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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.
21

Router Power Reduction through Dynamic Performance Control Based on Traffic Predictions

SATO, Ken-ichi, HASEGAWA, Hiroshi, ITO, Hiroyuki 10 1900 (has links)
No description available.
22

Energy Efficiency of the HVAC System of a Power Plant

Opara, Chigozie Ethelvivian 01 August 2015 (has links)
This study models the HVAC system of a power plant. It involved Computer simulations to study the energy demand by the HVAC system of the power plant as well as the energy demand of the system with modifications on the plant such as the building materials, use of energy efficient lighting, etc. Further studies on the energy demand of the system with the power plant located at different regions of the country were done to understand the effects of climate and locations. It is important to have an understanding of how a plant generating energy uses it for Heating, Ventilating and Air conditioning within the power plant building itself. This study has provided a better understanding of the energy use and how the HVAC system use in the offices and other areas located in the power plant building operates. The study included implementation of energy efficient measures in the choice of building materials for the building. The U.S. Department of Energy (DOE) EnergyPlus program was used to model the HVAC system of the power plant making use of the parameters and modified parameters of the power plant. The results of this study show that the energy demand of the HVAC system of a power plant is significantly affected by the choice of materials for the building. It was found that there is a reduction in the power demand of the HVAC system of the plant by about an average of about 21.7 % at the different the locations. It was also found that this resulted in the amount of energy saved per year of about 87,600 kWh. This gives an average cost savings per year of about $10,512.
23

Gestão energética e ambiental de edificações : avaliação de metodologias para certificação /

Ruzene, Juliana Santos. January 2011 (has links)
Resumo: O sistema LEED (Leadership in Energy and Environmental Design) consiste numa metodologia para avaliar o desempenho energético e ambiental de edificações ao longo de seu ciclo de vida, tendo como objetivo direcionar ações para o conceito de edificações sustentáveis (green buildings) e fornecer uma padronização para medir a dimensão ambiental relativa dos projetos. No Brasil, a Eletrobrás, através do Programa Nacional de Conservação de Energia Elétrica (Procel) e em parceria com o Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (Inmetro), lançaram a Etiqueta Nacional de Eficiência Energética em Edificações (ENCE), para edifícios comerciais, de serviços e públicos, reconhecendo edificações que reduzam o consumo de energia elétrica e água. Neste trabalho foi realizado um estudo de certificação energética e ambiental de edificações, bem como a identificação de alternativas técnicas para o enquadramento em níveis mais adequados e correspondente estudo de viabilidade econômica. Como estudo de caso, o edifício da Fundação existente no Campus de Guaratinguetá da UNESP foi analisado de acordo com os preceitos da avaliação de desempenho de ambas as metodologias. Com base nos resultados obtidos, foram realizadas sugestões de tecnologias e modificações possíveis de serem implantadas / Abstract: The LEED system (Leadership in Energy and Environmental Design) is a methodology for evaluating the energetic and environmental performance of buildings throughout their life cycle, aiming to guide actions for the concept of green building and provide a standard for measuring the size on environmental projects. In Brazil, Eletrobras, through the National Program for Energy Conservation (PROCEL) and in partnership with the National Institute of Metrology, Standardization and Industrial Quality (Inmetro), launched the Label National Energy Efficiency in Buildings (ENCE), for commercial buildings, and public service, recognizing buildings that reduce the consumption of electricity and water. In this research report it was presented an environmental and energetic certification of buildings study, as well as the analysis of technical solutions for the framework in more appropriate levels, and corresponding economic feasibility study. As a case study, the Foundation's existing building on the campus of UNESP at Guaratinguetá was analyzed in accordance with the principles of performance evaluation of both approaches. Based on these results, suggestions were made of possible technologies and changes being implemented / Orientador: José Antonio Perrella Balestieri / Coorientador: Rubens Alves Dias / Banca: Luiz Roberto Carrocci / Banca: Ricardo Dias Martins de Carvalho / Mestre
24

Computer simulation of intelligent building facades

Wren, Duncan E. January 2000 (has links)
The economic and environmental benefits secured through the increased integration of photovoltaic (PV) technology into the built environment are undeniable and provide the principal motivation for this research. Present delays in the technology transfer of building integrated photovoltaics (BIPV) can be attributed to the following; material cost, performance guarantee, increased installation complexity and unfamiliar technology. It is well understood that the temperature of a PV material receiving solar irradiation, will increase with solar intensity, while reducing in electrical efficiency. It therefore makes economic sense to minimise the increase in PV material temperature and maximise electrical energy yield. Through the addition of a convecting fluid, flowing over the surface of heated PV material, heat transfer will be induced. With the added benefit of warm air capture from an integrated photovoltaic/thermal (PVT) collector, the economic benefits are increased. But, to ensure maximum utilisation of both thermal and electrical energy production, a significantly more complex control system has to be employed than that for a PV system on its own. Modelling the energy flows within a multifunctional PVT building facade presents a problem of considerable complexity. Previous work in this area has centred on performing finite element analysis of the system in order to find solutions to complex algorithms. It requires considerable computational power to perform these calculations and often the results produced are much more detailed than required. Within this thesis, a fully operational PVT facade model is presented, giving the potential for improved multifunctional facade design. This new model has been developed into a software program for use within the TRNSYS environment. By using the TRNSYS software, a detailed building model has been created and integrated with the new PVT facade model. Simulations were then undertaken to evaluate the energy transfers between internal and external environments and the electrical and thermal energy capturing capabilities of the facade. Simulated results have been evaluated against experimental data taken from a fully operational PVT facade. The results conclude that the presented model simulates the energy flows around, through and within the facade (radiative, conductive, convective and electrical) very well. Performance enhancing development work is due to take place on the operational facade analysed in this work, very soon. This new facade model will be used as a tool to evaluate the proposed changes to the building prior to this development work being undertaken.
25

An investigation into the drivers and barriers to energy efficiency within medium and large manufacturing firms operating within the eThekwini municipal area

Singh, Resham January 2017 (has links)
Preliminary investigations on energy efficiency of manufacturing firms operating in South Africa have shown that no previous study on the barriers and drivers to energy efficiency was conducted. It was also found that South Africa is the only member within the Brazilian, Russian, Indian, Chinese and South African (BRICS) community that has not conducted any formal study on the drivers and barriers to Energy efficiency despite the current energy challenges the country faces. Whilst the National Energy Efficiency Strategy (NEES) was developed and targets were set to improve the country’s efficiency landscape, this strategy failed to account for the barriers and drivers to energy efficiency operating within the local context. This research study sets out to investigate whether an energy efficiency gap exists within manufacturing firms operating in the eThekwini Municipal Area (EMA) and by inference, the national context. It goes on further to analyse the drivers and barriers to Energy Efficiency (EE) within such firms. Such drivers and barriers are then analysed by firm characteristics and across manufacturing sectors. The results are interesting and contribute well to the general body of knowledge on EE in South Africa. It was found that whilst there is a degree of adoption and awareness of EE technologies amongst manufacturing firms, the quality of the adoption profile is poor. This poor quality profile suggests the possibility of an energy efficiency gap. The barriers and drivers that were found to be significant were also found to be mostly similar across manufacturing sectors. A main finding is that firms are very sensitive to cost and are mainly driven to adopt EE technologies only where there exists an opportunity for cost savings. It was also found that taken together, institutional barriers pose the greatest hurdle to EE adoption. Several interesting results were found in terms of how the barriers and drivers vary with the characteristics of the firm. The findings of this research indicate that more can be achieved in terms of energy efficiency within the manufacturing subsectors in South Africa. Policy-makers should take into consideration the salient findings of this research when drafting new policy on energy efficiency. / Dissertation (MEng)--University of Pretoria, 2017. / Graduate School of Technology Management (GSTM) / MEng / Unrestricted
26

SUPPORTING APPROXIMATE COMPUTING ON COARSE GRAINED RE-CONFIGURABLE ARRAY ACCELERATORS

Dickerson, Jonathan 01 December 2019 (has links)
Recent research has shown approximate computing and Course-Grained Reconfigurable Arrays (GGRAs) are promising computing paradigms to reduce energy consumption in a compute intensive environment. CGRAs provide a promising middle ground between energy inefficient yet flexible Freely Programmable Gate Arrays (FPGAs) and energy efficient yet inflexible Application Specific Integrated Circuits (ASICs). With the integration of approximate computing in CGRAs, there is substantial gains in energy efficiency at the cost of arithmetic precision. However, some applications require a certain percent of accuracy in calculation to effectively perform its task. The ability to control the accuracy of approximate computing during run-time is an emerging topic.
27

An Experimental Study of the Electrodeposition of Lead

Roberts, Ira Clifford 06 1900 (has links)
This thesis aimed to study some of the general principles underlying electrodeposition together with experimental facts regarding the effects of changing constituents of the plating solutions, variations in hydrogen-ion concentrations, and variation in current density used in the electrodeposition of lead.
28

Analytical Framework to Study Energy Efficiency Policy Portfolios across Countries/States

Bhattacharjee, Suchismita 17 August 2010 (has links)
Energy conservation and implementation of effective energy efficiency policies have become imperative to curbing the escalating consumption of energy. The imbalance in the supply and demand of a country's energy has increased the importance of implementing energy efficiency policies. Proper replication of strategic energy efficiency policies that are known to be successful in one country, along with development of new approaches, can be helpful in developing the energy policy portfolio of another country. Some OECD (Organization of Economic Cooperation and Development) countries like Denmark, Finland, France, Germany, Italy, the United Kingdom and the United States have benefited from their energy policies during the most recent energy crisis. The motivation of this research is to provide a tool for developing countries, which are still in the stage of formulating their energy efficiency policies, to compare energy efficiency policy portfolios across countries. These countries can improve their energy efficiency policy portfolios based on lessons learned from the developed countries. The research develops a framework to compare energy efficiency policy portfolios across countries / states. Although this framework can be adopted for any type of energy policy, targeting any sector with few modifications, the current focus is on policies that target the residential building sector to reduce energy consumption. The research begins with identification of the functional domains that influence human behavior–people, economy, environment and technology–followed by identification of the factors affecting household energy consumption. It uses the four functional domains as the evaluation framework's four axes. The various factors affecting household energy consumption are positioned in the framework based on association with the functional domains. The energy efficiency policies implemented in a country are positioned in the same framework based on the pattern of diffusion of each type of policy. In addition, a prototype method is developed to identify the factors targeted by each energy efficiency policy implemented in a country. This evaluation method allows for a uniform assessment process of how energy efficiency policies target specific socio-economic factors that are known to affect energy consumption. The proposed framework will facilitate the work of policy makers and other decision makers with a powerful tool for evaluating and comparing their individual policies, or their complete portfolio of energy efficiency policies, to those from other states or countries, and to benefit from the lessons learned. / Ph. D.
29

The Non-Energy Benefits of Industrial Energy Efficiency : Investments and Measures

Nehler, Therese January 2016 (has links)
Improved industrial energy efficiency is viewed as an important means in the reduction of CO2 emissions and climate change mitigation. Various energy efficiency measures for improving energy efficiency exists, but even evaluated as cost-effective, there seems to be a difference between the energy efficiency measures that theoretically could be undertaken and which measures that actually are realised. On the other hand, industrial energy efficiency measures might yield extra effects, denoted as non-energy benefits, beyond the actual energy savings or energy cost savings. Based on interviews and a questionnaire, results showed that the Swedish industrial firms studied had observed various non-energy benefits. However, few of the non-energy benefits observed were translated into monetary values and included in investment calculations. Results indicated that this non-inclusion could be explained by lack on information on how to measure and monetise the benefits, but even if not translated into monetary values, some of the non-energy benefits were sometimes used qualitatively in investment decisions. The utilisation of the benefits seemed to depend on the type and the level of quantifiability among the perceived benefits. This thesis has also explored energy efficiency measures and non-energy benefits for a specific industrial energy-using process – compressed air. A literature review on energy efficiency in relation to compressed air systems revealed a large variation in which measures that could be undertaken to improve energy efficiency. However, few publications applied a comprehensive perspective including the entire compressed air system. Few non-energy benefits of specific energy efficiency measures for compressed air systems were identified, but the study provided insights into how non-energy benefits should be studied. This thesis suggests that energy efficiency and non-energy benefits in compressed air systems should be studied on specific measure level to enable the observation of their effects. However, the studies also addressed the importance of having a systems perspective; the whole system should be regarded to understand the effects of energy efficiency measures and related non-energy benefits.
30

A game theoretic approach to improve energy efficiency of wireless sensor nodes / Willem Christoffel Petzer

Petzer, Willem Christoffel January 2015 (has links)
Wireless sensor networks (WSNs) are becoming increasingly pervasive in a number of applications. Due to the nature of WSNs, one of their biggest constraints is limited node energy. As WSNs grow in popularity, the prevalent issue remains to keep wireless sensor nodes alive for as long as possible, or risk disrupting the network. This dissertation develops a model based on the principles of game theory to improve the energy efficiency of wireless sensor nodes and increase the network lifetime by influencing the way routing takes place. The benefit of this model is a routing algorithm that is easily implementable and increases network lifetime by improving energy efficiency in the network. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015

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