المؤلفون: Bailey, Matthew Marlando

مرشدي الرسالة: Aerospace and Ocean Engineering, Devenport, William J., Schetz, Joseph A., Lowe, K. Todd, Walker, Eric L.

مصطلحات موضوعية: Accuracy, Blockage, Boundary Pressure, Calibration, Lift Interference, Slotted-Wall, Transonic Wind Tunnel Testing, Validation, Ventilated Wall, Wall Interference, Wall Signature

الوصف: Correcting wind tunnel data for wall interference is a critical part of relating the acquired data to a free-air condition. Accurately determining and correcting for the interference caused by the presence of boundaries in wind tunnels can be difficult especially for facilities employing ventilated boundaries. In this work, three varying levels of ventilation at the National Transonic Facility (NTF) were modeled and calibrated with a general slotted wall (GSW) linear boundary condition to validate the computational model used to determine wall interference corrections. Free-air lift, drag, and pitching moment coefficient predictions were compared for a range of lift production and Mach conditions to determine the uncertainty in the corrections process and the expected domain of applicability. Exploiting a previously designed statistical validation method, this effort accomplishes the extension of a calibration and validation for a boundary pressure wall interference corrections method. The foundational calibration and validation work was based on blockage interference only, while this present work extends the assessment of the method to encompass blockage and lift interference production. The validation method involves the establishment of independent cases that are then compared to rigorously determine the degree to which the correction method can converge free-air solutions for differing interference fields. The process involved first establishing an empty-tunnel calibration to gain both a centerline Mach profile of the facility at various ventilation settings, and to gain a baseline wall pressure signature undisturbed by a test article. The wall boundary condition parameters were then calibrated with a blockage and lift interference producing test article, and final corrected performance coefficients were compared for varying test section ventilated configurations to validate the corrections process and assess its domain of applicability. During the validation process discrimination between homogeneous and discrete implementations of the boundary condition was accomplished and final results indicated comparative strength in the discrete implementation's ability to capture experimental flow physics. Final results indicate that a discrete implementation of the General Slotted Wall boundary condition is effective in significantly reducing variations caused by differing interference fields. Corrections performed with the discrete implementation of the boundary condition collapse differing measurements of lift coefficient to within 0.0027, drag coefficient to within 0.0002, and pitching moment coefficient to within 0.0020.
Doctor of Philosophy
The purpose of conducting experimental tests in wind tunnels is often to acquire a quantitative measure of test article aerodynamic characteristics in such a way that those specific characteristics can be accurately translated into performance characteristics of the real vehicle that the test article intends to simulate. The difficulty in accurately simulating the real flow problem may not be readily apparent, but scientists and engineers have been working to improve this desired equivalence for the better part of the last half-century. The primary aspects of experimental aerodynamics simulation that present difficulty in attaining equivalence are: geometric fidelity, accurate scaling, and accounting for the presence of walls. The problem of scaling has been largely addressed by adequately matching conditions of similarity like compressibility (Mach number), and viscous effects (Reynolds number). However, accounting for the presence of walls in the experimental setup has presented ongoing challenges for ventilated boundaries; these challenges include difficulties in the correction process, but also extend into the determination of correction uncertainties. Exploiting a previously designed statistical validation method, this effort accomplishes the extension of a calibration and validation effort for a boundary pressure wall interference corrections method. The foundational calibration and validation work was based on blockage interference only, while this present work extends the assessment of the method to encompass blockage and lift interference production. The validation method involves the establishment of independent cases that are then compared to rigorously determine the degree to with the correction method can converge free-air solutions for differing interference scenarios. The process involved first establishing an empty-tunnel calibration to gain both a centerline Mach profile of the facility at various ventilation settings, and to gain a baseline wall pressure signature undisturbed by a test article. The wall boundary condition parameters were then calibrated with a blockage and lift interference producing test article, and final corrected performance coefficients were compared for varying test section ventilated configurations to validate the corrections process and assess its domain of applicability. During the validation process discrimination between homogeneous and discrete implementations of the boundary condition was accomplished and final results indicated comparative strength in the discrete implementation's ability to capture experimental flow physics. Final results indicate that a discrete implementation of the General Slotted Wall boundary condition is effective in significantly reducing variations caused by differing interference fields. Corrections performed with the discrete implementation of the boundary condition collapse differing measurements of lift coefficient to within 0.0027, drag coefficient to within 0.0002, and pitching moment coefficient to within 0.0020.

وصف الملف: ETD; application/pdf

الإتاحة: http://hdl.handle.net/10919/95882Test

مستخلص: A new cultivar of Heuchera plant named ‘MS2020’ that is characterized by its young foliage that is bronze in color and mature foliage that is bronzy green-yellow in color with veins that are similar in color to the leaf lamina, its good winter hardiness with hardiness at least to U.S.D.A. Zone 4, and its strong garden performance.

مستخلص: A new cultivar of Heuchera plant named ‘PP2020’ that is characterized by its foliage that is gray-green to grey in color with dark green veins on the upper surface and purple in color on the lower surface that become more purple in late summer and fall, its cold winter hardiness at least to U.S.D.A. Zone 4, and its strong garden performance.

المؤلفون: Bailey, Matthew James

المساهمون: Hilton, Adrian Douglas Mark, Guillemaut, Jean-Yves

مصطلحات موضوعية: Depth from Defocus, Thick Lens Model, Multi-View Reconstruction, Neural Rendering

الوصف: Defocus formation from a finite aperture is a well-known phenomenon, occurring in many forms of photographic media. Although defocus is often exploited for artistic reasons, a surprising amount of information about the scene structure is encoded in the camera's blurring function. The aim of this work is to explore how this can be leveraged to recover 3D geometry from scenes with complex reflectance. Depth from defocus (DFD) is a well-established field that aims to reconstruct scene geometry from analysis of the defocus appearance, usually by modelling the camera as a thin lens. While many existing methods achieve approximate depth maps suitable for some applications, the majority are limited to geometrically inconsistent single-view reconstructions. The first contribution generalises image formation to a thick lens, and proposes a novel calibration procedure for accurate defocus modelling. This approach is shown to significantly outperform traditional thin lens assumptions in macro-scale scene reconstruction. The second contribution generalises reconstruction to multiple views, and evaluates the com- plementary properties of defocus and stereo information in a novel reconstruction framework. Unlike conventional multi-view stereo (MVS), which depends on photometric consistency be- tween views, DFD requires only a single viewpoint for reconstruction. This makes defocus-based approaches naturally robust to view-dependent materials considered challenging for traditional MVS. Conversely, textures which are invariant to defocus can be suitable for correspondence. This complementary relationship is investigated to determine the benefits of combining defocus information with stereo cues; with performance evaluated on per-viewpoint depth maps as well as complete 3D reconstructions. The results demonstrate an improvement over DFD alone even in specular and reflective datasets, and outperform state-of-the-art MVS. The third contribution explores the novel application of neural rendering to defocus modelling. Specifically, the recent advances in deep learning are leveraged to solve for three latent variables encoded as pixel intensities in a focal stack: the scene depth and radiance, and the camera point spread function. This is in contrast to the majority of existing defocus-based literature, which assume at least one of these variables is known. These quantities are disentangled by modelling each as a multilayer perception network, and trained end-to-end on the appearance of each pixel under different camera settings. This approach allows novel refocused images to be rendered that accurately capture the bokeh produced by specular highlights with arbitrary aperture shapes. Since the networks are trained according to a convolutional defocus model, the synthesised images can generalise to unconstrained aperture diameters, and achieve depth of field effects that exceed what was observed during training.

الوصول الحر: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.887813Test

المؤلفون: Koc, Soner, Lloyd, Michael W, Grover, Jeffrey W, Xiao, Nan, Seepo, Sara, Subramanian, Sai Lakshmi, Ray, Manisha, Frech, Christian, DiGiovanna, John, Webster, Phillip, Neuhauser, Steven, Srivastava, Anuj, Woo, Xing Yi, Sanderson, Brian J, White, Brian, Lott, Paul, Dobrolecki, Lacey E, Dowst, Heidi, Bailey, Matthew, Cortes-Sanchez, Emilio, Scherer, Sandra, Yang, Chieh-Hsiang, Fujita, Maihi, Chu, Zhengtao, Zhao, Ling, Butterfield, Andrew, Akcakanat, Argun, Boning, Gao, Evans, Kurt, Fang, Bingliang, Gibbons, Don, Jensen, Vanessa, Keener, Dara, Kim, Michael, Kopetz, Scott, Majidi, Mourad, Menter, David, Minna, John, Park, Hyunsil, Yang, Fei, Timmons, Brenda, Wang, Jing, Westin, Shannon, Yap, Timothy, Zhang, Jianhua, Zhang, Ran, Ha, Min Jin, Chen, Huiqin, Xi, Yuanxin, Girard, Luc, Yucan, Erkan, Kirby, Bryce P, Dai, Bingbing, Xu, Yi, Sorokin, Alexey, Gale, Kelly, Augustine, Jithesh, Scott, Stephen, Meraz, Ismail, Fingerman, Dylan, Kossenkov, Andrew, Liu, Qin, Xiao, Min, Wickramasinghe, Jayamanna, Lin, Haiyin, Ramirez-Salazar, Eric, Nathanson, Kate, Tetzlaff, Mike, Xu, George, Yennu-Nanda, Vashisht G, Aft, Rebecca, Andrews, Jessica, Asaro, Alicia, Cao, Song, Chen, Feng, Davies, Sherri, DiPersio, John, Fields, Ryan, Foltz, Steven, Fuh, Katherine, Lim, Kian, Held, Jason, Hoog, Jeremy, Jayasinghe, Reyka G, Li, Yize, Luo, Jinqin, Ma, Cynthia, Mashl, Jay, Mo, Chia-Kuei, Rodriguez, Fernanda, Sun, Hua, Terekhanova, Nadezhda V, Tipton, Rose, VanTine, Brian, Wang-Gillam, Andrea, Wendl, Mike, Wu, Yige, Wyczalkowski, Matt, Yao, Lijun, Zhou, Daniel Cui

المصدر: NAR Cancer. 4(2)

مصطلحات موضوعية: Biological Sciences, Bioinformatics and Computational Biology, Biomedical and Clinical Sciences, Oncology and Carcinogenesis, Cancer, Networking and Information Technology R&D (NITRD), Biotechnology, 2.6 Resources and infrastructure (aetiology), Aetiology, Good Health and Well Being, PDXNet Consortium

الوصف: We created the PDX Network (PDXNet) portal (https://portal.pdxnetwork.orgTest/) to centralize access to the National Cancer Institute-funded PDXNet consortium resources, to facilitate collaboration among researchers and to make these data easily available for research. The portal includes sections for resources, analysis results, metrics for PDXNet activities, data processing protocols and training materials for processing PDX data. Currently, the portal contains PDXNet model information and data resources from 334 new models across 33 cancer types. Tissue samples of these models were deposited in the NCI's Patient-Derived Model Repository (PDMR) for public access. These models have 2134 associated sequencing files from 873 samples across 308 patients, which are hosted on the Cancer Genomics Cloud powered by Seven Bridges and the NCI Cancer Data Service for long-term storage and access with dbGaP permissions. The portal includes results from freely available, robust, validated and standardized analysis workflows on PDXNet sequencing files and PDMR data (3857 samples from 629 patients across 85 disease types). The PDXNet portal is continuously updated with new data and is of significant utility to the cancer research community as it provides a centralized location for PDXNet resources, which support multi-agent treatment studies, determination of sensitivity and resistance mechanisms, and preclinical trials.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/8kb3c410Test

المؤلفون: Bailey, Matthew

المساهمون: Wilson, Mark

مصطلحات موضوعية: Collagen, Computational chemistry

الوصف: Collagen IV networks play a key structural role in the human ocular lens capsule. However, their structure is not well understood, and is hypothesised to undergo significant changes over a lifetime, resulting in a loss of ability to accommodate different focal depths. In this thesis, a range of computational models and methods are developed, which aim to help better understand the properties of 2D networks of biopolymers, especially inspired by collagen IV. The available experimental images of collagen-containing networks are assessed and an image analysis protocol is developed. A Monte Carlo method is designed, which introduces disorder into simplified graph-based networks by switching edges. In addition, Molecular Dynamics is used to simulate coarse-grained polymers which attract one another at their headgroups. These coarse-grained polymers are shown to self-assemble into a variety of interesting network structures. The coarse-grained polymer approach is combined with a Molecular Statics scheme to calculate mechanical properties of the network, and understand how the networks behave when stretched. A model that can mimic the ageing of the network over a lifetime is developed. To better understand how lens capsule motion may damage collagen IV networks, the rupturing behaviour of the polymer networks is examined by stretching ordered hexagonal networks linearly and sinusoidally until they break. This is compared to the rupturing behaviour of networks containing defects. The MD method is used to assess the surface roughness and dimensionality of polymer networks, which is quantified by a fractal dimension. Finally, a new type of persistence diagram is used to quantify and visualise damage to ring structures in a network over time.

الوصول الحر: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.869851Test

المؤلفون: Umeaghadi, Chibuike C., Lucock, Thomas, Hartley, Richard, Berry, Jessica, Bailey, Matthew T.

مصطلحات موضوعية: Geology, FOS Earth and related environmental sciences

الوصف: Permanent disposal of radioactive waste in deep geological repositories (DGRs) relies on engineered barriers, such as crushed rock backfills, to ensure wastes are isolated and contained. The performance of crushed rock backfill, during construction, operation and closure, relies on optimizing its mechanical properties. This paper explores how density and composition influence the strength of (i) crushed halite and (ii) crushed gypsum-mudstone mixtures of the Triassic Mercia Mudstone Group which is a potential DGR host rock in the UK. Unconfined compressive strength (UCS) testing of compacted halite demonstrated that strength correlated with compaction density, with UCS increasing from 220 kPa at a density of 1.72 g cm −3 up to 6600 kPa at the maximum achieved density of 1.83 g cm −3 . Direct shear testing revealed an angle of internal friction for crushed halite samples of 39–40° at a density of 1.5 g −3 . Direct shear testing of gypsum-mudstone composites from 100% gypsum to 100% mudstone revealed ...

الإتاحة: https://doi.org/10.6084/m9.figshare.c.7237251Test
https://geolsoc.figshare.com/collections/Physico-mechanical_properties_of_halite_and_of_gypsum-mudstone_crushed_rock_backfills_of_the_Mercia_Mudstone_Group/7237251Test

المؤلفون: Hagemann, Cathleen, Bailey, Matthew CD, Carraro, Eugenia, Stankevich, Ksenia S, Lionello, Valentina Maria, Khokhar, Noreen, Suklai, Pacharaporn, Moreno-Gonzalez, Carmen, O'Toole, Kelly, Konstantinou, George, Dix, Christina L, Joshi, Sudeep, Giagnorio, Eleonora, Bergholt, Mads S, Spicer, Christopher D, Imbert, Albane, Tedesco, Francesco Saverio, Serio, Andrea

المصدر: PLoS Biol , 22 (3) , Article e3002503. (2024)

مصطلحات موضوعية: Microtechnology, Cell Culture Techniques, Microfluidics, Printing, Three-Dimensional, Lab-On-A-Chip Devices

الوصف: Cell culture devices, such as microwells and microfluidic chips, are designed to increase the complexity of cell-based models while retaining control over culture conditions and have become indispensable platforms for biological systems modelling. From microtopography, microwells, plating devices, and microfluidic systems to larger constructs such as live imaging chamber slides, a wide variety of culture devices with different geometries have become indispensable in biology laboratories. However, while their application in biological projects is increasing exponentially, due to a combination of the techniques, equipment and tools required for their manufacture, and the expertise necessary, biological and biomedical labs tend more often to rely on already made devices. Indeed, commercially developed devices are available for a variety of applications but are often costly and, importantly, lack the potential for customisation by each individual lab. The last point is quite crucial, as often experiments in wet labs are adapted to whichever design is already available rather than designing and fabricating custom systems that perfectly fit the biological question. This combination of factors still restricts widespread application of microfabricated custom devices in most biological wet labs. Capitalising on recent advances in bioengineering and microfabrication aimed at solving these issues, and taking advantage of low-cost, high-resolution desktop resin 3D printers combined with PDMS soft lithography, we have developed an optimised a low-cost and highly reproducible microfabrication pipeline. This is thought specifically for biomedical and biological wet labs with not prior experience in the field, which will enable them to generate a wide variety of customisable devices for cell culture and tissue engineering in an easy, fast reproducible way for a fraction of the cost of conventional microfabrication or commercial alternatives. This protocol is designed specifically to be a resource for biological labs with ...

وصف الملف: text

العلاقة: https://discovery.ucl.ac.uk/id/eprint/10189468/1/journal.pbio.3002503.pdfTest; https://discovery.ucl.ac.uk/id/eprint/10189468Test/

الإتاحة: https://discovery.ucl.ac.uk/id/eprint/10189468/1/journal.pbio.3002503.pdfTest
https://discovery.ucl.ac.uk/id/eprint/10189468Test/

المؤلفون: Bailey, Matthew C. D., du Hoffmann, Johann F., Dalley, Jeffrey W.

المصدر: Brain and Neuroscience Advances ; volume 8 ; ISSN 2398-2128 2398-2128

الوصف: In their recently published study, Gil, Valente and Shemesh combined behaviour, functional magnetic resonance imaging, electroencephalography and causal interventions to establish and validate a cortical processing substrate underlying the transition from static to dynamic visual states in the rat. Their research highlights the superior colliculus as the primary mediator of visual temporal discrimination by showing a direct correlation between behavioural and cortically derived flicker fusion frequency thresholds. This work provides the first empirical evidence addressing the previously established disparity between behavioural and cortically derived flicker fusion frequency thresholds. It demonstrates how important convergent multimodal approaches are to mapping and validating previously disputed cortical pathways. Here, we discuss and evaluate their work, suggesting possible future applications in the field of behavioural neuroscience.

الإتاحة: https://doi.org/10.1177/23982128241251685Test

المؤلفون: Kulasekara, D. Nuwangi, Bailey, Matthew D., Ward, Cassandra L., Allen, Matthew J.

المساهمون: National Institutes of Health, American Chemical Society Petroleum Research Fund

المصدر: Dalton Transactions ; ISSN 1477-9226 1477-9234

الوصف: Two cryptates of trivalent uranium are compared with respect to luminescence, solid-state structure, and electrochemistry.

الإتاحة: https://doi.org/10.1039/d4dt00521jTest
http://pubs.rsc.org/en/content/articlepdf/2024/DT/D4DT00521JTest