identifier: Clausnitzer, Arthur R., Jr. <https://research.library.mun.ca/view/creator_az/Clausnitzer=3AArthur_R=2E,_Jr=2E=3A=3A.html>   (2018) The seventeenth-century English cod fisheries of Newfoundland and New England, circa 1600-1713: an archaeological and historical comparison.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
This dissertation presents the results of a comparative study of English colonial-period fisheries sites from the Gulf of Maine and the English Shore of Newfoundland. Through a combination of archaeological and historical analysis, this dissertation sought to answer questions about the role of early resource-extraction industries in colonial societies, especially regarding the transition from a migratory to a permanent European presence in North America, and the construction of new social structures and identities.
The expansion of Europeans into North America was motivated by a desire for new sources of wealth; the Atlantic Cod was one of the most important of these resources. The lightly salted and dried flesh of the codfish possessed not only economic, but also social, political, and strategic value. European exploitation of North American cod began at the start of the 16th century in Newfoundland; within the century it expanded southward to the Gulf of Maine and the adjacent New England territories of Massachusetts Bay and Maine. European exploitation in both regions originated with the cod fishery, yet by the end of the 17th century, differences had appeared in the social structures of English settlements in each region. Newfoundland remained largely dependent on the health and success of the cod fisheries to maintain its social structures. Maine was similar, yet with enough differences to be considered a distinct culture in its own right; Massachusetts Bay was an aberration in colonial history, quickly developing a relatively stable social, political, and economic structure which earned the colony a degree of independence not seen elsewhere in the English colonial world.
This dissertation examines archaeological collections from six colonial fishing sites, three each from Newfoundland and New England, in an attempt to understand how the inhabitants lived and worked within the confines of the fisheries and the attendant socio-economic structures. Combined with a critical reevaluation of the existing historiography, this answered not only the research objectives of this dissertation but also allowed the construction of a novel research framework intended to help create a new and unified way of looking at all early resource-extraction industries.


identifier: Spencer, Elizabeth <https://research.library.mun.ca/view/creator_az/Spencer=3AElizabeth=3A=3A.html>   (2018) The bear necessities of conservation messaging: exploring how to effectively communicate safety information to people visiting bear country.  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

abstract: Reducing human–bear conflict is an ongoing challenge for wildlife managers. Traditional wildlife education involves a variety of text-based educational material of which little evaluation has been done. The overarching goal of this thesis is to examine current bear aware programs found in North America and suggest some of the reasons why they may be ineffective. Analysis of seven ‘bear programs’ was conducted and a survey (n=279) administered at the Alaska Wildlife Conservation Center during the summer of 2014. Findings suggest that the large number of messages found in bear aware programs explain some of the confusion among participants. Additionally, the research examines how a person’s risk perception to a hypothetical bear encounter can be influenced by the medium used in the survey. The research concludes that using experiential education techniques may be more effective at increasing knowledge levels and developing effective emotional responses during bear encounters than traditional educational material.


identifier: Chatterjee, Tanaya <https://research.library.mun.ca/view/creator_az/Chatterjee=3ATanaya=3A=3A.html>   (2018) Predictors of depression in older adults with multiple sclerosis.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Canada’s growing population of older people with MS (PwMS) has warranted a closer look into factors associated with depression that may interfere with healthy aging. At the same time, researchers, clinicians, and medical professionals treating PwMS with mood disorders have spoken about the difficulty they face when having to determine a diagnosis of depression in this population. This difficulty arises because both MS and depression share various psychological and neurological symptoms (e.g., fatigue, pain, sleep difficulties, psychomotor retardation, and cognitive difficulties). It is also found that these overlapped symptoms vary when completing a self-report measure of depression, versus when medically diagnosed by a psychiatrist. As such, we aim to investigate the personal and disease-related factors that are associated with self-reported depressive symptoms and medically diagnosed depression (i.e. depression diagnosed by a medical professional). Following this, we aim to determine the risk factors for depression in older PwMS.
This study used secondary data collected from the original study, the Canadian survey of health, lifestyle, and aging with multiple sclerosis. Data of the original study was collected from 743 Canadians (> 55 years of age and living with MS for >20 years). In this present study, presence of self-reported depressive symptoms was defined as a score of ≥ 8 on the depression component of the Hospital Anxiety and Depression Scale (HADS-D). Presence of medically diagnosed depression was determined by the item that asked participants if they have received a diagnosis of depression by their medical professional. Logistic regression was used to identify variables that predicted depression.
Self-reported depressive symptoms were found in 30.5% of the population, while medically diagnosed depression was found in 25.7%. 11.7% of PwMS had both self-identified depressive symptoms and were diagnosed with depression by their medical professional. Low social support, high perceived disability, and additional comorbid physical conditions were independent predictors of depression in older PwMS in our cohort.
Depression is prevalent in older PwMS. Clinicians should be cognizant of the overlap of symptoms between MS and depression and should employ possible ways to minimize over-diagnosing or underdiagnosing depression in this population. Identifying risk factors for depression is imperative because at-risk individuals may be thoroughly assessed for depression and will be able to receive treatment more promptly.


identifier: Trenholm, Sharon Barter <https://research.library.mun.ca/view/creator_az/Trenholm=3ASharon_Barter=3A=3A.html>   (2018) Identifying the necessary components of a police decision-making model.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
As police officers are entrusted with significant amounts of discretion and power in instances potentially involving arrest, use of force, search, and seizure, their decisions have serious consequences. Yet, very little research has been conducted into police officer thinking and decision-making. The objective of this research was to identify the necessary components of a decision-making model which can be used to prepare police officers to appropriately exercise their discretion when dealing with ambiguous, time-pressured, and consequential situations. The research on critical thinking (CT) and decision-making in policing was reviewed and supplemented with research from related disciplines. Multiple decision-making models were identified, discussed, and compared. The recognition/metacognition (R/M) model developed by Cohen, Freeman, and Thompson (1998) was identified as potentially adaptable for use in policing.
As CT is considered best learned in domain specific environments, the police context for decision-making must be explored. A multimethod study was designed and conducted. Frontline police officers were the focus as they are particularly impacted by time, access to information, and stress effects. Responses to Critical Incident Analysis Interviews were combined with findings from the literature, to prepare a questionnaire. Canadian police services were contacted and invited to participate in a survey of frontline police decision-making. The services which agreed to participate forwarded the invitation to frontline police personnel. Respondents provided their information through an online survey. The sampling was non-random, as self-selection occurred at the service and individual levels. The results indicated that a model of police decision-making should include recognition and metacognition components taught through a domain specific approach. The five identified themes of: information, safety, planning, respite, and articulation should be used for scenario creation. A Recognition-CT Police Decision-Making Model is proposed.
The information collected was detailed and rich, but cannot be confidently stated to be representative of all Canadian police officers, and while having many strengths, qualitative studies can also be prone to researcher bias. Even with these caveats, this research provides important information to improve our understanding of the complex and ambiguous environment in which police decision-making occurs. Suggestions for future research on police decision-making and the role of CT are also discussed.


identifier: Snelgrove, Andrew Michael Graham <https://research.library.mun.ca/view/creator_az/Snelgrove=3AAndrew_Michael_Graham=3A=3A.html>   (2018) MicroRNA-146a: a potential therapeutic target in multiple sclerosis.  Masters thesis, Memorial University of Newfoundland.

abstract:
Multiple sclerosis (MS) is a neuroinflammatory disease characterized by
demyelinated neurons in the central nervous system. Decreased levels of the
anti-inflammatory microRNA-146a have previously been observed in
macrophages/microglia in MS patients compared to controls. Therapeutically
elevating microRNA-146a expression in MS may produce a conducive
environment for remyelination. Inflammatory cytokines were assessed from both
primary mouse and human macrophages and microglia, and THP-1
macrophages that were transfected with a microRNA-146a mimic and polarized
towards a pro-inflammatory phenotype. Inflammatory cytokines and MS-relevant
targets were measured following activation; neuro- and oligodendrogenesis were
also assessed in vitro while the effect of microRNA-146a on myelin phagocytosis
was also examined. MicroRNA-146a may decrease pro-inflammatory TNF but
may have little to no effect on IL-6; RhoA may decrease in both mouse and
human macrophages. MicroRNA-146a increased myelin phagocytosis of
unstimulated primary mouse microglia. Finally, in vitro experiments suggest that
supernatants collected from LPS-stimulated murine macrophages transfected
with a microRNA-146a mimic do not affect neurogenesis or oligodendrogenesis.
It is suggested that increasing microRNA-146a may promote an anti-inflammatory
environment beneficial for promoting remyelination in MS.


identifier: Chatterjee, Abhijit <https://research.library.mun.ca/view/creator_az/Chatterjee=3AAbhijit=3A=3A.html>   (2018) Mechanistic study of surface enhanced Raman scattering for high sensitivity PAH detection in water.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The main objective of this thesis is the study of surface enhanced Raman scattering (SERS) mechanisms in order to fabricate efficient SERS substrates for the trace detection of PAHs. SERS is gaining tremendous attention in environmental pollutant sensing. SERS mainly relies on the plasmonic enhancement of the Raman signal from metal nanoparticles on the SERS substrate. In addition, metal-molecule charge transfer upon analyte adsorption is also important. Therefore, a study of the SERS enhancement mechanism is crucial in order to design an efficient SERS substrate. Polycyclic aromatic hydrocarbons (PAHs; phenanthrene, pyrene etc.) gained our attention due to their impact on the environment. PAHs dissolve in water at trace concentrations. Therefore, PAH sensing is challenging using typical environmental monitoring techniques. In this thesis, the SERS technique was employed to detect PAHs (phenanthrene and pyrene) with enhancement factors (EFs) of 10⁵ to 10⁶.
The SERS activities of different types of substrates (metal-semiconductor, bimetallic, metal-insulator) were tested, and the Raman enhancement mechanism was investigated using plasmon absorption studies, scanning probe microscopy, and other spectroscopic techniques. A synergistic effect of electromagnetic and chemical enhancement on the SERS performance was illustrated with scanning probe microscopy. This thesis presents new applications or extensions of materials characterization methods, including Kelvin probe force microscopy (KPFM) and electrostatic force microscopy (EFM), to the SERS mechanism question.
A range of materials was used to create the SERS substrates through multilayer deposition. In all cases, the top layer consisted of Au, Ag, or both. These plasmonic materials were supported by ZnO or silica spheres, whose morphology contributed to hotspot formation, plasmon tuning, and surface hydrophobicity. Substrate's surface morphology was tuned by varying the film preparation methods. Some methods allowed for independent tuning of surface roughness and surface area, two distinct contributors to enhancement.
The semiconducting and insulating supports also electronically impacted the top metal layer. By varying the method of preparation of the ZnO, or by adding an insulating poly(methyl methacrylate) (PMMA) interlayer, both morphology and the electronic interactions were tuned. Different surface electronic interations between the metal and the analyte were linked to chemical enhancement.
Among Au/ZnO substrates, Au possessed a partial positive surface charge as a result of Fermi level equilibrium with certain types of ZnO, while defect-rich ZnO led to a negative surface charge on Au. Bimetallic films with Au and Ag similarly generated a positive or negative surface charge on the substrate depending on which metal was on top. The direct measurement of surface charge, enabled by EFM explained why these surface charges impacted the EFs in an analyte-specific way.
Tuning the SERS activity of Au/ZnO by the elimination of impurities in ZnO was also studied. The types of ZnO impurities and defects were identified by X-ray diffraction (XRD), Raman, thermogravimetric analysis (TGA), cathodoluminescence (CL), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), which were also used to identify changes in defects and impurities during the optimization of substrate preparation.


identifier: Geneve, Haytem <https://research.library.mun.ca/view/creator_az/Geneve=3AHaytem=3A=3A.html>   (2017) Characterization of the structure in asphalts by employing x-ray technique.  Masters thesis, Memorial University of Newfoundland.

abstract:
Asphalt binder of five samples were taken from different parts of Canada. Thin films samples (l mm) were prepared by heating onto glass slides at 150°C for 10 min. Structural studies of asphalt in crude oil were performed by X-ray diffraction (XRD). The Jadeᵀᴹ software program was used for the initial analysis. XRD was performed with copper K-α radiation at 40 kV and 40 mA at a scan rate of 0.001° 2θ per second. The XRD data were first fitted with the Pearson VII features and then with pseudo-Voigt features and then modeled in the Mathematica© using the Fermi Generalized Function (GFF). The results are discussed in terms of their accuracy with different combinations of backgrounds such as (Linear, Level, Fixed, Parabolic, 3rd order Polynomial, 4th order Polynomial).
The outcomes discussed are related to the accuracy of profile fitting when the exponents of Pearson VII and pseudo- Voigt Lorentzian differ. The Lorentzian values of Pseudo- Voigt are 0.4, 0.7, and 0.9 whereas the Exponent values of Pearson VII are 0.6, 0.8, and 1.2, and 3 backgrounds (4th order polynomial, 3rd order polynomial, and parabolic) were applied in profile fitting. Further, profile fitting and accuracy extend to crystallite parameters calculated results.


identifier: Giovannini-Green, Zachary E.M. <https://research.library.mun.ca/view/creator_az/Giovannini-Green=3AZachary_E=2EM=2E=3A=3A.html>   (2018) Utilization of benzodiazepines and antipsychotics amongst senior citizens in Newfoundland and Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: The utilization of benzodiazepines and antipsychotics amongst senior citizens in the community and in long-term care has long been a concern for families and health care providers. The two studies presented in this thesis examined prescription patterns in seniors over sixty-five; first over time, then over geographical area. The use of benzodiazepines and antipsychotics remained stable over the three years of the study. Within the community, benzodiazepines and antipsychotics were also more prescribed in urban than rural areas. The difference in prevalence of benzodiazepine prescriptions in long-term care facilities was significant depending on the regional authority, whereas it was not significant for antipsychotic prescriptions. This research into the utilization of benzodiazepines and antipsychotics in the province is valuable because it provides a more thorough examination into utilization than has been previously undertaken in Newfoundland and Labrador.


identifier: Fisher-Power, Leanne <https://research.library.mun.ca/view/creator_az/Fisher-Power=3ALeanne=3A=3A.html>   (2018) Contaminant transport in natural sediments: influence of soil organic matter and Fe/Al-oxyhydroxides on heavy metals (Cu, Zn) and nanoparticles (titanium dioxide).  Masters thesis, Memorial University of Newfoundland.

abstract: Contaminant transport in subsurface environments may be significantly influenced by contents of aquifer sediments, such as soil organic matter (SOM) and Fe/Al-oxyhydroxides, though their effects are not fully known. This thesis systematically explored the influences of SOM and Fe/Al-oxyhydroxides on two common groundwater contaminants, engineered nanoparticles (titanium dioxide nTiO2) and heavy metals (Cu and Zn), in two projects using the same natural sediment. Project 1 found dissolved SOM enhanced nTiO₂ transport by adsorbing onto nTiO₂ surface and stabilizing it in suspension, whereas solid SOM and Fe/Al-oxyhydroxides reduced transport by attracting nTiO₂ when surface charges were opposite. In project 2, Cu adsorption was strongly dependent on SOM and Fe/Al-oxyhydroxide content, with lesser effects for Zn. Depleted SOM decreased adsorption when pH was <6.5, whereas depleted Fe/Al-oxyhydroxides decreased adsorption when pH was >6.5. Both projects contributed to knowledge of the roles of SOM and Fe/Al-oxyhydroxides in governing contaminant transport in natural sediments.


identifier: Newhook, Nicholas <https://research.library.mun.ca/view/creator_az/Newhook=3ANicholas=3A=3A.html>   (2018) Natural killer cells generate memory-type responses to human cytomegalovirus-infected fibroblasts.  Masters thesis, Memorial University of Newfoundland.

abstract: Natural killer (NK) cells are cytotoxic lymphocytes that selectively respond against abnormal cells. Human cytomegalovirus (HCMV) infection causes expansion of NKG2C⁺CD57⁺ NK cells in vivo and NKG2C⁺ NK cells proliferate when cultured with HCMV-infected cells. This raises the possibility of an NK-cell subset selectively responding against a specific pathogen and accruing memory. To test this possibility, we compared proliferation, natural cytotoxicity and interferon-γ (IFN-γ) production of NK cells from HCMV-seropositive and HCMV-seronegative individuals co-cultured with HCMV-infected or uninfected MRC-5 cells. There was no significant difference in proliferation of NK cells from HCMV-seropositive or seronegative individuals against uninfected MRC-5 cells, but significantly more NK cells from the HCMV-seropositive groups proliferated in response to HCMV-infected MRC-5 cells. Natural cytotoxicity of NK cells against K562 cells increased following co-culture with HCMV-infected versus uninfected MRC-5 cells only for the HCMV-seropositive group. After co-culture with HCMV-infected MRC-5 cells, proliferating NK cells from HCMV-seropositive donors selectively produced IFN-γ when re-exposed to HCMV-infected MRC-5 cells. Both NKG2C⁺ and NKG2C⁻ NK cells proliferated in co-culture with HCMV-infected MRC-5 cells, with the fraction of proliferating NKG2C⁺ NK cells directly correlating with the circulating NKG2C⁺ fraction. These data illustrate an at least partly NKG2C-independent human NK-cell memory-type response against HCMV.


identifier: Power, Ernest James <https://research.library.mun.ca/view/creator_az/Power=3AErnest_James=3A=3A.html>   (2018) The risk and protective factors of alcohol consumption identified within a youth centre on the west coast of Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The current study sought to explore why the at-risk youth of Corner Brook, Newfoundland, have been choosing to consume alcohol or not. This was accomplished by conducting semi-structured interviews, and compiling the common risk and protective factors associated with their use. Overall, participants indicated that they largely chose to consume alcohol either because they thought it was fun, it would help them cope with various problems, or because they were pressured into doing so. On the other hand, they also chose to avoid or consume less alcohol once they were educated on its dangers, kept busy, and had a safe place to go such as the local Community Youth Network. Furthermore, it is important to consider how participants described education in the current study, which was learning from both personal and vicarious experiences, in addition to being told the cold hard facts of alcohol consumption, in combination with a personal story, from a trusted adult, who communicated this information in a very passive way. The implications of these findings are discussed.


identifier: Shears, Jennifer S. <https://research.library.mun.ca/view/creator_az/Shears=3AJennifer_S=2E=3A=3A.html>   (2018) Comparing methods to facilitate sit to stand post-stroke.  Masters thesis, Memorial University of Newfoundland.

abstract:
Introduction: Sit-to-stand (STS) is a prerequisite to walking and independent living.
Following stroke, patients often perform STS asymmetrically. Physiotherapists use
different techniques to help patients relearn symmetry in STS. The effects of two
techniques, verbal and manual cueing on STS symmetry post-stroke were compared.
Methods: A randomized outcome-blinded intervention trial was conducted in a stroke
rehabilitation unit. 10 participants were randomly assigned to a manual or verbal cue
group. Participants completed 40 repetitions of STS daily for ten days. Sitting and
standing symmetry, measures of lower limb mobility, balance and gait were assessed.
Results: Standing symmetry, balance and lower limb mobility significantly improved in
both groups with no significant differences between groups. STS symmetry did not
change following training.
Conclusion: Both verbal and manual cueing led to improved standing symmetry,
however STS remained asymmetrical. The improvements observed in both manual and
verbal cueing techniques suggest that effective cueing combined with massed-practice of
STS result in improved overall functional mobility.


identifier: Branton, Sarah <https://research.library.mun.ca/view/creator_az/Branton=3ASarah=3A=3A.html>   (2018) Intrinsic DNA features are determinants of activation-induced cytidine deaminase (AID) recruitment and activity.  Masters thesis, Memorial University of Newfoundland.

abstract:
While most cells strive to guard their genomic DNA from damage, B lymphocytes
of the immune system actively damage their genomic DNA in order to mount a more robust
antibody response. They do so by expressing the DNA-mutating enzyme activationinduced
cytidine deaminase (AID). Although AID action is critical to antibody
diversification, AID-mediated damage outside of antibody loci is a leading cause of
leukemia/lymphomas. It is known that AID acts on single-stranded DNA and mutates
genes that are highly transcribed; however, the mechanisms for AID targeting to specific
genes or loci have yet to be elucidated. It has been hypothesized that one of the many
factors involved in the targeting of AID is the topology of the DNA itself, as it is thought
that AID can only deaminate supercoiled but not relaxed double-stranded DNA (dsDNA).
We hypothesized that features of the DNA inherent to a gene (i.e. sequence, structure and
topology) are important determinants of AID recruitment. Contrary to the current model
that transcription significantly increases AID activity, we found that transcription is not
necessary for AID activity, as AID efficiently deaminated both supercoiled and relaxed
linear DNA in the absence of transcription. Moreover, DNA secondary structure may be
of greater importance than primary sequence in attracting AID to its target, and that these
structures may be liberated through dsDNA breathing and/or in conjunction with
transcription.


identifier: Zhang, Chen <https://research.library.mun.ca/view/creator_az/Zhang=3AChen=3A=3A.html>   (2018) Opportunistic routing and network coding in multi-hop wireless mesh networks.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The rapid advancements in communication and networking technologies boost the capacity
of wireless networks. Multi-hop wireless networks are extremely exciting and rapidly
developing areas and have been receiving an increasing amount of attention by researchers.
Due to the limited transmission range of the nodes, end-to-end nodes may situate beyond
direct radio transmission ranges. Intermediate nodes are required to forward data in order
to enable the communication between nodes that are far apart. Routing in such networks
is a critical issue.
Opportunistic routing has been proposed to increase the network performance by utilizing
the broadcast nature of wireless media. Unlike traditional routing, the forwarder
in opportunistic routing broadcasts date packets before the selection of the next hop.
Therefore, opportunistic routing can consider multiple downstream nodes as potential
candidate nodes to forward data packets instead of using a dedicated next hop. Instead
of simply forwarding received packets, network coding allows intermediate nodes to combine
all received packets into one or more coded packets. It can further improve network
throughput by increasing the transmission robustness and efficiency. In this dissertation,
we will study the fundamental components, related issues and associated challenges about
opportunistic routing and network coding in multi-hop wireless networks.
Firstly, we focus on the performance analysis of opportunistic routing by the Discrete
Time Markov Chain (DTMC). Our study demonstrates how to map packet transmissions in the network with state transitions in a Markov chain. We will consider pipelined
data transfer and evaluate opportunistic routing in different wireless networks in terms
of expected number of transmissions and time slots.
Secondly, we will propose a regional forwarding schedule to optimize the coordination of
opportunistic routing. In our coordination algorithm, the forwarding schedule is limited
to the range of the transmitting node rather than among the entire set of forwarders.
With such an algorithm, our proposal can increase the throughput by deeper pipelined
transmissions.
Thirdly, we will propose a mechanism to support TCP with opportunistic routing and
network coding, which are rarely incorporated with TCP because the frequent occurrences
of out-of-order arrivals in opportunistic routing and long decoding delay in network coding
overpower TCP congestion control. Our solution completes the control feedback loop of
TCP by creating a bridge between the sender and the receiver. The simulation result
shows that our protocol significantly outperforms TCP/IP in terms of network throughput
in different topologies of wireless networks.


identifier: Jiang, Fan <https://research.library.mun.ca/view/creator_az/Jiang=3AFan=3A=3A.html>   (2018) Efficient low-complexity data detection for multiple-input multiple-output wireless communication systems.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The tradeoff between the computational complexity and system performance in multipleinput
multiple-output (MIMO) wireless communication systems is critical to practical applications.
In this dissertation, we investigate efficient low-complexity data detection schemes
from conventional small-scale to recent large-scale MIMO systems, with the targeted applications
in terrestrial wireless communication systems, vehicular networks, and underwater
acoustic communication systems.
In the small-scale MIMO scenario, we study turbo equalization schemes for multipleinput
multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) and multipleinput
multiple-output single-carrier frequency division multiple access (MIMO SC-FDMA)
systems. For the MIMO-OFDM system, we propose a soft-input soft-output sorted QR decomposition
(SQRD) based turbo equalization scheme under imperfect channel estimation.
We demonstrate the performance enhancement of the proposed scheme over the conventional
minimum mean-square error (MMSE) based turbo equalization scheme in terms of
system bit error rate (BER) and convergence performance. Furthermore, by jointly considering
channel estimation error and the a priori information from the channel decoder,
we develop low-complexity turbo equalization schemes conditioned on channel estimate for
MIMO systems. Our proposed methods generalize the expressions used for MMSE and
MMSE-SQRD based turbo equalizers, where the existing methods can be viewed as special
cases. In addition, we extend the SQRD-based soft interference cancelation scheme
to MIMO SC-FDMA systems where a multi-user MIMO scenario is considered. We show
an improved system BER performance of the proposed turbo detection scheme over the
conventional MMSE-based detection scheme.
In the large-scale MIMO scenario, we focus on low-complexity detection schemes because
computational complexity becomes critical issue for massive MIMO applications. We first propose an innovative approach of using the stair matrix in the development of massive
MIMO detection schemes. We demonstrate the applicability of the stair matrix through
the study of the convergence conditions. We then investigate the system performance and
demonstrate that the convergence rate and the system BER are much improved over the
diagonal matrix based approach with the same system configuration. We further investigate
low-complexity and fast processing detection schemes for massive MIMO systems where a
block diagonal matrix is utilized in the development. Using a parallel processing structure,
the processing time can be much reduced. We investigate the convergence performance
through both the probability that the convergence conditions are satisfied and the convergence
rate, and evaluate the system performance in terms of computational complexity,
system BER, and the overall processing time. Using our proposed approach, we extend
the block Gauss-Seidel method to large-scale array signal detection in underwater acoustic
(UWA) communications. By utilizing a recently proposed computational efficient statistic
UWA channel model, we show that the proposed scheme can effectively approach the system
performance of the original Gauss-Seidel method, but with much reduced processing delay.


identifier: Pichardo Marcano, Fritz J. <https://research.library.mun.ca/view/creator_az/Pichardo_Marcano=3AFritz_J=2E=3A=3A.html>   (2018) Phylogeny and historical biogeography of the Neotropical palm tribe Euterpeae (Arecaceae).  Masters thesis, Memorial University of Newfoundland.

abstract:
Tribe Euterpeae is a group of Neotropical palms that comprises 33 species in 5
genera distributed from Central America to Southeastern Brazil and Bolivia, including
the Caribbean islands. Some species are important elements of Amazonian forests
since they can be among the 10 most abundant trees. Some members of this tribe are
economically important for their oil production and edible palm heart. In this study
I aimed to clarify the intergeneric and interspecific relationships within Euterpeae
and estimate the time and place of origin of its taxa. I also tested for changes in
inflorescence types in the tribe. I reconstructed a phylogenetic tree with maximum
likelihood and a dated Bayesian phylogenetic tree using one plastid (trnD-trnT) and
four low-copy nuclear DNA regions (CISP4, WRKY6, RPB2, and PHYB). I used five
fossil and two secondary calibration points to estimate divergence times. I amplified
sequences from 27 Euterpeae species including 7 infra-specific taxa and 41 outgroup
taxa. The tribe and each genus were monophyletic with high support. Hyospathe was
sister to the rest of the genera. Euterpe was sister to Neonicholsonia and Prestoea
was sister to Oenocarpus. The ancestral inflorescence type of Euterpeae is likely
one with rachillae all around the main axis from which the hippuriform (horsetail
shape) inflorescence of Oenocarpus originated. Some widely distributed species with
infra-specific taxa (Euterpe precatoria, Prestoea acuminata and Hyospathe elegans)
were not monophyletic, which invites a revision of these species circumscriptions. The Euterpeae diverged from its sister clade Areceae at around 46 million years ago (Mya),
while the crown age of the Euterpeae was estimated at around 40 Mya. Although
Euterpeae’s origin occurred in the Eocene most of the extant genera had crown ages
after the middle Miocene (<17 Mya) with some species originating later during the
Pliocene to Pleistocene. This work represents the most complete molecular phylogeny
of the group, and inclusion of the few missing narrow endemic taxa will provide a
more complete understanding of the interspecific relationships of the tribe.


identifier: Macpherson, Katherine <https://research.library.mun.ca/view/creator_az/Macpherson=3AKatherine=3A=3A.html>   (2018) Benthic habitat mapping of an Atlantic cod (Gadus morhua) refuge, Smith Sound, Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract:
After the northern cod collapse, a surviving component of this stock took refuge in Smith Sound, a sub-arctic Newfoundland fjord. While benthic habitats used by recovering fish populations can provide important ecological services, habitats within this refuge have not been mapped. This study mapped Smith Sound’s benthic habitats using Van Veen grab and videos samples of the seafloor. Habitats were mapped by combining ground truthing data with multibeam bathymetry terrain derivatives using a Maximum Likelihood Classifier. Eight habitats were observed and mapped with an overall map accuracy of 84.76% (Kappa 80.40%). Multiple habitats were observed that could be linked to cod ecology and services of an ecological refuge. Known spawning areas were characterised predominantly by Sandy Mud habitat, bordered by Small Boulders and Gravel habitats.
Sub-optimal habitat consisted of Gravelly Muddy Sand with Small Boulders, bordered by Large Boulders. The habitats were linked to cod ecology providing shelter, sustenance and opportunities for reproduction, all services required by a refuge.


identifier: Derraugh, Lesley S. <https://research.library.mun.ca/view/creator_az/Derraugh=3ALesley_S=2E=3A=3A.html>   (2018) Hegemonic masculinity and rape culture: negotiating manhood at a Canadian university.  Masters thesis, Memorial University of Newfoundland.

abstract: Using in-depth qualitative interviews with 12 male-identified individuals between the ages of 19 and 25 recruited from the Memorial University community, this project examines how men negotiate the complexities of hegemonic masculinity in a society in which that hegemonic masculinity is constructed as violent. This research is prompted by the current crisis in North America of campus rape culture and grounded in the need to identify solutions to the rate of sexual violence occurring in university communities. To examine masculinities in this context, I explore this key question: How do male-identified individuals understand and negotiate the intricacies of masculinity and societal expectations of what it means to “be a man”? to explore this, I turn to the following sub-questions: a) to what extent do participants identify with hegemonic notions of masculinity? b) what developmental experiences have most influenced their self-identification (either positively or negatively) with traditional masculine norms? c) how is rape culture understood, perceived and perpetuated (or challenged) by male-identified university students? Drawing on the theoretical work of gender researchers such as Raewyn Connell and Michael Kimmel, this thesis will include insights into the ways in which masculinities are being reproduced, challenged and resisted.


identifier: Walley, Meghan <https://research.library.mun.ca/view/creator_az/Walley=3AMeghan=3A=3A.html>   (2018) Examining precontact Inuit gender complexity and its discursive potential for LGBTQ2S+ and decolonization movements.  Masters thesis, Memorial University of Newfoundland.

abstract: Anthropological literature and oral testimony assert that Inuit gender did not traditionally fit within a binary framework. Men’s and women’s social roles were not wholly determined by their bodies, there were mediatory roles between masculine and feminine identities, and role-swapping was—and continues to be—widespread. However, archaeologists have largely neglected Inuit gender diversity as an area of research. This thesis has two primary objectives: 1) to explore the potential impacts of presenting queer narratives of the Inuit past through a series of interviews that were conducted with Lesbian Gay Bisexual Transgender Queer/Questioning and Two-Spirit (LGBTQ2S+) Inuit and 2) to consider ways in which archaeological materials articulate with and convey a multiplicity of gender expressions specific to pre-contact Inuit identity. This work encourages archaeologists to look beyond categories that have been constructed and naturalized within white settler spheres, and to replace them with ontologically appropriate histories that incorporate a range of Inuit voices.


identifier: Gyimah, Asare <https://research.library.mun.ca/view/creator_az/Gyimah=3AAsare=3A=3A.html>   (2018) Agricultural drainage impacts on the photosynthetic capacity and water use efficiency of boreal peatlands.  Masters thesis, Memorial University of Newfoundland.

abstract:
Even though boreal peatlands cover a relatively small area of the Earth’s surface compared to forested areas, they are known to contain approximately a quarter of the total organic carbon in the soil. As a globally important store of carbon and terrestrial surface water, natural peatland ecosystems are known as a sink for atmospheric carbon dioxide (CO₂) since the rate of carbon accumulation through photosynthesis exceeds the rate of decomposition. The slow decomposition rate and the subsequent accumulation of carbon under the anoxic condition are mainly due to the high water table depth (WTD) in peatland ecosystems. However, peatlands have been drained for agricultural purposes.
Peatland drainage for agricultural purposes helps to improve soil aeration condition by deepening the water table depth. This keeps the soil dry and improves plant growth and development. Since plants control their stomata in order to optimize the trade-off between the amount of carbon absorbed and the amount of water loss, I anticipated that the improved plant growth and development through drainage could also impact on the evapotranspiration rate (ET) (a critical component in the water balance of terrestrial ecosystems) and hence, the water use efficiency (WUE) of peatland ecosystems. Therefore, this study was aimed to investigate the effects of peatland drainage for agriculture on the photosynthetic capacity (represented as gross primary productivity (GPP)) and the WUE of boreal peatlands, on a plot and site scale. Here, a comparison was made between agriculturally drained and a natural peatland during the 2016 growing season.
GPP was found to be significantly higher among the subplots affected by drainage compared to the hummock and hollow subplots at the natural site. Site average showed that, during the 2016 growing season, GPP (mgCO₂/m²/s) was significantly higher at the drained site (0.468 ± 0.04) compared to the natural site (0.093 ± 0.01) (p < 0.001). The seasonal pattern of GPP was linked to WTD. WTD variation and its effect on the physical and hydrothermal properties of the peat (e.g., electrical conductivity (EC) and peat temperature at 5cm depth (T₅)), was seen to account for most of the variation in GPP at the drained subplots and site relative to the natural site. Respectively, a decrease in soil moisture (SM), EC, and increase in T₅, significantly explained ~ 44%, 49% and 27% of variation in GPP at the drained site. The combined effect of EC and T₅ accounted for approximately 61% of the variation in GPP at the drained site. Growth in the hollow subplot was also seen to be at its peak when the WTD was at its deepest point. However, the deepest WTD seen at the hummock subplot did not lead to any production increase. This was attributed in part to the extremely lower water table depth at the hummock and its effect on water availability for plant growth and development, and the inability of the peat makeup to hold on to water during the summer when the water level dropped.
In spite of statistically similar ET rate between the hummock and hollow subplots, the results showed a higher WUE (i.e., the ratio of GPP to ET) when GPP is high. However, when comparing the drained and natural sites, higher ET rate at the drained site still resulted in a higher WUE due to its significantly higher GPP rate, making GPP the primary controller of WUE. WUE (mgCO₂/mgH₂O) was significantly higher (0.047 ± 0.01) at the drained site relative to the natural site (0.005 ± 0.00). Between the hummock and hollow subplots, WUE (mgCO₂/mgH₂O) was significantly higher at the hollow subplot (0.010 ± 0.001) compared to the hummock subplot (0.005 ± 0.001). No significant difference in WUE was found among the plant functional types (PFTs) as GPP was statistically the same for the sedge, shrub and the grass subplots at the drained site. This study suggests that land use changes, microforms and PFTs would be significant in regulating the carbon and hydrological cycle in peatland ecosystems, and thus land use practices, microforms and PFTs need to be explicitly parameterized in modeling the carbon and hydrological cycle in peatland ecosystems.


identifier: Kurdin, Anton <https://research.library.mun.ca/view/creator_az/Kurdin=3AAnton=3A=3A.html>   (2018) Improving trauma care in low resource settings.  Masters thesis, Memorial University of Newfoundland.

abstract:
Introduction: Caring for traumatic injuries often requires significant resources that may
be sparse in certain environments, such as rural communities and Low and Middle
Income Countries. To improve trauma care in low resource settings, strategies focusing
on education and telemedicine have been proposed. However, such methods have not
been thoroughly evaluated and their effectiveness remains unknown.
Objectives: 1) To evaluate the novel use of a Trauma Evaluation and Management
course and its effectiveness as a low-cost alternative to ATLS for providing trauma
teaching in Low and Middle Income Countries; 2) To assess the effectiveness of
telemedicine for providing remote trauma teleconsultations.
Methods: The Trauma Evaluation and Management course was provided to health care
professionals in Haiti and Bangladesh. The participants were asked to complete a survey
which was analyzed to determine the effectiveness, the potential for modifications and
the versatility of the course. To determine the feasibility of remote trauma management, a
simulation study was constructed to test the feasibility of providing an accurate
representation of an injured patient using telemedicine. Two modes of telemedicine were
tested against a control group: a conventional ceiling mounted camera and a handheld
device.
Results: Health care professionals in Bangladesh and Haiti provided excellent
evaluations of the Trauma Evaluations and Management course. Areas for improvement
focused on modifications to reflect the low resource setting and included considerations
for lack of specialist referrals, unavailability of patient transfers to high level facilities
and a greater role for ancillary and nursing staff. Regarding the use of telemedicine for
remote trauma management, Situational Awareness scores did not demonstrate any
difference between control and the two intervention groups.
Conclusions: Educational initiatives, such as the Trauma Evaluation and Management
course, are an effective method of trauma teaching and are well suited for Low and
Middle Income Countries. With the advancements in technology, the use of telemedicine
is a viable option for remote trauma management.


identifier: Petersen, Bui K. <https://research.library.mun.ca/view/creator_az/Petersen=3ABui_K=2E=3A=3A.html>   (2018) Structure and agency in bargaining: practice, routines, truce, and individual differences.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
This thesis uses a practice theoretical lens to examine the social process of negotiation, particularly in the context of union-management negotiations. The use of a practice lens helps address some fundamental gaps in the existing negotiation and industrial relations literatures, where the focus generally is only on either the micro (behavioural) or macro (structural) aspects of negotiations. Furthermore, most empirical research on negotiation behaviour has tended to separate the negotiations from their natural context. Therefore, we have very limited knowledge about the interactions between behaviour, process, practice, and structure.
In this thesis, I use the practice theoretical approach, generally referred to as strategy-as-practice. This approach emphasizes the need to see all behaviour as socially situated, and practices as instrumental in the maintenance of structures. Therefore, it helps address the micro-macro divide, especially in terms of the tension between agency and structure. For my investigation, I chose to examine multiple cases of collective agreement negotiations within a small Nordic jurisdiction. I used a qualitative grounded theory approach that included a) observations of bargaining meetings; b) interviews with negotiators; and c) archival sources, such as meeting reports, collective agreements, email correspondence, and news media.
The theoretical model that emerged from my findings suggests that collective bargaining is a highly routinized process that produces a truce. On the one hand, this truce provides stability and reduces volatility in industrial relations; on the other, it induces rigidity and inertia, significantly reducing the ability of individual negotiators to influence process and outcomes. However, this model also suggests that individual negotiators do have some individual agency in shaping outcomes, albeit marginally. More importantly, the model shows the critical role negotiators play in enacting and maintaining the routine truce through practice. The thesis also examines the sources for the varying degrees of agency individual negotiators demonstrated, including individual skills, experience, education, cognition, relationships, as well as the status of the occupation they represent.


identifier: Mazumdar, Bishakha <https://research.library.mun.ca/view/creator_az/Mazumdar=3ABishakha=3A=3A.html>   (2018) Outcomes of bridge employment: a mixed method examination of retirees' expectations and experiences.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
There is a growing tendency among present day retirees to engage in bridge jobs before their final exit from the labour force; however, few studies examine the bridge employment experience from the perspective of the employees themselves. Although there is ample literature addressing the factors that contribute to the growth of bridge employment, minimal academic attention has been directed towards understanding the needs and expectations of actual bridge employees. This gap in literature needs to be addressed in order to design a workplace suited for the needs and abilities of this matured workforce. I conducted a mixed methods study among bridge employees to fulfill this gap and shed light on how workplaces can be more accommodative to yield the best potential of this employment arrangement.
In my first study, an online survey of 195 bridge employees, I found that people who engaged in nonstandard work had better life and work satisfaction. Additionally, bridge employees’ perception of the fulfillment of the psychological contract by their organizations is associated with positive impacts on their satisfaction with life, marital adjustment quality, and key job attitudes.
In my second study, I conducted in-depth interviews with 26 bridge employees. I found that there is an association between retirees’ motives for taking on bridge jobs and their expectations from these jobs. More specifically, bridge employees who were highly cognizant of life’s limitations, both in terms quality of life as one ages and of life span in general, ensured bridge jobs complemented their other priorities in life. Their expectations and satisfaction in bridge jobs largely depended on relationships with co-workers and on bridge employees’ perceptions of organizational policy. Bridge employees who did not express the realization that life is limited, seemed to approach bridge jobs as a new phase of their career, and expected organizations to create opportunities for their skills to be utilized.
Utilizing the frameworks of psychological contract theory and socioemotional selectivity theory, my study provides important directions for successful recruitment and retention of bridge employees as well as for creating a supportive work environment for them.


identifier: Frazao, Fabio Soares <https://research.library.mun.ca/view/creator_az/Frazao=3AFabio_Soares=3A=3A.html>   (2018) Including seed dispersers into individual-based forest models.  Masters thesis, Memorial University of Newfoundland.

abstract:
Tropical forests provide many ecosystem services to human beings, many of which
are mediated by animals. Nonetheless, there are few software tools that allow
ecologists to explicitly include animals in forest models. I developed packages to
implement individual-based models of trees and animals. The animal model focused
on arboreal seed dispersers and includes a decision-making algorithm based
on the behaviour of primates. I first describe the models independently and provide
examples of how the software can be used to address questions of ecological
concern, such as the effect of selective logging on carbon stocks, how deforestation
and fragmentation affect animal movement and the impacts of defaunation on seed
dispersal. Finally, I describe how to integrate seed dispersers into forest models. I
found that this integration is not always necessary and provide guidelines on how
to decide if seed dispersal should be explicitly modelled.


identifier: Adedigba, Sunday Adeshina <https://research.library.mun.ca/view/creator_az/Adedigba=3ASunday_Adeshina=3A=3A.html>   (2017) Dynamic risk assessment of process operations.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Process engineering systems have become increasingly complex and more vulnerable to potential accidents. The risks posed by these systems are alarming and worrisome. The operation of these complex process engineering systems requires a high level of understanding both from the operational as well as the safety perspective. This study focuses on dynamic risk assessment and management of complex process engineering systems’ operations. To reduce risk posed by process systems, there is a need to develop process accident models capable of capturing system dynamics in real-time. This thesis presents a set of predictive process accident models developed over four years. It is prepared in manuscript style and consists of nine chapters, five of which are published in peer reviewed journals. A dynamic operational risk management tool for process systems is developed, considering evolving process conditions. The obvious advantage of the developed methodologies is that it dynamically captures the real time changes occurring in the process operations. The real time risk profile provided by the methodologies developed serve as performance indicator for operational decision making.
The research has made contributions on the following topics: (a) process accident model considering dependency among contributory factors, (b) dynamic safety analysis of process systems using a nonlinear and non-sequential accident model, (c) dynamic failure analysis of process systems using principal component analysis and a Bayesian network, (d) dynamic failure analysis of process systems using a neural network and (e) an integrated approach for dynamic economic risk assessment of process systems.


identifier: Liu, Bo <https://research.library.mun.ca/view/creator_az/Liu=3ABo=3A=3A.html>   (2018) Enhanced photocatalytic oxidation of polycyclic aromatic hydrocarbons in offshore produced water.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The growing amount and environmental impact of offshore oily wastewater especially offshore produced water (OPW) have drawn significant attention in recent years. The petroleum hydrocarbons in wastewater can have severe negative effects in a long term on coastal and marine ecosystems if without sufficient treatment before discharge. Polycyclic aromatic hydrocarbons (PAHs) as a representative of dissolved chemical compounds or environmental pollutants in oily wastewater have been a major issue of marine environments due to their carcinogenic or mutagenic, toxic, persistent and bio-accumulative properties. To reduce the negative impact of produced water to the marine ecosystem, it is required to remove all toxicants especially PAHs before discharge. Various challenges have been identified in implementing conventional technologies (e.g., physical separation, chemical oxidation and biological remediation) for treating the dissolved organic pollutants (e.g., PAHs). Therefore, the research and development of more effective technologies to address these concerns are much desired. Photocatalysis generates powerful oxidative radicals which can rapidly mineralize organics especially aromatic compounds, offering a great potential use in removing PAHs from oily wastewater. However, the photocatalytic degradation of organics can be dramatically inhibited by the complex matrix of OPW. Limited in-depth studies were reported on the behaviors and interactions of different components in produced water during photocatalysis. The mechanisms of the interferences are of utmost importance to the development of highly efficiency treatment technologies. The generation of intermediates caused by the complex matrix and inhibited treatment process could further lead to the increase in the toxicity of treated effluent to the marine ecosystem, and consequently reduce its potential in natural attenuation. In addressing these challenges and fulfill the knowledge gaps, this research is focused on the evaluation of the key factors and the mechanisms of OPW matrix in photocatalysis, and the development of enhanced photocatalytic oxidation processes to aid the OPW treatment, thus can achieve both high efficiency in removal of PAHs, and low toxicity and high biodegradability of the effluent.
The matrix effect was first investigated in a suspensive photocatalytic oxidation system, in which the synthesized TiO2 nanoparticles were used. It is indicated that the degradation of PAHs was inhibited by the impurities in OPW matrix in many ways: the alkaline-earth cations caused the flocculation of the particle; the insoluble particulate matters competed with PAHs in the adsorption on TiO2; the competition and the fouling effect of other dissolved organic matters were deteriorating the process.
To enhance the treatment process, immobilized TiO2 was used instead and it was compared with the TiO2 nano-particles. Improvements were found in both naphthalene adsorption and degradation in the immobilized photocatalytic oxidation system, indicating immobilized TiO2 was more efficient and durable than TiO2 nanoparticles in oily wastewater treatment. The competition of hydrocarbons especially phenols played a key role in the degradation of PAHs. The fouling on the catalyst surface was verified by the scaling of alkaline-earth metals and the deposition of organic matters.
Further improvement was aimed at developing a novel UV-light-emitted diode (UV-LED)/TiO2 nanotube array (TNA)/ozonation process for treating OPW. The involvement of ozone was to reduce the competition of other organics and enhance the degradation efficiency. The TNA with hollow 1-D tubular nano-structures was applied because of the combined advantage of nano-particle and immobilization, as well as high quantum yield. UV-LED has the advantage of high energy efficiency and long-life time. In the integrated system, the removal of PAHs can be achieved within 30-min treatment with the half-lives reduced to less than 10 mins. Factorial analysis demonstrates that the best dose of TNA is 0.2 g/L. Light intensity affects the generation of iodine radicals, which is a strong scavenger of ozone thus reduces the efficiency of PAHs removal. Ozone dose is a dominated factor that promotes the degradation. Further results indicate that the degradation of phenols and PAHs with higher solubility favors to undergo to ozone-inducted oxidation, while PAHs with lower solubility are more likely oxidized on the catalyst surface.
The toxicity and biodegradability of OPW treated by photocatalytic oxidation were investigated during and after the treatment. Studies on the intermediates formed during the photocatalytic ozonation treatment in the presence of halogen ions reveal the mechanism and various reaction pathways of aromatic compounds. Iodization and bromination were the dominant interfering reactions in sequential stages. Two multivariable regression models were developed to quantify the contributions of key toxicants (e.g., total PAHs, total phenols, dibromo-pentane and bromoform) to the acute toxicity of OPW during the treatment processes. It was observed that by removing the total PAHs and total phenols, the acute toxicity was increased from 3% to 57%, and the biodegradability (BOD₂₈/COD ratio) was doubled more than 80% by the integrated UV-LED/TNA/ozonation process. Further, the biodegradation rate of bromoform was much faster than those of phenols, indicating that the proposed technology features high efficiency and has low impact on marine environment.
In this research, I have investigated the matrix effect of OPW on photocatalysis and the impacts to the suspended and immobilized TiO₂. A novel integrated UV-LED/TNA/ozonation process was developed to treat OPW. The efficiency of the process, the effects of operational parameters, the intermediates and degradation pathways, and their contribution to the acute toxicity and biodegradability of treated effluent were investigated.
The scientific contributions of the research are: 1) revealing and summarizing the key mechanisms of OPW matrix and their key effects on photocatalysis, 2) understanding the interactions of OPW composition with catalyst surface, 3) fulfilling the knowledge gaps on the removal of PAHs from OPW by the UV-A (365 nm) photocatalytic ozonation process, including the interactive mechanisms of the adsorption and photocatalytic oxidation, the behaviors of halogenic ions, and the effects of the operational factors, 4) proposing the altered photodegradation pathways of aromatic organic matter in the presence of halogen ions, and 5) proposing toxicity contribution models targeted on the most toxic compounds in OPW with/without photocatalytic ozonation.
The findings of this thesis work also help 1) develop a better strategy to countermeasure the difficulties in the application of photocatalytic oxidation for treating OPW, 2) develop an advanced alternative option for the OPW management, and 3) monitor the composition and toxicity changes during the process and hence the production of by-products in the OPW treatment practice.


identifier: Alzahrani, Fahad <https://research.library.mun.ca/view/creator_az/Alzahrani=3AFahad=3A=3A.html>   (2018) Shear behaviour of steel fibre-reinforced high strength lightweight concrete beams without web reinforcement.  Masters thesis, Memorial University of Newfoundland.

abstract:
The main objective of this investigation was to determine the influence of adding
two different shapes with different lengths of steel fibres on the shear behaviour of
lightweight and normal weight concrete beams with normal and high concrete grades.
Thirty-six prisms of (100 mm wide, 100 mm deep, and 400 mm long) and seventy
two cylindrical samples of (100 mm diameter  200 mm high) were cast and tested to
determine the concrete mechanical properties for specimens. These samples were tested
in order to discover the role of steel fibres on enhancing concrete properties in general.
The modulus of rupture, flexural toughness, toughness, compressive strength and
splitting tensile strength were inspected based on the small-scaled material samples.
In the structural experiment, a group of twelve large-scaled reinforced concrete
beams without shear reinforcement were primarily analyzed, designed and tested in the
structures lab at Memorial University of Newfoundland (MUN). These specimens were
built to study the load-deflection curves, shear and flexural behaviour, concrete and steel
strains and the ultimate load resistance. Simply supported beams with dimensions of
(200 mm wide, 400 deep, and 2900 mm long) were structurally tested, analyzed and
discussed. in order to investigate the previous responses. Three factors were proposed in
this experiment. The first factor was the type of the aggregates and the second parameter
taken into consideration was the concrete compressive strength that divided the beams
into two groups of high and normal strengths. Thirdly, two different lengths of steel
fibres with different end-shapes were considered as the third variable in order to evaluate
the effects of the length of the steel fibres on the shear behaviour. All beams contained
1.46% of longitudinal tension reinforcement ratio. Besides this, a fixed concrete cross section was suggested for all beams. Testing specimens were setup on a specified constant shear span-to-depth ratio of 3. According to a recommendation by ACI, a fixed volume fraction of 0.75% of steel fibres was added to SFRC beams. The specimens with long fibres resisted higher shear stresses and were more ductile than the ones reinforced with shorter fibres. Overall, the presence of both short and long steel fibres improved beams shear resistance by a range varied from 35% to 72% compared to reference RC beams. However, shear strength of beams with long steel fibres enhanced more by an average amount of 10% in contrast with short SFs beams.


identifier: Fabretto, Cristina <https://research.library.mun.ca/view/creator_az/Fabretto=3ACristina=3A=3A.html>   (2018) Strengthening the intercultural communicative competence of international undergraduate engineering students for co-op work term placement.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Co-op programs pose unique challenges for international students without a strong
command of the English language and sufficient familiarity with the professional
context. This research investigates the challenges faced by international students enrolled
at Memorial University in the Bachelor of Engineering co-op program, and the efforts of
the faculty (FEAS) in addressing these students’ needs. With a rise in popularity of co-op
programs in Canada and a projected steady growth in foreign enrolment, it is crucial to
understand better how this cohort’s ability to communicate in professional settings
impacts their mandatory co-op employment.
The following study was designed as a qualitative case study. It includes 18 semistructured
interviews with FEAS international undergraduate students, key informants
from FEAS and the university, and representatives from the engineering industry directly
involved with work term placements. In discussing the findings, I draw on the conceptual
framework of communicative competence (Hymes, 1972) and examine employers’
language expectations through the lenses of the Common European Framework of
Reference for Languages (CEFR) and the Canadian Language Benchmarks (CLB), as
internationally accredited scales of English language proficiency currently in use in
Canada. I rely on these two frameworks to discuss implications for practice and
formulate possible directions for future research.
The study indicates that significant differences in the quality of communication
(Spitzberg, 1989) among FEAS international students reflect in large disparities in
recruitment rate and in long-term career prospects. Findings revealed that certain behaviours and levels of communication are required for successful hiring and
placement. Given the high stakes of work terms, international students’ language ability
(Bachman, 2010) and intercultural competence (Deardorff, 2011) need to be evaluated
specifically against co-op program requirements. Furthermore, as current pedagogical
practices are not always effective, alternative approaches are needed that promote greater
transparency, consistency and continuity of learning and progress from enrolment to
graduation. Program mandated co-op employment of international engineering students
is still an under-researched area which, as this research shows, warrants greater
interdisciplinary attention. This dissertation represents a first step in that direction.


identifier: Cribb, Courtney <https://research.library.mun.ca/view/creator_az/Cribb=3ACourtney=3A=3A.html>   (2018) School counsellors' views on sexting among students.  Masters thesis, Memorial University of Newfoundland.

abstract:
Sexting is a relatively recent phenomenon that involves the sending, receiving and
sharing of sexually explicit photos through cell phone messages and online social media
platforms (Chalfen, 2009; Lenhart, 2009; Ringrose et al., 2012). Research has
demonstrated that some youth are engaging in sexting and that this behaviour affects
schools and school professionals. The present study was designed to explore school
counsellors’ views on their experiences with student sexting. A qualitative research
design was employed and semi-structured interviews were conducted with five
participants. Results from this study were divided into three major themes: Prevention
and Preparation, School Counsellors’ Roles, Responsibilities and Introspection and
School Counsellors’ Perspectives on Specific Aspects of Student Sexting. School
counsellors’ are in a unique position to support students. More research is necessary to
establish effective sexting prevention and intervention strategies for students and proper
training for school counsellors, staff and parents.


identifier: Al-Khamaisah, Belal <https://research.library.mun.ca/view/creator_az/Al-Khamaisah=3ABelal=3A=3A.html>   (2018) Analytical solutions of 3D heat conduction in flux channels with nonuniform properties complex structure.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
In the microelectronics industry, thermal issues due to self-heating are major problems
that affect the performance, efficiency, and reliability of devices. The recent
trend of producing advanced devices with smaller sizes, high power densities, and
extreme performance makes thermal management an increasingly important factor in
the development of microelectronic systems. In most applications, the microelectronic
systems are modeled as rectangular flux channels, where heat is generated in one or
more small heat-source areas and flows by conduction through the system to spread
the heat into a larger convective heat-sink area, where the generated heat is then
transferred by convection into an ambient fluid.
In this work, analytical solutions for the temperature distribution and thermal
resistance in three-dimensional (3D) flux channels with nonuniform properties and
complex structures are obtained. First, general analytical solutions in 3D isotropic
flux channels with nonuniform heat transfer coefficients along the sink plane are presented
using the method of separation of variables combined with the method of least
squares. Different parametric studies have been conducted to study the effect of different
variable heat transfer coefficient functions with the same average conductance on
the temperature field. Second, general analytical solutions of 3D isotropic flux channels
with temperature-dependent thermal conductivities and a uniform heat transfer
coefficient along the sink plane are presented by means of the Kirchhoff transform
method. The solutions are used to study the effect of the temperature-dependent
thermal conductivity on the temperature rise and thermal resistance for different conductivity
functions. Third, general analytical solutions in 3D flux channels of multilayered
structures consisting of a finite number of orthotropic layers with constant
and temperature-dependent thermal conductivities are obtained. All the analytical
solutions have been verified by conducting numerical simulations based on the finite
element method (FEM) using the Analysis of Systems (ANSYS) software package.


identifier: Hamed, Mohamed <https://research.library.mun.ca/view/creator_az/Hamed=3AMohamed=3A=3A.html>   (2018) Structural performance of a proposed UHP-FRC shield in harsh environment.  Masters thesis, Memorial University of Newfoundland.

abstract:
Offshore structures are used in harsh ice-infested environments. Shields for such structures are necessary to protect them from ice abrasion. An ice shield is proposed using ultra high performance fibre reinforced concrete (UHP-FRC). This type of concrete is attractive due to its high abrasion resistance that would be beneficial to protect the structure from ice-wear. In order to examine the interaction between the ice shield and the offshore structure, composite flexural and shear specimens were investigated in this thesis.
Ten flexural specimens were cast and tested. All specimens were made with two layers of concrete. The top layer was UHP-FRC and the bottom layer was high performance fibre reinforced concrete (HP-FRC). The parameters tested were the thickness of the top layer (50 mm and 75 mm), the spacing between the shear connectors (390 mm and 195 mm), and the type of shear connectors (shear keys and T-headed studs). The structural behaviour of the specimens was examined in terms of crack development, specimen deformation, strains in steel and concrete, horizontal shear slip and capacity, and ultimate capacity.
The results revealed that the thickness of the top layer did not have a significant effect on the serviceability behavior of the specimens. However, increasing the thickness led to an increase in the ultimate capacity. The specimens with 390 mm spacing between the shear keys were unable to develop a full composite action and had an interface failure. The specimens with T-headed studs and 195 mm developed fully composite action with high ductility.
Direct shear specimens were also cast and tested. The shear specimens duplicated the interface geometry of the flexural specimens and had the same parameters. The results of the direct shear tests were compared to the predictions of different code and some proposed equations in the literature. The results of the comparison revealed that most code and proposed equations can adequately predict the interface capacity of the composite specimens. In addition, the interface shear capacity of both the flexural and the direct shear tests were compared. It was concluded that the shear specimens yielded higher shear capacity than the flexural specimens for the specimens with shear keys that failed due interface failure.


identifier: Elsersy, Mohamed Said <https://research.library.mun.ca/view/creator_az/Elsersy=3AMohamed_Said=3A=3A.html>   (2018) Joint optimization for wireless sensor networks in critical infrastructures.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Energy optimization represents one of the main goals in wireless sensor network design
where a typical sensor node has usually operated by making use of the battery with
limited-capacity. In this thesis, the following main problems are addressed: first, the
joint optimization of the energy consumption and the delay for conventional wireless sensor networks is presented. Second, the joint optimization of the information quality and
energy consumption of the wireless sensor networks based structural health monitoring
is outlined. Finally, the multi-objectives optimization of the former problem under several constraints is shown. In the first main problem, the following points are presented:
we introduce a joint multi-objective optimization formulation for both energy and delay
for most sensor nodes in various applications. Then, we present the Karush-Kuhn-Tucker
analysis to demonstrate the optimal solution for each formulation. We introduce a method
of determining the knee on the Pareto front curve, which meets the network designer interest for focusing on more practical solutions. The sensor node placement optimization has
a significant role in wireless sensor networks, especially in structural health monitoring.
In the second main problem of this work, the existing work optimizes the node placement
and routing separately (by performing routing after carrying out the node placement).
However, this approach does not guarantee the optimality of the overall solution. A joint
optimization of sensor placement, routing, and flow assignment is introduced and is solved
using mixed-integer programming modelling. In the third main problem of this study, we
revisit the placement problem in wireless sensor networks of structural health monitoring by using multi-objective optimization. Furthermore, we take into consideration more
constraints that were not taken into account before. This includes the maximum capacity
per link and the node-disjoint routing. Since maximum capacity constraint is essential
to study the data delivery over limited-capacity wireless links, node-disjoint routing is
necessary to achieve load balancing and longer wireless sensor networks lifetime. We list
the results of the previous problems, and then we evaluate the corresponding results.


identifier: Penney, Michelle <https://research.library.mun.ca/view/creator_az/Penney=3AMichelle=3A=3A.html>   (2018) Genome-wide association studies investigating a histological variant and time-to-metastasis of colorectal cancer.  Masters thesis, Memorial University of Newfoundland.

abstract: Colorectal cancer is a common and complex disease with significant impact on patients and their families. Despite the extensive research conducted on this disease, there is still significant variability in tumor characteristics and disease outcomes. The unknown variability may be explained, in part, by germline genetic variations. This dissertation aimed to identify genetic polymorphisms associated with colorectal cancer tumor histology as well as with the long-term risk and/or timing of metastasis in colorectal cancer using appropriate study designs and statistical methods. As a result of these comprehensive analyses, we identified a set of polymorphisms that significantly increase the discriminatory accuracy of a model for distinguishing between mucinous and non-mucinous colorectal tumors. In addition, we identified ten polymorphisms significantly associated with time-to-metastasis of colorectal cancer after adjusting for significant baseline characteristics. Once replicated, these results could assist in better understanding the complex biological mechanisms behind colorectal tumor histology and distant metastasis.


identifier: Rahman, Mohammed Abdul <https://research.library.mun.ca/view/creator_az/Rahman=3AMohammed_Abdul=3A=3A.html>   (2018) Electrochemical analysis of H₂S corrosion on 13% chromium stainless steel.  Masters thesis, Memorial University of Newfoundland.

abstract: The chemical reactions between steel and a corrosive environment cause severe corrosion, which has become a significant concern for the oil and gas industry due to the increase in the number of oil field shutdowns and equipment failures as the exploration of sour oil fields has considerably increased in the last decade. This research studies the effect of the hydrogen sulphide (H₂S) environment on 13% chromium stainless steel, one of the most commonly used corrosion resistant alloy in the oil industry for sour oil fields containing hydrogen sulphide. The corrosion behaviour, including corrosion rates, the effect of environmental conditions and the formation of protective films, were examined during the study. A series of experiments was performed using the conventional electrochemical method to study the effects of temperature, pH and immersion time on the corrosion behaviour of 13% chromium stainless steel in the H₂S environment. Corrosion behaviour was monitored using the polarisation resistance technique. A scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) was used to conduct morphological characterization and X-ray diffraction (XRD) was used to study the crystal structure of corrosion products. This study shows that each environmental parameter has a significant impact on corrosion behaviour.


identifier: Chang, Nicholas Bruce <https://research.library.mun.ca/view/creator_az/Chang=3ANicholas_Bruce=3A=3A.html>   (2018) Evaluating the reliability of four-dimensional computed tomography scans of the wrist.  Masters thesis, Memorial University of Newfoundland.

abstract:
Introduction: Four-dimensional CT (or 4D CT) scans are a novel approach to diagnosing
musculoskeletal pathology. Although still in its infancy, there has been a surge of interest
in identifying clinical applications for musculoskeletal 4D CT. The scapholunate joint has
received the most attention thus far due to the complex articulations and challenges faced
with prompt diagnosis of scapholunate injuries. The objective of this thesis is to review
current literature on musculoskeletal 4D CT and to evaluate the inter- and intra-rater
reliability of the assessment of scapholunate stability in 4D CT wrist scans.
Methodology: 4D CT scans of thirteen healthy volunteers and four patients were
prepared. Seven orthopaedic and plastic surgeons were recruited to qualitatively assess
the stability of the scapholunate joint in the 4D CT scans. Statistical analysis included
percent agreement, Fleiss’ kappa, and Gwet’s AC1 coefficient.
Results: The percent agreement amongst all raters was 0.80392 (95% CI: 0.675 - 0.932).
Fleiss’ Kappa was 0.54895 (95% CI: 0.252 - 0.846) and Gwet’s AC₁ was 0.54895 (95% CI:
0.391 - 0.915). The intraclass correlation coefficient (ICC) for intra-rater reliability was
0.71631 (95% CI: 0.5567 – 0.8423).
Conclusion: Our pilot study suggests good inter- and intra-rater reliability for the
qualitative assessment of scapholunate instability in 4D CT scans. Although further
studies are required, this thesis highlights the vast potential of 4D CT as a non-invasive
diagnostic technique of dynamic musculoskeletal injuries.


identifier: Harris, Trevor <https://research.library.mun.ca/view/creator_az/Harris=3ATrevor=3A=3A.html>   (2018) Marine performance evaluation of a fast rescue craft.  Masters thesis, Memorial University of Newfoundland.

abstract:
Marine performance evaluation was carried out aboard a fast rescue craft utilized
by the Canadian Coast Guard. The experiments were conducted in late 2016 in the
waters off Conception Bay South, NL and St. John’s, NL. The three primary focus
areas of the study were vessel performance, fuel economy, and human kinetics.
The evaluated vessel has a unique propulsion arrangement and is the first to
be outfitted in Canada with Mercury Marine DSI 3.0 spark-ignited diesel outboard
motors. Motivations to use this type of engine are to unify the Coast Guard’s fuel
supply and to also allow engine re-start after inversion. The Canadian Coast Guard
is interested in this vessel’s performance in comparison to the rest of the fleet because
of these intrinsic advantages.
The performance tests concluded that the vessel is very reactive to helm input.
It also has much greater directional stability as its speed increases. It can reach its
maximum speed in 250 metres, taking approximately 20 seconds to do so. At a full
speed of 38 knots, the vessel can execute a 180ᴼ turn in just over 200 metres, and just
under 20 metres at manoeuvring speed. The vessel can also tow a 19.7 metre fishing
vessel at speeds up to 4.5 knots.
The trials showed that the fuel economy was not overly sensitive to wind speed,
wind direction, or even wave height. The fuel consumption curve fits a resistance
curve that is typical of a planing craft. Its maximum range of 56 nautical miles is
achieved at its optimal cruising speed of 24.6 knots.
The vessel motions show that the accelerations in the Z direction are the most
prominent. The accelerations in the X direction are the lowest, with accelerations in the Y directions being slightly higher. The maximum observed Z acceleration was
4.76 times gravity. The helmsman’s ability to maintain heading is increased with
speed due to the higher directional stability observed at higher speeds. Wave height
also has a prominent effect on the helmsman’s ability to maintain heading.


identifier: MacIsaac, Brian K. <https://research.library.mun.ca/view/creator_az/MacIsaac=3ABrian_K=2E=3A=3A.html>   (2017) Toward the integration of education and school-based behavioural supports: the B.E.S.T. program in northern Nova Scotia.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Emotional behavioural disorders (EBD) in school-aged children are significant and serious issues affecting a global population. This study is an examination of the Behavioural Education Support and Training Program (B.E.S.T.), a school-based program centered on psychosocial rehabilitation for children with EBD. The program is based in eight elementary schools across the Chignecto Central Regional School Board (CCRSB) in Northern Nova Scotia. Historical quantitative data were utilized to analyze students’ emotional and behavioural functioning in classrooms, playground, cafeteria, and/or related environments within each school. The study results expand upon existing descriptive and quasi-experimental studies that demonstrated the importance of longitudinal intervention, the effectiveness of integrated therapy, and progressive change in educational systems. The study data showed that school-based intervention for children with EBD has positive results for decreasing behavioural dysfunction.


identifier: Piercey, Nikita-Rae <https://research.library.mun.ca/view/creator_az/Piercey=3ANikita-Rae=3A=3A.html>   (2018) Exploring the protective factors involved in maintaining couples' relationships when raising a child with autism spectrum disorder.  Masters thesis, Memorial University of Newfoundland.

abstract:
Currently there is room for increased exploration into the protective factors that help to
mitigate relationship discord and increase relationship satisfaction in couples who are
raising a child or children with autism spectrum disorder (ASD). This study considered
the experiences and perspective of couples who are raising a child with ASD together.
The researcher employed qualitative methods to conduct semi-structured interviews with
eight couples to gather a rich understanding of their perspectives, understandings, and
experiences in raising a child with ASD. The researcher’s analysis of the data revealed a
number of themes that emerged from these semi-structured interviews. The major themes
that highlight couples’ resilience are Commitment, Communication, Adaptation, and
Positive Outlook. Further research should be conducted to explore the needs and
perspectives of couples raising children with ASD to continue to develop and implement
appropriate services for this population.


identifier: Arman, Riyadul <https://research.library.mun.ca/view/creator_az/Arman=3ARiyadul=3A=3A.html>   (2018) Numerical modeling of upheaval buckling of initially imperfect submarine pipelines buried in loose and dense sand.  Masters thesis, Memorial University of Newfoundland.

abstract: Offshore pipelines are being utilized as one of the most convenient and efficient means of transporting oil and gas. Usually pipelines travel a long distance through a variety of soil conditions. The oil pipelines are operated at high temperature and high pressure to assure the flow and prevent wax formation inside the pipeline. The rise in temperature and internal pressure result in longitudinal expansion of the pipeline, which might cause lateral or upheaval buckling when the longitudinal movement of the pipe is restrained. The pipelines are generally buried to minimize heat loss and interference with other marine activities. For buried pipelines, soil offers resistances to lateral and upheaval buckling. The lateral soil restraint is higher than the uplift resistance and therefore the pipelines are more likely to experience upheaval buckling. Under these circumstances, upheaval buckling may occur that could cause failure in some cases. The resistance to upheaval buckling is provided by submerged weight of the pipe as well as the shearing resistance of the backfill soil. The two most popular burial methods of offshore pipelines, jet trenching and plowing, generally deposit the backfill soil in a loose to medium dense state; however, it could be subsequently densified due to environmental loading. Physical model tests show an increase and post-peak decrease of the uplift resistance with upward displacement of pipelines both for loose and dense sands. In the present study, finite element analysis is conducted to investigate the upheaval buckling behavior of submarine pipelines buried in loose and dense sands. The force–displacement behavior that considers the variation of uplift resistance for a wide range of upward displacement is studied. Different types of buckling (i.e., snap and stable bucking) for various initial imperfection ratios, burial depth and density of sand are thoroughly investigated. The importance of incorporation of the post-peak reduction of uplift soil resistance in the finite element analysis of the upheaval buckling is highlighted.


identifier: Ryan, Amanda <https://research.library.mun.ca/view/creator_az/Ryan=3AAmanda=3A=3A.html>   (2018) Ice wear and abrasion of marine concrete: design of experimental apparatus and procedures.  Masters thesis, Memorial University of Newfoundland.

abstract:
Abrasion of marine concrete structures from passing ice is an ongoing problem that leads
to loss of structural integrity over time. The purpose of this study is to develop new
experimental approaches and apparatus that would allow long term testing of ice wear on
concrete samples as a prelude to a larger study that will investigate the wear of concrete
by ice.
This thesis has drawn on the experiences of previous work to identify the important
issues, including those areas where different approaches may be beneficial. A review has
been completed of previously used tests setups, contributing factors and areas of
uncertainty. This has resulted in two conceptual designs that approach the problem from
slightly different angles. The first is a lab scale apparatus that aims to standardize the
testing methods for concrete wear due to ice. The conceptual design of a new apparatus
will allow wide ranging load applications, long test durations and the inclusion of
surrounding water. The second is an in-situ apparatus that has been developed to allow
direct comparison between concrete mixtures in terms of wear resistance under realistic
but uncontrolled ice conditions.
Pilot experiments have been completed and reviewed to refine the initial concept and to
determine effective means of abrasion measurement. These experiments provided insight
into important features of the designed apparatus, trial results from measurements of iceinduced
wear on concrete and useful information on concrete wear experiments in
general.


identifier: Bishop, Bonnie <https://research.library.mun.ca/view/creator_az/Bishop=3ABonnie=3A=3A.html>   (2018) The human dimensions of the "Wolf Capital of the World" initiative.  Masters thesis, Memorial University of Newfoundland.

abstract: Conflict regarding how wildlife should be managed often occurs because different groups have varying attitudes, values, and behaviors. Spirit Way Inc., an NGO in Thompson, Manitoba, was established for the purpose of creating new opportunities to diversify Thompson’s economy. Spirit Way Inc. realized the economic potential of wolves and thus made the decision to develop an initiative called the “Wolf Capital of the World”. Within Thompson, there is no quantitative knowledge of whether or not public support exists for the “Wolf Capital of the World” initiative. The purpose of this research is to understand public attitudes, beliefs, and values toward wolves and the “Wolf Capital of the World” initiative. In addition, this research aims to facilitate management understanding of research results. This research will fill a knowledge gap and can be integrated into the consideration of key issues surrounding wolves, wolf-related tourism, and the “Wolf Capital of the World”.


identifier: Hassan Nejad, Hesam <https://research.library.mun.ca/view/creator_az/Hassan_Nejad=3AHesam=3A=3A.html>   (2018) Experimental investigation of surfactant-enhanced washing and supercritical CO₂: extraction processes for waste drilling mud remediation.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Waste drilling mud is the second largest waste stream produced in the oil and gas industry
after produced water and cannot be discharged or landfilled without proper treatment to
meet regulatory requirements. Various contaminants are present in the waste drilling mud,
including petroleum hydrocarbons, heavy metals, BTEX (benzene, toluene, ethyl benzene,
and xylenes), polycyclic aromatic hydrocarbons (PAHs), and other hazardous materials
typically originating from the base drilling fluids. Strict environmental regulations are in
place regarding the disposal of the waste drilling mud and cuttings to minimize their effect
to the environment. Therefore, the waste drilling mud must be properly treated before being
released into the environment. Different technologies have been proposed for waste drilling
mud remediation; however, most of them are unable to meet the strict environmental
regulation limits.
In this thesis, different technologies to treat the waste drilling mud are reviewed. After a
technical comparison, physical treatment technologies were selected as the most suitable
methods. The main aim of this study is to investigate the abilities of the methods of
surfactant-enhanced washing and supercritical CO₂ extraction, to treat the waste drilling
mud and remove the hazardous petroleum hydrocarbons to meet the strict environmental
regulations. The specific objectives of the study are to: (1) characterize the waste drilling
mud using particle size distribution, X-ray diffraction (XRD), inductively coupled plasma
optical emission spectrometer (ICP-OES), scanning electron microscope (SEM), and gas
chromatography GC analyses; (2) identify of the most efficient, environmentally-friendly,
and cost-effective technologies to treat the waste drilling mud; (3) screen and select the best surfactants for drilling mud remediation using interfacial tension and sorption analyses; (4)
experimentally determine the impacts of significant factors on the efficiency of the two
physical processes, surfactant-enhanced washing and supercritical CO2 extraction (SCE);
(5) optimize both the surfactant-enhanced washing and supercritical CO₂ extraction
processes; and (6) evaluate both the physical treatment processes considering efficiency,
environmental impacts, and possible separation and/or recovery of hydrocarbons.
A technical review was completed by considering key factors in an efficient process for
waste drilling mud remediation, including efficiency, particle size effect, environmental
impact, cost, energy requirement, and processing time. Surfactant-enhanced washing and
supercritical CO₂ extraction were selected as two viable, efficient, and environmentallyfriendly
physical treatment methods. Three surfactants, one anionic (Alfoterra 145-8S 90),
one non-ionic (Triton 100), and one biosurfactant (Saponin), were experimentally analyzed,
and Triton 100 (TX-100) was selected as the best surfactant based on the interfacial tension
and sorption analyses. Experiments were conducted to investigate the effect of different
parameters on the surfactant-enhanced washing process’ efficiency, using Triton 100 as the
most suitable surfactant, including (i) contact time, (ii) surfactant concentration, and (iii)
temperature, and to obtain the optimized operating conditions. The supercritical CO₂
extraction experiments were also designed and conducted to investigate the effects of three
parameters, including (i) temperature, (ii) pressure, and (iii) contact time on the process’
efficiency.
The result of this study suggested that even though the surfactant-enhanced washing was
able to remove up to 70% of the petroleum hydrocarbons, the process could not be employed to treat the waste drilling mud to meet the landfilling regulations. The
supercritical CO₂ extraction process, however, was capable of removing the petroleum
hydrocarbons up to more than 97% when operated at the optimized conditions and could
effectively remediate the waste drilling mud considering the initial total petroleum
hydrocarbon concentration).
Based on the results of this study, supercritical CO₂ extraction (SCE) process was
recommended as an efficient and environmentally-friendly method to remove the total
petroleum hydrocarbons from the waste drilling mud to meet the provincial, national, and
universal environmental regulations. The SCE process could easily separate the
hydrocarbons from the waste mud effectively and in a short amount of time. The
supercritical CO₂ extraction process could be tested and implemented for other
contaminated substances with petroleum hydrocarbons as well. Although further
investigation may be required, the results of this study can be a guide for future research
on similar remediation processes.


identifier: Sharma, Ishor <https://research.library.mun.ca/view/creator_az/Sharma=3AIshor=3A=3A.html>   (2018) Dietary patterns colorectal cancer risk and survival in Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract:
Diet patterns commonly used in epidemiological research are derived using different
methods, yet there have been few studies assessing if and how research results may vary
in the same population across diet patterns.
This study assesses and compares five different diet patterns identified by Principal
Component Analysis (PCA), Cluster Analysis (CA), Alternate Mediterranean Diet (Alt-
Med), Dietary Inflammation Index (DII), and Recommended Food Score (RFS).
Colorectal cancer risk and patient’s survival is estimated using different patterns as an
independent variable. Comparisons are made using hazards ratio, correlation coefficients
and distributions of individuals in clusters.
Disease outcome estimation varied with diet patterns used and is mainly attributed to
differences in its foundation. Hazards ratios for DFS varied from 1.82; (95% CI- 1.07-
3.09) for processed meat pattern identified by PCA to HR 2.19; (95% CI 1.03-4.67) for
cluster characterized by meat and dairy products and HR 1.95; (95% CI 1.13-3.37) for
cluster characterized by refined grains, sugar, soft drinks. Only cluster characterized by
refined grains, sugar, soft drinks had higher risk of OS (HR 2.05; 95% CI 1.18-3.57). All
the diet indices showed similar null associations with both DFS and OS except Poor
adherence to altMED increased the risk of all-cause mortality (HR 1.62; 95% CI 1.04-
2.56).