Contaminación de suelos y aguas subterraneas por vertidos industriales

In the industrialised countries, soil and groundwater contamination caused by uncontrolled spills of industrial wastes is one of the most critical environmental problem, because its removal is expensive and difficult to carry out, and the effects persist during many years. In Spain this problem is especially notorious due to an inadequate management policy derived from the absence of coordination between the different involved sectors. The treatment installations are inot enough, so it has produced spillings in streams and soils or its storage in uncontrolled landfillings.The experiences and guidelines of the Environmental Protection Agency from United States have served to the industrialised countries to evaluate this kind of contamination. This methodology is based on its identification and delimitation in soil and groundwater. After the design of a monitoring and control program it can be established the correcting measures. For this reason it is important to know the transfer processes of pollutants between the saturated and not saturated medium, for this reason it is essential the use of geochemical and geophysical methods and their combination with hydrogeological methods.In Spain, this kind of studies is only carried out recently. A case history is the contamination of the alluvial aquifer of the Besos river (Barcelona) by Cr-VI and other heavy metals and organic microcontaminants

Replication of the densovirus of Casphalia extranea (Lepidoptera Limacodidae) on an established cell line

Les larves du Lépidoptère #Casphalia extranea ravagent périodiquement les plantations de palmier à huile et de cocotier en Côte d'Ivoire. Le principal agent pathogène capable de réguler les populations de ce ravageur est un densovirus (#Parvoviridae). En dehors de son hôte, ce virus se multiplie dans la lignée cellulaire SPC BM40 de #Bombyx mori$. Le taux de multiplication du virus en culture in vitro est de 10 au bout de 15 jours. C'est la première fois qu'un densovirus se reproduit en lignée cellulaire. (Résumé d'auteur

Universality in Bacterial Colonies

The emergent spatial patterns generated by growing bacterial colonies have been the focus of intense study in physics during the last twenty years. Both experimental and theoretical investigations have made possible a clear qualitative picture of the different structures that such colonies can exhibit, depending on the medium on which they are growing. However, there are relatively few quantitative descriptions of these patterns. In this paper, we use a mechanistically detailed simulation framework to measure the scaling exponents associated with the advancing fronts of bacterial colonies on hard agar substrata, aiming to discern the universality class to which the system belongs. We show that the universal behavior exhibited by the colonies can be much richer than previously reported, and we propose the possibility of up to four different sub-phases within the medium-to-high nutrient concentration regime. We hypothesize that the quenched disorder that characterizes one of these sub-phases is an emergent property of the growth and division of bacteria competing for limited space and nutrients.Comment: 12 pages, 5 figure

A detailed stream sediment Geochemical survey in the Canoves St. Pere de Vilamajor area (Montseny massif. NE Spain)

Se ha realizado una prospección geoquímica táctica de sedimentos aluviales en el Brea de Cánoves-St. Pere de Vilamajor (Macizo del Montseny, Barcelona), como consecuencia de una exploración geoquimica estratégica de sedimentos aluviales previa, en la que se localizó un Brea anómala en Pb, Zn, Cu, As, Cd, Ni, y Co. El Brea estudiada tiene 35 km2 y esta constituida por materiales sedimentarios y volcánicos del Paleozoica, metamorfizados en mayor o menor grado e intruidos por el granito de Vallfornés, y materiales detríticos terciarios. Las muestras, recogidas con una densidad de 7 por Km2 fueron, an alizadas mediante espectrofotometria de absorción atómica para el Pb, Zn, Cu, Ni, Co, As, Cd y Ag, con analisis adicionales para el Sn y W con fluorescencia de rayos X. La interpretación estadistica de los resultados mediante técnicas univariables y multivariables permitió localizar y delimitar los sectores mas anórnalos. Posteriores reconocimientos geológicos de detalle permitieron descubrir un nuevo tipo de mineralización estratiforme relacionado con los niveles volcano-sedimentarios del Ordovícico superior hasta el momento desconocido en las Cadenas Costero Catalanas, asi como sus removilizaciones debido al emplazamiento del granito de Vallfornés, que originaron mineralizaciones de tipo skarn y filonianas

Conversion of levulinic acid to gamma-valerolactone over Zr-containing metal-organic frameworks: Evidencing the role of Lewis and Bronsted acid sites

[EN] Zr-containing UiO-66 and MOF-808 are evaluated for converting levulinic acid (LA) into gamma-valerolactone (GVL) through various routes: (i) Step-wise esterification of LA to n-butyl levulinate (nBuL) and Meerwein-PonndorfVerley (MPV) reduction to GVL; (ii) One-pot two-steps esterification with n-butanol followed by MPV reduction with sec-butanol; and (iii) direct conversion of LA into GVL through a tandem reaction. Selection of this multistep complex reaction evidences the participation of the different acid sites (Lewis or Bronsted) of the material in each individual step: Bronsted-induced acid sites catalyze esterification reaction efficiently, while Lewis acid sites are the preferred sites for the MPV step. Sulfation of MOF-808 is used to enhance the Bronsted acidity of MOF-808, which improves the performance for esterification. However, the sulfate groups introduced are detrimental for the MPV step, since they reduce the intra-pore space available to form the required bulky transition state. These results evidence the need to find the best equilibrium between Bronsted and Lewis acid sites to optimize the outcome of this multistep reaction.Financial support by the Spanish Government is acknowledged through projects MAT2017-82288-C2-1-P and the Severo Ochoa program (SEV-2016-0683). Aula-CEMEX is also acknowledged for a fellowship to JMG.Guarinos, J.; Cirujano, F.; Rapeyko, A.; Llabrés I Xamena, FX. (2021). Conversion of levulinic acid to gamma-valerolactone over Zr-containing metal-organic frameworks: Evidencing the role of Lewis and Bronsted acid sites. Molecular Catalysis. 515:1-11. https://doi.org/10.1016/j.mcat.2021.111925S11151

The Myrmecophilic cricket Myrmecophilus in Spain (Orthoptera, Myrmecophilidae)

Two species of myrmecophilous crickets, Myrmecophilus acervorum and Myrmecophilus ochraceus, are here established as present in the Iberian Peninsula. The generic host range for M. acervorum is limited to one genus, Lasius. The host range of M. ochraceus is wider, Camponotus, Messor, Monomorium, and Tetramorium. The identity of specimens from the Balearic Islands remains controversial

Spin Two Glueball Mass and Glueball Regge Trajectory from Supergravity

We calculate the mass of the lowest lying spin two glueball in N=1 super Yang-Mills from the dual Klebanov-Strassler background. We show that the Regge trajectory obtained is linear; the 0++, 1-- and 2++ states lie on a line of slope 0.23 -measured in units of the conifold deformation. We also compare mass ratios with lattice data and find agreement within one standard deviation.Comment: 17 pages, 2 figure

Computational material design for acoustic cloaking

A topology optimization technique based on the topological derivative and the level set function is utilized to design/synthesize the micro-structure of a pentamode material for an acoustic cloaking device. The technique provides a micro-structure consisting of a honeycomb lattice composed of needle-like and joint members. The resulting metamaterial shows a highly anisotropic elastic response with effective properties displaying a ratio between bulk and shear moduli of almost 3 orders of magnitude. Furthermore, in accordance with previous works in the literature, it can be asserted that this kind of micro-structure can be realistically fabricated. The adoption of a topology optimization technique as a tool for the inverse design of metamaterials with applications to acoustic cloaking problems is one contribution of this paper. However, the most important achievement refers to the analysis and discussion revealing the key role of the external shape of the prescribed domain where the optimization problem is posed. The efficiency of the designed micro-structure is measured by comparing the scattering wave fields generated by acoustic plane waves impinging on bare and cloaked bodies.Peer ReviewedPostprint (published version