Zientzia eta etika: patologia eta iruzurra ikerketa zientifikoan

Zientzia jarduera objektiboa eta neurri handi batean eszeptikoa izan arren, hezur-haragizko zientzialarien ahuleziek eta kanpoko presioek autoengainura (Zientzia Patologikoa) edo baldintzapeko iruzurrera eraman dezakete ikerlaria. Lan zientifiko bat argitaratzeko gainditu behar diren iragazkiak asko izan arren, engainuaz ohartu aurretik, praktika txarrak erabiliz ohore handiak jaso dituzten kasuak egon badaude. Kasu hauek arruntagoak dira Biomedikuntzan eta Fisikan, baina ez dugu ahaztu behar Paleontologia, gure Euskal Herri hurbilean azken Zientzia arlo horretako praktika txarren kasu batzuk gertatu baitira. Lan honetan Zientzian gertatzen diren praktika txarreko kasu horien zergatia azaltzen saiatzen gara. Praktika txarren kasu berri eta klasiko batzuk berrikusi ostean, ikerketa zientifikoarekin eta argitalpenekin loturiko kontu etikoez zientzialari gazteak irakastea proposatzen da. Zientzian praktika onen entrenamendua unibertsitateko (eta bigarren hezkuntzako) ikasketetan egin beharko litzateke, zeren egun ez baita horrelakorik aipatu ere egiten

Interaction dynamics and autonomy in cognitive systems

The concept of autonomy is of crucial importance for understanding life and cognition. Whereas cellular and organismic autonomy is based in the self-production of the material infrastructure sustaining the existence of living beings as such, we are interested in how biological autonomy can be expanded into forms of autonomous agency, where autonomy as a form of organization is extended into the behaviour of an agent in interaction with its environment (and not its material self-production). In this thesis, we focus on the development of operational models of sensorimotor agency, exploring the construction of a domain of interactions creating a dynamical interface between agent and environment. We present two main contributions to the study of autonomous agency: First, we contribute to the development of a modelling route for testing, comparing and validating hypotheses about neurocognitive autonomy. Through the design and analysis of specific neurodynamical models embedded in robotic agents, we explore how an agent is constituted in a sensorimotor space as an autonomous entity able to adaptively sustain its own organization. Using two simulation models and different dynamical analysis and measurement of complex patterns in their behaviour, we are able to tackle some theoretical obstacles preventing the understanding of sensorimotor autonomy, and to generate new predictions about the nature of autonomous agency in the neurocognitive domain. Second, we explore the extension of sensorimotor forms of autonomy into the social realm. We analyse two cases from an experimental perspective: the constitution of a collective subject in a sensorimotor social interactive task, and the emergence of an autonomous social identity in a large-scale technologically-mediated social system. Through the analysis of coordination mechanisms and emergent complex patterns, we are able to gather experimental evidence indicating that in some cases social autonomy might emerge based on mechanisms of coordinated sensorimotor activity and interaction, constituting forms of collective autonomous agency

Influence of magnetic relaxation on magnetoelastic resonance-based detection

The phenomenon of magnetic relaxation in amorphous ferromagnetic alloys can result in an undesired time evolution of the magnetization that produces serious drawbacks in the use of these materials in sensor applications. The present work studies, at room temperature, the influence of magnetic relaxation on the performance of an amorphous ferromagnetic ribbon as the main element of a magnetoelastic resonance (MER)-based sensor. The time evolution was observed through the evolution of the MER signal, in particular through the variation experienced by the resonance frequency fr, which is the main parameter used for sensing. It is found that, after the bias field is changed to a given value, and under constant excitation conditions, fr increases with time in a typical relaxation behavior with a relaxation amplitude ∆fr and a relaxation time τ that depend on the excitation conditions. The amplitude of the excitation h turned out to be a key factor on the relaxation, since larger excitation field amplitudes (h ⩾ 100 mOe) result in a considerable decrease of relaxation times (τ < 460 s) and a reduction of the variation of the resonance frequency (∆fr < 77 Hz). The influence of this relaxation on the sensor performance and the possible approaches to overcome this problem are evaluated and applied to the case of a magnetoelastic sensor, operating as mass sensor, for monitoring a chemical precipitation reaction.The authors would like to thank the financial support from the Basque Government under μ4IIOT project (KK-2021/00082, Elkartek program) and the University Basque Research Groups Funding under Grant IT1479-22. Beatriz Sisniega acknowledges the financial support from the Basque Government through FPI Grant PRE_2021_2_0145

Spontaneous Zero-Field Cooling Exchange Bias in Ni–Co–Mn–Sn Metamagnetic Heusler Sputtered Film

Metamagnetic off-stoichiometric Heusler alloys are actively being investigated because of their great potential as magnetocaloric materials. These properties are intimately related to the nanoscale homogeneity of their magnetic properties, mainly due to a strong influence of the nature of the exchange interactions between Mn atoms on the magnetism of the alloys. In this work, a spontaneous exchange bias phenomenon on a Ni–Co–Mn–Sn metamagnetic Heusler sputtered film is presented and studied in detail. More particularly, a series of DC magnetization curves measured as a function of the temperature demonstrates that the system exhibits canonical spin glass-like features. After a careful study of the field-cooling and zero-field-cooling curves measured on this system, the existence of magnetic inhomogeneities is inferred, as a consequence of the competition between ferromagnetic and antiferromagnetic exchange interactions between Mn atoms. Further AC susceptibility measurements on this system demonstrate that the underlying exchange bias phenomenon can be attributed to a magnetic clusters model based on superferromagnetic-like interactions present in the film. These findings suggest that the spontaneous exchange bias exhibited by the studied system is a consequence of the formation of this superferromagnetic-like state.This research was funded by the Hellenic Foundation of Research and Innovation (HFRI) and the General Secretariat for Research and Innovation (GSRI) of Greece (grant M.M.ME.H.A., no. 2530); by the H2020 Excellent Science-Marie Skłodowska-Curie Actions with the individual fellow no.753025; and the Spanish Government under grant no. RTI2018 094683-B-C5

Effect Of Nb And Cu On The Crystallization Behavior Of Understoichiometric Nd–Fe–B Alloys

In this work, we present a complete study of the influence of Nb and Cu addition on the crystallization behavior of Nd-lean Nd-Fe-B melt-spun alloys. Alloys with compositions Nd10-x-yFe84B6NbxCuy (x = 1, y = 0 and x = 0.5, y = 0.5) were melt-spun at different wheel speeds (15-40 m s(-1)) to obtain samples in amorphous, highly disordered and nanocrystalline structures. The crystallization process, induced by different heat treatments, was studied by means of differential thermal analysis and x-ray powder thermodiffraction. Magnetic properties of as-made and heat-treated ribbons were measured by magnetometry. The as-made amorphous samples showed a crystallization to the 2: 14: 1 hard magnetic phase at T-1 similar to 350 degrees C. Doping with Nb results in an increase of T1, and addition of Cu lowers T1. This behavior is explained in terms of an inhibition of grain growth by Nb and a nucleation enhancement by Cu additions. During the crystallization process, a secondary phase (identified as a bcc-Fe-rich phase) is formed. The amount of such a phase increases with the annealing temperature. Coercivity increases upon annealing reaching maxima at 700-750 degrees C. This can be explained in terms of competition between the two phases formed: the 2: 14: 1 hard phase and the soft bcc-Fe-rich phase. The highest coercivity of the Nd-lean samples is observed when the microstructure is appropriate and both phases are exchange-coupled.This work has received funding from the DOE BES-DE-FG02-90ER45413 and the European Union MSCA grant agreement No 691235 (INAPEM). Technical and human support provided by SGIker (UPV/EHU, GV/EJ and ESF) is gratefully acknowledged

A new approach for the fabrication of cytocompatible PLLA-magnetite nanoparticle composite scaffolds

Magnetic biomimetic scaffolds of poly(L-lactide) (PLLA) and nanoparticles of magnetite (nFe3O4) are prepared in a wide ratio of compositions by lyophilization for bone regeneration. The magnetic properties, cytotoxicity, and the in vitro degradation of these porous materials are closely studied. The addition of magnetite at 50 °C was found to produce an interaction reaction between the ester groups of the PLLA and the metallic cations of the magnetite, causing the formation of complexes. This fact was confirmed by the analysis of the infrared spectroscopy and the gel permeation chromatography test results. They, respectively, showed a displacement of the absorption bands of the carbonyl group (C=O) of the PLLA and a scission of the polymer chains. The iron from the magnetite acted as a catalyser of the macromolecular scission reaction, which determines the final biomedical applications of the scaffolds—it does so because the reaction shortens the degradation process without appearing to influence its toxicity. None of the samples studied in the tests presented cytotoxicity, even at 70% magnetite concentrations.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry Department under the ELKARTEK, HAZITEK and PIBA programs. Supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013, project POCI-01-0145-FEDER-028237 and grant SFRH/BD/111478/2015 (S.R.) is acknowledged

Removal of Tetracycline Pollutants by Adsorption and Magnetic Separation Using Reduced Graphene Oxide Decorated with Alpha-Fe₂O₃ Nanoparticles

Nanocomposites of reduced graphene oxide (RGO) with ferromagnetic alpha-Fe₂O₃ nanoparticles have been prepared in-situ by thermal treatment. The structure and morphology of the hybrid material were studied by X-ray photoelectron spectroscopy, Raman, X-ray diffraction, and transmission electron microscopy. The results show a hybrid material highly modified with alpha-Fe₂O₃ nanoparticles distributed on the graphene surface. The adsorption kinetics show the presence of alpha-Fe₂O₃ nanoparticles on the RGO surface, and the amount of remaining functional groups dominated by ionization and dispersion. The adsorption kinetics of this adsorbent was characterized and found to fit the pseudo-second-order model. The alpha-Fe₂O₃ nanoparticles on RGO modify the electrostatic interaction of RGO layers and tetracycline, and adsorption properties decreased in the hybrid material. Adsorption isotherms fit with the Langmuir model very well, and the maximum capacity adsorption was 44.23 mg/g for RGO and 18.47 mg/g for the hybrid material. Magnetic characterization of the hybrid material shows ferromagnetic behavior due to the nanosize of alpha-Fe₂O₃ with a saturation magnetization, Ms = 7.15 Am/kg, a remanence Mr = 2.29 Am/kg, and a coercive field, Hc = 0.02 T.Rodolfo Cruz-Silva acknowledges the support from the Center of Innovation (COI) Program “Global Aqua Innovation Center for Improving Living Standards andWater-sustainability” from Japan Science and Technology Agency, JST. Authors thank M. Nava for the specific surface area measurements of the materials

Sensor Applications of Soft Magnetic Materials Based on Magneto-Impedance, Magneto-Elastic Resonance and Magneto-Electricity

The outstanding properties of selected soft magnetic materials make them successful candidates for building high performance sensors. In this paper we present our recent work regarding different sensing technologies based on the coupling of the magnetic properties of soft magnetic materials with their electric or elastic properties. In first place we report the influence on the magneto-impedance response of the thickness of Permalloy films in multilayer-sandwiched structures. An impedance change of 270% was found in the best conditions upon the application of magnetic field, with a low field sensitivity of 140%/Oe. Second, the magneto-elastic resonance of amorphous ribbons is used to demonstrate the possibility of sensitively measuring the viscosity of fluids, aimed to develop an on-line and real-time sensor capable of assessing the state of degradation of lubricant oils in machinery. A novel analysis method is shown to sensitively reveal the changes of the damping parameter of the magnetoelastic oscillations at the resonance as a function of the oil viscosity. Finally, the properties and performance of magneto-electric laminated composites of amorphous magnetic ribbons and piezoelectric polymer films are investigated, demonstrating magnetic field detection capabilities below 2.7 nT.The authors would like to thank the financial support from the Basque Government under ACTIMAT (Etortek program), PE12UN025 (Saiotek program) and IT711-13 (Research Groups) projects; and from the Spanish Government under project MAT2011-27573-C04. Andoni Lasheras wants to thank the Basque Government for financial support under PhD Grant. Technical and human support provided by SGIker (UPV/EHU), especially by Inaki Orue, is gratefully acknowledged

Zientzia eta etika: patologia eta iruzurra ikerketa zientifikoan

Zientzia jarduera objektiboa eta neurri handi batean eszeptikoa izan arren, hezur-haragizko zientzialarien ahuleziek eta kanpoko presioek autoengainura (Zientzia Patologikoa) edo baldintzapeko iruzurrera eraman dezakete ikerlaria. Lan zientifiko bat argitaratzeko gainditu behar diren iragazkiak asko izan arren, engainuaz ohartu aurretik, praktika txarrak erabiliz ohore handiak jaso dituzten kasuak egon badaude. Kasu hauek arruntagoak dira Biomedikuntzan eta Fisikan, baina ez dugu ahaztu behar Paleontologia, gure Euskal Herri hurbilean azken Zientzia arlo horretako praktika txarren kasu batzuk gertatu baitira. Lan honetan Zientzian gertatzen diren praktika txarreko kasu horien zergatia azaltzen saiatzen gara. Praktika txarren kasu berri eta klasiko batzuk berrikusi ostean, ikerketa zientifikoarekin eta argitalpenekin loturiko kontu etikoez zientzialari gazteak irakastea proposatzen da. Zientzian praktika onen entrenamendua unibertsitateko (eta bigarren hezkuntzako) ikasketetan egin beharko litzateke, zeren egun ez baita horrelakorik aipatu ere egiten