Depósito Académico
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Las colecciones que forman el Depósito Académico se asemejan a la estructura organizativa de la Universidad de Navarra a fecha de 2010: Facultades, Departamentos, Escuelas, etc.
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- Tiebas Castle’ tuiles vernissées: Characterization, raw clay provenance, and manufacturing technology(Elsevier B.V., 2024) Durán, A. (Adrián); Lasheras, E. (Esther); Ruiz-Ardanaz, I. (Iván); Úriz-Asiain, O. (Orreaga)Tiebas Castle was built between 1254 and 1264 as a royal residence of the kings of Navarre. The Castle was decorated with architectural luxuries imported from the French court. Some decorative elements of this French style are the polychrome roof tiles, called tuiles verniss ́ees; and the glazed floor tiles, called carreaux de pavement. Both are the unique that have been found in the Iberian Peninsula. Elemental and mineralogical analysis allowed us to distinguish two different types of pastes that were used for both tuiles verniss ́ees and carreaux de pavement: yellowish and reddish. The reddish paste was composed mainly of quartz, and to a lesser extent of haematite and illite. The yellow pastes were very rich in calcite and other calcium-bearing minerals (gehlenite, anorthite, diopside or wollastonite) and poorer in quartz and haematite. The different colour tones of the yellow paste samples allowed them to be classified into five subgroups (YP-1, YP-2, YP-3, YP-4, and YP-5). This classification turned out to coincide with a somewhat different mineral composition. The study of the mineral phases newly formed (gehlenite, anorthite, diopside and wollastonite) or destroyed (illite) during firing allowed us to estimate the maximum firing temperature of each of the subgroups. The temperature ranges for each subgroup were as follows: 750–800 ◦C (YP-5), 850–900 ◦C (YP-4), 900–925 ◦C (YP-3), 925–950 ◦C (YP-2), and 950–1000 ◦C (YP- 1). The study of its possible raw materials allowed us to identify that the yellow pastes from tuiles vernissées and carreaux de pavement were prepared from a mixture of two clays. One of them was the decalcification clay (A15 clay) with which they also made the reddish pastes. The other component of the mixture was the marl from Castle hill. The proportion that the artisans used of both raw materials was 1:2 (twice as much marl as decalcification clay).
- Structure and activity of amphiphilic PEO-PPO-based polymeric micelles and gels incorporating host–guest complexes of miltefosine as novel formulations for the treatment of leishmaniasis(Elsevier, 2024) Aydillo-Miguel, C. (Carlos); González-Gaitano, G. (Gustavo); Nguewa, P.A. (Paul Alain); Smith, G.N. (Gregory N.); Dirany, Z. (Zeinab)Hypothesis: Poloxamines are amphiphilic block copolymers that self-assemble forming polymeric micelles (PMs) and hydrogels. They have emerged as promising colloidal carriers for their potential in improving drug delivery and controlled release through their multi-responsive properties. Tetronic® 1307 (T1307) PMs and gels have been used herein as vehicles of host–guest complexes of cyclodextrins (CDs) and miltefosine (MF), an amphiphilic, anti-parasitic drug effective against leishmaniasis. Experiments: The association of MF to αCD, βCD, and HPβCD and the topology of the complexes have been fully characterized by NMR spectroscopy. Then, the structure of the complex-loaded PMs and hydrogels investigated using diffusion nuclear magnetic resonance (DOSY), small angle neutron scattering (SANS), and dynamic light scattering (DLS). The antileishmanial activity of the constructs was evaluated against Leishmania major promastigotes and amastigotes, as well as their cytotoxicity in macrophages. Findings: All the CDs investigated form highly stable inclusion complexes with MF in a 2CD:1MF stoichiometry that lead to considerable proportions of complexed drug at high dilution, the HPβCD providing the highest stability and compatibility with the poloxamine. The complex incorporates preferentially into the hydrophilic shell of the PMs, inducing the elongation of the aggregates and the dehydration of the micellar core, formed mainly by the PPO blocks. At high concentration of polymer and physiological temperature, the complex-loaded PMs pack in a BCC-type paracrystal network. The micellar formulations of the CD-complexed MF reduced the cytotoxicity of the drug, while enhancing its antileishmanial activity. This approach could improve the currently available treatments, facilitating the administration of MF at lower concentrations and achieving relevant therapeutic effects, not only through the intravenous route, but also as topical formulations through injectable thermogels for the treatment of the cutaneous and mucocutaneous forms of the disease.
- Obtaining and characterization of air lime renders with phase change materials(Itecons, 2023) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)To improve the thermal efficiency of the building envelope of the architectural heritage buildings, modified air lime-based rendering mortars were designed with the addition of various microencapsulated phase change materials (PCMs) in proportions of 5, 10 and 20% by weight of lime. In a first part, the composition of the various renders was optimised by means of various additives, such as adhesion improvers, dispersing agents and a pozzolanic admixture (metakaolin). The characteristics of the rendering mortars were evaluated, including their adhesion on absorbent substrates, cracking, etc. The microstructure of the mortars was studied by optical microscopy, scanning electron microscopy and mercury intrusion porosimetry. It was found that the optimised recipes achieved an adequate distribution of PCM within the binding matrix, and with reasonable compatibility. The thermal effect on the render was studied by measuring thermal conductivities and enthalpies attributed to phase changes. In addition, a hotbox demo model was designed for the evaluation of the thermal performance. The results have shown that the addition of PCM in air lime renders is a feasible option to improve thermal efficiency and increase the thermal comfort of building occupants.
- Preparation of multifunctional hydrophobic- an hydro-oleophobic coatings with self-cleaning capacities for stone construction materials(Itecons, 2023) Alvarez-Galindo, J.I. (José Ignacio); Navarro-Blasco, I. (Iñigo); Tena-Santafé, V.M. (Víctor M.); Fernandez-Alvarez, J.M. (José María)This work presents the development, application and characterisation of multifunctional coatings that act as a barrier to water access to the interior of building materials while at the same time having self-cleaning and atmospheric pollutant degradation capabilities. To this end, two carrier media, a 3D superhydrophobic agent (SPHB) and a 3D hydrooleophobic agent (OHB), have been used to reduce the access of water and oily liquids. Two nanoparticulated photocatalysts (TiO2-ZnO 25/75 and Bi2O3-ZnO 8/92 heterostructures) have been incorporated in them, whose mission is to degrade by photocatalysis both dirt accumulated on the construction material and to degrade surrounding atmospheric pollutants. These photocatalysts have been chosen because of their improved sensitivity to the visible light spectrum. To avoid the known tendency of nanoparticles to agglomerate, which would result in lower photocatalytic activity, dispersing agents, non-ionic surfactants (Tween20, TritonX100 and Brij35), were used in the preparation of the coatings. These suspensions were applied as coatings on stone materials commonly used in Built Heritage, such as sandstone, limestone and granite. The effectiveness of the coatings was evaluated by studying their hydrophobicity, oleophobicity and photocatalytic activity. The coatings showed high compatibility with the stone substrates. The presence of dispersant increased the hydrophobicity of the coatings. The TiO2-ZnO photocatalyst was more active in the SPHB medium than the Bi2O3-ZnO composition, while the trend was reversed in the OHB medium tests (average abatements between 8 and 10% of nitric oxide and high selectivity). After accelerated weathering tests, it was found that the thickness of the coatings did not change significantly, showing hydrophobic efficiency and self-cleaning capacity.
- Estudio Voltamétrico de la complejación del cobre(II) en las Rías Gallegas(Universidade de Aveiro, 2000) Cobelo-García, A. (Antonio); Prego, R. (Ricardo); Fernandez-Alvarez, J.M. (José María)En el presente trabajo se propone una metodología que permite la cuantificación de la fracción lábil y la concentración total de Cu en las Rías Bajas Gallegas.
- Sustainable management of lignocellulosic wastes: Temperature strategies for anaerobic digestion of artichoke(Elsevier, 2021) Diego-Díaz, B. (Beatriz) de; Fernández-Rodríguez, J. (Juana); Peñas-Esteban, F.J. (Francisco Javier)Lignocellulosic residues are a widely available energy resource, but their conversion into biogas through biomethanation may be hindered by a chemical structure with strong bonds. A strategy based on temperature-phased anaerobic digestion (TPAD) is here applied to optimize anaerobic digestion of artichoke as a representative lignocellulosic waste. The experiments consist of a first thermophilic stage conducted at 55 °C (7 and 5 days), followed by a second mesophilic stage at 35 °C. In addition, for comparison, single-stage temperature trials are carried out within the most common conditions for biomethanation (mesophilic at 35 °C, and thermophilic at 55 °C), as well as at the intermediate range (42 °C). In general, biomethanation of artichoke residues under TPAD configuration provides better performance than single-stage systems. Particularly, the best performance is observed for the TPAD arrangement using a thermophilic phase of 7 days. Thus, at this optimal configuration, volatile solids (VS) removal of 54%, and biogas and methane yields of 442 mL/g-VS and 375 mL-CH4/g-VS were reached, respectively. Moreover, a kinetic model coupling biogas generation and substrate consumption has been applied. Good agreement is found for both variables in each system tested. The calculated non-biodegradable substrate (S∞) is lower in TPAD systems (mean 49.6%) compared with that of single-stages (average 53.9%). The maximum specific growth rate of biomass (μM) is higher for TPAD digesters (mean 0.0625 d−1), although the thermophilic single-stage reactor reaches a close value (0.0615 d−1). The biogas yield (α) is similar for all conditions (0.358 L/g-VS), but with a maximum value of 0.428 L/g-VS for the TPAD digester with the 7-days thermophilic period. Therefore, temperature-phased anaerobic digestion has proved to be an efficient strategy for sustainable management of artichoke wastes.
- New trends in physicochemical characterization of solid lignocellulosic waste in anaerobic digestion(Elsevier, 2019) Diego-Díaz, B. (Beatriz) de; Álvarez-García, M. (Mariano); Durán, A. (Adrián); Fernández-Rodríguez, J. (Juana)In this paper, the use of techniques such as TGA, FTIR-ATR and XRD has provided valuable information about the lignocellulosic wastes in anaerobic digestion (AD) processes. A deep study of their break-down in solid state could improve the management of these recalcitrant substrates. Representative wastes (artichoke –ART-, asparagus –ASP-, the co-digestion of both –AcoD- and pure cellulose –CELL-) were assessed in batch. The main obtained results were related to biochemical parameters. As the biomethanization progressed, hemicellulose, cellulose and lignin were weakened as shown by TGA, and cellulose crystallinity decreased as demonstrated by XRD. Additionally, results from FTIR-ATR allowed hypothesizing that the formation of acetate in solid state did not always lead to its solubilisation, thus hindering biogas formation. AcoD and CELL were the most successful in releasing the newly formed acetate from the solid fraction to the aqueous medium, increasing its bioavailability, which was supported by the higher biogas production.
- Acid and alkali chemical treatments on synthetic and natural cellulosic, fibroin and keratin-based fabrics: study of structural changes(Taylor & Francis, 2023) Olguín, C. (Catherine); Durán, A. (Adrián); Fernández-Rodríguez, J. (Juana); Azcona, J. (Jesús)Full Article Figures & data References Supplemental Citations Metrics Reprints & Permissions Read this article Abstract The characterization of fabrics after applying different degradation conditions appears to be a key factor to understand their behaviour for different applications. Depending on the treatment, morphologic and polymorphic changes may arise in the polymeric chain structure that composes textile fibers. In this paper, a systematic and comparative study between different types of natural and synthetic textile fabrics was carried out in order to shed light on the structural changes occurring under acid and alkali treatments. The natural fabric polymers studied had a cellulose-based composition from plants (cotton, linen and jute), or a protein-based one from animals (silk and wool). The synthetic fabric was polyester. Different treatment times were assessed: 15 min, 1, 2, 4, 8 and 24 h and compared to the initial condition of the fabrics (standard). In the cellulosic fabrics, the alkali provoked the polymorphic transformation of the amorphous CI into CII. However, the acid treatment did not cause any remarkable alteration in the structure. In protein fabrics, the acid treatment increased the amorphicity of the structures, leading to further degradation but not affecting the conformation of proteins, and the alkali dissolved the fabrics. Polyester was not affected by the chemical solutions (neither acid nor alkali).
- Validation of an efficiency calibration procedure for a coaxial n-type and a well-type HPGe detector used for the measurement of environmental radioactivity(Elsevier, 2016) Cartas-Aguila, H.A. (Héctor A.); Morera-Gómez, Y. (Yasser); Nuñez-Duartes, C. (Carlos); Alonso-Hernández, C. M. (Carlos Manuel)To obtain reliable measurements of the environmental radionuclide activity using HPGe (High Purity Germanium) detectors, the knowledge of the absolute peak efficiency is required. This work presents a practical procedure for efficiency calibration of a coaxial n-type and a well-type HPGe detector using experimental and Monte Carlo simulations methods. The method was performed in an energy range from 40 to 1460 keV and it can be used for both, solid and liquid environmental samples. The calibration was initially verified measuring several reference materials provided by the IAEA (International Atomic Energy Agency). Finally, through the participation in two Proficiency Tests organized by IAEA for the members of the ALMERA network (Analytical Laboratories for the Measurement of Environmental Radioactivity) the validity of the developed procedure was confirmed. The validation also showed that measurement of 226Ra should be conducted using coaxial n-type HPGe detector in order to minimize the true coincidence summing effect.
- Thermal characterization, polymorphism, and stability evaluation of Se-NSAID derivatives with potent anticancer activity(Springer, 2023) Ramos-Inza, S. (Sandra); Sirera-Bejarano, R. (Rafael); Sanmartin-Grijalba, C. (Carmen); Encío, I. (Ignacio); Font, M. (María); Plano-Amatriain, D. (Daniel); Almagro, E. (Eneko); Lizarraga, E. (Elena)Stability, thermal characterization, and identification of possible polymorphism are relevant in the development of novel therapeutic drugs. In this context, thirty new nonsteroidal anti-inflammatory drug (NSAID) derivatives containing selenium (Se) as selenoesters or diacyl diselenides with demonstrated anticancer activity were thermally characterized in order to establish thermal stability criteria and detect possible polymorphic forms. Compounds were analyzed by a combination of thermogravimetry, differential scanning calorimetry, and X-ray diffraction techniques, and five different calorimetric behaviors were identified. Two compounds based on naproxen (I.3d and I.3e) and an indomethacin-containing derivative (II.2) presented two crystalline forms. The stability under acid, alkaline and oxidative conditions of selected polymorphs was also assessed using high-performance liquid chromatography. In addition, the cytotoxic activity of Se-NSAID crystal- line polymorphs was studied in several cancer cell lines in vitro. Remarkably, no significant differences were found among the polymorphic forms tested, thus proving that these compounds are thermally qualified for further drug development.