Boundary value problems have been treated both in the discrete and the continuous case. In both settings, the consideration of eigenvalues and eigenfunction as well as the Green function are common tools. However, the separation of variables technique, that is very popular in the continuous case, has not been developed for networks. In this work, we deal with the discrete version of separation of variables in order to obtain the Green function for product networks. We will show how the Green function of a product network can be obtained in terms of the Green function of one of the factor networks and the eigenvalues and eigenfunctions of some Schr\"odinger operators of the other factor network.
Palacios-Trujillo, A.; de Gracia, A.; Haurie, L.; Cabeza, L. F.; Fernández , A.I.; Barreneche, C. Materials Vol. 11, num. 1, p. 171-1-171-12 DOI: 10.3390/ma11010117 Data de publicació: 2018-01-12 Article en revista
The implementation of organic phase change materials (PCMs) in several applications such as heating and cooling or building comfort is an important target in thermal energy storage (TES). However, one of the major drawbacks of organic PCMs implementation is flammability. The addition of flame retardants to PCMs or shape-stabilized PCMs is one of the approaches to address this problem and improve their final deployment in the building material sector. In this study, the most common organic PCM, Paraffin RT-21, and fatty acids mixtures of capric acid (CA), myristic acid (MA), and palmitic acid (PA) in bulk, were tested to improve their fire reaction. Several flame retardants, such as ammonium phosphate, melamine phosphate, hydromagnesite, magnesium hydroxide, and aluminum hydroxide, were tested. The properties of the improved PCM with flame retardants were characterized by thermogravimetric analyses (TGA), the dripping test, and differential scanning calorimetry (DSC). The results for the dripping test show that fire retardancy was considerably enhanced by the addition of hydromagnesite (50 wt %) and magnesium hydroxide (50 wt %) in fatty acids mixtures. This will help the final implementation of these enhanced PCMs in building sector. The influence of the addition of flame retardants on the melting enthalpy and temperatures of PCMs has been evaluated.
Cabrera, F.; Gómez-Soberón, J.M.; Almaral Sánchez, Jorge Luis; Arredondo-Rea, S.P.; Mendivil, J. International Journal of Civil Engineering Vol. 16, num. 1, p. 107-121 DOI: 10.1007/s40999-016-0071-9 Data de publicació: 2018 Article en revista
As a result of the large quantities of glass residues being generated, research is currently underway for efficient, economic and eco-friendly alternatives, among them the incorporation of recycled glass in mortar as a substitute for natural sand; this work has researched and studied recycled glass substitutions of 0, 15, 30, 60 and 100 %. A basic characterization of both sands was carried out with the aim of comparing both materials (granulometric profiles, density and absorption). Compressive and flexural strength were studied with regard to the mechanical behavior of the mortar in question; regarding deformation, the basic, drying and total shrinkage were determined. The results of the research show that the recycled glass sands are less dense than the standard sand used, and the latter has a higher absorption coefficient. With regard to compressive and flexural strength, the mortars with recycled glass reported lower resistance than the natural sand mortars, with the 15 % recycled glass combination being the closest to the natural mortar. On the other hand, in the case of deformation due to drying shrinkage (the most significant), the recycled mortars showed even more favorable results than the natural mortar; the 100 % glass content had the lowest shrinkage rate in the experimental phase. The study concludes that mortars with 15 % recycled sand may feasibly be used in applications with low mechanical requirements, with their low rates of shrinkage deformation being an additional advantage.
This paper investigates how the characteristics of operational processes—systematic and project-based—affect the impact of adopting the safety management systems on different performance metrics. The proposed approach allows the development of a framework which matches safety problems and risks encompassed by organizational tasks with solutions generated by new safety knowledge linked to the adoption of the OHSAS 18001 standard. Our analysis of the effect over work accidents, as well as operational and economic performance of implementing the OHSAS 18001 in Spanish manufacturing, construction and professional services organizations during 2006–2009 shows that organizations modify existing safety practices to mitigate work accidents, and that safety learning effects widely vary across industry sectors. Organizations whose current knowledge is mostly codified and processes are highly systematic benefit more from safety knowledge and experience, whereas the effects of the OHSAS 18001 dilute in organizations whose knowledge is high in tacitness, and whose processes difficult the visibility of the consequences of work accidents. This study has important implications for managing knowledge acquisition processes. The findings offer valuable insights on how managers can develop communication and coordination actions to cope with the potential incompatibilities between safety management systems, the properties of knowledge and work environmental conditions.
We obtain sufficient conditions for the existence and uniqueness of a positive compact almost automorphic solution to a logistic equation with discrete and continuous delay. Moreover, we provide a counterexample to some results in literature which deal with the uniqueness of almost periodic solutions to logistic type equations.
In the Mexican republic, around 33.600 tons of construction wastes are generated every day, Mexico City contributing for around 7.000 tons/day, with fewer than 1.000 tons/ day being sent to be recycled. This study relates to sustainable alternatives for recycling construction wastes, focusing on the manufacture of sustainable bricks using recycled aggregates (RA). The objective of this research was to manufacture RA-bricks of mixtures integrating clay excavation wastes, recycled binding ggregates from concrete having a particle size distribution of 3/8” and recycled mixed aggregates and binding wastes with a particle size distribution ranging from 1/4” to fines, wood cutting wastes and a liquid mixture of water and Opuntia ficus-indica (mucilage) extract as natural additive or stabilizer. A sustainable manufacturing process was used in which the clay material typically used in the traditional manufacturing of RA-bricks was replaced by excavation wastes of originally unknown composition obtained during the construction of two buildings, in order to investigate whether various excavation wastes having appropriate clay contents can be used as raw materials for manufacturing recycled aggregates bricks. Before using these wastes, preliminary particle size distribution, plasticity and hardness tests were performed in order to determine the appropriate residue dosages for manufacturing the bricks. The results showed that excavation wastes different from the clay soil usually used ensure the quality requested by the Mexican standard for non-structural adobe bricks. Currently, further studies are being conducted to promote their use in the manufacture of building elements.
In this paper, the analysis of simple models of five-storey buildings using recycled concrete as aggregate, with different configurations in plan (square and rectangular) and with regularity in height, are shown. For these structures concretes with different percentages of coarse aggregate by recycled concrete of
15%, 30%, 60% and 100% are considered. The designs are made according to the Mexico City Regulations, in the area considered as hard soil. For these designs the mechanical parameters reported in the literature are considered for the same percentages of coarse aggregate replacement. The resulting designs are subjected to a reduced group of characteristic accelerograms of the location zone, obtaining maximum responses in displacements and mechanical elements. With the resultant designs, the trends of variation in the concrete volume and the needed reinforcing steel for each case are verified, thus defining the initial cost of each model. The analysis state trends in the variation of the maximum elastic responses.
The procedure was done again for a 10-storey building with a less regular configuration and closer to professional practice in Mexico City area. In this case replacement percentages of 0%, and 20% are considered, the trends obtained in the simple models are verified.
This paper deals with the problem of inferring the signals and parameters that cause neural activity to occur. The ultimate challenge being to unveil brain’s connectivity, here we focus on a microscopic vision of the problem, where single neurons (potentially connected to a network of peers) are at the core of our study. The sole observation available are noisy, sampled voltage traces obtained from intracellular recordings. We design algorithms and inference methods using the tools provided by stochastic filtering that allow a probabilistic interpretation and treatment of the problem. Using particle filtering, we are able to reconstruct traces of voltages and estimate the time course of auxiliary variables. By extending the algorithm, through PMCMC methodology, we are able to estimate hidden physiological parameters as well, like intrinsic conductances or reversal potentials. Last, but not least, the method is applied to estimate synaptic conductances arriving at a target cell, thus reconstructing the synaptic excitatory/inhibitory input traces. Notably, the performance of these estimations achieve the theoretical lower bounds even in spiking regimes.
Licensee MDPI, Basel, Switzerland. This article presents a methodology to process information from a Terrestrial Laser Scanner (TLS) from three dimensions (3D) to two dimensions (2D), and to two dimensions with a color value (2.5D), as a tool to document and analyze heritage buildings. Principally focused on the loss of material in stone, this study aims at creating an evaluation method for loss control, taking into account the state of conservation of a building in terms of restoration, from studying the pathologies, to their identification and delimitation. A case study on the Cathedral of the Seu Vella de Lleida was completed, examining the details of the stone surfaces. This cathedral was affected by military use, periods of abandonment, and periodic restorations.
Lopez, P.; Tarquis Alfonso, A.; Matulka, A.M.; Skadden, B.; Redondo, J. M. Chaos solitons and fractals Vol. 105, p. 128-136 DOI: 10.1016/j.chaos.2017.10.011 Data de publicació: 2017-12-01 Article en revista
A multifractal analysis on a finite-range-scale of the plume concentration images at different experimental conditions (the height of the source Ho), where the measure is the grey value of the image (from 0 to 255), was applied to study its structure through time. The multifractal spectrum showed the characteristic inverse U-shape and a similar evolution in all Ho. The variation of the Hölder exponent (¿a) presented different amplitudes at different moments and increased with time. The symmetry of the spectrum (¿f) decreased with time achieving negative values (from left hand asymmetry evolving to right asymmetry). We show the different behaviour of axial velocity (W) with ¿a and ¿f. There is a linear relation of entrainment coefficient (ae) and the entropy dimension (a1). Therefore, the multifractal spectrum and the derived parameters can be used as markers of plume evolution as well as to study the effect of experimental conditions.
Al verso de la portada. Proyecto HAR2013-45096-Recuperación y difusión de los archivos fotográficos de la arquitectura moderna para el desarrollo de un patrimonio visual operativo. Investigador principal: Antonio Armesto (Universitat Politècnica de Catalunya) ; equipo de investigación: Juan Antonio Cortés (Universidad de Valladolid), Carlos Labarta (Universidad de Zaragoza), Cristina Gastón Guirao (Universitat Politècnica de Catalunya)
Descripció del recurs: 30 d'octubre de 2017
Click 2 recoge las intervenciones realizadas en el marco del Segundo Seminario Internacional de Arquitectura y Fotografía celebrado en la sede del Arquinfad, en Barcelona, los días 31 de marzo y 1 de abril de 2016.
Estas ponencias continúan con la serie de conferencias sobre la fotografía de arquitectura moderna en América Latina iniciada en la primera edición del Seminario. En esta ocasión, las exposiciones se refirieren a los ámbitos nacionales de Argentina, Uruguay, México y Caribe. Se suman por tanto a los reportajes sobre Brasil, Colombia, Ecuador, Venezuela y Chile, del año anterior, para completar un primer recorrido sobre el continente que constituye un umbral desde el cual continuar avanzando. Asimismo, en esta segunda edición del Seminario se contó con la presencia de Horacio Fernández quien dedicó su intervención a los fotolibros de ciudad latinoamericanos, aportando con ello una nueva dimensión al discurso visual sobre el fenómeno urbano, la arquitectura y su gente. Por su parte, Juan Antonio Cortés ofreció un valioso contrapunto con su comentario crítico a las imágenes de arquitectura y ciudad de Aleksandr Ródchenko.
Como complemento a los contenidos expuestos en las sesiones públicas, este libro se incorpora como anexo la transcripción de la entrevista realizada en Bogotá a Germán Téllez Castañeda, la que inaugura la serie de conversaciones con fotógrafos de arquitectura que nos proponemos emprender. También, el testimonio personal de Carlos Labarta del recuento de una serie de observaciones, de detalles de intensificación urbana.
Click 2 gathers the lectures carried out in the framework of the Second Seminar on Architecture and Photography, held in Barcelona, from the 31 of March to the 1 of April, 2016.
These presentations followed the series of conferences about Modern Architectural Photography in Latin America that started in the first edition of the Seminar. In that occasion the expositions referred to the national scopes of Argentina, Uruguay, México and Caribe. Therefore, the above were added to the reports of Brazil, Colombia, Ecuador, Venezuela y Chile of the year before, to complete a first survey on the continent that constitutes a key point from where to continue advancing. In that light, the presence of Horacio Fernández who devoted his presentation to the Latin American photobooks was counted on the Second Edition of the Seminar, contributing a new dimension to the visual discourse on the urban phenomenon, the architecture and its people. On the other hand, Juan Antonio Cortés offered another valuable point of view with his critical comment on the images about city and architecture by Aleksandr Ródchenko.
As a complement to the contents exposed in the public sessions, the transcription of the interview held in Bogota with Germán Téllez Castañeda is added as a link to this book. It opens a series of conversations with architectural photographers we propose to carry out. Also Carlos Labarta writing about some observations of urban intensification details have been added.
Actualmente es frecuente en diversos ámbitos profesionales y educativos el debate sobre las
condiciones físicas de los centros escolares y sobre todo de los patios. La necesaria revisión y actualización de aspectos estrictamente pedagógicos y de las condiciones espaciales en su configuración formal y funcional, convergen en procesos de reflexión para el cambio y la innovación. Las diagnosis desde diversos enfoques coinciden en identificar, sugerir, reclamar y proponer acciones y proyectos para la mejora de los espacios escolares, dada su vital importancia en la educación y socialización tanto en la escuela como en la ciudad. Proponemos una reflexión para promover el patio escolar como proyecto de arquitectura y de espacio colectivo urbano: por un lado destacando la vigencia y actualidad de las metodologías de enseñanza basadas en la estrecha relación entre espacios interiores y exteriores, en sus planteamientos pedagógicos. Y por otro, haciendo un repaso a la coyuntura actual que se está dando en Barcelona, y en Cataluña en general, donde se están llevando a cabo iniciativas de intervención y mejora en los patios y entornos escolares, asociadas a un cambio de modelo educativo y de ciudad en curso. Del proceso mostramos tres casos de intervención en tres centros, proyectos que se caracterizan por ser estratégicos, participativos, de baja inversión y de alto impacto en la mejora de la habitabilidad del patio escolar y la ciudad.
Maldonado, A.; Lacasta, A.M; Giró-Paloma, J.; Chimenos, J. M.; Haurie, L.; Formosa, J. Construction & building materials Vol. 155, p. 209-216 DOI: 10.1016/j.conbuildmat.2017.07.227 Data de publicació: 2017-11-30 Article en revista
Magnesium Phosphate Cement (MPC) has become an essential reference for investigators seeking alternatives to the use of Ordinary Portland Cement (OPC) in building sector because of its high environmental impact. The research group developed a MPC formulated with low-grade MgO (LG-MgO) by-product, which could be considered as a sustainable MPC (sust-MPC). This research focuses on the incorporation of different percentages of Microencapsulated Phase Change Materials (MPCM) into sust-MPC, due to their ability to reduce energy consumption of heating, ventilating, and air conditioning (HVAC) systems. The study consists of an exhaustive characterization of thermal sustainable MPC (TS-MPC) dosages which incorporate air-entraining additive (AEA) and MPCM to improve their thermal behaviour. Thus, TS-MPC would reduce the use of HVAC systems contributing to the decrease of CO2 emissions and increasing energy efficiency in buildings. Moreover, properties such as bulk density, porosity, thermal conductivity, modulus of elasticity, compressive strength, and flexural strength are analysed to evaluate the potential use of these cements as a part of a passive conditioning system. Results show the proper behaviour of these cements to reduce thermal oscillation in buildings. Experimental results demonstrated the relation between the amount of the MPCM and the AEA percentage as well as the thermal and mechanical properties of the TS-MPC due to their contribution to increase the porosity. Furthermore, it should be noted the increase of porosity and the reduction of thermal conductivity of the optimal formulation, which are 60% higher and 50% lower than the sust-MPC obtained without MPCM and additive, respectively.
This paper presents the reinforcement system for the restoration of the Vistabella Church’s Tower (La Secuita, Tarragona). The intervention was carried out due to evident chronic pathologies that affected the resistant behaviour and stability of the steeple. After some numerical approaches (structural analysis and damage assessment) it became clear that, in relation the wind action, the lightness of such a masonry construction along with the feebleness of the connections between the structural members were at the basis of the problem. In order to provide additional vertical load without substantively modifying the structural scheme, a solution based on external prestressed bars, was implemented. The procedure, the theory that supports it and the results of the follow-up are described in detail, these being the objective of the paper.
Buran, P.; Bär, M.; Alonso, S.; Niedermayer, T. Chaos : an interdisciplinary journal of nonlinear science Vol. 27, num. 11, p. 113110-1-113110-9 DOI: 10.1063/1.5010787 Data de publicació: 2017-11-01 Article en revista
Electrical turbulence in cardiac tissue is associated with arrhythmias such as life-threatening ventricular fibrillation. Recent experimental studies have shown that a sequence of low-energy electrical far-field pulses is able to terminate fibrillation more gently than a single high-energy pulse which causes severe side effects. During this low-energy antifibrillation pacing (LEAP), only tissue near sufficiently large conduction heterogeneities, such as large coronary arteries, is activated. In order to optimize LEAP, we performed extensive simulations of cardiac tissue perforated by blood vessels, employing two alternative cellular models that exhibit electrical turbulence at a similar length scale. Moreover, the scale of blood vessels in our two-dimensional simulations was chosen such that the threshold for single pulse defibrillation matches experimental values. For each of the 100 initial conditions, we tested different electrical field strengths, pulse shapes, numbers of pulses, and periods between the pulses. LEAP is successful for both models, albeit with substantial differences. One model exhibits a spectrum of chaotic activity featuring a narrow peak around a dominant frequency. In this case, the optimal period between low-energy pulses matches this frequency and LEAP greatly reduces the required energy for successful defibrillation. For pulses with larger energies, the system is perturbed such that underdrive pacing becomes advantageous. The spectrum of the second model features a broader peak, resulting in a less pronounced optimal pacing period and a decreased energy reduction. In both cases, pacing with five or six pulses which are separated by the dominant period maximizes the energy reduction.
The problem (LFP) of finding a feasible solution to a given linear
semi-infinite system arises in different contexts. This paper provides
an empirical comparative study of relaxation algorithms for (LFP).
In this study we consider, together with the classical algorithm, imple-
mented with different values of the fixed parameter (the step size), a
new relaxation algorithm with random parameter which outperforms
the classical one in most test problems whatever fixed parameter is
taken. This new algorithm converges geometrically to a feasible so-
lution under mild conditions. The relaxation algorithms under com-
parison have been implemented using the Extended Cutting Angle
Method (ECAM) for solving the global optimization subproblems.
Forcada, N.; Serrat, C.; Rodríguez-Puente, S.; Bortolini, R. Journal of management in engineering Vol. 33, num. 6, p. 1-8 DOI: 10.1061/(ASCE)ME.1943-5479.0000552 Data de publicació: 2017-11 Article en revista
It is vital to select the right project bidders, as this affects the success of a project. Although there are numerous methods for assessing bidders, communication is rarely taken into account. This paper discusses the results of a survey on communication key performance indicators (KPIs) and the success of construction projects. Data were collected from 390 construction partners in Spain. The results indicate that the most significant communication KPI is the quality of information: basically, its accuracy and timeliness. In addition, experienced respondents placed less importance on communication flow structures and communication management than did inexperienced respondents. Experienced respondents distrusted new trends and/or management theories and mainly relied on experience. The findings also reveal that the communication flow structure, the communication and information management plan, and the channels of communication are relevant aspects for the success of a project. The results of this research can be used to assess bidders' communication abilities and systems.
Entre la década de 1950 y 1960 dos arquitectos barceloneses exploraron las posibilidades técnicas de la arquitectura en un contexto dominado por el conformismo realista que la situación política determinaba. Fieles a un contacto directo con la fabricación industrial, que sus primeros trabajos había propiciado, el tándem Tous y Fargas se valió de referentes internacionales, especialmente norteamericanos, para la reproducción de soluciones constructivas y metodologías de producción innovadoras. Con la eficiencia técnica como premisa, sus trabajos persiguieron incidir en la industria constructiva local mediante la proposición de prototipos residenciales como la Casa Door y la Casa Solanas.
Between the 1950s and 1960s two Barcelona architects explored the technical possibilities of architecture
in a context dominated by the realistic conformism determined by the political situation. Faithful to a direct contact with the industrial manufacturing, which Tous & Fargas made use of thanks to their first works, they used international references, especially from North America, for the reproduction of constructive solutions and innovative production methodologies. With technical efficiency as a premise, their works sought to
influence the local construction industry by proposing residential prototypes such as the Door House and the Solanas House.
Alonso, S.; Radszuweit, M.; Engel, H.; Baer, M. Journal of physics D. Applied physics Vol. 50, num. 43, p. 434004-1-434004-16 DOI: 10.1088/1361-6463/aa8a1d Data de publicació: 2017-11-01 Article en revista
The cytoskeleton of the organism Physarum polycephalum is a prominent example of a complex active viscoelastic material wherein stresses induce flows along the organism as a result of the action of molecular motors and their regulation by calcium ions. Experiments in Physarum polycephalum have revealed a rich variety of mechanochemical patterns including standing, traveling and rotating waves that arise from instabilities of spatially homogeneous states without gradients in stresses and resulting flows. Herein, we investigate simple models where an active stress induced by molecular motors is coupled to a model describing the passive viscoelastic properties of the cellular material. Specifically, two models for viscoelastic fluids (Maxwell and Jeffrey model) and two models for viscoelastic solids (Kelvin–Voigt and Standard model) are investigated. Our focus is on the analysis of the conditions that cause destabilization of spatially homogeneous states and the related onset of mechano-chemical waves and patterns. We carry out linear stability analyses and numerical simulations in one spatial dimension for different models. In general, sufficiently strong activity leads to waves and patterns. The primary instability is stationary for all active fluids considered, whereas all active solids have an oscillatory primary instability. All instabilities found are of long-wavelength nature reflecting the conservation of the total calcium concentration in the models studied.
PE), Estartit (one float TG) and Barcelona (one radar TG PE, and two of APB Autoridad Portuaria Barcelona)
harbours ant their application to altimeter calibration is discussed.
The first campaign was dedicated to the Alt-B TOPEX altimeter bias determination in March 1999 at Cape of
Begur, NW Mediterranean. A Baleares in situ bias estimation calibration campaign with Spanish-French
cooperation was made on September 2013 for the altimeters of Jason-2 and Saral/AltiKa in the Ibiza island area. A similar Spanish/French experience with Jason-1 was made in June 2003 in this geographical area under IBIZA 2003 campaign. It is presented Sonmicat, the integrated sea level system aims at providing continuous high-quality continuous measurementof sea (and land) levels at the coast from tide gauges and modern geodetic techniques for geodetic techniques for studies on long-term sea level trends and calibration of radar altimeters. Finally, an airborne Lidar campaign was carried out in July 2014, with two strips along two laser ICESat target tracks, one along Barcelona harbour. A direct comparison between ICESat and LIDAR DTM results is outlined. The main objective is the integrationof spaceborne, airborne and in-situ data for the establishement of calibration of radar and laser space missions in this local area of the western Mediterranean in the framework of Global Change.
Las primeras fases del Polígono de Trinitat Nova (1952-1953 y 1959), constituyen un ejemplo relevante de ensayo de nuevas propuestas de vivienda social que se enmarcan en uno de los debates más vivos entorno a la arquitectura: la necesidad de crear vivienda y cómo se debe organizar ésta atendiendo a los postulados de modernidad.
La comunicación que presentamos muestra cómo en Trinitat Nova se asumen plenamente los postulados entorno a la vivienda defendidos en los diferentes debates: la propuesta de agrupación y desarrollo de los edificios en bloques aislados, la atención a las condiciones mínimas de la vivienda y la preocupación por los elementos constructivos y materiales empleados.
Además, se indaga en las diferencias y similitudes entre la propuesta de vivienda social de Trinitat Nova, las Viviendas del Congreso Eucarístico (también de 1952), una promoción auspiciada por el obispado de Barcelona, con una clara voluntad de barrio modélico. La comparación nos muestra claramente las limitaciones de Trinitat Nova respecto a la Viviendas del Congreso Eucarístico. Si bien a nivel urbano, ambas propuestas ofrecen elementos relevantes de modernidad, en el ámbito específico de la vivienda, el programa, la superficie y el planteamiento constructivo de Trinitat Nova respecto a las Viviendas del Congreso Eucarístico, son más precarios y austeros, hasta el punto que condiciona, efectivamente, su pervivencia.
Josep Puig i Cadafalch, seguint els batecs del temps, fou capaç de virar diverses vegades la seva trajectòria arquitectònica a la recerca d'una arquitectura del nou-cents sense abandonar mai aquelles dimensions antagòniques que Raimon Casellas li atribuïa: un "adorador del passat" i un "idòlatra de la renovació".
Any discussion of contemporary mosaics must highlight the hydraulic tile. Its contribution to the renovation of cladding materials in architecture was essential at a time of transformation marked by industrialisation of production processes. First, this tile, which was both economical and a contribution to hygiene, was a modern and efficient response to the requirements of surfacing in large-scale constructions after the end of the nineteenth century. Second, in comparison with the variety of existing techniques, it represented a qualitative leap forward in terms of industrial design.
The subject of this study is hydraulic mosaics designed and laid in the last third of the nineteenth century and early years of the twentieth. It will focus on Catalan production and, in particular, the most prominent and long-lived company, the mosaic tile manufacturer Escofet. The aim is to draw attention to recognition of the hydraulic tile as cladding which excelled with its high degree of artistic creativity in adapting, from the outset, to the distinctive elements of industrial design, namely business strategy, autonomous production with regard to the projects of architecture, its niche in the market and the evolution of consumer tastes, as well as its links with cultural and social factors of the time.
We aim to reach not only other researchers but also students who can find
relevant information in the articles for their areas of study. Not only do we have a
clear, well-structured publication to make it more appealing to the reader, but also
we look for interesting and in-depth discussions, ideas and projects to promote
serious research work developed in Europe. This has been our main motto since
This year’s publication includes the areas of Economy and Management, Health,
Mathematics, Mechanical and Electrical Engineering. In conjunction with this, as in
the three last previous numbers, we have included the specific area on International mobility, Intensive Programmes and Erasmus+
Tous y Fargas fueron un caso singular en el ámbito de la arquitectura española de la segunda mitad del siglo XX. Desde la experimentación técnica e industrial de sus primeros trabajos, desarrollaron una arquitectura inconforme con los condicionantes realistas característicos de la época, propiciados por el contexto económico, político y social. Pese a ello, alcanzaron un éxito notable con realizaciones de corte tecnológico y dando soporte a la innovación industrial de sistemas constructivos. Sin embargo, durante la última etapa de su colaboración son visibles rasgos propios de la deriva pragmática a la que se veía sometida buena parte de la arquitectura del último cuarto del siglo XX. El exceso de preocupación mercantil por el producto inmobiliario, la sistematización excesiva de los modelos tipológicos y los sistemas constructivos, la carencia de un discurso teórico consistente o el abandono de la investigación técnica como premisa de innovación son algunos de los síntomas que caracterizan la arquitectura pragmática de sus últimos trabajos.
Tous & Fargas were a unique case in the field of Spanish architecture of the second half of the 20th century. From the technical and industrial experimentation of their first works, they developed a nonconformist architecture within the realistic conditions characteristic of the time, propitiated by the economic, political and social context. Despite of this, they achieved a remarkable success carrying out designs of technological type and giving support to the industrial innovation of constructive systems. However, during the last stage of their collaboration, traits characteristic of the pragmatic drift are visible to which much of the architecture of the last quarter of the 20th century was subjected. The excess of mercantile concern for the real estate product, the excessive systematization of the typological models and the constructive systems, the lack of a consistent theoretical discourse or the abandonment of the technical investigation as a priority of innovation are some of the symptoms that characterize the pragmatic architecture of their latest works.
A rockfall is a mass instability event frequently observed in road cuts, open pit mines and quarries, steep slopes and cliffs. After its detachment, the rock mass may disaggregate and break due to the impact with the ground surface, thus producing new rock fragments. The consideration of the fragmentation of the rockfall mass is critical for the calculation of the trajectories of the blocks and the impact energies and for the assessment of the potential damage and the design of protective structures. In this paper, we present RockGIS, a GIS-based tool that simulates stochastically the fragmentation of the rockfall, based on a lumped mass approach. In RockGIS, the fragmentation is triggered by the disaggregation of the detached rock mass through the pre-existing discontinuities just before the impact with the ground. An energy threshold is defined in order to determine whether the impacting blocks break or not. The distribution of the initial mass between a set of newly generated rock fragments is carried out stochastically following a power law. The trajectories of the new rock fragments are distributed within a cone. The fragmentation model has been calibrated and tested with a 10,000 m3 rockfall that took place in 2011 near Vilanova de Banat, Eastern Pyrenees, Spain.
En esta comunicación nos proponemos analizar técnica y constructivamente la evolución de la obra de Benavent. Para poder hacer este estudio hemos realizado una clasificación de su obra atendiendo a criterios formales definidores de cada uno de los periodo y a la accesibilidad a los materiales de construcción así como la facilidad de la mano de obra, muy vinculados a los diferentes momentos políticos y económicos. Por lo expuesto, hemos agrupado la obra de Benavent en cuatro momentos:
- de 1922 a 1929 - de 1930 a 1936 - de 1939 a 1949 - de 1950 a 1969
Para cada uno de los periodos analizaremos un edificio de vivienda prototípico del momento, un estudio
que pondremos en paralelo con la obra escrita de Pere Benavent, ya que su aportación a la arquitectura
traspasa el ámbito profesional y lo convierte en un referente de la historia de la construcción. Su obra
Cómo debo construir, además de otros escritos, es fundamental para conocer la trascendencia de la figura
Nitrogen recovery and valorization is gaining interest due to the current need for nitrogen removal, so it is of great interest that ammonium-selective sorbents be evaluated. In this study, a zeolitic material synthesized from coal fly ash (Ze–Na) in sodium form as well as its modification to potassium form (Ze–K) were evaluated as sorbent materials for the recovery of ammonium from wastewater effluents. The sorption performance was assessed through three consecutive sorption-desorption cycles reporting opposite behavior in terms of ammonium sorption capacity. Decreasing in the case of Ze–Na and to slightly increase for Ze–K due to alkaline activation of zeolite surface. The maximum sorption capacities obtained were 109 ± 4 mg NH4/g and 33 ± 1 mg NH4/g for Ze–Na and Ze–K, respectively. It is important to point out that in the case of Ze–Na, the maximum sorbent capacity was obtained during the first sorption cycle whereas in the case of Ze–K, it was obtained during the last working cycle due to the alkaline regeneration. Kinetic studies showed that after every regeneration step, the sorption kinetics turn faster as alkaline desorption increased the zeolite-specific surface, thus increasing the size of porous and enhancing the diffusion through the particle. Results obtained indicate that sorption capacity decreased significantly after every working cycle using Ze–Na whereas Ze–K followed the opposite behavior despite its initial lower sorption capacity.