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

Impactos da ?Institucionaliza??o?: um olhar a partir de encontros / Impacts of "Institutionalization": a look from meetings

Bull?, Fl?via do Carmo 19 February 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-11T11:33:38Z No. of bitstreams: 1 2016 - Flavia do Carmo Bull?.pdf: 4444495 bytes, checksum: 19e04e016eea5f26f73dac4089a22471 (MD5) / Made available in DSpace on 2017-05-11T11:33:38Z (GMT). No. of bitstreams: 1 2016 - Flavia do Carmo Bull?.pdf: 4444495 bytes, checksum: 19e04e016eea5f26f73dac4089a22471 (MD5) Previous issue date: 2016-02-19 / This study has the objective to discuss the impacts caused by Resolution N? 1 CNE/CEB from march 2011 that fixo perating standard of Child hood Education Units linked to Federal Public Administration, their agencies and foundations and determining that the Child hood Education Units maintained and administered by Federal Universities or integrate the federal system of education maintained by Union may establish operating conditions according to Law n? 9.394/96 and National Council of basic education's orientations. Considering the tension relations established be tween the private and the universal, wetake the UFRJ Childhood Education School as monad, believing that these are ''miniatures of these, finite copies images in which circum scribe a subject that say sit self, but not only, open space some other that not it self''(GAGNEBIN, 2004, p. 80). There by, we intend to comprehend the transformations, arising trajctory history path, the impressions and the concerns caused in the actors that in the past and yet in the present, has be endirectly related to this context and that, from this study, meet e a chother dialogically with the purpose of associate tow rite this screen play. Holding me to these senses, thes pecific purposes reveal the subjects that turn sinto to objects our research firm the potency of its exotopic look in front of "germination of new", assuming in front of this scenery a responsive atitude. Showing and narrating starting in his perspective the story about the institutionatizazion this place. / Esta pesquisa tem por objetivo discutir os impactos ocasionados pela Resolu??o N? 1 CNE/CEB de mar?o de 2011 que fixa normas de funcionamento das unidades de Educa??o Infantil ligadas ? Administra??o P?blica Federal direta, suas autarquias e funda??es e determinando que as unidades de Educa??o Infantis mantidas e administradas por universidades federais ou que integrem o sistema federal de ensino mantido pela Uni?o possam estabelecer condi??es de funcionamento de acordo com o que determina a Lei n? 9.394/96 e as orienta??es do Conselho Nacional de Educa??o B?sica. Considerando as rela??es de tens?o estabelecidas entre o particular e o universal, tomamos a Escola de Educa??o Infantil da UFRJ como m?nada, acreditando que estas s?o ?miniaturas de sentido, imagens exemplares finitas nas quais se circunscreve um sujeito que diz de si, mas n?o somente, abrindo espa?o a algo outro que n?o si mesmo? (GAGNEBIN, 2004, p. 80). Assim, intencionamos compreender as transforma??es, decorrentes de sua trajet?ria hist?rica, as impress?es e as inquieta??es causadas nos atores que no passado e ainda no presente, estiveram diretamente relacionados a esse contexto e que a partir deste estudo se encontram dialogicamente com o objetivo de participarem da escrita deste roteiro. Apegando-me a esses sentidos, os sujeitos se revelam e se tornam objetos da nossa pesquisa, afirmando a pot?ncia de seu olhar exot?pico diante da ?germina??o do novo?, assumindo diante deste cen?rio uma atitude responsiva, demonstrando e narrando a partir de sua perspectiva a hist?ria desse processo de institucionaliza??o
12

[en] TRANSMISSION EXPANSION PLANNING CONSIDERING THE INTERMITTENCY OF WIND GENERATION / [pt] PLANEJAMENTO DA EXPANSÃO DA TRANSMISSÃO CONSIDERANDO A INTERMITÊNCIA DA GERAÇÃO EÓLICA

JERSON ERASMO LEON ALMEIDA 23 January 2018 (has links)
[pt] O planejamento da expansão da transmissão (PET) visa identificar os novos reforços a serem implementados na rede do sistema elétrico de potência, necessá-rios para assegurar uma adequada interligação entre a demanda e a geração do sistema, ambas previstas para o horizonte de planejamento. Um bom plano de expansão deve garantir o equilíbrio entre os custos de investimento e operação, mantendo um nível satisfatório de continuidade no fornecimento de energia. En-tretanto, a identificação de boas soluções para o PET tem se tornado uma tarefa cada vez mais difícil. Isso se deve, principalmente, às características e dimensões dos sistemas atuais, incluindo o aumento na dependência de fontes renováveis, e à não linearidade e natureza combinatória do problema de otimização. Nesta dissertação é proposta uma nova metodologia para resolver o proble-ma PET com alta penetração de energia renovável, em particular a eólica. A me-todologia é baseada na aplicação de uma nova ferramenta de otimização para so-lução do PET estático, a qual é classificada como metaheurística construtiva, onde soluções viáveis de boa qualidade são paralelamente construídas a partir da topo-logia inicial, por meio de adições graduais de reforços mais atrativos para a rede. Outras heurísticas são também utilizadas. Ênfase é dada à modelagem de cenários de geração eólica, que representam a energia renovável da rede a ser planejada, a qual deverá permitir uma operação flexível e adaptada à intermitência destas fon-tes. São utilizados o critério de segurança N-1 e o modelo linear DC de rede, com a consideração de perdas ôhmicas. Uma variante do sistema IEEE RTS, com inserção de fontes eólicas, é utilizada para testar a metodologia proposta. / [en] Transmission expansion planning (TEP) aims to identify the new reinforce-ments to be installed in the electric power system, necessary to ensure an adequate interconnection between demand and generation of the system, both foreseen for the planning horizon. A good expansion plan should ensure a balance between investment and operating costs, while maintaining a satisfactory level of continui-ty in the energy supply. However, identifying good expansion solutions for TEP has become an increasingly difficult task. This is mainly due to the characteristics and dimensions of the current systems, including the increase in the dependence of renewable sources, and the nonlinearity and combinatorial nature of the optimi-zation problem. In this dissertation, a new methodology is proposed to solve the TEP prob-lem with high penetration of renewable energy, in particular wind power. The methodology is based on the application of a new optimization tool for static TEP solution, which is classified as a constructive metaheuristic, where feasible solu-tions of good quality are simultaneously constructed from the initial topology of the network, through incremental additions of reinforcements more attractive to the grid. Other heuristics are also used. Emphasis is given to the modeling of wind power scenarios, which represent the renewable energy of the network to be planned, which should allow a flexible operation and adapted to the intermittency of these sources. The security criterion N-1 and the linear DC network model are used, with the consideration of ohmic losses. A variant of the IEEE RTS sys-tem, with insertion of wind sources, is used to test the proposed methodology.
13

Sustainable Implementation of Photovoltaic Technologies in Mauritius : A study on the energy system in Mauritius and the effect of solar power generation on frequency stability / Hållbar implementering av solceller på Mauritius : En studie av energisystemet på Mauritius och inverkan av solkraft på frekvensstabilitet

Bang Jensen, Maria Isabel, Lundberg, Simon January 2020 (has links)
Mauritius is an isolated island with ambitious targets for renewable energy generation and plans to invest in more solar power. The aim of this study is to assess how the implementation of photovoltaic technologies might affect the frequency stability in Mauritius and thus assess whether solar power can help the country obtain their targets for green energy generation. The research question is answered by conducting a literature study and simulating relevant scenarios in Matlab and Simulink. By simulating the frequency response for a production disturbance with different values for system inertia and PV capacity, the inertia requirements for frequency stability is assessed. Mauritius appears to have a high potential for increasing solar power generation. Based on the simulations, their electrical grid seems to be able to maintain frequency stability with PV capacity corresponding to the generation targets for 2020, 2025 and 2030, even for low amounts of system inertia. However, the significance of these results are called into question because of the varying quality of input data. With more accurate, specific data, the applicability of the results can be improved. Nevertheless, the study can be used as a guideline on how to use the given model to evaluate frequency stability in isolated power systems in island states. Ways to further this study is to evaluate other stability challenges related to PV production such as the reactive power in the system, voltage stability and rotor angle stability. / Mauritius är en isolerad ö som har sett en stor ekonomisk växt de sista åren. För att möta en ökande efterfrågan på el på ett hållbart sätt har Mauritius satt ambitiösa mål för förnybar energiproduktion som bland annat innebär betydande investeringar i solkraft. Målet med denna studie är att utvärdera hur implementeringen av utökad solcellskapacitet skulle kunna påverka frekvensstabiliteten i nätet på Mauritius och således fastställa ifall solenergin kan bidra till deras mål om ökad grön energiproduktion, utan att öka risken för strömavbrott. Frågeställningen besvaras genom att först utföra en litteraturstudie och sedan använda en matematisk modell, utvecklad av Danilo Obradovic från KTH, för att simulera relevanta scenarier i Matlab och Simulink. Simuleringarna visar frekvenssvaret vid produktionsbortfall som relateras till den mängd svängmassa som behövs för att säkerställa frekvensstabilitet vid olika mängder solceller. Litteraturstudien visar att Mauritius har god tillgång på solinstrålning och solceller verkar vara en lämplig teknologi för att utnyttja denna energin. Enligt de simuleringar som genomförts verkar Mauritius kunna bibehålla frekvensensstabilitet om den installerade solcellskapaciteten ökas till de planerade nivåerna i 2020, 2025 och 2030, även för låga värden på systemets svängmassa. Slutsatserna bör dock analyseras kritiskt då indatan som används för simuleringarna är av varierande kvalitet. Med bättre och mer specifik indata kan den föreslagna metodiken och modellen användas för att dra mer relevanta slutsatser för Mauritius. Metodiken som använts i denna studie kan därav ses på som en riktlinje för hur frekvensstabiliteten i isolerade elnät kan undersökas. Vidare kan studien utökas genom att utvärdera sociala och ekonomiska aspekter och även andra stabilitetsfrågor relaterade till en ökad mängd solceller, så som den reaktiva effekten i systemet, spänningsstabilitet och rotorvinkelstabilitet.
14

Alternative Electricity Market Systems for Energy and Reserves using Stochastic Optimization

Wong, Steven January 2005 (has links)
This thesis presents a model that simulates and solves power system dispatch problems utilizing stochastic linear programming. The model features the ability to handle single period, multiple bus, linear DC approximated systems. It determines capacity, energy, and reserve quantities while accounting for N-1 contingency scenarios (single loss of either generator or line) on the network. Market systems applying to this model are also proposed, covering multiple real-time, day-ahead, and hybrid versions of consumer costing, transmission operator payment, and generator remuneration schemes. The model and its market schemes are applied to two test systems to verify its viability: a small 6-bus system and a larger 66-bus system representing the Ontario electricity network.
15

Alternative Electricity Market Systems for Energy and Reserves using Stochastic Optimization

Wong, Steven January 2005 (has links)
This thesis presents a model that simulates and solves power system dispatch problems utilizing stochastic linear programming. The model features the ability to handle single period, multiple bus, linear DC approximated systems. It determines capacity, energy, and reserve quantities while accounting for N-1 contingency scenarios (single loss of either generator or line) on the network. Market systems applying to this model are also proposed, covering multiple real-time, day-ahead, and hybrid versions of consumer costing, transmission operator payment, and generator remuneration schemes. The model and its market schemes are applied to two test systems to verify its viability: a small 6-bus system and a larger 66-bus system representing the Ontario electricity network.
16

Batterimatning som reservdrift på mellanspänningsnätet / Battery storage as a power reserve in the mid-voltage grid

Högerås, Johanna January 2017 (has links)
The grid in the northern part of Sweden is characterized by long radial lines with just a few customers. To secure electricity supply it is necessary to have a redundant feeding alternative. A loop structured grid which is used in the more populated urban area is a poor solution in the rural areas both regarding economy and technology due to the long distances. To feed the northern grid in Sweden a battery energy storage system (BESS) is therefore a solution that could secure the power delivery. An important aspect to investigate is how the electric power quality changes with the new feeder, but more importantly to secure disconnection of supply at fault occurrence.   This thesis investigates how a battery storage system installed at the end of a mid-voltage line affects the electric power quality and the protection system compared to a reference case which represents the line today. The mid-voltage line is an existing line in the northern grid and is a good representation of the general northern grid.     The results obtained from this study show that the loop impedance does not necessarily have to deteriorate with the new feeder, which means that the voltage quality in this aspect does not change. This is only true for this particular grid when the impedance contribution from the mid-voltage grid is small and the contribution from the low-voltage grid is large because of long and weak distribution low-voltage lines.     The inverter is the limiting factor for the short circuit currents, and the short circuit power and current decrease with the new feeder. At fault occurrence in the low voltage grid the short circuit current does not affect the fuse blow. However the inverter will disconnect for all fault occurrences in the mid-voltage grid, and for faults with high short circuit power in the low voltage grid. This means that the selectivity will decrease, but the system will have a high security level.   For this particular grid the results show that the transformer can be isolated from the ground. A residual overvoltage relay is enough for disconnection of grounding faults. Directional ground fault protection is not necessary for this line with this particular characteristics. If the sensitivity for the disconnection of grounding faults with high transition impedances is adjusted according to ground fault currents in island operation, the sensitivity then decreases at the event of a fault during normal operations when the battery storage system is charging. The sensitivity might also be tuned according to normal operation, which then results in a higher sensitivity than necessary during island operation.
17

Global Commercial Aircraft Fuel Burn and Emissions Forecast: 2016 to 2040

Padalkar, Rahul Rajaram 13 October 2017 (has links)
This thesis discusses enhancements to the Global Demand Model (GDM). The model addresses the need to predict: a) number of flights Worldwide by Origin-Destination (OD) airport pair, b) the number of seats (surrogate of demand) by OD airport pair, c) the fleet evolution over time, d) fuel consumption by OD pair and aircraft type, and emissions by OD pair and aircraft type. The model has developed an airline fleet assignment module to predict changes to the airline fleet in the future. Specifically, the model has the capability to examine the fuel and emission benefits of next generation N+1 aircraft and advanced NASA's N+2 aircraft are adopted in the future. / Master of Science / This thesis discusses enhancements to a model, Global Demand Model (GDM), developed at Air Transportation Systems Laboratory at Virginia Tech. The model addresses the need to predict: a) number of flights Worldwide by Origin-Destination (OD) airport pair, b) the number of seats (surrogate of demand) by OD airport pair, c) the fleet evolution over time, d) fuel consumption by OD pair and aircraft type, and emissions by OD pair and aircraft type. The model has developed an airline fleet assignment module to predict changes to the airline fleet in the future. Specifically, the model has the capability to examine the fuel and emission benefits if next generation N+1 aircraft and advanced NASA’s N+2 aircraft are adopted in the future.
18

Simulação do co-tratamento de resíduo de tanque séptico em estação de tratamento de esgoto doméstico

Pistorello, Josiane January 2018 (has links)
O presente trabalho avaliou a possibilidade de receber e tratar resíduo de tanques sépticos num sistema dimensionado para tratar esgoto doméstico. Neste sentido, o objetivo deste estudo foi avaliar o co-tratamento deste resíduo numa estação de tratamento de esgoto composta por processo de lodos ativados. Para a realização desta avaliação utilizou-se o modelo matemático ASM1 e o software WRc Stoat 5.0. O modelo ASM1 descreve a remoção de matéria orgânica carbonácea, a nitrificação e a desnitrificação. Para atender ao objetivo proposto, foram realizadas simulações de quatro grupo de cenários, sendo que em cada grupo a ETE operava com uma vazão fixa e foi alterada a parcela de resíduo de tanque séptico a ser tratada no sistema. Para a realização das simulações, previamente realizou-se a estruturação do modelo matemático ao sistema de tratamento selecionado, ajustes dos coeficientes estequiométricos e parâmetros cinéticos e determinaram-se as concentrações de entrada e o fracionamento da DQO e do nitrogênio para o esgoto bruto e para o resíduo de tanque séptico. As simulações geraram como resultado a possibilidade de, num sistema dimensionado para uma vazão média de 180 m3/h e operado com uma vazão de 45 m3/h de esgoto doméstico receber 4,3 m3/h de resíduo de tanque séptico sem comprometer os padrões de lançamento. Já, no caso da mesma ETE operando com 90 m3/h, 135 m3/h e 162 m3/h, as parcelas possíveis de serem recebidas de resíduo de tanque séptico e concomitantemente atendendo aos padrões de lançamento definidos na legislação foram 3,6 m3/h, 3,3 m3/h e 2,9 m3/h. Os resultados obtidos permitem concluir que é viável co-tratar resíduo de tanque séptico com o esgoto doméstico e ao mesmo tempo atender aos padrões de lançamento definidos na legislação, desde que respeitados os fatores limitantes e as cargas máximas. O recebimento e o tratamento do resíduo de tanque séptico em sistemas projetados para esgoto doméstico mostram-se como práticas que podem ser implantados na gestão dos sistemas de esgotamento sanitário. Esta aplicação poderia contribuir para ampliar a correta destinação dos esgotos e consequentemente com a melhoria dos índices de atendimento do esgotamento sanitário. / The present work evaluated the possibility of receiving and treating septic tank residue in a system designed to treat domestic sewage. Therefore, the objective of this study was to evaluate the co-treatment of this residue in a sewage treatment plant with an activated sludge process. The ASM1 model and software WRc Stoat 5.0 were used to perform this evaluation. The ASM1 model describes the removal of carbonaceous organic matter, nitrification and denitrification processes. To attend the proposed objective, simulations of four scenarios group were realized and in each group the system operated with a fixed flow and was changed the portion of septic tank residue. Before running the simulations, the mathematical model was structured to the selected treatment system, adjustments of the stoichiometric coefficients and kinetic parameters and were determined the inputs and fractionations concentration of the COD and nitrogen for the sewage and the septic tank residue. The simulation results show that is possible, in a system designed for an average flow of 180 m3/h and underloaded with a domestic sewage flow of 45 m3/h to receive 4.3 m3/h of septic tank residue without compromising the standards. For systems operating at 90 m3/h, 135 m3/h and 162 m3/h, the possible parcels to be received from septic tank residue without compromising standards defined in the legislation were, respectively, 3.6 m3/h, 3.3 m3/h and 2.9 m3/h. The results allow the conclusion that it is feasible to co-treat septic tank residue with domestic sewage and at the same time respect the standards defined in the legislation, once the limiting flowrates and maximum loads are respected. The acceptance and treatment of septic tank residue in systems designed for domestic sewage are practices that can be implemented in the management of sanitary sewage systems. That can be enplaned to improve the management of sewage systems, therefore, expanding the correct destination of wastewater and consequently contribute to the improvement of sanitary sewage index.
19

Contribution à la théorie des gaz de fermions ultrafroids fortement polarisés

Giraud, Sébastien 10 June 2010 (has links) (PDF)
Cette thèse traite du problème à N+1 corps dans les gaz de fermions ultrafroids fortement polarisés. Il s'agit de la situation où un unique atome d'une espèce de spin est immergé dans une mer de Fermi d'atomes de l'autre espèce.<br /> <br /> La première partie utilise une approche hamiltonienne basée sur un développement général de la fonction d'onde du système faisant intervenir un nombre arbitraire de paires particule-trou. Nous montrons que la série d'approximations successives construite converge très rapidement et nous obtenons ainsi une solution essentiellement exacte pour l'énergie et la masse effective du polaron. En dimension 1, dans deux cas particuliers, ce problème peut être résolu analytiquement. La comparaison avec notre série d'approximations est excellente et confirme l'efficacité de ce développement. Enfin, nous précisons les différents cas limites, ainsi que l'influence du rapport des masses entre les deux espèces de spin.<br /> <br /> Dans une deuxième partie, nous utilisons le formalisme des diagrammes de Feynman pour décrire à la fois le polaron et l'état lié. Pour le polaron, nous construisons une théorie équivalente à l'approche hamiltonienne. Pour l'état lié, nous obtenons à nouveau une série d'approximations dont la convergence très rapide vers la solution exacte est parfaitement comprise. Cette approche nous fournit donc une solution quasi-exacte au problème tout au long de la transition BEC-BCS. Enfin, en comparant les énergies des deux quasi-particules, nous étudions la position de la transition polaron - état lié.
20

Nelaimingų atsitikimų darbe tyrimas: teoriniai ir praktiniai aspektai / Investigation of accidents at work: theoretical and practical aspects

Žemaitytė, Kristina 25 November 2010 (has links)
Darbe nagrinėjama nelaimingų atsitikimų, įvykusių darbe, tyrimo procedūra – teoriniai ir praktiniai aspektai. Analizuojami teisės aktai, reguliuojantys nelaimingų atsitikimų darbe tyrimą, aptariant nelaimingų atsitikimų darbe sampratą, išskiriant nelaimingo atsitikimo darbe pagrindinius tikslus, tyrimą atliekančius subjektus ir institucijas, analizuojant tyrimo metu surašomų dokumentų formas ir turinį, tyrimo terminus. Nelaimingų atsitikimų darbe tyrimas pagal teisės aktuose nustatytas tyrimą atliekančių subjektų teises ir pareigas skirstomas į kelias stadijas, išskiriamos kiekvienos stadijos trūkumai, siūlomos reglamentavimo pataisos. Atliekant nelaimingų atsitikimų darbe tyrimą reglamentuojančių teisės aktų analizę remiamasi Lietuvos Vyriausiojo Administracinio Teismo, Lietuvos Aukščiausiojo Teismo ir Lietuvos Respublikos Konstitucinio Teismo praktika, apžvelgiami Lietuvos Respublikos valstybinės darbo inspekcijos, Lietuvos Respublikos socialinės apsaugos ir darbo ministerijos pateikti statistiniai duomenis apie šalyje įvykusius nelaimingus atsitikimus darbe per pastaruosius trejus metus. Didelis dėmesys darbe skiriamas analizuojant sąlygas ir atvejus, kada nelaimingi atsitikimai darbe yra pripažįstami draudiminiais ir kada nedraudiminiais įvykiais, pateikiant administracinių teismų praktiką nagrinėjant ginčus dėl nelaimingų atsitikimų darbe pripažinimo nedraudiminiais įvykiais. / Theoretical and practical aspects of investigation of accidents at work are analyzed in this Master work. In the paper are analyzed legal acts, which regulate the procedure of investigation of accidents at work, also the conception of accidents and incidents at work is on the course of discussion. The main purposes of investigation of accidents at work are mentioned, subjects and institutes, which have the right to organize and perform the procedure of investigation, and their position in investigation are disputed. There are analyzed the different forms of documents, which are filled in during the investigation of accidents at work, and the period of investigation in this Master work. The procedure of investigation of accidents at work is divided in to several parts according to the subjects’ actions which take place in the procedure of investigation. Also the changes of legal acts are suggested. The analysis is based on the cases of the General Administrative Court of Lithuania the Supreme Court of Lithuania, the Constitutional Court of Lithuania, legislation, the information statistics about the accidents at work during the three years of the National Labour Inspection and the Social Security and Labour Ministry of Lithuania. The main attention in this Master work is given to analyze the conditions and the cases, when the accidents at work are accepted as the insurance events. This analysis is based on the cases of Administrative Courts.

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