1,580 research outputs found
Tracing the impact of proposals from participatory processes: methodological challenges and substantive lessons
Improving the distillate prediction of a membrane distillation unit in a trigeneration scheme by using artificial neural networks
An Artificial Neural Network (ANN) has been developed to predict the distillate produced in a permeate gap membrane distillation (PGMD) module with process operating conditions (temperatures at the condenser and evaporator inlets, and feed seawater flow). Real data obtained from experimental tests were used for the ANN training and further validation and testing. This PGMD module constitutes part of an isolated trigeneration pilot unit fully supplied by solar and wind energy, which also provides power and sanitary hot water (SHW) for a typical single family home. PGMD production was previously estimated with published data from the MD module manufacturer by means of a new type in the framework of Trnsys® simulation within the design of the complete trigeneration scheme. The performance of the ANN model was studied and improved through a parametric study varying the number of neurons in the hidden layer, the number of experimental datasets and by using different activation functions. The ANN obtained can be easily exported to be used in simulation, control or process analysis and optimization. Here, the ANN was finally used to implement a new type to estimate the PGMD production of the unit by using the inlet parameters obtained by the complete simulation model of the trigeneration unit based on Renewable Energy Sources (RES)
Modeling the Multi-layer Nature of the European Air Transport Network: Resilience and Passengers Re-scheduling under random failures
We study the dynamics of the European Air Transport Network by using a
multiplex network formalism. We will consider the set of flights of each
airline as an interdependent network and we analyze the resilience of the
system against random flight failures in the passenger's rescheduling problem.
A comparison between the single-plex approach and the corresponding multiplex
one is presented illustrating that the multiplexity strongly affects the
robustness of the European Air Network.Comment: 12 pages, 5 figures - Accepted for publication in European Physical
Journal Special Topic
Proposal to study transitions
It is proposed to clear some of the puzzles of B decay to the broad
states by studying the corresponding decay with strange
states at LHCb. Interpretation of the results
should be easier due to the narrowness of the state.Comment: 21 page
Quantification of sprouting angiogenesis under the effect of different growth factors involved in the tumor microenvironmen
One of the most important problems in tumor control is the management of metastatic process. Angiogenesis or the formation of new blood vessels from preexisting ones plays a crucial role in the expansion of the tumor by providing oxygen, nutrition and conduits for cancer cells to invade and metastasize new tissues¹. Abnormalities of growth factors (GFs) released such as PDGFs (Platelet Derived Growth Factor) could be involved in malignant human diseases2,3. Inflammation and cancer present similar mechanisms of development including angiogenesis or cell proliferation4. In order to know the effect on sprouting promotion of GFs existent in the tumor environment such as VEGF (Vascular Endothelial Growth Factor), PDGF, BMP2 (Bone Morphogenetic Protein 2) or TGF-ß (Transforming Growth Factor-ß), we have developed a microfluidic-based test based on devices designed by Farahat et al. (2012)5, which allows to the user the quantification of sprouting formation under the effect of these GFs. TGF-ß pathway involved in tumor progression in multiple human cancers, instigates phenotypical changes affecting to the cell growth, differentiation and migration6. Knowing the overexpression of GFs such as VEGF or BMP2 in tumors7,8, we aimed to compare its effect on endothelial cells in angiogenesis. Analyzing the promotion of sprout in normal conditions under GFs addition would be possible to determine which of these molecules could decrease or promote the advance of the endothelial cells. The results obtained in this work indicated that VEGF is the most important factor to enhance the angiogenic process while non-specific factors such as BMP2 or TGF-ß show a low effectiveness. In the case of PDGF, the negative effect of this molecule observed in our assays could be explained by the non-optimal balance of concentration. Furthermore, we are currently working to quantify the effect of fluid flow on the sprouting promotion
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Augmented Reality in Maintenance: An information-centred design framework
Augmented Reality (AR) visualization capabilities can impact on maintenance. From enhancing performance to retrieving feedback, AR can close the information loop between maintenance information systems and the operations supported. Though, the design of AR applications is not aligned with current information systems, which prevents maintenance information to be used and improved properly. In this paper, industrial collaboration contributed to determine a framework for AR integration in maintenance systems. The framework describes information types, formats and interactions modes for AR to enhance efficiency improvements in maintenance of complex equipment. Semi-structured interviews and surveys with maintainers were conducted to determine the maintenance challenges and also to validate the framework proposed. Therefore, exposing future research in topics such as multimodal interaction, information contextualization and performance analysis to achieve the complete integration of AR in maintenance
Pinturas anticorrosivas para la protección de carenas de barcos: VII
Se ha realizado la optimización de una serie de composiciones de pinturas anticorrosivas, ensayadas con anterioridad en balsas experimentales como etapa previa a la iniciación de experiencias sobre carenas de embarcaciones.
En las formulaciones se emplean cinco pigmentos anticorrosivos (minio, silicocromato básico de plomo, sulfato de plomo-aluminio y cromatos básicos de cinc de diferente solubilidad). Los mismos fueron dispersados en un barniz de resina fenólica-aceite de tung, al cual se incorporaron diferentes proporciones de caucho clorado de 20 cP.
Sistemas de pinturas aplicados sobre paneles con diferente tratamiento de superficie, fueron ensayados en línea de flotación y en carena en la balsa de Puerto Belgrano.The optimizing of a series of anticorrosion paints tested previously in experimental rafts has been done.
This is a new approach to this subject, before the application of that paints on ship bottoms. Five anticorrosion pigments (lead oxide, basic lead silicochromate, basic lead sulfate-aluminium and two basic zinc chromates of different solubilities) were used in the formulations. The pigments and extenders were dispersed in a binder based in a phenolic varnish where different quantities of chlorinated rubber (20 cP) had been incorporated.
The paint systems were applied on plates with different surface treatment and tested in the experimental raft at Puerto Belgrano
Contribución al estudio del comportamiento de las pinturas antiincrustantes
Se ha estudiado, mediante ensayos en balsa de 18 meses de duración, el comportamiento de pinturas antiincrustantes elaboradas en base a compuestos orgánicos de estaño: TBTO, TBTF, TPTF y TBTS. Los mismos se usaron solos, asociados con óxido cuproso y con TPLA. Las pinturas se prepararon empleando caucho clorado o resinas vinílicas para la formulación de los correspondientes vehículos.
Sólo tres de las pinturas preparadas exclusivamente con TBTF, TPTF o TBTS se mantienen sin fouling durante un período de 12 a 15 meses. Los mejores resultados se logran cuando estos compuestos están asociados al óxido cuproso. Lo mismo ocurre en el caso del TPLA.By means of raft tests we have studied the antifouling properties of paints prepared with TBTO, TBTF, TPTF and TBTS. That substances were employed alone or associated with cuprous oxide and TPLA. The samples were prepared with chlorinated rubber and vinyl binders.
After a immersion period of 15 months, only three of the paints with TBTF, TPTF or TBTS gave good results. The best antifouling activity correspond to the organotin cornin' pounds, associated with cuprous oxide. TPLA is a good reinforcement toxic for paints based on cuprous oxide or in organotins
Exergy assessment and exergy cost analysis of a renewable-based and hybrid trigeneration scheme for domestic water and energy supply
Exergy and exergy cost analyses are proposed as complementary methods for the assessment and better understanding of the efficiency of a hybrid trigeneration system based on renewable energy sources. The system combines photovoltaic/thermal collectors, an evacuated tube collector and a wind turbine and produces electricity, sanitary hot water and desalted fresh water for a single family house. The system includes two desalination technologies (reverse osmosis and membrane distillation) that consume power and heat respectively, and two kinds of energy storage devices (a hot water tank and two lead-acid batteries). The assessment is based on simulations developed by using TRNSYS software. As a first level of detail, exergy analysis is applied in ten-minute basis to selected plant components. As a second level of detail, it is proposed to apply exergy-based indicators that summarize the system behavior during a longer period of time (monthly basis). By using aggregated values, exergy accumulation terms become negligible, what allows applying symbolic thermoeconomics to calculate exergy cost and to analyze in depth the process of cost formation. The system has an exergy efficiency of 7.76% (6.68 due to electricity, 0.33 due to fresh water and 0.75 due to sanitary hot water)
Solar-assisted heat pump coupled to solar hybrid panels
A water-water solar-assisted heat pump (SAHP) is going to be installed on an academic building at the University of Zaragoza (Spain). It integrates a heat pump heating system with photovoltaics/thermal collectors and seasonal storage. Considerably higher performances than a conventional type air-source heat pump are expected to be reached. This paper shows the simulation of the system performed in trnsys, a graphically based software used to simulate the behaviour of transient systems. The obtained energy and monetary savings are analysed
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