Energy technologies interact with the economic, social and environmental systems, and do so not only directly but indirectly as well, through upstream and downstream processes. In addition, the interactions may produce positive and negative repercussions. To make informed decisions on the selection of energy technologies that assist a nation in reaping the socio-economic benefits of power generation technologies with minimal effects on the natural environment, energy technologies need to be understood in the light of the multifaceted system in which they function. But frequently, as disclosed by the literature review conducted in this research, the evaluation of energy technologies lacks clear benchmarks of appropriate assessments, which has resulted in difficulty to compare and to gauge the quality of various assessment practices. The assessment methods and tools tend to be discipline specific with little to no integrations. Parallel with the tools, the technology assessment studies offer piecemeal information that limits deeper understanding of energy technologies and their consequent socio-economic-environmental repercussions. Improved energy technology assessment requires the use of a holistic and integrative approach that traverses the disciplinary nature of energy technology assessment tools, examines the long-term implications of technologies while at the same time embracing energy technologies’ positive-and-negative interactions with the economic, social and environmental systems and in this manner offering economic, social and environmental indicators to assist decision makers in the decision-making process. Accordingly, this study focuses on improving the assessment of energy technologies through the application of a holistic and integrative approach, specifically system dynamics approach along a life-cycle viewpoint. Precisely, focus is on coal-based electricity generation and in particular, the Kusile coal-fired power station near eMalahleni as a case study. A COAL-based Power and Social Cost Assessment (COALPSCA) Model was developed for: (i) understanding coal-based power generation and its interactions with resource inputs, private costs, externalities, externality costs and hence its consequent socio-economic, and environmental impacts over its lifetime and fuel cycle; (ii) aiding coal-based power developers with a useful tool with a clear interface and graphical outputs for detecting the main drivers of private and externality costs and sources of socio-environmental burdens in the system; (iii) aiding energy decision makers with a visual tool for making informed energy-supply decisions that takes into account the financial viability and the socio-environmental consequences of power generation technologies; and for (iv) understanding the impacts of various policy scenarios on the viability of coal-based power generation. The validation of the COALPSCA Model was also conducted. Five structural validity tests were performed, namely structure verification, boundary adequacy, parameter verification, dimensional consistency and extreme condition tests. Behavioural validity was also conducted which included an analysis of the sensitivity of the model outcomes to key parameters such as the load factor, discount rate, private cost growth rates and damage cost growth rates using univariate and multivariate sensitivity analysis. Finally, while attempts were made to incorporate most of the important aspects of power generation in a coal-fired power plant, not all intrinsic aspects were incorporated due to lack of data, gaps in knowledge and anticipated model complication. The shortcomings of the model were highlighted and recommendations for future research were made. / Thesis (PhD)--University of Pretoria, 2015. / tm2015 / Economics / PhD / Unrestricted

Cette recherche doctorale ambitionne d'étudier et d'analyser les dynamiques fondamentales qui lient la Norvège et la Russie dans la région arctique. Sur le plan de la démarche scientifique, nous avons fait le choix de nous rapprocher du paradigme de l'Anthropocène. Aussi, cette recherche souhaite valoriser l'approche interdisciplinaire. La région de Barents est un cas pertinent en ce qui concerne les questions structurelles que notre civilisation thermo-industrielle a conduites tels que le changement climatique, la politique énergétique, la militarisation et l'épuisement des ressources. En outre, il met en évidence les intérêts croissants des puissances économiques pour la région polaire. En premier lieu, la Chine qui a établi des partenariats stratégiques dans la région, notamment avec la Norvège et la Russie. De plus, cette thèse étudie avec attention les questions fondamentales entre ces deux pays tels que la pêche, la sûreté nucléaire, les relations sur l'archipel du Svalbard ou encore la coopération transfrontalière. Elle présente et discute aussi la façon dont les deux pays ont géré et maintenu leur coopération régionale, à part des dynamiques géopolitiques mondiales. Cette dynamique bilatérale a commencé en 1993, après la Guerre froide, à travers la mise en place du Conseil euro-arctique de Barents (BEAC). Cette organisation intergouvernementale a façonné le développement régional dans le nord de l'Europe. Pendant 25 ans, les acteurs locaux de la région de Barents ont démontré leur capacité à atténuer et maintenir cette gouvernance originale. En effet, la crise ukrainienne de 2014 et l'annexion de la Crimée par la Fédération de Russie ont initié une rupture significative entre les pays occidentaux et la Russie. À la lumière de ce changement géopolitique, nous discutons de la résilience de ces relations bilatérales à mesure que le système international devient instable et perturbé. Enfin, notre objectif est d'élever une nouvelle approche méthodologique dans les relations internationales, car la dynamique du système Terre (ESD) et la dynamique des systèmes humains (HSD) semblent être sur une trajectoire de collision à travers le XXIe siècle. À cet égard, les relations entre la Norvège et la Russie, comme puissances énergétiques, ont une position très spécifique. D'une part, les deux sont d'importants fournisseurs d'énergie pour le reste du continent européen. D'autre part, à mesure que le système international subit une pression croissante provenant du système Terre, les deux pays tentent de mettre en place une stratégie durable et pertinente. Finalement, cette nouvelle trajectoire peut affecter et transformer leurs relations. / This dissertation aims to study and analyze key dynamics between Norway and Russia in the Arctic region. Under the Anthropocene paradigm, this research keeps an interdisciplinary approach. The Barents region is a relevant case regarding structural issues that our thermo-industrial civilization drove such as climate change, energy policy, militarization and resources depletion. Besides, it highlights increasing interests from world powers concerning the Polar region. In the first instance, China has established key partnerships in the region including Norway and Russia. Furthermore, this dissertation pays attention on core issues between these two countries such as fisheries, nuclear safety, relations over the Svalbard Archipelago or even the cross-border cooperation. It will introduce and discuss how both countries have managed their cooperation in a safety area far from global geopolitics dynamics. This bilateral dynamic started in 1993, after the Cold War, through the establishment of the Barents Euro-Arctic Council (BEAC). This intergovernmental organization shaped the regional development in the Northern part of Europe. For 25 years, local stakeholders in the Barents region demonstrated their abilities to mitigate and maintain this original governance. Indeed, the Ukrainian crisis in 2014 and the annexation of Crimea by the Russian Federation opened up a major rift between the Western countries and Russia. In the light of this geopolitical shift, we discuss the resiliency of this bilateral relations as the international system gets volatile and disturbed. Finally, our purpose is to rise new methodical approach in International Relations as Earth System Dynamics (ESD) and Human System Dynamics (HSD) appear to be on a collision course through the XXIst century. In that respect, the relations between Norway and Russia, as energy powerhouses, hold a very specific position. On the one hand, both are a strong energy supplier to the rest of the European continent. On the other hand, as the international system is under an increasing pressure following the Earth System disruption, both countries are trying to set up a sustainable and relevant strategy from that context which may lastly affect their relations.

In this research, a focus is on the development of simplified models to represent the behavior of electric machinery within the time-domain models of power systems. Toward this goal, a generator model is considered in which the states include the machine’s active and reactive power. In the case of the induction machine, rotor slip is utilized as a state and the steady-state equivalent circuit of the machine is used to calculate active and reactive power. The power network model is then configured to accept the generator and induction machine active and reactive power as inputs and provide machine terminal voltage amplitude and angle as outputs. The potential offered by these models is that the number of dynamic states is greatly reduced compared to traditional machine models. This can lead to increased simulation speed, which has potential benefits in model-based control. A potential disadvantage is that the relationship between the reactive power and terminal voltage requires the solution of nonlinear equations, which can lead to challenges when attempting to predict system dynamics in real-time optimal control. In addition, the accuracy of the generator model is greatly reduced with variations in rotor speed. Evaluation of the models is performed by comparing their predictions to those of traditional machine models in which stator dynamics are included and neglected.

Daily life of our societies is strongly linked with the usage of natural resources. However, the vital resources of our planet especially energy is a limited resource. The energy consumption in the manufacturing industry is increasing and becoming noticeable; moreover it is being consumed in ways that can’t be sustained. There is great concern about minimizing the consumption of energy usage in the manufacturing industry and sustaining the natural carrying capacity of the ecosystem as well. This is one of the important challenges in today’s industrial world. This research work looks into one of the energy intensive manufacturing processes i.e. the casting process in automotive industry. Here the casting process for cylinder head manufacturing at one of the manufacturing plant in Europe is studied for identifying the most energy intensive steps namely melting, holding and pouring. Parameters that influence these steps and the relationships for energy consumption and dissipation have also been identified through extensive literature survey. By applying system dynamics modeling and simulation approach the interaction between each parameter in the overall process is analyzed in regard to energy consumption. By varying values of the parameters that have the highest impact in the process, the breakthrough opportunities that might dramatically reduce energy consumption during melting and holding have been explored, and potentially energy-saving areas based on the findings have also been identified. The output from this research work enables the company to identify potential avenues to optimize energy usage in the production and hence sustain its manufacturing.

During the last two decades, many companies have reshored their manufacturing operations to the home country, reversing previous offshoring decisions. Reshoring is a strategic decision for manufacturing companies because it is costly, complex, dynamic; thus, it is an important topic for research. Nevertheless, there is a research gap in how the reshoring decision-making process is modeled. Therefore, the overall purpose of this research is to increase the understanding of the reshoring decision-making process. The purpose is fulfilled through two research questions: (1) what is the state-of-the-art of reshoring decision-making process? and (2) how the reshoring decision-making process can be explored using a system dynamics model? The research design includes a literature review, modeling, and an expert interview.  The findings indicate that the state-of-the-art of reshoring decision-making process comprises the drivers, barriers, and other factors are variables that motivate or hinder reshoring decision-making. However, their behavior varies over time and context. Environment and sustainability topics are not completely neglected in the decision-making process. Nevertheless, they are not a priority in reshoring decisions. The developed system dynamics model identifies relationships between the variables of reshoring decisions and how one variable can have a cause-and-effect relationship with another. During modeling of the reshoring decision-making, the complexity considerably increases as more variables are considered in the model. The developed system dynamics model provides a holistic view of the variables, their relationships, dynamics, and the overall complexity of the reshoring decision-making process.  The research has implications for researchers because it increases the understanding of reshoring decision-making concerning the variables involved and relationships among them. Furthermore, this research contributes to the overall topic of reshoring by addressing modeling aspects. The research has implications for practitioners because it contributes to increasing the practitioners’ visualization of the decision-making, which can be used to communicate with various stakeholders. In order to advance this highly relevant field, it is recommended to quantify relationships among the variables that the developed system dynamic model can be simulated.

The concept of the circular economy has been introduced to China and encouraged to be implemented in manufacturing industries by the government in recent years. The implementation of a circular economy in the mobile phone product system can potentially serve as a solution to reducing a significant amount of waste mobile phones. However, the development of a circular economy in China is still at the beginning phase. To help with the promotion of a circular economy, this thesis was proposed. The aim is to explore the possibility to promote a circular economy in the mobile phone product system in China and the main target group is mobile phone producers. The main methodology of this thesis was system dynamics modeling. A system dynamic model was developed to analyze the potential sustainability profits and economic profits. A questionnaire and a literature review were conducted to collect relevant data for the model. The study proposed three strategies (old-for-new, eco-design, and product service system) for producers to promote a circular economy. The profitability of the three scenarios was evaluated and then a sensitivity analysis of the parameters in the model was conducted. According to the model results, the old-for-new strategy was the most profitable and the strategy of the product- service system could not bring additional profit to producers if only economic profits were considered. The general suggestion for producers on maximizing the profitability was propagandizing the significance of mobile phone collection and recycling to increase consumers’ awareness.

Sustainability is one of the challenges in today’s world. With limited resources at hand and hazardous impact of manufacturing processes on the environment, there is an increasing need for sustainable manufacturing. Sustainability actually has a broad meaning and is an all-inclusive concept. In this thesis what we are more interested in and focus on, are energy consumption and environmental impacts. Using system dynamics modeling and simulation, we can more easily understand the behavior of processes. Our selected processes are turning, milling and drilling operations in crankshaft machining and using system dynamics concept we model these processes with regards to energy consumption and environmental concerns. The output of this thesis work can be eventually used as a decision support tool to decide how to make processes more sustainable.

In recent years, blockchain has received more attention in different areas wheredifferent chains show unique properties. Society has been strongly affected by thegrowth of technology and digitalization. Despite the success, the banking system is ina stagnant state in the development of the transaction system. Smart contracts havemore significant potential to be used against blockchain. The contract does not requiremanual handling but could operate independently during all hours of the day. Inaddition, limit them by being applied solely to enable an overview of completedtransactions. A challenge seen with implementing the technology from the bank'sperspective is a new type of form of cooperation. If Ethereum succeeds in proving itselfin its Proof of stake model, there is great potential for a more significant part of thebanking industry to start using smart contracts. The purpose of the study was toinvestigate the effects of implementing smart contracts in a dynamic transaction systemover time. Data obtained from interviews and literature study was the basis formodeling the system. The study aimed to carry out simulations to then be able toevaluate the effects. According to the interviews, blockchain is seen more as a tool tosolve particular problems. The simulations show how the entities in the system areaffected over time when the technology smart contracts are applied.

The U.S. Navy has been confronted with budget cuts and constraints during recent years. This reduction in budget compels the U.S. Navy to limit the number of manpower and personnel to control costs. Reducing the total ownership cost (TOC) has become a major topic of interest for the Navy as plans are made for current and future fleets. According to the U.S. Government Accountability Office (GAO, 2003), manpower is the most influential component of determining the life cycle cost of a ship. The vast majority of the TOC is comprised of operating and support (O&S) costs which account for approximately 65 percent of the TOC. Manpower and personnel costs account for approximately 50 percent of O&S costs. This research focused on tradeoff analysis and cost estimation between manpower and new technology implementation. Utilizing concepts from System Dynamics Modeling (SDM), System Dynamics Causal Loop diagrams (CLD) were built to identify major factors when implementing new technology, and then stocks and flows diagrams were developed to estimate manpower cost associated with new technology implementation. The SDM base model reflected an 18 months period for technology implementation, and then compared different technology implementation for different scenarios. This model had been tested by the public data from Department of the Navy (DoN) Budget estimates. The objective of this research was to develop a SDM to estimate manpower cost and technology tradeoff analysis associated with different technology implementations. This research will assist Navy decision makers and program managers when objectively considering the impacts of iii technology selection on manpower and associated TOC, and will provide managers with a better understanding of hidden costs associated with new technology adoption. Recommendations were made for future study in manpower cost estimation of ship systems. In future studies, one particular type of data should be located to test the model for a specific manpower configuration.

Due to environmental health and nutrient impact concerns, the conventional on-site sewage collection, treatment, and disposal systems are no longer able to meet the nutrient reduction requirements for wastewater effluent and may represent a large fraction of pollutant loads. The loads include not only nitrogen (N) and phosphorus (P), but also pathogens such as fecal coliform and E. coli which indicate the presence of other disease-causing bacteria flowing into aquatic system that adversely affect public health. A subsurface upflow wetland, which is an effective small-scale wastewater treatment system with low energy and maintenance requirements and operational costs, fits the current nutrient and pathogen removal situation having received wide attention throughout the world. Within this research study, a subsurface upflow wetland system (SUW), including four parallel SUW (three planted versus one unplanted), were constructed as a key component of the septic tank system receiving 454 liters per day (120 GPD) influent using the green sorption media along with selected plant species. It was proved effective in removing both nutrients and pathogens. During a one month test run, the planted wetlands achieved a removal efficiency of 84.2%, 97.3 %, 98.93 % and 99.92%, compared to the control wetland, 10.5%, 85.7 %, 99.74 % and 100.0 %, in total nitrogen (TN), total phosphorus (TP), fecal coli and E.Coli, respectively. Denitrification was proved to be the dominant pathway for removing N as evidenced by the mass balance and real-time PCR analyses. A simplified compartmental dynamics simulation model of constructed subsurface upflow wetlands was also developed to provide a dependable reference and tool for design of constructed subsurface upflow wetland.