The acidic, non-oxidative dissolution of galena nanocrystals has been studied using both microscopic and wet-chemical methods. The effects of particle size, shape, aggregation state, and grain proximity on dissolution rates were investigated. Nearly monodisperse galena nanocrystals with an average diameter of 14.4 nm and a truncated cubic shape were synthesized. In the dissolution experiments of dispersed nanocrystals, galena nanocrystals attached on the surface of a TEM grid were exposed to deoxygenated HCl solutions (pH 3) at 25 °C. Capping groups on nanocrystals were removed via a washing process, and chemistry of nanocrystals was examined using X-ray photoelectron spectroscopy (XPS). The evolution of the size and shape of the pre- and post-dissolution nanocrystals were studied using transmission electron microscopy (TEM), and the dissolution rate was calculated directly according to the size shrinking of galena nanocrystals. To assess the size effect, galena microcrystals (~ 3 μm) were synthesized and dissolved under similar conditions to the dispersed nanocrystals. The results showed that the nanocrystals dissolved at a surface area normalized rate of one order of magnitude faster than the microcrystals. In addition, dissolution rate is orientationdependent on a single nanocrystal. High-resolution TEM (HRTEM) images indicated the {111} and {110} faces dissolve faster than {100} faces on galena nanocrystals, rationalized by the average coordination number of ions on each of these faces. To assess the aggregation effect, dissolution experiments of aggregated galena nanocrystals were conducted using a wet-chemical method, and the results were compared with the rates of microcrystals and dispersed nanocrystals. These experiments showed that the rate of aggregated nanocrystals is in the same order of magnitude as the rate of microcrystals, but one order of magnitude smaller than that of dispersed nanocrystals. Finally, the effect of the close proximity between nanocrystals on dissolution was observed by HRTEM. Dissolution was greatly inhibited on nanocrystal surfaces that were closely adjacent (1-2nm, or less) to other nanocrystals, which is probably relevant to the slow dissolution of aggregated nanocrystals. The dissolution phenomena of galena nanocrystals observed in this study is likely important for understanding the environmental fate and behavior of nanoparticles in aquatic systems. / Ph. D.

There is growing interest in the application of high-resolution radars in autonomous vehicles due to their affordability and high angular resolution. However, the azimuth ambiguity caused by the large physical distance between radar antennas relative to the signal wavelength is a challenge for its application. The problem of multiple extended target tracking using high-resolution radar measurements with azimuth ambiguity is considered. A novel pseudo-3D assignment (P3DA) method based on the pseudo measurement set (PMS) is proposed to resolve the azimuth ambiguity. This method can resolve mono (single) and split (duplicated) azimuth ambiguities common in extended target tracking. The Lagrangian relaxation based on a flexible search (LR-FS) algorithm is proposed to solve the P3DA-PMS problem efficiently. Simulation and experiment results show that the proposed algorithm outperforms conventional methods that do not address the azimuth ambiguity of extended target tracking. Since data association with only one data frame will lose information about target evolution and cannot change an association later based on subsequent measurements, a novel two-step multiframe assignment method is proposed to resolve split and azimuth ambiguity separately. In the first step, the split ambiguity is resolved by the PMS-to-PMS association, resulting in a merged PMS (MPMS). In the second step, the azimuth ambiguity is resolved by the Track-to-MPMS association. Numerical results show that the proposed method performs better than the P3DA-PMS-based method. The vehicles tracking with high-resolution radars need to provide information about their orientation and shape to achieve lidar-like performance. Due to self-occlusion, the L-shape model is frequently utilized to depict the structure of a typical vehicle. Since the measurement accuracy of high-resolution radars is not as high as that of lidars, radar measurement noise cannot be ignored. Moreover, as a side effect of using large wavelengths, multiple measurements may be produced per time step due to multipath effects. As a result, more outliers and inliers can be generated in high-resolution radar measurements. A novel lognormal likelihood-aided L-shape model is proposed to approximate the distribution of high-resolution radar measurements of vehicles. Numerical results evaluated on simulation data and the KITTI dataset show that the proposed algorithm achieves smaller orientation and position errors and larger generalized intersection over union (GIoU) compared to existing L-shape fitting algorithms for lidar measurements. / Dissertation / Doctor of Philosophy (PhD)

The decreasing price of displays has enabled exploration of ever-larger high-resolution displays. Previous research has shown that as the display grows larger, users prefer to physically navigate, which has proven benefits. However, increasing the display size so radically creates a new difficulty in interaction. The paradigm has changed from sitting at a desktop computer to taking users' physical navigation into account and designing more mobile interactions. Currently, when users move, they change the scale at which they are viewing information without changing the interaction scale. This is a problem because tasks change at different levels of visual scale. Mulitscale interaction aims to exploit users’ movement by linking it to interaction, changing the interaction scale depending on users’ distance from the display. This work accomplishes three things: first, we define the design space of multiscale interaction; secondly, through a case study, we explore the design issues for a specific area of the design space; lastly, we evaluate one application through a user study that compares it to two other interaction types. We wanted to know, do users in fact benefit from the linkage of physical navigation with interaction? Results show a trend of a natural link between user distance and interaction scale, even with the other techniques that did not enforce this link. In addition, multiscale interaction benefits from the link by having more consistent performance. They also show that while participants using multiscale interaction tend to move more, they benefit from this additional movement, unlike with the other interaction types. / Master of Science

Tiling multiple monitors to increase the amount of screen space has become an area of great interest to researchers. While previous research has shown user performance benefits when tiling multiple monitors, little research has analyzed whether much larger high-resolution displays result in better user performance. The work in this paper evaluates user performance on an even larger, twenty-four monitor, high-resolution (96 DPI), high pixel-count (approximately 32 million pixels) display for single-users in both flat and curved forms. The first experiment compares user performance time, accuracy, and mental workload on multi-scale geospatial search, route tracing, and comparison tasks across one, twelve (4x3), and twenty-four (8x3) tiled monitor configurations. Using the same tasks, we evaluated conditions that uniformly curve the twelve and twenty-four monitor displays. Results show that, depending on the task, larger viewport sizes improve performance time with less user frustration. Findings also reveal that curving large displays improves performance time as users interacted with less strenuous physical navigation on the curved conditions. A second study sought to understand why curving the display, effectively bringing all pixels into visible range, improved performance so as to provide guidelines for using such large displays. The study tested for region biases, performance gaps in comparing virtually distant objects, and degree of detail of user insights while measuring the physical navigation required. Results clearly show that significantly less movement is required when physically navigating the curved display. Performance measures reveal that users favor the left regions of the flat display, while there appears to be no region bias on the curved display. Furthermore, user performance time increased as the virtual distance between objects increased, and there is a tradeoff in insight detail between the two forms. In conclusion, larger, high-resolution displays improve user performance, and curving such displays further improves performance, removing any biases towards regions of the display, potentially reducing the performance drop of virtually far apart objects, reducing the amount of physical navigation necessary, and enabling more detailed insights. Based on these findings, one should always curve multiple monitor displays for single users, and if space is an issue, start curving once the display reaches four or five monitors wide. / Master of Science

No / Surface plasmon microscopes are mostly built around the prism based Kretschmann configuration. In these systems, an image of a sample can be obtained in terms of an intensity map, where the intensity of the image is dependent on the coupling of the light into the surface plasmons. Unfortunately the lateral resolution of these systems relies on the ability of plasmons to propagate along the metallised layer and is usually limited to a few microns unless special measures are taken. The widefield surface plasmon microscope (WSPR), used here enables surface plasmon imaging at significantly higher lateral resolutions than prism based systems. In this study we demonstrate the functionality of the WSPR by imaging a sequence of binding events between micro-patterned extracellular matrix proteins and their specific antibodies. Using the WSPR system a change in contrast was observed with each binding event. Images produced via the WSPR system were analyzed and compared qualitatively and quantitatively. Consequently, we confirm that the WSPR microscope described here can be used to study sequential monomolecular layer binding events on a micron scale. These results have significant implications in the development of new micron scale bioassays.

Yes / Detecting multiple ocular diseases in fundus images is crucial in ophthalmic diagnosis. This study introduces the Fundus-DeepNet system, an automated multi-label deep learning classification system designed to identify multiple ocular diseases by integrating feature representations from pairs of fundus images (e.g., left and right eyes). The study initiates with a comprehensive image pre-processing procedure, including circular border cropping, image resizing, contrast enhancement, noise removal, and data augmentation. Subsequently, discriminative deep feature representations are extracted using multiple deep learning blocks, namely the High-Resolution Network (HRNet) and Attention Block, which serve as feature descriptors. The SENet Block is then applied to further enhance the quality and robustness of feature representations from a pair of fundus images, ultimately consolidating them into a single feature representation. Finally, a sophisticated classification model, known as a Discriminative Restricted Boltzmann Machine (DRBM), is employed. By incorporating a Softmax layer, this DRBM is adept at generating a probability distribution that specifically identifies eight different ocular diseases. Extensive experiments were conducted on the challenging Ophthalmic Image Analysis-Ocular Disease Intelligent Recognition (OIA-ODIR) dataset, comprising diverse fundus images depicting eight different ocular diseases. The Fundus-DeepNet system demonstrated F1-scores, Kappa scores, AUC, and final scores of 88.56%, 88.92%, 99.76%, and 92.41% in the off-site test set, and 89.13%, 88.98%, 99.86%, and 92.66% in the on-site test set.In summary, the Fundus-DeepNet system exhibits outstanding proficiency in accurately detecting multiple ocular diseases, offering a promising solution for early diagnosis and treatment in ophthalmology. / European Union under the REFRESH – Research Excellence for Region Sustainability and High-tech Industries project number CZ.10.03.01/00/22_003/0000048 via the Operational Program Just Transition. The Ministry of Education, Youth, and Sports of the Czech Republic - Technical University of Ostrava, Czechia under Grants SP2023/039 and SP2023/042.

Globally, deformation along obliquely converging plate margins produce a wide variety of complex fault patterns, including crustal pop-ups, fault duplex structures, restraining bends, and flower structures. Depending on the plate velocity, plate obliquity, crustal rheology, length-scale, and climate, the evolution of faulting into translational and vertical strain can range in complexity and fault slip partitioning (i.e. vertical vs. horizontal strain). In this dissertation I studied two restraining bends to understand how these factors influence patterns of deformation along two major plate boundaries: The North American-Caribbean and the North AmericanPacific plate boundaries. First, I estimate the exhumation and cooling history along the Blue Mountains restraining bend in Jamaica using multiple thermochronometers. Three phases of cooling have occurred within Jamaica: 1) initial rock crystallization and rapid emplacement of plutons from 75-68 Ma, 2) slow cooling from 68-20 Ma, and 3) two-stage exhumation from 20 Ma – Present. During the most recent phase of Jamaica’s cooling history, two stages of exhumation have been identified at 0.2 mm/yr (20 – 5 Ma) and ~1 mm/yr (5 Ma – Present). Given the plate velocity to exhumation rate ratio during the most recent phase, we suggest that the climate of Jamaica increases the erosivity of the Blue Mountain suite, whereby the Blue Mountains may be in an erosional stead-state. Second, I studied the long-term evolution of a restraining bend at San Gorgonio Pass in southern California by relating fault kinematics within the uplifted San Bernardino Mountains to the nearby Eastern California shear zone. Using highresolution topography (i.e. UAV and lidar surveys), I studied the plausibility of faulting along two potentially nascent faults within the San Bernardino Mountains, namely the Lone Valley and Lake Peak faults. We found that while both faults display evidence for Quaternary faulting, deciphering true fault slip rates was challenging due to the erosive nature of the mountainous landscape. Coupled with evidence of Quaternary faulting along other faults within the San Bernardino Mountains, we suggest a western migration of the Eastern California shear zone. / PHD / The deformation of rocks along tectonic plate boundaries provides insight into how the upper crust behaves, and is dependent on the crustal strength, plate velocity, temporal and spatial scales, and climate. At most convergent plate boundaries, plate motion is oblique to the plate boundary, resulting in zones of transpression: compression and translation. Geologists refer to these features as restraining bends. What factors dictate how faults within restraining bends evolve is a major question in the field of tectonics. In this dissertation I studied two major restraining bends which differ in both scale (i.e. length to width ratio) and climate, namely the Blue Mountains restraining bend in Jamaica and the restraining bend at San Gorgonio Pass in southern California. Along the Blue Mountains restraining bend, it was not understood when or how fast this mountain range was being exhumed due to the tectonic forces being applied to the plate boundary. I use a technique called thermochronometry, whereby instead of measuring the age of rock crystallization, I measure when the rock cools below a certain temperature. Different minerals have different closure temperatures, and by using multiple minerals, I determined the cooling path of the rocks in the Blue Mountains since they crystalized in the late Cretaceous (~75 million years ago). We found that the rocks experienced three different phases of cooling, with a more recent phase being divided into two stages since 20 Ma: Blue Mountain rocks being exhumed at a rate of 0.2 mm/yr from 20 – 5 Ma (relatively slow) and ~1 mm/yr from 5 – 0 Ma (relatively fast). I concluded that the climate of Jamaica weathers and erodes rocks so efficiently that the Blue Mountains are in an erosional balance between plate tectonic forces and climatic forces. My second chapter identifies small, unstudied faults within the San Bernardino Mountains, and determined that these faults display enough evidence that they should be considered a earthquake hazard. The restraining bend itself is migrating towards the southeast and is being influenced by other faults in the area. What once was a predominantly transpressional system, is now being influenced mainly by strike-slip faulting.

This thesis concerns the application of aberration corrected scanning transmission electron microscopy (STEM) to the quantitative analysis of industrial Pd-Pt core-shell catalyst nanoparticles. High angle annular dark field imaging (HAADF), an incoherent imaging mode, is used to determine particle size distribution and particle morphology of various particle designs with differing amounts of Pt coverage. The limitations to imaging, discrete tomography and spectral analysis imposed by the sample’s sensitivity to the beam are also explored. Since scattered intensity in HAADF is strongly dependent on both thickness and composition, determining the three dimensional structure of a particle and its bimetallic composition in each atomic column requires further analysis. A quantitative method was developed to interpret single images, obtained from commercially available microscopes, by analysis of the cross sections of HAADF scattering from individual atomic columns. This technique uses thorough detector calibrations and full dynamical simulations in order to allow comparison between experimentally measured cross section to simulated ones and is shown to be robust to many experimental parameters. Potential difficulties in its applications are discussed. The cross section approach is tested on model materials before applying it to the identification of column compositions of core-shell nanoparticles. Energy dispersive X-ray analysis is then used to provide compositional sensitivity. The potential sources of error are discussed and steps towards optimisation of experimental parameters presented. Finally, a combination of HAADF cross section analysis and EDX spectrum imaging is used to investigate the core-shell nanoparticles and the results are correlated to findings regarding structure and catalyst activity from other techniques. The results show that analysis by cross section combined with EDX spectrum mapping shows great promise in elucidating the atom-by-atom composition of individual columns in a core-shell nanoparticle. However, there is a clear need for further investigation to solve the thickness / composition dualism.

Three-dimensional porous single crystals (PSCs) are a recent development in the growing world of mesoporous material. The mesoporosity allows for the material to retain their nanoproperties whilst being bulk in size. The current work concentrates on chromium oxide and cobalt oxide PSCs formed in the templates SBA-15 and KIT-6. HRTEM is the main technique used in this investigation, looking at the morphology and single crystallinity of these materials. A growth mechanism for the PSC material is proposed based on HRTEM observations. XRD studies revealed that the confinement effect, caused by the mesopores, reduces the temperature for both cobalt and chromium oxide crystallisation, as well as a different intermediate route from the metal nitrates. The properties of chromium oxide PSC are also investigated magnetically and catalytically. Some metal oxides in different templates are also presented, despite no PSC forming. HRTEM work on other nanomaterials, based on collaboration, is also presented.

In the past decades, numerous single-molecule techniques have been developed to investigate individual bio-molecules and cellular machines. While a lot is known about the structure, localization, and interaction partners of such molecules, much less is known about their mechanical properties. To investigate the weak, non-covalent interactions that give rise to the mechanics of and between proteins, an instrument capable of resolving sub-nanometer displacements and piconewton forces is necessary. One of the most prominent biophysical tool with such capabilities is an optical tweezers. Optical tweezers is a non-invasive all-optical technique in which typically a dielectric microsphere is held by a tightly focused laser beam. This microsphere acts like a microscopic, three-dimensional spring and is used as a handle to study the biological molecule of interest. By interferometric detection methods, the resolution of optical tweezers can be in the picometer range on millisecond time scales. However, on a time scale of seconds—at which many biological reactions take place—instrumental noise such as thermal drift often limits the resolution to a few nanometers. Such a resolution is insufficient to resolve, for example, the ångstrom-level, stepwise translocation of DNA-binding enzymes corresponding to distances between single basepairs of their substrate. To reduce drift and noise, differential measurements, feedback-based drift stabilization techniques, and ‘levitated’ experiments have been developed. Such methods have the drawback of complicated and expensive experimental equipment often coupled to a reduced throughput of experiments due to a complex and serial assembly of the molecular components of the experiments. We developed a high-resolution optical tweezers apparatus capable of resolving distances on the ångstrom-level over a time range of milliseconds to 10s of seconds in surface-coupled assays. Surface-coupled assays allow for a higher throughput because the molecular components are assembled in a parallel fashion on many probes. The high resolution was a collective result of a number of simple, easy-to-implement, and cost-efficient noise reduction solutions. In particular, we reduced thermal drift by implementing a temperature feedback system with millikelvin precision—a convenient solution for biological experiments since it minimizes drift in addition to enabling the control and stabilization of the experiment’s temperature. Furthermore, we found that expanding the laser beam to a size smaller than the objective’s exit pupil optimized the amount of laser power utilized in generating the trapping forces. With lower powers, biological samples are less susceptible to photo-damage or, vice versa, with the same laser power, higher trapping forces can be achieved. With motorized and automated procedures, our instrument is optimized for high-resolution, high-throughput surface-coupled experiments probing the mechanics of individual biomolecules. In the future, the combination of this setup with single-molecule fluorescence, super-resolution microscopy or torque detection will open up new possibilities for investigating the nanomechanics of biomolecules.