Calderón
Calderón es el repositorio institucional del CUD (Centro Universitario de la Defensa) en la ENM (Escuela Naval Militar). El CUD, siguiendo las iniciativas Open Access, pone a disposición de la Comunidad este repositorio donde se da acceso a la producción investigadora, principalmente en forma de Trabajos Fin de Grado, pero también Trabajos Fin de Máster, y otros artículos de investigación publicados por el personal docente e investigador del Centro.
Algunos de los documentos publicados en este repositorio tienen restringido el acceso. Para solicitar su consulta, o para plantear cualquier duda respecto a los contenidos de este respositorio, puede:
- Enviar un correo electrónico a [email protected].
- Llamar por teléfono al 986 80 49 89.
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DESEI+D Congreso Nacional de i+d en Defensa y SeguridadInvestigación Comunidad que acoge aquellos artículos de investigación publicados por los docentes del CUD-ENM.Recursos educativos Comunidad en la que se alojan recursos educativos vinculados a la docencia en el CUD-ENMTrabajos Fin de Grado Comunidad en donde se recopilan las memorias de los Trabajos de fin de Grado en Ingeniería Mecánica del CUD-ENMTrabajos Fin de Máster Comunidad en donde se recopilan las memorias/resúmenes presentados como trabajos fin de máster impartidos en el CUD-ENM
Recent Submissions
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Construction and Building Materials Electroprecipitation of inorganic borates, with different solubility, within monumental
(Construction and building materials, 2023) Feijoo, Jorge; Gómez-Villalba, L.S.; Ríos, A. de los; Fort, Rodrigo
Biodeterioration is a serious threat to the preservation of cultural heritage. Currently, the chemical treatments used to combat it must fulfil a series of restrictions to ensure that they are not harmful to humans or the environment. Borates satisfy these conditions but due to its high degree of leaching its application is limited to indoor areas. The use of electroprecipitation may to increase the range of applicability by allowing to precipitate, along the entire section of the stony materials, of a mixture of boron salts with different solubility (zinc, magnesium, and sodium borates) to cover a wide range of moisture conditions. The results obtained show that electroprecipitation
not only increases the penetration depth of boron compounds but also allows the formation of compounds of different solubility, which allows the treatment to last over time. Furthermore, the treatment increased the mechanical properties and reduced the porosity of the stones treated, all without causing significant aesthetic changes.
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Measuring the Electro-osmotic Permeability Coefficient in Single Bricks
(Journals of materials in civil engineering, 2024) Eslami, Naser; Feijoo, Jorge; Paz García, Juanma, Franzoni, Elisa; Ottosen, Lisbeth M.
The transport process electroosmosis (EO) has been suggested to be used for
dewatering damp brick masonry for decades. Still, it is debated whether EO can be obtained in bricks. By use of an advanced EO laboratory cell, this paper reports that an EO flow can be generated in two types of Danish bricks. The electroosmotic permeability coefficient was shown to be dependent on both intrinsic properties of bricks, such as pore size distribution, and extrinsic properties, such as zeta potential. Results showed that the brick with a higher pore volume but with a lower surface charge the EO permeability coefficient is lower.
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Effects of paraffin additives, as phase change materials, on the behavior of a traditional lime mortar
(Construction and building materials, 2022) Feijoo, Jorge; Álvarez-Feijoo, M.A.; Fort, Rafael; Arce, Elena; Duygu, Ergenç
This study refers to the inclusion of phase change materials (PCMs) in porous building materials as an alternative means of improving their thermal behavior, assessing the changes caused in their physical-mechanical and durability properties. Specifically, an organic paraffin wax was selected for direct incorporation into lime mortars using different concentrations by weight. The results show that PCMs improve the thermal properties of the mortar while reducing its accessible porosity. This increases the mortars’ resistance to water and soluble salts. However, excessive PCM content
causes stresses within the mortar that can jeopardize its structure.
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Addition of ferrocyanide-based compounds to repairing joint lime mortars as a protective method for porous building materials against sodium chloride damage
(Materials and structures, 2021) Feijoo, Jorge; Duygu, Eugenç; Fort, Rafael; Buergo, Mónica Álvarez de
Soluble salts are considered one of the main agents in weathering of porous materials used in building constructions. In this work, a comparison in terms of protection against the damage caused by salts, durability and harmful effects of the application of a joint lime repair mortar, with and without K4Fe(CN)6 in its composition, for bonding sandstone blocks contaminated with NaCl was evaluated. Results show that the introduction of ferrocyanide allowed: 1) to protect the mortar during the curing process, hindering the entry of salts into its pores during drying; 2) to improve the carbonation of
the mortar and its adhesion to the porous materials´ surface and 3) to remove
chlorides from the surrounding materials, reaching percentages of reduction close to 100%. All of these without causing aesthetic damage to the materials and maintaining a protective capacity against NaCl over time that allows considering this treatment not only as a shock treatment but also as a preventive measure.
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In-situ electrochemical synthesis of inorganic compounds for materials conservation: assessment of their effects on the porous structure
(Ceramics International, 2021) Gómez Villalba, Luz Stella; Feijoo, Jorge; Rabanal, María Eugenia; Fort, Rafael
This study refers to the application of in-situ electrochemical synthesis as an alternative
method to improve the properties of porous materials against harmful external agents
that deteriorate them. It is oriented to an understanding of the effects of crystallisation
on the pore structure of different compounds commonly used in the restoration and
conservation of porous materials (historic ceramics, building walls, sculptures, or
biomedical applications). It analyses the microstructural, chemical details, and stability
of the neo-formed phases that modify the pore network. The electrochemical synthesis
was carried out at ambient temperature (20°C), over high porous sandstone for
crystallising Ca carbonate, Mg carbonate, Ca phosphate, and Ca oxalate compounds.
Based on the neo-formed minerals, a comparison was made depending on their
specific properties defining how they affected the pore structure. The characterisation
included polarised light optical microscopy, environmental and field emission scanning
electron microscopy, digital image analysis, cathodoluminescence(CL-ESEM),energydispersive
X-ray spectroscopy, and X-ray microdiffraction. Aragonite, hydromagnesite,
hydroxyapatite, and whewellite were identified as the majority phases depending on
the treatment. Phase transformation, dehydration, and dissolution-re-precipitation
processes suggested different degrees of stability, including aragonite/calcite (CaCO3
treatment) and hydromagnesite/magnesite (MgCO3 treatment) transformations and
simultaneous crystallisation of brushite/hydroxyapatite ((Ca 3 (PO 4 ) 2 treatment).
Electrocrystallisation induced changes in inter-granular porosity, the development of
secondary porosity inherent to the minerals, and differences in pore cementation
depending on its mineralogy. Among the treatments, Mg carbonate reduced porosity
most effectively, followed in descending order by calcium carbonate and calcium
phosphate, being the calcium oxalate the less effective.