Uncertainty studies of topographical measurements on steel surface corrosion by 3D scanning electron microscopy

Pitting corrosion is a damage mechanism quite serious and dangerous in both carbon steel boiler tubes for power plants which are vital to most industries and stainless steels for orthopedic human implants whose demand, due to the increase of life expectation and rate of traffic accidents, has sharply increased. Reliable methods to characterize this kind of damage are becoming increasingly necessary, when trying to evaluate the advance of damage and to establish the best procedures for component inspection in order to determine remaining lives and failure mitigation. A study about the uncertainties on the topographies of corrosion pits from 3D SEM images, obtained at low magnifications (where errors are greater) and different stage tilt angles was carried out by using an in-house software previously developed. Additionally, measurements of pit depths on biomaterial surfaces, subjected to two different surface treatments on stainless steels, were carried out. The different depth distributions observed were in agreement with electrochemical measurements.Facultad de Ingeniería (FI)Facultad de Ciencias ExactasLaboratorio de Investigaciones de Metalurgia Física (LIMF)Centro de Química Inorgánica (CEQUINOR)Centro de Investigación y Desarrollo en Ciencias Aplicadas (CINDECA

Development of EEG-based technologies for the characterization and treatment of neurological diseases affecting the motor function

This thesis presents a set of studies applying signal processing and data mining techniques in real-time working systems to register, characterize and condition the movement-related cortical activity of healthy subjects and of patients with neurological disorders affecting the motor function. Patients with two of the most widespread neurological affections impairing the motor function are considered here: patients with essential tremor and patients who have suffered a cerebro-vascular accident. The different chapters in the presented thesis show results regarding the normal cortical activity associated with the planning and execution of motor actions with the upper-limb, and the pathological activity related to the patients' motor dysfunction (measurable with muscle electrodes or movement sensors). The initial chapters of the book present i) a revision of the basic concepts regarding the role of the cerebral cortex in the motor control and the way in which the electroencephalographic activity allows its analysis and conditioning, ii) a study on the cortico-muscular interaction at the tremor frequency in patients with essential tremor under the effects of a drug reducing their tremor, and finally iii) a study based on evolutionary algorithms that aims to identify cortical patterns related to the planning of a number of motor tasks performed with a single arm. In the second half of the thesis book, two brain-computer interface systems to be used in rehabilitation scenarios with essential tremor patients and with patients with a stroke are proposed. In the first system, the electroencephalographic activity is used to anticipate voluntary movement actions, and this information is integrated in a multimodal platform estimating and suppressing the pathological tremors. In the second case, a conditioning paradigm for stroke patients based on the identification of the motor intention with temporal precision is presented and tested with a cohort of four patients along a month during which the patients undergo eight intervention sessions. The presented thesis has yielded advances from both the technological and the scientific points of view in all studies proposed. The main contributions from the technological point of view are: ¿ The design of an integrated upper-limb platform working in real-time. The platform was designed to acquire information from different types of noninvasive sensors (EEG, EMG and gyroscopic sensors) characterizing the planning and execution of voluntary movements. The platform was also capable of processing online the acquired data and generating an electrical feedback. ¿ The development of signal processing and classifying techniques adapted to the kind of signal recorded in the two kinds of patients considered in this thesis (patients with essential tremor and patients with a stroke) and to the requirements of online processing and real-time single-trial function desired for BCI applications. Especially in this regard, an original methodology to detect onsets of voluntary movements using slow cortical potentials and cortical rhythms has been presented. ¿ The design and validation in real-time of asynchronous BCI systems using motor planning EEG segments to anticipate or detect when patients begin a voluntary movement with the upper-limb. ¿ The proof of concept of the advantages of an EEG system integrated in a multimodal human-robot interface architecture that constitutes the first multimodal interface using the combined acquisition of EEG, EMG and gyroscopic data, which allows the concurrent characterization of different parts of the body associated with the execution of a movement. The main scientific contributions of this thesis are: ¿ The study of the EEG-based anticipation of voluntary movements presented in Chapter 5 of the thesis was the first demonstration (to the author's knowledge) of the capacity of the EEG signal to provide reliable movement predictions based on single-trial classification of online data of healthy subjects and ET patients. This study also provides, for the first time, the results of a BCI system tested in ET patients and it represents an original approach to BCI applications for this group of patients. ¿ It has been presented the first neurophysiological study using EEG and EMG data to analyze the effects of a drug on cortical activity and tremors of patients with ET. In addition, the obtained results have shown for the first time that a significant correlation exists between the dynamics of specific cortical oscillations and pathological tremor manifestation as a consequence of the drug effects. ¿ It has been proposed for the first time an experiment to inspect whether the EEG signal carries enough information to classify up to seven different tasks performed with a single limb. Both the methodology applied and the validation procedure are also innovative in this sort of studies. ¿ It has been demonstrated for the first time the relevance of combining different cortical sources of information (such as BP and ERD) to estimate the initiation of voluntary movements with the upper-limb. In this line, special relevance may be given to the positive results achieved with stroke patients, improving the results presented by similar previous EEG-based studies by other research groups. It has also been proposed for the first time an upper-limb intervention protocol for stroke patients using BP and ERD patterns to provide proprioceptive feedback tightly associated with the patients' expectations of movement. The effects of the proposed intervention have been studied with a small group of patients

Gamificación como herramienta docente aplicada a las tutorías de grupo en la Educación Superior

[EN] Our general objective consists in using gamification as a teaching tool in order to get a higher level of students’ involvement in the tutorials, as well as, increasing the motivation to learn Pathophysiology in the Pharmacy Degree. Not all the students groups are uniform, and also the teachers have nonconscious prejudices for each group. Hence, every student group has its own idiosyncrasy. We have the hypothesis that the game can give us really valuable information to let us develop suitable teaching techniques to enhance the motivation for each particular group. Games offers a more relaxed scenario compared to master class or exam, therefore we can ask questions as a team contest that stimulate the comprehension and integration of contents, and at the same time to brainstorm and to learn from mistakes. Games also offers teachers a better interaction with students to reflect on how to motivate each specific group. Our conclusion is, in general terms, that gamification in tutorials let students be more actives in the session. Moreover, for teachers it is an excellent tool to get to know the student’s profile and to find the best way to increase the motivation for learning in each specific group.[ES] El objetivo general del presente trabajo es utilizar la gamificación como herramienta docente para conseguir una mayor implicación del alumnado en las tutorías y aumentar la motivación frente al conocimiento de la asignatura de Fisiopatología en el Grado de Farmacia.No todos los grupos de estudiantes son iguales, y además el profesorado tiene sus prejuicios no conscientes para cada grupo. Nuestra hipótesis de trabajo se basa en que cada grupo tiene su idiosincrasia y a través del juego podemos obtener información muy valiosa que nos permita desarrollar en un futuro técnicas docentes apropiadas para cada grupo de alumnos que hagan resurgir la motivación. Desde el juego, con una perspectiva más relajada comparada con la clase magistral o con el examen, podemos plantear preguntas a modo de concurso por equipos que favorezcan el asentamiento, interiorización e integración de los contenidos, y al mismo tiempo desatar una lluvia de ideas, enseñar a partir del error e interactuar más directamente con los alumnos para reflexionar sobre cómo los docentes podemos motivar y llegar a cada grupo concreto.La conclusión general de este trabajo es que la gamificación en tutorías hace que los alumnos participen activamente en la sesión. Además, desde el punto de vista del profesorado ofrece una herramienta para conocer mejor el perfil de su alumnado y definir la mejor manera en cada caso para aumentar la motivación por la asignatura.Serna García, E.; Pereda, J.; Mauricio, MD.; Pérez, S. (2019). Gamificación como herramienta docente aplicada a las tutorías de grupo en la Educación Superior. En IN-RED 2019. V Congreso de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València. 750-758. https://doi.org/10.4995/INRED2019.2019.10442OCS75075

Solubility of CO2 in three cellulose-dissolving ionic liquids

The solubility of CO2 in three cellulose-dissolving ionic liquids (1-ethyl-3-methylimidazolium diethylphosphate, [Emim][DEP], 1-allyl-3-methylimidazolium chloride, [Amim][Cl], and 1-butyl-3-methylimidazolium chloride, [Bmim][Cl]) at temperatures within 298 and 356 K and pressures up to 6.5 MPa was determined using a Van Ness-type apparatus (static isochoric). It was demonstrated that this device can work in isothermal and isoplethal modes, being the latter faster and more precise. Moreover, it was possible to determine CO2 solubilities in metastable liquid [Bmim][Cl]. Experimental data were modeled using the Extended Henry's law correlation and the group contribution equation of state. New parameters for the binary interaction of CO2 with ionic liquid groups were calculated.Fil: Pérez, Eduardo. Universidad de Valladolid; EspañaFil: de Pablo, Laura. Universidad de Valladolid; EspañaFil: Segovia, J. Juan. Universidad de Valladolid; EspañaFil: Moreau, Alejandro. Universidad de Valladolid; EspañaFil: Sánchez, Francisco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Pereda, Selva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Bermejo, María Dolores. Universidad de Valladolid; Españ

Event-related desynchronization-based versus bereitchaftspotential-based classfiers in stroke patiens

To compare the most well-known volitional movement-related electrophysiological phenomena for upper-limb movements in stroke patients, as source of movement classifiers.Peer Reviewe

Corrosión de la soldadura de un acero inoxidable supermartensítico mediante una minicelda electroquímica

En el presente trabajo se investigó la influencia de los ciclos térmicos de una soldadura en la corrosión localizada de aceros inoxidables martensíticos de bajo carbono. A tal fin se utilizó una minicelda electroquímica (MCE) y se evaluó separadamente el metal de soldadura (MS), el metal base (MB) y la zona afectada por el calor (ZAC) como también diferentes áreas dentro del cordón de soldadura multipasada.Facultad de Ingenierí

Lung Myofibroblasts Are Characterized by DownRegulated Cyclooxygenase-2 and Its Main Metabolite, Prostaglandin E2

Background: Prostaglandin E2 (PGE(2)), the main metabolite of cyclooxygenase (COX), is a well-known anti-fibrotic agent. Moreover, myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA), fibroblast expansion and epithelial-mesenchymal transition (EMT) are critical to the pathogenesis of idiopathic pulmonary fibrosis (IPF). Our aim was to investigate the expression of COX-2 and PGE(2) in human lung myofibroblasts and establish whether fibroblast-myofibroblast transition (FMT) and EMT are associated with COX-2 and PGE(2) down-regulation. Methods: Fibroblasts obtained from IPF patients (n = 6) and patients undergoing spontaneous pneumothorax (control, n = 6) and alveolar epithelial cell line A549 were incubated with TGF-beta 1 and FMT and EMT markers were evaluated. COX-2 and alpha-SMA expression, PGE(2) secretion and cell proliferation were measured after IL-1 beta and PGE(2) incubation. Results: Myofibroblasts from both control and IPF fibroblast cultures stimulated with IL-1 beta showed no COX-2 expression. IPF fibroblasts showed increased myofibroblast population and reduced COX-2 expression in response to IL-1 beta. TGF-beta 1 increased the number of myofibroblasts in a time-dependent manner. In contrast, TGF-beta 1 induced slight COX-2 expression at 4 h (without increase in myofibroblasts) and 24 h, but not at 72 h. Both IPF and control cultures incubated with TGF-beta 1 for 72 h showed diminished COX-2 induction, PGE(2) secretion and alpha-SMA expression after IL-1 beta addition. The latter decreased proliferation in fibroblasts but not in myofibroblasts. A549 cells incubated with TGF-beta 1 for 72 h showed down-regulated COX-2 expression and low basal PGE(2) secretion in response to IL-1 beta. Immuno-histochemical analysis of IPF lung tissue showed no COX-2 immuno-reactivity in myofibroblast foci. Conclusions: Myofibroblasts are associated with COX-2 down-regulation and reduced PGE(2) production, which could be crucial in IPF development and progression

Uncertainty studies of topographical measurements on steel surface corrosion by 3D scanning electron microscopy

Pitting corrosion is a damage mechanism quite serious and dangerous in both carbon steel boiler tubes for power plants which are vital to most industries and stainless steels for orthopedic human implants whose demand, due to the increase of life expectation and rate of traffic accidents, has sharply increased. Reliable methods to characterize this kind of damage are becoming increasingly necessary, when trying to evaluate the advance of damage and to establish the best procedures for component inspection in order to determine remaining lives and failure mitigation. A study about the uncertainties on the topographies of corrosion pits from 3D SEM images, obtained at low magnifications (where errors are greater) and different stage tilt angles was carried out by using an in-house software previously developed. Additionally, measurements of pit depths on biomaterial surfaces, subjected to two different surface treatments on stainless steels, were carried out. The different depth distributions observed were in agreement with electrochemical measurements.Facultad de Ingeniería (FI)Facultad de Ciencias ExactasLaboratorio de Investigaciones de Metalurgia Física (LIMF)Centro de Química Inorgánica (CEQUINOR)Centro de Investigación y Desarrollo en Ciencias Aplicadas (CINDECA

Comparative study of fluoride conversion coatings formed on biodegradable powder metallurgy Mg: The effect of chlorides at physiological level

The development of a biodegradable metallic implant demands a precisely defined degradation profile and adequate mechanical properties. Mg has been proposed for this purpose but it has an excessively high corrosion rate and insufficient yield strength. In the present work pure Mg mechanically reinforced by a powder metallurgy (Mg(PM)) route and treated with KF was used. The effect of chlorides, at the physiological level, on four fluoride conversion coatings (F-CC) formed on Mg(PM) was evaluated comparatively. The behavior of Mg(PM) during fluoride treatments (0.01 M–0.3 M fluoride-containing solutions) before and after the addition of chlorides (8 g L− 1 NaCl) was investigated by conventional corrosion techniques and by scanning electrochemical microscopy (SECM) complemented with SEM observations and EDX analysis. Results showed that the composition and the microstructural characteristics of the F-CCs as well as their corrosion behavior change with KF concentration and immersion time. Treatments in the 0.01 M–0.1 M KF range prove to be effective to protect Mg(PM) against corrosion in the absence of chlorides while higher KF solution concentration (0.3 M) adversely affects the corrosion resistance of this metal. In the presence of chloride ions the F-CCs progressively lose their fluoride content and their corrosion resistance at a rate that depends on the treatment conditions. Such temporary corrosion protection is appropriate for biodegradable implants.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Caracterización superficial de 316LVM blastinizado y pasivado para su aplicación como biomaterial

El objetivo del presente trabajo fue evaluar los efectos que producen el proceso de blastinizado y pasivados químicos en los parámetros de rugosidad, el comportamiento frente la corrosión por picado y el endurecimiento superficial. Con este fin se utilizó acero inoxidable austenítico AISI 316 LVM con diferentes preparaciones superficiales, todas basadas en blastinizado con partículas de sílice