Preparación de un nuevo material híbrido orgánico/inorgánico mediante la intercalación de colina en bronce de molibdeno

Intercalation of a organic compound, 2-hydroxyl etil trimetil ammonium, in the layered host molybdenum bronzes was achieved. Full characterization of solids was performed using chemical analysis, X-ray diffaction, thermal analysis and IR spectroscopy. Using fresh sodium hydrated layered molybdenum bronce yields a monofasic layered solid. The hybrid organic-inorganic compound exhibs a high lamellar order, which is stable at temperatura below 550 K, then collapsing by combustion of organic component. All features show that blue molybdenum bronzes will be a good host for intercalation.<br><br>Se aborda la intercalación de un compuesto orgánico, 2-hidroxil etil trimetil amonio (Colina), entre las láminas de bronce azul de molibdeno. El sólido obtenido se caracteriza mediante análisis químico (AQ), difracción de rayos-X (XRD), análisis térmico (DTA y TG) y espectroscopia infrarroja (FT-IR). La utilización de un bronce sódico de molibdeno recién preparado facilita la incorporación de la molécula orgánica, dando lugar a la formación de una única fase laminar. El material híbrido muestra un alto ordenamiento laminar, estable a temperaturas inferiores a los 550 K, que se descompone por combustión del componente orgánico. Los resultado obtenidos indican que el bronce azul de molibdeno puede ser un buen candidato para la obtención de compuestos de intercalación

Participatory scenario development for integrated assessment of nutrient flows in a Catalan river catchment

Rivers in developed regions are under significant stress due to nutrient enrichment generated mainly by human activities. Excess nitrogen and phosphorus emissions are the product of complex dynamic systems influenced by various factors such as demographic, socio-economic and technological development. Using a Catalan river catchment, La Tordera (North-East of Spain), as a case study of an integrated and interdisciplinary environmental assessment of nutrient flows, we present and discuss the development of narrative socio-economic scenarios through a participatory process for the sustainable management of the anthropogenic sources of nutrients, nitrogen and phosphorus. In this context, scenarios are an appropriate tool to assist nutrient emissions modelling, and to assess impacts, possible pathways for socio-economic development and associated uncertainties. Evaluated against the 1993–2003 baseline period, scenarios target the 2030 horizon, i.e. through the implementation process of the Water Framework Directive (Directive 2000/60/EC). After a critical examination of the methodology used in the participatory development of socio-economic scenarios, we present four possible futures (or perspectives) for the Catalan river catchment conceived by stakeholders invited to a workshop. Keys to the success of such a participatory process were trust, which enhanced openness, and disagreements, which fostered the group's creativity for scenario development. The translation of narrative socio-economic scenarios into meaningful nutrient emission scenarios is also discussed. By integrating findings of natural sciences and socio-economic analysis, we aim to assist decision makers and stakeholders in evaluating optimal management strategies for the anthropogenic sources of nitrogen and phosphorus

CO2 hydrogenation over Ru hydrotalcite-derived catalysts

The hydrogenation of CO2 over Ru catalysts is structure sensitive, the selectivity of the process can be driven either to the production of CH4 or CO depending on Ru particles and support features. Herein, Ru-based MgAl-HT (HT=hydrotalcite) derived catalysts with different Ru loadings (0.5, 1.0 and 2.0 wt%) and promoted with La3+ were prepared, characterized, and tested for CO2 methanation at high Gas Hourly Space Velocity values (480 L/gcat h) feeding a CO2/H2/N2 = 1/4/1 v/v mixture. The MgAlOx mixed oxide obtained after calcination at 600 °C and reduction provided weak, medium and mainly strong basic sites, able to activate the CO2 molecule, and hosted very small Ru nanoparticles (1–3 nm). However, the catalysts displayed a low activity in the low temperature range and a poor selectivity to CH4. The addition of La3+, despite contributing to the basicity, did not have any significant effect on performance. In a comparison between Ru- and Ni-HT-derived catalysts, tested under similar reaction conditions, Ni largely overperformed Ru

Is coracohumeral distance associated with pain-function, and shoulder range of movement, in chronic anterior shoulder pain?

Background: The aim of this study was twofold: (i) to assess the intrarater reliability of coracohumeral distance; (ii) to investigate the level of association between coracohumeral distance measured by ultrasonography, and pain-disability and shoulder range of movement, in patients suffering from chronic anterior shoulder pain. Methods: An observational, cross sectional study was carried out. A convenience sample comprised of 87 patients with chronic anterior shoulder pain was assessed from 3 primary care centres. Main outcomes as pain and function were measured through the shoulder pain and disability index. Furthermore, shoulder range of movement-free of pain in shoulder elevation, as well as coracohumeral distance at both 0 and 60 degrees, were collected. Results: Absence of any correlation was found between coracohumeral distance and shoulder pain and disability index at both 0 and 60 degrees of shoulder elevation. Furthermore, absence of any correlation was found between coracohumeral distance measurements and active shoulder range of movement -free of pain. Conclusions: There was poor association between coracohumeral distance and shoulder pain and function, as well as with shoulder range of movement, in patients with chronic anterior shoulder pain. Hence, clinicians should consider, not only increasing this space, but also other possibilities in their therapies, when patients with anterior shoulder pain are treated

Conflictos socioambientales y alternativas de la sociedad civil

Los conflictos socioambientales se multiplican en todo el mundo. Giran en torno a la contaminación industrial, las actividades mineras, el cambio de uso de suelo, la deforestación, la construcción de presas, la introducción de semillas genéticamente modificadas, el mal manejo de desechos sólidos y la privatización de tierra, agua y biodiversidad, entre otros. ¿Cuáles son las causas subyacentes a estos conflictos? ¿Quiénes son los protagonistas? ¿Cuáles son sus demandas, propuestas y estrategias? ¿En qué medida han contribuido a proteger o sanear el medio ambiente? ¿Hay conflictos locales que se convierten en glocales con la intervención de la sociedad civil? Estas interrogantes se abordan en este libro, que recoge inventarios de conflictos ambientales en México, en especial en Jalisco.ITESO, A.C

Mining conflicts around the world: Common grounds from an Environmental Justice perspective

Abstract. This report aims at exploring contemporary mining conflicts in the context of the sustainable development and environmental justice movement. This is done based on 24 real case studies from 18 different countries which are described by local activists and scholars. While 17 of the reported cases focus on conflicts related to metal mining (e.g. gold, silver, copper, zinc, and lead), four address uranium mining and one refers to coal mining. As an example of a new frontier in the industry, a sand mining conflict from India is also reported. All of these cases are directly chosen and reported, either in factsheet or in-depth study format, by EJOs, as part of a knowledge sharing activity well-established in EJOLT between EJOs and the academic community. Although the cases covered here are all quite unique and diverse in terms of type of conflict and geographical setting, they all share a common frame of analysis. First, the project and type of conflict are characterized in a nutshell, with some basic factual background that describe the companies involved, and the communities and locations affected. The roots of the conflicts are explored next, as well as relevant socioeconomic, cultural, health, and ecological impacts and related community claims. Where relevant, means of resistance are also specified with their influence on the project and/or the outcome of the conflict. The report then offers a synthesis of the described mining cases, review their commonalities, link gained insights with research needs and discuss some policy recommendations that might follow from this analysis. Despite its limitations, compiling such a diverse set of mining conflicts that builds on EJO knowledge promotes mutual learning and collaboration among stakeholders, EJOs and academia, which is one of the key objectives of EJOLT

Wacker-oxidation of Ethylene over Pillared Layered Material Catalysts

This paper concerns the Wacker oxidation of ethylene by oxygen in the presence of water over supported Pd/VOx catalysts. High surface area porous supports were obtained from layer-structured materials, such as, montmorillonite (MT), laponite (LT) (smectites), and hydrotalcite (layered double hydroxide, LDH) by pillaring. Before introduction of Pd, supports MT and LDH were pillared by vanadia. The laponite was used in titania-pillared form (TiO2-LAP) as support of Pd/VOx active component. Acetaldehyde (AcH), acetic acid (AcOH) and CO2 were the products with yields and selectivities, depending on the reaction conditions and the properties of the applied catalyst. Under comparable conditions the pillared smectite catalysts gave higher AcH yield than the pillared LDH catalyst. UV vis spectroscopic examination suggested that the pillared smectites contained polymeric chains of VO4, whereas only isolated monomeric VO4 species were present in the pillared LDH. The higher catalytic activity in the Wacker oxidation was attributed to the more favorable redox property of the polymeric than of the monomeric vanadia. The V3+ ions in the polymeric species can reduce O2 to O2- ions, whereas the obtained V5+ ions are ready to pass over O to Pd0 to generate PdO whereon the oxidation of the ethylene proceeds