Development of carbon fiber acrylonitrile styrene acrylate composite for large format additive manufacturing

The increasing interest of Large Format Additive Manufacturing (LFAM) technologies in various industrial sectors mainly lies on the attainable production of pieces reaching several cubic meters. These new technologies require the development of optimized materials with two-folded capabilities, able to satisfy functional in-service requirements but also showing a proper printability. Acrylonitrile Styrene Acrylate (ASA) is among the most interesting thermoplastic materials to be implemented in a LFAM device due to its excellent wettability and mechanical properties. This research focuses on the development and characterization of ASA and carbon fiber (CF) ASA composites suitable for LFAM. The rheological, thermal and mechanical properties of neat ASA and ASA containing 20 wt% CF are addressed. The results evidence the higher performance of the CF loaded composite compared to the raw ASA polymer (i.e., the 20 wt% CF composite shows a 350% increase in flexural Young's Modulus and a 500% increment in thermal conductivity compared with neat ASA). Additionally, both materials were successfully printed along perpendicular directions (X and Z), showing the maximum tensile strain for the composite printed along the X orientation as was expected. The results of the flexural tests are comparable or slightly higher than those of injected parts. Finally, the fracture surface was analysed, identifying different types of porosity

Coyuntura y problemática jurídica de las ayudas estatales en los aeropuertos regionales europeos

The significance of the chosen topic resides on the air transport sector transcendence, more specifically the airport sector, which it has got relevance in the European Union economical and social development. The role of this transport means and their infrastructures are crucial for the achievement of the European Union´s objectives set in their own Treaties. These ones are concerning accessibility and territorial connection, as well as the development of disadvantaged regions. Small and secondary airports could be the key of this development. In accordance to the previously mentioned, these airports present difficulties to achieve a sufficient economical return to survive. European Union aspires to an open market fully focused on free competition; despite they possess a limited market power with respect to its users due to their low passenger traffic volume and low capacity. However European Union is aware of this conflict and the difficulty of reaching a healthy free competition market without a public intervention. For this reason, European Union concentrates their efforts into their prerogatives in competition issue with the aim to optimally control of State aids and to avoid not affected the domestic market. This work is based in the European Commision's previous decisional practice, as well as in the previous Guidelines. In the same way, it proposes a critical view of how State members can finance their airports and users according to new civil aviation and services of general economic interest

As regras de René Descartes aplicadas aos regulamentos contábeis. Representação fiel da informação.

René Descartes puts the reason on the individual. For him, knowledge is not based solely on experience or practice, knowledge acquired in this way does not reveal the truth, whereas if it is obtained by reason it does. In this order of ideas, for Descartes, knowledge must have as its main quality the evidence or certainty, discards the experience, which is why he sought rules to lead to reason and thus be able to reveal truths. Descartes developed the principle of, mathematicalization of philosophical research, which consisted of ordering according to a method four rules or postulates which are: Evidence, analysis, deduction and verification, they can be linked with the International Financial Reporting Standards to help the faithful representation of financial information.René Descartes sitúa la razón sobre el individuo. Para él, el conocimiento no se basa solo en la experiencia o en la práctica, el conocimiento adquirido de esta manera no revela la verdad; solo el que se obtiene mediante la razón. En este orden de ideas, para Descartes, el conocimiento debe tener como principal cualidad la evidencia o certeza, motivo por el cual buscó reglas para conducir a la razón y, de este modo, poder revelar verdades. Descartes desarrolló el principio de matematización de la investigación filosófica, el cual consistió en ordenar, según un método, cuatro reglas o postulados: Evidencia, análisis, deducción y comprobación. Las cuales se pueden vincular con las Normas Internacionales de Información Financiera para ayudar a la representación fiel de la información financiera.René Descartes coloca a razão no indivíduo. Para ele, o conhecimento não se baseia apenas na experiência ou na prática, o conhecimento adquirido dessa forma não revela a verdade, enquanto que se obtém pela razão que o faz. Nessa ordem de ideias, para Descartes, o conhecimento deve ter como principal qualidade a evidência ou a certeza, descarta ndo a experiência, razão pela qual buscou regras para levar à razão e, assim, ser capaz de revelar verdades. Descartes desenvolveu o princípio da.mathização da pesquisa filosófica, que consistia em ordenar de acordo com um método quatro regras ou postulados que são: Evidências, análises, dedução e verificação, eles podem ser vinculados com as Normas Internacionais de Relatórios Financeiros para ajudar a representação fiel das informações financeiras

New Morphiceptin Peptidomimetic Incorporating (1S,2R,3S,4S,5R)-2-Amino-3,4,5-trihydroxycyclopen-tane-1-carboxylic acid: Synthesis and Structural Study

We present the synthesis and structural study of a new peptidomimetic of morphiceptin, which can formally be considered as the result of the replacement of the central proline residue of this natural analgesic drug with a subunit of (1S,2R,3S,4S,5R)-2-amino-3,4,5-trihydroxycyclopentane-1-carboxylic acid, previously obtained from L-idose. An optimized synthesis of this trihydroxylated cispentacin derivative is also reported. Molecular docking calculations on the target receptor support a favorable role of the hydroxy substituents of the non-natural β-amino acid incorporated into the peptidomimeticThis work has received financial support from the Spanish Ministry of Science and Innovation (CTQ2009-08490), the Xunta de Galicia (Centro Singular de Investigación de Galicia, Centro singular de investigación de Galicia accreditation 2019-2022, ED431G 2019/03; Project CN2011/037, project ED431C 2018/04 and Project GRC2014/040), the Principado de Asturias (FICYT IDI/2018/000181) and the European Union (European Regional Development Fund-ERDF). Partial financial support by Arcelor Mittal (R&D-Principado de Asturias; FUO-286-18). Conicyt research fellowship to ML (PFCHA/Doctorado Nacional/2018-21180427)S

Perspectives, Metodologies i Tecnologies en el desplegament de l'educació STEM

L'educació STEM es presenta sovint com una proposta innovadora i excitant que, tant al servei de l'augment de vocacions com orientada a millorar l'alfabetització de la població en aquest àmbit, ha arribat amb força al panorama educatiu també del nostre país. Quan ens preguntem, però, com fer-ho a les aules, veiem que sovint les propostes d'educació STEM es vinculen de forma reduccionista a certes metodologies concretes (com per exemple l'aprenentatge basat en projectes) o a certes tecnologies (com ara les tecnologies programables). En fer-ho, s'està obviant que qualsevol perspectiva, metodologia o tecnologia educativa que serveixi per a millorar tant les competències de l'àmbit científic-tecnològic de l'alumnat com el seu posicionament respecte el mateix serà adient, i que en educació STEM, com en totes les propostes educatives, és important la tria de què ensenyar i com fer-ho al servei de per a què ho volem fer.STEM education is often introduced as an innovative and exciting aproach that, both in the service of increasing vocations and aimed at improving citizens' literacy in this field, has strongly reached the educational landscape of our country. When we ask ourselves, however, how to do this in the classroom, we see that STEM education initiatives are often linked to specific methodologies (such as project-based learning) or to certain technologies (such as programmable technologies) in a reductionist way. In doing so, it is being ignored that any perspective, methodology or educational technology that serves to improve both students' STEM competence and their stance towards the STEM field will be appropriate. This is because in STEM education, as in all educational proposals, it is important to choose what to teach and how to do it in the service of what for.La educación STEM se presenta a menudo como una propuesta innovadora y excitante que, ya sea al servicio del aumento de vocaciones como orientada a mejorar la alfabetización de la población en este ámbito, ha llegado con fuerza al panorama educativo también de nuestro país. Pero cuando nos preguntamos cómo hacerlo en las aulas, a menudo vemos que las propuestas de educación STEM se vinculan de forma reduccionista a ciertas metodologías concretas (como por ejemplo el aprendizaje basado en proyectos) o a ciertas tecnologías (como las tecnologías programables). Al hacerlo, se está obviando que cualquier perspectiva, metodología o tecnología educativa que sirva para mejorar tanto las competencias del ámbito científico-tecnológico del alumnado como su posicionamiento hacía el mismo será adecuado, y que en educación STEM, como en todas las propuestas educativas, es importante la elección de qué enseñar y cómo hacerlo al servicio de para qué lo queremos hacer

Recent global warming induces the coupling of dissimilar long-term sedimentary signatures in two adjacent volcanic lakes (Azores Archipelago, Portugal)

Paleoclimatological information derived from the study of lacustrine sedimentary records is not only biased by taphonomical processes but also by potential differences in the expression of climate variability in the sediments due to site-specific factors. Using a multiproxy approach (the elemental and isotopic compositions of organic matter, diatom assemblages, and marker pigments of algae and cyanobacteria), we study the different environmental signatures recorded since the Little Ice Age (LIA) in the sediments of two volcanic lakes located within the same caldera on S~ao Miguel Island (Azores Archipelago). Lake Santiago is a crater lake whose eutrophic status in the last stage of the LIA was linked to external nutrient inputs associated with this humid period. Its post-LIA evolution was forced by changes in the thermal structure of the water, which determined its degree of mixing and therefore nutrient availability through recycling from the hypolimnion. In contrast, the decadal to centennial limnological evolution of Lake Azul, a caldera lake 2.5 km from Lake Santiago, shows geochemical and micropaleontological signatures disconnected from climate variability until 1980/1990 CE due to its greater exposure to the fallout of tephra after a catastrophic eruption in c. 1290 CE. Only after 1980/1990 CE did a global warming scenario induce a common ecological restructuring of both lakes, involving the replacement of turbulence-loving algal taxa by species adapted to strengthening water column stratification. Nevertheless, this shift was relatively gradual in Lake Azul but more sudden in Lake Santiago, indicating that the local site-specific components still had an effect on the expression of climate change in the sediments. Despite the short history of anthropogenic pressure (compared to their continental counterparts) and the large atmospheric patterns operating over the Azores Archipelago, the sedimentary records of these two adjacent oceanic volcanic lakes reacted quite differently to climate changes

Diatom-inferred ecological responses of an oceanic lake system to volcanism and anthropogenic perturbations since 1290 CE

The impacts of natural- and human-induced processes on lake ecosystems in remote oceanic islands remain to be fully elucidated. These lakes are excellent candidates to analyze the importance of anthropogenic vs. natural forces driving lacustrine long-term ecological evolution from previous pristine pre-colonized conditions. Disentangling the effects of both is particularly relevant in highly active volcanic areas, where catastrophic eruptions can act as an atypical natural driver altering the lake's long-term ecological trajectories. In this paper we study past ecological changes occurring in Lake Azul (São Miguel island), a crater lake from the remote Azorean archipelago, to address which were the main causes of its long-term trophic history. We analyzed diatom assemblages, sedimentology, and bulk organic matter of sediments deposited since ca. 1290 CE, when a huge local eruption occurred. This episode drove the evolution of Lake Azul through six distinct phases, commencing with a restart of ecological succession after tephra deposition disrupted biogeochemical cycling. The alteration was so profound that the lake underwent a state of oligotrophic conditions for approx. 650 yr. Nutrients were sourced by fish-induced internal recycling and the overflow of the near Lake Verde during this period, rather than by allochthonous nutrient inputs modulated by climate variability and/or vegetation cover changes in the watershed after the official Portuguese colonization. It was only after recent artificial fertilization when the system overcame the volcanic-induced long-term resilience. This over-fertilization and a reduction in water turnover exacerbated the recent symptoms of eutrophication after 1990 CE. Contrary to other studies, Lake Azul constitutes an uncommon case of long-term resilience to trophic change induced by a cataclysmic volcanic eruption. It brings new insights into the fate of lake ecosystems which might be affected by similar events in the future

Diabetes asociada al inicio del tratamiento antirretroviral

The rise in life expectancy in HIV patients due to medical advances in antiretroviral therapy highlights the importance of chronic comorbidities and cardiovascular risk management in these patients. After their development, first Protease Inhibitors were related to metabolic adverse effects, including hyperglycemia. We present a case of a patient who developed new-onset Diabetes mellitus associated with the initiation of antiretroviral therapy with these drugs.El aumento de la esperanza de vida de los pacientes diagnosticados de VIH gracias a los avances en el tratamiento antirretroviral en los últimos años ha puesto de manifiesto la importancia de un buen control de las comorbilidades crónicas y los factores de riesgo cardiovascular en estos pacientes. Tras su aparición, los primeros inhibidores de la proteasa fueron relacionados con la aparición de efectos adversos metabólicos, entre los que destacaba la hiperglucemia. Describimos un caso de un paciente que presenta un debut diabético en relación con el inicio del tratamiento antirretroviral con estos fármacos

Impact of the historical introduction of exotic fishes on the chironomid community of Lake Azul (Azores Islands)

Little is known about the effect of top predator introduction in historically fishless communities, especially on remote islands. This issue is important because it might strongly affect climate reconstructions derived from biota assemblages such as chironomids. Head capsule larval remains of chironomids have been studied in a 660 years lacustrine sedimentary sequence from Lake Azul (Sao Miguel Island, Azores archipelago) to assess the extent and timescale of the effect of the predator introduction occurring in this historically fishless lake. Analysis of similarity showed that the chironomid assemblage was statistically different before and after predator introduction (R = 0.78; p < 0.001). Abundance of chironomids was about 40% greater in the fishless lake period compared to the period in the presence of predator. Results show major change in chironomid assemblage coinciding with the first time of goldfish introduction (around 1790 CE), followed by carp (1890 CE) and pike (1979 CE) introductions. The composition of feeding group guilds changed following a pattern characterized by a decrease in abundance of detritivorous and predaceous taxa and an increase in abundance of grazing chironomid taxa. This study suggests that predator introduction was the most important factor affecting the chironomid assemblages in this natural, Azorean fishless lake, but predators did not affect all chironomid species. Other external forcings like major climate oscillations, anthropogenic activities in the catchment basin, and volcanic eruptions seem to play an additional role. The latest stage of the warm and arid Medieval Climate Anomaly (1000-1300 CE) favoured the occurrence of some warm-adapted chironomid taxa, which were absent through the Little Ice Age (ca. 1450-1850 CE) cool period

Physical activity intervention program through walking routes in sedentary university students

Objective: Effect of a physical activity program on body composition and physical condition with university teacher students. Methods: 51 university students from the Faculty of Education and Sport Sciences, University of Vigo (Spain), participated in the study. Students performed a 6-week protocol, using the walking routes designed in the university's own facilities. Two cohorts, experimental group and control group were analyzed, before and after the program. The 6-minute walking test, countermovement jump (CMJ), flexibility through active straight leg raise, rate of perceived exhaustion (RPE) and heart rate (HR) were evaluated, and a bioimpedance measurement was used to evaluate the basal and final metabolism. Results: On the 6-minutes walking test, CMJ, and flexibility of the right leg significant differences were found between the experimental and the control group. There were no significant differences in either group for any RPE. In the bioimpedance, there were significant differences in fat and lean mass in the left leg. Conclusion: The analyzed data indicates an improvement in aerobic endurance, jumping and flexibility capacities at the end of the program. But for body composition, in general there were no significant variations