Modelado dinámico y control de la ventilación pulmonar

La ventilación asistida es un mecanismo de soporte vital utilizado cuando las demandas de aire no pueden ser satisfechas por el paciente. La propuesta de procesos de identificación y la obtención de modelos son la base de aplicaciones clínicas como detección y diagnóstico de enfermedades, monitoreo respiratorio, optimización de tratamientos y diseño de equipos de ventilación robustos y autónomos.Área: TICs, Electrónica e Informática

The role of reactive oxygen species in oxidative-induced neoplastic transformation

The generation of reactive oxygen species (ROS) is a normal occurrence in the life of a cell. ROS are derived from both exogenous and endogenous sources and take part in a plethora of normal physiological mechanisms from host immunity to cell cycle regulation. However, ROS also exhibit a deleterious, disruptive character that means they must now be taken seriously as a genuine carcinogenic agent able to alter a variety of pathways leading to the initiation of cancer. The two-sidedness of ROS means that the relationship between ROS and the onset and progression of cancer is hard to determine. ROS and reactive nitrogen species (RNS) are able to initiate cancer through the damage of DNA leading to the genetic instability that drives the early stages of cancer. Simultaneously, they can activate a number of signalling cascades and transcription factors that facilitate uncontrolled cell growth. The production of ROS in neoplastic cells can lead to the production of new blood vessels that provide the machinery for subsequent metastasis and tumour invasion. It is important that the role of ROS in these pathways are fully elucidated in order to provide potential therapies measures

Molecular targeting in inflammatory bowel disease an investigation to identify novel chemokine targets for the potential development of new therapeutic agents for inflammatory bowel disease

Purpose Inflammatory bowel disease is characterised by intense mucosal recruitment of activated leukocytes. As chemokines determine inflammatory leukocyte recruitment and retention, the expression of the entire chemokine family within colonic mucosa from IBD patients was compared to non-inflamed and inflamed controls. Methods A microarray of cDNAs, representing the entire chemokine superfamily and their cognate receptors, was hybridised with probes derived from colonoscopic biopsies. While expression levels of individual chemokines and their receptors have been measured in colon tissue previously, no one has attempted to analyse transcription levels of the entire chemokine superfamily in parallel The array levels were correlated with histopathological inflammatory scores and expression of their cognate receptors by quantitative PCR and immunohistochemistry. Flow cytometry was performed on mucosally-derived colonic cells. Caco-2, HT29, T84, primary colonic epithelium and keratinocyte cell lines were stimulated with combinations of IL-1f , TNF-u, and LPS, and analysed using the same microarray. Results Expression of a distinct subset of chemokines, consisting of CXCL's 1-3 and 8 and CCL20, was up regulated in active colonic IBD, compared to non-inflamed areas or tissue from controls. This expression pattern correlated with histopathological inflammatory scores Increased expression of their cognate receptors, CXCR1, CXCR2 and CCR6, was confirmed by quantitative PCR and immunohistochemistry. Flow cytometric revealed an increase of CCL20 expression on epithelial cells in IBD specimens, particularly in severe disease. An identical chemokine response was induced in Caco-2 cells by stimulation with IL-1p, but not TNF-a By contrast, IL-1p and TNF-a were synergistic in HT29 and keratinocytes. Conclusion IL-1fi and TNF-a appear to be the pivotal mediators of a coordinated epithelial chemokine response that dominates the mucosal environment in ulcerative colitis. These data suggest several new therapeutic targets for IBD, as well as identifying a previously unrecognised coordinated epithelial chemokine response

Control of an active rectifier with an inductive-capacitive-inductive filter using a Twisting based algorithm

This paper presents a novel controller for an active rectifier with an inductive-capacitive-inductive filter. The proposed control scheme comprises two levels. The internal level, is a current controller based on the second order sliding mode Twisting algorithm, which robustly ensures an unity power factor at the connection point. The slower external level is a PI controller in charge of regulating the output DC voltage to a desired reference. The controller setup also includes a finite-time observer of the current derivative that can be used to avoid direct (and sometimes problematic) numerical differentiation. Finally, simulation results are presented to validate the proposed control scheme.Instituto de Investigaciones en Electrónica, Control y Procesamiento de SeñalesConsejo Nacional de Investigaciones Científicas y Técnica

Energy-based modelling and simulation of a series hybrid electric vehicle propulsion system

This paper presents an energy-based model of a series hybrid electric vehicle. The proposed propulsion system has a new configuration using a wound-rotor synchronous generator (WRSM) and a doublyfed induction machine (DFIM). From the classic dq dynamical equations of the WRSM and DFIM the port-controlled Hamiltonian models of each machine is described. One of the abilities of the port-based models is that the complete model is easy to obtain by means of interconnection rules. Following this, the Hamiltonian model of the whole system is obtained. Similarly, the bond graph approach allows to build a complex model by interconnecting several subsystems. This paper also contains bond graph models of the machines and the propulsion system. Numerical simulations are also presented in order to validate the proposed models.Peer ReviewedPostprint (author’s final draft

Stability Criteria for Input Filter Design in Converters with CPL: Applications in Sliding Mode Controlled Power Systems

Microgrids are versatile systems for integration of renewable energy sources and non-conventional storage devices. Sliding Mode techniques grant excellent features of robustness controlling power conditioning systems, making them highly suitable for microgrid applications. However, problems may arise when a converter is set to behave as a Constant Power Load (CPL). These issues manifest in the stability of internal dynamics (or Zero Dynamics), which is determined by the input filter of the power module. In this paper, a special Lyapunov analysis is conducted to address the nonlinear internal dynamics of SM controlled power modules with CPL. It takes advantage of a Liérnad-type description, establishing stability conditions and providing a secure operation region. These conditions are translated into conductance and invariant region diagrams, turning them into tools for the design of power module filters.Fil: Anderson Azzano, Jorge Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales. Universidad Nacional de La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales; ArgentinaFil: Moré, Jerónimo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales. Universidad Nacional de La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales; ArgentinaFil: Puleston, Pablo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales. Universidad Nacional de La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales; Argentin

Efficiency Optimisation of an Experimental PEM Fuel Cell System via Super Twisting Control

A robust control solution is proposed to solve the air supply control problem in autonomous polymer electrolyte membrane fuel cells (PEMFC) based systems. Different second order sliding mode (SOSM) controllers are designed using a model of a laboratory test fuel cell generation system. Very good simulation results are obtained using such algorithms, showing the suitability of the SOSM approach to PEMFC stack breathing control. Subsequently, for experimental validation, a controller based on one of the previously assessed SOSM algorithms, namely a Super Twisting, is successfully implemented in the laboratory test bench. Highly satisfactory results are obtained, regarding dynamic behaviour, regulation error and robustness to uncertainties and external disturbances.Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señale

Singularity crossing phenomena in nonlinear electrical circuits

In a nonlinear system a singular crossing point is a singular point such that there is at least one solution crossing through it. In this article we study a family of nonlinear electrical circuits, that can be represented by nonlinear Implicit Differential Equations -IDEs-. We set conditions that ensure the existence of singular crossing points in these circuits. There are different approaches to this problem for a given general IDE, but the results we get for this family of circuits allow us to find these points in an extremely simple way. The results are illustrated in a concrete example.Facultad de Ingenierí

Efficiency Optimisation of an Experimental PEM Fuel Cell System via Super Twisting Control

A robust control solution is proposed to solve the air supply control problem in autonomous polymer electrolyte membrane fuel cells (PEMFC) based systems. Different second order sliding mode (SOSM) controllers are designed using a model of a laboratory test fuel cell generation system. Very good simulation results are obtained using such algorithms, showing the suitability of the SOSM approach to PEMFC stack breathing control. Subsequently, for experimental validation, a controller based on one of the previously assessed SOSM algorithms, namely a Super Twisting, is successfully implemented in the laboratory test bench. Highly satisfactory results are obtained, regarding dynamic behaviour, regulation error and robustness to uncertainties and external disturbances.Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señale

Energy-maximising tracking control for a nonlinear heaving point absorber system commanded by second order sliding modes

Energy-maximising control has proven to be of fundamental aid in the pathway towards commercialisation of wave energy conversion technology. The WEC control problem is based upon the design of a suitable control law capable of maximising energy extraction from the wave resource, while effectively minimising any risk of component damage. A particularly well-established family of WEC controllers is based upon a composite structure, where an optimal velocity reference is generated via direct optimal control procedures, followed by a suitable tracking control strategy. This paper presents the design and synthesis of a second order sliding mode controller to attain a reference tracking for a wave energy system. The presented approach can inherently handle parameter uncertainty in the model, which is ubiquitous within hydrodynamic modelling procedures. Furthermore, the proposed sliding mode controller has relatively mild computational requirements, and finite-time convergence to the designed surface, hence being an ideal candidate for real-time energy-maximising control of WEC systems. Copyright (C) 2022 The Authors