In the past decade, the grouting industry has made significant technological advancements in real-time monitoring of flow rate and pressure of pumped grout, stable grout mix design, and with grout curtain concepts dealing with placement and orientation. While these practices have resulted in improved construction practices in the grouting industry, current design guidelines for grout curtains are still predominately based on qualitative measures such as engineering judgment and experience or are based on proprietary methods. This research focused on the development of quantitative guidelines to evaluate the effectiveness of a grout curtain in porous media using piezometric and hydraulic flow data. In this study, a laboratory-scale physical seepage model was developed to aid in the understanding and development methodology to evaluate the effectiveness of a grout curtain. A new performance parameter was developed based on a normalization scheme that utilized the area of the grout curtain and the area of the improved media. The normalization scheme combined with model-based Lugeon values that correspond to pore pressure and flow rate measurements at different soil unit weights and grout curtain spacings, produced a mathematical equation that can be used to quantify the effectiveness of a grout curtain. This study found a relationship that takes into account soil unit weight, grout curtain spacing and a new performance parameter that can be used to help predict the effectiveness of a grout curtain.

Linkages between the controls on depressional storage and catchment streamflow response were examined in a wetland dominated basin in the Canadian Prairie Pothole region through a combination of field monitoring and modelling. Snowmelt, surface storage, water table elevation, atmospheric fluxes, and streamflow were monitored during spring snowmelt and summer in a 1 km2 sub-catchment containing a semi-permanent pond complex connected via an intermittent stream. Snow accumulation in the basin in spring of the 2013 study year was the largest in the 24-year record. Rainfall totals in 2013 were close to the long term average, though June was an anomalously wet month. The water budget of the pond complex indicates that there was a significant subsurface contribution to surface storage, in contrast to previous studies in this region. Following snowmelt, subsurface connectivity occurred between uplands and the stream network due to activation of the effective transmission zone in areas where the water table was located near the ground surface, allowing significant lateral movement of water into the stream network. Modelling results suggest there was significant infiltration into upland soils during the study period and that upland ponds are an important consideration for accurately simulating catchment discharge. The flux of groundwater to the wetland complex during periods of subsurface connectivity was also important for maintaining and re-establishing surface connectivity and streamflow. As the observed period of surface and subsurface hydrological connectivity was one of the longest on record in the catchment due to very wet conditions, the results of this study denote observations of the wet extremes of the hydrological regime important for proper understanding, modelling, and prediction of streamflow in the region.

There is a growing need to better understand the relationship between time, strain rate, and temperature on the load-deformation behaviour of clay soils in engineering applications. These applications may include: infrastructure constructed in northern regions where climate change is a growing concern; disposal of nuclear waste; and, industrial structures, such as furnaces, foundries, and refrigeration plants. Temperature variations may induce changes in internal pressure in the soil, swelling and shrinkage, and affect the mechanical properties of the soil. This thesis presents thermal numerical modeling for two instrumented field sites in northern Manitoba. Thermal conductivity testing on samples from these sites and field data are used to calibrate these thermal numerical models. Various boundary conditions are examined. The capabilities of the models are evaluated to determine if the models adequately simulate and predict changes in temperature in geotechnical structures. A discussion is presented on the strengths and weaknesses in the models and the predictive capabilities of the models. The thesis then shifts into understanding the concepts of thermoplasticity and viscoplasticity and the mathematics relating these concepts. Mathematical models that describe these concepts are examined and compared with traditional soil mechanics approaches. The concepts of thermoplasticity and viscoplasticity are combined in an encompassing elastic thermo-viscoplastic (ETVP) model using a semi-empirical framework. A sensitivity analysis is used to evaluate quantitatively the response of the model. The model is then validated qualitatively against published laboratory data. Applications of the ETVP model are discussed.

We have employed a differential detector combined with dielectrophoretic (DEP) translation in a microfluidic channel to monitor dielectric response of single cells and particularly to track phenomenon related to apoptosis. Two different cell lines were studied; Chinese hamster ovary cells (CHO) and MRC5 cells. Dielectric response was quantified by a factor called Force Index. Force Index was studied statistically to identify apoptotic subpopulations. Another direction of this work was to monitor changes in the cytoplasm conductivity following inhibition of mitochondrial ATP production by Oligomycin. To make the DEP response mostly sensitive to the cytoplasm conductivity, medium conductivity and DEP frequency were adjusted such that Clausius Mossotti factor and hence DEP response become less sensitive to cell radius. Chinese hamster ovary cells were used in this work and the impact of different concentrations of Oligomycin has been studied. We show that following exposure to Oligomycin at 8 μg/ml, cytoplasm conductivity drops. The majority of the changes takes place within one hour of exposure to the drug. Furthermore, double shell models has been used to estimate cytoplasm conductivity in a medium with conductivity of 0.42 S/m and the drop in the cytoplasm conductivity following treatment with Oligomycin was estimated to be ≈ 0.16 S/m. The magnitude of the decrease in the cytoplasm conductivity is evidence that Glycolysis is active as an energy production pathway within the cell. This approach can be used to quantify Glycolysis versus mitochondria ATP production which has an application in Warburg effect in cancer cells and monitoring bioprocesses.

This thesis primarily focuses on the systematic understanding of structure – reactivity relationships in two representative systems: bixbyite and related structures as well as indium doped CeO2. Topotactic reaction routes have gained significant attention over the past two decades due to their potential to access kinetically controlled metastable materials. This has contributed substantially to the understanding of solid state reaction pathways and provided first insights into mechanisms. Contrary to the widely used ex-situ methods, in – situ techniques including powder x-ray diffraction and thermogravimetric – differential thermal analysis have been employed extensively throughout this work in order to follow the reaction pathways in real time. Detailed analysis of the AVO3 (A = In, Sc) bixbyite reactivity under oxidative conditions has been carried out and a variety of novel metastable oxygen defect phases have been identified and characterized. The novel metastable materials have oxygen deficient fluorite structures and consequently are potential ion conductors. Structural aspects of the topotactic vs. reconstructive transformations are illustrated with this model system. The structure – reactivity study of AVO3 phases was extended to AVO3 perovskite family. Based on the research methodologies and results from AVO3 bixbyite reactivity studies a generalized mechanistic oxidation pathway has been established with a non-vanadium phase, ScTiO3 bixbyite. However, there is stark contrast in terms of structural stability and features beyond this stability limit during AVO3 and ScTiO3 bixbyite reaction pathways. A series of complex reaction sequences including phase separation and phase transitions were identified during the investigation of ScTiO3 reactivity. The two-step formation pathway for the fluorite – type oxide ion conductor Ce1-xInxO2-δ (0 ≤ x ≤ 0.3) is being reported. The formation of the BaCe1-xInxO3-δ perovskites and the subsequent CO2-capture reaction with the formation of Ce1-xInxO2-δ (0 ≤ x ≤ 0.3) has been investigated in detail. The two-step formation pathway is contrasted with the unsuccessful direct method. The stability and the extent of In – doping for the CeO2 fluorite phases that can be achieved through this CO2 – capture method are reported. The necessity and strategies for the selection of appropriate intermediate precursors for the preparation of doped CeO2 are also reported.

Scientific development requires profound understandings of micromechanical and nanomechanical systems (MEMS/NEMS) due to their applications not only in the technological world, but also for scientific understanding. At the micro- or nano-scale, when two objects are brought close together, the existence of stiction or adhesion is inevitable and plays an important role in the behavior operation of these systems. Such effects are due to surface dispersion forces, such as the van der Waals or Casimir interactions. The scientific understanding of these forces is particularly important for low-dimensional materials. In addition, the discovery of materials, such as graphitic systems has provided opportunities for new classes of devices and challenging fundermental problems. Therefore, invesigations of the van der Waals or Caismir forces in graphene-based systems, in particular, and the solution generating non-touching systems are needed. In this study, the Casimir force involving 2D graphene is investigated under various conditions. The Casimir interaction is usually studied in the framework of the Lifshitz theory. According to this theory, it is essential to know the frequency-dependent reflection coefficients of materials. Here, it is found that the graphene reflection coefficients strongly depend on the optical conductivity of graphene, which is described by the Kubo formalism. When objects are placed in vacuum, the Casimir force is attractive and leads to adhesion on the surface. We find that the Casimir repulsion can be obtained by replacing vacuum with a suitable liquid. Our studies show that bromobenzene is the liquid providing this effect. We also find that this long-range force is temperature dependent and graphene/bromobenzene/metal substrate configuration can be used to demonstrate merely thermal Casimir interaction at room temperature and micrometer distances. These findings would provide good guidance and predictions for practical studies.

Dirvožemio elektrinio laidumo (EC) matavimas yra vienas iš perspektyviausių ir dažniausiai naudojamų tiksliosios žemdirbystės tyrimų būdų. Tyrimais yra nustatyta tiesioginė jo priklausomybė su dirvožemio granuliometrine sudėtimi. Apibendrinant galima teigti, kad EC yra priemonė, leidžianti išsiaiškinti dirvožemio savybes, nuo kurių priklauso ne tik žemės ūkio, bet ir energetinių augalų, skirtų atsinaujinančios energijos gamybai, derlingumo dėsningumai. Dirvožemio elektrinis laidumas nustatytas mobiliu įrenginiu „Veris 3150 MSP“ (JAV, Veris Technogies Ltd.). Jame įrengta navigacinė sistema. Matavimai atlikti dviejuose dirvožemio pjūviuose (paviršiniame ir giluminiame): nuo dirvožemio paviršiaus iki 30 cm gylio ir 0–90 cm gylyje. Dirvožemio savybių žemėlapiai sudaryti naudojant kompiuterinę programą „SMS Advanced“ JAV, AgLeader Ltd.). Atliktų dirvožemio elektrinio laidumo tyrimų patikimumą įrodo gauta tiesinė tarpusavio priklausomybė (R2 = 0,91) tarp elektrinio laidumo nustatyto įrenginiu „Veris 3150 MSP“ ir elektrinio laidumo nustatyto laboratorijoje. Atlikus dirvožemio granuliometrinės sudėties tyrimus nustatyta, kad didėjant molio (< 2 m) ir dulkių (2–50 m) daliai dirvožemyje, jo elektrinis laidumas didėja. Labai smulkaus smėlio (50–100 m) dalelės įtakos dirvožemio elektriniam laidumui įtakos neturi, o dirvožemyje didėjant dar didesnių (> 100 m) smėlio dalelių daliai – jo elektrinis laidumas mažėja. / Soil electrical conductivity (EC) measurement is one of the most perspective and widely used research methods of precision agriculture. Various studies proved its direct correlation to soil texture. In summary, it can be stated that EC is a measure that allows defining such characteristics of soil that do influence the productivity laws not only of agricultural, but also of energy crops. Soil electrical conductivity was measured using a mobile unit Veris 3150 MSP (USA, Veris Technogies Ltd.) equipped with GPS system. Measurements were performed in two sections of soil depth (shallow and deep): from the surface up to 30 cm depth and 0–90 cm depth. Soil characteristic maps were created using computer program SMS Advanced (USA, AgLeader Ltd.). The reliability of soil electric conductivity research is proved by direct relationship (R2 = 0.91) between electrical conductivity obtained using Veris MSP and that in the laboratory. The analysis of soil texture showed that the increasing part of clay (< 2 m) and silk (2–50 m) in soil increases electrical conductivity of soil. Extremely small particles of sand (50–100 m) do not influence soil electrical conductivity, while higher amount of larger particles (> 100 m) of sand reduces its electrical conductivity.

Organic electrical energy storage (EES) is a growing field of research that is expected to play an important role in the future, as the need for sustainable EES increases. Conducting redox polymers (CRPs), i.e. conducting polymers with incorporated redox active moieties e.g. as pendant groups (PGs), are proposed as a promising class of compounds for this purpose. Redox cycling of the PGs can be utilized for high charge storage capacity, while the conducting polymer backbone provides fast charge transport through the material. Some of the major challenges with small-molecule systems for EES could be solved by using CRPs, e.g. capacity fading due to dissolution of the active compound, and high resistance due to slow charge transport between molecules. The latter issue is often solved by adding large amounts of conducting additives to the active material, drastically lowering the specific capacity. In this project, CRPs are shown to be able to function in battery cells without any additives, making both high capacity and high power possible. Although several CRPs have been reported in the literature, very few detailed studies have been conducted on the electrochemical processes of the two systems (i.e. the conducting polymer backbone and the redox active PGs). An important factor to consider in CRP design is the possibility for interaction between the two redox systems, which could be either beneficial or detrimental to the function as EES material. In this thesis, CRP model systems composed of hydroquinone functionalized polypyrrole have been studied, and they exhibit separate redox reactions for the PGs and the backbone, overlapping in potential. Significant interaction between them was observed, as oxidation of the PGs has severe impact on the backbone: When the oxidized and hydrophobic p-benzoquinone PGs are formed, they pack and force the polymer backbone to twist, localizing the bipolarons, and decreasing the conductivity. This is accompanied by a contraction of the polymer film and expulsion of electrolyte. Overall, the interaction in these polymers is destructive for their EES function, and it could be eliminated by introduction of a long linker unit between the PGs and the backbone.

No description available.

This thesis describes the design, construction and application of a novel vacuum system for the preparation of thin films of organic charge-transfer compounds. The method of thermal evaporation was used for four materials: tetrathiafulvalene (TTF) and three of its derivatives, dimethyltetrathiafiilvalene (DiMe-TTF), trimethyltetrathiafiilvalene (TriMe-TTF) and bis(ethylenedithio)tetrathiafiilvalene (BEDT-TTF). The resulting thin layers were characterised using optical and electron microscopy, infrared/visible spectroscopy and dc conductivity measurements down to 77K.Thin films of tetrathiafulvalene, after doping with iodine, exhibited a maximum value of dc, in-plane room temperature conductivity σ of 8.0+2.4 S cm(^-1). Semiconducting behaviour was exhibited over the range 77-300 K with AE = 0.09+0.02 eV. The effect of the deposition rate on fihn morphology is reported. TTF iodide layers were also prepared by co- evaporating the two components. These films exhibited a maximum conductivity of 2.9+0.4 S cm(^-1) at room temperature. Again, semiconducting behaviour was noted over the range 77- 300 K with AE = 0.2+0.02 eV. A comparison of the optical, structural and electrical properties of the two types of films is made. DiMe-TTF and TriMe-TTF thin films were also successfully prepared. Doping with iodine resulted in in-plane, dc room temperature conductivities of 10(^-6) and 10(^-7) S cm(^-1), respectively. These values, together with data from optical spectroscopy, suggested that both salts were in the full charge-transfer state. (BEDT-TTF) iodide thin films were deposited by evaporating the organic compound and subsequent doping. Doped films possessed a dc, in-plane room temperature conductivity of 10(^-3) S cm(^-1).Annealing these layers at 60ºC resulted in an increase in conductivity with a final value of 1.6 S cm(^-1). Semiconducting behaviour over the range 77-300 K was exhibited by the annealed films (ΔE = 0.028 eV).Finally, thin film transistors, incorporating TTF and BEDT-TTF doped layers, were fabricated and their electrical characteristics measured.