4,168 research outputs found

    Design mobile satellite system architecture as an integral part of the cellular access digital network

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    The Cellular Access Digital Network (CADN) is the access vehicle through which cellular technology is brought into the mainstream of the evolving integrated telecommunications network. Beyond the integrated end-to-end digital access and per call network services provisioning of the Integrated Services Digital Network (ISDN), the CADN engenders the added capability of mobility freedom via wireless access. One key element of the CADN network architecture is the standard user to network interface that is independent of RF transmission technology. Since the Mobile Satellite System (MSS) is envisioned to not only complement but also enhance the capabilities of the terrestrial cellular telecommunications network, compatibility and interoperability between terrestrial cellular and mobile satellite systems are vitally important to provide an integrated moving telecommunications network of the future. From a network standpoint, there exist very strong commonalities between the terrestrial cellular system and the mobile satellite system. Therefore, the MSS architecture should be designed as an integral part of the CADN. This paper describes the concept of the CADN, the functional architecture of the MSS, and the user-network interface signaling protocols

    Investigation of the existence of hybrid stars using Nambu-Jona-Lasinio models

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    We investigate the hadron-quark phase transition inside neutron stars and obtain mass-radius relations for hybrid stars. The equation of state for the quark phase using the standard NJL model is too soft leading to an unstable star and suggesting a modification of the NJL model by introducing a momentum cutoff dependent on the chemical potential. However, even in this approach, the instability remains. In order to remedy the instability we suggest the introduction of a vector coupling in the NJL model, which makes the EoS stiffer, reducing the instability. We conclude that the possible existence of quark matter inside the stars require high densities, leading to very compact stars.Comment: 4 pages, 2 figures; prepared for IV International Workshop on Astronomy and Relativistic Astrophysics (IWARA 2009), Maresias, 4-8 Oct 200

    Avaliação das necessidades energéticas no doente crítico

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    Introdução: Os doentes críticos são um grupo de do- entes francamente hipermetabólicos que necessitam de um suporte nutricional adequado às suas necessidades. Objectivos: Verificar o melhor método para determinar as neces- sidades energéticas de doentes críticos. Material e métodos: Estudo transversal analítico no qual foram recolhidos dados demográficos, determinado o consumo energético quer por calorimetria indirecta, quer pela fórmula de Harris-Benedict e além disso calculado o fator de stress de pacientes internados entre 2004 e 2009. Resultados: Incluíram- se neste estudo 139 doentes (33% feminino, 67% masculino). Foram efetuadas 298 medidas pela calorimetria indireta, com tempo útil médio de 9 horas, que foram compa- radas às necessidades energéticas calculadas a partir da equação de Harris-Benedict. Encontraram-se diferenças significativas entre os resultados obtidos. O consumo energético mensurado foi 27,9 Kcal/kg (mediana), e quando comparado à equação de Harris-Benedict, evidenciou-se um valor subestimado em 25% (7 Kcal/kg). A mediana do fator de stress encontrado para a correção da fórmula de Harris- Benedict foi de 1,31. Discussão e conclusão: Embora exista uma variabilidade do consumo energético nesses doentes, a fórmula de Harris-Benedict, quando associada a um fator stress entre 1,25 – 1,35, poderá ser um método eficaz na avaliação das necessidades nutricionais. Por outro lado, pode-se optar também por uma abordagem mais simplificada, utilizando valores energéticos entre 25 a 30 Kcal por quilograma de peso. Obviamente, a calorimetria indireta continua a ser o “gold standard’’ da avaliação do consumo energético, já que nos permite adequar as necessidades energéticas em função do consumo energético in- dividual de acordo com o gasto real de cada doente

    Inclusion Body Myositis Treated with Alemtuzumab

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    nclusion body myositis (IBM) is a chronic inflammatory myopathy with a progressive course. It is more common in the later years of life and usually presents with limb weakness. We present the case of a patient who developed proximal weakness in the lower limbs and, four years later, facial asymmetry. Blood analysis revealed high lactate dehydrogenase and creatinine kinase values. The diagnosis was obtained through muscle biopsy which met the histological criteria for IBM. The patient started treatment with alemtuzumab, leading to stabilisation of the symptoms in two years. Learning points: IBM should be considered in the differential diagnosis of muscle weakness.Patients may present uncommon symptoms, such as prominent facial involvement.Alemtuzumab may potentially be beneficial in limiting the progression of IBM.info:eu-repo/semantics/publishedVersio

    CFD AND SWIMMING: PRACTICAL APPLICATIONS

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    In this presentation topics in swimming simulation from a computational fluid dynamics perspective are discussed. This perspective means emphasis on the fluid mechanics and computational fluid dynamics methodology applied in swimming research. This talk presents new information based on recent scientific research conducted at the Research Centre in Sports Sciences, Health Sciences and Human Development (CIDESD, Vila Real, Portugal). We concentrated on numerical simulation results, considering the scientific simulation point-of-view and especially the practical implications with swimmers and coaches. Computational Fluid Dynamics has been applied to swimming in order to understand its relationships with performance. The numerical techniques have been applied to the analysis of the propulsive forces generated by the propelling segments and to the analysis of the hydrodynamic drag forces resisting forward motion
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