Current sheets at three-dimensional magnetic nulls:effect of compressibility

The nature of current sheet formation in the vicinity of three-dimensional (3D) magnetic null points is investigated. The particular focus is upon the effect of the compressibility of the plasma on the qualitative and quantitative properties of the current sheet. An initially potential 3D null is subjected to shearing perturbations, as in a previous paper [Pontin et al., Phys. Plasmas, in press (2007)]. It is found that as the incompressible limit is approached, the collapse of the null point is suppressed, and an approximately planar current sheet aligned to the fan plane is present instead. This is the case regardless of whether the spine or fan of the null is sheared. Both the peak current and peak reconnection rate are reduced. The results have a bearing on previous analytical solutions for steady-state reconnection in incompressible plasmas, implying that fan current sheet solutions are dynamically accessible, while spine current sheet solutions are not.Comment: to appear in Physics of Plasmas. This version contains updated figures and references, additional discussion, and typos are fixed. This is the second in a series of papers - the first of which (by the same authors) is located at astro-ph/0701462. A version with higher quality figures can be found at http://www.maths.dundee.ac.uk/~dpontin

Life cycle environmental and cost evaluation of heating and hot water supply in social housing nZEBs

This paper presents a comparative analysis of different space heating and hot water systems for a social housing project in Santurtzi, Spain. The building, comprising 32 apartment units and currently under construction, has been designed to minimize thermal energy demand, while ensuring comfort and quality of the internal environment for the social housing occupiers. The selection of the heating and hot water energy systems has been carried considering a life cycle perspective both for environmental and economic impacts. Different alternatives have been analysed which compare conventional gas boiler installation, which has been the norm for this type of social housing for the last decades, with various options based on heat pump technology. Life cycle analysis of the environmental effects of electrification of the thermal energy demand through heat pumps show a potential for reducing life cycle CO2 emissions. The economic evaluation done through life cycle costing, comparing investment, maintenance, replacement and operational costs of gas boiler with aerothermal and geothermal heat pump solutions, have shown however that gas heating solutions are still the most competitive economically. Increasing the overall efficiency of those heating and hot water systems that include heat pump technology, while reducing their uncertainty in operation is a key element to ensure competitiveness of heat pumps in the current market.The work presented in this article is part of an analysis carried within AZEB project ‘Affordable Zero Energy Buildings’, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 754174

CDS wide slit time-series of EUV coronal bright points

Wide slit (90" x 240" ) movies of four Extreme Ultraviolet coronal bright points (BPs) obtained with the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SoHO) have been inspected. The wavelet analysis of the He I 584.34 Å, O V 629.73 Å and Mg VII/IX 368 Å time-series confirms the oscillating nature of the BPs, with periods ranging between 600 and 1100 s. In one case we detect periods as short as 236 s. We suggest that these oscillations are the same as those seen in the chromospheric network and that a fraction of the network bright points are most likely the cool footpoints of the loops comprising coronal bright points. These oscillations are interpreted in terms of global acoustic modes of the closed magnetic structures associated with BPs

Development of a Smart Modular Heat Recovery Unit Adaptable into a Ventilated Façade

This paper presents the designing aspects and first experimental characterization of an adaptable Smart Modular Heat Recovery Unit (SMHRU) developed under the scope of the E2VENT Project. This SMHRU is being designed as a part of an adaptable renovation module for the retrofitting of multi-storey residential building from the 60's, 70's across Europe that embeds the SMHRU and an energy storage system based on a phase change material. This heat recovery unit will be adjustable to be integrated into the ventilated façade cavity, and able to recover heat from ventilation air, preheating the ventilation air in winter and precooling it in summer. This will allow an efficient combination of consumption reduction and acceptable air indoor quality. The first part of the paper presents designing considerations and thermal stationary analysis of the heat recovery unit, which is based on experimental correlations obtained for air-to-air compact offset-strip-fin plate heat exchangers. Secondly CFD analysis of the distributor of the SMHRU is presented. Finally prototype first performance estimation based on experimental results is presented.This work has been developed under the project “E2VENT: Energy Efficient Ventilated Façades” funded by the Horizon 2020 framework of the European Union, Project No. 637261

Jets in coronal holes: Hinode observations and 3D computer modelling

Recent observations of coronal hole areas with the XRT and EIS instruments onboard the Hinode satellite have shown with unprecedented detail the launching of fast, hot jets away from the solar surface. In some cases these events coincide with episodes of flux emergence from beneath the photosphere. In this letter we show results of a 3D numerical experiment of flux emergence from the solar interior into a coronal hole and compare them with simultaneous XRT and EIS observations of a jet-launching event that accompanied the appearance of a bipolar region in MDI magnetograms. The magnetic skeleton and topology that result in the experiment bear a strong resemblance to linear force-fee extrapolations of the SOHO/MDI magnetograms. A thin current sheet is formed at the boundary of the emerging plasma. A jet is launched upward along the open reconnected field lines with values of temperature, density and velocity in agreement with the XRT and EIS observations. Below the jet, a split-vault structure results with two chambers: a shrinking one containing the emerged field loops and a growing one with loops produced by the reconnection. The ongoing reconnection leads to a horizontal drift of the vault-and-jet structure. The timescales, velocities, and other plasma properties in the experiment are consistent with recent statistical studies of this type of events made with Hinode data.Comment: 10 pages, 4 figures. Revised version submitted to ApJ Letter

Beneficio social de la pedagogía en la tecnología de la salud. Social benefit of pedagogy in health technology

El perfeccionamiento de la Educación Médica Superior es un punto que siempre ha estado vigente en todo el colectivo pedagógico que cumple con esta honrosa misión, y una arista significativa en este proceso es la aparición de la Tecnología de la Salud en el Nuevo Modelo Pedagógico, en nuestro trabajo expondremos los factores sociales que se benefician con la profundización de la pedagogía como ciencia dentro de la carrera y la importancia de ello para la formación de profesores tutores, aspecto de gran importancia dentro del Nuevo Modelo Pedagógico basado en la enseñanza tutelar a partir del segundo año de formación. Palabras clave: TUTOR, TECNOLOGÍA DE LA SALUD, ENSEÑANZA, EDUCACIÓN PARA LA SALUD. ABSTRACT The training at High Medical Education is an always present aspect in the pedagogical staff in charge of this honorable mission and it also represents a significant aspect in the process of Health Technology emergence in the New Pedagogical Model; in our work we will expose the social factors which benefit from the deep pedagogy as a science within the major and its importance for the formation of tutor professors which is considered an important aspect of the New Pedagogical Model based on the Tutelary Teaching from second year on. Key words: TUTOR, HEALTH TECHNOLOGY, TEACHING, HEALTH EDUCATION

Beneficio social de la pedagogía en la tecnología de la salud. Social benefit of pedagogy in health technology

El perfeccionamiento de la Educación Médica Superior es un punto que siempre ha estado vigente en todo el colectivo pedagógico que cumple con esta honrosa misión, y una arista significativa en este proceso es la aparición de la Tecnología de la Salud en el Nuevo Modelo Pedagógico, en nuestro trabajo expondremos los factores sociales que se benefician con la profundización de la pedagogía como ciencia dentro de la carrera y la importancia de ello para la formación de profesores tutores, aspecto de gran importancia dentro del Nuevo Modelo Pedagógico basado en la enseñanza tutelar a partir del segundo año de formación. Palabras clave: TUTOR, TECNOLOGÍA DE LA SALUD, ENSEÑANZA, EDUCACIÓN PARA LA SALUD. ABSTRACT The training at High Medical Education is an always present aspect in the pedagogical staff in charge of this honorable mission and it also represents a significant aspect in the process of Health Technology emergence in the New Pedagogical Model; in our work we will expose the social factors which benefit from the deep pedagogy as a science within the major and its importance for the formation of tutor professors which is considered an important aspect of the New Pedagogical Model based on the Tutelary Teaching from second year on. Key words: TUTOR, HEALTH TECHNOLOGY, TEACHING, HEALTH EDUCATION

Presence and Function of Dopamine Transporter (DAT) in Stallion Sperm : Dopamine Modulates Sperm Motility and Acrosomal Integrity

Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility. In the present study, using immunodetection methods, we revealed the presence of several proteins important for the dopamine uptake and signalling in mammalian sperm, specifically monoamine transporters as dopamine (DAT), serotonin (SERT) and norepinephrine (NET) transporters in equine sperm. We also demonstrated for the first time in equine sperm a functional dopamine transporter using 4-[4-(Dimethylamino)styryl]-N-methylpyridinium iodide (ASP+ ), as substrate. In addition, we also showed that dopamine (1 mM) treatment in vitro, does not affect sperm viability but decreases total and progressive sperm motility. This effect is reversed by blocking the dopamine transporter with the selective inhibitor vanoxerine (GBR12909) and non-selective inhibitors of dopamine reuptake such as nomifensine and bupropion. The effect of dopamine in sperm physiology was evaluated and we demonstrated that acrosome integrity and thyrosine phosphorylation in equine sperm is significantly reduced at high concentrations of this catecholamine. In summary, our results revealed the presence of monoamine transporter DAT, NET and SERT in equine sperm, and that the dopamine uptake by DAT can regulate sperm function, specifically acrosomal integrity and sperm motility