Study of photon emission by electron capture during solar nuclei acceleration. 2: Delimitation of conditions for charge transfert establishment

The conditions for establishment of charge transfer during acceleration of nuclei up to Fe, for typical conditions of solar flare regions T = 5 x 10 to the 3rd power to 2.5 x 10 to the 8th power degrees K were explored. Results show that such conditions are widely assorted, depending on the acceleration mechanism, the kind of projections and their velocity, the target elements, the source temperature and consequently on the degree of ionization of matter and the local charge state of the accelerated ions. Nevertheless, in spite of that assorted behavior, there are some general tendencies that can be summarized as follows. In atomic H electron capture is systematically established from thermal energies up to high energies, whatever the element and for both acceleration process. For a given element and fixed temperature (T), the probability and energy domain of electron capture and loss with Fermi are higher than with Betatron acceleration. For a given acceleration process the heavier the ion the higher the probability and the wider the energy range for electron capture and loss. For given acceleration mechanism and fixed element the importance and energy domain of capture and loss increase with T: for those reasons, the energy range of charge equilibrium (illustrated with solid lines on the next figs.) is wider with Fermi and increases with temperature and atomic number of projectiles. For the same reasons, electron loss is smaller while the lighter the element, the lower the temperature and the Betatron process, such that there are conditions for which electron loss is not allowed at low energies, but only electron capture is established

Study of photon emission by electron capture during solar nuclei acceleration. 3: Photon production evaluations

Lower limits of photon fluxes were evaluated from electron capture during acceleration in solar flares, because the arbitrary q sub c asterisk assumed in this work evolves very slow with velocity, probably much more slowly than the physical actual situation: in fact, more emission is expected toward the IR region. Nevertheless the authors claim to show that the factibility of sounding acceleration processes, charge evolution processes and physical parameters of the source itself, by the observational analysis of this kind of emissions. For instance, it would be interesting to search observationally, for the predicted flux and energy drift of F sub e ions interacting with the atomic 0 and F sub e of the source matter, or, even more feasible for the X-ray lines at 4.2 keV and 2.624 + 0.003 KeV from Fe and S ions in ionized Fe at T = 10 to the 7th power K respectively, the 418 + or - 2 eV and 20 + or - 4 eV lines of Fe and S in ionized Fe at 5 x 10 to the 6th power K, which are predicted from Fermi acceleration

Study of non-thermal photon production under different scenarios in solar flares. 1: Scenarios and formulations

In order to study the overall phenomenology involved in solar flares, it is necessary to understand their individual manifestation before building a corresponding description of the global phenomenon. Here the concern is with the production of X and gamma rays in solar flares. Flares are initiated very often within the closed magnetic field configurations of active centers. According (2) when beta = kinetic energy density/magnetic energy density approximately 0.2, the magnetic trap configuration is destructed within the time scale of the impulsive phase of flares ( 100 s). A first particle acceleration stage occurs during this phase as indicated by impulsive microwave and hard X-rays bursts. In some flare events, when the field strength beta is very high, the broken field lines may close again, such that later, in the course of the flash and main phases more hot plasma of very high conductivity is created, and so, the field and frozen plasma expand outward, as the kinetic pressure inside the closed loops increases. The magnetically trapped particles excite strong Alfven wave turbulence of small transverse scale

Study of photon emission by electron capture during solar nuclei acceleration, 1: Temperature-dependent cross section for charge changing processes

The study of charge changing cross sections of fast ions colliding with matter provides the fundamental basis for the analysis of the charge states produced in such interactions. Given the high degree of complexity of the phenomena, there is no theoretical treatment able to give a comprehensive description. In fact, the involved processes are very dependent on the basic parameters of the projectile, such as velocity charge state, and atomic number, and on the target parameters, the physical state (molecular, atomic or ionized matter) and density. The target velocity, may have also incidence on the process, through the temperature of the traversed medium. In addition, multiple electron transfer in single collisions intrincates more the phenomena. Though, in simplified cases, such as protons moving through atomic hydrogen, considerable agreement has been obtained between theory and experiments However, in general the available theoretical approaches have only limited validity in restricted regions of the basic parameters. Since most measurements of charge changing cross sections are performed in atomic matter at ambient temperature, models are commonly based on the assumption of targets at rest, however at Astrophysical scales, temperature displays a wide range in atomic and ionized matter. Therefore, due to the lack of experimental data , an attempt is made here to quantify temperature dependent cross sections on basis to somewhat arbitrary, but physically reasonable assumptions

Study of non-thermal photon production under different scenarios in solar flares. 2: The Compton inverse and Bremsstrahlung models and fittings

Energy spectra of photons emitted from Bremsstrahlung (BR) of energetic electrons with matter, is obtained from the deconvolution of the electron energy spectra. It can be inferred that the scenario for the production of X-rays and gamma rays in solar flares may vary from event to event. However, it is possible in many cases to associated low energy events to impulsive acceleration, and the high energy phase of some events to stochastic acceleration. In both cases, flare particles seem to be strongly modulated by local energy losses. Electric field acceleration, associated to neutral current sheets is a suitable candidate for impulsive acceleration. Finally, that the predominant radiation process of this radiation is the inverse Compton effect due to the local flare photon field

Experimental test for interpreting the increase in sensibility of doped CR-39

In recent years the sensibility of CR-39 to nuclear tracks has been increased by doping the corresponding monomer with dioctyl phtalate. At this regard, two theoretical approaches are current managed to explain this phenomenon: either the doping react with the active radicals in the chain blocking them, stopping crosslinking between chains, or alternatively that the doping gets between them giving wider space between the crosslinkined chains

Cumulant expansion framework for internal gradient distributions tensors

Magnetic resonance imaging is a powerful, non invasive tool for medical diagnosis. The low sensitivity for detecting the nuclear spin signals, typically limits the image resolution to several tens of micrometers in preclinical systems and millimeters in clinical scanners. Other sources of information, derived from diffusion processes of intrinsic molecules as water in the tissues, allow getting morphological information at micrometric and submicrometric scales as potential biomarkers of several pathologies. Here we consider extracting this morphological information by probing the distribution of internal magnetic field gradients induced by the heterogeneous magnetic susceptibility of the medium. We use a cumulant expansion to derive the dephasing on the spin signal induced by the molecules that explore these internal gradients while diffuse. Based on the cumulant expansion, we define internal gradient distributions tensors (IGDT) and propose modulating gradient spin echo sequences to probe them. These IGDT contain microstructural morphological information that characterize porous media and biological tissues. We evaluate the IGDT effects on the magnetization decay with typical conditions of brain tissue and show their effects can be experimentally observed. Our results thus provide a framework for exploiting IGDT as quantitative diagnostic tools

Interpretación genética de las mineralizaciones de Pb-Zn del Ordovicico superiro de La Vall d'Aran (Lérida)

Las mineralizaciones de PbZn del Ordovícico superior de La Vall d'Aran son de tipo estratiforme, asociadas a facies calcáreo-detríticas. La mena está constituida mayoritariamente por esfalerita, pirrotina y galena, habiéndose detectado además 12 especies minerales secundarias.El área estudiada se ha dividido en dos zonas: Bossost y el valle del río Unyola. En total se han investigado ocho afloramientos de mineralización, formando parte todos ellos del mismo tipo, tanto morfológico como mineralógico, de yacimiento.A partir del estudio macro y microscópico de las mineralizaciones, se hapodido determinar que éstas han sufrido un metamorfismo el cual ha dado lugar a una serie de texturas de deformación y recristalización en los minerales. En algunos puntos, sin embargo, donde las mineralizaciones se han visto menos afectadas por la deformación, se han observado estructuras sedimentarias en los sulfuros.Por todo ello, se puede deducir que las mineralizaciones estudiadas son de origen sedimentario, anteriores al metamorfismo herciniano que las ha afectado y que no están relacionadas con el hidrotermalismo tardihercinico asociado a la intrusión de las granodioritas de la zona axial pirenaica

Discovery of a wide companion near the deuterium burning mass limit in the Upper Scorpius association

We present the discovery of a companion near the deuterium burning mass limit located at a very wide distance, at an angular separation of 4.6+/-0.1 arcsec (projected distance of ~ 670 AU) from UScoCTIO108, a brown dwarf of the very young Upper Scorpius association. Optical and near-infrared photometry and spectroscopy confirm the cool nature of both objects, with spectral types of M7 and M9.5, respectively, and that they are bona fide members of the association, showing low gravity and features of youth. Their masses, estimated from the comparison of their bolometric luminosities and theoretical models for the age range of the association, are 60+/-20 and 14^{+2}_{-8} MJup, respectively. The existence of this object around a brown dwarf at this wide orbit suggests that the companion is unlikely to have formed in a disk based on current planet formation models. Because this system is rather weakly bound, they did not probably form through dynamical ejection of stellar embryos.Comment: 10 pages, including 4 figures and 2 table

Malnutrition secondary to gastrojejunal stricture after biliopancreatic diversion

Context: Bariatric surgery has beneficial effects on obesity and associated comorbidities such as glycaemic control in type 2 diabetes, dyslipidaemia, hypertension, and renal and hepatic function. Nevertheless, this surgery is not free of complications and possible side effects due to restrictive and/or malabsorptive related components. Case description: We report the case of a 60-year-old woman whose past medical history included morbid obesity, hypertension and Scopinaro biliopancreatic diversion (BPD) with duodenal switch in 1998. In 2015, she attended the emergency department hypotensive with bad general condition and reporting chronic constitutional symptoms. A wide variety of tests were performed including endoscopic studies as her symptoms were not immediately correlated with the BPD surgery. Finally, she was diagnosed from gastrojejunal stricture which caused her severe malnutrition. The patient underwent successful surgical management. Discussion: BPD is one of the most effective surgical procedures for obesity, with an overall 5-year loss of excess body weight higher than 72%. Nonetheless, it is associated with long-term complications such as protein malnutrition and vitamin deficiencies due to malabsorption. Being surgically challenging, with high risk of nutritional complications and lifelong needed for the follow-up, BPD is rarely performed nowadays. Conclusions: Bariatric Surgery is a well-known effective therapeutic measure to improve obesity and cardiovascular related disease. However, this case highlights the importance of robust multidisciplinary lifelong surgical and medical follow-up in all BPD patients. BPD complications can be minimised and recognised early with patient and healthcare staff education on the importance of lifetime follow-up and adherence to dietary and supplement regimes