Iniciación al mundo profesional y la investigación en ingeniería: integración de metodologías docentes

En este trabajo se expone el desarrollo de la asignatura optativa "Energía del Hidrógeno" de la titulación de Ingeniero Naval y Oceánico (E.T.S. I. Navales UPM) que se ha venido impartiendo a alumnos de los cursos 4º y 5º indistintamente y tiene asignados 4,5 créditos de docencia. La asignatura se organiza de modo que permite acercar a los alumnos que la cursan al ejercicio de la profesión y al conocimiento de la actividad investigadora. Una parte de los temas la imparte el profesor y otra parte la preparan e imparten los alumnos formando grupos. Trabajando en equipo, los alumnos estudian y profundizan en los temas de la asignatura, algunos de los cuales diseñan, preparan, escriben y finalmente exponen, tras varias sesiones de tutoría con el profesor. Moderan un debate sobre el tema expuesto y diseñan y organizan una sesión de aprendizaje cooperativo. A lo largo del curso habitualmente manejan documentación y artículos científicos en lengua inglesa. Se graban las clases y se publican en la plataforma virtual de enseñanza y/o Youtube, se escriben artículos científicos y se siguen unas pautas establecidas para elaborar los documentos generados. Se organizan visitas externas y se realizan prácticas de laboratorio. Se sigue el método de b-learning con evaluación continua y coevaluación y se aplica a lo largo de todo el curso la metodología de Aprendizaje Cooperativo. El conjunto de actividades desarrolladas y el modo de impartir la asignatura constituye una metodología fácilmente aplicable a cursos de Máster y actualmente se está trabajando en las modificaciones requeridas para su implantación en el Máster de Ingeniería Naval y Oceánica.Los autores desean agradecer a la Universidad Politécnica de Madrid su ayuda y soporte en este trabajo, en el marco del Proyecto de Innovación Educativa IE1415-08002

Conceptual design of offshore platform supply vessel based on hybrid diesel generator-fuel cell power plant

Nowadays increasing fuel prices and upcoming pollutant emission regulations are becoming a growing concern for the shipping industry worldwide. While fuel prices will keep rising in future years, the new International Convention for the Prevention of Pollution from Ships (MARPOL) and Sulphur Emissions Control Areas (SECA) regulations will forbid ships to use heavy fuel oils at certain situations. To fulfil with these regulations, the next step in the marine shipping business will comprise the use of cleaner fuels on board as well as developing new propulsion concept. In this work a new conceptual marine propulsion system is developed, based on the integration of diesel generators with fuel cells in a 2850 metric tonne of deadweight platform supply vessel. The efficiency of the two 250 kW methanol-fed Solid Oxide Fuel Cell (SOFC) system installed on board combined with the hydro dynamically optimized design of the hull of the ship will allow the ship to successfully operate at certain modes of operation while notably reduce the pollutant emissions to the atmosphere. Besides the cogeneration heat obtained from the fuel cell system will be used to answer different heating needs on board the vesse

Performance of Sulfonated Poly(Vinyl Alcohol)/Graphene Oxide Polyelectrolytes for Direct Methanol Fuel Cells

The use of nanotechnology along with the consideration of a functionalization and stabilization approach to poly(vinyl alcohol) (PVA) is considered useful for the preparation of cost-effective polyelectrolyte membranes. A set of nanocomposite and crosslinked membranes based on PVA/sulfosuccinic acid (SSA)/graphene oxide (GO) are prepared and analyzed as polyelectrolytes in direct methanol fuel cells (DMFCs). The crosslinking and sulfonation by the use of SSA enhances the stability and increase the proton-conducting sites in the PVA structure. The presence of GO augments the stability, remarkably decreases the methanol crossover, and enhances power density curves. An optimum value for proton conductivity is found for the 0.50 wt% of GO proportion, which decreases with higher concentrations of GO. Given the power density curve dependency on both the proton conductivity and the crossover reduction, the performance of these membranes as polyelectrolytes in DMFCs is strictly related to the balance between both factors. Therefore, a proportion of GO of 0.75 wt% may assure suitable proton conductivity of 3 mS cm−1 and high resistance to methanol permeability, reaching promising power density of 16 mW cm−2 with lower hydration levels

Performance of sulfonated poly(vinyl alcohol)/graphene oxide polyelectrolytes for direct methanol fuel cells

"This is the peer reviewed version of the following article: [Performance of sulfonated poly(vinyl alcohol)/graphene oxide polyelectrolytes for direct methanol fuel cells], which has been published in final form at [10.1002/ente.202000124]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] The use nanotechnology along with the consideration of a functionalization and stabilization approach to the poly(vinyl alcohol) (PVA) was considered useful for the preparation of cost-effective polyelectrolyte membranes. A set of nanocomposite and crosslinked membranes based in PVA/SSA/GO were prepared and analyzed as polyelectrolytes in direct methanol fuel cells (DMFCs). The crosslinking and sulfonation by the use of sulfosuccinic acid (SSA) enhanced the stability and increased the proton conducting sites in the PVA structure. The presence of graphene oxide (GO) augmented the stability, remarkably decreased the methanol crossover and enhanced power density curves. An optimum value for proton conductivity was found for the 0.50%wt of GO proportion, which decreased to higher concentrations of GO. Given the power density curve dependency on both the proton conductivity and the crossover reduction, the performance of these membranes as polyelectrolytes in DMFCs is strictly related to the balance between both factors. Therefore, a proportion of GO of 0.75%wt may assure suitable proton conductivity 3 mS·cm-1 and high resistance to methanol permeability, reaching promising power density of 16 mW·cm-2 with lower hydration levels.The Spanish Ministry of Economy, Industry, and Competitiveness is acknowledged for the projects ENE2017-86711-C3-1-R, ENE2017-86711-C3-2-R, ENE2017-90932-REDT, and UPOV13-3E-1947. The Spanish Ministry of Education, Culture, and Sports is thanked for the predoctoral FPU grant for O. Gil-Castell (grant no. FPU13/01916).Gil-Castell, Ó.; Santiago, Ó.; Pascual-Jose, B.; Navarro, E.; Leo, TJ.; Ribes-Greus, MD. (2020). Performance of sulfonated poly(vinyl alcohol)/graphene oxide polyelectrolytes for direct methanol fuel cells. Energy Technology (Online). 8(7):1-10. https://doi.org/10.1002/ente.2020001241108

Systemwide Clinical Ultrasound Program Development: An Expert Consensus Model.

Clinical ultrasound (CUS) is integral to the practice of an increasing number of medical specialties. Guidelines are needed to ensure effective CUS utilization across health systems. Such guidelines should address all aspects of CUS within a hospital or health system. These include leadership, training, competency, credentialing, quality assurance and improvement, documentation, archiving, workflow, equipment, and infrastructure issues relating to communication and information technology. To meet this need, a group of CUS subject matter experts, who have been involved in institution- and/or systemwide clinical ultrasound (SWCUS) program development convened. The purpose of this paper was to create a model for SWCUS development and implementation

Comparative exergy analysis of direct alcohol fuel cells using fuel mixtures

Within the last years there has been increasing interest in direct liquid fuel cells as power sources for portable devices and, in the future, power plants for electric vehicles and other transport media as ships will join those applications. Methanol is considerably more convenient and easy to use than gaseous hydrogen and a considerable work is devoted to the development of direct methanol fuel cells. But ethanol has much lower toxicity and from an ecological viewpoint ethanol is exceptional among all other types of fuel as is the only chemical fuel in renewable supply. The aim of this study is to investigate the possibility of using direct alcohol fuel cells fed with alcohol mixtures. For this purpose, a comparative exergy analysis of a direct alcohol fuel cell fed with alcohol mixtures against the same fuel cell fed with single alcohols is performed. The exergetic efficiency and the exergy loss and destruction are calculated and compared in each case. When alcohol mixtures are fed to the fuel cell, the contribution of each fuel to the fuel cell performance is weighted attending to their relative proportion in the aqueous solution. The optimum alcohol composition for methanol/ethanol mixtures has been determined

Marine Practice Guidelines for Fuel Cell Applications

This paper focuses on the implementation of fuel cells in marine systems as a propulsion system and energy source. The objective is to provide an overview of the pertinent legislation for marine applications of fuel cells. This work includes a characterization of some guidelines for the safe application of fuel cell systems on ships. It also describes two ships that have implemented fuel cells to obtain energy, the Viking Lady, the first marine ship to include this technology, and Greentug, a reference for new tug

Use of agroindustrial waste to obtain cellulose from oil palm bagasse (Elaeis guinnensis)

Obtain cellulose from oil palm agro-industrial waste that meets standard physicochemical characteristics to produce value-added products. Bagasse fibers from the palm agroindustry were used to obtain cellulose, by means of the acid – alkaline hydrolysis methodology. The samples obtained in each stage and the cellulose obtained were characterized by Fourier Transform Infrared Spectroscopy (FTIR) technique and thermogravimetric analysis (TGA). The final characterized product presented a band corresponding to 1370 cm1 characteristic of cellulose. The peak at 1731 cm-1 is related to C=O bonds of unconjugated ketones present in hemicellulose. Major thermal event for treated fiber near to 355 °C, and a high residual mass indicate a good chemical treatment for hemicellulose and lignin elimination. During the process, a fiber yield of 39.3% cellulose was obtained from oil palm bagasse. Obtaining cellulose from a highly polluting residue such as palm bagasse and with high production figures in our state, this makes it a potential for use to generate biopolymers in combination with natural polysaccharides providing sustainable benefits and economic impact promoting sustainable development by replacing conventional fossil plastics. In addition to obtaining value-added products for the same agribusiness and in sectors such as the food industry.Objective: To obtain cellulose from oil palm agroindustrial waste that meets standard physicochemical characteristics to produce value-added products.   Design/methodology/approach: Bagasse fibers from the palm agroindustry were used to obtain cellulose, by means of the acid – alkaline hydrolysis methodology. The samples obtained in each stage and the cellulose obtained were characterized by the Fourier Transform Infrared Spectroscopy (FTIR) technique and thermogravimetric analysis (TGA). Results: The final characterized product presented a band corresponding to 1370 cm1 which is a characteristic value of cellulose. The peak at 1731 cm-1 is related to C=O bonds of unconjugated ketones present in hemicellulose. A major thermal event for treated fiber near 355 °C and the high residual mass indicate a good chemical treatment for hemicellulose and lignin elimination. Study limitations/implications: A fiber yield of 39.3% cellulose was obtained during the process from oil palm bagasse. Findings/conclusions: Obtaining cellulose from a highly polluting residue such as palm bagasse and with high production figures in our state, makes it a potential for use to generate biopolymers in combination with natural polysaccharides, providing sustainable benefits and economic impact and promoting sustainable development by replacing conventional fossil plastics, in addition to obtaining value-added products for the same agribusiness and in sectors such as the food industry