identifier: Abdalla, Younis E. <https://research.library.mun.ca/view/creator_az/Abdalla=3AYounis_E=2E=3A=3A.html>   (2020) Detection of copy-move forgery in digital images using different computer vision approaches.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Image forgery detection approaches are many and varied, but they generally all serve
the same objectives: detect and localize the forgery. Copy-move forgery detection
(CMFD) is widely spread and must challenge approach. In this thesis, We first investigate
the problems and the challenges of the existed algorithms to detect copy-move
forgery in digital images and then we propose integrating multiple forensic strategies
to overcome these problems and increase the efficiency of detecting and localizing
forgery based on the same image input source. Test and evaluate our copy-move
forgery detector algorithm presented the outcome that has been enhanced by various
computer vision field techniques. Because digital image forgery is a growing problem
due to the increase in readily-available technology that makes the process relatively
easy for forgers, we propose strategies and applications based on the PatchMatch
algorithm and deep neural network learning (DNN). We further focus on the convolutional
neural network (CNN) architecture approach in a generative adversarial
network (GAN) and transfer learning environment. The F-measure score (FM), recall,
precision, accuracy, and efficiency are calculated in the proposed algorithms and
compared with a selection of literature algorithms using the same evaluation function
in order to make a fair evaluation. The FM score achieves 0.98, with an efficiency rate
exceeding 90.5% in most cases of active and passive forgery detection tasks, indicating
that the proposed methods are highly robust. The output results show the high efficiency of detecting and localizing the forgery across different image formats for active
and passive forgery detection. Therefore, the proposed methods in this research
successfully overcome the main investigated issues in copy-move forgery detection as
such: First, increase efficiency in copy-move forgery detection under a wide range
of manipulation process to a copy-moved image. Second, detect and localized the
copy-move forgery patches versus the pristine patches in the forged image. Finally,
our experiments show the overall validation accuracy based on the proposed deep
learning approach is 90%, according to the iteration limit. Further enhancement of
the deep learning and learning transfer approach is recommended for future work.


identifier: Burella, Giorgio <https://research.library.mun.ca/view/creator_az/Burella=3AGiorgio=3A=3A.html>   (2020) Long- and short-term solutions for mitigating hazardous noise exposure and noise levels on board vessels from the small-scale fishing fleet of Newfoundland and Labrador.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

abstract:
Fish harvesting in Newfoundland and Labrador (NL) is prominently a small-scale industry.
This is an important activity in the rural NL, providing a mean of livelihood and identity
to many coastal communities. Fishing is also one of the most dangerous professions both
in the province and worldwide, with high incidence of reported casualties, accidents, and
injuries. Among many health and safety issues of the fish harvesting profession, elevated
noise levels pose a subtle threat. Prolonged exposure to noise is known to induce noise-induced
hearing loss (NIHL), and high noise levels are known to reduce the habitability of
fishing vessels, increase fatigue, and ultimately add to the risk of accidents and injuries.
This PhD research aims to assess noise-related hazards on the small-scale NL fishing fleet
(less than 24m length overall) and to provide short-term (minimal vessel and gear modification,
use of protection devices), and long-term (integration of an acoustic design for noise
control on fishing vessels) solutions to mitigate on-board high noise levels and exposures.
The research features: a) a comprehensive survey of noise levels and occupational noise
exposures on-board a representative sample of 12 vessels, in order to identify the dominant
noise sources, measure the in-situ acoustic insulation, assess the compliance with habitability
criteria of living spaces and the risk of hazardous noise exposures; b) the study of the
perception of risk of noise-related hazards from owner/operators of the fleet; c) the development
of a numerical model validated using experimental data for the acoustic transmission
and the study of possible noise control interventions to mitigate noise to acceptable levels
on a case study vessel. In this research activity a job-based method for noise exposure assessment was used, as opposed to the task-based method used in other studies on fishing
vessels, and the noise components that lead to hazardous noise exposures were identified
in order to provide effective solutions to mitigate noise exposure. Furthermore, for the
first time state-of-the-art Statistical Energy Analysis (SEA) and graph theory were used
to model noise transmission on a small-sized fishing vessel and reveal the dominant noise
transmission mechanisms. Based on these findings, effective noise control interventions
were proposed and evaluated.
These assessments are necessary to provide recommendations and guidelines, and introduce
design and operational criteria to control noise levels on small fishing vessels from
NL and worldwide more in general. Indeed, noise control solutions identified in the case-study
vessel can be used on similar vessels, and the numerical method based on SEA as
shown in this research can be applied to design of noise control on new vessels.


identifier: Zrini, Zoe A. <https://research.library.mun.ca/view/creator_az/Zrini=3AZoe_A=2E=3A=3A.html>   (2020) Using data storage tags to study fish physiology and behaviour.  Masters thesis, Memorial University of Newfoundland.

abstract: Data storage tags (DSTs) are implantable devices that record and store physiological, environmental and/or behavioural data from free-living animals. A recently developed DST from Star-Oddi records heart rate (fH), electrocardiograms (ECGs), tri-axial acceleration and temperature. In my first chapter, I found that parameters of acceleration could predict the swimming speed, tail beat frequency and behaviour of Atlantic salmon (Salmo salar), and that the DST could record changes in fH associated with recovery from surgery, the diurnal (day / night) cycle and temperature. In my second chapter, I used Star-Oddi’s micro fH logger to show that the lumpfish (Cyclopterus lumpus) has a low maximum fH compared to most fishes, experiences tachycardia when acutely exposed to increased hydrostatic pressure and for periods as long as one hour, and that hydrostatic pressure alters their fH response to decreasing oxygen levels (hypoxia). These data support the use of biologging tags (which have recently been miniaturized and made more affordable) to better understand how aquatic animals respond to changes in their environment, and their ecology.


identifier: Campbell, Rory <https://research.library.mun.ca/view/creator_az/Campbell=3ARory=3A=3A.html>   (2020) Machine learning state evaluation in prismata.  Masters thesis, Memorial University of Newfoundland.

abstract:
Strategy games are a unique and interesting testbed for AI protocols due their complex
rules and large state and action spaces. Recent work in game AI has shown that
strong, robust AI agents can be created by combining existing techniques of deep
learning and heuristic search. Heuristic search techniques typically make use of
an evaluation function to judge the value of a game state, however these functions
have historically been hand-coded by game experts. Recent results have shown
that it is possible to use modern deep learning techniques to learn these evaluation
functions, bypassing the need for expert knowledge.
In this thesis, we explore the implementation of this idea in Prismata, an online
strategy game by Lunarch Studios. By generating game trace training data with
existing state-of-the-art AI agents, we are able to use a Machine Learning (ML)
approach to learn a new evaluation function. We trained several evaluation models
with various parameters in order to compare prediction time with prediction accuracy.
To evaluate the strength of our learned model, we ran a tournament between
AI players which differ only in their state evaluation strategy. The results of this
tournament demonstrate that our learned model when combined with the existing
Prismata Hierarchical Portfolio Search system, produces a new AI agent which is
able to defeat the previously strongest agents. A subset of the research presented
in this thesis was the subject of a publication in the Artificial Intelligence and Interactive
Digital Entertainment (AIIDE) 2019 Strategy Games Workshop [1].


identifier: Eskandari, Navid <https://research.library.mun.ca/view/creator_az/Eskandari=3ANavid=3A=3A.html>   (2020) Asphaltene deposition simulation in porous media during CO₂ injection using Lattice Boltzmann Method.  Masters thesis, Memorial University of Newfoundland.

abstract: Carbon dioxide (CO₂) injection in oil reservoirs is a potential means of Enhanced Oil Recovery (EOR) and reducing greenhouse gas. Change in the thermodynamic condition and composition due to the CO₂ injection process may trigger the asphaltene precipitation and deposition which directly affects the efficiency of the EOR process. Predicting the possibility of the asphaltene issue under different operating conditions can help the oil industry for better process design, handle the potential operational problems and estimate the production cost. In spite of, the existence of different modeling approaches based on conventional numerical methods, the lack of a flexible and more comprehensive modeling approach is inevitable. The new and advanced numerical method, called the Lattice Boltzmann Method (LBM) covers the limitations of the conventional numerical methods in dealing with complex boundary conditions and incorporating the microscopic interactions. This study is aiming at the modeling of the Asphaltene deposition, and it’s effect on the fluid flow in porous media during an immiscible injection of CO₂ with applying the LBM as the main simulator engine that gets fed by the given phase behavior to take the asphaltene deposition into account as well. Porosity and CO₂ injection velocity are the changing factors in this study. Applying the same condition on two mediums, it has been seen that the recovery factor is 22.5% higher and deposited asphaltene is 2.56% lower in a more porous medium that is attributed to uniform pore size distribution and higher absolute permeability of the more porous case. Furthermore, the fingering phenomena seem to be high in a less porous medium which causes an early breakthrough. Studies on the CO₂ injection velocity effect showed that by increasing CO₂ injection velocity by 2 times and 3 times, the recovery factor increases 4% and decreases 6%, respectively. A decrease in recovery factor is attributed to the asphaltene deposition at which the deposited asphaltene is two times higher at injection velocity of 3


identifier: Smith, Jennifer Joan Elizabeth <https://research.library.mun.ca/view/creator_az/Smith=3AJennifer_Joan_Elizabeth=3A=3A.html>   (2020) Pedagogical studies in virtual offshore safety training.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
To better prepare the offshore workforce for emergencies, operators and regulators need to use evidence-based safety training. This research aims to provide such evidence by employing an experimental program to evaluate virtual environment (VE) training as a plausible means to enhance mandatory offshore egress training. Combining VE technology with a well-designed, pedagogically informed training program, and carefully selected data-mining tools, can support the development of trainee competence in emergencies by providing artificial experience in credible situations and tracking trainee performance throughout the VE training.
Evidence from this research supports the use of VE training to address pedagogical gaps in the training. Key gaps include the following: 1) conventional training is predominantly provided by fixed-time instruction, which results in crews with nominal competence, 2) the frequency of recurrency training is not informed by evidence on crews’ susceptibility to forget training, 3) crews’ learning outcomes are not measured or monitored, which results in no information to assess training transfer, and 4) due to safety constraints, muster drills lack the realism of how emergency situations unfold in real life.
Lessons from pedagogical theory and data-mining methodology were used to provide empirical and modeling evidence to inform offshore and maritime domains on the application of VE training. The scope of the research involved using the VE training as a human behaviour laboratory during a longitudinal study. The context of the study was to teach the necessary egress skills to evacuate a virtual oil platform during an emergency.
To address the pedagogical gaps and evaluate VE training, this thesis is comprised of four research papers. The first paper investigates the influence of the simulation-based mastery learning (SBML) pedagogical framework on the development of competence at the different learning phases, specifically the acquisition, retention, and transfer of egress skills. The second paper uses human performance data from the VE training to develop a decision tree (DT) diagnostic tool to compare the efficacy of different delivery methods for VE training. The third paper evaluates the retention and maintenance of the VE training after a period of 6 to 9-months. The fourth paper uses DT modeling to evaluate skill transfer and develop a predictive tool to analyze the efficacy of VE training on a systemic level to support future adaptive training programs.
The overall contribution of this research is the use of pedagogical frameworks and data-mining tools to improve the design, delivery, and assessment, of VE training. The concept of this work is established in the context of offshore and maritime safety, however the approaches are generalizable to many virtual training applications in other domains.


identifier: Siegwart Collier, Laura <https://research.library.mun.ca/view/creator_az/Siegwart_Collier=3ALaura=3A=3A.html>   (2020) Climate change impacts on berry shrub performance in treeline and tundra ecosystems.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Climate variability and warming are directly, indirectly and irrefutably driving widespread changes in global aquatic and terrestrial ecosystems, with disproportionate poleward impacts. Across Arctic treeline and tundra, understanding how current and future changes will negatively affect subsistence resources is critical to mitigating climate change impacts on Indigenous peoples and northern flora and fauna.
In this study, I looked to Inuit knowledge and western scientific approaches at local and regional scales across Inuit Nunangat (Inuit regions of Canada, including Nunavut, Nunavik, and Nunatsiavut) to explore and test the impacts of climate variability and warming on treeline and tundra berry species, which are critical resources in Arctic ecological and cultural systems. My central hypothesis, which is rooted in local, traditional and scientific knowledge, is that climate-driven expansion of tall-shrub canopies will negatively impact fruit production of dwarf berry shrubs.
Through mixed methods approaches, including participatory interviews, climate analyses, ecological surveys, and experimental warming at different spatial and temporal scales, this study identifies the fundamental role of local processes in driving and explaining changes in dwarf berry shrub growth (abundance and height) and fruit production (occurrence and abundance of fruit) in eastern Low Arctic and Sub-Arctic Canada. The results consistently demonstrate that growth and fruit production of truly prostrate berry shrubs (i.e. Vaccinium vitis-idaea and Empetrum nigrum) with limited phenotypic plasticity in height growth are most at risk from warming and tundra shrubification in comparison to berry shrubs with greater height growth plasticity (V. uliginosum) due to canopy impacts on local resources. With this knowledge, I anticipate that the boundaries between low and tall shrub tundra plant communities will be zones of significant change in berry resources. Local resource mapping, with a specific focus on these transition zones will be critical to identifying priority areas for berry resource conservation and active management to ensure future access to a sustainable source of these culturally important resources.


identifier: Pike, Howard <https://research.library.mun.ca/view/creator_az/Pike=3AHoward=3A=3A.html>   (2020) Can we stop learning safety by accident?  Masters thesis, Memorial University of Newfoundland.

abstract:
The question has been asked in many forums, why are major accidents still occurring? Awareness is an important basic learning factor to properly manage the lessons to be learned from major accidents. Over time, the recommendations made following an accident may be forgotten, procedures allowed to lapse, changes are made to equipment and the accident is just waiting to happen again. The memory within an organization that should help to prevent process safety accidents decays thus allowing accidents to repeat. It has been 38 years since the loss of all 84 crew members on the Ocean Ranger, the largest mobile offshore drilling unit of its day. At 1:10 a.m. EST on February 15, 1982, the Ocean Ranger’s crew sent a mayday call and abandoned the rig at 1:30 a.m. No one survived. There were no eye witnesses to tell what happened. Investigators were left with some technical evidence and the testimony from others. While the investigation report and recommendations from a Royal Commission into the Ocean Ranger tragedy changed the offshore safety regime of the time, can we learn more by re-examining the past? Can we stop learning safety by accident?
Safety and environmental risk go hand in hand with industrial development. However, it is unclear whether there is a linear or nonlinear relationship between risk and industrial development. Perhaps, it is case dependent. Some industrial endeavors such as offshore development, activities in a harsher environment, or development requiring new technologies (untested and untrusted technologies) may pose a higher risk (nonlinear) than more conventional industrial development activities (e.g., petroleum refineries, petrochemical plants, pipeline transportation, and the like). Public perception plays a critical role in defining the risk versus development relationship. The public perception of risk is dependent on awareness and understanding of potential hazards and their likelihood of occurrence, and most importantly, effective communication of these along with the associated uncertainty. Public awareness can have a profound effect on the development of public policy, which in many cases is driven more by perception rather than by sound science. Two commonly used concepts of policy and decision-making will be investigated, the Precautionary Principle (PP) and As Low As Reasonably Practicable (ALARP). A clearer understanding of both approaches with an illustrative example will be provided. A process to help readers understand where and when PP versus ALARP would be most applicable is proposed.


identifier: Calvo, Samir Elias Avendaño <https://research.library.mun.ca/view/creator_az/Calvo=3ASamir_Elias_Avenda=F1o=3A=3A.html>   (2020) Échanges en noir et blanc: les enjeux double dans le film Renaissance de Christian Volckman.  Masters thesis, Memorial University of Newfoundland.

abstract:
The film Renaissance, a feature black and white science fiction animated film, proves the
power of the image exploited by the cinema, in particular that of animation. Released in 2006, this
film, directed by Christian Volckman, combines a series of technical and scriptwriting elements
from various moments in the history of cinema, in particular a scenario which makes a link with
classical cinema, particularly with the American Black Film of the fifties, with thrillers, and their
archetypes. Additionally, the film uses an animation technique which combines both traditional 2D
animation with modern 3D animation, which is based on capturing movements by creating a work
where the visual aesthetics reminds us of video games. From this perspective, Renaissance is a
unique film that fits into a new type of cinema: transludic cinema. The analysis presented here
considers three perspectives: intermedial, video game and narratological, which aim to demonstrate
how in Renaissance, various media elements intersect with the objective of producing a hybrid that
generates a new aesthetic. All of this is encompassed in the exploration of the central theme of
duality within the narrative of this fictional black and white animated film.


identifier: Tang, Yongfeng <https://research.library.mun.ca/view/creator_az/Tang=3AYongfeng=3A=3A.html>   (2020) Why do large-scale land protests in China succeed or fail?  Masters thesis, Memorial University of Newfoundland.

abstract:
Land protests account for a large portion of all protests in China, but existing scholarship on
this topic does not explain under which conditions large-scale land protests succeed or fail.
This thesis will attempt to answer this question by focusing on five large-scale land protests
that happened in China from 2012 to 2017. I argue that large-scale land protests are more
likely to succeed under three conditions: when 1) domestic media reports on this protest are
supportive or on the protesters’ side; 2) the protests are violent, and 3) the protests occur in
the early stages of a developmental project. Those conditions do not work in isolation, but
they coincide with protest success in those five cases that I investigated in this research.
Using media analysis and doing a one-and-a-half-month-long period of fieldwork in China, I
found that domestic media in China played two roles in determining the outcome of a protest:
a “catalyst” role or a “watchdog” role. I also distinguished between short-term outcomes and
long-term outcomes and found that the success of a short-term outcome will not necessarily
guarantee the long-term outcome of a protest. Thirdly, I found that not only does the level of
violence of the protest matter, but also which side used violence first affects the outcome of a
large-scale land protest. This research contributed to the literature on contentious politics in
China by highlighting under what conditions do large-scale land protests in China tend to
succeed in the Xi Jinping era.


identifier: Ahmadi, Hamid <https://research.library.mun.ca/view/creator_az/Ahmadi=3AHamid=3A=3A.html>   (2020) Effect of an inverted seated position with upper arm blood flow restriction on neuromuscular fatigue.  Masters thesis, Memorial University of Newfoundland.

abstract:
Change in body position, in addition to disturbances to the homeostasis of our body,
can exacerbate neuromuscular fatigue. Experiencing a voluntary or involuntary inverted
position is a stressful condition and can alter sympathetic nervous system activity, which has
been suggested as a primary mechanism that may inhibit neuromuscular and cardiovascular
function. Moreover, there is a possibility of complete or partial blood flow due to limb
compression during life-threatening conditions such as overturned vehicles. Blood flow
restriction (BFR) due to a decrease in perfusion to a target muscle, moderate to high intensity
muscle contractions, and BFR (partial occlusion during a contraction with low intensity) can
lead to force reductions and dependency on type II fibres. This shift to an anaerobic phase
yields metabolic by-products accumulation, stimulating muscle fibres afferents with small
diameters (group III and IV). The increases in peripheral inputs to the central level may cause
inhibition of final motor output, fatigue-induced greater perceived pain and effort, and
increased cardiovascular stress.
In view of many interacting systems during inversion, the purpose of this thesis was
to explore how BFR of the upper arm while participants were securely inverted can influence
isometric force production, muscle activity, fatigue, perceived pain, and cardiovascular
responses. Understanding the possible mechanisms can be used by safety and survival
centers during limited time rescue missions.


identifier: Bobby, Pradeep <https://research.library.mun.ca/view/creator_az/Bobby=3APradeep=3A=3A.html>   (2020) Scattering from stratified media with a rough surface: application to sea ice ridges.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Sea ice ridging is the dominant factor contributing to sea ice thickness, which has
impacts on climate change and transportation. It is important to know the age of
sea ice ridges, since ice age affects the strength of the ice and its ability to persist
through the summer melt season. However, information on the age of sea ice ridges
is not commonly available. The goal of this thesis is to develop a method to distinguish
between first year and multi-year sea ice ridges using simulations of scattering
signatures in the range 100-500 MHz. This goal is achieved by modifying existing
scattering models, developing a sea ice model and comparing simulation results.
The research is based on Walsh’s scattering approach, which was originally developed
to model high frequency (HF) radar propagation across a rough surface or
through stratified media and three updates to the scattering model are made. In
the first update, Walsh’s method is modified from assuming the surface is a good
conductor to be applicable to scattering from general dielectrics. Secondly, Walsh
used a simplified scattering geometry, which implicitly assumed small surface slopes.
By using the correct scattering geometry the method is extended to general surface
slopes. The vertical component of the electric field is the most important for propagation
across the surface, but the horizontal components of the field are relevant for
penetration through the surface. The third update to the model is the derivation of
the x-component of the electric field.
Sea ice ridges are modeled as having a rough surface over stratified media. The
total scatter is the sum of the surface and subsurface scatter. The subsurface scatter
is a function of the field transmitted through the surface, the scatter from the layers
and the transmission up through the underside of the rough surface. The subsurface
scatter is found by considering all the scattering events in terms of scattering
coefficients.
The field transmitted down through the rough surface is found using a novel
application of the boundary conditions at the surface. Due to the overlying rough
surface, the scatter from the layers may be simplified to have the same structure as the
Fresnel reflection coefficients for parallel and perpendicular radiation. Determining
the field transmitted up through the underside of the surface may be found in a
similar way as the first transmitted field, except that the underside of the surface has
an inverted shape requiring that the rough surface scattering equations be rederived.
To this point in the research sea ice ridges have been described in a general manner
as having a rough surface over stratified media. To justify this approach and provide
sufficient details for comparing scattering behaviour, a model describing the structure
and internal characteristics of sea ice ridges is developed. The objective is not to fully
describe sea ice ridges, but to include the factors that contribute to scattering in the
frequency range from 100−500 MHz. Both first year and multi-year ridges have three
layers consisting of the top of sail, remainder of sail and consolidated layer.
Due to the lossy nature of sea ice, the salinity in the top layer of the ice dominates
the scattering behaviour, but changes in the density, porosity and temperature of
the ice also impact the scattered field. Since the ridge surface is assumed to have a
sinusoidal profile with a long correlation length with respect to the radar wavelength,
the surface and subsurface scatter may be separated spatially. However, simulations
based on the characteristics of first year and multi-year ridges indicate that the total scatter is greater for multi-year ridges due to the subsurface contribution. This
suggests that it should be possible to discriminate between first year and multi-year
ridges for realistic surface geometries.


identifier: Kianian, Morteza <https://research.library.mun.ca/view/creator_az/Kianian=3AMorteza=3A=3A.html>   (2020) Pipeline-backfill-trench interaction during large lateral displacements.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Subsea pipelines, particularly in shallow areas, are usually buried inside trenches backfilled with pre-excavated material as cost-effective protection against the environmental, constructional, and operational loads. The design of buried pipelines against potential lateral displacements is a challenging task that is usually simplified by assuming a uniform soil surrounding the pipeline. However, the remolded backfill and its lower stiffness compared with the native ground can significantly affect the failure mechanisms around the moving pipe and the mobilized lateral soil resistance. Having a trench backfilled with a material softer than the native seabed soil will lead to a complicated pipe-soil interaction problem which has not been entirely explored in the literature. In this study, the lateral pipeline-backfill-trench interaction and the resultant soil failure mechanisms were investigated by centrifuge models (in partially drained conditions) and also numerical simulations (in undrained conditions). Particle image velocimetry (PIV) analysis was conducted to capture the interactive soil displacements and failure mechanisms during centrifuge tests. It was observed that the interactive effects of pipeline, backfill, and trench precede their individual shear strengths.
The advanced numerical simulations were developed by using the Coupled Eulerian-Lagrangian (CEL) approach with two different Eulerian materials behaving in undrained conditions. The numerical simulations in undrained conditions show a good agreement with the previously conducted centrifuge tests in terms of lateral load-displacement response and failure mechanisms. The investigated parameters are pipe roughness, pipe weight, pipe initial embedment into the trench-bed, backfill strength properties, soil strain-softening, native soil tension cut-off, and burial depth. The effects of influential parameters are comprehensively examined using the developed numerical model, and the results show good agreement with some previously conducted centrifuge tests.
The study revealed the significance of the pipeline-trenchbed interaction in the mobilization of the lateral soil resistance and several other mechanisms not yet addressed in the literature. As a result, several new research avenues were identified, and the ground was prepared for proposing solutions to improve the prediction of the lateral response of buried pipelines in the near future.


identifier: Dong, Xiaoyu <https://research.library.mun.ca/view/creator_az/Dong=3AXiaoyu=3A=3A.html>   (2020) Numerical modelling of pipeline and riser seabed interaction.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Subsea risers and pipelines are widely used in offshore industries especially for the production of oil and gas resources. Due to complex subsea environment, a variety of risks are challenging the operation or serviceability life of subsea pipelines and risers. Subsea riser and pipeline-seabed interaction are proven to have significant effect on its performance. This interaction can be modeled by two main approaches, beam-spring, and continuum approach. Beam-spring model provided the most efficient and economical way to estimate the response of soil. While with more explorations in fields, more sophisticated and accurate models are required and thus continuum models are developed to give more details on the soil behavior around the pipe.
Two challenging topics in pipeline and riser seabed interaction were selected,
1- the effect of riser-seabed interaction on fatigue life in touchdown zone,
2- the effect of trenching/backfilling on lateral response of buried pipelines.
The first one was modelled by beam-spring approach and the second one investigated by continuum approach. The abstracts of the conducted research works are independently discussed below:
A.1. Part I Pipeline-Seabed Interaction
Subsea pipelines are often protected by burying in the subsea trenches to mitigate the effects of the functional and environmental loads. Depending on the trenching methodology (pre-lay or post-lay trenching), trenching and laying the pipeline may take place at the same time or in a different period of time. Using the excavated material for backfilling of the pipeline is a common practice and a cost-effective solution. Depending on trenching methodology, construction strategy, and environmental loads, the backfilling material may experience different degrees of remolding resulting in a softer material with a range of shear strengths. The difference between the stiffness of the backfill and native material affects the soil failure mechanisms under the lateral pipeline displacement. The relative displacement between the pipeline and the surrounding soil that may occur due to the ground movements, faults, slope instabilities, ice gouging, etc. exerts forces on the pipeline. The amplitude of these forces on the pipeline depends on several parameters, including the submerged weight of the mobilized backfilling and native soil, the horizontal component of shearing resistance offered by interacted soil, and the suction behind the pipe. And the load-displacement curve becomes important in terms of the design of the embedded pipelines. Under different circumstances, trenched pipelines might be displaced at different velocities (could be from millimeters per year to very high), resulting in different drainage conditions (including undrained condition, partially drained condition, and drained condition). Partially drainage condition in pipe-soil interaction has been a very challenging topic since it requires a coupled analysis with the pore fluid pressure to explore the induced excess pore pressure which affects the responses of the pipe, internal soil deformation, and also the failure mechanism in the soil. However, most of the published works only explored the undrained condition of soil.
These parameters in turn depend on several parameters such as the properties of the backfill and the native soil, trench geometry, burial depth and confining pressure, pipeline roughness, pipeline size, loading rate (drained/undrained), soil stress history, the backfill extent of consolidation, and the over-consolidation ratio (OCR) of native soil . In this thesis, a coupled large deformation finite element (LDFE) model using re-meshing and interpolation technique with small strain (RITSS) was developed to give prediction of the pipeline force-displacement response together with the computation of the induced excess pore pressure within large deformations. This coupled LDFE model was proven to have advantages in modelling pipe-soil interaction under drained and partially drained conditions using the ABAQUS built-in coupled pore fluid pressure method, which cannot work with the popular existing LDFE method such as Coupled Eulerian Lagrangian (CEL) method. And the LDFE model was proved to be a strong tool for comprehensive investigation of the progressive failure mechanisms around the pipeline considering the varying pipeline-backfill-trench interaction effects.
A.2. Part II Riser-Seabed Interaction
Steel catenary risers (SCR) are popular amongst the riser families because of their lower cost and technical advantages such as applicability in a wider range of sizes and water depths. The survey results obtained by remote operating vehicles (ROV) have proved the complex non-linear seabed response to riser fluctuations in the touchdown zone (TDZ), where SCR penetrates into the seabed and cyclically creates trenches often with several diameters deep. The oscillatory motions of SCR in the touchdown zone result in a complex riser interaction mechanism with surrounding media including fluid and soil. Some of the influential parameters contributing to these non-linear hysteretic interactions are: soil stiffness degradation under cyclic loads and riser penetration into the seabed, mobilization of suction force within uplift motions of riser, trench base softening and damping, erosive mechanism by water velocity field around the SCR in TDZ and consequent variation of flow pattern of displaced water, the riser dynamics influenced by internal multi-phase flow regimes and also vessel motions (velocity and frequencies), and vortex-induced vibration (VIV).
The existing non-linear hysteretic riser-seabed interaction models have been verified in wave-induced fatigue assessment. However, the effect of non-linear seabed interaction on the riser fatigue under riser vibrations has never been examined. In this work, the performance of the non-linear hysteretic models was investigated in slug-induced fatigue damages in touchdown zone which is a key contributor to fatigue damage. For this purpose, first the nodal and global performance of the most popular models was comprehensively examined, and its pros and cons were thus explored. Then an advanced and novel model was developed to simulate the riser slugging and slug-induced fatigue, which has never been done in the past due to extreme complexity. This model was incorporated into slug-induced fatigue analysis and it was indicated that the model was applicable to these type of analysis with acceptable level of accuracies. The research work showed that the slug-induced vibrations can combine with the wave-induced oscillations and create critical case scenarios. Therefore, it is critical to consider the combined effects of slugging and wave in riser fatigue analysis and fill the knowledge gap.


identifier: Li, Fuxiang <https://research.library.mun.ca/view/creator_az/Li=3AFuxiang=3A=3A.html>   (2020) Global dynamics of periodic infectious disease models with time-dependent delays.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Many infectious diseases have seasonal trends and exhibit variable periods of peak
seasonality. Understanding the population dynamics due to seasonal changes becomes
very important for predicting and controlling disease transmission risks. For some
directly transmitted and vector-borne diseases, the length of the incubation period
strongly depends on the temperature.
This thesis is devoted to the study of the global dynamics of some periodic epidemic
models with periodic incubation periods. We start with a classical SEIRS epidemic
model with a time-dependent latent period in Chapter 2. Moreover, vector-borne diseases,
such as West Nile virus, bluetongue, and malaria, are always highly dependent
on seasonal change, especially the temperature. To investigate the seasonal effects and
temperature-dependent delays on West Nile virus, we present a periodic functional
differential equations model with the vertical transmission, the periodic maturation
delay, and the periodic extrinsic incubation period in Chapter 3. In Chapter 4, we
propose a bluetongue model with seasonality and temperature-dependent incubation
period, which describes the dynamics of bluetongue transmission via cattle and sheep
as hosts and midges as vectors. To explore the effects of the spatial and temporal
heterogeneity in hosts and vectors, and only vector movements on the spread of bluetongue,
we develop a nonlocal periodic reaction-diffusion model of bluetongue disease
with periodic time delays in Chapter 5.
Based on the theory of the basic reproduction ratio, we derive and numerically
compute the basic reproduction ratio for our models. By the theory of dynamical
systems, we show that the basic reproduction ratio acts as a threshold parameter for
the global dynamics for each model. Numerical simulations or case studies are carried
out to illustrate the analytic results and help us provide some new findings. At the
end of this thesis, we present a brief summary and some interesting future works.


identifier: DeVries, Megan <https://research.library.mun.ca/view/creator_az/DeVries=3AMegan=3A=3A.html>   (2020) Indemnification and the building of Canadian pipelines.  Masters thesis, Memorial University of Newfoundland.

abstract:
The Canadian Federal Government’s purchase of the Trans Mountain pipeline in 2018 was seen
by many as a singular action to support the pipeline industry. However, this research will
contend that this is not the case because this thesis will show that the federal government has
indemnified the oil and gas pipeline industry in Canada over the past 60 years. This will be
shown by focusing on three large-scale positive examples of Federal Government
indemnification, they are the modern Trans Mountain pipeline expansion, the 1970’s building of
Line 9 and the initial construction of the TransCanada pipeline project in the 1950’s. All of these
cases relied on direct government fiscal and political support to indemnify the projects so that
they could obtain financing and eventually be constructed. By using process tracing this thesis
shows how the Canadian federal government has in essence been indemnifying all large-scale
pipeline projects throughout a large part of Canada’s history. Explanations for why this
support has existed are then explored through a lens of industry structure, and the thesis posits
that the pipeline industry’s structure (using the metric of industry size, firm size, profit rate,
market concentration and geographical dispersion) is one explanatory factor as to why this policy
of indemnification has existed in Canada for such a long period of time.


identifier: Tebianian, Hamed <https://research.library.mun.ca/view/creator_az/Tebianian=3AHamed=3A=3A.html>   (2020) Development of multi-MHz Class-D soft-switching inverters.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Wireless Power Transmission (WPT) systems are becoming rapidly mature and accessible to customers, and it is expected that they are going to take a large share of the electrical equipment market around the world in the near future. Many tech companies and university research labs have recently focused on design, development, and optimization of different blocks of these systems. WPT systems can be designed to transfer power either through electric fields or magnetic fields. Operating at the multi-MHz frequency will bring about the smaller size of the wireless link for both types of WPT systems.
The advent of Wide Bandgap (WBG) devices like Gallium Nitride (GaN) FETs and Silicon Carbide (SiC) MOSFETs has paved the road to design multi-MHz inverters and use them as the Radio Frequency (RF) power source in the transmitter of WPT systems. Designing an efficient inverter which can maintain its soft-switching performance while facing variable load or delivering variable output power is one of the major design challenges in this field. The second challenge in this area is related to the difficulties of Electromagnetic Compatibility (EMC) of the inverter, which is the direct result of operating at MHz switching frequency range. The Electromagnetic Interference (EMI) level can be reduced by designing a stronger filter or trying to remove the harmonics from the switching source.
In this thesis, to tackle the first challenge mentioned above regarding soft switching, the Dynamic Dead-Time Control (DDTC) approach is proposed and utilized to sustain the soft-switching of a multi-MHz Full-Bridge (FB) Class-D inverter over the full range of active load and output power. Simulation results are presented to show that dynamically controlling the Dead-Time (DT) during input DC voltage control and load variations, reduces switch-node voltage overshoot, prevents large current spikes in the switching devices, and reduces associated high switching loss. Finally, experimental results obtained from the prototype of the system are provided to validate the effectiveness of the proposed approach.
Then, a soft-switching multi-MHz multi-level Class-D inverter is developed to address the second challenge of EMI issues associated with MHz switching frequency operation.The inverter is designed to eliminate the 3rd and 5th harmonics from its output voltage waveform. This will, in turn, make it possible to meet EMC and achieve the same level of harmonic attenuation on the output of the inverter with a smaller size and more efficient output EMI filter as opposed to utilizing a bulky, high-order, High-Quality (HQ) filter. The impact of DT on the modulation parameters of the multi-level inverter is investigated through mathematical analysis, and the results are utilized during the system simulations and practical implementation. A prototype is built to validate the theoretical and simulation analysis on a practical testbed. The harmonic analysis comparison carried out between the experimental results obtained from the multi-level inverter and FB Class-D inverter prototypes shows how the multi-level inverter is capable of suppressing unwanted 3rd and 5th harmonic to a much lower level which in turn leads to smaller size and more efficient output filter.


identifier: Asgari, Mojtaba <https://research.library.mun.ca/view/creator_az/Asgari=3AMojtaba=3A=3A.html>   (2020) Attribute lattice: a graph-based conceptual modeling grammar for heterogeneous data.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
One key characteristic of big data is variety. With massive and growing amounts of data
existing in independent and heterogeneous (structured and unstructured) sources, assigning consistent
and interoperable data semantics, which is essential for meaningful use of data, is an increasingly
important challenge. I argue, conceptual models, in contrast to their traditional roles in
the Information System development, can be used to represent data semantics as perceived by the
user of data. In this thesis, I use principles from philosophical ontology, human cognition (i.e.,
classification theory), and graph theory to offer a theory-based conceptual modeling grammar for
this purpose. This grammar reflects data from users of data perspective and independent from data
source schema. I formally define the concept of attribute lattice as a graph-based, schema-free
conceptual modeling grammar that represents attributes of instances in the domain of interest and
precedence relations among them. Each node in an attribute lattice represents an attribute - a true
statement (predicate) about some instances in the domain. Each directed arc represents a precedence
relation indicating that possessing one attribute implies possessing another attribute.
In this thesis, based on the premise that inherent classification is a barrier that hinders semantic
interoperation of heterogeneous data sources, a human cognition based conceptual modeling
grammar is introduced as an effective way to resolve semantic heterogeneity. This grammar
represents the precedence relationship among attributes as perceived by human user and provides
a mechanism to infer classes based on the pattern of precedences. Hence, a key contribution of
attribute lattice is semantic relativism – that is, the classification in this grammar relies on the pattern of precedence relationship among attributes rather than fixed classes. This modeling grammar
uses the immediate and semantic neighbourhoods of an attribute to designate an attribute as
either a category, a class or a property and to specify the expansion of an attribute – attributes
which are semantically equal to the given attribute. The introduced conceptual modeling grammar
is implemented as an artifact to store and manage attribute lattices, to graphically represent them,
and integrate lattices from various heterogeneous sources.
With the ever-increasing amount of unstructured data (mostly text data) from various data
sources such as social media, integrating text data with other data sources has gained considerable
attention. This massive amount of data, however, makes finding the data relevant to a topic of
interest a new challenge. I argue that the attribute lattice provides a robust semantic foundation to
address this information retrieval challenge from unstructured data sources. Hence, a topic modeling
approach based on the attribute lattice is proposed for Twitter. This topic model conceptualizes
topic structure of tweets related to the domain of interest and enhances information retrieval
by improving the semantic interpretability of hashtags.


identifier: Dinh, Nhat Minh <https://research.library.mun.ca/view/creator_az/Dinh=3ANhat_Minh=3A=3A.html>   (2020) Early kick detection using data-driven Bayesian network: model development and experimental testing.  Masters thesis, Memorial University of Newfoundland.

abstract: Safety is one of the keys to success for offshore oil and gas development projects. Drilling operation becomes more and more complicated when moving to deeper water and harsher conditions, which requires a higher level of safety. Kick is an event that happens when the hydrostatic pressure of drilling mud is lesser than the formation pressure which let the formation fluid enter the wellbore. Detection of a kick event as soon as it happens will spare drillers more time to make decision and take necessary actions. An uncontrolled or unaware kick event may lead to a well blowout which causes major damage to infrastructure, could kill people and costs lots of money. The conventional method of kick detection entails monitoring surface parameters such as stand-pipe pressure, mud pit volume, changing in flow rate and other drilling parameters can lead to the delay in detection. Some recent studies have successfully proved the ability to employ downhole parameters to realize kick. The new methods show the robust results in detection and the improvement in detection time. Besides, data-driven Bayesian network (BN) has shown to solve the problem in historical data, which is usually available, unlike expensive, and insufficient, expert knowledge. This work presents the application of data-driven BN using downhole parameters to early kick detection. The work includes three main parts: 1) creating and testing a data-based Bayesian network based on historical experiment data and synthetic data; 2) designing drilling sample, setting up and conducting experiments with the new large drilling simulator (LDS); 3) validating the data-based Bayesian network with the data from the LDS experiment. Upon the success of this work, the developed BN model will serve an efficient and effective way to detect kick early, which will enable appropriate corrective actions. The new setup of experiment with LDS can be used to conduct further experimentation to simulate more complicated kick scenarios during drilling operation.


identifier: Degray, Amanda <https://research.library.mun.ca/view/creator_az/Degray=3AAmanda=3A=3A.html>   (2020) Indigenous risk perceptions and land-use in Yellowknife, NT.  Masters thesis, Memorial University of Newfoundland.

abstract: For over 50 years, industrial gold mining in Wı̨ìlı̨ìcheh polluted and poisoned Dene bodies and lands with seemingly no care or concern for the First Nation’s subsistence lifestyles, spiritual, or cultural practices. This thesis captures the voices, experiences, and memories of the Yellowknives Dene related to the legacy effects of industrial mining on their traditional territory. By intersecting the literatures of environmental justice, settler colonialism, and risk perception, this thesis creates a spatial narrative of environmental injustice based on the unique histories and experiences of Dene land-users living and engaging in one of Canada’s most contaminant landscapes. By drawing on Indigenous land-use studies specifically, this thesis documents Dene lived experiences, perceptions of, and responses to locally sourced industrial pollution, and addresses Dene concerns and land-use practices beyond the borders of the Giant Mine Remediation Site (GMRP) site.


identifier: Hotton, Véronique <https://research.library.mun.ca/view/creator_az/Hotton=3AV=E9ronique=3A=3A.html>   (2020) Vernaculaire Franco-Ontarien et défis de traduction: une étude de Fucking Carl, de Caroline Yergeau et Louis-Philipe Roy.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis presents a translation into Cap Breton English of Caroline Yergeau and Louis-Philipe Roy’s play Fucking Carl. This unpublished one-act play was originally written in the Ontarian variety of French. The first chapter of this thesis is a theatrical and literary analysis of the play, with particular attention to the flow of the dramatic action and the role of the characters’ vernacular French in the plot. Theories of sociolinguistics are used to deepen this analysis. The second chapter covers loose (or free) translation, and the importance of the translator’s agency. In the third chapter, difficulties that arose in the translation process are analyzed in detail alongside their solutions.


identifier: Moran, E. Joe <https://research.library.mun.ca/view/creator_az/Moran=3AE=2E_Joe=3A=3A.html>   (2020) The spread and persistance of Rabies in the Arctic: a modeling study.  Masters thesis, Memorial University of Newfoundland.


identifier: Knutson, Sonja <https://research.library.mun.ca/view/creator_az/Knutson=3ASonja=3A=3A.html>   (2019) International education leadership experiences in Canadian universities: policy and practice.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Over the past decade, Canadian universities have experienced significant growth in the numbers of international students and the revenue they represent, a result of both federal policy and the revenue needs of universities. As revenue generation has become an essential element in balancing budgets with international student income as the most significant and stable revenue opportunity, the position of the Senior International Officer (SIO), has inevitably gained prominence. Little empirical research is available on the SIO position, a senior administrative position that exists in most universities in Canada and is accountable for all international activity in Canadian universities. SIOs are expected to add economic value to their institutions and by extension their region or country, as well as to contribute to transformative humanistic goals, such as the development of globally aware graduates (Yemini, 2015). The inherent tension in attracting international students for economic reasons together with the transformative discourse of internationalization is a challenge of SIOs working in Canadian universities.
This dissertation explores the impact of the Canadian federal policy context and the expectations of universities with respect to the SIO role on the experiences of those in the role. The focus of the study is on the tensions of the SIO role in balancing expectations to achieve both economic and transformational outcomes, and will employ a qualitative, critical approach. The study itself is divided into three phases: a chronological analysis of federal international education policy in Canada from its beginnings until the present day; a critical discourse analysis of the executive search position briefs through which Canadian universities attract SIOs to the leadership role; and a critical examination of interviews with the incumbents recruited into the university SIO role. The purpose of the research is to understand the experiences of these leaders in carrying out their mandates for campus internationalization. The findings show that SIOs are concerned with the growing focus at this time on internationalization for economic outcomes at both the federal and institutional levels. While SIOs continue to support these economic outcomes, the research shows they find covert ways to implement a more comprehensive internationalization to achieve academic and socio-cultural outcomes. This dissertation demonstrates that SIOs in Canada are committed to a comprehensive approach to internationalization, despite the overwhelming focus on economic outcomes in the discourse of federal policy and institutional expectations and aims for international education.


identifier: Ferdous, Md. Saimoom <https://research.library.mun.ca/view/creator_az/Ferdous=3AMd=2E_Saimoom=3A=3A.html>   (2020) Electromagnetic backscatter modelling of icebergs at c-band in an ocean environment.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
This thesis outlines the development of an electromagnetic (EM) backscatter model of icebergs. It is a necessary first step for the generation of in-house synthetic aperture radar (SAR) data of icebergs to support optimum iceberg/ship classifier design. The EM modelling was developed in three stages. At first, an EM backscatter model was developed to generate simulated SAR data chips of iceberg targets at small incidence angles. The model parameters were set to mimic a dual polarized dataset collected at C-Band with the Sentinel-1A satellite. The simulated SAR data chips were compared with signatures and radiometric properties of the satellite data, including total radar cross section (TRCS). A second EM model was developed to mimic the parameters of a second SAR data collection with RADARSAT-2; this second data collection was at larger incidence angles and was fully polarimetric (four channels and interchannel phase). The full polarimetric SAR data allowed for a comparison of modelled TRCS and polarimetric decompositions. Finally, the EM backscatter models were tested in the context of iceberg/ship classification by comparing the performance of various computer vision classifiers using both simulated and real SAR image data of iceberg and vessel targets. This step is critical to check the compatibility of simulated data with the real data, and the ability to mix real and simulated SAR imagery for the generation of skilled classifiers.
An EM backscatter modelling tool called GRECOSAR was used for the modelling work. GRECOSAR includes the ability to generate small scenes of the ocean using Pierson-Moskowitz spectral parameters. It also allows the placement of a 3D target shape into that ocean scene. Therefore, GRECOSAR is very useful for simulating SAR targets, however it can only model single layer scattering from the targets. This was found to be limiting in that EM scattering throughout volume of the iceberg could not be generated. This resulted in EM models that included only surface scattering of the iceberg. In order to generate realistic SAR scenes of icebergs on the ocean, 3D models of icebergs were captured in a series of field programs off the coast of Newfoundland and Labrador, Canada. The 3D models of the icebergs were obtained using a light detection and ranging (LiDAR) and multi-beam sonar data from a specially equipped vessel by a team of C-CORE. While profiling the iceberg targets, SAR images from satellites were captured for comparison with the simulated SAR images.
The analysis of the real and simulated SAR imagery included comparisons of TRCS, SAR signature morphology and polarimetric decompositions of the targets. In general, these comparisons showed a good consistency between the simulated and real SAR scene. Simulations were also performed with varying target orientation and sea conditions (i.e., wind speed and direction). A wide variability of the TRCS and SAR signature morphology was observed with varying scene parameters.
Icebergs were modelled using a high dielectric constant to mimic melting iceberg surfaces as seen during field work. Given that GRECOSAR could only generate surface backscatter, a mathematical model was developed to quantify the effect of melt water on the amount of surface and volume backscatter that might be expected from the icebergs. It was found that the icebergs in a high state of melt should produce predominantly surface scatter, thus validating the use of GRECOSAR for icebergs in this condition.
Once the simulated SAR targets were validated against the real SAR data collections, a large dataset of simulated SAR chips of ships and icebergs were created specifically for the purpose of target classification. SAR chips were generated at varying imaging parameters and target sizes and passed on to an iceberg/ship classifier. Real and simulated SAR chips were combined in varying quantities (or targets) resulting in a series of different classifiers of varying skill. A good agreement between the classifier’s performance was found. This indicates the compatibility of the simulated SAR imagery with this application and provides an indication that the simulated data set captures all the necessary physical properties of icebergs for ship and iceberg classification.


identifier: Smith, Tim A. <https://research.library.mun.ca/view/creator_az/Smith=3ATim_A=2E=3A=3A.html>   (2020) Measuring marine currents using underwater acoustics.  Masters thesis, Memorial University of Newfoundland.

abstract:
The speed of sound in water rises and falls with temperature, current speed, salinity, and pressure. Precisely measured underwater acoustic travel times can be used to calculate these parameters for a body of water. If the salinity and pressure along the acoustic path is known, a system of two underwater hydrophones transmitting bi-directionally can indirectly measure both temperature and water velocity. Summing the bi-directional travel times isolates the temperature component, while subtracting the travel times isolates the component of current speed.
There has been much work in using this method for current point detectors as well as networks covering very large distances (> 100km). The feasibility of using acoustic travel times for measurements in the 100m - 3km range has been less explored. Accurate measurements at this range may be valuable in iceberg tracking for the offshore oil and gas industry, as well as in building high resolution maps for environmental studies. This range presents some new challenges, as a distributed network must remain highly synchronized to obtain sufficiently accurate travel times. Multipath travel is also highly problematic in this range.
A system has been developed and used to measure tidal currents in the North Atlantic Ocean. The design was built from the ground up. The hardware, software, and data processing are built to work with non-specialized low-cost equipment in a variety of harsh marine deployment conditions. Field testing showed that the system was capable of measuring currents to within ±4cm/s across a 130m range. Quantitative error analysis is included which shows that much higher accuracies could be achieved at the 1km range.


identifier: Leggo, Angelina <https://research.library.mun.ca/view/creator_az/Leggo=3AAngelina=3A=3A.html>   (2020) Local Irishness: storytelling, heritage, and place attachment in Douglastown, Québec.  Masters thesis, Memorial University of Newfoundland.

abstract: The community of Douglastown, on the Gaspé Peninsula in eastern Québec, has experienced profound change in recent years. An increase in migration to the area has relegated the once majority Anglophone population to a minority in the region. In response, community members use a history of Irish immigration to the area to differentiate themselves from other places in the Gaspésie and across the province. They likewise use this legacy to strengthen and express place attachment, celebrate their heritage and history, emphasize their language, and continue the traditions of the Catholic Church, both within and outside of their community. Through interviews, participant observation, mapping, and local research, I show how stories in Douglastown revolve around these multiple expressions if Irishness and how this has created a framework for defining belonging in the past that still resonates within the community today.


identifier: Awoonor-Williams, Ernest <https://research.library.mun.ca/view/creator_az/Awoonor-Williams=3AErnest=3A=3A.html>   (2020) Modelling covalent modification of cysteine residues in proteins.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Cysteine is a unique amino acid because of the chemical reactivity of its thiol (–SH)
side chain. For that reason, cysteine serves several essential roles in biochemistry, and
its reactivity is critical for the catalytic activity of several biological enzymes. This significance
of cysteine residues has been exploited in designing covalent-modifier drugs,
particularly kinase inhibitors, which have proven to be successful cancer chemotherapeutic
agents in recent years. The reactivity of cysteine thiol group is complex,
but a measure of its acidity or pKₐ is a strong determinant of its reactivity towards
druggable targets—and can help guide the selection of appropriate druggable targets
for covalent modification. Relatively few experimental pKₐ’s of cysteine residues in
proteins have been reported, and methods for the computation of cysteine pKₐ’s have
received little attention.
This thesis presents studies undertaken to investigate the reactivity and covalent
modification of cysteine residues in proteins. The introductory chapter lays the
groundwork that becomes the basis for subsequent chapters in the thesis. This chapter
provides a general introduction to covalent modification and the techniques used to investigate
the biophysical properties of residue-specific nucleophilic targets for covalent
modification. The first two chapters following the introduction are focused on predictive
pKa assessments and validation studies on different computational methods in
accurately calculating experimental cysteine pKₐ’s. In the latter chapters, advanced
computational and multiscale methods are adopted to investigate the reactivity of
druggable cysteines in protein kinases commonly implicated in diverse clinical indications,
as well as model all the steps in the covalent modification mechanism of a
kinase target. The thesis concludes by providing a concise summary of the research
findings and future directions stemming from the work.
The fundamental studies presented herein expand our current knowledge of modelling
the covalent inhibition of druggable cysteines in enzyme targets and could go a
long way to inform drug design and discovery.


identifier: Bøe, Kristin <https://research.library.mun.ca/view/creator_az/B=F8e=3AKristin=3A=3A.html>   (2019) An integrated approach to studying the relationship between anadromy and iteroparity in Atlantic salmon (Salmo salar).  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Atlantic salmon is an anadromous species capable of spawning more than once during its lifecycle, being iteroparous. Increasing conservation concern has led to increased attention being paid to the potential short-term mitigating effects that iteroparous individuals may serve to populations suffering from low juvenile to adult recruitment. Despite the current research focus on repeat spawning Atlantic salmon, little is still known about how the iteroparous life cycle affects intrapopulation variation in marine movements and potential implications for population dynamics. The current thesis applied an integrated approach to studying the relationship between anadromy and iteroparity in Atlantic salmon from Newfoundland (Canada). Acoustic telemetry, scale pattern, stable isotope, fatty acid and mark-recapture analyses were included as analytical methods to investigate aspects of the relationship between iteroparity and anadromy and its importance in shaping the marine migratory patterns of Atlantic salmon. Using acoustic telemetry applied to 78 kelts and 90 smolts from two populations, I found that life stage influenced migratory movements and behaviour during the nearshore marine phase. Specifically, migratory movements were characterized by faster, more directed and less nocturnal movements by kelts as compared to smolts. These contrasts, however, varied by population, and the source of this variation was suggested to include responses to temporal and physical contrasts in the biotic and abiotic environment that shape the constraints imposed by trade-offs such as those between the need to reduce predation risk and increase growth and mass-gain. Using fatty acid (FA) and stable isotope analyses applied to 72 returning adults, I also found that life stage, as well as spawning history, influence migratory movements and dietary patterns during the at-sea phase. Specifically, significant differences in FA composition and ratios of δ¹⁵N in dorsal muscle tissue were identified, which supported the hypothesized divergent use of dietary sources among the different spawning history groups. Significant differences in FA composition, as well as lipid density, were also found among the different spawning histories in 69 post-spawned Atlantic salmon sampled as they emigrated from the river. Furthermore, patterns in lipid density were consistent with patterns in kelt return rates to consecutive repeat spawning. Consecutively spawned kelts and females had significantly higher lipid density than first-time spawned kelts and males, and consecutively spawned kelts and females experienced higher return rates compared to first-time spawned kelts and males. It was suggested that these spawning history related contrasts in energetic and nutritional state in post-spawned Atlantic salmon may be a carry-over effect of contrasts in the non-breeding area as affected by spawning-history dependent migration strategies, or alternatively, may represent an adaptive response to increased survival and recovery potential with age.


identifier: Ankindinova, Olga <https://research.library.mun.ca/view/creator_az/Ankindinova=3AOlga=3A=3A.html>   (2020) High-resolution seismic and core-based stratigraphy of the Southwestern Black Sea shelf during the Holocene.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The paleo-environmental evolution of the Black Sea during the last 12,000 years is studied using high-resolution seismic-stratigraphic and geochemical results for two long composite cores from the southwestern shelf, constrained by 56 radiocarbon dates on mollusc shells. A grid of Huntec deep-tow seismic-reflection profiles (~9150 line-km), complemented by 72 gravity cores and 25 piston cores reveals a prominent shelf-crossing transgressive unconformity α which is overlain in most areas by, in succession, allounit 1b (~12.5–7.4 cal ka BP) between α and the α1 submarine unconformity/correlative conformity, allounit 1c (~7.4–5.3 cal ka BP) between the α1 and α2 submarine unconformities/correlative conformities, and allounit 1d (deposited since ~5.3 cal ka BP).
The ⁸⁷Sr/⁸⁶Sr isotopic signature in molluscs shows four stages of increase corresponding to salination associated with the reconnection of the Black Sea to the global ocean: 12,145–9580 cal yr BP (stage A; stable, brackish lacustrine conditions); 9580–9490 cal yr BP (stage B: freshish waters); 9465–9380 cal yr BP (stage C; sharp ⁸⁷Sr/⁸⁶Sr increase to a plateau spanning 350–400 years); ~8985 cal yr BP to the present day (stage D; step-wise salination). The existence of the first plateau provides strong evidence against catastrophic flooding of a lowstand Black Sea as proposed by other workers. δ¹⁸O and δ¹³C values in ostracod species Palmoconcha agilis and Loxoconcha lepida define three isotopic substages corresponding to a transition from the Neoeuxine Lake to modern conditions. These are mirrored in trace-element/Ca data, which reveal a Neoeuxine Lake stage (12.1–9.4 cal ka BP), the transition from lacustrine to marine conditions (9.4–6.3 cal ka BP) and the establishment of marine conditions (6.3–0 cal ka BP). At ~6.3 cal ka BP, isotopic data and trace-element/Ca ratios exhibit a major shift contemporaneous with a sharp increase in water temperature from 12–14°C to 17–19°C. This shift coincides with the weakening of Black Sea outflow and the proliferation of marine organisms.
This study proves that the level of the Neoeuxine Lake must have been significantly higher than −70 m at the time of the reconnection at 9.4 cal ka BP with the gradual step-like transition to present-day conditions.


identifier: Zaki, Rowyda Adel Abdelrahman <https://research.library.mun.ca/view/creator_az/Zaki=3ARowyda_Adel_Abdelrahman=3A=3A.html>   (2020) Abrasion and impact resistance of concrete under Arctic conditions.  Masters thesis, Memorial University of Newfoundland.

abstract: This research program aims to investigate the mechanical properties, impact resistance, and abrasion resistance of steel fibers reinforced concrete under cold temperatures. The abrasion and impact resistance of steel fiber reinforced concrete were also evaluated before and after exposure to salt scaling. The studied parameters are the type of concrete (self-consolidated concrete and vibrated concrete), type of steel fibers (SFs) (coated and uncoated), SFs end conditions (needle, single-hooked ends and double-hooked ends), length of SFs (35 mm and 60 mm), volumes of SFs (0%, 0.35%, and 1%), saturation condition, coarse aggregate size (10 mm and 20 mm), coarse to fine aggregate ratio (0.7 and 2), and cement content (300 kg/m³ and 550 kg/m³). The mechanical properties of concrete were evaluated by conducting compressive strength, splitting tensile strength (STS) and flexural strength (FS) tests. The impact resistance was assessed by conducting two tests; drop weight test and flexural impact test. Meanwhile, the abrasion resistance of concrete was evaluated by performing rotating cutter test and sand blasting test. The results showed that salt scaled concrete specimens exhibited a considerable reduction in the impact and abrasion resistance compared to non-scaled concrete specimens. However, adding SFs (especially coated SFs) alleviated this reduction and contributed to improve the abrasion and impact resistance of salt scaled concrete surface. The results also revealed that decreasing the temperature below the room temperature (25ᴼC) contributed to enhancing the compressive strength, STS, FS, abrasion resistance, and impact resistance of concrete mixtures. In the meantime, the effect of cold temperatures in enhancing the mechanical properties and abrasion resistance was more pronounced in the saturated samples compared to unsaturated samples. The results also showed that despite the negative effect of cold temperature in increasing the brittleness of concrete, using SFs helped to alleviate the low temperature brittleness of concrete and improved its mechanical properties and impact resistance.


identifier: Khan, Bushra <https://research.library.mun.ca/view/creator_az/Khan=3ABushra=3A=3A.html>   (2020) Operational risk assessment for shipping in Arctic waters.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Arctic navigation has many complexities due to its particular features such as ice, severe weather conditions, remoteness, low temperatures, lack of crew experience, and extended period of darkness or daylight. For these reasons, vessels, such as oil tankers, dry cargo ships, offshore supply vessels, research vessels, and passenger ships operating in the Arctic waters may pose a high risk of collision with ice and other ships causing human casualties, environmental pollution and the loss of assets. This thesis presents a conceptual framework that is focused on collision modelling. In order to understand the process of risk escalation and to attempt a proactive approach in constituting the collision models for Arctic navigation, the present thesis identifies various risk factors that are involved in a collision. Furthermore, the thesis proposes the probabilistic framework tools that are based on the identified risk factors to estimate the risks of collision in the Arctic. The proposed frameworks are used to model the collision based risk scenarios in the region. They are developed with the use of Bayesian Networks, the Nagel-Schreckenberg (NaSch), and Human Factor Analysis and Classification (HFACS) models. In the present thesis, the proposed models are theoretical in nature, but they can be useful in developing a collision monitoring system that provides a real time-estimate of collision probability that could help avoid collisions in the Arctic. Further, the estimated probabilities are also useful in decision making concerning safe independent and convoy operations in the region.
The proposed frameworks simplifies maritime accident modeling by developing a practical understanding of the role of physical environment, navigational and operational related aspects of ships, and human errors, such as individual lapses, management failures, organizational failures, and economic factors in the collision related accidents in the Arctic.
This research also identifies the macroscopic properties of maritime traffic flow and demonstrates how these properties influence collision properties. The thesis also presents an innovative accident model for ice-covered waters that estimates the collision probability and establishes the relationship between the macroscopic properties of the traffic flow with the contributory accidental risk factors in the region.
The main focus of the present thesis is, to better understand, communicate, and incorporate specific risk factors into the maritime risk assessment processes, involve shipping organizations to agree on best practice methodologies and make the data sources easily available, and modify the Arctic risk management processes by implementing effective risk assessment techniques and appropriate risk treatment.


identifier: Pinksen, Jasmine <https://research.library.mun.ca/view/creator_az/Pinksen=3AJasmine=3A=3A.html>   (2020) Effects of clear-cut created ecotones on nocturnal macromoths in western Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract:
Human land use practices, especially clearing of native vegetation, tend to increase edges, creating ecotones. Ecotones are important transition zones for conservation, as they are species rich and promote biological diversity, thus they have become a focus of habitat management. Arthropod groups are known to be significantly more abundant and/or taxonomically diverse at the edges compared to the interior of the adjacent habitats There is, however, a knowledge gap with respect to lepidopteran diversity across anthropogenic ecotones in boreal forests.
To address one of these knowledge gaps, I asked how forestry-created ecotones influence nocturnal macromoth assemblages in the eastern boreal forest. I sampled moths in western Newfoundland, Canada, to determine their responses at the local spatial scale. Sampling took place in four replicate sites, each with light traps placed in a clear-cut, adjacent forest, and the edge between them. Edges supported the highest abundance of nocturnal macromoths, forests supported an intermediate amount, and clear-cuts supported the lowest. The difference between the habitat that supported the highest abundance and the habitat that supported the lowest, i.e.edges and clear-cuts, was significant.While boasting many unique species, edges represented a macro-moth assemblage composition that was intermediate between clear-cuts and forests, and all habitats differed significantly. While composition differed significantly between the three habitats, there was no significant difference in species diversity among the three habitat types. The results of my study suggest that, like natural disturbance created edges, forest-clear-cut edges may serve as unique habitats for macro-moth assemblages in the boreal forest. These results also have important implications for the maintenance of biodiversity in the boreal and forestry in the context of natural disturbance emulation.


identifier: Cheng, Zhaohai <https://research.library.mun.ca/view/creator_az/Cheng=3AZhaohai=3A=3A.html>   (2020) Improving the size selectivity of trawl codends for northern shrimp (Pandalus borealis) and redfish (Sebastes spp.) fisheries in the North Atlantic.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
A bottom trawl is a towed fishing gear that is designed to catch commercially important species that live in close proximity to the seafloor. In the Northwest Atlantic, bottom trawls are widely used to harvest shrimp, redfish, and various groundfish species. Coastal fishing fleets in both Canada and Iceland have been using bottom trawls to harvest northern shrimp (Pandalus borealis) and redfish (Sebastes spp.) for several decades. The codend of these fishing gears plays an important role in reducing unintended bycatch of non-targeted species and sizes of animals. Careful design and engineering of these codends is a necessary step in the fishing gear development cycle.
In this thesis, I conducted different experiments, including laboratory and field work, to improve the size selectivity of codends for northern shrimp and redfish in the North Atlantic. In my first experiment, I compared the performance of different codends on the size selectivity of shrimp in the coastal fishery of Iceland. I compared codends of same nominal mesh size (42 mm) constructed using netting in the traditional orientation (T0, two-panel) against experimental codends constructed using netting rotated 45ᴼ (T45, two-panel) and 90ᴼ (T90, four-panel). My results revealed that the T90 codend retained significantly less shrimp between 9 and 19 mm carapace length than the T0 codend, and between 15 and 19 mm than the T45 codend. Since discarding of undersized shrimp is prohibited in Iceland, using the T90 codend would enable fishers to use their quotas more efficiently. In my second experiment, I compared the performance of two different codends on the size selectivity of redfish in a commercial fishery off the south coast of Iceland. The codends varied in their design, mesh size (inside-knots measurement), and construction (i.e., knotted vs. knotless). My results showed that there was no significant difference in size selectivity between the codends at lengths greater than 29 cm for S. norvegicus and 19 cm for S. viviparous. At smaller lengths, size selectivity was undetermined due to small catches at those sizes. In my third experiment, I compared the performance of four different codends on the size selectivity of redfish in eastern Canada (Unit 1, Gulf of St. Lawrence). I evaluated a traditional diamond mesh codend with a nominal mesh size of 90 mm and three experimental T90 codends of different nominal mesh sizes (90, 100, 110 mm). My results demonstrated that the traditional codend was not size selective, catching greater than 97% of redfish over all of the length classes observed. Overall, my results reveal that T90 codends improve size selectivity in which large proportions of undersized fish are successfully released. In my final experiment, I examined the hydrodynamic performance of full-scale T0 and T90 codends with and without a cover net using the flume tank located at the Fisheries and Marine Institute. I measured flow velocity, mesh shape, mesh opening, and drag at various towing velocities. The results showed that the flow velocity inside each codend was lower than the towing velocity. T90 codends had higher flow velocity and better mesh opening than the T0 near the terminal end of the codend. The total drag of each T90 codend was significantly higher than the T0. With the cover net, the flow velocity in the area between codend and the cover did not change significantly for the T0 codend, but was significantly different for the T90 (90 mm) codend.
In summary, the findings from this thesis confirm the importance of codend design on the size selectivity of bottom trawls. Changes in mesh size and mesh orientation in particular, were shown to significantly affect the size selectivity of northern shrimp (Iceland) and redfish (Iceland and Canada). These results could prove helpful in the pursuit of sustainable fisheries, whereby smaller undesirable or non-targeted animals can be released from codends during towing operations, preventing their unnecessary capture and mortality.


identifier: Sohrabi, Tayebeh <https://research.library.mun.ca/view/creator_az/Sohrabi=3ATayebeh=3A=3A.html>   (2020) A case study of social skills development in bilingual preschool-age children.  Masters thesis, Memorial University of Newfoundland.

abstract: This study presents a case study of preschool-age dual-language learners’ social skills development. The research focuses on several widely recognized dimensions of children’s social development: communication, cooperation, emotional management, and problematic behaviours. The case study utilized several methods for data collection, including non-participant observation and semi-structured interviews. Five dual-language preschool-age children participated in the qualitative data collection, and two early childhood educators participated in the qualitative data collection through interviews and classroom observations. The results indicate that the main reason for dual-language children’s exclusion is their language limitations rather than their appearance or other factors that would contribute to them being considered an outsider. Also, the main barrier in the social skills development of dual-language children seems to be negative feelings such as frustration and hesitation that this group of children experience in relationships with others, which appear to inhibit them from interacting with others. The role of early childhood educators, peers and parents in the social skills development of this group of children is significant.


identifier: Carter, Matthew Paul <https://research.library.mun.ca/view/creator_az/Carter=3AMatthew_Paul=3A=3A.html>   (2020) The potential impacts of a high penetration of electric vehicles on the Newfoundland Transmission System.  Masters thesis, Memorial University of Newfoundland.

abstract:
The deployment of electric vehicles is expected to drastically increase throughout the developed world for the foreseeable future. This trend is attributed to the growing acceptance of electric vehicles driven by the emergence of numerous environmental, economic and technical incentives promoting their adoption. This revolutionary change will likely have a monumental impact on most power systems. A large scaled uptake of electric vehicles could also prove beneficial as they have the capability to instantaneously supply active and reactive power back to the grid using Vehicle-2-Grid technology.
This thesis will focus on the Newfoundland Transmission System and investigate the positive and negative impacts associated with a high penetration of electric vehicles. Load flow and power system stability simulations were performed using PSS®E to support this investigation by quantifying the effect of varying levels of electric vehicle penetration in the province. The results of the load flow analysis concluded that, in the absence of any demand-side management strategies, substantial system capacity upgrades would likely be required to avoid jeopardizing system reliability.
The power system stability analysis revealed that a large amount of electric vehicles with Vehicle-2-Grid capability could collectively be utilized to minimize or avoid under frequency load shedding following the sudden loss of the Labrador Island-Link HV dc bipole. A strong correlation was discovered between the net total of HVdc power imports/exports (Net DC) and the total number of connected electric vehicles that would be required to avoid under frequency load shedding on the Island Interconnected System.
The investigation has ultimately demonstrated that without the necessary power system integration or demand-side management strategies, a high penetration of electric vehicles in Newfoundland could lead to needless capital expenditures. Newfoundland and Labrador Hydro would also forgo the benefits of improved frequency response provided through Vehicle-to-Grid technology.


identifier: Morgan, Michael <https://research.library.mun.ca/view/creator_az/Morgan=3AMichael=3A=3A.html>   (2020) Development of a novel time-of-flight laser rangefinder for opto-mechatronic applications.  Masters thesis, Memorial University of Newfoundland.

abstract: A Laser rangefinder is an opto-electric device used to determine the distance between two objects. There are many applications for laser rangefinders in industries such as unmanned vehicles, defence sectors, scientific exploration, and outdoor sporting activities. In this work a novel time-of-flight laser rangefinder was designed to deliver range information while meeting size weight and power constraints. The laser rangefinder consists of three main systems, optical, electrical, and mechanical. The optical system consists of collimating transmitting optics and a focusing mirror for receiving optics. The electrical system is comprised of a pulsing circuit providing a narrow pulse with high peak current, a receiving circuit for identifying the return signal, and an FPGA controller for triggering the pulse and calculating distance. The mechanical system is made up of the housing of the laser rangefinder which ensures concentricity and spacing of the optical system.


identifier: Herder, Erin Coleen <https://research.library.mun.ca/view/creator_az/Herder=3AErin_Coleen=3A=3A.html>   (2020) Temporal and spatial changes in benthic mollusc (bivalves and gastropods) communities in inner Frobisher Bay, Nunavut, Baffin Island over fifty years.  Masters thesis, Memorial University of Newfoundland.

abstract: Benthic fauna are a crucial part of the marine ecosystem providing many ecosystem services. Unfortunately, Arctic coastal marine environments are under tremendous pressure from changing climate conditions and it is becoming increasingly important to understand community changes occurring in these environments. Long-term ecological studies in the Canadian Arctic are rare, however, Frobisher Bay provides a unique opportunity to study long-term change in the marine benthos because historical benthic community datasets exist for this region. We focused on the molluscs as indicators of long-term change by comparing community temporal and spatial changes between 1967-1976 and 2016. Significant changes in community composition were observed between these two time periods and shifts in functional trait characteristics were also observed. These changes coincided with long-term environmental change in the region. Our results highlight the need for long-term systematic sampling which is fundamental to our understanding of Arctic marine ecosystems and for identifying long-term ecosystem change.


identifier: McEvoy, Christopher <https://research.library.mun.ca/view/creator_az/McEvoy=3AChristopher=3A=3A.html>   (2020) Soil and groundwater remediation using risk based corrective action: case study.  Masters thesis, Memorial University of Newfoundland.

abstract:
Around the world, there are numerous sites that have contaminated soil and groundwater from gas station operations. The contamination concentration levels found in these sites range from high to low and are caused by various scenarios such as leaks/punctures in underground storage tanks, overfilling of storage tanks, and accidental spills, etc. The main contaminants found from these sites are predominantly total petroleum hydrocarbons (TPH), in which the main chemical constituents are benzene, toluene, ethylbenzene, and mixed xylenes (BTEX) that are known to have health and environmental effects.
This study creates a fictional scenario where a gas station located in Happy Valley – Goose Bay, NL has released a large volume of TPH contamination into the soil and groundwater in and around surrounding areas. The use of „Risk Based Corrective Action‟ (RBCA) utilizes a tiered based consistent decision making methodology to aid in the overall optimal selection of soil and groundwater remediation technologies of soil vapour extraction and air sparging. These technologies combined together will bring the desired contaminant concentration levels back to safe conditions with zero adverse risks to human health and the surrounding environment.


identifier: Spiwak, Alexa D. <https://research.library.mun.ca/view/creator_az/Spiwak=3AAlexa_D=2E=3A=3A.html>   (2020) A slator or two: exploring the 17th-century slate industry at Ferryland.  Masters thesis, Memorial University of Newfoundland.

abstract: While the use of slate as a building material was not unheard of in the New World, the early 17th-century English colony at Ferryland, Newfoundland was unique among contemporaneous North American settlements in its large-scale use of local slate. First governed by a Welshman, the colony’s historical documents and previously undertaken archaeological investigations point to the presence of a substantial slate industry, complete with at least one quarry and a number of skilled tradesmen. Slate is ubiquitous at the colony, making it one of the most important materials used in its construction. However, very little is known about the quarry, the process used to manufacture the many thousands of roof slates used to cover the early buildings or the lives of the craftsmen that called Ferryland home. Using archaeological and ethnographic data, this project seeks to determine how 17th-century quarrying and slate working processes in Newfoundland may have deviated from those of the Old World, as well as confirming possible quarry sites proposed by previous research. Moreover, this project seeks to connect the practices of 17th-century slaters to those of the 19th and 20th centuries, when Newfoundland experienced a resurgence in both the slate quarrying industry and a Welsh cultural presence.


identifier: Alrbee, Khalifa B. <https://research.library.mun.ca/view/creator_az/Alrbee=3AKhalifa_B=2E=3A=3A.html>   (2020) Experimental modeling of heat transfer in Taylor flow in mini-scale tubing.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Heat transfer enhancement in mini / micro scale channels is desired in most compacted devices. Typically, these devices experience a high heat generation. In this regard several approaches were invented to increase heat dissipation rates. Taylor flow provides a promising technique to enhance heat transfer within mini / micro scale channels.
Taylor flow parameters and channel geometries are experimentally and theoretically studied to improve the thermal performance of mini / micro channels. The present dissertation aims to investigate heat transfer enhancement using the Taylor flows of gas-liquid and liquid-liquid flows in straight and curved tubes. The influence of the liquid slug length on heat transfer is examined when the isothermal boundary condition is applied to the heat transfer surface. This study also examines the effect of nanoparticle inclusion in the continuous and Taylor flows as new achievement in this regard. This dissertation will address heat transfer enhancement in the mini scale tubes over eight chapters as follows.
The first chapter provides a brief introduction and shows the originality, novelty, and importance of using the Taylor flows in the heat transfer enhancement. The second chapter summarizes a survey on the past attempts to investigate heat transfer of Taylor flows. The third and fourth chapters are devoted to study heat transfer in Taylor flows of gas-liquid and liquid-liquid in mini scale straight tubes. These experiments examine the effect of the liquid slug length on the thermal behavior of the Taylor / slug flows. In the fifth and sixth chapters, the thermal behavior of Taylor flows inside curved / coiled geometry are experimentally studied, and new empirical models were developed using the experimental data. The experiments considered the effects of three parameters, tube curvatures, liquid slug ratios, and Prandtl numbers. The seventh chapter addresses the heat transfer enhancement of nanofluids and compares with the conventional liquids. The study demonstrated the effect of nanoparticle concentration on heat transfer in continuous and Taylor flows.
The last chapter provides a summary and conclusion of the present study. Recommendations for the future studies are also stated to highlight the important aspects for further investigation.