Fission dynamics investigated in inverse kinematics in reactions induced by relativistic 236U projectiles

Since its discovery in 1939, nuclear fission has represented one of the most intriguing processes in nuclear physics due to its complex theoretical description. In this work, we aim to contribute to a better understanding of fission studying its dynamics. For this, fission reactions induced by relativistic 236U projectiles in inverse kinematics are investigated. The large range of excitation energy and deformation covered by this nucleus make it very suitable to perform this kind of studies. The analysis of observables sensitive to the dynamics of the process will allow to constrain the value of the dissipation parameter responsible for coupling collective and intrinsic degrees of freedom and to investigate other significant features in the description of nuclear fission, such as the angular momentum gained by the fissioning system or the level densities of the deformed nuclei. We have also proposed to improve the experimental technique using (p,2p)-induced fission reactions to measure the excitation energy of the fissioning system

Actitude cara á publicidade en Internet e o uso de Ad Blockers

Traballo Fin de Grao en Administración e Dirección de EmpresasA publicidade busca xerar actitudes nos consumidores. Co nacemento de Internet e a súa implantación como medio de marketing, esta reinvéntanse e aparecen novos formatos na rede. Así, os usuarios están expostos a continuos impactos publicitarios a través deste medio, que poden chegar a ser excesivos de xeito que a publicidade online remate por acadar a denominación de molesta e intrusiva. Esta percepción dá lugar á aparición dos bloqueadores de publicidade online ou Ad Blockers, que están acadando gran desenvolvemento e cada ano gañan máis adeptos. Nesta investigación realízase un estudo sobre a actitude do usuarios cara á publicidade online e as motivacións que teñen para bloqueala. Así, buscaremos a causa do seu rexeitamento na rede e analizaremos o formato de patrocino no marco das redes sociais

Clock and Orientation-Robust Simultaneous Radio Localization and Mapping at Millimeter Wave Bands

This paper proposes a radio simultaneous location and mapping (radio-SLAM) scheme based on sparse multipath channel estimation. By leveraging sparse channel estimation schemes at millimeter wave bands, namely high resolution estimates of the multipath angle of arrival (AoA), time difference of arrival (TDoA), and angle of departure (AoD), we develop a radio-SLAM algorithm that operates without any requirements of clock synchronization, receiver orientation knowledge, multiple anchor points, or two-way protocols. Thanks to the AoD information obtained via compressed sensing (CS) of the channel, the proposed scheme can estimate the receiver clock offset and orientation from a single anchor transmission, achieving sub-meter accuracy in a realistic typical channel simulation.Comment: This is the author's pre-print version of a paper accepted for presentation in IEEE WCNC 2023, Glasgow, Scotlan

Fenton and Photo-Fenton Nanocatalysts Revisited from the Perspective of Life Cycle Assessment

This study provides an overview of the environmental impacts associated with the production of different magnetic nanoparticles (NPs) based on magnetite (Fe3O4), with a potential use as heterogeneous Fenton or photo-Fenton catalysts in wastewater treatment applications. The tendency of Fe3O4 NPs to form aggregates in water makes necessary their decoration with stabilizing agents, in order to increase their catalytic activity. Different stabilizing agents were considered in this study: poly(acrylic acid) (PAA), polyethylenimine (PEI) and silica (SiO2), as well as the immobilization of the magnetite-based catalysts in a mesoporous silica matrix, SBA-15. In the case of photo-Fenton catalysts, combinations of magnetite NPs with semiconductors were evaluated, so that magnetic recovery of the nanomaterials is possible, thus allowing a safe discharge free of NPs. The results of this study suggest that magnetic nanoparticles coated with PEI or PAA were the most suitable option for their applications in heterogeneous Fenton processes, while ZnO-Fe3O4 NPs provided an interesting approach in photo-Fenton. This work showed the importance of identifying the relevance of nanoparticle production strategy in the environmental impacts associated with their useThis research was supported by two projects granted by Spanish Ministry of Science and Innovation: MODENA Project CTQ2016-79461-R and CLUSTERCAT Project MAT2015-67458-P, and Fundación Ramón Areces, Spain (Project CIVP18A3940). The authors belong to the Galician Competitive Research Groups ED431C-2017/22 and ED431C-2017/29 and CRETUS InstituteS

Plataforma Hardware-Software para el desarrollo de habilidades STEM

Robotics not only play a significant role in medicine, manufacturing, or aerospace industry, but also in education. According to governmental studies carried out in the United States and Europe, careers related to STEM skills like engineering, are constantly increasing worldwide. Due to this, several countries have been implementing STEM education. But, in Colombia this initiative just recently started to take place. Currently, it is possible to find several STEM educational robotic kits on the market such as boost from Lego, Cozmo from Anki, Mbot from Makeblocks and Dash from Make wonder. In this trend, the STEM robotic kit proposed in this document, pretends to be a hardware grounding to implement a whole STEAM program. It intends to encourage children to develop their science, tech, math, and artistic outcomes. Also, the kit offers a differential plus from others because it has two interactive components: an elephant-bot called Eli, a robot easy to assemble inspired in the protection of African elephants; and, an intuitive user interface, called "Experiencia Chamali" made up of three modules. The first one consists of assembly the robot, the second one is designed for developing of spatial perception throughout maze challenges, and the last one is made for test the robot's movements live. Two groups of children between 6 and 11 years old tested the robotic platform. During the activity, the groups reinforced STEM skills such as teamwork, communication, and problem-solving as a conclusion of test results. The children divided the assembly of the elephant-bot into several tasks on their initiative to make an agile construction. Also, in the challenge of the labyrinth, they worked collaboratively on the spatial location. Finally, the members of each group worked as a team decorating the physical labyrinth freely and observing the movements of the "elephant-bot" in this environment

Comunidades de marcoinvertebrados edáficos en diferentes sistemas de uso del terreno en la cuenca del Río Otún, Colombia.

In the Andean Mountains some agroecosystems are adequate environments for biodiversity conservation or for the readaptation, recolonization and natural recovery of species. To evaluate this phenomenon, soil macroinvertebrate communities were studied in different land uses of the Otún watershed in Colombia. Nineteen orders were found, with richness ranging from 12 to 16 groups per land use system; the forest had the highest while the plantations had the lowest diversity. Earthworms were the dominant group in terms of abundance (620 individuals m-2) and biomass (134.1 g.f.w. m-2). Highest diversity, frequency and homogeneity of distribution of the soil macrofauna were observed in the forest, together with a high percentage dominance and mixed dominance for certain epigeic groups such as millipedes, isopods and arachnids, considered indicators of more preserved ecosystems. The factorial correspondence analysis for macroinvertebrate abundance significantly separated (p < 0.01) the systems according to land use gradient and intervention level, with the first two components explaining 51% of the total variability. En los sistemas montañosos andinos algunos agrosistemas son ambientes propicios para la conservación de la biodiversidad o para la readaptación, recolonización y multiplicación natural de las especies. Para evaluar este fenómeno, en la cuenca del río Otún, Colombia se caracterizó la comunidad de macroinvertebrados edáficos en diferentes sistemas de uso del terreno. Se identificaron 19 órdenes con riqueza media estimada entre 12 y 16 grupos; el relicto de selva tuvo mayor y las plantaciones menor riqueza. Las lombrices de tierra fueron el grupo dominante en abundancia (620 ind. m-2) y biomasa (134,1 g.p.f. m-2). Se encontró los valores más altos de diversidad y una distribución más homogénea y frecuente de los macroinvertebrados en el relicto de selva, así como alto porcentaje de dominancia y porcentaje de dominancia combinada (PDC) para determinados grupos epígeos como diplópodos, isópodos y arácnidos, que se consideraron indicadores de ecosistemas más conservados. El Análisis Factorial de Correspondencia para abundancia de macroinvertebrados separó significativamente (p < 0.01) los sistemas de acuerdo al gradiente de uso y el nivel de intervención, y los dos primeros componentes explicaron el 51% de la variabilidad total

Towards improving the sustainability of bioplastics: Process modelling and life cycle assessment of two separation routes for 2,5-furandicarboxylic acid

Within the framework of an economy excessively dependent on fossil resources, the concept of sustainable development, aimed at obtaining environmentally friendly consumer goods, has given rise to the development of biorefineries. These facilities are based on the production of biofuels and platform chemicals from the most abundant raw material on the planet: biomass. The use of biomass such as wood or lignocellulosic residues makes it possible to seize opportunities offered by the implementation of renewable feedstocks, which in many cases can be embedded within the perspective of circular economy, through the exploitation of residual fractions. Among the multiple basic chemicals that can be obtained from biomass, 2,5-furandicarboxylic acid (FDCA) has a great potential, as it is the precursor of poly(ethylene furanoate) (PEF) polymer, which is considered a feasible substitute for poly(ethylene terephthalate) (PET). The purpose of this study is the simulation and environmental analysis of two separation routes for FDCA production with the objective of identifying the environmental hotspots at an early stage of the process design. The present study addresses the modelling of FDCA production from hydroxymethyl furfural (HMF) by heterogeneous catalysis using commercial Aspen Plus® V9 software. Two different downstream separation options resulting in purified FDCA were simulated: crystallization (Scenario A) and distillation (Scenario B). The estimation of the mass and energy balances were considered in the development of the data inventories required to conduct Life Cycle Assessment (LCA). LCA-assisted decision making identifies the conceptual configuration that would eventually lead to the least environmental burden. In the case of Scenario A, the stage with the highest environmental burden was the reaction unit, due to the use of HMF. In Scenario B, on the other hand, the separation stages contributed most to the impact due to their high energy demand. The combination of process simulation and LCA allowed acquiring a detailed vision of the process, through the analysis of the sensitivity of the environmental profile to different process parameters. The operating pressure in flash and distillation units for both scenarios affects plant operation by influencing total energy consumption and FDCA production. The sensitivity of environmental outcomes to these parameters was also studied, resulting in small variations. Thus, the results of this assessment provide strategic information of the early decision-making process on potential configurations for industrial-scale FDCA productionThis research was supported by EnzOx2 BBI JU-Project [grant agreement No 720297]. The authors belong to the Galician Competitive Research Group GRC ED431C 2017/29 and to the CRETUS Strategic Partnership [ED431E 2018/01]. All these programs are co-funded by FEDER (EU)S

Influence of pH and temperature in the performance of Zn phosphate conversion coatings

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe influence of variations in temperature (from 50 ◦C to 70 ◦C) and pH (2.4 and 2.9) in the Zn phosphate conversion treatment of a high-strength steel was assessed in this study. The effect of the temperature changes depends on the pH of the bath. The results evidenced an enhanced corrosion resistance with the increased temperature for baths at pH 2.4, whereas no relevant differences were concluded for baths at pH 2.9. This latter pH condition provided a better surface coverage, even with lower coating masses, than the former value. The microstructural analysis showed the development of films composed of smaller crystals for the treatments at pH 2.9. Impedance spectroscopy was established as a powerful tool with great potential for characterising phosphate layers. The accuracy of this methodology greatly depends on the equivalent circuit used for the simulation. A model based on the transmission line allows the reliable estimation of the percentage of exposed area (coating efficiency), the identification of changes in the film conductivity, and the qualitative analysis of its structureXunta de Galicia | Ref. ED431B2021/1