
The intertextual Anglosphere : whiteness in the nineteenth-century Boy's Own story
Get PDFThe nineteenth-century boy's own adventure story is a vehicle for the maintenance, and promotion, of ethnic identity. The establishment of ethnic self-consciousness is dependent upon a marked sense of difference; an alienation from, or perhaps opposition to, the Other. A shared myth of descent is in many ways a sine qua non of ethnicity. However, I am here concerned not so much with actual descent, but more with a sense of imputed common ancestry; a tribal belonging.It is helpful to look upon the literary works of this period as the products of the Anglosphere, for a shared ethnicity is the mortar that binds. Intertextuality can be presented as a textual adaptation, appropriation, or influence. The use of intertextuality in the Anglospheric children's novel is different from that to be found in contemporary works, for Anglospheric writers could make assumptions about a prospective readership in respect of Biblical knowledge and Classical allusions that their latter-day counterparts patently cannot. This thesis is not presented as a comprehensive investigation of the entire field of intertextuality in the Anglospheric boy's own adventure story, for such an undertaking would be monumental in scope and ambition. Instead, an examination of a subset of that field is carried out, which primarily entails comparative studies of four novels. It should be emphasised that these novels have not been chosen at random, but for sound rational and empirical reasons, all of which are explored in the following chapters. There is also an exploration of allusion, appropriation, and intertextuality in a historical context. Throughout this thesis the problem of identifying the legitimate parameters of intertextuality is discussed. How intertextuality is employed in Anglospheric children's literature can perhaps be studied most fruitfully in the borderlands that lie between the related concepts associated with ethnic identity.The very concept of the literary Anglosphere rests upon an inherited disposition of related peoples, for it would appear to reflect a spiritual morphology that is perhaps transmitted as much through atavism as through experience. There is without doubt a symbolic whiteness in the nineteenth-century boy's own adventure story, for the stories told invoke, implicitly and explicitly, the lineage, language, and customs, of their readers, which is to say their collective identity. The concept of intertextuality is central to any understanding of the whiteness that is emblematic of the nineteenth-century boy's own adventure story.The nineteenth-century boy's own adventure story is a vehicle for the maintenance, and promotion, of ethnic identity. The establishment of ethnic self-consciousness is dependent upon a marked sense of difference; an alienation from, or perhaps opposition to, the Other. A shared myth of descent is in many ways a sine qua non of ethnicity. However, I am here concerned not so much with actual descent, but more with a sense of imputed common ancestry; a tribal belonging.It is helpful to look upon the literary works of this period as the products of the Anglosphere, for a shared ethnicity is the mortar that binds. Intertextuality can be presented as a textual adaptation, appropriation, or influence. The use of intertextuality in the Anglospheric children's novel is different from that to be found in contemporary works, for Anglospheric writers could make assumptions about a prospective readership in respect of Biblical knowledge and Classical allusions that their latter-day counterparts patently cannot. This thesis is not presented as a comprehensive investigation of the entire field of intertextuality in the Anglospheric boy's own adventure story, for such an undertaking would be monumental in scope and ambition. Instead, an examination of a subset of that field is carried out, which primarily entails comparative studies of four novels. It should be emphasised that these novels have not been chosen at random, but for sound rational and empirical reasons, all of which are explored in the following chapters. There is also an exploration of allusion, appropriation, and intertextuality in a historical context. Throughout this thesis the problem of identifying the legitimate parameters of intertextuality is discussed. How intertextuality is employed in Anglospheric children's literature can perhaps be studied most fruitfully in the borderlands that lie between the related concepts associated with ethnic identity.The very concept of the literary Anglosphere rests upon an inherited disposition of related peoples, for it would appear to reflect a spiritual morphology that is perhaps transmitted as much through atavism as through experience. There is without doubt a symbolic whiteness in the nineteenth-century boy's own adventure story, for the stories told invoke, implicitly and explicitly, the lineage, language, and customs, of their readers, which is to say their collective identity. The concept of intertextuality is central to any understanding of the whiteness that is emblematic of the nineteenth-century boy's own adventure story
An open-source hybrid CFD-DSMC solver for high-speed flows
Get PDFA new open-source hybrid CFD-DSMC solver, called hyperFoam, has been implemented within the OpenFOAM framework. The capabilities of the OpenFOAM computational fluid dynamics (CFD) solver rhoCentralFoam for supersonic simulations were analysed, showing good agreement with state-of-the-art solvers such as DLR-Tau, and then enhanced, by incorporating the local time stepping (LTS) and adaptive mesh refinement (AMR) techniques. These aspects would later be used for the development of the hypersonic CFD code hy2Foam.;hyperFoam relies on hy2Foam and the direct direct simulation Monte Carlo (DSMC) code dsmcFoam to be able to resolve the flow physics while under the slip-transition regime. Using a mixture of Boyd's Gradient-Length-Local Knudsen number and a generalised modified Chapman-Enskog parameter, hyperFoam is capable of identifying the continuum and rarefied zones within the computational domain and solve each with its respective CFD or DSMC solver.;hyperFoam has been used to simulate several Couette flow with heat transfer test cases, each of different complexity. Good agreement was shown between the DSMC and hybrid results for these simulations. The hybrid code was then used to analyse a hypersonic cylinder. Reasonably similar accuracy was found between the DSMC and hybrid results for vibrationless N2 and N2-O2. However, forO2 important discrepancies were found due to an inconsistency between continuum and rarefied vibrational modelling.A new open-source hybrid CFD-DSMC solver, called hyperFoam, has been implemented within the OpenFOAM framework. The capabilities of the OpenFOAM computational fluid dynamics (CFD) solver rhoCentralFoam for supersonic simulations were analysed, showing good agreement with state-of-the-art solvers such as DLR-Tau, and then enhanced, by incorporating the local time stepping (LTS) and adaptive mesh refinement (AMR) techniques. These aspects would later be used for the development of the hypersonic CFD code hy2Foam.;hyperFoam relies on hy2Foam and the direct direct simulation Monte Carlo (DSMC) code dsmcFoam to be able to resolve the flow physics while under the slip-transition regime. Using a mixture of Boyd's Gradient-Length-Local Knudsen number and a generalised modified Chapman-Enskog parameter, hyperFoam is capable of identifying the continuum and rarefied zones within the computational domain and solve each with its respective CFD or DSMC solver.;hyperFoam has been used to simulate several Couette flow with heat transfer test cases, each of different complexity. Good agreement was shown between the DSMC and hybrid results for these simulations. The hybrid code was then used to analyse a hypersonic cylinder. Reasonably similar accuracy was found between the DSMC and hybrid results for vibrationless N2 and N2-O2. However, forO2 important discrepancies were found due to an inconsistency between continuum and rarefied vibrational modelling
3D-printing technology applied to the development of bio-inspired functional acoustic systems
Get PDFExamples of bio-inspired technology can be found almost everywhere in society: robots with specific capabilities, materials with unique physical and chemical properties, aerodynamic systems, and architectonic structures are a few examples of taking profit of evolution-driven processes to solve common engineering problems. One field of research taking advantage of bio-inspiration is that of acoustical engineering, aiming to find solutions to problems arising from the miniaturisation of microphones and loudspeakers. Studying the auditory organs of insects to seek inspiration for new design structures is one of the best ways to solve such an important problem. Another discipline of science that has experienced a research boom is that of materials science, as development of new materials has attracted the attention of researchers. In addition, three-dimensional (3D) printers have contributed to further development in materials science making the production process more efficient. The aim of this research is to bring these fields of science together to develop novel bioinspired, polymer-based sensors presenting functional specific acoustic properties after 3D-printing. While the study of complex biological hearing systems provides inspiration to develop sensors featuring specific properties, the use of polymer-based materials allows the customization of the manufacturing process, as the produced parts adapt to the desired needs. In this thesis one such insect auditory system that has been thoroughly studied is that of the desert locust Schistocerca gregaria as it presents a simple structure that allows for acoustic frequency selectivity and displays nonlinear acoustic phenomena. Prior to the development of a bio-inspired system, a mathematical description of the mechanical response of such a structure is presented. Furthermore, the physical behaviours measured on the locust tympanal membrane have been studied using finite element analysis. The 3D-printed functional sensors have been used to determine the degree of accuracy between experimental and theoretical results.Examples of bio-inspired technology can be found almost everywhere in society: robots with specific capabilities, materials with unique physical and chemical properties, aerodynamic systems, and architectonic structures are a few examples of taking profit of evolution-driven processes to solve common engineering problems. One field of research taking advantage of bio-inspiration is that of acoustical engineering, aiming to find solutions to problems arising from the miniaturisation of microphones and loudspeakers. Studying the auditory organs of insects to seek inspiration for new design structures is one of the best ways to solve such an important problem. Another discipline of science that has experienced a research boom is that of materials science, as development of new materials has attracted the attention of researchers. In addition, three-dimensional (3D) printers have contributed to further development in materials science making the production process more efficient. The aim of this research is to bring these fields of science together to develop novel bioinspired, polymer-based sensors presenting functional specific acoustic properties after 3D-printing. While the study of complex biological hearing systems provides inspiration to develop sensors featuring specific properties, the use of polymer-based materials allows the customization of the manufacturing process, as the produced parts adapt to the desired needs. In this thesis one such insect auditory system that has been thoroughly studied is that of the desert locust Schistocerca gregaria as it presents a simple structure that allows for acoustic frequency selectivity and displays nonlinear acoustic phenomena. Prior to the development of a bio-inspired system, a mathematical description of the mechanical response of such a structure is presented. Furthermore, the physical behaviours measured on the locust tympanal membrane have been studied using finite element analysis. The 3D-printed functional sensors have been used to determine the degree of accuracy between experimental and theoretical results
Molecular, biochemical and functional analysis of kinesins in Leishmania mexicana
Get PDFThis thesis was previously held under moratorium from 22 August 2019 to 22 August 2021.Leishmaniasis is a vector-borne disease that is caused by several species of the obligate intra-cellular protozoan parasite Leishmania. Leishmaniasis is a tropical and sub-tropical disease affecting between (12 – 15) million people worldwide. An estimated 1.5 to 2 million new cases occur and it causes 70,000 deaths per year. The flagellated protist Leishmania is one of the model organisms to study flagellar assembly. Here, we used L. mexicana as a model to investigate flagellar kinesin motor proteins. Kinesins are a large superfamily (KIFs). More than 15 kinesin families were classified by phylogenetic analysis (Wickstead et al., 2006). Kinesins are motor proteins that convert the energy from ATP hydrolysis into mechanical work to drive cargo along microtubules in a variety of cellular processes, organelle transport and cell division. Disruption of the normal function of these proteins has been shown to lead to many pathologies, including ciliopathy, neurodegenerative diseases and cancers. The current study presents a comprehensive biochemical and cell biological analysis of three kinesins thought to be associated with flagellum formation. Initially the cloning, mapping, and expression of the novel kinesin LmxKin29 were achieved. LmxKin29 is expressed in both the amastigote and promastigote life stages of L. mexicana. LmxKin29 can be assigned to the “orphan” kinesin family. Prior to the beginning of this work, the MAP kinase homologue LmxMPK3 was found to phosphorylate a peptide derived from LmxKin29 encompassing serine 551 and serine 554 (Rosenqvist, 2011; Emmerson, 2014). Here, a full-length GST-fusion protein of wild type LmxKin29 and five different mutants with substitutions of the putative serine or threonine phosphorylation sites, by alanine or aspartate, namely LmxKin29SA, LmxKin29SD, LmxKin29A2, LmxKin29A4 and LmxKin29554A were analysed. Using these mutants, it was possible to narrow down the site that is phosphorylated in activated His-LmxMPK3 as serine 554. To assess the function of LmxKin29 in L. mexicana single and double allele null mutants were generated. Morphological analysis of promastigotes displayed no obvious phenotypic differences comparing the mutants with wild type cells. Localisation studies using GFP-tagged LmxKin29 revealed that it is predominantly found in between the nucleus and the flagellar pocket, while in dividing cells LmxKin29 was found at the anterior and posterior ends of the cells. Hence, LmxKin29 might play a role in cytokinesis. Female Balb/c mice infected with ΔLmxKin29-/- null mutant promastigotes did not show a footpad lesion, whereas LmxKin29 add-back clones and single allele knockout clones caused the disease similar to wild type parasites. It was confirmed by ELISA that the serum of mice infected with L. mexicana wild type, single allele mutants and add-back mutants showed increased levels of IgG1 and IgG2a. However, the LmxKin29 null mutant scored very low similar to the level of uninfected mice serving as a negative control. The inability to cause lesions in the infected animal suggests that LmxKin29 is a potential drug target against leishmaniasis. On the other hand the absence of an immune response against the LmxKin29 null mutant clearly rules out these mutant parasites as an attenuated live vaccine. LmxOSM3.1 and LmxOSM3.2 were found to be homologous to flagellar kinesin-2 in trypanosomatids (L. major and T. brucei). They also showed sequence similarity with kinesin-2s of human kinesin KIF3A/B as well as with C. reinhardtii FLA8/FLA10 and C. elegans kinesin-like protein klp-20klp11. LmxOSM3.1GFP localisation was identified along the flagellum of L. mexicana promastigotes, while LmxOSM3.2RFP was localised at the tip of the flagellum. Hence, both kinesins might be involved in flagellum formation. LmxOSM3.1 has been identified previously as a substrate of LmxMPK3 and LmxMPK13. Kinase assays using GST-LmxOSM3.2 with activated LmxMPK3 showed that this kinase cannot phosphorylate LmxOSM3.2 in vitro. We can hypothesise that LmxOSM3.1 and LmxOSM3.2 are core IFT motors that are involved in the assembly and maintenance of the flagellum, whereas LmxOSM3.2 exhibit as an accessory motor that provides flagellum-specific functions.Leishmaniasis is a vector-borne disease that is caused by several species of the obligate intra-cellular protozoan parasite Leishmania. Leishmaniasis is a tropical and sub-tropical disease affecting between (12 – 15) million people worldwide. An estimated 1.5 to 2 million new cases occur and it causes 70,000 deaths per year. The flagellated protist Leishmania is one of the model organisms to study flagellar assembly. Here, we used L. mexicana as a model to investigate flagellar kinesin motor proteins. Kinesins are a large superfamily (KIFs). More than 15 kinesin families were classified by phylogenetic analysis (Wickstead et al., 2006). Kinesins are motor proteins that convert the energy from ATP hydrolysis into mechanical work to drive cargo along microtubules in a variety of cellular processes, organelle transport and cell division. Disruption of the normal function of these proteins has been shown to lead to many pathologies, including ciliopathy, neurodegenerative diseases and cancers. The current study presents a comprehensive biochemical and cell biological analysis of three kinesins thought to be associated with flagellum formation. Initially the cloning, mapping, and expression of the novel kinesin LmxKin29 were achieved. LmxKin29 is expressed in both the amastigote and promastigote life stages of L. mexicana. LmxKin29 can be assigned to the “orphan” kinesin family. Prior to the beginning of this work, the MAP kinase homologue LmxMPK3 was found to phosphorylate a peptide derived from LmxKin29 encompassing serine 551 and serine 554 (Rosenqvist, 2011; Emmerson, 2014). Here, a full-length GST-fusion protein of wild type LmxKin29 and five different mutants with substitutions of the putative serine or threonine phosphorylation sites, by alanine or aspartate, namely LmxKin29SA, LmxKin29SD, LmxKin29A2, LmxKin29A4 and LmxKin29554A were analysed. Using these mutants, it was possible to narrow down the site that is phosphorylated in activated His-LmxMPK3 as serine 554. To assess the function of LmxKin29 in L. mexicana single and double allele null mutants were generated. Morphological analysis of promastigotes displayed no obvious phenotypic differences comparing the mutants with wild type cells. Localisation studies using GFP-tagged LmxKin29 revealed that it is predominantly found in between the nucleus and the flagellar pocket, while in dividing cells LmxKin29 was found at the anterior and posterior ends of the cells. Hence, LmxKin29 might play a role in cytokinesis. Female Balb/c mice infected with ΔLmxKin29-/- null mutant promastigotes did not show a footpad lesion, whereas LmxKin29 add-back clones and single allele knockout clones caused the disease similar to wild type parasites. It was confirmed by ELISA that the serum of mice infected with L. mexicana wild type, single allele mutants and add-back mutants showed increased levels of IgG1 and IgG2a. However, the LmxKin29 null mutant scored very low similar to the level of uninfected mice serving as a negative control. The inability to cause lesions in the infected animal suggests that LmxKin29 is a potential drug target against leishmaniasis. On the other hand the absence of an immune response against the LmxKin29 null mutant clearly rules out these mutant parasites as an attenuated live vaccine. LmxOSM3.1 and LmxOSM3.2 were found to be homologous to flagellar kinesin-2 in trypanosomatids (L. major and T. brucei). They also showed sequence similarity with kinesin-2s of human kinesin KIF3A/B as well as with C. reinhardtii FLA8/FLA10 and C. elegans kinesin-like protein klp-20klp11. LmxOSM3.1GFP localisation was identified along the flagellum of L. mexicana promastigotes, while LmxOSM3.2RFP was localised at the tip of the flagellum. Hence, both kinesins might be involved in flagellum formation. LmxOSM3.1 has been identified previously as a substrate of LmxMPK3 and LmxMPK13. Kinase assays using GST-LmxOSM3.2 with activated LmxMPK3 showed that this kinase cannot phosphorylate LmxOSM3.2 in vitro. We can hypothesise that LmxOSM3.1 and LmxOSM3.2 are core IFT motors that are involved in the assembly and maintenance of the flagellum, whereas LmxOSM3.2 exhibit as an accessory motor that provides flagellum-specific functions
Gaussian process models for SCADA data based wind turbine performance/condition monitoring
Get PDFWind energy has seen remarkable growth in the past decade, and installed wind turbine capacity is increasing significantly every year around the globe. The presence of an excellent offshore wind resource and the need to reduce carbon emissions from electricity generation are driving policy to increase offshore wind generation capacity in UK waters. Logistic and transport issues make offshore maintenance costlier than onshore and availability correspondingly lower, and as a result, there is a growing interest in wind turbine condition monitoring allowing condition based, rather than corrective or scheduled, maintenance.;Offshore wind turbine manufacturers are constantly increasing the rated size the turbines, and also their hub height in order to access higher wind speeds with lower turbulence. However, such scaling up leads to significant increments in terms of materials for both tower structure and foundations, and also costs required for transportation, installation, and maintenance. Wind turbines are costly affairs that comprise several complex systems connected altogether (e.g., hub, drive shaft, gearbox, generator, yaw system, electric drive and so on).;The unexpected failure of these components can cause significant machine unavailability and/or damage to other components. This ultimately increases the operation and maintenance (O&M) cost and subsequently cost of energy (COE). Therefore, identifying faults at an early stage before catastrophic damage occurs is the primary objective associated with wind turbine condition monitoring.;Existing wind turbine condition monitoring strategies, for example, vibration signal analysis and oil debris detection, require costly sensors. The additional costs can be significant depending upon the number of wind turbines typically deployed in offshore wind farms and also, costly expertise is generally required to interpret the results. By contrast, Supervisory Control and Data Acquisition (SCADA) data analysis based condition monitoring could underpin condition based maintenance with little or no additional cost to the wind farm operator.;A Gaussian process (GP) is a stochastic, nonlinear and nonparametric model whose distribution function is the joint distribution of a collection of random variables; it is widely suitable for classification and regression problems. GP is a machine learning algorithm that uses a measure of similarity between subsequent data points (via covariance functions) to fit and or estimate the future value from a training dataset. GP models have been applied to numerous multivariate and multi-task problems including spatial and spatiotemporal contexts.;Furthermore, GP models have been applied to electricity price and residential probabilistic load forecasting, solar power forecasting. However, the application of GPs to wind turbine condition monitoring has to date been limited and not much explored.;This thesis focuses on GP based wind turbine condition monitoring that utilises data from SCADA systems exclusively. The selection of the covariance function greatly influences GP model accuracy. A comparative analysis of different covariance functions for GP models is presented with an in-depth analysis of popularly used stationary covariance functions. Based on this analysis, a suitable covariance function is selected for constructing a GP model-based fault detection algorithm for wind turbine condition monitoring.;By comparing incoming operational SCADA data, effective component condition indicators can be derived where the reference model is based on SCADA data from a healthy turbine constructed and compared against incoming data from a faulty turbine. In this thesis, a GP algorithm is constructed with suitable covariance function to detect incipient turbine operational faults or failures before they result in catastrophic damage so that preventative maintenance can be scheduled in a timely manner.;In order to judge GP model effectiveness, two other methods, based on binning, have been tested and compared with the GP based algorithm. This thesis also considers a range of critical turbine parameters and their impact on the GP fault detection algorithm.;Power is well known to be influenced by air density, and this is reflected in the IEC Standard air density correction procedure. Hence, the proper selection of an air density correction approach can improve the power curve model. This thesis addresses this, explores the different types of air density correction approach, and suggests the best way to incorporate these in the GP models to improve accuracy and reduce uncertainty.;Finally, a SCADA data based fault detection algorithm is constructed to detect failures caused by the yaw misalignment. Two fault detection algorithms based on IEC binning methods (widely used within the wind industry) are developed to assess the performance of the GP based fault detection algorithm in terms of their capability to detect in advance (and by how much) signs of failure, and also their false positive rate by making use of extensive SCADA data and turbine fault and repair logs.;GP models are robust in identifying early anomalies/failures that cause the wind turbine to underperform. This early detection is helpful in preventing machines to reach the catastrophic stage and allow enough time to undertake scheduled maintenance, which ultimately reduces the O&M, cost and maximises the power performance of wind turbines. Overall, results demonstrate the effectiveness of the GP algorithm in improving the performance of wind turbines through condition monitoring.Wind energy has seen remarkable growth in the past decade, and installed wind turbine capacity is increasing significantly every year around the globe. The presence of an excellent offshore wind resource and the need to reduce carbon emissions from electricity generation are driving policy to increase offshore wind generation capacity in UK waters. Logistic and transport issues make offshore maintenance costlier than onshore and availability correspondingly lower, and as a result, there is a growing interest in wind turbine condition monitoring allowing condition based, rather than corrective or scheduled, maintenance.;Offshore wind turbine manufacturers are constantly increasing the rated size the turbines, and also their hub height in order to access higher wind speeds with lower turbulence. However, such scaling up leads to significant increments in terms of materials for both tower structure and foundations, and also costs required for transportation, installation, and maintenance. Wind turbines are costly affairs that comprise several complex systems connected altogether (e.g., hub, drive shaft, gearbox, generator, yaw system, electric drive and so on).;The unexpected failure of these components can cause significant machine unavailability and/or damage to other components. This ultimately increases the operation and maintenance (O&M) cost and subsequently cost of energy (COE). Therefore, identifying faults at an early stage before catastrophic damage occurs is the primary objective associated with wind turbine condition monitoring.;Existing wind turbine condition monitoring strategies, for example, vibration signal analysis and oil debris detection, require costly sensors. The additional costs can be significant depending upon the number of wind turbines typically deployed in offshore wind farms and also, costly expertise is generally required to interpret the results. By contrast, Supervisory Control and Data Acquisition (SCADA) data analysis based condition monitoring could underpin condition based maintenance with little or no additional cost to the wind farm operator.;A Gaussian process (GP) is a stochastic, nonlinear and nonparametric model whose distribution function is the joint distribution of a collection of random variables; it is widely suitable for classification and regression problems. GP is a machine learning algorithm that uses a measure of similarity between subsequent data points (via covariance functions) to fit and or estimate the future value from a training dataset. GP models have been applied to numerous multivariate and multi-task problems including spatial and spatiotemporal contexts.;Furthermore, GP models have been applied to electricity price and residential probabilistic load forecasting, solar power forecasting. However, the application of GPs to wind turbine condition monitoring has to date been limited and not much explored.;This thesis focuses on GP based wind turbine condition monitoring that utilises data from SCADA systems exclusively. The selection of the covariance function greatly influences GP model accuracy. A comparative analysis of different covariance functions for GP models is presented with an in-depth analysis of popularly used stationary covariance functions. Based on this analysis, a suitable covariance function is selected for constructing a GP model-based fault detection algorithm for wind turbine condition monitoring.;By comparing incoming operational SCADA data, effective component condition indicators can be derived where the reference model is based on SCADA data from a healthy turbine constructed and compared against incoming data from a faulty turbine. In this thesis, a GP algorithm is constructed with suitable covariance function to detect incipient turbine operational faults or failures before they result in catastrophic damage so that preventative maintenance can be scheduled in a timely manner.;In order to judge GP model effectiveness, two other methods, based on binning, have been tested and compared with the GP based algorithm. This thesis also considers a range of critical turbine parameters and their impact on the GP fault detection algorithm.;Power is well known to be influenced by air density, and this is reflected in the IEC Standard air density correction procedure. Hence, the proper selection of an air density correction approach can improve the power curve model. This thesis addresses this, explores the different types of air density correction approach, and suggests the best way to incorporate these in the GP models to improve accuracy and reduce uncertainty.;Finally, a SCADA data based fault detection algorithm is constructed to detect failures caused by the yaw misalignment. Two fault detection algorithms based on IEC binning methods (widely used within the wind industry) are developed to assess the performance of the GP based fault detection algorithm in terms of their capability to detect in advance (and by how much) signs of failure, and also their false positive rate by making use of extensive SCADA data and turbine fault and repair logs.;GP models are robust in identifying early anomalies/failures that cause the wind turbine to underperform. This early detection is helpful in preventing machines to reach the catastrophic stage and allow enough time to undertake scheduled maintenance, which ultimately reduces the O&M, cost and maximises the power performance of wind turbines. Overall, results demonstrate the effectiveness of the GP algorithm in improving the performance of wind turbines through condition monitoring
Aerodynamic engineering of a pulmonary prime-pull vaccine against Tuberculosis
Get PDFTuberculosis (TB) remains the infectious disease with the highest mortality alongside HIV. Despite the existence of the Bacillus Calmette-Guerin (BCG) vaccine there is an unmet need for an effective vaccine against pulmonary TB, the most common form of TB. Traditional vaccines were based on live-attenuated organisms, but nowadays the development of subunit vaccines is attracting the attention of researches largely as a result of the improved safety profile. However, many subunit vaccines lack potent immunogenicity, therefore the inclusion of an adjuvant within the subunit vaccine formulation may be required.;Due to the optimal biological properties of the lipids, liposomes are extensively studied as delivery systems along with polymer-based particulate systems such as the well-known poly(lactic-co-glycolic acid) family (PLGA). The cationic liposomal adjuvant formulation (CAF) 01, which is based on the cationic surfactant dimethyldioctadecylammonium (DDA) bromide and the immunopotentiator trehalose 6,6'-dibehenate (TDB) from Mycobacterium tuberculosis, has previously been shown to be a strong adjuvant system against several diseases such as TB. CAF01 is commonly prepared by the thin film method which has several drawbacks including scale-up and reproducibility.;In contrast, controllable technologies such as microfluidics have advantages in material preparation such as uniform flow and mixing, high efficiency, continuous operation, easy control and low cost. Therefore, initial studies were focused towards method optimisation of CAF01 through microfluidics, followed by in vivo evaluation of the optimised formulation (biodistribution and immunisation studies). The second part of the thesis was based in the formulation PLGA nano- and microparticles using microfluidics and the double emulsion method respectively.;All formulations were characterised according to their size, polydispersity and surface charge as empty particulate systems and incorporating either ovalbumin (OVA) as a model antigen or the vaccine candidate Ag85B-ESAT6-Rv2660c (H56). Selected PLGA particles were formulated as dry powders for inhalation and for the delivery of the H56 tuberculosis antigen into the deep lungs (alveoli). In vitro deposition within the lungs was evaluated using a Pharmacopoeia approved airway simulator, while cell viability, particle uptake and antigen processing was assessed in three macrophages cell lines.;Finally, a prime-pull vaccine approach for protection against pulmonary TB was investigated. An immunisation protocol consisting of parenteral (subcutaneous) priming with the TB vaccine candidate H56 alongside CAF01 followed by respiratory mucosal boosting of the H56 within PLGA nano- and micropaticles was carried out in order to elucidate if intranasal administration of the H56 antigen produces the desired immunological responses for the protection against pulmonary TB.;The immune responses generated indicate the retention of the immunogenicity of the antigen encapsulated within a lyophilised PLGA delivery system, demonstrating the successful scale independent manufacture of polymer based delivery systems encapsulating antigens for inhalation/aerolisation delivery to the lung mucosa.Tuberculosis (TB) remains the infectious disease with the highest mortality alongside HIV. Despite the existence of the Bacillus Calmette-Guerin (BCG) vaccine there is an unmet need for an effective vaccine against pulmonary TB, the most common form of TB. Traditional vaccines were based on live-attenuated organisms, but nowadays the development of subunit vaccines is attracting the attention of researches largely as a result of the improved safety profile. However, many subunit vaccines lack potent immunogenicity, therefore the inclusion of an adjuvant within the subunit vaccine formulation may be required.;Due to the optimal biological properties of the lipids, liposomes are extensively studied as delivery systems along with polymer-based particulate systems such as the well-known poly(lactic-co-glycolic acid) family (PLGA). The cationic liposomal adjuvant formulation (CAF) 01, which is based on the cationic surfactant dimethyldioctadecylammonium (DDA) bromide and the immunopotentiator trehalose 6,6'-dibehenate (TDB) from Mycobacterium tuberculosis, has previously been shown to be a strong adjuvant system against several diseases such as TB. CAF01 is commonly prepared by the thin film method which has several drawbacks including scale-up and reproducibility.;In contrast, controllable technologies such as microfluidics have advantages in material preparation such as uniform flow and mixing, high efficiency, continuous operation, easy control and low cost. Therefore, initial studies were focused towards method optimisation of CAF01 through microfluidics, followed by in vivo evaluation of the optimised formulation (biodistribution and immunisation studies). The second part of the thesis was based in the formulation PLGA nano- and microparticles using microfluidics and the double emulsion method respectively.;All formulations were characterised according to their size, polydispersity and surface charge as empty particulate systems and incorporating either ovalbumin (OVA) as a model antigen or the vaccine candidate Ag85B-ESAT6-Rv2660c (H56). Selected PLGA particles were formulated as dry powders for inhalation and for the delivery of the H56 tuberculosis antigen into the deep lungs (alveoli). In vitro deposition within the lungs was evaluated using a Pharmacopoeia approved airway simulator, while cell viability, particle uptake and antigen processing was assessed in three macrophages cell lines.;Finally, a prime-pull vaccine approach for protection against pulmonary TB was investigated. An immunisation protocol consisting of parenteral (subcutaneous) priming with the TB vaccine candidate H56 alongside CAF01 followed by respiratory mucosal boosting of the H56 within PLGA nano- and micropaticles was carried out in order to elucidate if intranasal administration of the H56 antigen produces the desired immunological responses for the protection against pulmonary TB.;The immune responses generated indicate the retention of the immunogenicity of the antigen encapsulated within a lyophilised PLGA delivery system, demonstrating the successful scale independent manufacture of polymer based delivery systems encapsulating antigens for inhalation/aerolisation delivery to the lung mucosa
Effect of density change on flux response systems
No full textFlux response technology is a technique for using differential measurements of flow rates as changes occur caused by adsorption, reaction and desorption in a continuous flow reactor. This work looks at using a gas chromatographic column as the reactor and uses the concepts of capillary and perturbation viscometry to quantify the effects of density change on fluxresponse on the reactor. Experiments were conducted using basic equipment including a volume and different resistance set up in a Wheatstone bridge arrangement so that differential measurements can be obtained. Firstly, changes were made by perturbing the flow into the system with pressure. Secondly, changes were made to the system by perturbing with a gas flow. Measurements were taken using a differential pressure transducer (DPT) to measure the flux response and the results were used to determine the volume in the system. Further experiments were conducted to validate theoretical derivations of the operation of a gas density detector (GDD) which could be used as a gas chromatographic detector. Experiments using nitrogen and argon as the main and perturbation gases were completed. Results were obtained using the DPT and the GDD and verified the theoretical derivations. The results showed that when the perturbation gas is of a higher density to that of the main gas, there is a distinct positive step in the both the DPT and GDD readings. There is negative step when the perturbation gas has a lower density which was as expected. Helium experiments proved problematic as there were potential issues with viscosity change affecting the detector response producing some anomalous results so further work is required to investigate this. Additional work using different gas components would be advantageous.Flux response technology is a technique for using differential measurements of flow rates as changes occur caused by adsorption, reaction and desorption in a continuous flow reactor. This work looks at using a gas chromatographic column as the reactor and uses the concepts of capillary and perturbation viscometry to quantify the effects of density change on fluxresponse on the reactor. Experiments were conducted using basic equipment including a volume and different resistance set up in a Wheatstone bridge arrangement so that differential measurements can be obtained. Firstly, changes were made by perturbing the flow into the system with pressure. Secondly, changes were made to the system by perturbing with a gas flow. Measurements were taken using a differential pressure transducer (DPT) to measure the flux response and the results were used to determine the volume in the system. Further experiments were conducted to validate theoretical derivations of the operation of a gas density detector (GDD) which could be used as a gas chromatographic detector. Experiments using nitrogen and argon as the main and perturbation gases were completed. Results were obtained using the DPT and the GDD and verified the theoretical derivations. The results showed that when the perturbation gas is of a higher density to that of the main gas, there is a distinct positive step in the both the DPT and GDD readings. There is negative step when the perturbation gas has a lower density which was as expected. Helium experiments proved problematic as there were potential issues with viscosity change affecting the detector response producing some anomalous results so further work is required to investigate this. Additional work using different gas components would be advantageous
The use of non-ionic surfactant vesicles to prevent radiocontrast media-associated damage
Get PDFRadiocontrast media administered during routine bio-imaging procedures represents a cause of hospital-associated, acute kidney injury or contrast-induced nephropathy. The exact mechanism of disease is not well characterised, although, a number of existing theories exist. The absence of adequate preventative or treatment measures poses a risk to poorly defined, susceptible patients. The initial goal is to formulate and characterise a novel iohexol-non-ionic surfactant vesicle (IOX-NIV) delivery system in line with FDA recommendations. This work adds to current knowledge of IOX-associated cytotoxicity and its influence on vessel function. IOX-NIVs were prepared using a 3: 3: 1 mol. ratio of surfactant VIII/ cholesterol/ dicetyl phosphate using high shear homogenisation. Dynamic light scattering was used to determine physical characteristics including size, polydispersity index (PDI) and particle distribution. Phase analysis light scattering was used to measure surface charge. NIVs were purified using ultracentrifugation prior to the quantification of IOX encapsulation efficiency and release using high performance liquid chromatography. Toxicity of IOX, empty-NIV and IOX-NIV was tested on renal and vascular cells using assays including the Resazurin metabolic indicator assay, thymidine-incorporation, CellTox Green™ assay and ApoToxGlo™ assay. IOX-NIVs were reproducibly produced (n = 3) with an average size of 204 ± 24 nm, low PDI of 0.13 ± 0.04, surface charge of -26 ± 1 mV and EE of 22 ± 3%. Vesicle processing through ultracentrifugation or sterile filtration did not significantly alter physical properties. IOX-NIVs maintained physicochemical stability throughout 37 weeks storage at 4 and 25 °C. A time- and temperature-dependent change in IOX-NIV colour was observed prior to an increase in size (1671 ± 1498 nm) and PDI (0.7 ± 0.31), followed by a loss in negativity (-15 ± 3 mV) and EE (4 ± 3 %), specifically at temperatures of 37 and 50°C (p < 0.001). Hydrated IOX-NIVs displayed a typical 'burst' release profile under physiological conditions in vitro, whereby 73 ± 2 % of IOX was released after 48 h. IOX exposure led to decreased renal and vascular metabolism where cells underwent rounding and a loss in adherence, features of which express similarities to cells undergoing apoptosis or as a result of exposure to hyperosmolar agents. In addition, IOX inhibited receptor-independent vasoconstriction, while IOX-NIV treated groups expressed a response similar to the control. Characterisation of IOX-NIVs showed the synthesis of a stable system with physical features desirable for administration as an intravenous contrast agent. IOX-NIVs expressed relatively low toxicity in vitro. Overall, IOX-NIV show great potential as a clinically compatible product, however, future in vivo safety and efficacy studies are required.Radiocontrast media administered during routine bio-imaging procedures represents a cause of hospital-associated, acute kidney injury or contrast-induced nephropathy. The exact mechanism of disease is not well characterised, although, a number of existing theories exist. The absence of adequate preventative or treatment measures poses a risk to poorly defined, susceptible patients. The initial goal is to formulate and characterise a novel iohexol-non-ionic surfactant vesicle (IOX-NIV) delivery system in line with FDA recommendations. This work adds to current knowledge of IOX-associated cytotoxicity and its influence on vessel function. IOX-NIVs were prepared using a 3: 3: 1 mol. ratio of surfactant VIII/ cholesterol/ dicetyl phosphate using high shear homogenisation. Dynamic light scattering was used to determine physical characteristics including size, polydispersity index (PDI) and particle distribution. Phase analysis light scattering was used to measure surface charge. NIVs were purified using ultracentrifugation prior to the quantification of IOX encapsulation efficiency and release using high performance liquid chromatography. Toxicity of IOX, empty-NIV and IOX-NIV was tested on renal and vascular cells using assays including the Resazurin metabolic indicator assay, thymidine-incorporation, CellTox Green™ assay and ApoToxGlo™ assay. IOX-NIVs were reproducibly produced (n = 3) with an average size of 204 ± 24 nm, low PDI of 0.13 ± 0.04, surface charge of -26 ± 1 mV and EE of 22 ± 3%. Vesicle processing through ultracentrifugation or sterile filtration did not significantly alter physical properties. IOX-NIVs maintained physicochemical stability throughout 37 weeks storage at 4 and 25 °C. A time- and temperature-dependent change in IOX-NIV colour was observed prior to an increase in size (1671 ± 1498 nm) and PDI (0.7 ± 0.31), followed by a loss in negativity (-15 ± 3 mV) and EE (4 ± 3 %), specifically at temperatures of 37 and 50°C (p < 0.001). Hydrated IOX-NIVs displayed a typical 'burst' release profile under physiological conditions in vitro, whereby 73 ± 2 % of IOX was released after 48 h. IOX exposure led to decreased renal and vascular metabolism where cells underwent rounding and a loss in adherence, features of which express similarities to cells undergoing apoptosis or as a result of exposure to hyperosmolar agents. In addition, IOX inhibited receptor-independent vasoconstriction, while IOX-NIV treated groups expressed a response similar to the control. Characterisation of IOX-NIVs showed the synthesis of a stable system with physical features desirable for administration as an intravenous contrast agent. IOX-NIVs expressed relatively low toxicity in vitro. Overall, IOX-NIV show great potential as a clinically compatible product, however, future in vivo safety and efficacy studies are required
Writing regeneration : literary construction of urban change in postindustrial Glasgow
Get PDFStrathclyde theses - ask staff. Thesis no. : T15216This thesis examines literary engagement with - and resistance to - changing modes of urban regeneration in Glasgow, from its year as the 1990 European City of Culture to the 2014 Commonwealth Games. It not only considers how deindustrialisation and urban regeneration are represented in local writing, but interrogates the impact of urban transformation on the social production of literature, and argues that literary activity has, in turn, influenced the social and material processes of regeneration. It identifies a growing tendency for writers to become involved in participatory work exploring, and potentially mediating, the social impact of regeneration, and contends that this emergent mode of literary labour carries hazards for authors and communities.Drawing on perspectives from cultural policy studies, urban sociology, and new working-class studies to illuminate intersections between regeneration and literary work, it uses a variety of texts, archival sources and interviews to develop a case study approach. Each chapter focuses on a distinct type of urban space and period of urban transformation. Chapter One, concerned with cultural spaces, considers literary protest against Glasgow's 'Culture Year'. It demonstrates that while many writers contributed to events in 1990, such as the Glasgow's Glasgow exhibition and Writing Together festival, its literary legacy remains one of radical resistance. Chapter Two turns to domestic spaces, considering collaborative literary work in the context of housing regeneration - particularly Alison Irvine's This Road is Red (2011) which memorialises the Red Road Flats' social history. Chapter Three focuses on contests over public space, attending to the relationship between literary practice, community development and public health. Its principle case studies include Benjamin Obler's novel portraying the Pollok Free State protest camp, Javascotia (2009), and Alison Irvine's Nothing is Lost (2015) which reflects on the use and ownership of public spacein Glasgow's East End during the Commonwealth Games.This thesis examines literary engagement with - and resistance to - changing modes of urban regeneration in Glasgow, from its year as the 1990 European City of Culture to the 2014 Commonwealth Games. It not only considers how deindustrialisation and urban regeneration are represented in local writing, but interrogates the impact of urban transformation on the social production of literature, and argues that literary activity has, in turn, influenced the social and material processes of regeneration. It identifies a growing tendency for writers to become involved in participatory work exploring, and potentially mediating, the social impact of regeneration, and contends that this emergent mode of literary labour carries hazards for authors and communities.Drawing on perspectives from cultural policy studies, urban sociology, and new working-class studies to illuminate intersections between regeneration and literary work, it uses a variety of texts, archival sources and interviews to develop a case study approach. Each chapter focuses on a distinct type of urban space and period of urban transformation. Chapter One, concerned with cultural spaces, considers literary protest against Glasgow's 'Culture Year'. It demonstrates that while many writers contributed to events in 1990, such as the Glasgow's Glasgow exhibition and Writing Together festival, its literary legacy remains one of radical resistance. Chapter Two turns to domestic spaces, considering collaborative literary work in the context of housing regeneration - particularly Alison Irvine's This Road is Red (2011) which memorialises the Red Road Flats' social history. Chapter Three focuses on contests over public space, attending to the relationship between literary practice, community development and public health. Its principle case studies include Benjamin Obler's novel portraying the Pollok Free State protest camp, Javascotia (2009), and Alison Irvine's Nothing is Lost (2015) which reflects on the use and ownership of public spacein Glasgow's East End during the Commonwealth Games
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