The South China Sea claimants base their claims on ancient documentation and archeological evidence. However, they largely ignored the territories until the 1960s, when natural resources speculations began. The 1982 UNCLOS magnified interest as claimants hoped to extend exclusive economic rights from their claims rather than continental coastlines. Another possible factor behind Chinese claims is the theory that Beijing desires to establish Chinese hegemony in the region. Beijing's shift from bilateral diplomacy and military aggression to multilateral diplomacy has created debate among Sinologists. Many argue China lacked the power necessary to assert its claims and now can finally attempt assertion again, thus the naval buildup. Others argue that natural resources drive China's SCS policy and still others believe bureaucratic infighting drives policy. Economic data shows a possible causal relationship between trade and China's political behavior. The 1996 U.S. Presidential campaign slogan, "It's the economy stupid," apparently applies to Beijing's SCS approach as well. The U.S. approach to the disputes remains one of ambivalence. As long as the United States maintains freedom of navigation through the area, Washington should remain concerned but uninvolved. Beijing largely feels the same way, with the important addition of guaranteeing access to the region's natural resources.

Morphologic change of ephemeral stream cross-sections is a natural component of fluvial geomorphology but disruptions to natural erosion and deposition by anthropogenic disturbances has the potential for cascading impacts down the channel corridor. The proximal impact of a natural gas pipeline construction on ephemeral stream cross-section geometry in southern Arizona was evaluated from July 2014 (pre-construction) to July 2016 (two years post construction). Cross-sections at three locations (upstream the pipeline Right-Of-Way (ROW)), through the middle of the ROW, and downstream of the ROW) were measured using Light Detection And Ranging (LIDAR) and field methods for 16 ephemeral streams. Results of both the LIDAR and field measurements indicated insignificant difference in cross-sectional area change between upstream, across, and downstream-ROW cross-sections [(F 2,64) = 0.341, p = 0.73; (F2,18)= 0.980, p = 0.395]. Sediment generated during pipeline construction appeared to have moved beyond the physical confines of the study site, which limited the assessment of larger-scale geomorphic impacts. Furthermore, the 2014-2016 study period experienced only small (high-recurrence frequency) precipitation events, indicating the absence of large flows capable of significant morphologic change. To further explain differences in cross-section area change between LIDAR datasets, a linear regression model was used to assess the predictive value of nine variables: year of measurement, drainage area, drainage density, basin slope, upstream-, across-, downstream-ROW cross-section locations, percent bare soil in basin, percent mesquite in basin, total precipitation, and number of storms with average precipitation above 25 mm/hour. Though the amount of bare soil in the basin and the second study period (February 2015-July 2016) at least partially explained the changes in cross-section area, the model was not a strong predictor of morphologic change during the 2014-2016 study period. The majority of the variability in cross-sectional area change in the study basins remained unexplained.

Currently, in the United States, on-road vehicles are primarily powered by petroleum fuels (gasoline and diesel). These vehicles have caused serious climate change effects from emissions of greenhouse gas (GHG) and health and environmental impacts from criteria air pollutant (CAP). The recent success of shale gas development has brought industry interest in using natural gas to power on-road vehicles. In addition to low costs and wide availability of this national fuel source, natural gas is a common feedstock to produce alternative fuels. The question arises of whether using natural gas for transportation could help or hinder the environment. In this dissertation, I study the economic and environmental effects of a wide range of natural gas fuel pathways for a selection of light duty (LDV) and medium and heavy duty (MHDV) vehicle types. I choose to focus on two environmental metrics: GHGs and CAPs emitted over the life cycle of each potential pathway for natural gas use. First in Chapters 2 and 3, I use life-cycle analysis to understand the emissions of GHGs from different natural gas pathway for LDVs and MHDVs. Then in Chapter 4 I focus on the CAP emissions from these vehicles. Overall, I find that none of the natural gas pathways eliminate life cycle air emissions. In fact, only a few pathways reduce life cycle GHG emissions and/or life cycle air pollution damages compared to baseline petroleum fuels (gasoline for light-duty vehicles (LDVs) and diesel for heavy-duty vehicles (HDVs)). For the cases of light duty vehicles (LDVs) and transit buses, battery electric vehicles (BEVs) powered by natural gas-based electricity provide significant reduction in life cycle GHG emissions and life cycle air pollution damages (for almost all counties) compared to the baseline petroleum fuels. However, the actual electricity that charges BEVs may not be natural gas-based electricity in most parts of the U.S. When powered by U.S. grid electricity (using average emission factors for 2010 and 2014), BEVs reduce life cycle GHG emissions to a lesser extent but increase life cycle air pollution damages significantly. Compressed natural gas (CNG), while reducing GHG emissions and CAP emissions (except CO) at tailpipe, are more likely to increase life cycle GHG emissions and increase life cycle air pollution damages in the majority of U.S. counties. For heavy-duty trucks, CNG sparking-ignition (SI) trucks and liquefied natural gas (LNG) high-pressure direct ignition (HPDI) trucks have mixed environmental impacts. While they are unlikely to reduce life cycle GHG emissions compared to diesel, they reduce life cycle air pollution damages in 76-99% of U.S. counties for local-haul tractor-trailers and in 32-71% of U.S. counties for long-haul tractor-trailers. In Chapters 5 and 6, I examine the economic impacts of natural gas fuel pathways for two vehicle types, tractor-trailers and transit buses. I study the economic feasibility of a national natural gas refueling infrastructure for long-haul trucks in U.S., which is a prerequisite for natural gas tractor-trailers. I find that a transition to natural gas fuels in long-haul trucks is more expensive when the shares of natural gas trucks are below 5% because of low refueling demands and over-capacity of the refueling infrastructure to ensure network coverage. At higher shares of natural gas trucks, both the total refueling capacity and the net economic benefits of the national refueling infrastructure increase almost linearly as adoption increases. Finally, in Chapter 6, I provide an economic-technology assessment for transit buses by considering both life cycle ownership costs and life cycle social costs due to GHG emissions and CAP emissions. Transit buses are early adopters of alternative fuel technologies because of funding supports and operation characteristics (such as high fuel consumption and private refueling infrastructure). I find that the availability of external funding is crucial for transit agencies to adopt any alternative fuel option. Without external funding, only rapid-charging battery electric buses (BEBs) have lower ownership & social costs than conventional diesel buses. When external funding is available to reduce bus purchase costs by 80%, BEBs become much more cost-effective. In this case, life cycle ownership and social costs of BEBs are 37-43% lower than conventional diesel buses. Including life cycle social costs does not change the ranking of alternative fuel options. The findings in this dissertation suggest different strategies of using natural gas for different vehicle markets. Natural gas is best used in electric power generation than to produce gaseous or liquid fuels for powering on-road LDVs. The use of CNG and LNG for heavy-duty trucks may continue as there are less alternative fuel options but issues such as methane leakage should be addressed to avoid important climate change effect. Finally, natural gas-based transportation fuels can at best partially mitigate climate change or air pollution damages, so other mitigation strategies in the transportation sector are ultimately needed to achieve sustainable transportation.

Natural gas has become the UK’s foremost primary energy source, providing some 39% of our energy needs. The National Transmission System (NTS) has developed from its humble beginnings when natural gas was first discovered in the North Sea in the 1960s to become a complex interconnected network delivering up to 550 million cubic meters of gas daily. Gas has also become an increasingly important energy source for power generation, currently generating 35% of our electricity. This presents major challenges for the planning and operation of both the electricity and gas networks as their interdependence grows into the future. With the government’s goal of drastically reducing emissions from power generation by 2020, Combined Cycle Gas Turbine units, and therefore the NTS, will have to offer a new degree of flexibility to quickly respond to the intermittency of the growing penetration of wind generation on the electricity transmission system. Coupling this with the decline in the UK natural gas resources resulting in the NTS becoming reliant on imports to meet demand, it is becoming increasingly difficult to decouple the security of the gas supply from the security of the electricity supply in the UK. This study presents the modelling challenge of assessing this growing interaction and provides a robust methodology for completing a security analysis using detailed network models of the UK gas and electricity transmission systems. A thorough investigation of the intraday operation of the two systems in 2020 is presented given the growth of wind generation in the UK. The results are analysed and the implications for combined modelling and assessment are discussed as we enter a new era for UK energy security.

This master thesis aims to examine the relationship between energy consumption and economic growth and between energy consumption and greenhouse emissions for the EU countries, using a panel time series data from 1996 to 2012 within a multivariate framework for 26 EU countries. The energies are composed from oil consumption, natural gas consumptions, and renewable energies including the biomass as a distinct part. To do that, Unit Root Tests, cointegration test, Pairwise Granger causality tests, and Error Correction Model are employed to find out the type of the causal relationship. The main results to denote are that, there is in the short run, a positive unidirectional causal relationship running from oil consumption to economic growth. We can as well denote a positive bidirectional causal relationship between renewable energies and economic growth and between greenhouse emissions and economic growth. However, there is an unexpected negative bidirectional causal relationship between biomass consumption and gas consumption. From the greenhouse emissions perspective, we can see in the short run, a negative bidirectional causal relationship between greenhouse emissions and renewable energies, and a positive unidirectional causal relationship running from both oil consumption and biomass consumption...

Doctor of Philosophy / Department of Chemical Engineering / Keith L. Hohn / Extensive research has gone into developing and modeling the three-way catalyst (TWC) to reduce the emissions of hydrocarbons, NOx and CO from gasoline-fueled engines level. However, much less has been done to model the use of the three-way catalyst to treat exhaust from natural gas-fueled engines. Our research address this gap in the literature by developing a detailed surface reaction mechanism for platinum based on elementary-step reactions. A reaction mechanism consisting of 24 species and 115 elementary reactions was constructed from literature values. All reaction parameters were used as found in the literature sources except for steps modified to improve the model fit to the experimental data. The TWC was simulated as a one-dimension, isothermal plug flow reactor (PFR) for the steady state condition and a continuous stirred-tank reactor (CSTR) for the dithering condition. This work describes a method to quantitatively simulate the natural gas engine TWC converter performance, providing a deep understanding of the surface chemistry in the converter. Due to the depletion of petroleum oil and recent volatility in price, synthesizing value-added chemicals from biomass-derived materials has attracted extensive attention. 1, 3-butadiene (BD), an important intermediate to produce rubber, is conventionally produced from petroleum. Recently, one potential route is to produce BD by dehydration of 2, 3-butanediol (BDO), which is produced at high yield from biomass. This reaction was studied over two commercial forms of alumina. Our results indicate acid/base properties greatly impact the BD selectivity. Trimethylamine can also modify the acid/base properties on alumina surface and affect the BD selectivity. Scandium oxide, acidic oxide or zirconia dual bed systems are also studied and our results show that acidic oxide used as the second bed catalyst can promote the formation of BD, while 2,5-dimethylphenol is found when the zirconia is used as the second bed catalyst which is due to the strong basic sites.

The aim of the Master's thesis is to map the importance and role of liquefied natural gas in Europe and to assess its significance for future energy security of the EU. Working with the general characteristics of natural gas and LNG dedicated to LNG infrastructure and LNG position in the gas market in Europe. The fundamental part of the thesis analyzes the importance of LNG for energy security of European countries. Theoretical framework of the thesis comprises the concept of energy security of Daniel Yergin, which is followed by an approximation of EU energy policy. The end of thesis describes an European project North-South Energy Corridor that will significantly strengthen the energy security of Central European countries.

This diploma thesis deals with the energy policy of the Russian Federation in the period from 2000 to 2008 and its prospects until 2030. First of all, I analyse particular targets of the energy policy of Russia and put them in a broader framework. Consequently, I focus my attention on three economic targets that need to be met if Russia is to become an "energetic superpower". Firstly, I search for the answer to the question whether Russia has enough oil and gas for foreigner markets and whether it can provide for their export in order to be able to act successfully as an "energetic superpower". Secondly, whether Russia will succeed when exporting oil and natural gas to world markets and whether it will manage to diversify transport routes for its exports. Thirdly, whether the effort to "make the economy move" supported by raw-material exports has been successful and whether this situation can continue. The thesis further follows each answer to these questions in two dimensions of time. A hindsight shall first clarify how successful the energy policy of Russia was when meeting these targets until 2008, or what problems Russia had to face while trying to meet them. In consequence, this provides a basis for a foresight.

[pt] Neste estudo, os esforços são concentrados em se buscar a redução das emissões em motores Diesel-gás. Assim, são apresentados resultados experimentais, obtidos em dinamômetro de bancada, das emissões e desempenho de um motor do ciclo Diesel (turbo alimentado e com intercooler), para operar, reversivelmente, como motor Diesel-gás ou Diesel original. Inicialmente, foram executados ensaios nas duas versões, Diesel e Diesel-gás; logo, os resultados respectivos foram comparados em termos de emissões e desempenho do motor. A seguir, na operação Diesel-gás, foi avaliado o método da restrição parcial do ar de admissão, a fim de produzir uma mistura efetivamente mais rica para a mesma quantidade do gás natural. Os resultados obtidos mostraram uma notável redução nas emissões de monóxido de carbono e hidrocarbonetos não queimados, para toda a faixa de operação avaliada. Por outro lado, as emissões de material particulado continuaram sendo ínfimas em altas taxas de substituição e os níveis de óxidos de nitrogênio apresentaram certo incremento em altas cargas do motor. Quanto ao rendimento térmico, verificam-se acréscimos quando é alcançado certo valor de taxa de substituição. Contudo, os resultados de emissões e rendimento térmico apresentam melhores resultados em baixas cargas do motor (abaixo de 50% da plena carga). Assim, além de reduzirem-se os níveis de certas emissões em altas cargas, verificou-se uma contribuição adicional do presente trabalho no que diz respeito à redução, de forma parcial, de um dos principais problemas envolvendo a combustão em motores Diesel-gás: a queima incompleta de misturas pobres em cargas baixas. / [en] The focus of this study is the reduction of emissions in Gas-Diesel engines. The experimental results of emissions and performance of a Diesel cycle engine (with turbo and intercooler), obtained by a dynamometer, are presented for operation as Gas-Diesel and as original Diesel engine. First, two kinds of operation were tested: Diesel and Gas-Diesel; then, the respective results of emissions and performance of the motor were compared. After, in Gas-Diesel operation, was evaluated the method of the partial restriction of the admission air, to produce a richer mixture with the same quantity of natural gas used before. The obtained results show a notable reduction of the emissions of carbon monoxide and unburned hydrocarbons for the whole range of evaluated operation. On the other hand, the particulate emissions had kept minims at high rates of substitution and the nitrogen oxides levels presented a bit of increase at high engine load. The thermal performance increases when is achieved a determinate substitution rate value. However, the emissions and thermal performance results have a better behavior at low engine loads (below 50% of the full load). Thus, beyond the levels of some emissions are reduced at high loads, in addition, a reduction was found, of partial form, from one of the main problems involving combustion in Gas-Diesel engines: the incomplete burning of poor mixtures in low loads.

A utilização de gás natural tem ganhado espaço na matriz energética brasileira, principalmente dentro do setor industrial. Para um conjunto de segmentos e processos industriais, a utilização de gás natural como energético ou matéria prima envolve significativos ganhos do ponto de visto ambiental, técnico e econômico. A hipótese motivadora deste trabalho está relacionada ao potencial papel de indutor do desenvolvimento regional que a disponibilidade de gás natural possui. Uma vez que a presença de gasodutos exibe um evidente padrão de concentração espacial bem definido, seria natural esperar que as indústrias que levassem em conta a disponibilidade deste energético em sua decisão de localização se tornassem mais concentradas, acompanhando o traçado dos principais gasodutos. Foram definidas duas principais vias de análise: (i) a avaliação do nível de concentração geográfica (ou espacial) da indústria, verificando-se a existência de padrões distintos para a média da indústria e um grupo de setores definidos como heavy users de gás natural (cerâmica, têxtil e química), e (ii) a avaliação e mapeamento das correlações espaciais entre o emprego industrial (proxy da atividade industrial) e a presença de gasodutos. Para o Brasil, os resultados não permitiram concluir pela existência de relação entre concentração industrial e disponibilidade de gás natural. Porém, para o Estado de São Paulo verificou-se que existe uma forte correlação positiva entre a presença de gasodutos e o nível de emprego para os segmentos heavy users, mesmo quando se consideram os efeitos de outras variáveis relevantes (custos de transporte, qualificação da mão de obra e ganhos com a especialização). / The use of natural gas has gained space in the Brazilian energy matrix, especially in the industrial sector. For a set of segments and industrial processes, the use of natural gas as a fuel or raw material involves significant environmental, technical and economic gains. The hypothesis motivating this work is the potential role that the availability of natural gas has as a promoter of regional development. The natural gas pipelines exhibits a clear pattern of spatial concentration, therefore it would be natural to expect that industries that took into account the availability of energy in their location decision became more concentrated, following the route of main pipelines. We defined two main pathways of analysis: (i) assessing the level of industry geographical (or spatial) concentration, verifying the existence of distinct patterns for the industry as a whole and a group of sectors defined as heavy users of natural gas (ceramics, textiles and chemicals), and (ii) the assessment and mapping of the spatial correlations between manufacturing employment (a proxy for industrial activity) and the presence of pipelines. For Brazil, the results failed to establish the existence of a relationship between industrial concentration and availability of natural gas. However, for the State of São Paulo has been found that there is a strong positive correlation between the presence of pipelines and employment for heavy users segments, even when considering the effects of other relevant variables (transportation costs, qualification of labor and gains from specialization - agglomeration economies).