Egusquiza, M.; Egusquiza, E.; Valentin, D.; Valero, M.; Presas, A. Engineering failure analysis Vol. 81, p. 234-244 DOI: 10.1016/j.engfailanal.2017.06.048 Data de publicació: 2017-11 Article en revista
In this paper, an uncommon failure of a Pelton turbine has been analyzed. After the monitoring system detected a sudden increase in the vibration levels, the turbine was inspected. The inspection showed that a fragment of one bucket broke off during operation. Moreover there were several buckets with cracks, always located in the same side of the buckets. An analysis of the detached fragment revealed a fatigue problem.After the damage was found, the vibration signatures measured by the monitoring system before damage, with damage and after repair, were analyzed. Before damage occurred, an excessive axial vibration and the excitation of several natural frequencies of the turbine were detected in the measured vibration.In order to identify the origin of the problem the first task was to analyze the dynamic response of the turbine. A numerical model of the runner using the finite element method (FEM) was done. Experimental research using modal analysis techniques (EMA) was also carried out in the turbine runner. The results of the numerical model were compared with the experimental results obtained. With the validated numerical model natural frequencies and mode-shapes were determined and studied.The next step was to determine experimentally the influence of the mounting conditions on the runner dynamics and the transmissibility of the runner vibrations to the machine bearings where the monitoring sensors are located.From the results of this study it was concluded that the natural frequencies excited during machine operation had axial mode shapes indicating that axial forces were applied to the runner. In a Pelton turbine, this can only be produced by a misaligned jet.To determine the influence of a misaligned jet on the bucket stresses, the dynamic behavior of the runner was performed. The dynamic force of the water jet was applied to the runner bucket. The results showed that with a misaligned jet the dynamic stress distribution increases in one side of the bucket with a maximum stress located where the cracks appeared.
Cushioning is an important aspect in hydraulic cylinder performance. The piston has to be decelerated before it strikes the end cap in order to avoid stresses in the cylinder components and reduce vibration that can be transmitted to the machine. One of the least-studied methods is internal cushioning by grooves in the piston. In this method, the flow is throttled with adequately designed grooves when the piston reaches the outlet port position. The purpose of the present work is to present a method to estimate the pressure-drop coefficients for a certain design of piston grooves in order to provide a model to develop a dynamic system simulation of the cushion system. The method is based on a computational fluid dynamic simulation of flow through piston grooves to the outlet port for each piston’s static position. The results are compared with experimental measurements, and a correction, based on Reynolds number, is proposed. Good agreement, below 16%, was obtained for all the positions but particularly for the last grooves, for which the numerical result’s deviation to the experimental measurements was less than 10%. In general, the numerical simulation tended to underestimate the pressure drop for the first grooves and overestimate the calculation for the last grooves.
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
Consideration is given to the possibility to use changes in buoyancy as a negative reactivity feedback mechanism during temperature transients in heavy liquid metal fast reactors (HLMFRs). It is shown that by the proper use of heavy pellets in the fuel elements, fuel rods could be endowed with a passive self-ejection mechanism and then with a negative feedback. A first estimate of the feasibility of the mechanism is calculated by using a simplified geometry and model. If in addition, a neutron poison pellet is introduced in the bottom of the fuel, then when the fuel element is displaced upward by buoyancy force, the reactivity will be reduced not only by disassembly of the core but also by introducing the neutron poisson from the bottom. The use of induced buoyancy opens up the possibility of introducing greater amounts of actinides into the core, as well as providing a palliative solution to the problem of positive coolant temperature reactivity coefficients that could be featured by the HLMFRs.
Segalas, J.; De Eyto, A.; McMahon, M.; Joore, P.; Crul, M.; Wever, R.; Jimenez, A. European Roundtable for Sustainable Consumption and Production p. 80 Data de presentació: 2017-10-04 Presentació treball a congrés
The potential use of changes in buoyancy as a reactivity feedback mechanism during temperature transients in heavy liquid metal fast reactors (HLMFRs) is discussed. It is shown that with the use of ballast pellets (~15% volume fraction) introduced in combination with fuel pellets, fuel rods will be endowed with a reliable self-ejection mechanism that is able to compensate temperature transients. Utilizing a simplified model, an estimate of the negative reactivity insertion expected from this mechanism is derived. The use of ballast pellets opens up the possibility of introducing greater amounts of actinides into the core, as well as providing a solution to the classical problem of positive coolant temperature reactivity coefficients in fast reactors.
The trochoidal-gear technology has been growing in groundbreaking fields. Forthcoming applications are demanding to this technology a step forward in the conceiving stage of positive displacement machines. The compendium of the qualities and the inherent characteristics of
trochoidal-gear technology, especially towards the gerotor pump, together with scale/size factor and magnetic-driven transmission has led to the idea of a magnet-sleeve-sealed variable flow mini trochoidal-gear pump. From its original concept, to the last phase of the design development, the proof of concept, this new product will intend to overcome problems such as noise, vibration, maintenance, materials, and dimensions. The paper aims to show the technological path followed from the concept, design, and model, to the manufacture of the first prototype, where the theoretical and numerical approaches are not always directly reflected in the prototype performance results.
Early in the design process, from a standard-commercial sintered metal mini trochoidal-gear unit, fundamental characteristics and dimensional limitations have been evaluated becoming the strategic parameters that led to its configuration. The main technical challenge to confront is being sealed with non-exterior driveshaft, ensuring that the whole interior is filled and wetted with working fluid and helping the hydrodynamic film formation, the pumping effect, and the heat dissipation. Subsequently, the mini pump architecture, embodiment, methodology, materials, and manufacture are presented. The trend of applications of polymer composite materials and their benefits wanted to be examined with this new mini pump prototype, and a pure polyoxymethylene mini trochoidal-gear set has been designed and manufactured. Finally, both the sintered and the polymer trochoidal-gear units have been experimentally tested in an in-house full-instrumented mini test bench. Although the main goal of the presented work is the development of a new mini trochoidal-gear pump prototype rather than a numerical study, the results have been compared with numerical simulation. Subsequently, the prototype of the mini trochoidal-gear pump is a feasible proof of concept supported by functional indexes and the experimental results.
Sustainability and internationalization are key factors within educational programmes and institutions nowadays. Offering programmes that focus on these factors at undergraduate level has been a priority at the Schoolof Engineering of Vilanova i la Geltrú (EPSEVG), Barcelona , and since 2012, it has run the International Design Project Semester (IDPS) Erasmus mobility programme.
IDPS trains engineering design students by applying Project Based Learning in intercultural groups. The working language is English and the programme is designed for bachelor degree students in their 7th or 8th semester. The IDPS programme offered at the EPSEVG emphaises the indtroduction of competences in sustainability andhuman technology
Sustainability and internationalization are key factors within educational programmes and institutions nowadays. Offering programmes that focus on these factors at undergraduate level has been a priority at the Schoolof Engineering of Vilanova i la Geltrú (EPSEVG), Barcelona , and since 2012, it has run the International Design Project Semester (IDPS) Erasmus mobility programme.
IDPS trains engineering design students by applying Project Based Learning in intercultural groups. The working language is English and the programme is designed for bachelor degree students in their 7th or 8th semester. The IDPS programme offered at the EPSEVG emphaises the indtroduction of competences in sustainability andhuman technology.
The research Institute for Sustainability Science and Technology under the Masterdegree in Sustainability Science and Technology organises the course Action Reserach Workshop on Science and Technology for Sustainability (5 ECTS). The purpose of the course is to put together civil society organisations, local administrations, students and educators to collaboratively undertake responsible research, using transdisciplinary Action-Research methodologies through service learning.
The Research Institute for Sustainability Science and Technology under the Master degree in Sustainability Science and Technology organises the course Action Research Workshop on Science and Technology for Sustainability (5 ECTS). The purpose of the course is to put together civil society organisations, local administrations, students and educators to collaboratively undertake responsible research, using trandisciplinary Action-Research methodologies through service learning.
Until now mechanisms responsible for the observed deuterium enrichment in some planets or celestial bodies are tge resykt if serveral thermal (Jeans escape) as well as non-thermal escape mechanisms. In this work, we will conjecture the possible contribution from the solar wind interacting with the magnetic fields of the planet or celestial body. The most interesting feature of this hypothesis, is that the enrichment of deuterium is not due to the preferential escape of hydrogen from the atmosphere, but rather, the enrichment is generated by external injection of deuterium into the atmosphere with solar wind or galactic clouds as sources. The hypothesis also open the possibility that planets and celestial bodies may have been enriched with deuterium in the past when solar system passed through a galactic cloud. If so, there is speculative possibility of geological records where an abrupt enrichment of deuterium may disclose the transit of the solar system through such a galactic cloud in the past, an then a sort of "deuterium-age" could be suggested.
Consideration is given to the formation and collapse of supersaturated tropospheric cavities on Mars for dust vertical transportat extreme altitudes as a tentative mechanism explaining the martian march-2012 plume. It will be shown that if, during the night-time radiative cooling is exarcerbated by suspended dust surrounding a tropospheric parcel and then impeding heat flow from the surface into the parcel and if, additionally the parcel itself is devoid of condensation nuclei (dust aerosol on Mars) a supersaturated cavity might be generated. Then, with the first rays of sunlight in the morning -and the beginning of the daily dust activity, any dust incursion into the cavity driven by local winds, could trigger the condensation of the parcel and the subsequent vigorous prompt collapse of the cavity. Utilizing a simplified geometrical model, it is shown that the collapse and rebound of such tropospheric cavities could provide enough energy to lift dust well into the thermosphere and then a possible explanation to the extremely high-altitude plumes seen on Mars. The proposed hypothesis seems consistent with the high-altitude plume seen at Mars 2012 at Cimmeria region -and still unresolved, occurred at the Martian terminator (the day-night boundary) when the atmosphere could be coldest because has been without the heat of the sun for the longest time and the beginning of the dust activity driven by solar heating. Finally the possibility that the local strong magnetic field in Cimmeria region may have played a role in triggering the formation of the hypothesized supersaturated tropospheric cavity or "magnetocavity" was also discussed.
The possible role of magnetic anomalies on Mars in gravitational enhancement of separation of charged dust is considered. It is known that charges become spatially separated by differential transport and gravitational sedimentation because the charge polarity of particles od dust depends on the particle size - where smaller particles are negatively charged and larger particles are positively charged; thus smaller and predominantly negative charged particles populate higher regions of dust devils, and larger, positively charged particles fall to the ground. This study shows that gravitational separation could be enhanced by the presence of magnetic anomalies on Mars owing to the generation of a type of magnetobarrier that prevents gravitational settling of charged dust particles beyond a certain size threshold.
The basis of a novel method for seawater desalination is outlined. In this work, pressure-retarded osmosis (PRO) energy is obtained and used posteriorly for the reverse osmosis (RO) process for seawater desalination. Although PRO process coupled with an RO process has been studied in the past, however, in this work, there is a fundamental difference. Instead of bringing river or wastewaters with low salinity to the coast to be mixed with the seawater to run the PRO process, here is the seawater which is deliberately salinized. This technique has one important consequence, namely, that it is no longer required to be in places where rivers or wastewaters flow into the sea. This important difference eliminates this until now somehow paradoxical requirement if one considers that regions needing desalination are generally poor of water resources. On the other hand, it is not a coincidence that regions needing desalination plants are also regions with rich open salt deposits in the neighborhood; high evaporation, high concentration of salt deposits, and the need for freshwater are all of them directly correlated. Therefore, the idea proposed in the paper is consistent with the problem. The high evaporation in the region which is causing the need for desalination also is creating the solution to do this by using the salt deposits created. The economic feasibility of this method is preliminarily assessed in terms of the thermodynamic limits of extractable energy and then with the cost of the salt required to obtain this energy which is compared with the price from electrical grid. It was found that in order to reduce the amount of salt required for the process, and to make the cost of energy competitive, it is necessary to direct the hypersaline draw solution (draw solution) in a cyclic loop and to have the highest possible volume fraction for the nonsalinized solution (feed solution). Additional R&D is required to explore the possibilities of this concept.
Segalas, J.; De Eyto, A.; McMahon, M.; Joore, P.; Crul, M.; Wever, R.; Jimenez, A. International Conference on Engineering and Product Design Education p. 18 Data de presentació: 2017-09-07 Presentació treball a congrés
The basis of a novel method for passive solar water heating homologous to the thermosiphon but driven by induced salinity, which causes a fluid to circulate without the need for a mechanical pump and with inverse natural convection (downward heat transfer), is outlined. The brinesiphon, like the thermosiphon, operates by harnessing the tendency of a less dense fluid to rise above a denser fluid, resulting in fluid motion through a collector, but with two exceptions: first, the
buoyancy is controlled by induced salinity gradients rather than thermal gradients, and second, as a result, natural convection is in the opposite direction than that in the homologous thermosiphon concept; i.e., hot fluid flows down, and cold fluid rises. A brinesyphon may be more suitable for solar domestic water heating systems than the thermosiphon because the direction of flow allows downward transfer from a solar collector to a lower storage tank without any type of mechanical pumping system.
We evaluated the hydrogeochemical characteristics of water from the old flooded Sierra Almagrera mines to determine the possible origin of its geothermal fluids, to establish a geological-geochemical model of the geothermal system, and evaluate the site’s geothermal potential. The mine water contained high concentrations of chloride (59.6 g/L), Na (28 g/L), K (1.75 g/L), Ca (7.2 g/L), Mg (0.63 g/L), and Li (66 mg/L), especially in water from the old dewatering system. Metal concentrations were especially elevated in the old mine shafts, with high amounts of Fe (1990 mg/L), Mn (600 mg/L), Zn (460 mg/L), Pb (4 mg/L), and Ni (11.4 mg/L). The Cl/Br molar ratios of the water was high, which may indicate the possible leaching of natural halite from the evaporite deposits in the aquifer recharge area. The mine water had the most elevated temperatures and are, possibly, representative of the extent of equilibration in most of the reservoir. The estimated mean temperatures in the geothermal reservoir, based on the triangular (Giggenbach) Na-K-Mg diagram, was 190ºC for equilibrated waters, which may justify the development of this geothermal resource. The geothermal characteristics imply convection of groundwater to 2500-3000 m below sea level, in agreement with the hydrodynamic model proposed.
Consideration is given to the possibility of ocean thermal energy conversion (OTEC) by the deliberate salinization of surface seawater. The proposed technique is similar to traditional OTEC, with one important exception: rather than cold water being brought from the bottom to the surface, the warm surface water is circulated to the bottom, cooled there, and lifted back to the surface. The entire process is driven by the induced salinity gradient at the surface. As a result, there is no need for a pumping system to bring the cold bottom water to the surface. Two methods are explored for surface salinity enhancement, namely solar evaporation and the direct addition of salt to the seawater.
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Castilla, R.; Gamez-Montero, P.J.; Raush, G.; Codina-Macia, Esteban Journal of fluids engineering. Transactions of ASME Vol. 139, num. 11, p. 1-9 DOI: 10.1115/1.4037060 Data de publicació: 2017-07-21 Article en revista
A new approach based on the open source tool OpenFOAM is presented for the numerical simulation of a mini gerotor pump working at low pressure. The work is principally focused on the estimation of leakage flow in the clearance disk between pump case and gears. Two main contributions are presented for the performance of the numerical simulation. On one hand, a contact point viscosity model is used for the simulation of solid–solid contact between gears in order to avoid the teeth tip leakage. On the other hand, a new boundary condition has been implemented for the gear mesh points motion in order to keep the mesh quality while moving gears with relative velocity. Arbitrary coupled mesh interface (ACMI) has been used both in the interface between clearance disk in inlet/outlet ports and between clearance disk and interteeth fluid domain. Although the main goal of the work is the development of the numerical method rather than the study of the physical analysis of the pump, results have been compared with experimental measurement and a good agreement in volumetric efficiency and pressure fluctuations has been found. Finally, the leakage flow in the clearance disk has been analyzed.
The response of an elastic membrane to an external flow and its significance with regard to aerodynamic drag enhancement technique is discussed. It is shown that because the response of an elastic membrane to an external flow and the development of Kelvin-Helmholtz instabilities due to the relative motion between the atmosphere and the spacecraft, the flapping of the membrane will translate in a ulsating pressure onto the walls which added to the skin drag friction will increase the apparent drag force exerted by the surrounding media, i.e, a drag enhancement technique. Utilizing a simplified linear and inviscid stability analysis an estimate for the response of the membrane as well as the drag enhancement was obtained. The technique could be particularly interesting for descent spacecraft vehicles in planets with reduced atmosphere as Mars.
Consideration is given to the possibility of using the sands of Phobos or Deimos as aerobraking thecnique for landing large payloads on Mars. In this technique -properly called as "sandbraking", the spacecraft before starting its entry stage into the Martian atmosphere is loaded with sands from Phobos or Deimos in a sand station orbiting at Phobos or Deimos transfer orbit where the sand has been previously transported from a permanent outpost at the surface of these moons. Then, during the last descent stage through the Martian atmosphere, the sand load is released at once at a certain distance in front of the spacecraft. Because the atmospheric drag od the sand, the tiny sand particles -initially at the same velocity than the spacecraft at the moment they are released, will be promptly decelerated and as a result will collide a time later against the front of the spacecraft with a relative velocity close to the terminal velocity of the spacecraft if the distance (and then the travel time) is enough. By using a proper pusher-plate located at the fronto of the spacecraft this momentum exchange can be harnessed for braking the spacecraft. Two key factors make this technique attractive, namely: on one hand the inexhaustible availability of sand from Phobos and Deimos, and on the other hand the very small escape velocity (Delta-v budget of these moons. The very small escape velocity of Phobos and Deimos translate in that a small amount of chemical rocket fuel brought from the Earth can be transformed in a very huge amount of sand load. All in all the overall process can be observed either as a technique for densification of the atmosphere of Mars in front of the spacecraft, or, as changing a high exhaust velocity chemical rocket fuel for a very slow "exhaust velocity" (the terminal velocity of the spacecraft) but with a very large amount of fuel and then with a very high energy efficiency i.e., the thrust generated pr unit of power, which is the ideal rocket propulsion system for braking a spacecraft against planetary gravity.
It is well known that hydrodynamic drag reduction can be obtained by locally surround-ing an immersed solid boundary with another low viscosity-fluid resulting in a lubricating effect. In aerodynamics propulsion, this principle has been used in the so called super-cavitation, in which the viscous drag resistance acting on a, say, torpedo or submarine is substantially reduced by enclosing the body in a low-viscosity gas bubble. In this paper we are exploring the same idea but in an opposite direction, namely: we want to know if creating a high-viscosity fluid layer or film can result in an anti-lubricating effect in which the viscous drag resistance is substantially increased, i.e., a drag enhancement technique. The main motivation behind this idea is in application to the Red planet for landing large payloads as for example in future human missions with payloads several factors larger than an unmanned spacecraft and where the thin atmosphere of Mars sharply reduce the aerobraking capabilities. Utilizing a simplified turbulent layer model the theoretical justification of this rather intuitive idea is outlined. Some preliminary computational fluid dynamics calculations were performed which encourage further research.
An, B.; Bergadà, J.M.; Mushyam, A. International Conference on Computational and Mathematical Methods in Science and Engineering p. 114-122 Data de presentació: 2017-07-08 Presentació treball a congrés
In the present paper it is presented the flow around a 2D square cylinder which is located downstream of a splitter plate and at a certain distance of it. The fluid velocity below and above the splitter plate is different, several velocity ratios are considered, it is interesting to see that the downstream vortex shedding frequency and amplitude highly depends on the velocity ratio defined upstream. So far, the Reynolds numbers evaluated fall into the laminar unsteady regime, yet the interaction between the upstream mixing layer and the wake generate fully different downstream vortex shedding for different upstream velocity ratios, lift, drag and Strouhal numbers are as well highly dependent on the velocity ratios. In the present paper, the comparison between the results obtained via CFD finite volumes and Lattice Boltzmann Method are being presented. For these initial cases studied the agreement is very good.
Prakash, B.; Mellibovsky, F.; Bergadà, J.M. International Conference on Computational and Mathematical Methods in Science and Engineering p. 1712-1721 Data de presentació: 2017-07-07 Presentació treball a congrés
Active Flow Control is implemented over NACA 2412 airfoil using Steady Suctionand Steady Blowing techniques. The pre-stall angle of attack (AOA) 12 0 is studied at a high Reynolds number (Re chord ) of 3.1*10 6 for two-dimensional, incompressible and steady flow conditions. A wide range of parametric value set is considered for Slot location (l s ), Velocity magnitude ratio (U j /U 0 ), slot width (w) and angle of perturbation (ß) using both steady suction and steady blowing independently. The numerical modeling is done using the corresponding solver in OpenFOAM, an open source CFD framework. The turbulence modeling is done using Reynolds Averaged Navier Stokes (RANS) equations, specifically k-k l -¿ model implementation in OpenFOAM. The impact of the parametric set on aerodynamic coefficients, lift (C l ) and drag( C d ), and flow separation is illustrated. Along with, the relevant boundary layer physics are explained.
Campus Bizia Lab (Campus Lab) is a programme of the University of the Basque Country and seeks to develop a collaborative process to address sustainability challenges/problems through transdisciplinary approaches involving administrative staff, students and faculty, translating the principles of sustainability into practice. The main aim of the Programme is to create a transdisciplinary community and to change the Campus practices towards sustainability.
2016/17 course has been a pilot experience with 24 Bachelor´s Degree Dissertations (TFG) and 1 Master’s Degree Dissertations (TFM) from 11 Faculties (Engineering, Education, Science, Pharmacy, Economics and business).
The challenges addressed in the TFG and TFM dissertations on sustainability have been designed and based on needs analysis in the Campuses with the participation of the staff. They not only provide a return in terms of participants (students, faculty and staff) learning, but also contribute to a more sustainable management of the university itself
Summ, T.; Prakash, B.; Bergadà, J.M.; Wierschem, A.; Mellibovsky, F. International Conference on Computational and Mathematical Methods in Science and Engineering p. 1954-1964 Data de presentació: 2017-07-07 Presentació treball a congrés
The NACA 2412 profile was numerically studied via employing 2D-DNS and implementing Active Flow Control (AFC), the Reynolds number considered was 6757, being the angle of attack of 8º. Initially, the basic flow without implementing AFC was considered, the point in which the boundary layer separates as well as the y+ value along the profile length were evaluated. A single groove location, just before the separation point, was considered, periodic forcing was employed to both modify the location of the separation point and change the separation area where vortices are present. This was undertaken resulting in a reduction of the drag coefficient while increasing the lift. Via studying a set of frequencies and amplitudes linked with the AFC periodic actuation, it was obtained the optimum set of parameters to minimize the drag while maximizing the lift.
Baghaei, M.; Bergadà, J.M.; Del Campo, D. International Conference on Computational and Mathematical Methods in Science and Engineering p. 166-176 Data de presentació: 2017-07-07 Presentació treball a congrés
When aimed to modify the downstream vortex shedding of a given bluff body, whether any road vehicle or wing profile, the use of Active Flow Control (AFC) appears to be an efficient technology. Among the different (AFC) methodologies the use of periodic forcing is ment to have better efficiency since it requires less energy to activate the shear layer, the reason behind this efficiency lies on the fact that periodic forcing interacts with the shear layer natural instabilites. In the present paper, one of the devices widely emloyed to generate pulsating flow, is carefully studied via 3D-CFD and using OpenFOAM. Initially the base flow is being determined and compared with previous experimental results, in a second step several internal dimensions of the fluidic actuator are being modified to characterize the output frequency and amplitude variations, among the conclusions obtained it is found that a given fluidic actuator is capable of generating several output frequencies and amplitudes when modifying some internal dimensions while maintaining a constant incoming flow Reynolds number.
Sustainability issues are widely recognized as wicked problems, which should not be considered as problems to be solved, but as conditions to be governed. There is a general agreement on the need to reform scientific expertise to deal with sustainability challenges, by developing new ways of knowledge production and decision-making. In that
sense, Sterling maintains that the nature of sustainability requires a fundamental change of epistemology and education. Transdisciplinary approaches to knowledge emphasize phenomena complexity, disrupting and transcending epistemological structures to progressively reflect and gain understanding. In relation to engineering education, the Barcelona Declaration highlights the sustainability competences, that engineering students should achieve.
The Universitat Politècnica de Catalunya (UPC Barcelona Tech), aware of the new sustainability competences that engineers should have, offers a master degree in Sustainability Science and Technology that trains students to become agents of change for sustainability. Transdisciplinarity (Td) and Service learning (SL) are approaches applied. Learning environment, challenges and lessons learnt when applying such learning approaches are explained in following sections.
Sanchez, F.; Segalas, J.; Vidal, E.; Martin, C.; Lopez, D.; Climent, J.; Cabre, J. Jornadas de Enseñanza Universitaria de la Informática p. 19-26 Data de presentació: 2017-07-06 Presentació treball a congrés
EDINSOST es un proyecto financiado por el Programa Estatal de I+D+i, y está orientado a afrontar los Retos de la Sociedad. El proyecto tiene por objetivo la formación de titulados capaces de liderar la resolución de los retos de nuestra sociedad mediante la integración de la formación en sostenibilidad en el Sistema Universitario Español. En el proyecto participan 55 investigadores de 9 universidades españolas. Para conseguir su objetivo, el proyecto ha defini-do el mapa de la competencia en sostenibilidad de 15 titulaciones. A partir del mapa se establecerán las estrategias didácticas más apropiadas para la formación en sostenibilidad, se diagnosticará el estado de las necesidades formativas en sostenibilidad del profesorado y del estudiantado y, finalmente, se elaborarán propuestas de capacitación para ambos colectivos. En este artículo se presenta el proyecto EDINSOST y el mapa de la competencia Sostenibilidad del grado en Ingeniería Informática como primer resultado del proyecto. El mapa es fácilmente adaptable a cualquier titulación de educación superior.
The Research Institute for Sustainability Science and Technology under the Master degree in Sustainability Science and Technology organises the course Action Research Workshop on Science and Technology for Sustainability (5 ECTS). The authors have been coordinating the course during the academic years 13/14, 14/15 and 15/16. The purpose of the workshop is to put together civil society organisations, local administrations, students and educators to collaboratively undertake responsible research, performing transdisciplinary learning environments and by using an action-research framework, to answer questions such as: Who are we researching for? Who profits from our research? What are the impacts of our research? Which methodologies and tools should be used when dealing with sociotechnical sustainability challenges?
Students work on real projects, related to local sustainability problems, represented by a community entity (Service learning and Campus Lab). Action research methodology is used with a two-cycle approach. In each real-life project, students, faculty and stakeholders are asked to follow the action-reflexion process of action research projects: Action 1- Jointly defining: Project purpose; Customer and interest; Involved actors; Reflexion 1- Students define: research question, initial situation, needed additional information, action Strategy, Tasks planning and distribution: Action 2 - Items returning and discussing with stakeholders, Reflexion 2 - revising and reformulating.
Having now run the workshop three times, we can conclude that: First, students realized the significance of framing an investigation under a research methodological framework that allows bringing research to the community, enhancing transdisciplinarity in any initiative or action in sustainability science. They set out the importance of some topics and the difficulty to hold them. Second, the formulation of the problem became one of the most arduous tasks in the process; difficulties were mainly related to the perception of the problem from distinct community group motivations. Third, interaction and communication with stakeholders and the recognition of their role was problematic as engineering students are not usually trained to work in wicked problems nor accompany stakeholders during the whole process. Finally, it is relevant to highlight that during the process students faced conflict and frustrating situations both within their team and with stakeholders. To help tackle this problem, an Emotional Intelligence module was introduced in the workshop which proved useful in helping students to solve some paralyzing situations, which could otherwise have stopped the progress of the project. We suggest that engineering students need specific training in transdisciplinary research and in conflict resolution, to avoid collapsing in frustration when dealing with real transdisciplinary sustainability transitions.
Due to its potential toxic properties, metal mobilization is of major concern in areas surrounding Pb-Zn mines. In the present study, metal contents and toxicity of soils, water extracts from soils, and mine drainage waters from an abandoned F-Ba-Pb-Zn mining area in Osor (Girona, NE Spain) were evaluated through chemical extractions and ecotoxicity bioassays. Toxicity assessment in the terrestrial compartment included lethal and sublethal endpoints on earthworms Eisenia foetida, arthropods Folsomia candida and several plant species whereas aquatic tests involved bacteria Vibrio fischeri, microalgae Raphidocelis subcapitata and crustaceans Daphnia magna. Metal quantifications revealed high concentrations of Ba (250-5110 mg kg-1), Pb (940->5000 mg kg-1) and Zn (2370-11300 mg kg-1) that exceeded intervention values to protect human health. Risks for the aquatic compartment were identified through the release of drainage waters and by leaching and run-offs from metal-contaminated soils. Cd (1.98-9.15 µg L-1), Pb (2.11-326 µg L-1) and Zn (280-2900 µg L-1) in water samples surpassed international values of aquatic life criteria. Terrestrial ecotoxicity tests were in accordance with metal quantifications and identified the most polluted soil as the most toxic. Avoidance and reproduction tests with earthworms showed the highest sensitivity to metal contamination. Aquatic bioassays with extracts from soils confirmed the results from terrestrial tests and detected severe toxic effects caused by the mine drainage waters. Algal growth inhibition was the most sensitive aquatic endpoint. In view of the results, the application of a containment or remediative procedure in the area is encouraged.
This is a copy of the author 's final draft version of an article published in the journal Environmental geochemistry and health.
The final publication is available at Springer via
Raush, G.; Gamez-Montero, P.J.; Castilla, R.; Codina-Macia, Esteban Flow measurement and instrumentation Vol. 55, p. 13-22 DOI: 10.1016/j.flowmeasinst.2016.10.014 Data de publicació: 2017-06-01 Article en revista
All positive displacement pumps produce a pulsating flow. The present paper reports the experimental measurement of steady flow pulsations in the outlet of the internal wheeled pump. In the measured flow, the manufacturing tolerance are responsible of part of the spectra of the whole pulsation. Time-Resolved Particle Image Velocimetry technique has been used for this purpose. The flow pulsation measurement from a direct visualization of the velocity profile was carried out. The flow rate signal is derived from ad-hoc integration algorithm of the radial velocity profile, where the area discretization is a constant parameter that is relevant to minimize PIV errors by velocity gradients regions near the wall. Spectrographic analysis on the experimental data reveled low frequency components related with manufacturing tolerances. Measurements of this non-invasive procedure are compared with detailed CFD numerical results obtained from an improved gerotor model where manufacturing tolerances have been included. To be compared, cross-power spectral density analysis has been applied. The results reported in the paper show a method to provide a fast non-invasive flow pulsation measurement not only for pumps but also could be extended to compare aging effects of other kind of fluid power devices.
A double acting cylinder operation has been fully monitored in its key functional parameters, focused on characterization of end-of-stroke cushioning and starting phases. Being the cylinder performance reliant in the piston constructive geometry, the number and location of piston circumferential grooves is a significant parameter affecting the internal cushioning system performance. An eddy current displacement sensor assembled in the piston allows assessment of piston radial displacement inside the cylinder tube, which is directly related with the studied operating phases. Due to such 3D displacements, the piston becomes as an active and self-adjusting element along the functional cycle of the cylinder. Mechanical joints orientation and operating pressure are also relevant parameters affecting piston radial displacement and, thus, the cushioning and starting performance. Computational Fluid Dynamics (CFD) results confirm the observed functional role of the perimeter grooves; the flow and pressure distributions, where develops a significant radial force, are also in accordance with the registered radial displacement.