977 resultados para perturbações periódicas


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Esta dissertação apresenta uma avaliação dinâmica da conexão Tucuruí-Manaus-Macapá ao Sistema Interligado Nacional frente a pequenas e grandes perturbações. Todos os dados utilizados foram obtidos da base de dados do Operador Nacional do Sistema Elétrico. No entanto, os parâmetros dos estabilizadores dos sistemas de potência das usinas de Macapá não estão sintonizados para a interconexão e as usinas de Manaus não apresentam dispositivos suplementares amortecedores. Sendo assim, o objetivo deste trabalho é projetar estabilizadores de sistemas de potência para as usinas hidrelétricas de Coaraci Nunes e Balbina, e também para as usinas térmicas de Mauá e Aparecida, através de técnicas de respostas em frequência baseada no critério de Nyquist. A utilização dos estabilizadores tem como finalidade o amortecimento dos modos eletromecânicos que surgem quando os sistemas isolados do Amapá e do Amazonas passam a ser integrados ao sistema interligado nacional. Os projetos são avaliados em diversos cenários operativos através de simulações no domínio do tempo.

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Pós-graduação em Engenharia Elétrica - FEIS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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To establish guidelines based on cientific evidences for the management of cryopyrin associated periodic syndromes. The Guideline was prepared from 4 clinical questions that were structured through Pico (Patient, Intervention or indicator, Comparison and Outcome), to search in key primary scientific information databases. After defining the potential studies to support the recommendations, these were graduated considering their strength of evidence and grade of recommendation. 1215 articles were retrieved and evaluated by title and abstract; from these, 42 articles were selected to support the recommendations. 1. The diagnosis of Caps is based on clinical history and clinical manifestations, and later confirmed by genetic study. Caps may manifest itself in three phenotypes: FCAS (mild form), MWS (intermediate form) and Cinca (severe form). Neurological, ophthalmic, otorhinolaryngological and radiological assessments may be highly valuable in distinguishing between syndromes; 2. The genetic diagnosis with NLRP3 gene analysis must be conducted in suspected cases of Caps, i.e., individuals presenting before 20 years of age, recurrent episodes of inflammation expressed by a mild fever and urticaria; 3. Laboratory abnormalities include leukocytosis and elevated serum levels of inflammatory proteins; 4. Targeted therapies directed against interleukin-1 lead to rapid remission of symptoms in most patients. However, there are important limitations on the long-term safety. None of the three anti-IL-1β inhibitors prevents progression of bone lesions.

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To establish guidelines based on scientific evidence for the management of periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome. The Guideline was prepared from 5 clinical questions that were structured through PICO (Patient, Intervention or indicator, Comparison and Outcome), to search in key primary scientific information databases. After defining the potential studies to support the recommendations, these were graduated considering their strength of evidence and grade of recommendation. 806 articles were retrieved and evaluated by title and abstract; from these, 32 articles were selected to support the recommendations. 1. PFAPA is a diagnosis of exclusion established on clinical grounds, and one must suspect of this problem in children with recurrent and periodic febrile episodes of unknown origin, or with recurrent tonsillitis interspersed with asymptomatic periods, especially in children in good general condition and with preservation of weight and height development; 2. Laboratory findings are nonspecific. Additional tests do not reveal pathognomonic changes; 3. The evidence supporting an indication for surgical treatment (tonsillectomy with or without adenoidectomy), is based on two non-blinded randomized clinical trials with small numbers of patients; 4. The use of prednisone at the onset of fever in patients with PFAPA proved to be an effective strategy. There is still need for more qualified evidence to support its use in patients with PFAPA; 5. Despite promising results obtained in studies with IL-1ß inhibitors, such studies are limited to a few case reports.