Adaptative ECT System Based on Reconfigurable Electronics

In this work we present a novel scheme for the design of electrical capacitance tomography systems that is based on the use of reconfigurable electronics. The objective of this strategy is to generate an adaptable and portable prototype for the processing electronics, i.e., an instrument suitable to be easily transported and applied to different ECT sensors and scenarios with no need of hardware redesign. In order to show the benefits of this approach, a prototype of the processing electronics for the readings of the inter-electrode capacitance values has been implemented using a Programmable System on Chip (PSoC) that allows configuring both analog and digital blocks included in the design. The result is a compact and portable instrument that can work with any ECT sensor up to 8 electrodes. The measurements are sent through a wireless Bluetooth link to an external smart-device such as smartphone, where the permittivity distribution is reconstructed using a custom-developed Android application.Junta de Andalucía (University Professor and Researcher Training Program – FPDI grant)EI BIOTiC under project MPTIC1

Non-Intrusive Tank-Filling Sensor Based on Sound Resonance

Different types of fill-level measurement systems exist in the market, but most of them imply some type of intrusion in the tank itself. In this paper, a reconfigurable system based on sound resonance for measuring the fill-level of a tank from the exterior is presented. A relation between sound resonance frequencies and the content of the tank has been found, especially as the tank gets closer to being full. A prototype has been created using reconfigurable technologies combined with wireless communications in order to control the system from an ad hoc application. With this prototype, the fill-level of different tanks has been measured with good resolution, especially when the tank is over half of its capacity

Bitumen chemical modification by thiourea dioxide

This work evaluates a novel bitumen modification through the use of a chemical agent, thiourea dioxide, substance which has been traditionally used as a reducing agent. Thermogravimetric analysis demonstrated the formation of new chemical compounds, most probably originated through reactions between products from thiourea dioxide thermal decomposition and some highly polar bitumen molecules. As a result of these reactions, which continues even after 60 days, bitumen permanent deformation resistance at high temperature is enhanced, as indicated by a significant increase in its viscosity and elastic features. On the other hand, thiourea dioxide addition produces changes in the bitumen colloidal nature, which improve its flexibility at low in-service temperatures, and consequently its resistance to thermal cracking under loading. In fact, dynamic bending tests indicated a remarkable decrease in the value of binder glass transition temperature, which was further corroborated by differential scanning calorimetry. As a conclusion, thiourea dioxide can be seen as a promising modifiying agent, which can extend the in-service temperature range at which bitumen would present a satisfactory performance.This work is part of a research project sponsored by a MEC-FEDER Programme (Research Project MAT2007-61460) and by a Junta de Andalucía Programme (TEP6689). The authors gratefully acknowledge its financial support. A.A.Cuadri also acknowledges the concession of MEC FPU research fellowship (AP2008-01419).This work is part of a research project sponsored by a MEC - FEDER P rogramme (Research Project MAT2 007 - 61460) and by a Junta de Andaluc í a Programme (TEP6689). The authors gratefully acknowledge its financial support. A.A.Cuadri also acknowledges the concession of MEC FPU research fellowship (AP2008 - 01419).This work is part of a research project sponsored by a MEC-FEDER Programme (Research Project MAT2007-61460) and by a Junta de Andalucia Programme (TEP6689). The authors gratefully acknowledge its financial support. A.A. Cuadri also acknowledges the concession of MEC FPU research fellowship (AP2008-01419)

Design and implementation of an OFDMA-TDD physical layer for WiMAX applications

[Abstract]: This work describes the design, implementation, and performance evaluation of an orthogonal frequency division multiple access (OFDMA) time-division duplexing (TDD) physical layer (PHY) compliant with the worldwide interoperability for microwave access (WiMAX) standard using a costeffective software-defined radio (SDR) platform containing field programmable gate array (FPGA) and digital signal processor (DSP) modules. We show that the proposed SDR architecture is capable of supporting the wide variety of configuration options described in the WiMAX standard while fulfilling the stringent requirements of WiMAX OFDMA TDD PHYs. The architecture allows for the implementation of all TDD functionalities in the downlink and the uplink at both the base station and the mobile station. The proposed design is shown to efficiently use the available FPGA and DSP resources. We also carried out specific experiments that take into account the frame and the downlink map messages detection over ITU-R wireless channel models to illustrate the performance of the proposed design. Finally, we discuss the utilization of the proposed hardware architecture to implement the wirelessMAN-advanced air interface.This work has been partially supported by Indra Sistemas S.A., the Spanish Ministry of Defence with the technical direction of PEC/ITM under grant DN8644-COINCIDENTE, MINECO of Spain under grant TEC2010-19545-C04-01 and Xunta de Galicia, Spain, under grant 2012/287. The authors wish to thank J. M. Camas-Albar from Indra Sistemas S.A. for his help.Xunta de Galicia; 2012/28

A Real-Time Implementation of the Mobile WiMAX ARQ and Physical Layer

This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s11265-014-0890-3.[Abstract] This paper presents an innovative software-defined radio architecture for the real-time implementation of WiMAX transceivers. The architecture consists of commercially available field-programmable gate array and digital signal processor modules. We show how the architecture can be used for the real-time implementation of a full-featured standard-compliant time-division duplex WiMAX physical layer together with the ARQ functionality of the MAC layer. Both the mobile and the base station contain a transmitter and a receiver to enable real-time concurrent downlink and uplink communications. The design supports the different configurations defined by the standard and the WiMAX Forum. This work also provides the verification and validation of the proposed real-time implementation based on repeatable and reproducible performance evaluation considering the reference scenarios defined by the WiMAX Forum, including both static and mobile scenarios. Typical figures of merit such as physical-layer bit and frame error rates and MAC-layer throughput are obtained with the help of a custom-made real-time channel emulator implementing the channel models defined by the WiMAX Forum.This work has been partially supported by Indra Sistemas S.A. and the Spanish Ministry of Defence with the technical direction of PEC/ITM under grant DN8644-COINCIDENTE. The authors wish to thank J. M. Camas-Albar from Indra Sistemas S.A. for his help. This work has been additionally funded by Xunta de Galicia, Ministerio de Ciencia e Innovacin of Spain, and FEDER funds of the European Union under grants with numbers 2012/287, TEC2010-19545-C04-01, and CSD2008-00010.Xunta de Galicia; 2012/28

Real-time validation of a SDR implementation of TDD WiMAX standard

[Abstract]: This paper focuses on the validation of an innovative software- defined radio architecture for a WiMAX system based on commercially available field-programmable gate array and digital signal processor modules. We provide a realtime implementation of a standard-compliant time-division duplex physical layer including a mobile and a base station as well as downlink and uplink communications, thus obtaining a full-featured physical layer. Additionally, a set of different configurations are supported as described in the standard and in the WiMAX Forum. The main contribution of the paper consists in a reproducible and repeatable validation of the implementation in representative scenarios. At the same time, a characterization of the performance exhibited by the system is provided based on bit error rate measurements carried out using a custom-made, real-time channel emulator.This work has been partially supported by Indra Sistemas S.A. and the Spanish Ministry of Defence with the technical direction of PEC/ITM under grant DN8644-COINCIDENTE. The authors wish to thank J. M. Camas- Albar from Indra Sistemas S.A. for his help. This work has been additionally funded by Xunta de Galicia, Ministerio de Ciencia e Innovación of Spain, and FEDER funds of the European Union under grants with numbers 10TIC003CT, 09TIC008105PR, TEC2010-19545- C04-01, and CSD2008-00010.Xunta de Galicia; 10TIC003CTXunta de Galicia; 09TIC008105P

Thermal, rheological and microstructural characterisation of commercial biodegradable polyesters

Growing environmental concerns along with new regulations are forcing the industries to seek renewable raw materials for their products. In this sense, this work studies the thermo-rheological properties of commercial biodegradable polyesters: two polylactic acids (PLAs), a polycaprolactone (PCL) and a PLA/PCL blend. A comprehensive material characterization by means of thermogravimetry/differential thermal analysis (TG/DTA), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), frequency sweep tests and polarized light microscopy was carried out. The results have shown that the material thermal/thermo-rheological properties and, therefore, its microstructure, are strongly dependent on its thermal history. This fact arises from the slow recrystallization kinetics shown by PLA. Interestingly, PCL may play the role of nucleating agent for the PLA crystallization, making it faster. This issue must be carefully considered so that a reliable material characterization is achieved.This work is part of a research project sponsored by the “Ministerio de Economía y Competitividad” (ref. MAT2011-29275-C02-01). The authors gratefully acknowledge its financial support. A.A. Cuadri also thanks “Ministerio de Educación” for the concession of a F.P.U. research grant (AP2008-01419).This work is part of a research project sponsored by the "Ministerio de Economia y Competitividad" (ref. MAT2011-29275-C02-01). The authors gratefully acknowledge its financial support. A.A. Cuadri also thanks "Ministerio de Educacion" for the concession of a F.P.U. research grant (AP2008-01419)

Effect of digestive enzymes on the bioactive properties of goat milk protein hydrolysates

The aim of this research was to study the influence of the gastrointestinal digestion on the bioactivity of goat milk protein hydrolysates prepared with subtilisin, trypsin and a combination of these two enzymes. All hydrolysates had excellent angiotensin converting enzyme (ACE) inhibitory activity, antioxidant activity and bile acid-binding capacity. Peptide profiles and bioactivities were mainly altered during the intestinal digestion, whereas the effect of the gastric digestion was negligible. The influence of the intestinal digestion varied depending on the hydrolysate and the bioactivity studied. In the case of ACE inhibitory activity, it exclusively decreased when peptides were produced with trypsin. In contrast, antioxidant activity and bile acid-binding capacity improved after the gastrointestinal digestion, regardless the enzymatic treatment conducted. Hydrolysis employing mixtures of subtilisin and trypsin is considered a good approach to produce peptides that maintain, or even enhance, their bioactivity after digestion.Consejería de Innovación, Ciencia y Empresa of Junta de Andalucía (project P12-AGR-1993)Consejería de Innovación, Ciencia y Empresa of Junta de Andalucía (postdoctoral position of F. Javier Espejo-Carpio - project TEP-02579

Coinage metal complexes bearing fluorinated N-Heterocyclic carbene ligands

The synthesis of novel fluorinated symmetrical and unsymmetrical imidazolium salts as well as their corresponding coinage metal complexes is described. The silver derivatives were prepared using Ag2O as the metal source and the subsequent (NHC)AgX complexes were successfully employed in the preparation of the corresponding Cu(I) and Au(I) complexes through transmetallation reactions. Halide extrusion from (NHC)AuCl complexes in the presence of labile ligands also allowed the isolation of Au(I) cationic complexes [(NHC)Au(L)]X. The molecular structures of relevant examples of the neutral and ionic complexes have been unambiguously determined by X-ray studies.The authors thank Agencia Estatal de Investigación (AEI)/FEDER (CTQ2017-82893-C2-1-R, CTQ2016- 75960-P), Red Intecat CTQ2016-81923-REDC, the AGAUR (2017 SGR 1257), and CERCA Program/Generalitat de Catalunya for financial support. M. D. R. thanks the Ministerio de Educación y Ciencia (MEC) for a FPU fellowship and C. G.-M. thanks Agencia Estatal de Investigación for a FPI predoctoral fellowship

A clustering-based method for single-channel fetal heart rate monitoring

Non-invasive fetal electrocardiography (ECG) is based on the acquisition of signals from abdominal surface electrodes. The composite abdominal signal consists of the maternal electrocardiogram along with the fetal electrocardiogram and other electrical interferences. These recordings allow for the acquisition of valuable and reliable information that helps ensure fetal well-being during pregnancy. This paper introduces a procedure for fetal heart rate extraction from a single-channel abdominal ECG signal. The procedure is composed of three main stages: a method based on wavelet for signal denoising, a new clustering-based methodology for detecting fetal QRS complexes, and a final stage to correct false positives and false negatives. The novelty of the procedure thus relies on using clustering techniques to classify singularities from the abdominal ECG into three types: maternal QRS complexes, fetal QRS complexes, and noise. The amplitude and time distance of all the local maxima followed by a local minimum were selected as features for the clustering classification. A wide set of real abdominal ECG recordings from two different databases, providing a large range of different characteristics, was used to illustrate the efficiency of the proposed method. The accuracy achieved shows that the proposed technique exhibits a competitve performance when compared to other recent works in the literature and a better performance over threshold-based techniques.This work has been partially funded by Banco Santander and Centro Mixto UGR-MADOC through project SIMMA (code 2/16). The contribution of Antonio García has been partially funded by Spain's Ministerio de Educación, Cultura y Deporte (Programa Estatal de Promoción del Talento y su Empleabilidad en I+D+i, Subprograma Estatal de Movilidad, within Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016) under a "Salvador de Madariaga" grant (PRX17/00287)