Jose Ygnacio Pastor

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• PhD in Physics
• Professor (Full) at Universidad Politécnica de Madrid

The cement industry's commitment to reducing CO2 emissions has led to exploring alternative processes and supplementary cementitious materials (SCMs). These include alkali-activated binders or geopolymers, promising cement alternatives due to their pozzolanic properties and superior strength and durability, especially at high temperatures. Using ab...

Self-passivating W-11.4Cr-0.6Y (in wt.%) alloy is a plasma-facing candidate armour material in fusion power plants. In the present work, the as-sintered material, fabricated via ball milling and field-assisted sintering, was annealed at 1000 ◦C for varying durations to induce phase decomposition. This process leads to the transformation of the init...

The self-passivating yttrium-containing WCr alloy has been developed and researched as a potential plasma-facing armour material for fusion power plants. This study explores the use of yttria (Y2O3) powders instead of yttrium elemental powders in the mechanical alloying process to assess their applicability for this material. Fabricated through fie...

Revisión de residuos industriales utilizados para la captura de CO2 y su utilización en construcción que han sido objeto de estudio dentro del proyecto CSTO2NE. Hacemos un repaso al trabajo realizado y en curso, con énfasis en la carbonatación acelerada con CO2 gaseoso y CO2 supercrítico de cementos base EAF slag (Electric Arc Furnace Slag).

Developing new materials to be applied in extreme environments is an opportunity and a challenge for the future. High entropy alloys are new materials that seem promising approaches to work in nuclear fusion reactors. In this work, FeTaTiVW high entropy alloys were developed and characterized with Molecular Dynamic and Hybrid Molecular Dynamic Mont...

The Cu-Y2O3 and CuCrZr-Y2O3 materials have been devised as thermal barriers in nuclear fusion reactors. It is expected that in the nuclear environments, the materials should be working on extreme conditions of irradiation. In this work the Cu-Y2O3 and CuCrZr-Y2O3 were prepared and then irradiated in order to understand the surface irradiation resis...

The effects of post-treatment temperature-based methods for accelerating the ageing of PLA were studied on 1D single-PLA filaments after fused filament fabrication (FFF). The goal was to answer the questions whether the PLA can be safely aged—i.e., without degrading—at higher temperatures; at which temperatures, if any; how long it takes for the PL...

The effect of Mg particles on the thermal, chemical, physical, and primarily mechanical properties of 3D-printed PLA/Mg composites is studied in this paper. Recently, new colloidal processing has been proposed to introduce Mg particles into the PLA matrix, which ensures good dispersion of the particles and better thermal properties, allowing for th...

The effects of post-treatment temperature-based methods on 1D single PLA filaments after FFF have been studied. This lets to decouple the variables related to the 3D structure (layer height, raster angle, infill density, and others) from the variables solely related to the material (molecular weight, molecular orientation, crystallinity, and others...

This paper aimed to study the physical and chemical changes taking places in a hybrid alkaline-belite cement (HYP, with a high level of fly ash, 47.5%) paste at high temperature. To investigate the influence of chemical and mineralogical differences on the behavior of cementitious materials when exposed to high temperature, an alkaline-activated fl...

The effect of Mg particles on PLA's thermal, chemical, physical, and mechanical properties has been studied. The thermal and physical properties have been studied by differential scanning calorimetry, analysing the stability of the α and α’-crystals of the PLA. A colloidal route was used to introduce Mg particles inside the PLA matrix, ensuring a g...

The physical ageing of polylactic acid (PLA) is a phenomenon that changes the material’s properties over time. This ageing process is highly dependent on ambient variables, such as temperature and humidity. For PLA, the ageing is noticeable even at room temperatures, a process commonly referred to as natural ageing. Stopping the ageing by freezing...

Two hybrid dental materials available for computer-aided design and manufacturing (CAD/CAM) dental restorations have been selected to explore their potential. On the one hand, the scarcely investigated polymer-based material Vita Enamic® (VE) and, on the other hand, the leucite-based material IPS Empress® CAD (EC). Their micro-structure and mechani...

One of the most critical technology challenges regarding the European demonstrational fusion reactor (DEMO) project is to develop a heat-exhaust system (divertor) that fulfils the required structural design criteria at the heat flux loads and irradiation dose level foreseen for the DEMO divertor, which is predicted to be an order of magnitude highe...

CrNbTaVWx with (x = 1 and 1.7) high entropy alloys have been devised for thermal barriers between the plasma-facing tungsten tiles and the copper-based heat sink in the first wall of fusion nuclear reactors. These novel materials were prepared by ball milling and consolidated by Upgrade Field Assisted Sintering Technology at 1873 K under an applied...

The properties of polylactic acid (PLA) filaments have not yet been analysed in detail, and they are strongly affected by the extrusion process used in some additive manufacturing systems. Here we present the mechanical, thermal, physical, and fractographical properties of an extruded filament (not the bulk material or scaffolds), the basic buildin...

Bone cement, frequently based on poly (methyl methacrylate), is commonly used in different arthroplasty surgical procedures and its use is essential for prosthesis fixation. However, its manufacturing process reaches high temperatures (up to 120 °C), producing necrosis in the patients’ surrounding tissues. To help avoid this problem, the addition o...

The ITER based conceptual design of EU DEMO divertor envisages tungsten monoblocks as plasma-facing material joined to a CuCrZr cooling tube with a thick Cu-OHFC interlayer. Since divertor configuration will define the power exhaust capabilities of the reactor, additional concepts have been developed within the EUROfusion WPDIV project. In this reg...

Bone cement, mainly based in PMMA, is commonly used in different arthroplasty surgical proce-dures, and its use is essential for prosthesis fixation. However, its manufacturing process reaches high temperatures that can produce necrosis in the patients' surrounding tissues. In order to con-tribute to avoid this problem, the addition of graphene cou...

Metallic tungsten and tungsten carbide are some of the more relevant candidates proposed because of their high melting point, shielding capabilities and resistance to neutron damage. In this work, the microstructural and high temperature mechanical characterization of WC matrices with additions of 10, 20 and 50 vol% of W, dispersed by colloidal pro...

This study aims to evaluate the microstructural and mechanical properties of three commercial resin-based materials available for computer-aid design and manufacturing (CAD/CAM)-processed indirect dental restoration: LavaTM Ultimate Restorative (LU), 3M ESPE; Brilliant Crios (BC), COLTENE and CerasmartTM (CS), GC Dental Product. The three types of...

The preliminary conceptual design of both the blanket and the divertor of the future DEMO reactor envisages tungsten as plasma-facing material joined to Eurofer 97 steel as the structural element. Therefore, the development of new joining technologies to constitute these first wall components has become an essential task in the fusion community. In...

To soften the extreme sintering conditions of Tungsten Carbide (WC), a 3 wt.% of metallic nickel (Ni) was added to the starting powders. To ensure a fair distribution of the second phase and an intimate mixture of the phases, the colloidal process was adopted. A commercial Ni and a in-house synthesised nanosized nickel were used as sintering aids....

This study was designed to determine the mineralogical and microstructural changes taking place in a hybrid alkaline cement (HYC = 30% Portland cement clinker + 70% (slag + fly ash + alkaline activator)) exposed to high temperatures. The cement pastes were heated for 2 h at 400 °C, 600 °C, 800 °C or 1000 °C and subsequently air- or water-cooled. Th...

Modern theories on NeuroLearning state that when emotions are linked to the learning process, it is much more difficult to forget what has been learned (Pherez, Vargas, & Jerez, 2018; Ninaus, et al., 2019) In this regard, gamification can be particularly effective in fixing the information by directly applying the knowledge acquired playfully (Part...

Instagram is nowadays a popular social network, with over 1 million users worldwide on mobile devices (Clement, 2019), so it has become an essential application among young people. This makes Instagram an excellent channel to reach students, a mainly young audience.

The development of a divertor target for DEMO is of great importance, being able to sustain the harsh environment that is imposed on this component. To fulfill the loading requirements, different concepts were developed within the EUROfusion WPDIV project. The baseline concept is based on the ITER divertor target W-monoblock design. It is made of t...

The high-temperature mechanical behaviour of a pre-industrial hybrid alkaline cement (HYC) was studied. The HYC in question contained 30 % Portland clinker and 70 % of a blend of slag, fly ash and a solid activator (mix of alkaline salts with a predominance of Na2SO4). The material was tested during exposure to high temperatures to establish its co...

The particle reinforcement of fusion-relevant tungsten through the incorporation of tungsten sub-carbide W2C particles at the grain boundaries is demonstrated as an effective way of eliminating the harmful W oxide, enhancing densification and stabilising the composite's microstructure and flexural strength at room and high temperatures. The W2C par...

This study aimed to determine the physical, mechanical, mineral and microstructural properties of a industrially manufactured hybrid cement (HYP), consisting 47,5 % Belite clinker + 47,5 % FA + 5 % solid alkaline activator. The effect of the curing temperature (25ºC, or 85 ºC) on hydration kinetics and on compressive strength development (in paste...

In the production of dental restorations, there are, currently, two main types of materials: ceramics and resin composites. These latter kinds are typically suggested because of their quick fabrication, easy reparation and increased crossed link density compared with conventional light-cured materials. However, it is not clear for the specialist wh...

It has been investigated the potential application of a bio-inspired 3D model for decreasing the time required to perform the geometrical optimization of a hip prosthesis stem. This research assumes that nature has already found the best solution for many situations, proved to be real for many cases, what has been demonstrated for the specific situ...

The main requirements of tungsten materials for structural divertor applications comprise properties like high thermal conductivity, high-temperature strength and stability, high recrystallization temperature, and enough ductility for an operation period of about two years under massive neutron load [1]. However, the mechanical properties of tungst...

Self-passivating tungsten based alloys for the first wall armor of future fusion reactors are expected to provide a major safety advantage compared to pure tungsten in case of a loss-of-coolant accident with simultaneous air ingress, due to the formation of a stable protective scale at high temperatures in presence of oxygen which prevents the form...

This study evaluates the microstructural and mechanical behaviour of two tungsten (W) − 2 wt.% vanadium (V) alloys and compares them with a pure W reference material. All the materials were processed by hot isostatic pressing (HIP). However, some differences were introduced during the fabrication process of the W-2 V alloys: one was processed with...

WC-Cu cermets have been devised for thermal barriers between the plasma facing tungsten tiles and the copper-based heat sink in the first wall of nuclear fusion reactors. Composite materials with 50 and 75 v/v% WC have been prepared by hot pressing at 1333 and 1423 K with pressures of 37 and 47 MPa, respectively. Microstructural changes have been i...

This work focuses on the evaluation of modified surfaces on Ti produced by powder metallurgy. These newly designed surface modifications are achieved by deposition and diffusion of a stable aqueous suspension prepared in one case from micro-sized Nb powder (Ti β-stabilizer element) and in another case from Nb plus the addition of ammonium chloride,...

Power exhaust and materials lifetime have been identified as key challenges for next-generation fusion devices. A water-cooled monoblock divertor, consisting of tungsten as the plasma facing material and copper-based composites as the heat sink, has been proposed as the baseline material. However, there is a large mismatch in the coefficient of the...

The combination of tungsten carbide and copper as a thermal barrier could effectively reduce the thermal mismatch between tungsten and copper alloy, which are proposed as base armour and heat sink, respectively, in the divertor of future fusion reactors. Furthermore, since the optimum operating temperature windows for these divertor materials do no...

Copper and its alloys are used as heat sink materials for next generation fusion devices and will be joined to tungsten as an armour material. However, the joint of W and Cu experiences high thermal stresses when exposed to high heat loads so an interlayer material could effectively ensure the lifetime of the component by reducing the thermal misma...

Tungsten is a candidate to be used as plasma facing materials in future fusion nuclear reactors. There, the material has to withstand large radiation fluxes and thermal loads. Nowadays, nanostructured tungsten (NW) seems to exhibit a better radiation-resistance than the coarse grained. However, the thermal stability of NW is still an open question....

The use of self-passivating tungsten alloys for the first wall armor of future fusion reactors is advantageous concerning safety issues in comparison with pure tungsten. Bulk W-10Cr-0.5Y alloy manufactured by mechanical alloying followed by HIP resulted in a fully dense material with grain size around 100 nm and a dispersion of Y-rich oxide nanopar...

The exhaust of power and particles is regarded as a major challenge in view of the design of a magnetic confinement nuclear fusion demonstration power plant (DEMO). In such a reactor, highly loaded plasma facing components (PFCs), like the divertor targets, have to withstand both severe heat flux loads and considerable neutron irradiation. Existing...

A series of Al2O3/Y2O3-stabilized zirconia (Y-TZP) ceramic composites with different zirconia contents (5 and 40 vol% Y-TZP) and fabricated by different green processing techniques (a novel tape casting and conventional slip casting) were studied. The microstructure and mechanical properties of the composites were investigated systematically, by me...

This study aimed to determine the physical-mechanical, mineralogical and microstructural properties of a pre-industrially manufactured hybrid cement (HYC) containing 5% alkaline activator and less than 30% clinker. The effect of the initial curing temperature (25 ± 1 or 85 °C for 20 h) on hydration kinetics and the development of compressive streng...

Self-passivating tungsten based alloys will provide a major safety advantage compared to pure tungsten when used as first wall armor of future fusion reactors, due to the formation of a protective oxide layer which prevents the formation of volatile and radioactive WO3 in case of a loss of coolant accident with simultaneous air ingress. Bulk WCr10T...

This is the second part of a study in which the aim is to evaluate the influence of adding 2 or 4 wt.% vanadium (V) and 0.5 wt.% yttria (Y2O3) to pure tungsten (W) and the effects on the mechanical properties at high temperature. In the first part, the microstructure at room temperature was analysed. These W-based alloys were processed by powder me...

This study and a second part dedicated to the mechanical characterization provide a better knowledge of tungsten (W)-vanadium (V) alloys reinforced with yttrium oxide (Y2O3) particles, which have been scarcely investigated. Two W alloys (W-2 or 4 wt.% V-0.5 wt.% Y2O3) and a pure W material processed by powder metallurgy and consolidated by hot isos...

This paper reports on a comparative study of the mechanical performance at high temperatures of a commercial Portland cement (CEM I 42.5 (OPC)), a hybrid cement (CEM HYC = 30% clinker + 32.5 % BFS + 32.55 % FA + 5 % alkaline activator) and a geopolymer (fly ash-activated with waterglass solution). Two types of mechanical tests were conducted on sam...

Tungsten (W) and its alloys are very promising materials for producing plasma-facing components (PFCs) in the fusion power reactors of the near future, even as a structural part in them. However, whereas the properties of pure tungsten are suitable for a PFC, its structural applications are still limited due to its low toughness, ductile to brittle...

Tungsten and tungsten-based alloys are considered to be candidate materials for next-generation nuclear fusion reactors. Unfortunately, their use in structural applications is compromised due to their inherent brittleness. To improve this crucial feature, it is necessary to accurately measure their fracture toughness as a real property independent...

The purpose of this research is to characterise the mechanical properties of multicrystalline silicon for photovoltaic applications that was crystallised from silicon feedstock with a high content of several types of impurities.

Solar sintering is a technology that enabled the production of a dense ceramic body, thereby improving the functional and structural properties of ceramic and metals. In this experimental work, the density, microstructure, mechanical and magnetic properties of NiZn ferrites sintered in a solar furnace and in a conventional electrical furnace were c...

W-2Ti and W-1TiC alloys were produced by mechanical alloying and consolidation by hot isostatic pressing. The composition and microstructural characteristics of these alloys were studied by X-ray diffraction, energy dispersion spectroscopy and scanning electron microscopy. The mechanical behavior of the consolidated alloys was characterized by micr...

This study evaluates the mechanical behaviour of an Y2O3-dispersed tungsten (W) alloy and compares it to a pure W reference material. Both materials were processed via mechanical alloying (MA) and subsequent hot isostatic pressing (HIP). We performed non-standard three-point bending (TPB) tests in both an oxidising atmosphere and vacuum across a te...

Nanostructured tungsten (nanoW) coatings have been deposited by DC magnetron sputtering. First, the influence of the sputtering power on the adhesion of the coatings to the substrate was investigated by depositing coatings at powers varying from 30 up to 220 W. Non-delaminated coatings were achieved at powers ≤50 W. Second, the influence of coating...

Directionally solidified Al2O3–Er3Al5O12–ZrO2 eutectic rods were processed using the laser floating zone method at growth rates of 25, 350 and 750 mm/h to obtain microstructures with different domain size. The mechanical properties were investigated as a function of the processing rate. The hardness, ∼15.6 GPa, and the fracture toughness, ∼4 MPa m1...

The purpose of this research is the mechanical characterisation of multicrystalline silicon crystallised from silicon feedstock with a high content of aluminium for photovoltaic applications. The mechanical strength, fracture toughness and elastic modulus were measured at different positions within the multicrystalline silicon block to quantify the...

Collaborative e-learning is increasingly appealing as a pedagogical approach that can positively affect student learning. We propose a didactical model that integrates multimedia with collaborative tools and peer assessment to foster collaborative e-learning. In this paper, we explain it and present the results of its application to the "Internatio...

Here we show that potassium-doped tungsten foil should be preferred to pure tungsten foil when considering tungsten laminate pipes for structural divertor applications. Potassium-doped tungsten materials are well known from the bulb industry and show an enhanced creep and recrystallization behaviour that can be explained by the formation of potassi...

Nanofibrillar Al2O3–Y3Al5O12–ZrO2 eutectic rods were manufactured by directional solidification from the melt at high growth rates in an inert atmosphere using the laser-heated floating zone method. Under conditions of cooperative growth, the ternary eutectic presented a homogeneous microstructure, formed by bundles of single-crystal c-oriented Al2...

The mechanical behavior of three tungsten (W) alloys with vanadium (V) and lanthana (La2O3) additions (W-4%V, W-1%La2O3, W-4%V-1%La2O3) processed by hot isostatic pressing (HIP) have been compared with pure-W to analyze the influence of the dopants. Mechanical characterization was performed by three point bending (TPB) tests in an oxidizing air atm...

This paper describes the CyberAula 2.0 project which presents an integrated solution for videoconferencing and lecture recording as a mechanism to support subjects which need to be promoted or discontinued within the framework of the European convergence process. Our solution is made up of a web portal, a videoconferencing tool and an economical an...

En este trabajo se han estudiado las propiedades mecanicas de fibras superconductoras Bi2Sr2CaCu2O8+� fabricadas por solidificacion direccional inducida por laser y crecidas a distintas velocidades. Se realizaron ensayos de traccion directa e indirecta (ensayo brasileno para evaluar la resistencia a traccion en las direcciones longitudinal y trans...

Esta investigación se ha centrado en el estudio de un eutéctico cerámico Al2O3/YAG fabricado por solidificación direccional mediante el método de bridgman. Se han realizado ensayos de tenacidad de fractura por flexión en tres puntos y se ha medido el módulo de elasticidad entre temperatura ambiente y 1650 ºC. Así mismo se han utilizado dos velocida...

In this research the mechanical behaviour of pure tungsten (W) and its alloys (2wt.% Ti–0.47wt.% Y2O3 and 4wt.% Ti–0.5wt.% Y2O3) is compared. These tungsten alloys, have been obtained by powder metallurgy. The yield strength, fracture toughness and elastic modulus have been studied in the temperature interval of 25°C to 1000°C. The results have sho...

The flexure strength of directionally-solidified Al2O3-ZrO2(Y2O3) and Al2O3-Y3Al5O12 eutectic ceramic composites processed by the laser-heating floating zone method was studied from 25ºC to 1427ºC. The effect of microstructure, residual stresses and temperature on the flexure strength and the associated fracture mechanisms was assessed for each mat...

The flexure strength of tetragonal ZrO2(Er2O3) single-crystal monofilaments manufactured by the laser-heated floating zone method was measured as a function of the environment (air vs. water) and temperature (from 25 to 800ºC) at loading rates spanning three orders of magnitude to ascertain their susceptibility to the environmental conditions. Thes...

Eutectic rods of Al2O3–Er3Al5O12 were grown by directional solidification using the laser-heated floating zone method at rates in the range 25–1500 mm/h. Their microstructure and mechanical properties (hardness, toughness and strength) were investigated as a function of the growth rate. A homogeneous and interpenetrated microstructure was found in...

En este trabajo se han evaluado las propiedades mecánicas a 77 y a 300 K de dos grafitos policristalinos con microestructuras muy diferentes y de un compuesto C/C. Se realizaron ensayos de flexión en tres puntos y de tenacidad, y en éstos últimos se midió in situ la iniciación y la evolución del daño en el fondo de la entalla con un microscopio de...

a b s t r a c t In this research the mechanical behaviour of pure tungsten (W) and its alloys (2 wt.% Ti–0.47 wt.% Y 2 O 3 and 4 wt.% Ti–0.5 wt.% Y 2 O 3) is compared. These tungsten alloys, have been obtained by powder metal-lurgy. The yield strength, fracture toughness and elastic modulus have been studied in the temperature interval of 25 °C to...

Resumen: Se han estudiado las fibras eutécticas Al 2 O 3 -Er 3 Al 5 O 12 -ZrO 2 procesadas por fusión zonal por láser a distintas velocidades. Con el aumento de la velocidad de procesado se ha observado un refinamiento de la microestructura así como un cambio en la morfología de la misma. Se ha determinado mediante piezoespectroscopía que la fase a...

W and W alloys are currently considered promising candidates for plasma facing components in future fusion reactors but most of the information on their mechanical properties at elevated temperature was obtained in the 1960s and 1970s. In this investigation, the strength and toughness of novel Y2O3-doped W–Ti alloys manufactured by powder metallurg...

This paper discusses the results of tests conducted to ascertain at high temperatures the mechanical behavior of cements whose most prominent characteristic is the absence or near absence of Portland cement in their composition. More specifically, it reports on the study of three binders: (a) Portland cement (control); (b) 100% sodium silicate-acti...

RESUMEN En este trabajo se realiza un estudio comparativo del comportamiento mecánico, en función de la temperatura, entre un cemento Portland comercial, utilizado de referencia y dos nuevos materiales cementantes. Los ensayos realizados se han centrado en muestras de cemento portland , muestras de cenizas volantes activadas con un 100% de silicato...

Nowadays, the electronic industry demands small and complex parts as a consequence of the miniaturization of electronic devices. Powder injection moulding (PIM) is an emerging technique for the manufacturing of magnetic ceramics. In this paper, we analyze the sintering process, between 900 degrees C and 1300 degrees C, of Ni-Zn ferrites prepared by...

Bending strength and toughness of β-SiC foams were measured from ambient temperature to 1400°C. It was found that SiC was able to maintain the mechanical properties up to 1200°C even after long-term exposure at this temperature. Creep deformation was not detected and the negative effects of oxidation at this temperature were balanced by the healing...

The mechanical behavior of pure W, W-0.5wtpct Y2O3, and W-4wtpct Ti manufactured by powder metallurgy was studied from ambient temperature to 1000°C. Y2O3 nanoparticles were added to inhibit grain growth and improve oxidation resistance, while Ti is a sintering activator. Strength and toughness were measured from the three-point bend tests in smoot...

The development of nuclear fusion is rapidly becoming a vital necessity in view of the continuing rise of the world’s energy demand. Nuclear fusion offers a virtually endless source of energy that is both environmentally friendly and capable of meeting any foreseeable energy demand. The progress of fusion constitutes one of the greatest technologic...

The purpose of this study was to characterize a poly(methyl methacrylate) bone cement that was loaded with the antibiotic gentamicin sulphate (GS) and lactose, which served to modulate the release of GS from cement specimens. The release of GS when the cement specimens were immersed in phosphate-buffered saline at 37 degrees Celsius was determined...

In this experimental work, the effect of solid loading on rheology and final properties of alumina parts produced by powder injection moulding (PIM) was analyzed. Alumina feedstocks containing different powder loadings between 50 and 60vol. % were prepared. The binder system was based on high density polyethylene (HDPE), paraffin wax (PW) and stear...

Surface coatings of pseudo-binary Al2O3–Zr2O3(Y2O3) eutectic oxides were produced by laser melting of the surface of conventionally sintered materials using a high-power diode laser. It was possible to obtain smooth, homogeneous, and crack-free coatings up to 50 × 7 mm2 in area by carefully controlling the processing conditions (laser power, travel...