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An Examination of Farmer Perceptions, Social Acceptance, and the Disruptive Potential of Agrivoltaics in Northwest India
Get PDFAgrivoltaics, the innovative combination of solar energy with agriculture, are theorised to provide holistic benefits across the food-energy-water nexus and address rising concerns of land competition within energy transitions. Across various feasibility studies, there are noted potential socioeconomic benefits of agrivoltaics, such as increased dual- income streams for farmers and energy security. However, due to agrivoltaics’ nascency, there is limited research examining community perceptions and lived experiences outside of the Global North. India is an early leader in agrivoltaics installations in Asia; however these sites are predominantly demonstration, research, or pilot sites and no specific policy or regulation has been introduced. Despite India’s semi-arid northwestern states being theorised to provide opportunities for agrivoltaics given appropriate policy, a history of land dispossession and marginalisation from renewable energy development contributes to distrust among farming communities. Further, the small-scale agricultural environment prominent in the sub-continent emphasises a requirement for further technological innovation to adapt agrivoltaics to a new context.
A combination of desk-based and field research speaking with experts, community organisers, and farmers in Delhi, Haryana, and Maharashtra contribute to a greater understanding of the prospects of agrivoltaics in India and potentially other Global South contexts. Employing social acceptance, energy justice, and disruptive innovation perspectives, this thesis will evaluate how agrivoltaics and decentralised solar are framed in national publications in comparison to implementation strategies, the existence of an enabling environment, and future pathways for agrivoltaics scale-out in India. These factors engender greater insight into social acceptance of agrivoltaics in South Asia, as well as illustrating the technology’s potential in small-scale, rural, or non-traditional settings. This thesis advances agrivoltaics scholarship through the examination of stakeholder and farmer perceptions of the technology in India, while also illustrating the importance of flexibility and experimentation to foster just energy transitions among vulnerable populations
Defining Quality in a Wood Ant - Aphid - Tree Foraging Network
Get PDFQuality distance trade-offs shape foraging dynamics, but defining quality can be complex. Ants ‘farm’ aphids to collect honeydew, a significant food source for Formica lugubris wood ant colonies. Previous modelling and empirical data indicate that ant colonies do not invest equally in all trees where honeydew is foraged: they treat different trees and their associated aphid populations as being higher or lower value food sources. Honeydew composition varies based on tree and aphid species. Ants could be looking for specific sugars, amino acids, plant defence compounds, or other components of aphid honeydew. Using worker investment as an indicator of a site’s value to the colony, we aim to define “quality” based on the chemical composition of the food retrieved. We collected samples from trees (phloem), aphids (material), and ants (crop contents) on low and high investment sites. Through metabolomic analysis, we investigated the metabolites flowing over the tree-aphid-ant processing pipeline and the final composition of crop contents. We found distinct metabolomic profiles of low and high investment sites in all three sample types (Phloem Sap, Aphid Material, and Crop Contents). Our results provide the first data about what components of the resources provided by trees are treated by ants as high quality, and suggest future work to further elucidate this line of inquiry into resource use by Red Wood Ants
Post-diagnostic psychoeducation and autistic adult’s experiences of disclosure
No full textLay Summary
Literature Review
“Psychoeducation” involves to learning and understanding one’s own mental health condition and is a commonly used component in talking therapy. Some adult autism services within the UK routinely offer psychoeducation adapted for autism to support recently diagnosed autistic people to learn about autism and help them come to terms with the diagnosis. It is unknown whether autism psychoeducation for newly diagnosed adults is effective as no systematic review of the research literature has been done. The aim of this review is to find out whether autism psychoeducation designed for autistic adults without a learning disability is effective for improving autistic people’s quality of life and mental health, including depression, anxiety, and self-esteem. The review also explores whether psychoeducation increases acceptance and knowledge of an autism diagnosis.
The results showed that psychoeducation on its own or when combined with another common psychological therapy, such as mindfulness-based therapies and cognitive behavioural therapy, had some positive effects for improving depression, anxiety, and quality of life in autistic adults. Only a few studies reported data for self-esteem, knowledge, and acceptance. There were no effects on self-esteem but some positive effects were shown for knowledge and acceptance. Quality appraisal of the study indicated that study designs varied across studies and sample size were insufficient in some studies. Furthermore, there is currently no standardised tools for measuring knowledge and acceptance of autism which could have increased the risk of bias for these two measures. A further methodological limitation of the studies published to date was that only a very small number of studies involved autistic people in the design and delivery of the interventions.
Empirical Project
Increasing number of people are receiving diagnosis of autism in adulthood. However, there are very few studies exploring autistic adult’s experiences of “disclosure”, that is, to tell others about their autism. The aim of this study is to explore autistic adults’ experiences of telling other people that they are autistic after receiving their diagnosis as an adult. Twelve autistic adults were interviewed about their experiences of disclosing their diagnosis and Interpretative Phenomenological Analysis was used to analyse the data. The interviews showed that disclosure served different functions for autistic people, including allowing them to access support, to be themselves, and to help others. Autistic people telling others about their diagnosis require them to make decisions about things like how much information to disclosure and to think about feelings and reactions of others. Some people started telling others about their potential diagnosis even before a formal diagnosis is received. There are both good and bad sides of disclosure. Some are positive experiences, like feeling accepted and finding a community. However, sometimes experiences can be negative, such as people not believing them, and these are often because of people have assumptions about autism. These experiences could also be emotionally challenging for autistic people and can also stop autistic people from having their needs met. Autistic people varied greatly on the support they received around disclosure and more consistent post-diagnostic support is needed
Fundamentals of self-acceleration and morphological evolution of premixed hydrogen flames
No full textGlobal warming, primarily driven by CO2 emissions from fossil fuel combustion, necessitates a shift to sustainable energy sources. Hydrogen, being carbon-free and renewable, is essential for achieving net-zero emissions and addressing the global energy crisis. The combustion of hydrogen, particularly in a lean premixed condition, offers significant benefits: controlling flame speeds, reducing exhaust gas temperatures, and lowering nitrogen oxide (NOx) emissions. However, these flames are susceptible to thermodiffusive and hydrodynamic instabilities, which may induce self-acceleration and significantly impact the turbulent burning velocity across various combustion systems, thereby elevating fire and explosion risks. Identifying the regimes of cellular instability and self-acceleration could enhance combustion modelling, a critical tool in the design of combustion systems and in assessing fire and explosion hazards. To address these challenges, a full investigation and understanding on self-acceleration characteristics of hydrogen-air flames under various conditions was conducted, with a particular focus on flame speed and flame surface area. This research employed advanced experimental techniques, including Schlieren imaging, Particle Image Velocimetry (PIV), a 3D swinging laser sheet system, and Direct Numerical Simulation (DNS) supported by the Advanced Flow Simulator for Turbulence Research (ASTR).
Using Schlieren imaging system, the onset of instability was identified by the critical stretch rate, where the flame speed deviates rapidly from its previous response to stretch. Notably, the critical Peclet number (Pecl) increased with higher equivalence ratios and temperatures, indicating a more stable flame. Conversely, Pecl decreased with increased initial pressure due to the associated decrease in the flame speed Markstein number (Mab). Correlations of Pecl and Kacl were developed as a function of Mab with increasing pressure, facilitating the estimation of the severity of large-scale atmospheric hydrogen flames. Comprehensive quantitative data on the self-acceleration of unstable laminar hydrogen-air flames was obtained, revealing self-similarity after instability onset. The previously assumed acceleration exponent α = 1.5 was found to be invalid, with derived α values ranging from 1.125 to 1.39. Higher acceleration exponents were observed in the lean condition, while lower exponents were found in the rich condition. A modified theoretical expression for the constant (A) was proposed and validated against experimentally derived results, highlighting a global pulsating acceleration pattern during the acceleration phase after flame instability.
Particle Image Velocimetry (PIV) was utilized to explore the disturbance of unstable laminar hydrogen-air outwardly propagating spherical flames. It was found that self-acceleration of gas velocities ahead of the front, and shared the same acceleration exponents as the flame front. The power spectral density (PSD) displayed by the flow ahead of the flame front exhibited similarity to flame front fluctuations, attributed to wrinkled flame front-driven gas disturbance. Higher local gas velocities were observed just ahead of the tips of the cellular structures, compared to other regions along the flame front, particularly for the extra lean conditions.
3D laser sheet measurements were employed to quantify the flame surface area of hydrogen flames. For planar flames, the parameters ϵ, representing the deviation of the Lewis number from a critical value, and ω2, derived from classical linear stability analysis to represent thermal-diffusive effects, both exhibit a distinct linear correlation with the enhancement in flame surface area observed in planar flames. This suggests that the 3D swinging laser sheet system is an effective method for investigating flame surface area. For spherical flames, the stretch factor I_0 (the ratio of the increase in flame burning velocity to the enhancement in flame surface area) exceeds 1 when the equivalence ratio (ϕ) is 0.3 (lean condition), particularly under high-pressure conditions.
The morphological characteristics and acceleration behaviour of cellular flames were investigated using Direct Numerical Simulation (DNS) with simplified chemical kinetics. The DNS results indicate that the self-acceleration capacity of thermodiffusively unstable flames (ϕ = 0.4) is significantly higher compared to thermodiffusively stable cases (ϕ = 0.6, 0.8). The stretch factor I_0 for thermodiffusively unstable flames exceeds unity, whereas for thermodiffusively stable flames, it remains approximately equal to one. This suggests that, in thermodiffusively stable flames, the primary contribution to acceleration arises from increased flame surface area. In contrast, thermodiffusively unstable flames exhibit additional mechanisms contributing to self-acceleration. Further analysis of local normal strain rates revealed elevated values at the tips of the finger-like protrusions within the cellular flame structures, indicative of rapid expansion at these points. The significant variations in normal strain rates in thermodiffusively unstable flames are attributed to enhanced flame instabilities or localised effects. Species distribution analysis showed that active radicals, such as OH, O, and H, are highly concentrated at these protrusion tips, referred to as ‘leading points’. In thermodiffusively unstable flames, the high mass diffusivity of hydrogen results in the formation of more ‘leading points’, altering the dynamics of flame expansion. This leads to elevated local normal strain rates and increased concentrations of active species like hydroxide radical (OH) , oxygen radical (O) , hydrogen radical (H) at these locations. Consumption rates of hydrogen and production rates of water are strongly influenced by curvature, with positive curvature regions enhancing localised combustion due to hydrogen's high diffusivity under lean conditions
Enhancing Bayesian Optimization for Compiler Auto-tuning
Get PDFModern compilers offer a wide range of passes for code optimisation. Selecting the right combination and order of these passes, known as phase ordering, can improve the performance of compiled binaries. Autotuning, which refers to automatically searching the space of possible pass combinations, is a powerful technique for compiler phase ordering. However, its practical adoption remains challenging due to the vast search space of compiler optimisations and the high cost of evaluating candidate configurations.
This thesis enhances compiler autotuning by leveraging Bayesian optimisation (BO) to efficiently explore the complex space of compiler phase ordering. BO builds an online surrogate model to approximate the objective function to reduce evaluation overhead. It uses an acquisition function (AF) to guide sampling, improving search efficiency. While promising, applying BO to compiler autotuning requires addressing multiple open challenges.
First, standard BO struggles with high-dimensional search spaces like compiler phase ordering. To address this, this thesis introduces a simple yet effective AF initialisation strategy to enhance BO's ability to navigate high-dimensional optimisation spaces.
Second, the complex interactions between compiler passes make it difficult to model the relationship between pass sequences and performance to build an effective surrogate model. To tackle this, a new compiler autotuning strategy is proposed to incorporate compilation statistics to model these interactions. This method improves BO's search efficiency, requiring only one-third of the search budget compared to previous approaches while delivering higher-performance binaries.
Finally, a real-world program often contains multiple source files and complex compilation workflows. Applying compiler autotuning to such settings requires efficiently allocating the search budget across the compilation targets. To address this, this thesis presents an adaptive BO scheme that dynamically allocates search budgets across source files and develops a framework to automate compiler autotuning setup.
Together, these contributions improve the efficiency, scalability, and usability of BO-based compiler autotuning, making it a more practical tool for autotuning compiler phase ordering
Neural Network Based Flow Recovery and Magnetic Structure Identification in the Solar Atmosphere
Get PDFEnergy transport is a fundamental aspect of solar atmospheric dynamics. Plasma motions
can generate concentrated magnetic flux, driving large-scale transients such as solar flares
and coronal mass ejections, which pose an increasing threat to space- and ground-based
infrastructure. However, direct measurement of plasma flows on the Sun remains unfeasible, raising a critical question: how can plasma flows be accurately recovered from observations?
In a step toward answering this question this thesis employs the neural network Deep-
Vel for estimating flows in new scenarios including active regions and the chromosphere, thus enabling the estimation of flows by assimilating data from state-of-the-art simulations. DeepVel was further extended to higher regions of the solar atmosphere, where a reduced optical thickness results in less coherent apparent motions. By training on a simulation containing
swirling motions in the chromosphere, the networks ability to identify coherent swirls against an incoherent background was tested using a vortex detection method. Network performance was evaluated by undergoing cross-validation with simulations, performing error analysis and comparing with the widely-used Fourier-based local correlation tracking technique. Its ability to imitate the physics present was also tested for the first time by identifying through
Lagrangian coherent structures in the recovered flows.
Results highlight that DeepVel is highly capable for identifying coherent flow structures,
that determine the evolving flow dynamics, across simulations. These flow structures were
shown to correspond well to the presence of emerging active regions thus presenting a promising performance for use with real-world observations for forecasting and tracking the presence of active regions. Despite currently available data, both simulated and observed, tests indicate success in applying DeepVel to chromospheric plasmas
Sun Xiaoxiang (1921-2018) - The Father of Modern Landscape Architecture in China
No full textSun Xiaoxiang (1921–2018) concluded his career with ‘solitary cultivation and silent dedication.’ Spanning over 70 years, his career mirrored the modernisation of Chinese landscape architecture. Trained in horticulture during the Republican era, Sun rose to prominence in the early years of the People’s Republic of China. His designs for the Hangzhou Botanical Garden and Viewing Fish at Flower Harbour Park helped define a Chinese socialist landscape style, merging art and science, that diverged from Soviet models. Although Soviet experts critiqued his work as lacking Chineseness, Sun’s approach marked a pivotal shift in design philosophy. The Cultural Revolution led to a career vacuum, but the reform era in the 1980s reopened international engagement. Sun gained global recognition, notably bridging the Chinese Society of Landscape Architecture with IFLA and earning the title ‘the first teacher of landscape architecture in China’ from Carl Steinitz. His paintings and lectures abroad served as cultural diplomacy, presenting Western audiences with a literati-rooted vision of the Chinese landscape. While he led the field toward broader concepts such as ‘Earthscape,’ his ambition to institutionalise it as a discipline remained unrealised. Despite completing 25 projects, many of his visions were altered or unbuilt—however, affirming his commitment to non-iconographic, time-tested design. This research traces the career of Sun Xiaoxiang, whose work was shaped by shifting social and political contexts that emphasised nationalism, science, and service to the people at different moments in time. The study also highlights the complex tensions between “new” and “traditional” approaches in Sun’s perspectives with younger generations, thereby unpacking the evolving dimensions and conceptualisations of contemporary landscape architecture in China. By following Sun’s path across successive political eras, this research explores intergenerational dynamics and underscores how Chinese landscape architecture continues to develop between tradition and modernity, as well as between national identity and global engagement
AN INVESTIGATION INTO THE MECHANISM OF ACTION OF THE LNCRNA CASC20 ON OSTEOGENESIS AND CHONDROGENESIS
Get PDFCASC20 encodes a long noncoding RNA (lncRNA) and is hypothesised to be a novel regulator of bone formation through promotion of osteogenesis and a reduction in chondrogenesis.
Understanding the role CASC20 plays could help uncover novel therapeutic approaches for treatment and/or prevention of diseases such as heterotopic ossification (HO), where GWAS has shown CASC20 is associated with susceptibility. This thesis describes the work done to investigate the role of CASC20 in musculoskeletal development and its mechanism of action. lncRNAs can act via decoy, scaffold or guide mechanisms and evidence was gathered to determine which of these is responsible for the actions of CASC20.
An RNA-sequencing analysis of murine cells expressing CAS20 during osteogenic differentiation was performed to observe changes in gene expression and identify CASC20 micro (mi)RNA targets. This work was then repeated in primary, adipose-derived human mesenchymal stromal cells (hMSCs), isolated from the stromal vascular fraction (SVF) in knee fat pads obtained from patients undergoing joint replacement surgery. The hMSCs were transduced with a CASC20 overexpressing (OE) or control (CTRL) lentivirus and differentiated to observe the effects of CASC20 on osteogenesis and chondrogenesis. However, whilst these cells were able to differentiate, the process of lentiviral transduction with CASC20 caused them to lose their differentiative capacity. Pilots with adenoviral transduction demonstrated this was a viable alternative to be used going forward for CASC20 overexpression in primary hMSCs.
Future work is ongoing to investigate whether the action of CASC20 is through BMP2, a neighbouring gene critical to osteogenesis, by clustered regularly interspaced palindromic repeats (CRISPR) deletion of CASC20 regions. This work alongside that described in this thesis helps provide further insight into the action of CASC20 and its role as a potential novel regulator of bone formation
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