Dissertations / Theses on the topic 'Mobil oil'

This thesis answers the question “How does the application of the Swedish adjustment rule correspond to the OECD point of view regarding intragroup loans to thinly capitalised companies?” The question is answered by using the traditional legal method and by examining the way the adjustment rule is applied by the Supreme Administrative Court, the Swedish approach when using the arm’s length principle in Swedish law is then compared to the approach recommended by the OECD.

From a tax point of view intragroup prices on commodities and services are of vital importance for multinational enterprises, since these prices in the end affects the total corporate taxation. Also the way of financing a company can have tax implications since it could be an advantage for an MNE to arrange financing of companies within the group through loans rather than contribution of equity capital. A company with a disproportionate debt to equity ratio is considered thinly capitalised and since interest payments are considered deductible expenses, which dividends are not, it provides a way to transfer untaxed profits within a group. This may be an incentive for MNEs to intentionally thinly capitalise companies by providing them with capital through loans instead of equity contributions.

The Swedish provision regulating transfer pricing between associated enterprises is the adjustment rule which expresses the arm’s length principle. The purpose of the rule is to adjust erroneous pricing between associated enterprises and it has four requisites that have to be fulfilled in order to be applicable. In the thesis it is concluded that nothing in the preambles to the adjustment rule points at the provision being applicable to thin capitalisation, on the contrary they indicate that it should have a narrow application. Through case law it has been established that the adjustment rule is not applicable to thin capitalisation situations in the sense that it can not be used to reclassify a loan into equity contribution. The provision is, in such a situation, only applicable to adjust interest rates that deviate from rates on the open market. The arm’s length principle expressed in article 9.1 of the OECD Model Tax Convention however seems to have a broader application than the adjustment rule. It is stated in the commentary to the article that it may be applied to prima facie loans, i.e. it can reclassify a loan into equity contribution if the surrounding circumstances points at it being the true nature of the transaction.

The conclusions drawn when comparing the reasoning of the Supreme Administrative Court with the OECD regarding the application of the arm’s length principle, is that the way the OECD reason regarding the true nature of a transaction is based on the same idea as the reasoning of the Swedish court. The Swedish Supreme Court however uses this type of reasoning when applying the substance over form principle and not when applying the adjustment rule. In other words, the difference is that the adjustment rule is not acknowledged the same scope of application as article 9.1.

Regarding the need to legislate against thin capitalisation in Sweden it is the authors’ opinion that since no examination of the problem has been performed, it is necessary to examine whether thin capitalisation in reality constitutes a problem for the Swedish revenue. Not until it is established if a problem exists should there be a discussion regarding the construction of such a provision.

Answers were sought to two research questions concerning Mobil Oil Company's corporate advertising appearing in The New York Times between 1984 and 1990:1. What issues/events throughout the campaign received the most attention in Mobil's corporate advertisements? 2. How did yearly political/event changes affect Mobil's corporate advertisements?This study, which was based on a study by Anderson (1984), was completed in two steps. First, a coder read and summarized all 365 advertisements. These advertisements were categorized according to three dependent variables: energy policy, Mobil's economic/political commentary and image advertisements. The results of this process answered the first question.The second part of analysis involved using each year's breakdown of advertisements and comparing it to the political tone of the year. The Congressional Quarterly Almanac was used to recreate the tone for each year.Image advertisements accounted for slightly more than 53 percent of the 365 advertisements carried by Mobil in the time period. Mobil's economic/political commentary accounted for nearly 38 percent of the advertisements. Energy policy advertisements accounted for nearly nine percent of the advertisements.The findings, also, showed that as energy-related issues received attention in the media, Mobil increased its usage of these advertisements. After a review of the political tone of each year, it was concluded that Mobil uses its corporate advertising program to both respond to current events affecting the oil industry or large corporations and to create a favorable image with its consumers.
Department of Journalism

The ever-increasing levels of greenhouse gas emissions has led to the scientific community starting to explore the viability of electrical aircraft system, with the most prominent research and product development for hybrid electric system, which forms the transition phase from combustion to fully electric aircrafts. The primary objective of this thesis is to find solutions towards thermal management of the electrical components of a hybrid electric aircraft propulsion system, which generate a significant amount of heat while operating at heavy load conditions required to propel an aircraft. In view of these objectives a micro channel cold plate liquid cooling system, has been dynamically modelled using a combination of lumped parameter and thermal resistance methods of heat transfer analysis. The study investigates the prospects of using Mobil Jet Oil II, typically used as an aircraft lubricant as a coolant for the thermal management system. The primary components of this model are lithium ion battery, DC-AC inverter, permanent magnet motor, cross flow finned micro channel heat exchanger, centrifugal pump and ducts. The electrical components have been dimensioned according to energy storage and load requirements considering their efficiencies and gravimetric power/energy. The system has been simulated and analyzed under different scenarios considering the coolant inlet temperature, air temperature across the heat exchanger and on two-time horizons. Analysis has been done to study the dynamic trends of the component temperature and the coolant at different stages of the system. The scope of the study includes an evaluation of the added weight of the thermal management system under different time horizons and their comparison with results from a reference study. From the simulation results it can be concluded that Mobil Jet Oil II is a promising option as a coolant and therefore its use as a common fluid for gas turbine lubrication and as coolant, will benefit the aircraft as now no extra coolant reservoir is required, allowing reduction in weight carried by the aircraft.

The use of mobile and wireless Information and Communication Technology (ICT) tools in geographically distributed project organizations appears to be an appropriate application of new technical capabilities in an existing business environment. But to successfully introduce and adopt a suitable mobile ICT-based project communication platform in an existing operational setting involves a complex framework of socio-technical issues that have to be considered.

This Licentiate thesis presents the results of an ongoing doctoral research project. The study explores the implementation process of mobile computing tools at Sweden’s largest construction company, with the aim of improving information management and project communication of production site operations in construction projects. The research project highlights the interdependencies between the creation of usefulness and its resulting benefits. It emphasizes user-oriented implementation as the enabling process for realizing technology fit and user acceptance of the mobile computing tools, as well as achieving long-term benefit and business value of the ICT investment.

The studied case specifically addresses the neglected mobile and flexible information needs and communication demands of management staff at construction sites. The fundamental issue is to identify what the usefulness perspective of mobile computing for construction operations consists of relating to both technology and the different groups of people who are supposed to use it. Generic access, mobility of project data and individual adaptation of information and communication resources are technological aspects that are emphasized and discussed in the context of creating usefulness and benefit of mobile computing in construction projects. The often present political dimension of ICT implementation within an organization is also highlighted. The socio-technical introduction and adoption process of mobile computing involves balancing various perspectives and agendas inherent on different organizational levels in order to achieve an acceptable outcome for all the actors involved.

Topics for further research are discussed and refined relating to the ongoing case study and the conceptual framework presented.

Web Services are self-contained, self-describing, modular applications that can be published, located, and invoked through XML artefacts across the Web. Web services technologies can be applied to many kinds of applications, where they offer considerable advantages compared to the old world of product-specific APIs, platform-specific coding, and other &ldquo
brittle&rdquo
technology restrictions. Currently there are millions of web services available on the web due to the increase in e-commerce business volume. Web services can be discovered using public registries and invoked through respective interfaces. However how to automatically find, compose, invoke and monitor the web services is still an issue. The automatic discovery, composition, invocation and monitoring of web services require that semantics will be attached to service definitions. The focus of this thesis is on the composition of web services. The approach taken is to extend the DAML-S ontology that is used to define the semantics of services to include the &ldquo
succeeding services&rdquo
for any service provided. These definitions for individual service instances are declared by the service providers. They are presented to the users of the service to construct a workflow in a mobile environment. The workflow generated is represented both graphically in the mobile device and in XML-format as a BPEL4WS document. The aim of this thesis is to prove that it is possible to build a semi-automatic web service composition utility incorporating semantic constructs, using a mobile device. The generated workflow is suitable for deployment on an engine where it can be executed multiple times with different configurations.

Mobile source emissions are a major contributor to global and local air pollution. Governments and regulatory agencies have been increasing the stringency of regulations in the transportation sector for the last ten years to help curb transportation sector air pollution. The need for regulations has been emphasized by scientific research on the impacts from ambient pollution, especially research on the effect of particulate matter on human health. The particulate emissions from diesel vehicles, diesel particulate matter (DPM) is considered a known or probable carcinogen in various countries and increased exposure to DPM is linked to increased cardiovascular health problems in humans. The toxicity of vehicle emissions and diesel particulate emissions in particular, in conjunction with an increased awareness of potential petroleum fuel shortages, international conflict over petroleum fuel sources and climate change science, have all contributed to the increase of biodiesel use as an additive to or replacement for petroleum fuel. The goal of this research is to determine how this increased use of biodiesel in the particular emission testing setup impacts urban air quality. To determine if biodiesel use contributes to a health or climate benefit, both the size range and general composition were investigated using a comprehensive comparison of the particulate component of the emissions in real time. The emissions from various biodiesel and diesel mixtures from a common diesel passenger vehicle were measured with a cavity ring-down transmissometer (CRDT) coupled with a condensation particle counter, a SMPS, a nephelometer, NOx, CO, CO2, and O3 measurements. From these data, key emission factors for several biodiesel and diesel fuel mixtures were developed. This approach reduces sampling artifacts and allows for the determination of optical properties, particle number concentration, and size distributions, along with several important gas phase species' concentrations. Findings indicate that biodiesel additions to diesel fuel do not necessarily have an air quality benefit for particulate emissions in this emission testing scenario. The often cited linear decrease in particulate emissions with increasing biodiesel content was not observed. Mixtures with half diesel and half biodiesel tended to have the highest particulate emissions in all size ranges. Mixtures with more than 50% biodiesel had slightly lower calculated mass for light absorbing carbon, but this reduction in mass is most likely a result of a shift in the size of the emission particles to a smaller size range, not a reduction in the total number of particles. Evaluation of the extensive optical properties from this experimental set-up indicates that biodiesel additions to diesel fuel has an impact on emission particle extinction in both visible and near-IR wavelengths. The B99 mixture had the smallest emission factor for extinction at 532 nm and at 1064 nm. For the extinction at 532 nm, the trend was not linear and the emission factor peaked at the B50 mixture. Results from intensive properties indicate that emissions from B5 and B25 mixtures have Ångström exponents close to 1, typical for black carbon emissions. The mixtures with a larger fraction of biodiesel have Ångström exponent values closer to 2, indicating more absorbing organic matter and/or smaller particle size in the emissions. Additional experimental testing should be completed to determine the application of these results and emission factors to other diesel vehicles or types of diesel and biodiesel fuel mixtures.

There has been very little research into the bioanalytical application of Microemulsion High Performance Liquid Chromatography (MELC), a recently established technique for separating an active pharmaceutical ingredient from its related substances and for determining the quantity of active drug in a dose. Also, the technique is not good at separating hydrophilic drugs of very similar chemical structures. Different phase diagrams of oil (octane or ethyl acetate), co-surfactant (butanol), surfactant (sodium dodecyl sulphate (SDS) or Brij-35) and buffer (Phosphate pH 3) were developed and several nanoemulsion mobile phases identified. Nanoemulsion mobile phase that is, prepared with SDS, octane, butanol and a phosphate buffer, failed to separate hydrophilic compounds with a very close chemical structure, such as terbutaline and salbutamol. A nanoemulsion mobile phase containing a non-ionic surfactant (Brij-35) with ethyl acetate, butanol and a phosphate buffer, was, however, successful in achieving a base line separation, and the method was validated for simultaneous determination of terbutaline and salbutamol in aqueous and urine samples. An oil-in-water (O/W) NELC method was developed and validated for the determination of formoterol in an Oxis® Turbuhaler® using pre-column fluorescence derivatisation. Although the same mobile phase was extended for separation of formoterol in urine, the formoterol peak's overlap with endogenous peaks meant that fluorescence detection could not determine formoterol in urine samples. Solid phase extraction, concentrating the final analyte 40 times, enabled determination of a low concentration of formoterol in urine samples by UV detection. The method was validated and an acceptable assay precision %CV <4.89 inter-day and %CV <2.33 intra-day was achieved. Then after the application of O/W nanoemulsion mobile phase for HPLC was extended for the separation of lipophilic drugs. The nanoemulsion liquid chromatography (NELC) method was optimised for the determination of salmeterol and fluticasone propionate in good validation data was achieved. This thesis shows that, in general, the performance of O/W NELC is superior to that of conventional High Performance Liquid Chromatography (HPLC) for the analysis of both hydrophilic and lipophilic drugs in inhaled dosage formulations and urine samples. It has been shown that NELC uses cheaper solvents and that analysis time is faster for aqueous and urine samples. This considerable saving in both cost and time will potentially improve efficiency within quality control.

There has been very little research into the bioanalytical application of Microemulsion High Performance Liquid Chromatography (MELC), a recently established technique for separating an active pharmaceutical ingredient from its related substances and for determining the quantity of active drug in a dose. Also, the technique is not good at separating hydrophilic drugs of very similar chemical structures. Different phase diagrams of oil (octane or ethyl acetate), co-surfactant (butanol), surfactant (sodium dodecyl sulphate (SDS) or Brij-35) and buffer (Phosphate pH 3) were developed and several nanoemulsion mobile phases identified. Nanoemulsion mobile phase that is, prepared with SDS, octane, butanol and a phosphate buffer, failed to separate hydrophilic compounds with a very close chemical structure, such as terbutaline and salbutamol. A nanoemulsion mobile phase containing a non-ionic surfactant (Brij-35) with ethyl acetate, butanol and a phosphate buffer, was, however, successful in achieving a base line separation, and the method was validated for simultaneous determination of terbutaline and salbutamol in aqueous and urine samples. An oil-in-water (O/W) NELC method was developed and validated for the determination of formoterol in an Oxis® Turbuhaler® using pre-column fluorescence derivatisation. Although the same mobile phase was extended for separation of formoterol in urine, the formoterol peak¿s overlap with endogenous peaks meant that fluorescence detection could not determine formoterol in urine samples. Solid phase extraction, concentrating the final analyte 40 times, enabled determination of a low concentration of formoterol in urine samples by UV detection. The method was validated and an acceptable assay precision %CV <4.89 inter-day and %CV <2.33 intra-day was achieved. Then after the application of O/W nanoemulsion mobile phase for HPLC was extended for the separation of lipophilic drugs. The nanoemulsion liquid chromatography (NELC) method was optimised for the determination of salmeterol and fluticasone propionate in good validation data was achieved. This thesis shows that, in general, the performance of O/W NELC is superior to that of conventional High Performance Liquid Chromatography (HPLC) for the analysis of both hydrophilic and lipophilic drugs in inhaled dosage formulations and urine samples. It has been shown that NELC uses cheaper solvents and that analysis time is faster for aqueous and urine samples. This considerable saving in both cost and time will potentially improve efficiency within quality control.

Le Web d'aujourd'hui représente un espace où les utilisateurs recherchent, découvrent et partagent des informations. Dans ce cadre, les processus de découverte de services Web jouent un rôle fondamental. Un tel processus permet de faire le lien entre des informations publiées par des fournisseurs de services et des requêtes créées par les internautes. Généralement, un tel processus repose sur une recherche " textuelle " ou à base de " mots-clés ". Or, ce type de recherche ne parvient pas à toujours identifier les services les plus pertinents. Notre idée est de concevoir un système plus " intelligent ", permettant d'utiliser, lors du processus de découverte, une base de connaissances associées aux informations, comme c'est le cas pour le Web sémantique. Cette thèse présente un prototype pour la découverte de services Web sémantiques, utilisant des caractéristiques non-fonctionnelles (descriptives) des services. Notre approche emploie le langage OWL-S (Web Ontology Language for Services) pour définir un modèle de description des paramètres non-fonctionnels des services. Ce modèle a pour but de faciliter la découverte de services Web sémantiques. Ce modèle représente le centre de notre contribution, étant utilisé pour la conception des interfaces et des requêtes. Deux interfaces sont développées, l'une s'adressant aux fournisseurs de services, alors que la deuxième interface est conçue pour l'utilisateur final. L'algorithme de recherche présenté dans cette thèse a pour but d'améliorer la précision et la complétude du processus de découverte de services.

Made available in DSpace on 2014-12-17T14:53:02Z (GMT). No. of bitstreams: 1 JoaoPLN_DISSERT.pdf: 2086259 bytes, checksum: 2a57554e118e00d9a44cdf572e29af7a (MD5) Previous issue date: 2010-12-23
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
This paper presents metaheuristic strategies based on the framework of evolutionary algorithms (Genetic and Memetic) with the addition of Technical Vocabulary Building for solving the Problem of Optimizing the Use of Multiple Mobile Units Recovery of Oil (MRO units). Because it is an NP-hard problem, a mathematical model is formulated for the problem, allowing the construction of test instances that are used to validate the evolutionary metaheuristics developed
O presente trabalho apresenta estrat?gias metaheur?sticas baseadas no framework dos Algoritmos Evolutivos (Gen?ticos e Mem?ticos) com a adi??o da t?cnica Vocabulary Building para a resolu??o do Problema de Otimiza??o do Emprego de Unidades M?veis de Pistoneio (UMPs). Por se tratar de um problema NP-?rduo, uma modelagem matem?tica ? formulada para o problema, permitindo a constru??o de inst?ncias testes que s?o utilizadas para validar as metaheur?sticas evolutivas desenvolvidas

Steam distillation is the most widely accepted process for the large scale production of volatile essential oils from herbaceous material and is also regarded as the standard practice throughout the flavour and fragrance industry. A mobile essential oil distillation unit for the extraction of oils from herbaceous materials would be extremely valuable to the essential oil industry in South Africa. Using a mobile platform, the extraction technology could be taken to rural areas where essential oil crops are grown in order to extract and then analyse the oils produced. Existing systems in South Africa are static distillation units which are usually owned by commercial growers that are generally positioned large distances away from the rural areas. The objective of this project was to design, construct and test a prototype mobile distillation unit for the extraction of essential oils from herbaceous materials. The unit was to have a charge vessel capacity of approximately 250 kg of plant material and should be able to perform in-field distillations in areas where electricity is not available. A literature review on all the essential oil extraction methods, the theory behind steam distillation and oil isolation and the effect that each of the distillation components have on the distillation process was performed. A small test distillation unit was set up in a laboratory in order to investigate the effects of varying steam flow . rates on the distillation time, oil yield and oil quality. A double charge vessel unit was designed, constructed and mounted onto a frame which in turn was fixed onto a trailer to be hauled by a light delivery vehicle (LDV). The steam generator with all its ancillary equipment was fixed onto a separate trailer. The unit could thus be easily transported and in-field distillations on various crops could be conducted. Field distillations were conducted with two crop types, namely rose geranium and lemon grass. Satisfactory results were obtained as the oil yields were within the expected oil yield range.
Thesis (M.Sc.)-University of KwaZulu-Natal, 2005.

The primary focus of this dissertation is on the assessment of fugitive methane emissions from near and far-field sources. Methane is the second most prevalent greenhouse gas (GHG) emitted in the United States from anthropogenic activities. Due to measurement and model limitations, there is not an accurate assessment of how much methane in the atmosphere is due to anthropogenic sources. This dissertation focuses on measuring the methane emissions from two of the three largest anthropogenic sources -- landfills and natural gas systems. All measurements are made with a single fixed or single mobile sensor. Methods are developed to assess the source strength for both near (i.e. natural gas) and far-field (i.e. landfill) sources using either the fixed or mobile sensor.

For far-field measurements, a standardized version of a mobile tracer correlation measurement method was developed and used for assessment of methane emissions from 15 landfills in 56 field deployments from 2009 to 2013. A total of 1876 mobile tracer correlation measurement transects were attempted over 131 field sampling days.

Transects were analyzed using signal to noise ratio, plume correlation, and emission rate difference method quality indicators. The application of the method quality indicators yield 456 transects (33\%) that pass data acceptance criteria.

For near-field sources, techniques are developed for 1) fixed sensors sampling through time downwind of a source and 2) mobile sensors passing across plumes downwind of a source. For the fixed sensor, the lateral plume geometry is reconstructed from the fluctuating wind direction using a derived relationship between the wind direction and crosswind plume position. The crosswind plume spread is estimated with two different methods (modeled and observed), and subsequently used a Gaussian plume inversion to estimate the source strengths. For the fixed sensor, the sensor takes measurements for about 20 minutes and we are able to reconstruct the ensemble average of the plume.

For the mobile sensor, the vehicle drives through the plume in the crosswind direction.

The measurements show the lateral plume geometry of an instantaneous plume. The instantaneous plume has a narrowed Gaussian structure.

Two techniques are tested using data from controlled methane release experiments; these two techniques are 1) linear-squares and 2) a probabilistic approach. For the probabilistic approach, Bayesian inference tools are applied and special attention is paid to the relevant likelihood functions for both short time averaged concentrations from a single fixed sensor and spatial transects of instantaneous concentration measurements from a mobile sensor. The two techniques are also tested on measurements downwind of multiple natural gas production facilities in Wyoming for the fixed sensor and in Colorado for the moving sensor. The results for both the fixed and mobile techniques show promise for use with gas sensors on industry work trucks, opportunistically providing surveillance over a region of well pads.

Dissertation

The compressor for air supply to the fuel cell stack is a critical component of the balance of plant, especially for mobile applications. The main requirements of the compressor are the performance regarding pressure ratio, mass flow and efficiency at minimal size and weight. The turbo compressor technology is ideally suited to cope with these requirements. The lifetime requirement and the necessity of oil and particle free air supply advised to employ air bearings. The fuel cell air supply requirements are in conflict with the turbo compressor pressure ratio and mass flow characteristics. Possible solutions and their impact onto compressor design and fuel cell operation are described in this paper. The chosen system design approach considering all design aspects and its interactions during the design phase is beneficial in order to achieve the most lightweight and efficient air supply system for fuel cells. Experimental validation of an air bearing turbo compressor for a 100 kW fuel cell stack on an aerodynamic test rig verifies the predicted performance.

Distributed mobile conversion facilities using either fast pyrolysis or torrefaction processes can be used to convert forest residues to more energy dense substances (bio-oil, bio-slurry or torrefied wood) that can be transported as feedstock for bio-fuel facilities. All feedstock are suited for gasification, which produces syngas that can be used to synthesise petrol or diesel via Fischer-Tropsch reactions, or produce hydrogen via water gas shift reactions. Alternatively, the bio-oil product of fast pyrolysis may be upgraded to produce petrol and diesel, or can undergo steam reformation to produce hydrogen. Implementing a network of mobile facilities reduces the energy content of forest residues delivered to a bio-fuel facility as mobile facilities use a fraction of the biomass energy content to meet thermal or electrical demands. The total energy delivered by bio-oil, bio-slurry and torrefied wood is 45%, 65% and 87% of the initial forest residue energy content, respectively. However, implementing mobile facilities is economically feasible when large transport distances are required. For an annual harvest of 1.717 million m3 (equivalent to 2000 ODTPD), transport costs are reduced to less than 40% of the total levelised delivered feedstock cost when mobile facilities are implemented; transport costs account for up to 80% of feedstock costs for conventional woodchip delivery. Torrefaction provides the lowest cost pathway of delivering a forest residue resource when using mobile facilities. Cost savings occur against woodchip delivery for annual forest residue harvests above 2.25 million m3 or when transport distances greater than 250 km are required. Important parameters that influence levelised delivered costs of feedstock are transport distances (forest residue spatial density), haul cost factors, thermal and electrical demands of mobile facilities, and initial moisture content of forest residues. Relocating mobile facilities can be optimised for lowest cost delivery as transport distances of raw biomass are reduced. The overall cost of bio-fuel production is determined by the feedstock delivery pathway and also the bio-fuel production process employed. Results show that the minimum cost of petrol and diesel production is 0.86 $ litre-1 when a bio-oil feedstock is upgraded. This corresponds to a 2750 TPD upgrading facility requiring an annual harvest of 4.30 million m3. The minimum cost of hydrogen production is 2.92 $ kg-1, via the gasification of a woodchip feedstock and subsequent water gas shift reactions. This corresponds to a 1100 ODTPD facility and requires an annual harvest of 947,000 m3. The levelised cost of bio-fuel strongly depends on the size of annual harvest required for bio-fuel facilities. There are optimal harvest volumes (bio-fuel facility sizes) for each bio-fuel production route, which yield minimum bio-fuel production costs. These occur as the benefits of economies of scale for larger bio-fuel facilities compete against increasing transport costs for larger harvests. Optimal harvest volumes are larger for bio-fuel production routes that use feedstock sourced from mobile facilities, as mobile facilities reduce total transport requirements.
Graduate
0791
drbrown@uvic.ca

Residual hydrocarbons residing above or within an aquifer can serve as a continuous time-variant source of contamination to the aquifer. The primary mechanism for contamination is the movement of water past the immobile oil, leaching the partially soluble components from the oil phase into the aqueous phase, and transporting them to or within the aquifer. This research has focused on modeling the transport process. Three models for simulating the dissolution and transport from a residual oil zone are presented and evaluated: a "two-site" model, an "apparent" non-linear partitioning model, and a numerical equilibrium model. The two-site model is shown to be the most descriptive. The apparent partitioning model has been incorporated into a horizontal transport model. The capability and the limitations of the modified horizontal transport model are demonstrated for a hypothetical site. In addition, the effect of decoupling the transport equations for a multicomponent oil is investigated.

Students in Open Distance Learning (ODL) face a myriad of challenges including a low proficiency in English. While research has identified vocabulary as important in improving language proficiency and the pertinent role of interaction in vocabulary development, there remains a dearth of research on how to enhance vocabulary in ODL, a context which is characterised by the distance between students and the institution. In searching for an intervention that would support vocabulary development, including interaction, while taking cognisance of the distance between students and lecturers, this study explored the use of mobile learning (mlearning). Because mlearning technologies offer ubiquitous flexibility and accessibility, they were deemed fit for purpose for ODL which is established on the principles of openness, flexibility and student‐centredness. Using the design‐based research (DBR) method within a pragmatic paradigm, this study designed, implemented and evaluated mobile‐based interventions for vocabulary development. The first phase of the study involved the analysis of the problem through a literature review. The literature and theoretical framework were used to ground the second phase of DBR, which included the development of the intervention prototype in the form of a mobile‐based vocabulary development app called VocUp. The intervention was implemented, tested and refined in three iteration stages, which formed the third phase of DBR. The iterations included a VocUp only stage, followed by a WhatsApp only stage, and ended with a VocUp plus WhatsApp stage. The last phase of DBR involved a reflection and a production of artefacts and guidelines for practice in ODL. Data were collected through interviews and WhatsApp chats from students registered for a first‐year English module. The results were 1) that vocabulary should be explicitly taught, allow for rehearsal opportunities and contain assessment while acknowledging the instrumental role of interaction; 2) mobile interventions should balance the pedagogic benefits with the technological qualities; and 3) the advantages and challenges of using WhatsApp and VocUp can be successfully combined into a hybrid model of both platforms. This study’s contribution to the body to knowledge includes the newly‐designed VocUp as an artefact; a revised model of the CoI theoretical framework called MODeL as well as principles guiding the application of the MODeL in authentic ODL contexts.
English Studies
D. Litt. et Phil. (English)

Rising world petroleum prices and global warming are contributing to interest in renewable energy sources, including energy produced from agricultural crops and waste sources of biomass. A network of small mobile pyrolysis units may be the most cost effective system to convert biomass from agricultural feedstocks to bio-crude oil. Mobile pyrolysis units could be moved to the feedstock production fields thereby greatly simplifying feedstock logistics. In the North Central (NC) region of the U.S., possible feedstocks are corn stover, energy sorghum, and switchgrass. A grid-based Geographic Information System (GIS) program was developed to identify optimum locations for mobile pyrolysis units based on feedstock availability in the NC region. Model builder was used to automate the GIS analysis. Network analysis was used to find the best route to move the mobile pyrolysis units to new locations and to identify the closest refinery to transport the bio-crude oil. To produce bioenergy from feedstocks, the removal of biomass from agricultural fields will impact the hydrology and sediment transport in rural watersheds. Therefore, the hydrologic effects of removing corn stover from corn production fields in Illinois (IL) were evaluated using the Soil Water Assessment Tool (SWAT). The SWAT model was calibrated and validated for streamflow and sediment yields in the Spoon River basin in IL using observed data from the USGS. The modeling results indicated that as residue removal rates increased, evapotranspiration (ET) and sediment yields increased, while streamflows decreased. Biochar is a carbon-based byproduct of pyrolysis. To ensure that the mobile pyrolysis system is economically and environmental sustainable, the biochar must be land applied to the feedstock production fields as a soil amendment. An assessment of hydrologic changes due to the land application of biochar was made using the SWAT model in the Spoon River basin and changes in soil properties due to incorporation of biochar into the soil obtained from laboratory experiments by Cook et al. (2012). Model simulations indicated that a biochar application rate of 128 Mg/ha decreased water yield, and sediment yield in surface runoff and increased soil moisture and ET.

Action planning has been used in the field of robotics for solving long-running tasks. In the robot architectures field, it is also known as the deliberative layer. However, there is still a gap between the symbolic representation on the one hand and the low-level control and sensor representation on the other. In addition, the definition of a planning problem for a complex, real-world robot is not trivial. The planning process could become intractable as its search spaces become large. As the defined planning problem determines the complexity and the computationability for solving the problem, it should contain only relevant states. In this work, a novel approach which amalgamates Description Logic (DL) reasoning with Hierarchical Task Network (HTN) planning is introduced. The planning domain description as well as fundamental HTN planning concepts are represented in DL and can therefore be subject to DL reasoning; from these representations, concise planning problems are generated for HTN planning. The method is presented through an example in the robot navigation domain. In addition, a case study of the RoboCup@Home domain is given. As proof of concept, a well-known planning problem that often serves as a benchmark, namely that of the blocks-world, is modeled and solved using this approach. An analysis of the performance of the approach has been conducted and the results show that this approach yields significantly smaller planning problem descriptions than those generated by current representations in HTN planning.