Diseño de una instalación solar térmica para la producción de agua caliente sanitaria

Treballs Finals de Màster d'Enginyeria Química, Facultat de Química, Universitat de Barcelona. Curs: 2019-2020. Tutor: Ricard TorresIn this project, the design of a solar thermal installation for the production of domestic hot water (DHW) for a building in Barcelona has been carried out. Firstly, the energy consumption of the building was determined from statistical data provided by the CTE and meteorological data. Subsequently, the collector model has been selected according to its performance characteristics, area and price. The necessary capture area has been calculated to cover the minimum fraction of demand stipulated by the current law by different methods, heuristics and energy balances of the elements of the installation. The energy balances have been made taking into account the heat losses of different elements of the installation determined from the thermal resistances of the selected equipment, as well as convection losses due to the action of the wind. This has meant an iterative calculation, as it was necessary to know beforehand the appropriate dimensioning of the pipes, including insulation, together with the meters of pipe and the layout of the collectors. The collectors have been arranged on the terrace facing south with a 40 degree slope, and properly separated from the surrounding obstacles to minimize losses due to shading. The final result of the collector system has been represented in a plan for easy understanding. Once the catchment area has been determined, the rest of the elements are sized. The support equipment has been sized based on consumption data of the different elements of the houses applying a simultaneity factor, considering a zero solar contribution of the collectors. The design of the heat exchanger was carried out by determining the useful area of exchange and the overall heat transfer coefficient, considering a counter-current exchange. A return network has been designed for the points of consumption furthest away from the DHW storage tank, based on a partial recirculation of the building's consumption. An exhaustive study has been carried out on the load losses of the elements including the necessary accessories (elbows, valves) in order to size the pumping equipment for each circuit. Once the size of all the elements was known, it was possible to determine the amount of fluid that could be found in each circuit, allowing the sizing of the expansion vessels. With all the elements already designed, an environmental study has been carried out to find out the amount of fuel (natural gas) saved and the CO2 emissions avoided. With the data of fuel savings and the costs of the materials of the installation, the economic viability study of the project is carried out for a useful period of 25 years, with the help of a subsidy from the Barcelona City Council

Agressivitat i adolescència : un problema social?

La preocupació per l'agressivitat a les escoles de secundària ha augmentat considerablement durant els darrers anys. En aquest article, fonamentat en una recerca empírica duta a terme en instituts de secundària, intentem proporcionar eines per comprendre el fenomen de l'agressivitat com a element intrínsec en les relacions socials quotidianes a l'adolescència. Analitzem com l'agressivitat s'estructura socialment d'una manera concreta segons la localització social i cultural, especialment a partir del gènere i la classe social. També aprofundim en l'agressivitat a partir de tres dimensions: 1) les jerarquies establertes a l'escola entre els joves; 2) la segregació entre nois i noies i els seus mons de vida, i 3) la importància del control i l'autocontrol.La preocupación por la agresividad en los centros de secundaria ha aumentado considerablemente durante los últimos años. En este artículo, fomentado en base a una investigación empírica llevada a cabo en institutos de secundaria, intentamos proporcionar herramientas para comprender el fenómeno de la agresividad como elemento intrínseco en las relaciones sociales cotidianas de la adolescencia. Analizamos como la agresividad se estructura socialmente de una forma concreta según la localización social y cultural, especialmente a partir del género y la clase social. También profundizamos en la agresividad a partir de tres dimensiones: 1) las jerarquías establecidas en la escuela entre los jóvenes; 2) la segregación entre chicos y chicas y sus mundos de vida, y 3) la importancia del control y autocontrol.In Catalonia (Spain) there is a growing concern about agressiveness in secondary schools. In this article, based on an empirical research carried out in secondary schools, we try to provide tools to understand agressiveness as an inherent element of everyday social relations in adolescence. We analyze how agressiveness is socially structured depending on social and cultural position, particularly in relation to gender and social class. We also analyze agressiveness from three different dimensions: 1) school hierarchical pecking-order; 2) segregation between boys and girls and their life worlds; 3) the importance of control and self-control

Influence of structure and UV-light absorption on the electrical conductivity of TiO2 and comparison with its catalytic activity

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EndoTrainer: a novel hybrid training platform for endoscopic surgery

Purpose Endoscopy implies high demanding procedures, and their practice requires structured formation curricula supported by adequate training platforms. Physical platforms are the most standardised solution for surgical training, but over the last few years, virtual platforms have been progressively introduced. This research work presents a new hybrid, physic-virtual, endoscopic training platform that exploits the benefits of the two kind of platforms combining realistic tools and phantoms together with the capacity of measuring all relevant parameters along the execution of the exercises and of providing an objective assessment performance. Methods The developed platform, EndoTrainer, has been designed to train and assess surgical skills in hysteroscopy and cystoscopy following a structured curricula. The initial development and validation is focused on hysteroscopic exercises proposed in the Gynaecological Endoscopic Surgical Education and Assessment (GESEA) Certification Programme from The Academy and European Society for Gynaecological Endoscopy (ESGE) and analyses the obtained results of an extensive study with 80 gynaecologists executing 30 trials of the standard 30 degree endoscope navigation exercise. Results The experiments demonstrate the benefits of the presented hybrid platform. Multi-variable statistical analysis points out that all subjects have obtained statistically significant improvement in all relevant parameters: shorter and safer trajectories, improved 30-degree endoscope navigation, accurate positioning over the targets and reduction of the execution time. Conclusion This paper presents a new hybrid approach for training, and evaluating whether it provides an objectivable improvement of camera navigation endoscopic basic skills. The obtained results demonstrate the initial hypothesis: all subjects have improved their camera handling and navigation skills.Peer ReviewedPostprint (published version

Association of the tumour necrosis factor alpha -308 but not the interleukin 10 -627 promoter polymorphism with genetic susceptibility to primary sclerosing cholangitis

BACKGROUND AND AIMS Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown aetiology. Abnormalities in immune regulation and genetic associations suggest that PSC is an immune mediated disease. Several polymorphisms within the tumour necrosis factor α (TNF-α) and interleukin 10 (IL-10) promoter genes have been described which influence expression of these cytokines. This study examines the possible association between polymorphisms at the −308 and −627 positions in the TNF-α and IL-10 promoter genes, respectively, and susceptibility to PSC. METHODS TNF-α −308 genotypes were studied by polymerase chain reaction (PCR) in 160 PSC patients from Norway and the UK compared with 145 ethnically matched controls. IL-10 −627 genotypes were studied by PCR in 90 PSC patients compared with 84 ethnically matched controls. RESULTS A total of 16% of Norwegian PSC patients and 12% of British PSC patients were homozygous for the TNF2 allele compared with 3% and 6% of respective controls. The TNF2 allele was present in 60% of PSC patients versus 30% of controls (ORcombined data=3.2 (95% confidence intervals (CI) 1.8–4.5); pcorr=10−5). The association between the TNF2 allele and susceptibility to PSC was independent of the presence of concurrent inflammatory bowel disease (IBD) in the PSC patients; 61% of PSC patients without IBD had TNF2 compared with 30% of controls (ORcombined data=3.2 (95% CI 1.2–9.0); pcorr=0.006 ). There was no difference in the −627 IL-10 polymorphism distributions between patients and controls in either population. The increase in TNF2 allele in PSC patients only occurs in the presence of DRB1*0301 (DR3) and B8. In the combined population data, DRB1*0301 showed a stronger association with susceptibility to PSC than both the TNF2 and B8 alleles (ORcombined data=3.8, pcorr=10−6 v ORcombined data=3.2, pcorr=10−5 vORcombined data =3.41, pcorr=10−4, respectively). CONCLUSIONS This study identified a significant association between possession of the TNF2 allele, a G→A substitution at position −308 in the TNF-α promoter, and susceptibility to PSC. This association was secondary to the association of PSC with the A1-B8-DRB1*0301-DQA1*0501-DQB1*0201 haplotype. No association was found between the IL-10 −627 promoter polymorphism and PSC

Vertically aligned carbon nanotubes for microelectrode arrays applications

In this work a methodology to fabricate carbon nanotube based electrodes using plasma enhanced chemical vapour deposition has been explored and defined. The final integrated microelectrode based devices should present specific properties that make them suitable for microelectrode arrays applications. The methodology studied has been focused on the preparation of highly regular and dense vertically aligned carbon nanotube (VACNT) mat compatible with the standard lithography used for microelectrode arrays technology

Caracterització ampelogràfica i molecular de la varietat sumoll negre

L'estudi de varietats autòctones de vinya a Catalunya és una de les principals activitats de l'Institut Català de la Vinya i el Vi (INCAVI), que té per objectiu tant la conservació de la biodiversitat com el coneixement del seu comportament agronòmic i potencial enològic. En el treball es realitza la descripció ampelogràfica de la varietat sumoll, de la qual distingim tres variants segons la forma i les dimensions de la baia: el·líptica, el·líptica llarga i esfèrica (baia de dimensions més reduïdes). S'identifiquen totes les mostres recollides mitjançant tècniques d'anàlisi molecular per tal de confirmar-ne la pertinença a aquesta varietat. Aquesta caracterització permet obtenir un coneixement de la distribució geogràfica de la varietat, així com l'aclariment de les sinonímies i homonímies existents.El estudio de variedades autóctonas de vid en Cataluña es una de las principales actividades del Institut Català de la Vinya i el Vi (INCAVI), que tiene por objetivo tanto la conservación de la biodiversidad como el conocimiento de su comportamiento agronómico y su potencial enológico. En el trabajo se realiza la descripción ampelográfica de la variedad sumoll, de la que se diferencian tres variantes según la forma y dimensiones de la baya: elíptica, elíptica larga y esférica (baya de menores dimensiones). Se identifican todas las muestras recogidas mediante técnicas de análisis molecular para confirmar que pertenecen a esta variedad. La caracterización permite obtener información de la distribución geográfica de la variedad, así como el conocimiento de las sinonimias y homonimias existentes

A comparative study of eubacterial communities by PCR-DGGE fingerprints in anoxic and aerobic biotrickling filters used for biogas desulfurization

La desulfuración biológica ha demostrado ser un proceso técnica y económicamente viable al utilizar filtros percoladores que pueden realizarse en condiciones aerobias y anóxicas. Sin embargo, las comunidades microbianas implicadas en el proceso son diferentes debido principalmente al uso de diferentes aceptores finales de electrones. El análisis de las comunidades microbianas en estos sistemas anóxicos no se han abordado hasta ahora. El objetivo del presente trabajo es analizar la comunidad de eubacterias en los dos tipos de biorreactores a lo largo del proceso de biodesulfuración a lo largo del biofiltro de lecho empacado y durante el tiempo de operación. El análisis se llevó a cabo mediante el estudio de los perfiles moleculares de los productos obtenidos a partir 16S PCR-DGGE, El análisis del perfil microbiano en el biorreactor aeróbico reveló que la comunidad era más diversa y estratificada que la obtenida en los dos biorreactores anóxicos, influida por factores ambientales. El principal OTU implicada en este proceso es el género Thiobacillus, aunque se detectaron diferentes especies en función de cada condición de operación

Redesigning the coumarin scaffold into small bright fluorophores with far-red to NIR emission and large Stokes' shifts useful for cell imaging

Among the palette of previously described fluorescent organic molecules, coumarins are ideal candidates for developing cellular and molecular imaging tools due to their high cell permeability and minimal perturbation of living systems. However, blue-to-cyan fluorescence emission is usually difficultin in vivo applications due to the inherent toxicity and poor tissue penetration of short visible light wavelengths. Here, we introduce a new family of coumarin-based fluorophores, nicknamed COUPY, with promising photophysical properties, including emission in the far-red/near-infrared (NIR) region, large Stokes shifts, high photostability, and excellent brightness. COUPY fluorophores were efficiently synthesized in only three linear synthetic steps from commercially available precursors, with the N-alkylation of a pyridine moiety being the key step at the end of the synthetic route, as it allows for the tuning of the photophysical properties of the resulting dye. Owing to their low molecular weights, COUPY dyes show excellent cell permeability and accumulate selectively in nucleoli and/or mitochondria of HeLa cells, as their far-red/NIR fluorescence emission is easily detected at a concentration as low as 0.5 μ M after an incubation of only 20 min. We anticipate that these coumarin scaffolds will open a way to the development of novel coumarin-based far-red to NIR emitting fluorophores with potential applications for organelle imaging and biomolecule labeling