We present the results of our study of the shear deformation zone in free-standing thin polymer films as a probe of entanglement in confined systems. A stretching system was used to uniaxially strain thin polystyrene (PS) films. Atomic force microscopy was used to measure the thicknesses of the shear deformation zone (SDZ), hc, and the film thicknesses h. The maximum extension ratio 2 - h/hc, was measured as a function of film thickness. The results show that A increases with the decreasing film thickness which implies an increase in the entanglement molecular weight in confinement. The same experiments were carried out for thin PS film with different molecular weights. A tentative model was developed to explain the experimental results and found to be in good agreement with the data. More exciting is the fact that the model predicts a scaling dependence on the polymer molecular weight which was also observed. / Thesis / Master of Applied Science (MASc)

Quartz-rich mylonites present along the Moine Thrust Zone are well suited for the application of various analytical techniques designed for investigating the flow processes by which rock deformation occurred. These analytical techniques were applied to a suite of samples from the footwall and hangingwall of the Moine thrust exposed along the Allt Pol aâ Mhadaich stream located in the northern part of the Assynt window. Vorticity analyses were performed to determine the relative contributions of pure and simple shear deformation within the penetratively deforming thrust sheets. Integration of vorticity data with 3D strain analyses demonstrated that sub-vertical shortening perpendicular to the flow plane, accompanied by thrust transport parallel extension, occurred during mylonitization, and was driven by emplacement of the overlying Moine nappe. Quartz c-axis fabrics in the mylonites are characterized by well-defined asymmetric Type-1 cross girdles in which internal and external skeletal asymmetries are indicative of a top-to-the-WNW shear sense, compatible with regional thrusting. These c-axis fabrics were also used to estimate deformation temperatures. Differential flow stresses associated with mylonitization were estimated from the grain size of dynamically recrystallized quartz. Deformation temperature and flow stress data were then incorporated into a dislocation creep flow law for quartz to estimate strain rates. Finally, along strike variation in these flow properties at the base of the Moine nappe to the north and south of the APM section were investigated and results from the APM section compared with previously published studies of mylonites exposed in eastern Assynt that occupy similar structural positions. / Master of Science

Channeling has already been an observed phenomenon that often occurs during settling and sedimentation processes of finer materials. However, it has been regarded as a minor factor affecting settling process, e.g. settling velocity or consolidation rate. In this study, settling behaviors of talcs, kaolins and attapulgite were reviewed by experiments with small and large settling columns with special focus on channel formation during sedimentation. The large settling column is equipped with twenty eight measuring points, which are connected to pressure transducers for measuring pore pressure changes during settling. Throughout the study, channel formation was observed and related to the experimental conditions affecting it. The excess pore pressure changes were measured during the large column tests. Channels occurred under flocculation in zone settling and also in consolidation zones; pressure drop was observed near channels in some cases. It was apparent that channels work as a facilitator to dissipate the excess pore water pressure. It is summarized that not only initial concentration but also the material properties, such as specific gravity and shape of particles, can affect the channel formation. / Master of Science

The double difference earthquake location algorithm, implemented in the program HYPODD, was used to relocate a data set of approximately 1000 earthquakes in the eastern Tennessee seismic zone (ETSZ), using a recently developed velocity model. The double difference algorithm is used to calculate accurate relative hypocenter locations by removing the effects of un-modeled velocity structure. The study examines the earthquake hypocenter relocations in an effort to resolve fault orientations and thereby gain insights into the tectonics of the seismic zone. The analysis involves visual comparison of three-dimensional perspective plots of the hypocenter relocations oriented according to focal mechanism nodal planes derived from events within several, dense clusters of earthquakes. The northwestern boundary of the seismic zone corresponds to the steep magnetic gradient of the New York-Alabama lineament. The double-difference relocations reinforced previous interpretations of a vertical boundary between seismic and relatively aseismic crust at that location. Areas at the northeastern and southwestern ends of the ETSZ exhibit northwest trending hypocenter alignments, which are perpendicular to the overall northeastern trend of the seismic zone. These alignments agree with focal mechanism nodal plane orientations and are interpreted as seismogenic faults. In the central, most seismically active portion of the ETSZ, relocations appear to indicate a diffuse zone of hypocenters that are west-striking and north-dipping. The orientation of this zone of earthquake hypocenters is consistent with an existing seismic reflection profile that images mid to upper crustal reflectors with apparent dips of approximately 35 degrees to the north. The interpreted fault planes are all consistent with an east-northeast oriented, sub-horizontal maximum regional compressive stress, consistent with findings in previous studies. / Master of Science

The White Mountain shear zone (WMSZ) is a zone of intense penetrative deformation that lies along the western front of the northern White-Inyo Range in eastern-most California and western-most Nevada. The northern half of the WMSZ is characterized by a NNE to NNW-striking steeply dipping foliation and associated shallowly plunging NNE to NW-trending stretching lineations. S-C fabrics observed in outcrop, microstructural shear sense indicators and kilometer-scale foliation geometry all indicate dextral movement. Localized discrete zones of coeval steeply plunging stretching lineations are present in the northern half of the WMSZ. Microstructural data from these domains indicate a high component of pure shear within a separate coeval kinematic framework and hence a transpressional history. The WMSZ appears to be tectonically related to both the Sierra Crest shear system to the west and the Santa Rita shear system to the south. Correlation between the WMSZ and the Santa Rita shear system indicates that Late Cretaceous dextral transpression may extend up to ~120 km along the western front of the White-Inyo Range. Cross-cutting relationships with Late Cretaceous plutons bracket the age of the WMSZ at between 72-92 Ma. A lack of annealing recrystallization in deformed quartz and the presence of high temperature crystallographic fabrics near the margins of the ca. 72 Ma Boundary Peak pluton indicate significant strain accumulation within the WMSZ subsequent to emplacement of the Boundary Peak pluton. These observations extend the duration of Late Cretaceous dextral transpression in eastern California to at least as recent as 72 Ma. / Master of Science

Great (Mw >8.5) earthquakes occur over long temporal intervals that extend beyond current historical (written and oral) records along most subduction zone coastlines often leading to the underestimation of magnitude, recurrence, and spatial extent of these events. Paleoseismic studies target low energy depositional environments that record primary and secondary evidence of earthquake occurrence within the coastal stratigraphy over much longer temporal scale, thus improving our understanding of the behavior of subduction zone earthquakes. Diatoms preserved within coastal stratigraphic records are sensitive to earthquake-induced environmental change and are useful bioindicators in paloesiesmology studies. The two studies in this dissertation employ diatoms to create novel approaches to investigate behavior and recurrence of earthquakes along two subductions zones: Alaska-Aleutian subduction zone and the Cascadia subduction zone. In these chapters we use diatoms to explore 1) the potential for combined slip along the Patton Bay splay fault system and the eastern Alaska-Aleutian subduction zone within Prince William Sound, Alaska, and 2) lacustrine turbidite source mechanisms in Ozette Lake, Washington to potentially improve the spatial and temporal earthquake record for the northern Cascadia subduction zone. This work has implications for improving our earthquake chronologies along subduction zone coastlines and making important contributions to coastal hazards assessments. / Doctor of Philosophy / Subduction zones are capable of producing great (>Mw 8.5) earthquakes with accompanying tsunamis that can impact nearby coastlines with devastating force. Great earthquakes occur over long timescales (thousands of years) and are often not captured in short historical records, leaving questions about the recurrence, behavior, and range of potential future earthquakes along these boundaries. Paleoseismology, the study of earthquake history, employs methods that use the earthquake-induced environmental changes along subduction zone coastlines to provide long-term records of earthquake occurrence. Diatoms, a type of siliceous microalgae entrained in coastal sediments, react to changes in pH, salinity, water depth, and sediment type, and are important indicators of environmental change that can be used to expand our understanding of earthquake behavior. This dissertation uses diatoms in two projects that explore the earthquake history along the Alaska-Aleutian subduction zone and the Cascadia subduction zone. First, we determine that secondary faults, called splay faults, in Prince William Sound are likely triggered only by slip along the Alaska-Aleutian subduction zone, suggesting that combined slip has occurred during four of the eight total megathrust earthquakes in the last ~4,200 years. Second, we investigate the sediment origins of the youngest six deposits (turbidites) in Ozette Lake, linking them to diatoms located on the subaqueous delta and shallow lake surfaces, leading us to infer the source is likely earthquake-induced slope failure. Both projects help to expand our understanding of subduction zone earthquake behavior, and will help inform future hazards assessments for coastal communities.

No / This is the second in a series of three papers from a project that has attempted to answer the question ‘does the application of agrochemicals accelerate the corrosion of archaeological metals in the top 50cm of the soil?’. We have approached it through a combination of field-based experiments, by establishing laboratory microcosms and by using geochemical modelling techniques to understand the processes involved. This paper reports on two different experimental approaches in the laboratory - a microcosm designed to mimic one of the burial sites (the ‘Lab Bin’ experiments), and a simpler one to understand the reaction between metal samples and concentrated aqueous solutions of the fertilizers and laboratory reagents used (the ‘Lab Beaker’ experiments). The bins were monitored for in situ corrosion and aqueous effluent collected for13 weeks, after which they were excavated and the metal coupons examined. The Lab Beakers were monitored for in situ corrosion for seven weeks, and then the coupons examined. We focus here on a sub-set of the data relating to the behaviour of the thinnest samples of copper in each case. As with the field data previously reported, the results are sometimes contradictory, but on balance this project has demonstrated that applied agricultural chemicals are likely to accelerate the rate of corrosion of metal objects within 50cm of the surface. In particular, it is likely that any fertilizers containing KCI will be particularly aggressive.

No / This is the third in a series of papers from a pilot project that has attempted to answer the question ‘does the application of agrochemicals accelerate the corrosion of archaeological metals in the top 50cm of the soil?’. We have approached it by a combination of field-based experiments, by establishing laboratory microcosms and by using geochemical modeling techniques to understand the processes involved. This paper reports on the geochemical modelling simulations that trace the potential corrosion pathways followed in two sets of laboratory microcosm experiments (‘Lab Beakers’ and ‘Lab Bins’) and one field experiment (at Palace Leas). This approach uses soil solution as the fluid mediating corrosion in the soil vadose zone. Soil solution was displaced following controlled exposure to fertilizers. Modelling using The Geochemists Workbench was carried out to mimic the experimental conditions, and predictions were compared with image analysis results, limited XRD analysis and published corrosion observations. We focus here on a sub-set of the data relating to the behaviour of the thinnest samples of copper in each case. As with the field and laboratory data previously reported, the results are sometimes contradictory, but on balance this project has demonstrated that applied agricultural chemicals are likely to accelerate the rate of corrosion of metal objects within 50cm of the surface. In particular, it is likely that any fertilizers containing KCI (‘potash’) will be particularly aggressive. Geochemical modeling generates plausible corrosion predictions based on post-depositional interaction between archaeological copper and soil solution, and appears to be useful in helping to simplify and understand corrosion pathways in naturally complex systems.

No / Part of a project that has attempted to answer the question ‘does the application of agrochemicals accelerate the corrosion of metals in the top 50cm of the soil? ’ is reported. We have approached the question by a combination of field-based experiments (on two sites), establishing laboratory microcosms (one involving simple aqueous systems and the other a series of simulated burial experiments) and by using geochemical modelling techniques to understand the processes involved. Two different experimental approaches in the field are documented — one using in situ monitoring of corrosion potentials and the other assessing the degree of induced corrosion using image analysis on recovered samples. The first was carried out on arable land close to the University of Bradford to which we applied different fertilizer regimes. The second was established on land owned by the University of Newcastle at Palace Leas, Morpeth, Northumberland, which has a documented field management regime extending back over one hundred years. We focus here on a sub-set of the data relating to the behaviour of the thinnest samples of copper in each case. There does seem to be some evidence of an effect resulting from the applied fertilizer, but the data are sometimes contradictory. We suggest a number of improvements for future field experiments that monitor in situ corrosion in the vadose zone.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Although extensive research has been conducted on urban freeway capacity estimation methods, minimal research has been carried out for rural highway sections, especially sections within work zones. This study filled that void for rural highways in Kansas. This study estimated capacity of rural highway work zones in Kansas. Six work zone locations were selected. An average of six days’ worth of field data was collected, from mid-October 2013 to late November 2013, at each of these work zone sites. Two capacity estimation methods were utilized, including the Maximum Observed 15-minute Flow Rate Method and the Platooning Method divided into 15-minute intervals. The Maximum Observed 15-minute Flow Rate Method provided an average capacity of 1469 passenger cars per hour per lane (pcphpl) with a standard deviation of 141 pcphpl, while the Platooning Method provided a maximum average capacity of 1195 pcphpl and a standard deviation of 28 pcphpl. Based on observed data and analysis carried out in this study, the recommended capacity to be used is 1500 pcphpl when designing work zones for rural highways in Kansas. This research provides the proposed standard value of rural highway work zone capacities so engineers and city planners can effectively mitigate congestion that would have otherwise occurred due to impeding construction/maintenance.