Advanced optical microscopies for materials: new trends

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/32166This article summarizes the new trends of Optical Microscopy applied to Materials, with examples of applications that illustrate the capabilities of the technique

Nanotecnología y sostenibilidad en el aula: lo pequeño al rescate de problemas globales

Reproducció del document publicat a: https://theconversation.com/nanotecnologia-y-sostenibilidad-en-el-aula-lo-pequeno-al-rescate-de-problemas-globales-184178La nanotecnología aporta a los estudiantes la posibilidad de entender y practicar tecnología y pensar en los retos globales del futuro de manera práctica y positiva

Aplicaciones de la Microscopía de Fuerza Atómica (AFM) cómo método de caracterización de polímeros

Este proyecto pretende ser una herramienta útil para el ingeniero que quiera aplicar la Microscopía de Fuerza Atómica (AFM) como técnica de caracterización de Materiales poliméricos. En primer lugar se describen algunas técnicas de caracterización superficial competitivas con el AFM, es decir el SEM y el TEM (Microscopía Electrónica) para describir seguidamente el AFM. El AFM, es una técnica que poco a poco va ganándose adeptos como herramienta útil de caracterización a nivel de topografía, dureza, adhesión, medidas in situ, etc. En el capítulo 3 se describirá la técnica, los diferentes modos y posibilidades que presenta y su uso más concreto dentro del campo de los polímeros (por ejemplo, se describe como preparar una muestra polimérica para su posterior caracterización por AFM). Para concluir este capítulo se introducirá el tema de los Biopolímeros y como el AFM puede ser una herramienta útil para caracterizarlos. Por último, en el capítulo 4 se describen algunos ejemplos para que el Ingeniero pueda ver casos prácticos donde el AFM puede ser una herramienta importante de caracterización y que además, permite solucionar problemas que aparecen en otras técnicas más comúnmente utilizadas, como por ejemplo, la microscopía óptica y electrónica. Por lo tanto, esta técnica puede ser una herramienta útil en caracterización de polímeros de interés tecnológico como el poliéster PEN (substrato en células fotovoltaicas), poliéster del ácido málico (biopolímero) o polímeros clásicos como el polipropileno (embalaje) o en estudios de adhesión matriz-polímero (Si-PEN), entre otros

Esta es la razón por la que los logros de Messi, Federer y Kipchoge no son estrictamente humanos

Reproducció del document publicat a: https://theconversation.com/esta-es-la-razon-por-la-que-los-logros-de-messi-federer-y-kipchoge-no-son-estrictamente-humanos-191694La nanotecnología da alas a los deportistas, y una potencia que raya el dopaj

Talleres de divulgación científica, una herramienta para la comunicación de la ciencia e ingeniería de materiales

Los talleres de divulgación científica son excelentes escaparates para comunicar ciencia de una manera entretenida sin perder el rigor científico. En las edades educativas de primaria y secundaria se fomentan las vocaciones científicas y en edades preuniversitarias se promueven futuras carreras científicas en ciencia e ingeniería de materiales. Se presenta en este trabajo un breve resumen de un taller que intenta cumplir estos dos objetivos

Comparative effects of macro-sized aluminum oxide and aluminum oxide nanoparticles on erythrocyte hemolysis: influence of cell source, temperature and size

Al2O3 is the most abundantly produced nanomaterial and has been used in diverse fields, including the medical, military and industrial sectors. As there are concerns about the health effects of nanoparticles, it is important to understand how they interact with cells, and specifically with red blood cells. The hemolysis induced by three commercial nano-sized aluminum oxide particles (nanopowder 13 nm, nanopowder <50 nm and nanowire 2-6 nm × 200-400 nm) was compared to aluminum oxide and has been studied on erythrocytes from humans, rats and rabbits, in order to elucidate the mechanism of action and the influence of size and shape on hemolytic behavior. The concentrations inducing 50% hemolysis (HC50) were calculated for each compound studied. The most hemolytic aluminum oxide particles were of nanopowder 13, followed by nanowire and nanopowder 50. The addition of albumin to PBS induced a protective effect on hemolysis in all the nano-forms of Al2O3, but not on Al2O3. The drop in HC50 correlated to a decrease in nanomaterial size, which was induced by a reduction of aggregation Aluminum oxide nanoparticles are less hemolytic than other oxide nanoparticles, and behave differently depending on the size and shape of the nanoparticles. The hemolytic behavior of aluminum oxide nanoparticles differs from that of aluminum oxide

Assessing anodic microbial populations and membrane ageing in a pilot microbial electrolysis cell

Bioelectrochemical system[EN] First large-scale experiences of bioelectrochemical systems (BES) are underway. However, there is still little knowledge on how the different elements that integrate a BES behave in near real-life conditions. This paper aims at assessing the impact of long-term operation on the cation exchange membrane and on the anodic biofilm of two 16 L Microbial Electrolysis Cells (MEC) designed for hydrogen production and ammonia recovery from pig slurry. Membrane deterioration was examined by physical, chemical and microscopy techniques at different locations, revealing a strong attachment of microorganisms and a significant decay in membrane properties such as ion exchange capacity and thermal stability. Anode microbial communities did not show a dramatic shift in the eubacteria composition at different sampling areas, although the relative abundance of some bacterial groups showed a clear vertical stratification. After 100 days of continuous operation, MEC performance did not declined significantly maintaining ammonium transport rates and H2 production rates of 15.3 gN d−1 m−2 and 0.2 LH2·L−1reactor·d−1 respectively.SIMinisterio de Economía y CompetitividadJunta de Castilla y LeónMinisterio de Educación, Cultura y Deport

Microbial community dynamics in two-chambered microbial fuel cells: effect of different ion exchange membranes

The utilization of different kinds of ion exchange membrane is a common practice in bioelectrochemical systems such as two-chambered microbial fuel cells (MFCs). However, little is known on the effect of the membrane materials on the anodic microbial community diversity.ResultsThe effect of two cationic and one anionic exchange membranes (Nafion N-117, Ultrex CMI-7000, and Ultrex AMI-7000) on the microbial community dynamics of Eubacteria and Archaea has been assessed in two-chambered MFCs. The experimental results indicated that the eubacterial community in the anodic chamber was not affected by the membrane materials, being predominant populations of Bacteroidetes (Porphyromonadaceae) and β-proteobacteria (Alcaligenaceae and Comamonadaceae). On the other hand, the archaeal counterpart appears to be highly dependent on the type of membrane used, as it was evidenced by the selective enrichment of Methanosarcina sp. in the MFC equipped with the membrane Nafion N-117 which was the MFC that showed the highest current production.Conclusions The results obtained in the present study suggest that membrane materials affect archaeal diversity whereas both anodofilic eubacteria and methanogenic archaea populations could play an important role on the overall MFC process performance

Feasibility of an online antigen self-testing strategy for SARS-CoV-2 addressed to health care and education professionals in Catalonia (Spain). The TESTA’T- COVID Project

We aimed to assess the feasibility of TESTA'T COVID strategy among healthcare and education professionals.in Spain during the peak of the 6th wave caused by Omicron variant. Kits were ordered online and sent by mail, participants answered an online acceptability/usability survey and uploaded the picture of results. 492 participants ordered a test, 304 uploaded the picture (61.8%). Eighteen positive cases were detected (5.9%). 92.2% were satisfied/very satisfied with the intervention; and 92.5% found performing the test easy/very easy. We demonstrated that implementing online COVID-19 self-testing in schools and healthcare settings in Spain is feasible

The Traspena meteorite: heliocentric orbit, atmospheric trajectory, strewn field, and petrography of a new L5 ordinary chondrite

The Traspena meteorite fell on 2021 January 18 about 20 km south-east of the city of Lugo (Galiza, Spain), shortly after a huge and bright fireball crossed the sky for 4.84 s. Astrometric measurements obtained from the fireball cameras of the Universidade de Santiago de Compostela (USC) as well as from many casual videos were used to determine the atmospheric trajectory of this meteoroid which penetrated the atmosphere and generated sound waves that were detected at three seismic stations. The original meteoroid had a diameter of about 1.15 m and a mass around 2620 kg. It impacted the Earth’s atmosphere with a steep entry angle of about 76∘.7 from a height of 75.10 km until fading away at 15.75 km with a velocity of 2.38 km s−1. Before the impact, this small asteroid was orbiting the Sun with a semimajor axis of 1.125 au, a moderate eccentricity of 0.386, and a low inclination of 4∘.55. A weak evidence of dynamic link with the PHA (Potential Hazardous Asteroid) Minos was investigated. During the atmospheric entry, two major fragmentation events occurred between heights of 35 and 29 km at aerodynamic pressures between 1 and 5 MPa. The strewn field was computed after calculating the individual dark flights of the main body along with two smaller fragments. Fortunately, 2 month after the superbolide, a 527-g meteorite was found. It was examined using several geochemical and petrographic analyses which allowed us to classify it as a moderately shocked (S3) L5 ordinary chondrite with a bulk density of 3.25 g cm−3This paper was supported by the Xunta de Galicia (Spain) under the ED431B 2020/38 grantS