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Fluidized bed combustion technology is increasingly used for biomass fuels, due to the high variability of their energy density and composition. However, this technology is still susceptible to ash-related issues. Agglomeration is caused by ash melting onto or reacting with bed material to form alkali silicate melts, allowing bed particles to adhere together. Accumulation of agglomerates causes bed defluidization, and consequently unscheduled downtime. This thesis investigates agglomeration mechanisms and mitigation measures at the pilot-scale, focusing on agricultural fuels that have received less attention in literature and may be of interest for boiler operators. When burning wheat straw, the magnesium-iron silicate bed material olivine lengthened defluidization times versus silica sand, though this was not sufficient to make the fuel viable. The additives kaolin and dolomite prevented bed defluidization entirely when burning miscanthus, but had no effect with wheat straw, despite chemically reacting with both fuel ashes. In combination with thermochemical modelling, it was proposed that the poor breakdown of wheat straw pellet sand release of ash to their surface allows the pellet to act as a seed for agglomerate formation, hence additives proving ineffective. Agglomeration mechanisms were studied with different fuels, bed materials and additives. This included a novel analysis of agglomerates from different bed locations, and a spatially defined study of agglomerates from tests with additives, both of which revealed mechanisms in greater detail than previously reported. A novel thermochemical modelling approach using FactSage was applied to agglomerate compositional data, together with an appraisal of the software for agglomeration studies. Through collaboration with project sponsor Sembcorp Energy UK on their "Wilton 10" bubbling fluidized bed boiler, a 5-year fuel data set was studied to determine fuel quality improvement potential. Several analytical methods were applied, including a machine learning algorithm. Recommendations were made regarding fuel quality and sampling.

Academies may represent one of the most significant British educational reforms in recent history. However in reviewing the current research, little consideration has been given to investigating the culture of academies and acknowledging the significant role this can have in judging their effectiveness. One method of examining an organisation’s culture is the cultural web model and it was subsequently the purpose of this thesis is to assess this model, as a tool for analysing an academy’s culture. In order to achieve this, a complementary mixed-method case study approach was utilised for the teaching and non-teaching staff at an academy. This included questionnaires to Staff with No Responsibility (SNR), focus groups on Staff with Management Responsibility (SMR) and interviews with the Senior Leadership Team (SLT). Findings from this research successfully demonstrate the model’s ability to offer valuable insight into an academy’s culture as well as identifying improvements to its practice. This has also been supplemented with a new method for selecting an organisational culture model and modifications to the future deployment of the cultural web, for both a generic and education setting. Consequently, this thesis may be valuable to those practitioners wishing to analyse the culture of other academies and organisations.

As part of an effort to be a world leader in international efforts in reducing atmospheric carbon dioxide levels, the UK Government has set itself ambitious targets to reduce carbon dioxide emissions by 80% relative to 1990 levels by 2050. To meet this target, there is a strong emphasis in reducing carbon emissions from the domestic sector through the reduction of energy consumption in UK households by improving the energy efficiency of the housing stock, and the behaviours of the occupants. The Department of Energy and Climate Change have indicated that Local Authorities in England are potentially to work in partnership with businesses and community organizations to facilitate delivery; and as a promoter of domestic energy efficiency policies. Consultation with 11 Local Authorities across England confirmed that they are lacking a reliable mechanism that can detect areas within their administrative boundaries that are most in need of intervention to improve the energy efficiency of the housing stock. For the year 2008 the regression models demonstrate that geographical variations in the size of the house, median household income, and air temperature account for 64% of the variation in English domestic gas consumption, and that variations in the size of the house, median household income, and proportion of households connected to the national gas grid account for 73% of the variation in domestic electricity consumption. The predicted values from these regression models serve as benchmarks of domestic gas and electricity consumption in England having accounted for household income, house size, house type, tenure, and climatic differences and could be used to identify areas within Local Authorities with higher than expected energy consumption for energy efficiency interventions. These results contribute to the wider academic debate over how best to achieve the overall aims of household CO2 reductions by moving beyond a purely technical or behavioural-based approach to reducing domestic energy consumption.

This thesis investigates phonetic and phonological variation in the bilingual repertoire of adolescent Welsh-English bilinguals living in North Wales. It contributes to linguistic research by, firstly, providing an account of language variation in an under-studied area (N. Wales) and context (regional minority language bilingualism) and, secondly, by examining cross-linguistic variation, and the constraints on this variation, in bilingual speech. The two variables under discussion differ in how they are realised in the two languages: /l/ is thought to be heavily velarised in both languages as a result of long-term contact and phonological convergence. Variation in the production of /r/ and realisation of coda /r/ has hitherto been reported as language-specific, though frequent transfer is said to occur from Welsh to English in predominantly Welsh-speaking areas (e.g. Penhallurick 2004: 110; Wells 1982: 390).The first aim of the study is therefore to quantify claims of phonological convergence and transfer in the speech of Welsh-English bilinguals by using a variationist sociolinguistics methodology (e.g. Labov 1966), which also considers the influence of linguistic and extra-linguistic factors on variation. Particular attention is paid to differences between a majority Welsh-speaking town and a town where English is the main language. A further distinction is made between those from Welsh-speaking homes and those from English-speaking homes who have acquired Welsh through immersion education. The second aim is to make empirically-informed theoretical claims about the nature of phonological convergence and transfer, and conceptualise cross-linguistic interaction in the speech of Welsh-English bilinguals in light of existing frameworks. Data (sociolinguistic interviews and wordlists) were collected in Welsh and English from 32 Welsh-English bilinguals aged 16-18. The sample was equally stratified in terms of speaker sex, home language, and area. The two towns compared in the study are Caernarfon (N.W. Wales, where c.88% of the population speak Welsh) and Mold (N.E. Wales, where c. 20% Welsh of the population speak Welsh). The results indicate that English [ɫ] tends to be lighter than Welsh [ɫ] in word-initial onset position for females, and in word-medial intervocalic position for both males and females. The data also show linguistic influences on the realisation of [ɫ] in both languages, and differences between males and females. The realisation of coda /r/ and production of [r] and [ɾ] in English are confined to the speech of those from Welsh-speaking homes in Caernarfon. In Welsh, use of [ɹ] is widespread and is constrained by a more complex interaction between area, home language, and sex. On the basis of these findings, I conclude that features which have undergone phonological convergence due to long-term language contact may be subject to language-specific constraints when implemented phonetically. In terms of transfer, I argue for a ternary distinction between interference, transfer, and transfer which is constrained by linguistic and/or extra-linguistic factors (cf. Grosjean 2012). Finally, I suggest that Mufwene’s (2001) notion of the ‘feature pool’ is the most succinct way of conceptualising Welsh-English transfer and differentiate between more focussed accents of English and a less-focussed variety of North Wales Welsh.

The research described in this thesis focussed on the bond resistance of grouted soil nails in clay. Physical modelling took the form of large scale element tests in the laboratory of drilled and grouted nails in a stiff clay. Nails were installed under different boundary stresses; testing was conducted at different constant rates of pull-out and also under sustained load conditions. Observed behaviour was compared with that predicted by measurements of interface shear resistance obtained in a conventional shear box. Numerical modelling was carried out in an attempt to improve understanding of the effects of installation processes on nail performance, and to investigate the trends in behaviour observed during laboratory tests. For this purpose, a one-dimensional finite element computer program was developed to include the effects of consolidation and the out-of-plane soil displacements associated with nail axial loading. The physical modelling showed that the loading rate has a significant effect on bond resistance. This has consequences for the interpretation of data from constant rate of displacement pull-out testing, the conventional method of verifying bond resistance in the field. It is suggested that this type of testing is inappropriate in low permeability soils, because capillary suctions develop which lead to increased bond resistance. Results from laboratory sustained load tests show that lower values of bond resistance are mobilised under the static load conditions more likely to exist in a real soil nailed structure. The numerical modelling confirms the behaviour observed during the laboratory tests, and shows that the mechanisms by which bond is mobilised are complex, depending critically on the dilation and consolidation characteristics of the soil. Nail installation procedures are modelled, and grout pressures are shown to strongly influence bond resistance. Interface tests show trends in behaviour similar to those observed during pull-out testing. However, difficulties exist in the qualitative use of interface test data to predict nail bond resistance.

A study has been conducted into improving construction design through the application of the lean thinking paradigm. Its objective was to identify the issues relating to design efficiency and how a lean thinking approach might address these issues. The investigation consisted of examining work already undertaken in the field by other researchers"to identify the state of the art. The change order request system was examined to gain first insights into waste in construction design, and to gauge the size of the opportunity for the application of lean thinking. An Electronic Data Gathering Tool (EDGT) was then developed to allow further exploration of the design decision making process at the system / sub-system level. The EDGT was used on three live construction projects. From the data recorded a design planning tool, Design Decision Planner (DDP), was created to help improve control of the design process and lead to a more standardised approach to construction design. Standardising the approach to product development is an important component of lean thinking. The main recommendations for making construction design lean are: Use DDP to plan and improve control of the design decision making process, assign design responsibility and to make the process more transparent. 2. Measuring progress against planned design is a useful process metric. 3. Improve the designer's cost and programme visibility when choosing between design options. 4. Redefine the role of the quantity surveyor from cost controller to value for money assessor. The role needs to be better integrated into the design process to reach its full potential. 5. Need to develop more rigorous methods of assessing the buildability of design options. This problem could be eased in the short-term by incorporating construction professionals into the early design phases. 6. Designers need to use more process reason drivers when choosing between design options, not just functional criteria. 7. The change order request system could be redesigned to identify the root causes of contract issue design changes and, hence, improve the design decision making process.

Agricultural intensification is the principal driver of many of our global environmental crises, including the alarming declines of terrestrial insect populations. To curb its negative impacts, it is imperative that we reduce pesticide use and shift agriculture to sustainable, agroecological pest control methods. Natural pest control (NPC) can reduce pest damage and make agriculture more biodiversity (and people) friendly by conserving natural enemy habitat in and around farms. However, a general approach to natural pest control has proved challenging to develop. More understanding is needed of the community ecology of these complex systems and of the impacts of farm management, both at the local and landscape scale. My dissertation explores key components of these knowledge gaps, investigating the role of interaction complexity, through non-consumptive effects, and the impact of local farm management perturbations on natural pest control communities. I use the coffee agroecosystem and ant-mediated natural pest control as a model system to explore these questions, prioritizing an experimental approach to promote mechanistic understanding. In my first Chapter, I expand on the broader issues above and situate my work in the context of knowledge gaps in this field. In Chapter 2, I conduct an empirical experiment investigating the non-consumptive effect of an aggressive, coffee-foraging ant that removes pests from plants and throws them to the ground. I show how this effect mediates multi-predator interactions and spatial complementarity, and also enhances overall pest damage suppression. I also demonstrate how this interaction can be driven by variation in alternative resources for the non-consumptive predator. In Chapter 3, I model the dynamics of this interaction more generally and demonstrate how non-consumptive effects can stabilize the complex dynamics of spatially coupled oscillators, mediate multi-predator interactions, and enhance pest regulation. In Chapter 4, I explore the broad impacts of disturbance through coffee cutting and renovation. This disturbance disrupted ground cover and coffee plant density, which reduced diversity and shifted the composition of the whole ant community. Arboreal ants were especially affected, with a significant reduction in species richness and abundance for several years, until an eventual recovery five years after disturbance. In Chapter 5, I show how contrasting farm management (high-input sun monoculture vs low-input shaded polyculture) impacts ant habitat through the epiphyte communities on coffee plants, where higher diversity and abundance of epiphytes in the less intensive farm may be driven by differences in the frequency of coffee plant pruning and distance from nearby forest patches. In Chapter 6, I demonstrate the impacts of experimental removal of coffee epiphytes on ant communities and pest control. I show that this intensive practice significantly reduces ant diversity, activity, and abundance on coffee, and ant-mediated pest damage reduction. I also show how this disturbance may interact with climate stress to exacerbate impacts on ants. In Chapter 7, I attempt to synthesize my results and place them in the context of our broader understanding. I explore how these findings illuminate the importance of interaction complexity (non-consumptive effects), which can result in non-intuitive impacts, compared to direct consumptive pest regulation. I also provide greater mechanistic understanding of the impacts of local farm intensification and perturbations, by experimentally testing several types of disturbance on ant natural pest control. I conclude with a discussion of the broader implications and suggestions for future research on these subjects.

In photosynthesis, solar energy is absorbed and converted into chemical energy. Chlorophyll embedded in proteins absorb light and transfer excitation energy to reaction centers where charge separation occurs. However, the solar flux incident on photosynthetic organisms is highly variable, requiring complex feedback systems to regulate the excitation pressure on reaction centers and prevent excess absorbed energy from causing damage. Upon exposure to transient high intensity light, processes to dissipate excess absorbed energy are activated. This is routinely observed upon exposure of a photosynthetic sample to actinic light as the quenching of chlorophyll fluorescence, and often broadly referred to as non-photochemical quenching (NPQ). Understanding NPQ and its regulation at a quantitative and mechanistic level is an important challenge for optimizing crop yields and design of biomimetic solar devices for energy harvesting.The regulation of NPQ allows for photosynthetic organisms to responds to changes in light intensity that occur on multiple timescales, from as little as a few seconds due to e.g. changes in shading of a leaf, to daily oscillations due to the position of the sun in the sky, and even seasonal oscillations. Various biochemical regulators of NPQ have been identified from measurements of the chlorophyll fluorescence of model organisms upon chemical and genetic manipulation. In vascular plants such as Arabidopsis thaliana, the rapidest regulation of NPQ is triggered by a pH gradient across the thylakoid membrane (∆pH) that is mediated by the PsbS protein. ∆pH simultaneously regulates the concentration of various xanthophylls, that are thought to influence direct photochemical mechanisms of quenching via the chemical composition of pigment-protein complexes and structural aspects of pigment-protein complex fluctuations and membrane organizations. However, the various regulatory responses often depend on shared biochemical regulatory components, such as the accumulation of the carotenoid zeaxanthin or the presence of the pH-sensitive PsbS protein. This makes distinguishing contributions of different regulatory responses to the overall response a challenging problem.The biochemical regulation of NPQ ultimately activates photochemical mechanisms of energy dissipation, where excess solar energy absorbed by chromophores is dissipated via a non-radiative process to prevent photodamage. Proposed mechanisms include the nonradiative decay of an excited state of xanthophylls, a xanthophyll radical cation formation and recombination, and chlorophyll-chlorophyll charge separation and recombination. However, the electronic states of the chromophores proposed to be involved in energy dissipation indicate that even small fluctuations in the protein environment could preference which mechanisms are most favorable for any particular chromophore and therefore suggests that the quenching process is heterogeneous and dependent on a number of factors including protein conformation and membrane organization. Therefore, understanding the mechanisms through which photosynthetic systems dissipate excess energy and regulate excitation pressure in response to variable light conditions requires extensive quantitative measurements and modeling of the photosynthetic system and energy dissipation.Developing a comprehensive understanding of the regulation of NPQ and the underlying photochemical mechanisms of energy dissipation is an challenging question in the study of NPQ and photosynthesis. Although numerous elements of the regulatory response of NPQ have been identified, each of the elements of the regulatory response occur on various timescales that contribute to the overall response. What are the timescales of these regulatory responses? What are the mechanisms of energy dissipation and which do various regulatory processes activate? How much do these mechanisms contribute to the overall quenching response? This work describes attempts to address these questions through the use of time correlated single photon counting (TCSPC) measurements of the chlorophyll fluorescence of Arabidopsis thaliana over multiple periods of exposure to high intensity actinic light and subsequent dark recovery to inform kinetic modeling of the regulation in order to attempt to distinguish features of the regulatory processes and connect the regulatory processes to proposed photochemical mechanisms of energy dissipation in a quantitative manner. The work makes important steps toward the ability to incorporate energy dissipation into first principles models of the photosynthetic system that relate membrane scale models of energy transfer to experimental observations, and establishing predictive models of how modifications of the regulatory systems will influence the resulting quenching and yields of photosynthesis for the optimization of crop yields.Chapter 1 contains a review discussing efforts to model energy dissipation, or quenching, in Arabidopsis thaliana and their connections to models of regulatory systems that control quenching. First, theory used to describe energy transfer and experimental data obtained to construct energy transfer models of the photosynthetic antenna system that underlie the interpretation of chlorophyll fluorescence quenching is reviewed. Second, experimental evidence leading to proposed molecular mechanisms of quenching and the implications for modeling are discussed. The initial incorporation of depictions of proposed mechanisms into quantitative energy transfer models is reviewed. Finally, the necessity of connecting energy transfer models that include molecular models of quenching mechanisms with regulatory models is discussed.Chapter 2 discusses experimental TCSPC measurements were performed on Arabidopsis thaliana to quantify the dependence of the response of NPQ to changes in light intensity on the presence and accumulation of zeaxanthin and lutein. Measurements were performed on wild type and mutant plants deficient in one or both of the xanthophylls, as well as a transgenic line that accumulates lutein via an engineered lutein epoxide cycle. Changes in the response of NPQ to light acclimation in wild type and mutant plants were observed between two successive light acclimation cycles, suggesting that the character of the rapid and reversible response of NPQ in fully dark-acclimated plants is substantially different than in conditions plants are likely to experience due to changes in light intensity during daylight. Mathematical models of the response of zeaxanthin- and lutein-dependent reversible NPQ were constructed that accurately describe the observed differences between the light acclimation periods. Finally, the wild-type response of NPQ was reconstructed from isolated components present in mutant plants with a single common scaling factor, which enabled deconvolution of the relative contributions of zeaxanthin- and lutein- dependent NPQ.Chapter 3 discuses measurements undertaken In order to simultaneously resolve timescales of regulatory processes operating on different timescales, but with shared biochemical regulators, TCSPC measurements were performed on several Arabidopsis thaliana mutants during periodic actinic light exposure. Over successive periods of actinic light, TCSPC measurements show distinct intra-period and inter-period dynamics and demonstrate complex roles of the biochemical regulators PsbS and zeaxanthin in both fast and slow timescale responses of NPQ. Comparison between mutant lines suggests evidence of a role of PsbS in the longer timescale quenching response not previously emphasized. Finally, a mathematical model was constructed demonstrating how short timescale, rapidly reversible quenching processes and longer timescale quenching processes combine to produce the overall quenching response.Chapter 4 discusses aspects of analyzing and interpreting snapshot fluorescence lifetime data obtained from in vivo samples using complex actinic exposure patterns to probe and quantify aspects of the regulatory response of quenching. First, a technique involving interleaving data from measurements on separate leaves to achieve increased actinic timescale resolution is discussed, including the application of filters to remove artifacts of leaf-to-leave systematic variability that introduce high frequency oscillation in the data. Second, the application of singular value decomposition on complex data sets for validation and filtering is discussed.Chapter 5 summarizes conclusions of this work and provides an outlook towards future steps necessary for the optimization of crop yields.

Species’ functional traits are an important part of the ecological complexity that determines the provisioning of ecosystem services. In biological pest control, predator response to pest density variation is a dynamic trait that impacts the provision of this service in agroecosystems. When pest populations fluctuate, farmers relying on biocontrol services need to know how natural enemies respond to these changes. Here we test the effect of variation in coffee berry borer (CBB) density on the biocontrol efficiency of a keystone ant species (Azteca sericeasur) in a coffee agroecosystem. We performed exclosure experiments to measure the infestation rate of CBB released on coffee branches in the presence and absence of ants at four different CBB density levels. We measured infestation rate as the number of CBB bored into fruits after 24 hours, quantified biocontrol efficiency (BCE) as the proportion of infesting CBB removed by ants, and estimated functional response from ant attack rates, measured as the difference in CBB infestation between branches. Infestation rates of CBB on branches with ants were significantly lower (71%-82%) than on those without ants across all density levels. Additionally, biocontrol efficiency was generally high and did not significantly vary across pest density treatments. Furthermore, ant attack rates increased linearly with increasing CBB density, suggesting a Type I functional response. These results demonstrate that ants can provide robust biological control of CBB, despite variation in pest density, and that the response of predators to pest density variation is an important factor in the provision of biocontrol services. Considering how natural enemies respond to changes in pest densities will allow for more accurate biocontrol predictions and better-informed management of this ecosystem service in agroecosystems.

Triple-negative breast cancers are defined by a lack of oestrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression. They are associated with poor prognosis and lack targeted therapies due to the absence of suitable molecular targets. Tumour addiction genes can make suitable molecular targets as cancer cells can become addicted to the expression of tumour addiction genes and the activity of their proteins to deal with the additional stresses that are collateral to the tumorigenic process. One of the additional stresses that malignant cells commonly have to survive through is the phenomenon of centrosome amplification. In order to survive in the presence of centrosome amplification, cancer cells upregulate the expression of the kinesin KIFC1. The work presented in this thesis characterised the role of KIFC1 as a malignant cell selective tumour addiction gene in breast cancer cell line models in-vitro and in-vivo using multiple RNAi techniques. The addiction of cancer cells to KIFC1 was revealed to be due to its requirement for the generation and maintenance of a bipolar mitotic spindle in centrosome amplified cells. These cells can display multipolar mitosis in the absence of the KIFC1 dependent clustering mechanism which can produce more than two inviable progeny. Moreover, using pericentrin immunohistochemistry staining on routinely collected formalin-fixed paraffin-embedded tissue, a potential patient stratification centrosome abnormality biomarker has been developed. This biomarker assay demonstrated its ability to predict the effect of KIFC1 targeting on cell population growth in breast cancer cell line models. Finally, this study revealed evidence that drug induced centrosome amplification can result in increased sensitivity to KIFC1 depletion in combination with Cisplatin, CP-466722 (ATM inhibitor), Oxamflatin (HDAC inhibitor), PD0325901 (MEK1/2 inhibitor), and Selumetinib (MEK1 inhibitor). Overall, the work from this thesis validated KIFC1 as a potential therapeutic target for centrosome amplified breast cancers either alone or in combination with centrosome amplification inducing compounds and developed a potential patient stratification biomarker to identify tumours with inherent centrosome amplification.