Intensity contrast of solar network and faculae close to the solar limb, observed from two vantage points

The brightness of faculae and network depends on the angle at which they are observed and the magnetic flux density. Close to the limb, assessment of this relationship has until now been hindered by the increasingly lower signal in magnetograms. This preliminary study aims at highlighting the potential of using simultaneous observations from different vantage points to better determine the properties of faculae close to the limb. We use data from the Solar Orbiter/Polarimetric and Helioseismic Imager (SO/PHI), and the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI), recorded at $\sim60^\circ$ angular separation of their lines of sight at the Sun. We use continuum intensity observed close to the limb by SO/PHI and complement it with the co-observed $B_{\rm LOS}$ from SDO/HMI, originating closer to disc centre (as seen by SDO/HMI), thus avoiding the degradation of the magnetic field signal near the limb. We derived the dependence of facular brightness in the continuum on disc position and magnetic flux density from the combined observations of SO/PHI and SDO/HMI. Compared with a single point of view, we were able to obtain contrast values reaching closer to the limb and to lower field strengths. We find the general dependence of the limb distance at which the contrast is maximum on the flux density to be at large in line with single viewpoint observations, in that the higher the flux density is, the closer the turning point lies to the limb. There is a tendency, however, for the maximum to be reached closer to the limb when determined from two vantage points. We note that due to the preliminary nature of this study, these results must be taken with caution. Our analysis shows that studies involving two viewpoints can significantly improve the detection of faculae near the solar limb and the determination of their brightness contrast relative to the quiet Sun

The ratio of horizontal to vertical displacement in solar oscillations estimated from combined SO/PHI and SDO/HMI observations

In order to make accurate inferences about the solar interior using helioseismology, it is essential to understand all the relevant physical effects on the observations. One effect to understand is the (complex-valued) ratio of the horizontal to vertical displacement of the p- and f-modes at the height at which they are observed. Unfortunately, it is impossible to measure this ratio directly from a single vantage point, and it has been difficult to disentangle observationally from other effects. In this paper we attempt to measure the ratio directly using 7.5 hours of simultaneous observations from the Polarimetric and Helioseismic Imager on board Solar Orbiter and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. While image geometry problems make it difficult to determine the exact ratio, it appears to agree well with that expected from adiabatic oscillations in a standard solar model. On the other hand it does not agree with a commonly used approximation, indicating that this approximation should not be used in helioseismic analyses. In addition, the ratio appears to be real-valued.Comment: Accepted for publication in Astronomy & Astrophysics. 8 pages, 8 figure

Coronal voids and their magnetic nature

Context: Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these coronal features is not well understood. // Aims: We study the magnetic properties of the weakly emitting extended regions, which we name coronal voids. In particular, we aim to understand whether these voids result from a reduced heat input into the corona or if they are associated with mainly unipolar and possibly open magnetic fields, similar to coronal holes. // Methods: We defined the coronal voids via an intensity threshold of 75% of the mean quiet-Sun (QS) EUV intensity observed by the high-resolution EUV channel (HRIEUV) of the Extreme Ultraviolet Imager on Solar Orbiter. The line-of-sight magnetograms of the same solar region recorded by the High Resolution Telescope of the Polarimetric and Helioseismic Imager allowed us to compare the photospheric magnetic field beneath the coronal voids with that in other parts of the QS. // Results: The coronal voids studied here range in size from a few granules to a few supergranules and on average exhibit a reduced intensity of 67% of the mean value of the entire field of view. The magnetic flux density in the photosphere below the voids is 76% (or more) lower than in the surrounding QS. Specifically, the coronal voids show much weaker or no network structures. The detected flux imbalances fall in the range of imbalances found in QS areas of the same size. // Conclusions: We conclude that coronal voids form because of locally reduced heating of the corona due to reduced magnetic flux density in the photosphere. This makes them a distinct class of (dark) structure, different from coronal holes

Coronal voids and their magnetic nature

Context. Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these coronal features is not well understood.Aims. We study the magnetic properties of the weakly emitting extended regions, which we name coronal voids. In particular, we aim to understand whether these voids result from a reduced heat input into the corona or if they are associated with mainly unipolar and possibly open magnetic fields, similar to coronal holes. Methods. We defined the coronal voids via an intensity threshold of 75% of the mean quiet-Sun (QS) EUV intensity observed by the high- resolution EUV channel (HRIEUV) of the Extreme Ultraviolet Imager on Solar Orbiter. The line-of-sight magnetograms of the same solar region recorded by the High Resolution Telescope of the Polarimetric and Helioseismic Imager allowed us to compare the photospheric magnetic field beneath the coronal voids with that in other parts of the QS.Results. The coronal voids studied here range in size from a few granules to a few supergranules and on average exhibit a reduced intensity of 67% of the mean value of the entire field of view. The magnetic flux density in the photosphere below the voids is 76% (or more) lower than in the surrounding QS. Specifically, the coronal voids show much weaker or no network structures. The detected flux imbalances fall in the range of imbalances found in QS areas of the same size. Conclusions. We conclude that coronal voids form because of locally reduced heating of the corona due to reduced magnetic flux density in the photosphere. This makes them a distinct class of (dark) structure, different from coronal holes

Cuidadores informales: los pilares de la dependencia en el Alzheimer

Treball final de Grau en Infermeria. Codi: IN1138. Curs acadèmic 2014-2015Introducción: Los cuidadores informales son los encargados de prestar la ayuda necesaria a los pacientes con enfermedad de Alzheimer (EA). Por ello el objetivo de esta revisión se centra en definir el impacto del cuidado sobre los cuidadores informales. Material y métodos: Se realizó una revisión integradora de la literatura durante el periodo de febrero a marzo de 2015. Se incluyó un total de 14 artículos entre los años 2010-2015 de las bases de datos Scopus, Pubmed, Scielo, Cochrane y Lilacs y se realizó una lectura crítica de los mismos. Resultados: Se evidencian los factores que influyen sobre la calidad de vida de los cuidadores así como el perfil característico de los mismos. La calidad metodológica obtenida de los estudios está entre calidad media y alta. Conclusiones: El cuidado de los pacientes con EA recae normalmente sobre un único cuidador y tiene importantes repercusiones en la vida de estos cuidadores informales.Introduction: Informal caregivers are responsible for providing the necessary assistance to patients with Alzheimer's disease (AD). Therefore the aim of this review is focused on defining the impact of care on informal caregivers. Materials and methods: an integrative literature review was carried out during the period from February to March 2015. A total of 14 articles were included in the years 2010-2015 from the data bases Scopus, Pubmed, Scielo, Lilacs and Cochrane and a critical reading of them was performed. Results: The factors influencing the quality of life of caregivers and their characteristic profile are evidenced. The methodological quality of the studies obtained is between medium and high quality Conclusions: The care of patients with AD usually falls on a single caregiver and has a major impact on the lives of the aforementioned informal caregivers

An empirical modelling of porous sound absorbing materials made of recycled foam

Polyurethane foam waste is one of the residues of the manufacturing processes in textile industry, the disposal of which is becoming a severe environmental problem. In this paper the sound absorption properties of different materials developed from ground polyurethane foam waste are studied. Because these recycled materials exhibit good sound absorbing properties they are viable alternatives to conventional materials for practical applications. Experimental measures have been carried out to determine the characteristic wave impedance and propagation constant of these materials. Modelling of the acoustic behaviour has been done using the Dunn and Davern model and Voronina model. The first model presents deviations in the results so the experimental results have been used to report corrections to the empirical model. The Voronina model has been applied to verify that it serves to model the behaviour of these kinds of recycled materials. Both models converge and present acceptable results.This work has been supported by the Ministerio de Ciencia e Innovacion (BIA2010-17723), the Inter-University and Scientific Cooperation Program of AECID (A/023748/09) and Conicyt-Fonde-cyt under Grant No. 1110605.Rey Tormos, RMD.; Alba Fernández, J.; Arenas, JP.; Sanchis Rico, VJ. (2012). An empirical modelling of porous sound absorbing materials made of recycled foam. Applied Acoustics. 73(6-7):604-609. https://doi.org/10.1016/j.apacoust.2011.12.009S604609736-

Autocuidados y educación terapéutica en hipertensión. Una revisión integradora

La educación terapéutica en los pacientes hipertensos debe dirigirse a la modificación de hábitos de vida relacionados con la alimentación, el ejercicio, o la adherencia a las recomendaciones, para conseguir una mejor evolución de la enfermedad. El objetivo de este estudio fue revisar la literatura reciente relacionada y conocer las mejores medidas para permitir una elevada tasa de cumplimiento de las recomendaciones

The Polarimetric and Helioseismic Imager on Solar Orbiter

This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, while hosting the potential of a rich return in further science. Methods. SO/PHI measures the Zeeman effect and the Doppler shift in the Fe I 617.3 nm spectral line. To this end, the instrument carries out narrow-band imaging spectro-polarimetry using a tunable LiNbO3 Fabry-Perot etalon, while the polarisation modulation is done with liquid crystal variable retarders. The line and the nearby continuum are sampled at six wavelength points and the data are recorded by a 2k × 2k CMOS detector. To save valuable telemetry, the raw data are reduced on board, including being inverted under the assumption of a Milne-Eddington atmosphere, although simpler reduction methods are also available on board. SO/PHI is composed of two telescopes; one, the Full Disc Telescope, covers the full solar disc at all phases of the orbit, while the other, the High Resolution Telescope, can resolve structures as small as 200 km on the Sun at closest perihelion. The high heat load generated through proximity to the Sun is greatly reduced by the multilayer-coated entrance windows to the two telescopes that allow less than 4% of the total sunlight to enter the instrument, most of it in a narrow wavelength band around the chosen spectral line. Results. SO/PHI was designed and built by a consortium having partners in Germany, Spain, and France. The flight model was delivered to Airbus Defence and Space, Stevenage, and successfully integrated into the Solar Orbiter spacecraft. A number of innovations were introduced compared with earlier space-based spectropolarimeters, thus allowing SO/PHI to fit into the tight mass, volume, power and telemetry budgets provided by the Solar Orbiter spacecraft and to meet the (e.g. thermal) challenges posed by the mission's highly elliptical orbit