Estudio de la idoneidad de un nuevo hormigón estructural fabricado con áridos ligeros reforzados con fibra de carbono sinterizados a partir de residuos

The suitability of three new lightweight aggregates containing carbon fiber residues (CAs) as components in structural lightweight concrete has been studied. Prismatic concrete specimens were prepared using these CAs as a coarse fraction. Additional specimens of normal-weight aggregate, commercial lightweight aggregate and mortar were prepared for comparison. The CA-concrete samples (CACs) have yielded compressive strength values between 35 and 55 MPa as well as low density and thermal conductivity results. Furthermore, the CACs have displayed the highest ratios of mechanical strength over density and the thermal conductivity, which means that there is a better balance between their mechanical and physical properties than in the other samples studied. These results indicate that the new CAs could have great potential for use in structural lightweight concrete, also complying with the principles of the Circular Economy.Este estudio pretende comprobar la idoneidad de unos novedosos áridos ligeros sinterizados con residuos de fibra de carbono (CAs) en la fabricación de hormigón ligero estructural. Se prepararon probetas prismáticas de hormigón, utilizando estos CAs como fracción gruesa, comparándose a su vez con probetas fabricadas con un árido convencional, un árido ligero comercial y mortero. Las muestras de hormigón con los áridos CA (en adelante CAC) han dado lugar a valores de resistencia a compresión entre 35 y 55 MPa, así como a resultados bajos de densidad y conductividad térmica, mostrando además las ratios más altas al relacionar estos tres parámetros. Esto indicaría por tanto un mejor equilibrio entre las propiedades mecánicas y físicas que los obtenidos en las otras muestras estudiadas. Estos resultados apuntan a que los nuevos CAs podrían tener un gran potencial para su uso en hormigón ligero estructural, cumpliendo además los principios de la Economía Circular

Caracterización de las reflexiones de estudiantes del máster en formación del profesorado de matemáticas de educación secundaria obligatoria y bachillerato sobre el recuerdo de su experiencia escolar en matemáticas de secundaria

Este estudio es un primer paso para analizar la identidad profesional de estudiantes para profesor de matemáticas de secundaria. A pesar de tratarse de una muestra limitada y en un contexto concreto, los resultados reflejan la situación en la que se encuentran los futuros profesores de matemáticas de secundaria cuando están realizando un máster profesionalizante, lo que puede ser importante para el diseño y desarrollo de dicho máster a la vez que abre perspectivas de futuro en diferentes sentidos

Can statistical methods optimize complex multicomponent mixtures for sintering ceramic granular materials? A case of success with synthetic aggregates

The relationship between the proportions of multicomponent mixtures with the technological properties of ceramic granular materials (synthetic aggregates) has been studied using statistical methods. The four phases involved in the formulations have been: kaolin (K) as aluminosilicate source; cork powder (C) as organic carbon source; sodium carbonate (N) as flux and pyrite (P) as source of iron and sulfur. The Mixture Experiments - Design of Experiments (ME-DOE) has been the statistical methodology applied from the initial configuration of the 36 starting formulations to the final validation of the models and optimums. After granulation, artificial aggregates have been obtained by sintering in a rotary kiln, and their main technological properties have been determined. Bloating index (BI), particle density (ρrd), water absorption (WA24) and crushing strength (S) were selected as the four key characteristics to be modeled and optimized, using response surface and effect plots to assess the effect of K, C, N and P on such properties. 32 out of 36 starting varieties met the density criteria for lightweight aggregates. In the optimum formulations obtained, the minimum percentage of K was 83 wt%, so that the variations in the percentages of P, C and N were the critical variables for determining the final properties of the aggregate. The contrast between experimental and estimated data has shown that the models fit adequately, indicating that this type of approach may have enormous potential for future research on artificial aggregates and other ceramic materialsThis research was conducted as a part of the ECO-MET-AL Project, PID2019-109520RB-I00 / AEI / 10.13039/501100011033, “Can industrial and mining metalliferous wastes produce green lightweight aggregates? Applying the Circular Economy” funded by the Spanish Ministry of Science, Innovation and Universities and ERDF funds, framed in the “Ayudas a “Proyectos I + D + i" en el marco de los Programas Estatales de Generación de Conocimiento y Fortalecimiento Científico y Tecnológico del Sistema de I + D + i y de I + D + i orientada a los Retos de la Sociedad, Convocatoria 2019”. Thanks also to the SCAI of the University of Jaén, the University of Castilla-La Mancha and the University of Málaga for their service

CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)

Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced

Heavy metal chemical fractionation and immobilization in lightweight aggregates produced from mining and industrial waste

The fractionation of five heavy metals in a washing aggregate sludge, a sewage sludge, a clay-rich sediment, the mixtures of these materials and the lightweight aggregates manufactured with them has been deterined by applying the optimized European Community Bureau of Reference sequential extraction procedure in order to evaluate the effects of the heating process on the extraction of these elements. Additionally, preparation of eluates by aggregate leaching has been performed in accordance with the UNE-EN-1744-3 standard. The availability of all the studied heavy metals has been reduced by the thermal treatment, since most of the heavy metals have become part of the undigested material in the lightweight aggregates. Nickel has been the heavy metal that has presented the highest concentration in the eluates obtained after completion of the single extraction procedure in the lightweight aggregates. The studied lightweight aggregates may be used in lightweight concrete manufacturing from the standpoint of heavy metal leaching

Microstructure and Mineralogy of Lightweight Aggregates Produced from Washing Aggregate Sludge and Clay-rich Sediment

Lightweight aggregates (LWAs) can be used in a wide range of applications, such as: acoustic and thermal insulation, manufacturing of structural lightweight concrete, geotechnical applications, and gardening (Bodycomb and Stokowski, 2000). Each application depends on the physical and chemical properties of LWAs. In turn, it has been reported (Rice and Dekker, 1998) that important ceramic properties, such as density and water absorption, are intrinsically correlated with the LWA microstructure. Additionally, Farran (1956) showed that the mineralogical composition of the LWAs is the main factor to consider in the study of concrete fracture, since the mineralogy of the LWAs mainly determines the adhesive behaviour between the cement paste and the aggregate. Here, we describe the mineralogy and microstructure of various artificial LWAs produced by pelletizing and sintering washing aggregate sludge (W) and clay-rich sediment (C). The heating temperature and dwell time effects on the mineralogy and microstructure of the studied LWAs are evaluated. In turn, the influence of these characteristics on the bloating index (BI), density, water absorption (WA24h), and compressive strength (S) are analyzed.Peer Reviewe

Microstructure and mineralogy of lightweight aggregates produced from washing aggregate sludge, fly ash and used motor oil

The microstructures and mineralogical compositions of lightweight aggregates (LWAs) manufactured with washing aggregate sludge (WS), fly ash (FA) and used motor oil (UMO) have been studied. Most LWAs with WS and FA exhibited an external layer and a glassy core with isolated pores. LWAs with WS and UMO did not present external shells or signs of bloating. Iron oxides, within the external layer, and pyrrhotite, in the inner glass, were observed. The mineralogical analyses revealed the neo-formation of plagioclase and pyroxene, along with minor gehlenite. Some relationships could be established: (i) the presence of larger pores is related to a decrease in the dry particle density values, (ii) when the LWA lacks the external layer, the water absorption values were dependent on the size and amount of each type of pore (open or closed), and (iii) the neo-formation of Ca-plagioclase and the consumption of quartz improved the compressive strength values

Microstructure and mineralogy of lightweight aggregates manufactured from mining and industrial wastes

The microstructure and mineralogy of lightweight aggregates manufactured with washing aggregate sludge, sewage sludge and a clay-rich sediment have been studied. The mineralogical analysis revealed the neo-formation of plagioclase and pyroxene group minerals and a minor presence of gehlenite. Some relationships may be established: (i) heating temperature and dwell time affect the formation of new porosity; (ii) the disappearance of pyroxenes could produce changes in the density of the solid material in the lightweight aggregates; (iii) when an external glassy film is not present, water absorption values depend on the size and number of each type of pore