1,713 research outputs found

    Development and test of resistive superconducting fault current limiter; acting time and its recovery conditions

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    Resistive-type of superconducting fault current limiters (RSFCL) have been developed for medium voltage class aiming to operate at 1 MVA power capacity and short time recovery (< 2 s). A RSFCL in form of superconducting modular device was designed and constructed using 50 m-length of YBCO coated conductor tapes for operation under 1 kV / 1 kA and acting time of 0.1 s. In order to increase the acting time the RSFCL was combined with an air-core reactor in parallel to increase the fault limiting time up to 1 s. The tests determined the electrical and thermal characteristics of the combined resistive/ inductive protection unit. The combined fault current limiter reached a limiting current of 583 A, corresponding to a limiting factor of 3.3 times within an acting time of up to 1 s

    Necessidades sentidas pelo familiar do doente com esquizofrenia

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    A esquizofrenia é uma das perturbações psiquiátricas mais enigmáticas e devastadora, devido aos efeitos debilitantes que ocorrem ao longo do curso da doença. Este, é um dos principais problemas de saúde pública e afeta, além dos doentes, os seus familiares causando inúmeros prejuízos funcionais e sociais. Aos familiares é pedido que entendam e aceitem a doença, protejam e estimulem o doente; tarefas, muitas vezes, complicadas diante das vivências diárias. Após o diagnóstico da doença, os familiares deparam-se com algumas necessidades, que se poderão agrupar por: necessidades de informação, psicológicas, espirituais, emocionais e económicas. O presente trabalho tem como finalidade explorar as necessidades sentidas pelo familiar do doente com esquizofrenia, para que possamos ajudá-lo a compreender e adaptar-se à situação de doença, de forma a possibilitar a relação entre ambos e minorizar os problemas que daí advém. Esta investigação tem como objetivos: identificar o conhecimento que a família, do doente portador de esquizofrenia, tem acerca da doença; Compreender de que forma a família se adapta à doença; Identificar a necessidade de intervenção do enfermeiro junto da família do doente com esquizofrenia. Este é um estudo de natureza qualitativa, descritivo, de caráter retrospetivo. Na elaboração deste estudo foram respeitados os princípios enunciados no relatório de Belmont. O grupo de participantes foi selecionado de acordo com uma técnica de amostragem não probabilista intencional, resultando 10 indivíduos, de ambos os sexos, familiares de doentes com o diagnóstico de esquizofrenia. Para a recolha de dados recorremos a entrevista exploratória semi estruturada, aplicada aos familiares de utentes com esquizofrenia. Foram seguidos os pressupostos de Bardin na análise de conteúdo, procedendo-se a análise categorial , tendo sido criadas categorias e subcategorias. Assim, o estudo permitiu constatar que os familiares têm um conhecimento empírico da doença, descrevendo os sintomas e os efeitos colaterais, mas não conseguem enquadrar a mesma face a patologias psiquiátricas semelhantes. São escassos os conhecimentos que os familiares têm acerca da esquizofrenia, 8 dos familiares desconhecem a doença e 2 confundem-na com outras patologia. Isto reflete-se no quotidiano familiar, verificando-se a necessidade de intervenção dos enfermeiros, no sentido de colmatar dúvidas dos mesmos. A doença mental e, em particular, a esquizofrenia afeta profundamente a família, sofrendo alterações de rotina familiar (9 familiares), de trabalho (2 familiares) e sociais (6 familiares), advindo destas implicações económicas e situações de doença noutros membros da família. Todos os familiares inquiridos têm necessidade que lhe seja fornecida informação, para que, numa situação de crise saibam como proceder, seja através de ações, seja para proceder à hospitalização do paciente

    Observations of the F-region ionospheric irregularities in the South American sector during the October 2003 "Halloween Storms"

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    The response of the ionospheric F-region in the South American sector during the super geomagnetic storms on 29 and 30 October 2003 is studied in the present investigation. In this paper, we present ionospheric sounding observations during the period 29-31 October 2003 obtained at Palmas (a near equatorial location) and Sao Jose dos Campos (a location under the southern crest of the equatorial ionospheric anomaly), Brazil, along with observations during the period 27-31 October 2003 from a chain of GPS stations covering the South American sector from Imperatriz, Brazil, to Rio Grande, Argentina. Also, complementary observations that include sequences of all-sky images of the OI 777.4 and 630.0 nm emissions observed at El Leoncito, Argentina, on the nights of 28-29 (geomagnetically quiet night) and 29-30 (geomagnetically disturbed night) October 2003, and ion densities observed in the South American sector by the DMSP F13, F14 and F15 satellites orbiting at about 800 km on 29 and 30 October 2003 are presented. In addition, global TEC maps derived from GPS observations collected from the global GPS network of International GPS Service (IGS) are presented, showing widespread and drastic TEC changes during the different phases of the geomagnetic disturbances. The observations indicate that the equatorial ionospheric irregularities or plasma bubbles extend to the Argentinean station Rawson (geom. Lat. 33.1° S) and map at the magnetic equator at an altitude of about 2500 km.Facultad de Ciencias Astronómicas y Geofísica

    IRI-2001 model predictions compared with ionospheric data observed at Brazilian low latitude stations

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    International audienceIn this work, the F-region critical frequency (foF2) and peak height (hmF2) measured by digital ionosondes at two Brazilian low-latitude stations, namely Palmas (10.17° S, 48.20° W, dip ?10.80°) and São José dos Campos (23.20° S, 45.86° W, dip ?38.41°), are compared with the IRI-2001 model predictions. The comparison at the latter station shows quite a reasonable agreement for both parameters. The former station exhibits a better agreement for hmF2 than for foF2. In general, the model generates good results, although some improvements are still necessary to implement in order to obtain better simulations for equatorial ionospheric regions

    The natural science of cosmology

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    The network of cosmological tests is tight enough now to show that the relativistic Big Bang cosmology is a good approximation to what happened as the universe expanded and cooled through light element production and evolved to the present. I explain why I reach this conclusion, comment on the varieties of philosophies informing searches for a still better cosmology, and offer an example for further study, the curious tendency of some classes of galaxies to behave as island universes.Comment: Keynote lecture at the seventh International Conference on Gravitation and Cosmology, Goa India, December 201

    Updated Big Bang Nucleosynthesis Bounds on Long-lived Particles from Dark Sectors

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    As electromagnetic showers may alter the abundance of Helium, Lithium, and Deuterium, we can place severe constraints on the lifetime and amount of electromagnetic energy injected by long-lived particles. Considering up-to-date measurements of the light element abundances that point to Yp=0.245±0.003Y_p=0.245\pm 0.003,(D/H)=(2.527±0.03)×10−5({\rm D/H})= (2.527\pm 0.03)\times 10^{-5},(7Li/H)=1.58−0.28+0.35×10−10(^7{\rm Li/H})=1.58 ^{+0.35}_{-0.28} \times 10^{-10}, (6Li/7Li)=0.05(^6{\rm Li/^7 Li})=0.05, and the baryon-to-photon ratio obtained from the Cosmic Microwave Background data, η=6.104×10−10\eta=6.104 \times 10^{-10}, we derive upper limits on the fraction of electromagnetic energy produced by long-lived particles. Our findings apply to decaying dark matter models, long-lived gravitinos, and other non-thermal processes that occurred in the early universe between 102−101010^2-10^{10} seconds.Comment: 7 pages, 3 figure
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