Vibration-based adaptive novelty detection method for monitoring faults in a kinematic chain

Postprint (published version

Vigilância da Gripe em Portugal no inverno 2013/2014

Introdução: O Programa Nacional de Vigilância da Gripe tem como objetivos: recolha, análise e divulgação da informação sobre a atividade gripal em Portugal. A vigilância clínica e laboratorial possibilita a determinação semanal das taxas de incidência de síndroma gripal (SG), identificação/ caracterização do vírus influenza, deteção de surtos, vírus emergentes com potencial pandémico e risco para a saúde pública. Foi analisada e descrita a atividade gripal em Portugal, na época de 2013/2014. Materiais e Métodos: Em 2013/2014, colaboraram: a Rede de Médicos-Sentinela (Rede MS), possibilitando o cálculo da taxa de incidência da síndroma gripal. Na componente laboratorial, colaboram Rede MS, Rede de Serviços-Urgência, médicos projeto-EuroEVA e Rede Portuguesa Laboratórios Diagnóstico Gripe com envio de amostras respiratórias para pesquisa/caraterização do vírus influenza. Resultados: Em 2013/2014, a atividade gripal foi moderada. O período epidémico ocorreu entre as semanas 1/2014 e 8/2014, valor máximo 80,7 casos SG / 100000 habitantes na semana 4/2014. A análise laboratorial a 869 exsudados-nasofaringe permitiu a identificação do vírus influenza em 467 (54%) casos de SG. Destes, 460 (98,5%) do tipo A: 279 (32%) do subtipo A(H1)pdm09 e 181 (21%) do subtipo AH3. Foram detetados 7 vírus influenza do tipo B. Discussão e Conclusão: Na época 2013/2014, a atividade gripal foi moderada com taxas de incidência semelhantes às 2012/2013. O período epidémico ocorreu mais cedo em relação a 2012/2013 e foi de menor duração. O vírus influenza do tipo A foi predominante com co-circulação dos dois subtipos: A(H1)pdm09 e A(H3). Os vírus detetados são genética e antigenicamente semelhantes às estirpes vacinais e sensíveis ao oseltamivir e zanamivir

Fundamental frequency suppression for the detection of broken bar in induction motors at low slip and frequency

Producción CientíficaBroken rotor bar (BRB) is one of the most common failures in induction motors (IMs) these days; however, its identification is complicated since the frequencies associated with the fault condition appear near the fundamental frequency component (FFC). This situation gets worse when the IM slip or the operation frequency is low. In these circumstances, the common techniques for condition monitoring may experience troubles in the identification of a faulty condition. By suppressing the FFC, the fault detection is enhanced, allowing the identification of BRB even at low slip conditions. The main contribution of this work consists of the development of a preprocessing technique that estimates the FFC from an optimization point of view. This way, it is possible to remove a single frequency component instead of removing a complete frequency band from the current signals of an IM. Experimentation is performed on an IM operating at two different frequencies and at three different load levels. The proposed methodology is compared with two different approaches and the results show that the use of the proposed methodology allows to enhance the performance delivered by the common methodologies for the detection of BRB in steady state.CONACyT scholarship (415315)Project FOFI-UAQ 2018 FIN201812PRODEP UAQ-PTC-385 gran

Role of SARS-CoV-2 in Modifying Neurodegenerative Processes in Parkinson’s Disease: A Narrative Review

The COVID-19 pandemic, caused by SARS-CoV-2, continues to impact global health regarding both morbidity and mortality. Although SARS-CoV-2 primarily causes acute respiratory distress syndrome (ARDS), the virus interacts with and influences other organs and tissues, including blood vessel endothelium, heart, gastrointestinal tract, and brain. We are learning much about the pathophysiology of SARS-CoV-2 infection; however, we are just beginning to study and understand the long-term and chronic health consequences. Since the pandemic’s beginning in late 2019, older adults, those with pre-existing illnesses, or both, have an increased risk of contracting COVID-19 and developing severe COVID-19. Furthermore, older adults are also more likely to develop the neurodegenerative disorder Parkinson’s disease (PD), with advanced age as the most significant risk factor. Thus, does SARS-CoV-2 potentially influence, promote, or accelerate the development of PD in older adults? Our initial focus was aimed at understanding SARS-CoV-2 pathophysiology and the connection to neurodegenerative disorders. We then completed a literature review to assess the relationship between PD and COVID-19. We described potential molecular and cellular pathways that indicate dopaminergic neurons are susceptible, both directly and indirectly, to SARS-CoV-2 infection. We concluded that under certain pathological circumstances, in vulnerable persons-with-Parkinson’s disease (PwP), SARS-CoV-2 acts as a neurodegenerative enhancer to potentially support the development or progression of PD and its related motor and non-motor symptoms

Genetic algorithm methodology for the estimation of generated power and harmonic content in photovoltaic generation

Producción CientíficaRenewable generation sources like photovoltaic plants are weather dependent and it is hard to predict their behavior. This work proposes a methodology for obtaining a parameterized model that estimates the generated power in a photovoltaic generation system. The proposed methodology uses a genetic algorithm to obtain the mathematical model that best fits the behavior of the generated power through the day. Additionally, using the same methodology, a mathematical model is developed for harmonic distortion estimation that allows one to predict the produced power and its quality. Experimentation is performed using real signals from a photovoltaic system. Eight days from different seasons of the year are selected considering different irradiance conditions to assess the performance of the methodology under different environmental and electrical conditions. The proposed methodology is compared with an artificial neural network, with the results showing an improved performance when using the genetic algorithm methodology.CONACYT (scholarship 415315)FOFI –UAQ 2018 (project FIN201812)PRODEP (project UAQ-PTC-385

Spectral kurtosis based methodology for the identification of stationary load signatures in electrical signals from a sustainable building

Producción CientíficaThe increasing use of nonlinear loads in the power grid introduces some unwanted effects, such as harmonic and interharmonic contamination. Since the existence of spectral contamination causes waveform distortion that may be harmful to the loads that are connected to the grid, it is important to identify the frequency components that are related to specific loads in order to determine how relevant their contribution is to the waveform distortion levels. Due to the diversity of frequency components that are merged in an electrical signal, it is a challenging task to discriminate the relevant frequencies from those that are not. Therefore, it is necessary to develop techniques that allow performing this selection in an efficient way. This paper proposes the use of spectral kurtosis for the identification of stationary frequency components in electrical signals along the day in a sustainable building. Then, the behavior of the identified frequencies is analyzed to determine which of the loads connected to the grid are introducing them. Experimentation is performed in a sustainable building where, besides the loads associated with the normal operation of the building, there are several power electronics equipment that is used for the electric generation process from renewable sources. Results prove that using the proposed methodology it is possible to detect the behavior of specific loads, such as office equipment and air conditioning.Universidad de Valladolid y Consejo Mexicano de Ciencia y Tecnología (CONACYT) - (grant 743842)Universidad Autónoma de Querétaro, Fondo para el Desarrollo del Conocimiento (FONDEC-UAQ 2020) - (project FIN202011

Cracking in asphalt materials

This chapter provides a comprehensive review of both laboratory characterization and modelling of bulk material fracture in asphalt mixtures. For the purpose of organization, this chapter is divided into a section on laboratory tests and a section on models. The laboratory characterization section is further subdivided on the basis of predominant loading conditions (monotonic vs. cyclic). The section on constitutive models is subdivided into two sections, the first one containing fracture mechanics based models for crack initiation and propagation that do not include material degradation due to cyclic loading conditions. The second section discusses phenomenological models that have been developed for crack growth through the use of dissipated energy and damage accumulation concepts. These latter models have the capability to simulate degradation of material capacity upon exceeding a threshold number of loading cycles.Peer ReviewedPostprint (author's final draft

DETECCIÓN DE FALLA DE RODAMIENTO EN UNA CADENA CINEMÁTICA VÍA EMISIÓN ACÚSTICA

ResumenLas cadenas cinemáticas son componentes esenciales en la mayoría industrias, compuestas principalmente por motores de inducción, cajas de engranes, etc.., las fallas de estás provocan grandes pérdidas monetarias. Para evitarlos se utilizan sistemas automatizados de monitorización. Existen diferentes técnicas de monitoreo con diferentes metodologías, la emisión acústica (EA) es uno de los métodos de monitoreo no invasivo para la detección de fallas en estos sistemas. En este trabajo se presenta el desarrollo de un sistema de adquisición de señales de EA y una metodología basada en el análisis de estas señales para la detección de falla de rodamiento en un banco de pruebas de una cadena cinemática, la identificación de los componentes relacionados con la falla para el análisis es respaldado por su modelo teórico. Los resultados obtenidos muestran la detección de falla en rodamiento en altas frecuencias y la metodología para el análisis de la EA.Palabras Claves: Detección de fallas, emisión acústica, FFT, rodamientos. DETECTION OF BEARING FAILURE IN A CINEMATIC CHAIN VIA ACOUSTIC EMISSIONAbstractKinematics Chains are essential components in most industries, composed mainly of induction motors, gearboxes, etc.., failures within them cause great monetary losses. To avoid this, automated monitoring systems are used. There are different monitoring techniques with different methodologies, the acoustic emission (AE) is one of the methods of noninvasive monitoring for the detection of failures in these systems. This work presents the development of an AE signal acquisition system and a methodology based on the analysis of these signals for the detection of bearing failure in a test bench of a kinematic chain. The identification of the components related to the fault for the analysis is supported by its theoretical model. The obtained results show the detection of failure in rolling in high frequencies and the methodology for the analysis of the AE. Keywords: Acoustic emission, bearings, faults detection, FFT

Hierarchical approach for fatigue cracking performance evaluation in asphalt pavements

In this paper, a hierarchical approach is proposed for the evaluation of fatigue cracking in asphalt concrete pavements considering three different levels of complexities in the representation of the material behaviour, design parameters characterization and the determination of the pavement response as well as damage computation. Based on the developed hierarchical approach, three damage computation levels are identified and proposed. The levels of fatigue damage analysis provides pavement engineers a variety of tools that can be used for pavement analysis depending on the availability of data, required level of prediction accuracy and computational power at their disposal. The hierarchical approach also provides a systematic approach for the understanding of the fundamental mechanisms of pavement deterioration, the elimination of the empiricism associated with pavement design today and the transition towards the use of sound principles of mechanics in pavement analysis and design