5 research outputs found
Hydrogen recovery from waste gas streams to feed (High-temperature PEM) fuel cells: environmental performance under a life-cycle thinking approach
Fossil fuels are being progressively substituted by a cleaner and more environmentally friendly form of energy, where hydrogen fuel cells stand out. However, the implementation of a competitive hydrogen economy still presents several challenges related to economic costs, required infrastructures, and environmental performance. In this context, the objective of this work is to determine the environmental performance of the recovery of hydrogen from industrial waste gas streams to feed high-temperature proton exchange membrane fuel cells for stationary applications. The life-cycle assessment (LCA) analyzed alternative scenarios with different process configurations, considering as functional unit 1 kg of hydrogen produced, 1 kWh of energy obtained, and 1 kg of inlet flow. The results make the recovery of hydrogen from waste streams environmentally preferable over alternative processes like methane reforming or coal gasification. The production of the fuel cell device resulted in high contributions in the abiotic depletion potential and acidification potential, mainly due to the presence of platinum metal in the anode and cathode. The design and operation conditions that defined a more favorable scenario are the availability of a pressurized waste gas stream, the use of photovoltaic electricity, and the implementation of an energy recovery system for the residual methane stream.The authors are grateful for the funding of the Spanish Ministry of Economy and Competitiveness through the Ceres-Procom Project CTM2016-76176 (AEI/FEDER, UE) and the funding of European Union through the Project SOE1/P1/E0293 (INTERREG SUDOE/FEDER, UE), “Energy Sustainability at the Sudoe Region: Red PEMFC-Sudoe”
Effectiveness of an intervention for improving drug prescription in primary care patients with multimorbidity and polypharmacy:Study protocol of a cluster randomized clinical trial (Multi-PAP project)
This study was funded by the Fondo de Investigaciones Sanitarias ISCIII (Grant Numbers PI15/00276, PI15/00572, PI15/00996), REDISSEC (Project Numbers RD12/0001/0012, RD16/0001/0005), and the European Regional Development Fund ("A way to build Europe").Background: Multimorbidity is associated with negative effects both on people's health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12months, as compared with usual care. Methods/Design: Design:pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65-74years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3months). Sample size: n=400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle. Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes. Trial registration: Clinicaltrials.gov, NCT02866799Publisher PDFPeer reviewe
Contribution to the haracterization of metal mesh vibration isolators
El aislamiento de vibraciones es una parte fundamental del diseño de máquinas. Este aislamiento se aborda con la interposición de distintos elementos resilientes, los aisladores, cuya función es disminuir la amplitud de las vibraciones mecánicas que se transmiten desde un emisor a un receptor. Para un diseño eficiente y eficaz de los aisladores, es fundamental poder predecir el comportamiento de estos, para lo cual es necesario, en primer lugar, caracterizar con la suficiente precisión el comportamiento de dichos aisladores, y, después, modelizar ese comportamiento matemáticamente de forma que pueda ser implementado dentro de las herramientas de simulación dinámica. Además, la caracterización permite profundizar en el conocimiento de los principios físicos de su funcionamiento.
Existen numerosos tipos de aisladores, y, aunque en realidad ninguno tiene un comportamiento perfectamente lineal, en algunos casos se puede aproximar como tal. No obstante, en otros casos no es posible asumir un comportamiento lineal, lo que dificulta notablemente la caracterización de estos. Este último es el caso de los aisladores de vibraciones de malla metálica, también llamados de cojín metálico, los cuales tienen un carácter no lineal y su comportamiento no es del todo entendido, y, por ello, su caracterización resulta compleja. No obstante, las características de este tipo de elemento aislador son de gran interés para su utilización en muy variadas aplicaciones. En este trabajo se lleva a cabo un estudio experimental con el objetivo de contribuir a la caracterización del comportamiento de este tipo de aisladores, estudiando el efecto que distintas condiciones de funcionamiento y de parámetros constructivos tiene en su respuesta dinámica, mediante ensayos de laboratorio tanto cuaestáticos como dinámicos.Vibration isolation is a fundamental part of machine design. This isolation is approached with the interposition of various resilient elements, the isolators, whose function is to reduce the amplitude of mechanical vibrations transmitted from a emitter to a receiver. For an efficient and effective design of the isolators, it is essential to be able to predict their behavior, for which it is necessary, firstly, to characterize with sufficient precision the behavior of these isolators, and then to model this behavior mathematically so that it can be implemented within the dynamic simulation tools. In addition, characterization allows to deepen the knowledge of the physical principles of their operation.
There are numerous types of isolators, and, although in reality none of them have perfectly linear behavior, in some cases it can be approximated as such. However, in other cases it is not possible to assume linear behavior, which makes their characterization very difficult. The latter is the case of metal mesh vibration isolators, also called metal cushion isolators, which have a non-linear character and their behavior is not fully understood, and, therefore, their characterization is complex. However, the characteristics of this type of isolator element are of great interest for its use in a wide variety of applications. In this work, an experimental study is carried out with the aim of contributing to the characterization of the behavior of this type of insulators, studying the effect that different operating conditions and construction parameters have on their dynamic response, by means of quasi-static and dynamic laboratory tests.
Keywords: Vibration isolation, characterization, metal mesh isolators, nonlinearity, quasi-static tests, dynamic tests.Máster en Ingeniería Industria
Design of hydraulic dynamometer for engine testing up to 500 HP
RESUMEN: El objeto del presente proyecto es el diseño de un banco de ensayo con un dinamómetro hidráulico, que permita realizar pruebas en motores de hasta 500 CV y capaz de adaptarse a diferentes tipos de motores. Dicha máquina deberá poder soportar motores de camión con un peso máximo de 2 toneladas y poder adaptarse a sus dimensiones. Para ello, se ha seleccionado un dinamómetro en función de los requisitos establecidos y se ha diseñado toda la estructura de la bancada, el equipamiento necesario para poder realizar una fácil adaptación de esta a las necesidades de ensayo y los cálculos necesarios para conseguir una máquina resistente con el menor coste posible, capaz de realizar las adaptaciones mencionadas. En los documentos del proyecto se incluyen los cálculos, los planos detallados de los elementos de la máquina y de la instalación de la misma, el pliego de condiciones y la partida presupuestaria de este proyecto.ABSTRACT: The purpose of this project is the design of a test bench with a hydraulic dynamometer, which allows tests to be carried out on engines of up to 500 hp and is capable of adapting to different types of engines. This machine must be able to support lorry engines with a maximum weight of 2 tonnes and be able to adapt to their dimensions. To this end, a dynamometer has been selected in accordance with the established requirements and the entire structure of the bench has been designed, as well as the necessary equipment to be able to easily adapt it to the test needs and the necessary calculations to achieve a resistant machine at the lowest possible cost, capable of carrying out the aforementioned adaptations. The project documents include the calculations, detailed plans of the elements of the machine and its installation, the specifications and the budget item for this project.Grado en Ingeniería en Tecnologías Industriale
Contribution to the characterization of vibration isolators based on metal mesh
The prediction of the behavior of vibration isolators is essential for effective and efficient design of these devices, as well as for accurately characterizing the isolator behavior. In this work, an experimental study was performed to characterize the behavior of metal-mesh isolators. Although these elements’ performance is of great interest because of their usage in several applications, their characterization is complex due to their nonlinear nature, among other factors. This study’s aim was to obtain the quasi-static behavior of these isolators, although dynamic tests are required for their complete characterization. These quasi-static tests allowed for the highlighting of some characteristics in a simpler and faster manner and also provided a starting point for designing future dynamic tests. The quasi-static tests performed resulted in the calculation of the hysteresis cycle under different operating conditions and manufacturing parameters. The study of different insulator characteristics, such as the energy dissipation coefficient and stiffness, led to interesting conclusions about the isolator performance. From the results, it was observed that the relative density affected most the nonlinear behavior of the insulator. Moreover, to correctly characterize their behavior, not only the Coulomb’s damping but also the viscous damping had to be considered.This research was funded by PID2020-116572RA-I00/AEI/10.13039/501100011033