Design Aspects of a Broadband Beam-Reconfigurable Leaky-Wave Antenna

Design aspects of a novel beam-reconfigurable pla-nar series-fed array are addressed to achieve beam steering with frequency tunability over a relatively broad bandwidth. The design is possible thanks to the use of the complementary strip-slot, which is an innovative broadly matched microstrip radiator, and the careful selection of the phase shifter parameters.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Metal hydrides for hydrogen storage at low charging pressures

LaNi5 alloys are been extensively study as hydrogen storage material due their easy activation and good kinetics. LaNi5 alloys, containing substitutional elements such as Al or Ce, allow adjustments of the equilibrium pressure and absorption kinetics of the metallic hydrides making them storage candidate materials susceptible to be used in fuel cells systems. In this work, the thermodynamic properties of LaNi5-yAly and LaNi5, La1-xCexNi5 alloys were evaluated using a purpose built Sievert-type apparatus

The potential of arbuscular mycorrhizal fungi to enhance metallic micronutrient uptake and mitigate food contamination in agriculture: prospects and challenges

Optimizing agroecosystems and crops for micronutrient uptake while reducing issues with inorganic contaminants (metal(loid)s) is a challenging task. One promising approach is to use arbuscular mycorrhizal fungi (AMF) and investigate the physiological, molecular and epigenetic changes that occur in their presence and that lead to changes in plant metal(loid) concentration (biofortification of micronutrients or mitigation of contaminants). Moreover, it is important to understand these mechanisms in the context of the soil microbiome, particularly those interactions of AMF with other soil microbes that can further shape crop nutrition. To address these challenges, a two-pronged approach is recommended: exploring molecular mechanisms and investigating microbiome management and engineering. Combining both approaches can lead to benefits in human health by balancing nutrition and contamination caused by metal(loid)s in the agro-ecosystemThis work was supported by grant PID2021-1255210B-I00 funded by MCIN/AEI/10.13039/ 501100011033 and by ‘ERDF A way of making Europe’, by the ‘European Union’. NC is a University of Ottawa Research Chair in Microbial Genomics, and his research on AMF genetics and genomics is supported by the Discovery Program of the Natural Sciences and Engineering Research Council (RGPIN2020-05643) and a Discovery Accelerator Supplements Program (RGPAS2020-00033

A comparative analysis of configurations of linear Fresnel collectors for concentrating solar power

Linear Fresnel collector arrays present some relevant advantages in the domain of concentrating solar power because of their simplicity, robustness and low capital cost. However, they also present important drawbacks and limitations, notably their average concentration ratio, which seems to limit significantly the performance of these systems. First, the paper addresses the problem of characterizing the mirror field configuration assuming hourly data of a typical year, in reference to a configuration similar to that of Fresdemo. For a proper comparative study, it is necessary to define a comparison criterion. In that sense, a new variable is defined, the useful energy efficiency, which only accounts for the radiation that impinges on the receiver with intensities above a reference value. As a second step, a comparative study between central linear Fresnel reflectors and compact linear Fresnel reflectors is carried out. This analysis shows that compact linear Fresnel reflectors minimize blocking and shading losses compared to a central configuration. However this minimization is not enough to overcome other negative effects of the compact Fresnel collectors, as the greater dispersion of the rays reaching the receiver, caused by the fact that mirrors must be located farther from the receiver, which yields to lower efficiencies

Experimental analysis of a coiled stirred tank containing a low cost PCM emulsion as a thermal energy storage system

This article presents the results of heat transfer coefficient and volumetric energy density measurements in an agitated tank containing a low-cost phase change material emulsion, heated by water flowing in a coil. For the stirring a three-stage impeller is placed in the central axis of a 46 l commercial tank. By measuring the temperature dependency on time and solving the transient enthalpy balance, the heat transfer coefficient between the helical coil and the agitated phase change material emulsion is determined, based on the impeller Reynolds number. The thermal energy storage efficiency has also been analysed. This phase change material emulsion shows a phase change temperature range between 30 and 50 °C. Its solid content is about 60% with an average size of 1 µm. The results have shown that the overall heat transfer coefficient is around 3.5–5.5 times higher when a stirring rate of 290–600 rpm is used. Furthermore, even at the lowest stirring rate, the thermal energy storage efficiency improves from 76-77%–100%, without detriment to the energy consumption of the stirrer

Búsqueda y análisis de nuevos materiales PCM-TES de bajo coste

Este trabajo se centra en el almacenamiento de energía térmica mediante cambio de fasesólido‐líquido y sólido‐sólido. Los trabajos realizados hasta ahora respecto al almacenamientotérmico de energía mediante materiales de cambio de fase (PCM), demuestran que es viabletécnicamente para algunas aplicaciones. Sin embargo, el alto precio de los materiales hace quesu explotación comercial a gran escala no se haya producido hasta el momento. El objetivo esencontrar PCM de bajo coste a partir de residuos, subproductos o productos naturales. En elconcepto de bajo coste se incluye no sólo el bajo precio sino también un bajo impactoambiental por eso se incluyen productos naturales que pueden tener un precio elevado. Se habuscado en bases de datos de residuos, de Autorizaciones Ambientales Integradas y se hansolicitado muestras en distintos foros. Se han realizado pruebas a treinta sustanciasconseguidas (glicerinas de obtención de biodiesel, aceites usados, parafinas, subproductos defibras, aceites de pirólisis, yeso y aceites naturales) y hasta el momento se han obtenidoresultados interesantes para siete de ellas. Se está trabajando en la caracterización completade los materiales seleccionados que comprende entre otros: subenfriamiento, histéresis y ladeterminación de la conductividad térmica a partir de la difusividad térmica, capacidadcalorífica y densidad. El conocimiento de las magnitudes descritas es imprescindible paradiseñar y/o simular correctamente los sistemas en los que se incluyen estos materiales:cambios de volumen para diseñar su encapsulación o viscosidad para dimensionar las bombaspor ejemplo. Además se siguen buscando otras sustancias

Hydroponics as a valid tool to assess arsenic availability in mine soils

The low solubility of As in mine soils limits its phytoavailability. This makes the extrapolation of data obtained under hydroponic conditions unrealistic because the concentration in nutrient solution frequently overexposes plants to this metalloid. This work evaluates whether As supply in hydroponics resembles, to some extent, the As phytoavailable fraction in soils and the implications for phytoremediation. Phytotoxicity of As, in terms of biomass production, chlorophyll levels, and As concentrations in plants, was estimated and compared in both soils and hydroponics. In order for hydroponic conditions to be compared to soil conditions, plant exposure levels were measured in both cultures. Hydroponic As concentration ranging from 2-8 μM equated to the same plant organ concentrations from soils with 700-3000 mg kg-1. Total and extractable As fractions exceeded those values, but As concentrations in pore water were bellow them. According to our results (i) hydroponics should include doses in the range 0-10 μM As to allow the extrapolation of the results to As-polluted soils, and (ii) phytoextraction of As in mining sites will be limited by low As phytoavailabilityThis study was supported by the Spanish Ministry of Education and Science, project CTM 2007-66401-CO2/TECNO, and by Comunidad de Madrid, project S-0505/AMB/029

Unlocking co-creation for green innovation: an exploration of the diverse contributions of universities

In the context of the green transition, universities have much to offer in joint green innovation projects with business, government and citizens. As hubs of diverse expertise, universities are uniquely placed to build interdisciplinary teams and bridge gaps between society and industry. Their regional ties also enable them to engage with the local ecosystem. This paper draws from ten international case studies of university partnerships with industry and society in green mobility, green energy and green products, services and processes. The comparative evidence gathered from interviews with representatives from these initiatives examines universities’ practices for green co-creation. Additionally, the paper outlines policy recommendations crucial to supporting these initiatives, essential for the global success of sustainable development efforts

Unlocking co-creation for green innovation: 10 international case studies

Document associated with policy paper titled "Unlocking co-creation for green innovation : an exploration of the diverse contributions of universities." OECD Science, Technology and Industry Policy Papers #163, ISSN 2307-495