174 research outputs found

    A Machine Learning Approach to Monitor Air Quality from Traffic and Weather data

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    Knowing the amount of air pollutants in our cities is of great importance to help decision makers in the definition of effective strategies aimed at maintaining a good air quality, which is a key factor for a healthy life, especially in urban environments. Using a data set from a big metropolitan city, we realize the uAQE: urban Air Quality Evaluator, which is a supervised machine learning model able to estimate air pollutants values using only weather and traffic data. We evaluate the performance of our solution by comparing the predicted pollutant values with the real measurements provided by professional air monitoring stations. We use the predicted pollutants to compute a standard Air Quality Index (AQI) and we map it into a set of five qualitative AQI classes, which can be used for decision making at the city level. uAQE is able to predict the AQI class value with an accuracy of 0.8

    Aeroservoelastic Wind-Tunnel Tests of a Free-Flying, Joined-Wing SensorCraft Model for Gust Load Alleviation

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    A team comprised of the Air Force Research Laboratory (AFRL), Boeing, and the NASA Langley Research Center conducted three aeroservoelastic wind-tunnel tests in the Transonic Dynamics Tunnel to demonstrate active control technologies relevant to large, exible vehicles. In the first of these three tests, a full-span, aeroelastically scaled, wind-tunnel model of a joined-wing SensorCraft vehicle was mounted to a force balance to acquire a basic aerodynamic data set. In the second and third tests, the same wind-tunnel model was mated to a new, two-degree-of-freedom, beam mount. This mount allowed the full-span model to translate vertically and pitch. Trimmed flight at -10% static margin and gust load alleviation were successfully demonstrated. The rigid body degrees of freedom required that the model be own in the wind tunnel using an active control system. This risky mode of testing necessitated that a model arrestment system be integrated into the new mount. The safe and successful completion of these free-flying tests required the development and integration of custom hardware and software. This paper describes the many systems, software, and procedures that were developed as part of this effort. The balance and free ying wind-tunnel tests will be summarized. The design of the trim and gust load alleviation control laws along with the associated results will also be discussed

    Microstructure-sensitive fatigue modelling of medical-grade fine wire

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    This work presents a modelling methodology to assess the sensitivity to microstructure in high‐cycle fatigue performance of fine wires made from MP35N alloy (35Ni‐35Co‐20Cr‐10Mo in wt%) used as conductors in cardiac leads. The model consists of a microstructure generator that creates a mesh of a statistically representative microstructure, a finite element analysis using a crystal plasticity constitutive model to determine the local response behaviour of the microstructure, and a postprocesser using fatigue indicating parameters to assess the likelihood of fatigue crack initiation. The fatigue crack initiation potency for selected microstructure attributes, boundary and interface conditions, and loading profiles is determined by computing the Fatemi‐Socie fatigue indicating parameter over a physically relevant volume of scale. Case studies are used to investigate (1) the influence of nonmetallic inclusion proximity to the wire surface on fatigue potency and (2) the transition life demarcating lives primarily controlled by fatigue crack initiation versus microcrack fatigue growth

    Crack tip microplasticity mediated by microstructure gradients

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    Traditional fracture theories infer damage at cracks (local field) by surveying loading conditions away from cracks (far field). This approach has been successful in predicting ductile fracture, but it normally assumes isotropic and homogeneous materials. However, myriads of manufacturing procedures induce heterogeneous microstructural gradients that can affect the accuracy of traditional fracture models. This work presents a microstructure-sensitive finite element approach to explore the shielding effects of grain size and crystallographic orientation gradients on crack tip microplasticity and blunting. A dislocation density-based crystal plasticity model conveys texture evolution, grain size effects, and directional hardening by computing the constraint from dislocation structures. The results demonstrate that the microstructure can act as a buffer between the local and far fields that affects the crack tip microplasticity variability. For nominal opening loading, grain size and texture affect the local ductility and induce a non-negligible multiaxial plastic deformation. Furthermore, driving forces based on measuring displacements away from the crack tip are less affected by the microstructure, which suggests that traditional experimental methods smear out important crack tip variability

    Effect of polyethylene microplastics on activated sludge process Accumulation in the sludge and influence on the process and on biomass characteristics

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    [EN] According to previous research, it has been proved that wastewater treatment plants (WWTPs) can retain more than 90 % of the MPs contained in wastewater. However, a significant fraction of the MPs removed in WWTPs is retained in the sludge floc and this may lead to an environmental issue since biosolids can be used as fertilizers. The purpose of this research was to evaluate how the presence of polyethylene (PE) could interfere with the activated sludge performance. For this, a sequencing batch reactor (SBR) was continuously fed during 93 days with synthetic sewage and PE microbeads. It was observed that 98 +/- 2% of the total amount of MPs that entered SBR was accumulated in the activated sludge. Despite the high accumulation of MPs in the sludge, the depuration performance of the reactor was not compromised. However, the presence of MPs decreased the richness (Chao1) and abundance-based coverage estimators (ACE) and diversity (Shannon) of the bacterial community on day 93. Based on the analysis of the diversity indices and the relative abundances of microbial taxa, it was concluded that MPs had selective effects on activated sludge microbial community. However, MPs did not affect the abundance of nitrifying and denitrifying bacteria in the sludge.Authors thank the Spanish Ministry of Science, Innovation and Universities for the financial support (Reference of the project: RTI2018-096916-B-I00)Alvim, CB.; Castelluccio, S.; Ferrer-Polonio, E.; Bes-Piá, M.; Mendoza Roca, JA.; Fernández-Navarro, J.; Alonso Molina, JL.... (2021). Effect of polyethylene microplastics on activated sludge process Accumulation in the sludge and influence on the process and on biomass characteristics. Process Safety and Environmental Protection. 148:536-547. https://doi.org/10.1016/j.psep.2020.10.01453654714

    Aeroservoelastic Wind-Tunnel Test of the SUGAR Truss Braced Wing Wind-Tunnel Model

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    The Subsonic Ultra Green Aircraft Research (SUGAR) Truss-Braced Wing (TBW) aeroservoelastic (ASE) wind-tunnel test was conducted in the NASA Langley Transonic Dynamics Tunnel (TDT) and was completed in April, 2014. The primary goals of the test were to identify the open-loop flutter boundary and then demonstrate flutter suppression. A secondary goal was to demonstrate gust load alleviation (GLA). Open-loop flutter and limit cycle oscillation onset boundaries were identified for a range of Mach numbers and various angles of attack. Two sets of control laws were designed for the model and both sets of control laws were successful in suppressing flutter. Control laws optimized for GLA were not designed; however, the flutter suppression control laws were assessed using the TDT Airstream Oscillation System. This paper describes the experimental apparatus, procedures, and results of the TBW wind-tunnel test. Acquired system ID data used to generate ASE models is also discussed.2 study

    Autoinforme de adolescentes ADA: manual de aplicación, corrección e interpretación

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    Es conocida la idea de Wordsworth (1770-1850) de que el niño es el padre del hombre, frase que se convierte en sentencia si a ese niño y a ese adolescente no se lo considera más allá de las fronteras delineadas por las creencias imperantes histórica, social y familiarmente. Ese es, en ciernes, el adulto que devendrá por cada vez más años, según el aumento de la expectativa de vida, por tanto, toda acción que emprendamos para procurar esclarecer e intervenir en etapas tempranas, supone una apuesta fuerte a descender sus problemas en salud mental, sus conflictos familiares y sociales, los costes que de ellos devienen y por, sobre todo, aumentar sus posibilidades de bienestar para tanto tiempo por vivir. Cuando comenzamos a trabajar hace años en el ámbito de la clínica con niños y adolescentes y posteriormente con adultos, fuimos viendo con claridad cómo esa frase de Wordsworth se iba dibujando en la vida de las personas que atendíamos, tomando forma de tristeza hasta llegar a la desesperanza, miedo tan atrapante que impedía tanto y le abroquelaba tras múltiples corazas y defensas, ansiedad que lo volvían desdichado, ira que lo hacían cometer actos violentos aún con los que aseguraba amar, desajuste y falta de adaptación porque pensaba tan diferente y así sentía y no entendía y no se entendía. Recorrimos varios trechos del camino junto a esas y otras formas de sufrimiento psíquico y eso nos impulsó a buscar estrategias de evaluación más rápidas y eficientes, a indagar sobre cómo la ciencia explicaba lo que ocurría y en tanto seguir intentando atisbar alguna luz que ayude a quien padece y al profesional que le atiende. Así nace este desarrollo instrumental, en habla hispana, al sur de las Américas, con el apoyo de mucha gente y con el expertís que nos proveyó el equipo de investigación de la Prof. López Soler en la Universidad de Murcia y la generosidad académica que distingue a muchos de nuestros colegas. En una imperdible entrevista realizada a Sir Michel Rutter en 2008 en la Universidad de Oxford por los profesores Tansey e Iversen, recorriendo su historia académica y su trabajo en la isla de Wight, su reconocidísimo aporte al esclarecimiento de los trastornos del espectro autista, nos muestra una de sus fortalezas cuando dice que en ciencia se necesita cuestionar los propios hallazgos “despiadadamente”, preguntándose reiteradamente sobre la evidencia y las formas de encontrarla, sin dejar de hacer lugar para lo inesperado. Este desarrollo instrumental sigue esas premisas de Rutter y así se fueron edificando las bases conceptuales, buscando evidencias que pudiéramos transformar en reactivos, en esa encrucijada, de la que habla Rutter, entre lo psicosocial, lo biológico, lo clínico y la investigación académica, atendiendo a lo posible, creando un espacio para lo impensado, y al final contar con una forma de indagar sobre el sufrimiento psíquico de los adolescentes y también sobre su resiliencia y bienestar. Fue un camino largo, de muchas idas y vueltas, pero donde aprendimos tanto y de tantas personas, en especial de los jóvenes que, con esa franca generosidad que les caracteriza, nos hicieron partícipes de su mirada y sus confidencias. Mayor y mejor razón es difícil de encontrar.Para acceder a los Cuestionarios, Encuesta sociodemográfica y Consentimiento del Protocolo ADA, el profesional que así lo desee podrá solicitarlo a [email protected] brindando información básica para realizar el envío
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