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The community arts movement in Scotland, 1962-1990
Get PDFThis thesis traces the underexplored history of the community arts movement as it developed in urban Scotland between 1962, the year the organisation that became the Craigmillar Festival Society was founded, and 1990, the year Glasgow celebrated its year as European City of Culture. It draws primarily on 24 oral history interviews conducted with practitioners working in Scotland during this period.;Bringing these oral testimonies into dialogue with visual and documentary sources, it offers a unique perspective on the social, cultural and political beliefs, objectives and intentions - as well as the concrete achievements - of community artists. This methodology also yields new insights into the relationship between surviving or recorded murals, photographs, playbooks, films and videos, and the processes by which they were made.;Setting the movement within its historical context, this thesis makes a contribution to the growing literature on Scottish culture and counterculture, demonstrating that community arts arose out of a particular convergence of community action, popular culture, welfare state paternalism, and a countercultural emphasis on freedom and self-expression. This thesis also positions community art within the broader fields of community action and community development.;It argues a history of the movement contributes to our understanding of the ways in which urban policy was negotiated, implemented and contested at the grassroots during this period. In particular, it situates community arts and community arts practitioners in relation to the growth of social inclusion policies. As such it contributes to the historiography on community action, urban protest and urban governance.This thesis traces the underexplored history of the community arts movement as it developed in urban Scotland between 1962, the year the organisation that became the Craigmillar Festival Society was founded, and 1990, the year Glasgow celebrated its year as European City of Culture. It draws primarily on 24 oral history interviews conducted with practitioners working in Scotland during this period.;Bringing these oral testimonies into dialogue with visual and documentary sources, it offers a unique perspective on the social, cultural and political beliefs, objectives and intentions - as well as the concrete achievements - of community artists. This methodology also yields new insights into the relationship between surviving or recorded murals, photographs, playbooks, films and videos, and the processes by which they were made.;Setting the movement within its historical context, this thesis makes a contribution to the growing literature on Scottish culture and counterculture, demonstrating that community arts arose out of a particular convergence of community action, popular culture, welfare state paternalism, and a countercultural emphasis on freedom and self-expression. This thesis also positions community art within the broader fields of community action and community development.;It argues a history of the movement contributes to our understanding of the ways in which urban policy was negotiated, implemented and contested at the grassroots during this period. In particular, it situates community arts and community arts practitioners in relation to the growth of social inclusion policies. As such it contributes to the historiography on community action, urban protest and urban governance
Development of thermally efficient, ultrathin, diamond-based µLED neural implants for versatile optogenetics
Get PDFOptogenetics helps revolutionise the study of neural networks by allowing localised, genetically targeted, millisecond-timescale optical stimulations of neurons. Optogenetic implants embedded with LED sources hold great potential for experimental neuroscience, as they dispense with external optical coupling and enable site-specific light delivery to deep-brain regions. Although this technology has attracted firm interest in recent years, a long-standing question is whether these devices can attain optical powers or pulse rates suited for high-illumination protocols or circuit-level stimulation (e.g P > 50mW.mm2), while keeping average or peak Joule heating of tissue within commonly accepted "safe" boundaries (e.g 4% at irradiance ILED = 100mW.mm-2) and c) their reliable transfer onto highly textured substrates, yielding an advanced printing method via adhesive picodroplets. For the first time, the probe dimensions (shank LxWxT = 5.5mm x 150µm x 25µm) and large irradiance range (up to ~300mW/mm2 per LED at 3mA driving current) approach those of state-of-the-art monolithic Silicon-based optrodes, with a thermal performance improved by more than an order of magnitude. This is predicted to allow a uniquely wide set of optogenetic protocols including extended/high-power optical pulses at high duty cycles, capable of stimulating thousands of neurons while keeping peak tissue temperature increase below 1°C. Process scalability on commercial wafers is demonstrated on a polycrystalline diamond membrane (20mm diameter, 50µm thickness), opening the way for novel, inexpensive diamond-based tools for neurophotonics and biomedical applications.Optogenetics helps revolutionise the study of neural networks by allowing localised, genetically targeted, millisecond-timescale optical stimulations of neurons. Optogenetic implants embedded with LED sources hold great potential for experimental neuroscience, as they dispense with external optical coupling and enable site-specific light delivery to deep-brain regions. Although this technology has attracted firm interest in recent years, a long-standing question is whether these devices can attain optical powers or pulse rates suited for high-illumination protocols or circuit-level stimulation (e.g P > 50mW.mm2), while keeping average or peak Joule heating of tissue within commonly accepted "safe" boundaries (e.g 4% at irradiance ILED = 100mW.mm-2) and c) their reliable transfer onto highly textured substrates, yielding an advanced printing method via adhesive picodroplets. For the first time, the probe dimensions (shank LxWxT = 5.5mm x 150µm x 25µm) and large irradiance range (up to ~300mW/mm2 per LED at 3mA driving current) approach those of state-of-the-art monolithic Silicon-based optrodes, with a thermal performance improved by more than an order of magnitude. This is predicted to allow a uniquely wide set of optogenetic protocols including extended/high-power optical pulses at high duty cycles, capable of stimulating thousands of neurons while keeping peak tissue temperature increase below 1°C. Process scalability on commercial wafers is demonstrated on a polycrystalline diamond membrane (20mm diameter, 50µm thickness), opening the way for novel, inexpensive diamond-based tools for neurophotonics and biomedical applications
Is UK surveillance law suitable for the digital age?
Get PDFThis thesis examines the suitability of UK surveillance law for the digital age in terms of its protection of privacy. It argues that UK law regulating state surveillance fails to recognise the undulations of the contemporary surveillance landscape brought about by the digitalisation of society and that this has negatively impacted both individual and societal interests in privacy.;Privacy is underlined as a cornerstone of liberal democratic society that continues to be relevant and worthy of legal protection in the digital age. It is argued that the legal tradition needs to engage more fully with other disciplines, particularly surveillance studies, to ensure that expectations of privacy within the digital age are properly reflected, and protected, by law. This thesis helps bridge this gap by adopting a multidisciplinary approach to the assessment of UK surveillance law.;In particular, it is argued that the ownership of surveillance has been democratised in the digital age, enabling the individual to participate in surveillance. It is argued that, this too, needs to be recognised in order to protect the benefits of the contemporary surveillance landscape bestowed on civil society. The main argument of this thesis is that the law needs to attune to the technological and cultural changes the contemporary surveillance landscape has undergone in order to preserve privacy in the digital age. This thesis concludes with recommendations as to how UK surveillance law can be improved so that this can be achieved.This thesis examines the suitability of UK surveillance law for the digital age in terms of its protection of privacy. It argues that UK law regulating state surveillance fails to recognise the undulations of the contemporary surveillance landscape brought about by the digitalisation of society and that this has negatively impacted both individual and societal interests in privacy.;Privacy is underlined as a cornerstone of liberal democratic society that continues to be relevant and worthy of legal protection in the digital age. It is argued that the legal tradition needs to engage more fully with other disciplines, particularly surveillance studies, to ensure that expectations of privacy within the digital age are properly reflected, and protected, by law. This thesis helps bridge this gap by adopting a multidisciplinary approach to the assessment of UK surveillance law.;In particular, it is argued that the ownership of surveillance has been democratised in the digital age, enabling the individual to participate in surveillance. It is argued that, this too, needs to be recognised in order to protect the benefits of the contemporary surveillance landscape bestowed on civil society. The main argument of this thesis is that the law needs to attune to the technological and cultural changes the contemporary surveillance landscape has undergone in order to preserve privacy in the digital age. This thesis concludes with recommendations as to how UK surveillance law can be improved so that this can be achieved
Chalcogenopyrylium dye functionalised gold nanoparticles for use as red-shifted SERS nanotags
Get PDFSurface enhanced Raman spectroscopy (SERS) in the near infrared (NIR) is a largely unexplored area in Raman spectroscopy, particularly at laser excitation wavelengths greater than 1100 nm. This thesis explores the use of a 1280 nm Raman spectrometer for NIR Raman active nanotag design and application. The NIR region of the electromagnetic spectrum is of specific interest due to the absorption and scattering properties in biological matter throughout this optical window. Research described in chapter 3 of this thesis highlights the use of a relatively novel class of chalcogenopyrylium (CP) dye molecules, which in combination with the broad extinction profile of large gold nanoparticles (AuNPs) provide an intense SERS response upon 1280 nm laser excitation, previously unachievable with commercially available Raman reporter molecules at this excitation wavelength. However, the structural design of these dyes specifically relating to their SERS performance is unreported. The relationship between CP dye molecule binding orientation, determined via sum frequency generation vibrational spectroscopy (SFG-VS), and their SERS response was investigated deducing that due to the polarisation throughout the backbone of the CP dye molecule, an optimal SERS response was achieved when the CP dye molecule is as perpendicular to the NP surface as possible. Due to the increasing technological advances surrounding counterfeit and fraudulent goods, investigation into the design of a nanotag that could be selectively detected by only those with the knowledge of how to detect it could be incredibly advantageous in the fight against consumer goods piracy and in the secure labelling of important documents.;Chapter 4 of this thesis reports the design of such a nanotag using an already established CP dye as the Raman reporter and a novel, purposefully designed, CP based dye blocking molecule (BM) which is able to block or mask the SERS signal from the Raman reporter at 785 nm laser excitation, only providing a SERS response, from the nanotag, upon excitation with a 1280 nm laser source. This resulted in the ability to obtain a SERS response with a 1280 nm Raman spectrometer that was not achieved at 785 nm laser excitation, by either complete signal elimination or by masking from the BM itself. This could provide the ability to invisibly tag and detect items of vital importance in which no one else, unless equipped with this nanotag, 1280 nm Raman spectrometer and system knowledge could or should be able to identify. In order for biomedical research to advance away from dated, bulkier, fixed instrumentation, performance of handheld instrumentation, capable of being adapted into a clinical environment, needs to be explored. Previous group work has investigated the performance of CP dye based nanotags at depth through biological tissues by use of spatially offset Raman spectroscopy (SORS). As SORS is a technique which will acquire a Raman measurement at a pre-determined depth, work was also carried out in order to deduce the depth at which a conventional 785 nm Raman spectrometer could detect these nanotags in tissue samples. However, the ability to probe through biological barriers using further red-shifted excitation wavelengths has not yet been studied.;Chapter 5 of this thesis reports and compares the depth, in tissue samples, at which CP dye based nanotags can be detected using portable conventional handheld Raman spectrometers of laser excitation wavelengths: 785, 1064 and 1280 nm. Recent reports have emerged, in the literature, employing CP dye based nanotags in a variety of biological applications including localisation within and detection of cancerous tumours, cell-based cancer models and in ex vivo multiplexing platforms, however, to date their cytotoxicity has gone unreported. Chapter 6 of this thesis examines the cytotoxicity of five CP based dye nanotags, two of which have already been employed and reported in biological applications, to a healthy prostate cancer cell line and additionally demonstrates their level of detectability in cells. Finally, towards the end of this research, CP dye molecules containing alkyne moieties were made available. Alkyne tags are of extreme interest in biological, and in particular cellular, applications due to the fact their characteristic alkyne peak occurs in the 'biologically silent' region of the spectrum. The ability to perform as SERS active nanotags, providing the characteristic alkyne peak in the 'biologically silent' region of the spectrum, at a 1064 nm laser excitation wavelength is demonstrated and discussed.Surface enhanced Raman spectroscopy (SERS) in the near infrared (NIR) is a largely unexplored area in Raman spectroscopy, particularly at laser excitation wavelengths greater than 1100 nm. This thesis explores the use of a 1280 nm Raman spectrometer for NIR Raman active nanotag design and application. The NIR region of the electromagnetic spectrum is of specific interest due to the absorption and scattering properties in biological matter throughout this optical window. Research described in chapter 3 of this thesis highlights the use of a relatively novel class of chalcogenopyrylium (CP) dye molecules, which in combination with the broad extinction profile of large gold nanoparticles (AuNPs) provide an intense SERS response upon 1280 nm laser excitation, previously unachievable with commercially available Raman reporter molecules at this excitation wavelength. However, the structural design of these dyes specifically relating to their SERS performance is unreported. The relationship between CP dye molecule binding orientation, determined via sum frequency generation vibrational spectroscopy (SFG-VS), and their SERS response was investigated deducing that due to the polarisation throughout the backbone of the CP dye molecule, an optimal SERS response was achieved when the CP dye molecule is as perpendicular to the NP surface as possible. Due to the increasing technological advances surrounding counterfeit and fraudulent goods, investigation into the design of a nanotag that could be selectively detected by only those with the knowledge of how to detect it could be incredibly advantageous in the fight against consumer goods piracy and in the secure labelling of important documents.;Chapter 4 of this thesis reports the design of such a nanotag using an already established CP dye as the Raman reporter and a novel, purposefully designed, CP based dye blocking molecule (BM) which is able to block or mask the SERS signal from the Raman reporter at 785 nm laser excitation, only providing a SERS response, from the nanotag, upon excitation with a 1280 nm laser source. This resulted in the ability to obtain a SERS response with a 1280 nm Raman spectrometer that was not achieved at 785 nm laser excitation, by either complete signal elimination or by masking from the BM itself. This could provide the ability to invisibly tag and detect items of vital importance in which no one else, unless equipped with this nanotag, 1280 nm Raman spectrometer and system knowledge could or should be able to identify. In order for biomedical research to advance away from dated, bulkier, fixed instrumentation, performance of handheld instrumentation, capable of being adapted into a clinical environment, needs to be explored. Previous group work has investigated the performance of CP dye based nanotags at depth through biological tissues by use of spatially offset Raman spectroscopy (SORS). As SORS is a technique which will acquire a Raman measurement at a pre-determined depth, work was also carried out in order to deduce the depth at which a conventional 785 nm Raman spectrometer could detect these nanotags in tissue samples. However, the ability to probe through biological barriers using further red-shifted excitation wavelengths has not yet been studied.;Chapter 5 of this thesis reports and compares the depth, in tissue samples, at which CP dye based nanotags can be detected using portable conventional handheld Raman spectrometers of laser excitation wavelengths: 785, 1064 and 1280 nm. Recent reports have emerged, in the literature, employing CP dye based nanotags in a variety of biological applications including localisation within and detection of cancerous tumours, cell-based cancer models and in ex vivo multiplexing platforms, however, to date their cytotoxicity has gone unreported. Chapter 6 of this thesis examines the cytotoxicity of five CP based dye nanotags, two of which have already been employed and reported in biological applications, to a healthy prostate cancer cell line and additionally demonstrates their level of detectability in cells. Finally, towards the end of this research, CP dye molecules containing alkyne moieties were made available. Alkyne tags are of extreme interest in biological, and in particular cellular, applications due to the fact their characteristic alkyne peak occurs in the 'biologically silent' region of the spectrum. The ability to perform as SERS active nanotags, providing the characteristic alkyne peak in the 'biologically silent' region of the spectrum, at a 1064 nm laser excitation wavelength is demonstrated and discussed
Development of a low cost design toolkit for sizing air-cooled heat exchangers using open source heat transfer correlations
Get PDFThe exorbitant costs associated with heat exchanger design software e.g. ASPEN EDR, HTRI X-Suite etc., means that most engineering firms especially SMEs, struggle to purchase and use these tools for in-house design purposes. Therefore, heat exchanger design for these engineering firms is dependent on charts, graphs and 'passed down' knowledge. Unfortunately in most cases, the accuracy of these design data sources cannot be verified which means that every heat exchanger designed, is not sized correctly to deliver the heat duty required.The aim of this project was to build a low cost toolkit capable of designing and rating Circular - Fin, Tube-in-Plate Fin and Plain Tube Heat Exchangers air-cooled heat exchangers.Heat transfer correlations were obtained from publicly available data and the validation process involved designing air-cooled heat exchangers using these correlations. Thereafter, the design process was repeated using the industry standard software, ASPEN Exchanger Design & Rating (EDR). The results were then compared. The outcome indicated that when geometrical characteristics and operating conditions stayed within the boundaries specified by the open source correlations, the largest deviation will occur in the Tube-in-Plate heat exchanger with an over-prediction of 14% of the area ratio (Gas side vs. Fluid side of the heat exchanger) when compared with the ASPEN EDR results. The Plain Tube heat exchanger showed a 7.5% over-prediction for the staggered tube layout and an 8% over-prediction for the inline tube layout. The Circular-Fin heat exchanger gave the best result with a 6% over-prediction for the compared area ratios.Based on these results, the toolkit was developed using the Excel Visual Basic for Applications (VBA) programming language. The NIST Reference fluid Properties (REFPROP) database was used to obtain the thermophysical properties of the interacting fluids and was also integrated into the toolkit using the VBA programming language.The exorbitant costs associated with heat exchanger design software e.g. ASPEN EDR, HTRI X-Suite etc., means that most engineering firms especially SMEs, struggle to purchase and use these tools for in-house design purposes. Therefore, heat exchanger design for these engineering firms is dependent on charts, graphs and 'passed down' knowledge. Unfortunately in most cases, the accuracy of these design data sources cannot be verified which means that every heat exchanger designed, is not sized correctly to deliver the heat duty required.The aim of this project was to build a low cost toolkit capable of designing and rating Circular - Fin, Tube-in-Plate Fin and Plain Tube Heat Exchangers air-cooled heat exchangers.Heat transfer correlations were obtained from publicly available data and the validation process involved designing air-cooled heat exchangers using these correlations. Thereafter, the design process was repeated using the industry standard software, ASPEN Exchanger Design & Rating (EDR). The results were then compared. The outcome indicated that when geometrical characteristics and operating conditions stayed within the boundaries specified by the open source correlations, the largest deviation will occur in the Tube-in-Plate heat exchanger with an over-prediction of 14% of the area ratio (Gas side vs. Fluid side of the heat exchanger) when compared with the ASPEN EDR results. The Plain Tube heat exchanger showed a 7.5% over-prediction for the staggered tube layout and an 8% over-prediction for the inline tube layout. The Circular-Fin heat exchanger gave the best result with a 6% over-prediction for the compared area ratios.Based on these results, the toolkit was developed using the Excel Visual Basic for Applications (VBA) programming language. The NIST Reference fluid Properties (REFPROP) database was used to obtain the thermophysical properties of the interacting fluids and was also integrated into the toolkit using the VBA programming language
Managing circular economy-oriented niche innovation networks within a triple helix-based governance framework : the cases of industrial biotechnology and remanufacturing in Scotland
Get PDFTransition from a linear to circular economy requires fundamental restructuring of the global production-consumption systems. Such restructuring is dependent on the development and proliferation of niche technologies and innovations which promote 'inner loop' activities necessary to achieve such a transition such as reuse, repair and remanufacturing. To achieve this, the approach to managing innovation must be redesigned to cope with the increased complexity of moving from linear value chains to circular 'inner loop' value webs of material reuse. This thesis therefore examines a novel innovation policy tool which employs a triple helix-based niche manager to strategically manage 'inner loop' niche innovation networks in-line with the broader circular economy transition.;This thesis undertook in-depth studies of two triple helix-based niche managers in Scotland (the Industrial Biotechnology Innovation Centre and the Scottish Institute for Remanufacturing) between September 2015 and March 2018. A novel methodological approach using social network analysis was developed. This allowed each triple helix-based niche manager's impact on their respective niche innovation networks' structure and composition to be empirically measured; and as such, the network members' capacity to develop 'inner loop' innovations. By combining the social network analysis of 86 network members with 173 network member surveys and triple helix-based niche manager focus groups, the reasons behind the changes in network structure and composition are explored in depth.;This thesis finds that the triple helix-based niche managers were able to perform key nurturing and empowering roles necessary for steering the innovation networks in-line with a circular trajectory. In terms of nurturing, they were able to build diverse networks, increase shared learning and raise expectations of the niche. In terms of empowering the innovation networks, they were able to connect niche actors with regime actors, direct circular economy funding into the niche and lobby policy makers in terms of niche requirements.Transition from a linear to circular economy requires fundamental restructuring of the global production-consumption systems. Such restructuring is dependent on the development and proliferation of niche technologies and innovations which promote 'inner loop' activities necessary to achieve such a transition such as reuse, repair and remanufacturing. To achieve this, the approach to managing innovation must be redesigned to cope with the increased complexity of moving from linear value chains to circular 'inner loop' value webs of material reuse. This thesis therefore examines a novel innovation policy tool which employs a triple helix-based niche manager to strategically manage 'inner loop' niche innovation networks in-line with the broader circular economy transition.;This thesis undertook in-depth studies of two triple helix-based niche managers in Scotland (the Industrial Biotechnology Innovation Centre and the Scottish Institute for Remanufacturing) between September 2015 and March 2018. A novel methodological approach using social network analysis was developed. This allowed each triple helix-based niche manager's impact on their respective niche innovation networks' structure and composition to be empirically measured; and as such, the network members' capacity to develop 'inner loop' innovations. By combining the social network analysis of 86 network members with 173 network member surveys and triple helix-based niche manager focus groups, the reasons behind the changes in network structure and composition are explored in depth.;This thesis finds that the triple helix-based niche managers were able to perform key nurturing and empowering roles necessary for steering the innovation networks in-line with a circular trajectory. In terms of nurturing, they were able to build diverse networks, increase shared learning and raise expectations of the niche. In terms of empowering the innovation networks, they were able to connect niche actors with regime actors, direct circular economy funding into the niche and lobby policy makers in terms of niche requirements
Investigating the performance and emission characteristics of diesel-LPG engine operation
Get PDFIn the last couple of decades, attention has been placed on reducing atmospheric emissions globally, including the enforcement of stricter requirements which target emissions from internal combustion engines. This is not surprising considering the spate of public attention about the health impacts of atmospheric pollution. Then again there are concerns about their environmental impact. Consequently, engine developers, end-users, and researchers, increasingly are reconsidering the century-long idea of dual fuel engines. While there have been successful attempts to develop viable, sustainable alternatives to power diesel engines, the extent to which engine performance and emissions may be affected remains unknown. Therefore, this study evaluates the performance and emission characteristics of a diesel engine modified to run simultaneously with diesel and liquefied petroleum gas (LPG). The aim of this research is to numerically investigate the performance and emission characteristics associated with dual fuel engine operation (wherein LPG and diesel fuels are simultaneously used) with regards to the diesel engine operation at various operating regimes, taking into consideration different fuel mass ratios. With this in mind, this study presents a one-dimensional model developed using AVL BOOST to simulate the diesel and diesel-LPG engine operational modes. The model is calibrated using the peak cylinder pressure, the timing of the peak cylinder pressure, power and torque. For the maximum LPG scenario (70% diesel and 30% LPG) investigated at 2435 rpm, compared to the diesel engine operation, the maximum cylinder pressure was shown to increase from 77.16 bar to 93.42 bar representing an increase of 21.07%. Additionally, at 2435 rpm, the results from the study suggest a fairly linear increment in power when LPG mass ratio in the diesel-LPG fuel mixture is increased from 10 to 30%. It is remarkable that the highest mass ratio of LPG used in the diesel-LPG fuel mixture produces the highest brake thermal efficiency at 2435 rpm. Regardless of the speed, increasing the LPG fuel mass ratio in the diesel-LPG fuel mixture leads to a reduction in the nitrogen oxide (NOx) emissions because the formation of NOx depends on the oxygen concentration and the presence of LPG,leads to reduction of the oxygen concentration at the onset of NOx formation whichconsequently causes the NOx emissions to reduce.In the last couple of decades, attention has been placed on reducing atmospheric emissions globally, including the enforcement of stricter requirements which target emissions from internal combustion engines. This is not surprising considering the spate of public attention about the health impacts of atmospheric pollution. Then again there are concerns about their environmental impact. Consequently, engine developers, end-users, and researchers, increasingly are reconsidering the century-long idea of dual fuel engines. While there have been successful attempts to develop viable, sustainable alternatives to power diesel engines, the extent to which engine performance and emissions may be affected remains unknown. Therefore, this study evaluates the performance and emission characteristics of a diesel engine modified to run simultaneously with diesel and liquefied petroleum gas (LPG). The aim of this research is to numerically investigate the performance and emission characteristics associated with dual fuel engine operation (wherein LPG and diesel fuels are simultaneously used) with regards to the diesel engine operation at various operating regimes, taking into consideration different fuel mass ratios. With this in mind, this study presents a one-dimensional model developed using AVL BOOST to simulate the diesel and diesel-LPG engine operational modes. The model is calibrated using the peak cylinder pressure, the timing of the peak cylinder pressure, power and torque. For the maximum LPG scenario (70% diesel and 30% LPG) investigated at 2435 rpm, compared to the diesel engine operation, the maximum cylinder pressure was shown to increase from 77.16 bar to 93.42 bar representing an increase of 21.07%. Additionally, at 2435 rpm, the results from the study suggest a fairly linear increment in power when LPG mass ratio in the diesel-LPG fuel mixture is increased from 10 to 30%. It is remarkable that the highest mass ratio of LPG used in the diesel-LPG fuel mixture produces the highest brake thermal efficiency at 2435 rpm. Regardless of the speed, increasing the LPG fuel mass ratio in the diesel-LPG fuel mixture leads to a reduction in the nitrogen oxide (NOx) emissions because the formation of NOx depends on the oxygen concentration and the presence of LPG,leads to reduction of the oxygen concentration at the onset of NOx formation whichconsequently causes the NOx emissions to reduce
Automated, quantitative process analysis by NMR
Get PDFThis thesis comprises a series of studies and investigations into applications of Nuclear Magnetic Resonance (NMR) to automated and quantitative process analysis.The work will cover the use of different nuclei, permanent and superconducting magnets, and quantitation by univariate and multivariate approaches. Customised programmes and scripts accompany the experimental work on each of these aspects.Chapter 1 is an introduction to the history and status of NMR, as relevant to these works.Chapter 2 describes the development and validation of a fully automated 35Cl NMR quantitation method for chloride in solution. The method is embedded in existing walk-up software on a 400 MHz spectrometer and yields quantitative results with linearity R2 = 0.999 and a detection limit of 0.1% w/w for a 10 mg sample.Chapter 3 covers investigations into the capabilities and limitations of a 43 MHzbench top NMR spectrometer for samples in a tube and in flow. Aspects including long-term stability, characterisation of samples in flow, non-linearity of receiver andamplifier and synthesis of accurate shaped pulses are assessed.;Chapter 4 builds on this information and describes the development and programming of an automated custom interface designed for non-expert users that allows the bench top spectrometer to be used to rapidly supply quantitative results for atline process samples. Relative quantitation is achieved through a combination of sum integration and deconvolution. Chapter 5 then extends the capabilities of the benchtop spectrometer through the development of a quantitative method for reaction mixtures of a pharmaceutical process using partial least squares modelling of 1H spectra. The model is developed such that results were shown to be independent of typical spectral variations expected in real samples.The thesis concludes with remarks on potential future extensions to the work discussed here.This thesis comprises a series of studies and investigations into applications of Nuclear Magnetic Resonance (NMR) to automated and quantitative process analysis.The work will cover the use of different nuclei, permanent and superconducting magnets, and quantitation by univariate and multivariate approaches. Customised programmes and scripts accompany the experimental work on each of these aspects.Chapter 1 is an introduction to the history and status of NMR, as relevant to these works.Chapter 2 describes the development and validation of a fully automated 35Cl NMR quantitation method for chloride in solution. The method is embedded in existing walk-up software on a 400 MHz spectrometer and yields quantitative results with linearity R2 = 0.999 and a detection limit of 0.1% w/w for a 10 mg sample.Chapter 3 covers investigations into the capabilities and limitations of a 43 MHzbench top NMR spectrometer for samples in a tube and in flow. Aspects including long-term stability, characterisation of samples in flow, non-linearity of receiver andamplifier and synthesis of accurate shaped pulses are assessed.;Chapter 4 builds on this information and describes the development and programming of an automated custom interface designed for non-expert users that allows the bench top spectrometer to be used to rapidly supply quantitative results for atline process samples. Relative quantitation is achieved through a combination of sum integration and deconvolution. Chapter 5 then extends the capabilities of the benchtop spectrometer through the development of a quantitative method for reaction mixtures of a pharmaceutical process using partial least squares modelling of 1H spectra. The model is developed such that results were shown to be independent of typical spectral variations expected in real samples.The thesis concludes with remarks on potential future extensions to the work discussed here
Dynamical models for novel diffraction techniques in SEM
No full textThe scanning electron microscope is a powerful nanocharacterisation tool for a variety of materials including semiconductors and metals. Less known for its diffraction abilities than its transmission counterpart, scanning electron microscopy (SEM)can be used in a number of diffraction modalities to provide information on crystal imperfections at the nanoscale level. This comes with the added benefit of SEM requiring minimal sample preparation. Models for diffraction in the SEM are still being developed and improved, hence in this work I explore the physics and implementations of such models. I focus on the two main branches of SEM diffraction techniques:incident beam channelling, or diffraction in, powerful when it comes to resolving individual dislocations close to the surface; and back(/forward)scattering diffraction,or diffraction out, which provides a variety of information about grain distribution,orientation and strain. Both of these diffraction modalities involve the same physical processes, so it makes sense to use the same models, namely dynamical scattering in the column approximation. I use the two beam Bloch waves approach for electron channelling contrast imaging (ECCI) of threading dislocations (TDs) normal to the surface in wurtzite group-III nitride materials. I also introduce and use the notion of ECC-strain to study crystal features and to predict the behaviour of TDs contrast.For the electron back(/forward)scatter modality, I show the first application of the new energy-weighted dynamical scattering capabilities of EMsoft to study the novel transmission mode (TKD) of the SEM.The scanning electron microscope is a powerful nanocharacterisation tool for a variety of materials including semiconductors and metals. Less known for its diffraction abilities than its transmission counterpart, scanning electron microscopy (SEM)can be used in a number of diffraction modalities to provide information on crystal imperfections at the nanoscale level. This comes with the added benefit of SEM requiring minimal sample preparation. Models for diffraction in the SEM are still being developed and improved, hence in this work I explore the physics and implementations of such models. I focus on the two main branches of SEM diffraction techniques:incident beam channelling, or diffraction in, powerful when it comes to resolving individual dislocations close to the surface; and back(/forward)scattering diffraction,or diffraction out, which provides a variety of information about grain distribution,orientation and strain. Both of these diffraction modalities involve the same physical processes, so it makes sense to use the same models, namely dynamical scattering in the column approximation. I use the two beam Bloch waves approach for electron channelling contrast imaging (ECCI) of threading dislocations (TDs) normal to the surface in wurtzite group-III nitride materials. I also introduce and use the notion of ECC-strain to study crystal features and to predict the behaviour of TDs contrast.For the electron back(/forward)scatter modality, I show the first application of the new energy-weighted dynamical scattering capabilities of EMsoft to study the novel transmission mode (TKD) of the SEM
Self-exciting point processes and their applications to crime data
Get PDFSelf-exciting point processes describe a type of point process where the occurrence of an event leads to an increased probability of a future event taking place. Such subsequent events can be said to have been 'triggered' by the previous event. Originally used to model earthquakes, in recent years this class of processes has been utilised in crime modelling to describe how crime events can propagate future crime. In this thesis we look at ways of building on the existing literature which uses self-exciting point processes to model crime, with the intention of improving the ability to predict when and where future crime may occur.;We introduce a new parametric form for the triggering function, which can be utilised in situations where an initial event does not immediately lead to an increased risk of further events, but rather the risk increases over a period of time after the event. We also introduce adaptations to existing non-parametric methods which offer us fresh insight into the dynamics of crime. We validate our models using publicly available crime data from the city of Chicago.Self-exciting point processes describe a type of point process where the occurrence of an event leads to an increased probability of a future event taking place. Such subsequent events can be said to have been 'triggered' by the previous event. Originally used to model earthquakes, in recent years this class of processes has been utilised in crime modelling to describe how crime events can propagate future crime. In this thesis we look at ways of building on the existing literature which uses self-exciting point processes to model crime, with the intention of improving the ability to predict when and where future crime may occur.;We introduce a new parametric form for the triggering function, which can be utilised in situations where an initial event does not immediately lead to an increased risk of further events, but rather the risk increases over a period of time after the event. We also introduce adaptations to existing non-parametric methods which offer us fresh insight into the dynamics of crime. We validate our models using publicly available crime data from the city of Chicago
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