Esterification of Free Fatty Acids with Glycerol within the Biodiesel Production Framework

Companies in the field of the collection and treatment of waste cooking oils (WCO) for subsequent biodiesel production usually have to cope with high acidity oils, which cannot be directly transformed into fatty acid methyl esters due to soap production. Since glycerine is the main byproduct of biodiesel production, these high acidity oils could be esterified with the glycerine surplus to transform the free fatty acids (FFA) into triglycerides before performing the transesterification. In this work, commercial glycerol was esterified with commercial fatty acids and commercial fatty acid/lampante olive oil mixtures over tin (II) chloride. In the first set of experiments, the esterification of linoleic acid with glycerol excess from 20 to 80% molar over the stoichiometric was performed. From 20% glycerol excess, there was no improvement in FFA reduction. Using 20% glycerol excess, the performance of a biochar obtained from heavy metal-contaminated plant roots was compared to that of SnCl2. Then, the effect of the initial FFA content was assessed using different oleic acid/lampante olive oil mixtures. The results illustrated that glycerolysis was impeded at initial FFA contents lower than 10%. Finally, the glycerolysis of a WCO with 9.94% FFA was assayed, without success

Modulating Strain in Twisted Pyrene-Fused Azaacenes

The design and synthesis of strained aromatics provide an additional insight into the relationship between structure and properties. In the last years, several approaches to twist pyrene-fused azaacenes have been developed that allow to introduce twists of different sizes. Herein, we describe the synthesis of a new set of twisted dibenzotetraazahexacenes constituted by fused pyrene and quinoxaline residues that have been distorted by introducing increasingly larger substituents on the quinoxaline residues. Their twisted structure has been demonstrated by single-crystal X-ray diffraction. Furthermore, absorption, fluorescence, electrochemical and theoretical studies shine light on the effects of the substituents and twists on the optoelectronic and redox properties.This work was carried out with support from the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country, Diputación de Guipúzcoa, Gobierno Vasco (PIBA_2022_1_0031 and BERC programme) and Gobierno de España (Projects PID2021-124484OB-I00 and CEX2020-001067-M financed by MCIN/AEI/10.13039/501100011033). Project (PCI2022-132921) funded by the Agencia Estatal de Investigación through the PCI 2022 and M-ERA.NET 2021 calls. This project has received funding from the European Research Council (ERC) under the European Union's Horizon2020 research and innovation programme (Grant Agreement No. 722951). This work was funded by the European Union under the Horizon Europe grant 101046231. Technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF) is acknowledged. In addition, support through the project IF/00894/2015, the advanced computing project 2021.09622.CPCA granting access to the Navigator cluster at LCA-UC, and within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) is gratefully acknowledged

Disrupción en el uso de la web 2.0 en los hoteles independientes

Las tecnologías de la Web 2.0 en ocasiones no se muestran nada claras, cuando se ha de demostrar como un mayor o menor uso de las redes sociales, afectará de forma negativa o positiva a la mejora de la reputación on-line. En esta ocasión, el estudio muestra un caso singular, donde un establecimiento de la ciudad de Sevilla, ha ocupado en los dos últimos años el puesto número uno en Tripadvisor, haciendo poco uso de esta redes sociales en la Web 2.0. Singular porque el uso que se hace de estas tecnologías para mantenerse en este primer puesto, no es siempre el más adecuado, y se produce a menudo un cierto nivel de disrupción, al romperse la línea de comunicación, y el ritmo de publicación.The Web 2.0 technologies is sometimes not at all clear, when you have to show as a greater or lesser use of social media, negative or positive affect on improving the way online reputation. This time, the study shows a unique case, where a property of the city of Seville, has occupied in the past two years the number one spot on Tripadvisor, making little use of this social networking on the Web 2.0. Singular that the use made of these technologies to stay in first place this is not always the most appropriate, and often produces a certain level of disruption, breaking the communication line, and the rate of publication

Cultura web 2.0 aplicada en el sector hotelero de Sevilla, para hoteles independientes

Internet y las nuevas tecnologías 2.0 están cambiando la forma en la que los consumidores se acercan al sector servicios, y además facilita a los establecimientos hoteleros contactar más fácilmente con sus clientes. Este trabajo de fin de Máster se ha centrado en los hoteles independientes, y como éstos afrontan este nuevo reto. El punto de partida de la investigación ha tratado de averiguar, a través de una prueba piloto, que se está haciendo en la actualidad en estos hoteles. Para finalizar, se propone una aproximación al modelo adecuado para que los hoteles independientes saquen el mayor provecho a la Web 2.0, y maximizar estas nuevas herramientas para poder alcanzar mejor sus objetivos de comunicación promoción, comercialización y venta de productos y servicios hoteleros.Internet and the new technologies are changing the form that the consumers approach the sector services, and more concretely to the sector of the hotels. The new technologies and applications of the Web 2.0, it would facilitate to these establishments to contact easier his consumers. For them one proposes this study as point of item of an investigation that tries to see that they are doing at present these hotels, and to show him as the above mentioned tools them his aims of communication might help to reach better promotion, commercialization and sale of products and hotel services

Production of Oxygenated Fuel Additives from Residual Glycerine Using Biocatalysts Obtained from Heavy-Metal-Contaminated Jatropha curcas L. Roots

This work aims to shed light on the use of two biochars, obtained from the pyrolysis at 550 C of heavy-metal-contaminated Jatropha curcas L. roots, as heterogeneous catalysts for glycerol esterification using residual glycerine. To do this, glycerine from biodiesel production was purified. In a first step, H3PO4 or H2SO4 was used to remove non-glycerol organic matter. The glycerol-rich phase was then extracted with ethanol or propanol, which increased the glycerol content from 43.2% to up to 100%. Subsequently, the esterification of both purified glycerine and commercial USP glycerine was assayed with acetic acid (AA) or with acetic anhydride (AH) at 9:1 molar ratio to glycerol using Amberlyst-15 as catalyst. Different reaction times (from 1.5 to 3 h) and temperatures (100–115 C when using AA and 80–135 C when using AH) were assessed. Results revealed that the most suitable conditions were 80 C and 1.5 h reaction time using AH, achieving 100% yield and selectivity towards triacetylglycerol (TAG) almost with both glycerines. Finally, the performance and reuse of the two heterogeneous biocatalysts was assessed. Under these conditions, one of the biocatalysts also achieved 100% TAG yield.VI Plan Propio de Investigación y Transferencia of University of Seville grant VIPPIT-2019-I.

Motherhood performance on cartoons broadcast on television

A lo largo de la vida se asumen diferentes procesos socializadores y se convive con diferentes agentes de socialización. La exposición progresiva a informaciones y mensajes, a través de los medios de comunicación, nos lleva a ‘cultivar’ la forma de comprender el mundo, asentando creencias, representaciones mentales y actitudes. Centrando la mirada en el público infantil, por considerarse éste un público vulnerable, y tomando como referencia los roles y estereotipos representados a través de los dibujos animados emitidos en televisión, el objetivo del presente trabajo es analizar la representación que se hace de la maternidad en la animación televisiva. Para ello, y mediante la técnica del cuestionario, se pregunta a un total de 1275 estudiantes pre-adolescentes de la Comunidad de Andalucía cuáles son sus dibujos animados favoritos siendo éstos: Los Simpsons, Shin-chan, American Dad, Padre de Familia, Doraemon y Phineas y Ferb. Teniendo en cuenta la evolución que los personajes femeninos están experimentando en las series de ficción, se pretende comprobar si en los dibujos animados los personajes femeninos que ejercen el rol de madres representan la nueva versión de la modernidad de una mujer con aspiraciones profesionales, inteligente y resolutiva. Aplicando la metodología del análisis de contenido se demuestra que las mujeres continúan representando el esquema androcéntrico quedando limitadas al espacio interior y siendo, al mismo tiempo, el pilar fundamental del núcleo familiar tradicional

Analysis of trap states in AlGaN/GaN self-switching diodes via impedance measurements

The presence of trap states in self-switching diodes (SSD) based on an AlGaN/GaN heterojunction has been identified by means of their AC characterization between 75 kHz to 30 MHz in a wide temperature range, from 80 K to 300 K. Measurements allow us to determine two different characteristic energies of the traps, 12 meV and 61 meV, being associated to a distribution of surface states and one discrete bulk trap, respectively. The impact of the trapping effects on microwave detection at zero-bias has also been analyzed in the same temperature range, the measured responsivity showing an unusual enhancement and a low-frequency roll-off at low temperatures.Spanish MINECO and FEDER through project TEC2017-83910-R and Junta de Castilla y León and FEDER through project SA254P1

Nosocomial outbreak of Pseudomonas aeruginosa endophthalmitis

We describe an outbreak of nosocomial endophthalmitis due to a common source, which was determined to be trypan blue solution prepared in the hospital's pharmacy service. We assume that viable bacteria probably gained access to the trypan blue stock solution during cooling after autoclaving. The temporal cluster of Pseudomonas aeruginosa endophthalmitis was readily perceived on the basis of clinical and microbiological findings, and an exogenous source of contamination was unequivocally identified by means of DNA fingerprinting. © 2006 by The Society for Healthcare Epidemiology of America. All rights reserved

Tutorización británica combinada con TIC y evaluación por rúbrica

Memoria ID-083. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2013-2014

Trap-related frequency dispersion of zero-bias microwave responsivity at low temperature in GaN-based self-switching diodes

[EN]The zero-bias microwave detection capability of self-switching diodes (SSDs) based on AlGaN/GaN is analyzed in a wide temperature range, from 10 K to 300 K. The measured responsivity shows an anomalous enhancement at low temperature, while the detected voltage exhibits a roll-off in frequency, which can be attributed to the presence of surface and bulk traps. To gain a deep insight into this behavior, a systematic DC and AC characterization of the diodes has been carried out in the mentioned temperature range. DC results confirm the existence of traps and AC measurements allow us to identify their properties. In particular, impedance studies enable to distinguish two types of traps: at the lateral surfaces of the channel, with a wide spread of relaxation times, and in the bulk.Spanish MINECO and FEDER through project TEC2017-83910-R and the Junta de Castilla y León and FEDER through project SA254P18