Single-isomer sulfated cyclodextrins (SISCDs) have proven to be reliable, effective, robust means for separation of enantiomers by capillary electrophoresis (CE). SISCD derivatives used as chiral resolving agents in CE can carry the sulfo groups either at the C2, C3 or C6 positions of the glucopyranose subunits which provides varied intermolecular interactions to bring about favorable enantioselectivities. The first single-isomer, sulfated β-CD that carries the sulfo group at the C2 position, the sodium salt of heptakis(2-O-sulfo-3-O-methyl-6-Oacetyl) cyclomaltoheptaose (HAMS) has been synthesized. The purity of each synthetic intermediate and of the final product was determined by HILIC and reversed phase HPLC. The structural identity of each intermediate and the final product was verified by 1D, and 2D NMR, and MALDI-TOF mass spectrometry. HAMS has been used as chiral resolving agent for the CE separation of a set of nonionic, weak base and strong acid enantiomers in pH 2.5 background electrolytes. Rapid separations with satisfactory peak resolution values were obtained for the enantiomers of most of the nonionic and weak base analytes. Typically, low concentrations of HAMS were required to effect good enantiomer resolution. The trends in the effective mobilities and separation selectivities as a function of HAMS concentrations followed the predictions of the ionic strength-corrected charged resolving agent migration model (CHARM model). HAMS showed poor complexation with the anionic strong electrolyte enantiomers for which no peak resolution was observed. The separation patterns observed with HAMS as chiral resolving agent were compared with those of other β-cyclodextrin analogues, including heptakis(2-O-methyl- 3-O-acetyl-6-O-sulfo)-b-cyclodextrin (HMAS), heptakis(2-O-methyl-3,6-di-O-sulfo)-b- cyclodextrin (HMdiSu), heptakis(2,3-di-O-acetyl-6-O-sulfo)-b-cyclodextrin (HDAS) and heptakis(2,3-di-O-methyl-6-O-sulfo)-b-cyclodextrin (HDMS).

The semicircular canals detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity presumably require more precise gaze stabilization mechanisms because they experience degradation of spatial resolution at a lower threshold of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here the relationship between semicircular canal radius of curvature, eye size, and visual acuity is examined in a large sample of therian mammals. These results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that interspecific variation in semicircular canal radius of curvature is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. / text

A statistical downscaling approach based on multiple linear-regression is used to investigate the predictability of land surface winds over the Canadian prairies and Ontario. This study's model downscales mid-tropospheric predictors (wind components and speed, temperature, and geopotential height) from reanalysis products to predict historical wind observations at thirty-one airport-based weather surface stations in Canada. The model's performance is assessed as a function of: season; geographic location; averaging timescale of the wind statistics; and wind regime, as defined by how variable the vector wind is relative to its mean amplitude. Despite large differences in predictability characteristics between sites, several systematic results are observed. Consistent with recent studies, a strong anisotropy of predictability for vector quantities is observed, while some components are generally well predicted, others have no predictability. The predictability of mean quantities is greater on shorter averaging timescales. In general, the predictability of the surface wind speeds over the Canadian prairies and Ontario is poor; as is the predictability of sub-averaging timescale variability. These results and the relative predictability of vector and scalar wind quantities are interpreted with theoretically- and empirically-derived wind speed sensitivities to the resolved and unresolved variability in the vector winds. At most sites, and on longer averaging timescales, the scalar wind quantities are found to be highly sensitive to unresolved variability in the vector winds. These results demonstrate limitations to the statistical downscaling of wind speed and suggest that deterministic models which resolve the short-timescale variability may be necessary for successful predictions. / Graduate

With rapid technology scaling, flip-flops are becoming more susceptible to metastability due to tighter timing budgets and the more prominent effects of process, temperature, and voltage variation that can result in frequent setup and hold time violations. This thesis presents a detailed methodology and analysis on the design of metastable-hardened, high-performance, and low-power flip-flops. The design of metastable-hardened flip-flops is focused on optimizing the value of τ mainly due to its exponential relationship with the metastability window δ and the mean-time-between-failure (MTBF). Through small-signal modeling, τ is determined to be a function of the load capacitance and the transconductance in the cross-coupled inverter pair for a given flip-flop architecture. In most cases, the reduction of τ comes at the expense of increased delay and power. Hence, two new design metrics, the metastability-delay-product (MDP) and the metastability-power-delay-product (MPDP), are proposed to analyze the tradeoffs between delay, power and τ. Post-layout simulation results have shown that the proposed optimum MPDP design can reduce the metastability window δ by at least an order of magnitude depending on the value of the settling time and the flip-flop architecture. In this work, we have proposed two new flip-flop designs: the pre-discharge flip-flop (PDFF) and the sense-amplifier-transmission-gate (SATG) based flip-flop. Both flip-flop architectures facilitate the usage in both single and dual-supply systems as reduced clock-swing flip-flop and level-converting flip-flop. With a cross-coupled inverter in the master-stage that increases the overall transconductance and a small load transistor associated with the critical node, the architecture of both the PDFF and the SATG is very attractive for the design of metastable-hardened, high-performance, and low-power flip-flops. The amount of overhead in delay, power, and area is all less than 10% under the optimum MPDP design scheme when compared to the traditional optimum PDP design. In designing for metastable-hardened and soft-error tolerant flip-flops, the main methodology is to improve the metastability performance in the master-stage while applying the soft-error tolerant cell in the slave-stage for protection against soft-error. The proposed flip-flops, PDFF-SE and SATG-SE, both utilize a cross-coupled inverter on the critical path in the master-stage and generate the required differential signals to facilitate the usage of the Quatro soft-error tolerant cell in the slave-stage.

Enhancing the ability to predict airflow around the Vertical Tail Plane (VTP) of an aircraft is vital in the aviation industry. The size of the VTP is driven by a particular flight condition - loss of an engine during take-off and low speed climb. Nowadays, Computational Fluid Dynamics (CFD) is the main tool used by engineers to assess VTP flows. However, due to uncertainties in the prediction of VTP effectiveness, aircraft designers keep to a conservative approach, which risks oversizing of the tail plane, adding more drag. Uncertainties emerge from difficulties in predicting the massive separation that occurs on the swept tail when it is approached by a flow at high incidence. Furthermore, the deployment of the control surface (the rudder) over the tail plane and the skewed flow along the span increase the CFD challenges. Improved predictive capabilities of the flow around VTPs would enable a more optimal design approach with potential drag saving. The correct prediction of flow separation is the essence of this study. Currently, the industry uses steady Reynolds-Averaged Navier-Stokes (RANS) simulations to analyse VTPs flow. In order to assess RANS performance, the study of airflow detaching from a backward rounded ramp is performed and the results are compared to Large-Eddy Simulations (LES). The analysis shows that, even though RANS may predict the onset of flow separation correctly, they completely miss the location of flow reattachment over the ramp, and this affects the whole flow solution. Moreover, the flow features a strong anisotropy at the onset of separation, difficult to be captured by RANS. The analysis shows that RANS cannot predict production of turbulent kinetic energy in the detached flow region correctly, discouraging flow mixing, and delaying flow reattachment. A hybrid RANS/LES carried out on the same test case shows the benefits of using eddy-resolving simulations for detached flows. The prediction of the locations of the separation and reattachment points differs by only 1% from the highly-resolved simulation. The VTP investigation carried out in this thesis uses a wind tunnel model tested at Airbus. The study starts with steady RANS approaches for different turbulence models. RANS simulations produce acceptable results for the flow at low incidence levels. On the contrary, at high incidence, when flow separation occurs, RANS methods fail. The second step of the research consists of using unsteady RANS (URANS) simulations for VTP flows at high sideslip angles. The introduction of time-accuracy brings important benefits. Nevertheless, the results still show some inaccuracies (around 20% error). Finally, restarting from the flow solutions obtained by URANS simulations, higher fidelity hybrid RANS/LES techniques in the form of Delayed Detached-Eddy Simulations (DDES) are used to assess the characteristics of the separated flow around the tail plane. Results show a remarkable improvement of the flow solution. The pressure distribution matches experimental results favourably, and this translates into an improved prediction of the aerodynamic loads over the VTP. This leads towards a new strategy for the assessment of the flow over aircraft VTPs, amounting to an important contribution to the design of future aircraft.

This thesis deals with analysis of the current situacion in the firm Antonín Král. Then the evaluation of the firm, and the proposals of improvement. Expecially of the conflicts in the workplace and absence from work. First part is focused on explication of the facts. The second part deals with Antonín Král company introducing and analysis of this company. By this analysis are descovered deficiencis. The last part contains my proposals to solve absence, conflicts and how to involve employes in to the firm. Conclusion is the Brogure of solution of conflict on workplace.

Simulation of a wall jet in an enclosure performed to predict the effect of pulsation flow on improving the performance of mixing ventilation systems which are routine practices in industry. Comparing two flows with equal amount for constant and pulsation modes, it was found out that the same global airflow pattern exists for both of the cases but with generation of more eddies and local periodically velocity variations for pulsation mode. This periodic generation of turbulence at pulsatile ventilation flows happen despite the relatively low Reynolds numbers of such flows.Bigger size of boundary layer and higher turbulent kinetic energy for pulsation mode in comparisonwith the same flow rate in constant velocity mode could result in more ventilation capacity with no need to increase the use of energy. It was seen that while a higher constant velocity rate could produce the same acceptable results in terms of higher efficiency in ventilation, a lower pulsated flow could yields it without the risk of draught. Regarding the thesis procedure, the computational solution started with a grid independency study. 2-Dimensional simulation failed to simulate the results similar to the experimental data. No URANS model was able to yield good outcome in 2D mode. The study was continued with 3D SST-kω which yielded good prediction of velocity profiles near the wall regions. For predicting turbulence parameters in the center of the domain SST-URANS was not helpful so, simulation switched to SAS which was successful to some extent to get close to reality.

BACKGROUND: Obesity is a global health problem that is associated with wide range of diseases, including atherosclerosis and Nonalcoholic fatty liver (NAFL) disease. Hepatic inflammation can cause cirrhosis, hepatic decompensation (liver failure) and cancer. Recent research now looks at the chronic systemic effects and inter-organ communication between atherosclerosis potentially promoting the development of NAFL. The resolution of inflammation is regulated naturally in the body by specialized pro-resolving mediators (SPMs). Immunoresolvents like ⍹6-derived Lipoxin A4 are suggested as a therapeutic strategy to overcome chronic inflammation and disease. In this study we investigated the therapeutic potential of Lipoxin A4 (LXA4) in cholesterol fed rabbit model of hypercholesterolemia, with atherosclerotic plaques and confined vascular endothelial injury and its effect on the progression of NAFL. OBJECTIVE: This is a continuation of studies pioneered in the Hamilton lab and an extension of the recent study by Taylor et. al in 201811 linking aortic plaque and liver disease. We will now investigate the therapeutic potential of Lipoxin A4 on lipid-rich atherosclerotic plaques in cholesterol fed rabbits and its effect on the progression of NAFL to NASH. METHODS: In vivo magnetic resonance imaging (MRI) measured aortic atherosclerotic inflammation (with plaque Gd-enhancement), plaque size (vessel wall area), and composition, within rabbits fed normal chow or a 1% cholesterol-enriched diet. Biomarkers in the blood were monitored in the rabbits, with follow-up by histology, which included Masson’s trichrome staining. Light Microscopy was used for liver imaging. Ex vivo MRI, T1W imaging was used to quantify VWA (vessel wall area), with Image J programming. RESULTS: Cholesterol-fed rabbits with and without aortic injury developed hypercholesterolemia, NAFL, and atherosclerotic plaques in the aorta. Elevated plasma gamma-glutamyl transferase (GGT; p =0.014) and the ratio of liver enzymes aspartate and alanine aminotransferases (AST/ALT; p = 0.033) confirmed the progression of steatosis to non-alcoholic steatohepatitis (NASH). Histological images showed less fibrosis in those rabbits fed 1% CHOL diet with injury treated with LipoxinA4, when compared to 1% CHOL diet and injury alone. The plasma biomarkers showed a decrease in cholesterol (79%) and triglycerides (49.9%) in those rabbits given LXA4 therapy. The LXA4 treated 1% CHOL diet with injury group showed a marked decrease in the aorta vessel wall area when compared to the 1% CHOL diet with injury, without treatment; as seen in ex vivo, MRI T1W imaging. CONCLUSION: Lipoxin implementation in cholesterol fed rabbits that have localized regions of highly inflamed aortic atherosclerotic plaques, may contribute to the attenuation on the progression of NAFL to NASH as seen in histology and plasma biomarkers including; cholesterol and triglycerides. Lipoxin as a therapeutic has an effect on treating atherosclerotic plaques and attenuating atherosclerosis progression.

Code comprehension is crucial for software development, as it ensures that code is easy to read andunderstand.Identifiers, such as variable-, function-, and methodnames playa significant role in code comprehension, and it isimportantthat they are written using meaningful names so thateveryone understands their usage. However, sometimes theycontainabbreviations that can have significantly differentexplanationsdepending on the context they are written in, which couldnegatively impact comprehension if the context is notfully known.Large code bases can be hard to navigate but with thehelp ofCode Visualization Tool (CVT) they can provide anoverviewthat helpfully displays the program’s flow and call graphs.Tohelp with abbreviations in large code bases this studywasconducted to investigate the use of Abbreviation Resolver(AR)techniques integrated into a CVT called Doxygen to seethe effecton identifier comprehension. A survey was performed ontwoopen-source projects with questions about thecomprehensionof different methods using their identifiers with bothresolvedidentifiers and abbreviated identifiers. The survey utilizedAR toanalyze participant ́s understanding of abbreviations todetermine it ́s usefulness. The findings suggest that the use ofa CVTwith an integrated AR helps in understanding uncommonanddomain-knowledge abbreviations which contribute toimprovedcode comprehension.

Sediment transport is ubiquitous in aquatic environments, and the study of sediment transport is important for both engineering and environmental reasons. However, the understanding and prediction of sediment transport are hindered by its complex dynamics and regimes. In this dissertation, the open-source solver SediFoam is developed for high-fidelity particle-resolving simulations of various sediment transport problems based on open-source solvers OpenFOAM and LAMMPS. OpenFOAM is a CFD toolbox that can perform three-dimensional flow simulations on unstructured mesh; LAMMPS is a massively parallel DEM solver for molecular dynamics. To enable the particle-resolving simulation of sediment transport on an arbitrary mesh, a diffusion-based algorithm is used in SediFoam to obtain the averaged Eulerian fields from discrete particle data. The parallel interface is also implemented for the communication of the two open-source solvers. Extensive numerical simulations are performed to validate the capability of SediFoam in the modeling of sediment transport problems. The predictions of various sediment transport regimes, including `flat bed in motion', `small dune' and `vortex dune', are in good agreement of with the experimental results and those obtained by using interface resolved simulations. The capability of the solver in the simulation of sediment transport in the oscillatory boundary layer is also demonstrated. Moreover, this well-validated high-fidelity simulation tool has been used to probe the physics of particle dynamics in self-generated bedforms in various hydraulic conditions. The results obtained by using SediFoam not only bridge the gaps in the experimental results but also help improve the engineering practice in the understanding of sediment transport. By using the particle-resolving simulation results and the insights generated therein, the closure terms in the two-fluid models or hydro-morphodynamic models can be improved, which can contribute to the numerical modeling of sediment transport in engineering scales. / Ph. D. / The study and prediction of sediment transport are important for both engineering and environmental reasons. However, the understanding of sediment transport is hindered by the complex dynamics of sediment particles in turbulent flow. In this dissertation, the open-source solver SediFoam is developed for the simulations of various sediment transport problems. Both turbulent flow and particle motions can be resolved by using SediFoam, and thus high-fidelity predictions can be provided. The SediFoam is validated extensively with respect to various sediment transport applications, including “flat bed in motion”, “dune generation and migration”, and “sediment transport in oscillatory flow”. The results obtained by using SediFoam are in good agreement of with available data in the literature. By using this well-validated high-fidelity simulation tool, the physics of particle dynamics in sediment bed and self-generated dunes are investigated. Physical insights of sediment transport that have not been captured by experimental measurements are provided by the high-fidelity simulations. Although the domain length in high-fidelity simulations is only 0.1 m, the results can also be used to improve low-fidelity numerical modeling in macro-scale engineering problems.