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Image database for the scientific paper: Deep Learning Algorithm, Based on Convolutional Neural Networks, for Equivalent Electrical Circuit Recommendation for Electrochemical Impedance Spectroscopy

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Pérez Herranz, Valentín|||0000-0002-4010-0888
  • Giner Sanz, Juan José|||0000-0003-0441-6102
  • Sáez Pardo, Fermín
The present dataset is the database and image database used to train and test the Convolutional Neural Network models of the scientific paper: Deep Learning algorithm, based on convolutional neural networks, for electrical equivalent electrical circuit recommendation for Electrochemical Impedance Spectroscopy




Modeling and Evaluation of Oxy-Combustion and In Situ Oxygen Production in a Two-Stroke Marine Engine

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Serrano, J.R.|||0000-0003-0692-3917
  • Arnau Martínez, Francisco José|||0000-0003-2902-0630
  • Calvo, Alejandro
  • Burgos, Rossana
[EN] Considering the concerns for emissions reduction in the maritime sector, the present paper evaluates, through modeling and simulation, oxy-fuel combustion in a two-stroke ship engine (2SE) and the best production system configuration to obtain the required oxygen (O2). An initial model of a ship engine is calibrated with the engine manufacturer's data and then adapted to work with O2 as the oxidant to eliminate nitrogen oxide (NOx) emissions and with exhaust gas recirculation (EGR) to control the in-cylinder combustion temperature. Mixed Ionic-Electronic Conducting (MIEC) membranes produce the necessary O2 from the ambient air, which is heated up and pressurized by a heat exchanger and turbocharging coupled system to provide the air conditions required for the proper operation of the MIEC. Several layouts of this system are evaluated for the full load engine operating point to find the optimum O2 production system configuration. Results reveal that the engine operating under oxy-fuel combustion conditions avoids NOx emissions at the expense of higher brake-specific fuel consumption (BSFC) to obtain the original brake torque, and also expels a stream composed exclusively of CO2 and H2O, which facilitates the separation of CO2 from exhaust gases., This research has been partially supported by Grant CIPROM/2021/061 funded by Generalitat Valenciana. Also partially supported by Grant PID2021-123351OB-I00 funded by MCIN/AEI/10.13039/501100011033 and, as appropriate, by ERDF A way of making Europe . And also partially funded by Programa de Ayudas de Investigación y Desarrollo PAID-01-22, from Universitat Politècnica de València (UPV) which granted the Rossana s pre-doctoral contract.




Optimizing the use of light in supported TiO2 photocatalysts: Relevance of the shell thickness

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Cabezuelo-Gandia, Oscar
  • Diego-López, Ander|||0000-0001-5947-9579
  • Atienzar Corvillo, Pedro Enrique|||0000-0002-0356-021X
  • Marín García, Mª Luisa|||0000-0002-9789-8894
  • Bosca Mayans, Francisco
[EN] Heterogeneous photocatalysts have attracted significant interest over the last few years. In this sense, improved photocatalytic properties for SiO2@TiO2 materials have been correlated with higher semiconductor's specific surface area and adsorption capability. However, the reported TiO2 shell optimizations did not consider the percentage of the photo-excited electron-hole (e¿-h+) pairs occurring in the inaccessible surface of the TiO2 shell. The present study aimed to find the best TiO2 shell thickness for the optimal harvest of light. For this purpose, the sol¿gel method was modified by applying a precise humid airflow to get a uniform deposition of titania on the surface of the SiO2 particles. As a result, photocatalysts with a robust and homogeneous TiO2 shell of different thicknesses (from 14 to 42 nm) with well-defined particle size for TiO2 crystals (ca. 12 nm) were obtained. The SiO2@TiO2 materials were extensively characterized. Finally, their photocatalytic activity was evaluated against methylene blue under irradiation by UVA light. Analysis of the results revealed that the most efficient photocatalyst has a TiO2 shell thickness of ca. 30 nm. Emission and photocurrent studies also agreed with the photocatalytic results suggesting a reduced e¿-h+ recombination rate. Thereby, for the first time, the relevance of shell thickness in supported photocatalysts has been demonstrated., The authors would like to acknowledge the Spanish Ministry of Science, Innovation, and Universities (PID2019-110441RB-C33 financed by MCIN/AEI/10.13039/501100011033 and TED2021-131952B-I00 financed by MCIN/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR). O. Cabezuelo and A. Diego-Lopez are indebted to the Universitat Politecnica de Valencia for the corresponding Predoctoral FPI fellowship (FPI-UPV/Subprograma 1). The authors would like to acknowledge the Servei de Microscopia Electronica from the Universitat Politecnica de Valencia (UPV) for the support on the composite characterization and sample preparation.Funding for the open access charge provided by CRUE-Universitat Politecnica de Valencia is acknowledged.r Funding for the open access charge provided by CRUE-Universitat Politècnica de València is acknowledged.




Association between Dietary Intake and Faecal Microbiota in Children with Cystic Fibrosis

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Viteri-Echeverría, Jazmín Dayumara|||0000-0002-7692-9161
  • Calvo-Lerma, Joaquim
  • Ferriz-Jordán, Miguel
  • Garriga, María
  • García Hernández, Jorge|||0000-0003-1258-6128
  • Heredia Gutiérrez, Ana Belén|||0000-0001-6629-9779
  • Ribes-Koninckx, Carmen
  • Andrés Grau, Ana María|||0000-0002-6132-3167
  • Asensio-Grau, Andrea|||0000-0001-9591-5534
[EN] A "high-fat, high-energy diet" is commonly recommended for children with cystic fibrosis (CF), leading to negative consequences on dietary patterns that could contribute to altered colonic microbiota. The aim of this study was to assess dietary intake and to identify possible associations with the composition of faecal microbiota in a cohort of children with CF. A cross-sectional observational study was conducted, including a 3-day food record simultaneously with the collection of faecal samples. The results showed a high fat intake (43.9% of total energy intake) and a mean dietary fibre intake of 10.6 g/day. The faecal microbiota was characterised at the phylum level as 54.5% Firmicutes and revealed an altered proportion between Proteobacteria (32%) and Bacteroidota (2.2%). Significant associations were found, including a negative association between protein, meat, and fish intake and Bifidobacterium, a positive association between lipids and Escherichia/Shigella and Streptococcus, a negative association between carbohydrates and Veillonella and Klebsiella, and a positive association between total dietary fibre and Bacteroides and Roseburia. The results reveal that a "high-fat, high-energy" diet does not satisfy dietary fibre intake from healthy food sources in children with CF. Further interventional studies are encouraged to explore the potential of shifting to a high-fibre or standard healthy diet to improve colonic microbiota., The authors would like to thank the Universitat Politècnica de València for the pre-doctoral
contract from Vicerrectorado de Investigación given to Jazmín Viteri Echeverría (PAID-01-22). This
project was funded with the First Project Grant (PAID-06-22) and Postdoctoral Research Fostering Grant (PAIDPD-22) from Vicerrectorado de Investigación (Universitat Politècnica de València)
awarded to Andrea Asensio-Grau.




Synthesis and mechanistic insights of SiO2@WO3@Fe3O4 as a Novel Supported Photocatalyst for Wastewater Remediation under Visible Light

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Diego-López, Ander|||0000-0001-5947-9579
  • Cabezuelo, Oscar
  • Vidal Moya, José Alejandro
  • Marín García, Mª Luisa|||0000-0002-9789-8894
  • Bosca Mayans, Francisco
[EN] A new optimized photocatalyst for wastewater remediation at neutral pH has been developed and fully characterized. The catalyst features microparticles of SiO2 as a supporting substrate and a uniform shell of WO3 nanoparticles externally decorated with Fe3O4 nanocrystals. The photocatalytic activity of SiO2@WO3@Fe3O4 was evaluated and compared to its SiO2@WO3 counterpart on the photodegradation of methylene blue (MB) under visible light, with and without H2O2. Best results were obtained for SiO2@WO3@Fe3O4 in the presence of H2O2, whose potential for wastewater remediation was further evaluated on the photodegradation and mineralization of a contaminant of emerging concern such as diclofenac (DCF). Furthermore, a photocatalytic mechanism was proposed based on the performed electron paramagnetic resonance (EPR) experiments, which provided evidence for the intermediates generated in all the involved photocatalytic processes. Hence it was proven that .OH is the species responsible for the photocatalyzed oxidation of MB and DCF. The generation of .OH is boosted by a synergistic effect between Fe3O4 and WO3 in the presence of light and H2O2., The authors would like to acknowledge the Spanish Ministry of Science, Innovation, and Universities (PID2019-110441RB-C33 financed by MCIN/AEI/10.13039/501100011033 and TED2021-131952B-I00 financed by MCIN/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR) . A. Diego-Lopez and O. Cabezuelo are indebted to the Universitat Politecnica de Valencia for the Predoctoral FPI fellowship (FPI-UPV/Subprograma 1) . The authors would like to acknowledge the Servei de Microscopia Electronica from the Universitat Politecnica de Valencia (UPV) for the support on the composite characterization and sample preparation.




Effect of Extrusion Compression Ratio and Particle Size of Rice on the Sectional Expansion Index of Third-Generation Snacks

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Vicente-Jurado, Diana
  • García-Segovia, Purificación|||0000-0002-4968-5050
  • Gutiérrez Cano, José Daniel
  • Martínez-Monzó, Javier|||0000-0002-1123-2304
  • Catalá Civera, José Manuel|||0000-0002-0617-1762
  • Igual Ramo, Marta|||0000-0001-5128-5489
[EN] Third-generation (3G) rice pellets were obtained using rice flour (RF) and rice grits (RG), raw materials of similar compositions but different particle sizes. The samples were mixed with water to 25% moisture and extruded using a laboratory single-screw extruder (Kompakt KE 19/25 extruder) and three compression ratios (1:1, 2:1, and 3:1). The pellets were expanded using a microwave oven subjected to 1000 W/g power. After evaluating the expansion kinetics and the sectional expansion index (SEI), it was observed that the 3:1 compression ratio allowed for greater expansion, while the particle difference showed no significant difference (p > 0.05) in the SEI., This research was funded by the FPI Ph.D. contract granted by Universitat Politècnica de València Subprograma 1 (PAID-01-22).




3D Point Cloud and GIS Approach to Assess Street Physical Attributes

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Orozco-Carpio, Patricio Rodrigo|||0009-0007-3437-7390
  • Viñals, Mª José|||0000-0002-7589-7815
  • López González, María Concepción|||0000-0001-7542-3559
[EN] The present research explores an innovative approach to objectively assessing urban streets attributes using 3D point clouds and Geographic Information Systems (GIS). Urban streets are vital
components of cities, playing a significant role in the lives of their residents. Usually, the evaluation of some of their physical attributes has been subjective, but this study leverages 3D point clouds and digital terrain models (DTM) to provide a more objective perspective. This article undertakes a microurban analysis of basic physical characteristics (slope, width, and human scale) of a representative street in the historic centre of Valencia (Spain), utilizing 3D laser-scanned point clouds and GIS tools. Applying the proposed methodology, thematic maps were generated, facilitating the objective identification of areas with physical attributes more conducive to suitable pedestrian dynamics.
This approach provides a comprehensive understanding of urban street attributes, emphasizing the importance of addressing their assessment through advanced digital technologies. Moreover, this versatile methodology has diverse applications, contributing to social sustainability by enhancing the quality of urban streets and open spaces., This research was funded by the project "Analysis and Development of HBIM Integration into GIS for Creating a Cultural Heritage Tourism Planning Protocol" (ref. PID2020-119088RB-I00), funded by the Ministry of Science and Innovation, Government of Spain, and the "Programa de Ayudas de Investigacion y Desarrollo (PAID-01-22)" by the Universitat Politecnica de Valencia. The APC will be funded by Universitat Politecnica de Valencia.




Numerical and Optical Assessment of Different Solutions for Pollutant Emission Reduction in Compression Ignition Engines

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Khalid, Usama Bin|||0000-0002-4009-9688
[ES] La reducción de la huella de carbono de los motores de combustión interna así como de sus emisiones contaminantes es necesaria para la supervivencia de esta tecnología, especialmente para aplicaciones de uso medio y pesado. En la última década, investigadores y fabricantes han explorado diferentes enfoques para lograr este objetivo. En este sentido, el uso de combustibles alternativos y tecnologías alternativas se considera una vía potencial para alcanzarlo.

Dentro del ámbito de los combustibles alternativos, los e-fuels y los biocombustibles están ganando relevancia, ya que pueden ser utilizados sin modificaciones importantes en la tecnología de motores de combustión interna. El primer término se refiere a combustibles que pueden ser tanto gaseosos como líquidos y que se producen a partir de electricidad renovable mediante un proceso sintético que consume dióxido de carbono y agua. El segundo se refiere a combustibles producidos a partir de biomasa y residuos orgánicos. Entre los e-fuels, destacan los éteres dimetílicos de oximetileno, y entre los biocombustibles, es particularmente notable el aceite vegetal hidrotratado. Por un lado, los primeros destacan por reducir drásticamente las emisiones contaminantes, aunque presentan problemas como una menor densidad energética y compatibilidad con los motores convencionales cuando se utilizan en estado puro. Por otro lado, el aceite vegetal hidrotratado presenta propiedades similares a las del diésel y se considera un buen sustituto de este a pesar de reducir menos las emisiones contaminantes que los éteres de dimetileno de oximetileno. Sin embargo, ambos combustibles, cuando se producen exclusivamente a partir de recursos renovables, pueden reducir drásticamente la huella de carbon.

Otra forma de abordar la reducción de las emisiones contaminantes, que ha proporcionado grandes avances en el pasado, es el diseño de nuevo hardware directamente implicado en el proceso de combustión. Desde geometrías complejas del cuenco del pistón o de toberas de los inyectores hasta nuevos conceptos como la inyección de combustible por conductos para aplicaciones pesadas, que mejoran el proceso de mezcla aire-combustible aumentando la eficiencia y reduciendo la formación de contaminantes. No obstante, es necesario comprender mejor su impacto en el proceso de combustión y en el rendimiento del motor para su correcta aplicación en soluciones commercials.

A la luz de lo anterior, la presente tesis se centra en avanzar en el conocimiento del comportamiento de los combustibles alternativos y los nuevos conceptos de hardware en las condiciones de funcionamiento de los motores de encendido por compresión y su impacto en el rendimiento de la combustión y la formación de contaminantes. Estas evaluaciones se realizan tanto mediante simulaciones numéricas detalladas como mediante experimentos llevados a cabo en un motor de encendido por compresión ópticamente accesible, utilizando diversas técnicas ópticas. Los resultados ponen de relieve que estos dos enfoques prometedores pueden reducir en gran medida la formación de contaminantes en el interior del motor de encendido por compresión y pueden ser una solución potencial al problema cada vez mayor de la huella de carbono y las emisiones contaminantes de los motores de encendido por compresión., [CA] La reducció de la petjada de carboni dels motors de combustió interna així com de les seues emissions contaminants és necessària per a la supervivència d'esta tecnologia, especialment per a aplicacions d'ús mitjà i pesat. En l'última dècada, investigadors i fabricants han explorat diferents enfocaments per a aconseguir este objectiu. En este sentit, l'ús de combustibles alternatius i tecnologies alternatives es considera una via potencial per a aconseguir-ho.

Dins de l'àmbit dels combustibles alternatius, els e-fuels i els biocombustibles estan guanyant rellevància, ja que poden ser utilitzats sense modificacions importants en la tecnologia de motors de combustió interna. El primer terme es refereix a combustibles que poden ser tant gasosos com líquids i que es produeixen a partir d'electricitat renovable mitjançant un procés sintètic que consumeix diòxid de carboni i aigua. El segon es refereix a combustibles produïts a partir de biomassa i residus orgànics. Entre els e-fuels, destaquen els èters dimetílics d'oximetilè, i entre els biocombustibles, és particularment notable l'oli vegetal hidrotratat. D'una banda, els primers destaquen per reduir dràsticament les emissions contaminants, encara que presenten problemes com una menor densitat energètica i compatibilitat amb els motors convencionals quan s'utilitzen en estat pur. D'altra banda, l'oli vegetal hidrotratat presenta propietats similars a les del dièsel i es considera un bon substitut d'este malgrat reduir menys les emissions contaminants que els èters dimetílics d'oximetilé. No obstant això, tots dos combustibles, quan es produïxen exclusivament a partir de recursos renovables, poden reduir dràsticament la petjada de carboni.

Una altra manera d'abordar la reducció de les emissions contaminants, que ha proporcionat grans avanços en el passat, és el disseny de nou maquinari directament implicat en el procés de combustió. Des de geometries complexes del bol del pistó o de toveres dels injectors fins a nous conceptes com la injecció de combustible per conductes per a aplicacions pesades, que milloren el procés de mescla aïre-combustible augmentant l'eficiència i reduint la formació de contaminants. No obstant això, és necessari comprendre millor el seu impacte en el procés de combustió i en el rendiment del motor per a la seua correcta aplicació en solucions comercials.

A la llum de l'anterior, la present tesi se centra en avançar en el coneixement del comportament dels combustibles alternatius i els nous conceptes de maquinari en les condicions de funcionament dels motors d'encesa per compressió i el seu impacte en el rendiment de la combustió i la formació de contaminants. Estes avaluacions es realitzen tant mitjançant simulacions numèriques detallades com mitjançant experiments duts a terme en un motor d'encesa per compressió òpticament accessible, utilitzant diverses tècniques òptiques. Els resultats posen en relleu que estos dos enfocaments prometedors poden reduir en gran manera la formació de contaminants a l'interior del motor d'encesa per compressió i poden ser una solució potencial al problema cada vegada major de la petjada de carboni i les emissions contaminants dels motors d'encesa per compressió., [EN] The reduction of the carbon footprint of internal combustion engines and the pollutant emissions is mandatory for the survival of this technology, especially for medium and heavy-duty applications. In the last decade, researchers and manufacturers have explored different approaches to achieve this goal. In this sense, the use of alternative fuels and alternative technologies is considered as a potential pathway to reach this objective.

Within the scope of alternative fuels, e-fuels and biofuels are gaining relevance as they can be utilized without major modifications of the internal combustion engine technology. The former term refers to fuels that can be both gaseous or liquid and are produced from renewable electricity in a synthetic process consuming carbon dioxide and water. The latter refers to fuels produced from biomass and organic waste. Among e-fuels, oxymethylene dimethyl ethers stand out, and among biofuels, hydrotreated vegetable oil is particularly notable. On the one hand, oxymethylene dimethyl ethers drastically reduce pollutant emissions however suffer challenges like lower energy density, and compatibility with conventional engines when utilized in pure form. On the other hand, hydrotreated vegetable oil presents similar properties as compared to diesel and is considered a good drop in fuel for fossil diesel despite providing a lesser pollutant reduction when compared with oxymethylene dimethyl ethers. However, these fuels, when produced solely from renewable resources, can drastically reduce the carbon footprint.

Another way to address pollutant emission reduction, which has provided great advances in the past, is the design of new hardware directly involved with the combustion process. From complex piston bowl geometries or injector nozzles to new concepts like ducted fuel injection for heavy-duty applications, which improves the air-fuel mixing process increasing efficiency and reducing pollutant formation. Nevertheless, a better understanding of their impact on the combustion process and engine performance is required for proper implementation in commercial solutions.

In light of the aforementioned text, the current thesis is focused on advancing the knowledge of the behaviour of alternative fuels and new hardware concepts under operating conditions of compression ignition engines and their impact on combustion performance and pollutant formation. These assessments are done both by detailed numerical simulations and experiments carried out in an optically accessible compression ignition engine, utilizing a variety of optical techniques. Results highlight that these two promising approaches can greatly reduce the pollutant formation inside the compression ignition engine and can be a potential solution to the ever-increasing carbon footprint and pollutant emissions problem of compression ignition engines., The author would like to acknowledge the financial support received
through contract UPV - Subprograma 2 (PAID-01-22) del Vicerrectorado de
Investigaciòn, which was incremental in the development of this thesis at I.U.I.
CMT – Clean Mobility & Thermofluids, Universitat Politècnica de València.
Furthermore, author also acknowledges the grant Ayudas Para Movilidad de
Estudiantes de Doctorado de la Universitat Politècnica de València - 2022,
which made his research stay possible at Sandia National Laboratories.




Experimental assessment of a heavy-duty fuel cell system in relevant operating conditions

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Desantes J.M.|||0000-0002-4124-9393
  • Novella Rosa, Ricardo|||0000-0002-5123-6924
  • López-Juárez, Marcos|||0000-0001-9886-4728
  • Nidaguila, I.
[EN] During the past few years, the research interest in fuel cell systems (FCS) has increased significantly. Thus, this kind of powertrain is now at high Technology Readiness Levels (TRLs) and even starting to be commercialized. However, the currently available technology still has room for optimization. The existing bibliography shows studies mainly related to stack-level characterization or FCS studies with a poor level of detail. The present paper focuses on producing a detailed database about the performance of a specific FCS designed for heavyduty vehicle (HDV) applications. The obtained dataset provides information about the influence of ambient conditions on the performance of the system, plus information about the anode and cathode circuits. These factors represent an important novelty with respect to other pieces of literature present in the actual research framework. Additionally, the obtained data regarding the performance of an FCS is highly significant for HDV manufacturers in the transportation sector and eases the pathway to the optimization of these technologies. The written piece of research proves the importance of studying the ambient conditions. The experimental campaign has shown that increasing relative humidity can improve the performance of the membrane up to a 2% for a 25% change in the humidity level. Additionally, the study shows the importance of implementing an appropriate supply gas strategy, both for anode and cathode, and designing the right purging mechanisms for H2 2 at the anode inlet. The obtained results show how there exist a relation between the optimal efficiency operating point and a H2 2 excess from the supply strategy., This research has been partially funded by Universitat Politecnica de Valencia through the support program for research and development (PAID-01-22) and was performed in the frame of the ALL-IN Zero project, which is funded by the European Union's Horizon Europe research and innovation program under grant agreement No 101069888. Funding for open access charge: CRUE-Universitat Politecnica de Valencia.




Evaluation of the ducted fuel injection concept for medium duty engines and multi-hole nozzles: An optical analysis

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Pastor, José V.|||0000-0003-4113-4681
  • Micó, Carlos|||0000-0001-5787-6212
  • De Vargas Lewiski, Felipe
  • Khalid, Usama Bin|||0000-0002-4009-9688
[EN] Ducted Fuel Injection (DFI) is a strategy still in development, which has proved to be effective in reducing soot emissions in compression ignition engines. It works by driving the spray, formed by a high-pressure fuel injection, through a small duct co-axial to the spray itself, which is expected to affect the mixture formation and combustion process, in turn leading to noticeable reduction in soot formation. This strategy has been mostly deployed in spray vessels or in some cases in heavy duty engines consisting of mostly 2-to-4-hole nozzle injectors. For this reason, the work here is aimed to study the potential of DFI in a medium-duty single-cylinder optical engine fueled with conventional diesel having an 8-hole nozzle injector. Two different optical techniques including OH* chemiluminescence and 2-color pyrometry have been utilized to perform the analysis regarding combustion evolution and soot formation. A parametric analysis regarding different geometrical parameters including stand-off distance, diameter and length of duct has been carried out regarding the DFI performance. Results indicate that DFI does decrease the soot emissions in the context of this study and the duct geometrical parameters influence combustion evolution and soot formation ultimately affecting the device's performance. However, the scale of soot reduction is not as high as reported in previous studies, which is limited by specific boundary conditions including combustion chamber design, piston geometry utilized in this study., This work has been partially funded by Universitat Politecnica de Valencia through grant agreement UPV Subprograma 2 (PAID-01-22).




Cell-to-cell dispersion impact on zero-dimensional models for predicting thermal runaway parameters of NCA and NMC811

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • García Martínez, Antonio|||0000-0001-5783-4936
  • Pastor, José V.|||0000-0003-4113-4681
  • Monsalve-Serrano, Javier|||0000-0001-8593-095X
  • Golke, Diego
[EN] The battery electric vehicle is the leading technology for reducing greenhouse gas emissions using clean and renewable energy. However, concerns due to battery thermal runaway are becoming more severe as the battery energy density increases. Fast-calculation models capable of predicting the heat released during the thermal runaway phenomenon can help to develop safety mechanisms according to the battery chemistry. The current study assesses the battery thermal runaway variability for two different battery chemistries, nickel cobalt aluminium oxides and nickel manganese cobalt oxides, for 3 different states of charge (100%, 80% and 50%), two different battery sizes (18,650 and 21,700), and two different battery health (pristine and aged). The tests are performed in the accelerating rate calorimeter using the heat-wait-seek protocol and repeated 5 times (each battery condition) for statistical analysis of the main thermal runaway parameters. A model using the Arrhenius equation was developed, calibrated, and validated. The model was developed considering 5 steps during temperature evolution to the reliable prediction of thermal runaway characteristics, considering inputs as states of charge, capacity fade (solid electrolyte interface growth), energy density, battery end mass and initial voltage. The experimental tests show that temperature rise rate, when the exothermic is detected, and battery end mass play an important role in the self-heating duration and maximum temperature, respectively, which are key parameters to understanding scattering behaviour. Considering these effects during modelling, the model can forecast the primary features of a thermal runaway, including maximum temperature, onset temperature, and duration of the whole battery thermal runaway process, all within the average difference of no more than 3%. For this reason, the model proposed seems to be a suitable tool for battery safety mechanism design as it considers the state of charge, energy density and ageing effects., The authors acknowledge the Vicerrectorado de investigacion de la Universitat Politecnica de Valencia for supporting this research through Programa de Ayudas de Investigacion y desarrollo (PAID-01-22). This research is part of the projects TED2021-132220B-C21 and TED2021-130488 A-I00, funded by the MCIN/AEI/10.13039/501100011033 and the European Union "NextGenerationEU"/PRTR. This research is part of the project PID2021-124696OB-C21, funded by Ministerio de Ciencia e Innovacion, Agencia Estatal de Investigacion and FEDER (MCIN/AEI/1 0.13039/501100011033/FEDER, UE).




Selective cycloaddition of ethylene oxide to CO2 within the confined space of an amino acid-based metal-organic framework

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Bilanin-Artigado, Cristina
  • Escamilla, Paula
  • Ferrando-Soria, Jesus
  • Leyva Perez, Antonio|||0000-0003-1063-5811
  • Armentano, Donatella
  • Pardo, Emilio
[EN] Host-guest chemistry within the confined space of metal-organic frameworks (MOFs) offers an almost unlimited myriad of possibilities, hardly accessible with other materials. Here we report the synthesis and physical characterization, with atomic resolution by single-crystal X-ray diffraction, of a novel water-stable tridimensional MOF, derived from the amino acid S-methyl-l-cysteine, {SrZn6[(S,S)-Mecysmox](3)(OH)(2)(H2O)}9H(2)O (1), and its application as a robust and efficient solid catalyst for the cycloaddition reaction of ethylene/propylene oxide with CO2 to afford ethylene/propylene carbonate with yields of up to 95% and selectivity of up to 100%. These results nicely illustrate the great potential of MOFs to be game changers for the selective synthesis of industrially relevant products, representing a powerful alternative to the current heterogeneous catalysts., We acknowledge MCIN (PID2019-104778GB-I00, PID2020-115100GB-I00, CEX2019-000919-M and CEX2021-001230-S), the Generalitat Valenciana (SEJI/2020/034 and PROMETEO/2021/054), the Ministero dell'Istruzione, dell'Università e della Ricerca and the Fondazione CARIPLO (2019 2090). E. P. acknowledges the financial support from the European Research Council under the European Union's Horizon 2020 Research and Innovation Programme/ERC Grant Agreement No. 814804, MOF-reactors. D. A. also acknowledges the financial support from the European Union NextGenerationEU under the National Recovery and Resilience Plan (NRRP) of Ministero dell'Università e della Ricerca (MUR) (Project Code PE0000021, Network 4 Energy Sustainable Transition NEST). C. B. thanks ITQ for a contract. C. B. thanks ITQ and UPV (PAID-01-22) for a contract. J. F.-S. thanks the Ramón y Cajal program (RYC2019-027940-I). This study forms part of the Advanced Materials programme (MFA/2022/048) and was supported by MCIN with funding from the European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana.




Real-Time Monitoring of Visitor Carrying Capacity in Crowded Historic Streets Through Digital Technologies

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Viñals, Mª José|||0000-0002-7589-7815
  • Orozco-Carpio, Patricio Rodrigo|||0009-0007-3437-7390
  • Teruel, Penelope
  • Gandía-Romero, Jose M.|||0000-0003-0257-3286
[EN] This paper addresses methodological issues related to the identification and monitoring of visitor overcrowding and congestion situations in historic centres. Once the visitor carrying capacity
was estimated for public spaces, taking into consideration the standards of quality and comfort for visitor experience and those related to the desired conditions for heritage assets¿ conservation, digital real-time monitoring tools were implemented in an experimental urban area in Valencia, Spain, in order to know, through the establishment of proxemic triggers, when the standards were violated
(or may soon be violated); then, the carrying capacity was exceeded, and management actions may be required. The results show that these digital monitoring tools are very efficient and accurate in
micro-scale public spaces, user-friendly and affordably priced., This research was funded by the project Analysis and Development of HBIM Integration
into GIS for Creating a Cultural Heritage Tourism Planning Protocol (ref. PID2020-119088RB-I00),
funded by the Ministry of Science and Innovation, Government of Spain, and the Programa de
Ayudas de Investigación y Desarrollo (PAID-01-22) by the Universitat Politècnica de València.




Impact of hydrogen substitution for stable lean operation on spark ignition engines fueled by compressed natural gas

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Molina, Santiago|||0000-0001-7879-2421
  • Ruiz-Rosales, Santiago|||0000-0001-9536-3696
  • Gómez-Soriano, Josep|||0000-0002-2742-9224
  • Olcina-Girona, Miguel|||0000-0002-4501-1251
[EN] Compressed Natural Gas (CNG) appears as a midterm solution to conventional fuels, such as gasoline and diesel. The low carbon content and the possibility of being obtained from renewable sources (animal or agriculture waste, landfills, waste of the industry food or aquatic biomass) make CNG an attractive option to reduce Greenhouse Gases (GHG) emission. Applying lean combustion strategies on CNG improves efficiency levels while reducing pollutant emissions. In these conditions, heat transfer losses are reduced, and the thermal efficiency increased, especially at partial loads where increasing air dilution is one of the main strategies to reduce pumping losses. Hydrogen (H2) addition helps to enhance combustion in these diluted conditions and to reduce the combustion instability. This combustion concept has been widely studied over the last years, however further research is still needed. This investigation focuses on how hydrogen substitution affects the performance and emissions (both CO2 and pollutant) of a port fuel injection (PFI) spark ignition (SI) engine fueled by CNG. Thus, the main objective of this investigation is to contribute to the existent knowledge about dual-fuel combustion strategies based on CNG and H2 blends. Results demonstrated that hydrogen substitution helps to reduce the CO2 emissions by two ways: improving the engine efficiency and substituting part of the main carbon-based fuel. Despite of this advantage, NOx emissions are not reduced, and they will require after-treatment systems to deal with current pollutant regulations., This research has been partially funded by FEDER, Spain and the Spanish Government through project RTI2018-102025-B-I00 (CLEANFUEL). M. Olcina-Girona is partly supported by an FPI contract (FPI S2-22-37816) of the Programa de Apoyo para la Investigacion y Desarrollo (PAID 01 22) of the Universitat Politecnica de Valencia.




Comparative analysis of powertrain architectures for fuel cell light commercial vehicles in terms of performance and durability

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Novella Rosa, Ricardo|||0000-0002-5123-6924
  • López-Juárez, Marcos|||0000-0001-9886-4728
  • González-Domínguez, David
  • Nidaguila, I.
[EN] At the present time, the critical climate situation has raised awareness about the importance of developing carbon-free technologies. In this context, fuel cell systems (FCS) have become one of the key technologies in the pathway to decarbonization. Given that road transport is a major contributor to greenhouse gas (GHG) emissions, this paper focuses on a specific segment of this sector: light commercial vehicles (LCVs). The current market situation shows that LCV manufacturers have not yet decided what is the appropriate powertrain architecture for this kind of vehicle. Thus, the current paper studies a wide range of possible FCS-based propulsive system designs, changing the size of the FCS, electric battery and H2 tank. These propulsive system architectures are analyzed concerning the performance of the vehicle, in terms of consumption and range, and the durability of its FCS. The evaluation of these different designs will be highly valuable for the LCV industry and manufacturers, as it allows to understand the optimal powertrain solution. The study demonstrates that a significant increase in range can be achieved with only a minor penalty in hydrogen consumption. Additionally, the research indicates that it is feasible to employ one of the most durable FCS designs while meeting LCV mission requirements with minimal consumption penalty. In conclusion, this paper provides valuable data to the ongoing research in this field, offering a detailed analysis of the impact of H2 consumption, autonomy, and durability of the FCS across various vehicle architectures under typical LCV driving conditions., This research has been partially funded by Universitat Politecnica de Valencia through the support program for research and de-velopment (PAID-01-22) and by the Generalitat Valenciana (Conselleria d'Innovacio, Universitats, Ciencia i Societat Digital) as a part of the DEFIANCE research project (CIPROM/2021/039) through the PROMETEO funding program. The activities of this work are also part of TED2021-131463B-I00 (DIVERGENT) funded by MCIN/AEI/10.13039/501100011033 and the European Union "NextGenerationEU"/PRTR .