Lake sturgeon, recently recommended to be listed as an endangered species under the Species at Risk Act, inhabit the various impoundments of the Winnipeg River system. Downstream passage through hydroelectric generating stations represents one of the major data gaps in our understanding of how hydroelectric development may be impacting lake sturgeon populations. Acoustic telemetry was used to investigate coarse-scale movements of juveniles, sub-adult and adults throughout the Slave Falls Reservoir, a 10 km long Winnipeg River impoundment, to assess patterns of downstream passage susceptibility and investigate fine-scale movements in the vicinity of the Slave Falls Generating Station. Movements of juveniles and sub-adults were generally restricted to areas of interconnected deep-water habitat, with movements through the shallow river narrows that sub-divide the Slave Falls Reservoir being rare. Adults did move through these narrows, albeit infrequently. Juveniles and sub-adults tagged in the lowermost section of the reservoir, as well as several adults tagged throughout the reservoir, were found to periodically utilize habitat immediately upstream of Slave Falls, where they would be susceptible to entrainment. Mean entrainment rates were estimated at 3.1% per year for adults tagged throughout the reservoir, and 17.9% per year for sub-adults tagged in the lowermost section of the reservoir. Fine-scale movement tracking revealed that three of eleven observed downstream passage events occurred via bottom-draw regulating gates, while another four events were also reasoned to have occurred via this route. The routes of the remaining four could not be determined. Eight of the eleven downstream passage events observed in this study were survived. While the survival of the remaining three fish could not be confirmed, it is highly likely that they also survived. Length-at-age analysis, supported by genetic methods, revealed that 23 of 151 (15.2%) of the lake sturgeon between 525 and 750 mm (fork length) captured in the 6 km stretch of river downstream of Slave Falls were fast-growing outliers, reasoned to have passed downstream through the Slave Falls Generating Station.

Spatio-temporal variation in action intervals during ventricular fibrillation (VF) suggestthat the excitable gap may also be distributed spatio-temporally. The observation leadus to hypothesize that distributed pacing can be used to modify and entrain electricalactivation during VF. We tested this hypothesis using simulated VF and animal studies. We simulated VF in a 400 by 400 cell matrix. Simulation results showed that activationpattern could be entrained using spatially distributed stimulation. Up to a certain limit,increasing stimulus strength and density led to improved entrainment. Best entrainmentwas obtained by pacing at a cycle length similar to the intrinsic cycle length. In order to verify whether activation could be entrained experimentally, eight opticallyisolated biphasic TTL addressable stimulators were fabricated. Distributed stimulationwas tested during electrically induced VF in two canines and two swine. Resultsshowed that electrical activation could be entrained in both species. Similar to that insimulation, better entrainment was obtained with denser pacing distribution and atpacing cycle length similar to the intrinsic cycle length. As expected, entrainment wasaffected by tissue thickness. Our results show that spatio-temporally distributed pacingstrength stimuli can be used to modify activation patterns during VF.

Lake sturgeon, recently recommended to be listed as an endangered species under the Species at Risk Act, inhabit the various impoundments of the Winnipeg River system. Downstream passage through hydroelectric generating stations represents one of the major data gaps in our understanding of how hydroelectric development may be impacting lake sturgeon populations. Acoustic telemetry was used to investigate coarse-scale movements of juveniles, sub-adult and adults throughout the Slave Falls Reservoir, a 10 km long Winnipeg River impoundment, to assess patterns of downstream passage susceptibility and investigate fine-scale movements in the vicinity of the Slave Falls Generating Station. Movements of juveniles and sub-adults were generally restricted to areas of interconnected deep-water habitat, with movements through the shallow river narrows that sub-divide the Slave Falls Reservoir being rare. Adults did move through these narrows, albeit infrequently. Juveniles and sub-adults tagged in the lowermost section of the reservoir, as well as several adults tagged throughout the reservoir, were found to periodically utilize habitat immediately upstream of Slave Falls, where they would be susceptible to entrainment. Mean entrainment rates were estimated at 3.1% per year for adults tagged throughout the reservoir, and 17.9% per year for sub-adults tagged in the lowermost section of the reservoir. Fine-scale movement tracking revealed that three of eleven observed downstream passage events occurred via bottom-draw regulating gates, while another four events were also reasoned to have occurred via this route. The routes of the remaining four could not be determined. Eight of the eleven downstream passage events observed in this study were survived. While the survival of the remaining three fish could not be confirmed, it is highly likely that they also survived. Length-at-age analysis, supported by genetic methods, revealed that 23 of 151 (15.2%) of the lake sturgeon between 525 and 750 mm (fork length) captured in the 6 km stretch of river downstream of Slave Falls were fast-growing outliers, reasoned to have passed downstream through the Slave Falls Generating Station.

Siphonic roof drainage systems are finding increasing acceptance amongst architects and builders of large commercial buildings in Australia. The benefits of siphonic roof drainage over conventional roof drainage systems include underground excavation savings, higher flow volumes, fewer outlets and stormwater harvesting and reuse potential. Siphonic roof drainage systems are generally designed using the steady state Bernoulli and the Colebrook-White equations. Both of these equations assume a full bore flow regime which only occurs for short periods in siphonic systems. This means that the majority of storm events do not cause the system to run at its full capacity or efficiency. In Australia, systems are designed to cope with a maximum design rainfall intensity, usually the 1 in 100 year storm event. While the performance of siphonic roof drainage systems at this rainfall intensity is well understood, the system performance at lower rainfall intensities and unsteady flow regimes is largely unknown. This research aims to investigate and identify the improvements which can be effected to the overall performance of siphonic roof drainage by the removal of air from the system. The research will also investigate the effect the air entrainment has on siphonic flows. / PhD Doctorate

Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Jacobs, Laurence; Committee Co-Chair: Kurtis, Kimberly; Committee Member: DesRoches, Reginald.

The suprachiasmatic nucleus (SCN) of the hypothalamus is the master mammalian pacemaker, co-ordinating the multitude of cell-autonomous circadian oscillators across the body to ensure internal synchrony, as well as maintaining an adaptive phase relationship with the light-dark cycle via projections from the retina. Intercellular communication between SCN clock neurons synchronises their oscillations, resulting in coherent output signals to the periphery. Vasoactive intestinal peptide (VIP), a neuropeptide expressed in the retinorecipient ventrolateral region of the SCN, is vital to this circuit-level co-ordination by signalling to its cognate VPAC2 receptor. In addition, VIP is important for the integration of light input into the SCN oscillation. The aims of the work presented in this thesis were to determine the roles of the VIP and VPAC2 cells in controlling circadian rhythmicity, and to elucidate the mechanisms of VIP signalling that underpin these roles. The first two experimental chapters utilise intersectional genetics and viral transduction to address separable roles for the VIP and VPAC2 cell populations. By diphtheria toxin-mediated cell ablation, or by adjusting cell-autonomous periodicity or rhythmicity specifically in these cell populations, I have identified that the VPAC2 cells are important for period setting and rhythmicity of both the SCN ex vivo and mouse behaviour in vivo, while the VIP cells play a vital role in behavioural rhythmicity and phase coherence across the SCN. The next two chapters use application of VIP to SCN slices to address mechanisms of phase-resetting through pharmacological manipulation and microarray analysis. I find that VIP has long lasting effects on all major circadian parameters of the SCN slice oscillation at both the cellular and circuit levels, and that it achieves this through a diversity of molecular pathways, in particular through cAMP/Ca2+ response elements within gene promoters. The final chapter focuses primarily on DUSP4, a negative regulator of the MAP kinase pathway that I have demonstrated to be upregulated by VIP. Here I demonstrate that DUSP4 affects the steady-state period of SCN slices, as well as influences phase shifting characteristics of both slices and mice. To conclude, the work presented here furthers our knowledge of neuropeptidergic communication in mammalian pacemaking. I have undertaken extensive characterisation of the molecular mechanisms through which the VIP neuropeptide influences SCN oscillators, and I have determined differential roles for the VIP and VPAC2 neurons in circadian timekeeping.

abstract: Glottal fry is a vocal register characterized by low frequency and increased signal perturbation, and is perceptually identified by its popping, creaky quality. Recently, the use of the glottal fry vocal register has received growing awareness and attention in popular culture and media in the United States. The creaky quality that was originally associated with vocal pathologies is indeed becoming “trendy,” particularly among young women across the United States. But while existing studies have defined, quantified, and attempted to explain the use of glottal fry in conversational speech, there is currently no explanation for the increasing prevalence of the use of glottal fry amongst American women. This thesis, however, proposes that conversational entrainment—a communication phenomenon which describes the propensity to modify one’s behavior to align more closely with one’s communication partner—may provide a theoretical framework to explain the growing trend in the use of glottal fry amongst college-aged women in the United States. Female participants (n = 30) between the ages of 18 and 29 years (M = 20.6, SD = 2.95) had conversations with two conversation partners, one who used quantifiably more glottal fry than the other. The study utilized perceptual and quantifiable acoustic information to address the following key question: Does the amount of habitual glottal fry in a conversational partner influence one’s use of glottal fry in their own speech? Results yielded the following two findings: (1) according to perceptual annotations, the participants used a greater amount of glottal fry when speaking with the Fry conversation partner than with the Non Fry partner, (2) statistically significant differences were found in the acoustics of the participants’ vocal qualities based on conversation partner. While the current study demonstrates that young women are indeed speaking in glottal fry in everyday conversations, and that its use can be attributed in part to conversational entrainment, we still lack a clear explanation of the deeper motivations for women to speak in a lower vocal register. The current study opens avenues for continued analysis of the sociolinguistic functions of the glottal fry register. / Dissertation/Thesis / Masters Thesis Speech and Hearing Science 2015

Une fontaine peut se créer quand la flottabilité d'un rejet vertical s'oppose à sa quantité de mouvement. Ce type d'écoulement connaît beaucoup d'applications que ce soit dans la nature (panaches issus des éruptions volcaniques) ainsi que dans l'industrie du bâtiment (chauffage et refroidissement) ou dans le domaine des risques (rejets accidentel de gaz lourd). Dans cette thèse, nous nous focalisons sur l'étude des fontaines turbulentes miscibles. Dans le premier chapitre nous reformulons le modèle théorique de Morton et al. (1956) pour traiter le cas des fontaines en milieu linéairement stratifié. La résolution de ce modèle permet d'obtenir des relations analytiques pour la hauteur de la fontaine et sa hauteur d'étalement. Ce modèle est, par la suite, étendu au cas des panaches et des jets turbulents en milieu linéairement stratifié. Dans le second chapitre, nous proposons un modèle théorique permettant d'étudier une fontaine turbulente miscible en régime établi. Pour calibrer ce modèle, des simulations numériques aux grandes échelles (LES) sont utilisées pour obtenir une estimation des valeurs des constantes associées aux phénomènes d'échanges turbulents entre les parties ascendante et descendante de la fontaine. L'objectif du dernier chapitre est d'apporter, à partir d'expérimentations en laboratoire, des informations quantitatives sur l'influence de forts écarts de masses volumiques dans les écoulements de type fontaine. Les expériences sont réalisées pour des fontaines gazeuses (mélange air/hélium) en régime établi. / A fountain can occur when the buoyancy of a vertically released fluid opposes its momentum. Such flows have many applications in nature (plumes issuing from volcanic eruption), building industry (cooling or heating) or in the area of risk management (accidental release of heavy dangerous gas). In this thesis, we focus on the study of miscible turbulent fountains. In the first chapter, we revisit the theoretical model of Morton et al. (1956) to handle the case of fountains in linearly stratified fluid. The resolution of this model allows us to obtain analytical relations for the fountain height as well as the spreading height of its horizontal layer. This model is subsequently extended to the case of turbulent jets and plumes in linearly stratified fluid. In the second chapter, we propose a theoretical model for the study of a turbulent miscible fountain in a steady state. To calibrate this model, large eddy simulations (LES) are used to obtain an estimate of the values of the constants associated with the additional terms appearing in the equations. The objective of the final chapter is to provide, from laboratory experiments, quantitative information on the influence of strong density differences on the behaviour of a turbulent fountain. These experiments shows that all the classical relations valid for the Boussinesq case can be extended to the non-Boussinesq case by using an appropriate definition of the Froude number.

Anthropogenic Climate Change is amongst the greatest challenges of human civilization. A key area that will play a large role in mitigating its effects are clean fossil fuel applications. Clean coal combustion is one such application with an urgent timeline. This can be achieved with an oxygen-fired pressurized fluidized bed combustor with downstream carbon capture and sequestration. In relation to pressurized fluidization processes, understanding the influence of pressure on bed hydrodynamics and in turn their effect on parameters including fuel residence time is essential. For the proposed combustor, the heat exchanger boiler tubes are submerged in the fluidized bed such that the effect of a horizontal tube bank on the fuel residence time is also of great importance. The main focus of present work was to evaluate the impact of gas velocity, pressure, presence of a tube bank and fuel feed rate on the average fuel residence time. Experiments were conducted under cold flow conditions in a pilot-scale pressurized fluidized bed with an inner diameter of 0.15 m. The fluidization material was relatively large glass beads (1.0 mm in diameter) while the fuel particles were simulated with smaller glass beads (40 to 138 μm in diameter), susceptible to entrainment. Operating pressures and superficial gas velocities tested were between 101.3 and 1200 kPa and 0.4 and 1.1 m/s respectively. To simulate coal combustors, experiments were then conducted in a continuous mode where the fuel particles were continuously fed to the fluidized bed of large particles over a desired period of time. Downstream, entrained particles were continuously captured to determine the entrainment rate and mass of fuel particles inside the fluidized bed at steady state, which yielded the average fuel residence time. The combination of elevated pressure with the tube bank present was found to enhance gas bubble break up and reduce the average gas bubble size. In turn, this increased the average fuel residence time of 83 μm particles by nearly 3 fold to a value of 77 s in comparison to 27 s at atmospheric pressure. The effect of gas velocity was not found to be statistically significant under the range tested. Similarly the effect of increased fuel feed rate by 50% neither had a statistically significant impact.

abstract: Previous literature on synchronization to music using finger tapping tasks in a laboratory or otherwise controlled setting has led to some invaluable, albeit dated, theories about time and synchronization. In an effort to modernize some of the approaches utilized in research on music synchronization, this study applies established theories of music entrainment to a fieldwork study. Specifically, this study focuses on the extent to which participants of Capoeira, a Brazilian martial art disguised as a dance, synchronize to external timekeepers by analyzing icti in several types of movements and comparing them to musical rhythmic beats. Sports psychology studies have shown that the presence of music can have involuntary effects on exercise. For example, walkers and runners will spontaneously synchronize gait to auditory signals. However, runners do not normally focus on choreology, acrobatics, and environmental stimuli while exercising. This study contributes to this field of research by adding observations and analyzing degrees of synchronization in a martial art, which may be more cognitively demanding than running. In Capoeira, participants are still expected to attend to music. The degree of synchronization that occurs in a Capoeira class can then be compared with synchronization in martial arts that have music solely as a background component. These future studies would be analyzing music entrainment in real-life environments with physical activities that are more cognitively complex than running. Moreover, these future studies can help to confirm or challenge current theories of attention and music entrainment and synchronization. / Dissertation/Thesis / Masters Thesis Music 2020