Borroto-Ramírez, A.; Bruyère, S.; Thurieau, N.; Gendarme, C.; Jimenez-Pique, E.; Roa, J.J.; Pierson, J.F.; Mücklich, F.; Horwat, D. Journal of alloys and compounds Vol. 729, p. 137-143 DOI: 10.1016/j.jallcom.2017.09.153 Fecha de publicación: 2017-12-30 Artículo de revista
Zr1-xMox thin films were synthesized on glass substrates by co-sputtering molybdenum and zirconium targets in the presence of argon with x in the 0.32–0.95 range. From X-ray diffraction analyses and transmission electron microscopy images it was possible to observe an evolution of the samples structure from a nano-crystalline solid solution of Zr in the bcc lattice of Mo to clusters of Zr(Mo) nano-crystalline in an amorphous matrix. The coherence length deduced from X-ray diffractograms was around 1 nm–8 nm depending on the composition. Mechanical measurements show that the films exhibited high hardness H, low Young's modulus E and therefore high H/E ratio compared with the bulk of Zr and Mo. We also found a low friction coefficient values for all the samples. Finally, an inverse Hall-Petch effect was observed for coherence length lower than 6 nm.
The feasibility of using ultrasound transmission method to assess raw earthen materials is investigated. Results indicate that this technique is effective at controlling the drying process of raw earthen materials. Near the hygrometric equilibrium, there is a linear relationship between the moisture content of the earthen material and the ultrasound transmission speed, which increases during the drying process. For the tested compressed earth, the hygrometric equilibrium is reached when the ultrasound transmission speed is over 1100 m/s. In addition, ultrasound transmission method is useful to reliably calculate the dynamic Young's modulus of raw earthen materials.
El iESD es una herramienta software basada en una metodología novedosa que tiene por objetivo facilitar la toma de decisiones técnicas en la fase de pre diseño de rehabilitaciones energéticas en edificios no residenciales, promoviendo el desarrollo de edificios nZEB con un coste óptimo. El motor de cálculo se basa en la definición arquitectónica del edificio en cuanto a soluciones pasivas (volumetría, orientación, transmitancias...) y activas (climatización, energías renovables...), así como en las condiciones climáticas y los perfiles de operación del edificio. Es una combinación de modelos matemáticos que caracterizan los vectores de demanda energética anual de un edificio con el uso de algoritmos de optimización evolutiva.
An optimization framework is presented to support the model builder in elucidating compartmental models that plausibly describe data obtained during experimentation. Here, one specifies a priori the maximum number of compartments and type of flows to contemplate during the optimization. The mathematical model follows a ‘superstructure’ approach, which inherently considers the different feasible flows between any pair of compartments. The model activates those flows/compartments that provide the optimal fit for a given set of experimental data. A regularized log-likelihood function is formulated as the performance metric. To deal with the resulting set of differential equations orthogonal collocation on finite elements is employed. A case study related to pharmacokinetics of an oncological agent demonstrates the advantages and limitations of the proposed approach. Numerical results show that the proposed approach can provide 33% smaller mean square prediction error in comparison with a compartmental model previously suggested in the literature.
In this work, we study a one-parameter family of differential equations and the different scenarios that arise with the change of parameter. We remark that these are not bifurcations in the usual sense but a wider phenomenon related with changes of continuity or differentiability. We offer an alternative point of view for the study for the motion of a system of two particles which will always move in some fixed line, we take R for the position space. If we fix the center of mass at the origin, the system reduces to that of a single particle of unit mass in a central force field. We take the potential energy function U(x)=|x|ß, where x is the position of the single particle and ß is some positive real number.
Roitero, E.; Lasserre, F.; Roa, J.J.; Anglada, M.; Mücklich, F.; Jimenez-Pique, E. Journal of the european ceramic society Vol. 37, num. 15, p. 4876-4887 DOI: 10.1016/j.jeurceramsoc.2017.05.052 Fecha de publicación: 2017-12 Artículo de revista
The aim of this study is to characterize in detail the microstructural changes and collateral damage induced by direct laser patterning on the surface of dental-grade zirconia (3Y-TZP) employing an interference setup with the 532 and 355. nm harmonics of a Nd:YAG laser (pulse duration of 10. ns).Laser-material interaction mainly results in thermal effects for both wavelengths studied. Upon laser irradiation the material locally melts producing pattern and establishing a steep thermal gradient on the surface. This generates a. ~. 1. µm thick heat affected zone where microcracking, directional recrystallization, phase transformation (from tetragonal to monoclinic, t ¿. m) and texturization (ferroelastic domain switching) take place. In addition, surface coloration results from the activation of F-centers as a consequence of high energy radiation exposure. No chemical segregation or diffusion was detected. All these microstructural changes should be taken into account to ensure integrity and long-term reliability of the zirconia components.
The most singular characteristic of pervious concrete is its interconnected porosity that allows water to flow through at high rates. The objective of this paper is to develop and validate an advanced DEM-CFD model to assess the permeability of pervious concrete numerically, taking into account the influence of the composition and of the compaction process. An extensive experimental program with 1 aggregate grading size, 4 paste contents and 3 degrees of compaction was conducted to validate the numerical approach. Results show that the DEM-CFD model is capable of predicting the permeability depending on the variables considered here. Moreover, flow parameters derived from the numerical simulations help understand the experimental results. The study confirms that, instead of relying on trial and error experiments, it is possible to use advanced numerical models to accelerate the definition of mixes and the production process, reducing the time, efforts and costs required.
The contribution of hydrogen bonding interactions to the formation of local density inhomogeneities in supercritical water at near-critical conditions has been extensively studied by means of molecular dynamics simulations. The results obtained have revealed the strong effect of water molecules forming one and two hydrogen bonds on the determination of the local density augmentation in the fluid. The local structural order has also been studied in terms of the trigonal and tetrahedral order parameters, revealing the correlation between local orientational order and hydrogen bonding. The dynamics of the structural order parameters exhibit similarities with local density ones. The local structural analysis performed in terms of nearest neighbors around the individual molecules provides additional significant evidence about the existence of a liquid-like to gas-like structural transition in supercritical water at the density range close to 0.2 ¿c, further supporting previous suggestions based on the interpretation of experimental thermodynamic data.
Guha, A.; Williams, E.R.; Boldi, R.; Satori, G.; Nagy, T.; Bór, J.; Montaña, J.; Ortega, P. Journal of atmospheric and solar-terrestrial physics Vol. 165-166, p. 25-37 DOI: 10.1016/j.jastp.2017.11.003 Fecha de publicación: 2017-12 Artículo de revista
The Earth's naturally occurring Schumann resonances (SR) are composed of a quasi-continuous background component and a larger-amplitude, short-duration transient component, otherwise called ‘Q-burst’ (Ogawa et al., 1967). Sprites in the mesosphere are also known to accompany the energetic positive ground flashes that launch the Q-bursts (Boccippio et al., 1995). Spectra of the background Schumann Resonances (SR) require a natural stabilization period of ~10–12 min for the three conspicuous modal parameters to be derived from Lorentzian fitting. Before the spectra are computed and the fitting process is initiated, the raw time series data need to be properly filtered for local cultural noise, narrow band interference as well as for large transients in the form of global Q-bursts. Mushtak and Williams (2009) describe an effective technique called Isolated Lorentzian (I-LOR), in which, the contributions from local cultural and various other noises are minimized to a great extent. An automated technique based on median filtering of time series data has been developed. These special lightning flashes are known to have greater contribution in the ELF range (below 1 kHz) compared to general negative CG strikes (Huang et al., 1999; Cummer et al., 2006). The global distributions of these Q-bursts have been studied by Huang et al. (1999) Rhode Island, USA by wave impedance methods from single station ELF measurements at Rhode Island, USA and from Japan Hobara et al. (2006). The present work aims to demonstrate the effect of Q- bursts on SR background spectra using GPS time-stamped observation of TLEs. It is observed that the Q-bursts selected for the present work do alias the background spectra over a 5-s period, though the amplitudes of these Q- bursts are far below the background threshold of 16 Core Standard Deviation (CSD) so that they do not strongly alias the background spectra of 10–12 min duration. The examination of one exceptional Q-burst shows that appreciable spectral aliasing can occur even when 12-min spectral integrations are considered. The statistical result shows that for a 12-min spectrum, events above 16 CSD are capable of producing significant frequency aliasing of the modal frequencies, although the intensity aliasing might have a negligible effect unless the events are exceptionally large (~200 CSD). The spectral CSD methodology may be used to extract the time of arrival of the Q-burst transients. This methodology may be combined with a hyperbolic ranging, thus becoming an effective tool to detect TLEs globally with a modest number of networked observational stations.
The search for environmentally neutral alternative fuels had revived the interest for microalgae-bacteria wastewater treatment systems. The potential achieving of bioproducts from microalgae biomass has also greatly contributed. The reactions that occur in these systems are complex, and the degree of scientific knowledge is still scarce compared to that of conventional bacteria wastewater treatments. Mathematical models offer a great opportunity to study the simultaneous effect of the multiple factors affecting microalgae and bacteria, thus allowing for the prediction of final biomass production, and contributing to the system design optimization in terms of operation and control. During the last decades, numerous models describing microalgae growth have been proposed. However, a lower number of integral models considering microalgae as well as bacteria is available. In this paper, the evolution of microalgae models from simple steady-state models (usually dependent on one factor) to more complex dynamic models (with two or more factors) has been revised. A summary of integrated microalgae-bacteria models has been reviewed, outlining their main features and presenting their processes and value parameters. Eventually, a critical discussion on integrated models has been put forward.
An integral mechanistic model describing the complex interactions in mixed algal-bacterial systems was developed. The model includes crucial physical, chemical and biokinetic processes of microalgae as well as bacteria in wastewater. Carbon-limited microalgae and autotrophic bacteria growth, light attenuation, photorespiration, temperature and pH dependency are some of the new features included. The model named BIO_ALGAE was built using the general formulation and structure of activated sludge models (ASM), and it was implemented in COMSOL Multiphysics™ platform. Calibration and validation were conducted with experimental data from two identical pilot HRAPs receiving real wastewater. The model was able to simulate the dynamics of different components in the ponds, and to predict the relative proportion of microalgae (58–68% in average of total suspended solids (TSS) and bacteria (30–20% in average of TSS). Microalgae growth resulted strongly influenced by the light factor fL(I), decreasing microalgae concentrations from 40 to 60%. Furthermore, reducing the influent organic matter concentration of 50% and 70%, model predictions indicated that microalgae production increased from (8.7 g TSS m- 2d- 1 to 13.5 g TSS m- 2d- 1) due to the new distribution of particulate components. The proposed model could be an efficient tool for industry to predict the production of microalgae, as well as to design and optimize HRAPs.
Nadal, A.; Alamús, R.; Pipia, L.; Ruiz , A.; Corbera, J.; Cuerva, E.; Rieradevall, J.; Josa, A. Science of the total environment Vol. 601-602, p. 1-15 DOI: 10.1016/j.scitotenv.2017.03.214 Fecha de publicación: 2017-12-01 Artículo de revista
The integration of rooftop greenhouses (RTGs) in urban buildings is a practice that is becoming increasingly important in the world for their contribution to food security and sustainable development. However, the supply of tools and procedures to facilitate their implementation at the city scale is limited and laborious. This work aims to develop a specific and automated methodology for identifying the feasibility of implementation of rooftop greenhouses in non-residential urban areas, using airborne sensors. The use of Light Detection and Ranging (LIDAR) and Long Wave Infrared (LWIR) data and the Leica ALS50-II and TASI-600 sensors allow for the identification of some building roof parameters (area, slope, materials, and solar radiation) to determine the potential for constructing a RTG. This development represents an improvement in time and accuracy with respect to previous methodology, where all the relevant information must be acquired manually.
The methodology has been applied and validated in a case study corresponding to a non-residential urban area in the industrial municipality of Rubí, Barcelona (Spain). Based on this practical application, an area of 36,312 m2 out of a total area of 1,243,540 m2 of roofs with ideal characteristics for the construction of RTGs was identified. This area can produce approximately 600 tons of tomatoes per year, which represents the average yearly consumption for about 50% of Rubí total population.
The use of this methodology also facilitates the decision making process in urban agriculture, allowing a quick identification of optimal surfaces for the future implementation of urban agriculture in housing. It also opens new avenues for the use of airborne technology in environmental topics in cities.
Romanini, M.; Del Barrio, M.; Macovez, R.; Ruiz, M.; Capaccioli, S.; Tamarit, J. Ll. Scientific reports Vol. 7, num. 1346, p. 1-11 DOI: 10.1038/s41598-017-01464-2 Fecha de publicación: 2017-12-01 Artículo de revista
We probe the temperature- and pressure-dependent specific volume (v) and dipolar dynamics of the amorphous phase (in both the supercooled liquid and glass states) of the ternidazole drug (TDZ). Three molecular dynamic processes are identified by means of dielectric spectroscopy, namely the a relaxation, which vitrifies at the glass transition, a Johari-Goldstein ßJG relaxation, and an intramolecular process associated with the relaxation motion of the propanol chain of the TDZ molecule. The lineshapes of dielectric spectra characterized by the same relaxation time (isochronal spectra) are virtually identical, within the studied temperature and pressure ranges, so that the time-temperature-pressure superposition principle holds for TDZ. The a and ßJG relaxation times fulfil the density-dependent thermodynamic scaling: master curves result when they are plotted against the thermodynamic quantity Tv¿, with thermodynamic exponent ¿ approximately equal to 2. These results show that the dynamics of TDZ, a system characterized by strong hydrogen bonding, is characterized by an isomorphism similar to that of van-der-Waals systems. The low value of ¿ can be rationalized in terms of the relatively weak density-dependence of the dynamics of hydrogen-bonded systems.
The Discrete Element Method (DEM) has been used for modelling continua, like concrete or rocks. However, it requires a big calibration effort, even to capture just the linear elastic behavior of a continuum modelled via the classical force-displacement relationships at the contact interfaces between particles. In this work we propose a new way for computing the contact forces between discrete particles. The newly proposed forces take into account the surroundings of the contact, not just the contact itself. This brings in the missing terms that provide an accurate approximation to an elastic continuum, and avoids calibration of the DEM parameters for the purely linear elastic range.
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.
Context. Requirements engineering is a discipline with numerous challenges to overcome. One of these challenges is the implementation of requirements reuse approaches. Although several theoretical proposals exist, little is known about the practices that are currently adopted in industry.
Objective. Our goal is to contribute to the investigation of the state of the practice in the reuse of requirements, eliciting current practices from practitioners, and their opinions whenever appropriate. Besides reuse in general, we focus on requirement patterns as a particular strategy to reuse.
Method. We conducted an exploratory survey based on an online questionnaire. We received 71 responses from requirements engineers with industrial experience in the field, which were analyzed in order to derive observations.
Results. Although we found that a high majority of respondents declared some level of reuse in their projects (in particular, non-functional requirements were identified as the most similar and recurrent among projects), it is true that only a minority of them declared such reuse as a regular practice. Larger IT organizations and IT organizations with well-established software processes and methods present higher levels of reuse. Ignorance of reuse techniques and processes is the main reason preventing wider adoption. From the different existing reuse techniques, the simplest ones based on textual copy and subsequent tailoring of former requirements are the most adopted techniques. However, participants who apply reuse more often tend to use more elaborate techniques. Opinions of respondents about the use of requirement patterns show that they can be expected to mitigate problems related to the quality of the resulting requirements, such as lack of uniformity, inconsistency, or ambiguity. The main reasons behind the lack of adoption of requirement patterns by practitioners (in spite of the increasing research approaches proposed in the community) are related to the lack of a well-defined reuse method and involvement of requirement engineers.
Corada, M.; Candela, L.; Torres-Fuentes, N.; Pintado-Herrera, M.; Paniw, M.; González-Mazo, E. Science of the total environment Vol. 605-606, p. 770-783 DOI: 10.1016/j.scitotenv.2017.06.049 Fecha de publicación: 2017-12 Artículo de revista
This study is focused on the Guadalete River basin (SW, Spain), where extreme weather conditions have become common, with and alternation between periods of drought and extreme rainfall events. Combined sewer overflows (CSOs) occur when heavy rainfall events exceed the capacity of the wastewater treatment plants (WWTP), as well as pollution episodes in parts of the basin due to uncontrolled sewage spills and the use of reclaimed water and sludge from the local WWTP. The sampling was carried out along two seasons and three campaigns during dry (March 2007) and extreme rainfall (April and December 2010) in the Guadalete River, alluvial aquifer and Jerez de la Frontera aquifer. Results showed minimum concentrations for synthetic surfactants in groundwater (< 37.4 µg·L- 1) during the first campaign (dry weather conditions), whereas groundwater contaminants increased in December 2010 as the heavy rainfall caused the river to overflow. In surface water, surfactant concentrations showed similar trends to groundwater observations. In addition to surfactants, pharmaceuticals and personal care products (PPCPs) were analyzed in the third campaign, 22 of which were detected in surface waters. Two fragrances (OTNE and galaxolide) and one analgesic/anti-inflammatory (ibuprofen) were the most abundant PPCPs (up to 6540, 2748 and 1747 ng·L- 1, respectively). Regarding groundwater, most PPCPs were detected in Jerez de la Frontera aquifer, where a synthetic fragrance (OTNE) was predominant (up to 1285 ng·L- 1).
Mendez, C.; Podestá, J.; Lloberas-Valls, O.; Toro, S.; Huespe, A.; Oliver, J. International journal for numerical methods in engineering Vol. 112, num. 10, p. 1353-1380 DOI: 10.1002/nme.5560 Fecha de publicación: 2017-12 Artículo de revista
A topology optimization technique based on the topological derivative and the level set function is utilized to design/synthesize the micro-structure of a pentamode material for an acoustic cloaking device. The technique provides a micro-structure consisting of a honeycomb lattice composed of needle-like and joint members. The resulting metamaterial shows a highly anisotropic elastic response with effective properties displaying a ratio between bulk and shear moduli of almost 3 orders of magnitude. Furthermore, in accordance with previous works in the literature, it can be asserted that this kind of micro-structure can be realistically fabricated. The adoption of a topology optimization technique as a tool for the inverse design of metamaterials with applications to acoustic cloaking problems is one contribution of this paper. However, the most important achievement refers to the analysis and discussion revealing the key role of the external shape of the prescribed domain where the optimization problem is posed. The efficiency of the designed micro-structure is measured by comparing the scattering wave fields generated by acoustic plane waves impinging on bare and cloaked bodies.
Yang, J.; Roa, J.J.; Schwind, M.; Odén , M.; Johansonn Joesaar, M.; Llanes, L. Materials characterization Vol. 134, p. 302-310 DOI: 10.1016/j.matchar.2017.11.004 Fecha de publicación: 2017-12 Artículo de revista
The metallic binder phase dictates the toughening behavior of WC-Co cemented carbides (hardmetals), even though it occupies a relative small fraction of the composite. Studies on deformation and phase transformation of the binder constituent are scarce. Grinding represents a key manufacturing step in machining of hardmetal tools, and is well-recognized to induce surface integrity alterations. In this work, metallurgical alterations of the binder phase in ground WC-Co cemented carbides have been assessed by a combination of electron back scattered diffraction and transmission electron microscopy techniques. The Co-base binder experiences a martensitic phase transformation from fcc to hcp crystal structure, predominantly in the first 5 µm below the surface. The hcp fraction decreases gradually along a depth of 10 µm. Surface Co displays severe plastic deformation under the highest strain, resulting in formation of nanocrystalline grains in the first micrometer below the surface. Microstructural refinement within the binder phase is observed even at greater depth. Stacking faults were detected in most of the refined grains. The metallurgical alterations of the binder phase modify the local stress distribution during grinding, which affects the discerned subsurface microcracking. The resulting residual stress profile is the sum of multiple subsurface changes, such as phase transformation, severe plastic deformation and grain refinement, where it is discerned that the depth profile of the transformed hcp-Co fraction coincides with the grinding-induced residual stress profile.
The assessment of historical structures requires appropriate knowledge of the behaviour of the investigated materials. Concerning masonry, its mechanical characterisation is a challenging task, since its composite nature requires the careful evaluation of the behaviour of its material components. In particular, the experimental assessment of the strength of existing mortar in historical structures still encounters several difficulties. This study investigates a novel Minor Destructive Testing (MDT) technique virtually equivalent to the vane test used for soils. The instrumentation, called herein Torque Penetrometric Test (TPT), is composed of a steel nail with four protruding teeth and a torque wrench. The test consists in inserting the toothed nail into a mortar joint and then applying a torque by means of a dynamometric key, until reaching the failure of the material. This work presents a novel interpretation theory based on basic concepts of fracture mechanics and applied to the micro-mechanical analysis of the stress state induced by the instrument on the investigated mortar. The proposed interpretative theory is validated through the execution of experimental tests in the laboratory and in a historical masonry building. The test proves to be effective for a quick in-situ MDT evaluation of the strength of existing mortars.
Linares, J.I.; Cantizano González, A.; Arenas, E.; Moratilla, B.; Martin, V.; Batet, L. Energy Vol. 140, num. Part 1, p. 307-317 DOI: 10.1016/j.energy.2017.08.105 Fecha de publicación: 2017-12-01 Artículo de revista
The EUROfusion research program is currently exploring alternative solutions for a future fusion power plant with DEMO (DEMOnstration Power Plant) prototype. One of the most important issues arising from a dual coolant lithium lead blanket-based reactor is the correct integration of the four thermal sources in order to achieve the highest electricity production. This study analyses the technical feasibility of supercritical CO2 Brayton power cycles. Starting with a classical re-compressed cycle, which is taken as the baseline case, two alternative proposals are investigated. On the one hand, a modified re-compressed layout with only one recuperator is studied, and is found to achieve the same electric efficiency as that of the baseline case (34.6%). On the other hand, an optimised recuperated layout is proposed, which achieves a 33.6% electric efficiency. A parametric study is conducted in order to optimise the heat exchanger size. When the re-compressed layout is optimised, a loss of efficiency (5%) is experienced. In the case of the recuperated layout optimisation the efficiency loss is reduced to 3%, achieving a reduction in heat exchanger size of 2/3.
We investigate the well-posedness, the exponential stability, or the lack thereof, of thermoelastic systems in materials where, in contrast to classical thermoelastic models for Kirchhoff type plates, two temperatures are involved, related by an elliptic equation. The arising initial boundary value problems for different boundary conditions deal with systems of partial differential equations involving Schrödinger like equations, hyperbolic and elliptic equations, which have a different character compared to the classical one with the usual single temperature. Depending on the model -- with Fourier or with Cattaneo type heat conduction -- we obtain exponential resp. non-exponential stability, thus providing another examples where the change from Fourier's to Cattaneo's law leads to a loss of exponential stability.
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.
Hydrogeological models of mountain regions present the opportunity to understand the role of geological factors on groundwater resources. The effects of sedimentary facies and fracture distribution on groundwater flow and resource exploitation are studied in the ancient fan delta of Sant Llorenç de Munt (central Catalonia, Spain) by integrating geological field observations (using sequence stratigraphy methods) and hydrogeological data (pumping tests, hydrochemistry and environmental isotopes). A comprehensive analysis of data portrays the massif as a single unit, constituted by different compartments determined by specific layers and sets of fractures. Two distinct flow systems—local and regional—are identified based on pumping test analysis as well as hydrochemical and isotopic data. Drawdown curves derived from pumping tests indicate that the behavior of the saturated layers, whose main porosity is given by the fracture network, corresponds to a confined aquifer. Pumping tests also reflect a double porosity within the system and the occurrence of impervious boundaries that support a compartmentalized model for the whole aquifer system. Hydrochemical data and associated spatial evolution show the result of water–rock interaction along the flow lines. Concentration of magnesium, derived from dolomite dissolution, is a tracer of the flow-path along distinct stratigraphic units. Water stable isotopes indicate that evaporation (near a 5% loss) occurs in a thick unsaturated zone within the massif before infiltration reaches the water table. The hydrogeological analysis of this outcropping system provides a methodology for the conceptualization of groundwater flow in similar buried systems where logging and hydrogeological information are scarce.
The final publication is available at Springer via http://dx.doi.org/10.1007/s10040-017-1618-9
Chiumenti, M.; Neiva, E.; Salsi, E.; Cervera, M.; Badia, S.; Moya, J.; Chen, Z.; Lee, C.; Davies, C. Additive Manufacturing Vol. 18, p. 171-185 DOI: 10.1016/j.addma.2017.09.002 Fecha de publicación: 2017-12 Artículo de revista
In this work a finite-element framework for the numerical simulation of the heat transfer analysis of additive manufacturing processes by powder-bed technologies, such as Selective Laser Melting, is presented. These kind of technologies allow for a layer-by-layer metal deposition process to cost-effectively create, directly from a CAD model, complex functional parts such as turbine blades, fuel injectors, heat exchangers, medical implants, among others. The numerical model proposed accounts for different heat dissipation mechanisms through the surrounding environment and is supplemented by a finite-element activation strategy, based on the born-dead elements technique, to follow the growth of the geometry driven by the metal deposition process, in such a way that the same scanning pattern sent to the numerical control system of the AM machine is used. An experimental campaign has been carried out at the Monash Centre for Additive Manufacturing using an EOSINT-M280 machine where it was possible to fabricate different benchmark geometries, as well as to record the temperature measurements at different thermocouple locations. The experiment consisted in the simultaneous printing of two walls with a total deposition volume of 107 cm3 in 992 layers and about 33,500 s build time. A large number of numerical simulations have been carried out to calibrate the thermal FE framework in terms of the thermophysical properties of both solid and powder materials and suitable boundary conditions. Furthermore, the large size of the experiment motivated the investigation of two different model reduction strategies: exclusion of the powder-bed from the computational domain and simplified scanning strategies. All these methods are analysed in terms of accuracy, computational effort and suitable applications.
A study of the solvent extraction process of Nd(III) from chloride solutions has been carried out using an ionic liquid (AliOle) prepared from Aliquat 336 (Methyl-tri(octyl/decyl)ammonium chloride) and Oleic Acid. The IL was chosen among other homemade ionic liquids and commercial extractants due to its high Nd(III) extraction ability and good phase separation. Increasing AliOle concentration improves the extraction of Nd(III) as expected. The pH of the aqueous phase strongly influences the extraction process. The appropriate equilibrium pH region has been established in the range 5–6.5. The effect of chloride concentration in the aqueous phase has been investigated. High concentrations of Cl- anion contribute to increasing the extraction yield by promoting neodymium(III) speciation in the aqueous phase. Two extraction models are proposed from experimental data. Chloride concentration in the aqueous phase determines the Nd(III) extraction mechanism. The models consider extraction of Nd3 + species when chloride concentration in the solution is low and NdCl2 + species when chloride concentration is high. Competitive extraction between HCl and the metal ions is also included in the models. They are able to reproduce feasibly the experimental Nd(III) extraction extension.
Properties related with the charge storage capacity have been evaluated for three-layered films made with two sheets of poly(3,4-ethylenedioxythiophene) separated by a sheet of poly(N-methylpyrrole) or poly(3,4-ethylenedioxythiophene-co-N-methylpyrrole) (3l-PEDOT/PNMPy or 3l-PEDOT/P(EDOT-co-NMPy), respectively). The most distinctive trend of the copolymer, which shows electrochemical properties intermediate between those of the two homopolymers, is the formation of a biphasic structure, EDOT- and NMPy-rich blocks organizing separately. The ability to exchange charge reversibly is higher for 3l-PEDOT/P(EDOT-co-NMPy) than for 3l-PEDOT/PNMPy, the electroactivity and electrostability of such two 3-layered films being significantly better than that of single-layered PEDOT. Advantages of 3l-PEDOT/P(EDOT-co-NMPy) are mainly based on the nanophase-segregated structure of the copolymer. Thus, the intermediate layer can be considered as random disposition of ultrathin dielectrics having nanometric length and width. In terms of charge storage, the intermediate layer of 3l-PEDOT/P(EDOT-co-NMPy) can be viewed as a thin reservoir filled of heterogeneously distributed nanometric supercapacitors that are connected in series among them and in parallel to the PEDOT layers. The superiority of 3l-PEDOT/P(EDOT-co-NMPy) as organic electrochemical supercapacitor compared to other 3-layered systems, has been proved by powering a red LED bulb.
Dietary flavonoids exhibit many biologically-relevant functions and can potentially have beneficial effects in the treatment of pathological conditions. In spite of its well known antioxidant properties, scarce structural information is available on the interaction of flavonoids with membrane receptors. Advances in the structural biology of a specific class of membrane receptors, the G protein-coupled receptors, have significantly increased our understanding of drug action and paved the way for developing improved therapeutic approaches. We have analyzed the effect of the flavonoid quercetin on the conformation, stability and function of the G protein-coupled receptor rhodopsin, and the G90V mutant associated with the retinal degenerative disease retinitis pigmentosa. By using a combination of experimental and computational methods, we suggest that quercetin can act as an allosteric modulator of opsin regenerated with 9-cis-retinal and more importantly, that this binding has a positive effect on the stability and conformational properties of the G90V mutant associated with retinitis pigmentosa. These results open new possibilities to use quercetin and other flavonoids, in combination with specific retinoids like 9-cis-retinal, for the treatment of retinal degeneration associated with retinitis pigmentosa. Moreover, the use of flavonoids as allosteric modulators may also be applicable to other members of the G protein-coupled receptors superfamily.
Botella, R.; Perez, F.; Riahi, E.; López-Montero, T.; Miro, R.; Martinez, A. Construction & building materials Vol. 156, p. 809-818 DOI: 10.1016/j.conbuildmat.2017.09.036 Fecha de publicación: 2017-12 Artículo de revista
This paper's objective is to evaluate the reversible phenomena that take place when asphalt materials are subjected to cyclic loads, i.e., self-heating and thixotropy. A strain sweep test was adapted to capture the stiffness variation of binders with the change in strain amplitude. The evolution of the internal temperature of the binder during the test was measured. Results show that the temperature can increase very significantly during cyclic testing and can account for a great part of all stiffness reduction captured during the test at different strain amplitudes. These results led to the conclusion that internal heating should be very important in asphalt mixtures as well. For that reason two types of time sweep tests were performed on the same mixture, with the introduction of rest periods in one of them long enough to let the inside temperature of the material lower after cycling. The results showed that the specimen that was allowed to cool down did not experience any loss of stiffness, while the specimen submitted to the conventional time sweep test failed in a few cycles. These results show the importance of the sequencing of loading and discourage the application of the Miner's law to estimate pavement life.
Isarn, I.; Massagués, L.; Ramis, X.; Serra, À.; Ferrando, F. Composites. Part A, applied science and manufacturing Vol. 103, p. 35-47 DOI: 10.1016/j.compositesa.2017.09.007 Fecha de publicación: 2017-12-01 Artículo de revista
A series of boron nitride (BN) composites, with different BN content, were prepared and characterized by cationic curing of DGEBA/BN formulations. As cationic initiator a commercial benzylanilinium salt was used. This cationic system shows good latent characteristics that were not lost on adding the filler. The performance of the catalytic system was optimized by varying the amount of initiator and adding little proportions of glycerol. The kinetics of the curing process was evaluated by calorimetric measurements. The addition of BN allowed increasing thermal conductivity without loss of mechanical properties like Young modulus, impact resistance, adhesion and other thermal characteristics like Tg or thermal stability. In addition, dielectric properties were improved with the increment of filler.
To tackle the increasing challenges of agricultural production, the complex agricultural ecosystems need to be better understood. This can happen by means of modern digital technologies that monitor continuously the physical environment, producing large quantities of data in an unprecedented pace. The analysis of this (big) data would enable farmers and companies to extract value from it, improving their productivity. Although big data analysis is leading to advances in various industries, it has not yet been widely applied in agriculture. The objective of this paper is to perform a review on current studies and research works in agriculture which employ the recent practice of big data analysis, in order to solve various relevant problems. Thirty-four different studies are presented, examining the problem they address, the proposed solution, tools, algorithms and data used, nature and dimensions of big data employed, scale of use as well as overall impact. Concluding, our review highlights the large opportunities of big data analysis in agriculture towards smarter farming, showing that the availability of hardware and software, techniques and methods for big data analysis, as well as the increasing openness of big data sources, shall encourage more academic research, public sector initiatives and business ventures in the agricultural sector. This practice is still at an early development stage and many barriers need to be overcome.
Ortiz, J. A.; de la Fuente, A.; Mena Sebastia, F.; Segura, I.; Aguado, A. Construction & building materials Vol. 156, p. 230-241 DOI: 10.1016/j.conbuildmat.2017.08.188 Fecha de publicación: 2017-12 Artículo de revista
This research focuses on designing and characterizing steel-fibre-reinforced self-compacting concrete using recycled aggregates (SFR-SCC-RA). Six different concrete dosages have been designed, and two extensive mechanical and physical characterization programs have been conducted. The first program was developed in a concrete production plant to verify the compatibility of the new material with the existing production systems. The second program was developed in a laboratory under controlled temperature and humidity conditions. Although compressive strengths greater than 25 N/mm2 have been reached (which allows the material to be classified as structural), the design in this initial phase is oriented to applications with limited mechanical requirements (e.g., foundations, earth retaining walls and pavements, in which design forces are moderate).
González, N.; Custal, M.A.; Tomara, G.; Psarras, G.; Riba, J.; Armelin, E. European polymer journal Vol. 97, p. 57-67 DOI: 10.1016/j.eurpolymj.2017.10.001 Fecha de publicación: 2017-12 Artículo de revista
Natural rubber (NR) nanocomposites have been prepared with hydroxylated barium titanate filler (BaTiO3-OH), employing emulsion polymerization followed by vulcanization process. The addition of barium titanate, a compound with high dielectric permittivity, was envisaged to increase the insulating properties of NR films, thereby reducing the electrical stress and the possibility of undesired arcing on their surfaces. The content of perovskite particles greatly affected both, the mechanical and the electrical properties, of the vulcanized films. It was observed that the optimum functionalized nanoparticle concentration is around 0.25–0.50 phr, range in which the elongation of break was maintained between 874–935% and the tensile strength was between 4.40–4.80 MPa; whereas the dielectric permittivity (¿') is slightly lower than the pristine NR or the NR compounded with high content of BaTiO3 nanoparticles. The dielectric study revealed the presence of two dielectric relaxation modes: (i) glass to rubber transition (a-relaxation) and (ii) interfacial polarization (IP), known as Maxwell-Wagner-Sillars (MWS) polarization. The comparison between small concentrations of non-functionalized and functionalized BaTiO3 inside NR polymeric films lead to the conclusion that the dielectric breakdown strength is high for non-functionalized fillers, supposedly due to less IP polarization phenomena.
We study the structure of D -modules over a ring R which is a direct sum- mand of a polynomial or a power series ring S with coefficients over a field. We relate properties of D -modules over R to D -modules over S . We show that the localization R f and the local cohomology module H i I ( R ) have finite length as D -modules over R . Furthermore, we show the existence of the Bernstein-Sato polynomial for elements in R . In positive characteristic, we use this relation between D -modules over R and S to show that the set of F -jumping numbers of an ideal I ¿ R is contained in the set of F -jumping numbers of its extension in S . As a consequence, the F -jumping numbers of I in R form a
Aznar, A.; LLoveras, P.; Romanini, M.; Del Barrio, M.; Tamarit, J. Ll.; Cazorla, C.; Errandonea, D.; Mathur, N.; Planes, A.; Moya, X.; Mañosa Carrera, Lluis Nature communications num. 8, p. 1-6 Fecha de publicación: 2017-11-29 Artículo de revista
Current interest in barocaloric effects has been stimulated by the discovery that these pressure-driven thermal changes can be giant near ferroic phase transitions in materials that display magnetic or electrical order. Here we demonstrate giant inverse barocaloric effects in the solid electrolyte AgI, near its superionic phase transition at ~420 K. Over a wide range of temperatures, hydrostatic pressure changes of 2.5 kbar yield large and reversible barocaloric effects, resulting in large values of refrigerant capacity. Moreover, the peak values of isothermal entropy change (60 J K-1 kg-1 or 0.34 J K-1 cm-3) and adiabatic temperature changes (18 K), which we identify for a starting temperature of 390 K, exceed all values previously recorded for barocaloric materials. Our work should therefore inspire the study of barocaloric effects in a wide range of solid electrolytes, as well as the parallel development of cooling devices.
The dynamics of a DC-AC self-oscillating LC resonant inverter with a zero current switching strategy is considered in this paper. A model that includes both the series and the parallel topologies and accounts for parasitic resistances in the energy storage components is used. It is found that only two reduced parameters are needed to unfold the bifurcation set of this extended system: one is related to the quality factor of the LC resonant tank, and the other accounts for the balance between serial and parallel losses. Through a rigorous mathematical study, a complete description of the bifurcation set is obtained and the parameter regions where the inverter can work properly is emphasized.
Con la frase precedente, el profesor Jacques Heyman empieza su libro Análisis de estructuras. Un estudio histórico (1998). Y es que sin duda, el cálculo estructural, tan determinante hoy en día, prácticamente no trascendió hasta Galileo. Desde Vitruvio hasta los primeros Tratados, prácticamente no encontramos referencias al cálculo estructural.
Se plantea en esta comunicación un breve análisis de la relación de la obra con la estructura viendo que lo que realmente prima en este periodo considerado es el diseño geométrico frente al estructural. Este hecho implica hacer trabajar el material con tensiones de trabajo bajas a la vez que obliga a un diseño geométrico muy cuidadoso.
Para este análisis nos centraremos en la figura del maestre Carlín (Charles Galter de Ruan) y especialmente en sus trabajos de la Catedral de Barcelona y de Sevilla
Empezando por CPUs de un solo procesador, y pasando por aceleradores discretos, los supercomputadores han avanzado enormemente utilizando todos los transistores disponibles en el chip, y especializando los diseños para cada tipo de cálculo. Actualmente, los nodos de cálculo de un sistema de Computación de Altas Prestaciones (CAP) utilizan CPUs de múltiples procesadores, optimizados para el cálculo serial de instrucciones, y múltiples aceleradores (aceleradores gráficos, o many-core), optimizados para el cálculo paralelo. El diseño de un sistema CAP de nueva generación requiere no solo mejorar el rendimiento de cálculo, sino también mejorar la eficiencia energética. La siguiente generación de sistemas requiere mejorar un orden de magnitud en ambas métricas simultáneamente.Esta tesis doctoral explora optimizaciones específicas para sistemas CAP para hacer un mejor uso de los transistores, y para mejorar las prestaciones de forma transparente ejecutando las aplicaciones en múltiples aceleradores en paralelo. Primero, analizamos varios conjuntos de aplicaciones CAP, y las comparamos con aplicaciones para servidores y escritorio, identificando las principales diferencias que nos indican cómo ajustar la arquitectura para CAP. En las aplicaciones CAP, también analizamos la parte secuencial del código y la parte paralela de forma separada, . El resultado de este análisis nos lleva a proponer una arquitectura multiprocesador asimétrica (ACMP) , con un procesador optimizado para el código secuencial, y múltiples procesadores, más pequeños, optimizados para el procesamiento paralelo. Nuestros resultados muestran que reducir el tamaño de las estructuras del front-end (fetch, y predicción de saltos) en los procesadores paralelos nos proporciona un 16% extra de área en el chip, y una reducción de consumo del 7%.Como mejora a nuestra arquitectura ACMP, proponemos explotar el hecho de que todos los procesadores paralelos ejecutan el mismo código al mismo tiempo. Evaluamos una propuesta en que los procesadores paralelos comparten la caché de instrucciones, con la intención de que uno de ellos precargue las instrucciones para los demás procesadores (prefetching), sin aumentar la latencia media de acceso. Nuestra exploración de los distintos parámetros determina que el punto óptimo requiere una interconexión de alto ancho de banda para acceder a la caché compartida, y el uso de unos pocos line buffers para mantener el ancho de banda y la latencia necesarios. Nuestras proyecciones muestran un ahorro adicional del 11% en área y el 5% en energía, sin impacto en el rendimiento. Estos ahorros de área y energía permiten a un multiprocesador incrementar la eficiencia energética, o aumentar el rendimiento añadiendo procesador adicionales.Por último, estudiamos el efecto de usar múltiples aceleradores (GPU) en una arquitectura con tiempo de acceso a memoria no uniforme (NUMA). Una vez alcanzado el límite de número de transistores y tamaño máximo por chip, la siguiente generación de aceleradores deberá utilizar múltiples chips para aumentar el número de procesadores y el ancho de banda de acceso a memoria. Sin embargo, es muy difícil mantener la ilusión de un tiempo de acceso a memoria uniforme en un sistema multi-GPU sin reescribir el código de la aplicación. Nuestra investigación sobre sistemas multi-GPU muestra retos significativos en el diseño de la interconexión entre las GPU y la jerarquía de memorias cache. Nuestros resultados muestran que se puede explotar el comportamiento en fases de las aplicaciones para optimizar la configuración de la interconexión y las cachés de forma dinámica, minimizando el impacto de la arquitectura NUMA. Nuestro diseño mejora el rendimiento de un sistema con una única GPU en 1.5x, 2.3x y 3.2x (el 89%, 84%, y 76% del máximo teórico) usando 2, 4, y 8 GPUs en paralelo. Siendo su implementación posible hoy en dia, los nodos de cálculo con múltiples aceleradores son una alternativa atractiva para futuros sistemas CAP.
We propose an ultrafast femtosecond time scale trichromatic p-pulse illumination scheme for coherent excitation and manipulation of low-lying Rydberg states in rubidium. Selective population of nP3/2 levels with principal quantum numbers n¿12 using 75-fs laser pulses is achieved. The density-matrix equations of a four-level ladder system beyond the rotating-wave approximation have to be solved to clarify the balance between the principal quantum numbers, the duration of the laser pulses, and the associated ac-Stark effects for the fastest optimal excitation. The mechanism is robust for femtosecond control using different level configurations for applications in ultrafast quantum information processing and spectroscopy.
There is evidence that the use of some reporting guidelines, such as the Consolidated Standards for Reporting Trials, is associated with improved completeness of reporting in health research. However, the current levels of adherence to reporting guidelines are suboptimal. Over the last few years, several actions aiming to improve compliance with reporting guidelines have been taken and proposed. We will conduct a scoping review of interventions to improve adherence to reporting guidelines in health research that have been evaluated or suggested, in order to inform future interventions.
Onecha, Belén; Lopez, D.; Caballero, I.; Sanz, J. Jornadas sobre Innovación Docente en Arquitectura p. 176-189 DOI: 10.5821/jida.2017.5226 Fecha de presentación: 2017-11-16 Presentación de trabajo en congreso
La enseñanza en un primer curso de estudios universitarios es un desafío a todos los niveles, que se ha visto amplificado desde la llegada a la universidad de las generaciones nacidas bajo la omnipresencia de la tecnología y las redes sociales.
Como respuesta, el equipo de profesores de la asignatura Bases para la Técnica, troncal de primer curso de Arquitectura Superior de Barcelona, ha aplicado diversos métodos “Agile” de trabajo en equipo y de Aprendizaje Cooperativo Informal durante los cursos 2015-16 y 2016-17.
Esta comunicación describe y analiza el grado de complejidad y de efectividad de dichos métodos o técnicas docentes aplicadas durante las clases taller, que perseguían, tanto captar la atención y el interés de los alumnos, como enfatizar los conceptos clave explicados durante las clases teóricas, mejorando así la comprensión global.
La enseñanza en un primer curso de estudios universitarios es un desafío a todos los niveles, que se ha visto amplificado desde la llegada a la universidad de las generaciones nacidas bajo la omnipresencia de la tecnología y las redes sociales. Como respuesta, el equipo de profesores de la asignatura Bases para la Técnica, troncal de primer curso de Arquitectura Superior de Barcelona, ha aplicado diversos métodos “Agile” de trabajo en equipo y de Aprendizaje Cooperativo Informal durante los cursos 2015-16 y 2016-17. Esta comunicación describe y analiza el grado de complejidad y de efectividad de dichos métodos o técnicas docentes aplicadas durante las clases taller, que perseguían, tanto captar la atención y el interés de los alumnos, como enfatizar los conceptos clave explicados durante las clases teóricas, mejorando así la comprensión global.
University first year teaching is a challenge at all levels, that has been magnified since the arrival at university of students generation born under the ubiquity of new technologies and social networks. In response to this situation, the teachers team of Basis for Architecture Technique, compulsory subject of first year studies in the Architecture Faculty of Barcelona, has applied Agile methods and Informal Cooperative Learning to the practical classes of the academic years from 2015 to 2017. This communication describes and analyses the complexity and effectiveness of these teaching and learning activities, whose main objectives were to get the students attenttion and engagement and to enhance the key concepts explained during theorical classes, with the result of improving global understanding.
Although carbon dioxide (CO2) is well known as one of the major green-house gases, it is also an economical C1 resource. Thus, CO2 has been regarded as an appealing starting material for the synthesis of polymers, like polycarbonates by the reaction with epoxides. Herein the reaction between natural epoxidized soybean oil (ESO), propylene oxide (PO) and CO2 under high pressure (4.0 MPa) with the presence of Co-Zn double metal cyanide (Co-Zn DMC) catalyst was studied. Temperature and reaction time were varied accordingly and the products obtained were characterized by FTIR, GPC and 1H NMR. The results obtained indicate the formation of polycarbonates in the samples collected with yields vary from 60 to 85%. The number average molecular weight (Mn) of the resultant polymer prepared at reaction temperature of 80 °C and reaction time of 6 h can reach up to 6498 g/mol.
Analizar los resultados de un programa de atención integral en pacientes de edad avanzada con fractura de cadera.
Estudio de intervención no aleatorizado de los pacientes intervenidos de fractura de cadera en el Hospital de la Fundación Althaia en Manresa. El modelo asistencial del grupo control fue el tradicional, centralizando las decisiones en el traumatólogo. En cambio, en el grupo intervención se utiliza un modelo multidisciplinar con la colaboración activa, entre otros profesionales, de traumatólogos y geriatras.
La incidencia global de complicaciones postoperatorias fue menor en el grupo intervención, así como también la mortalidad intrahospitalaria, con diferencias que no son estadísticamente significativas. El período de hospitalización se redujo en el grupo intervención.
Los resultados muestran que el abordaje integral y multidisciplinar en los pacientes de edad avanzada con fractura de cadera permite reducir las complicaciones postoperatorias y la mortalidad del paciente hasta los 6meses, así como también el total de días de ingreso en el hospital.
To analyse the results of a comprehensive care programme in elderly patients with hip fracture.
Non-randomised intervention study with patients undergoing hip fracture in Althaia Hospital (Manresa). The care model of the control group was the traditional, with the orthopaedist centralising decisions. By contrast, in the intervention group, a multidisciplinary model was used with the active collaboration, among other professionals, of orthopaedic surgeons and geriatricians.
The overall incidence of postoperative complications was lower in the intervention group, as was hospital mortality, with differences that were not statistically significant. The period of hospitalisation was reduced in the intervention group.
The results show that the multidisciplinary approach in elderly patients with hip fracture reduces postoperative complications and patient mortality up to 6months, as well as the total days of hospitalisation.
Este estudio se ha llevado a cabo en el sector de la minería a cielo abierto,en Cataluña y Aragón, se ha entrevistado a empresarios, facultativos y trabajadores de las explotaciones mineras visitadas. La gran mayoría de las empresas que se dedican a la extracción de piedra ornamental y áridos, está constituida por pequeñas y medianas explotaciones. Las exigencias psicológicas de los trabajadores de estas industrias mineras no so favorables para la salud, al igual que el trabajo activo, el apoyo social, la estima y la inseguridad en el trabajo.
Las principales dificultades en relación con la exposición a factores de riesgo psicosocial derivados de las características de la organización del trabajo son, por orden de prevalencia: exigencias psicológicas cuantitativas, (45,7); la inseguridad (28,1); la falta de influencia (24,5) y el refuerzo (21,1).
El estado del arte es una forma de aludir a lo que se sabe sobre una materia, lo que se ha dicho hasta el momento que ha sido más relevante. En este sentido la pretensión de este documento es situar al lector interesado en cuál es la situación de conocimiento actual sobre la identidad organizacional. Esta materia ha ido tomando relevancia en la investigación científica sobre dirección de empresas en los últimos años. De hecho, la identidad organizacional se ha revelado como un activo intangible de gran influencia en las organizaciones, hasta tal punto que su errónea evaluación o tratamiento puede conllevar graves repercusiones para la organización, incluso su desaparición. La identidad organizacional ha adquirido el interés científico, si bien los investigadores más relevantes en esta materia coinciden en que los trabajos de investigación no han alcanzado su culminación, más bien se encuentran en fases iniciales y animan a continuar investigando en este área de conocimiento.
Working Paper del Departamento de Organización de Empreses de la Universitat Politècnica de Catalunya sobre la investigación en identidad organizacional.