1,112 research outputs found

    Paleoflora del Oligoceno de Mallorca

    Get PDF
    Abstract not availabl

    Implosion Symmetry of Laser-Irradiated Cylindrical Targets

    Get PDF
    We consider the symmetry of cylindrical implosions of laser targets with parameters corresponding to experiments proposed for the LIL laser facility at Bordeaux: eight laser beams in octahedrical configuration, delivering a total of 50 kJ of 0.35 (xm laser light in 5 ns, impinging on 1.26 mm diameter polystyrene cylindrical shells filled with deuterium at 30 bar and 5.35 mg cm"3; this configuration allows to place diagnostics along the symmetry axis to evaluate directly the uniformity of implosion. Numerical studies have been carried out by using the hydrodynamic computer codes MULTI and CHIC, including one-dimensional, and two-dimensional R-Z and R-6 simulations. Deuterium is compressed into a 1 mm long and 50 |xm diameter filament, with density ranging from 2 to 6 g cm-3 and temperatures above 1000 eV. In spite of the reduced numbers of beams, a good symmetry can be achieved with a careful choice of the irradiation pattern. The heat transport smoothing between laser absorption zone and ablation layer plays a fundamental role in the attenuation of residual non-uniformities. Also, it has been found that the radiation transport determines the radial structure of the compressed filament

    On a Watson-like Uniqueness Theorem and Gevrey Expansions

    Get PDF
    We present a maximal class of analytic functions, elements of which are in one-to-one correspondence with their asymptotic expansions. In recent decades it has been realized (B. Malgrange, J. Ecalle, J.-P. Ramis, Y. Sibuya et al.), that the formal power series solutions of a wide range of systems of ordinary (even non-linear) analytic differential equations are in fact the Gevrey expansions for the regular solutions. Watson's uniqueness theorem belongs to the foundations of this new theory. This paper contains a discussion of an extension of Watson's uniqueness theorem for classes of functions which admit a Gevrey expansion in angular regions of the complex plane with opening less than or equal to (\frac \pi k,) where (k) is the order of the Gevrey expansion. We present conditions which ensure uniqueness and which suggest an extension of Watson's representation theorem. These results may be applied for solutions of certain classes of differential equations to obtain the best accuracy estimate for the deviation of a solution from a finite sum of the corresponding Gevrey expansion.Comment: 18 pages, 4 figure

    Las células presentadoras de antígeno y su papel en el síndrome reproductivo y respiratorio porcino

    Get PDF
    Las células presentadoras de antígeno son aquellas células encargadas de capturar, procesar y presentar antígenos con la finalidad de lograr una respuesta inmune efectiva por parte del organismo. Su papel, como centinelas, es crucial durante el transcurso de diversas enfermedades infecciosas. El estudio de estas células tras la infección con el virus del Síndrome Reproductivo y Respiratorio Porcino nos da información para abordar nuevas estrategias de control frente a esta enfermedad.Antigen presenting cells are able to capture, process and present antigens in order to develop an effective immune response. The role of these cells during infectious diseases is crucial to control the disease. Thus, the study of these cells after the infection with Porcine Reproductive and Respiratory Syndrome Virus gives us useful information on how to control this disease

    Bases de la respuesta inflamatoria en la forma respiratoria del PRRS

    Get PDF
    El Síndrome Reproductivo y Respiratorio Porcino (PRRS) es una enfermedad de distribución mundial que causa graves pérdidas económicas al sector porcino. Este virus no sólo es importante como agente causal del PRRS sino también por su participación en el desarrollo del Complejo Respiratorio Porcino. Su interacción con las defensas pulmonares, la alteración de la respuesta inmune y su persistencia en los órganos linfoides conlleva a que los cerdos tengan dificultades para luchar contra la enfermedad.Porcine Reproductive and Respiratory Syndrome (PRRS) is considered as the most economically important disease of the modern swine industry. The importance of this virus lies in not only being the causative agent of PRRSV, but also due to its implication in the onset of the Porcine Respiratory Disease Complex. The interaction of the virus with pulmonary defenses, the impairment of the immune response as well as the viral persistence in lymphoid organs make overcoming the disease diffi cult to infected pigs

    Ni Catalysts Supported Over TiO2, SiO2 and ZrO2 for the Steam Reforming of Glycerol

    Get PDF
    A 72-year-old man was admitted with one blade of a huge pair of shears in his left thorax. His hemodynamics deteriorated due to life-threatening vascular lesions. An urgent thoracotomy revealed several injuries to the intercostal vessels and left apical inferior lung lobe. The blade tip was stuck in the posterior chest wall, 2 cm adjacent to the descending aorta. The blade was removed, the lung was sutured, and the patient made a good recovery

    The hydrodynamic efficiency of laser-target acceleration

    Get PDF
    The acceleration of a thin foil using a laser pulse is studied. It is shown that the acceleration efficiency eta H is heavily dependent on the behaviour of the corona ejected by the foil: there is no universal relation eta H( Delta M/M0),M0 and Delta M being initial foil mass and ablated mass, respectively. Known results on the coronal flow are used to check the theory against experimental data available in the literature; effects due to both a non-planar corona, and the time-dependence of the laser irradiance, are considered. The agreement with experiments is substantially better than that for previous analyses. Acceleration of thin spherical shells is also discussed

    Error analysis of free probability approximations to the density of states of disordered systems

    Full text link
    Theoretical studies of localization, anomalous diffusion and ergodicity breaking require solving the electronic structure of disordered systems. We use free probability to approximate the ensemble- averaged density of states without exact diagonalization. We present an error analysis that quantifies the accuracy using a generalized moment expansion, allowing us to distinguish between different approximations. We identify an approximation that is accurate to the eighth moment across all noise strengths, and contrast this with the perturbation theory and isotropic entanglement theory.Comment: 5 pages, 3 figures, submitted to Phys. Rev. Let

    Photocatalytic Approaches to Circular Economy: CO2 Photoreduction to Regenerated Fuels and Chemicals and H2 Production from Wastewater

    Get PDF
    The photoreduction of CO2 is an unconventional process to regenerate fuels and chemicals storing solar radiation. A new photoreactor has been designed recently to achieve high productivity during the process, i.e. up to 39 mol/h kgcat of HCOOH or 1.4 mol/h kgcat of CH3OH, which are unprecedented results with respect to literature, especially with a very simple commercial TiO2 catalyst. The production of hydrogen through photoreforming of aqueous solutions of organic compounds is also considered as a way to exploit solar energy storage in the form of hydrogen. Different sugars were selected as substrates derived from the hydrolysis of biomass or from wastewater (food or paper industry). A significant amount of H2 was obtained with very simple catalyst formulations, e.g. 14 mol kgcat-1 h-1 were obtained at 4 bar, 80 \u2daC over commercial TiO2 samples, added with 0.1 mol% of Pt and using glucose as substrate. This result is very remarkable with respect to similar research in conventional photoreactors. Both the routes represent a circular way to regenerate valuable products from gaseous or liquid wastes. Our attention was predominantly focused on the development of innovative reactors, possibly operating under unconventional conditions, with fine tuning of the operation parameters. The exploitation potential of these results under solar irradiation is presented
    corecore