Optimal Control of a PEM Fuel Cell for the Inputs Minimization

The trajectory tracking problem of a proton exchange membrane (PEM) fuel cell is considered. To solve this problem, an optimal controller is proposed. The optimal technique has the objective that the system states should reach the desired trajectories while the inputs are minimized. The proposed controller uses the Hamilton-Jacobi-Bellman method where its Riccati equation is considered as an adaptive function. The effectiveness of the proposed technique is verified by two simulations

Implementación de un sistema de control interno en Hospibanda Cia. Ltda, ubicada en la provincia de Cotopaxi, cantón Latacunga

El trabajo de investigación tuvo como objetivo principal la Implementación de un Sistema De Control Interno en la Empresa HOSPIBANDA CIA. LTDA. Ubicada en La Provincia de Cotopaxi, Cantón Latacunga, permitiendo encontrar las falencias existentes en cada área al momento de realizar las actividades administrativas - financieras. Los datos que se obtuvieron fueron analizados, procesados convirtiéndose en base fundamental del desarrollo de la misma a través de la aplicación de encuestas al personal administrativo, financiero, empleados y clientes. Los funcionarios no desarrollan su labor con parámetros técnicos, especialmente al registro, la Contabilidad, la custodia de especies valoradas, por lo cual podemos señalar una falta de respaldos de información, señalando claramente la deficiencia existente en el control de la empresa. La propuesta presenta soluciones a los diferentes inconvenientes que tiene la Empresa HOSPIBANDA CIA. LTDA., por la carencia de información, capacitación, y el desconocimiento de sus procesos, actividades en las cuales dan señal de una escasa forma de control, por lo cual mediante la Implementación del Sistema de Control Interno permitirá mejorar las áreas que han visto afectadas un funcionamiento inadecuado a las necesidades de la empresa, razón por el cual el trabajo investigativo, lograra que las labores sean realizadas mediante estándares de calidad

Dynamic Model of a Wind Turbine for the Electric Energy Generation

A novel dynamic model is introduced for the modeling of the wind turbine behavior. The objective of the wind turbine is the electric energy generation. The analytic model has the characteristic that considers a rotatory tower. Experiments show the validity of the proposed method

Estado de conservación de Paramuricea clavata (Risso, 1826) (Anthozoa, Alcyonacea) en las islas Chafarinas (mar Mediterráneo)

The red gorgonian Paramuricea clavata (Risso, 1826) is affected by the combined effects of environmental stress factors and diseases in the Mediterranean area. Samplings at different depths in two sites of Chafarinas Islands (South–Western Mediterranean Sea) were carried out to quantify the degree of injuries on red gorgonian colonies. The results showed that shallow colonies displayed a higher rate of injuries than deep colonies. Overall, the conservation status of the population was worse than previously considered in this area.En la zona del Mediterráneo, la gorgonia roja Paramuricea clavata (Risso, 1826) sufre los efectos combinados de factores de estrés ambiental e infecciones. Se realizaron muestras a diferentes profundidades en dos sitios de las islas Chafarinas (mar Mediterráneo sudoccidental) para cuantificar el grado de daño que presentaban las colonias. Los resultados mostraron que las colonias de aguas más superficiales presentaban una mayor tasa de daño que las colonias de aguas más profundas. En conjunto, el estado de conservación de la población era peor de lo que se había considerado previamente en esta zona

Proportional Derivative Control with Inverse Dead-Zone for Pendulum Systems

A proportional derivative controller with inverse dead-zone is proposed for the control of pendulum systems. The proposed method has the characteristic that the inverse dead-zone is cancelled with the pendulum dead-zone. Asymptotic stability of the proposed technique is guaranteed by the Lyapunov analysis. Simulations of two pendulum systems show the effectiveness of the proposed technique

Class-E power converters for AC (50/60 Hz) wireless transmission

In this paper, class-E power amplifiers (PAs) and rectifiers, operating at UHF band, are properly integrated in efficient AC-to-RF and RF-to-AC converters for their use in 50/60 Hz wireless power transmission (WPT). Slightly modifying a center-tap full-wave rectifier, it is proved that a 915 MHz frequency carrier may be high-level amplitude modulated by each of the semi-cycles of the utility waveform. Assuming those components are transmitted by means of orthogonal antenna polarizations, the high-fidelity recovery of both semi-sinusoids in the remote position is also demonstrated, to be stepped-up and combined at the ∆ port of an additional center-tap transformer. GaN HEMT packaged devices were selected for the designed PAs, while Schottky diodes for the rectifiers, resulting in average efficiency figures of 83.3% and 75.4%, respectively.The authors would like to thank the Ministry of Economy and Competitiveness by the financial support provided through projects TEC2014-58341-C4-1-R and TEC2014- 58341-C4-2-R, co-funded with FEDER. José R. PérezCisneros also thanks the support to his stay at the Univ. of Cantabria provided by the pre-doctoral mobility grant EEBBI-15-10447

Design of a liposomal formulation aimed to vaccines administration

Antigen is not the single component involved in the pharmacological response for vaccines but additional factors such as formulation and adjuvant compounds play a relevant role. Several strategies based on the use of liposomes are currently assayed in this field. According to this, the aim of the present work was the design, preparation and characterization of a pharmaceutical vehicle able to produce a rapid delivery of adjuvants and a slow release of antigen. From the know-how a theoretical vehicle was design and proposed as optimal formulation and this was then prepared and characterized. The “proposed formulation” is based on albumin coated liposomes made of egg phosphatidylcholine, cholesterol and diethyldodeccyiamonium. The applied procedure carried out in absence of organic solvents allowed for obtaining liposomes with a 20-70 nm aerodynamic diameter range and a zeta potential mean value of 61.9 ±2.08 mV and also for its coating with albumin. Coated particles showed a spherical shape and a size range of 2-10 µm which does not fulfil parenteral formulations requirements but are optimal for nasal or dermatological administration routes.Los efectos de una vacuna dependen no solo del antígeno, sino también de factores relacionados con la formulación; la elección del sistema de liberación junto con el empleo de potenciadores inmunológicos son aspectos de gran relevancia. Actualmente existen numerosas estrategias en desarrollo en este campo basados en la utilización de liposomas. El objetivo de este  trabajo ha sido el diseño y la preparación de un vehículo para la administración de vacunas, capaz de liberar inmediatamente el coadyuvante y más lentamente el antígeno.  Analizando los conocimientos previos se realizó, en una primera fase,  el diseño teórico del vehículo y seguidamente la preparación y caracterización del mismo. La “formulación propuesta” se basa en la microencapsulación de liposomas, constituidos por fosfatidilcolina, colesterol y dimetildioctadecil amonio, con albumina bovina. El procedimiento experimental aplicado, que transcurre en ausencia de disolventes orgánicos,  permite obtener liposomas con un potencial zeta de  61,9 ±2,08 mV y tamaño entre 20 y 70 nm así como su inclusión en partículas esféricas de albúmina, cuyo rango de tamaño resultó ser de 2-10 µm. Con estas características el vehículo no podría administrarse por vía parenteral pero si nasal o transdérmica

Polymer [Pd(CH2SO2C6H4Me)2]n, a precursor to remarkably stable Pd organometallics

Producción CientíficaA polymer [Pd(CH2SO2C6H4Me)2]n is obtained by thermolysis of cis-[Pd(CH2SO2C6H4Me)2(NCMe)2] to release the MeCN ligands. The corresponding coordination sites are then occupied by weak Pd–O bonds, easier to break than the previous Pd–N bonds. This allows us to produce from the polymer cis complexes containing ligands weaker than NCMe, such as acetone or water. The complexes cis-[Pd(CH2SO2C6H4Me)2{OC(CD3)2}2], cis-[Pd(CH2SO2C6H4Me)2(OH2)2], and cis-[Pd(CH2SO2C6H4Me)2(OH2){OC(CD3)2}], and cyclic dimers [Pd(CH2SO2C6H4Me)2(OH2)]2 with bridging methylsulphone groups are formed. The Pd : PPh3 : OH2 1 : 1 : 1 reaction of the polymer produces cis-[Pd(CH2SO2C6H4Me)2(OH2)(PPh3)], which isomerizes to trans-[Pd(CH2SO2C6H4Me)2(OH2)(PPh3)], with water O-coordinated to Pd and making hydrogen bonds to the two SO2 groups as seen in its X-ray structure. A similar role is played by RNH2 groups in the structures of trans-[Pd(CH2SO2C6H4Me)2(NH3)(PPh3)] and the dimer μ-(N2H4)(trans-[Pd(CH2SO2C6H4Me)2(PPh3)])2. In addition to these interesting intramolecular hydrogen bonding properties provided by the SO2 groups, the structural and 1H NMR data available suggest that the CH2SO2C6H4Me group is an interesting kind of strong alkyl σ donor, with high trans influence, and forms very stable Pd complexes extraordinarily resistant to reductive elimination and to hydrolysis by water at room temperature.2018-08-08Ministerio de Economía, Industria y Competitividad (Projects CTQ2014-52796-P and CTQ2016-80913-P)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA256U13; UIC 176

Review of UAV positioning in indoor environments and new proposal based on US measurements

Este documento se considera que es una ponencia de congresos en lugar de un capítulo de libro.10th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2019) Pisa, Italy, September 30th - October 3rd, 2019The use of unmanned aerial vehicles (UAVs) has increased dramatically in recent years because of their huge potential in both civil and military applications and the decrease in prize of UAVs products. Location detection can be implemented through GNSS technology in outdoor environments, nevertheless its accuracy could be insufficient for some applications. Usability of GNSS in indoor environments is limited due to the signal attenuation as it cross through walls or the absence of line of sight. Considering the big market opportunity of indoor UAVs many researchers are devoting their efforts in the exploration of solutions for their positioning. Indoor UAV applications include location based services (LBS), advertisement, ambient assisted living environments or emergency response. This work is an update survey in UAV indoor localization, so it can provide a guide and technical comparison perspective of different technologies with their main advantages and drawbacks. Finally, we propose an approach based on an ultrasonic local positioning system.Universidad de AlcaláJunta de Comunidades de Castilla-La ManchaMinisterio de Economía, Industria y Competitivida

Influencia del sexo, la edad y el índice de masa corporal en la anatomía del colon sano. Variaciones anatómicas del colon sano

Objective: This study analyzes the influence of sex, age and body mass index on the anatomy of the colon as determined by three-dimensional reconstructions from computed tomography scans. Methods: 130 patients were included, each of whom underwent a three-dimensional reconstruction of the colon from abdominal CT scans without obvious signs of pathology. Information corresponding to sex, age and body mass index was obtained from each patient, and morphometric data obtained from measurements taken at the pubic symphysis, superior and inferior mesenteric artery, hepatic angle, splenic angle, ileocecal junction and sigmoid-descending colon junction were considered. Results: Morphological analysis showed an important anatomical variability of the reconstructed colon. Statistical analysis showed significant differences in the measurements obtained when grouping subjects by sex, age (under 65 years vs over 65 years) and body mass index (normopese, overweight and obese). Conclusions: Colon anatomical variations can be studied with three-dimensional reconstructions from CT scans, indicating that sex, age and body mass index have a significant influence on such variability.Objetivo: Este estudio analiza la influencia del sexo, la edad y el índice de masa corporal en la anatomía del colon, determinada por reconstrucciones tridimensionales, a partir de tomografías computarizadas. Metodología: Se incluyeron 130 pacientes, a cada uno de los cuales se les realizó una reconstrucción tridimensional del colon, a partir de tomografías computarizadas abdominales sin signos evidentes de patología. De cada paciente se obtuvo información correspondiente a las variables sexo, edad e índice de masa corporal, y se consideraron los datos morfométricos obtenidos de las mediciones realizadas en la sínfisis púbica, arteria mesentérica superior e inferior, ángulo hepático, ángulo esplénico, unión ileocecal y unión del colon sigmoideo-descendente. Resultados: El análisis morfológico mostró una importante variabilidad anatómica del colon reconstruido. El análisis estadístico mostró diferencias significativas en las medidas obtenidas al agrupar a los sujetos por sexo, edad (menores de 65 años vs mayores de 65 años) e índice de masa corporal (normopeso, sobrepeso y obesidad). Conclusiones: Las variaciones anatómicas del colon pueden estudiarse con reconstrucciones tridimensionales a partir de tomografías computarizadas, lo que indica que el sexo, la edad y el índice de masa corporal tienen una influencia significativa en dicha variabilidad