Rare Earths and the Balance Problem: How to Deal with Changing Markets?

The balance between the market demand and the natural abundance of the rare-earth elements (REEs) in ores, often referred to as the Balance Problem (or the Balancing Problem), is a major issue for REE suppliers. The ideal situation is a perfect match between the market demand for and the production of REEs, so that there are no surpluses of any of the REEs. This means that the rare-earth industry must find new uses for REEs that are available in excess and search for substitutes for REEs that have either limited availability or are high in demand. We present an overview of the trends in the applications for the different REEs and show that the demand for REEs for use in magnets, catalysts, and alloys is still increasing, while the application of REEs in polishing agents, glass, and ceramics are stable. On the other hand, the use of REEs in nickel–metal-hydride (NiMH) batteries and lamp phosphors is decreasing. These changes in the REE market have an influence on the Balance Problem, because the REEs that can be recycled from fluorescent lamps, cathode-ray tubes (CRTs), and NiMH batteries have to be at least partly reused in other applications. Magnesium and aluminum alloys offer an opportunity to mitigate the Balance Problem caused by these changes in the REE market. This is illustrated for REEs that can be recycled from fluorescent-lamp phosphor waste, CRT phosphors, and NiMH batteries. At present, five REEs (Nd, Eu, Tb, Dy, and Y) are being considered as very critical by Europe, the United States, and Japan, but we forecast that in the medium term, only neodymium will remain a critical REE. This paper discusses the relationship between criticality and the Balance Problem and shows how this relationship influences the market for specific REEs.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No 680629 (REMAGHIC: New Recovery Processes to produce Rare Earth-Magnesium Alloys of High Performance and Low Cost) (project website: http://www.remaghic-project. eu). KB and PTJ acknowledge funding from the European Community’s Seventh Framework Programme ([FP7/2007–2013]) under Grant Agreement No. 607411 (MC-ITN EREAN: European Rare Earth Magnet Recycling Network) (project website of EREAN: http:// www.erean.eu). Paul McGuiness (Sciencewriter.si, Slovenia) is acknowledged for the drawing of the figures

Electrochemical treatment of a graphitic forging lubricant effluent: The effect of chloride concentration and current density

The graphite removal and the chemical oxygen demand (COD) reduction by the electrochemical treatment of an effluent containing a lubricant (oil in water emulsion with graphite) was investigated. The electrochemical cell used a pair of aluminum plates. Since the effluent conductivity was very low, NaCl was used as supporting electrolyte and different current densities as well as different distance between the electrodes were applied. In lower current densities, higher chloride concentrations implied in smaller COD values. The same behavior was observed when electrode distance was decreased. All the tested conditions presented significant graphite removal and COD reductions larger than 94%GKN Driveline Brazil is gratefully acknowledged for all the financial support and material given to the execution of this paper. Also, Capes, FAPERGS, CNPq, and Cyted are thanked for their financial support.Borsa, MB.; Jungblut, R.; Pérez-Herranz, V.; Müller, L.; Moura Bernardes, A.; Bergmann, C. (2016). Electrochemical treatment of a graphitic forging lubricant effluent: The effect of chloride concentration and current density. Separation Science and Technology. 51(1):126-134. doi:10.1080/01496395.2015.1086799S12613451

Prácticas Sociales de Comunicación/Educación: Sistematización de un proyecto pedagógico popular

Trabajo Final para optar al grado académico de Licenciatura en Comunicación Social, Universidad Nacional de Córdoba. Calificación 9 (Nueve) Orientación InvestigaciónEntendemos a la comunicación/educación como un campo teórico transdisciplinario: la comunicación como instancia constitutiva del sujeto social y la educación como diálogo que tiene la intencionalidad de posibilitar una lectura crítica que permita la transformación del sujeto. En este trabajo mediante la sistematización de experiencias, haremos el análisis de las prácticas sociales de comunicación/educación del proyecto pedagógico popular que se desarrolla en la escuela Héctor Valdivielso situada en la localidad de Malvinas Argentinas, Córdoba.Fil: Müller, Melisa. Universidad Nacional de Córdoba. Facultad de Ciencias de la Comunicación; Argentina.Fil: Pérez Nungeser, Florencia. Universidad Nacional de Córdoba. Facultad de Ciencias de la Comunicación; Argentina.Fil: Rossati, Yohana Lourdes. Universidad Nacional de Córdoba. Facultad de Ciencias de la Comunicación; Argentina

Electrodeposition of diamond-like carbon films on titanium alloy using organic liquids: Corrosion and wear resistance

AbstractDiamond-like carbon (DLC) films have been studied as coatings for corrosion protection and wear resistance because they have excellent chemical inertness in traditional corrosive environments, besides presenting a significant reduction in coefficient of friction. Diamond-like carbon (DLC) films obtained by electrochemical deposition techniques have attracted a lot of interest, regarding their potential in relation to the vapor phase deposition techniques. The electrochemical deposition techniques are carried out at room temperature and do not need vacuum system, making easier this way the technological transfer. At high electric fields, the organic molecules polarize and react on the electrode surface, forming carbon films. The aim of this work was to obtain DLC films onto Ti6Al4V substrate using as electrolyte: acetonitrile (ACN) and N,N-dimethylformamide (DMF). The films were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy, potentiodynamic polarization and wear tests. The results show that these films can improve, significantly, the corrosion resistance of titanium and its alloys and their wear resistance

Estudos potenciométricos de soluções aquosas de Ferro (II) e Ferro (III) em presença de bórax e silicato de sódio

Potentiometric studies in borax I Fe+2-Fe+3-Pt and sodium silicate I Fe+2-Fe+3-Pt solutions were done. It is observed,by means of potencial variations a high affinity of borax and sodium silicate with Fe+2 and a poor affinity with Fe+3.Determinou-se a variação do potencial num eletrodo de platina brilhante imerso em soluções de Ferro (II) e Ferro (III) adicionadas de bóraxe silicato de sódio. Tanto o bórax quanto o silicato mostraram taxas altas de variação de potencial apenas no sistema Fe+2 / Pt (DE/DV= 82 mv/ml para bórax - Ferro (II) e DE/DV = 20 mv/ml para silicato - Ferro (II). Para o sistema Fe+3/Pt as taxas foram idênticas para bórax e silicato e muito baixas (DE/DV = 2mv/ml)

Enhanced and Reusable Poly(hydroxy urethane)-Based Low Temperature Hot-Melt Adhesives

[EN] Poly(hydroxy urethane)s (PHUs) based on 5-membered cyclic carbonates have emerged as sustainable alternatives to conventional isocyanate-based polyurethanes. However, while from the point of view of sustainability they represent an improvement, their properties are still not competitive with conventional polyurethanes. In this work, the potential of PHUs as reversible hot-melt adhesives is discussed. We found that with a judicious choice of reagents (ie., the dicyclic carbonate and diamine), the detrimental hydrogen bonding between the soft segment of the chains and the pendant hydroxyl groups was partially avoided, thus imparting PHUs with hot-melt adhesion properties (i.e., adhesion at elevated temperatures and cohesiveness at a temperature lower than T-g/T-m). The importance of a balanced hard to soft segment ratio, along with the relevance of the chain extender in the final properties, is highlighted. Addition of aliphatic diamines (HMDA, 1,12-DAD) resulted in rubbery materials, while the employment of cydoaliphatic (CBMA) or aromatic ones (MXDA, PXDA) led to materials with hot-melt adhesive properties. The thermoreversibility of all compositions was assessed by rebonding specimens after lap-shear tests. Lap-shear strength values that were comparable to the virgin adhesives were observed. The breaking and reformation of hydrogen bonding interactions was demonstrated by FTIR measurements at different temperatures, as well as by rheological frequency sweep experiments. In order to mitigate the negative impact of the low molar mass PHUs and to enhance the service temperature of the adhesives, a hybrid PHU was prepared by adding a small amount of an epoxy resin, which acts as a cross-linker. These hybrid PHUs maintain the thermoreversibility displayed by thermoplastic PHUs while providing better adhesion at elevated temperatures. We believe that this work provides some important insights into the design of PHU-based hot-melt adhesives.The authors would like to acknowledge the technical and human support provided by SGIker (UPV/EHU and ERDF, EU). A.G.-L. acknowledges the University of the Basque Country for the predoctoral fellowship received to carry out this work. The authors would also like to acknowledge the technical support provided by Amaia Agirre for the GPC analysis. ORIBAY Group Automotive also wants to acknowledge the HAZITEK program for the final support of the project n degrees ZL-2019/00193. This project has been partly supported by the European Union's Horizon 2020 research and innovation program under Marie Sklodowska-Curie grant agreement No. 955700. C.D. thanks FNRS for financial support. The authors of Liege thank the "Fonds National pour la Recherche Scientifique" (F.R.S.-FNRS) and the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO) for financial support in the frame of the EOS project n degrees O019618F (ID EOS: 30902231). C.D. is F.R.S.-FNRS Research Director

High-Impact PLA in Compatibilized PLA/PCL Blends: Optimization of Blend Composition and Type and Content of Compatibilizer

In this work, the effectiveness of seven commercial compatibilizers is tested in polylactide (PLA)/poly(ε-caprolactone) (PCL) blends with different compositions to obtain a high-impact PLA. None of the compatibilizers is effective for 90/10 and 80/20 PLA/PCL compositions, as no improvement of the impact strength is observed. For the 70/30 composition, compatibilizers having glycidyl methacrylate (GMA) and acrylate groups in their structure are proved the most effective, as the morphological change towards co-continuity induced by them leads to significant impact strength improvements (of ≈345% and 90% with respect to the neat PLA and the noncompatibilized PLA/PCL 70/30 blend, respectively). The 70/30 PLA/PCL composition, as it shows the best balance of properties, and the best compatibilizer (ElvaloyPTW) are chosen to carry out the optimization of the compatibilizer content. It is found that adding 6 phr to the blend results in highly toughened and ductile blends while maintaining a high modulus and yield strength values. Larger compatibilizer contents lead to even higher impact strength values, but the low-strain mechanical properties are notably reduced. Thus, in this work, a simple and easily scalable method to produce high-impact PLA is shown, as it implies the compounding of three commercially available components without involving any toxic solvents.A.F.-T. acknowledges the grant from the University of the Basque Country (UPV/EHU) to perform her Ph.D. studies. The Basque Government funded this work through the grant IT1503-22. V.S. acknowledges the Spanish Ministry of Science and Innovation (grant number PID2021-127847OB-I00) for funding

O REFLEXO DAS TECNOLOGIAS NA CONSTRUÇÃO E DESCONSTRUÇÃO DA SOCIEDADE

Study in order to reflect on the main reflections of the technologies in the construction and deconstruction of society. The guiding question sought to reflect the extent to which technologies contribute to the construction and deconstruction of society. Resorted to literature with dialectical approach. Technology can contribute to building a more just society by developing the ability to access, adapt and create new knowledge and social possibilities. As seen, those who are not willing to understand and make use of the computer, run the risk of being excluded, including and especially the world of work. It was concluded that technologies influence society in every way, is education, labor, environment, health, and especially in interpersonal relationships.Este artigo tem a finalidade de analisar os principais impactos ocasionados pelas tecnologias na construção e desconstrução da sociedade. A questão norteadora buscou refletir em que medida as tecnologias contribuem para a construção e a desconstrução da sociedade. Recorreu-se a pesquisa bibliográfica com abordagem dialética. Assim, a  tecnologia pode contribuir para a construção de uma sociedade mais justa por desenvolver a habilidade de acessar, adaptar e criar novo conhecimento e possibilidades sociais. Conforme visto, àqueles que não se dispuserem a entender e a fazer uso da informática, correm o risco de serem excluídos, inclusive e, principalmente, do mundo do trabalho. Foi possível concluir que as tecnologias influenciam a sociedade em todos os sentidos, isto é, na educação, no trabalho, no meio ambiente, na saúde, e principalmente, nas relações interpessoais

Benchmarking of different approaches to forecast solar irradiance

Ponencia presentada en: 24th European Photovoltaic Solar Energy Conference and Exhibition celebrada del 21-25 de septiembre de 2009 en Hamburgo.Power generation from photovoltaic systems is highly variable due to its dependence on meteorological conditions. An efficient use of this fluctuating energy source requires reliable forecast information for management and operation strategies. Due to the strong increase of solar power generation the prediction of solar yields becomes more and more important. As a consequence, in the last years various research organisations and companies have developed different methods to forecast irradiance as a basis for respective power forecasts. For the end-users of these forecasts it is important that standardized methodology is used when presenting results on the accuracy of a prediction model in order to get a clear idea on the advantages of a specific approach. In this paper we introduce a benchmarking procedure to asses the accuracy of irradiance forecasts and compare different approaches of forecasting. The evaluation shows a strong dependence of the forecast accuracy on the climatic conditions. For Central European stations the relative rmse ranges from 40 % to 60 %, for Spanish stations relative rmse values are in the range of 20 % to 35 %

Cationically photocured epoxy/polycaprolactone materials processed by solution electrospinning, melt electrowriting and 3D printing: Morphology and shape memory properties

Epoxy/polycaprolactone (PCL) blends containing cationic photo-initiator were prepared by both solution and melt blending. These materials were processed by solvent casting, solution electrospinning (SE), melt electrowriting (MEW), and Fused Deposition Modeling (FDM) 3D printing. The final materials were obtained after UV curing at room temperature. FTIR, and gel content measurements showed that all the materials were crosslinked and that the PCL was part of the network. The shape memory abilities (measured by DMA experiments) depended on the processing technique. Thus, the fixity and recovery ratios were optimal for electrospun fibers, while the 3D printed sample was not able to recover any shape, probably because of the poor adhesion between the printed layers. According to AFM images, samples obtained by MEW and 3D printing produced materials with spherulitic morphology, while solution electrospinning rendered fibers with Shish-Kebab-type crystalline morphology. The latter was highly anisotropic, and many chains were oriented along the nanofiber axis interdispersed with amorphous regions where the epoxy resin formed covalent links with the PCL chains. This morphology conferred extraordinary solvent resistance and shape memory properties to the electrospun mats. The latter manifested a very high affinity towards chloroform, and accordingly, they displayed potential applications as chloroform sensors.AJM acknowledges funding by the Basque Government through grant IT1503-22. LI acknowledges funding by the Basque Government through grant IT1667-22