The relative ease of tuning the properties of two-dimensional materials compared to their three-dimensional counterparts offers great potential to achieve previously inaccessible multifunctional devices. In this Dissertation, we use strain engineering as a non-destructive way to control the properties of two-dimensional materials, employing density functional theory and chemical vapor deposition. In the first part of the Dissertation, density functional theory is used to investigate the effect of biaxial strain on the structural, electronic, and magnetic properties of pristine and Janus Cr-trihalide monolayers. We find that the broken inversion symmetry of the Janus monolayers X3-Cr2-Y3 (X, Y = Cl, Br, and I) enhances their functionality by making the magnetic anisotropy tunable by strain and inducing an out-of-plane electric polarization. A very negative magnetic anisotropy energy of ̶ 3.77 meV per formula unit is realized in the Cl3-Cr2-I3 monolayer under ̶ 5% strain. In the second part of the Dissertation, we perform a comprehensive investigation of thermally strained monolayer MoS2, both theoretically and experimentally, to tune the sulfur vacancy density. Due to a dominant role of the intralayer electrostatic interaction, compressive (tensile) biaxial strain decreases (increases) the sulfur vacancy formation energy and, thus, increases (decreases) the probability of creating sulfur vacancies. This fundamental relationship opens a new venue for defect engineering of transition metal dichalcogenides.

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The following dissertation is an examination of arguments against physicalism. Physicalism is a thesis in the philosophy of mind that is constituted by two central claims: (1) the ontological claim that everything that exists is ontologically physical and that human beings are among such things; (2) the explanatory claim that all facts about human beings and all explanations of their behaviour are dependent on and determined by physical facts and explanations. It has frequently been asserted that there are properties that escape capture in physicalist accounts of human behaviour, thereby undermining (2). Such properties are usually thought to be lacking causal powers, and hence have been called "epiphenomenal." The epiphenomenalist objections have long been thought to represent a serious obstacle to physicalism. My aim is to show that the objections that are motivated by epiphenomena} properties are unconvincing. My discussion proceeds in two stages. In the first stage I examine the epiphenomenalist objections in detail and show that in their most persuasive forms they demonstrate that physicalism has certain explanatory inadequacies. The critics of physicalism believe that these shortcomings lead to the denial of the explanatory completeness of physicalism, and I try to make their case as charitably as I can. In the second stage of the argument I invoke the relation of psycho-physical supervenience and show that the desired conclusion does not follow, even if we admit that physicalism has certain explanatory failings. The overall conclusion ofthis dissertation is that the epiphenomenalist objections to physicalism are completely undermined and hence that properties which were thought to be epiphenomena! do not represent a serious obstacle to physicalisrn as was previously thought. My intention is that this discussion push forward work in the philosophy of mind and point the way to a more adequate articulation of physicalism. / Thesis / Doctor of Philosophy (PhD)

Biodegradable polyesters are considered as one of the most cost effective and environmentally friendly solutions to waste-disposal problems associated with traditional thermoplastics. The technologies for converting the resins into useful items require knowledge about the rheological properties of these materials. Adequate rheological models are essential for the design and optimization of the process technologies. Rheological properties of two commercial biodegradable polyesters- poly(lactic acid) (PLA) and aliphatic-aromatic co-polyester (AAC) Ecoflex -have been investigated using parallel plate and capillary rheometers. Results from a study on the extrusion instabilities of biodegradable polymers are reported for the first time. The experimental studies found that the biodegradable polyesters exhibit pseudoplastic (shear-thinning) behaviour and the Cox-Merz rule is obeyed. A Cross model was proposed to describe their shear-thinning behaviour. The viscosity of both PLA grades is more temperature sensitive than the viscosity of Ecoflex. It was observed that the extensional viscosity of Ecoflex is larger than that of PLA and that the extensional viscosity of biodegradable polymers is similar to that of LLDPE. The experimental results indicate that biodegradable polymer melts slip at the die wall. It was observed that with increasing shear rate PLA exhibits sharkskin and gross melt fracture while Ecoflex exhibits only gross melt fracture. With regards to flow instabilities PLA behaves like linear polyolefins, however without exhibiting stick-spurt phenomenon. While Ecoflex behaves like branched LDPE, its gross melt fracture starts at higher values of wall shear stress than LDPE. Both biodegradable materials exhibit small extrudate swell: up to 28% for PLA and up to 34% for Ecoflex, which is comparable to that of rigid PVC. It was observed that biodegradable polymers substantially degrade during extrusion processing. It was also found that blending PLA and Ecoflex produced immiscible blends. Melts of these blends exhibited sharkskin and gross melt fracture at higher shear stresses than the neat resins. This effect was attributed both to degradation during blending and to some sort of lubricating effect. / Thesis / Master of Applied Science (MASc)

Polypyrrole nanocylinders were fabricated by chemically synthesizing polypyrrole within the pores of nanoporous polycarbonate particle track-etched membranes and alumina membranes. The morphology of the nanostructures was characterized by transmission electron microscopy and scanning electron microscopy. The polycarbonate membrane-templated nanocylinders were cigar-shaped, with the diameter at the center being up to 2.5 times the diameter at the ends. The nanostructures produced in alumina membranes were linear aggregates of blobs. The electrical conductivity of the nanocylinders was measured by leaving the nanocylinders embedded in the insulating template membrane and measuring the trans-membrane resistance. The smallest diameter polycarbonate membrane-templated nanocylinders exhibited a slightly lower conductivity relative to the larger diameter nanocylinders. The temperature dependence of the resistance with and without the application of a magnetic field was in accordance with Mott variable range hopping at temperatures above 5 ± 1 K and Efros-Shklovskii variable range hopping at temperatures below 5 ± 1 K. Based on the measurements in the Mott regime, the localization length, the density of states at the Fermi energy, and the temperature dependence of the average hopping distance were calculated. / Thesis / Master of Science (MS)

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This research sought to integrate measurement and prediction of surface macrotexture for use in pavement management systems. This was achieved through two experiments, the first modeled the behavior of a binder-rich stone matrix asphalt when subjected to traffic loading using a heavy vehicle simulator to report the effect on pavement macrotexture. The second experiment compared high-speed macrotexture measurement devices on a variety of surfaces and under various operating conditions. The change in macrotexture due to traffic loading showed that as the cumulative load increased, the macrotexture decreased due to bleeding on the pavement's surface. A regression model determined that, on average, the macrotexture's root mean square (RMS) decreased 0.14 mm per million equivalent single axle load applied. A comparison of RMS and mean profile depth (MPD) outputs indicated that RMS was more sensitive to changes in macrotexture due to bleeding. In comparing devices, pairwise device agreement was evaluated using a Limits of Agreement. The results demonstrate good repeatability for each of the devices tested. The agreement analysis showed that not all high-speed devices can be used interchangeably for all pavement surfaces. Data acquisition speed was found to be a factor in macrotexture parameter calculation for two of the devices. The effect of speed was found to be worse on randomly textured surfaces than on transversely textured surfaces. / Master of Science / This thesis sought to integrate the collection and prediction of a pavement surface property known as macrotexture for use in the management of pavement networks. This was achieved through two experiments, the first of which modeled the behavior of asphalt concrete with a higher than typical asphalt content when subjected to simulated traffic to determine the effect on pavement macrotexture. The second experiment compared five high-speed macrotexture measurement devices on a variety of pavement surface types and under various operating conditions. The change in macrotexture due to traffic loading showed that as the cumulative traffic increased, the macrotexture decreased due to the asphalt coming out on the surface, referred to as bleeding. For the comparison of measurement devices data were processed using current industry standards. The results demonstrate good repeatability for each of the devices tested. The analysis also showed that not all high-speed devices can be used interchangeably for all pavement surface types. Vehicle speed was found to be a factor for two of the devices. The effect of speed was found to vary by surface type. Finally, vehicle acceleration was shown to influence the parameters produced by one of the devices, demonstrating that care should be taken to gather high-quality datasets for the critical pavement characteristic of macrotexture.