Numerical simulation of the shear stress produced by the hot metal jet on the blast furnace runner

During steel casting process a jet of molten metal runs out of the blast furnace hearth and strikes the runner. The continuous impact of hot fluids causes significant damage to its surface, which is made of refractory concrete. In particular, the initial impact on the dry runner is expected to be critical. This work deals with the analysis of the mechanical impact on the runner through the numerical simulation of the process. We propose an incompressible turbulent isothermal Navier-Stokes model, where turbulence is modelled considering two models (standard and SST). The interface dynamics is described by applying the Volume of Fluid (VOF) method, while the surface tension vector is provided by the Continuum Surface model (CSF). Their numerical results are performed in 2D. A comparative analysis of the most suitable transient turbulent multiphase model is presented by simulating benchmark physical experiments. The shear stress arising from the impact of the jet on the runner is also analyzed. An improvement of the classical analytical expression given in [1] is proposed. Both, the chosen turbulence model, and the formulas to compute the shear stress are validated using two benchmark laboratory tests and three numerical experiments. Numerical results are given for the impact of the jet on the dry runner of the blast furnaceThis work was supported by FEDER and Xunta de Galicia [grant number ED431C 2017/60, ED431C 2021/15], the Ministry of Economy, Industry and Competitiveness through the Plan Nacional de I+D+i [grant number MTM2015-68275-R], Agencia Estatal de Investigación [PID2019-105615RB-I00/AEI/10.13039/501100011033] and by the Vicerreitoría de Investigación e Innovación da Universidade de Santiago de Compostela via the Programa de Becas de Colaboración en Investigación 2016S

Transient thermal response with nonlocal radiation of a blast furnace main trough

A mathematical model for the transient thermal behaviour of the main trough of a blast furnace (BF) is presented. The proposed model consists of the transient heat equation with mixed radiation-convection boundary conditions to model the cooling process. The heat equation is coupled with an integral equation posed on the inner boundary, which models the radiative heat exchange on the internal cavity formed by the trough and the refractory cover placed over the trough. The main scope of this work is to address the evolution of the temperature field during a full BF tapping. A reliable algorithm, capable of simulating entire trough campaigns, is presented. The open-source computing platform FEniCS is used to numerically solve the model using a finite element method. A manufactured solution test for the heat diffusion coupled with 2D nonlocal radiation is defined with the purpose of verifying the implementation, comparing the performance of different time discretization schemes and the adaptive time stepping algorithm. Concerning the BF tapping problem, the results show that during the time interval corresponding to a single tapping, the temperature in the radiation enclosure swiftly reaches the steady state value. Nevertheless, to obtain a steady state in the bulk of the solids, much longer time scales are needed due to the large thermal inertia of the structureThis work was partially supported by ERDF and Xunta de Galicia funds under the ED431C 2017/60 and the ED431C 2021/15 grants, by the Ministerio de Ciencia, Innovación y Universidades through the Plan Nacional de I+D+i (MTM2015-68275-R) and the grant BES-2016-077228, and by the Agencia Estatal de Investigación through project [PID2019-105615RB-I00 / AEI / 10.13039/501100011033]S

Novel methodologies for solving the inverse unsteady heat transfer problem of estimating the boundary heat flux in continuous casting molds

In this article, we investigate the estimation of the transient mold-slab heat flux in continuous casting molds given some thermocouples measurements in the mold plates. Mathematically, we can see this problem as the estimation of a Neumann boundary condition given pointwise state observations in the interior of the domain. We formulate it in a deterministic inverse problem setting. After introducing the industrial problem, we present the mold thermal model and related assumptions. Then, we formulate the boundary heat flux estimation problem in a deterministic inverse problem setting using a sequential approach according to the sequentiality of the temperature measurements. We consider different formulations of the inverse problem. For each one, we develop novel direct methodologies exploiting a space parameterization of the heat flux and the linearity of the mold model. We construct these methods to be divided into a computationally expensive offline phase that can be computed before the process starts, and a cheaper online phase to be performed during the casting process. To conclude, we test the performance of the proposed methods in two benchmark casesAgencia Estatal de Investigación, Grant/Award Number: PID2019-105615RBI00/AEI; European Research Council, Grant/Award Number:765374; H2020 Marie Skłodowska-Curie Actions, Grant/Award Number: 681447; Ministerio de Economía, Industria y Competitividad, Gobierno de España, Grant/Award Number: MTM2015-68275-RS

Integration of mathematics teaching with learning objects in classical and professional high school education

This article presents results of a research aimed at creating didactic material for the mathematics teaching-learning process in the high school and professional-technical education, which was developed within the period of a professional master's program. This research is the result of a cooperative work involving two study and research groups linked to both the respective master's program and institutions of integrated technical and high school education. All products were from masters' degree students and professors in the master’s degree program, who work in institutions of basic and professional education. Two products are highlighted: a "Repository of Learning Objects for Secondary and Professional Education (ROAMEP)" and a book (in press), which presents the productions and studies in the areas of mathematics and professional education. The Learning Objects (LOs) address most of the mathematics content in high school education and mathematics applications in professional technical courses. The LOs were created in the digital format, and some of them make the use of the dynamic geometry software whereas others involve activities without the use of digital technologies. In order to integrate mathematics education and professional education, the activities for technical courses address knowledge on technology including electricity, mechanics, and chemistry, involving questions of mathematical models and introduction to differential and integral calculus in addition to the knowledge required for secondary education

Didactic resources of the natural and urban environment in Geology teaching: Area of Monforte de Lemos (Lugo)

Se propone una estrategia de aprendizaje con un eje central: la visita virtual empleando Tecnologías Geoespaciales (TGs), a través de puntos de importancia geológica del área de Monforte de Lemos (Lugo). Durante la visita se trabajan aspectos relacionados con (i) la tectónica y plegamientos, (ii) los recursos geológicos y mineros, (iii) la historia de los monumentos identitarios de la zona, y (iv) el paisaje, a través de fichas duales, con una parte A orientada al alumno y una parte B orientada al profesor. En las fichas del alumno se presentan descripciones de las paradas y actividades a realizar, mientras que en las fichas del profesor se ofrece información acerca de las competencias a evaluar, así como otras lecturas y recomendaciones para ampliar el alcance de la actividad. Los objetivos que se persiguen son el entrenamiento en el manejo de entornos virtuales de aprendizaje y la promoción de un aprendizaje situado. La estrategia permite el empleo de las Tecnologías de Información y Comunicación (TIC), al tiempo que ayuda al alumno a conectar su realidad cotidiana con los contenidos curriculares.A learning strategy is proposed centered around a central axis: the virtual tour through points of geological importance of the Monforte de Lemos (Lugo) area, which uses Geospatial Technologies (GTs). Throughout the tour, aspects related to (i) plate tectonics and folding bedding planes, (ii) geological and mining resources, (iii) history of landmark monuments in the area, and (iv) the landscape, are worked on through dual worksheets--with Part A oriented towards the student, and a Part B oriented towards the teacher. The student’s worksheet shows the description of the locations and didactic activities to be carried out with the work material contained in the sheet. Information on what to evaluate, as well as further readings and recommendations to expand upon the activity, appear in the teacher’s sheet. The objectives pursued are training in the management of Virtual Learning Environments and the promotion of situated learning. The strategy allows the use of Information and Communication Technologies (ICT) while helping students to connect their daily reality with the academic curriculum

Análise da proposta de um curso de capacitação em GeoGebra para professores de matemática da rede pública de ensino oferecido de forma remota

Esse trabalho traz considerações sobre um minicurso oferecido para professores de matemática da rede pública de ensino. O minicurso compõe um projeto de extensão que foi aprovado no Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, cujo título é curso de capacitação em GeoGebra, e se trata de um trabalho colaborativo entre cinco professores de Matemática da Educação Básica Técnica e Tecnológica da referida Instituição, todos lotados no Departamento de Matemática do Campus Nova Gameleira, em Belo Horizonte, sendo que cada professor ofereceu um minicurso num módulo desse Curso de Capacitação. Esse artigo apresenta um dos minicursos, intitulado Geometria no GeoGebra – Polígonos e Sólidos Geométricos e foi oferecido de forma remota, por meio de atividades assíncronas, no período de agosto a dezembro de 2020, para três turmas diferentes. Como atividades assíncronas foram disponibilizados seis vídeos que seriam assistidos pelos participantes e, ao final, teriam que enviar um plano de aula como conclusão do minicurso. A carga horária do minicurso foi de 200 minutos semanais, incluindo o tempo para assistir os vídeos e elaborar a atividade de conclusão

Reconstructed human pigmented skin/epidermis models achieve epidermal pigmentation through melanocore transfer

Funding: We thank the Electron Microscopy Facility at the Instituto Gulbenkian de Ciência, the Pathological Anatomy service in the Instituto Português de Oncologia de Lisboa Francisco Gentil (IPOLFG) and the Histology Facility at CEDOC for technical assistance. This project was supported by Fundação para a Ciência e a Tecnologia (FCT), Portugal through FCT Unit iNOVA4Health – UIDB/04462/2020 and UIDP/04462/2020, a programme financially supported by FCT / Ministério da Ciência, Tecnologia e Ensino Superior, through national funds, grant PTDC/BIA-CEL/29765/2017, PhD fellowships 2020.08528.BD (SLV), PD/BD/128164/2016, PD/BD/137442/2018 (MVN) and PD/BD/136905/2018 (JC) and the FCT Investigator Program to DCB (IF/00501/2014/CP1252/CT0001).The skin acts as a barrier to environmental insults and provides many vital functions. One of these is to shield DNA from harmful UV radiation, which is achieved by skin pigmentation arising as melanin is produced and dispersed within the epidermal layer. This is a crucial defence against DNA damage, photo-ageing and skin cancer. The mechanisms and regulation of melanogenesis and melanin transfer involve extensive crosstalk between melanocytes and keratinocytes in the epidermis, as well as fibroblasts in the dermal layer. Although the predominant mechanism of melanin transfer continues to be debated and several plausible models have been proposed, we and others previously provided evidence for a coupled exo/phagocytosis model. Herein, we performed histology and immunohistochemistry analyses and demonstrated that a newly developed full-thickness 3D reconstructed human pigmented skin model and an epidermis-only model exhibit dispersed pigment throughout keratinocytes in the epidermis. Transmission electron microscopy revealed melanocores between melanocytes and keratinocytes, suggesting that melanin is transferred through coupled exocytosis/phagocytosis of the melanosome core, or melanocore, similar to our previous observations in human skin biopsies. We therefore present evidence that our in vitro models of pigmented human skin show epidermal pigmentation comparable to human skin. These findings have a high value for studies of skin pigmentation mechanisms and pigmentary disorders, whilst reducing the reliance on animal models and human skin biopsies.publishersversionepub_ahead_of_prin

Traditional plants from Asteraceae family as potential candidates for functional food industry

Traditional plants have been used in the treatment of disease and pain due to their beneficial properties such as antioxidant, antiinflammation, analgesic, and antibiotic activities. The Asteraceae family is one of the most common groups of plants used in folk medicine. The species Achillea millefolium, Arnica montana, Bellis perennis, Calendula officinalis, Chamaemelum nobile, Eupatorium cannabinum, Helichrysum stoechas, and Taraxacum officinale have been used in different remedies in Northwest Spain. Besides health benefits, some of them like C. nobile and H. stoechas are already employed in cooking and culinary uses, including cocktails, desserts, and savory dishes. This study aimed to review the current information on nutritive and beneficial properties and bioactive compounds of these plants, which are not mainly used as foods but are possible candidates for this purpose. The report highlights their current uses and suitability for the development of new functional food industrial applications. Phenolic compounds, essential oils, and sesquiterpene lactones are some of the most important compounds, being related to different bioactivities. Hence, they could be interesting for the development of new functional foods.The research leading to these results received institutioanl and financial support from the: Programa de Cooperación Interreg V-A España—Portugal (POCTEP) 2014–2020 (Projects Ref.: 0181_NANOEATERS_01_E and 0377_IBERPHENOL_6_E); MICINN supporting the Ramón&Cajal grant for M. A. Prieto (RYC-2017-22891); Xunta de Galicia and University of Vigo for supporting the post-doctoral grant of María Fraga Corral (ED481B-2019/096) and the pre-doctoral grant of P. García- Oliveira (ED481A-2019/295); to Xunta de Galicia for the program EXCELENCIA-ED431F 2020/12; to Ibero-American Program on Science and Technology (CYTED – AQUA-CIBUS, P317RT0003); by EcoChestnut Project (Erasmus+ KA202) that supports the work of M. Carpena; by the Bio Based Industries Joint Undertaking (JU) under grant agreement no. 888003 UP4HEALTH Project (H2020-BBI-JTI-2019), the JU receives support from the European Union’s Horizon 2020 Research and Innovation Program and the Bio Based Industries Consortium.info:eu-repo/semantics/publishedVersio

Ash pollen immunoproteomics: Identification, immunologic characterization, and sequencing of 6 new allergens

Immunoproteomics, IgE-inhibition assays and cDNA-cloning reveals that ash and olive allergenic protein profiles are mostly equivalent, thus explaining their high cross reactivity. Our data suggest simplifying diagnosis of patients by using indistinctly ash or olive pollen