Investigaciones financiadas por la Unión Europea (OpenAire) - Europar Batasunak finantzatutako ikerketak (OpenAire)

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Open Access
300 GHz optoelectronic transmitter combining integrated photonics and electronic multipliers for wireless communication
(MDPI, 2019) Ali, Muhsin; Pérez Escudero, José Manuel; Guzmán Martínez, Robinson Cruzoe; Lo, Mu Chieh; Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; García Muñoz, Luis Enrique; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
THz communications systems at carrier frequencies above 200 GHz are the key to enable next-generation mobile communication networks with 100 Gbit/s wireless data rates. One of the key questions is, which carrier frequency generation technique will be the most suitable. This is currently addressed by two separate approaches, electronics-based and photonics-based. We present in this paper a truly microwave photonic approach that benefits from the main key features of each, bandwidth, tunability, stability and fiber compatibility from photonics and power handling capability from the electronics. It is based on a Photonic Local Oscillator (PLO), generating a 100 GHz frequency, fed into an electronic frequency multiplier. A high speed uni-travelling carrier photodiode (UTC-PD) provides the 100 GHz PLO for Schottky tripler diodes, generating 300 GHz signal. To feed the UTC-PD, we present a photonic integrated mode locked laser source. According to the simulations and measurements, the developed transmitter can produce a maximum of 12 μWof THz power at 280 GHz.
Open Access
Addressing the impact of surface roughness on epsilon-near-zero silicon carbide substrates
(American Chemical Society, 2023) Navajas Hernández, David; Pérez Escudero, José Manuel; Martínez Hernández, María Elena; Goicoechea Fernández, Javier; Liberal Olleta, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Epsilon-near-zero (ENZ) media have been very actively investigated due to their unconventional wave phenomena and strengthened nonlinear response. However, the technological impact of ENZ media will be determined by the quality of realistic ENZ materials, including material loss and surface roughness. Here, we provide a comprehensive experimental study of the impact of surface roughness on ENZ substrates. Using silicon carbide (SiC) substrates with artificially induced roughness, we analyze samples whose roughness ranges from a few to hundreds of nanometer size scales. It is concluded that ENZ substrates with roughness in the few nanometer scale are negatively affected by coupling to longitudinal phonons and strong ENZ fields normal to the surface. On the other hand, when the roughness is in the hundreds of nanometers scale, the ENZ band is found to be more robust than dielectric and surface phonon polariton (SPhP) bands.
Open Access
Addressing the issue of trust in elementary teachers' maths-specific education: ANFoMAM project
(Charles University (Chequia), 2019) Celi, Valentina; Cogolludo, José Ignacio; Gil Clemente, Elena; Lizasoain Iriso, María Inmaculada; Millán Gasca, Ana; Moler Cuiral, José Antonio; Regoliosi, Luigi; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
To improve primary school teachers' maths-specific education at university, our project will develop a series of workshops, as ready-to-use instruments, which closely consider children's way of learning and their relationship with mathematics. Thus, the interest of participants in children is exploited in sessions which take into account both their professional work as teachers and their own childhood experiences. The aim is to help participants to evolve in the key aspect of trust. The paper describes the objectives and first results of the ANFoMAM project, supported by the Erasmus Plus Programme in the area of strategic partnerships for innovation in higher education in Europe.
Open Access
Advanced graphene-based transparent conductive electrodes for photovoltaic applications
(MDPI, 2019) Fernández, Susana; Boscá, Alberto; Pedrós, Jorge; Inés Ortigosa, Andrea; Fernández Vallejo, Montserrat; Arnedo Gil, Israel; González, José Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
New architectures of transparent conductive electrodes (TCEs) incorporating graphene monolayers in different configurations have been explored with the aim to improve the performance of silicon-heterojunction (SHJ) cell front transparent contacts. In SHJ technology, front electrodes play an important additional role as anti-reflectance (AR) coatings. In this work, different transparent-conductive-oxide (TCO) thin films have been combined with graphene monolayers in different configurations, yielding advanced transparent electrodes specifically designed to minimize surface reflection over a wide range of wavelengths and angles of incidence and to improve electrical performance. A preliminary analysis reveals a strong dependence of the optoelectronic properties of the TCEs on (i) the order in which the different thin films are deposited or the graphene is transferred and (ii) the specific TCO material used. The results shows a clear electrical improvement when three graphene monolayers are placed on top on 80-nm-thick ITO thin film. This optimum TCE presents sheet resistances as low as 55 Ω/sq and an average conductance as high as 13.12 mS. In addition, the spectral reflectance of this TCE also shows an important reduction in its weighted reflectance value of 2-3%. Hence, the work undergone so far clearly suggests the possibility to noticeably improve transparent electrodes with this approach and therefore to further enhance silicon-heterojunction cell performance. These results achieved so far clearly open the possibility to noticeably improve TCEs and therefore to further enhance SHJ contact-technology performance.
Open Access
Advances in fiber optic DNA-based sensors: a review
(IEEE, 2021) Santano Rivero, Desiree; Urrutia Azcona, Aitor; Ruiz Zamarreño, Carlos; Del Villar, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
DNA is becoming increasingly important in the domain of optical fiber sensors, either as a tool for biosensing, or as a target to detect. In this review the main contributions of the last years are presented both in the domain of wavelength and intensity based configurations. This review comprises the use of natural single strand DNA (ssDNA) sequences as receptors for the detection of ssDNA sequences through hybridization, synthetic nucleic acids receptors for detection of complementary ssDNA sequences, and sensors based on natural and synthetic ssDNA receptors used for the detection of non-DNA targets. Parameters such as sensitivity, detection range and limit of detection are analyzed and discussed in detail to the purpose of comparing the different technologies and knowing the future lines to follow in the domain of fiber optic DNA-based sensors.
Open Access
Agent-based modelling and simulation for hub and electric last mile distribution in Vienna
(Elsevier, 2023) Ballano Biurrun, Aitor; Al-Rahamneh, Anas; Serrano Hernández, Adrián; Faulín Fajardo, Javier; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA26-2022
With the rise of e-commerce and door-to-door sales, last-mile deliveries are gaining more and more importance. As a result, last-mile distribution has become one of the most sensitive logistics processes due to its uniqueness, difficulties in meeting schedules, and high costs. Therefore, this work explores the use of urban consolidation centers to ease these last-mile difficulties. For that purpose, a hub in the city center of Vienna has been selected to deliver up to 150 clients disseminated by the city. This suitability is assessed by defining convenient simulation settings in order to replicate parcel demands in the city. Experiments are based in different hub-based fleets (traditional internal combustion vehicles or electric cargo bikes), demand patterns, and delivery frequency strategies by means of a biased randomization vehicle routing optimization heuristic. Results quantify the effects of having an urban consolidation center and highlight the use of electric cargo bikes for the last-mile distribution.
Open Access
Aggregator to electric vehicle LoRaWAN based communication analysis in vehicle-to-grid systems in smart cities
(IEEE, 2020) Klaina, Hicham; Picallo Guembe, Imanol; López Iturri, Peio; Astrain Escola, José Javier; Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Estadística, Informática y Matemáticas
Recently, there has been growing attention to the power grid management due to the increasing concerns on global warming. With the advancement in electric vehicles (EV) industry and the evolution in batteries, EVs become an important contributor to the grid with capability of bidirectional power exchange with the grid. In this context, Vehicle-to-Grid (V2G) systems enable multiple functionalities between EVs and the corresponding aggregator. Thus, reliable, long-range communication capabilities between aggregator and EVs is compulsory. In this paper, wireless channel analysis for aggregator and electrical vehicle communication using Long-Range Wide Area Network (LoRaWAN) technology in V2G is presented, in order to test a low-cost solution with large coverage and reduced power consumption profile. Wireless channel and system-level measurements have been performed in a real urban scenario between EV's charging station in Pamplona (Spain) and a vehicle in motion using LoRaWAN 868 MHz devices. Wireless channel characterization is performed by implementing a full 3D urban scenario model, including elements such as buildings, vehicles, users and urban infrastructure such as lamp posts and benches. By means of in-house developed 3D Ray Launching algorithm with hybrid simulation capabilities, estimations of received power levels, signal to noise ratio and time domain parameters have been obtained, for the complete volume of the scenario under test in dense urban conditions. V2G end to end communication has been validated by implementing an intra-vehicle Controller Area Network-BUS (CAN BUS) data gathering system connected to the vehicle LoRaWAN transceiver and subsequently, to a cloud-based web service. The results show that the accurate deterministic based radio channel analysis enables to optimize the network design of LoRaWAN networks in a vehicular environment, considering inter-vehicular and infrastructure links, enabling scalable, low cost end to end data exchange for the deployment of ancillary V2G services.
Open Access
Aldosterone impairs mitochondrial function in human cardiac fibroblasts via A-kinase anchor protein 12
(Springer, 2018) Ibarrola Ulzurrun, Jaime Francisco; Sádaba Sagredo, Rafael; Martínez Martínez, Ernesto; García Peña, Amaia; Gaínza Calleja, Alicia; Ciencias de la Salud; Osasun Zientziak
Aldosterone (Aldo) contributes to mitochondrial dysfunction and cardiac oxidative stress. Using a proteomic approach, A-kinase anchor protein (AKAP)-12 has been identified as a down-regulated protein by Aldo in human cardiac fibroblasts. We aim to characterize whether AKAP-12 down-regulation could be a deleterious mechanism which induces mitochondrial dysfunction and oxidative stress in cardiac cells. Aldo down-regulated AKAP-12 via its mineralocorticoid receptor, increased oxidative stress and induced mitochondrial dysfunction characterized by decreased mitochondrial-DNA and Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expressions in human cardiac fibroblasts. CRISPR/Cas9-mediated knock-down of AKAP-12 produced similar deleterious effects in human cardiac fibroblasts. CRISPR/Cas9-mediated activation of AKAP-12 blunted Aldo effects on mitochondrial dysfunction and oxidative stress in human cardiac fibroblasts. In Aldo-salt-treated rats, cardiac AKAP-12, mitochondrial-DNA and PGC-1α expressions were decreased and paralleled increased oxidative stress. In myocardial biopsies from patients with aortic stenosis (AS, n = 26), AKAP-12, mitochondrial-DNA and PGC-1α expressions were decreased as compared to Controls (n = 13). Circulating Aldo levels inversely correlated with cardiac AKAP-12. PGC-1α positively associated with AKAP-12 and with mitochondrial-DNA. Aldo decreased AKAP-12 expression, impairing mitochondrial biogenesis and increasing cardiac oxidative stress. AKAP-12 down-regulation triggered by Aldo may represent an important event in the development of mitochondrial dysfunction and cardiac oxidative stress.
Open Access
Ammonia gas optical sensor based on lossy mode resonances
(IEEE, 2023) Armas, Dayron; Zubiate Orzanco, Pablo; Ruiz Zamarreño, Carlos; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This letter presents the fabrication and characterization of an ammonia (NH 3) gas optical sensor based on lossy mode resonances (LMRs). A chromium (III) oxide (Cr 2 O 3) thin film deposited onto a planar waveguide was used as LMR supporting coating. The obtained LMR shows a maximum attenuation wavelength or resonance wavelength centered at 673 nm. The optical properties of the coating can be modified as a function of the presence and concentration of NH 3 in the external medium. Consequently, the refractive index of the Cr 2 O 3 thin film will change, producing a red-shift of the resonance wavelength. Obtained devices were tested for different concentrations of NH 3 as well as repetitive cycles. Concentrations as low as 10 ppbv of NH 3 were detected at room temperature. Machine learning regression models were used to mitigate the cross-sensitivity of the device under temperature and humidity fluctuations.
Open Access
Analysis of copy number alterations reveals the lncRNA ALAL-1 as a regulator of lung cancer immune evasion
(Rockefeller University Press, 2020) Athie, Alejandro; Marchese, Francesco P.; González, Jovanna; Lozano, Teresa; Raimondi, Ivan; Juvvuna, Prasanna Kumar; Abad, Amaya ; Marin-Béjar, Oskar; Serizay, Jacques; Martínez, Dannys; Ajona, Daniel; Pajares Villandiego, María Josefa; Sandoval, Juan; Montuenga, Luis M.; Kanduri, Chandrasekhar ; Lasarte, Juan José; Huarte, Maite ; Ciencias de la Salud; Osasun Zientziak
Cancer is characterized by genomic instability leading to deletion or amplification of oncogenes or tumor suppressors. However, most of the altered regions are devoid of known cancer drivers. Here, we identify lncRNAs frequently lost or amplified in cancer. Among them, we found amplified lncRNA associated with lung cancer-1 (ALAL-1) as frequently amplified in lung adenocarcinomas. ALAL-1 is also overexpressed in additional tumor types, such as lung squamous carcinoma. The RNA product of ALAL-1 is able to promote the proliferation and tumorigenicity of lung cancer cells. ALAL-1 is a TNFα− and NF-κB–induced cytoplasmic lncRNA that specifically interacts with SART3, regulating the subcellular localization of the protein deubiquitinase USP4 and, in turn, its function in the cell. Interestingly, ALAL-1 expression inversely correlates with the immune infiltration of lung squamous tumors, while tumors with ALAL-1 amplification show lower infiltration of several types of immune cells. We have thus unveiled a pro-oncogenic lncRNA that mediates cancer immune evasion, pointing to a new target for immune potentiation.
Open Access
Analysis of gyrobianisotropic media effect on the input impedance, field distribution and mutual coupling of a printed dipole antenna
(Springer Nature, 2022) Bouknia, Mohamed Lamine; Zebiri, Chemseddine; Sayad, Djamel; Elfergani, Issa; Matin, Mohammad; Alibakhshikenari, Mohammad; Alharbi, Abdullah G.; Hu, Yim Fun; Abd-Alhameed, Raed; Rodriguez, Jonathan; Falcone Lanas, Francisco; Limiti, Ernesto; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this paper, we present an analytical study for the investigation of the effects of the magnetoelectric elements of a reciprocal and nonreciprocal bianisotropic grounded substrate on the input impedance, resonant length of a dipole antenna as well as on the mutual coupling between two element printed dipole array in three configuration geometries: broadside, collinear and echelon printed on the same material. This study examines also the effect of the considered bianisotropic medium on the electric and magnetic field distributions that has been less addressed in the literature for antenna structures. Computations are based on the numerical resolution, using the spectral method of moments, of the integral equation developed through the mathematical derivation of the appropriate spectral Green's functions of the studied dipole configuration. Original results, for chiral, achiral, Tellegen and general bi-anisotropic media cases, are obtained and discussed with the electric and magnetic field distributions for a better understanding and interpretation. These interesting results can serve as a stepping stone for further works to attract more attention to the reciprocal and non-reciprocal Tellgen media in-depth studies. © 2022, The Author(s).
Open Access
Analysis of low power wide area network wireless technologies in smart agriculture for large-scale farm monitoring and tractor communications
(Elsevier, 2022) Klaina, Hicham; Picallo Guembe, Imanol; López Iturri, Peio; Campo-Bescós, Miguel; Azpilicueta Fernández de las Heras, Leyre; Aghzout, Otman; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this paper, the assessment of multiple scenario cases for large-scale farm monitoring using Low-Power Wide-Area Network (LPWAN) based near-ground sensor nodes with the interaction of both tractors and farmers are presented. The proposed scenario under analysis considers multiple communication links, namely nodes to infrastructure, nodes to tractor, nodes to farmer, tractor to infrastructure and farmer to infrastructure communications. Moreover, these scenarios are proposed for tractors and agricultural equipment performance improvement and tracking, as well as resources management within the farm field. Different link type configurations are tested in order to consider the impact of ground, spatial distribution as well as infrastructure elements. The results show that LPWAN-based WSNs can provide better performance in terms of coverage and radio link quality results than ZigBee for a non-flat large-scale farm field in both cases of near-ground fixed nodes and moving tractor and farmer. The proposed systems are validated by cloud-based platforms for LoRaWAN, Sigfox and NB-IoT communications, providing flexible and scalable solutions to enable interactive farming applications.
Open Access
Analysis of the association between polymorphisms in intergenic regions of Staphylococcus aureus genes involved in biofilm formation and periprosthetic joint infections
(2022) Morales Laverde, Liliana Andrea; Lasa Uzcudun, Íñigo; Solano Goñi, Cristina; Ciencias de la Salud; Osasun Zientziak
In this thesis, we have focused on studying variants found in IGRs adjacent to the most important genes involved in S. aureus biofilm formation; the icaADBCR locus, and the genes encoding the family of surface adhesins. For this purpose, we sequenced the whole genome of a collection of 71 S. aureus isolates from periprosthetic joint infections (PJI) and wound infections stored at the Clinical Bacteriological Laboratory of the Sahlgrenska University Hospital and at the Culture Collection University of Gothenburg (CCUG), respectively. In the first chapter, we explored the regulatory regions of the icaADBCR locus to identify patterns that might be associated with an increased capacity of the isolates to produce PIA/PNAG and form a biofilm. This study compared the regulatory regions of the icaADBCR locus in the genomes of PJI and wound isolates with those in the genome of the reference strain MW2. From these analyses, strains were grouped based on the SNPs found in the IGRs of the operon and also within the coding region of the transcriptional regulator IcaR. These regions showed high conservation rates, and no pattern associated with the origin of the isolates, either PJI or wounds, was detected. On the other hand, using transcriptional fusions between the regulatory region of the icaADBCR locus and the green fluorescent protein gene (gfp), we demonstrated that the expression of icaADBC genes was not affected by the presence of variations in IGRs. Notably, a SNP within the coding region of icaR, which results in an amino acid change in the transcriptional repressor IcaR V176E, led to a significant increase in the transcription of the icaADBC operon and the production of PIA/PNAG. Using a Galleria mellonella infection model, we were able to demonstrate a significant reduction in S. aureus virulence associated with the increase in PIA/PNAG production. In the second chapter, we focused on analyzing the association between SNPs in the promoter regions of genes encoding adhesion-related proteins with adhesins expression levels and therefore, the ability of the strain to adhere to medical devices. Genome analyses of PJI and wound isolates showed different profiles in the content of adhesin-encoding genes. Some of these, such as sasG and cna, were lineage-associated, and fifteen genes were present in the whole collection of strains. When the variability in the SNPs contained in regulatory regions that control the expression of each adhesin was investigated, different variation rates were found among the isolates. Following the same approach as in chapter I, based on transcriptional fusions between regulatory regions and the gfp gene, results showed that each genetic lineage contained a specific profile of adhesins expression under the same environmental condition. Moreover, we developed a biomaterial-associated murine infection model together with a metagenomic analysis to simultaneously compare the capacity of different S. aureus isolates to colonize medical implants. In summary, our results evidenced that SNPs in the IGRs flanking the genes encoding factors important for biofilm development may contribute to the generation of variability in the capacity of S. aureus to colonize medical implants. In particular, our results revealed that IGRs controlling the expression of the icaADBC locus and production of the PIA/PNAG exopolysaccharide are highly conserved and that very few silent SNPs can be detected between strains. On the contrary, SNPs in the IGRs of genes encoding surface adhesins provide a profile of proteins expression that is specific for each S. aureus clonal complex (CC). Altogether, these studies emphasize the importance of investigating the potential impact of SNPs inside IGRs on gene expression and specific bacterial traits, such as pathogen colonization success.
Open Access
Analysis of the genetic diversity and structure across a wide range of germplasm reveals prominent gene flow in apple at the European level
(BioMed Central, 2016) Urrestarazu Vidart, Jorge; Denancé, Caroline; Ravon, Elisa; Guyader, Arnaud; Guisnel, Rémi; Feugey, Laurence; Poncet, Charles; Lateur, Marc; Houben, Patrick; Ordidge, Matthew; Fernández Fernández, Felicidad; Evans, Kate M.; Paprstein, Frantisek; Sedlak, Jiri; Nybom, Hilde; Garkava Gustavsson, Larisa; Miranda Jiménez, Carlos; Gassmann, Jennifer; Kellerhals, Markus; Suprun, Ivan; Pikunova, Anna V.; Krasova, Nina G.; Torutaeva, Elnura; Dondini, Luca; Tartarini, Stefano; Laurens, François; Durel, Charles Eric; Producción Agraria; Nekazaritza Ekoizpena
Background: The amount and structure of genetic diversity in dessert apple germplasm conserved at a European level is mostly unknown, since all diversity studies conducted in Europe until now have been performed on regional or national collections. Here, we applied a common set of 16 SSR markers to genotype more than 2,400 accessions across 14 collections representing three broad European geographic regions (North + East, West and South) with the aim to analyze the extent, distribution and structure of variation in the apple genetic resources in Europe. Results: A Bayesian model-based clustering approach showed that diversity was organized in three groups, although these were only moderately differentiated (FST = 0.031). A nested Bayesian clustering approach allowed identification of subgroups which revealed internal patterns of substructure within the groups, allowing a finer delineation of the variation into eight subgroups (FST = 0.044). The first level of stratification revealed an asymmetric division of the germplasm among the three groups, and a clear association was found with the geographical regions of origin of the cultivars. The substructure revealed clear partitioning of genetic groups among countries, but also interesting associations between subgroups and breeding purposes of recent cultivars or particular usage such as cider production. Additional parentage analyses allowed us to identify both putative parents of more than 40 old and/or local cultivars giving interesting insights in the pedigree of some emblematic cultivars. Conclusions: The variation found at group and subgroup levels may reflect a combination of historical processes of migration/selection and adaptive factors to diverse agricultural environments that, together with genetic drift, have resulted in extensive genetic variation but limited population structure. The European dessert apple germplasm represents an important source of genetic diversity with a strong historical and patrimonial value. The present work thus constitutes a decisive step in the field of conservation genetics. Moreover, the obtained data can be used for defining a European apple core collection useful for further identification of genomic regions associated with commercially important horticultural traits in apple through genome-wide association studies.
Open Access
Analysis of the suitability of the EOLO wind-predictor model for the spanish electricity markets
(MDPI, 2023) Martínez-Lastras, Saray; Frías Paredes, Laura; Prieto-Herráez, Diego; Gastón Romeo, Martín; González-Aguilera, Diego; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
Wind energy forecasting is a critical aspect for wind energy producers, given that the chaotic nature and the intermittence of meteorological wind cause difficulties for both the integration and the commercialization of wind-produced electricity. For most European producers, the quality of the forecast also affects their financial outcomes since it is necessary to include the impact of imbalance penalties due to the regularization in balancing markets. To help wind farm owners in the elaboration of offers for electricity markets, the EOLO predictor model can be used. This tool combines different sources of data, such as meteorological forecasts, electric market information, and historic production of the wind farm, to generate an estimation of the energy to be produced, which maximizes its financial performance by minimizing the imbalance penalties. This research study aimed to evaluate the performance of the EOLO predictor model when it is applied to the different Spanish electricity markets, focusing on the statistical analysis of its results. Results show how the wind energy forecast generated by EOLO anticipates real electricity generation with high accuracy and stability, providing a reduced forecast error when it is used to participate in successive sessions of the Spanish electricity market. The obtained error, in terms of RMAE, ranges from 8%, when it is applied to the Day-ahead market, to 6%, when it is applied to the last intraday market. In financial terms, the prediction achieves a financial performance near 99% once imbalance penalties have been discounted.
Open Access
Analytical ray transfer matrix for the crystalline lens
(OSA Publishing, 2022) Navarro, Rafael; Lockett-Ruiz, Verónica; López García, José Luis; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
We present the formulation of a paraxial ray transfer or ABCD matrix for onion-type GRIN lenses. In GRIN lenses, each iso-indicial surface (IIS) can be considered a refracting optical surface. If each IIS is a shell or layer, the ABCD matrix of a GRIN lens is computed by multiplying a typically high number of translation and refraction matrices corresponding to the K layers inside the lens. Using a differential approximation for the layer thickness, this matrix product becomes a sum. The elements A, B, C, and D of the approximated GRIN ray transfer matrix can be calculated by integrating the elements of a single-layer matrix. This ABCD matrix differs from a homogeneous lens matrix in only one integration term in element C, corresponding to the GRIN contribution to the lens power. Thus the total GRIN lens power is the sum of the homogeneous lens power and the GRIN contribution, which offers a compact and simple expression for the ABDC matrix. We then apply this formulation to the crystalline lens and implement both numerical and analytical integration procedures to obtain the GRIN lens power. The analytical approximation provides an accurate solution in terms of Gaussian hypergeometric functions. Last, we compare our numerical and analytical procedures with published ABCD matrix methods in the literature, and analyze the effect of the iso-indicial surface’s conic constant (Q) and inner curvature gradient (G) on the lens power for different lens models.
Open Access
Anomalous relative intensity noise transfer in ultralong random fiber lasers
(Optical Society of America, 2020) Rota Rodrigo, Sergio; Rizzelli, Giuseppe; Leandro González, Daniel; Nuño, J.; López-Amo Sáinz, Manuel; Institute of Smart Cities - ISC
We present, for the first time, an experimental demonstration of RIN noise transfer dampening at low frequencies in random distributed feedback ultralong Raman fibre lasers based on conventional telecommunication fibres. Furthermore, we present a thorough theoretical description of the phenomenon and demonstrate how our model can be used to predict the observed behaviour, identifying the general requirements for system improvement through RIN transfer reduction.
Open Access
Antenna mutual coupling suppression over wideband using embedded periphery slot for antenna arrays
(MDPI, 2018) Alibakhshikenari, Mohammad; Virdee, Bal S.; Shukla, Panchamkumar; See, Chan H.; Abd-Alhameed, Raed; Khalily, Mohsen; Falcone Lanas, Francisco; Limiti, Ernesto; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This paper presents a new approach to suppress interference between neighbouring radiating elements resulting from surface wave currents. The proposed technique will enable the realization of low-profile implementation of highly dense antenna configuration necessary in SAR and MIMO communication systems. Unlike other conventional techniques of mutual coupling suppression where a decoupling slab is located between the radiating antennas the proposed technique is simpler and only requires embedding linear slots near the periphery of the patch. Attributes of this technique are (i) significant improvement in the maximum isolation between the adjacent antennas by 26.7 dB in X-band and >15 dB in Ku and K-bands; (ii) reduction in edge-to-edge gap between antennas to 10 mm (0.37 ); and (iii) improvement in gain by >40% over certain angular directions, which varies between 4.5 dBi and 8.2 dBi. The proposed technique is simple to implement at low cost.
Open Access
Anti-inflammatory and chondroprotective effects induced by phenolic compounds from onion waste extracts in ATDC-5 chondrogenic cell line
(MDPI, 2022) Paesa, Mónica; Ancín Azpilicueta, Carmen; Velderrain-Rodríguez, Gustavo; Martín-Belloso, Olga; Gualillo, Oreste; Osada, Jesús; Rodríguez Yoldi, María Jesús; Mendoza, Gracia; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
Osteoarthritis is a prevalent degenerative condition that is closely related to the destruction and inflammation of cartilage. The high prevalence of this pathology exhorts researchers to search for novel therapeutic approaches. Vegetable–fruit wastes have emerged as a promising origin of anti-inflammatory and antioxidant compounds that, in some cases, may also exert chondroprotective effects. This study aims to decipher the potential of onion waste products in the inhibition of molecular events involved in osteoarthritis. Onion extracts showed a high content of phenolic compounds and antioxidant properties. Cytocompatibility was demonstrated in the chondrogenic cell line ATDC-5, exerting viability percentages higher than 90% and a slight increase in the S phase cycle cell. The induction of inflammation mediated by the lipopolysaccharide and onion extracts’ treatment substantially inhibited molecular markers related to inflammation and cartilage degradation, highlighting the promising application of onion extracts in biomedical approaches. The in silico analyses suggested that the results could be attributed to protocatechuic, ellagic, and vanillic acids’ greater cell membrane permeability. Our work provides distinctive information about the possible application of waste onion extracts as functional components with anti-inflammatory and chondroprotective characteristics in osteoarthritis.
Open Access
Antioxidant properties of leaves from different accessions of grapevine (vitis vinifera L.) cv. tempranillo after applying biotic and/or environmental modulator factors
(Elsevier, 2015-01-17) Torres Molina, Nazareth; Antolín, M. Carmen; Goicoechea, Nieves; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Within climate change scenario, the maintenance of grape quality and wine characteristics will be the main concern for viticulture in the future years. However, changes in the composition of grapevine pruning wastes (i.e., leaves and stems) could be another interesting aspect as important antioxidant source for pharmaceutical industry due its richness in phenolic compounds beneficial for human health. To date, the effect of biotic and environmental factors in the accumulation of these compounds in leaves had received little attention. Therefore, the aims of study were (1) to evaluate the effect of biotic (mycorrhizal inoculation) and environmental (temperature) factors, alone or combined, on phenolic composition and antioxidant activity of leaf extracts of grapevine and (2) to determine whether such effects differed among accessions of the same cultivar of grapevine. The study was carried out using container-grown grapevines grown in greenhouses. Dormant Vitis vinifera (L.) cuttings of different accessions of Tempranillo were selected to get fruit-bearing cuttings. At transplanting, half of the plants of each accession were inoculated with the mycorrhizal inoculum and after fruit set, plants were exposed to two temperature regimes (24 °C/14 °C and 28 °C/18 °C (day/night)) to commercially berry ripe. Results showed that total phenolic content, antioxidant compounds like flavonols and anthocyanins, and antioxidant activity of leaves were improved with mycorrhizal inoculation under high temperature conditions. It was concluded that mycorrhizal inoculation of grapevines could contribute to preserve high level of antioxidant compounds of leaves in a future climate change scenario. However, the effects were strongly dependent of accession assayed, which indicated a significant intra-varietal diversity in the response of Tempranillo to biotic and environmental factors.