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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.
51

Nízkoenergetické stavby ako zdroj úspory energie / Low-energy buildings as a source of energy savings

Smoleňová, Daniela January 2009 (has links)
The issue of low energy construction is currently actual and often discussed topic. The main reason is continuously increasing consumption and price of energy. Additionally, projections show this trend is not going to rapidly change in the upcoming years. The construction of buildings in low energy standard should become one of the most significant sources in energy savings in European Union for the upcoming period. Low energy constructions in contrast with standard constructions are distinguished not only because of low energy consumption and lower operating expenses but also for its favorable impact on the environment. The main purpose of this thesis will be the assessment of economical effectiveness of current low energy constructions and underline the importance of energy saving constructions by using LCA method as one of the possibilities in increasing the quality of environment.
52

Desenvolvimento do processo de biopolpação de eucalipto em escala piloto para produção de polpas termomecânicas e quimiotermomecânicas / Development of the eucaliptus biopulping process in a pilot scale to produce thermomechanical and chemithermomechanical pulps

Pavan, Paulo César 11 August 2008 (has links)
Na escala evolutiva dos processos de polpação de alto rendimento (PAR), a mais recente promessa é a biopolpação, ou seja, o pré-tratamento microbiológico do cavaco de madeira utilizado na polpação. Esse pré-tratamento tem o potencial de reduzir o consumo de energia necessária ao refino em até 38%, e ainda, ou consequentemente, melhorar importantes propriedades mecânicas deficientes nas PAR, como rasgo, estouro, e tração. Enorme atenção foi dispensada ao assunto nos últimos 20 anos com importantes avanços na compreensão dos mecanismos envolvidos, e ainda, com a condução de testes em escala piloto (50 ton de cavacos) por inoculação direta do fungo. Entretanto, esses testes foram conduzidos e se mostraram eficazes num clima temperado, com madeira típica da América do Norte. O presente trabalho detalha o desenvolvimento, implantação e operação de uma planta piloto para biotratamento de cavacos (inoculação e incubação) de Eucalyptus grandis, usados num processo de escala industrial de polpação termimecânica (TMP) e quimiotermomecânico (CTMP). Também estão detalhados nessa tese os esforços para se alcançar a eficácia desejada desse biotratamento. Vários testes em diferentes escalas - incluindo 40-50 ton - foram conduzidos em diferentes épocas do ano, sob as condições normalmente encontradas nos pátios de cavacos da indústria de celulose. Diferentes fungos (Ceriporiopsis subvermispora e Phanerochaete chrysosporium) e sistemas de inoculação (inoculação por aspersão e inoculação por semente) foram testados, e o escalonamento de um processo anteriormente factível apenas em nível laboratorial foi desenvolvido. Os resultados mostram que os sistemas de inoculação de C. subvermispora por aspersão com micélio suspenso em água e um auxiliar de crescimento foram sujeitos à contaminação dos cultivos por bolores primários, de ocorrência natural no ambiente de pátios de cavacos de indústrias de celulose. Por outro lado, o sistema de inoculação com cavacos pré-cultivados (inoculação por semente) mostrou-se eficaz na escala piloto, pois não esteve sujeito a ocorrência de contaminantes durante a incubação dos cavacos. Esse sistema de inoculação gerou resultados condizentes com a literatura em termos de economia de energia de refino que foram de 18% e 27% nos processos TMP e CTMP, respectivamente. No caso da inoculação por aspersão com P. chrysosporium, os cultivos não apresentaram contaminação por bolores primários, provavelmente devido à temperatura de incubação que nesse caso foi de 38 oC. Nesse experimento foi possível reduzir o consumo de energia em 18,5% no processo CTMP. Uma avaliação da viabilidade financeira do processo é apresentada e simulações de benefícios econômicos foram feitas para diferentes cenários de custo de energia elétrica e níveis de redução no consumo de energia. As simulações mostraram que benefícios econômicos da ordem de R$10/ton de polpa produzida podem ser obtidos para uma redução no consumo de energia da ordem de 20% advinda do biotratamento. Embora esperados, ganhos de propriedades mecânicas das biopolpas quando comparadas às polpas convencionais não foram observados, fato que limitou a extensão da análise econômica de considerar um processo integrado com máquina de papel na substituição de polpa kraft por polpas bio-CTMP ou bio-TMP. / In the evolution of the high yield pulping processes (HYP) biopulping have been considered the latest promise. Biopulping, defined as the microbiological pretreatment of wood chips prior to the pulping process, have the potential to reduce the refining energy consumption in 38%. Besides this benefit, or consequently, it can also enhance important mechanical properties usually poor in HYP pulps like tear, burst and tensile strength. Considerable efforts have been deposited in this issue during the last 20 years with important advances on understanding the involved mechanisms. Between these efforts trials were conducted in a pilot scale (50 ton of wood chips) by the direct spraying of the fungus. However such successful tests were conducted in a region of temperate climate, with a wood typically found in North America. The present work details the development, installation and operation of a pilot plant to biotreat (inoculation and incubation) Eucalyptus grandis wood chips used in an industrial thermomechanical (TMP) and chemithermomechanical (CTMP) mill. The efforts spent to reach the desired efficacy of this biotreatment are also presented. Several trials with different scales - including 40-50 ton trials - were conducted in different seasons, under the conditions normally found in woodyards of a tropical pulp mill. Different fungi (Ceriporiopsis subvermispora and Phanerochaete chrysosporium) and different inoculation systems (by direct spraying and by seed introduction) were tested, and one of them developed at the first time in this pilot scale. The results show that when C. subvermispora was used with the direct spraying systems of the mycelium suspended in water with corn steep liquor the pile was strongly contaminated by primary molds of natural occurrence at an industrial woodyard tropical environment. On the other hand, the inoculation using pre-cultivated wood chips (seed system) was successfully conducted in pilot scale since it does not showed expressive contamination during the incubation period. The refining of the wood chips prepared by seed inoculation resulted in energy savings of 18% and 27% for the TMP and CTMP processes, respectively. By using the P. chrysosporium the pile was not contaminated by primary molds either, probably due to the higher incubation temperature, around 38 oC. The CTMP processing of the wood chips incubated in this experiment refining energy saving of 18.5% was observed. An economic evaluation of the biopulping process is presented and saving of R$10/ton was simulated for a 20% reduction in refining energy saving. The enhancement of the mechanical properties of the biopulp compared to the reference was not observed, regardless being expected. This fact limited the extension of the economical simulation, since the replacement of kraft pulp by bio-TMP or bio-CTMP is usually considered in an integrated paper mill.
53

Consumo de energia em dispositivos móveis Android: análise das estratégias de comunicação utilizadas em Computation Offloading / Energy consumption on Android mobile devices: communication strategies analysis used in Computation Offloading

Chamas, Carolina Luiza 14 December 2017 (has links)
Os dispositivos móveis passaram por grandes transformações na última década e tornaram-se complexos computadores dotados de grande poder de processamento e memória, além de prover aos usuários diversos recursos como sensores e câmeras de alta resolução. O uso de dispositivos móveis para diversas tarefas aumentou consideravelmente, o que levantou uma grande preocupação com o o alto consumo de energia desses dispositivos. Portanto, estudos tem sido realizados no sentido de encontrar soluções para diminuir o custo de energia das aplicações que executam em dispositivos móveis. Uma das alternativas mais utilizadas é o \\textit{computation offloading}, cujo objetivo é transferir a execução de uma tarefa para uma plataforma externa com o intuito de aumentar desempenho e reduzir consumo de recursos, como a bateria, por exemplo. Decidir sobre usar ou não esta técnica implica entender a influência de fatores como a quantidade de dados processados, a quantidade de computação envolvida, e o perfil da rede. Muitos estudos tem sido realizados para estudar a influência de diversas opções de rede wireless, como 3G, 4G e Wifi, mas nenhum estudo investigou a influência das escolhas de comunicação no custo de energia. Portanto, o objetivo deste trabalho é apresentar uma investigação sobre a influência da quantidade de dados, da quantidade de computação e dos protocolos de comunicação ou estilo arquitetural no consumo de energia quando a técnica de \\textit{computation offloading} é utilizada. Neste estudo, foram comparados REST, SOAP, Socket e RPC na execução de algoritmos de ordenação de diferentes complexidades aplicados sobre vetores de diversos tamanhos e tipos de dados. Os resultados mostram que a execução local é mais econômica com algoritmos menos complexos, pequeno tamanho de entrada e tipo de dados menos complexos. Quando se trata de execução remota, o REST é a escolha mais econômica seguida por Socket. Em geral, REST é mais econômico com vetores do tipo Object, independentemente da complexidade do algoritmo e tamanho do vetor, enquanto Socket é mais econômico com entradas maiores e com vetores de tipos primitivos, como Int e Float / Mobile devices have significantly changed in the last decade and they become complex computer machines equipped with large processing power and memory. Moreover, they provide users with several resources such as sensors and high resolution cameras. The usage of mobile devices has significantly increased in the past years, which raised an important concern regarding the high energy consumption. Therefore, several investigations have been conducted aiming at finding solutions to reduce the energy cost of mobile applications. One of the most used strategy is called computation offloading, whose main goal is to transfer the execution of a task to an external platform aiming at increasing performance and reducing resource consumption, including the battery. Deciding towards offloading certain tasks requires to understand the influence of the amount of data, amount of computation, and the network profile. Several studies have investigated the influence of different wireless flavours, such as 3G, 4G and wifi, but no study has investigated the influence of the communication choices on the energy cost. Therefore, the purpose of this research project is to present an investigation on the influence of the amount of data, amount of computation and the communication protocols and architectural style on the energy consumption in the context of the computation offloading technique. In this study, we compare REST, SOAP, Socket and RPC when executing algorithms of different complexities and different input sizes and types. Results show that local execution is more economic with less complex algorithms and small input data. When it comes to remote execution, REST is the most economic choice followed by Socket. In general, REST is the most economic choice when applied on Object type arrays, regardless the complexity and size, while Socket is the most economic choice with large arrays and primitive types such as integers and floats
54

Consumo de energia em dispositivos móveis Android: análise das estratégias de comunicação utilizadas em Computation Offloading / Energy consumption on Android mobile devices: communication strategies analysis used in Computation Offloading

Carolina Luiza Chamas 14 December 2017 (has links)
Os dispositivos móveis passaram por grandes transformações na última década e tornaram-se complexos computadores dotados de grande poder de processamento e memória, além de prover aos usuários diversos recursos como sensores e câmeras de alta resolução. O uso de dispositivos móveis para diversas tarefas aumentou consideravelmente, o que levantou uma grande preocupação com o o alto consumo de energia desses dispositivos. Portanto, estudos tem sido realizados no sentido de encontrar soluções para diminuir o custo de energia das aplicações que executam em dispositivos móveis. Uma das alternativas mais utilizadas é o \\textit{computation offloading}, cujo objetivo é transferir a execução de uma tarefa para uma plataforma externa com o intuito de aumentar desempenho e reduzir consumo de recursos, como a bateria, por exemplo. Decidir sobre usar ou não esta técnica implica entender a influência de fatores como a quantidade de dados processados, a quantidade de computação envolvida, e o perfil da rede. Muitos estudos tem sido realizados para estudar a influência de diversas opções de rede wireless, como 3G, 4G e Wifi, mas nenhum estudo investigou a influência das escolhas de comunicação no custo de energia. Portanto, o objetivo deste trabalho é apresentar uma investigação sobre a influência da quantidade de dados, da quantidade de computação e dos protocolos de comunicação ou estilo arquitetural no consumo de energia quando a técnica de \\textit{computation offloading} é utilizada. Neste estudo, foram comparados REST, SOAP, Socket e RPC na execução de algoritmos de ordenação de diferentes complexidades aplicados sobre vetores de diversos tamanhos e tipos de dados. Os resultados mostram que a execução local é mais econômica com algoritmos menos complexos, pequeno tamanho de entrada e tipo de dados menos complexos. Quando se trata de execução remota, o REST é a escolha mais econômica seguida por Socket. Em geral, REST é mais econômico com vetores do tipo Object, independentemente da complexidade do algoritmo e tamanho do vetor, enquanto Socket é mais econômico com entradas maiores e com vetores de tipos primitivos, como Int e Float / Mobile devices have significantly changed in the last decade and they become complex computer machines equipped with large processing power and memory. Moreover, they provide users with several resources such as sensors and high resolution cameras. The usage of mobile devices has significantly increased in the past years, which raised an important concern regarding the high energy consumption. Therefore, several investigations have been conducted aiming at finding solutions to reduce the energy cost of mobile applications. One of the most used strategy is called computation offloading, whose main goal is to transfer the execution of a task to an external platform aiming at increasing performance and reducing resource consumption, including the battery. Deciding towards offloading certain tasks requires to understand the influence of the amount of data, amount of computation, and the network profile. Several studies have investigated the influence of different wireless flavours, such as 3G, 4G and wifi, but no study has investigated the influence of the communication choices on the energy cost. Therefore, the purpose of this research project is to present an investigation on the influence of the amount of data, amount of computation and the communication protocols and architectural style on the energy consumption in the context of the computation offloading technique. In this study, we compare REST, SOAP, Socket and RPC when executing algorithms of different complexities and different input sizes and types. Results show that local execution is more economic with less complex algorithms and small input data. When it comes to remote execution, REST is the most economic choice followed by Socket. In general, REST is the most economic choice when applied on Object type arrays, regardless the complexity and size, while Socket is the most economic choice with large arrays and primitive types such as integers and floats
55

Modeling and optimization of wastewater treatment process with a data-driven approach

Wei, Xiupeng 01 May 2013 (has links)
The primary objective of this research is to model and optimize wastewater treatment process in a wastewater treatment plant (WWTP). As the treatment process is complex, its operations pose challenges. Traditional physics-based and mathematical- models have limitations in predicting the behavior of the wastewater process and optimization of its operations. Automated control and information technology enables continuous collection of data. The collected data contains process information allowing to predict and optimize the process. Although the data offered by the WWTP is plentiful, it has not been fully used to extract meaningful information to improve performance of the plant. A data-driven approach is promising in identifying useful patterns and models using algorithms versed in statistics and computational intelligence. Successful data-mining applications have been reported in business, manufacturing, science, and engineering. The focus of this research is to model and optimize the wastewater treatment process and ultimately improve efficiency of WWTPs. To maintain the effluent quality, the influent flow rate, the influent pollutants including the total suspended solids (TSS) and CBOD, are predicted in short-term and long-term to provide information to efficiently operate the treatment process. To reduce energy consumption and improve energy efficiency, the process of biogas production, activated sludge process and pumping station are modeled and optimized with evolutionary computation algorithms. Modeling and optimization of wastewater treatment processes faces three major challenges. The first one is related to the data. As wastewater treatment includes physical, chemical, and biological processes, and instruments collecting large volumes of data. Many variables in the dataset are strongly coupled. The data is noisy, uncertain, and incomplete. Therefore, several preprocessing algorithms should be used to preprocess the data, reduce its dimensionality, and determine import variables. The second challenge is in the temporal nature of the process. Different data-mining algorithms are used to obtain accurate models. The last challenge is the optimization of the process models. As the models are usually highly nonlinear and dynamic, novel evolutionary computational algorithms are used. This research addresses these three challenges. The major contribution of this research is in modeling and optimizing the wastewater treatment process with a data-driven approach. The process model built is then optimized with evolutionary computational algorithms to find the optimal solutions for improving process efficiency and reducing energy consumption.
56

Energy Saving Curtain : ENERGY INVENTORY AND CONSERVATION POSSIBILITIES

Zou, Fan January 2008 (has links)
<p>This paper presents the energy saving curtains, in order to make the</p><p>consumers be more aware of the energy efficiency of the energy saving</p><p>curtains, the paper gave related analysis and conclusions.</p><p>The work was performed by using the Parasol Program, developed by Lunds University, Sweden. The Program is used for quantifying the influence of window size, glass type, textile type, wall thermal insulation and sun shading on annual energy use and indoor thermal comfort. The results which are obtained from the calculations are applicable to similar climatic and environment conditions. Calculations were performed to investigate the potential for using sunshade devices to reduce annual energy demand for cooling and heating. Different materials and dimensions of the energy saving</p><p>curtain are used as variables in the analysis. The results indicated that for the current climatic conditions and other related factors, the total reduction rate of the annual energy consumption of office used buildings in Stockholm is estimated generally 20% -30% lower comparing to those buildings without energy saving curtain system. That means at least 20% of energy cost can be saved by the energy saving curtain system.</p>
57

Energy Audit and Accounting for Riksbyggen Fastighetsservice, Gävle

Liu, Yuanyuan, Shen, Yang January 2009 (has links)
<p>Riksbyggen Fastighetsservice is a company whose businesses cope with building construction and related services. The local office of Riksbyggen Fastighetsservice in Gävle has been studied in this project. The local office locates in Näringen 20:4, which was constructed in 1989.</p><p> </p><p>The aim of this project is to make a diagnosis of the current situation; find out the most applicable way of optimizing the operation of the facility in order to reduce the energy consumption, to study costs and possible savings and provide assistance with future energy management.   </p><p> </p><p>Firstly, a study of Energy Balance was conducted. The transmission losses was 57761 KWh; mechanical ventilation losses 3855 KWh; hot tap water heat losses 9579 KWh; natural transmission and infiltration 6897 KWh. On the other hand, heat gain from internal heat was 12707 KWh; solar radiation 8521 KWh; and supply heat 56806 KWh.</p><p> </p><p>Secondly, the energy costs have been checked out. 29655 KWh of electricity was consumed in 2008. 5948 KWh was used by 20 fuses electricity and 23707 KWh was for 25 fuses. Lighting, electrical equipment and machine composed the electricity consumption. Lighting consumes 13278 KWh; equipment consumes 6452 KWh; and machine consumes 9925 KWh. Lighting electricity was composed by office lighting and workshop lighting with 4798 KWh and 8480 KWh respectively.</p><p> </p><p>Electricity cost is very complicated and flexible in Sweden according to effect and consumption. The total cost of electricity consists of electricity commerce fee and electricity transmission net. Electricity commerce fee includes annual fixed fee, electricity fee, energy certificate and tax. Electricity transmission fee includes annual fixed transmission fee, grid fee and tax. Tax plays vital important role which results in huge total cost. The local office spent 43356 kr on electricity in 2008. 4798 kr was spent on office lighting, and 8480 kr was spent on workshop lighting.</p><p> </p><p>On the other hand district heating fee is composed by annual fixed fee, effect fee, energy fee and tax. The local office spent 37142 kr on 56.806 MWh of district heating in 2008. Thus, the local office purchased 86461 KWh of energies and spent 80498 kr in total in 2008.</p><p> </p><p>Thirdly, to assist its energy traces and management, three tables were designed. One table is for annual energy consumption and cost in each month with all information of sub-terms on costs. One table is for annual electricity consumption for each electrical equipment and cost in accordance. Another table is for district heating consumption and cost. </p><p> </p><p>At last, energy saving possibilities was explored. One way is applying improvements or maintenance of the office construction. The result of Energy Balance shows that transmission losses were 57761 KWh which occupies 74% of the total losses, and it is the biggest bite. As the office was constructed in 1989, if improvements and maintenance can be applied to the insulation of floor, roof and walls, or change the windows, the heat losses can be reduced.</p><p> </p><p>However, the other solution might be much more applicable and financial sound. Just go to Clas Ohlson to buy LED 1 W and 3 W lamps to replace the current bulbs. Spending 3009 kr to buy 51 LED incandescent bulbs of 1W effect, and 3576 kr on 24 LED fluorescent of 3W effect, will save 12057 kr every year. The lighting electricity consumption will be reduced from 13278 KWh / year to 264 KWh / year. Instead of spending 16017 kr on lighting, 98% will be reduced, and only 318 kr will be paid. Moreover, the payback is really nice, only 0.42 year. Action! The sooner the better! 20% of energy cost will be saved!</p>
58

Design and Development of an Intelligent Energy Controller for Home Energy Saving in Heating/Cooling System

Abaalkhail, Rana 18 January 2012 (has links)
Energy is consumed every day at home as we perform simple tasks, such as watching television, washing dishes and heating/cooling home spaces during season of extreme weather conditions, using appliances, or turning on lights. Most often, the energy resources used in residential systems are obtained from natural gas, coal and oil. Moreover, climate change has increased awareness of a need for expendable, energy resources. As a result, carbon dioxide emissions are increasing and creating a negative effect on our environment and on our health. In fact, growing energy demands and limited natural resource might have negative impacts on our future. Therefore, saving energy is becoming an important issue in our society and it is receiving more attention from the research community. This thesis introduces a intelligent energy controller algorithm based on software agent approach that reduce the energy consumption at home for both heating and cooling spaces by considering the user’s occupancy, outdoor temperature and user’s preferences as input to the system. Thus the proposed approach takes into consideration the occupant’s preferred temperature, the occupied and unoccupied spaces, as well as the time spent in each area of the home. A Java based simulator has been implemented to simulate the algorithm for saving energy in heating and cooling systems. The results from the simulator are compared to the results of using HOT2000, which is Canada’s leading residential energy analysis and rating software developed by CanmetENERGY’s Housing, Buildings, Communities and Simulation (HBCS) group. We have calculated how much energy a home modelled will use under emulated conditions. The results showed that the implementation of the proposed energy controller algorithm can save up to 50% in energy consumption in homes dedicated to heating and cooling systems compared to the results obtained by using HOT2000.
59

Innovative industrielle Erdgasbeheizungssysteme auf der Basis der Porenbrennertechnologie für Hochtemperaturanwendungen

Reusse, Ekaterina 19 February 2013 (has links) (PDF)
Im Rahmen der Dissertation wurde ein vollkeramischer Porenbrenner entwickelt, der im Bereich hoher Prozesstemperaturen eingesetzt werden kann. Die Brennerentwicklung umfasste die Entwicklung und Auswahl von geeigneten Komponenten wie ein Gehäuse und eine Flammensperre sowie die Anpassung an die Brennergeometrie. Die entwickelten Porenbrenner wurden Tests im Freibrand und im Hochtemperaturofen im Labor unterzogen. Eine entscheidende Rolle für die Bewertung des Brennersystems spielte die Qualifizierung unter Realbedingungen. Das Brennersystem wurde in Ofenanlagen zur Glasherstellung eingesetzt. Durch die Versuche in einer Arbeitswanne für die Herstellung von Behälterglas und in einer Vorwärmtrommel für die Herstellung von Kunstglas wurde der Nachweis der Industrietauglichkeit erbracht. Es wurden dabei die Vorteile wie Energieeinsparnis, verbesserte thermische Homogenität und niedrige CO- und NOx-Emissionen gezeigt.
60

Design and Development of an Intelligent Energy Controller for Home Energy Saving in Heating/Cooling System

Abaalkhail, Rana 18 January 2012 (has links)
Energy is consumed every day at home as we perform simple tasks, such as watching television, washing dishes and heating/cooling home spaces during season of extreme weather conditions, using appliances, or turning on lights. Most often, the energy resources used in residential systems are obtained from natural gas, coal and oil. Moreover, climate change has increased awareness of a need for expendable, energy resources. As a result, carbon dioxide emissions are increasing and creating a negative effect on our environment and on our health. In fact, growing energy demands and limited natural resource might have negative impacts on our future. Therefore, saving energy is becoming an important issue in our society and it is receiving more attention from the research community. This thesis introduces a intelligent energy controller algorithm based on software agent approach that reduce the energy consumption at home for both heating and cooling spaces by considering the user’s occupancy, outdoor temperature and user’s preferences as input to the system. Thus the proposed approach takes into consideration the occupant’s preferred temperature, the occupied and unoccupied spaces, as well as the time spent in each area of the home. A Java based simulator has been implemented to simulate the algorithm for saving energy in heating and cooling systems. The results from the simulator are compared to the results of using HOT2000, which is Canada’s leading residential energy analysis and rating software developed by CanmetENERGY’s Housing, Buildings, Communities and Simulation (HBCS) group. We have calculated how much energy a home modelled will use under emulated conditions. The results showed that the implementation of the proposed energy controller algorithm can save up to 50% in energy consumption in homes dedicated to heating and cooling systems compared to the results obtained by using HOT2000.

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