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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.
81

A new perspective on the U.S. energy efficiency: The political context

Antunes, J.J.M., Neves, J.C., Elmor, L.R.C., Araujo, M.F.R.D., Wanke, P.F., Tan, Yong 24 March 2023 (has links)
Yes / This paper offers a new perspective on the energy efficiency literature by bringing evidence of political contextual factors as the predictors of energy efficiency. Specifically, we posit that the Democrat administration is more energy-efficient considering the reduction of environmental impact, in contrast, the Republican administration is more efficient considering only financial expenditures leading to the production of economic growth. In addition, we predict that political administration tenure is negatively correlated with green energy efficiency and that political distancing moderates the relationship between political party administration and energy efficiency. This study sheds light on these matters by performing an efficiency analysis of fifty North American states through a bootstrap DEA non-parametric model, followed by Tobit regressions to evaluate our hypotheses concerning the effect of the contextual factors on the calculated efficiency scores. / This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
82

Identification of energetically efficient mature cows and characterization of biological differences between efficient and inefficient cows / Identificação de vacas energeticamente eficientes e caracterização de diferenças biológicas entre vacas eficientes e ineficientes

Reis, Bárbara Roqueto dos 11 January 2019 (has links)
Beef cows classified as efficient utilize less resources to achieve the same output than inefficient animals in a sustainable environment. The objective of this study was to utilize a mathematical model to identify beef cows that use energy more efficiently to support maintenance requirements and calf growth based an energy efficiency index (EEI). The EEI was computed as the ratio of metabolizable energy requirements (MER) of the cow to weaning weight of the calf. Data were collected from one herd of 69 Angus crossbred cows over two consecutive years for a performance experiment. The EEI was used to rank the cows for efficiency, cows with low EEI are more efficient because they require less metabolizable energy for the same calf weaning weight. After the cows were ranked in year 1, low (n=8) and high (n=8) EEI cows were selected for an energy metabolism experiment during late lactation and late gestation in year 2. Relationships among performance and efficiency traits were computed with PROC CORR of SAS. Metabolism experiment data were analyzed as a randomized complete block design using PROC MIXED of SAS with side of barn as the random blocking factor. Correlation coefficients were considered different from zero and LSmeans were considered different at P < 0.05. The EEI was strongly negatively correlated (P < 0.05) with model predicted peak milk and calf weaning weight, and moderately, positively correlated (P < 0.05) with cow body weight in both years such that more efficient cows weaned heavier calves and had lesser body weight. Energy efficiency index was moderately, positively correlated (P < 0.05) among years indicating that those cows ranked as efficient in one year tend to be more efficient cows in subsequent years. Low EEI cows had lesser (P < 0.05) dry matter digestibility during late lactation, but not during late gestation than high EEI cows. There were no differences in energy metabolism between low and high EEI cows during late lactation or late gestation. In conclusion, more efficient cows based on EEI wean heavier calves and require less energy but the mechanism by which low EEI cows are more efficient does not appear to be differences in the energy partitioning. / Vacas de corte classificadas como eficientes utilizam menos recursos para obter o mesmo resultados que animais ineficientes em um ambiente sustentável. O objetivo do presente estudo foi a utilização de um modelo matemático para identificar vacas de corte que utilizam energia de forma mais eficiente para suportar sua exigência de mantença e a exigência de crescimento do bezerro baseado no índice de eficiência energética (IEE). O Índice de eficiência energética foi computado como a relação entre a exigência de mantença da vaca e o peso do bezerro ao desmame. Foram utilizadas 69 vacas cruzadas da raça Angus durante dois anos consecutivos para um experimento de desempenho. As vacas foram ranqueadas pelo IEE, vacas com menor IEE são mais eficientes, pois necessitam de menos energia metabolizável para o mesmo peso ao desmame de bezerros. Após os animais serem ranqueadas por eficiência no ano 1, vacas com baixo (n=8) e alto (n=8) EEI foram selecionas para um experimento de metabolismo energético durante o fim da lactação e fim da gestação no segundo ano. Foi utilizado o PROC CORR do SAS para as análises de desempenho e eficiência. As interpretações dos resultados do experimento de metabolismo foram realizadas utilizando o PROC MIXED do SAS sendo o lado da baia como efeito aleatório do bloco. Os coeficientes de correlação foram considerados diferente de zero e a medias foram consideradas diferentes quando P<0.05. O índice de eficiência energética foi negativamente correlacionado (P<0.05) com o pico de leite predito pelo modelo e com o peso do bezerro ao desmame, e teve o correlação positiva moderada (P<0.05) com o peso corporal das vacas nos dois anos de estudo, vacas mais eficientes desmamaram bezerros mais pesados e possuem menor peso corporal. Entre os anos, EEI apresentou uma correlação positiva moderada (P<0.05) indicando que as vacas consideradas eficientes tendem a ser eficientes nos próximos anos. Vacas com baixo IEE apresentaram (P<0.05) menor digestibilidade da matéria seca durante o fim da lactação em relação as vacas com alto IEE, porém, não apresentaram diferenças durante o fim da gestação. Vacas com baixo e alto IEE não apresentaram diferença estatística em relação ao metabolismo energético durante o fim da gestação e lactação. Como conclusão, vacas eficientes baseada no IEE desmamam bezerros mais pesados e necessitam de menor quantidade de energia, entretanto, o mecanismo pelo qual vacas com menor IEE se apresentam mais eficientes não se apresenta relacionado com as diferenças no particionamento de energia.
83

Kartläggning och utvärdering av svenska energinätverk : Företagsnätverk och samarbeten inriktade på energi / Identification and evaluation of Swedish energy efficiency networks : Company networks and collaboration focused on energy

Broberg, Nicklas January 2014 (has links)
Industrins energianvändning medför koldioxidutsläpp som bidrar till klimatförändringar. Inom EU och Sverige eftersträvas en konkurrenskraftig industri. För att uppnå båda delarna förespråkas det att företag energieffektiviserar och minskar sin energianvändning. Trots att energieffektivisering ofta är kostnadseffektivt existerar det ändå ett energieffektiviseringsgap där kostnadseffektiva åtgärder inte implementeras av olika anledningar. Energinätverk kan då vara ett potentiellt arbetssätt som medför energieffektivisering och bidrar till företagsutveckling. I EU och Sverige ges redan finansiellt stöd som kan medföra att energinätverk bildas för såväl små och medelstora företag som för stora företag. Det existerar otaliga projektvarianter på energinätverk med olika uppbyggnad och utförande. Kunskapen om dessa nätverk inriktade mot energieffektivisering och energianvändning är begränsad. Arbetets syfte är därför att kartlägga svenska energinätverk för att kunna avgöra om de fungerar väl genom att utvärdera dem från ett samhällsperspektiv. För att identifiera energinätverk skedde insamling av dokument och intervjuer där slumpmässiga val tilläts i form av snöbollsmetoden. En bakomliggande förstudie har också genomförts där 8 energinätverk identifierats, vilka integrerats som en del i arbetets kartläggning. Sammantaget resulterade det i att identifiera 35 nätverksprojekt som kan bestå av enstaka nätverk, flera nätverk eller utgöra etapper för ett enskilt nätverk. De identifierade energinätverken är indelade efter större nätverk samt övriga nätverk som delats in i fyra generella nätverksformer: kluster, industridistrikt, regionala strategiska nätverk och strategiska nätverk samt alternativa nätverksformer för nätverk som inte kunde placeras in. En utvärdering har utförts med hjälp av programteori på det bakomliggande styrmedlet ”Ansökan om stöd till informations-, utbildnings- och samverkansprojekt 2013-2014” där det framkom att stödet tillåter en rad olika energinätverk och kan egentligen inte ses som särskilt styrande när det gäller utformning och genomförande av ett energinätverk. Vidare rekommenderas det att en separering görs för samverkansprojekt i form av energinätverk då det kan medföra mer riktade och konkreta energinätverk med tydligare mål och uppföljning. Detta tillåter fortfarande en variation på nätverkens uppbyggnad. Energinätverk med ett effektivt informations- och kunskapsutbyte har potentialen att medföra en innovativ företagsutveckling. Energinätverk utan en offentlig finansiering verkar inte initieras i Sverige. Avsiktsförklaringar eller avtal i de strategiska nätverken tros leda till att konkreta resultat har redovisats för nätverksprojekten i större grad än för de regionala strategiska nätverken. För de större energinätverken rekommenderas en fortsatt branschinriktning eftersom deras energianvändning är mer komplicerad att kartlägga. De övriga energinätverken bör istället prioritera intresserade deltagare som har möjlighet att träffas och sedan branschanpassa om möjligt. Detta då flera nätverksprojekt har vittnat om problem med nätverksbildandet som går ut över projektets genomförande. Vidare framstår skapandet av effektiva energinätverk som en mognadsprocess där flera bakomliggande projekt kan vara en anledning till ett kartlagt nätverksprojekt. Slutligen behövs det forskning på hur deltagande företag ser på energinätverk som ett stödjande och utvecklande styrmedel. / The industrial energy use causes carbon emissions that contribute to climate change. Simultaneously within EU and Sweden a competitive industry is pursued. In the aim to achieve both aspects energy efficiency and a reduced energy use is advocated for companies. Although energy efficiency often is cost-effective there exists an energy efficiency gap where cost-effective measures remain unimplemented for different reasons. Energy efficiency networks can in this case be a potential approach for increasing the degree of implementation, resulting in energy efficiency and company development. Financial support is already given from EU and Sweden that could lead to energy efficiency networks, for both small and medium-sized enterprises as well as for large enterprises. There exist numerous projects variations in energy efficiency networks with different structures and designs. The knowledge of these networks aimed towards energy efficiency and energy use is very limited. The aim of this work is therefore to identify Swedish energy efficiency networks in order to determine whether they work well by evaluating them from a public perspective. To identify energy efficiency networks documents where collected and interviews were held in which random selection was allowed in the form of snowball method. An underlying study has previously been carried out in which a number of networks was identified, which are integrated as a part of the work identification. Overall, this resulted in the identification of 35 different networks projects, which may consist of a single network, multiple networks or stages of a single network. The identified energy networks are divided by larger networks and other networks that have been split into four general networks forms cluster, industrial districts, regional strategic networks and strategic networks as well as alternative network forms for the networks that could not be associated. An evaluation has been performed on the underlying policy instrument “Application for financial support to information, education and collaborative projects 2013-2014” which stated that the support allows a wide range of energy efficiency networks and cannot be seen as a particular ruling in the design and implementation of an energy efficiency network. Furthermore it is recommended that a separation is made for collaborative projects in the form of energy efficiency networks in the support system since it would likely lead to more target and specific energy efficiency networks with clearer objectives and follow up. This would still allow a very large variety of network constructions. Energy efficiency networks with an efficient information and knowledge sharing has the potential to make enterprises more innovative. However, energy efficiency networks without an initial public financing does not seem to be initialized spontaneously in Sweden. Letters of intent or agreements in the strategic networks are believed to lead into reports with concrete results unlike for the regional strategic networks with no agreements. For the larger energy efficiency networks there is a point with being branch-specific because their energy use is more complex to audit. The other energy efficiency networks should instead find interested participants primarily. In combination with this, the participants should have the opportunity to meet and later on branch adapt if possible. This is because several network projects have stated problems with network formation that affects the projects. Furthermore, it appears that the creation of an efficient energy efficiency network sometimes is a maturation process in which several underlying projects can be a reason for an identified network project. Finally, we need further research on how the participating enterprises see energy efficiency networks as a supporting and developmental instrument.
84

Métodos de gestão de projetos aplicados aos programas de eficiência energética da ANEEL / Project management methods applied to ANEEL's energy efficiency programs

Tiozo, Carla 21 August 2018 (has links)
Orientador: Gilberto De Martino Jannuzzi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-21T01:49:15Z (GMT). No. of bitstreams: 1 Tiozo_Carla_M.pdf: 11074971 bytes, checksum: 02c6575fdc28a40f6b4cabc39efa3f11 (MD5) Previous issue date: 2012 / Resumo: Com o objetivo de sinalizar a necessidade de uma gestão estruturada dos programas de eficiência energética e sugerir a utilização de métodos de gerenciamento de projetos para assegurar que a economia de energia ensejada realmente seja alcançada e a um custo viável, esta dissertação tem como objeto de estudo o Projeto Comunidade Eficiente VI realizado pela LIGHT S.A. no período de 2009 a 2011 em comunidades de baixo poder aquisitivo do estado do Rio de Janeiro. Utilizou-se uma pesquisa descritiva para (i) apresentar os principais instrumentos regulatórios aplicados pelo Governo Federal para delinear os programas de eficiência energética e (ii) elencar práticas de gerenciamento de projetos e uma pesquisa aplicada para analisar, num caráter ex-post facto, os processos utilizados para a realização do referido projeto. Após a análise dos dados, identificou-se oportunidades de melhorias e pontos de controle para aumentar o sucesso de entrega do serviço ou equipamento na primeira tentativa, cumprir os prazos estabelecidos no cronograma, melhorar a comunicação com os parceiros envolvidos e com os clientes, assegurar a destinação correta de geladeiras e lâmpadas recolhidas, entre outros. Diante desses resultados, com a finalidade de auxiliar no acompanhamento de projetos de eficiência energética indica-se nove indicadores e para facilitar a interpretação de um conjunto destes indicadores apresenta-se um modelo de cockpit básico / Abstract: In order to reinforce the need for a structured management of energy efficiency programs and to suggest the use of project management methods to ensure that the planned energy savings can be achieved at a viable cost. The objective of this essay was to study the Efficient Community Project VI carried out by LIGHT S/A during the period of 2009-2011 in low-income communities in the Rio de Janeiro. A descriptive research was used to (i) present the main regulatory instruments applied by the Federal Government to outline the energy efficiency programs and (ii) categorize the project management methods and applied research to analyze, in an ex-post facto character, the processes employed for the fulfillment of the referred project. After analyzing the results, several improvement opportunities and control points were identified to (a) increase the success of delivery of service or equipment on the first attempt; (b) meet the deadlines set out in schedule; (c) improve communication with partners and customers; (d) ensure the correct disposal of refrigerators and light bulbs collected, among others. Based on these results, nine indicators were identified in order to assist in the monitoring of energy efficiency projects. A basic model cockpit is presented to facilitate the interpretation of a set of these indicators / Mestrado / Planejamento de Sistemas Energeticos / Mestra em Planejamento de Sistemas Energéticos
85

Energy efficiency : the regulatory framework for SADC and South Africa / Rachel Lekunze Kungwe

Angwe, Rachel Lekunze January 2014 (has links)
Energy is the main driving force behind all human activities. Energy use is blamed for its contribution to greenhouse gas, environmental degradation among others. Energy efficiency has been identified as an important tool to address these issues. Recognising the important role of energy efficiency, the Southern African Development Community (SADC) introduced policy measures to address energy efficiency at both regional and national levels. South Africa (a member state of SADC) followed by introducing policies, legislation, tax incentives and voluntary measures such as SANS standards and ISO 50001 to address energy use via energy efficiency. The aim of this study is to assess South Africa’s framework pertaining to energy efficiency and determine whether they correspond to the SADC energy frameworks. In this study, it is indicated that energy efficiency does not have a universally acceptable definition. SADC’s frameworks pertaining to energy efficiency are quite vague compared to South Africa’s policy framework. South Africa’s policies, legal frameworks and voluntary instruments correspond with the SADC frameworks and even go beyond these frameworks. It is recommended that SADC’s frameworks should specify measures of attaining energy efficiency within its mandated tools, urge member states to develop legislation as well as voluntary measures as means of attaining energy efficiency. The South African Minister of Energy on the other hand, should fulfil the mandate of the Electricity Regulation Act and the National Energy Act by enacting regulations pertaining to energy efficiency. Incentives for the introduction of voluntary energy efficiency measures should also be developed. / LLM (Environmental law and governance), North-West University, Potchefstroom Campus, 2015
86

Energy efficiency : the regulatory framework for SADC and South Africa / Rachel Lekunze Kungwe

Angwe, Rachel Lekunze January 2014 (has links)
Energy is the main driving force behind all human activities. Energy use is blamed for its contribution to greenhouse gas, environmental degradation among others. Energy efficiency has been identified as an important tool to address these issues. Recognising the important role of energy efficiency, the Southern African Development Community (SADC) introduced policy measures to address energy efficiency at both regional and national levels. South Africa (a member state of SADC) followed by introducing policies, legislation, tax incentives and voluntary measures such as SANS standards and ISO 50001 to address energy use via energy efficiency. The aim of this study is to assess South Africa’s framework pertaining to energy efficiency and determine whether they correspond to the SADC energy frameworks. In this study, it is indicated that energy efficiency does not have a universally acceptable definition. SADC’s frameworks pertaining to energy efficiency are quite vague compared to South Africa’s policy framework. South Africa’s policies, legal frameworks and voluntary instruments correspond with the SADC frameworks and even go beyond these frameworks. It is recommended that SADC’s frameworks should specify measures of attaining energy efficiency within its mandated tools, urge member states to develop legislation as well as voluntary measures as means of attaining energy efficiency. The South African Minister of Energy on the other hand, should fulfil the mandate of the Electricity Regulation Act and the National Energy Act by enacting regulations pertaining to energy efficiency. Incentives for the introduction of voluntary energy efficiency measures should also be developed. / LLM (Environmental law and governance), North-West University, Potchefstroom Campus, 2015
87

Three essays on energy efficiency and environmental policies in Canada

Gamtessa, Samuel Faye Unknown Date
No description available.
88

Activating Community to Enable Residential Energy Efficiency

Roswell, David 16 December 2013 (has links)
No description available.
89

Energy Aware Management of 5G Networks

Liu, Chang January 1900 (has links)
Doctor of Philosophy / Department of Electrical and Computer Engineering / Balasubramaniam Natarajan / The number of wireless devices is predicted to skyrocket from about 5 billion in 2015 to 25 billion by 2020. Therefore, traffic volume demand is envisioned to explode in the very near future. The proposed fifth generation (5G) of mobile networks is expected to be a mixture of network components with different sizes, transmit powers, back-haul connections and radio access technologies. While there are many interesting problems within the 5G framework, we address the challenges of energy-related management in a heterogeneous 5G networks. Based on the 5G architecture, in this dissertation, we present some fundamental methodologies to analyze and improve the energy efficiency of 5G network components using mathematical tools from optimization, control theory and stochastic geometry. Specifically, the main contributions of this research include: • We design power-saving modes in small cells to maximize energy efficiency. We first derive performance metrics for heterogeneous cellular networks with sleep modes based on stochastic geometry. Then we quantify the energy efficiency and maximize it with quality-of-service constraint based on an analytical model. We also develop a simple sleep strategy to further improve the energy efficiency according to traffic conditions. • We conduct a techno-economic analysis of heterogeneous cellular networks powered by both on-grid electricity and renewable energy. We propose a scheme to minimize the electricity cost based on a real-time pricing model. • We provide a framework to uncover desirable system design parameters that offer the best gains in terms of ergodic capacity and average achievable throughput for device-to-device underlay cellular networks. We also suggest a two-phase scheme to optimize the ergodic capacity while minimizing the total power consumption. • We investigate the modeling and analysis of simultaneous information and energy transfer in Internet of things and evaluate both transmission outage probability and power outage probability. Then we try to balance the trade-off between the outage performances by careful design of the power splitting ratio. This research provides valuable insights related to the trade-offs between energy-conservation and system performance in 5G networks. Theoretical and simulation results help verify the performance of the proposed algorithms.
90

Energy-efficient design in wireless communications networks

Xiong, Cong 27 August 2014 (has links)
The widespread application of wireless services and the requirements of ubiquitous access have recently triggered rapidly booming energy consumption in wireless communications networks. Such escalation of energy consumption in wireless networks causes high operational expenditure from electricity bills for operators, unsatisfactory user experience due to limited battery capacity of wireless devices, and a large amount of greenhouse gas emission. Green radio (GR), which emphasizes both energy efficiency (EE) and spectral efficiency (SE), has been proposed as an effective solution and is becoming the mainstream for future wireless network design. Unfortunately, EE and SE do not always coincide and may even sometimes conflict. In this dissertation, we focus on energy-efficient transmission and resource allocation techniques for orthogonal frequency division multiple access (OFDMA) networks and the joint energy-efficient design of OFDMA and other promising wireless communications techniques, such as cognitive radio (CR) and two-way relay. Firstly, we investigate the principles of energy-efficient design for pure OFDMA networks. As the first step, we study the fundamental interrelationship between EE and SE in downlink OFDMA networks and analyze the impacts of channel gain and circuit power on the EE-SE relationship. We establish a general EE-SE optimization framework, where the overall EE, SE and per-user quality-of-service (QoS) are all considered. Under this framework, we find that EE is quasiconcave in SE and decreases with SE when SE is large enough. These findings are very helpful guidelines for designing energy- and spectral-efficient OFDMA. To facilitate the application of energy-efficient resource allocation, we then investigate the energy-efficient resource allocation in both downlink and uplink OFDMA networks. For the downlink transmission, the generalized EE is maximized while for the uplink case the minimum individual EE is maximized, both under prescribed per-user minimum data rate requirements. For both transmission scenarios, we first provide the optimal solution and then develop an computationally efficient suboptimal approach by exploring the inherent structure and property of the energy-efficient design. Then we study energy-efficient design in downlink OFDMA networks with effective capacity-based delay provisioning for delay-sensitive traffic. By integrating information theory with the concept of effective capacity, we formulate and solve an EE optimization problem with statistical delay provisioning. We also analyze the tradeoff between EE and delay, the relationship between spectral-efficient and energy-efficient designs, and the impact of system parameters, including circuit power and delay exponents, on the overall performance. Secondly, we consider joint energy-efficient design of OFDMA and CR and two-way relay, respectively, to further enhance the EE and SE of wireless networks. We study energy-efficient opportunistic spectrum access strategies for an OFDMA-based CR network with multiple secondary users (SUs). Both worst EE and average EE of the SUs are considered and optimized subject to constraints including maximum transmit power and maximum interference to primary user (PU) system. For both cases, we first find the optimal solution and then propose a low-complexity suboptimal alternative. The results show that the energy-efficient CR strategies significantly boost EE compared with the conventional spectral-efficient CR ones while the low-complexity suboptimal approaches can well balance the performance and complexity. Then we study energy-efficient resource allocation for OFDMA-based two-way relay, which aims at maximizing the aggregated EE utility while provisioning proportional fairness in EE among different terminal pairs. Different from most exist energy-efficient design, we consider a new circuit power model, where the dynamic circuit power is proportional to the number of active subcarrier. For low-complexity solution, we propose an EE-oriented sequential subchannel assignment policy and discover the sufficient condition for early termination of the sequential subchannel assignment without losing the EE optimality. It is found that the energy-efficient transmission does not necessarily make all the subcarriers active, which is another useful principle for practical energy-efficient system design.

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