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Control strategy for constant-speed wind turbine in below rated wind speed
Get PDFThe objective of this thesis is to design a control strategy to improve power capture in below rated wind speed for constant speed pitch regulated wind turbines.To achieve the objective of this thesis, it is convenient to model rotor/wind-field interaction by a simple ordinary differential equation. It is also required to use a simple model to represent the dynamic behaviour of a grid connected constant speed horizontal axis wind turbine to assess the performance of the proposed control strategy. Simulink based simulations of the wind model and turbine dynamics combined with the control strategy is performed to analyse its performance and to estimate the extra power capture by using the control system in below rated wind speed in comparison to running the turbine with fixed blade pitch angle (without the use of control strategy) in the same region.The objective of this thesis is to design a control strategy to improve power capture in below rated wind speed for constant speed pitch regulated wind turbines.To achieve the objective of this thesis, it is convenient to model rotor/wind-field interaction by a simple ordinary differential equation. It is also required to use a simple model to represent the dynamic behaviour of a grid connected constant speed horizontal axis wind turbine to assess the performance of the proposed control strategy. Simulink based simulations of the wind model and turbine dynamics combined with the control strategy is performed to analyse its performance and to estimate the extra power capture by using the control system in below rated wind speed in comparison to running the turbine with fixed blade pitch angle (without the use of control strategy) in the same region
An articulated drill and hybrid tracking navigation system for orthopaedic surgery
Get PDFThe need for an articulated drill is driven by the increasing clinical requirement for improving the surgical outcomes and decreasing the complications of the THA procedure. Besides that, after the total hip arthroplasty (THA) procedure, there is also probability of the patient ending up with unequal leg lengths, which are referred to as a leg-length discrepancy (LLD). One way to reduce the risk in THA procedure is improving accurate placement and alignment of implants using robotic technology. In Total Hip Arthroplasty (THA), the usage of robotic orthopaedic surgery per se is applied in the acetabular cup positioning and orientation, and femoral stem positioning. However, in robotic orthopaedic surgery with tracking and navigation system, the femoral stem insertion depends on hand-rasping method and confirmation of position by placing tracking marker at the neck shaft of femoral stem after insertion. Besides that, femoral milling with navigation for anatomical femoral stem insertion was not feasible due to its slightly curved profile. This is because current tools are not able to track milling that follows the curve profile of anatomical femoral stem. The emergence of robotic micro-tools give opportunity for developing an articulated drill system that has the ability to mill inside femoral canal when it is combined with CAOS and is trackable under minimally invasive approach.;The research has the objectives of design and development of articulated drill sheath with motor control from straight shaft to bendable shaft, design and development of hybrid tracking system, combination between optical tracking system and potentiometer tracking system in order to track surgical tool inside the bone, design and development of navigation software for articulated drill sheath, to measure reaction force when milling in different bending configurations and rake angles, and understanding the static performance of articulated drill system under different configurations, and confirm the capability of the articulated drill system to sustain bending when milling under different configuration, to analyse the 3D geometry of curved tunnel from milling guided by the navigation system, and test the accuracy of the navigation system in milling the femoral stem shape inside femur sawbone.;Articulated drill tip sheath with motor control from straight shaft to bendable shaft was designed and developed. Besides that, hybrid tracking system, combination between optical tracking system and potentiometer tracking system in order to track surgical tool inside the bone was also designed and developed. Streams of input from both optical tracking system and potentiometer tracking system are integrated in the navigation software of articulated drill navigation system. The navigation system for articulated drill sheath was designed and developed. The navigation system is a multi-modality computer-aided integration system. The navigation software is able to integrate optical tracking system and potentiometer tracking system.;Experiment on measurement of reaction force has been done. The reaction force when milling in different bending configuration and rake angles has been measured, and the static performance of articulated drill system under different configurations has been understood. The articulated drill system is bale to sustain bending in different configurations while milling the bone sample. The articulated drill system was integrated and was used for evaluative experiments in sawbones. 3D geometric analysis of the shape of the cut area experiment was done. The analysis of results confirmed that the tracking system is able to guide the articulated drill inside femur, in which a deviation from cut area and outline of femoral stem from navigation software was in range from -0.759 mm to 1.151 mm. Accuracy Analysis/Symmetry Analysis experiment was done. The accuracy of the navigation system is within 1.728 mm. Keywords - Robotics; Articulated; Tracking; Navigation; Hybrid Navigation; Orthopaedics; Total Hip arthroplasty (THA).The need for an articulated drill is driven by the increasing clinical requirement for improving the surgical outcomes and decreasing the complications of the THA procedure. Besides that, after the total hip arthroplasty (THA) procedure, there is also probability of the patient ending up with unequal leg lengths, which are referred to as a leg-length discrepancy (LLD). One way to reduce the risk in THA procedure is improving accurate placement and alignment of implants using robotic technology. In Total Hip Arthroplasty (THA), the usage of robotic orthopaedic surgery per se is applied in the acetabular cup positioning and orientation, and femoral stem positioning. However, in robotic orthopaedic surgery with tracking and navigation system, the femoral stem insertion depends on hand-rasping method and confirmation of position by placing tracking marker at the neck shaft of femoral stem after insertion. Besides that, femoral milling with navigation for anatomical femoral stem insertion was not feasible due to its slightly curved profile. This is because current tools are not able to track milling that follows the curve profile of anatomical femoral stem. The emergence of robotic micro-tools give opportunity for developing an articulated drill system that has the ability to mill inside femoral canal when it is combined with CAOS and is trackable under minimally invasive approach.;The research has the objectives of design and development of articulated drill sheath with motor control from straight shaft to bendable shaft, design and development of hybrid tracking system, combination between optical tracking system and potentiometer tracking system in order to track surgical tool inside the bone, design and development of navigation software for articulated drill sheath, to measure reaction force when milling in different bending configurations and rake angles, and understanding the static performance of articulated drill system under different configurations, and confirm the capability of the articulated drill system to sustain bending when milling under different configuration, to analyse the 3D geometry of curved tunnel from milling guided by the navigation system, and test the accuracy of the navigation system in milling the femoral stem shape inside femur sawbone.;Articulated drill tip sheath with motor control from straight shaft to bendable shaft was designed and developed. Besides that, hybrid tracking system, combination between optical tracking system and potentiometer tracking system in order to track surgical tool inside the bone was also designed and developed. Streams of input from both optical tracking system and potentiometer tracking system are integrated in the navigation software of articulated drill navigation system. The navigation system for articulated drill sheath was designed and developed. The navigation system is a multi-modality computer-aided integration system. The navigation software is able to integrate optical tracking system and potentiometer tracking system.;Experiment on measurement of reaction force has been done. The reaction force when milling in different bending configuration and rake angles has been measured, and the static performance of articulated drill system under different configurations has been understood. The articulated drill system is bale to sustain bending in different configurations while milling the bone sample. The articulated drill system was integrated and was used for evaluative experiments in sawbones. 3D geometric analysis of the shape of the cut area experiment was done. The analysis of results confirmed that the tracking system is able to guide the articulated drill inside femur, in which a deviation from cut area and outline of femoral stem from navigation software was in range from -0.759 mm to 1.151 mm. Accuracy Analysis/Symmetry Analysis experiment was done. The accuracy of the navigation system is within 1.728 mm. Keywords - Robotics; Articulated; Tracking; Navigation; Hybrid Navigation; Orthopaedics; Total Hip arthroplasty (THA)
Engineering synthetic biology routes for protein analysis using microfluidic systems
No full textMicrofluidics is increasingly being used in many areas of biotechnology and chemistry to achieve reduced reagent volumes, improved performance, integration, and parallelism, among other advantages. The sub-millimetre dimensions of microchannels tend to reduce reagent consumption and waste production, consequently leading to cost savings and permitting precious samples to be relished and divided up for additional assays. Furthermore, the system allows for parallelisation, this way many identical reactions or assays can be replicated on a single microfluidic chip hence increasing throughput, a quality very much desired by pharmaceutical companies.Different steps in a complex process can be combined into a single chip to enhance ease of use, portability and reducing human error-for example, in medical diagnostic devices.Membrane proteins are of great importance as subjects of physiological study,drug targets in high-throughput assays for drug discovery and drug safety screening1. Microfluidic devices can be used for manipulating and analysing proteins, greatly benefiting many of the applications mentioned. The ability to produce artificial membranes within a microfluidic platform is crucial for the realization of these advantages. Current methods of producing and studying artificial cell membranes are typically low-throughput and not automated.;This thesis presents the development of a fully integrated microfluidic system for the production of artificial lipid bilayers based on the miniaturisation of dropletinterface-bilayer (DIB) techniques. The platform uses a microfluidic design that enables formation, alternation, controlled positioning and long-term storage of arrays of droplet-interface-bilayers (DIBs) to mimic cell membrane processes. By encapsulating the desired cocktail of liposomes and metabolites into phospholipid stabilized water-in-oil (W/O) droplets, hundreds of DIBs were characterized. To ensure robustness of operation, we have investigated how lipid concentration,immiscible phase flow velocities and the device geometrical parameters affect the system performance. Finally, proof-of-concept data is shown where diffusive transport of molecules and ions across on-chip DIBs can be studied and quantified using fluorescence-based assays. The ability to quantitatively identify DIB permeation values demonstrates the suitability of our system for investigating processes occurringacross an artificial lipid bilayer in a miniaturised and scalable format.Microfluidics is increasingly being used in many areas of biotechnology and chemistry to achieve reduced reagent volumes, improved performance, integration, and parallelism, among other advantages. The sub-millimetre dimensions of microchannels tend to reduce reagent consumption and waste production, consequently leading to cost savings and permitting precious samples to be relished and divided up for additional assays. Furthermore, the system allows for parallelisation, this way many identical reactions or assays can be replicated on a single microfluidic chip hence increasing throughput, a quality very much desired by pharmaceutical companies.Different steps in a complex process can be combined into a single chip to enhance ease of use, portability and reducing human error-for example, in medical diagnostic devices.Membrane proteins are of great importance as subjects of physiological study,drug targets in high-throughput assays for drug discovery and drug safety screening1. Microfluidic devices can be used for manipulating and analysing proteins, greatly benefiting many of the applications mentioned. The ability to produce artificial membranes within a microfluidic platform is crucial for the realization of these advantages. Current methods of producing and studying artificial cell membranes are typically low-throughput and not automated.;This thesis presents the development of a fully integrated microfluidic system for the production of artificial lipid bilayers based on the miniaturisation of dropletinterface-bilayer (DIB) techniques. The platform uses a microfluidic design that enables formation, alternation, controlled positioning and long-term storage of arrays of droplet-interface-bilayers (DIBs) to mimic cell membrane processes. By encapsulating the desired cocktail of liposomes and metabolites into phospholipid stabilized water-in-oil (W/O) droplets, hundreds of DIBs were characterized. To ensure robustness of operation, we have investigated how lipid concentration,immiscible phase flow velocities and the device geometrical parameters affect the system performance. Finally, proof-of-concept data is shown where diffusive transport of molecules and ions across on-chip DIBs can be studied and quantified using fluorescence-based assays. The ability to quantitatively identify DIB permeation values demonstrates the suitability of our system for investigating processes occurringacross an artificial lipid bilayer in a miniaturised and scalable format
Synthesis and application of tagging agents in mass spectrometry-based targeted metabolomics studies
Get PDFMetabolomics is a technique which provides comprehensive metabolite profiling as well as metabolic pathway elucidation and potentially has a wide range of applications for medical research including disease diagnosis and monitoring. In this thesis, some synthetically prepared and existing tagging agents were applied to targeted quantitative analysis of certain metabolites in biological samples. The thesis is divided into six chapters: Chapter one provides a general introduction to metabolomics and to the use of chemical tagging in targeted analysis and briefly looks at the type of instrumentation used in metabolomics profiling. Chapter two, described the synthesis of the tagging agent trimethyl(p-aminophenyl) ammonium chloride (PMTA) and along with aniline and D5-aniline was assessed for suitability for the analysis of hexose sugars. The detection of the sugars by hydrophilic interaction chromatography (HILIC) in combination with mass spectrormetry (MS) was greatly improved along with chromatographic resolution allowing for easy identification of sugar isomers. In Chapter three, analysis of short chain fatty acids utilising N-(-3-Dimethylaminopropyl)-Nethylcarbodiimide hydrochlorice (EDC) and N, N-Dimethyl-p-phenylenediamine (DPD) as derivatizing agents was carried out on urine samples from the [sic].;The aim of the study was to evaluate the novel CDTREAT diet in comparison to the standard enteral nutrition (EEN) diet. The study confirmed that the detection and quantification of SCFAs by LCMS was greatly enhanced by derivatisation and showed no difference in the levels of SCFAs between the treatment and control groups which implies that the diets had similar effects on the levels of SCFAs in urine and thus could be deemed equivalent. In Chapter four, an investigation of the effect of ultramarathon exercise on oxylipin metabolites in plasma samples from the University of Kingston was carried out. In this study 2-fluoro-3-methyl pyridine (FMP) was utilised as a catalyst to add choline as a tagging agent which facilitated the sensitive detection and quantification of the oxylipins. These compounds are thought to have biological effects on blood flow. Statistical analysis of the results showed no significant change in the amounts of any of the oxylipins in the study pre and post-exercise.;In Chapter five, a study to determine the variation in four monosaccharides from stool samples of a group of IBS suffers plus controls was undertaken using D5-aniline as the tagging agent. The data generated in this study appears on analysis to indicate a clear difference in the levels of some sugars between each of the test groups (UC, CD and healthy controls) which might be a result of alteration in the microbiome in CD. This is significant because it implies that this could be developed as not only a diagnostic tool for IBS it can be used to differentiate between sufferers of CD and UC. In Chapter 6, 2-Hydrazino-1-methylpyridine (HMP), as well as a novel analogue of HMP, MHMP, and its deuterated analogue MHMP-d3 were synthesised. The HMP was passed on to a co-worker who utilised it in a separate study for the analysis of androgens in saliva. It was however not possible to detect any of the tagged steroids utilising MHMP-d3 which may be due to difficulties in obtaining the reagent in high purity.Metabolomics is a technique which provides comprehensive metabolite profiling as well as metabolic pathway elucidation and potentially has a wide range of applications for medical research including disease diagnosis and monitoring. In this thesis, some synthetically prepared and existing tagging agents were applied to targeted quantitative analysis of certain metabolites in biological samples. The thesis is divided into six chapters: Chapter one provides a general introduction to metabolomics and to the use of chemical tagging in targeted analysis and briefly looks at the type of instrumentation used in metabolomics profiling. Chapter two, described the synthesis of the tagging agent trimethyl(p-aminophenyl) ammonium chloride (PMTA) and along with aniline and D5-aniline was assessed for suitability for the analysis of hexose sugars. The detection of the sugars by hydrophilic interaction chromatography (HILIC) in combination with mass spectrormetry (MS) was greatly improved along with chromatographic resolution allowing for easy identification of sugar isomers. In Chapter three, analysis of short chain fatty acids utilising N-(-3-Dimethylaminopropyl)-Nethylcarbodiimide hydrochlorice (EDC) and N, N-Dimethyl-p-phenylenediamine (DPD) as derivatizing agents was carried out on urine samples from the [sic].;The aim of the study was to evaluate the novel CDTREAT diet in comparison to the standard enteral nutrition (EEN) diet. The study confirmed that the detection and quantification of SCFAs by LCMS was greatly enhanced by derivatisation and showed no difference in the levels of SCFAs between the treatment and control groups which implies that the diets had similar effects on the levels of SCFAs in urine and thus could be deemed equivalent. In Chapter four, an investigation of the effect of ultramarathon exercise on oxylipin metabolites in plasma samples from the University of Kingston was carried out. In this study 2-fluoro-3-methyl pyridine (FMP) was utilised as a catalyst to add choline as a tagging agent which facilitated the sensitive detection and quantification of the oxylipins. These compounds are thought to have biological effects on blood flow. Statistical analysis of the results showed no significant change in the amounts of any of the oxylipins in the study pre and post-exercise.;In Chapter five, a study to determine the variation in four monosaccharides from stool samples of a group of IBS suffers plus controls was undertaken using D5-aniline as the tagging agent. The data generated in this study appears on analysis to indicate a clear difference in the levels of some sugars between each of the test groups (UC, CD and healthy controls) which might be a result of alteration in the microbiome in CD. This is significant because it implies that this could be developed as not only a diagnostic tool for IBS it can be used to differentiate between sufferers of CD and UC. In Chapter 6, 2-Hydrazino-1-methylpyridine (HMP), as well as a novel analogue of HMP, MHMP, and its deuterated analogue MHMP-d3 were synthesised. The HMP was passed on to a co-worker who utilised it in a separate study for the analysis of androgens in saliva. It was however not possible to detect any of the tagged steroids utilising MHMP-d3 which may be due to difficulties in obtaining the reagent in high purity
Image analysis on hyperspectral corneal epithelium injuries using a new image enhancement and a novel mixing kernel
Get PDFThe work presented in this thesis is to improve the evaluation of corneal injuries with the aim of eliminating the application of eye stains. In the case of this study, a new algorithm of image enhancement, mixture deep learning classification, and a novel mixing kernel for support vector machine are proposed to provide objective measurements. The proposed algorithms of image enhancement and the mixing kernel in this study are to provide a new contribution to knowledge in the field of ophthalmology and machine learning. To the authors' knowledge, this is the first analysis of 25 corneal epithelium of porcine eyes using hyperspectral imaging combined with image processing algorithm. In addition, four series of experiments on the cornea were carried out with and without eye staining through the HSI scanning method. The analysis mainly focused on the eyes without staining, while the stained eyes were used as the ground truth images for the purpose of identifying the injured area.In this study, a new 8-Step Hyperspectral Image Enhancement (8-SHIE) was developed to differentiate the injured and healthy corneas. The results showed that the proposed algorithm was able to clearly highlight the boundary of the injury. This algorithm was further tested on the existing remote-sensing Indian Pines dataset in order to ascertain that it can work well with other hyperspectral images. Moreover, the algorithm can also be used to monitor the cornea healing process considering that the injured boundary can be viewed from band-to-band. Overall, it can be concluded that this algorithm is able to successfully separates the ten varying classes despite its main purpose of distinguishing the two classes. All the enhanced images are then classified using mixture deep-learning technique.This study also introduced a novel design of mixing kernels (3-ConvSvm) for binary classification in support vector machine classifier. Three standard kernels, namely RBF, polynomial, and RQK are combined in order to provide more learning flexibility due to the various parameters setting. The algorithms proposed aim to minimise the generalisation error during the classification when one or more parameters is tuned. Apart from that, the numerical experiments also showed that the new kernel performs similarly and sometimes even better than the standard kernels (RBF, polynomial, RQK, mixed two-kernels). Finally, the results revealed that the performance of 3-ConvSvm able to reduce the error loss by tuned the kernel parameters.The work presented in this thesis is to improve the evaluation of corneal injuries with the aim of eliminating the application of eye stains. In the case of this study, a new algorithm of image enhancement, mixture deep learning classification, and a novel mixing kernel for support vector machine are proposed to provide objective measurements. The proposed algorithms of image enhancement and the mixing kernel in this study are to provide a new contribution to knowledge in the field of ophthalmology and machine learning. To the authors' knowledge, this is the first analysis of 25 corneal epithelium of porcine eyes using hyperspectral imaging combined with image processing algorithm. In addition, four series of experiments on the cornea were carried out with and without eye staining through the HSI scanning method. The analysis mainly focused on the eyes without staining, while the stained eyes were used as the ground truth images for the purpose of identifying the injured area.In this study, a new 8-Step Hyperspectral Image Enhancement (8-SHIE) was developed to differentiate the injured and healthy corneas. The results showed that the proposed algorithm was able to clearly highlight the boundary of the injury. This algorithm was further tested on the existing remote-sensing Indian Pines dataset in order to ascertain that it can work well with other hyperspectral images. Moreover, the algorithm can also be used to monitor the cornea healing process considering that the injured boundary can be viewed from band-to-band. Overall, it can be concluded that this algorithm is able to successfully separates the ten varying classes despite its main purpose of distinguishing the two classes. All the enhanced images are then classified using mixture deep-learning technique.This study also introduced a novel design of mixing kernels (3-ConvSvm) for binary classification in support vector machine classifier. Three standard kernels, namely RBF, polynomial, and RQK are combined in order to provide more learning flexibility due to the various parameters setting. The algorithms proposed aim to minimise the generalisation error during the classification when one or more parameters is tuned. Apart from that, the numerical experiments also showed that the new kernel performs similarly and sometimes even better than the standard kernels (RBF, polynomial, RQK, mixed two-kernels). Finally, the results revealed that the performance of 3-ConvSvm able to reduce the error loss by tuned the kernel parameters
Phase behaviour and crystal nucleation in complex multicomponent system
Get PDFThe continuing research and use of co-crystallisation for separation, purification and modification of pharmaceutical materials in multiple industrial sectors can be attributed to the potential for high control of product quality attributes. Nucleation is a key phenomenon in crystallisation that can control product purity, morphology and crystal size distribution. Despite the use of co-crystallisation in manner mentioned above, not a lot is known about nucleation kinetics in multicomponent systems. This thesis aims to identify gaps in knowledge and presents useful tools and methods pertinent to co-crystallisation in three themes. The first part deals with co-crystallisation within the scope of identifying factors that influence co-crystal solubility phase diagram (Chapter 3) in a workflow. Co-crystal screening methods is considered with the objective to compare and contrast approaches to increase chances of forming a co-crystal and extend an already established co-crystal screening workflow (Chapter 4). The third part addresses nucleation kinetics in multicomponent systems. Once the phase diagram is elucidated the effect of solution stoichiometry on nucleation kinetics in ternary systems is then investigated (Chapter 5). In a move to increase our knowledge of heterogeneous nucleation, a new approach to determine induction time through thermal changes when transmission of light is not reliable was developed and used to measure nucleation rates of small organic molecules (Chapter 6). Therefore, scaling previous experimental limitations and opening up new opportunities for co-crystal studies. The author is confident that the workflow developed for co-crystal phase diagram and heterogeneous nucleation method presented in this thesis would benefit future research in cocrystal nucleation from solution by informing experimental design and experimental configuration.The continuing research and use of co-crystallisation for separation, purification and modification of pharmaceutical materials in multiple industrial sectors can be attributed to the potential for high control of product quality attributes. Nucleation is a key phenomenon in crystallisation that can control product purity, morphology and crystal size distribution. Despite the use of co-crystallisation in manner mentioned above, not a lot is known about nucleation kinetics in multicomponent systems. This thesis aims to identify gaps in knowledge and presents useful tools and methods pertinent to co-crystallisation in three themes. The first part deals with co-crystallisation within the scope of identifying factors that influence co-crystal solubility phase diagram (Chapter 3) in a workflow. Co-crystal screening methods is considered with the objective to compare and contrast approaches to increase chances of forming a co-crystal and extend an already established co-crystal screening workflow (Chapter 4). The third part addresses nucleation kinetics in multicomponent systems. Once the phase diagram is elucidated the effect of solution stoichiometry on nucleation kinetics in ternary systems is then investigated (Chapter 5). In a move to increase our knowledge of heterogeneous nucleation, a new approach to determine induction time through thermal changes when transmission of light is not reliable was developed and used to measure nucleation rates of small organic molecules (Chapter 6). Therefore, scaling previous experimental limitations and opening up new opportunities for co-crystal studies. The author is confident that the workflow developed for co-crystal phase diagram and heterogeneous nucleation method presented in this thesis would benefit future research in cocrystal nucleation from solution by informing experimental design and experimental configuration
The effect of sample pre-treatment and speciation of potentially toxic elements in freshwater sediments impacted by historical metal mining
No full textThis work involved evaluation of the impact of historical mining operations on potentially toxic elements (PTE) distribution in freshwater sediments from the catchment, of the River Derwent, UK. In parallel, the influence of sample pretreatment on the operational speciation (fractionation) of PTE in sediment with different matrix characteristics was investigated. Freeze, air, and oven drying separately caused less than 9 % changes in PTE fractionation relative to sediment extracted as received, while freeze storage for 12 months was worse (37.5 % changes). Iron was the analyte most prone to changes in fractionation. Sediments rich in iron (hydr)oxides appeared least stable. Harmonisation of sample pre-treatment procedures is recommended to increase results comparability.;The study confirmed that the River Derwent remains the main source of PTE contamination in the Derwent Reservoir and that the sediments are significantly enriched in Cd, Pb and Zn. Arsenic, Cd and Pb concentrations in sediments decreased along the length of the reservoir, possibly due to settlement of discrete sand-sized particles, whereas Mn concentration increased probably due to the accumulation of clay-and silt-size particles downstream. Hierarchical cluster analysis revealed three grouping: As, Cd, Cu and Pb (cluster one); Fe, Ni and Zn (cluster two); and Mn (cluster three). The potential mobility and bioavailability of As, Fe, Ni and Zn increased in sediment near the dam compared with the reservoir upstream probably due to weathering. The PTE pollution index was in the heavily- and severely- polluted range and the mean risk assessment code of PTE in the Derwent Reservoir sediments was Cd, Mn (˃ 50 %: very high risk) ˃ Zn (31- 50 %: high risk) ˃ Ni (11- 30 %: medium risk) ˃ As, Cu, Fe and Pb (1- 10 %: low risk). The study shows that historical mining sites are persistent source of PTE in water resources.This work involved evaluation of the impact of historical mining operations on potentially toxic elements (PTE) distribution in freshwater sediments from the catchment, of the River Derwent, UK. In parallel, the influence of sample pretreatment on the operational speciation (fractionation) of PTE in sediment with different matrix characteristics was investigated. Freeze, air, and oven drying separately caused less than 9 % changes in PTE fractionation relative to sediment extracted as received, while freeze storage for 12 months was worse (37.5 % changes). Iron was the analyte most prone to changes in fractionation. Sediments rich in iron (hydr)oxides appeared least stable. Harmonisation of sample pre-treatment procedures is recommended to increase results comparability.;The study confirmed that the River Derwent remains the main source of PTE contamination in the Derwent Reservoir and that the sediments are significantly enriched in Cd, Pb and Zn. Arsenic, Cd and Pb concentrations in sediments decreased along the length of the reservoir, possibly due to settlement of discrete sand-sized particles, whereas Mn concentration increased probably due to the accumulation of clay-and silt-size particles downstream. Hierarchical cluster analysis revealed three grouping: As, Cd, Cu and Pb (cluster one); Fe, Ni and Zn (cluster two); and Mn (cluster three). The potential mobility and bioavailability of As, Fe, Ni and Zn increased in sediment near the dam compared with the reservoir upstream probably due to weathering. The PTE pollution index was in the heavily- and severely- polluted range and the mean risk assessment code of PTE in the Derwent Reservoir sediments was Cd, Mn (˃ 50 %: very high risk) ˃ Zn (31- 50 %: high risk) ˃ Ni (11- 30 %: medium risk) ˃ As, Cu, Fe and Pb (1- 10 %: low risk). The study shows that historical mining sites are persistent source of PTE in water resources
A probability-based inspection method : principle and implementation
Get PDFMeasurement and inspection technology are important parts of manufacturing industry today. They provide important feedbacks to modern control systems, detect failures and flaws either online or offline, and hence enhance boost the productivity and improve the quality of final products. The continued development and evolution of measurement principles and systems have produced increasingly precise and reliable results. Published literature and industry practice show that better measurement results usually require both a "ruler" of finer scales and a better method to make more stable readings; however, these are bottlenecks in developing new methods and improving existing systems. In this thesis a probability-based method (PBM) for length measurement is proposed which produces measurement results more accurate than the physical scales on the "ruler". As a natural extension to the classic approach, this measurement model uses probability readings as indicators and evaluates the measurands. Around this method, a theory is established and proven for various levels of priori knowledge. Following this, real-world obstacles in implementation and practice usage of PBM are considered. For example, mis-alignments which not only cause trigonometric errors but also induce a discrete random behavior on the measurand, sources of sampling randomness consisting of synthetic parts and those from random errors, and impacts of laboratory gantry systems are fully investigated. A validation process is conducted using existing hardware with newly developed software. Multiple tests are conducted. The experiment results confirmed the validity of PBM and therefore shows that this method will make a positive contribution to the industrial inspection.Measurement and inspection technology are important parts of manufacturing industry today. They provide important feedbacks to modern control systems, detect failures and flaws either online or offline, and hence enhance boost the productivity and improve the quality of final products. The continued development and evolution of measurement principles and systems have produced increasingly precise and reliable results. Published literature and industry practice show that better measurement results usually require both a "ruler" of finer scales and a better method to make more stable readings; however, these are bottlenecks in developing new methods and improving existing systems. In this thesis a probability-based method (PBM) for length measurement is proposed which produces measurement results more accurate than the physical scales on the "ruler". As a natural extension to the classic approach, this measurement model uses probability readings as indicators and evaluates the measurands. Around this method, a theory is established and proven for various levels of priori knowledge. Following this, real-world obstacles in implementation and practice usage of PBM are considered. For example, mis-alignments which not only cause trigonometric errors but also induce a discrete random behavior on the measurand, sources of sampling randomness consisting of synthetic parts and those from random errors, and impacts of laboratory gantry systems are fully investigated. A validation process is conducted using existing hardware with newly developed software. Multiple tests are conducted. The experiment results confirmed the validity of PBM and therefore shows that this method will make a positive contribution to the industrial inspection
Leadership-as-communicative-practice : transforming situations through talk and text
Get PDFThe dominant concept of leadership among academics and practitioners foregrounds individual leaders and views leadership as a 'thing' that can be discovered. However, there is growing scholarly consensus that we need to challenge the assumptions that underpin traditional leadership theories and engage more effectively with the lived experience of leadership. This thesis responds to the call to consider leadership from different perspectives by applying the lens of process philosophy to leadership-as-practice (LAP), an emergent stream of research that has the potential to deepen our understanding of the dynamic nature of leadership as it is accomplished in everyday activities. To extend the existing understanding of LAP grounded in a process ontology, this thesis brings together two complementary Pragmatist informed theoretical perspectives: the performative theory of organizational communication developed by communicative constitution of organization (CCO) scholars; and John Dewey's theory of Inquiry. The concept of leadership-as-communicative-practice (LACP) proposes that leadership emerges in response to ambiguity and uncertainty and is a social and material process that transforms situations. This transformative change is accomplished through the complex entanglement of conversation and written texts. To explore LACP empirically, a nine-month immersive study was undertaken in a Scottish Health and Social Care Partnership. Through attending designated 'leadership' meetings, two issues emerged that were causing tension within the organization and necessitating leadership. These two situations were then shadowed as they unfolded. The emergent leadership movements within each situation were analysed using two co-productive lenses: Inquiry and co-orientation. Analysing turns in conversations suggested that co-orientation occurred across multiple timeframes, was characterized by dissent as well as consensus, and enabled the talking out of issues, relational dynamics and the discovery of new insights into the situation. Moreover, the findings highlighted the contribution of documents in carrying the almost imperceptible movements generated through co-orientation through time and space to transform situations. The study not only adds to the theoretical and empirical understanding of processual LAP, but also provides new insights into the challenges of studying leadership as an unfolding phenomenon. Specifically, shadowing situations is offered as an extension to the organizational shadowing literature that engages with the need for more mobile methods. LACP provides an alternative to the dominant leadership concept within organizations and lays the foundation for new approaches to developing leadership that attend to the processual, communicative dynamics of leadership practice.The dominant concept of leadership among academics and practitioners foregrounds individual leaders and views leadership as a 'thing' that can be discovered. However, there is growing scholarly consensus that we need to challenge the assumptions that underpin traditional leadership theories and engage more effectively with the lived experience of leadership. This thesis responds to the call to consider leadership from different perspectives by applying the lens of process philosophy to leadership-as-practice (LAP), an emergent stream of research that has the potential to deepen our understanding of the dynamic nature of leadership as it is accomplished in everyday activities. To extend the existing understanding of LAP grounded in a process ontology, this thesis brings together two complementary Pragmatist informed theoretical perspectives: the performative theory of organizational communication developed by communicative constitution of organization (CCO) scholars; and John Dewey's theory of Inquiry. The concept of leadership-as-communicative-practice (LACP) proposes that leadership emerges in response to ambiguity and uncertainty and is a social and material process that transforms situations. This transformative change is accomplished through the complex entanglement of conversation and written texts. To explore LACP empirically, a nine-month immersive study was undertaken in a Scottish Health and Social Care Partnership. Through attending designated 'leadership' meetings, two issues emerged that were causing tension within the organization and necessitating leadership. These two situations were then shadowed as they unfolded. The emergent leadership movements within each situation were analysed using two co-productive lenses: Inquiry and co-orientation. Analysing turns in conversations suggested that co-orientation occurred across multiple timeframes, was characterized by dissent as well as consensus, and enabled the talking out of issues, relational dynamics and the discovery of new insights into the situation. Moreover, the findings highlighted the contribution of documents in carrying the almost imperceptible movements generated through co-orientation through time and space to transform situations. The study not only adds to the theoretical and empirical understanding of processual LAP, but also provides new insights into the challenges of studying leadership as an unfolding phenomenon. Specifically, shadowing situations is offered as an extension to the organizational shadowing literature that engages with the need for more mobile methods. LACP provides an alternative to the dominant leadership concept within organizations and lays the foundation for new approaches to developing leadership that attend to the processual, communicative dynamics of leadership practice
An oral history of American trans lives from the 1950s to present
Get PDFThis is the first oral history thesis which investigates and complicates the established historical representation of trans individuals as portrayed in pop culture within the heteronormative and gendernormative historiography of America from the 1950s to present. From a cohort of 22 narrators of differing age and gender variance, I analyse 15 life history interviews conducted with members of the Gender Identity Center of Colorado-a place of refuge, support, friendship and understanding. The resulting oral history of trans American lives offers a historically-informed examination of gender variant individuals' lived experiences of growing up in a country that has long upheld gender normative binary roles of male and female, creating a discourse of gender variance as something deviant, monstrous, mentally unwell and therefore, warranting social condemnation. The original oral histories featured throughout this thesis strongly refutes this gender binary and America's need to uphold it and its ideals, creating rich individual and collective narratives of struggle and triumph over them.An oral history methodology, and theoretical grounding in transgender and liminality theory are central to the lived experience of each narrator featured for gauging their emotions, exclusion from normative gender society and making sense of their present from their pasts. I argue that America's binary ideals have a powerful influence over all trans lives, gender variant identities and lived experiences. Essentially, living under a gender binary is dangerous and damaging on multiple levels. Moreover, prior to embracing their gender variant identity, many trans Americans internalised forms of top-down gender policing observed in their communities and families, experiencing shame and guilt in 'transgressing' these ideals via cross-dressing and other gender variant behaviours. They had to reach a point where they felt comfortable challenging these binary norms to live on the gender spectrum as their 'authentic' selves. As such, this thesis enhances current scholarship on trans lives, and begins to address their relative absence in the historiography on modern America.This is the first oral history thesis which investigates and complicates the established historical representation of trans individuals as portrayed in pop culture within the heteronormative and gendernormative historiography of America from the 1950s to present. From a cohort of 22 narrators of differing age and gender variance, I analyse 15 life history interviews conducted with members of the Gender Identity Center of Colorado-a place of refuge, support, friendship and understanding. The resulting oral history of trans American lives offers a historically-informed examination of gender variant individuals' lived experiences of growing up in a country that has long upheld gender normative binary roles of male and female, creating a discourse of gender variance as something deviant, monstrous, mentally unwell and therefore, warranting social condemnation. The original oral histories featured throughout this thesis strongly refutes this gender binary and America's need to uphold it and its ideals, creating rich individual and collective narratives of struggle and triumph over them.An oral history methodology, and theoretical grounding in transgender and liminality theory are central to the lived experience of each narrator featured for gauging their emotions, exclusion from normative gender society and making sense of their present from their pasts. I argue that America's binary ideals have a powerful influence over all trans lives, gender variant identities and lived experiences. Essentially, living under a gender binary is dangerous and damaging on multiple levels. Moreover, prior to embracing their gender variant identity, many trans Americans internalised forms of top-down gender policing observed in their communities and families, experiencing shame and guilt in 'transgressing' these ideals via cross-dressing and other gender variant behaviours. They had to reach a point where they felt comfortable challenging these binary norms to live on the gender spectrum as their 'authentic' selves. As such, this thesis enhances current scholarship on trans lives, and begins to address their relative absence in the historiography on modern America
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