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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

Análise da Sustentabilidade Empresarial de Indústrias do setor de Cerâmica Vermelha do Estado da Paraíba

Silva Filho, Petrucio Dumont Mamede e 27 February 2014 (has links)
Made available in DSpace on 2015-04-16T14:49:14Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1746554 bytes, checksum: ffefb909ff874bcdf4e0461185bd14d3 (MD5) Previous issue date: 2014-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The growing concern with the current model of economic development and its consequences for society and the environment led authorities to undertake major global debates on sustainability. Converging with this fact, organizations of several industrial sectors are becoming more aware of their role in the sustainable development process, seeking to adapt their business activities to the precepts espoused by the triple bottom line model. Emerging in this scenario is the segment of the red ceramic industry, from the moment that the industry is a large consumer of energy and natural resources and generates residues. In this scenario, efforts to mitigate environmental and social impacts should be performed. By contextualizing this sector with the reality in Paraiba state, the environmental situation is delicate, since the regions of the rainforest and rural have an ecosystem important for the survival of native animal species, and their exploitation for providing firewood and clay can result in serious damage to the environment. Thus, it is opportune to analyze the sustainability of enterprises of this sector in the state. Thus, this study aims to evaluate business sustainability of red ceramic industries in the state of Paraíba, based on the Corporate Sustainability Grid (CSG). Hence, we attempted to calculate the Partial Sustainability Scores (EPS) and Corporate Sustainability Scores (ESE) to proceed with the positioning of the companies investigated on the Grid. Qualitative and quantitative in nature, the research is characterized as exploratory as to the purposes and on the means as field, literature, and multi-case study. Data were collected through structured questionnaire, in accordance with the environmental, social and economic dimensions of sustainability, applied in three ceramic industries. The results indicate that one company obtained Corporate Sustainability Score 3 (Satisfactory), showing that it harmonizes satisfactory performances in the three dimensions analyzed. The other two were Corporate Sustainability Score 1 (Weak), where one of them exhibited satisfactory performance only on the environmental dimension, and the other recorded satisfactory performance only on the social dimension. We conclude that the companies have conditions to improve their activities to suit a more sustainable reality, noting the weaknesses highlighted by the investigated sustainability indicators / A crescente preocupação com o modelo de desenvolvimento econômico vigente e com suas consequências para a sociedade e meio ambiente, motivou autoridades mundiais a realizarem importantes debates sobre Sustentabilidade. Alinhado a isso, organizações de diversos setores vem se tornando mais conscientes de seu papel no processo do Desenvolvimento Sustentável, buscando adequar suas atividades empresariais aos preceitos defendidos pelo modelo triple bottom line. Emergindo neste cenário está o segmento da indústria de cerâmica vermelha, no momento em que a indústria é grande consumidora de recursos naturais e energéticos, bem como geradora de resíduos. Diante deste cenário, esforços para mitigar seus impactos ambientais e sociais devem ser realizados. Ao contextualizar este setor na realidade paraibana, a conjuntura ambiental é delicada, no momento em que as regiões da zona da mata e agreste possuem ecossistema importante para sobrevivência de espécies nativas de animais, e sua exploração para provimento de lenha e argila pode acarretar em sérios danos ao meio ambiente. Desta forma, torna-se oportuna uma avaliação da sustentabilidade das empresas do setor no estado. Assim, o presente estudo tem como objetivo avaliar a sustentabilidade empresarial de indústrias de cerâmica vermelha do estado da Paraíba, a partir do Grid de Sustentabilidade Empresarial (GSE). Desta forma, buscou-se calcular os Escores Parciais de Sustentabilidade (EPS) e os Escores de Sustentabilidade Empresarial (ESE) para prosseguir com o posicionamento das empresas investigadas no GSE. De natureza qualitativa e quantitativa, a pesquisa se caracteriza quanto aos fins como exploratória, e quanto aos meios como sendo de campo, bibliográfica, e como estudo multi-caso. Os dados foram coletados a partir de questionário estruturado, em conformidade com as dimensões ambiental, econômica e social da sustentabilidade, aplicado em três indústrias de cerâmica. Os resultados indicam que uma empresa obteve Escore 3 de Sustentabilidade Empresarial (Satisfatória), mostrando que consegue conciliar desempenhos satisfatórios nas três dimensões analisadas. As outras duas obtiveram Escore 1 de Sustentabilidade Empresarial (Fraca), onde uma delas exibiu desempenho satisfatório apenas na dimensão ambiental, e a outra registrou desempenho satisfatório apenas na dimensão social. Conclui-se que as cerâmicas estudadas possuem condições de melhorar suas atividades para se adequarem a uma realidade mais sustentável, observando os pontos fracos evidenciados pelos indicadores de sustentabilidade investigados
12

Voltage Stability and Reactive Power Provision in a Decentralizing Energy System / Spannungshaltung und Blindleistungsmanagement bei zunehmend dezentraler Stromerzeugung - eine techo-ökonomische Analyse

Hinz, Fabian 19 December 2017 (has links) (PDF)
Electricity grids require the ancillary services frequency control, grid operation, re-establishment of supply and voltage stability for a proper operation. Historically, conventional power plants in the transmission grid were the main source providing these services. An increasing share of decentralized renewable energy in the electricity mix causes decreasing dispatch times for conventional power plants and may consequently lead to a partial replacement of these technologies. Decentralized energy sources are technically capable of providing ancillary services. This work focuses on the provision of reactive power for voltage stability from decentralized sources. The aim is to answer the question of how voltage stability and reactive power management can be achieved in a future electricity system with increasing shares of decentralized renewable energy sources in an economical and efficient way. A methodology that takes reactive power and voltage stability in an electricity system into account is developed. It allows for the evaluation of the economic benefits of different reactive power supply options. A non-linear and a linearized techno-economic grid model are formulated for this purpose. The analysis reveals an increasing importance of reactive power from the distribution grid in future development scenarios, in particular if delays in grid extension are taken into account. The bottom-up assessment indicates a savings potential of up to 40 mio. EUR per year if reactive power sources in the distribution grid provide reactive power in a controlled manner. Although these savings constitute only a small portion of the total cost of the electricity system, reactive power from decentralized energy sources contributes to the change towards a system based on renewable energy sources. A comparison of different reactive power remuneration mechanisms shows that a variety of approaches exist that could replace the inflexible mechanisms of obligatory provision and penalized consumption of reactive power that are mostly in place nowadays.
13

Voltage Stability and Reactive Power Provision in a Decentralizing Energy System: A Techno-economic Analysis

Hinz, Fabian 06 December 2017 (has links)
Electricity grids require the ancillary services frequency control, grid operation, re-establishment of supply and voltage stability for a proper operation. Historically, conventional power plants in the transmission grid were the main source providing these services. An increasing share of decentralized renewable energy in the electricity mix causes decreasing dispatch times for conventional power plants and may consequently lead to a partial replacement of these technologies. Decentralized energy sources are technically capable of providing ancillary services. This work focuses on the provision of reactive power for voltage stability from decentralized sources. The aim is to answer the question of how voltage stability and reactive power management can be achieved in a future electricity system with increasing shares of decentralized renewable energy sources in an economical and efficient way. A methodology that takes reactive power and voltage stability in an electricity system into account is developed. It allows for the evaluation of the economic benefits of different reactive power supply options. A non-linear and a linearized techno-economic grid model are formulated for this purpose. The analysis reveals an increasing importance of reactive power from the distribution grid in future development scenarios, in particular if delays in grid extension are taken into account. The bottom-up assessment indicates a savings potential of up to 40 mio. EUR per year if reactive power sources in the distribution grid provide reactive power in a controlled manner. Although these savings constitute only a small portion of the total cost of the electricity system, reactive power from decentralized energy sources contributes to the change towards a system based on renewable energy sources. A comparison of different reactive power remuneration mechanisms shows that a variety of approaches exist that could replace the inflexible mechanisms of obligatory provision and penalized consumption of reactive power that are mostly in place nowadays.
14

Приступи развоју базe података Општег информационог модела за електроенергетске мреже / Pristupi razvoju baze podataka Opšteg informacionog modela za elektroenergetske mreže / Approaches for Developing a Database for Common Information Model of Power Grids

Dević Saša 01 March 2019 (has links)
<p>Општи информациони модел (CIM) користи се за опис електроенергетске мреже и за размену података између оператера преносних електроенергетских система. Како је модел постајао све заступљенији, појавила се потреба за његовим складиштењем. У раду је развијен методолошки приступ за развој базе података која би подржала релативно једноставно складиштење и рад са инстанцама CIM модела, које описују тренутно, активно стање у систему. Такође, омогућено је и праћење претходних, историјских стања CIM инстанци, као и њихова рестаурација у жељено стање. Очекује се да предложени приступ олакша увођење CIM модела у различита, наменска програмска решења.</p> / <p>Opšti informacioni model (CIM) koristi se za opis elektroenergetske mreže i za razmenu podataka između operatera prenosnih elektroenergetskih sistema. Kako je model postajao sve zastupljeniji, pojavila se potreba za njegovim skladištenjem. U radu je razvijen metodološki pristup za razvoj baze podataka koja bi podržala relativno jednostavno skladištenje i rad sa instancama CIM modela, koje opisuju trenutno, aktivno stanje u sistemu. Takođe, omogućeno je i praćenje prethodnih, istorijskih stanja CIM instanci, kao i njihova restauracija u željeno stanje. Očekuje se da predloženi pristup olakša uvođenje CIM modela u različita, namenska programska rešenja.</p> / <p>Common Information Model (CIM) is used for describing power grid networks<br />and data exchange among transmission system operators (TSO). As the<br />model became widely used, there was a need to store such model. In this<br />thesis we present a methodological approach to development of a database<br />that supports relatively easy storing and managing CIM instances, which<br />describe current, active state of the system. Also, tracking changes and<br />restoring CIM instances to its previous states are supported. We expect that<br />such methodological approach would ease the implementation of CIM model<br />in various, domain specific software solutions.</p>

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