Model-order selection in statistical shape models

Statistical shape models enhance machine learning algorithms providing prior information about deformation. A Point Distribution Model (PDM) is a popular landmark-based statistical shape model for segmentation. It requires choosing a model order, which determines how much of the variation seen in the training data is accounted for by the PDM. A good choice of the model order depends on the number of training samples and the noise level in the training data set. Yet the most common approach for choosing the model order simply keeps a predetermined percentage of the total shape variation. In this paper, we present a technique for choosing the model order based on information-theoretic criteria, and we show empirical evidence that the model order chosen by this technique provides a good trade-off between over- and underfitting.Comment: To appear in 2018 IEEE International Workshop on Machine Learning for Signal Processing, Sept.\ 17--20, 2018, Aalborg, Denmar

Environmental and economic analysis to evaluate the valorization process of metallurgical waste and by‐products

Energy and resource efficiency are today key elements for the European industry. More specifically, the metallurgical industry is energy and resource-intensive, mostly located in big centralized plants, and it is today responsable for a large number of carbon emissions. While a big plant allows for stability in productivity, it also makes the process less adaptable towards innovative units/systems developed for more efficient use of energy and resources. Therefore, the future decarbonization targets might not be met without the development of new flexible and innovative technologies and strategies. In this context, the goal of the H2020 project CIRMET (innovative and efficient solution, based on modular, versatile, and smart process units for energy and resource flexibility in highly energy-intensive processes) is to develop and validate an innovative and flexible circular solution for energy and resource efficiency in a metallurgical plant, that can also be replicable to other sectors of the process industry. The proposed circular model, represented in Figure 1, is composed of three units: (1) a metallurgical furnace for the recovery of valuable metals from industrial metallurgical residues and by-products, (2) a unit for heat recovery from the furnace’s exhaust gases, and (3) a digital platform for the optimization of the whole process. The substitution of metallurgical coke (based on fossil carbon) with biobased material (Biochar) is also investigated, aiming at future carbon neutral emissions for energy intensive industries. Please click Additional Files below to see the full abstract. Please click Download on the upper right corner to see the presentation

Marine vertebrates impact the bacterial community composition and food webs of Antarctic microbial mats

The biological activity of marine vertebrates represents an input of nutrients for Antarctic terrestrial biota, with relevant consequences for the entire ecosystem. Even though microbial mats assemble most of the biological diversity of the non-marine Antarctica, the effects of the local macrofauna on these microecosystems remain understudied. Using 16S rRNA gene sequencing, 13C and 15N stable isotopes, and by characterizing the P and N-derived nutrient levels, we evaluated the effects of penguins and other marine vertebrates on four microbial mats located along the Antarctic Peninsula. Our results show that P concentrations, C/N and N/P ratios, and δ 15N values of “penguin-impacted” microbial mats were significantly higher than values obtained for “macrofauna-free” sample. Nutrients derived from penguin colonies and other marine vertebrates altered the trophic interactions of communities within microbial mats, as well as the relative abundance and trophic position of meiofaunal groups. Twentynine bacterial families from eight different phyla significantly changed with the presence of penguins, with inorganic nitrogen (NH4 + and NO3 −) and δ 15N appearing as key factors in driving bacterial community composition. An apparent change in richness, diversity, and dominance of prokaryotes was also related to penguin-derived nutrients, affecting N utilization strategies of microbial mats and relating oligotrophic systems to communities with a higher metabolic versatility. The interdisciplinary approach of this study makes these results advance our understanding of interactions and composition of communities inhabiting microbial mats from Antarctica, revealing how they are deeply associated with marine animal

Carbon pathways through the food web of a microbial mat from Byers peninsula, Antarctica

Microbial mats are complex communities that represent a large biomass fraction in non-marine Antarctic ecosystems. They confer structure to soils and constitute, by themselves, intricate microecosystems, where a great variety of microorganisms and microfauna contributes to the ecosystem functions. Although in recent years Antarctic microbial mats have been thoroughly investigated, trophic relationships within the communities remain unresolved. We therefore conducted a study of the trophic relationships of a microbial mat from Byers Peninsula, Antarctica, using DNA analysis and stable isotopes as trophic tracers. Our results suggested, based on a Bayesian mixing model, that at least four trophic levels are present within this microecosystem: primary producers (cyanobacteria and diatoms), primary consumers (rotifers and tardigrades), secondary consumers (nematodes) and decomposers (fungi). Nematodes would play a key role as top consumers of the community, connecting the two carbon inputs described into the system, as omnivores at the secondary trophic level. In addition, carbon pathways from primary trophic level to consumers take place quickly during the first 24 h after its incorporation in the primary producers, dispersing across all the trophic levels and reaching secondary consumers in less than 11 days. This suggests that, given the changing physical conditions and presumably short periods of activity, there is a fine temporal coupling among the organisms in the community, minimizing the redundancy in function performance among trophic level

Microstructural Evolution as a Function of Increasing Aluminum Content in Novel Lightweight Cast Irons

In the context of the development of new lightweight materials, Al-alloyed cast irons have a great potential for reducing the weight of the different part of the vehicles in the transport industry. The correlation of the amount of Al and its effect in the microstructure of cast irons is not completely well established as it is affected by many factors such as chemical composition, cooling rate, etc. In this work, four novel lightweight cast irons were developed with different amounts of Al (from 0 wt. % to 15 wt. %). The alloys were manufactured by an easily scalable and affordable gravity casting process in an induction furnace, and casted in a resin-bonded sand mold. The microstructural evolution as a function of increasing Al content by different microstructural characterization techniques was studied. The hardness of the cast irons was measured by the Vickers indentation test and correlated with the previously characterized microstructures. In general, the microstructural evolution shows that the perlite content decrease with the increment of wt. % of Al. The opposite occurs with the ferrite content. In the case of graphite, a slight increment occurs with 2 wt. % of Al, but a great decrease occurs until 15 wt. % of Al. The addition of Al promotes the stabilization of ferrite in the studied alloys. The hardness obtained varied from 235 HV and 363 HV in function of the Al content. The addition of Al increases the hardness of the studied cast irons, but not gradually. The alloy with the highest hardness is the alloy containing 7 wt. % Al, which is correlated with the formation of kappa-carbides and finer perlite.This work has been partially funded by the Basque Government through the project Elkartek LION: KK-2019/0004

Development of a Sustainable Metallurgical Process to Valorize Copper Smelting Wastes with Olive Stones-Based Biochar

Flue dust waste coming from a copper (Cu) smelting company has been valorized using a newly developed metallurgical process with the aim of recovering a dust concentrated in valuable metals, such as lead (Pb) and zinc (Zn), and studying the feasibility of replacing anthracite with biochar as reducing agent. Metallurgical trials using different mixtures of reducing agents have been performed in a furnace at 1400 °C. This furnace employs a high-power thermal plasma (HPTP) system as energy source. Using copper as the base metal, pellets containing a mixture of the waste, different reducing agents, and binder were introduced into the furnace for their dissolution. Recovery yields in the range of 45–85 wt.% for Pb and Zn were obtained in the flue dusts. All the trials proved the effectiveness of the developed process to enrich the flue dusts in valuable metals, including those only using biochar as reducing agent. Further trials will be carried out in order to better control the parameters involved in the metallurgical process developed and improve its efficiency.This research was funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 820670 (CIRMET) and by the European Institute of Innovation and Technology (EIT Raw Materials), a body of the European Union, under the Horizon 2020 EU framework programme for Research and Innovation (project agreement No. 19145-DIGISER++). The official website of the DIGISER ++ project is https://digiser.tech, accessed on 28 August 2022

New chromium steel grade for creep applications

In this study, a novel Chromium steel grade (COIN2) is produced as a result of a new steel composition and an innovative heat treatment. This new steel grade COIN2 evolves from the P92 steel grade and other novel steel grade recently created by the authors (COIN), and represents an enhancement of hardness, tensile properties, and creep behaviour with respect to them, which validates the metallurgical strategy used for further research in order to increase the efficiency of power plants and thus reduce the CO2 emissions. The characterization reveals a significant property improvement with the innovative thermal treatment, contributing to the production of a novel and more competitive steel grade for creep applications.This research was funded by the Basque Government under the ELKARTEK programme [KK-2019/00074]

New chromium steel grade for creep applications

In this study, a novel Chromium steel grade (COIN2) is produced as a result of a new steel composition and an innovative heat treatment. This new steel grade COIN2 evolves from the P92 steel grade and other novel steel grade recently created by the authors (COIN), and represents an enhancement of hardness, tensile properties, and creep behaviour with respect to them, which validates the metallurgical strategy used for further research in order to increase the efficiency of power plants and thus reduce the CO2 emissions. The characterization reveals a significant property improvement with the innovative thermal treatment, contributing to the production of a novel and more competitive steel grade for creep applications.This research was funded by the Basque Government under the ELKARTEK programme [KK-2019/00074]

Evaluating energy and resource efficiency for recovery of metallurgical residues using environmental and economic analysis

peer reviewedEnergy and resource efficiency are today key elements for the metallurgical industry in the context of the new European Green Deal. Although the currently available technologies have recently led to an optimisation of energy and materials use, the decarbonisation targets may not be met without the development of new and innovative technologies and strategies. In this context, the goal of the H2020 project CIRMET (Innovative and efficient solution, based on modular, versatile, and smart process units for energy and resource flexibility in highly energy-intensive processes) is to develop and validate an innovative and flexible circular solution for energy and resource efficiency in a metallurgical plant. The circular model proposed is composed of three units: (1) a metallurgical furnace for the recovery of valuable metals from industrial metallic wastes, (2) a unit for heat recovery from the furnace's exhaust gases, and (3) a digital platform for the optimisation of the whole process. Also, the circular model investigates the possibilities of substituting the metallurgical coke used in the furnace with biobased material (BIOCHAR). This study presents an environmental and economic assessment of the circular model, based on a real pilot testing campaign in which residues from non-ferrous metals production are treated for the recovery of metals, mechanical energy from waste heat, and inert fraction. Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) are used to assess the environmental and economic performances of the circular model. The results of the LCA and the LCC highlight the main environmental and economic hot spots of the proposed technologies. The environmental analysis showed the environmental positive effects of recovering secondary metals and energy. However, for some environmental impact categories (e.g. climate change), the benefits are balanced out by the high electricity and natural gas demand in the metallurgical furnace. In this regard, the substitution of metallurgical coke with BIOCHAR can significantly lower the environmental impacts of the whole process. The economic analysis showed the potential economic profitability of the whole process, depending mostly on the quantity and marketability of the recovered metals. For both environmental and economic analysis, the electricity demand in the metallurgical furnace represents the main barrier that can hinder the viability of the process. Therefore, looking for alternative energy sources (e.g. waste heat from other industries) is identified as the most effective strategy to push the sustainability of the whole process. As the proposed technology is under development, these preliminary results can provide useful insights and contribute to the environmental and economic optimisation of the technology

Innovar para el fomento de la igualdad y la inclusión en la UCM

Depto. de Ciencias de la Comunicación AplicadaFac. de Ciencias de la InformaciónFALSEsubmitte