Aplicación de secciones transversales pulidas y observación FE-SEM de relevantes generados a partir de flotación de minerales

Fine particles in tailings generated from the flotation of ores were observed. By using Field-emission scanning electron microscopy (FE-SEM), the fine particles were observed at submicron level with high resolution. For the cross section observation, the tailing samples were prepared by cross section polishing. With the combination of these techniques, we determined the distributions of the heavy metals and metalloids in the fine particles. As a result, when the particle surfaces were observed, the detection of Pb, Sb, Fe and/or As indicated that these elements coexist or separately exist in the 1−3 μm fine particles. In the cross section observation, the concentrations of Zn and Fe were found to be different in the particles.Se obsevaron partículas finas en relaves generados a partir de la flotación de minerales. Mediante el uso de barrido de emisión de campo (FE-SEM), se observaron las partículas finas a nivel submicrónico con alta resolución. Para la observación de la sección transversal, las muestras de relaves fueron preparados por la sección pulida. Con la combinación de estas técnicas, se determinó la distribución de los metales pesados y metaloides en las partículas finas. Como resultado, cuando se observaron las superficies de las partículas, la detección de Pb, Sb, Fe como se indica que estos elementos coexisten o existen por separado en las partículas finas 1-3um. En la observación de la sección transversal, se encontró que las concentraciones de Zn y Fe diferente en las partículas

Effect of Y2O3 addition on the microstructure and mechanical properties of an Al1.8CoCrCu0.5FeNi BCC HEA

The present study investigated the influence of Y2O3 addition by mechanical alloying (MA) on the microstructure evolution of a BCC High Entropy Alloy (HEA). The characterisation and mechanical properties of the alloy were explored using X-ray diffraction, SEM, EBSD, and nano-indentation. The sintered Al1.8CoCrCu0.5FeNi HEA shows a microstructure formed by an ordered BCC phase (Al-rich) and a second disordered BCC (Cr-rich), while a minor FCC (Cu-rich) appears. These BCC phases show a wide morphology evolution from cuboidal and wave-like structures to irregular shapes. The minor FCC phase also adopts several morphologies as the MA is performed. The introduction of oxide reinforcements and microstructure refinement through mechanical alloying yields a change in phase quantification and grain structure. In accordance with the hardness and elastic modulus values from ordered/disordered BCC phases, the disordered BCC shows higher values than the ordered one. The grain size reduction as well as the solid solution strengthening from the microstructure evolution consequence of the MA are shown to be the main contributors to the increase in hardness and elastic modulus in the consolidated samples.This research was supported by the Regional Government of Madrid under the programme S2018/NMT-4381-MAT4.0-CM project. Funding from PID2019-109334RB-C32 awarded by the Spanish Ministry of Science, Innovation and Universities is also acknowledged. J. Cornide also acknowledges funding from the Spanish Ministry of Science and Innovation (IJCI-2017-31348) and TED2021-130831B-I00 funded by MCIN/AEI/10.13039/501100011033 and NextGenerationEU/PRTR. Funding for APC: Universidad Carlos III de Madrid (Read & Publish Agreement CRUE-CSIC 2023)

Programación de un centro educativo ubicado en Puente Piedra empleando la herramienta de líneas de balance

Con el pasar de los años y debido a la gran demanda en la ejecución de obras, el sector de la construcción ha aumentado la competitividad y la optimización de dicho sector, requiriendo así un mayor control de los materiales de construcción y de programación de obras, ya que son influyentes en el costo directo de una obra. Con el fin de mejorar el control y la optimización de la ejecución de obras, se desarrollaron filosofías de construcción y herramientas de planificación tal como son las Líneas de Balance, los cuales son un sistema de gestión basada en la localización que nos permite visualizar, de una manera muy amigable y eficiente, el ritmo de trabajo con el cual se deben de realizar todas las actividades, la interacción entre las mismas y el impacto que puede conllevar el retraso o adelanto de una actividad sobre la actividad antecedente o consecuente. Por tal motivo, el presente proyecto de investigación desarrolla su atención en la aplicación de la metodología de programación de un proyecto con Líneas de Balance, aplicado en la construcción de un Centro Educativo de 2 niveles. Para ello, en primer lugar, se define el avance y rendimiento de las cuadrillas de trabajo para el desarrollo de las actividades seleccionadas. Asimismo, se identifican y eliminan los conflictos generados por los cuellos de botella. Luego, se realizan las Líneas de Balance y se comprueba la teoría de considerar dicha herramienta como una forma más simple y fácil de evaluar en comparación al diagrama Gantt. Por último, se analiza el beneficio del uso de las Líneas de Balance en nuevos proyectos de edificaciones

Symptom cluster analysis of long COVID-19 in patients discharged from the Temporary COVID-19 Hospital in Mexico City.

INTRODUCTION: Several reports have emerged describing the long-term consequences of COVID-19 and its effects on multiple systems. METHODS: As further research is needed, we conducted a longitudinal observational study to report the prevalence and associated risk factors of the long-term health consequences of COVID-19 by symptom clusters in patients discharged from the Temporary COVID-19 Hospital (TCH) in Mexico City. Self-reported clinical symptom data were collected via telephone calls over 90 days post-discharge. Among 4670 patients, we identified 45 symptoms across eight symptom clusters (neurological; mood disorders; systemic; respiratory; musculoskeletal; ear, nose, and throat; dermatological; and gastrointestinal). RESULTS: We observed that the neurological, dermatological, and mood disorder symptom clusters persisted in >30% of patients at 90 days post-discharge. Although most symptoms decreased in frequency between day 30 and 90, alopecia and the dermatological symptom cluster significantly increased (p < 0.00001). Women were more prone than men to develop long-term symptoms, and invasive mechanical ventilation also increased the frequency of symptoms at 30 days post-discharge. CONCLUSION: Overall, we observed that symptoms often persisted regardless of disease severity. We hope these findings will help promote public health strategies that ensure equity in the access to solutions focused on the long-term consequences of COVID-19

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Zoonosis, cambio climático y sociedad

La sociedad contemporánea se enfrenta a uno de los retos más grandes de la historia humana, el calentamiento global, mismo que acarrea enormes consecuencias, tales como los disturbios climáticos, así como los patrones de las enfermedades de origen animal transmisibles al hombre. Precisamente ante este escenario las instituciones educativas de nivel superior deben dar cumplimiento a su responsabilidad y ser las generadoras de alternativas de solución mediante el trabajo especializado de investigación; y para ello, la pesquisa científica es la mejor de las alternativas a nuestro alcance para comprender y encarar estos desafíos.Universidad Autónoma del Estado de México y Ediciones y Gráficos Eón, S.A. de C.V

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació