La Evaluación continuada en asignaturas numerosas: la experiencia de Fundamentos de Computadores

numerosas requiere de mucha dedicación por parte de los profesores y también de mecanismos sistemáticos que permitan realizarla de forma eficiente. En este artículo se presenta la solución que se ha adoptado en Fundamentos de computadores para poder hacer un seguimiento lo más individualizado posible de los alumnos. Si bien el rendimiento académico no ha mejorado significativamente, los resultados de la evaluación individual mediante examen revelan una fuerte correlación con los de la evaluación continuada. Esto puede permitir, en un futuro próximo, la transformación de los exámenes finales en pruebas de validación de la evaluación continuada y promover, con ello, una mayor participación de los alumnos en la misma.Peer Reviewe

Simulation-based optimization of cycle timing for CO2 capture and hydrogenation with dual function catalyst

[EN] CO2 methanation could play a significant role in the future energy system. The excess of renewable electric energy can be transformed into storable methane to balance the energy demand when required. Moreover, the CO2 methanation can be performed alternating steps of CO2 storage and reduction, avoiding expensive CO2 purification steps. In this work, we will use a previously developed and validated model to optimize by simulation the CO2 adsorption and hydrogenation cycles timing (t(CO2)/t(H2)). The performance of the catalyst is quantified by the CO2 conversion (X-CO2, %), H-2 conversion (X-H2, %) and CH4 production (Y-CH4, mmol g(-1) cycle(-1)). Long adsorption and hydrogenation times result in high CH4 productions per cycle, however, low CO2 and H-2 conversion. Therefore, adsorption times close to the catalyst saturation (t(CO2)=60 s) and moderate hydrogenation times are preferable. To better select the optimal hydrogenation time, a new catalytic parameter is set, the average formation rate of CH4 (rCH(4), mu mol g(-1) s(-1)). The optimal hydrogenation time is set at 120 s. In addition to having a high average formation rate of CH4, t(CO2)/t(H2)= 60/120 cycle timing would allow to work with three identical beds in parallel, one in adsorption mode and two in regenerating mode. With the optimum cycle timing of 60/120 the production of CH4 results in 148 mu mol g(-1) cycle(-1) (1.2 mu mol CH4 g(-1) s(-1)) and a CO2 and H-2 conversion of 25% and 43%, respectivelyThe financial support from the Economy and Competitiveness Spanish Ministry (CTQ2015-67597-C2-1-R and PID2019-105960RB-C21) and the Basque Government (IT1297-19) is acknowledged. The authors thank for technical and human support provided by SGIker (UPV/EHU Advanced Research Facilities/ ERDF, EU). One of the authors (ABL) also acknowledges the Economy and Competitiveness Spanish Ministry for his PhD grant (BES-2016-077855)

Simulador d'un processador amb Adobe Flash Player

Aquest Projecte pretén crear un simulador d'una màquina algorísmica, de caràcter didàctic amb Adobe Flash CS3 per a reproduir-lo amb Adobe Flash Lite Player, que és la versió per a dispositius mòbils. Simularà el comportament de la màquina algorísmica anomenada FEMTOPROC, que és capaç d'interpretar 4 instruccions molt senzilles: ADD, AND, NOT i JZ (jump if zero). Les diferents instruccions introduïdes que compondran un programa seran emmagatzemades en una memòria de 64 posicions de 8 bits cadascuna i hi haurà un Banc de Registres amb 8 registres de 8 bits, que es podrà inicialitzar al començament de la simulació.Este Proyecto pretende crear un simulador de una máquina algorítmica de carácter didáctico con Adobe Flash CS3 para reproducirlo con Adobe Flash Lite Player, que es la versión para dispositivos móviles. Simulará el comportamiento de la máquina algorítmica llamada FEMTOPROC, que es capaz de interpretar 4 instrucciones muy sencillas: ADD, AND, NOT y JZ (jump if zero). Las diferentes instrucciones introducidas que compondrán un programa serán almacenadas en una memoria de 64 posiciones de 8 bits cada una y habrá un Banco de Registros con 8 registros de 8 bits, que se podrá inicializar al principio de la simulación.This project aims to create a simulator of an algorithmic machine with didactic purposes with Adobe Flash CS3, in order to reproduce it with Adobe Flash Lite Player, which is the version for mobile devices. It will simulate the behavior of the algorithmic machine called FEMTOPROC, which is capable of interpreting 4 very simple instructions: ADD, AND, NOT and JZ (jump if zero). The different instructions that will compose a program will be stored in a 64x8bits memory and there will be a Bank of Records with 8 records of 8 bits, which will be initialized at the beginning of the simulation.Nota: Aquest document conté originàriament altre material i/o programari només consultable a la Biblioteca de Ciència i Tecnologia

Study on the promotional effect of lanthana addition on the performance of hydroxyapatite-supported Ni catalysts for the CO2 methanation reaction

[EN] The performance of nickel supported on lanthana-modified hydroxyapatite (HAP) catalysts is investigated in the CO2 methanation. The addition of La (1-6.6 wt%) leads to a surface enrichment following a sequential multilayer deposition model. Moreover, La addition systematically improves the dispersion of Ni particles and their reducibility, which in turn increases spectacularly the amounts of basic sites and their thermal stability. Such physicochemical changes impact positively on the activity of the catalysts in CO2 methanation. The estimated turnover frequency (TOF) suggest that the small Ni particles are the most efficient. The latter seem to provide a large density of very active defects on Ni-La2O3 interface. The optimized catalyst proves to be highly resistant to deactivation during 100 h time-on-stream (TOS). The samples were also assayed as dual function materials (DFMs) for CO2 adsorption and methanation. A scheme is proposed to describe the different steps involved in a CO2 adsorption/hydrogenation cycle.The financial support from the Science and Innovation Spanish Ministry (PID2019-105960RB-C21) and the Basque Government (IT1297-19) is acknowledged. The authors also acknowledge the technical support provided by SGIker (UPV/EHU Advanced Research Facilities/ERDF, EU)

Defining Adaptive Learning Paths For Competence-Oriented Learning

This paper presents a way to describe educational itineraries in a competence-oriented learning system in order to solve the problem of sequencing several independent courses. The main objective is to extract adaptive learning paths composed by the subset of needed courses passed in the right order. This approach improves the courses’ re-usability allowing courses to be included in different itineraries, improving the re-usability of the courses, and making possible the definition of mechanisms to adapt the learning path to the learner’s needs in execution tim

Ca doping effect on the performance of La1−xCaxNiO3/CeO2-derived dual function materials for CO2 capture and hydrogenation to methane

CO2 valorization in form of synthetic natural gas is a convenient way to store large amounts of intermittent energy produced from renewable sources for long periods of time. Here reported research addresses the development of novel dual function materials (DFMs) for the utilization of CO2 from simulated post-combustion effluent by cyclic adsorption and in-situ methanation. These DFMs, obtained after the controlled reduction of 20% La1−xCaxNiO3/CeO2-type precursors (with x = 0–0.5), are widely characterized before and after catalytic tests. XRD diffractograms, H2-TPD experiments and STEM-EDS images denote that Ca-doping shows low influence on materials composition, slight detrimental effect on textural properties and no influence on Ni, La and Ce distribution. Meanwhile, the concentration of Ca-based species increases as long as La3+ substitution by Ca2+ increases, which leads to a progressively promotion of medium and, especially, strong basic sites concentration (CO2-TPD). As a result, the 20% La0.5Ca0.5NiO3/CeO2-derived DFM almost doubles (188.8 µmol g−1) the CH4 production of the 20% LaNiO3/CeO2-derived DFM (96.5 µmol g−1) at high temperatures. Indeed, this novel DFM enhances the methanation capacity of the conventional 15% Ni-15% CaO/Al2O3 DFM (143.0 µmol CH4 g−1), with higher stability during long-term experiments and adaptability under variable feed compositions, which further support the applicability of these novel DFMs. Thus, Ca doping emerges as an effective way of tailoring CO2 adsorption and in-situ hydrogenation to CH4 efficiency of 20% LaNiO3/CeO2-derived DFMs.Support for this study was provided by Proyecto PID2019-105960RB-C21 by MCIN/AEI /10.13039/501100011033 and the Basque Government (Project IT1509-2022). One of the authors (JAOC) acknowledges the Post-doctoral Research Grant (DOCREC20/49) provided by the University of the Basque Country (UPV/EHU)

Aging studies on dual function materials Ru/Ni-Na/Ca-Al2O3 for CO2 adsorption and hydrogenation to CH4

Integrated CO2 capture and utilization (ICCU) is a promising alternative to revalue CO2. In this work, the influence of the aging process on dual function materials (DFMs) Ru/Ni-Na/Ca-Al2O3, for the conversion of CO2 into CH4 is studied. DFMs are characterized by N2 adsorption-desorption, XRD, H2 chemisorption, TEM and CO2-TPD. The catalytic behavior of the prepared DFMs is analyzed in consecutive cycles of CO2 adsorption and hydrogenation to CH4. The aging process notably limits the physicochemical properties, especially the metallic dispersion. However, the CH4 production decrease is less than 25% for aged Ru-DFMs, which makes them suitable for long-term operation. The aged DFM 4Ru-8Na2CO3/8CaO-Al2O3, presents a CH4 production greater than 275 µmol g−1 with high selectivity in the range 340–400 °C. On the other hand, the aging process is more noticeable for Ni-DFMs; in fact, it limits the CH4 production to half compared to reduced Ni-DFMs.The financial support from the Science and Innovation Spanish Ministry (PID2019-105960RB-C21) and the Basque Government (IT1297-19) is acknowledged. The authors thank for technical and human support provided by SGIker (UPV/EHU Advanced Research Facilities/ ERDF, EU). One of the authors (JAOC) acknowledges the post-doctoral research grant (DOCREC20/49) provided by the University of the Basque Country

How the presence of O2 and NOx influences the alternate cycles of CO2 adsorption and hydrogenation to CH4 on Ru-Na-Ca/Al2O3 dual function material

The Integrated Carbon Capture and Utilization-Methanation (ICCU-Methanation) requires a Dual Function Material (DFM), which firsts captures CO2 and then converts it into CH4, working in alternating adsorption and hydrogenation periods. The ICCU technology can be applied directly to a flue gas leaving a combustion chamber, which usually contains oxidizing species such as oxygen and nitrogen oxides. In this work, the stability of a DFM with composition 4%Ru-8%Na2CO3-8%CaO/Al2O3 is studied for the CO2 adsorption and hydrogenation in alternate cycles including O2 (0–10%) and NOx (0–2000 ppm) during the adsorption period. The variation of CO2 concentration in the usual range of flue gases (5–15%) has little influence on the global performance of the ICCU technology. However, the incorporation of O2 during the adsorption period decreases the production of CH4, and this decrease is even accentuated with increasing the oxygen concentration. This fact is mainly attributed to the oxidation of metal sites that limits the reduction behavior. On the other hand, the addition of NOx competes with CO2 for the basic adsorption sites, which slightly limits the amount of CO2 stored, and consequently the production of CH4. Helpfully, the proposed DFM presents high stability during the 207 cycles here performed, which corresponds to 34 h of time-on-stream, including different CO2 concentrations, and in the presence or absence of O2 and/or NOx. It is concluded that the proposed DFM formulation is competent for long-term operation in the presence of O2 and NOx during the CO2 adsorption period.The financial support from the Science and Innovation Spanish Ministry (PID2019-105960RB-C21) and the Basque Government (IT1509-22) is acknowledged. The authors thank for technical and human support provided by SGIker (UPV/EHU Advanced Research Facilities/ ERDF, EU)

Tuning basicity of dual function materials widens operation temperature window for efficient CO2 adsorption and hydrogenation to CH4

Mitigation of CO2 emissions by integrated CO2 capture and utilization (ICCU) is challenging. This work focuses on widening operation temperature window of the hydrogenation of adsorbed CO2 to CH4. For this, a set of dual function materials (DFMs) 4%Ru-x%Na2CO3-y%CaO/gamma-Al2O3 are prepared. DFMs are deeply characterized by N-2 adsorption-desorption, XRD, H-2 chemisorption, TEM, H2-TPR and CO2-TPD. The catalytic behavior, in cycles of CO2 adsorption and hydrogenation to CH4, is evaluated and the temporal evolution of the concentration of re-actants and products is analyzed. The presence of both adsorbents in the DFMs improves ruthenium dispersion and the basicity is modulated with the Na2CO3/CaO ratio. Ru-8Na/8Ca improves methane production over the whole temperature window compared to DFMs based only on a unique adsorbent. The best results are assigned to the promotion of contact between the carbonates of medium strength with the metallic sites, which boost the CO2 adsorption and hydrogenation to CH4.The financial support from the Science and Innovation Spanish Ministry (PID2019–105960RB-C21) and the Basque Government (IT1297–19) is acknowledged. The authors thank for technical and human support provided by SGIker (UPV/EHU Advanced Research Facilities/ ERDF, EU)

From Messengers to Receptors in Psoriasis: The Role of IL-17RA in Disease and Treatment.

The paradigm of psoriasis as a Th17-driven disease has evolved in the last years towards a much deeper knowledge of the complex pathways, mechanisms, cells, and messengers involved, highlighting the crucial role played by the IL-17 family of cytokines. All IL-17 isoforms signal through IL-17R. Five subunits of IL-17R have been described to date, which couple to form a homo- or heteroreceptor complex. Characteristically, IL-17RA is a common subunit in all hetero-receptors. IL-17RA has unique structural—containing a SEFIR/TILL domain—and functional—requiring ACT-1 for signaling—properties, enabling Th17 cells to act as a bridge between innate and adaptive immune cells. In psoriasis, IL-17RA plays a key role in pathogenesis based on: (a) IL-17A, IL-17F, and other IL-17 isoforms are involved in disease development; and (b) IL-17RA is essential for signaling of all IL-17 cytokines but IL-17D, whose receptor has not been identified to date. This article reviews current evidence on the biology and role of the IL-17 family of cytokines and receptors, with focus on IL-17RA, in psoriasis and some related comorbidities, and puts them in context with current and upcoming treatments.post-print1.096 K