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    1351 research outputs found

    Evaluation of the Specific Capacitance of High-Entropy Oxide-Based Electrode Materials in View of Their Use for Water Desalination via Capacitive Method

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    Water pollution and scarcity are serious concerns for the growing world population. To meet the ever-pressing demand of fresh water, a variety of desalting techniques of seawater have been developed. Due to its environmental friendliness, high efficiency, easy regeneration of the electrodes, ambient operating pressure, and low operating potential suitable for the use in remote areas, the capacitive deionization (CDI) method is one of the most sustainable among them. This work focuses on the preparation of high-entropy oxides (HEOs) and carbon/HEO composites and the evaluation of their specific capacitance in view of their possible use as CDI electrode materials. CrMnFeCoNi-HEO, having spinel structure (sHEO), is obtained in the form of nanoparticles (NPs) and nanofibers (NFs) by the sol–gel method and electrospinning, respectively. Composite NFs with embedded sHEO NPs or MgCoNiCuZn-HEO NPs with rock-salt structure (rHEO) are also produced. In the 5–100 mV s−1 scan rate range, the specific capacitance improves in the order C/rHEO NFs (8–32 F g−1) ≅ sHEO NPs (9–32 F g−1) < sHEO NFs (8–43 F g−1) < C/sHEO NFs (12–66 F g−1). The highest capacitance is obtained when the beneficial contributions of the carbon matrix and smaller-sized HEO NPs are synergistically coupled.This research received no external fundin

    Augmented Reality for Supporting Workers in Human–Robot Collaboration

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    This paper discusses the potential benefits of using augmented reality (AR) technology to enhance human–robot collaborative industrial processes. The authors describe a real-world use case at Siemens premises in which an AR-based authoring tool is used to reduce cognitive load, assist human workers in training robots, and support calibration and inspection tasks during assembly tasks. The study highlights the potential of AR as a solution for optimizing human–robot collaboration and improving productivity. The article describes the methodology used to deploy and evaluate the ARContent tool, which demonstrated improved usability, reduced task load, and increased efficiency in the assembly process. However, the study is limited by the restricted availability of workers and their knowledge of assembly tasks with robots. The authors suggest that future work should focus on testing the ARContent tool with a larger user pool and improving the authoring tool based on the shortcomings identified during the study. Overall, this work shows the potential for AR technology to revolutionize industrial processes and improve collaboration between humans and robots.This research received funding from the European Union’s Horizon 2020 research 765 and Innovation Programme under grant agreement No. 873087. The results obtained in this work reflect only the authors views and not the ones of the European Commission; the Commission is not responsible for any use that may be made of the information they contain

    Kinetic model for Pd-based membranes coking/deactivation in propane dehydrogenation processes

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    This work aims at providing insight into the deactivation mechanism of Pd-based membranes in propane dehydrogenation processes. Thermogravimetric analysis (TGA) experiments were conducted to study the adsorption and coking of propylene over conventional thin layer (TL) and double-skinned (DS) Pd-based membranes under several operating conditions. A mechanistic monolayer-multilayer coke growth model was selected to mathematically describe the membrane coking observed during TGA experiments. In addition, the reaction rate of coke formation and its influence on membranes deactivation has been studied. The deactivation model able to describe the hydrogen flux decay over time suggests that monolayer coke is the main responsible for the membrane deactivation. Multilayer coke also causes deactivation but with a smaller order than monolayer coke, for both the TL and the DS membranes. Among the two membrane types, DS membrane deactivates faster, i.e. with a higher order than the TL membrane, which is equal to 1.55 for the former and 0.51 for the latter. This is related to the higher number of active sites available in the controlling step of the deactivation reaction, which are most probably given by the addition of the ceramic Al2O3 protective layer. XPS spectra further confirms that, in the presence of Pd, Al2O3 sites contribute to carbon formation by evidencing a different nature of carbon formed on the two membranes. Finally, the experimental results of hydrogen permeation over time conducted on different membranes types and operative conditions confirmed the validity of the derived and parametrized kinetic models for coke formation and membrane deactivation. The experimental findings and the kinetic model derived in this work provide essential tools for the design and optimization of membrane reactors for dehydrogenation processes.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 814671 (BiZeolCat)

    Superhydrophobic and oleophobic microtextured aluminum surface with long durability under corrosive environment

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    Superhydrophobic (SHP) and oleophobic aluminum surfaces have been prepared through the combination of a scalable chemical microtexturing process and surface functionalization with long-chained polyfluoroalkyl moieties. The effect of an anodic layer on the microtextured surface has been assessed considering surface morphology, superhydrophobicity, surface mechanical properties and corrosion protection enhancement. The surface functionalization with polyfluoroalkyl moieties has been tackled in two different ways: (i) grafting of the polyfluoroalkyl moieties and (ii) deposition of a thin hybrid coating with low content of polyfluoroalkyl-containing compound. Aluminum surfaces showing high durability in salt spray environments, which maintain SHP and oleophobic properties at least up to 2016 h have been attained. Applications for this kind of surfaces range from easy-to-clean surfaces to anti-icing or anti-condensation functionalities that could be of interest for several sectors.This project received funding from the Clean Sky 2 Joint Undertaking (CSJU) under grant agreement No.821301 . The JU received support from the European Union´s Horizon 2020 (H2020) research and innovation program and the Clean Sky 2 JU members other than the Union

    Carbon molecular sieve membranes for selective CO2 separation at elevated temperatures and pressures

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    The use of Carbon Molecular Sieve Membranes (CMSM) for selective CO2 separation from post-combustion CO2-rich streams from steel plant was experimentally evaluated and reported in this paper. Efficient CMSMs were developed for such application and their promising potentials in operating at elevated temperatures and pressures were experimentally demonstrated. The best performance in terms of flux as well as perm-selectivity, above the Robeson upper bound, was obtained using a CMSM developed with ethylenediamine in the dip-coating stage of the fabrication. In fact, adding ethylenediamine was proven to be particularly important in narrowing down the pore size distribution to ultra-micropore and establishing effective CO2 adsorption site over the membrane surface and the pores wall. It was shown that using a tailored CMSM with a precursor synthesized by co-polymerization of ethylenediamine with Novolac can improve the CO2/N2 ideal perm-selectivity from 33 to 97 at operational conditions of 200 °C and 20 bar.The project has received funding through the NWO P16-10 project

    Novel Assessment Methodology for Laser Metal Deposition of New Metallic Alloys

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    Metal additive manufacturing technologies are gaining great interest. However, the existing metallic alloys are generally formulated for conventional manufacturing processes. Thus, it is necessary to adapt their chemical composition or develop new alloys for the manufacturing conditions of additive manufacturing processes. The main method for manufacturing metal powder is gas atomization, but it is very expensive with long manufacturing times. Therefore, it is necessary to develop alloy validation methods that simplify the development process of new alloys. This paper deals with a methodology based on thermodynamic heat transfer equations, simulation, and powderless tests. This novel methodology enabled the determination of the optimal conditions for the laser melting deposition process of the commercial AA7075 alloy with a reduced number of experimental tests with powder, reducing the difficulties inherent to powder processing. The developed process was divided into two stages. In the first stage, the heating of the substrate was studied. In the second stage, the depositions of single tracks were validated with the parameters extrapolated from the previous stage. Hence, it was possible to manufacture single tracks free of cracks with an adequate aspect ratio.This work was supported by the Department of Economic Development and Infrastructures of the Basque Government (Spain) through the ALAM project “Diseño de Aleaciones de Aluminio para la Fabricación Aditiva” ELKARTEK KK-2019-00069

    Does circular economy mitigate the extraction of natural resources? Empirical evidence based on analysis of 28 European economies over the past decade

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    Moving towards a circular economy (CE) has become one of the main strategic initiatives on a global scale in the search for sustainable economic systems. However, the conceptual relationship between sustainable development and the circular economy is a matter of ongoing debate. In particular, the extent to which CE initiatives are contributing to the mitigation of resource extraction seems to be a still unclear topic. This paper investigates the relationship between the extraction of natural resources and the CE, and also analyses the effects of critical socioeconomic drivers such as economic and population growth and economic structures. The analysis is based on a panel data covering 28 European countries during the period 2010–2019. Results confirm that promoting a shift towards more circular economic systems can reduce the extraction of primary resources. However, the mitigating effect of CE initiatives remains rather marginal when compared to the impact of economic growth. Namely, estimates show that the primary resources extracted annually linked to economic growth are roughly four times the resources saved by CE initiatives. The findings provide evidence that the circularity of economic systems should be approached from a systemic perspective that includes both production and consumption as well as waste management. In particular, complementary measures addressing behavioural consumption are needed if we want to achieve a sustainable development

    Multiclass insect counting through deep learning-based density maps estimation

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    The use of digital technologies and artificial intelligence techniques for the automation of some visual assessment processes in agriculture is currently a reality. Image-based, and recently deep learning-based systems are being used in several applications. Main challenge of these applications is to achieve a correct performance in real field conditions over images that are usually acquired with mobile devices and thus offer limited quality. Plagues control is a problem to be tackled in the field. Pest management strategies relies on the identification of the level of infestation. This degree of infestation is established through a counting task manually done by the field researcher so far. Current models were not able to appropriately count due to the small size of the insects and on the last year we presented a density map based algorithm that superseded state of the art methods for a single insect type. In this paper, we extend previous work into a multiclass and multi-stadia approach. Concretely, the proposed algorithm has been tested in two use cases: on the one hand, it counts five different types of adult individuals over multiple crop leaves; and on the other hand, it identifies four different stages for immatures over 2-cm leaf disks. In these leaf disks, some of the species are in different stadia being some of them micron size and difficult to be identified even for the non-expert user. The proposed method achieves good results in both cases. The model for counting adult insects in a leaf achieves a RMSE ranging from 0.89 to 4.47, MAE ranging from 0.40 to 2.15, and R2 ranging from 0.86 to 0.91 for 4 different species in its adult phase (BEMITA, FRANOC, MYZUPE and APHIGO) that may appear together in the same leaf. Besides, for FRANOC, two stadia nymphs and adults are considered. The model developed for counting BEMITA immatures in 2-cm disks obtains R2 values up to 0.98 for big nymphs. This solution was embedded in a docker and can be accessed through an app via REST service in mobile devices. It has been tested in the wild under real conditions in different locations worldwide and over 14 different crops.The authors would like to thank all field researchers that generated the dataset, carried out the annotation process, performed the validation in the wild, and in general, supported the work in Tecnalia and BASF specially to Javier Romero, Carlos Javier Jim ́enez, Amaia Ortiz, Aitor Alvarez and Jone Echazarra

    Visualizations for the evolution of Variant-Rich Systems: A systematic mapping study

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    Context: Variant-Rich Systems (VRSs), such as Software Product Lines or variants created through clone & own, aim at reusing existing assets. The long lifespan of families of variants, and the scale of both the code base and the workforce make VRS maintenance and evolution a challenge. Visualization tools are a needed companion. Objective: We aim at mapping the current state of visualization interventions in the area of VRS evolution. We tackle evolution in both functionality and architecture. Three research questions are posed: What sort of analysis is being conducted to assess VRS evolution? (Analysis perspective); What sort of visualizations are displayed? (Visualization perspective); What is the research maturity of the reported interventions? (Maturity perspective). Methods: We performed a systematic mapping study including automated search in digital libraries, expert knowledge, and snowballing. Results: The study reports on 41 visualization approaches to cope with VRS evolution. Analysis wise, feature identification and location is the most popular scenario, followed by variant integration towards a Software Product Line. As for visualization, nodelink diagram visualization is predominant while researchers have come up with a wealth of ingenious visualization approaches. Finally, maturity wise, almost half of the studies are solution proposals. Most of the studies provide proof-of-concept, some of them also include publicly available tools, yet very few face proof-of-value. Conclusions: This study introduces a comparison framework where to frame future studies. It also points out distinct research gaps worth investigating as well as shortcomings in the evidence about relevance and contextual considerations (e.g., scalability).This work is supported by the Spanish Ministry of Science, In- novation and Universities grant number RTI2018-099818-B-I00. Raul Medeiros enjoys a doctoral grant from the Spanish Ministry of Science and Innovation (PRE2019-087324)

    ICT architectures for TSO-DSO coordination and data exchange: a European perspective

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    The coordination between system operators is a key element for the decarbonization of the power system. Over the past few years, many EU-funded research projects have addressed the challenges of Transmission System Operators (TSO) and Distribution System Operators (DSO) coordination by implementing different data exchange architectures. This paper presents a review of the ICT architectures implemented for the main coordination schemes demonstrated in such projects. The main used technologies are analyzed, considering the type of data exchanged and the communication link. Finally, the paper presents the different gaps and challenges on TSO-DSO coordination related to ICT architectures that must still be faced, paying especial attention to the expected contribution of the EU-funded OneNet project on this topic. IEEECoordiNet H202

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