Thermoelectric materials: A brief historical survey from metal junctions and inorganic semiconductors to organic polymers

The use of thermoelectric technology is attractive in many potential applications, such as energy scavenging from waste heat. The basic principles for harvesting electricity from a temperature gradient were first discovered around 180 years ago, but the contemporary technology utilising inorganic semiconductors was only developed since the early 1950s. The widespread use of this platform has so far been limited by a combination of relatively low efficiency in energy conversion or by issues related to the utilisation of rare, expensive and/or toxic elements that can be difficult to process. Recently much interest has been focused on the use of organic materials in thermoelectric devices, prompted by the possibility of developing large-area, low-cost devices. Considerable research in the last 20 years has been focused on understanding and improving organic thermoelectric properties, with remarkable progress recently published for compounds such as PEDOT and others. Here we provide an overview into thermoelectricity, from the initial discoveries made by Johann Seebeck to modern practical applications including the current trends in organic thermoelectric research. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.We are grateful to the EPSRC Doctoral Training Centre in Plastic Electronics (grant number EP/G037515/1) for fundin

Dissolution and gettering of iron during contact co-firing

The dissolution and gettering of iron is studied during the final fabrication step of multicrystalline silicon solar cells, the co-firing step, through simulations and experiments. The post-processed interstitial iron concentration is simulated according to the as-grown concentration and distribution of iron within a silicon wafer, both in the presence and absence of the phosphorus emitter, and applying different time-temperature profiles for the firing step. The competing effects of dissolution and gettering during the short annealing process are found to be strongly dependant on the as-grown material quality. Furthermore, increasing the temperature of the firing process leads to a higher dissolution of iron, hardly compensated by the higher diffusivity of impurities. A new defect engineering tool is introduced, the extended co-firing, which could allow an enhanced gettering effect within a small additional tim

Modeling the mass transfer in biosorption of Cr (VI) y Ni (II) by natural sugarcane bagasse

Abstract The Cr (VI) and Ni (II) ion biosorption process by natural sugarcane bagasse in a fixed bed column was investigated. The characteristic removal parameters such as retention capacity, removal percent and unused bed length were experimentally determined at different operating conditions. Overall mass transfer coefficient was investigated and reported for the studied biosorption system. The breakthrough curves were simulated using Matlab2010a software to check the validity of the obtained overall mass transfer coefficients. Experimental data fitted well with predicted data (R 2 = 0.94). A statistical analysis was performed using the software Statgraphics Centurion-X V15.2.06 to compare the simulated and experimental data. No significant differences were observed between experimental and simulated data. The best operating conditions for Cr (VI) removal were 15 mg/L of inlet concentration and 1.5 g of biosorbent. For Ni (II) removal the best results were obtained with 25 mg/L of inlet concentration and 1.5 g of solid. The results obtained through the breakthrough curve showed high removal percentages (94.70 and 97.90% for chromium and nickel, respectively). Moreover, results indicated that sorption of these metals was irreversible and it was controlled by the mass transfer at the external film

El profesorado : el compromiso docente con la educación

También participaron Maria Dolors Hipólito i Sesé, Aurora Clemente Cavero, Jaume Oliver Jaume, Miquel F. Oliver Trobat, Avelino Sarasua, Ángel Vázquez Alonso y María Antonia Manassero MasEl volumen recoge dos conferencias, cuatro mesas redondas, ocho comunicaciones y dos grupos de trabajo acerca del nuevo perfil del docente y del compromiso del docente con la educación.BalearesES

Low cost using ultra-thin bifacial cells

This paper presents the global results of the BiThink project. This is a project financed by DG-TREN. The BiThink objective is to develop and demonstrate an industrial technology able to exert direct influence on the cost of photovoltaic systems. BiThink focuses on three key aspects: the use of bifacial cells and albedo modules as a simple way to increase the amount of energy collected, the increase in the number of wafers obtained from the slicing of silicon ingots and the use of a simple and at last an efficient manufacturing process, able to combine high mechanical yields with reasonable cell efficiency. BiThink shows impressive figures in terms of the consumption of silicon: 5.9 grams per Watt peak using conservative yield values. Another important result is the large amount of new technology developed in the project in the areas of ingot slicing, post-slicing wafer separation, screen printing diffusion, mechanical handling, crack detection, and thin solar cell interconnection

Proyecto de innovación en tutorías para alumnos de ingeniero químico

Resumen tomado de la publicaciónEl proyecto de acción tutorial se ha llevado a cabo en los cinco cursos de la titulación con un doble enfoque. Por una parte se han organizado grupos de tutoría de unos cinco alumnos en los que se han realizado actividades orientadas a mejorar el rendimiento académico, apoyo en la toma de decisiones, mejora del conocimiento que los alumnos tienen sobre la Universidad y los servicios y actividades que pueden realizar. Por otra parte, se han organizado actividades por cursos o varios cursos, para informar sobre temas generales de su interés, facilitar la realización de prácticas y apoyar a los alumnos de último curso en la incorporación al mercado laboral.NavarraUniversidad Pública de Navarra. Biblioteca Universitaria; Campus de Arrosadia; 31006 Pamplona; Tel. +34948169060; Fax +34948169069; [email protected]