Development of Magnetostrictive Transducer Prototype for Blockage Detection on Molten Salt Pipes

In solar thermal power plants molten salt is often used to store and transport the energy that is collected during the day. The external pipe temperature is measured to activate an electric heating system if the temperature approaches the melting point. However, salt solidification cannot be completely excluded from the plant management. Once occurred, the location of a salt blockage is very complex due to the high temperature of the pipe. Therefore, when this problem arises, power plants have to stop production with the consequences in time and cost that this entails. Electro-magnetic acoustic transducers can be used as non-destructive testing systems for this application. A method for salt blockage detection is proposed that is applicable in straight sections of pipes by employing torsional guided waves that are generated with magnetostrictive transducers. The present paper deals with the transducer conception and the design of the power supply to activate it. Two alternatives are proposed and compared to determine the improvement in the amplitude/noise ratio. Finally, the experimental results show the performance of the equipment in a small prototype, thus validating the technique presented

A scalable WebRTC platform based on open technologies

International Conference on Computer, Information and Telecommunication Systems (7th, 2018, Colmar, Francia

Prevalencia y factores de riesgo de enfermedad grasa hepática no alcohólica en pacientes con enfermedad inflamatoria intestinal.

Introducción: La patogénesis de la enfermedad hepática grasa no alcohólica (EHGNA) y de laenfermedad inflamatoria intestinal (EII) no son del todo bien conocidas. La EHGNA podría tenersu origen en la resistencia insulínica y en las alteraciones metabólicas ligadas al depósito de grasahepática, junto con una asociación con el síndrome metabólico y la obesidad. A ello, se suma lareciente irrupción de la microbiota intestinal como otra posible causa (teoría “multi-hit”). Elorigen de la EII más aceptado es el de una activación del sistema inmune en relación con ladisbiosis de la microbiota intestinal unida a desencadenantes ambientales en individuosgenéticamente predispuestos. Diferentes estudios han propuesto una relación entre EHGNA y EII,planteando la existencia de dos fenotipos de EHGNA en pacientes con EII: un fenotipo asociadoa factores de riesgo metabólico y un fenotipo asociado a factores inflamatorios de la EII(inmunomediado).Objetivos: 1) Evaluar la prevalencia de EHGNA y fibrosis asociada en pacientes con EII. 2)Identificar factores de riesgo metabólico y no metabólico para el desarrollo de EHGNA enpacientes con EII.Material y métodos: Estudio transversal que incluyó pacientes consecutivos con EII atendidosen Hospital Clínico de Zaragoza a lo largo de febrero de 2020. Para el diagnóstico de EHGNA yfibrosis se realizó: ecografía, elastografía de transición con CAP e índices serológicos.Resultados: Se incluyeron 144 pacientes. La prevalencia de EHGNA y de fibrosis asociada fuede 39,3% y 2,2%, respectivamente. Se identificaron como factores de riesgo metabólico deEHGNA en pacientes con EII: DM-II (OR=12,32), hipercolesterolemia (OR=3,31),hipertrigliceridemia (OR=5,14), IMC elevado (OR=1,44, por cada punto de IMC) y síndromemetabólico (OR=8,43). La dieta mediterránea se halló como posible factor protector (OR=0,437).En lo referente al fenotipo inmunomediado, solo la edad al diagnóstico de la EII se asoció aldesarrollo de EHGNA (OR=1,03).Conclusiones: 1) La prevalencia de EHGNA en pacientes con EII es elevada, siendo laprevalencia de fibrosis similar a la descrita en población general. 2) Se confirma la asociación defactores de riesgo metabólico en el desarrollo de EHGNA en pacientes con EII, 3) La dietamediterránea parece tener un papel protector en el desarrollo de EHGNA en pacientes con EII.<br /

Li-Po Battery Charger Based on the Constant Current/Voltage Parallel Resonant Converter Operating in ZVS

Battery requirements for electrical vehicles are continuously becoming more demanding in terms of energy density and reliability. Nowadays, batteries for drones must be able to supply 100 A for 15 min, not to mention the specifications required for batteries in electrical vehicles. These specifications result in more stringent specifications for battery chargers. They are required to be more efficient, flexible, and, as with any another power equipment, to have reduced size and weight. Since the parallel resonant converter can operate as a current source and as a voltage source, this paper presents a battery charger power stage for lithium ion polymer batteries, based on the above topology, operating in zero voltage switching mode, and implementing frequency and duty cycle control

Reappraisal of the outcome of healthcare-associated and community-acquired bacteramia: a prospective cohort study

Background: Healthcare-associated (HCA) bloodstream infections (BSI) have been associated with worse outcomes, in terms of higher frequencies of antibiotic-resistant microorganisms and inappropriate therapy than strict community-acquired (CA) BSI. Recent changes in the epidemiology of community (CO)-BSI and treatment protocols may have modified this association. The objective of this study was to analyse the etiology, therapy and outcomes for CA and HCA BSI in our area. Methods: A prospective multicentre cohort including all CO-BSI episodes in adult patients was performed over a 3-month period in 2006–2007. Outcome variables were mortality and inappropriate empirical therapy. Adjusted analyses were performed by logistic regression. Results: 341 episodes of CO-BSI were included in the study. Acquisition was HCA in 56% (192 episodes) of them. Inappropriate empirical therapy was administered in 16.7% (57 episodes). All-cause mortality was 16.4% (56 patients) at day 14 and 20% (71 patients) at day 30. After controlling for age, Charlson index, source, etiology, presentation with severe sepsis or shock and inappropriate empirical treatment, acquisition type was not associated with an increase in 14-day or 30-day mortality. Only an stratified analysis of 14th-day mortality for Gram negatives BSI showed a statically significant difference (7% in CA vs 17% in HCA, p = 0,05). Factors independently related to inadequate empirical treatment in the community were: catheter source, cancer, and previous antimicrobial use; no association with HCA acquisition was found. Conclusion: HCA acquisition in our cohort was not a predictor for either inappropriate empirical treatment or increased mortality. These results might reflect recent changes in therapeutic protocols and epidemiological changes in community pathogens. Further studies should focus on recognising CA BSI due to resistant organisms facilitating an early and adequate treatment in patients with CA resistant BSI

Universal Solar Battery Charger for Off-Grid Storage Systems

A solar battery charged is designed, developed and tested in order to prove it as low-cost solution for isolated storage systems