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Geomorphology of active fold-and-thrust belts and plateaux: unravelling tectonic and climatic controls
Get PDFOrogenic belts on Earth are varied, complex and are areas of seismic and landslide hazard. Understanding them means assessing relative tectonic (active faulting, deformation style, strain rate), climatic (precipitation, glaciation) and erosional (fluvial erosion, lithology) controls. Climatic and tectonic controls are interlinked and understanding the relative importance of each is important for understanding the global landscape system.
Geomorphic indices capture the landscape response to competition between climate and tectonics and reflect the spatial distribution of erosion. They can be applied over remote and large-scale geographic areas. I use geomorphic indices (hypsometric integral (HI), elevation-relief ratio (ZR), surface roughness (SR) and normalised channel steepness (ksn)) to identify areas of active deformation and erosion, highlight landscape variations and I interpret the results for potential tectonic and climatic drivers. Geomorphic indices are also compared to active strain rate, calculated from published geodetic data. High HI, SR and low ZR are found to occur in landscapes overlying areas of brittle crustal deformation (seismogenic faulting) in the Qilian Shan, Himalaya, Andes and Zagros.
In the central-eastern Tibetan Plateau geomorphic indices and precipitation data are used to identify a broad ˜WSW-ENE trending transition in the landscape where changes in landscape and precipitation are grouped and in alignment. I argue that this geomorphic-climatic transition zone represents a change from incised to non-incised landscapes, the location of which is controlled by the western extent of the East Asian summer monsoon rainfall. This modern pattern is consistent with a model of early Cenozoic growth of the eastern Tibetan Plateau, superimposed by incision driven by Miocene monsoon intensification; this model is supported by published erosion rate and thermochronology data.
Precipitation and strain rate are found to be strong controls on landscapes when fold-and-thrust belts are compared but are not found to be major controls on landscape within individual fold-and-thrust belts. Climate (precipitation) is found to be more strongly correlated with geomorphic indices than tectonics (strain rate) and this result has implications for further work in understanding climate-tectonic-landscape relationships
Multicomponent Solid Forms in Pharma, Hair Care and Dental Care
Get PDFThis work covers multicomponent solid forms including co-amorphous solid forms with active pharmaceutical ingredients (APIs) and, co-crystals, salts, hydrates and solvates to help model intermolecular interaction taking place in larger systems including polymers and proteins. A new prediction model was created to help identify which combinations of APIs and small molecule co-formers were likely to form co-amorphous systems. The prediction model suggests co-amorphous formation is related to the average molecular weight of the two components and the strength of the intermolecular interactions formed. A new co-amorphous screen containing mebendazole with 29 co-formers was performed and compared to the predicted results, which showed a predictive hit rate of 90%.
The dimer of vinylcaprolactam (bisVCap) was used in a co-amorphous screen with 13 APIs. The experimental results were compared to the predicted results with 11 out of 13 systems correctly predicted. The co-amorphous systems found were analysed by FTIR which identified new intermolecular interactions formed between bisVCap and the APIs, stabilising the co-amorphous state.
Crystals of a hydrogenated dimer of vinylpyrrolidone and hydrogen peroxide were grown by cooling crystallisation and characterised by SXRD. The structures were used to identify the bonding models present in a polyvinylpyrrolidone hydrogen peroxide complex. The crystal structures were combined with DFT calculations to produce two new proposed structures of the hydrogen bonding in the polyvinylpyrrolidone hydrogen peroxide complex.
A hair care mixture formed from a gluconamide and a gluconate and 3-hydroxypropyl ammonium salt, is known to strengthen hair fibres; however, the process is unknown. To identify potential interactions between the mixture and hair fibres, a range of crystals were grown. The crystals were identified by SXRD as two polymorphic forms of the gluconamide and three salts of 3-hydroxypropylammonium with sulfuric acid, methane sulfonic acid and oxalic acid. The new crystal structures and structures from the Cambridge structural database were used to speculate potential interactions formed. The gluconamide was identified to be a supramolecular gelator in aniline and benzyl alcohol. The gels were characterised by rheology, scanning electron microscopy, 1H NMR, FTIR and XRPD
Fabrication of functional and structured particles by inkjet printing of emulsions
Get PDFEmulsion solvent evaporation is a well-established method for generating microparticles from solutions of polymers in volatile organic solvents dispersed in an aqueous medium. Previous work has shown that this approach can also be used to deposit particles by inkjet printing where the particles are formed during the drying of a liquid ink on a substrate. The particle size distribution, however, was very broad. Here I demonstrate that inkjet printing of oil-in-water emulsions produced by microfluidics can generate micron-sized particles with a narrow size distribution (coefficient of variation <6%) and that these particles can self-assemble into ordered arrays with hexagonal packing. The conditions under which drops can be printed with a minimum of break up and coalescence of the oil droplets in the emulsion are explored. Factors affecting the size of the particles and the morphology of the deposit are described. This study uses polystyrene in dichloromethane as a model system, but the approach can be generalized to the production of structured and functional particles.
Besides, I explore the mechanism of formation of core-shell microcapsules by emulsion solvent evaporation, where the emulsion contains a shell-forming polymer and a core-forming poor solvent dispersed in a good solvent as the oil phase. Evaporation of the good solvent induces an internal phase separation within the oil droplets of the emulsion, triggering the formation of microcapsules. First I study the wetting conditions necessary to induce the internal phase separation within emulsions. Then I construct a ternary phase diagram to predict the formation process, either polymer-rich phase or poor solvent-rich phase can phase separate from the bulk solution, depending on the ratio of polymer to poor solvent. Then the physical parameters affecting the phase separation and hence the final morphology are explored. Finally, the conditions are optimised to minimise the effect of pseudo partial wetting to obtain a uniform morphology of core-shell microcapsules.
Last, I demonstrate the strategy of emulsion solvent evaporation can be used in the generation of hierarchical Murray materials with multi-scale interconnected pores by inkjet printing nanoparticle-containing emulsions, where silica nanoparticles are pre-dispersed in the discrete phase. A continuous monolayer of well-defined, hexagonally packed silica microspheres with hierarchical macro-meso porous structure is obtained. The porosity of the Murray material can be readily tuned by varying the size of the primary silica nanoparticles. Factors affecting the morphology of the deposit pattern have been explored. This study uses solid silica nanoparticles in discrete phase as a model system to produce macro-meso porous material with two-scale interconnected pores, but the strategy can be generalized to the porous nanoparticles for the production of more structured Murray material with multi-scale pores, like macro-meso-micro hierarchical porous materials
Measuring the impact of research access for human skeletal remains stored in English museum contexts.
Get PDFThis thesis evaluates the relationship between research and the preservation of skeletal remains stored in English museums, through the lens of researcher access to those collections. Preservation is an important issue in archaeology; however, it is under-represented in the bioarchaeological literature. This has led to a lack of understanding regarding the factors that most affect the preservation of human remains. Few studies have explored the impact of post-excavation factors on the preservation of human remains, and this study was proposed to address this shortage. The primary aim of this study was to assess to what extent research causes changes to the condition of skeletal remains, and whether the information we gain from research is balanced against the potential damage it may cause.
To achieve this aim, a new methodology was developed that involved the creation of a retrospective baseline condition assessment of the skeletal remains. Utilising this retrospective assessment enabled the change in preservation over time to be calculated without the need for a longitudinal study. The second aim was to evaluate other potential causes of deterioration to see if any had a greater impact than research through access. Where other factors affecting deterioration were discovered, their significance was discussed, as were the repercussions for museum storage and research.
The data collected from holdings of skeletal remains in institutions outside of London, showed that whilst research access did have an impact on the preservation of the skeletal remains studied, this impact was to a lesser degree than other factors evaluated in this research. Predominantly, the start (or retrospective baseline) preservation of the skeletal remains and the quality of the museum storage were the most significant factors that affected the preservation of the remains.
This thesis highlights the problems we, as researchers, as well as the skeletal remains we curate, could potentially face in the future. It recommends that greater consideration be given to the preservation of skeletal remains that are curated. Funding overall needs to be increased, whether this is through core government funding or an alternative source. Furthermore, planning for long term storage of skeletal collections is essential. The quality of museum storage and the amount of space available for storage must also be addressed, as these are significant issues in the long-term preservation and conservation of skeletal remains
Sympathy and the ‘Fallen Woman’ in the Victorian Novel, from Elizabeth Gaskell to Thomas Hardy
Get PDFThis thesis focuses on the significance of sympathy in representations of the ‘fallen woman’ in the Victorian realist novel. Beginning with Gaskell’s Ruth (1853) and ending with Hardy’s Jude the Obscure (1895), I explore the ways in which authors sought to encourage their readers to feel sympathy towards the fallen woman, and moreover, how the nature of sympathy is shaped by the writers’ narrative strategies and prevalent cultural attitudes towards women and their sexuality. Critics have typically argued that Victorian novelists adhered to Adam Smith’s model of sympathy – which understands sympathy as essentially self-reflexive – and are thus sceptical of sympathy leading to acts of kindness. However, this thesis argues that ‘fallen woman’ novels present a more complex case. In their fascination with the difficulty of sympathy, such texts evoke the reader’s sympathy in the act of struggling to understand the ‘fallenness’ of these characters.
The thesis examines novels that are notable for the diverse ways in which the fallen woman is placed within their narratives. Gaskell’s Ruth, Hardy’s Tess of the d’Urbervilles (1891), and Moore’s Esther Waters (1894) are centred on their fallen woman heroines, while in Eliot’s Adam Bede (1859), and Hardy’s Far from the Madding Crowd (1874) and Jude the Obscure, the fallen woman is a minor or secondary character. In doing so, I reveal how these novels function to extend the reader’s sympathy to those outside of their familiar group, drawing upon Raymond Williams’s concept of the ‘knowable community’. The concluding chapters explore how the transition at the end of the nineteenth century from the ‘fallen woman’ to ‘New Women’ fundamentally reshapes the dynamics of sympathy: Moore complicates questions of agency, morality and choice, while Hardy challenges the reader to engage with one of the period’s most challenging fictional characters, Sue Bridehead
Using nitrogen isotopes in macroalgae to determine and monitor sources of nitrogen pollution in estuarine and coastal areas: an in vitro study and case study in North East England, UK.
Get PDFThe growing human population in coastal areas, combined with the intensification of agricultural activity have increased the amount of dissolved inorganic nitrogen (DIN) delivered to estuaries and coastal waters. These high concentrations of DIN can cause eutrophication which in turn causes the growth of opportunistic macroalgae (seaweed) and anoxic conditions both in the water column and in the sediment. Stable nitrogen isotope ratios (δ15N) can be used to discern sources of excess nitrogen pollution in water. The δ15N values of nitrate in water often do not reflect the true δ15N source value owing to high temporal variation, and there are high analytical costs associated with obtaining δ15N values from water nitrate. As such, δ15N values can be measured in macroalgae samples to identify the bioavailable nitrogen inputs in an area. Macroalgae have been previously reported to be accurate biomonitors for sources of nitrogen in the environment, with fractionation assumed to be negligible; however, some workers report varying environmental and biological conditions can cause fractionation between the water column and macroalgal δ15N values. Tips of Fucus vesiculosus (F. vesiculosus) were incubated in isotopically-labelled artificial seawater solutions with varying temperatures and salinities to determine whether these factors affected equilibration of macroalgal δ15N values with δ15N-DIN values. Temperature and salinity were found to have a significant effect on the uptake of nitrogen isotopes by F. vesiculosus tips, suggesting varying these environmental conditions is likely to cause fractionation of nitrogen isotopes between the water column and macroalgal tissue. After 14 days of incubation there was a greater than 1 ‰ difference between δ15N and δ15N-DIN. Tips of F. vesiculosus were also collected from around the North East of England coastline every 2-3 months from October 2020 to July 2021. The tips were analysed for δ15N values. There was a significant difference in macroalgal δ15N values between sampling locations for each collection period in both the River Wear and Tyne and also along the North East coastline. For F. vesiculosus tips collected from the River Wear, the dominant source of nitrogen pollution was found to be treated sewage or manure with point source pollution from untreated sewage discharged from Combined Sewage Overflows (CSO’s). The River Tyne macroalgal tips appear to be impacted by untreated sewage, given the low δ15N values and the temporal variations. Tips collected from the North East coastline look to be affected by wastewater pollution, i.e., treated sewage or manure but are regulated by the unpolluted marine nitrogen. Tips from all sites record δ15N values in the unpolluted range in the winter months, potentially as a result of increased river discharges diluting any pollution δ15N values with lower terrestrial nitrogen δ15N values. There are also environmental and physiological factors that could influence the δ15N values recorded by macroalgae such as biogeochemical cycles, temperature and salinity. All sites followed the same temporal trend of δ15N values, suggesting an impact from environmental factors, rather than source changes. Therefore, δ15N values in F. vesiculosus tips can be used as an indicator of sources of nitrogen loading in the environment, including for point source pollution. However, δ15N values in F. vesiculosus tips are significantly affected by changes in temperature and salinity, and so more work is needed to quantify fractionation between water column and macroalgal δ15N caused by different factors. These data demonstrate that macroalgae can provide an efficient, low-cost alternative to current analytical methods for determining and monitoring nitrogen pollution
Structural Analyses of Behavioral Errors: The Case of Risk and Time Preferences
Get PDFThis thesis revives the interest in behavioral errors by evaluating their application in the decision making under risk in the first essay and observing their association to the econometric modeling of decision heuristics in time preferences in the second essay. The first essay considers task complexity as the underlying source of randomness in the decision making under risk. We evaluate three heteroskedastic models that specify the disturbance’s standard deviation as a function of ad hoc measures of task complexity. Our contribution is to adapt a stochastic model from the consumer behavior discipline to binary choice tasks over lotteries, which is the most common experimental method to elicit risk preferences. Our empirical results emphasize the importance of accommodating the impact of task complexity on behavioral errors by rejecting homoskedasticity in favor of at least two heteroskedastic models. Our analyses suggest that the models’ statistical goodness-of-fit is contributed by their ability to capture broader risk behaviors at individual level, which is useful for distinguishing decision makers. The second essay critically evaluates the decision heuristic models, which have been claimed to have better accuracy in explaining the individual’s time preferences than the structural discounting models. Our contention is that the seemingly superior performance of the heuristic discounting models is irrelevant to their ability to capture particular aspects of discounting behaviors but more an artefact of their oversimplified econometrics modeling. Their specification exhibits a linear approximation of a finite mixture of two behavioral error stories, which is not comparable to the structural discounting specifications with the representative agent model. The heuristic specifications can then be used as a simple diagnostic device for choosing between behavioral error specifications for the structural models. Finally, we contribute to the economic literature by showing that neglecting utility curvature completely reverses inferences about the relative performance of heuristic and structural discounting models
E. coli folate synthesis and C. elegans ageing: Investigating the effect of sulfamethoxazole on bacterial lawn morphology and metabolism
Get PDFThe gut microbiota is essential for host nutrition and may influence ageing. The nematode worm C. elegans provides a useful simplified model for investigating bacterial-host interactions. E. coli is used as a food source for C. elegans. Previous research has shown a decrease in E. coli folate synthesis results in extension of C. elegans lifespan. Potential detrimental effects of bacteria when producing normal amounts of folate are unlikely to be mediated by bacterial growth rate or direct effects of folate on the nematode. Potential toxicity of metabolic chemicals produced by wild type E. coli could explain the shorter lifespan of C. elegans. This thesis aims to understand the interaction between E. coli and C. elegans by investigating components that may be affected by folate synthesis and influencing lifespan.
Toxicity from bacterial formaldehyde synthesis was explored with a formaldehyde sensing lacZ reporter. A novel method was developed to quantify reporter output in a bacterial lawn. The lifespan of C. elegans maintained on E. coli constitutively expressing the formaldehyde detoxification enzymes FrmA/B was also investigated. Formaldehyde synthesis was not found to be a source of toxicity that accelerates C. elegans ageing. The effect of sulfamethoxazole on bacterial lawn growth, morphology and proliferation was examined and found to alter morphology, attenuate growth and impair proliferation compared to wild type and lifespan increasing mutant E. coli. A novel LC-MS/MS method was developed to analyse amino acids in agar. It revealed sulfamethoxazole alters bacterial amino acid metabolism associated with the serine-glycine pathway and growth. The absence of glycine in the media was also examined. It revealed changes to the exometabolome in both sulfamethoxazole treated and untreated conditions that may slow C. elegans ageing without altering bacterial growth.
This work developed novel methods for exploring the bacterial lawn and metabolism, providing insight into the mechanism of how sulfamethoxazole disruption of bacterial folate synthesis may influence C. elegans ageing
New insights into turbidity current structure and behaviour from direct measurements in the deep-sea
Get PDFSubmarine canyons are important conduits for transporting sediment, organic carbon, nutrients, and pollutants to the deep sea. Oceanic sediment density flows called turbidity currents are the main mechanism responsible for redistributing this material on a global scale. Turbidity currents can be very powerful, and carry exceptionally large sediment volumes at high speeds ( 95% of global data traffic, as well as oil and gas pipelines and other infrastructure for energy transport. Thus, it is crucial to understand how turbidity currents evolve over time and space. Yet, knowledge of how these seafloor flows behave is mostly derived from indirect studies, as the powerful nature of turbidity currents ensures that only a handful of direct measurements exist.
This thesis presents unusually high resolution (sub-minute) direct monitoring datasets for turbidity currents, from two submarine canyons in different locations. The first location is Monterey Canyon, offshore California, where turbidity current evolution is analysed through observations of flow behaviour and mixing processes. In particular, turbidity currents are shown to reverse in buoyancy (termed lofting), and rise vertically from the seafloor, after sufficient sediment had been deposited. The water column then took < 2 days to recover to pre-event conditions. These first deep-sea observations of lofting have important implications for the structure of deposits that can form valuable hydrocarbon reserves. Additionally, the amount of sediment and seawater entrained into turbidity currents is quantified at multiple locations along Monterey Canyon. It is shown that turbidity currents at this site grew in water volume by up to a factor of four, which is significantly smaller than predicted by previous numerical and lab-based models, and this discrepancy has important implications for improving seafloor hazard mitigation strategies. The second field dataset comes from the Congo Canyon off West Africa, and it is used to document how the front structure of turbidity currents evolves. At this site, turbidity currents travelling along the same flow path developed one of two different flow-front shapes. Faster turbidity currents developed a distinct head, while slower flows did not. For the first time, it is demonstrated that a thin lens of seawater can be pushed in front of faster flows, similar to air blasts observed during snow avalanches. Overall, this thesis delivers unique insight into how turbidity flows develop over time and space. Such analysis is timely, given that the spatial extent of seafloor infrastructure is predicted to increase by between 50-70% by 2028
A health-oriented emotion-centred origami-based PSS concept. A product-service system concept aimed to help users manage and reduce their stress more tangibly to improve their health and well-being.
Get PDFEmotions have a fundamental role in the experience, perception, cognition, and development of people (Barrett et al., 2016; Plutchik, 2001). Negative emotions such as stress, if not managed appropriately, may be a risk factor in developing diseases such as dementia, cardiovascular problems, and depression, amongst others (Dum et al., 2016; Sandi et al., 2001). This interdisciplinary research presents OrigamEase, a health-oriented emotion-centred origami-based PSS concept to help adults manage their stress more tangibly, in response to its main research question: How can engineering design research contribute to improving people’s emotional health and wellbeing? OrigamEase was designed throughout this research, and its design and testing served to develop a health & well-being oriented, emotion-centred engineering design methodology (HWOEED). Therefore, the design of this methodology is the result of the structuring and ordering of the developmental process of exploring, conducting and streamlining the research, design and testing of OrigamEase.
The design of OrigamEase (both the product and the service part) is based on the cognitive research stream of emotions and stress. Therefore, this research also aims to broaden the knowledge about the implications and management of the emotional experience of stress from an engineering and design point of view, complementing the available solutions for stress management through a structured, measurable, and tangible tool. The HWOEED methodology is influenced by Kansei Engineering and Design Thinking methodologies and integrates various engineering design research methods. However, this methodology proposes a different application of the integration of emotional considerations into engineering design processes., it seeks to improve the emotional experience of users to preserve and promote their health and well-being through specifically designed products, services or PSS. Therefore, these designs become the means and not the end of the engineering design efforts. Also, this methodology can be transferrable to other engineering design solutions.
OrigamEase was tested with 114 adults between 18 and 70 years old through three pilot tests (n=43) and six trial tests (n=71) using a concurrent triangulation mixed methods design. Then the results from these tests were contrasted with two control tests (n=22). The results show that using OrigamEase reduced the measured stress levels of participants (self-reported, heart rate and electrodermal activity) significantly, supporting the experiment hypothesis. Stress levels were recorded before and after using OrigamEase; then, a repeated-measures t-test was applied to find if these differences were significant or not. After using OrigamEase, 73.2% of participants reported feeling less stressed (mean reduction=13.94%), 85.5% experienced a reduction in their heart rate (mean reduction=9.8 bpm), and 78.9% had a lower electrodermal activity (mean reduction= 10.8 points). The testing of OrigamEase served as an initial application validation of the HWOEED methodology.
This research demonstrates that engineering and design fields not only can but need to contribute to research on emotions through interdisciplinary research. Emotions are a fundamental part of all human experiences, impacting a person’s health and well-being profoundly
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