71 research outputs found
Estudio de modelos multifísicos para la simulación holística y concurrente de circuitos impresos
La tesis titulada Estudio de Modelos Multifísicos para la Simulación Holística y Concurrente de Circuitos Impresos ha consistido en un análisis teórico y práctico sobre la viabilidad del modelado térmico y electromagnético, compatible con estructuras holísticas, para la simulación multifísica de circuitos impresos, que permita reproducir lo más fielmente posible su comportamiento térmico y electromagnético de forma concurrente. En este trabajo se han cubierto las siguientes etapas:
1. Estudio de diferentes modelos para la conducción, convección y radiación térmica en cuerpos simples de composición material homogénea, aplicables a la transmisión de calor unidireccional, así como su implementación en MATLAB/SIMULINK.
2. Estudio de técnicas para el modelado holístico (con un mínimo de 2 niveles) de cuerpos complejos de composición material heterogénea, a partir de los modelos simples implementados previamente sobre MATLAB/SIMULINK, que incluya la transferencia calorífica multidireccional y la visualización gráfica tridimensional.
3. Estudio de los modelos eléctricos y magnéticos, aplicables tanto a baja como a alta frecuencia, de componentes activos y pasivos, así como de los diferentes elementos de conexión de una placa de circuito impreso, pistas, áreas de soldadura, taladros metalizados, etc., y su implementación sobre el entorno MATLAB/SIMULINK.
4. Estudio de integración entre aplicaciones software de simulación que permitan una aproximación al ideal de la simulación multifísica concurrente de circuitos impresos.
De forma general, todos estos estudios y las implementaciones software surgidas de ellos se han complementado con sus correspondientes análisis de validez, mediante ensayos físicos y/o simulados realizados sobre prototipos y/o modelos que, a modo de probetas, han permitido contrastar los resultados de las pruebas originales realizadas sobre los modelos holísticos desarrollados. Fruto de estos trabajos se han obtenido varias publicaciones en congresos internacionales y revistas indexadas
Desarrollo de equipos electrónicos para su uso docente en materias tecnológicas: un caso práctico
El coste de algunos equipos electrónicos que se emplean en la docencia práctica de materias de tipo tecnológico impide en ocasiones la dotación completa de los laboratorios. Se plantea en este artículo un caso práctico de diseño y construcción de un prototipo de equipo electrónico para su uso en prácticas de asignaturas en las cuales se precise experimentar con la utilización de variadores electrónicos de velocidad. Los resultados obtenidos permiten asegurar que para determinados casos es posible desarrollar equipos de carácter didáctico que realizan funciones similares a los dispositivos industriales, a un coste sensiblemente inferior, obviando, por supuesto, el coste de desarrollo
Honey Bee Colonies Remote Monitoring System
Bees are very important for terrestrial ecosystems and, above all, for the subsistence of many
crops, due to their ability to pollinate flowers. Currently, the honey bee populations are decreasing
due to colony collapse disorder (CCD). The reasons for CCD are not fully known, and as a result, it is
essential to obtain all possible information on the environmental conditions surrounding the beehives.
On the other hand, it is important to carry out such information gathering as non-intrusively as
possible to avoid modifying the bees’ work conditions and to obtain more reliable data. We designed
a wireless-sensor networks meet these requirements. We designed a remote monitoring system
(called WBee) based on a hierarchical three-level model formed by the wireless node, a local data
server, and a cloud data server. WBee is a low-cost, fully scalable, easily deployable system with
regard to the number and types of sensors and the number of hives and their geographical distribution.
WBee saves the data in each of the levels if there are failures in communication. In addition, the nodes
include a backup battery, which allows for further data acquisition and storage in the event of
a power outage. Unlike other systems that monitor a single point of a hive, the system we present
monitors and stores the temperature and relative humidity of the beehive in three different spots.
Additionally, the hive is continuously weighed on a weighing scale. Real-time weight measurement
is an innovation in wireless beehive—monitoring systems. We designed an adaptation board to
facilitate the connection of the sensors to the node. Through the Internet, researchers and beekeepers
can access the cloud data server to find out the condition of their hives in real time
AMIGaS - Motivational Activities for Gender Equality in STEM
En el marco del proyecto de innovación docente, se han realizado una serie de actividades de promoción de la mujer en estudios y empleos de disciplinas STEM, acrónimo de los términos en inglés Science, Technology, Engineering and Mathematics (Ciencia, Tecnología, Ingeniería y Matemáticas). El objetivo ha sido contribuir a que las mujeres puedan obtener mejores oportunidades de trabajo y no se mantengan alejadas de los cambios económicos y sociales que conllevará la industria del futuro, marcada por la convergencia de tecnologías digitales, físicas y biológicas, y que cambiará el mundo tal y como lo conocemos. Para ello se han realizado una serie de seminarios que han consistido en apoyar la participación de mujeres en el ámbito científico-tecnológico. Consiguiendo una concepción del alumnado femenino de las disciplinas de Ciencia e Ingeniería sobre el trabajo que desempeñan mujeres cuyas trayectorias profesionales son de alta relevancia en el ámbito tecnológico. Con esta propuesta se ha contribuido a la lucha contra los estereotipos y que el acceso de la mujer a estas materias crezca al mismo nivel al que es demandado, ya que la tecnología se encuentra en todos los niveles de la sociedad actual.Within the framework of the educational innovation project, a series of activities have been carried out to promote women in studies and jobs in STEM disciplines, an acronym for Science, Technology, Engineering, and Mathematics. The aim has been to help women to obtain better job opportunities and not to stay away from the economic and social changes that the industry of the future, marked by the convergence of digital, physical and biological technologies, will bring, will bring, and will change the world as we know it. To this end, a series of seminars have been held which have consisted of supporting the participation of women in the scientific-technological field. Achieving a conception of the female student body of the disciplines of Science and Engineering on the work carried out by women whose professional trajectories are of high relevance in the technological field. This proposal has contributed to the fight against stereotypes and to ensure that women's access to these subjects grows to the same level as that at which they are demanded since technology is found at all levels of today's society
Oral Anticoagulation and Risk of Symptomatic Hemorrhagic Transformation in Stroke Patients Treated With Mechanical Thrombectomy: Data From the Nordictus Registry
Introduction: We aimed to evaluate if prior oral anticoagulation (OAC) and its type determines a greater risk of symptomatic hemorrhagic transformation in patients with acute ischemic stroke (AIS) subjected to mechanical thrombectomy. Materials and
Methods: Consecutive patients with AIS included in the prospective reperfusion registry NORDICTUS, a network of tertiary stroke centers in Northern Spain, from January 2017 to December 2019 were included. Prior use of oral anticoagulants, baseline variables, and international normalized ratio (INR) on admission were recorded. Symptomatic intracranial hemorrhage (sICH) was the primary outcome measure. Secondary outcome was the relation between INR and sICH, and we evaluated mortality and functional outcome at 3 months by modified Rankin scale. We compared patients with and without previous OAC and also considered the type of oral anticoagulants.
Results: About 1.455 AIS patients were included, of whom 274 (19%) were on OAC, 193 (70%) on vitamin K antagonists (VKA), and 81 (30%) on direct oral anticoagulants (DOACs). Anticoagulated patients were older and had more comorbidities. Eighty-one (5.6%) developed sICH, which was more frequent in the VKA group, but not in DOAC group. OAC with VKA emerged as a predictor of sICH in a multivariate regression model (OR, 1.89 [95% CI, 1.01–3.51], p = 0.04) and was not related to INR level on admission. Prior VKA use was not associated with worse outcome in the multivariate regression model nor with mortality at 3 months.
Conclusions: OAC with VKA, but not with DOACs, was an independent predictor of sICH after mechanical thrombectomy. This excess risk was associated neither with INR value by the time thrombectomy was performed, nor with a worse functional outcome or mortality at 3 months
Sex differences between women and men with COPD: A new analysis of the 3CIA study
Background: There is partial evidence that COPD is expressed differently in women than in men, namely on symptoms, pulmonary function, exacerbations, comorbidities or prognosis. There is a need to improve the characterization of COPD in females.
Methods: We obtained and pooled data of 17 139 patients from 22 COPD cohorts and analysed the clinical differences by sex, establishing the relationship between these characteristics in women and the prognosis and severity of the disease. Comparisons were established with standard statistics and survival analysis, including crude and multivariate Cox-regression analysis.
Results: Overall, 5355 (31.2%) women were compared with men with COPD. Women were younger, had lower pack-years, greater FEV1%, lower BMI and a greater number of exacerbations (all p < 0.05). On symptoms, women reported more dyspnea, equal cough but less expectoration (p < 0.001). There were no differences in the BODE index score in women (2.4) versus men (2.4) (p = 0.5), but the distribution of all BODE components was highly variable by sex within different thresholds of BODE. On prognosis, 5-year survival was higher in COPD females (86.9%) than in males (76.3%), p < 0.001, in all patients and within each of the specific comorbidities that we assessed. The crude and adjusted RR and 95% C.I. for death in males was 1.82 (1.69–1.96) and 1.73 (1.50–2.00), respectively.
Conclusions: COPD in women has some characteristic traits expressed differently than compared to men, mainly with more dyspnea and COPD exacerbations and less phlegm, among others, although long-term survival appears better in female COPD patients
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
Relationship between olive oil consumption and ankle-brachial pressure index in a population at high cardiovascular risk
The aim of this study was to ascertain the association between the consumption of different categories of edible olive oils (virgin olive oils and olive oil) and olive pomace oil and ankle-brachial pressure index (ABI) in participants in the PREDIMED-Plus study, a trial of lifestyle modification for weight and cardiovascular event reduction in individuals with overweight/obesity harboring the metabolic syndrome.
Methods: We performed a cross-sectional analysis of the PREDIMED-Plus trial. Consumption of any category of olive oil and olive pomace oil was assessed through a validated food-frequency questionnaire. Multivariable linear regression models were fitted to assess associations between olive oil consumption and ABI. Additionally, ABI ≤1 was considered as the outcome in logistic models with different categories of olive oil and olive pomace oil as exposure.
Results: Among 4330 participants, the highest quintile of total olive oil consumption (sum of all categories of olive oil and olive pomace oil) was associated with higher mean values of ABI (beta coefficient: 0.014, 95% confidence interval [CI]: 0.002, 0.027) (p for trend = 0.010). Logistic models comparing the consumption of different categories of olive oils, olive pomace oil and ABI ≤1 values revealed an inverse association between virgin olive oils consumption and the likelihood of a low ABI (odds ratio [OR] 0.73, 95% CI [0.56, 0.97]), while consumption of olive pomace oil was positively associated with a low ABI (OR 1.22 95% CI [1.00, 1.48]).
Conclusions: In a Mediterranean population at high cardiovascular risk, total olive oil consumption was associated with a higher mean ABI. These results suggest that olive oil consumption may be beneficial for peripheral artery disease prevention, but longitudinal studies are needed
Mortality prediction in chronic obstructive pulmonary disease comparing the GOLD 2015 and GOLD 2019 staging: a pooled analysis of individual patient data
In 2019, The Global Initiative for Chronic Obstructive Lung Disease (GOLD) modified the grading system for patients with COPD, creating 16 subgroups (1A–4D). As part of the COPD Cohorts Collaborative International Assessment (3CIA) initiative, we aim to compare the mortality prediction of the 2015 and 2019 COPD GOLD staging systems.
We studied 17 139 COPD patients from the 3CIA study, selecting those with complete data. Patients were classified by the 2015 and 2019 GOLD ABCD systems, and we compared the predictive ability for 5-year mortality of both classifications.
In total, 17 139 patients with COPD were enrolled in 22 cohorts from 11 countries between 2003 and 2017; 8823 of them had complete data and were analysed. Mean±sd age was 63.9±9.8 years and 62.9% were male. GOLD 2019 classified the patients in milder degrees of COPD. For both classifications, group D had higher mortality. 5-year mortality did not differ between groups B and C in GOLD 2015; in GOLD 2019, mortality was greater for group B than C. Patients classified as group A and B had better sensitivity and positive predictive value with the GOLD 2019 classification than GOLD 2015. GOLD 2015 had better sensitivity for group C and D than GOLD 2019. The area under the curve values for 5-year mortality were only 0.67 (95% CI 0.66–0.68) for GOLD 2015 and 0.65 (95% CI 0.63–0.66) for GOLD 2019
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