identifier: Adumene, Sidum <https://research.library.mun.ca/view/creator_az/Adumene=3ASidum=3A=3A.html>   (2021) Dynamic corrosion risk-based integrity assessment of marine and offshore systems.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Corrosion poses a serious integrity threat to marine and offshore systems. This critical issue leads to high rate of offshore systems degradation, failure, and associated risks. The microbiologically influenced corrosion (microbial corrosion), which is a type of corrosion mechanism, presents inherent complexity due to interactions among influential factors and the bacteria. The stochastic nature of the vital operating parameters and the unstable microbial metabolism affect the prediction of microbial corrosion induced failure and the systems’ integrity management strategy. The unstable and dynamic characteristics of the corrosion induced risk factors need to be captured for a robust integrity management strategy for corroding marine and offshore systems.
This thesis proposes dynamic methodology for risk-based integrity assessment of microbially influenced corroding marine and offshore systems. Firstly, a novel probabilistic network based structure is presented to capture the non-linear interactions among the monitoring operating parameters and the bacteria (e.g., sulfate-reducing bacteria) for the microbial corrosion rate predictions. A Markovian stochastic formulation is developed for the corroding offshore system failure probability prediction using the degradation rate as the transition intensity. The analysis results show that the non-linear interactions among the microbial corrosion influential parameters increase the corrosion rate and decrease the corroding system's failure time. Secondly, a dynamic model is introduced to evaluate the offshore system's operational safety under microbial corrosion induced multiple defect interactions. An effective Bayesian network - Markovian mixture structure is integrated with the Monte Carlo algorithm to forecast the effects of defects interactions and the corrosion response parameters’ variability on offshore system survivability under multispecies biofilm architecture. The results reveal the impact of defects interaction on the system's survivability profile under different operational scenarios and suggest the critical intervention time based on the corrosivity index to prevent total failure of the offshore system.
Finally, a probabilistic investigation is carried out to determine the parametric interdependencies' effects on the corroding system reliability using a Copula-based Monte Carlo algorithm. The model simultaneously captures the failure modes and the non-linear correlation effects on the offshore system reliability under multispecies biofilm structure. The research outputs suggest a realistic reliability-based integrity management strategy that is consistent with industry best practices. Furthermore, a dynamic risk-based assessment framework is developed considering the evolving characteristics of the influential microbial corrosion factors. A novel dynamic Bayesian network structure is developed to capture the corrosion's evolving stochastic process and the importance of input parameters based on their temporal interrelationship. The associated loss scenarios due to microbial corrosion induced failures are modeled using a loss aggregation technique. A subsea pipeline is used to demonstrate the model performance. The proposed integrated model provides a risk-based prognostic tool to aid engineers and integrity managers for making effective safety and risk strategies. This work explores the microbial corrosion induced failure mechanisms and develops dynamic risk-based tools under different operational scenarios for systems’ integrity management in the marine and offshore oil and gas industries.


identifier: Andrea, Kori A. <https://research.library.mun.ca/view/creator_az/Andrea=3AKori_A=2E=3A=3A.html>   (2021) Towards sustainable materials: earth abundant elements for transformations of CO₂ and epoxides.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

abstract:
The utilization of carbon dioxide (CO₂) as a renewable C-1 feedstock has received
significant attention in recent years. In particular the coupling and/or polymerization of
epoxides and CO₂ to yield cyclic and/or polycarbonates is a growing area of research
leading to the production of sustainable materials. Due to the high thermodynamic stability
of CO₂ these reactions typically proceed in the presence of a metal catalyst, while in the
recent literature organocatalysts have found promising results. In this thesis, both iron and
boron containing catalytic systems are reported that have shown excellent activity for these
reactions. In Chapter 2, a series of iron(III) chloride and iron(III) μ-oxo compounds
supported by tetradentate amino-bis(phenolate) ligands containing a homopiperazinyl
backbone were prepared and characterized by electronic absorption spectroscopy, magnetic
moment measurement, and MALDI-TOF mass spectrometry. We provide evidence that an
epoxide deoxygenation step occurs when employing monometallic iron(III) chlorido
species as catalysts. This affords the corresponding μ-oxo compounds which can then enter
their own catalytic cycle. Deoxygenation of epoxides during their catalytic reactions with
carbon dioxide is frequently overlooked and should be considered as an additional
mechanistic pathway when investigating catalysts. Through extensive studies of the iron
systems reported herein, we have shown a structure/geometry of the catalyst and product
selectivity relationship. This study (reported in Chapter 3) demonstrated that the highly
modifiable aminophenolate ligands can be tailored to yield iron complexes for both
CO₂/epoxide coupling and ring-opening copolymerization activity.
Metal-free catalysts have gained interest in the recent years as alternatives for these
transformations but is still in its infancy compared to transition metal-based systems. In
Chapter 4, we have shown that arylboranes can be used as catalysts in these
transformations to produce either cyclic or polycarbonates. Kinetic studies revealed a
process that was first-order in all reagents with the exception of CO₂, where an inverse
dependence was shown. Building upon this report and taking into account the extensive
research focused on Frustrated Lewis pairs and their ability to catalyze a range of
transformations such as hydrosilylations I chose to combine these two ideas. Via assisted
tandem catalysis BPh₃ could first catalyze the copolymerization of epoxides and CO₂ to
give polycarbonates and then with the addition of a silane could catalyse the hydrosilylation
of these materials. This work is reported in Chapter 5.
Finally, Chapter 6 reports the same arylborane systems as a catalyst for the block
copolymerization of epoxides, CO₂ and anhydrides in a controlled fashion. Further, by
switching from BPh₃ to the more Lewis acidic BCF, the carbonate block in the obtained
polymer could be selectivity degraded to the corresponding cyclic carbonate. This is the
first report of an arylborane for both the polymerization of epoxides, anhydrides, and CO₂
as well as the first for the selective depolymerization of these materials.


identifier: Pike, Katlyn A. <https://research.library.mun.ca/view/creator_az/Pike=3AKatlyn_A=2E=3A=3A.html>   (2021) Incivility and gender: considering instigator/target gender interactions.  Masters thesis, Memorial University of Newfoundland.

abstract:
In this study, I examine gender dyads, especially considering gender minorities, and how
uncivil behaviour would effect negative and positive affect, interactional justice, affective
commitment, and turnover intentions. In particular, I use the Dysempowerment Model (Kane &
Montgomery, 1998) to explain how incivility leads to these negative outcomes. In addition,
selective incivility (Cortina, 2008) is incorporated to illustrate how gender of the target may
result in higher rates of polluters, thus different (more significant) outcomes for female and
gender minority targets. Finally, I integrate gender status literature to hypothesize gender effects
based on the manager’s (instigator) gender. A 2 (incivility vs. control) x 3 (manager gender:
male, female, transgender) x 3 (participant/target gender: male, female, transgender) vignette-based
pseudo-experiment was conducted to test the hypotheses. Data collection was done online,
and participants were recruited through online means (Amazon Mechanical Turk, Social Media
recruitment, and Prolific). The main effects for incivility manipulation were all significant, but
the gender x incivility interaction effects were mainly nonsignificant. The significant results
support that relatively common, but rude, behaviours can cause tangible changes in negative
affect, interactional justice, job commitment, affective commitment, and positive affect. Some
unexpected interactions were found with respect to intentions to quit. Implications for future
research and practitioners are discussed.


identifier: Azarpour Hassankiadeh, Abbas <https://research.library.mun.ca/view/creator_az/Azarpour_Hassankiadeh=3AAbbas=3A=3A.html>   (2021) Dynamic assessment and optimization of catalytic hydroprocessing process: sensitivity analysis and practical tips.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Among the processes in petrochemical industry, hydroprocessing is an imperative process to produce
clean fuels. This process is still being improved despite its 70-year maturity. Catalyst deactivation is a
key aspect in the design and operation of catalytic processes in petrochemical industry. In this research,
a dynamic heterogeneous model is presented to evaluate the performance of an industrial
hydropurification/hydrotreating process in the purified terephthalic acid (PTA) production plant. This
process includes a trickle-bed reactor (TBR) packed with palladium supported on carbon (0.5wt.% Pd/C)
catalyst. In fact, this chemical production unit represents a three-phase catalytic system where some
chemical reactions take place. Therefore, an accurate and meticulous analysis is required to develop a
proper mathematical model, taking into account all transport phenomena occurring in the system. The
model considers the axial back-mixing, flow non-ideality, and the catalyst deactivation. Model
development leads to a set of partial differential equations consisting of nonlinear equations of the
reaction rates, nonlinear expression of the catalyst deactivation rate, mass balance of each component in
the reaction mixture, and energy balance of each phase. The model parameters are calculated using
suitable correlations. The set of partial differential equations is solved using proper numerical
techniques, including method of lines and finite difference method, in MATLAB software environment.
First, the model reliability is assessed through the comparison of the model results with the industrial
data. The validation phase confirms that the model results are accurate, and the developed model can be
used for further process evaluation. A sensitivity analysis is then implemented to assess the effects of
different operating parameters on the performance of the hydropurification/hydrotreating process. The
results reveal that axial dispersion model is more accurate than the plug flow model. Moreover, 4-
carboxybenzaldehyde (4-CBA) impurity in the reactor feed is the most detrimental parameter, affecting
the catalytic performance. It is found that reduction in the catalyst particle size can improve the catalyst performance by about 16%, and an increase in the catalyst particle porosity can enhance the catalyst
lifetime by around 8%. In this condition, the catalyst bed pressure drop is maintained at an acceptable
level. In addition, 13% increase in the hydrogen partial pressure enhances the catalyst lifetime by about
20%. It should be noted that pressure increase might lead to the reactor pressure fluctuation, leading to
an increase in the PTA powder turbidity. Therefore, reactor operation control is a critical factor.
Considering other hydrodynamic parameters, a decrease in liquid hourly space velocity and the catalyst
bed porosity improves the system performance in terms of catalyst lifetime and product quality. An
increase in the liquid-solid mass transfer and contacting efficiency has a slight positive impact on the
catalytic system performance. Product quality control can be carried out more properly if the feed
impurity concentration is managed/controlled efficiently. In this research, a practical strategy is
presented to effectively mix the feed streams having varying concentrations of the impurities (e.g., high
and low concentrations of 4-CBA). This can be achieved by suggesting a proper ratio control, keeping
the feed composition and flowrate at normal operating conditions. This strategy can also be employed
to deal with the off-spec PTA powder product. In addition, the effect of temperature on the sintering
mechanism of the Pd/C catalyst deactivation is investigated. The results reveal that temperature increase
can accelerate the decline rate of the Pd/C catalyst surface area. The reduced activity of Pd/C catalyst is
in an acceptable agreement with the normalized ratio of reduction in the surface area of pure Pd with
increasing temperature. In the last phase, an efficient methodology is proposed to assess the
hydroprocessing process in terms of energy and exergy performance. The process simulation and exergy
analysis are conducted using Aspen Plus® and MATLAB software packages. The results are in a
satisfactory agreement with the industrial data. It is concluded that the optimal operating conditions
result in 15% reduction in the exergy destruction; the optimal scenario can also reduce the operation
costs and the carbon tax at 9.96% ($20.5/h) and 14.75% ($14.54/h), respectively.


identifier: Faran, Muhammad <https://research.library.mun.ca/view/creator_az/Faran=3AMuhammad=3A=3A.html>   (2020) Potential of dairy digestate as a biofertilizer: effects on growth, yield and phytochemicals of lettuce in hydroponics.  Masters thesis, Memorial University of Newfoundland.

abstract: Lettuce (Lactuca sativa L) is a leafy vegetable containing an immense variety of minerals, vitamins and health-promoting secondary metabolites which are required for normal functioning of human body and health. Anaerobic digestate contains proportionately higher mineralized nutrients particularly ammonium-N (NH4⁺ -N) compared to undigested materials, and therefore has the potential to be used as a mineral nutrient source in soil based and soilless culture. A pilot study was conducted at St. Davids dairy farm site to investigate the effects of anaerobic dairy digestate (DD), inorganic nutrient solution (NS) and combine application of DD and NS on the growth, yield and quality indices of lettuce varieties in hydroponics under controlled environment conditions. Results showed that NS produced significantly higher leaf area (LA), chlorophyll content, root dry weight, yield, minerals and vitamins concentration of lettuce, compared to DD solution which produced lower LA, chlorophyll contents, yield and higher concentration of phenolics (chicoric acid, chlorogenic acid, luteoline, quercitin-3-b-d-gluconide, quercitin-3-glucoside and quercitin-b-malonyl) and antioxidants. Romaine lettuce showed superior performance and produced higher LA, chlorophyll contents, root dry weight, yield, minerals, vitamins, total phenolics, total antioxidants and polyphenols than Newham. It can be concluded that DD can be used as an organic fertilizer/nutrient source in hydroponics to enhance phenolics and antioxidants of lettuce without significant reduction in yield. Further research is needed to reduce Ammonium-N/Nitrate (NH4⁺/NO3⁻) in DD without dilution to avoid phytotoxic effects of NH4⁺ and loss of other macro and micro nutrient , and to establish the utilization of DD as a sole fertilizer source in hydroponic system.


identifier: Bui, Dung Thi Thu <https://research.library.mun.ca/view/creator_az/Bui=3ADung_Thi_Thu=3A=3A.html>   (2021) Vietnam's foreign policy strategy vis-à-vis China over the South China Sea issues.  Masters thesis, Memorial University of Newfoundland.

abstract:
When it comes to Vietnam's response to China's threat in the South China Sea, it can be said that
most of the arguments revolve around whether Vietnam employs a balancing, bandwagoning, or
hedging strategy toward China. Across the literature, there is a general consensus that since the
1990s, Vietnam has engaged in a hedging strategy against China’s threat in the SCS. However, the
rise of China and its increasing assertiveness in the SCS, coupled with current explanations of
Vietnam’s hedging strategy, caused difficulties in identifying Vietnam’s strategic behavior toward
China. Using “the patterns of hedging” built off of Koga’s hedging conceptualization (2018), this
paper attempts to identify what type of hedging strategy Vietnam uses and its effectiveness in
response to China’s aggressive actions in the SCS. The findings indicated first that Vietnam’s
policy toward China’s challenge in the SCS fell into the hedging spectrum but leaned more towards
soft hedging given a combination of economic bandwagoning and diplomatic balancing; second,
while China increases maritime encroachment in the SCS, rather than pure balancing and
bandwagoning, soft hedging is a less risky option for Vietnam against China.


identifier: Xia, Guoli <https://research.library.mun.ca/view/creator_az/Xia=3AGuoli=3A=3A.html>   (2021) Some aspects of rings whose elements satisfy a special property.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Throughout, rings are associative with identity 1 ≠ 0. The main focus of
this thesis is on the study of rings whose elements are sums of certain special
elements and, in this case, these elements are from the sets of nilpotents,
units, idempotents, involutions, and tripotents.
In Chapter 1, we provide some basic definitions and results in ring theory
which are needed for this thesis.
In Chapter 2, we study rings whose elements are sums of a nilpotent and
an idempotent (i.e., nil-clean rings). The motivation is the open question,
raised by Breaz et al., whether the ring of linear transformations of a countable
dimensional vector space over F₂ is a nil-clean ring. In Section 2:1,
we first prove that for a semisimple module M over a ring R with R ∕J(R)
Boolean, every endomorphism of M is a sum of an idempotent endomorphism
and a locally nilpotent endomorphism. As a consequence, it is proved
that, for a vector space V over a division ring D, every linear transformation
of V is a sum of an idempotent linear transformation and a locally nilpotent
linear transformation if and only if D ≅ F₂. In Section 2:2, we study nil
⁎-clean rings with emphasis on matrix rings. We show that a ⁎-ring R is a
nil ⁎-clean ring if and only if J(R) is nil and R ∕J(R) is a nil ⁎-clean ring.
Particularly, it is shown that for a 2-primal ⁎-ring R, with involution ⁎ given
by (aᵢj)* = (a*ᵢj)ᵀ , Mₙ(R) is a nil ⁎-clean ring if and only if J(R) is nil,
R ∕J(R) is Boolean, a* ─ a ∈ J(R) for all a ∈ R and Mₙ(F₂) is nil ⁎-clean.
Notice that the structure of nil-clean rings is unknown. We give a description
of nil-clean rings with nilpotency index at most 2 in Section 2:3.
In Chapter 3 we first give a review of known results regarding rings whose
elements are sums of nilpotents, idempotents, or tripotents. In Section 3:2 we
determine the structure for a more general class of rings i.e., rings in which
every element is a sum of a nilpotent and three tripotents that commute with
one another and, in the last section, we discuss when a group ring has such
property.
In Chapter 4, we focus on decomposing a matrix as a sum of certain special
matrices. In Section 4:1 we give the necessary and sufficient conditions
for an n x n matrix over an integral domain to be a sum of involutions and,
respectively, a sum of tripotents. We completely determine the integral domains
over which every n x n matrix is a sum of involutions and, respectively,
a sum of tripotents. We also show that every n x n matrix over an integral
domain R is a sum of two tripotents if and only if R ≅ Fₚ  where p = 2, 3, or
5.
The last chapter of the thesis is about rings whose elements are left
annihilator-stable. An element a in a ring R is left annihilator-stable (or
left AS) if, whenever Ra + l(b) = R with b ∈ R, then a ─ u ∈ l(b) for some
unit u in R, and the ring R is a left AS ring if each of its elements is left AS.
In this chapter, we show that the left AS elements in a ring form a multiplicatively
closed set, giving an affirmative answer to a question of Nicholson [66].
This result is further used to obtain a necessary and sufficient condition for
a formal triangular matrix ring to be left AS. As an application, we provide
examples of left AS rings R over which the triangular matrix rings Tₙ(R) are
not left AS for all n ≥ 2. These examples give a negative answer to another
question of Nicholson [66] whether R ∕J(R) being left AS implies that R is
left AS.


identifier: Foley, Heather Elizabeth <https://research.library.mun.ca/view/creator_az/Foley=3AHeather_Elizabeth=3A=3A.html>   (2021) Epidemiology and health care utilization associated with chronic pain in Newfoundland and Labrador, Canada: a population-based study using health administrative data.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Background: Chronic pain exerts a tremendous burden on individuals, families, and society, and has a high estimated prevalence (up to 54% globally and 44% in Canada) and direct health care cost ($7.2 billion in Canada in 2014). Most Canadian epidemiological and cost estimates do not include Newfoundland and Labrador; a knowledge gap potentially filled using health administrative data.
Aim: To extract information about chronic pain as a single chronic disease in Newfoundland and Labrador using health administrative data.
Methods: Health administrative data algorithms that identify cases of chronic pain as a single chronic disease were derived from the Newfoundland and Labrador Medical Care Plan Fee-for-Service Physician Claims File and Provincial Discharge Abstract Data of known chronic pain populations, and validated against an audit of the electronic medical records data of a primary care population sample. The most performant algorithm was used to identify chronic pain cases from fee-for-service physician claims data in Newfoundland and Labrador, which allowed estimation of both chronic pain incidence/prevalence, and chronic pain association with comorbidity presence and annual health care utilization.
Results: The most performant validated algorithm to ascertain chronic pain cases from Newfoundland and Labrador administrative data had 70.3% sensitivity, 66.8% specificity, and 40.3% positive predictive value. As defined by the algorithm, the 2009/10 age-standardized Newfoundland and Labrador chronic pain prevalence was estimated at 37,469 per 100,000 population and incidence rate was estimated at 4,585 per 100,000 person-years at risk. Estimates were higher in females, residents of urban areas, and with increasing age. Residents identified as chronic pain cases had two to four times the odds of having a chronic comorbidity and up to twice the rate of publicly funded health care utilization compared to residents not identified as chronic pain cases.
Conclusions: A health administrative data algorithm was derived and validated to identify chronic pain cases and estimate disease burden in residents attending fee-for-service physician encounters in Newfoundland and Labrador. The Chronic Pain Algorithm identified almost four out of ten Newfoundland and Labrador residents and they had a higher prevalence of comorbidities and utilization of publicly funded health services.


identifier: Bowering, Keri L. <https://research.library.mun.ca/view/creator_az/Bowering=3AKeri_L=2E=3A=3A.html>   (2021) Mobilization of soil dissolved organic matter in mesic boreal forests of Newfoundland and Labrador, Canada.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The mobilization of soil dissolved organic matter (DOM) distributes carbon and nutrients
within ecosystems and links terrestrial to aquatic environments. As a hydrologically and
biogeochemically mediated flux, DOM mobilization encapsulates a number of interacting
ecological processes. This presents a major challenge for identifying the main drivers of
DOM mobilization at different spatial and temporal scales. In this thesis, I use two mesic
boreal forest research platforms to investigate the drivers of DOM mobilization from the
organic horizon at different spatiotemporal scales. Using an experimentally harvested
site, I show that total annual DOC flux from O horizons is due to both vertical and lateral
flow, and was 30% percent greater in the harvested plots with significantly reduced organic
horizons. Additionally, the C:N of DOM and absorbance characteristics of samples
in both treatments demonstrated a stronger control of season over harvesting on the composition
of DOM mobilized. One of the most significant of these seasonal controls was
the snowpack insulation throughout winter. The lower C:N, higher SUVA₂₅₄nm and lower
molecular weight of chromophoric DOM mobilized during winter and snowmelt indicates
relatively more decomposed DOM, compared to that mobilized in summer and autumn.
This shows that the decomposition of soil organic matter underneath a consistently deep
snowpack is a key determinant of the composition of DOM mobilized from O horizons
during winter and the hydrologically significant snowmelt period. Additionally, I show
that air temperature and snowpack duration best explain DOM mobilization dynamics
both interannually within boreal sites and among boreal forest sites along a climate transect.
This suggests that air temperature indirectly affects DOC mobilization through a direct control on snowpack season length in these forests. Furthermore, climate influenced
differences in ecosystem properties such as organic horizon thickness, moss coverage and
stand density, may additionally influence DOM mobilization through a direct control on
soil hydrology. These results enhance our understanding of the relationship between boreal
forest soil organic matter and soil DOM and the potential impacts of climate change
on soil organic matter losses as DOM, contributing to a predictive understanding of forest
C and nutrient distribution and the potential effect on aquatic environments.


identifier: Asadi, Mohammad Bagher <https://research.library.mun.ca/view/creator_az/Asadi=3AMohammad_Bagher=3A=3A.html>   (2021) Numerical simulation of fluid-fluid and solid-fluid interactions: a lattice Boltzmann strategy.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
It is crucial to obtain a better understanding of fluid-fluid and solid-fluid interactions with several
applications in science and engineering disciplines. Associating fluids such as water, alcohols,
asphaltene might exist in many processes. Modeling associating fluids to explore phase
equilibrium behaviors is required for proper design, operation, and optimization of various
chemical and energy processes. Pseudopotential lattice Boltzmann method (LBM) can be a
promising and capable mesoscopic approach to study phase transition and thermodynamic
behaviors of complex fluid systems. Results of integrating the cubic equations of state (EOSs) with
LBM showed a considerable deviation from experimental data for associating fluids. Cubic-plus-association
(CPA) EOS is utilized in the LBM to increase the accuracy of modeling associating
fluids. A global optimization approach is applied to determine the optimum association parameters
of CPA EOS for water and primary alcohols in the lattice units. Maxwell equal area construction
is used to verify the thermodynamic consistency. By increasing the isotropy order of gradient
operator, the spurious velocities are decreased, and an extended form of CPA EOS is introduced
to find proper initial densities, which increase the stabilities at low reduced temperatures.
Simulating fluid flow at high Reynolds number is another aspect of an LBM study that needs
further improvement. In fluid flow in porous media, specifically at tight gas reservoirs, a high flow
rate might happen at pore throat. Therefore, to increase the stability of the model at high Reynolds
number, the central moments collision operator is implemented in the LBM. The advantages of
central moments collision operator are shown by comparing with multi relaxation time (MRT)
collision operator in the double shear layers test. It is found that using a higher order of isotropy
in the gradient operator can lead to a 34% reduction in spurious velocities. From the
thermodynamic consistency point of view, it is concluded that collision operators can also have an impact on the consistency of the model. Furthermore, the model validation is performed by
observing a straight line in the Laplace law test.
Surface wettability is known as an important concept to achieve a better understanding of fluid
flow and distribution in both porous and non-porous systems. Improving the solid-fluid interaction
can help to have a better understanding of thermodynamics of curved interfaces. The contact angle
is an important parameter to study the multiphase fluid flow in various systems such as porous
media and membranes. It helps to design better production, separation, treatment, and reaction
processes in different applications. In order to increase the accuracy and reliability of the model
for simulation of the surface wettability and absorption, a new solid-fluid interaction in the
pseudopotential approach is introduced. Usually, the surface wettability is reported by the contact
angle, which is measured by fitting a circle on the drop. Because the circle is a constant curvature
shape, it is not suitable to consider the disjoining pressure. A new strategy is presented based on
the Smoothing Splines to measure the contact angle without considering a constant curvature
shape of the interface profile. The new solid-fluid interaction exhibits the capability of simulating
extreme non-wetting surfaces without detaching the drop. The probability histogram of the density
domain appears to be a reliable tool to measure the phase density in the presence of a surface.
The results of the current research have a wide range of applications in energy and environment,
such as simulation of fluid flow in porous systems (e.g., shale reservoirs and membranes). Pores
and fractures are large in conventional permeable media and pressure-drive convective flow is
applicable in the framework of continuum flow. Shale reservoir have fine grains and pores in the
range on nanometer where fluid molecular distribution is inhomogeneous and surface adsorption
may be significant. Coupling the introduced method with nucleation theory provide a powerful
tool to simulate asphaltene precipitation in the porous media. The presence of water component as an associating fluid in some biological processes such as blood coagulation makes the presented
model an effective tool to simulate those processes.


identifier: Sultana, Naznin <https://research.library.mun.ca/view/creator_az/Sultana=3ANaznin=3A=3A.html>   (2020) Food policy and food security: a potential impact of food policy on household food security in rural Bangladesh.  Masters thesis, Memorial University of Newfoundland.

abstract: Food policy is a strategy that any government should pursue as part of their public policy. Food policy includes aspects such as food production, distribution, consumption, availability, purchasing procedures, and techniques of food processing and marketing. For developing the necessary level of food security, the food policy is working as an initiative at the domestic level which is also helpful to ensure a safe and adequate supply of food for the general public. In this research we study the impact of food support, which is part of the food policy, on the household’s daily calorie intake, as well as food security index, by using telephone interview survey data from three sub-districts of the Rajshahi district (Puthia, Paba and Charghat) in Bangladesh. The survey was conducted using 160 households from these three sub-districts, and among them 67 households (41.9 percent) were food support receivers while the rest, i.e. 93 households (58.1 percent) were food support non-receivers. In this research, the daily mean calorie intake, head count ratio, shortfall or surplus index and food security index are calculated to identify the extent of food insecurity among the respondents. The PSM (propensity score matching technique) is used to assess the effects of food policy on rural household’s food security. Results have shown that, dissimilarities exist in unobserved characteristics between the groups of food support receivers and non-receivers, as food prices and agricultural production may influence the household’s decision to receive government food support. This influenced both the calorie intake and food security index of the sample respondents. A comparison of the means of the matched sample, showed that the two groups did not differ in food expenditure. Therefore, the impact of government food support on the calorie intake or food security index in the present study may not be underestimated, due to the likely heterogeneity in agricultural production. The results also suggest that natural disasters like floods, cyclone, drought, and improper distribution of food which are unobserved characteristics for the sample may influence food support received. Descriptive statistics suggested that the age of the household head and income earning member did not differ in the matched sample. Therefore, households’ monthly income did not likely differ between the two groups. The results also indicate that there is no proper distribution of food supplied by the government among the rural households in the study area as well as food support is insufficient compared to necessity and, thus, food support receivers and non-receivers were unlikely to differ in this regard. Finally, the researcher generated some policy suggestions which might be useful to policy makers as well as decision-makers of the relevant authorities. The study recommended that government should keep an updated database including necessary information about the poor and marginalized people; should take measures to reduce corruption in the case of food distribution, and extend the food coverage to cover more poor people in order to implement the food support program effectively. Food policy can be efficiently implemented in a well-functioning socio-economic system. The study concludes that measures such as employment generation, control of food prices, support for producing more food locally and increasing the amount of subsidy for the agricultural sector could contribute to solving the problem of food insecurity at the level of rural households in the study area.


identifier: Tang, Xiaozhuo <https://research.library.mun.ca/view/creator_az/Tang=3AXiaozhuo=3A=3A.html>   (2021) Modelling abrupt shifts of fish recruitment and growth.  Masters thesis, Memorial University of Newfoundland.

abstract:
Regime shifts in marine ecosystems may result in abrupt changes in fish population dynamics, and not accounting for such shifts could have potentially large and far-reaching consequences for fisheries assessment and management decisions. In this work, I develop a methodology to model abrupt shifts in recruitment and somatic growth, which are two key processes in controlling fish population dynamics. In Chapter 1, I review the impacts of regime shifts on fish populations and find that abrupt shifts in productivity are very common among global fish species. In Chapter 2, I introduce the approach of modelling recruitment and regime shifts. The methodology includes a hidden Markov model for the unobserved environmental regimes, a stock-recruitment (SR) model for the regime-specific SR function, the maximum likelihood approach for evaluating the marginal likelihood, and the corrected Akaike information criterion (AICc) for the model selection. I conduct simulation tests to evaluate the performance of the method and results indicate that our method can objectively identify the unobserved environmental regimes and estimate regime-specific SR model parameters well. In Chapter 3, I extend the hidden Markov approach to model abrupt shifts in fish growth using a von Bertalanffy growth model (VBGM). Simulation results demonstrate that the method can accurately identify abrupt shifts in growth and estimate regime-specific growth parameters well. I apply both the hidden Markov stock-recruit model (HMSM) and the hidden Markov growth model (HMGM) to an Atlantic cod stock on the southern Grand Bank off Newfoundland, Canada. Results indicate that the cod stock has two distinct recruitment regimes and two distinct growth regimes, and our method identify one abrupt shift in recruitment and four abrupt shifts in somatic growth. I consider the methodology proposed in this thesis as a useful tool to model regime-like changes of fish population dynamics. In Chapter 4, I discuss the management implications of abrupt shifts in fish population dynamics and present the current
challenges of managing fish stocks under marine ecosystem regime shifts. I consider the conditions under which our method might be useful to better assess and manage fish populations under changing environmental regimes.


identifier: Nguyen, Thi-Hong-Xuan <https://research.library.mun.ca/view/creator_az/Nguyen=3AThi-Hong-Xuan=3A=3A.html>   (2021) Investigation of enzymatic hydrolysis process to valorize waste mussel shells.  Masters thesis, Memorial University of Newfoundland.

abstract:
Blue mussels (Mytilus edulis) are the most common mussel harvested with high value nutritional compounds including proteins, vitamins ( C, A, and B12), and minerals (iron and calcium). Blue mussels are filter feeders eating plankton from the water. Mussel farming is more sustainable form of aquaculture as fish meal, chemicals (antibiotics and additives) are not required and the risk of pathogens escaping into the coastal ecosystems is minimal. The worldwide aquaculture and processing of mussels is rapidly increasing and blue mussels are Canada’s top shellfish aquaculture product produced in every province in Atlantic Canada, as well as in Quebec and British Columbia. By-products from mussel aquaculture and processing, such as processed mussel shells, unmarketable and broken mussels, make up a significant waste stream from this industry and are currently difficult to valorize. Waste mussel shells are a potential source of bio-calcium carbonate and proteins. Protein enzymatic hydrolysis, a process where protein macromolecules are hydrolyzed to amino acids and peptides of smaller size. The process is a simple, effective, and environmentally friendly means of valorizing waste mussel shells, producing two product streams: mussel shells without residual meat and non-toxic hydrolysate. This study includes a review of literature on valorizations of waste mussel shells for the source of bio-calcium carbonate and proteins. The review shows the lack of kinetic studies for enzymatic hydrolysis of mussels, required for any scale up to a commercial process. In this study, mussel meat is removed from whole mussels by using enzymatic hydrolysis technology. The process is carried out using a food grade enzyme, Multifect PR 6L, and tap water at neutral pH, with no pH control, and a temperature 50ﾟC. To determine the rate of hydrolysis, the degree of
digested meat (DM) is used in this study instead of the degree of hydrolysis (DH). The enzyme and substrate concentrations were varied to determine the impact of these factors on the final digested meat and rate of reaction. The fraction of digested meat (or degree of shell cleaning) varied from 0.57 g/gₘₑₐₜ to 0.94 g/gₘₑₐₜ depending on the enzyme and substrate (meat) concentrations. Soluble protein concentration of the obtained hydrolysates was also analyzed. After evaluating a number of reaction rate mechanisms, the first-order model is suggested as the best model to describe the enzymatic hydrolysis of whole raw mussels. The soluble protein concentration in the resulting hydrolysate increases with the increases in the amount of digested meat.


identifier: Gong, Yu <https://research.library.mun.ca/view/creator_az/Gong=3AYu=3A=3A.html>   (2021) Greenhouse gas fluxes in a boreal peatland under experimental warming, nitrogen addition, and vegetation composition change.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Although peatlands cover only 3% of land surface over the world, they have stored a large amount of carbon due to the relatively higher rate of net primary production than decomposition. The Intergovernmental Panel on Climate Change (IPCC) shows that net zero carbon dioxide (CO₂) emissions should be reached around 2050 to limit warming to 1.5°C above pre-industrial levels. The carbon sink function of peatlands could help to reduce global warming (cooling function). However, it is unclear whether this carbon sink function of peatlands will be altered under future global changes such as climate warming, elevated nitrogen (N) deposition, and vegetation composition change. Moreover, methane (CH₄) and nitrous oxide (N₂O) are two potent greenhouse gases with 25 and 298 times higher global warming potential than CO₂, respectively. Their responses to the three global changes (climate warming, elevated nitrogen deposition, and vegetation composition change) are poorly known in peatland ecosystems, especially the interaction of the three global changes, which leads to an uncertainty in evaluating the cooling function of peatlands in the future.
In this thesis, the three global changes were mimicked in a boreal peatland located in western Newfoundland, Canada. The fluxes of greenhouse gases (CO₂, CH₄, and N₂O) and environmental variables were measured. The results showed that a change in vegetation composition played an essential role in net CO₂ uptake. With graminoid removal, net CO₂ uptake was significantly decreased, and combined warming and N addition (WN) further decreased CO₂ uptake owing to the detrimental effect of N on Sphagnum mosses. Shrub removal also decreased net CO₂ uptake, but CO₂ uptake could recover in the seventh year owing to the growth of graminoids. Warming
and N addition could promote graminoid growth, which might offset the loss of Sphagnum moss cover. Consequently, the net CO₂ uptake was not altered under the condition of shrub removal.
Graminoid removal significantly decreased CH₄ emissions due to the reduction of available carbon for CH₄ production and aerenchyma (air channels of some plants) for CH₄ transport from soil to the atmosphere. However, this negative effect was not observed under WN conditions, possibly owing to the alteration of temperature sensitivity. Shrub removal significantly decreased CH₄ emissions under warming treatment, but this negative effect was also not observed under WN conditions, which could be attributed to the growth of graminoids. The positive impact of graminoid growth on CH₄ emission could offset the negative effect of shrub removal.
Nitrogen addition significantly promoted N₂O emissions due to the increase of nitrogen availability for N₂O production. Warming could mitigate the positive effect of N addition under intact vegetation in the middle growing season, which could be attributed to the stimulation of N uptake by plants and less N for N₂O production. With the removal of graminoids or shrubs, WN significantly increased N₂O emissions in the early growing season owing to the alleviation of carbon and nitrogen limitation for N₂O production.
In summary, if the dominant vegetation shifts to shrubs, the net CO₂ uptake in peatlands would be decreased under climate warming and elevated N deposition. If the dominant vegetation shifts to graminoids, the net CO₂ uptake in peatlands would also be decreased in a short time (~ 3 years) under climate warming and elevated N deposition, but could recover in a long time (~7 years). No matter whether the dominant vegetation shifts to shrubs or graminoids, their impacts on CH₄ emissions would be negligible under climate warming and elevated N deposition. In contrast, no
matter whether the dominant vegetation shifts to shrubs or graminoids in the future, the N₂O emissions were significantly promoted under climate warming and elevated N deposition. Overall, taking all three greenhouse gases into account, the cooling function of peatlands would be reduced under future climate warming, elevated N deposition, and vegetation composition change. Besides peatland conservation, other effective measures should be taken in order to slow down the global temperature increase.


identifier: Yu, Miao <https://research.library.mun.ca/view/creator_az/Yu=3AMiao=3A=3A.html>   (2021) Development of herding agents for marine oil spill response.  Masters thesis, Memorial University of Newfoundland.

abstract:
This thesis tackles the development of herders as marine oil spill treating agents. In the first section of the thesis, a biosurfactant-based bioherder was generated and examined for marine oil spill response. The biosurfactant was produced by Rhodococcus erythropolis, a strain isolated from the North Atlantic Ocean. A commercial chemical herder, USN cold water blend, was used for performance comparison. Factors affecting herding effectiveness, including temperature, salinity, and oil/herder ratio, were investigated using the Design of Experiment methodology. Statistical analysis was employed to study the interactions among the factors on herding ability. Experimental results confirmed that the developed bio-herder can serve as an effective marine oil spill treating agent, and temperature and herder/oil ratio are significant factors affecting oil herding effectiveness.
In the second section of the thesis, molecular design was conducted to obtain environmentally friendly herder products for marine oil spill response. The quantitative structure-activity relationship between molecular structures of herders and their activities (herding ability and toxicity) was firstly established using 3D-QSAR modeling. Span surfactants were selected as the model key components of herders. Two QSAR (CoMFA and CoMSIA) models were constructed, and ten molecularly modified span compounds were obtained. Molecular docking was carried out to further examine the biodegradability of one newly designed molecular.
Through both studies, new herders (bio-herder and molecular modified herder) were generated, which are useful in herd production. In addition, the associated herding performance and environmental impacts were evaluated. Overall, this thesis work
contributes new knowledge to the field and provides more sustainable options for marine oil spill response operations.


identifier: Totoş, Onur <https://research.library.mun.ca/view/creator_az/Toto==015F=3AOnur=3A=3A.html>   (2021) 3D modelling and inversion of airborne gravity gradiometry and aeromagnetic data from Budgell Harbour, North-Central Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract:
Airborne gravity surveys have been become a popular tool for mineral exploration in the
past three decades, mostly because of considerable improvements in equipment. Airborne
methods make the data acquisition process rapid, more straightforward, and potentially
cheaper than ground surveys. 3D modeling and inversion of gravity gradiometry and
aeromagnetic datasets from Budgell Harbour, located in north-central Newfoundland, are
carried out. Reef-type platinum group mineralization is present in the area, as well as a
large scale, deep igneous intrusion (the Budgell Harbour Stock). The intrusion is thought
to be related to the same tectonic activity that resulted in the formation of the basins offshore
Newfoundland that are now being actively explored for hydrocarbons. 3D modeling
and inversion, specifically taking into account topography, are done for the gravity
gradiometry and magnetic data-sets. The inversions are typical unconstrained, minimum-structure
inversions. Joint inversion of the gravity gradiometry and magnetic data-sets is
also considered. The Earth model is parameterized in terms of an unstructured tetrahedral
mesh, which allows the topography to be modeled to the same accuracy with which it is
known. The goal is to develop 3D density and susceptibility models of the area, thus further
assessing the mineral potential of the area and better delineating the Budgell Harbour Stock.


identifier: Ansah, Lucy <https://research.library.mun.ca/view/creator_az/Ansah=3ALucy=3A=3A.html>   (2021) Ghana's foreign policy under Jerry John Rawlings: an analysis of Rawlings' decision to realign Ghana's relations from the Eastern to the Western Bloc in April 1983.  Masters thesis, Memorial University of Newfoundland.

abstract:
The study analyses Rawlings’ decision to realign Ghana’s relations from the East
to the West in April 1983. Although many scholarly works such as the works of Boafo-Arthur
(1993,1999), Adedeji (2001), Ahiakpor (1991) and Jeong (1998) have reported on Rawlings’
decision, only few have examined the events that led to this sudden shift. Therefore, this study
provides an in-depth analysis of the decision-making process that led to Rawlings’ realignment.
The foreign policy decision-making of developing countries regarding specific decisions taken
by its leaders are understudied. The study aims to fill in this gap by providing a detailed analysis
of a key foreign policy decision in Ghana under the leadership of Jerry John Rawlings. This
study draws mainly from secondary sources.
The findings from the study reveal that domestic and external factors accounted for
Rawlings’ sudden decision to shift from the East to the West in April 1983 in order to secure
Ghana’s economic survival. Ghana’s worsening economic crises and the inability of Ghana’s
Eastern bloc allies to assist it in addressing them influenced Rawlings’ decision to realign
Ghana’s relations from the East towards the West. The study further reveals that Rawlings’
personality might have also influenced his decision.


identifier: Saha, Ratnajit <https://research.library.mun.ca/view/creator_az/Saha=3ARatnajit=3A=3A.html>   (2020) Effect of biochar on the physicochemical properties and nitrogen transport of podzolic soil in a boreal ecosystem.  Masters thesis, Memorial University of Newfoundland.

abstract: This study is aimed at investigating the effects of biochar on the physicochemical properties and nitrogen transport in podzolic soils. Soil samples were collected from a research site in Pasadena, Newfoundland, Canada. Experimental treatments consisted of three types of soils {top, E-horizon and mixed soil (topsoil 2: E-horizon soil 1)}, two biochar types (granular and powder) and four biochar application rates (0%, 0.5%, 1% and 2% on a weight basis). A total of 210 most relevant and latest research articles were reviewed. Ten important physicochemical parameters of soil were investigated through a total of 72 experimental units and 54 leaching column experiments. Metadata analysis showed that only a few studies were conducted on the boreal podzolic soil. Soil porosity, field capacity and plant available water increased by 2.8%, 10%, and 12.9%, respectively compared to control when the soil was treated with powdered biochar. Nitrate leaching was reduced by 36% compared to control soil. Granular and powdered biochar were found to be hydrophobic and hydrophilic, respectively. A 2% biochar application rate showed greater impact in terms of improving hydraulic properties and reducing nitrogen leaching. The findings would be helpful to improve agricultural practices in the boreal podzolic soil.


identifier: Bellows, Lindsay Ann <https://research.library.mun.ca/view/creator_az/Bellows=3ALindsay_Ann=3A=3A.html>   (2021) The role of shame and self-compassion in the relationship between childhood social/relational bullying and disordered eating.  Masters thesis, Memorial University of Newfoundland.

abstract: Objective: Social and relational bullying (SRB) have been found to be associated with disordered eating, perhaps due to the heightened shame resulting from perceived social inferiority, low social rank, and/or negative evaluations from others. Self-compassion, a potential antidote to heightened shame, may act as a protective factor against the impact of SRB on disordered eating and shame. The current study aimed to address literature gaps by examining h ow SRB is related to disordered eating in emerging adulthood, whether this relationship is mediated by heightened shame, and whether self-compassion moderates the relationship between SRB and shame/disordered eating. Method: Participants (359 emerging adult undergraduate students aged 17-25) completed online self-report measures of recalled bullying and current disordered eating, shame, and self-compassion. Correlation coefficients between variables were generated and an advanced mediation model was used to determine whether self-compassion moderated the direct and indirect relationships between SRB and disordered eating, as mediated by shame. Results: SRB victimization was positively related to shame and disordered eating and negatively related to self-compassion in young adulthood with small-to-medium effect sizes. The association between SRB and disordered eating in adulthood was partially mediated by shame. Self-compassion did not moderate the relationship between SRB and disordered eating but it did moderate the path from SRB to shame. Conclusions: Childhood SRB is a significant predictor of disordered eating in emerging adulthood, partially through increased shame. Self-compassion m ay act as a buffer of the relationship between SRB and shame. Implications for clinical settings a nd anti-bullying awareness and prevention programs are discussed.


identifier: Dusseault, Marisa <https://research.library.mun.ca/view/creator_az/Dusseault=3AMarisa=3A=3A.html>   (2021) Investigating variability in marine mollusk carbonates using infrared spectroscopy and radiocarbon analysis.  Masters thesis, Memorial University of Newfoundland.

abstract:
Marine bivalve mollusks are complex hierarchical calcium carbonate (CaCO₃) materials
that are frequently used in archaeological studies and in chronologies that are
used to study marine environment and climate change. Radiocarbon (¹⁴C) analysis
of these materials is central to most of these studies. I study the variability of ¹⁴C
signatures within marine bivalve mollusk shells from British Columbia, Canada by
considering both the raw, uncalibrated fraction of modern carbon measurements and
the calibrated age ranges. I use infrared (IR) spectroscopy as a method to screen for
diagenesis - contamination or alteration of the original shell CaCO₃ - prior to radiocarbon
analysis, and as a method to investigate the natural variability in the composition
and structure of the shell CaCO₃. Using IR spectroscopy, I show that in three archaeological
samples of the butter clam (Saxidomus gigantea) from Sechelt, British
Columbia, only one shell contained contaminating calcite. However, analysis of the
relative IR peak intensities showed a consistent difference between the inner nacreous
aragonite layer and the outer crossed lamellar aragonite layer for all three shells. This
consistent difference is likely correlated with that natural variability in aragonite microstructures.
Three other archaeological shell samples from Deep Bay and Comox,
British Columbia, were analyzed for ¹⁴C at three different locations within each of the
shells. One sample displayed a variation in fraction of modern carbon within the shell
while the others did not. I highlight that ¹⁴C measurements are meaningless without
an understanding of date calibration and the choices that must be made when calibrating
marine and mixed marine-terrestrial samples. My results are a starting point
for developing best practices for ¹⁴C dating marine shell samples and for more focused
studies on the links between crystallinity, diagenesis, and ¹⁴C.


identifier: Pollard, Megan Ashley <https://research.library.mun.ca/view/creator_az/Pollard=3AMegan_Ashley=3A=3A.html>   (2021) Public perceptions of the risk and social acceptability of driving under the influence of cannabis.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Aside from alcohol, cannabis is the most commonly used substance amongst Canadians, especially those aged 18-24. A prominent risk associated with cannabis use is driving under the influence. Cannabis impairs key motor abilities and executive functions necessary for driving and increases the likelihood of being involved in a fatal accident. Despite this, many people believe that driving under the influence of cannabis is safe, particularly compared to driving under the influence of alcohol. Utilizing an experimental vignette design, the primary purpose of the current study was to examine public opinions about the dangerousness and social acceptability of driving under the influence of cannabis compared to alcohol or driving while tired. An additional aim was to determine how attitudes differed based on the sex of the driver. Participants (N=453) between the ages of 18 and 65 completed an online survey in which they were randomly assigned to one of six vignettes describing a 22-year-old driving under the influence. Participants then answered six questions about the dangerousness and social acceptability of the behavior described. A series of ANOVAs revealed a significant main effect of substance use across items. A significant main effect of sex was found on a measure of social acceptability. Post hoc tests revealed that driving under the influence of cannabis was considered less dangerous and more socially acceptable than driving under the influence of alcohol. Additionally, it was considered more socially acceptable for a female to drive while impaired than a male. Overall, these findings highlight the misconceptions that exist about the harms associated with cannabis use and have implications for the importance of awareness campaigns to educate about cannabis and driving.


identifier: Mondal, Saikat <https://research.library.mun.ca/view/creator_az/Mondal=3ASaikat=3A=3A.html>   (2020) Black hole horizons during extreme mass ratio mergers.  Masters thesis, Memorial University of Newfoundland.

abstract:
A marginally outer trapped surface (MOTS) is a quasi-local alternative to the
event horizon that captures the dynamical features of a black hole. Previously, Emparan
and Martínez have shown that the evolution of the event horizon during extreme
mass ratio (EMR) mergers can be solved exactly in the limit where the large black
hole becomes infinite in extent. In this project, we studied the evolution of MOTS
during EMR mergers in the same setup where MOTS can be locally approximated by
spacelike open surfaces with vanishing null expansion in the Schwarzschild geometry.
We defined these open surfaces as marginally outer trapped open surfaces (MOTOS),
which can be fully determined by the local properties of spacetime. We studied axisymmetric
MOTOS contained in constant time slices of Schwarzschild spacetimes
in different coordinate systems. In the Painlevé-Gullstrand coordinate system, we
found open and closed surfaces with an arbitrary number of self-intersections inside
the Schwarzschild horizon. We also extrapolate these results to predict possible behaviours
of MOTS during extreme mass ratio mergers based on previous numerical
studies of the evolution of MOTS during black hole mergers.


identifier: Yulmetova, Maria <https://research.library.mun.ca/view/creator_az/Yulmetova=3AMaria=3A=3A.html>   (2021) Assessing the potential of sentinel-1 and sentinel-2 satellite imagery for shoreline classification in support of oil spill preparedness and response.  Masters thesis, Memorial University of Newfoundland.

abstract:
Coastal zones are critical ecosystems that provide important habitat for marine animals, fish, shellfish, birds, and many other species. However, there is a risk of mineral oil impacting in these areas due to human activities offshore. Shoreline classification is the first step to establishing response contingency plans in case of an oil spill.
This study estimates the potential of using open-access, high-resolution Sentinel-1 and Sentinel-2 imagery for the mapping of shoreline types in support of oil spill preparedness and response activities. The two classification maps, depicting shoreline and coastal land cover, were produced using an advanced object-based Random Forest (RF) algorithm. Various features extracted from multi-source data, including spectral, texture, ratio, polarimetric features, and digital elevation model (DEM), were analyzed to identify the most valuable features for discrimination between different shoreline types. Multiple classification scenarios with the most useful features were then assessed and compared to find the best classification model.
The developed algorithm achieved accuracies of 87.10% and 84.75% of coastal land cover and shoreline maps. These results demonstrated the high potential of using freely available Sentinel-1 and -2 satellite data for coastal mapping.


identifier: Mital, Shweta <https://research.library.mun.ca/view/creator_az/Mital=3AShweta=3A=3A.html>   (2021) Early-stage cost-effectiveness analyses of new health care technologies.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
With the rapid pace of technological innovation in health care alongside rising health care costs, policymakers need to decide which innovations are worth adopting from an economic perspective. Cost-effectiveness analyses – especially those conducted at an early stage of the life cycle of a technology -- are useful tools to identify technologies which can yield better patient outcomes that justify the costs of these technologies.
In this thesis, I provide the first evidence on cost-effectiveness of four new health care technologies. In chapter 2, I investigate the cost-effectiveness of Teplizumab, the first-ever drug to prevent or delay onset of Type 1 diabetes. A market price for this drug has not yet been established and there exist differences in the drug’s efficacy based on genetic and antibody characteristics of patients. Thus, in this study, I identify price ranges within which the drug will be cost-effective for different patient groups. In chapter 3, I examine the cost-effectiveness of a novel, but highly controversial, weight loss technique – aspiration therapy – versus bariatric surgery. I find that even though aspiration therapy is not cost-effective versus bariatric surgery, it is cost-effective for patients who do not have access to bariatric surgery. In chapter 4, I assess the cost-effectiveness of using Elipse – the first procedureless intragastric balloon – as a substitute or complement to bariatric surgery for treatment of obesity, and find that providing Elipse prior to sleeve gastrectomy is the most cost-effective treatment approach. In chapter 5, I examine the cost-effectiveness of using artificial intelligence (AI) or polygenic risk scores (PRS) to risk-stratify women aged between 40 and 49 years for mammography screening and find that AI-based screening is cost-effective compared with PRS-based screening and screening based exclusively on existing guidelines by the United States Preventive Services Task Force, the American College of Obstetricians and Gynecologists and the American College of Radiology.
These four studies can serve to inform decision-making by manufacturers, policymakers, clinicians and other stakeholders with regard to these emerging technologies.


identifier: Miller, Mikayla <https://research.library.mun.ca/view/creator_az/Miller=3AMikayla=3A=3A.html>   (2021) Hunting for Rare-Earth-Element (REE)-bearing minerals in Northern Labrador: MLA-SEM analysis of surficial sediments within the glacial dispersion zone from the Strange Lake main zone deposit.  Masters thesis, Memorial University of Newfoundland.

abstract:
The Strange Lake area hosts important Zr-Nb-Y-REE deposits, associated with a small peralkaline
granite intrusion. The deposits and the host rocks contain unusual minerals, some of which are
essentially unique to this site. Geochemical data from glacial sediments or “tills” define dispersion from
the deposits for at least 35 km, and the Strange Lake area is regarded as a “type example” of linear
glacial dispersion from a point source. This thesis study uses Mineral Liberation Analysis – Scanning
Electron Microscopy (MLA-SEM) methods to investigate the mineralogy of glacial sediments and
document the dispersion of unusual (indicator) minerals. It is in part an assessment of the MLA-SEM
technique for use in indicator-mineral studies, which are increasingly important in mineral exploration.
Seventy-six samples of till were collected from an area extending for 35 km ENE of the Strange
Lake Main Zone deposit, aligned with the inferred direction of ice movement. Samples were processed
to separate the 0.125 - 0.18 mm size fraction for direct analysis, without any preferential separation of
denser minerals. MLA-SEM results thus directly document the abundances of 55 minerals, ranging from
common silicates to rare accessory minerals diagnostic of the Strange Lake deposits. This large database
was then evaluated using statistical and geographical analysis methods. Common silicates (e.g., quartz,
feldspars, garnet and amphiboles) collectively make up > 90% of typical till samples, but the rarest
indicator minerals occur at levels < 10 ppm. The reliability of data degrades at such low abundances (in
part due to probability effects) but systematic geographic variation patterns can still be discerned for
many such rare minerals. Numerous diagnostic minerals from Strange Lake were detected, although
their abundance was lower than expected from previous MLA-SEM analyses of drill core samples.
Many minerals show linked abundance variation (correlation or anti-correlation) and such
variation commonly has a geographic component. Systematic geographic variations for major minerals
and many minor minerals seem to correspond with regional contrasts in bedrock geology from west to
east, suggesting that patterns mostly record local provenance. Accessory minerals that are diagnostic of
Strange Lake also show systematic geographic abundance variations, which are superimposed on these
regional trends, but in some cases the patterns appear superficially similar. The most abundant and
persistent indicator minerals are the Ca-Zr silicate gittinsite and the Y-Ca-REE silicate gerenite, which are
also the most abundant in the Strange Lake source rocks. However, geographic variation patterns for
these minerals are rather different. Gerenite abundance diminishes in a down-ice direction, as expected,
but gittinsite seems to increase in abundance, which is unexpected. Other indicator minerals mostly
diminish in abundance in a down-ice direction but even some of the rarest (e.g., stetindite, gadolinite
and bastnaesite) remain sporadically detectable at 35 km from the source. The controls on dispersion
patterns are not fully understood, but likely involve mineralogical factors as well as aspects of the glacial
environment. MLA-SEM data suggest that many indicator minerals from Strange Lake typically form
small domains within larger particles of common minerals, and these host minerals may thus influence
dispersion patterns. In this context, it is interesting that the most persistent indicator minerals seem to
be preferentially associated with quartz, which is the most durable of common rock-forming minerals.
Like most research studies, this project did not answer all questions posed at the outset, and it
did not always follow the intended plan. However, the results indicate that the MLA-SEM method has
considerable potential for use in indicator-mineral studies, and point to interesting future research
directions connected to development of the method and its application to other geological problems.


identifier: Boutilier, Miranda <https://research.library.mun.ca/view/creator_az/Boutilier=3AMiranda=3A=3A.html>   (2021) Domain decomposition approaches for the generation of equidistributing parametric curves.  Masters thesis, Memorial University of Newfoundland.

abstract:
Moving mesh methods are often used to solve boundary value problems whose solutions
contain regions of rapid change. In this case, these moving mesh methods allow
us to concentrate a fixed number of nodes in these regions of high variance. These
meshes are obtained by solving a second order boundary value problem (BVP), which
arises from the equidistribution principle.
There are many real-world examples where boundary value problems are posed on
curves and surfaces. Here, we focus on the case where the problem is posed on a curve
that is able to be explicitly represented parametrically as x = (x₁(r), x₂(r), xₙ(r) ℝⁿ. When the solution has regions of rapid change or the curve on which the problem is
posed has regions of high variance or curvature, moving mesh methods allow us to find
a mesh that better resolves the function on the curve without adding additional nodes.
We consider combining the solution of mesh equations with the solution of differential
equations posed on parametric curves. These differential equations include both
time-dependent partial differential equations (PDEs) and time-independent boundary
layer problems.
In addition to considering the above on a single domain, we extend these methods
to form multi-domain iterations to solve these boundary value problems. Domain
decomposition allows us to harness the power of parallel computing, a topic that has
become popular in recent years with the increase of computing power. We provide
multi-domain iterations for both time-dependent and time-independent differential
equations posed on parametric curves; these include classical Schwarz and optimized
Schwarz methods. These iterations are formed such that they are able to be performed
in parallel. Numerical results are provided throughout to illustrate the results of the
iterations. This thesis also includes theoretical results that generalize known results
for classical Schwarz and optimized Schwarz methods to the case where the problem
is defined on a curve.


identifier: Yeo, JuDong <https://research.library.mun.ca/view/creator_az/Yeo=3AJuDong=3A=3A.html>   (2018) Antioxidant capacity and phenolic profiles of lentils as affected by processing.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Lentils are excellent sources of dietary fibre, carbohydrates, proteins, various vitamins, minerals,
and bioactive compounds such as phenolic compounds. Epidemiological studies have reported
their effects in lowering cholesterol and reducing the incidence of colon cancer, cardiovascular
diseases, and type-2-diabetes. In the present study, effects of germination, hydrothermal (boiling)
treatment, and dehulling on the antioxidant capacity of soluble- and insoluble-bound phenolics of
lentils were examined. Upon germination, an increasing trend in the antioxidant capacity in the
insoluble-bound phenolics (IBPs) and a declining trend in that of the soluble phenolics (except
total phenolic contents) were observed during 4 days of germination. Based on the results, a new
indicator, the ratio of insoluble-bound phenolics to soluble phenolics (SPs), was suggested as an
effective means to monitor changes in the antioxidant activity of lentils during germination. The
hydrothermal/boiling process also led to important findings. As expected, the hydrothermal
process decreased the content of insoluble-bound phenolics in the lentil cultivars tested due to the
release of bound phenolics from cell wall matrices. Interestingly, the decrease of bound phenolics
was not proportionally reflected in the increase of soluble phenolics, possibly due to the loss of
phenolics during the hydrothermal process via interaction with proteins and other seed components.
Among lentil cultivars used, the hulls of 3494-6 showed the most effective antioxidant potential,
while Maxim displayed the lowest in most measurements. Meanwhile, the dehulling process
revealed the predominant distribution of phenolics in the hulls as compared to the dehulled grains,
as observed for both soluble- and insoluble-bound phenolics of lentils in their antioxidant potential
and inhibitory activities against oxidation of LDL cholesterol and DNA strand breakage. In the
HPLC-ESI- MSᴺ analysis, different classes of soluble phenolics such as phenolic acids, flavonoids, and proanthocyanidins were found in the hulls of all four tested lentil cultivars examined. The
insoluble-bound phenolics has often been ignored in many evaluations by different research groups
and hence this work has expanded the depth of knowledge in the field of food phenolics.


identifier: Mirzabeigi Fini, Sara <https://research.library.mun.ca/view/creator_az/Mirzabeigi_Fini=3ASara=3A=3A.html>   (2020) Upper- and lower-body pain perception during DOMS: the effect of menthol-based topical analgesic application.  Masters thesis, Memorial University of Newfoundland.

abstract: Menthol-based analgesic gels have been proven to alleviate delayed onset muscle soreness (DOMS) pain perception. The difference in pain pressure threshold (PPT) between the lower vs. upper extremities is not well understood nor is there much research illustrating the effect of the menthol-based analgesic on pain perception between these extremities during DOMS. Thus, the purpose of this study was to compare the upper- and lower-body’s responses to pain 48 hours after DOMS induction and following menthol-based analgesic gel application. Fourteen participants were placed into two groups (placebo and experimental) and each performed 5 sets of 10 repetitions of eccentric contractions of the knee extensors and elbow flexors on an isokinetic dynamometer. PPT measurements were taken via a handheld algometer at baseline, immediately after and 48 hours after the DOMS protocol. After 48 hours the PPT was measured prior to and 15 minutes following gel application and every 5 minutes for 45 minutes thereafter. Statistical analysis revealed a significant difference for PPT in both groups between the knee extensors and elbow flexors (p<0.001). For experimental group both elbow flexors (48%) and knee extensors (26%) showed a decrease in PPT 48 hours after DOMS, but only the elbow flexors significantly reduced (p=0.018). The application of a menthol-based gel to the elbow flexors increased PPT at 30 minutes after gel application until the end of the test (p=0.018). The placebo group showed a significant reduction in their PPT values 48 hours after DOMS in both the elbow flexors (45%) and knee extensors (38%) (p=0.018). Unlike the experimental group the placebo group showed no change in PPT following its application. Pain perception is different in the lower and upper extremities and menthol-based analgesic reduced pain perception during DOMS.


identifier: Afshar, Majid <https://research.library.mun.ca/view/creator_az/Afshar=3AMajid=3A=3A.html>   (2021) Large-scale dimensionality reduction using perturbation theory and singular vectors.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Massive volumes of high-dimensional data have become pervasive, with the number
of features significantly exceeding the number of samples in many applications.
This has resulted in a bottleneck for data mining applications and amplified the
computational burden of machine learning algorithms that perform classification or
pattern recognition. Dimensionality reduction can handle this problem in two ways,
i.e. feature selection (FS) and feature extraction. In this thesis, we focus on FS, because,
in many applications like bioinformatics, the domain experts need to validate
a set of original features to corroborate the hypothesis of the prediction models. In
processing the high-dimensional data, FS mainly involves detecting a limited number
of important features among tens/hundreds of thousands of irrelevant and redundant
features.
We start with filtering the irrelevant features using our proposed Sparse Least
Squares (SLS) method, where a score is assigned to each feature, and the low-scoring
features are removed using a soft threshold. To demonstrate the effectiveness of SLS,
we used it to augment the well-known FS methods, thereby achieving substantially
reduced running times while improving or at least maintaining the prediction accuracy
of the models.
We developed a linear FS method (DRPT) which, upon data reduction by SLS,
clusters the reduced data using the perturbation theory to detect correlations between
the remaining features. Important features are ultimately selected from each cluster,
discarding the redundant features.
To extend the clustering applicability in grouping the redundant features, we
proposed a new Singular Vectors FS (SVFS) method that is capable of both removing
the irrelevant features and effectively clustering the remaining features. As such,
the features in each cluster solely exhibit inner correlations with each other. The
independently selected important features from different clusters comprise the final
rank. Devising thresholds for filtering irrelevant and redundant features has facilitated
the adaptability of our model to the particular needs of various applications.
A comprehensive evaluation based on benchmark biological and image datasets
shows the superiority of our proposed methods compared to the state-of-the-art FS
methods in terms of classification accuracy, running time, and memory usage.


identifier: Daher Moreno, Nora Elena <https://research.library.mun.ca/view/creator_az/Daher_Moreno=3ANora_Elena=3A=3A.html>   (2021) Cooperative organizational cultures: an important factor in promoting equal gender representation in leadership positions.  Masters thesis, Memorial University of Newfoundland.

abstract: The present study focuses on understanding the relationship between femininity and leadership intention in employees. Based on the theory of planned behaviour and social role theory, the indirect relationship between feminine gender role identity and leadership intention was analyzed through affective motivation to lead and perceived leadership self-efficacy. Additionally, drawing on person-environment fit theory, feminine gender role identity was examined as a moderator of the relationship between cooperative organizational culture and leadership intention. A cross-sectional survey was administered among a sample of 183 full-time employees and results demonstrated that, controlling for sex, perceived leadership self-efficacy mediated the relationship between feminine gender role identity and leadership intention. In addition, feminine gender role identity acted as a moderator strengthening the relationship between cooperative organizational culture and leadership intention, such that highly feminine individuals in high cooperative organizational cultures showed higher intentions to become leaders than individuals with less feminine identities. Limitations of the study and future research suggestions are discussed.


identifier: Brecht, Rüdiger <https://research.library.mun.ca/view/creator_az/Brecht=3AR=FCdiger=3A=3A.html>   (2021) Variational integrators for the rotating shallow water equations.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The numerical simulation of the Earth’s atmosphere plays an important role in
developing our understanding of climate change. The atmosphere and ocean can
be seen as a shallow fluid on the globe; here, we use the shallow water equations as
a first step to approximate these geophysical flows. Then, the numerical model can
only be accurate if it has good conservation properties, e.g. without conserving
mass the simulation can not be physical. Obtaining such a numerical model can
be achieved using numerical variational integration.
Here, we have derived a numerical variational integrator for the rotating shallow
water equations on the sphere using the Euler–Poincaré framework. First, the
continuous Lagrangian is discretized; then, the numerical scheme is obtained by
computing the discrete variational principle. The conservational properties and
accuracy of the model are verified with standard test cases.
However, in order to obtain more realistic simulations, the shallow water equations
need to include physical parametrizations. Thus, we introduce a new representation
of the rotating shallow water equations based on a stochastic transport
principle. Then, benchmarks are carried out to demonstrate that the spatial part
of the stochastic scheme preserves the total energy. The proposed random model
better captures the structure of a large-scale flow than a comparable deterministic
model.
Furthermore, to be able to carry out long term simulations we extend the discrete
Euler–Poincaré framework with a selective decay. The selective decay dissipates
an otherwise conserved quantity while conserving energy. We apply the
new framework to the shallow water equations to dissipate the potential enstrophy.
Then, we carry out standard benchmarks to demonstrate the conservation
properties. We show that the selective decay resolves more small scales compared
to a standard dissipation.


identifier: Moniri, Seyed Jalaleddin <https://research.library.mun.ca/view/creator_az/Moniri=3ASeyed_Jalaleddin=3A=3A.html>   (2021) Semi-parametric mixture models with ranked set samples.  Masters thesis, Memorial University of Newfoundland.

abstract:
Simple random sampling (SRS) is the common method in data collection. In many
applications, measuring the variable of interest is costly, but ranking the units can
be done easily. In these situations, one can use rank set sampling (RSS) to get more
representative samples from the population. This thesis investigates the estimation
of the semi-parametric finite mixture models (FMMs) with RSS. We develop a semiparametric
version of the Expectation-Maximization (EM) algorithm to obtain the
maximum likelihood (ML) estimate of the population with RSS data. We then
propose the ML estimation of FMM with RSS data in a semi-parametric framework.
Our numerical studies show that the proposed EM algorithm estimates more
efficiently the FMM. The proposed methods are finally applied to analyze the bone
mineral data.


identifier: Sadik, Sultan <https://research.library.mun.ca/view/creator_az/Sadik=3ASultan=3A=3A.html>   (2021) Leadership and employee perceived stress: moderating role of financial threat and co-worker support.  Masters thesis, Memorial University of Newfoundland.

abstract: This study investigated factors that influence the relationship between leadership styles (transformational and laissez-faire) and employee perceived stress during COVID-19 (N = 145). Using the Conservation of resources theory, I identified and tested two factors that may moderate the effects of leadership styles on employee perceived stress: financial threat and co-worker support. Co-worker support was found to moderate the relationship between transformational leadership and employee perceived stress. Financial threat was found to moderate the relationship between laissez-faire leadership and employee perceived stress. These findings contribute to the literature on leadership and employee stress and suggest that co-worker support and financial threat could moderate the positive or negative outcomes related to leadership styles.


identifier: Han, Tianshuang <https://research.library.mun.ca/view/creator_az/Han=3ATianshuang=3A=3A.html>   (2021) Examining layperson perceptions of police tactics in suspect interrogation.  Masters thesis, Memorial University of Newfoundland.

abstract:
Layperson perceptions of the use of explicit and implicit promises of leniency in a suspect interrogation were examined. Undergraduate students (N = 290) were assigned randomly to read one of six police transcripts including either (1) no coercion, (2) explicit promise of leniency, or one of four minimization tactics implying a promise of leniency, (3) minimizing seriousness, (4) face-saving excuses, (5) downplaying consequences, or (6) emphasizing benefits of cooperation. Participants were then asked to indicate their sentencing expectations, estimate confession rates, rate their perceptions of the interrogation, rate the interrogator, and rate the level of coercion, and render a verdict. Results revealed that most participants chose to convict the suspect (81%), despite their belief that the suspect’s confession was coerced (80.2%). Most participants (95%) indicated that the interrogator promised leniency when explicit leniency was offered, however, few people detected leniency when minimizing seriousness (22.2%) and face-saving excuses (37.1%) were used. Explicit leniency and emphasizing benefits of cooperation were viewed more negatively overall, while face-saving excuses were viewed less negatively, with lower estimated confession rates, perceived pressure, eagerness to elicit a confession, and aggressiveness of the interrogator. The perceived strength of evidence and severity of the consequences were the highest when minimizing seriousness was used. Sentencing expectations were influenced by interrogation outcomes but not by tactic type. If the suspect denied involvement and was later convicted, participants expected the sentence to be greater than if the suspect confessed during the interrogation. Participants also estimated that more guilty suspects would confess than innocent suspects across tactic types. Overall, these findings reinforce past findings that
confessions have strong evidentiary weight, and that confessions could influence potential jurors’ decision regardless of how they were obtained. Tactics involving minimizing seriousness and face-saving excuses put innocent suspects more at risk of wrongful convictions than others, likely because prospective jurors are less able to detect their coerciveness as much as that of explicit leniency and other types of minimization strategies. This research provided additional empirical evidence that jurors’ lay knowledge might not be able to evaluate confessions and expert testimony should be allowed to help them.


identifier: Lamichhane, Ashmita <https://research.library.mun.ca/view/creator_az/Lamichhane=3AAshmita=3A=3A.html>   (2021) The concept of perceived quota difficulty and its relevance to ethical decision making and sales performance.  Masters thesis, Memorial University of Newfoundland.

abstract:
This conceptual paper uses self-efficacy theory and draws upon the concept of task
difficulty to define the construct of perceived quota difficulty and its relevance to ethical
decision making and sales performance in the domain of sales. It is proposed that moral
judgment, a precursor to ethical behavior positively impacts sales performance. Two dimension
of salesperson performance – outcome and behavior performance are discussed and impact on
each is highlighted. It is further proposed that a salesperson’s perceived quota difficulty plays a
moderating role in the relationship between moral judgment and salesperson performance. A
pilot study was conducted with 46 salespeople working in various companies located in
Newfoundland and Labrador province of Canada. The measures were found to be reliable and
the use of the measures for future empirical work is recommended. The implication of the
proposed relationships to sales managers and organizations are presented. Limitations, future
direction, and conclusion have been outlined.


identifier: Azuelos, Sarelle <https://research.library.mun.ca/view/creator_az/Azuelos=3ASarelle=3A=3A.html>   (2021) Gender Based Analysis+ in Alberta’s big cities: the effects on local organizing.  Masters thesis, Memorial University of Newfoundland.

abstract:
Calgary and Edmonton have each launched strategies and initiatives to incorporate Gender Based Analysis Plus (GBA+) processes into their policy development in the last few years. Do these plans make a difference to grassroots organizers and non-profits working toward equity in these communities? Through seventeen semi-structured interviews with members of city administration, front line workers, grassroots organizers and heads of various non-profits, this thesis works to develop a better understanding of how and if municipal strategies have an impact on local organizing.
The majority of research on GBA+ examines the challenges of implementing GBA+ policy processes and the subsequent outcomes in international or Canadian federal contexts. This thesis will address gaps by focusing on gender-mainstreaming approaches in the municipalities of Calgary and Edmonton, and the impacts on local organizers outside of administration. Participants shared experiences of navigating bureaucratic structures to affect change and GBA+’s limited capacity for radical change. Furthermore, participants discussed the influence of private and public funding on equity-related organizing and links to extractive industries.


identifier: Jaimes Osorio, Ligia Elena <https://research.library.mun.ca/view/creator_az/Jaimes_Osorio=3ALigia_Elena=3A=3A.html>   (2021) Wavefield reconstruction, inversion and imaging using local solvers.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
In exploration geophysics, we usually implement non-invasive methods to image the
interior of the Earth. Seismic methods, for example, are ideal for this purpose because
they provide high-resolution images at large depths. During the construction of these
images, understanding how seismic waves propagate through the subsurface is vital.
Lacking analytical solutions for realistically complex models, numerical modeling becomes essential to comprehend the recorded data. Conventional modeling algorithms
are designed to solve the wave equation throughout the entire model, even though
we are often interested in only much smaller areas. To solve for the whole model
is computationally expensive, particularly when the algorithm repeatedly simulates
wavefields, as is often the case in common imaging techniques such as reverse time
migration and full waveform inversion. The main goal of this thesis is to explore and
understand the potential of local solvers under different scenarios, for instance, in the
presence of large impedance contrast re
ectors and complex geometries in different
domains. We first demonstrate that a local acoustic-elastic solver can model the amplitude with sufficient accuracy between the surface and the reflector of interest and
then can be used as a constraint in Amplitude Versus Offset (AVO) inversion. We
show that the amplitude combined with the phase improves the convergence of this
algorithm. However, the amplitude is not in perfect agreement with that obtained
with full elastic modelling. This motivates our interest in building a local elastic solver
that avoids the interchange between domains but keeps the computational, time, and
resources cost feasible. We implement the Multiple Point Sources (MPS) method in
a standard Finite Difference (FD) solver, computing the global wavefield in the local
domain successfully using only the ability to record and inject data at the boundary,
while being memory efficient. We test the robustness of the local elastic solver on
different elastic models and uses in AVO and Phase Versus Offset (PVO) inversions,
retrieving elastic parameters with high accuracy. To take the elastic solver to the next
level we assess the possibility of using converted wave modes during the inversion. To
this end we explore different imaging conditions based on different wave modes that
allow us to measure the focusing of the image to be ultimately used in conjunction
with the local elastic solver. Notice that all implementations and results are shown
in 2D.


identifier: DiLeo, Melissa <https://research.library.mun.ca/view/creator_az/DiLeo=3AMelissa=3A=3A.html>   (2021) Threat on campus: a study of select Ontario post-secondary threat assessment teams' experience with threat assessment policy.  Masters thesis, Memorial University of Newfoundland.

abstract: In Canada, there has been a total of 12 school shootings across the country over the past 40 years, four of which occurred in higher education; University of Alberta, Dawson College, Concordia University, and L’ecole Polytechnique (The Canadian Press, 2016; Payne, 2006; Rogerson, 2018; Watt, 2017). The safety of students is no longer considered to rest with one area of the campus community, such as campus security, and is instead considered to be a “we responsibility” (Mohandie, 2014, p. 131), involving administrators, parents, peers, and faculty reporting concerning behaviors to the campus team responsible for the evaluation of student dangerousness. These campus teams, commonly referred to as threat assessment teams (Meloy et al., 2014; Sokolow et al., 2016) determine the level of targeted violence risk posed by a student towards self or others (ATAP, 2006; Borum et al., 1999; Meloy et al., 2014). Limited research exists with a focus on how institutional threat assessment policies are developed at the post-secondary level. This study shed light on threat assessment in Canada through the utilization of policy in a uniquely Canadian education system, specifically within the province of Ontario. It is evident that different post-secondary institutions are choosing to support different models of threat assessment management (TAM). These different models included all aspects of violence prevention from team member selection, to policy and procedure development, to the tool used to determine level of risk.


identifier: Jiang, Qi <https://research.library.mun.ca/view/creator_az/Jiang=3AQi=3A=3A.html>   (2021) Evaluation of the micro liquid|liquid interface towards electroanalytical detection of Fe²⁺ and trace metal ions in terrestrial and seawater.  Masters thesis, Memorial University of Newfoundland.

abstract: As the primary production of phytoplankton is the foundation of the global carbon cycle, monitoring the spatiotemporal concentration of iron, which is a key micronutrient often limiting the growth of phytoplankton in the ocean, has been a focus in oceanic and terrestrial waters for several decades. Herein, we propose to evaluate a novel method of iron detection at a micro interface between water|1,2-dichloroethane (w|DCE) and water|ionic liquid (w|IL). Ligand assisted charge transfer of Fe²⁺ was monitored electrochemically using cyclic and differential pulse voltammetry (CV and DPV). Chapter 1 introduces some techniques used for detection of iron in the seawater and contemporary analytical methods in the field, as well as fundamental concepts of electrochemistry at the interface between two immiscible electrolyte solutions (ITIES), so-called liquid|liquid electrochemistry. Chapter 2 describes the main body of work in which four ligands were investigated toward facilitated Fe²⁺ transfer, including 1,10-phenathroline (phen), 1-nitroso-2-naphthol (N2N), 2-(2-thiazolylazo)-p-cresol (TAC), and salicylaldoxime (SAL). The overall complexation or binding constant for each ion was determined and compared versus Fe2+ coordination at the w|DCE micro-interface. Three Fe²⁺:phen, metal:ligand, stoichiometries were observed; however, only a single stoichiometry was recorded in the case of the other ligands. Chapter 3 describes a preliminary investigation of facilitated Fe²⁺ transfer reactions using phen at a water|ionic liquid (w|IL) interface, while Chapter 4 provides some overall conclusions and perspectives as to the direction of the field moving forward.


identifier: Roberts, Rebecca <https://research.library.mun.ca/view/creator_az/Roberts=3ARebecca=3A=3A.html>   (2021) Points of departure: revisiting London in Dickens’s Our Mutual Friend.  Masters thesis, Memorial University of Newfoundland.

abstract:
Dickens’s last completed novel, Our Mutual Friend [1865], is most often studied as a
conclusion to his literary career. Instead, this thesis focuses on this text as a transitional novel,
not a terminal one. It analyzes how Dickens repurposes his former narrative patterns and tropes
of the city in a society that was vastly different from the one he was writing in his earlier novels.
I examine how Our Mutual Friend creates a multi-perspective view of London through its use of
juxtaposition, fragmentation, and layering, which is representative of Dickens’s shifting focus to
a broader range of perspectives and his new interpretation of the city, including his increasing
belief that London in the late nineteenth century was a place lacking opportunity for its
inhabitants. I analyze Our Mutual Friend’s differences, including how Dickens alters his
representation of London, how he adjusts his use of the omniscient narrator, how he represents
public and private spaces in the city, how he uses and represents the movement of male
characters through London’s streets, how he moves away from a central protagonist, and how he
treats women who actively navigate the public space of the city. Through a series of close
readings, I compare these aspects of Our Mutual Friend to his earlier novels, most notably
Oliver Twist [1837], David Copperfield [1849], Bleak House [1852], Little Dorrit [1855], and
Great Expectations [1860]. While prior literary critics study Dickens’s representation of London
through a biographical lens and cite him as the authority on literature of the Victorian city, my
study takes a different approach by analyzing how his changing literary techniques make Our
Mutual Friend a departure from his earlier novels.