High-resolution error compensation in continuous conduction mode power factor correction stage without current sensor

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. V. M. López-Martín, F. J. Azcondo, and Á. de Castro, "High-resolution error compensation in continuous conduction mode power factor correction stage without current sensor", in 2012 15th International Power Electronics and Motion Control Conference (EPE/PEMC), Novi Sad (Serbia), 2012.Continuous conduction mode power factor correction (PFC) without input current measurement is a step forward with respect to previously proposed PFC digital controllers. Inductance volt-second (vsL) measurement in each switching period enables the estimation of input current, but an accurate compensation of the small errors in the measured vsL is required. Otherwise, they are accumulated over a half-cycle line, leading to an appreciable current distortion. A vsL estimation is proposed, measuring the input (vin) and the the output voltage (vo). Discontinuous conduction mode (DCM) occurs near input line zero crossings, and is also detected by measuring MOSFET vds. This article analyzes the current estimation error caused by errors in the on-time estimation and voltage measurements, and proposes the minimization of vsL errors by cancelling the difference between estimated DCM (TDCMinereb) and real DCM (TDCMin) times with a signal (vdig), generated in the digital device. Therefore, the current estimation is calibrated using digital signals during the operation in DCM. Feedfoward coarse time error compensation is carried out with the measured delay of the drive signal, and then a fine compensation is achieved with a feedback loop that adjusts vdig. Experimental results are shown for a 1 kW boost PFC converter.This work was supported in part by the Spanish Ministry of Science TEC - FEDER 2011-2361

Current error compensation for current-sensorless power factor corrector stage in continuous conduction mode

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. V. M. Lopez-Martin, F. J. Azcondo, and A. de Castro, "Current error compensation for current-sensorless power factor corrector stage in continuous conduction mode", 2012 IEEE 13th Workshop on Control and Modeling for Power Electronics (COMPEL), Kyoto (Japan), 2012, pp. 1-8A universal digital PFC current-sensorless controller based on control of estimated current is presented. Parasitic elements cause a small difference between the measured input voltage and the voltage across the inductance in a boost converter, which must be taken into account to estimate the input current in a sensorless PFC digital controller. To compensate for the deviation caused by the parasitic elements, and so minimize the current estimation error, the article proposes a digital feedback control technique that cancels the time difference between DCM operation time of the real input current (TinDCM) and the estimated current (TrebDCM). Experimental results, obtained using a boost PFC converter under different conditions, are shown for verification purposes.This work was supported by the Spanish Ministry of Science TEC FEDER 2011-2361

Autotuning digital controller for current sensorless power factor corrector stage in continuous conduction mode

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. V. M. López, F. J. Azcondo, F. J. Díaz, and Á. de Castro, "Autotuning digital controller for current sensorless power factor corrector stage in continuous conduction mode", 2010 IEEE 12th Workshop on Control and Modeling for Power Electronics (COMPEL), Boulder (CO), 2010, pp. 1-8A circuit that compensates the volt-seconds error across the inductor in current sensorless digital control for continuous conduction mode power factor correction (PFC) stage is presented. Low cost ad-hoc sigma-delta analog to digital converters (ΣΔ ADCs) are used to sample the PFC input and output voltage. Instead of being measured, the input current is estimated in a digital circuit to be used in the current loop. A nonlinear carrier control is implemented in the digital controller in order to obtain the power factor correction. Drive signal delays cause differences between the digital current and the real current, producing that volt-seconds error. The control algorithm is compensated taking into account the delays. The influence of a wrong compensation is presented. Experimental results show power factor values and harmonic content within the IEC 61000-3-2 Class C standard in different operation conditions. Furthermore, the use of this PFC stage for electronic ballasts to compensate the effect of the utility voltage fluctuation in HID lamps is also verified taking advantage of the digital device capabilities.This work is sponsored by the Spanish Ministry of Education and Science through the project CICYT-TEC 2008-0175

Evaluación formativa y compartida en los proyectos de trabajo tutorado, un ejemplo de buena práctica

En este trabajo se presenta una experiencia de buena práctica de aprendizaje y de evaluación formativa y compartida, llevada a cabo en Formación Inicial del Profesorado (FIP). Nos centramos en el papel que juega la metodología de “Proyectos de Aprendizaje Tutorado”, utilizado en cuarto curso de FIP, en la titulación de maestro de Educación Infantil, durante el primer cuatrimestre del curso 2016-2017, en la asignatura de “Expresión y comunicación corporal”. Los resultados han sido muy positivos, tanto en ventajas encontradas por parte del alumnado con la metodología de aprendizaje y el sistema de evaluación utilizado, como en satisfacción general y en la percepción de competencia adquirida durante la asignatura. Además, se obtienen valores muy altos en rendimiento y éxito académico. Se ha medido también la carga de trabajo del alumnado, que está dentro de las horas oficialmente previstas de trabajo no presencial. para mejorar la motivación de los estudiantes. Finalmente, se compararán los resultados académicos de los estudiantes derivados de la aplicación del modelo de enseñanza-aprendizaje tradicional con los obtenidos con la metodología basada en la clase invertida en los diferentes niveles educativos

La transformación de los procesos de evaluación en educación infantil mediante la formación permanente a través de la investigación-acción

Este estudio analiza en qué medida los procesos de formación permanente del profesorado basados en proyectos de investigación-acción parecen incidir en el desarrollo de sistemas de evaluación formativa y compartida en la práctica educativa. La investigación se lleva a cabo dentro de Proyecto de Innovación Docente; su finalidad es fomentar la innovación educativa en las escuelas, dirigida a transformar sus prácticas de aula por otras orientadas al aprendizaje inclusivo. Los resultados parecen indicar que los proyectos de formación permanente basados en procesos de reflexión y la investigación-acción conllevan un cambio en el pensamiento de las docentes, que les hace replantearse sus prácticas educativas, incluidos los procesos de evaluación. Con este estudio pretendemos ampliar una vía de trabajo que nos permita instaurar procesos de Evaluación Formativa y compartida en las aulas de Educación Infantil

A good practice of Formative and Shared Assessment in pre-service Teacher Education in Childhood Education

En este trabajo presentamos los resultados de una buena práctica llevada a cabo en la asignatura de Fundamentos de la educación física en educación infantil: los “Proyectos de Aprendizaje tutorado”. En la primera parte se describe la organización de la asignatura y el ejemplo de buena práctica. En la segunda parte se presentan los resultados obtenidos, que son muy positivos. Hay un cambio relevante en la carga de trabajo del profesor, que puede explicarse por los años de experiencia del profesorado que desarrolla la asignatura. Se refleja en conclusiones.In this work we present the results of a good practice carried out in the subject of Foundations of Physical Education in Early Childhood Education: the "Tutored Learning Projects". The first part describes the organization of the subject and the example of good practice. In the second part the results obtained are presented, which are very positive. There is a relevant change in the workload of the professor, which can be explained by the years of experience of the teaching staff that develops the subject. It is reflected in conclusions

Tutored learning projects as a good practice in physical education in the first course of double grade (childhood education and primary education)

En este trabajo presentamos los resultados de una buena práctica llevada a cabo en la asignatura de fundamentos de la educación física en educación infantil: los “Proyectos de Aprendizaje tutorado”. En la primera parte se describe la organización de la asignatura y el ejemplo de buena práctica. En la segunda parte se presentan los resultados obtenidos, que son muy positivos. Hay un cambio relevante en la carga de trabajo del profesor, que puede explicarse por los años de experiencia del profesorado que desarrolla la asignatura. Se refleja en conclusiones.In this paper we present the results of a good practice carried out in the subject of foundations of Physical Education in Early Childhood Education: the "Tutored Learning Projects". The first part describes the organization of the subject and the example of good practice. In the second part the results obtained are presented, which are very positive. There is a relevant change in the workload of the professor, which can be explained by the years of experience of the teaching staff that develops the subject. It is reflected in conclusions

Cellular integrin ¿5ß1 and exosomal adam17 mediate the binding and uptake of exosomes produced by colorectal carcinoma cells

Approximately 25% of colorectal cancer (CRC) patients develop peritoneal metastasis, a condition associated with a bleak prognosis. The CRC peritoneal dissemination cascade involves the shedding of cancer cells from the primary tumor, their transport through the peritoneal cavity, their adhesion to the peritoneal mesothelial cells (PMCs) that line all peritoneal organs, and invasion of cancer cells through this mesothelial cell barrier and underlying stroma to establish new metastatic foci. Exosomes produced by cancer cells have been shown to influence many processes related to cancer progression and metastasis. In epithelial ovarian cancer these extracellular vesicles (EVs) have been shown to favor different steps of the peritoneal dissemination cascade by changing the functional phenotype of cancer cells and PMCs. Little is currently known, however, about the roles played by exosomes in the pathogenesis and peritoneal metastasis cascade of CRC and especially about the molecules that mediate their interaction and uptake by target PMCs and tumor cells. We isolated exosomes by sizeexclusion chromatography from CRC cells and performed cell-adhesion assays to immobilized exosomes in the presence of blocking antibodies against surface proteins and measured the uptake of fluorescently-labelled exosomes. We report here that the interaction between integrin 5 1 on CRC cells (and PMCs) and its ligand ADAM17 on exosomes mediated the binding and uptake of CRC-derived exosomes. Furthermore, this process was negatively regulated by the expression of tetraspanin CD9 on exosome

Rhodamine-based sensor for real-time imaging of mitochondrial ATP in living fibroblasts

Mitochondria are essential for the production and maintenance of ATP in the eukaryotic cell. To image and monitor intracellular ATP level without cell breakage, biological and chemical sensors were developed in the last years. Here, we have internalized a rhodamine-based sensor RSL+ into living cells and monitored the mitochondrial ATP levels in cultured mouse embryonic fibroblasts. To evaluate the robustness of the sensor we imaged the changes of the mitochondrial ATP levels under non-physiological conditions upon incubation with FCCP, oligomycin, azide, deoxyglucose or phosphoenolpyruvate; all compounds that interfere with ATP homeostasis of the cell. The ATP sensor allowed us to determine the mitochondrial ATP levels in human skin fibroblasts where we observe a similar amount of ATP compared to mouse embryonic fibroblasts. We propose the RSL+ to be a valuable tool for the assessment of mitochondrial dysfunction in human cells derived from mitochondrial OXPHOS patients and for basic studies on bioenergetics metabolism

Prospects for practice-based philosophy of logic

We explore prospects for practice-based approaches to logical theory, in particular the link between classical and intuitionistic logic and the inferential structure of traditional practices of representation & argument in science and mathematics. After discussing some key notions about practice, we outline the connection between representation practices and classical logic, and then consider a spectrum of actual practices followed or proposed by (real) scientists. Intuitionistic logic helps to clarify the potential of practice-based approaches for understanding pluralism, and to hammer some key points about the general thesis.Ministerio de Economía y Competitividad FFI2009-1002