Interacting galaxies and cosmological parameters

We propose a (physical)-geometrical method to measure the present rates of the density cosmological parameters for a Friedmann-Lemaitre universe. The distribution of linear separations between two interacting galaxies,when both of them undergo a first massive starburst, is used as a standard of length. Statistical properties of the linear separations of such pairs of ``interactivated'' galaxies are estimated from the data in the Two Degree Field Galaxy Redshift Survey. Synthetic samples of interactivated pairs are generated with random orientations and a likely distribution of redshifts. The resolution of the inverse problem provides the probability densities of the retrieved cosmological parameters. The accuracies that can be achieved by that method on matter and cosmological constant densities parameters are computed depending on the size of ongoing real samples. Observational prospects are investigated as the foreseeable surface densities on the sky and magnitudes of those objects.Comment: 8 pages, 6 figure

PET waste as organic linker source for the sustainable preparation of MOF-derived methane dry reforming catalysts

A catalyst made of Ni0 nanoparticles highly dispersed on a lamellar alumina support was prepared by an environmentally-friendly route. The latter involved the synthesis of an aluminum-containing metalorganic framework (MOF) MIL-53(Al) in which the linkers were derived from the depolymerization of polyethylene terephthalate (PET) originating from plastic wastes. After demonstrating the purity and structure integrity of the PET-derived MIL-53(Al), this MOF was impregnated with nickel nitrate salt and then calcined to form a lamellar Ni-Al2O3 mixed metal oxide with a high surface area (SBET = 1276 m2 g-1, N2 sorption). This mixed oxide consisted of nickel aluminate nanodomains dispersed within amorphous alumina, as revealed by PXRD and TPR analyses. Subsequent reduction under H2 resulted in the formation of well-dispersed 5 nm Ni0 nanoparticles homogeneously occluded within the interlamellar porosity of the γ-alumina matrix, as attested by electron microscopy. This waste-derived catalyst displayed catalytic performances in the reaction of dry reforming of methane (DRM) as good as its counterpart made from a MOF obtained from commercial benzene-1,4-dicarboxylic acid (BDC). Thus, under similar steady state conditions, at 650 °C and 1 bar, the PET-derived catalyst led to CH4 and CO2 conversions as high as those on the BDC-derived catalyst, and its catalytic stability and selectivity towards DRM were excellent as well (no loss of activity after 13 h and H2:CO products ratio remaining at 1). Moreover, both catalysts were much better than those of a reference nickel alumina catalyst prepared by conventional impregnation route. This work therefore demonstrates the possibility of using plastic wastes instead of commercial chemicals to prepare efficient porous nickel-alumina DRM catalysts from MOFs, fostering the concept of circular economy

Modeling ultra-high frequency radiation emission in PIC codes

From the mysterious?ray bursts, which can be studied through the spatiotemporal structure of the radiation we receive, to the creation of sources of x-rays capable of probing nanoscale structures, radiation emission by relativistic charges is a key research field in plasma physics.The processes behind radiation emission in plasmas result from strongly non-linear many body interactions which involve relativistic effects, so they are best modeled through Particle-In-Cell (PIC) simulations. However, capturing this radiation directly in PIC simulations is very challenging due to the large disparity between the temporal and spatial scales associated with such phenomena. Current algorithms only describe radiation processes in the Fourier space (e.g.JRAD [1]), missing the spatiotemporal features of the emitted radiation, which is crucial to many fields, such as super-resolution microscopy [2] and astrophysics [3].info:eu-repo/semantics/publishedVersio

RaDiO: An efficient spatiotemporal radiation diagnostic for particle-in-cell codes

This work describes a novel radiation algorithm designed to capture the three-dimensional, space-time resolved electromagnetic field structure emitted by large ensembles of charged particles. The algorithm retains the full set of degrees of freedom that characterize electromagnetic waves by employing the Liénard-Wiechert fields to retrieve radiation emission. Emitted electric and magnetic fields are deposited in a virtual detector using a temporal interpolation scheme. This feature is essential to accurately predict field amplitudes and preserve the continuous character of radiation emission, even though particle dynamics is known only in a discrete set of temporal steps. Our algorithm retains and accurately captures, by design, full spatial and temporal coherence effects. We demonstrate that our numerical approach recovers well known theoretical radiated spectra in standard scenarios of radiation emission. We show that the algorithm is computationally efficient by computing the full spatiotemporal radiation features of High Harmonic Generation through a plasma mirror in a Particle-In-Cell (PIC) simulation.info:eu-repo/semantics/publishedVersio

Adquisición de datos digitales con protocolo VME sobre FPGA

En este artículo se presenta la realización sobre FPGA de un circuito con 16 filtros digitales. Un cambio en la entrada es validado cada vez que tres muestras consecutivas toman el mismo valor. El dato muestreado es accesible mediante protocolo VME estándar, incluyendo daisy-cbain para la gestión de interrupciones. El circuito de acceso VME se ha descrito en lenguaje de comportamiento VERILOG-XL, y sintetizado usando SYNERGY. El resto del circuito ha sido capturado y simulado empleando el entorno de diseño Framework II de Cadence. El circuito ha sido programado en una FPGA 1020A de Texas Instrument. Como resultado se ha obtenido una tarjeta de adquisición de datos con una densidad de componentes muy baja, y que está siendo actualmente empleada en sistemas de control industriales

Circuito ASIC para enlaces rápidos de comunicaciones por fibra óptica

El circuito integrado que aquí se describe ha sido diseñado con tecnología puramente digital, y tiene como función servir de interfase entre 8 enlaces rápidos de comunicaciones por fibra óptica y un procesador local que utiliza protocolo VME. Este trabajo se enmarca dentro del programa GAME y ha sido desarrollado en colaboración con la empresa SAINCO