Universidad del País Vasco / Euskal Herriko Unibertsitatea

• Leioa, Guipúzcoa, Spain
Recent publications
Induction hardening is a heat treatment that is frequently used to improve the mechanical properties of the surface of components typically subjected to contact loads, such as bearings or gears, extending component life. The simulation of the induction hardening process is very complex and time-consuming, which increases time-to-market in new industrial processes as the typical approach to define the induction hardening parameters is trial and error. In this work, we present a numerical study on the evolution of microstructural phases and hardness prediction for a complex industrial case, where the induction hardening process of a large-size pitch bearing is simulated. This kind of component is hardened by scanning, where there is relative movement between the inductor and workpiece and the inductor is followed by a quenching shower. Simulating scanning induction hardening is especially challenging as simultaneous heating and cooling occur, increasing the multiphysical interactions that must be simulated. The results show the evolution of the microstructure during induction heating and subsequent quenching accompanied by a prediction on the hardened case. A homogeneous hardened within the industrial span can be achieved in the workpiece after the combined static-scanning hardening is applied in the study.
Background: The ability of Candida to develop biofilms on inert surfaces or living tissues favors recalcitrant and chronic candidiasis associated, in many instances, with resistance to current antifungal therapy. Aim: The aim of this study was to evaluate the antifungal activity of citral, a phytocompound present in lemongrass essential oil, in monotherapy and combined with fluconazole against azole-resistant Candida planktonic cells and biofilms. The effect of citral combined with fluconazole was also analysed with regard to the expression of fluconazole resistance-associated genes in Candida albicans and the effectiveness of the combination therapy in a Caenorhabditis elegans model of candidiasis. Results: Citral reduced biofilm formation at initial stages and the metabolic activity of the mature biofilm. The combination of citral with fluconazole was synergistic, with a significant increase in the survival of C. elegans infected with Candida. RNA analysis revealed a reduction of the expression of the efflux pump encoded by MDR1, leading to a greater effect of fluconazole. Conclusion: Citral in monotherapy and in combination with fluconazole could represent an interesting therapy to treat recalcitrant Candida infections associated to biofilms.
First-episode psychosis (FEP) patients show structural brain abnormalities at the first episode. Whether the cortical changes that follow a FEP are progressive and whether age at onset modulates these changes remains unclear. This is a multicenter MRI study in a deeply phenotyped sample of 74 FEP patients with a wide age range at onset (15–35 years) and 64 neurotypical healthy controls (HC). All participants underwent two MRI scans with a 2-year follow-up interval. We computed the longitudinal percentage of change (PC) for cortical thickness (CT), surface area (CSA) and volume (CV) for frontal, temporal, parietal and occipital lobes. We used general linear models to assess group differences in PC as a function of age at FEP. We conducted post-hoc analyses for metrics where PC differed as a function of age at onset. We found a significant age-by-diagnosis interaction effect for PC of temporal lobe CT ( d = 0.54; p = 002). In a post-hoc-analysis, adolescent-onset (≤19 y) FEP showed more severe longitudinal cortical thinning in the temporal lobe than adolescent HC. We did not find this difference in adult-onset FEP compared to adult HC. Our study suggests that, in individuals with psychosis, CT changes that follow the FEP are dependent on the age at first episode, with those with an earlier onset showing more pronounced cortical thinning in the temporal lobe.
SWI/SNF complexes are major targets of mutations in cancer. Here, we combined multiple “-omics” methods to assess SWI/SNF composition and aberrations in LUAD. Mutations in lung SWI/SNF subunits were highly recurrent in our LUAD cohort (41.4%), and over 70% of the mutations were predicted to have functional impact. Furthermore, SWI/SNF expression in LUAD suffered an overall repression that could not be explained exclusively by genetic alterations. Finally, SWI/SNF mutations were associated with poorer overall survival in TCGA-LUAD. We propose SWI/SNF-mutant LUAD as a separate clinical subgroup with practical implications.
We propose a superconducting circuit architecture suitable for digital-analog quantum computing (DAQC) based on an enhanced NISQ family of nearest-neighbor interactions. DAQC makes a smart use of digital steps (single qubit rotations) and analog blocks (parametrized multiqubit operations) to outperform digital quantum computing algorithms. Our design comprises a chain of superconducting charge qubits coupled by superconducting quantum interference devices (SQUIDs). Using magnetic flux control, we can activate/deactivate exchange interactions, double excitation/de-excitations, and others. As a paradigmatic example, we present an efficient simulation of an $\ell \times h$ ℓ × h fermion lattice (with $2<\ell \leq h$ 2 < ℓ ≤ h ), using only $2(2\ell +1)^{2}+24$ 2 ( 2 ℓ + 1 ) 2 + 24 analog blocks. The proposed architecture design is feasible in current experimental setups for quantum computing with superconducting circuits, opening the door to useful quantum advantage with fewer resources.
The aim of this study was to assess the stability and differences between objective (O-Rx) and subjective (S-Rx) refraction for the assessment of the prediction error (PE). A secondary aim was to report the results of a monofocal intraocular lens (IOL). 100 subjects were included for whom S-Rx and O-Rx were obtained for all visits, and for visual performance, posterior capsular opacification incidence and Nd:YAG rates at 12 months. Either S-Rx and O-Rx showed a hyperopic shift from 1 to 6 months (p < 0.05) and stabilization after 6 months. S-Rx was related with the axial length (rho = −0.29, p = 0.007), obtaining a major tendency towards hyperopia in short eyes implanted with high-power IOLs. O-Rx showed a myopic shift in comparison to S-Rx (p < 0.05). This resulted in a decrease of the number of eyes in ±0.50 D and ±1.00 D from 79 to 67% and from 94 to 90%, respectively. The median (interquartile range) uncorrected and corrected visual acuities were 0.1 (0.29) and 0 (0.12) logMAR, respectively, and seven eyes required Nd:YAG capsulotomy at 12 months. Some caution should be taken in PE studies in which O-Rx is used or S-Rx is measured in a 1-month follow-up. Constant optimization should be conducted for this IOL after S-Rx stabilization.
To optimize and satisfy current industrial requirements, during the last decade new alternatives to conventional manufacturing processes are implemented into conventional machines, leading to multitasking machines. Especially hybrid machines combining additive and subtractive technologies (AM/SM), have become a potential solution for manufacturing and repairing operations in terms of material waste reduction, time consumption and flexibility. Nevertheless, this technology has implications for the machine and the auxiliary elements as well as other challenges: digitalization, process parameterization or CAD/CAM solutions. Thereby, this work proposes a new methodology for hybrid manufacturing systems, a programmed interface to interact between additive and subtractive technologies within the same environment. The developed application-programming interface (API) offers a CAM module oriented to AM with appropriate laser metal deposition (LMD) parameters, with three different options of strategy programming: Planar LMD, 3-axis LMD and 5-axis LMD. Additionally, the value of this work stems from the implementation of an algorithm to estimate the cladding geometry, so, the full resulting geometry can be considered as the new blank for SM. A height measuring laser sensor was implemented in the LMD machine to obtain the real height of the generated clad, critical for the next machining step. Finally, to validate the methodology, a blisk made of Hastelloy®X was built-up on Inconel®718 with LMD and milled to the final size. Dimensional deviation was measured after each process.
Nano-displacement sensing based on an extrinsic hybrid fiber Fabry-Perot interferometer is proposed and demonstrated. The lead-in fiber tip of such an interferometer consists of a strongly-coupled multicore fiber section fusion spliced to a single-mode fiber. The referred lead-in fiber tip is placed in front of a microscope slide, whose rear surface is coated with a high reflecting layer. The gap between the end-face of the fiber tip and the layer is composed of an air cavity in series with a glass one. Light exiting from the lead-in fiber tip is partially reflected at the fiber-air and air-glass interfaces and the reflecting layer generating three beams that are recoupled into the multicore fiber and combined with supermode interference. By making the optical path length of the air cavity slightly different from the glass one, it is possible to generate an envelope in the interference spectra with a larger period. Thus, by tracking the shift of such an envelope, displacements of 0.47 nm can be resolved. The nano-displacement sensing approach reported here is easy to implement; moreover, the sensitivity, resolution, and dynamic range can be reconfigured by an appropriate selection of the glass cavity.
The Perseverance rover (Mars 2020) mission, the first step in NASA’s Mars Sample Return (MSR) program, will select samples for caching based on their potential to improve understanding Mars’ astrobiological, geological, geochemical, and climatic evolution. Geochronologic analyses will be among the key measurements planned for returned samples. Assessing a sample’s shock history will be critical because shock metamorphism could influence apparent sample age. Shock effects in one Mars-relevant mineral class, plagioclase feldspar, have been well-documented using various spectroscopy techniques (thermal infrared reflectance, emission, and transmission spectroscopy, Raman, and luminescence). A subset of these data will be obtained with the SuperCam and SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instruments onboard Perseverance to inform caching decisions for MSR. Here, we review shock indicators in plagioclase feldspar as revealed in Raman, luminescence, and IR spectroscopy lab data, with an emphasis on Raman spectroscopy. We consider how this information may inform caching decisions for selecting optimal samples for geochronology measurements. We then identify challenges and make recommendations for both in situ measurements performed with SuperCam and SHERLOC and for supporting lab studies to enhance the success of geochronologic analyses after return to Earth.
Bioactive molecules are those capable of interacting with living organisms, causing changes in them. Wood extractives contain important amounts of these molecules, and some of them have good antioxidant and antimicrobial activity, which favors their use as preservatives. Several different extraction methods are employed to obtain the extractives, some of which have been used for a long time. However, these conventional methods have significant disadvantages, being the most important ones high solvent, energy, and time consumption. To overcome these drawbacks, new extraction techniques are being developed whose aim is also the optimization of the process. Separation techniques such as chromatography and molecular distillation allow extractives purification and the acquisition of the desired molecules. This review aims to provide an overview of the extraction and purification methods used for wood bioactive molecules. To this end, issues such as raw material, solvent type, solid/liquid ratio (SLR), temperature, pressure, and extraction time are discussed. The application of extractives as preservatives for low durability woods is also analyzed. The study concludes that the quality and quantity of bioactive molecules, besides depending on the raw material, are determined by the employed methods and solvents to obtain these molecules. Therefore, the choice of method and solvent is of fundamental importance to achieve the desired results.
Climate change is disproportionately affecting vulnerable communities, increasing existing risks and leading to further global inequalities. Drawing on the concept of urban adaptation justice, we evaluated the inclusion of vulnerable communities in the climate change adaptation planning process of İstanbul, a European coastal megacity with considerable vulnerability to climate change. For this, a policy content analysis structured around four criteria: (i) participation, (ii) capacity enhancement, (iii) governance, and (iv) justice integration into spatial planning, was carried out and supplemented by local expert consultations. Our findings indicate that while the objective of incorporating some aspects of justice in adaptation planning was recognized, there was a distinct lack of specific actions or evaluation tools. The expert consultations largely confirmed these findings, which were then connected to the socio-historical and political context of İstanbul and the wider Turkish region. Key conclusions include the failure of current adaptation policies to adequately consider vulnerabilities arising from a combination of urban marginalization interacting with neoliberal authoritarianism. We identify the need for understanding and integrating equitable climate change adaptation as a key dimension of urban decision-making for future policy-relevant research and practice.
The aim of this paper is to analyse the meaning of beach safety flags and their management along the Northern Spanish coast. There are more than 1000 small beaches, which are often in high demand by tourism during the summer season. To carry out the research, most of main beaches have been visited to observe and analyse the meaning of all the safety flags and their correct use depending on the oceanographic and meteorological conditions. The influence of the beach safety management and regulations on the use of beach safety signage has been also analysed. The results show that safety flag systems differ even between very close beaches where safety management is in the hands of different local governments. Outdated and local legal framework and the absence of an agreed system between the different organizations that provide lifeguarding services seem to be behind this lack of uniformity. A specific guide for beach safety flags and signage within a national safety beach plan agreed by all the autonomic or provincial governments may be a solution.
Floating offshore wind growth places the industry development close to commercial scale. However, the harsh environment with strong winds, waves, and currents, together with the increasing size of wind turbines and floater motions could affect power production and reduce system lifetime due to fatigue loads. In any case, operating the wind turbine close to the optimum efficiency value guaranteeing its reliability through fatigue load reduction could be achieved with a proper control strategy. This paper proposes a critical review of the state-of-art of floating wind turbine control technologies, discussing the advantages and drawbacks of the most used control algorithms and classifying them, to summarize the future trends of the research.
Hydroxyapatite (HA) is an emergent catalytic material able to contribute effectively to the improvement of a number of strategic applications, including energy transformation and the generation of high added‐value products processes. As a catalyst support, it is widely used because of its interesting structural and chemical properties. In this mini‐review, we report the application of HA as a catalyst support for the methane reforming reactions. A special attention will be paid on its promising results as a catalyst carrier in the dry reforming of methane (DRM), a process in which it has been mostly investigated. The key parameters that make HA‐based catalysts suitable are described with an emphasis on its competitive performance to the state‐of‐the‐art catalysts.
This study explores how the corporate entrepreneurship (CE) of state-owned enterprises (SOEs) evolves under varying conditions of state ownership and control, laws and norms, and competence in the market. For this purpose, we present a longitudinal case study focused on the Spanish postal operator Correos using qualitative archival data and interviews. Our results indicate that the willingness and capacity of an SOE to act entrepreneurially depends critically on its degree of autonomy from the state and on the extent to which its legal and market environments increase its dynamism, complexity, and hostility. We also show that the development of CE in an SOE may lead to improved service quality, operational efficiency, and business specialization; facilitate its market positioning; and foster its sustainability through the exploration and exploitation of strategic alliances that can increase its business scope.
We described a dinosaur tracksite found in the uppermost part of the Areia do Mastro Formation (lowermost Barremian, Lower Cretaceous), located at 1.5 km north of Cabo Espichel (Sesimbra, Portugal). The studied tracks are distributed in a heavily trampled limestone bed which crops out alongside the rocky beach. The studied trampled surface is highly dinoturbated, 541 tracks assigned to sauropods, ornithopods and theropods were identified. The majority of footprints (336) were produced by the herbivores. The dinoturbated level is a micritic nodular limestone, deposited in a very shallow subtidal to intertidal lagoon environment. Due to the intense bioturbation and limited exposed area, it is difficult to clearly define trackways, but the tracks can provide information about the producers and their behaviours. It is inferred that dinosaurs crossed this area at different times; the herbivores (sauropods and ornithopods) may possibly used the coastal area as passage between feeding spots, while carnivores frequented the area to hunt in groups or individually.
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• Mechanic Engineering
• Departamento de Economía Financiera II
• Departamento de Genética, Antropología Física y Fisiología Animal
• dept of physics
• Departamento de Economía Financiera II
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