Modeling the AC Electrokinetic Behavior of Semiconducting Spheres

We study theoretically the dielectrophoresis and electrorotation of a semiconducting microsphere immersed in an aqueous electrolyte. To this end, the particle polarizability is calculated from first principles for arbitrary thickness of the Debye layers in liquid and semiconductor. We show that the polarizability dispersion arises from the combination of two relaxation interfacial phenomena: charging of the electrical double layer and the Maxwell–Wagner relaxation. We also calculate the particle polarizability in the limit of thin electrical double layers, which greatly simplifies the analytical calculations. Finally, we show the model predictions for two relevant materials (ZnO and doped silicon) and discuss the limits of validity of the thin double layer approximation

Dipolophoresis and Travelling-Wave Dipolophoresis of Metal Microparticles

We study theoretically and numerically the electrokinetic behavior of metal microparticles immersed in aqueous electrolytes. We consider small particles subjected to non-homogeneous ac electric fields and we describe their motion as arising from the combination of electrical forces (dielectrophoresis) and the electroosmotic flows on the particle surface (induced-charge electrophoresis). The net particle motion is known as dipolophoresis. We also study the particle motion induced by travelling electric fields. We find analytical expressions for the dielectrophoresis and induced-charge electrophoresis of metal spheres and we compare them with numerical solutions. This validates our numerical method, which we also use to study the dipolophoresis of metal cylinders.Spanish Research Agency MCI under contract PGC2018-099217-B-I00

Maestros y estudiantes de maestro, juntos para una escuela más digital: Una experiencia de aprendizaje servicio

Los proyectos de aprendizaje servicio fomentan que la adquisición de unos conocimientos y habilidades determinados estén al servicio de las necesidades de la comunidad, mientras la propia comunidad se beneficia de ello. En este caso, se describe una experiencia de aprendizaje servicio hecha en una escuela pública de Cantabria que posibilitó que estudiantes de maestro hicieran de asesores en el colegio para implementar las tecnologías de la información en la etapa de infantil

Parameterisation and reliability of the functional reach test in people who suffer stroke

AIM: The aim of this study is to analyse the reliability, sensitivity and specificity of the parameterisation of FRT using inertial sensors to record kinematic variables in subjects who have had a stroke. Our hypothesis is that the IS will be reliable instruments for kinematic study of the FRT. METHODS: This is a cross-sectional study of 5 subjects over 65 years who suffer of stroke. During the execution of Funtional Reach Test the subjects carried two inertial sensors, one was placed in the lumbar and the other in the trunk. After analysing the data obtained in the kinematic registration by inertial sensors a number of direct and indirect variables were obtained. The variables extracted directly from FRT through the IS were distance, maximun angular lumbosacral/thoracic displacement, time maximun angular lumbosacral/thoracic displacement, time return starting position and total time. Using this data the speed and the acceleration of each one of them were calculated. A descriptive analysis of all kinematic outcomes recorded by the two inertial sensors was developed (trunk and lumbar) and the average range achieved in the FRT. Reliability measures were calculated by analysing the internal consistency the measures with 95% confidence interval of each outcome variable. The reliability was calculated in the functional reach and the outcomes measured by the IS. RESULTS: The values in the the Functional Reach Test obtained in the present study (2.06 ± 12.75cm) are similar to those obtained in other studies with this population and in the same age range. Intrasubject reliability values observed in the use of inertial sensors are all located above 0.820, ranging from 0.829 (time B_C lumbar area) and 0.891 (A_B displacement of the trunk). Likewise, the observed intersubject values range from 0.821 (Time B_C lumbar area) and 0.883 (B_C trunk displacement). On the other hand, the reliability of the FRT was 0.987 (0.983-0.992) and 0.983 (0.979-0.989) intersubject and intrasubject respectively. CONCLUSION: The main conclusion that can be reached is that the inertial sensors are a tool with excellent reliability, validity, sensitivity and specificity in the parameterisation of the Functional Reach Test in people who have had a stroke.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Vitamin D concentrations in familial combined hyperlipidemia: effects of lipid lowering treatment

BACKGROUND: Vitamin D deficiency has been linked to several cardiovascular risk factors but information regarding vitamin D concentrations in familial combined hyperlipidemia (FCHL) is lacking. Our objective was to examine vitamin D concentrations in patients with FCHL and to study the effects of lipid-lowering therapy. METHODS: We conducted a cross sectional study on 59 patients with FCHL and 48 healthy controls. We analyzed 25-hydroxyvitamin D (25(OH)D) concentrations and their association with lipid parameters, anthropometric measures, C-reactive protein and homeostasis model assessment (HOMA) index. Twenty-three patients with FCHL were also included in a longitudinal study conducted to analyze 25-hydroxyvitamin D concentrations before and after treatment for dyslipidemia. RESULTS: After adjustment for body mass index and seasonality, patients with FCHL had lower vitamin D concentrations than controls. Adjusted means (standard error of the mean (S.E.M)) for 25(OH)D according to the presence or absence of FCHL were 62.8 (3.6) nmol/L for patients with FCHL and 74.8 (4.1) nmol/L for controls (p = 0.021). In FCHL, hypovitaminosis D was associated with features of atherogenic dyslipidemia. After lipid-lowering therapy, vitamin D concentrations increased (51.0 ± 31.3 to 58.9 ± 24.6 nmol/L (P = 0.022)). However, changes in 25(OH)D concentrations did not correlate with changes in other parameters. CONCLUSIONS: Our findings suggest that FCHL is associated with decreased vitamin D concentrations and that treatment for dyslipidemia improves vitamin D status through an unknown mechanism. Further studies are needed to replicate these data in larger populations and to elucidate the mechanisms involved in this association

Comparison of models and standards for implementing IT service capacity management

Due to the recent and significant growth of the information technology (IT) services, industries need some sort of framework and / or standards for the management of their services, especially IT services. So, it becomes necessary and essential to define and adopt a set of best practices for providing and effectively managing the technology and services offered throughout its life cycle. Currently, the management of IT applications and services becomes more complex. Predicting and controlling the problems associated with system performance and capacity planning has become a difficult task. For large IT projects, the costs related to performance tuning, performance management and capacity planning, generally turn out to be the biggest and the most uncontrollable costs. In recent years, a number of frameworks aimed at covering certain issues of IT service management have been developed. One of these issues is the IT service capability management. In this paper, a comparison between the models and standards used today regarding capacity management are presented. A comparison of the strengths and weaknesses of each of the models/standards on the capacity management is presented, so that it can guide organizations to select the model/standard that best suits their needs

Estudio de la diversidad de plantas vasculares del sistema agroforestal dehesa y de otros usos del suelo en los municipios de Barcarrota y Olivenza (Badajoz)

Estudio en colaboración con el grupo de trabajo de ecología del paisaje del CIFOR-INIA enmarcado en el proyecto "El sistema agroforestal dehesa como sumidero de carbono: hacia un modelo conjunto de la vegetación y el suelo". Mediante el inventario con marcelas multiescalares, se relaciona la riqueza y abundancia de especies de plantas vasculares a las distintas tipologías o usos del suelo proporcionadas por el MFE50, entre otros objetivos

PFC P1319 ETSIN - Arrastrero congelador factoria

Proyecto Fin de de Carrera Escuela Técnica Superior de Ingenieros Navales. Objeto: Definición, calculo y desarrollo de los distintos cuadernos que componen el proyecto. Así como documentos de defensa. Elemento: ARRASTRERO CONGELADOR FACTORIA PARA LAS ESPECIES DE FONDO Y PELAGICO

Stability analysis for dusty plasma under grain charge fluctuations due to non-Maxwellian electron distributions

The most relevant characteristic of a complex plasma is the dust charge as well as the dust charging process itself which controls different collective and individual behaviors of the plasma. The dust charging has been exhaustively studied providing several theoretical approaches that have improved the early Orbital Motion Limited (OML) description [1, 2]. The OML is considered as a suitable model and, at least, it provides a certain perspective of the main plasma parameters involved in the charging processes. Recent works have stressed the importance of the electron and ion velocity distribution functions in addressing the description of plasma stability analysis under the frame of plasma fluid description, including dust charge fluctuations. The consideration of non-Maxwellian distribution functions has been proved to induce plasma departures from the usual Maxwellian equilibrium, specially under the development of intense electric fields that can accelerate charges till superthermal velocities [3]. In these cases, the distribution function tails fit well to a power-law dependence even for electrons. In this communication, we devote attention to the effect of non Maxwellian electron distribution functions on the collective plasma behavior through a linear analysis of perturbed fluid equations. The stability of a partially ionized complex plasma with a non Maxwellian electron population is studied by including this feature on the dust charge fluctuation for infinite and finite dust grain mass