identifier: Ali, Md Ashim <https://research.library.mun.ca/view/creator_az/Ali=3AMd_Ashim=3A=3A.html>   (2020) Effect of ship motions on propeller-hull interaction.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
It is important to consider the detailed hydrodynamics of the propeller, the associated
flow conditions and the hull interaction with effective wake distribution for developing
the best ship propulsion system design. Model experiments are conventionally used
to assess propeller flow and performance but are subject to scale effect and difficulties
in flow measurement. Computational Fluid Dynamics (CFD), using a viscous flow
solver, provides an alternate way to simulate propeller flow conditions. Although
simplified propeller flow models are currently available, this thesis extends the CFD
approach to develop a more comprehensive model that includes detailed propeller
geometry, ship motions and wave action.
Numerical self-propulsion simulations with propeller action and ship motions are
performed using a newly developed dynamic motion class based on the sliding mesh
method in OpenFOAM. Validation and verification are carried out in a step by
step manner. As a first step, a model incorporating bare hull resistance, wave
elevation on the hull surface, free surface wave contour, and axial velocity distribution
at several transverse planes for a fixed ship condition and dynamic ship condition
was developed and validated using available experimental data, and the comparison
between the simulations and the experiments showed good agreement. Propeller open
water simulations with detailed propeller geometry and using the body-force method
were developed and validated with experimental data in the second step. Because of the highly non-linear and rotational nature of the flow near to the propeller region,
curvature correction was implemented to the standard k − ω SST turbulence model
to improve the numerical predictions.
Prior to the third stage self-propulsion simulation, which combined the stage 1 and
2 simulations, a numerical wave tank was developed and validated. Numerical
self-propulsion simulations were performed for a ship at an even keel condition
with constant propeller rotational speed. The numerical calculation of the
skin friction correction, thrust coefficient, torque coefficient, and axial velocity
distribution downstream of the propeller, confirmed good accuracy against the
available experimental data. Then the developed dynamic motion class was extended
to models with ship sinkage and trim. Comparison with available data showed a
excellent agreement for all self-propulsion parameters. An expected increase in total
resistance and decrease in propeller thrust was observed due to ship motion.
As an alternative of detailed propeller geometry modelling, two body-force models
were developed for self-propulsion simulation when detailed flow features are not
required. The effective local velocity body-force model showed better numerical
predictions than nominal average velocity body-force method. The self-propulsion
simulation was performed in waves with forward speed using the developed dynamic
motion class and it was able to incorporate the rotating propeller with large ship
motions. The thrust generated by a propeller varied with encounter wave period and
was reduced compared to the even keel condition.


identifier: Ghiasi, Mohammad M. <https://research.library.mun.ca/view/creator_az/Ghiasi=3AMohammad_M=2E=3A=3A.html>   (2020) Implementing decision tree-based algorithms in medical diagnostic decision support systems.  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

abstract:
As a branch of healthcare, medical diagnosis can be defined as finding the disease based on the signs and symptoms of the patient. To this end, the required information is gathered from different sources like physical examination, medical history and general information of the patient. Development of smart classification models for medical diagnosis is of great interest amongst the researchers. This is mainly owing to the fact that the machine learning and data mining algorithms are capable of detecting the hidden trends between features of a database. Hence, classifying the medical datasets using smart techniques paves the way to design more efficient medical diagnostic decision support systems.
Several databases have been provided in the literature to investigate different aspects of diseases. As an alternative to the available diagnosis tools/methods, this research involves machine learning algorithms called Classification and Regression Tree (CART), Random Forest (RF) and Extremely Randomized Trees or Extra Trees (ET) for the development of classification models that can be implemented in computer-aided diagnosis systems. As a decision tree (DT), CART is fast to create, and it applies to both the quantitative and qualitative data. For classification problems, RF and ET employ a number of weak learners like CART to develop models for classification tasks.
We employed Wisconsin Breast Cancer Database (WBCD), Z-Alizadeh Sani dataset for coronary artery disease (CAD) and the databanks gathered in Ghaem Hospital’s dermatology clinic for the response of patients having common and/or plantar warts to the cryotherapy and/or immunotherapy methods. To classify the breast cancer type based on the WBCD, the RF and ET methods were employed. It was found that the developed RF and ET models forecast the WBCD type with 100% accuracy in all cases. To choose the proper treatment approach for warts as well as the CAD diagnosis, the CART methodology was employed. The findings of the error analysis revealed that the proposed CART models for the applications of interest attain the highest precision and no literature model can rival it. The outcome of this study supports the idea that methods like CART, RF and ET not only improve the diagnosis precision, but also reduce the time and expense needed to reach a diagnosis. However, since these strategies are highly sensitive to the quality and quantity of the introduced data, more extensive databases with a greater number of independent parameters might be required for further practical implications of the developed models.


identifier: Mpame, Chloe Louise <https://research.library.mun.ca/view/creator_az/Mpame=3AChloe_Louise=3A=3A.html>   (2020) Clothing: a statement of one's gender identity.  Masters thesis, Memorial University of Newfoundland.


identifier: Dinesh, O. Chandani <https://research.library.mun.ca/view/creator_az/Dinesh=3AO=2E_Chandani=3A=3A.html>   (2012) Arginine and small intestinal atrophy in parenterally-fed neonatal piglets.  Masters thesis, Memorial University of Newfoundland.

abstract: Piglets that are fed via total parenteral nutrition (TPN) experience profound gut atrophy and rapid decline in splanchnic blood flow compared to enterally-fed piglets. Sixty percent of total nutrient intake as enteral feeding is required to sustain “normal” small intestinal metabolism and morphology, which is likely not feasible with sick neonates. Whether the potential benefit of complete or partial enteral nutrition is related to single or multiple nutrients is not yet fully understood. However, the luminal presence of specific nutritive factors such as amino acids may act as trophic factors for intestinal recovery during TPN or enteral re-feeding. Arginine is a good candidate to investigate potential trophic effects as it is involved in many important metabolic pathways such as nitric oxide synthesis, ureagenesis, polyamine synthesis and protein synthesis. TPN-induced gut atrophy reduces intestinal de novo synthesis of arginine in neonates which may then limit arginine availability. We hypothesized that delivery of a high amount of dietary arginine alone into the gut could induce partial recovery from TPN-induced gut atrophy in neonatal piglets, while improving superior mesenteric artery (SMA) blood flow. We also hypothesized that enteral delivery of low amounts of arginine would result in attenuated responses compared to the high enteral arginine. Thus, our objectives were to assess the effect of route of intake and dietary concentration of arginine alone on tissue protein synthesis, SMA blood flow and gut morphology in TPN-fed neonatal Yucatan miniature piglets with small-intestinal atrophy. Twenty-four piglets (14 - 17 d old) were fed complete TPN, containing 1.0 g arginine/kg/d until study day 4 to induce atrophy, then switched to arginine-free TPN and randomized to receive a continuous intragastric infusion of either low arginine (0.6 g/kg/d) (IG-L Arg) (n = 6) or high arginine (1.6 g/kg/d) (IG-H Arg) (n = 6). A third group was randomized to receive high arginine intravenously (1.6 g/kg/d in TPN) (IV-H Arg) (n = 6). A group of sow-fed littermates (SF Reference) (n = 6) was also included. On study day 7, crypt cell proliferation and tissue specific protein synthesis rates were measured. This thesis demonstrated for the first time that the delivery of arginine alone intragastrically, irrespective of the amount provided, stimulated hepatic protein synthesis (P = 0.01) compared to intravenous delivery of arginine. SMA blood flow declined continuously during the period when all animals were receiving the same complete TPN. It further decreased following the initiation of the test diets and reached a plateau approximately 48 hours after the test diets were initiated. At steady state, SMA blood flow was significantly different among all treatment groups (P = 0.002). IV-H Arg treatment had the smallest reduction in blood flow (22% lower than baseline). The provision of high arginine enterally attenuated some of the reduction of blood flow, whereas the IG-L Arg piglets demonstrated the greatest reduction, at ~40% lower than baseline at study end. In piglets fed solely by TPN, some of the plasma indispensable amino acids were very high compared to the IG-H Arg piglets. Remarkably, the provision of only arginine into the gut resulted in a plasma profile of some of these amino acids that was very similar to sow-reared piglets. In spite of experiencing a greater amelioration of the reduction of SMA blood flow, the small intestinal morphological characteristics were not significantly improved compared to the other treatment groups. Although IG-H Arg was not as effective as IV-H Arg in sustaining SMA blood flow, morphological outcomes were not significantly worse than in the IV-H Arg piglets; indeed, the small intestine was significantly longer in the IG-H Arg piglets compared to IV-H Arg group, and all other outcomes were similar among treatment groups. These results suggest that IG delivery of arginine was likely beneficial as a trophic factor in gut-atrophied neonatal piglets.


identifier: Hanlon, Dillon <https://research.library.mun.ca/view/creator_az/Hanlon=3ADillon=3A=3A.html>   (2020) Temperature dependence of acoustic properties of natural snail mucus by Brillouin spectroscopy.  Masters thesis, Memorial University of Newfoundland.

abstract: Brillouin light scattering was used to understand how the acoustic and mechanical properties of gastropod mucus are influenced by temperature over the temperature range -11ᴼC ≤ T ≤ 52ᴼC. Two peaks were observed in spectra obtained in this study, one which was present throughout the full temperature range and at a frequency shirt of ~8.0 GHz, while the other peak appeared at a shift of ~18.5 GHZ but only for temperatures below ~ -3.0ᴼC. Results for the 8.0 GHz liquid mucus peak showed minor changes in both frequency shift and FWHM for temperatures greater than -2.5ᴼC. As well, the intensity of this peak showed an overall increase as temperature increases. For temperatures below -2.5ᴼC, the sound velocity for the mucus mode sh owed an overall increase as temperature decreased, with a difference of ~11% between the sound velocity at T = -3.0ᴼC (1550 m/s) and -11.0ᴼC (1750 m/s). Moreover, the liquid mucus bulk modulus was also obtained and also shows an overall increase as temperature decreases in this temperature regime. Additionally, this 8.0 GHz peak also revealed an exponential decrease in the FWHM as temperature increased with linewidth ranging from 12 GHz to 0.6 GHz for temperatures T = 11.0ᴼC and 52.0ᴼC respectively. Likewise, sound absorption values were also obtained in this study and showed an exponential decrease as temperature increased with values ranging from ~ 120 X 10⁻¹⁵ s²/m to ~15 X 10⁻¹⁵ s²/m over the temperature range -11.0ᴼC ≤ T ≤ 52ᴼC for all samples. From the sound absorption, the interaction energy between the molecules in the mucus was obtained and showed a large change in its values for temperatures above and below T = 2.5ᴼC. The second peak occurring at ~18.5 GHz deemed due to ice Ih showed very small changes in frequency and linewidth as temperature decreases, as well it was seen that as the temperature decreased the intensity of this peak generally increased. The sound velocity for this mode increases slightly as temperature decreases with values ranging from 3800 to 3860 m/s for temperatures T = -3.0ᴼC and T = -11.0ᴼC respectively. Likewise, the bulk modulus of the ice slightly increases in this temperature regime. Collectively, the results from this work suggest a phase transition between a viscous liquid state to a mixed solid-liquid state. Comparison of the results obtained in this study is made to similar liquid systems (i.e., water, water and polymer mixtures).


identifier: Power, Kendra Morgan <https://research.library.mun.ca/view/creator_az/Power=3AKendra_Morgan=3A=3A.html>   (2020) Sedimentology and palaeontology of the Withycombe Farm Borehole, Oxfordshire, England.  Masters thesis, Memorial University of Newfoundland.

abstract:
The pre-trilobitic lower Cambrian of the Withycombe Formation is a 194 m thick siliciclastic succession dominated by interbedded offshore red to purple and green pyritic mudstone with minor sandstone. The mudstone contains a hyolith-dominated small shelly fauna including: orthothecid hyoliths, hyolithid hyoliths, the rostroconch Watsonella crosbyi, early brachiopods, the foraminiferan Platysolenites antiquissimus, the coiled gastropod-like Aldanella attleborensis, halkieriids, gastropods and a low diversity ichnofauna including evidence of predation by a vagile infaunal predator.
The assemblage contains a number of important index fossils (Watsonella, Platysolenites, Aldanella and the trace fossil Teichichnus) that enable correlation of strata around the base of Cambrian Stage 2 from Avalonia to Baltica, as well as the assessment of the stratigraphy within the context of the lower Cambrian stratigraphic standards of southeastern Newfoundland.
The pyritized nature of the assemblage has enabled the study of some of the biota using micro-CT, augmented with petrographic studies, revealing pyritized microbial filaments of probable giant sulfur bacteria. We aim to produce the first complete description of the core and the abundant small pyritized fossils preserved in it, and develop a taphonomic model for the pyritization of the “small” shelly fossils.


identifier: Hajheidari, Maryam <https://research.library.mun.ca/view/creator_az/Hajheidari=3AMaryam=3A=3A.html>   (2020) The impact of long-term agricultural drainage on concentration and composition of Dissolved Organic Carbon (DOC) in a boreal peatland in western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract:
Although peatlands cover only 2.84% of the world’s land area, they play a key role in the global C cycle and store one-third of the global soil carbon.
Dissolved Organic Carbon (DOC) is one of the available forms of carbon in peatlands, which is lost from the peatland together with other forms of carbon, including dissolved inorganic carbon (DIC) and as the gases carbon dioxide (CO2) and methane (CH4). DOC contains both biologically available (labile) and recalcitrant components. In peatlands, the influence of DOC on the C cycle is more significant than in terrestrial and aquatic ecosystems, and thus understanding of any changes in DOC quality induced by peatland drainage is critical.
The quality and quantity of DOC determine the further role of DOC in biogeochemical cycles. Accordingly, this study investigated the effects of agricultural drainage on DOC in a boreal peatland in western Newfoundland, by quantifying (concentration) and qualifying (composition) of DOC in two drained and natural peatland sites. The effect of microforms in the natural site on quality and quantity of DOC, was also examined.
This study showed that long-term drainage increased DOC concentration both at the peat surface (10 cm) and at a depth of 40 cm by 32% and 47%, respectively. The quality of DOC was also affected by agricultural drainage and microforms (hummock or hollow). Agricultural drainage reduced the DOC aromaticity and transformed DOC from refractory to labile forms. In the natural sites, hummock had higher DOC concentration and showed more recalcitrant and humified DOC.
Although DOC in both the drained and the natural site was mainly plant-driven regardless of the different vegetation compositions and microforms, DOC at the drained site was of a plant-derived source over microbially processed DOC throughout the peat layers. Increasing DOC concentration following agricultural drainage shifts the Dissolved Organic Matter (DOM) from the microbial-derived source to a plant-derived source. Similarly, agricultural drainage increased the degree of humification at both peat depths.
Comparing two different depths of sampling revealed that the shallower sampling depth had greatest differences in DOC quantity and quality across the drained and natural sites. It means that the variation in DOC caused by any management changes has an intensive effect on shallower peat layers. Furthermore, there is more humified microbially-sourced DOC found at the deeper peat layers. Results also demonstrated the different DOC concentration and composition associated with different plant communities in the drained site and different microforms in the natural site.
Our study showed that establishment of reed canary grass followed by drainage in the drained peatland pasture site could introduce labile carbon compounds with a high degree of humification into the below ground environment during the growing season.
Results of this study support the fact that land management activities (such as agricultural drainage) have effects on DOC quantity together with quality of peatlands and also have a profound effect in increasing labile DOC at the deeper layers, which can affect the carbon balance of boreal peatland ecosystems. This raises the possibility of managing the plant community to control DOC concentration to reduce carbon losses from peatlands.
The effect of land management, plant community, and its effects on peat properties should be given more weight in large-scale carbon modeling.


identifier: Miah, Mohammad Islam <https://research.library.mun.ca/view/creator_az/Miah=3AMohammad_Islam=3A=3A.html>   (2020) Log data-driven predictive models and feature ranking in reservoir characterization.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Log-based reservoir characterization is one of the widely used techniques to estimate the reservoir properties and make decisions for hydrocarbon production. Use of the machine learning tools is becoming a more accessible approach for data-driven model development. The objective of this research is to identify and rank the most contributing log variables considering their relative performance for prediction of water saturation and rock strength using the machine learning tools. The single layer and multi-layer perception (MLP) artificial neural network (ANN) and the kernel function-based least-squares support vector machine (LS-SVM) techniques are employed for model development. The models can capture the non-linear behavior and high-dimensional complex relationships among real field log data variables. The mutual information (MI) is used to investigate the dependency of predictor subset variables in a model and to rank log variables according to their importance. The connectionist models are also examined to find reliable data-driven predictive models to estimate reservoir properties and rock strength. A new correlation is developed to obtain the in-situ rock strength of the siliciclastic rocks using the most important log parameters. The model predictions are compared/validated against the measured values as well as results obtained from existing log-based correlations. The approaches suggested in this study (connectionist and MI strategies) can assist engineers/operators to run a few numbers of logging tools for prediction of reservoir and rock properties to save the exploration costs. Also, it is expected that the introduced robust data-driven predictive models will enable engineers to better manage the wellbore stability and formation analysis in terms of technical, economic, and environmental aspects.


identifier: McNiven, Brad <https://research.library.mun.ca/view/creator_az/McNiven=3ABrad=3A=3A.html>   (2020) Optical properties and acoustic phonon dynamics of Bi₂Sr₂CaCu₂O₈₊δ crystals.  Masters thesis, Memorial University of Newfoundland.

abstract:
In this work, the optical properties and acoustic phonon behaviour of several Bi₂Sr₂CaCu₂O₈₊δ0
(Bi-2212) superconducting crystals were investigated. Reflectance imaging on Bi-2212
crystals was first performed and along with Kramers-Kronig analysis, allowed for the
extraction of the refractive index, extinction coefficient and both parts of the complex
dielectric function. With these measured reflectances, a newly refined optical contrast
method was presented and used in an attempt to obtain a secondary estimate of the
refractive index and extinction coefficient of these crystals. Brillouin light scattering
experiments were performed on Bi-2212 crystals at room temperature where six different
acoustic modes were observed; the Rayleigh surface mode, two quasi-transverse
bulk modes, the quasi-longitudinal bulk mode and two currently unknown modes. Using
the peak frequency shifts and widths of the quasi-transverse and surface modes,
the refractive index and extinction coefficient were extracted and used to calculate
both parts of the complex dielectric function which were then compared to results
found by reflectance analysis. The refractive index was then used to calculate the
velocities of the three bulk modes and two unknown modes for angles ranging from
approximately 3ᴼ to 21ᴼ from the [001] direction.


identifier: Abdo-Allah, Almahdi T M <https://research.library.mun.ca/view/creator_az/Abdo-Allah=3AAlmahdi_T_M=3A=3A.html>   (2020) Dynamic modeling and fuzzy logic control of a large building HVAC system.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Energy and cost-efficient management of a building’s thermal properties requires heating, ventilation and air conditioning (HVAC) systems controllers to be working at optimal settings. However, many HVAC systems employ nonlinear time variances to deal with issues that affect the system’s optimal operation. The present work considers an HVAC system at Memorial University’s S. J. Carew Building which has been mathematically modeled using a state space multi-input and multi-output system (MIMO) approach for analyses and control system design. An IDA-ICE (Indoor Climate and Energy) simulation program has been applied for modeling the building, note that the four-story Carew Building includes an air-handling unit (AHU) on every floor. Compared with real data for one year’s (2016) power consumption, the simulated annual power consumption for the building shows good agreement. Based on that data, two scenarios are applied for building the system models. Scenario 1 considers the HVAC system as a single unit with energy consumption (kWh) as inputs and zonal temperature and CO2 concentrations as outputs. By employing the MATLAB system identification toolbox, a MIMO-based system forms the basis for a state space model. In the model for Scenario 1, there are eight main AHU inputs (hot water power usage and power usage) and eight main outputs (return airflow temperature and CO2 levels). The state feedback controller obtains good results for both responses rise time and stability. In Scenario 2, there are four AHUs in total. Each of this scenario’s AHUs features three main inputs (hot water, internal-to-internal air flow, and external-to-internal air flow) and three main outputs (static air pressure, CO2 levels, and temperature). In the first AHU (AHU1), we apply state-of-the-art fuzzy logic controllers (FLCs) to control fan speeds, CO2 concentrations, and temperature in the building in accordance with the flow rates for air and hot water. This strategy represents a novel approach for adapting FLCs by modifying fuzzy rule using the Simulink. The modified system shows improved levels of thermal comfort. The final part of the work presents the design for a supervisor fuzzy logic controller (SFLC) that can be applied to the entire S. J. Carew Building HVAC control. This SFLC features 24 inputs and 12 outputs and employs a state-space model that considers each AHU as an individual system. The SFLC detailed design and system simulation results are presented in this thesis.


identifier: Delikta, Dylan <https://research.library.mun.ca/view/creator_az/Delikta=3ADylan=3A=3A.html>   (2020) Hegel's aesthetics and contemporary art: home, vagabondage and (w)hole.  Masters thesis, Memorial University of Newfoundland.

abstract: What is the condition that situates the ongoing transformations of contemporary art? What insights about the meaning of selfhood and our worlds might we find by exploring it? Through a close reading of Hegel’s Aesthetics, in which Hegel offers a phenomenological study of art’s development, my thesis posits an interpretation of contemporary art’s situation as the play between the human experiences of at-homeness and vagabondage in the world, which I name being-in-the-(w)hole. My reading of Hegel suggests that he points toward this experience of the (w)hole—art’s infinite determinability in expression and meaning—and how contemporary art can express this play as a site for the co-experiencing and co-defining of the meaning of self and world. By thematizing this play, I argue that the condition that situates contemporary art is that of dynamic equality, an equality in which all are recognized as able to interpret a shared object together.


identifier: Jacques, Julie <https://research.library.mun.ca/view/creator_az/Jacques=3AJulie=3A=3A.html>   (2020) Gonad enhancement of green sea urchin (Strongylocentrotus droebachiensis): importance of feed and containment system.  Masters thesis, Memorial University of Newfoundland.

abstract: Wild sea urchins are harvested for their gonads (roe or uni) throughout coastal areas of the world. The high value of urchin gonads on global seafood markets along with increasing popularity and demand worldwide have led to the development of formulated-feed-based gonad enhancement programs since the early 1990s. Along the coast of eastern Canada, there is an abundance of green sea urchin, Strongylocentrotus droebachiensis, representing a largely untapped resource for gonad enhancement. To gain knowledge on the conditions and systems that optimize green sea urchin gonad production, two studies were performed with Newfoundland green sea urchins fed proprietary formulated feeds. In the first study, we carried out two gonad enhancement experiments with urchins fed in conical tanks at a water temperature of 1, 3, or 6°C. The first experiment lasted 4 wk with urchins collected before the spawning period, and the second lasted 8 wk with urchins collected during the spawning period. Feed consumption, feces production, and gonadosomatic index (GSI) all nearly doubled at 6 compared to 1°C, and urchins maintained good physiological condition and high gonad production, regardless of temporal proximity to spawning. However, the feed imparted a bitter gonad taste. In the second study, we carried out a 7-wk experiment in a tiered raceway system with urchins fed at three different stocking densities (2.5, 6.5, and 10.5 kg urchins m⁻²), at a water temperature of 6°C. We also carried out concurrent trials with urchins fed kelp (Laminaria digitata), achieving a lower GSI than with the feed. Feed consumption was lowest in the most downstream raceway positions. Raceway position and urchin density influenced aggregation patterns, which reflected wild behaviours, however neither affected GSI. Regardless of different growing conditions and containment systems, in both studies urchins surpassed the GSI market target of ~10 to 15% in less than 7 wk, demonstrating the efficiency of formulated-feed-based gonad enhancement of Newfoundland green sea urchin.


identifier: Zhang, Xin <https://research.library.mun.ca/view/creator_az/Zhang=3AXin=3A=3A.html>   (2020) Analytical and experimental study of turbulent flow drag reduction and degradation with polymer additives.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Flow friction reduction by polymers is widely applied in the oil and gas industry for flow enhancement or to save pumping energy. The huge benefit of this technology has attracted many researchers to investigate the phenomenon for 70 years, but its mechanism is still not clear. The objective of this thesis is to investigate flow drag reduction with polymer additives, develop predictive models for flow drag reduction and its degradation, and provide new insights into the drag reduction and degradation mechanism.
The thesis starts with a semi-analytical solution for the drag reduction with polymer additives in a turbulent pipe flow. Based on the FENE-P model, the solution assumes complete laminarization and predicts the upper limitation of drag reduction in pipe flows. A new predictive model for this upper limit is developed considering viscosity ratios and the Weissenberg number - a dimensionless number related to the relaxation time of polymers. Next, a flow loop is designed and built for the experimental study of pipe flow drag reduction by polymers. Using a linear flexible polymer - polyethylene oxide (PEO) - in water, a series of turbulent flow experiments are conducted. Based on Zimm’s theory and the experimental data, a correlation is developed for the drag reduction prediction from the Weissenberg number and polymer concentration in the flow. This correlation is thoroughly validated with data from the experiments and previous studies as well.
To investigate the degradation of drag reduction with polymer additives, a rotational turbulent flow is first studied with a double-gap rheometer. Based on Brostow’s assumption, i.e., the degradation rate of drag reduction is the same as that of the molecular weight decrease, a correlation of the degradation of drag reduction is established, along with the proposal of a new theory that the degradation is a first-order chemical reaction based on the polymer chain scission.
Then, the accuracy of the Brostow’s assumption is examined, and extensive experimental data indicate that it is not correct in many cases. The degradation of drag reduction with polymer additives is further analyzed from a molecular perspective. It is found that the issue with Brostow’s theory is mainly because it does not consider the existence of polymer aggregates in the flow. Experimental results show that the molecular weight of the degraded polymer in the dilute solution becomes lower and the molecular weight distribution becomes narrower. An improved mechanism of drag reduction degradation considering polymer aggregate is proposed - the turbulent flow causes the chain scission of the aggregate and the degraded aggregate loses its drag-reducing ability. Finally, the mechanism of drag reduction and degradation is examined from the chemical thermodynamics and kinetics. The drag reduction phenomenon by linear flexible polymers is explained as a non-spontaneous irreversible flow-induced conformational-phase-change process that incorporates both free polymers and aggregates. The entire non-equilibrium process is due to the chain scission of polymers. This theory is shown to agree with drag reduction experimental results from a macroscopic view and polymer behaviours from microscopic views.
The experimental data, predictive models, and theories developed in this thesis provide useful new insights into the design of flow drag reduction techniques and further research on this important physical phenomenon.


identifier: Long, Jianbo <https://research.library.mun.ca/view/creator_az/Long=3AJianbo=3A=3A.html>   (2020) Forward modelling 3-D geophysical electromagnetic field data with meshfree methods.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Simulating geophysical electromagnetic (EM) data over real-life conductivity models
requires numerical algorithms that can incorporate realistically complex geometry
and topography. The most successful way to incorporate them is to use unstructured
meshes in the discretization of an Earth model. Current mesh-based numerical
methods that are capable of using such meshes have inherent drawbacks caused by
generating 3-D unstructured meshes conforming to irregular geometries. Such a mesh
generation process may become computationally expensive and unstable, and particularly
so for EM inversion computations in which the forward modelling may be
required many times. In this thesis I investigate the feasibility and applicability of
radial basis function-based finite difference (RBF-FD), a meshfree method, in forward
modelling 3-D EM data. In the meshfree method, the physical model is represented
using only a set of unconnected points, effectively overcoming the issues related to
the mesh generation. To improve numerical efficiency, unstructured point sets are
used in the computation for the first time for EM problems. The computation is
further accelerated by introducing a new type of radial basis function in the RBFFD
method. The convergence and accuracy of the proposed RBF-FD method are
demonstrated first via forward modelling gravity and gravity gradient data. The
computational efficiency of the meshfree method is compared with that of using a
more traditional finite element method. The meshfree method is then applied to
forward model magnetotelluric data of which the effectiveness is demonstrated using
three benchmark conductivity models from the literature. Faithful reproduction of the physics in the EM fields, e.g. discontinuous electric fields across the conductivity
contrasts, is achieved by proposing a hybrid meshfree scheme which is a modification
to standard meshfree algorithms. The hybrid method is also applied to simulate
controlled-source EM data in the frame of both total-field and primary-secondary field
approaches, in which the problems in dealing with singular source functions that cause
singularities in the EM fields are addressed. For these two approaches, the accuracies
of the proposed hybrid meshfree method in forward modelling the controlled-source
EM data are demonstrated by using idealized 1-D layered models and a 3-D marine
canonical disk model. The successful applications of the proposed meshfree method
in modelling the above EM data suggest that the meshfree technique has the potential
of becoming an important numerical method for simulating EM responses over
complicated conductivity models.


identifier: Alizadeh, Niyousha <https://research.library.mun.ca/view/creator_az/Alizadeh=3ANiyousha=3A=3A.html>   (2020) Characterization of Ocrl in Drosophila melanogaster.  Masters thesis, Memorial University of Newfoundland.

abstract: Disease modelling has enabled researchers to study a wide range of human diseases in the laboratory, overcoming many challenges. Parkinson Disease (PD) is a progressive neurodegenerative disorder that affects 1 to 2% of the human population over 65 years old, influencing cognitive ability and motor function. It is characterized by the inadequate function or the loss of dopamine-producing neurons of the substantia nigra pars compacta in the human midbrain. Impairment of several genes has been associated with disease progression. Recently, a polymorphism in Oculocerebrorenal Syndrome of Lowe protein (Ocrl), was identified as a risk factor for PD. As Ocrl is very well-conserved between mammals and insects, I have used D. melanogaster to create an Ocrl-dependant model of human PD. Ocrl is the D. melanogaster orthologue of human Ocrl, a PtdIns(4,5)P2 phosphatase encoding gene in which mutant forms can result in the X-linked disorder known as Oculocerebrorenal Lowe Syndrome. Directed manipulation of the single D. melanogaster version of Ocrl in neurons that include dopaminergic neurons was performed in order to produce an in vivo model of the development and progression of a unique version of PD. The directed loss of function of Ocrl in dopaminergic neurons, through the use of RNAi, resulted in a decreased locomotor ability and median lifespan of the flies over time. In complementary experiments, the directed interference of Ocrl expression in the developing eye, led to a reduction in the number of ommatidia and interommatidial bristles. Overexpression of Ocrl using D42 Gal4 and ddc Gal4 decreased lifespan, locomotor ability, the number of ommatidia and interommatidial bristles and increased lifespan by using TH Gal4. Crossing Ocrl with recombinant Ddc-GAL4/CyO; UAS-park RNAi/TM3 reduced lifespan overtime. Further investigation of Ocrl and its role in human disease progression is needed and crucial to our understanding of new therapeutic approaches for research into human disease.


identifier: Li, Ling <https://research.library.mun.ca/view/creator_az/Li=3ALing=3A=3A.html>   (2020) Dialogic reading with Mandarin-speaking children: effects on expressive vocabulary and narrative competence.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
This research study examines the effects of a home-based dialogic reading (DR)
intervention on the expressive vocabulary and narrative competence of
Mandarin-speaking children. DR is a shared-reading approach that emphasizes verbal
interactions between adults and young children. Expressive vocabulary is generally
conceived as children’s knowledge of word meanings in speaking or writing, and oral
expressive vocabulary is focused on in the present study. Narrative competence refers to
their ability to produce and comprehend stories. Three aspects of narrative production
were measured—macrostructure, microstructure, and evaluation. Narrative
comprehension was measured using comprehension questions that targeted story
grammar and problem resolution. In the present study, 81 Mandarin-speaking
kindergartners, aged four to five, were pretested on expressive vocabulary and narrative
competence and assigned to one of two conditions—DR or customary reading. Parents of
the children assigned to the DR group participated in three DR workshops and conducted
at least 48 one-on-one shared-reading sessions at home with their child during the
12-week intervention period. Expressive vocabulary and narrative competence were
retested immediately after the intervention and again four months later. In-home
observations of shared-reading sessions recorded on video were used to track the changes
in parents’ reading behaviours, and multiple measures were employed to collect program-evaluation data. The DR intervention yielded a greater effect on the children’s
expressive vocabulary at the delayed posttest stage. However, its effect on indicators of
narrative competence was not significant except for one indicator of narrative
microstructure—adverb density. Positive changes were found in the reading behaviours
of parents in the DR group over the intervention period, and positive feedback was also
obtained from the comprehensive evaluation of the DR program.


identifier: Bedford, Shannon <https://research.library.mun.ca/view/creator_az/Bedford=3AShannon=3A=3A.html>   (2020) Who knit ya? a study of mothers' sense of parenting competence in Newfoundland and Labrador.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The role mothers play is arguably one of the most influential and imperative factors in defining the family dynamic and child development, however the scholarship on the maternal experience remains sparse. Much of the focus on motherhood has been in the context of the intensive motherhood ideology, which posits that societal expectations place unrealistic demands on mothers. Little is known about the modern normative experience of motherhood, and therefore the focus of this project is to gain a socio-demographic understanding of the maternal experience for women in Newfoundland and Labrador (NL). As part of a province-wide study, 1082 mothers completed an online survey of their socio-demographic characteristics and a variety of motherhood scales. The current study examines some of the unique demographic and social aspects of motherhood in NL including differences between urban and rural populations, family structure, the prevalence of mobile work, and predictors of maternal sense of parental competence. The Circumplex Model of the family emphasizes the importance of cohesion and communication in family functioning, and these factors were considered in the context of understanding maternal sense of parenting competence. The parenting sense of competence scale (PSOC) was used as the main outcome measure for this study as it assesses how mothers feel about their skill and enjoyment within their parenting role. Two hierarchical multiple regressions aimed at predicting maternal self-efficacy and motherhood satisfaction on the PSOC were conducted using demographic variables, maternal mental health, and family variables in three separate blocks. The significant predictors of PSOC-Efficacy explained 28.1% of the variance and included maternal age, maternal mental health (OQ-45), co-parental communication (closeness), and child parent relationship (conflict and closeness). The predictive model of PSOC-Satisfaction included a number of significant predictors: child health, maternal mental health, and child parent relationship (conflict and closeness), which explained 45.3% of the variance. The results of this study bring forward a portrait of motherhood in NL, and contribute to the growing scholarship on maternal sense of parental competence.


identifier: Zhang, Xiaoxiao <https://research.library.mun.ca/view/creator_az/Zhang=3AXiaoxiao=3A=3A.html>   (2020) Fish out of water? A collective case study on identity negotiation of rural students in higher education.  Masters thesis, Memorial University of Newfoundland.

abstract:
Students from rural background are more likely to become the first generation in their families to attend higher education. Growing up in an environment where the geographical and cultural features are hugely contrasted with that of urban areas, rural students will come across more challenges and difficulties when they arrive in university, where they would meet students and faculty with different social class backgrounds and experience a diversity of cultures. The upward social mobility university brings will push for a transformation of identity, which can be a challenge to the rural students as they often lack the economic and cultural assets that are usually possessed by those students coming from well-off families.
This research adopted the qualitative research method and chose a collective case study research design to investigate the identity negotiation issues of rural students in higher education. Through interviewing ten participants who are currently studying at the Memorial University of Newfoundland, this research reveals some insights into the lives of rural students in a new social context, one that is largely different from where they came from. Drawn on Bourdieu’s sociological perspective, this research has found that since they were back in the rural community, these participants have started to “think outside the box” and have developed a reflexive habitus, which helps the participants to plan for higher education since they were young and decide to follow a different life path as most rural people. After they have entered university, they kept on modifying themselves to adjust to the lives in a different social context and conquer various academic and non-academic challenges brought by symbolic violence and social reproduction. In the end, they are able to develop a dual identity, which is consisted of their old rural identity and the new identity they have acquired in the university. This dual identity not only helps them to fit in the field of the university but to balance their lives between the rural context and the urban context.


identifier: Hesaraki, Reza <https://research.library.mun.ca/view/creator_az/Hesaraki=3AReza=3A=3A.html>   (2020) Remedial action schemes for power system performance enhancement using protective relaying.  Masters thesis, Memorial University of Newfoundland.

abstract:
Nowadays, according to the improvement of industries, and the growth of the population, the need for high-quality energy is felt more and more. One of the significant challenges in designing distributed power networks is providing reliable protection with the target of decreasing blackouts. This goal can be achieved by detecting faults in the power system and action to correct or remove the faults. In most cases, taking correct and quick remedial action to protect the power system is done by tripping. Generally, the protective relaying equipment is responsible for tripping in a power system.
In this thesis, various types of remedial action schemes for power system performance enhancement using protective relaying are studied in detail. The concept of power system protection consists of protection components, and their functionality is illustrated. Furthermore, several types of protective relays, and their general operating and design considerations are briefly investigated. Several protective relays such as analog overcurrent relay, digital overcurrent relay, and digital under-over frequency relay are investigated, modeled, and simulated in this thesis.
To study the power system frequency response, the System Frequency Response (SFR) model is derived and simulated in MATLAB Simulink environment, and the effect of some parameters of a generator on the system’s frequency response is examined. Additionally, a new method to model power system frequency response is proposed based on the factorial design method using the Design of Expert. The actual system and the final model are simulated, compared, and validated. The result shows that the model based on the proposed method can be used to estimate the system frequency response.
The concept of load curtailment (load shedding) and its different methods are discussed. A conventional underfrequency load shedding relay is simulated in MATLAB software to show how load shedding relays can enhance power system performance.
The significant factors which affect power system stability are identified. To show the effect of significant factors on power system stability, a standard IEEE 9-Bus and the IEEE 10-Generator 39-Bus New England Test System are simulated in the PowerWorld.
Finally, the concept of autoreclosing is studied in detail. An autorecloser relay is designed, simulated, and examined in MATLAB Simulink, and the proposed relay’s units are explained. Optimal autoreclosing methods are also presented in this thesis.


identifier: Ma, Yue <https://research.library.mun.ca/view/creator_az/Ma=3AYue=3A=3A.html>   (2020) Neither absence nor excess of FGF23 disturbs fetal phosphate metabolism in mice until after birth.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Fibroblast growth factor 23 (FGF23) plays an important role in maintaining phosphate homeostasis in adults largely though actions on the kidneys to excrete phosphate and reduce calcitriol. However, whether FGF23 is essential in maintaining phosphate homeostasis in fetuses had been largely unknown prior to my Ph.D. project, which hypothesized that FGF23 was important in regulating not only fetal serum phosphate and skeletal development, but also placental phosphate transport. However, studies in Phex null fetuses showed that excess FGF23 did not disturb any phosphate parameter or placental phosphate transport. Although the expression of Cyp24a1 was increased in the null placenta and kidneys and the expression of Klotho was decreased in the null kidneys, these changes did not disturb any physiological parameter related to phosphate, which suggests that FGF23 is not important in fetal phosphate regulation. Previous studies in Fgf23 null fetuses showed FGF23 absence did not alter fetal phosphate parameters, placental phosphate transport or skeletal development. These results led to my hypothesis that other FGF members might compensate for FGF23 loss by acting on the FGFR/Klotho receptor complex. However, studies in Klotho null fetuses showed that serum FGF23 was normal and that they had a similar phenotype as Fgf23 nulls – which rejected my hypothesis. Previous studies showed that Pth null fetuses developed hyperphosphatemia. I then studied Pth/Fgf23 double knockout (DKO) fetuses to determine if absence of FGF23 would potentiate hyperphosphatemia in Pth nulls. The results showed that DKO had the same elevation in serum phosphate as Pth nulls and there were no skeletal mineral content changes between the two genotypes either. I finally examined the postnatal time course of phosphate metabolism in neonatal Fgf23 nulls, Klotho nulls, and Phex nulls, respectively. The results showed Fgf23 nulls and Klotho nulls were normal at birth, but developed hyperphosphatemia, increased renal gene expression of NaPi2a and NaPi2c, and increased renal phosphate reabsorption between 5 and 7 days later. In contrast, excess FGF23 exerted effects in Phex nulls within 12 hours after birth, with the development of hypophosphatemia, reduced renal expression of NaPi2a and NaPi2c, and decreased renal phosphate reabsorption. In conclusion, my Ph.D. project suggests FGF23 is not an important regulator of fetal phosphate metabolism.


identifier: Lauriault, Patrick <https://research.library.mun.ca/view/creator_az/Lauriault=3APatrick=3A=3A.html>   (2020) An effective detection strategy and determining critical habitat characteristics for Boreal Felt Lichen (Erioderma pedicellatum) in Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: Boreal felt lichen (Erioderma pedicellatum) is a rare lichen that is listed as critically endangered by the IUCN. On the island of Newfoundland, Canada, the Central Avalon Forest Ecoregion is a hotspot for this species. The population in this region is relatively abundant, providing an opportunity to study its habitat requirements. I used occupied and unoccupied plots (each 5 m radius) to test critical habitat for boreal felt lichen. To ensure I effectively detected lichens in our plots, I developed a decoy lichen experiment to test the detection probability of these lichens. I applied the results from the decoy experiment to the habitat study. Although I could not consider time in the study, I discussed how the shortened lifespan of the host tree may constrain the temporal niche of boreal felt lichen. I identified critical habitat for boreal felt lichen, which will contribute to informed land use to help protect this population.


identifier: Rahaman, Md. Habibur <https://research.library.mun.ca/view/creator_az/Rahaman=3AMd=2E_Habibur=3A=3A.html>   (2020) Design, analysis and control of solar heating system with seasonal thermal energy storage.  Masters thesis, Memorial University of Newfoundland.

abstract: The majority of the electricity consumption in Canadian single-family house is for space heating and water heating. Currently, around 99% house in Canada using the conventional grid electricity for those purposes. To utilize the sun’s free energy for space heating and domestic water heating, first a sessional solar thermal energy storage system (SSTES) has been designed and investigated to determine their thermal and electrical performance of a house consists of four persons in the Canadian climate environment. The detailed mathematical formulation and sizing of each SSTES system component have been developed. Similarly, the components mathematical modelling, sizing of solar collector-based TES system, a hybrid solar Photovoltaic thermal (PV/T) based TES system, a Photovoltaic based TES system has been designed. To validate the feasibility and numerical studies of the developed STES configurations, all configurations have been simulated in a professional thermal simulation software named as PolySun, and only solar collector-based TES system has been designed and simulated at MATLAB/Simulink environment packages. The proposed TES system performance have been compared with the existing conventional system. All configurations have been tested using the solar radiation and other weather data of St. John’s city/NL city in Canada. The main objective to design a suitable TES system for space heating and water heating so that the residence can save high monthly electricity bill. For experimental validation, an open source IoT platform named openHAB smart home automation is used as a home server, an ESP32 Thing microcontroller board has been used as Microcontroller unit where all sensors and output devices (relays, thermostat settings channels) are connected for data acquisition and control. The proposed setup is able to monitor the TES system parameters, and able to control locally/remotely and manually/automatically. The proposed system is the low cost, low power consumption prototype which will be a commercial solution of TES system monitoring and remote control.


identifier: Stuckless, Brittney <https://research.library.mun.ca/view/creator_az/Stuckless=3ABrittney=3A=3A.html>   (2020) Foraging strategies and species interactions of four deep-sea invertebrates from the Northwest Atlantic.  Masters thesis, Memorial University of Newfoundland.

abstract: This study explored diets, foraging strategies, locomotor behaviours, and competitive dynamics in four abundant bathyal species from the Northwest Atlantic (the sea stars Ceramaster granularis, Hippasteria phrygiana, and Henricia lisa, and the gastropod Buccinum scalariforme). A combination of singleton trials, multi-animal trials, and simulated food fall experiments were conducted under cold, darkened laboratory conditions, using infrared-capable time-lapse recording. Feeding trials showed that scavenging is prevalent in all species studied. Frame-by-frame analysis of locomotor patterns revealed pulsing movement speeds in all species, an unreported but possibly widespread locomotor style for mobile benthic taxa. Multi-animal trials revealed a variety of cooperative and competitive behaviours in the focal species, altered by the number, size, and species identity of competitors. By combining singleton and multi-animal trials, this work provided data about how these species detect and assess potential food sources, and whether they can modify their foraging strategies or behaviour in competitive settings.


identifier: Stone, Maria <https://research.library.mun.ca/view/creator_az/Stone=3AMaria=3A=3A.html>   (2020) The effect of repeated exposure to a simulated moving environment on lower limb muscle co-contraction and balance.  Masters thesis, Memorial University of Newfoundland.

abstract:
The use of 6 Degrees of Freedom motion platforms to induce habituation to offshore motions is a relatively new area of study. One of the biggest challenges is assessing and determining the effectiveness of the training. This is assessed by measuring muscle activity of postural control muscles in the lower limb by analyzing changes in total muscle activity over the course of a trial or using an equation to compare co-contraction between muscle pairs, termed the co-contraction index (CCI). These techniques combined allow researchers to draw conclusions regarding the use of habituation as a preventative intervention to workplace injuries that may occur in offshore environments.
The purpose of the present study was to examine changes in lower limb muscle activity and interpret the effectiveness of implementing varied motion profiles on an individual’s ability to habituate to these environments.
Participants, with no previous experience in moving environments, were exposed to a total of 9, 5-minute trials of simulated motion, performed on a 6 degrees of freedom motion simulator. During trials 1, 8 and 9, muscle activation and video data were recorded. The remaining 6 trials consisted of varied motion sequences and were considered the habituation trials. Results indicated decreased total muscle activation, CCI and total number of steps taken values from pre-habituation to post-habituation trials. There were no significant changes between pre-habituation and retention trials, which were completed no longer than 48 hours after the habituation session. This indicates that longer-term effects did not occur. Frequency analysis of electromyographic data indicates there was no effect of fatigue from pre to post-habituation trials. The decrease in muscle activity seen can be indicative of decreased energy cost during postural control tasks. It is possible that this may lead to a decrease in the onset of fatigue and subsequently injury risk in maritime occupations.


identifier: Balluffi-Fry, Juliana <https://research.library.mun.ca/view/creator_az/Balluffi-Fry=3AJuliana=3A=3A.html>   (2019) Foraging for elements: mammalian responses to plant stoichiometry across scales.  Masters thesis, Memorial University of Newfoundland.

abstract: Energetic demands, nutritional needs, and the scale of foraging collectively influence terrestrial herbivore feeding decisions to meet nitrogen (N) intake requirements. I measured moose (Alces alces) selection for distributions of browse N content and biomass at three scales. Additionally, I measured snowshoe hare (Lepus americanus) preference for browse N content under varying energetic and nutritional demands using cafeteria experiments. I predicted that both herbivores would select for N content; this selection would be stronger for moose at smaller scales and for hares under greater nutritional demands and weaker for moose at larger scales and for hares under greater energetic demands. Moose responses did not support my scalar predictions, but I uncovered individual-level selection trade-offs. The hare experiments supported my energetic and nutritional demand predictions. Collectively, nutrient availability within terrestrial systems may influence herbivore movement and behaviours, although individuals remain flexible in how they respond to and attain limiting nutrients.


identifier: Athukorala, Dilanka Niroshan <https://research.library.mun.ca/view/creator_az/Athukorala=3ADilanka_Niroshan=3A=3A.html>   (2020) The seasonal and inter-annual variation in water export from a boreal forest headwater stream.  Masters thesis, Memorial University of Newfoundland.

abstract: Headwater streams are important locations representing access points to assess aquatic to terrestrial fluxes and source areas that control the water and solute fluxes to downstream aquatic environments. Boreal headwater streams are in post-glacial high latitude landscapes which show a wide range of topographical heterogeneity in landscapes containing high stores of organic matter highly susceptible to climate change. Boreal streams represent important sentinels for landscape changes relevant to global climate feedbacks. Catchment hydrology of boreal streams is controlled by the precipitation regime, particularly snow dynamics and the connection between the landscape elements and hydrology. Snowfall and snowpack dynamics are important features impacted by recent climate change over the last recent decades with potential to significantly impact catchment hydrology of boreal streams and thereby terrestrial to aquatic transport of water, solute, and nutrients in these high latitude landscapes. In this study, I investigated two key boreal headwater components (low gradient wetland and pond and upland forest regions) making up one third order stream watershed situated in western Newfoundland and Labrador in Canada. The second chapter describes a series of approaches evaluated for extending the rating curves required to obtain discharge estimates from continuously monitoring water level in remote, rocky small boreal streams beyond field measurement limited by access during key high flow periods. Results of this study suggest that the use of Ferguson flow resistant equations, which help to better inform the discharge-gauge height relationship through incorporation of stream geometry including stream cross-section, stream gradient, and stream bed grain size data, significantly improves discharge estimates. The third chapter focuses on the study of water flux dynamics of a third order stream in three years contrasting in winter and snowmelt dynamics. The goal of this work was to assess how annual and seasonal discharge and runoff ratios of this small stream varied with (1) differences in snowpack dynamics (i.e. little winter melt to complete snowpack loss in mid-winter); and (2) watershed attributes defined by two key boreal watershed elements (i.e. low gradient pond and wetland dominated and hillslope forest dominated regions). Results from this work indicate that reductions in spring snowmelt events can lead to reduced discharge on an annual basis and decrease the contribution of water from upland hillslope regions that rely on snowpack water storage in this catchment. This suggests reduction in hillslope lateral flow water inputs associated with a reduced spring snowmelt event may be associated with (1) reductions in overall stream water discharge, and (2) increases in the proportion of low gradient pond or wetland contributions to the aquatic environment in these boreal landscapes. Both of these may have important implications for the boreal terrestrial-aquatic fluxes as well as downstream aquatic ecosystems in this region in a future warmer climate.


identifier: Kumar, O. S. Sunish <https://research.library.mun.ca/view/creator_az/Kumar=3AO=2E_S=2E_Sunish=3A=3A.html>   (2020) Digital signal processing techniques for fiber nonlinearity compensation in coherent optical communication systems.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The capacity of long-haul coherent optical communication systems is limited by the
detrimental effects of fiber Kerr nonlinearity. The power-dependent nature of the
Kerr nonlinearity restricts the maximum launch power into the fiber. That results in
the reduction of the optical signal-to-noise ratio at the receiver; thereby, the maximum
transmission reach is limited. Over the last few decades, several digital signal
processing (DSP) techniques have been proposed to mitigate the effects of fiber nonlinearity,
for example, digital back-propagation (DBP), perturbation based nonlinearity
compensation (PB-NLC), and phase-conjugated twin wave (PCTW). However, low-complexity
and spectrally efficient DSP-based fiber nonlinearity mitigation schemes
for long-haul transmission systems are yet to be developed.
In this thesis, we focus on the computationally efficient DSP-based techniques that
can help to combat various sources of fiber nonlinearity in long-haul coherent optical
communication systems. With this aim, we propose a linear time/polarization coded
digital phase conjugation (DPC) technique for the mitigation of fiber nonlinearity
that doubles the spectral efficiency obtained in the PCTW technique. In addition,
we propose to investigate the impact of random polarization effects, like polarization-dependent loss and polarization mode dispersion, on the performance of the linear-coded
DPC techniques. We also propose a joint technique that combines single-channel
DBP with the PCTW technique. We show that the proposed scheme is computationally efficient and achieves similar performance as multi-channel DBP in
wavelength division multiplexed superchannel systems.
The regular perturbation (RP) series used to analytically approximate the solution
of the nonlinear Schrödinger equation (NLSE) has a serious energy divergence problem
when truncated to the first-order. Recent results on the transmission of high data-rate
optical signals reveal that the nonlinearity compensation performance of the first-order
PB-NLC technique decreases as the product of the transmission distance and
launch power increases. The enhanced RP (ERP) method can improve the accuracy of
the first-order RP approximation by partially solving the energy divergence problem.
On this ground, we propose an ERP-based nonlinearity compensation technique to
compensate for the fiber nonlinearity in a polarization-division multiplexed dispersion
unmanaged optical communication system. Another possible solution to improve
the accuracy of the PB-NLC technique is to increase the order of the RP solution.
Based on this idea, we propose to extend the first-order solution of the NLSE to the
second-order to improve the nonlinearity compensation performance of the PB-NLC
technique. Following that, we investigate a few simplifying assumptions to reduce the
implementation complexity of the proposed second-order PB-NLC technique.


identifier: Annadate, Ritesh <https://research.library.mun.ca/view/creator_az/Annadate=3ARitesh=3A=3A.html>   (2020) Studies on selected organocatalytic Mannich, vinylogous and conjugate addition reactions and the stereoselective synthesis of selected aspulvinones.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The functionalized γ-butenolide (2-(5H) furanone) motif is found in various natural products and hence the synthesis of butenolides is of considerable interest. The organocatalytic direct Mannich reaction of γ-crotonolactone with cyclic imines or in-situ generated iminium ions, to provide the functionalized butenolides is not reported. Several new bifunctional thiourea catalysts incorporating a chiral phosphoramide functionality, were prepared and examined in these reactions. These furanones are potential precursors for the synthesis of functionalized quinolizidines such as the homopumiliotoxins and indolizidines such as the pumiliotoxins. Details of these studies are described in Chapter 1.
The organocatalytic Michael addition of cyclic ketones and aldehydes to -nitrostyrenes, generated in-situ from the corresponding nitroacetates, was investigated. The use of pyrrolidine-based amine catalysts in the presence of a protonic acid was found to be optimal and provided enantiomerically enriched -nitro ketones or -nitro aldehydes in good yield. The utility of -nitro aldehydes in the synthesis of pyrrolidines was also established. Details of these studies are described in Chapter 2.
The aspulvinones, 3-aryl-5-arylidene tetronic acids, are a major group of fungal metabolites which have attracted considerable interest due to their biological activity. A modular synthesis of aspulvinones B, D and the recently isolated aspulvinone Q was developed. The methodology features a stereoselective aldol condensation of diazotetronic acid with aldehydes to provide the 5-arylidene diazotetronates. A catalytic, intermolecular C-H insertion reaction of 5-arylidene diazotetronates with arenes provides the aspulvinones. Variation of the aldehyde and the arene components furnishes synthetic analogues of the aspulvinones. These results are presented in Chapter 3. The first organocatalytic asymmetric direct vinylogous aldol reaction of isatin with -angelicalactone for the construction of 3-substituted-3-hydroxyindoles by using various phosphoramide-thiourea catalysts was developed. Details of these studies are described in Chapter 4.


identifier: Perreault, Andrea M. J. <https://research.library.mun.ca/view/creator_az/Perreault=3AAndrea_M=2E_J=2E=3A=3A.html>   (2020) Improving age-based fish stock assessments, with an application to American Plaice on the Grand Bank of Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract:
Age-based fish stock assessment models use available data to provide fisheries managers
with estimates of population processes and to determine sustainable harvest
rates. However, the data to inform these models is often complex and ignoring or
oversimplifying these complexities can result in unsustainable or sub-optimal harvesting
advice. This thesis improves age-based stock assessment models by accounting for
important variability in the data. I first simulation tested nine methods that aim to
account for the commonly used length-stratified age sampling design when estimating
growth parameters. My results showed that commonly used methods had poor
accuracy and the empirical proportion approach was optimal. Secondly, I developed
a state-space stock assessment model for American plaice that allowed for errors in
the underlying population processes and provided improvements in the retrospective
plots. This research improved our understanding of American plaice population dynamics
and growth and is a step forward in fitting more realistic integrated age-based
stock assessment models.


identifier: Westcott, Michael Richard <https://research.library.mun.ca/view/creator_az/Westcott=3AMichael_Richard=3A=3A.html>   (2019) Transforming the liberal state: gender, class, and ethnicity on the Newfoundland home front, 1914-1918.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
In 1914, the Dominion of Newfoundland was thrust into a total war effort. Like other British Dominions, Newfoundland committed its entire civilian population, economy, science, and technology to fighting the war. This dissertation examines how such commitment led to reconceptualizations of gender, class, and ethnicity for the sake of the war effort. Such reconceptualized identities were evident in wartime social phenomena such as prohibition, price control, food rationing, taxation, women’s war work, the treatment of enemy aliens, conscription and food rationing. In each of these cases, Newfoundland’s commitment to the war effort reconfigured gender, class, and ethnicity to help Newfoundland prosecute the war effort, and cope with conditions on the Homefront.
This dissertation will argue that alterations to wartime conceptions of gender, class and ethnicity not only allowed Newfoundland to maintain a total war effort but drastically changed the nature of liberal governance in the Dominion. Prior to the war, liberal thinkers focused on the rights of the individual, believing that the government should interfere with the daily lives of individuals as little as possible. As the war progressed, both liberals and Progressives argued that the government owed a duty to maintain the ranks of the Newfoundland Regiment. In return for soldier’s service, many argued that the government owed it to citizens to interfere in free markets, prohibit alcohol, and impose taxation to ensure that citizens maintained a certain standard of living.
As a result of the demands of both liberals and Progressives, the Newfoundland government abandoned the traditional liberal focus on the rights of the individual and committed to protecting the rights of all citizens by focusing on the rights of the community. By the end of the war, liberalism in Newfoundland looked much less like Classical Liberalism and much more like a burgeoning Social Liberalism that focused far less on the rights of the individual and far more on the rights of the community.


identifier: Krumsick, Kyle <https://research.library.mun.ca/view/creator_az/Krumsick=3AKyle=3A=3A.html>   (2020) Trophic and size spectra modeling reveal key species interactions and quantify community recovery dynamics within Newfoundland and Labrador fisheries ecosystems.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Recent efforts to shift towards ecosystem approaches to fisheries management require multi-species analyses across dynamic food webs and an understanding of trophic dynamics. My research analyzed the marine food web dynamics of Newfoundland and Labrador using stomach contents data and stable isotope ratios from fishes and invertebrates. A key facet of trophic ecology is the role a species fills in the food web. My first chapter quantified realized isotopic niches, a proxy for trophic niche, of representative dominant species using Bayesian ellipses and assess the potential competitive interactions that could prevent population recovery of groundfish species. Also essential in trophic ecology is the assessment of nutrient flow through an ecosystem. To understand the origin for the spatially varying isotopic niches, isotope mixing models were created in my second chapter to assess the strength of the interactions between all fish species and prey species and assess the key pathways of nutrient flow to the upper food web. Considering bioenergetic transfer through a system requires consideration of productivity resulting from growth and reproduction. This productivity analysis lends itself to the study of size spectra and the question of whether they may be used to assess community recovery. To do so, in my third chapter the empirical size structure I derived from the ecosystem surveys was compared to a theoretical pristine size structure derived through a combination of nitrogen stable isotopes and macroecological principles. Strong regionality was observed in isotopic signatures, with more trophic niche overlap, increased connectance and shorter food chain length in the less diverse, northern sites. Ontogenetic variation was observed in the isotopic niches and in the reconstructed diets. These trophic considerations may contribute to the observed differential recovery rates of fish stocks, illustrating the importance of considering competition and diet composition. The interactions of recovering groundfish species and economically important invertebrate species (i.e. shrimp and snow crab) were also highlighted. Although the Newfoundland and Labrador marine ecosystems were still far from fully recovered, recovery and continued sustainability of fish communities could be facilitated through balanced harvesting (though presently mostly theoretical) to limit the damaging impacts of fishery exploitation.


identifier: Curtis, (John) Conor <https://research.library.mun.ca/view/creator_az/Curtis=3A=28John=29_Conor=3A=3A.html>   (2020) Climate change's social justice ramifications for NL and related policy implications.  Masters thesis, Memorial University of Newfoundland.

abstract: Climate change has far-reaching impacts worldwide, and an increasing amount of literature cites the disproportionate burden climate change has on disenfranchised populations and those who have the least means to adapt. Climate change also has ramifications at multiple scales, local through provincial, for Newfoundland and Labrador (NL), Canada. However, while there have been multiple studies of these climate change impacts in NL, there remain gaps in knowledge on how these impacts might affect different groups and communities in different ways, as well as the role provincial policy has and might play in this impact distribution. This thesis assesses potential social justice impacts of climate change for NL. It then examines existing climate change adaption policy in NL, namely the 2011 Climate Change Action Plan and 2019 The Way Forward on Climate Change in NL, and the capacities that these policies have to aid in mitigation of and/or adaptation to social justice implications of climate change. Policy measures that may assist the mitigation of and/or adaption to these implications, including interactions between policy at local and provincial scales, are also discussed.


identifier: Colbert-Paddock, Sherri Lynn <https://research.library.mun.ca/view/creator_az/Colbert-Paddock=3ASherri_Lynn=3A=3A.html>   (2019) Integrating physical activity with academic outcomes for learning.  Masters thesis, Memorial University of Newfoundland.

abstract:
Although it is widely accepted that physical activity (PA) can benefit our overall
health, researchers are challenging the limitation of PA promotion primarily as energy
expenditure. Growing evidence supports the positive effects of PA on children’s
cognitive growth and function which can enhance their learning. Concerns for the health
of children alone has led to the realization of the need for more PA in schools. However,
many educators recognize that PA has a positive impact on concentration, learning and
academic success. A major barrier of increasing PA in schools is the current paradigm of
thought that ‘academics’ takes priority over PA. The trend to reduce opportunities for
PA during the school day in lieu of ‘academic’ instruction time is a growing concern.
The problem is that “academic” instructional time predominately means students sitting
in an often-congested classroom learning through mostly sedentary methods. Recent
research focusing on the benefits of PA to children’s cognitive growth and function
attempts to overcome the barriers to increasing PA in schools through the integration of
PA with curriculum outcomes traditionally taught in the classroom.
The current research study involved 86 grade four students from a public
elementary school. The researcher developed a unit of lessons in mathematics in
consultation with the grade four teachers and the curriculum guides set out by the school
district. For each lesson, two formats were developed, one was based on traditional
classroom methods and the other was integrated with physical activity. The physically
active lessons constituted the intervention while the classroom lessons served as the
control and a switched replication design was used. The learning outcomes taught for each lesson, both the traditional and PA lessons, were evaluated immediately after the
lesson through a short post-test/quiz administered by the classroom teacher to measure
what was learned. The student scores for the post-test/quiz were similar in both
conditions while PA was increased significantly during the intervention. This is
consistent with the results of other studies in that there were no significant positive
effects on the learning outcomes measured but neither were there negative effects when
PA was increased. Such results demonstrate that lessons can be taught effectively while
increasing the amount of PA in schools.
A unique component of this study was a qualitative focus group study following
the intervention which examined students’ perceptions of their learning experience during
the intervention. The key benefits perceived by participants were increased enjoyment
and enthusiasm for mathematics which promoted their engagement in the learning
activities due to enhanced opportunities for physical activity and social interaction.
These positive perceptions demonstrate potential for not only using a physically active or
movement-based approach to teach mathematical concepts but the potential to increase
student engagement and enjoyment in their learning experience.
The results of this study add to the limited research in this area. The traditional
teaching approach of our current school system, which uses predominantly sedentary
methods in a classroom setting, is challenged by the growing evidence that PA can be
integrated effectively into the school day. This type of teaching strategy has the potential
to increase PA for children during the school day, promote student engagement in
learning and, as a result, increase academic achievement.


identifier: Lu, Xushan <https://research.library.mun.ca/view/creator_az/Lu=3AXushan=3A=3A.html>   (2020) Three-dimensional finite-volume time-domain modeling of graphitic fault zones in the Athabasca Basin using unstructured grids.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
In this thesis, numerical modeling methods for geophysical time-domain electromag- netic (EM) problems and their applications in modeling graphitic faults in the Atha- basca Basin are investigated. A finite-volume time-domain numerical modeling method is developed. The method uses unstructured Delaunay-Voronoï dual meshes. Such unstructured meshes are more flexible and eﬃcient when models containing geological units with complex geometries and topography need to be considered. A model build- ing procedure is established to construct arbitrarily complex models with topography. The procedure locally refines the mesh quality at certain areas such as loop sources and receivers in order to obtain better numerical results.
For modeling time-domain EM problems, two approaches are used: the electric field approach and the potential approach. The electric field method directly solves the electric field Helmholtz equation while the potential method solves the Helmholtz equation expressed using vector and scalar potentials. The electric field method is simpler in theory and results in a smaller linear system of equations compared to
potential methods. The potential method, on the other hand, is more complex intheory and a larger linear system of equations needs to be solved. However, using the potentials method enables the decomposition of the electric field into galvanic and inductive parts, which is helpful for understanding the physics behind the behaviour of the EM fields in the ground. In addition, the linear system of equations is better conditioned which potentially allows the use of iterative methods to solve it.
Both methods are validated by comparing the modeling results with analytic solu- tions for homogeneous half-space models and numerical results for models presented in the literature. The modeling methods developed in this thesis are then applied to the modeling of real EM data collected in the Athabasca Basin. Thin, steeply dip- ping graphitic fault systems, which are linked to the formation of uranium deposits are present in the basin and have a large conductivity contrast with the background host. Because of the close relationship between the graphitic faults and the uranium deposits, time-domain EM surveys are important tools for uranium exploration in the basin. Geological models of the graphitic fault systems are discretized with unstruc- tured grids using the model building procedure developed in this thesis. Two real data sets that were previously collected from the Athabasca Basin are modeled and the modeling results are compared with the real data. The match between the calculated three-component responses and real data is good for models built based on geological information, drilling information, and trial-and-error. These models can help us to infer the complex geometry and conductivity features of the subsurface conductor be- yond the areas targeted by drilling. Therefore, 3D modeling of realistic, complicated
real-life conductive targets such as in the uranium exploration in the Athabasca Basin or any other classic mineral exploration for a conductive target with complex shape is an important tool.


identifier: Darijani, Meghdad <https://research.library.mun.ca/view/creator_az/Darijani=3AMeghdad=3A=3A.html>   (2020) A study of nonlinearity with spectral element method and linear slip effective medium theory.  Masters thesis, Memorial University of Newfoundland.

abstract:
In exploration seismology, mapping the Earth’s interior structure in more detail is
of great interest. The rocks’ microstructures, such as cracks, play an essential rule
in oil and gas exploration and production. We study elastic nonlinearity because
the microstructures are the main reason for this phenomenon. Nonlinearity is also
related to the velocity change due to perturbations in the stress filed within the rocks.
Many studies have observed the nonlinearity in field data as well as experimental data.
However, the exact underlying mechanism of this phenomenon is not well understood.
In this study, we provide some numerical examples of wave-perturbed cracked rocks
and study the effects of crack aperture size, change of velocity inside crack, and crack
orientation on the medium velocity change to better understand this phenomenon.
Similar to a few other studies, we study the travel-time delay in a small wave caused
by the propagation of a stronger wave. We show that there is a strong dependency
between the crack parameters and the travel-time delay.


identifier: Williams, Christopher <https://research.library.mun.ca/view/creator_az/Williams=3AChristopher=3A=3A.html>   (2020) Wide-angle, full waveform inversion with a sparse ocean-bottom seismometer dataset, imaging the Cyprus Arc from the Eratosthenes Seamount to the Hecataeus Rise.  Masters thesis, Memorial University of Newfoundland.

abstract:
Tectonophysicists working with wide-angle seismic reection and refraction data generally
rely on tomographic inversion and forward modelling techniques to produce
P-wave velocity models of the subsurface. Only recently, researchers have produced
high-resolution P-wave velocity models using full-waveform inversion (FWI). However,
they use ocean-bottom seismometer (OBS) datasets with a dense instrument spacing.
This study revisits a sparsely acquired OBS dataset from the geologically complex
Eastern Mediterranean to explore the feasibility of applying FWI to such a dataset.
With frequency domain viscoacoustic FWI, we observe an adequate decrease in the
objective function, suggesting that a high-resolution velocity model for the upper 15
km is obtainable through FWI with a typical OBS dataset. This decrease in the objective
function does not preclude convergence to a local minimum. The recovered FWI
model suffers from uncertainties in the starting model related to a complex geological
environment. Cognizant of model uncertainties, we interpret an accretionary prism
between the southern Eratosthenes continental block and the northern Hecataeus Rise
from the final FWI model.


identifier: Bhuiyan, Md Abdus Samad <https://research.library.mun.ca/view/creator_az/Bhuiyan=3AMd_Abdus_Samad=3A=3A.html>   (2020) Development of a canopy stress method for large eddy simulation over complex terrain.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
High-fidelity Large-Eddy Simulation (LES) of fluid flow over complex terrain has long
been a challenging computational problem. Complex terrain leads to increased velocity
gradients, turbulence production, and complex turbulent wakes. Body-fitted grids need a
high resolution to deal with additional effects of highly skewed cells that follow a terrain
of steep slope. Immersed boundary methods need special techniques like wall models to
numerically resolve the associated drag force. In flow over complex terrain, the characteristic
scale decreases locally which makes it a challenging endeavour for LES to mimic
the turbulent energy cascade, particularly when steep terrain produce vortices and streaky
structures that sustain turbulence away from the surface.
This thesis presents the canopy stress method in which the terrain is immersed into the
fluid, cutting the cells of a Cartesian grid, where the effects of terrain are treated by the
form drag and the skin friction drag. Heat transfer analysis of flow in pipes and porous
media is considered to study the sensitivity of canopy drag coefficients. A scale-adaptive
methodology is proposed to model the subgrid-scale terrain effects. The analysis of wind
tunnel measurements over mountains and forests shows that the scale-adaptive model dynamically
adjusts the dissipation rate by the scale of energetic eddies near complex terrain.
In regions without terrain effects, where subgrid turbulence is locally isotropic, the model
also provides accurate dissipation rate. These results suggest that combining the rotation
tensor and the vortex stretching vector with the strain tensor through the second-invariant
of the square of the velocity gradient tensor is a novel approach to improve the fidelity of
LES over complex terrain in which the dissipation becomes scale-aware; i.e. the rate of
turbulence dissipation is adjusted with the changes in the characteristic scales. The numerical
analysis of four distinct flow regimes (e.g., Chapters 3-6) illustrates the accuracy,
simplicity, and cost-effectiveness of the proposed LES methodology.


identifier: Merrell, Andrew Robert <https://research.library.mun.ca/view/creator_az/Merrell=3AAndrew_Robert=3A=3A.html>   (2020) Evolving governance: a comparative case study explaining positive self-government outcomes for Nunatsiavut government and the Miawpukek First Nation.  Masters thesis, Memorial University of Newfoundland.

abstract:
There are currently 27 indigenous groups with self-government agreements with the Government
of Canada, and many more with other types of governance agreements. All have faced lengthy
negotiation processes and institutional barriers in achieving success in self-government. Despite
increasing interest in the topic, research on the impacts of self-government at the community
level is still limited, and relatively little has been written about the evolution of self-government
in Newfoundland and Labrador. Scholars and policymakers continue to debate the benefits of
self-government. This thesis conducts a comparative analysis of two case studies. The first,
Miawpukek First Nation, is a Mi’kmaq community on the island of Newfoundland that
resembles a self-governing community in terms of policy but has no formal agreement. The
second, Nunatsiavut Government, is based on a formal self-government agreement and serves
the Labrador Inuit. The thesis first analyzes the data to demonstrate the statistical benefits of self-government agreements, comparing the data to that of the two cases. The thesis then uses
rational choice institutionalist and culturalist institutionalist approaches to analyze findings from
46 semi-structured, elite interviews conducted with residents of the two communities, together
with supporting documentation, such as policy studies and media reports. The thesis concludes
that the success of both governments in improving outcomes for residents is not a result of
formal agreements with the Crown or of access to resource revenues. Instead, the combination of
a well-organized, accountable local government, innovative policy initiatives tailored to
community needs, and the financial resources to deliver them, is the key to success in
governance.


identifier: Hunt, Sarah Louise <https://research.library.mun.ca/view/creator_az/Hunt=3ASarah_Louise=3A=3A.html>   (2020) Exploring colonization and mental health from the perspective of a First Nations community in Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract:
This thesis utilizes a critical discourse analysis methodology to explore the experiences of
members of a First Nations community in Labrador with mental health and addictions
care systems. In particular, an understanding of how colonization has impacted the mental
health of this community and the ways in which colonization is or is not considered
within the treatment provided within mental health and addictions services is explored
from the perspective of community members.
In addition, the thesis includes a review and guide for white social work researchers to
engage in politically-informed research with Indigenous communities in a way that is
respectful and ethical. This includes an analysis of the role of academia, the role of
research and the role of social work in preserving and reinforcing colonialist ideals, as
well as the ways in which research with Indigenous communities may be decolonized in
order to be more ethical, respectful, and responsible.


identifier: Muojeke, Somadina Innocent <https://research.library.mun.ca/view/creator_az/Muojeke=3ASomadina_Innocent=3A=3A.html>   (2020) Supervised data-driven approach to early kick detection during drilling operation.  Masters thesis, Memorial University of Newfoundland.

abstract:
The margin between pore pressure and fracture gradient in new offshore discoveries continues to get narrower. This poses greater risks and higher cost of ensuring safety of lives, facilities, and the environment. The 2010 Macondo blowout has fueled increased interests in monitoring downhole parameter for early kick detection. Early detection of kick is important part of the process safety. It provides opportunity to activate safety measures. However, after an extensive literature search, certain gaps were identified in early kick detection research. This ranged from limited availability of downhole drilling data from oil fields with downhole pressure and flow measurements for research purposes to limited modelling efforts that applies machine learning to downhole measurements in the area of early kick detection. Leveraging machine learning is crucial because of the tremendous advancements in artificial intelligence and information technology. This research provides a simple design approach to build machine learning kick detection models. In the absence of field data, we collect data from existing and new experiments that records downhole measurements. A simple model is rewarding when data processing is done downhole. The hardware used is typically battery powered. Simpler and fewer software operations will lead to less power consumption, smaller memory and simpler cooling requirements. This will lead to an increase battery run time, miniaturized designs/reduced bulk size, reduced maintenance frequency for such hardware, improved response time and lower costs.
In this thesis, we investigate the simplest supervised neural network-based machine learning kick detection system to ensure high reliability using experimental data. Building upon previous kick experiments conducted using a Small Drilling Simulator (SDS), we present a detailed design of a new kick experiment setup that uses a Large Drilling Simulator (LDS) and synthetic rock samples. We also provide a detailed design of synthetic rock sample with geometrical capability to trap high-pressure formation fluid within. The experiment setup produces new set of data from downhole parameter monitoring that will be used in testing the machine learning model. Parameters such as mud flow-out rate, conductivity, density, and downhole pressure from two previous drilling experiment that monitored downhole parameters are combined to build a data-driven model for early kick detection. This model combines an Artificial Neural Network (ANN) with a binary classifier at its output. Several input combinations are trained and tested. The model can be scaled to capture other types of drilling problems such as lost circulation and also applied in the LDS system. The model was tested and evaluated with data from the SDS system, SDS system with faulty conductivity data and different experimental drilling system. Abnormal pressure and flow regimes in the wellbore provide early warnings and are shown to be more significant parameters than others; however, solely relying on them can increase susceptibility to false alarm.


identifier: Downey, Beth <https://research.library.mun.ca/view/creator_az/Downey=3ABeth=3A=3A.html>   (2020) Theological polyphony in Michael Crummey's Galore.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis provides a close examination of religion in Michael Crummey’s Galore (2009), focussing particularly on the novel’s use of allusion—verbal, dramatic, and figurational—to harmonize its expansive polyphonic theology. Epiphany, encounter, the unexpected inbreaking of divinity into ordinary life is a central theme in Galore. It is expressed verbally and visually, often in terms that have meaning in several streams of spirituality all at once. These composite or bilingual figurations, which manage to allude simultaneously to more than one repository of spiritual meaning (for example Judeo-Christian, especially Catholic, iconography and Irish animist symbolism) are crucial features, ideal sites for excavating deeper theological insight into the novel. The two body chapters of this work engage the thesis topic at very different scales. Chapter 2, “A Miraculous Catch,” takes the wider view, examining theology in Galore as expressed through composite religious figurations of sea life. Chapter 3, “Fear, Trembling, and Carousing,” is devoted entirely to Galore’s central religious leader, Father Phelan. By analyzing a narrower subject in greater depth, this chapter works to both underline and expand upon the points made in Chapter 2, illuminating the two paradoxical themes—sacramentalism and agnosticism—that animate Galore’s core theology. These sacramental and agnostic “turns” are discussed throughout the thesis in relation to Christian traditions of cataphatic and apophatic theology. Finally, this work concludes with an overview of opportunities for further research into Galore and Crummey’s work more broadly, germane to the themes of this thesis and farther afield.


identifier: Knight, Robyn Michelle <https://research.library.mun.ca/view/creator_az/Knight=3ARobyn_Michelle=3A=3A.html>   (2020) Substrate composition and relationship to bacterial communities during production and fallow periods at hard-bottom aquaculture sites in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Newfoundland salmonid aquaculture is established in deep, sheltered bays and above hard-bottom substrates. Over time, organic waste accumulates on the seafloor, changing sediment chemistry and community structure. Visual markers including white bacterial mats are used to monitor organic enrichment but alternative methods may be more informative. I sampled substrates at two aquaculture sites in Newfoundland [experiencing production (active) and fallow (inactive) conditions], characterized abiotic features and bacterial communities, and tested for associations with bacterial mats. Organic enrichment and abiotic markers of aquaculture were prominent during both production and fallow periods, especially near cages. Bacterial mats were associated with elevated concentrations of organic matter, Zn, Cd and Cu. Bacterial community clusters show relationships with organic matter and Zn, and mats were associated with all identified bacterial community clusters. This research highlights the potential use of bacterial and abiotic markers for monitoring organic enrichment and site recovery at aquaculture sites in Newfoundland.