Engineering & Physical Sciences
Permanent URI for this communityhttps://hdl.handle.net/10399/17
Browse
2174 results
Search Results
Item Development of super resolution ultrasound techniques for feature extraction in prostate cancer detection(Heriot-Watt University, 2024-09) Mobberley, Andrew; Lu, Associate Professor Weiping; Sboros, Professor VassilisThis thesis investigates a super resolution ultrasound based approach to prostate cancer detection. It consists of two parts; the development of new super resolution ultrasound imaging (SRUI) methods, and their application to prostate cancer detection. SRUI is a new technique to map the dynamics and structure of the vascular bed below the wave diffraction limit by localising and tracking microbubbles in the bloodstream. In the first part of this thesis, two new SRUI methods are developed to address the current limitations associated with the particle tracking accuracy, and are validated using synthetic and in vivo ultrasound data. These high-quality results provide the basis for further analysis. In the second part of this thesis, two new methods have been applied for prostate cancer detection by identifying abnormal features in SRUI. The first is an imaging biomarker based scoring system, referred to as cancer detection by super resolution ultrasound, where each biomarker is scored, and cancer is identified via a higher score based on a group of biomarkers. The second is a machine learning classifier where biomarkers serve as inputs for automated cancer detection. Both methods have been applied to a cohort of patients with known cancer locations. The findings demonstrate the potential clinical viability of these methods.Item Compressive high-speed imaging system and reconstruction algorithm(Heriot-Watt University, 2025-08) Zhou, Zhaokang; Wang, Xu; Hong, JiashengHigh-speed imaging plays a vital role in fields such as biomedical diagnostics, combustion analysis, and astronomical observation, where phenomena evolve on microsecond or even nanosecond scales. Traditional imaging systems, constrained by the Shannon–Nyquist sampling theorem, require high-bandwidth sensors and large data storage, limiting scalability and cost-efficiency. Compressive sensing (CS) offers a paradigm shift by enabling the recovery of high dimensional signals from significantly fewer measurements. Applied to video capture, CS facilitates the design of snapshot imaging systems that reconstruct multiple frames from a single coded measurement. This thesis presents a novel hardware architecture: the Compressive Coded Rotating Mirror (CCRM) system, capable of achieving up to 1.4 million frames per second. The system employs a motor-driven rotating mirror in combination with static binary masks to spatially encode successive frames across different pixel columns, enabling high frame counts without relying on expensive digital mirror devices (DMD). To complement the hardware, we develop a reconstruction framework that integrates classical optimization (e.g., Generalized Alternating Projection and ADMM) with domain specific priors. A key innovation is the foreground–background decomposition strategy, which enhances reconstruction by leveraging temporal redundancy. The use of Total Variation regularization and plug-and-play denoisers further improves robustness across various dynamic scenes. Extensive experiments, including synthetic simulations and real-world capture of fast phenomena, validate the system’s effectiveness. The proposed CCRM system offers a scalable and cost-efficient solution for ultra-high-speed video acquisition.Item Laboratory astrochemistry of dust and ice(Heriot-Watt University, 2020-03) Taj, Skandar Mahmmood; McCoustra, Professor MartinThin film growth and desorption behaviour of simple molecules on interstellar dust grain analogue surfaces has been investigated using a range of surface science techniques including temperature programmed desorption (TPD), reflection-absorption infrared (RAIR) and reflection-adsorption UV-Visible spectroscopy. The systems investigated use amorphous silica (aSiO2) as a mimic for bare interstellar dust grains and thin adsorbed films of ammonia (NH3), benzene (C6H6), carbon monoxide (CO), compact and porous amorphous solid water (c-ASW and p-ASW) crystalline solid water (CSW), methanol (CH3OH) and methyl formate (HCOOOCH3, MF). The optical properties for benzene (C6H6) were investigated using a newly designed and constructed UV/Visible spectrometer. Preliminary measurements of C6H6 on a highly-orientated pyrolytic graphite (HOPG) surface give the refractive index (n) as 1.43 ± 0.07 for a film of thickness (d) 261±5 nm. MF on aSiO2 was investigated using TPD, RAIRS and ab initio calculations. The TPD of MF is consistent with wetting of the aSiO2 surface. The binding energy of the monolayer was found to be 29.8±0.1 kJ mol-1 and that of the multilayer is 26.4±5.5 kJ mol-1 . This indicates that MF coupling to the aSiO2 surface is weak and only slightly stronger than the MF interaction with itself. Below 95 K, MF is in an amorphous phase and above 95 K, it is crystalline. A combination of measurements of spontaneous dipole orientation and RAIR spectra with computational chemistry supports the idea that the basis motif of the lattice in crystalline cis-MF is a ring dimer structure. A simple method was developed to synthesise the vibrational line profile of CO on a heterogeneous surface. The procedure developed allows the conversion of a distribution of binding energies, Edes, into a continuous distribution of vibrational frequencies, which can in turn be compared with experimental RAIRS data. The interaction of CO with a range of astrophysically surfaces including CH3OH, CSW, c-ASW, amorphous silica and NH3 on the aSiO2 substrate was investigated using TPD. Extended Inversion Analysis was used to determine the pre-exponential factor, distribution of Edes and the entropy of activation (∆ǂS) for desorption of CO from each surface.Item Reconfigurable antennas and metasurfaces based on vanadium dioxide (VO2)(Heriot-Watt University, 2025-09) Gourley, Grant Jack; Anagnostou, Associate Professor DimitrisAbstract and full text unavailable. Restricted access until 01/01/2035. Please refer to PDF.Item High-radiance thulium thin-slab lasers(Heriot-Watt University, 2025-08) Sanwell, Jake; Esser, Professor Matthew Jan DanielAbstract and full text unavailable. Restricted access until 31.03.2028. Please refer to PDF.Item Optimising technetium-99m detection with a CMOS sensor : design and application of a multi-layer particle window(Heriot-Watt University, 2025-07) Yau, Suki; Thomson, Professor Robert. R.; Vyas, Doctor KunalAbstract and full text unavailable. Please refer to PDF. Restricted access until 01.10.2027.Item Advancing promoter enhanced KOH-based carbon capture with electrochemical regeneration(Engineering and Physical Sciences, 2025-07) Ochedi, Friday Ojodomo; Van der Spek, Professor MijndertThis thesis investigates a novel CO2 capture technology utilizing an alkaline solvent (KOH) for chemical absorption with electrochemical regeneration. A key challenge in this technology is the slow CO2 absorption kinetics of KOH-based solvents. To address this, a systematic screening methodology was developed to identify potential promoters capable of enhancing CO2 absorption rates. Promising candidates, including piperazine (PZ), glycinate, carbonic anhydrase (CA), and [Bmim][Ac], were evaluated based on their kinetic enhancement potential, electrochemical compatibility, and oxidative stability. The oxidative degradation behavior of PZ and glycinate in KOH-based blends was investigated to assess their long-term stability. The study revealed that both promoters undergo severe oxidative degradation, with glycinate exhibiting higher degradation rates than PZ. The presence of CO2 was found to inhibit degradation by reducing the concentration of hydroxyl ions. Comprehensive process modeling and techno-economic analysis were performed for the benchmark CESAR1 and the novel ConsenCUS carbon capture technologies. The results highlighted the potential of the ConsenCUS technology, particularly with the integration of CA as a promoter. The integration of CA demonstrated significant improvements, including a 6.5% reduction in solvent usage, a 50% decrease in absorber height, a 6.40% reduction in regeneration energy requirements, an 11% decrease in total capital requirement, a 4.4% decrease in operating cost, and a 10.7% decrease in the cost of CO2 avoided. Despite requiring 25% less capital investment than CESAR1, the ConsenCUS technology with CA shows mixed economic performance due to competing cost factors. The primary economic trade-off centers on capital costs versus operational costs: while ConsenCUS benefits from lower capital requirements and reduced thermal energy needs, it incurs 30% higher annual operational costs primarily due to electricity requirements for electrochemical regeneration. The economic comparison reveals minimal differences in key metrics, with CESAR1 showing slight advantages: 23 €/tonne lower capture costs, 3.8 €/tonne lower avoided costs, and 6 €/tonne lower steam costs compared to the consenCUS case. These marginal variations suggest that the economic viability of ConsenCUS technology is primarily controlled by electricity costs and the efficiency of the electrochemical regeneration process. The technology demonstrates economic competitiveness when paired with effective promoters like CA, and its commercial viability can be enhanced through future innovations targeting electrochemical process optimization and electricity cost reduction.Item New experiments in high-dimensional quantum photonics(Heriot-Watt University, 2025-06) Tyler, Max; Leach, Doctor JonathanQuantum computation and quantum communication are on the cusp of moving from theoretical concepts to practical applications, yet the robust generation, manipulation, and detection of photonic quantum states still remains challenging. This thesis introduces experimental techniques in high-dimensional quantum photonics to overcome these hurdles and pave the way for future quantum technologies. To address the generation challenge, we look at high-dimensional entanglement as a way to increase both information capacity and noise resilience of quantum channels. A novel indicator of entanglement, the quantum contrast (Q), is introduced to quantify the amount of quantum correlations in an entangled state. By studying Q under varying noisy conditions through theoretical, numerical, and experimental approaches, we demonstrate that, in specific cases, increasing the dimensionality enhances the robustness of entanglement - a critical factor for secure quantum communication and efficient quantum networks. On the manipulation front, we develop a multi-plane light converter (MPLC) using a spatial light modulator (SLM) to perform complex unitary transformations on spatial modes of light. This device is used to execute unambiguous state discrimination (USD) of non-orthogonal states, a measurement strategy that guarantees error-free identification of the original state at the cost of occasional inconclusive outcomes. The same MPLC setup achieves a 97.6% accuracy in a classical image classification task, showing its versatility and potential for both quantum measurements and classical optical processing. Together, these experiments offer key insights into the fundamental behaviour of high-dimensional quantum states and their practical manipulation. By bridging the gap between theoretical predictions and experimental implementations, this work advances our understanding of noise resilience in entangled systems and introduces robust methods for high-fidelity state discrimination. The developments presented here are critical steps toward realising secure, high-capacity quantum communication networks and scalable quantum computing platforms in real-world settings.Item Modelling and simulating affine-style cameras : an investigation into the use of thin-film directional filters in large-area cameras(Heriot-Watt University, 2022-12) McEntee, Thomas; Ritchie, Professor James; Lim, Doctor TheodoreThis thesis examines the behaviour of a large area thin-film camera. A new camera design, termed affine-style, was proposed which uses a thin-film directional filter to collimate light. This design had the benefits of being extremely scalable to different surface sizes and extremely thin (potentially several microns) allowing it to be integrated into surfaces such as walls or chassis. To determine the behaviour of this camera a novel model was established termed pseudo-affine. This camera was successfully simulated using a ray tracer and a realistic directional filter model. Whilst the simulation demonstrated such a camera is functional, it also showed that with current technology it is limited to short range usage, such as indoors, capturing large scale features, such as silhouettes of objects or humans, due to extreme blurriness. To achieve these discoveries this research developed the pseudo-affine camera model using the affine transform as a basis. Using this new model, the key controlling variables were identified, these determined the camera’s intrinsic properties such as the size of the sensor of the camera and its ability to collimate light, which in this project was termed affineness. Using these variables and the pseudo-affine theory a ray tracer model was developed and tested against a Söller collimation camera. Using the ray tracer model, a series of simulations further investigated the effects of the camera’s intrinsic and extrinsic variables. This showed that affine-style camera’s output quality is governed by the ratio between it Field-of-View size and the size of the feature being captured. The larger the ratio, the more the image became blurred, and the worse image quality became. The relationship between this ratio and image quality was calculated and was used as the foundation of a novel design methodology for the affine-style camera.Item Global sensitivity analysis of an agroforestry system(Heriot-Watt University, 2025-06) Ramil Brick, Elisa Sarah; Desmulliez, Professor Marc P. Y.Agroforestry systems are naturally complex with multiple input and output factors. Understanding how these inputs interact and influence the system can be significant in helping researchers and practitioners make more informed decisions and design more effective systems. Statistical methods such as global sensitivity analysis (GSA) investigate the effect of uncertainty in the inputs of a model on the uncertainty in the model’s output. This can provide informative insights into parameter relationships. However, there is little interdisciplinary work applying GSA in agroforestry thus far. Integrating GSA into agroforestry research has the potential to gain a deeper understanding of these systems and significantly impact the conclusions that can be drawn from the data. In this thesis, this is demonstrated by developing a tool combining the agroforestry simulation Hi-sAFe, developed by the French National Research Institute for Agriculture Food and the Environment (INRAE), and the uncertainty quantification framework UQLabs developed by the Federal Institute of Technology Zurich (ETH Zurich). The tool is tested on an experiment originally run by INRAE investigating the influence of latitude on light availability for intercrops in an alley cropping system. Using GSA, it was possible to identify an input factor not accounted for in this simulation proving an assumption of the original work could be erroneous. Furthermore, the next experiment was focused on agroforestry’s role on carbon farming. Due to the recent European Parliament agreement to certify carbon farming through agroforestry, there will likely be a rise in interest for quantifying and optimising carbon sequestration in agroforestry systems. Thus, GSA was again applied to a Hi-sAFe simulation to understand how the carbon-to-nitrogen ratio of soil organic matter, initial soil organic nitrogen content, and denitrification properties including depth and rate interact to influence total carbon humus stock in agro forestry systems. Results demonstrate that the influence of soil organic nitrogen is most influential. Overall, the main contribution of this work is introducing GSA to agroforestry research. The development of the GSA tool combining UQLabs and Hi-sAFe makes it accessible for agroforestry researchers to use GSA enabling them to gain deeper insights from their experiments.