Facultad de Ciencias
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- AnTimicrobial pHotocatalytic coatIngs on sustaiNable coNstruction matErials carrieRs (THINNER)(2024-10-31) Kaur, G. (Gurbir)
- Air lime renders with microencapsulated phase change materials: assessment of microstructural and thermal properties(Elsevier, 2024-11-22) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)Microencapsulated phase change materials (PCMs) have been successfully integrated into air lime-based rendering mortars to enhance thermal properties, aiming to boost the thermal efficiency of the buildings in which are applied. Two microencapsulated PCMs, with melting points at 18℃ and 24℃, were seamlessly introduced into fresh rendering mortars in varying proportions (5%, 10%, and 20% by weight of lime), in formulations that include different chemical additives, such as a superplasticizer (polycarboxylate ether) and an adhesion enhancer (starch-based additive). In some mixes, metakaolin (MK) was also added as a mineral admixture. Starch addition was seen to promote the formation of aragonite and vaterite (calcium carbonate polymorphs), facilitating the smooth integration of microcapsules within the lime matrix. Hotbox simulations with tested materials containing as low as 0.01 - 0.04 g of PCM per gram of dry mortar, yielded outstanding energy efficiency values (822.4 and 732.8 kJ/m2, respectively, for PCMs with melting points at 18℃ and 24℃). Temperature attenuations of up to 6.1°C during the heating stage and up to 3.9°C during the cooling stages were observed. This outcome not only emphasizes the potential for enhancing thermal efficiency through PCM incorporation into air lime renders but also hints at a remarkable future for energy-efficient construction materials.
- Estudio de la flora vascular y la micobiota micorrícica en quemados truferos de Navarra (España)(Comunità Montana dei Monti Martani Serano e Subasio, 2010) Cavero-Remon, R.Y. (Rita Yolanda); Gonzalez-Armada, M. (MB); Miguel-Velasco, A.M. (Ana Maria) deIn spite of the continuous advances in trufficulture there are still many questions about truffle growing, hence the big importance of studying the characteristics of the environment in which it best develops. In this study we have analysed the main ecological characteristics of the vascular flora growing in 24 holm oak brûles. This flora is special, very influenced by the alelopatic substances produced by the mycelium of the fungus, modifying the composition and the characteristics of the flora. As a result, plants grow smaller and with a lower covering. Sometimes they even present changes in their life-cycle. Therophytes typical of disturbed areas are dominant in plantations. Xerophile plants are also common. Besides, the species found in truffiers are proper of shaken, removed and generally sunny, dry and stony places, and many of them weeds. This corroborates the fact that the brûle is a very disturbed environment, both by fungus mycelium as by human intervention. On the other hand, monitoring the mycorrhizae is very important in truffle growing since it allows us to know if the plantations are properly developing or if truffle mycorrhizae have been replaced by other competing fungi. That is why we have carried out a below-ground study of the mycorrhizae appearing in the roots of the same holm-oaks, to check the presence of truffle mycorrhizae and to know if other mycorrhizal fungi are colonizing the roots.
- Actividad trufícola navarra. Cuestiones sin respuesta(Comunità Montana dei Monti Martani Serano e Subasio, 2010) Saez, R. (Raimundo); Miguel-Velasco, A.M. (Ana Maria) deIn Navarra, first plantations were carried out in 1989. The ignorance about truffle and trufficulture was total. Almost everything about truffle was unknown, almost even its existence, but as a consequence of the permanent search for new crops that contribute to diversify and improve agricultural productions of the region, it was decided with great interest to carry out the first plantations, and find information, mainly in France and Italy. Twenty years have passed. Technical and scientific advances have taken place but there are still many doubts. The expectations raised at first have not been reached in many cases. In spite of that, trufficulture is a reality, that covers important areas in those zones suitable for truffle growing, both in Navarra and in Spain, and it is still increasing. In Navarra, with the experience acquired, a few points can be made: • Mycorrhized plant production has evolve positively in Spain, which guarantees one of the most important factors in the reasonable trufficulture, together with land selection, climate or cultivation techniques. • The soil: lands selected for new plantations suit truffle needs. They are bigger plots, which is favourable to the correct management of plantation. • Irrigation: in new trufficulture the irrigation studies and practice have become very necessary. The experimentation in this subject is necessary to cover crop needs. • Spreading and training: promoting trufficulture as a diversification alternative in rural areas has been the aim reached through courses, trips, conferences, festivals, commercial exhibitions, competitions…, which has culminated with the creation of the first Truffle Museum in Spain.
- Transforming waste red mud into sustainable cementitious materials for self-cleaning applications(2024-12-11) Alvarez-Galindo, J.I. (José Ignacio); Navarro-Blasco, I. (Iñigo); Pavia, S. (Sara); Kaur, G. (Gurbir); Fernandez-Alvarez, J.M. (José María)The development of novel catalysts and photocatalytic materials is an active area of study in the field of remediation of air pollution. The aim of this study is to investigate the potential of red mud-based cement mortars for photocatalytic abatement of nitrogen oxides (NO and NOx) under solar irradiation. Red mud is an industrial by-product generated during the Bayer process for refining bauxite into alumina. It poses significant environmental challenges due to its highly alkaline nature and presence of toxic heavy metals. Typically, hematite (α-Fe2O3) and goethite (α-FeOOH) are the compounds or iron oxide phases which are found in abundance in red mud. Interestingly, hematite is a nontoxic and stable compound, which possesses a visible light active band gap and can be a potential catalyst for photocatalytic activity.
- The role of the adenylate kinase 5 gene in various diseases and cancer(Cambridge University Press, 2024) Sarim-Siddiqui, M. (M.); Saez-Castresana, J. (Javier); Shahi, M.H. (Mehdi Hayat)Adenylate kinases (AKs) are important enzymes involved in cellular energy metabolism. Among AKs, AK5 (adenylate kinase 5), a cytosolic protein, is emerging as a significant contributor to various diseases and cellular processes. This comprehensive review integrates findings from various research groups on AK5 since its discovery, shedding light on its multifaceted roles in nucleotide metabolism, energy regulation, and cellular differentiation. We investigate its implications in a spectrum of diseases, including autoimmune encephalitis, epilepsy, neurodegenerative disorders such as Alzheimer’s and Parkinson’s, diabetes, lower extremity arterial disease, celiac disease, and various cancers. Notably, AK5’s expression levels and methylation status have been associated with cancer progression and patient outcomes, indicating its potential as a prognostic indicator. Furthermore, AK5 is implicated in regulating cellular processes in breast cancer, gastric cancer, colorectal carcinoma, prostate cancer, and colon adenocarcinoma, suggesting its relevance across different cancer types. However, a limitation lies in the need for more robust clinical validation and a deeper understanding of AK5’s precise mechanisms in disease pathogenesis, despite its association with various pathophysiological conditions. Nonetheless, AK5 holds promise as a therapeutic target, with emerging evidence suggesting its potential in therapy development.
- Granular internal dynamics in a silo discharged with a conveyor belt(Cambridge University Press, 2021) Zuriguel-Ballaz, I. (Iker); Maza-Ozcoidi, D. (Diego); Gella, D. (Diego)The dynamics of granular media within a silo in which the grain velocities are controlled by a conveyor belt has been experimentally investigated. To this end, the building of coarse-grained field maps of different magnitudes has allowed a deep analysis of the flow properties as a function of two parameters: the orifice size and the belt velocity. First, the internal dynamics of the particles within the silo has been fully characterized by the solid fraction, the velocity of the particles and the kinetic stress. Then, the analysis of the vertical profiles of the same magnitude (plus the acceleration) has allowed connection of the internal dynamics with the flow rate. In particular, we show that the gamma parameter – which accounts for the integration of the normalized acceleration along the vertical direction – can successfully discriminate the kind of flow established within the silo (from the quasistatic regime to the free discharge) depending on the outlet size and belt velocity.
- Interactions between struvite and humic acid and consequences on fertilizer efficiency in a nonacidic soil(American Chemical Society, 2024) Seminario, I. (Iñigo); García-Mina, J.M. (José María); Erro, J. (Javier)The effect of humic acid extracted from peat (AHt) on improving the struvite (STR) fertilizing efficiency is explored. To this end, a soil incubation study is correlated to plant assays comparing STR, STR-AHt, and superphosphate (SSP). Characterization techniques confirm the incorporation of the AHt into the STR. The P-pool distribution of STR and SSP is similar in the soil incubation, with STR-AHt presenting a higher labile P at 90 days passing from 10 to 15% P from SSP and STR to 25% P with STR-AHt. However, when applied to barley and tomato, STR yields more shoot P content, aboveground biomass, and residual P in soil than SSP. STR-AHt does not improve the STR results. The poor correlation observed between soil incubation and plant trials highlights the role of the rhizosphere in testing the fertilizer efficiency of STR. Mechanistic assays indicate the key role of rhizosphere pH. Finally, molecular modeling reveals a higher stabilization of STR with AHt, which could reduce P release decreasing the fertilizing potential of STR-AHt, as observed in the pot trials.
- Potential use of red mud in cementitious materials for environmental remediation(2024-10-21) Alvarez-Galindo, J.I. (José Ignacio); Navarro-Blasco, I. (Iñigo); Pavia, S. (Sara); Kaur, G. (Gurbir); Fernandez-Alvarez, J.M. (José María)Red mud (RM), an industrial waste derived from aluminum production, is a significant environmental concern due to its high alkalinity and large volumes. However, RM can be leveraged in the construction industry for wide variety of applications, including production of low-carbon cementitious materials and for environmental remediation. Using RM as a cement replacement reduces the need for raw materials typically used in cement production, such as limestone and clay. This helps conserve natural resources and reduces the environmental impact of mining. At the same time, it addresses other environmental concerns simultaneously by reducing waste and potentially lowering the carbon footprint of construction industry. This study explores the photocatalytic performance of RM, and its subsequent use in cementitious materials as partial cement replacement. Red mud is rich in iron oxide, which is distributed in mineral phases such as hematite (Fe2O3) and goethite (FeOOH). Hematite (α-Fe2O3) is the most stable form of iron oxide and can be significant for photocatalytic applications point of view. In the initial phase of this study, the photocatalytic activity of RM was assessed by means of an abatement test to measure NOx reduction in solar irradiation. It was observed that RM has a potential of photocatalytic removal of nitrogen oxides, attributed to the adsorption of NO and NOx, as well as their subsequent photocatalytic degradation. In second stage of the study, RM-based cement mortars were prepared, and based on variables i.e., RM’s substitution levels as cement replacement, workability and compressive strength of mortars were investigated. The thermal properties and phase transitions of the investigated mortars were studied using thermogravimetric analysis (TGA). The compressive strength of RM-cement mortar at 28 days with optimal conditions (5% RM substitution) i.e., C3R5 is 31.19 MPa, showing 41% improvement over standard cement mortar. Scanning electron microscope (SEM) micrographs reveal abundant hydration products and strong interfaces in C3R5. By offering an environmentally friendly solution to RM management while simultaneously creating useful construction materials, this study represents a significant step towards more sustainable industrial practices and resource utilization.
- Optimization of Air Lime Concrete and Air Lime-based Ternary Mixtures with Sustainable Additives for Enhanced Performance in Heritage Buildings(2024-10-21) Alvarez-Galindo, J.I. (José Ignacio); Kyriakou; Çam, E. (Elif); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)The urgent need for sustainable, carbon-negative construction materials has been intensified due to global warming (Barbhuiya, 2023; Haik, 2020). Historic buildings face unique challenges in integrating eco-friendly parameters due to the necessity of compatibility of new materials with historic structures and mitigating their long-term impacts (ICOMOS, 2003). The replacement of OPC with lime in concretes and mortars enables lower carbon emissions and compatibility with historic buildings, although it exhibits higher porosity, water absorption and lower compressive strength than OPC (González-Sánchez, 2021; Rosell, 2023; Velosa, 2009). In this case, admixtures are used to improve the performance of lime-based mixes (Grist, 2013; Seabra, 2009). The study focuses on optimising lime concrete and air lime-based ternary mixes by incorporating eco-friendly additives, as different pozzolanic agents and fibres, to enhance their physical and mechanical properties to be used in restoration works. Silica fume, which is a by-product, and natural volcanic ash were selected as pozzolanic agents and added in different percentages between 0–30%. Hemp and basaltic fibres were included in 1%. The study evaluated the effects of different binders and additives through analyses such as fluidity, water retention, and setting time, also compressive strength tests (7th-28th days). The fresh state analyses revealed that adding silica fume reduced the slump values of the mortars by 13%, whereas volcanic ash and fibres had no significant impact on these values. It was also observed that mixtures containing volcanic ash exhibited lower water retention than those with silica fume. Additionally, the inclusion of basalt fibres reduced water retention in the lime-based ternary mortar by up to 4% compared to those containing hemp fibres. According to mechanical tests, cement and silica fume contributed to the compressive strength values of lime-based mixtures. However, volcanic ash and fibres negatively affected compressive strength values in the early stage. As a conclusion, using silica fume and cement in lime-based mixtures reduces the workability of mortars, contrary to volcanic ash and fibres, while increasing mechanical properties even in the early stages.