A numerical reservoir model was created to optimize CO₂ Huff-and-Puff operations in the Bakken Shale. Huff-and-Puff is an enhanced oil recovery treatment in which a well alternates between injection, soaking, and production. Injecting CO₂ into the formation and allowing it to “soak” re-pressurizes the reservoir and improves oil mobility, boosting production from the well. A compositional reservoir simulator was used to study the various design components of the Huff-and-Puff process in order to identify the parameters with the largest impact on recovery and understand the reservoir’s response to cyclical CO₂ injection. It was found that starting Huff-and-Puff too early in the life of the well diminishes its effectiveness, and that shorter soaking periods are preferable over longer waiting times. Huff-and-Puff works best in reservoirs with highly-conductive natural fracture networks, which allow CO₂ to migrate deep into the formation and mix with the reservoir fluids. The discretization of the computational domain has a large impact on the simulation results, with coarser gridding corresponding to larger projected recoveries. Doubling the number of hydraulic fractures per stage results in considerably greater CO₂ injection requirements without proportionally larger incremental recovery factors. Incremental recovery from CO₂ Huff-and-Puff appears to be insufficient to make the process commercially feasible under current economic conditions. However, re-injecting mixtures of CO₂ and produced hydrocarbon gases was proven to be technically and economically viable, which could significantly improve profit margins of Huff-and-Puff operations. A substantial portion of this project involved studying alternative numerical methods for modeling hydraulically-fractured reservoir models. A domain decomposition technique known as mortar coupling was used to model the reservoir system as two individually-solved subdomains: fracture and matrix. A mortar-based numerical reservoir simulator was developed and its results compared to a tradition full-domain finite difference model for the Cinco-Ley et al. (1978) finite-conductivity vertical fracture problem. Despite some numerical issues, mortar coupling closely matched Cinco-Ley et al.'s (1978) solution and has potential applications in complex problems where decoupling the fracture-matrix system might be advantageous. / text

Currently, it is very challenging to accurately monitor the response of patients to radiation therapy over the course of treatment. The initial response to ionizing radiation occurs in the cells at a molecular level, and effects of the response are not typically noticeable on short time scales. Surface-enhanced Raman Spectroscopy, or SERS, has proven to be a useful technique in the analysis of tissues and cells at a molecular level. Specifically, the use of targeted SERS probes allows for the detection of specific proteins on the cell membrane. The work presented here looks to assess the feasibility of using targeted SERS probes and two-dimensional SERS microscopy to measure the response of tumour cells to ionizing radiation, by identifying changes in the distribution of membrane proteins following exposure to clinically relevant doses of ionizing radiation (≤ 60Gy). Two different types of targeted SERS probes were investigated, based on the work of Grubisha et al. ([1]; Type I) and Qian et al. ([2]; Type II), both containing a gold nanoparticle core. In a simplified cellular experiment, biotin on the surface of biotinylated OVCAR5 cells was targeted with streptavidin-SERS probes, and the Type-II SERS probes showed the most promising results. However, SERS maps still provided less characteristic spectral signal than expected, and challenges remain in the development of a reproducible cellular imaging technique. Despite difficulties in cellular imaging, the functionality of the Type-II SERS probes was verified separately, using gold slides with a biotin monolayer in place of cells. Following verification, the SERS intensities provided by differently sized clusters of the SERS probes were characterized. To begin, both SERS maps and scanning electron microscope (SEM) images of gold slides were acquired after incubation with Type-II SERS probes for multiple times (1hr, 2hr, 3hr, 12hr). Data analysis of the SEM images provided a measure of the physical distribution of the SERS probes on the surface of the slide, while analysis of the SERS maps provided information about the spectral distribution of the probes. By relating the information provided by the SEM images and SERS maps, a simple polynomial relationship between SERS intensity and the number of clustered SERS probes providing the enhancement was determined, providing a framework for quantifiable SERS imaging. Finally, an independent experiment was devised to ensure that exposure to clinically relevant doses of ionizing radiation would affect the ability of the targeted protein to bind to SERS probes, thus leading to measurable differences in SERS maps of irradiated and unirradiated cells. A series of experiments utilizing the enzyme-linked immunosorbant assay (ELISA) was performed to test the effect of ionizing radiation-induced damage on the ability of streptavidin to bind to biotin, and the results confirmed that a noticeable reduction in binding could be detected at doses as low as 10 Gy. The results of this work demonstrate that following the development of a suitable cell/SERS probe incubation technique, Type-II SERS probes would be appropriate for use in quantifiable SERS imaging. Also, it is suggested that a measurable change in protein function will be present when comparing SERS maps of control cells to those of cells irradiated to clinically relevant doses. / Graduate

This laboratory project has been done to evaluate pressure pulsing as an Enhanced Oil Recovery (EOR) technique. To perform the study, a consistent laboratory methodology was developed, including the construction of a Consistent Pulsing Source (CPS). Tests compared pulsed and non-pulsed waterfloods in a paraffin or crude oil saturated medium, which also contained connate water (an irreducible water saturation). Results revealed that pulsed tests had maximum flow rates 2. 5--3 times higher, greater oil recovery rates, and final sweep efficiencies that were more than 10% greater than non-pulsed tests. The CPS design has proven very successful, and has since been copied by a major oil corporation. However, there are two limitations, both caused by fluctuating water reservoir levels. Longer pulsed tests (reservoir-depletion tests) were periodically paused to refill the water reservoir, resulting in reservoir depressurization and lower flow rates. The final effect of this was impossible to quantify without correcting the problem. The second CPS limitation was the change in pulse shape with time. However, it is not expected that this had any major effect on the results. The pulse pressure and period studies were limited by early tests, which did not have the necessary time duration. Both increasing pulse pressure and decreasing pulse period were found to increase the final sweep efficiency. Slightly decreasing porosity (0. 4% lower) was found to lower sweep efficiencies. However, the 34. 9% porosity results were not done until reservoir depletion, so it is difficult to quantitatively compare results. An emulsion appeared after water breakthrough when using the CPS on light oils (mineral oil). This may have been the result of isolated oil ganglia being torn apart by the sharp pulses. Although it is difficult to apply laboratory results to the field, this study indicates that pressure pulsing as an EOR technique would be beneficial. Doubled or tripled oil recovery rates and 10% more oil recovery than waterflooding would be significant numbers in a field operation. A valuable application would be in pulsing excitation wells to both pressurize the reservoir and enhance the conformance of the displacing fluid over a long-term period. It would also be valuable for short-term chemical injections, where mixing with the largest volume possible is desirable.

This thesis is concerned with the modelling of miscible fluid flow through porous media, with the intended application being the displacement of oil from a reservoir by a solvent with which the oil is miscible. The primary difficulty that we encounter with such modelling is the existence of a fingering instability that arises from the viscosity and the density differences between the oil and solvent. We take as our basic model the Peaceman model, which we derive from first principles as the combination of Darcy’s law with the mass transport of solvent by advection and hydrodynamic dispersion. In the oil industry, advection is usually dominant, so that the Péclet number, Pe, is large. We begin by neglecting the effect of density differences between the two fluids and concentrate only on the viscous fingering instability. A stability analysis and numerical simulations are used to show that the wavelength of the instability is proportional to Pe^−1/2, and hence that a large number of fingers will be formed. We next apply homogenisation theory to investigate the evolution of the average concentration of solvent when the mean flow is one-dimensional, and discuss the rationale behind the Koval model. We then attempt to explain why the mixing zone in which fingering is present grows at the observed rate, which is different from that predicted by a naive version of the Koval model. We associate the shocks that appear in our homogenised model with the tips and roots of the fingers, the tip-regions being modelled by Saffman-Taylor finger solutions. We then extend our model to consider flow through porous media that are heterogeneous at the macroscopic scale, and where the mean flow is not one dimensional. We compare our model with that of Todd & Longstaff and also models for immiscible flow through porous media. Finally, we extend our work to consider miscible displacements in which both density and viscosity differences between the two fluids are relevant.

During the dot com era the word 'personalisation' was a hot buzzword. With the fall of the dot com companies the topic has lost momentum. As the killer application for UMTS or the mobile internet has yet to be identified, the concept of Multi-Dimensional-Personalisation (MDP) could be a candidate. Using this approach, a recommendation of mobile advertisement or marketing (i.e., recommendations or notifications), online content, as well as offline events, can be offered to the user based on their known interests and current location. Instead of having to request or pull this information, the new service concept would proactively provide the information and services – with the consequence that the right information or service could therefore be offered at the right place, at the right time. The growing availability of "Location-based Services“ for mobile phones is a new target for the use of personalisation. "Location-based Services“ are information, for example, about restaurants, hotels or shopping malls with offers which are in close range/short distance to the user. The lack of acceptance for such services in the past is based on the fact that early implementations required the user to pull the information from the service provider. A more promising approach is to actively push information to the user. This information must be from interest to the user and has to reach the user at the right time and at the right place. This raises new requirements on personalisation which will go far beyond present requirements. It will reach out from personalisation based only on the interest of the user. Besides the interest, the enhanced personalisation has to cover the location and movement patterns, the usage and the past, present and future schedule of the user. This new personalisation paradigm has to protect the user's privacy so that an approach supporting anonymous recommendations through an extended 'Chinese Wall' will be described.

Much has been written about the way in which e-learning has changed learning in higher education without transforming it to meet the changing needs and expectations of stakeholders in the sector. The beliefs and practices of teachers in the sector have remained largely unchanged despite the widespread adoption of e-learning tools. This study used a phenomenographic approach to identify the conceptual frameworks of practitioners. Among the indicators used to define these frameworks were practitioners’ levels of engagement with e-learning tools and the broader concept of technology-enhanced learning. The study identified limited evidence of the transformation of beliefs and practices in the sector to a more student-centred paradigm, despite the adoption of the language associated with such a change by the majority of practitioners interviewed. It showed how many e-learning initiatives had led to the internalization of such change with the adoption of exemplars and best practice. Examples of externalization (where exemplars were adapted to context and the modifications passed to others) were much more limited. Cases were identified where practitioners had used e-learning as a means of reinforcing the existing, teacher-centred paradigm. The majority of practitioners, however, were identified as being in a ‘transitionary’ state, adopting the language and some of the practices of a ‘transformed’ state. This study, therefore, considered factors influencing the adoption of a more student-centred paradigm through the use of e-learning. Using Activity Theory, the barriers to such change were explained and lessons for future approaches to professional development derived. Through an exploration of collaborative technology-enhanced learning initiatives, the nature of learning communities that should be at the heart of such transformation were identified. This study should, therefore, be of value to practitioners wishing to innovate, those who design and deliver the professional development programmes to support them and those managing such change in HE.

Being exposed to serious games showed that some simulations widely vary in quality and learning outcome. In order to get to the bottom of best practices a detailed review of business management simulation literature was conducted. Additionally, an industry analysis was performed, by interviewing 17 simulation companies, testing a range of full and demo games, and conducting secondary research. The findings from both research efforts were then collated and cross-referenced against each other in order to determine three things: firstly, the practices and features used by simulation companies that have not yet been the subject of academic research; secondly, the most effective features, elements and inclusions within simulations that best assist in the achievement of learning outcomes and enhancement the user experience; and finally, 'best practices' in teaching a business management course in a university or company with the assistance of a simulation. Identified gaps in the current research were found to include the effectiveness of avatars, transparent pricing and the benefits of competing the simulation against other teams as opposed to the computer. In relation to the second and third objectives of the research, the findings were used to compile a business plan, with detailed recommendations for companies looking to develop a new simulation, and for instructors implementing and coordinating the use of a simulation in a business management context. (author's abstract)

<p>U radu je prikazan model podataka koji omogućava<br />predviđanje uspje&scaron;nosti studiranja na visoko&scaron;kolskim<br />ustanovama, kao i analizu vi&scaron;e tehnika predikcije.<br />Pored toga, prikazuje i prototipsku implementaciju<br />informacionog sistema za upravljanje obrazovnim<br />procesom koji omogućava kori&scaron;ćenje predikcije u<br />realnim informacionim sistemima.</p> / <p>The paper presents a data model that facilitates<br />prediction of students success in studying, as well as<br />a review of prediction techniques. It also presents a<br />prototype implementation of a learning management<br />information system that enables the use of prediction<br />of success in studying and represents a real-world<br />use case.</p>

The development of a nurse identity is known to be a gradual process which takes place by students through social interaction in both academic and clinical settings. It is a crucial element in retaining students within the nursing profession and enabling them to perform the nurse role competently and effectively. Constructing a nurse identity is a complex and individual process, but, it is recognised that it will contain universal traits such as caring and compassion. Failure to absorb a nurse identity by students is not well documented, but, it is thought to contribute towards the number of recruits who leave the profession prior to or on qualifying. This phenomenological study examines the ways in which student nurses construct and adopt a nurse identity whilst studying for the theoretical component of their nursing course. The lived experience of both traditional, classroom based student nurses and those studying by electronic learning (e-learning) is explored through in-depth interviews and participant observations. Elearning is being introduced into nurse education in place of traditional methods of teaching and the research examines the impact of this mode of learning on professional socialisation to the identity of a nurse. The study gathered data from in-depth interviews with six student nurses studying by traditional methods and, also, from six student nurses studying by e-learning; all students were in the third year of a Diploma in Nursing (Adult Branch) course (comparisons were made between the findings from the two groups of students, in order to discover if nurse identities and the ways in which these are formulated differ between traditional students and those studying by e-learning). Findings from the data disclosed similarities and differences between the two groups of students, however, definitive conclusions as to the effects of e-learning on the construction and adoption of nurse identities could not be made. The findings did disclose strengths and weaknesses in both types of education, and the overall conclusion was that e-learning could be a success in student nurse education only if it is introduced with sufficient funding and on a solid foundation of research and development, by nurse educators who are knowledgeable in this style of pedagogy.

In this thesis, the potential of enhanced geothermal system to provide adequate energy to a 10 MW electricity power plant from Prairie Evaporite Formation of Williston Basin was investigated. This formation partly consists of halite with low thermal resistance and high thermal conductivity, which translates into a lower drilling length to reach the desired temperature, comparing to other rock types. To this end, two numerical models with experimental data in south-west Manitoba (i.e. Tilston) and south-east Saskatchewan (i.e. Generic) were designed. The thermal reservoirs were located at 1.5 km (Tilston site) and 3 km (Generic site) with approximate thicknesses of 118 m. Considering an injection brine of 6% NaCl at 15°C, the final derived temperature at wellhead of the production wells were 43°C and 105°C respectively. Finally, the Generic site was concluded as a suitable candidate for electricity production by providing higher surfaced fluid temperature than the minimum of 80°C. / February 2017