Scattering polarization in the CaII Infrared Triplet with Velocity Gradients

Magnetic field topology, thermal structure and plasma motions are the three main factors affecting the polarization signals used to understand our star. In this theoretical investigation, we focus on the effect that gradients in the macroscopic vertical velocity field have on the non-magnetic scattering polarization signals, establishing the basis for general cases. We demonstrate that the solar plasma velocity gradients have a significant effect on the linear polarization produced by scattering in chromospheric spectral lines. In particular, we show the impact of velocity gradients on the anisotropy of the radiation field and on the ensuing fractional alignment of the CaII levels, and how they can lead to an enhancement of the zero-field linear polarization signals. This investigation remarks the importance of knowing the dynamical state of the solar atmosphere in order to correctly interpret spectropolarimetric measurements, which is important, among other things, for establishing a suitable zero field reference case to infer magnetic fields via the Hanle effect.Comment: 14 pages, 10 figures, 3 appendixes, accepted for publication in Ap

Impact pressures of turbulent high-velocity jets plunging in pools with flat bottom

Dynamic pressures created by the impact of high-velocity turbulent jets plunging in a water pool with flat bottom were investigated. Pressure fluctuations were sampled at 1kHz at the jet outlet and at the pool bottom using piezo-resistive pressure transducers, jet velocities of up to 30m/s and pool depth to jet diameter ratios from 2.8 to 11.4. The high-velocity jets entrain air in the pool in conditions similar to prototype applications at water release structures of dams. The intermittent character of plunge pool flows was investigated for shallow and deep pools, based on high order moments and time correlations. Maximum intermittency was observed for pool depths at 5.6 jet diameters, which approximate the core development length. Wall pressure skewness was shown to allow identifying the zone of influence of downward and upward moving current

The reform of the portuguese pension system: a micro-simulation approach

Doutoramento em Estudos do DesenvolvimentoThis thesis uses a Dynamic Microsimulation Model (DYNAPOR) to analyse the impact of a transition from a traditional Defined Benefit Pay-As-You-Go pension scheme to a Notional Defined Contribution system on both the financial and the social sustainability of the pension system in Portugal. The results show that while the NDC scenarios outperform the DB-PAYG system in terms of financial sustainability, it does so at cost of the social component. Additionally, the various features of the NDC pension system are proven to be essential in both curbing expenditure and improving adequacy and poverty alleviation.Esta tese utiliza um modelo de micro-simulação dinâmico (DYNAPOR) para analisar o impacto económico, financeiro e social da transição de um sistema de pensões pay-as-you-go de benefício definido para um sistema de contas nocionais em Portugal. Utiliza o modelo DYNAPOR para simular quatro cenários diferentes. Os resultados obtidos sugerem que uma transição para um sistema de contas nocionais semelhante ao que está em vigor na Suécia se traduz num melhoramento significativo da sustentabilidade financeira em relação ao previsto no sistema atual. Contudo, este melhoramento na sustentabilidade financeira acontece em detrimento da componente social do sistema de pensões. Mais, o impacto da componente redistributiva e de balanço automático do sistema NDC no alívio da pobreza e da despesa é comprovado pelos resultados.N/

Organização dos serviços para garantir acesso e promover vinculação do usuário de drogas

Na primeira unidade aborda os desafios e as propostas existentes para a organização do trabalho de acolhimento e cuidado do usuário de álcool e outras drogas por equipes multidisciplinares capazes de escuta qualificada. Trata da importância do registro como ferramenta de vinculação e das demais estratégias para garantir o acesso da clientela aos serviços. Na segunda unidade trata da construção do vínculo por meio da abertura de portas em diferentes lugares, da importância de conhecer o usuário, da flexibilidade do cuidado como ferramenta fundamental. Aborda, também, a consolidação do vínculo, por meio do trabalho em equipes interdisciplinares e em redes, da adequação da comunicação, das boas condições do ambiente e da construção do PTS. Em ambas as unidades, apresenta leituras complementares e referências.1.0Ministério da Saúd

Efficacy of Corncob and Rice Husk Biochar as Liming Agent and Phosphorus Source for Growth of Soybean in Two Acid Soils

Soil acidity, unavailability and high cost of conventional liming materials are major constraints to soybean production in the Western Region of Ghana. Research has shown that biochar produced from agricultural waste has high concentration of basic cations and available P that could be exploited for use as liming material and/or P source. However, the biochar type that will provide an ideal soil pH and P availability for soybean production in acid soils has received little attention. Therefore, for this study, two acid soils namely; Ankasa Series (Typic Hapludox) and Tikobo Series (Typic Hapludult) were amended with corncob and rice husk biochar types charred at 500 and 700 oC at a rate of 80 tons/ha in a pot experiment in a screen house to ascertain the efficacy of the biochar types as agricultural lime and P sources for soybean growth. The Ca equivalent of the biochar types from CaCO3 was amended to the soils to serve as realistic control. The soils were arranged in a completely randomized design in a screen house to allow for pH equilibration. After pH equilibration, inoculated soybean seeds were sown at stake. Nitrogen was applied at rates of 0 kg/ha and 10 kg/ha. Phosphorus from TSP was applied at 0 and biochar P equivalent to the non-biochar-amended soils. Extra 30 kg P/ha from TSP was applied to some of the biochar amended soils to ascertain if any, the combined effect of synthetic and biochar P on soybean growth. At flower initiation, the crops were harvested, root volume and P uptake determined. Amended with rice husk biochar charred at 700 oC, the shoot P uptake was 1.3 times more in both the Typic Hapludox and the Typic Hapludult than the same soils amended with conventional lime with equivalent biochar P from the synthetic source

Heating of the magnetized solar chromosphere by partial ionization effects

In this paper, we study the heating of the magnetized solar chromosphere induced by the large fraction of neutral atoms present in this layer. The presence of neutrals, together with the decrease with height of the collisional coupling, leads to deviations from the classical MHD behavior of the chromospheric plasma. A relative net motion appears between the neutral and ionized components, usually referred to as ambipolar diffusion. The dissipation of currents in the chromosphere is enhanced orders of magnitude due to the action of ambipolar diffusion, as compared to the standard ohmic diffusion. We propose that a significant amount of magnetic energy can be released to the chromosphere just by existing force-free 10--40 G magnetic fields there. As a consequence, we conclude that ambipolar diffusion is an important process that should be included in chromospheric heating models, as it has the potential to rapidly heat the chromosphere. We perform analytical estimations and numerical simulations to prove this idea.Comment: Accepted for publication by The Astrophysical Journa

Effects of caspofungin against Candida guilliermondii and Candida parapsilosis.

The in vitro activity of caspofungin (CAS) was investigated against 28 yeast isolates belonging to Candida albicans (n = 5), Candida guilliermondii (n = 10), and Candida parapsilosis (n = 13). CAS MICs obtained by broth dilution and Etest methods clearly showed a rank order of susceptibility to the echinocandin compound with C. albicans > C. parapsilosis > C. guilliermondii. Similarly, time-kill assays performed on selected isolates showed that CAS was fungistatic against C. albicans and C. parapsilosis, while it did not exert any activity against C. guilliermondii. In a murine model of systemic candidiasis, CAS given at doses as low as 1 mg/kg of body weight/day was effective at reducing the kidney burden of mice infected with either C. albicans or C. guilliermondii isolates. Depending on the isolate tested, mice infected with C. parapsilosis responded to CAS given at 1 and/or 5 mg/kg/day. However, the overall CFU reduction for C. guilliermondii and C. parapsilosis was approximately 100-fold less than that for C. albicans. Our study shows that CAS was active in experimental systemic candidiasis due to C. guilliermondii and C. parapsilosis, but this activity required relatively high drug dosages