Modelo de cuantificación del consumo energético en edificación

The research conducted in this paper focuses on the generation of a model for the quantification of energy consumption in building. This is to be done through one of the most relevant environmental impact indicators associated with weight per m2 of construction, as well as the energy consumption resulting from the manufacturing process of materials used in building construction. The practical application of the proposed model on different buildings typologies in Seville, will provide information regarding the building materials, the subsystems and the most relevant construction elements. Hence, we will be able to observe the impact the built surface has on the environment. The results obtained aim to reference the scientific community, providing quantitative data comparable to other types of buildings and geographical areas. Furthermore, it may also allow the analysis and the characterization of feasible solutions to reduce the environmental impact generated by the different materials, subsystems and construction elements commonly used in the different building types defined in this study.La investigación realizada en el presente trabajo plantea la generación de un modelo de cuantificación del consumo energético en edificación, a través de uno de los indicadores de impacto ambiental más relevantes asociados al peso por m2 de construcción, el consumo energético derivado del proceso de fabricación de los materiales de construcción empleados en edificación. La aplicación práctica del modelo propuesto sobre diferentes tipologías edificatorias en Sevilla aportará información respecto a los materiales de construcción, subsistemas y elementos constructivos más impactantes, permitiendo visualizar la influencia que presenta la superficie construida en cuanto al impacto ambiental generado. Los resultados obtenidos pretenden servir de referencia a la comunidad científica, aportando datos numéricos que podrán ser comparados en otras tipologías y ámbitos geográficos, a la vez que permitirán analizar y precisar mejoras en cuanto al impacto ambiental generado por los diferentes materiales, subsistemas y elementos constructivos habitualmente utilizados en las tipologías edificatorias definidas

Estudio comparativo de técnicas de preparación de muestraspara microscopía electrónica de transmisión de recubrimientos cerámicos proyectados por plasma

The development of advanced materials, with complex microstructures, is a permanent challenge to the development and application of new efficient techniques for microstructural characterization. In ceramic coatings on metals, there exist a differential ion-milling ratio between both components, limiting in principle the use of conventional techniques. In this work, we report on a comparative study of TEM sample preparation techniques for plasma-sprayed ceramic coatings. Firstly, we have used a procedure derived from the conventional one (polishing, dimpling, ion milling), and alternatively a new technique using focused ion-beam milling. The material selected for this study is fine-grained alumina that was plasma-sprayed on a steel substrate. The efficiency of both techniques is discussed along with the most significant microstructural features of the material subject of study

Electrocatalytic behavior of tetrathiafulvalene (TTF) and extended tetrathiafulvalene (exTTF) [FeFe] hydrogenase mimics

TTF- and exTTF-containing [(μ-S2)Fe2(CO)6] complexes have been prepared by the photochemical reaction of TTF or exTTF and [(μ-S2)Fe2(CO)6]. These complexes are able to interact with PAHs. In the absence of air and in acid media an electrocatalytic dihydrogen evolution reaction (HER) occurs, similarly to analogous [(μ-S2)Fe2(CO)6] complexes. However, in the presence of air, the TTF and exTTF organic moieties strongly influence the electrochemistry of these systems. The reported data may be valuable in the design of [FeFe] hydrogenase mimics able to combine the HER properties of the [FeFe] cores with the unique TTF propertie

Microstructure and mechanical properties of high temperature protonic conductors fabricated by melt growth

Se han estudiado conductores protónicos de alta temperatura (CPAT) fabricados por fusión de zona flotante asistida por láser (SrCe0.9Y0.1O3-δ , SrCe0.8Y0.2O3-δ , SrZr0.9Y0.1O3-δ , SrZr0.8Y0.2O3-δ , Sr3 (Ca1.18Nb1.82)O9-δ y SrTi0.95Sc0.05O3-δ ). La caracterización microestructural se ha realizado mediante Microscopía Electrónica de Barrido y Transmisión (MEB, MET). Los materiales tienen una estructura celular, con células de anchuras entre 10-50 µm y regiones intercelulares superiores a 1 µm de espesor. El análisis de difracción indica que las células son cristalinas y que la región intercelular es amorfa. La MET revela que las células presentan múltiples defectos planares, separadas por regiones rotadas con la misma estructura cristalográfica. Las propiedades mecánicas a altas temperaturas fueron estudiadas a partir de ensayos de compresión bajo velocidad de deformación y carga constantes. Nuestros materiales resisten tensiones de 500 MPa a 700 ºC, 400 MPa a 1100 ºC y 370 MPa a 1300 ºC, observándose deformación plástica a 1100 ºC y 1300 ºC. El mejor comportamiento mecánico fue obtenido para los sistemas Sr3 (Ca1.18Nb1.82)O9- δ _ y SrZr0.9Y0.1O3-δ . Las tensiones y resistencias en fluencia de estos sistemas son mejores que las de las cerámicas policristalinas CPAT de similar estructura y composición. Después de los ensayos mecánicos, las muestras fueron estudiadas por MEB y MET. La fractura comenzó a propagarse siguiendo las regiones intercelulares. En las muestras deformadas plásticamente se detecta la actividad de dislocaciones.High temperature protonic conductors (HTPC) were successfully fabricated by melt growth using the laser heated floating zone method (SrCe0.9Y0.1O3-δ , SrCe0.8Y0.2O3-δ , SrZr0.9Y0.1O3-δ , SrZr0.8Y0.2O3-δ , Sr3 (Ca1.18Nb1.82)O9-δ and SrTi0.95Sc0.05O3-δ ). Microstructural characterization was performed by scanning and transmission electron microscopy (SEM, TEM). The materials have a cellular microstructure, with cell width ranging between 10-50 µm and intercellular regions up to 1 µm thick. The diffraction analysis indicates that the cells are crystalline, and the intercellular regions are amorphous. TEM reveals that the cells present multiple planar defects, separating rotated regions with of same crystallographic structure. The high temperature mechanical properties were studied by compression tests performed under constant strain rate and constant load. Remarkable high temperature strengths of 500 MPa at 700 o C, 400 MPa at 1100 o C and 370 MPa at 1300 o C were measured, being the plastic deformation evident at 1100 ºC and 1300 ºC. The best mechanical behavior was obtained for the systems Sr3 (Ca1.18Nb1.82)O9-δ and SrZr0.9Y0.1O3-δ . The strengths and creep resistance of these systems are better than the ones of polycrystalline HTPC ceramics of similar structure and composition. After the mechanical tests, the samples were studied by SEM and TEM. The fracture started to propagate following the intercellular regions. In the plastically deformed samples, dislocation activity was found

Phosphite Bearing [(μ-ADT)RFe2(CO)6] (ADT = Azadithiolate) Moieties: A Tool for the Building of Multimetallic [FeFe]-Hydrogenase Mimics

A new phosphite ligand having three [(μ-ADT)RFe2(CO)6] (R= p-HOC6H4) moieties (2) has been prepared in good yield by the reaction of complex [(μ-ADT)RFe2(CO)6] (R= p-HOC6H4) 1a with PCl3. Coordination of this phosphite to [PdCl2(MeCN)2] or [PtCl2(DMSO)2] forms heterometallic square planar complexes 5 (C84H48Cl2Fe12N6O42P2MS12) (M = Pt, Pd) in excellent yields. Three-legged piano stool complexes 6 (C52H39Cl2Fe6N3O21PMS6) (M = Rh, Ir) were obtained by the reaction of phosphite 2 with [MCl2Cp*]2(M = Rh, Ir) in good yields. The formation of complexes 5 and 6 demonstrates the versatility of this new ligand for forming different heteropolymetallic complexes under mild reaction conditions. Moreover, the open-chain derivatives [(μ-ADT)RFe2(CO)6] (R= HOCH2CH2, o-HOC6H4) (1b and 1c, respectively) form cyclic complexes 4 by spontaneous intramolecular CO substitution by the P atom in one of the three [FeFe] fragments. The electrocatalytic behavior of complexes 2 and 4 upon the addition of AcOH is similar to that of related [(μ-ADT)Fe2(CO)6] derivatives. The successive additions of AcOH cause an increase in the current intensity in the wave at about -1.80 V for heteropolymetallic complexes 5 and 6. However, the appearance of a new wave around -1.40 V in complexes 5 points to an acid-promoted side reaction in the electrochemical proces

Deformación plástica de compuestos mullita/óxido de itrio

Los compuestos a partir de mullita (3Al2 O3 .2SiO2 ) presentan unas magníficas propiedades mecánicas y térmicas. Las mismas características que hacen de la mullita resistente a la deformación plástica, dificultan su densificación. El óxido de itrio es uno de los aditivos más utilizados para reducir la temperatura de sinterización de la mullita. Adicionalmente la presencia de silicatos vítreos (en este caso Y2 Si2 O7 ) incrementan la ductilidad. En esta investigación se han usado muestras de mullita con diversas cantidades de Y2 O3 (0%, 5% y 9% en peso). Los detalles sobre el procesado y caracterización de los compuestos han sido objeto de una publicación previa. Se ha estudiado comparativamente la ductilidad de estos materiales mediante experimentos de deformación en compresión a alta temperatura. Los ensayos se han desarrollado entre 1300 y 1400ºC, en atmósfera de aire, cubriendo un rango de tensiones de compresión entre 0.69 y 34.4 MPa.Mullite (3Al2 O3 .2SiO2 ) based composites have excellent mechanical and thermal properties. The same characteristics that give mullite good resistance to plastic deformation also make its sintering difficult. Yttria is one of the most commonly used additives to reduce sintering temperatures in mullite. Additionally vitreous silicates (Y2 Si2 O7 ) could improve ductility. In this work we have used mullite samples with various amounts of Y2 O3 (0, 5 and 9 wt.%). Details of processing and characterization of these composites have been the subject of a previous publication. We have compared the ductility of these composites by means of compressive deformation tests at elevated temperatures. Creep tests were performed at temperatures between 1300 and 1400ºC, in air, in a stress range of 0.69 to 34.5 MPa

Recalce en condiciones de emergencia: 40 viviendas cercanas al río Guadalquivir, España

The reconstruction works in buildings under emergency conditions and, more specifically, the foundation repaired has been poorly documented in rehabilitation. This is due, in some extend, to not make public this type of reports mainly due to its complexity and possible related responsibilities. In the present article, the foundation recovery of a building with 40 flats, located in Seville, Spain, near the Guadalquivir River which was affected by the excavations of an underground parking lot are explained. Three different techniques are considered and compared; finally, the micropile solution implemented is explained, technically and economically. Micropiles were chosen due to, among other aspects, the soil quality. The experience gives rise to three main factors in a successful work: the organization, the scheduling and the neighbors’ participation in the work programming.Las intervenciones en edificaciones en circunstancias de emergencia, y en concreto los recalces de cimentaciones son circunstancias poco documentadas dentro de la rehabilitación. Esto se debe, en parte, a la complejidad técnica y la tendencia a evitar hacer públicos datos que puedan conllevar responsabilidades derivadas. En el artículo se expone el recalce de un edificio de 40 viviendas en Sevilla, cercanas al Río Guadalquivir, afectado por la construcción contigua de un aparcamiento subterráneo. También se establece una comparativa entre tres técnicas consideradas, y finalmente, se explica, técnica y económicamente el método de micropilotes adoptado. Éste se elige, entre otras razones, debido a la calidad del suelo. De la experiencia se ha podido inferir que el éxito de la intervención se ha conseguido debido a tres factores: la organización de la obra, el estudio de los plazos y la implicación de los propietarios afectados

Qualitative Research by a Non-Hierarchical Team

In this and subsequent issues, The Qualitative Report will publish eight articles about a journal written by Edward B. Emerson (1805-1834), a younger brother of American philosopher and writer Ralph Waldo Emerson. This introduction will describe the origins of the project, the sources, the process and the outcomes of the collaboration. The authors hope to document and illustrate the richness and value of interdisciplinary qualitative inquiry, while providing specifics of how the Emerson Journal Project evolved. We provide examples to illustrate the characteristics of effective teamwork, but also present the challenges along the way and how they were surmounted. The breadth of the topics in the journal and the range of expertise within the team have resulted in the use of different approaches to examine Emerson’s text. It is the authors’ goal that these essays will enhance the reading of Emerson´s journal, while contributing to the social and historical understanding of the Caribbean