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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Policy and Practice Audit and GHG Reduction Strategy Recommendations for the City of Arroyo Grande

Cochran, Cheryl Lynn 01 June 2012 (has links) (PDF)
In preparation for a Climate Action Plan, this policy and practice audit provides an overview of current city policies and practices with the potential to impact greenhouse gas (GHG) emissions reduction goals. The audit builds upon information previously collected in a GHG emissions inventory report to identify policies that are consistent or inconsistent with emissions reductions goals. Preliminary GHG emissions reductions recommendations address policy gaps and opportunity areas in suggesting strategies to achieve GHG emissions reductions.
12

A Comparative Study of Diesel Ignited Methane and Propane Dual Fuel Low Temperature Combustion in a Single Cylinder Research Engine

Raihan, Mostafa Shameem 13 December 2014 (has links)
The objective of this thesis is to investigate and compare the performance and emissions characteristics of diesel-ignited methane and diesel-ignited propane dual fuel LTC in a single cylinder research engine (SCRE) at a constant engine load of 5.1 bar net indicated mean effective pressure (IMEP) and at a constant engine speed of 1500 RPM. Percentage of energy substitution of propane or methane (0 - 90 percent), diesel injection timing (SOI: 355 CAD – 280 CAD), rail pressure (200 bar – 1300 bar) and boost pressure (1.1 bar – 1.8 bar) were varied to quantify their impact on engine performance and engine-out ISNOx, ISHC, ISCO, and smoke emissions. Advancing SOI to 310 CAD and beyond yielded simultaneous ISNOx and smoke emissions. A rail pressure of 500 bar was the optimal one for both fueling combinations while increasing boost pressure over 1.2 bar had a very little effect on ISNOx and smoke emissions.
13

Cooling, heating, and power systems energy performance and non-conventional evaluation based on energy use

Fumo, Nelson 09 August 2008 (has links)
Cooling, Heating and Power (CHP) systems have been recognized as a key alternative for thermal energy and electricity generation at or near end-user sites. CHP systems can provide electricity while recovering waste heat to be used for space and water heating, and for space cooling. Although CHP technology seems to be economically feasible, because of the constant fluctuations in energy prices, CHP systems cannot always guarantee economic savings. However, a well-designed CHP system can guarantee energy savings, which makes necessary the quantification of non-conventional benefits from this technology in order to offset any economic weakness that can arise as consequence of energy prices. Some aspects that could be included in a non-conventional evaluation are: building energy rating, emission of pollutants, power reliability, power quality, fuel flexibility, brand and marketing benefits, protection from electric rate hikes, and benefits from promoting energy management practices. This study focuses on two aspects: building energy rating and emission reduction of pollutants, related to CHP system energy performance. Two methodologies have been developed in order to estimate the energy related benefits from CHP technology. To determine the energy performance, a model has been developed and implemented to simulate CHP systems in order to estimate the building-CHP system energy consumption. The developed model includes the relevant variables governing CHP systems such as: type and size of the components, individual component efficiencies, system operating mode, operational strategy, and building demand for power, heating, and cooling. The novelty of this model is the introduction of the Building Primary Energy Ratio (BPER) as a parameter to implement a primary energy operational strategy, which allows obtaining the best energy performance from the building-CHP system. Results show that the BPER operational strategy always guarantees energy savings. On the other hand, results from a cost-oriented operational strategy reveal that for critical design conditions, high economic savings can be obtained with unacceptable increment of energy consumption. For Energy Star Rating and Leadership in Energy and Environmental Design (LEED) Rating, results show that CHP systems have the ability to improve both ratings.
14

Carbon emissions reduction and financial performance of Johannesburg Stock Exchange 's SRI companies

Worae, Thomas Adomah January 2017 (has links)
Thesis (Ph. D. (Accounting)) -- University of Limpopo, 2017. / This research examined the effect of carbon emissions reduction on financial performance Johannesburg Stock Exchange’s SRI companies. Empirical results of corporate fossil energy-based dependence on environment and economic performance thus far have been ambiguous. The major objective of this research was to examine the effect of emissions and energy intensity on market and accounting based performance measures. This research adopted the positivist paradigm approach and therefore used a quantitative causal research approach. Archival data was collected from fourteen JSE’s SRI companies for seven years. The research applied a panel data analysis, a total of 98 observations were derived from panel data set. Multiple linear and causal econometric models were applied in the data analyses namely ordinary least squares (OLS), fixed effects and dynamic models. OLS results showed a significant effect of energy usage intensity (ENGINT) on return on assets (ROA), and return on sales (ROS), with carbon emissions intensity (EMSINT) exhibiting a significant effect on return on assets (ROA), and return on sales (ROS). When the study controlled for omitted variable bias and possible orthogonality condition, a significant negative effect of energy intensity (ENGINT) on equity returns (EQRTNS) was found. Impulse response analysis revealed that shocks in energy intensity on average tend to decrease firms’ financial value, while shocks in emissions intensity on average increase firms’ financial value within the sampled companies. Whilst testing for causality, the Panel Granger causal analysis showed unidirectional effect of EMSINT on EQRTNS, and bidirectional causal relationship between EMSINT and MVE/S at 1% significant level. This research made a contribution by extending the model used by previous researchers through the use of multiple market and accounting based performance measures which were analysed using advanced econometric models: Arellano-Bond DPD model, impulse response function in short PVARs and Bootstrap dynamic panel threshold model. In addition, this thesis suggested a model to advance future research on carbon emissions and firm performance and managerial decision propensity for carbon reduction. / Carbon Disclosure Project and School of Accountancy of the University of Limpopo
15

Design of a novel rotary compact power pack for the series hybrid electric vehicle : design and simulation of a compact power pack consisting of a novel rotary engine and outer rotor induction machine for the series hybrid electric vehicle powertrain

Amirian, Hossein January 2010 (has links)
Hybrid electric vehicles significantly reduce exhaust emissions and increase fuel economy. Power packs are the most fundamental components in a series powertrain configuration of a hybrid vehicle, which produce the necessary power to run the vehicle. The aim of this project is to design a compact power pack for a series hybrid vehicle, using virtual prototyping. The hybrid electric vehicle characteristics and configurations are analysed, followed by an explanation of the principles of induction machines. A new type of rotary induction machine with an outer rotor construction is designed to be coupled with the novel rotary internal combustion engine with rotating crankcase in order to form the compact power unit for the hybrid vehicle. The starting and generation performance of the designed machine is analysed by an electric machine simulator, called JMAG. ADVISOR software is studied and utilised to simulate the overall vehicle performance, employing different categories of power packs in the powertrain. Results show that the proposed compact power pack has the best performance in terms of fuel economy, emissions and battery charging compared to the existing power unit options. Over the city cycle, fuel economy is increased by up to 47 % with emission reduced by up to 36 % and over the highway cycle, fuel economy is increased by up to 69 % with emission reduced by up to 42 %.
16

Potential for synthesis between REDD+ and community forest management as understood through the lens of global political ecology

Chretien, Jonathon 31 January 2013 (has links)
Global climate change is one of the defining issues of the 21st century. The phenomenon of natural climate variation being pushed beyond normal ranges has been fueled largely by industrial activities and those which support them (i.e. land-use change and the over-exploitation of natural resources). The urgency is well established with reports demonstrating an increased occurrence of rare, highly damaging weather events, and shifts in the natural range of species. The necessity of action on climate change has resulted in the development of novel global initiatives designed to address the problem across global and regional scales. Reducing Emissions from Deforestation and forest Degradation (REDD+) is emblematic of this new wave of conservation strategy. It brings together parties which are often seen as opposed on environmental issues in collaborative environmental practise. This thesis explores the development of REDD+ as an effective and equitable solutions to this problem. REDD+ is a policy architecture designed for global deployment, the success of which will depend largely upon the engagement and involvement of local community groups. Community forest management (CFM) may inform the REDD+ design process, and enhance both land-use strategies by way of synergy. The pathway to that point is, however, uncertain and marred with potential pitfalls. This thesis uses the instructive and critical lens of political ecology to assess the potential for integrating greater CFM elements into the REDD+ policy structure. It explores how the narratives of CFM and REDD+ clash at discursive levels, while also identifying elements of each which may make them mutually beneficial. The thesis finds that much of the conflict between positions on REDD+ are the result of contrasting environmental understandings, some of which are informed by negative experiences with past environmental conservation initiatives. Greater community-centric attributes may assist in improving the local and regional acceptability of REDD+ projects by appealing to the “alternative” values of forest-dependent peoples. Some suggested policy modifications are made to improve the overall design of REDD+ to be inclusive of the concerns of forest user groups, and potential areas for future research projects are discussed. / Thesis (Master, Environmental Studies) -- Queen's University, 2013-01-28 14:57:55.951
17

Energia nas operações de desmonte de rocha e suas influências na moagem de minérios

Carlos, Marcelo Ribeiro January 2017 (has links)
Energia é um insumo estratégico na mineração, pois é fundamental na viabilidade das operações mineiras e importante na manutenção de custos operacionais baixos e competitivos. Por esse motivo, toda iniciativa que visa a busca por eficiência no consumo de energia é importante para a competitividade das mineradoras. Vários insumos energéticos são utilizados nas operações unitárias de mineração. Os exemplos mais comuns são diesel, eletricidade, gás natural, carvão e explosivos. O objetivo desse trabalho é estudar, do ponto de vista energético, as atividades realizadas no processo de desmonte de rochas, em um complexo minerador de minério de ferro, visando a melhor utilização da energia no desmonte de rocha para aperfeiçoar as operações unitárias subsequentes de processamento de minérios. Um foco maior foi dado à economia de energia nas moagens de bolas da planta de beneficiamento e concentração, provocada pelas modificações e melhorias realizadas no desmonte de rocha. A metodologia consistiu na análise de diversos desmontes de rocha variando a razão de carga de explosivos no complexo minerador alvo desse trabalho. Os produtos desses desmontes foram acompanhados até a sua entrada na planta de beneficiamento. Durante o processamento desses materiais nas moagens da planta, foram coletadas e analisadas as grandezas elétricas resultantes e comparadas com uma linha de base gerada antes do início do trabalho. Os dados foram analisados com o objetivo de visualizar a influência do aumento da razão de carga na performance energética da operação de moagem. Em paralelo, também, foram analisadas as situações operacionais e dificuldades existentes nas medições de campo e nos acompanhamentos de consumos energéticos dos processos unitários, assim como a infraestrutura necessária para que uma variável tão importante como energia elétrica possa ser monitorada de forma adequada. Por fim, foi abordada a importância, a metodologia e os resultados da redução de emissões de CO2 provenientes da economia de energia de todo o trabalho realizado em campo. Os resultados apresentados mostram que mesmo com um aumento significativo da alimentação de material compacto (maior WI) nas moagens, o consumo energético total dessa operação unitária não aumentou. Isso gerou uma potencial economia específica de energia e a consequente redução de emissões de CO2 na atmosfera, além de viabilizar o processamento de material mais compacto nas mesmas linhas de processo. Esse comportamento sugere que uma melhor energia gasta no desmonte de rocha pode impactar positivamente na produtividade e nos custos de produção do minério ao longo de sua cadeia produtiva. / Energy is a mining strategic source, critical in mining operations feasibility and important to maintain low operational costs in a competitive level. For this reason, any initiative aimed at searching for energy efficiency is important for mining companies’ competitiveness. Mining operations need several energy sources. Most common examples are diesel, electricity, natural gas, coal and explosives. This text aims to address, from an energy perspective, a study carried out in an iron ore mining complex, which had as main objective to reach a better rock blasting energy utilization to improve subsequent mining operations. A greater focus was given to energy savings in ball mills operations of a beneficiation and concentration plant, impacted by modifications and improvements made in rock blasting. Methodology consisted in monitoring several rock blasting, carried out in this mining complex, varying explosive charge ratio. Products of those rock blasting were monitored until they entered the processing plant. During ore processing in plant´s ball mills, electrical variables were collected and analyzed, comparing to a baseline generated before the beginning of this research. All data were analyzed to show influence of explosive charge ratio increase on energy performance of the milling operation. In parallel, operational issues and difficulties in field measurements of energy consumptions were described, as well as the necessary infrastructure that allows the variable electricity to be adequately monitored. Besides, the methodology and results of CO2 emissions reduction from energy savings of all fieldwork were discussed. The research data shows that even with a significant increase in compact feed (higher Work Index), total energy consumption of mill operation did not increase. This scenario generate a potential specific energy savings and consequent reduction in CO2 emissions in the atmosphere. In addition, enables more compact material to be processed in the same process lines. This behavior suggests that a better energy spent on rock blasting can positively affect productivity and ore production costs along its production chain.
18

Estudo do comportamento de misturas asfálticas mornas em revestimentos de pavimento com adição de borracha moída de pneu. / Study of behavior of rubberized warm mix asphalt.

Merighi, Cecilia Fortes 02 March 2015 (has links)
Este trabalho apresenta um estudo realizado com uma mistura asfáltica morna utilizando ligante aditivado com agente surfactante e borracha moída de pneus inservíveis. Um trecho experimental foi executado com a mistura asfáltica morna, localizado na SPA-248-055, Pista Oeste, entre os quilômetros 3+000 e 6+000 e comparado ao trecho de referência, localizado na mesma rodovia, entre os quilômetros 1+000 e 3+000. Foram feitos também ensaios fundamentais para caracterização do ligante modificado com borracha e com aditivo químico para mistura morna e também ensaios para verificar o comportamento mecânico da mistura de usina, de modo que possibilitou comparar seus resultados com uma mistura de referência, com produção na temperatura a quente. Os ensaios realizados para verificação do comportamento mecânico foram: resistência à tração, módulo de resiliência, fadiga e resistência à formação de trilha de roda no simulador de tráfego francês do LCPC. Comparando a mistura asfáltica morna com uma mistura de referencia, os resultados obtidos foram satisfatórios. Além destes experimentos também foram realizados ensaios de resistência ao dano por umidade induzida (DUI). No caso deste estudo, os resultados foram satisfatórios. Durante a produção da mistura asfáltica, foi realizada a análise da redução de emissões de poluentes, no momento da produção da mistura. Os resultados indicaram que há redução de poluentes como fumos totais, fumos solúveis e compostos orgânicos voláteis (VOC). Tanto o trecho experimental quanto o trecho de referência foram avaliados durante 3 anos quanto aos parâmetros de desempenho do pavimento, como irregularidade e condição de superfície. Os resultados obtidos mostram o comportamento positivo da mistura asfáltica morna, quando comparado ao pavimento do trecho de referência, ao longo de dois anos de observação. / This paper presents a study of a warm asphalt mix using binder additive with surfactant agent and tire crumb rubber. A test section was performed with the warm asphalt mixture, located in SPA-248-055, West Lane, between kilometers 3+00 to 6+000 and compared to the reference section, a hot mix section, located on the same highway, between kilometers 1 + 000 and 3 + 000. Basic tests were also made to characterize the rubber-modified binder and to verify the mechanical behavior of the plant mixture, than compared to results of a reference hot mixture. The tests performed to check the mechanical behavior were: tensile strength, resilient modulus, fatigue and rooting in French LCPC traffic simulator. Comparing the warm asphalt mixture with a mixture of reference, the results achieved were satisfactory. In addiction, in this research were also performed induced moisture damage, and check the adhesion of the binder to the aggregate. In the case of this study, the results were acceptable. During warm asphalt mix and hot mix production, analysis of reducing pollutant emissions were recorded. The results indicated that there is a reduction of pollutants such as total smoke, fumes soluble and organic volatile compounds. Both the experimental section and the reference section were evaluated for 3 years for pavement performance parameters such as roughness and surface condition. The results show a positive behavior of warm asphalt mix compared to the reference pavement section over two years of observation.
19

Energia nas operações de desmonte de rocha e suas influências na moagem de minérios

Carlos, Marcelo Ribeiro January 2017 (has links)
Energia é um insumo estratégico na mineração, pois é fundamental na viabilidade das operações mineiras e importante na manutenção de custos operacionais baixos e competitivos. Por esse motivo, toda iniciativa que visa a busca por eficiência no consumo de energia é importante para a competitividade das mineradoras. Vários insumos energéticos são utilizados nas operações unitárias de mineração. Os exemplos mais comuns são diesel, eletricidade, gás natural, carvão e explosivos. O objetivo desse trabalho é estudar, do ponto de vista energético, as atividades realizadas no processo de desmonte de rochas, em um complexo minerador de minério de ferro, visando a melhor utilização da energia no desmonte de rocha para aperfeiçoar as operações unitárias subsequentes de processamento de minérios. Um foco maior foi dado à economia de energia nas moagens de bolas da planta de beneficiamento e concentração, provocada pelas modificações e melhorias realizadas no desmonte de rocha. A metodologia consistiu na análise de diversos desmontes de rocha variando a razão de carga de explosivos no complexo minerador alvo desse trabalho. Os produtos desses desmontes foram acompanhados até a sua entrada na planta de beneficiamento. Durante o processamento desses materiais nas moagens da planta, foram coletadas e analisadas as grandezas elétricas resultantes e comparadas com uma linha de base gerada antes do início do trabalho. Os dados foram analisados com o objetivo de visualizar a influência do aumento da razão de carga na performance energética da operação de moagem. Em paralelo, também, foram analisadas as situações operacionais e dificuldades existentes nas medições de campo e nos acompanhamentos de consumos energéticos dos processos unitários, assim como a infraestrutura necessária para que uma variável tão importante como energia elétrica possa ser monitorada de forma adequada. Por fim, foi abordada a importância, a metodologia e os resultados da redução de emissões de CO2 provenientes da economia de energia de todo o trabalho realizado em campo. Os resultados apresentados mostram que mesmo com um aumento significativo da alimentação de material compacto (maior WI) nas moagens, o consumo energético total dessa operação unitária não aumentou. Isso gerou uma potencial economia específica de energia e a consequente redução de emissões de CO2 na atmosfera, além de viabilizar o processamento de material mais compacto nas mesmas linhas de processo. Esse comportamento sugere que uma melhor energia gasta no desmonte de rocha pode impactar positivamente na produtividade e nos custos de produção do minério ao longo de sua cadeia produtiva. / Energy is a mining strategic source, critical in mining operations feasibility and important to maintain low operational costs in a competitive level. For this reason, any initiative aimed at searching for energy efficiency is important for mining companies’ competitiveness. Mining operations need several energy sources. Most common examples are diesel, electricity, natural gas, coal and explosives. This text aims to address, from an energy perspective, a study carried out in an iron ore mining complex, which had as main objective to reach a better rock blasting energy utilization to improve subsequent mining operations. A greater focus was given to energy savings in ball mills operations of a beneficiation and concentration plant, impacted by modifications and improvements made in rock blasting. Methodology consisted in monitoring several rock blasting, carried out in this mining complex, varying explosive charge ratio. Products of those rock blasting were monitored until they entered the processing plant. During ore processing in plant´s ball mills, electrical variables were collected and analyzed, comparing to a baseline generated before the beginning of this research. All data were analyzed to show influence of explosive charge ratio increase on energy performance of the milling operation. In parallel, operational issues and difficulties in field measurements of energy consumptions were described, as well as the necessary infrastructure that allows the variable electricity to be adequately monitored. Besides, the methodology and results of CO2 emissions reduction from energy savings of all fieldwork were discussed. The research data shows that even with a significant increase in compact feed (higher Work Index), total energy consumption of mill operation did not increase. This scenario generate a potential specific energy savings and consequent reduction in CO2 emissions in the atmosphere. In addition, enables more compact material to be processed in the same process lines. This behavior suggests that a better energy spent on rock blasting can positively affect productivity and ore production costs along its production chain.
20

Energia nas operações de desmonte de rocha e suas influências na moagem de minérios

Carlos, Marcelo Ribeiro January 2017 (has links)
Energia é um insumo estratégico na mineração, pois é fundamental na viabilidade das operações mineiras e importante na manutenção de custos operacionais baixos e competitivos. Por esse motivo, toda iniciativa que visa a busca por eficiência no consumo de energia é importante para a competitividade das mineradoras. Vários insumos energéticos são utilizados nas operações unitárias de mineração. Os exemplos mais comuns são diesel, eletricidade, gás natural, carvão e explosivos. O objetivo desse trabalho é estudar, do ponto de vista energético, as atividades realizadas no processo de desmonte de rochas, em um complexo minerador de minério de ferro, visando a melhor utilização da energia no desmonte de rocha para aperfeiçoar as operações unitárias subsequentes de processamento de minérios. Um foco maior foi dado à economia de energia nas moagens de bolas da planta de beneficiamento e concentração, provocada pelas modificações e melhorias realizadas no desmonte de rocha. A metodologia consistiu na análise de diversos desmontes de rocha variando a razão de carga de explosivos no complexo minerador alvo desse trabalho. Os produtos desses desmontes foram acompanhados até a sua entrada na planta de beneficiamento. Durante o processamento desses materiais nas moagens da planta, foram coletadas e analisadas as grandezas elétricas resultantes e comparadas com uma linha de base gerada antes do início do trabalho. Os dados foram analisados com o objetivo de visualizar a influência do aumento da razão de carga na performance energética da operação de moagem. Em paralelo, também, foram analisadas as situações operacionais e dificuldades existentes nas medições de campo e nos acompanhamentos de consumos energéticos dos processos unitários, assim como a infraestrutura necessária para que uma variável tão importante como energia elétrica possa ser monitorada de forma adequada. Por fim, foi abordada a importância, a metodologia e os resultados da redução de emissões de CO2 provenientes da economia de energia de todo o trabalho realizado em campo. Os resultados apresentados mostram que mesmo com um aumento significativo da alimentação de material compacto (maior WI) nas moagens, o consumo energético total dessa operação unitária não aumentou. Isso gerou uma potencial economia específica de energia e a consequente redução de emissões de CO2 na atmosfera, além de viabilizar o processamento de material mais compacto nas mesmas linhas de processo. Esse comportamento sugere que uma melhor energia gasta no desmonte de rocha pode impactar positivamente na produtividade e nos custos de produção do minério ao longo de sua cadeia produtiva. / Energy is a mining strategic source, critical in mining operations feasibility and important to maintain low operational costs in a competitive level. For this reason, any initiative aimed at searching for energy efficiency is important for mining companies’ competitiveness. Mining operations need several energy sources. Most common examples are diesel, electricity, natural gas, coal and explosives. This text aims to address, from an energy perspective, a study carried out in an iron ore mining complex, which had as main objective to reach a better rock blasting energy utilization to improve subsequent mining operations. A greater focus was given to energy savings in ball mills operations of a beneficiation and concentration plant, impacted by modifications and improvements made in rock blasting. Methodology consisted in monitoring several rock blasting, carried out in this mining complex, varying explosive charge ratio. Products of those rock blasting were monitored until they entered the processing plant. During ore processing in plant´s ball mills, electrical variables were collected and analyzed, comparing to a baseline generated before the beginning of this research. All data were analyzed to show influence of explosive charge ratio increase on energy performance of the milling operation. In parallel, operational issues and difficulties in field measurements of energy consumptions were described, as well as the necessary infrastructure that allows the variable electricity to be adequately monitored. Besides, the methodology and results of CO2 emissions reduction from energy savings of all fieldwork were discussed. The research data shows that even with a significant increase in compact feed (higher Work Index), total energy consumption of mill operation did not increase. This scenario generate a potential specific energy savings and consequent reduction in CO2 emissions in the atmosphere. In addition, enables more compact material to be processed in the same process lines. This behavior suggests that a better energy spent on rock blasting can positively affect productivity and ore production costs along its production chain.

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