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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.
131

Eficiência energética em indústria frigorífica: desafios de implantação

Frozza, Janquiel Fernando 28 August 2013 (has links)
Esta pesquisa tem por objetivo efetuar uma investigação acerca da eficiência energética nas indústrias, com foco na identificação dos potenciais de conservação de energia e possíveis barreiras para se implantar um sistema de gestão de energia, tendo como principais motivações o lançamento do Plano Nacional de Eficiência Energética (PNEf), que prevê uma grande economia de energia para os próximos anos, e da norma ABNT NBR ISO 50001- Sistema de gestão de energia. Num primeiro instante, fez-se um estudo dos principais métodos de gestão e eficiência energética que estão sendo empregados nas indústrias. Após o desenvolvimento de estudos preliminares, realizou-se uma auditoria energética em um frigorífico de abate de aves situado na região Sudoeste do Paraná. Nesta auditoria foram estabelecidos os centros de maior consumo, as linhas de base dos principais insumos energéticos e potenciais de conservação de energia dos principais módulos temáticos. Verificou-se que o sistema de refrigeração representa aproximadamente 81% do consumo de energia elétrica da planta e que do total de 11 módulos temáticos existentes, três deles representam aproximadamente 97% do consumo de energia elétrica da planta, sendo motores, sistema de refrigeração e sistema de ar comprimido. Constatou-se também, com uma análise econômica de perdas, que há potenciais de conservação de energia, principalmente em motores. Por fim, identificaram-se as principais barreiras para se implantar um sistema de gestão de energia em uma planta, principalmente no que se refere à elaboração de linhas de base e indicadores de desempenho energético. Tais barreiras demonstram uma falsa expectativa do PNEf para alcançar as atuais metas se não houver maior impacto dos progressos induzidos (por políticas públicas). / This research has an objective to investigate the electrical power efficiency in industries, aiming to identify potential energy saving and possible barriers to deploy an energy management system, having as one of its priorities the main motivations to the release of a National Plan of Electrical Efficiency (NPEE), in which forecast a great power saving for the following years and the norm ABNT NBR ISO 50001-Energy management system. At a first moment, a study was made about the main methods of electrical efficiency management, in which are being introduced in industries. After the development of preliminary studies, an electrical audit was carried out in a poultry slaughter cooler on the southwest region of Paraná. On the audit were established the centers of greater consumption and the baselines of the main energetic imputs and potential ways of electrical energy saving from the main thematic modules.It has been verified that the cooling system represents approximately 81% of electrical energy consumption of the plant and of the total of eleven modules; three of them represent approximately 97% of the power consumption of the entire plant, as engines, cooling system and compressed air system. It has been also found out, with an economic analysis of losses, there are potentials means of power saving, especially when it comes to engines. At last, was identified the main barriers to deploy an energy management system in a plant, mainly as regards the elaboration of baselines and indicators of electrical performance. These barriers have shown a fake expectation of the NPEE to reach the present goals if there's no impact on the progresses prompted (by public politics.)
132

Eficiência energética aplicada na indústria de bebidas em sistemas de refrigeração e ar comprimido: estudo de casos

Mendes, Jair Eduardo Alves [UNESP] 16 January 2014 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-16Bitstream added on 2014-06-13T21:00:27Z : No. of bitstreams: 1 000755220.pdf: 14142750 bytes, checksum: 102189dd2a552dfabaaa76b366358524 (MD5) / A eficiência energética aos poucos vai ganhando espaço nas indústrias, em função da redução dos custos de produção, pela política de sustentabilidade e de preocupação ambiental empregada atualmente. As indústrias de bebidas, como a que o trabalho foi implantado, utilizam muito o sistema de refrigeração e o de ar comprimido. Praticamente 50% do consumo destas fábricas são em função destas utilidades. O objetivo desta dissertação foi desenvolver uma metodologia para ser usada como ferramenta na identificação de oportunidades de redução do consumo de energia em sistemas de refrigeração e ar comprimido. A metodologia desenvolvida foi baseada em conceitos de refrigeração e ar comprimido e, em alguns estudos de casos de eficiência energética implantados em algumas unidades fabris. Este trabalho mostra como esta metodologia foi criada para melhorar a eficiência energética de sistemas de refrigeração e de ar comprimido. Posteriormente esta metodologia foi utilizada em outras unidades desta mesma indústria para reduzir o consumo de energia elétrica. Inicialmente há uma breve descrição dos principais componentes destes sistemas e de conceitos que ajudam na melhoria da eficiência deles. Por fim, são apresentadas algumas boas práticas e projetos implementados que ajudaram na criação da ferramenta ou foram implementados a partir do uso dela. Os resultados do trabalho mostram a ferramenta pronta para ser usada e uma redução do consumo de energia elétrica de mais de 37 GWh/ano, que significam mais de R$ 6.000.000,00 por ano. A principal conclusão desta dissertação é que a metodologia foi criada e, independente do tipo de configuração destes dois sistemas, é possível utilizá-la para melhorá-los / Energy efficiency is slowly gaining ground in the industry, especially due to the cost reduction in the production process its present, also to the sustainability policy and environmental concern employed nowadays. Beverage industries use cooling system and compressed air system a lot. Almost 50% of the electricity consumption in these plants refers to those utilities. The objective of this dissertation was to develop a methodology that can be used as a tool for identifying opportunities to reduce energy consumption in those cooling and compressed air systems. The methodology was based on concepts of cooling and compressed air, and also in some case studies in which energy efficiency was implemented in beverage plants. This dissertation shows how this methodology was created to improve the energy efficiency in cooling and air compressed systems. Later this methodology was used in other plants of the same company in which the case study was done to reduce electricity consumption. The study starts with a short description of the main components of these systems and concepts that help to improve their efficiency. And concludes with some good practices operation and projects implemented, which helped to develop the tool or have been implemented using it. The outcome shows that the tool is ready for use and that there is an important reduction in electricity consumption, amount to more than 37 GWh / year, which means more than R$ 6,000,000.00 a year. The main conclusion of this dissertation is that methodology was developed and it is possible to use the methodology to improve the cooling and air compressed systems, apart from the configuration and automation of the equipments in the plant
133

Projeto de uma ULA de inteiros e de baixo consumo em tecnologia CMOS / Design of a low-power integer ALU on CMOS technology

André Berti Sassi 20 June 2013 (has links)
A redução no consumo de potência em circuitos eletrônicos tem se tornado um dos requisitos mais importantes em projetos, especialmente com o recente aumento no número e na variedade de dispositivos móveis ou operados à bateria. Em tais dispositivos, o gerenciamento eficiente de energia é, muitas vezes, considerado mais importante que sua capacidade de processamento. Unidades lógico-aritméticas (ULAs) são componentes fundamentais em processadores, sendo responsáveis por executar as instruções que envolvem processamento numérico ou lógico. Normalmente, a ULA é o componente de maior consumo em um processador, o que a torna alvo de diversos estudos sobre técnicas para redução de consumo. Este trabalho apresenta um resumo sobre consumo de potência em circuitos digitais CMOS e as principais técnicas para sua redução, assim como os fundamentos para o projeto de ULAs, incluindo um estudo sobre algumas topologias para construção de somadores, deslocadores e multiplicadores e uma visão geral sobre a implementação de operações com números de ponto-flutuante e sobre a organização interna da ULA. É realizado o projeto de uma ULA de números inteiros de 16 bits em uma tecnologia CMOS de 0,35 \'mü\'m com aplicação de algumas das técnicas de redução de consumo apresentadas, que opera a uma frequência máxima de 212 MHz em tensão de alimentação de 3,3 V, consumindo, em média, 57 \'mü\'W e ocupando uma área de 0,121 \'MM POT.2\'. Este projeto é, ainda, comparado a uma ULA de referência, projetada na mesma tecnologia e com mesmas características funcionais, mas sem a utilização de quaisquer técnicas de redução de consumo. / The power consumption reduction in electronic circuits has turned one of the most important design requirements, especially with the recent increase of the number and variety of mobile or battery operated devices. In such devices, the efficient energy management is, many times, considered more important than its processing capability. Logic and arithmetic units (ALUs) are fundamental components in processors, being responsible for executing the instructions involving logic and numeric processing. Usually, the ALU is the most power consuming component in a processor, which makes it the target of several studies about power reduction techniques. This work presents a brief about power consumption in CMOS digital circuits and the major techniques for its reduction as well the fundamentals of ALU design, including a study about some topologies for adders, shifters and multipliers and a general view about floating-point number operations and about ALUs internal organization. It is realized the design of a 16-bit integer ALU in a 0,35 \'mü\'m CMOS technology with the application of some presented power reduction techniques that operates on a maximum frequency of 212 MHz on 3,3 V supply voltage, consuming, on average, 57 \'mü\'W and occupying an area of 0,121 \'MM POT.2\'. This design is also compared to a reference ALU, designed on the same technology and with same functional characteristics, but without using any power reduction techniques.
134

Aplicação de celulases no refino de fibras celulósicas Kraft branqueadas de eucalipto. / Cellulases application to the refining of bleached kraft pulp cellulose fibres.

Roberto Publio 27 June 2012 (has links)
O presente trabalho teve como objetivo avaliar os efeitos de celulases comerciais na superfície de fibras celulósicas branqueadas de eucalipto, bem como o impacto destes efeitos durante o refino. Após tratamento enzimático realizado em laboratório sob condições controladas, as polpas de fibra seca foram submetidas a refino em moinho PFI em vários níveis de energia e os resultados foram avaliados por meio dos ensaios físico-mecânicos realizados em folhas manuais formadas em laboratório e ensaios de morfologia de fibra, que tinham como objetivo evidenciar alguns efeitos provocados pelas enzimas utilizadas como auxiliar de refino. As análises dos dados obtidos mostraram que para a fibra seca tratada com produto denominado Maxymize 2530, foi possível obter valores 31% maiores de resistência à tração e 21% maiores de resistência interna (Scott Bond), valores estes sem refino mecânico. Estes valores foram similares aos encontrados para a fibra nunca seca, o que mostrou que a enzima pôde compensar o efeito \"Hornification\" causado pelo processo de secagem da fibra. Para a fibra seca pré-tratada com celulase e refinada em moinho PFI, foi possível obter um valor de Scott Bond de 100 lb.ft/in² com um consumo específico de energia 36% menor quando comparado com a fibra seca refinada em moinho PFI sem pré-tratamento enzimático. O mesmo aconteceu para os valores de resistência a tração, onde se obteve um valor de 70 kNm/kg com consumo específico de energia 57% menor. O planejamento experimental realizado contribuiu para a otimização de dosagem e variáveis do pré-tratamento enzimático, e com isso tornou possível a viabilização financeira da aplicação de celulases como auxiliar de refino. Todos os resultados foram ilustrados por imagens de Microscopia Eletrônica de Varredura (MEV), que evidenciou o aumento do nível de fibrilação externa das fibras tratadas com enzimas. / This study aimed to evaluate the effects of commercial cellulases on the surface of bleached eucalyptus fibers, as well as the impact of these effects during refining. After enzymatic treatment performed in the laboratory under controlled conditions, the dried pulps were subjected to refining in PFI mill at various energy levels and the results were evaluated by physical-mechanical tests performed on handsheets formed in laboratory and morphology fiber tests, which were intended to show some effects caused by the enzymes used as an aid to refining. The data analysis showed that for the dry fiber treated with compound Maxymize 2530, it was possible to obtain values 31% higher tensile strength and 21% higher Scott Bond test, these values without mechanical refining. These values are similar to those found for the never dried fiber, which showed that the enzyme could compensate the \"Hornification\" caused by the drying process of the fiber. To the dried fiber pre-treated with cellulase and refined in a PFI mill, it was possible to obtain a value of Scott Bond 100 lb.ft /in² with a specific energy consumption was 36% lower when compared to the dried fiber refined in a PFI mill without pre -enzymatic treatment. The same happened to the values of tensile strength, which presented a value of 70 kNm/kg with a specific energy consumption with 57% lower. The experimental design carried out contributed to the optimization of dosage and variables of enzymatic pre-treatment, and thereby made possible the financial feasibility of the application of cellulases as an aid to refining. All results are illustrated by images of scanning electron microscopy (SEM), which showed an increase in the level of external fibrillation of fibers treated with enzymes.
135

Impactos da redução do consumo de energia eletrica em Manaus atraves de medidas de eficiencia energetica em climatização residencial / Impacts of electric energy consumption in Manaus by actions of energy efficiency in home climatization

Silva, Vladimir Freitas Paixão e 11 March 2008 (has links)
Orientadores: Gilberto De Martino Jannuzzi, Elizabeth Ferreira Cartaxo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T11:39:09Z (GMT). No. of bitstreams: 1 Silva_VladimirFreitasPaixaoe_M.pdf: 2710715 bytes, checksum: bbdac7d8cccb290379966ac18bb1f00d (MD5) Previous issue date: 2008 / Resumo: Esta dissertação tem como objetivo avaliar os impactos da redução do consumo de energia elétrica em Manaus através de medidas de eficiência energética em climatização residencial. A escolha da correta orientação geográfica, a pintura das paredes e dos telhados com cores claras, a inclusão de isolamento térmico EPS (Isopor) no forro, a inclusão de isolamento reflexivo por baixo do telhado e a abertura de áticos, foram medidas de eficiência energética aplicadas na residência do estudo de caso para avaliar a redução das cargas térmicas dos seus respectivos recintos internos (quartos). Outra medida de eficiência energética utilizada foi a substituição de condicionadores de ar do tipo janela de baixa eficiência por equipamentos de alta eficiência. As estimativas das cargas térmicas resultantes das aplicações das medidas de eficiência energética foram obtidas por meio da utilização do software CARRIER E20-II, HAP, v4.33., cuja licença de uso é encontrada à venda no mercado nacional. Definidas as cargas térmicas dos quartos, foram especificados os condicionadores de ar do tipo janela que seriam usados na climatização desses ambientes. O emprego combinado dessas medidas de eficiência energética permitiu que fossem quantificadas as respectivas economias de consumos e de redução de demanda de energia elétrica e seus efetivos impactos sobre o Sistema Manaus. / Abstract: This thesis aims to assess the impacts of electricity consumption reduction in Manaus through energy efficiency measures applied in home climatization. The choice of correct geographical orientation, walls and roofs painting with clear colors, the inclusion of thermal insulation EPS (Styrofoam) in the lining, the inclusion of reflective insulation under the roof, attic opening and closing, are energy efficiency measures applied in the case study residence to reduce the thermal loads on their respectives rooms. Another efficiency measure used was the replacement of low efficiency window air-conditioners for high-efficiency ones. The resulting thermal loads from the application of these measures were obtained through the use of software CARRIER E20-II, HAP, v4.33., whose using license is found for sale on the domestic market. Defined the rooms thermal loads, the cooling capacities of the window air-conditioners were specified to be used in the cooling of these environments. The combined employment of these energy efficiency measures has allowed quantify their electric energy consumption economies and demand reductions and its impacts on the Manaus System. / Mestrado / Planejamento de Sistemas Energeticos / Mestre em Planejamento de Sistemas Energéticos
136

Neighbourhood Watch : social resource monitoring

Elsmore, Chris January 2010 (has links)
No description available.
137

The impact of electricity on economic growth in South Africa

Ndlovu, Vanessa Constance January 2013 (has links)
Since 1994, with many of its sanctions lifted, South Africa became a stronger economic power house in Africa leading the continent‘s industrial output and mineral production and generating a large proportion of Africa‘s electricity. The South African economy has since been growing at a fast pace which has also led to an increase in the demand for electricity. South Africa‘s generating capacity has remained constant through a consistently increasing demand, leading to an electricity shortfall. An immediate threat to South Africa‘s continued economic growth is a capacity constraint in terms of energy supply. Increasing economic growth coupled with the rapid industrialisation and mass electrification programme of the last decade, as well as planned and unplanned maintenance and coal stock pile problems led, in January 2008, to demand out stripping supply. With electricity being an important component of economic development, it is vital that the impact of the supply of electricity on the economic growth of the country be well understood. Currently few studies have been done on the analysis of this relationship in South Africa specifically and how this relationship impacts specific sectors of the economy that contributes to the total GDP of the country. This study has assumed rigorous application of Granger technique with proper statistical verification of assumptions, selection of relevant variables and provides trusted statistical forecasts. In an attempt to understand this relationship, an Econometric model has been developed to assess the impact of electricity supply and price on the economic growth of South Africa. In the empirical analysis section of this study it was found that with a forecast for GDP, past values of electricity prices and coal sales may be used to forecast electricity supply. It was also found that if we have a forecast value of future electricity price we can use past values of electricity supply and coal sales to forecast GDP for the next quarter. We also found that electricity supply is granger caused by GDP; electricity price; and total coal sales. And that economic growth is granger caused by electricity supply; electricity price; and total coal sales. It was concluded that in order for government to improve the economic growth of South Africa, a major focus on the energy industry is needed to ensure sustainable supply capacity. The energy sector, as was shown in the study, has a major impact in the functioning of the Gross Domestic Product of the country.
138

Comparison of Wireless Communication Technologies used in a Smart Home : Analysis of wireless sensor node based on Arduino in home automation scenario

Horyachyy, Oleh January 2017 (has links)
Context. Internet of Things (IoT) is an extension of the Internet, which now includes physical objects of the real world. The main purpose of Internet of Things is to increase a quality of people’s daily life. A smart home is one of the promising areas in the Internet of Things which increases rapidly. It allows users to control their home devices anytime from any location in the world using Internet connectivity and automate their work based on the physical environment conditions and user preferences. The main issues in deploying the architecture of IoT are the security of the communication between constrained low-power devices in the home network and device performance. Battery lifetime is a key QoS parameter of a battery-powered IoT device which limits the level of security and affects the performance of the communication. These issues have been deepened with the spread of cheap and easy to use microcontrollers which are used by electronic enthusiasts to build their own home automation projects. Objectives. In this study, we investigated wireless communication technologies used in low-power and low-bandwidth home area networks to determine which of them are most suitable for smart home applications. We also investigated the correlation between security, power consumption of constrained IoT device, and performance of wireless communication based on a model of a home automation system with a sensor node. Sensor node was implemented using Arduino Nano microcontroller and RF 433 MHz wireless communication module. Methods. To achieve the stated objectives of this research following methods were chosen: literature review to define common applications and communication technologies used in a smart home scenario and their requirements, comparison of wireless communication technologies in smart home, study of Arduino microcontroller technology, design and simulation of a part of  home automation project based on Arduino, experimental measurements  of execution time and power consumption of Arduino microcontroller with RF 433 MHz wireless module when transmitting data with different levels of security, and analysis of experimental results. Results. In this research, we presented a detailed comparison of ZigBee, WiFi, Bluetooth, Z-Wave, and ANT communication technologies used in a smart home in terms of the main characteristics. Furthermore, we considered performance, power consumption, and security. A model of a home automation system with a sensor node based on Arduino Nano was described with sleep management and performance evaluation. The results show that the battery lifetime of Arduino in a battery-powered sensor node scenario is determined by the communication speed, sleep management, and affected by encryption. Conclusions. The advanced communication strategy can be used to minimize the power consumption of the device and increase the efficiency of the communication. In that case, our security measures will reduce the productivity and lifetime of the sensor node not significantly. It’s also possible to use symmetric encryption with smaller block size.
139

Efficient Bi-Directional Communications for Low-Power Wireless Mesh Network / 低消費電力無線メッシュネットワークにおける高能率双方向通信

Okumura, Ryota 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(情報学) / 甲第23328号 / 情博第764号 / 新制||情||130(附属図書館) / 京都大学大学院情報学研究科通信情報システム専攻 / (主査)教授 原田 博司, 教授 守倉 正博, 教授 大木 英司 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM
140

Zigbee zařízení pro monitorování spotřeby elektrické energie / Zigbee node for monitoring of electric energy consumption

Štefany, Martin January 2012 (has links)
Master's thesis designs a device for monitoring of electric energy consumption with ability to send measured data wirelessly using ZigBee technology. Theoretical part describes basic principles for measuring electric power and energy and also a possibility of digital measurement. Thesis provides short overview of already existing solutions for electric consumption measurement available on the market as well. Further the ZigBee standard is described together with one of its software implementations named BitCloud from Atmel Corporation. Design of the device deals with the selection of suitable integrated circuit for the consumption measurement and optimal voltage and current sensors. Then also its connection with the wireless module named ZigBee using SPI bus, power supply for the entire device and also the design of PCB. There is also a firmware implementation for the designed device based on BitCloud. Description of the firmware together with calibration process implemented is also part of the thesis. Finally, basic device testing and packet analysis of communication between designed device and ZigBee network coordinator is described.

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