Constant Phase Element in the Time Domain: The Problem of Initialization

This research was partially funded by the TIC105 research group of the University of Granada.The constant phase element (CPE) is found in most battery and supercapacitor equivalent circuit models proposed to interpret data in the frequency domain. When these models are used in the time domain, the initial conditions in the fractional differential equations must be correctly imposed. The initial state problem remains controversial and has been analyzed by various authors in the last two decades. This article attempts to clarify this problem by proposing a procedure to prepare the initial state and defining a decay function that reveals the effect of the initial state in several illustrative examples. This decay function depends on the previous history, which is reflected in the time needed to prepare the initial state and on the current profile assumed for this purpose. This effect of the initial state is difficult to separate and can lead to the misinterpretation of the CPE parameter values.University of Granada TIC10

A physics-based fractional-order equivalent circuit model for time and frequency-domain applications in lithium-ion batteries

This work was partially supported by the Regional Government of Andalusia under project P18-RT-3303 from Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI 2020), by the Spanish Ministry of Science and Innovation and by FEDER funds via Project MCI-20-PID2019-110955RB-I00, by the Principality of Asturias via project AYUD/2021/50994, and by the FPU-UGR-Banco Santander Program for Predoctoral Scholarships. Funding for open access charge: Universidad de Granada / CBUAEquivalent circuit models (ECMs) remain the most popular choice for online applications in lithium-ion batteries because of their simpler parameterization and lower computational requirements in comparison to electrochemical models. Nevertheless, standard ECMs lack physical insight and fail to accurately reproduce cell behavior under a wide range of operating conditions. For this reason, the development of physics-informed ECMs becomes essential so as to provide a better description of the physical processes while maintaining a reduced computational complexity. In this article, we propose a novel physics-based ECM derived directly from an electrochemical model, so that there is a clear correlation between circuit states and internal battery states, as well as circuit and physical parameters. The proposed model yields an RMS error below 1.46 mV for cell voltage, 0.28% for the surface concentration in the active material particles, 0.6% for the electrode-averaged electrolyte concentration and 0.32 mV for the charge-transfer overpotentials. Another key feature of this model is the relationship between circuit parameters and those identified in frequency-domain tests, which allows us to characterize and validate the model experimentally. We understand that the presented model constitutes an alternative to standard ECMs as well as electrochemical models as it combines advantageous characteristics from both of them.Regional Government of Andalusia P18-RT-3303Spanish Ministry of Science and InnovationFEDER: MCI-20-PID2019-110955RB-I00Principality of Asturias AYUD/2021/50994PU-UGR-Banco SantanderUniversidad de Granada / CBU

A fractional-order model for calendar aging with dynamic storage conditions

Funding for open access charge: Universidad de Granada / CBUA.Due to the increasing importance of lithium-ion batteries in electric vehicle and renewable energy applications, battery aging is a subject of intense research. Although many laboratory experiments are performed under well-controlled static conditions, batteries are stored and operated under varying conditions of temperature and state of charge in their real-life performance, so that a suitable model for predicting the effects of calendar aging in lithium-ion batteries with dynamic conditions is highly desirable. In this paper, we review previous models to calculate capacity loss due to calendar aging under variable temperature and state-of-charge conditions according to experimentally observed power-law behavior, and propose a novel model based on fractional calculus. To validate the new model, we compare its predictions with experimental results showing that it can reproduce the non-monotonic behavior that is observed when the state of charge or the temperature change significantly. This is an interesting application of fractional calculus since this characteristic is not obtained with non-fractional models.Universidad de Granada / CBU

Cribado de problemas de salud mental en atención primaria

Tesis de la Universidad Complutense de Madrid, Facultad de Medicina, Departamento de Psiquiatría, leída el 12-07-2017Los problemas de salud mental comprenden tanto trastornos mentales propiamente dichos como otros problemas de salud relacionados con los riesgos del consumo de sustancias. En total son responsables de más del 13% de la carga total de morbilidad mundial y corresponden con la pérdida de hasta un 37% de años de vida de buena salud en términos de discapacidad. La relevancia de estos trastornos, tanto actualmente como por su proyección futura con una tendencia creciente, plantea la necesidad de abordarlos como problemas de salud pública.La magnitud de los problemas referidos en la población general, no sólo en la medicina, demuestra la necesidad de llegar a más personas que las que solicitan asistencia y de disponer de herramientas para la detección precoz de problemas relacionados con la salud mental como el trastorno bipolar y el consumo de drogas.Los programas de cribado que forman parte de los mecanismos de prevención de segundo nivel de los sistemas de salud, han demostrado eficacia para diversas patologías tanto orgánicas como de salud mental adelantando el diagnóstico y aumentando la supervivencia en algunos pacientes.La labor de la Atención Primaria de Salud en la detección precoz de algunos de esos trastornos mencionados ha sido un papel ampliamente constatado en algunas patologías de salud mental como la depresión, y para algunas drogas aisladas como el tabaco y el alcohol. Sin embargo, la evidencia respecto de la eficacia en el cribado del trastorno bipolar o en la detección precoz simultánea del consumo de riesgo de todas las drogas consumidas por un mismo individuo aún es escasa...Health mental issues include a wide range of situations from proper mental diseases to other mental health related conditions such as drug using problems. As a whole they are responsible of 13% of total burden of diseases with a 37% loss of healthy life years. The size of the problems described above, as for its importance nowadays as for its importance in near future, it stablishes the need of coping with them as public health issuesBecause of the size and the importance of these problems in general population, not only in medicine and primary care practices, it is clear to us the need of achieving a wider target population than the one seeking medical advice in terms of screening of mental health issues such bipolar disorder or drug use screening.Screening programs as part of the second level of preventive measurements have already demonstrated its efficacy for several health conditions whether they are organic or mental health conditions. When available, they help diagnosing sooner and they help by increasing survival rates in patients.Primary Health Care is a gatekeeper and a key point when it comes to screening of diseases and it has already been shown that it is effective for conditions such as depression or isolated drug screening (tobacco and alcohol). However, it has not been demonstrated when speaking of bipolar disorder or all-type of drug use related problems...Depto. de Medicina Legal, Psiquiatría y PatologíaFac. de MedicinaTRUEunpu

Aprendizaje de hechos y conceptos en educación física. Una propuesta metodológica

Uno de los principales elementos de preocupación de la mayoría de especialistas en Educación Física es como llegar a transmitir de una forma significativa los contenidos teóricos a sus alumnos. Este objetivo no siempre se consigue, pues existen muchos problemas a la hora de transmitirlos. Las investigaciones en la materia muestran que uno de los grandes problemas es el desconocimiento que poseen muchos profesores de cómo llevar los conocimientos teóricos a las clases de Educación Física expresados en hechos, conceptos y sistemas conceptuales. Insuficiencia que está asociada al propio proceso de formación inicial y permanente en cuanto a qué, cómo y cuándo enseñar y evaluar hechos y conceptos en Educación Física. Así pues, el objetivo del siguiente artículo consiste en dar respuestas a estas interrogantes científicas y mostrar una propuesta práctica a través de un enfoque integral físico-educativo en las clases de Educación Física

Cribado de problemas de salud mental en atención primaria

Los problemas de salud mental comprenden tanto trastornos mentales propiamente dichos como otros problemas de salud relacionados con los riesgos del consumo de sustancias. En total son responsables de más del 13% de la carga total de morbilidad mundial y corresponden con la pérdida de hasta un 37% de años de vida de buena salud en términos de discapacidad. La relevancia de estos trastornos, tanto actualmente como por su proyección futura con una tendencia creciente, plantea la necesidad de abordarlos como problemas de salud pública.La magnitud de los problemas referidos en la población general, no sólo en la medicina, demuestra la necesidad de llegar a más personas que las que solicitan asistencia y de disponer de herramientas para la detección precoz de problemas relacionados con la salud mental como el trastorno bipolar y el consumo de drogas.Los programas de cribado que forman parte de los mecanismos de prevención de segundo nivel de los sistemas de salud, han demostrado eficacia para diversas patologías tanto orgánicas como de salud mental adelantando el diagnóstico y aumentando la supervivencia en algunos pacientes.La labor de la Atención Primaria de Salud en la detección precoz de algunos de esos trastornos mencionados ha sido un papel ampliamente constatado en algunas patologías de salud mental como la depresión, y para algunas drogas aisladas como el tabaco y el alcohol. Sin embargo, la evidencia respecto de la eficacia en el cribado del trastorno bipolar o en la detección precoz simultánea del consumo de riesgo de todas las drogas consumidas por un mismo individuo aún es escasa..

Continuous harmonic analysis and power quality measurements in three-phase systems

A virtual instrument, named Power Quality Meter, is presented for (a) measuring power consumption and harmonics in three-phase systems, under non-sinusoidal and imbalance conditions (b) detecting, classifying and organizes power disturbance events. Measurement of the power consumption follows the formulation proposed by the members of the IEEE Working Group on Nonsinusoidal Situations (1996). So, definitions are based on the analysis of functions in the frequency domain, separating the fundamental terms from the harmonic terms of the Fourier series. The virtual instrument has been developed too for monitoring and measuring power disturbances, which are automatically classified and organized in a database while they are being recorded. Software tools use the database structure to present summaries of power disturbances and locate an event by severity or time of occurrence. Records of actual measurements are included to demonstrate the versatility of the instrument

A compact model of the ZARC for circuit simulators in the frequency and time domains

Equivalent-circuit models containing fractional-order elements are often employed to make use of fractionalorder calculus in the frequency and time domains in a variety of applications. Many of these circuits contain constant-phase elements that appear in parallel with a resistor in a configuration called ZARC. But to avoid fractional order derivatives and include it in circuit simulators, the ZARC itself can also be replaced by equivalent circuit models that only contain integer order elements, such as resistors and capacitors. In this article, a novel compact model is presented to substitute the ZARC by a multiple-RC network. This model is valid for a continuous value of the order exponent and is applicable over a very wide range of frequencies, making it useful in both the frequency and time domains. Since it uses only basic functions and operators, it has been easily implemented as a subcircuit in circuit simulators. The validity of the model has been verified and it has been compared with some previously proposed passive circuit models. The model has also been discussed in relation to the initialization problem, which is an often overlooked challenge in fractional-order circuits.Universidad de Granada/CBU

Molecular Physiology of Kainate Receptors

28 páginas, 15 figuras, 3 tablas.A decade ago, our understanding of the molecular properties of kainate receptors and their involvement in synaptic physiology was essentially null. A plethora of recent studies has altered this situation profoundly such that kainate receptors are now regarded as key players in the modulation of transmitter release, as important mediators of the postsynaptic actions of glutamate, and as possible targets for the development of antiepileptic and analgesic drugs. In this review, we summarize our current knowledge of the properties of kainate receptors focusing on four key issues:1) their structural and biophysical features, 2) the important progress in their pharmacological characterization,3) their pre- and postsynaptic mechanisms of action, and4) their involvement in a series of physiological and pathological processes. Finally, although significant progress has been made toward the elucidation of their importance for brain function, kainate receptors remain largely an enigma and, therefore, we propose some new roads that should be explored to obtain a deeper understanding of this young, but intriguing, class of proteins.Work in the laboratory of J. Lerma has been supported by grants from the Spanish Ministry of Education and Culture (DGICYT Grants PB93/0150 and UE96/0007 as well as DGESIC Grants PM-0008/96 and PM99–0106), the Ministry of Health (FISSS Grant 95/0869), the Comunidad de Madrid (Grant 08.5/ 0042/1998), and the European Union (Grant BIO2-CT930243). J. C. López-García is the recipient of a long-term fellowship awarded by EMBO.Peer reviewe

Do Age and Educational Stage Influence No-Mobile-Phone Phobia?

Technological progress not only brings with it resources that improve and facilitate the day-to-day life of the people who make up society but also entails health risks, with the emergence of terms, such as nomophobia, which is considered an anxiety disorder produced by the fear that not having a mobile phone generates in a person. This research aims to identify the relationship and influence between levels of nomophobia and the age or educational stage of students. The research method is based on a correlational and predictive design of quantitative methodology. The instrument used is the NMP-Q questionnaire. The study population is students from different educational stages (obligatory secondary education, baccalaureate, vocational training and university). The results show that students over 12 years old present an average level of “nomophobia” (no-mobile-phone phobia), namely, not being able to communicate with the family where the highest levels are presented. We conclude that students over 12 years of age and of any educational stage present an average level of nomophobia, and it cannot be determined that either the educational stage or the age are determining factors in the presentation of this problem. This can occur at any age and at any level of the different educational stages, although there are risk indicators that we should bear in mind to avoid the appearance of nomophobia.I+D+I Project Research of Results Transfer Office (OTRI) of the University of Granada (Reference: CNT 4439