Dylan Walsh - Academia.edu (original) (raw)
Papers by Dylan Walsh
Общество с ограниченной ответственностью «Капитал», 2020
Early prediction of future acetabular development is important to determine an additional surgery... more Early prediction of future acetabular development is important to determine an additional surgery for developmental dysplasia of the hip (DDH). The purpose of this study was to investigate the predictive factors of acetabular development using MRI. We retrospectively investigated dislocated 40 hips and 34 normal hips in 37 pediatric patients (9 males and 28 females) with DDH who underwent open reduction after walking age. We evaluated the cartilaginous acetabulum and labrum of the patients using coronal MRI T2*-weighted images at 5 years of age. The mean age at the time of surgery was 22 months, and the mean age at the final survey was 19 years. We divided patients into two groups in accordance with the Severin classification at the final follow-up. Groups with good outcomes (affected 26 hips and unaffected 27 hips) and poor outcomes (14 hips and 7 hips) were compared using the MRI parameters on each side. Predictive factors of acetabular development were identified using univariate and multiple logistic regression analyses. Using multiple logistic regression analysis, labral acetabular roof depth and labral hip center distance at 5 years of age represented predictors after open reduction (odds ratio 0.27, P = 0.035; odds ratio 3.4, P = 0.028, respectively) on the affected side, and bony hip center distance represented a predictor on the unaffected side (odds ratio 2.6, P = 0.049). Acetabular development in the unaffected side could be predicted by bony assessment, while acetabular development in the affected side had to be assessed by labrum using MRI.
Cochlear Implants International, 2022
Soft Matter, 2022
Favorable polymer-substrate interactions induce surface orientation fields in block copolymer (BC... more Favorable polymer-substrate interactions induce surface orientation fields in block copolymer (BCP) melts. In linear BCP processed near equilibrium, alignment of domains generally persists for a small number of periods before...
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
This research focuses on the development of large-eddy simulation (LES) of wind farm aerodynamics... more This research focuses on the development of large-eddy simulation (LES) of wind farm aerodynamics using computational fluid dynamics (CFD) software simulate the conditions wind farms go under with special interest in wake effects caused between turbines, and the effect on wakes when topography is included in these simulations. This report will focus on the development of LES models, the development of LES models of wind turbines to assess the downstream effect of the wakes caused by the wind turbines. To do this, simulations where created in ANSYS Fluent CFD solver and the results were analyzed and compared to each other. The first simulation in this research is a simulation of the lowest part of the atmosphere the atmospheric boundary layer (ABL). The preliminary ABL simulation shows that mixing at lower levels of the atmosphere can cause rapid changes in wind speeds with small elevations with the dominate changes occurring in the first 200 meters above ground level and this can pl...
El Programa de Mejoramiento Integral de Barrios (PMIB), liderado por la Secretaria Distrital del ... more El Programa de Mejoramiento Integral de Barrios (PMIB), liderado por la Secretaria Distrital del Habitat (SDHT), surge como una iniciativa que busca intervenir y mejorar las condiciones fisicas de los barrios, desarrollando en el proceso acciones integrales que involucran gestion social con participacion ciudadana. El proposito de este documento es evaluar los efectos del PMIB sobre el valor del suelo y el area construida en Bosa Occidental, una localidad de Bogota, Colombia. Los resultados indican que la zona intervenida presenta un crecimiento de 8,45% en el valor del suelo superior a la zona de control (estadisticamente significativo al 1%). Por otro lado, el valor del metro cuadrado no presenta diferencias significativas entre las zonas comparadas. Lo anterior significa que las intervenciones del programa generan un efecto positivo en el valor del suelo, aumentado el patrimonio de sus habitantes.
Significant research and development have occurred for pervious concrete, but its acceptance in c... more Significant research and development have occurred for pervious concrete, but its acceptance in cold climates is still limited. Vulnerability to freeze-thaw and salt exposure has led to uncertainty about its long-term performance. Additionally, the current standardized freeze-thaw testing procedure is not recommended for pervious concrete, as it is not representative of field conditions. This study employed testing processes that are more representative of field conditions to determine the effects of the inclusion of sand as a fine aggregate; fly ash, slag and silica fume as cementitious alternatives, and construction practices on freeze-thaw durability and deicing salts exposure of pervious concrete. The use of pervious concrete itself is considered a best management practice in stormwater management; possibility of substituting cement with a waste product such as fly ash, slag and silica fume promotes sustainability even further.
Public events in urban environments often suffer from large amounts of congestion and unpredictab... more Public events in urban environments often suffer from large amounts of congestion and unpredictable journey times due to the high volume of drivers in the surrounding road network e.g. concerts. To address this problem, the co-operative slot-based driver guidance system is proposed. This system applies traffic shaping measures in an attempt to organise the flow of traffic, leading to more accurate journey time predictions and alleviating congestion. This project explores whether this slot-based system is a more beneficial form of driving, rather than the current unco-operative approach. The system that was developed focused on analysing the feasibility and potential benefits gained from incorporating this driver guidance into event management plans. The potential benefits include more accurate journey time predictions and an overall better-organised flow of traffic. Existing research has been completed for slot-based driving scenarios for highway on-ramp merging and intersections. H...
Soft Matter, 2020
A structure–property–process relation is established for a diblock bottlebrush copolymer solution... more A structure–property–process relation is established for a diblock bottlebrush copolymer solution, through a combination of rheo-neutron scattering, imaging, and rheological measurements.
Journal of Polymer Science, 2021
Nature Communications, 2020
The properties of a polymer are known to be intrinsically related to its molecular weight distrib... more The properties of a polymer are known to be intrinsically related to its molecular weight distribution (MWD); however, previous methodologies of MWD control do not use a design and result in arbitrary shaped MWDs. Here we report a precise design to synthesis protocol for producing a targeted MWD design with a simple to use, and chemistry agnostic computer-controlled tubular flow reactor. To support the development of this protocol, we constructed general reactor design rules by combining fluid mechanical principles, polymerization kinetics, and experiments. The ring opening polymerization of lactide, the anionic polymerization of styrene, and the ring opening metathesis polymerization are used as model polymerizations to develop the reactor design rules and synthesize MWD profiles. The derivation of a mathematical model enables the quantitative prediction of the experimental results, and this model provides a tool to explore the limits of any MWD design protocol.
Macromolecules, 2021
We investigate, by direct numerical simulations, the dynamics of the damped and forced nonlinear ... more We investigate, by direct numerical simulations, the dynamics of the damped and forced nonlinear Schrödinger (NLS) equation in the presence of a time periodic forcing and for certain parametric regimes. It is thus revealed, that the wave-number of a plane-wave initial condition dictates the number of emerged Peregrine type rogue waves at the early stages of modulation instability. The formation of these events gives rise to the same number of transient "triangular" spatio-temporal patterns, each of which is reminiscent of the one emerging in the dynamics of the integrable NLS in its semiclassical limit, when supplemented with vanishing initial conditions. We find that the L 2-norm of the spatial derivative and the L 4-norm detect the appearance of rogue waves as local extrema in their evolution. The impact of the various parameters and noisy perturbations of the initial condition in affecting the above behavior is also discussed. The long time behaviour, in the parametric regimes where the extreme wave events are observable, is explained in terms of the global attractor possessed by the system and the asymptotic orbital stability of spatially uniform continuous wave solutions. The damped and AC-driven nonlinear Schrödinger equation, a prototypical model for complex dynamical behavior, when supplemented with the simplest case of plane wave initial conditions, exhibits behavior which supports the universality of the Peregrine rogue wave and semiclassical type dynamics. These dynamics may be used to explain extreme event formation in the presence of non-integrable perturbations that describe damping and external forcing effects.
Общество с ограниченной ответственностью «Капитал», 2020
Early prediction of future acetabular development is important to determine an additional surgery... more Early prediction of future acetabular development is important to determine an additional surgery for developmental dysplasia of the hip (DDH). The purpose of this study was to investigate the predictive factors of acetabular development using MRI. We retrospectively investigated dislocated 40 hips and 34 normal hips in 37 pediatric patients (9 males and 28 females) with DDH who underwent open reduction after walking age. We evaluated the cartilaginous acetabulum and labrum of the patients using coronal MRI T2*-weighted images at 5 years of age. The mean age at the time of surgery was 22 months, and the mean age at the final survey was 19 years. We divided patients into two groups in accordance with the Severin classification at the final follow-up. Groups with good outcomes (affected 26 hips and unaffected 27 hips) and poor outcomes (14 hips and 7 hips) were compared using the MRI parameters on each side. Predictive factors of acetabular development were identified using univariate and multiple logistic regression analyses. Using multiple logistic regression analysis, labral acetabular roof depth and labral hip center distance at 5 years of age represented predictors after open reduction (odds ratio 0.27, P = 0.035; odds ratio 3.4, P = 0.028, respectively) on the affected side, and bony hip center distance represented a predictor on the unaffected side (odds ratio 2.6, P = 0.049). Acetabular development in the unaffected side could be predicted by bony assessment, while acetabular development in the affected side had to be assessed by labrum using MRI.
Cochlear Implants International, 2022
Soft Matter, 2022
Favorable polymer-substrate interactions induce surface orientation fields in block copolymer (BC... more Favorable polymer-substrate interactions induce surface orientation fields in block copolymer (BCP) melts. In linear BCP processed near equilibrium, alignment of domains generally persists for a small number of periods before...
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
This research focuses on the development of large-eddy simulation (LES) of wind farm aerodynamics... more This research focuses on the development of large-eddy simulation (LES) of wind farm aerodynamics using computational fluid dynamics (CFD) software simulate the conditions wind farms go under with special interest in wake effects caused between turbines, and the effect on wakes when topography is included in these simulations. This report will focus on the development of LES models, the development of LES models of wind turbines to assess the downstream effect of the wakes caused by the wind turbines. To do this, simulations where created in ANSYS Fluent CFD solver and the results were analyzed and compared to each other. The first simulation in this research is a simulation of the lowest part of the atmosphere the atmospheric boundary layer (ABL). The preliminary ABL simulation shows that mixing at lower levels of the atmosphere can cause rapid changes in wind speeds with small elevations with the dominate changes occurring in the first 200 meters above ground level and this can pl...
El Programa de Mejoramiento Integral de Barrios (PMIB), liderado por la Secretaria Distrital del ... more El Programa de Mejoramiento Integral de Barrios (PMIB), liderado por la Secretaria Distrital del Habitat (SDHT), surge como una iniciativa que busca intervenir y mejorar las condiciones fisicas de los barrios, desarrollando en el proceso acciones integrales que involucran gestion social con participacion ciudadana. El proposito de este documento es evaluar los efectos del PMIB sobre el valor del suelo y el area construida en Bosa Occidental, una localidad de Bogota, Colombia. Los resultados indican que la zona intervenida presenta un crecimiento de 8,45% en el valor del suelo superior a la zona de control (estadisticamente significativo al 1%). Por otro lado, el valor del metro cuadrado no presenta diferencias significativas entre las zonas comparadas. Lo anterior significa que las intervenciones del programa generan un efecto positivo en el valor del suelo, aumentado el patrimonio de sus habitantes.
Significant research and development have occurred for pervious concrete, but its acceptance in c... more Significant research and development have occurred for pervious concrete, but its acceptance in cold climates is still limited. Vulnerability to freeze-thaw and salt exposure has led to uncertainty about its long-term performance. Additionally, the current standardized freeze-thaw testing procedure is not recommended for pervious concrete, as it is not representative of field conditions. This study employed testing processes that are more representative of field conditions to determine the effects of the inclusion of sand as a fine aggregate; fly ash, slag and silica fume as cementitious alternatives, and construction practices on freeze-thaw durability and deicing salts exposure of pervious concrete. The use of pervious concrete itself is considered a best management practice in stormwater management; possibility of substituting cement with a waste product such as fly ash, slag and silica fume promotes sustainability even further.
Public events in urban environments often suffer from large amounts of congestion and unpredictab... more Public events in urban environments often suffer from large amounts of congestion and unpredictable journey times due to the high volume of drivers in the surrounding road network e.g. concerts. To address this problem, the co-operative slot-based driver guidance system is proposed. This system applies traffic shaping measures in an attempt to organise the flow of traffic, leading to more accurate journey time predictions and alleviating congestion. This project explores whether this slot-based system is a more beneficial form of driving, rather than the current unco-operative approach. The system that was developed focused on analysing the feasibility and potential benefits gained from incorporating this driver guidance into event management plans. The potential benefits include more accurate journey time predictions and an overall better-organised flow of traffic. Existing research has been completed for slot-based driving scenarios for highway on-ramp merging and intersections. H...
Soft Matter, 2020
A structure–property–process relation is established for a diblock bottlebrush copolymer solution... more A structure–property–process relation is established for a diblock bottlebrush copolymer solution, through a combination of rheo-neutron scattering, imaging, and rheological measurements.
Journal of Polymer Science, 2021
Nature Communications, 2020
The properties of a polymer are known to be intrinsically related to its molecular weight distrib... more The properties of a polymer are known to be intrinsically related to its molecular weight distribution (MWD); however, previous methodologies of MWD control do not use a design and result in arbitrary shaped MWDs. Here we report a precise design to synthesis protocol for producing a targeted MWD design with a simple to use, and chemistry agnostic computer-controlled tubular flow reactor. To support the development of this protocol, we constructed general reactor design rules by combining fluid mechanical principles, polymerization kinetics, and experiments. The ring opening polymerization of lactide, the anionic polymerization of styrene, and the ring opening metathesis polymerization are used as model polymerizations to develop the reactor design rules and synthesize MWD profiles. The derivation of a mathematical model enables the quantitative prediction of the experimental results, and this model provides a tool to explore the limits of any MWD design protocol.
Macromolecules, 2021
We investigate, by direct numerical simulations, the dynamics of the damped and forced nonlinear ... more We investigate, by direct numerical simulations, the dynamics of the damped and forced nonlinear Schrödinger (NLS) equation in the presence of a time periodic forcing and for certain parametric regimes. It is thus revealed, that the wave-number of a plane-wave initial condition dictates the number of emerged Peregrine type rogue waves at the early stages of modulation instability. The formation of these events gives rise to the same number of transient "triangular" spatio-temporal patterns, each of which is reminiscent of the one emerging in the dynamics of the integrable NLS in its semiclassical limit, when supplemented with vanishing initial conditions. We find that the L 2-norm of the spatial derivative and the L 4-norm detect the appearance of rogue waves as local extrema in their evolution. The impact of the various parameters and noisy perturbations of the initial condition in affecting the above behavior is also discussed. The long time behaviour, in the parametric regimes where the extreme wave events are observable, is explained in terms of the global attractor possessed by the system and the asymptotic orbital stability of spatially uniform continuous wave solutions. The damped and AC-driven nonlinear Schrödinger equation, a prototypical model for complex dynamical behavior, when supplemented with the simplest case of plane wave initial conditions, exhibits behavior which supports the universality of the Peregrine rogue wave and semiclassical type dynamics. These dynamics may be used to explain extreme event formation in the presence of non-integrable perturbations that describe damping and external forcing effects.