Paint on whiteboard desktop

Es un proyecto para la creación de una herramienta aplicable al uso de pizarras digitales. Pintar sobre el escritorio o aplicaciones abiertas.

Experimental and computational study on the synthesis and characterization of self-assembling meso/macroporous materials in highly concentrated emulsions

Report for the scientific sojourn carried out at Massachusetts General Hospital Cancer Center-Harvard Medical School, Estats Units, from 2010 to 2011. The project aims to study the aggregation behavior of amphiphilic molecules in the continuous phase of highly concentrated emulsions, which can be used as templates for the synthesis of meso/macroporous materials. At this stage of the project, we have investigated the self-assembly of diblock and triblock surfactants under the effect of a confined geometry being surrounded by the droplets of the dispersed phase. These droplets limit the growth of the aggregates, deeply modify their orientation and hence alter their spatial arrangement as compared to the self-assembly taking place far enough from any boundary surface, that is in the bulk. By performing Monte Carlo simulations, we have showed that the interface between the dispersed and continuous phases as well as its shape has a significant impact on the structural order of the resulting aggregates and hence on the potential applications of highly concentrated emulsions as reaction media, drug delivery systems, or templates for meso/macroporous materials. Due to the combined effect of symmetry breaking and morphological frustration, very intriguing structures, such as square columnar liquid crystals, twisted X-shaped aggregates, and helical phases of cylindrical aggregates, never observed in the bulk for the same model surfactant, have been found. The presence of other more conventional structures, such as micelles and cubic and hexagonal liquid crystals, formed at low and high amphiphilic concentrations, respectively, further enhance the interest on this already rich aggregation behavior.

Highly concentrated bitumen emulsions. A state of the art, review of experimental results

Les emulsions concentrades o altament concentrades de betum són un camp molt poc estudiat avui en dia. El treball és un estat de l'art de tots els papers que hi ha sobre aquest tema desde el mètode tradicional fins el HIPR (High Internal Phase Ratio).

Scale-up model obtained from the rheological analysis of highly concentrated emulsions prepared at three scales

We examine the scale invariants in the preparation of highly concentrated w/o emulsions at different scales and in varying conditions. The emulsions are characterized using rheological parameters, owing to their highly elastic behavior. We first construct and validate empirical models to describe the rheological properties. These models yield a reasonable prediction of experimental data. We then build an empirical scale-up model, to predict the preparation and composition conditions that have to be kept constant at each scale to prepare the same emulsion. For this purpose, three preparation scales with geometric similarity are used. The parameter N¿D^α, as a function of the stirring rate N, the scale (D, impeller diameter) and the exponent α (calculated empirically from the regression of all the experiments in the three scales), is defined as the scale invariant that needs to be optimized, once the dispersed phase of the emulsion, the surfactant concentration, and the dispersed phase addition time are set. As far as we know, no other study has obtained a scale invariant factor N¿Dα for the preparation of highly concentrated emulsions prepared at three different scales, which covers all three scales, different addition times and surfactant concentrations. The power law exponent obtained seems to indicate that the scale-up criterion for this system is the power input per unit volume (P/V).

Phase behavior and rheological analysis of reverse liquid crystals and W/I2, W/H2 gel emulsions using an amphiphilic block copolymer.

This article reports the phase behavior determi- nation of a system forming reverse liquid crystals and the formation of novel disperse systems in the two-phase region. The studied system is formed by water, cyclohexane, and Pluronic L-121, an amphiphilic block copolymer considered of special interest due to its aggregation and structural proper- ties. This system forms reverse cubic (I2) and reverse hexagonal (H2) phases at high polymer concentrations. These reverse phases are of particular interest since in the two-phase region, stable high internal phase reverse emulsions can be formed. The characterization of the I2 and H2 phases and of the derived gel emulsions was performed with small-angle X-ray scattering (SAXS) and rheometry, and the influence of temperature and water content was studied. TheH2 phase experimented a thermal transition to an I2 phase when temperature was increased, which presented an Fd3m structure. All samples showed a strong shear thinning behavior from low shear rates. The elasticmodulus (G0) in the I2 phase was around 1 order of magnitude higher than in theH2 phase. G0 was predominantly higher than the viscousmodulus (G00). In the gel emulsions,G0 was nearly frequency-independent, indicating their gel type nature. Contrarily to water-in-oil (W/O) normal emulsions, in W/I2 and W/H2 gel emulsions, G0, the complex viscosity (|η*|), and the yield stress (τ0) decreased with increasing water content, since the highly viscous microstructure of the con- tinuous phase was responsible for the high viscosity and elastic behavior of the emulsions, instead of the volumefraction of dispersed phase and droplet size. A rheological analysis, in which the cooperative flow theory, the soft glass rheology model, and the slip plane model were analyzed and compared, was performed to obtain one single model that could describe the non-Maxwellian behavior of both reverse phases and highly concentrated emulsions and to characterize their microstructure with the rheological properties.

Looking beneath Dalí's paint: non-destructive canvas analysis

A new analytical method was developed to non-destructively determine pH and degree of polymerisation (DP) of cellulose in fibres in 19th 20th century painting canvases, and to identify the fibre type: cotton, linen, hemp, ramie or jute. The method is based on NIR spectroscopy and multivariate data analysis, while for calibration and validation a reference collection of 199 historical canvas samples was used. The reference collection was analysed destructively using microscopy and chemical analytical methods. Partial least squares regression was used to build quantitative methods to determine pH and DP, and linear discriminant analysis was used to determine the fibre type. To interpret the obtained chemical information, an expert assessment panel developed a categorisation system to discriminate between canvases that may not be fit to withstand excessive mechanical stress, e.g. transportation. The limiting DP for this category was found to be 600. With the new method and categorisation system, canvases of 12 Dalí paintings from the Fundació Gala-Salvador Dalí (Figueres, Spain) were non-destructively analysed for pH, DP and fibre type, and their fitness determined, which informs conservation recommendations. The study demonstrates that collection-wide canvas condition surveys can be performed efficiently and non-destructively, which could significantly improve collection management.

Is there really a backlash against multiculturalism policies? New evidence from the multiculturalism policy index

In much of the western world, and particularly in Europe, there is a widespread perception that multiculturalism has ‘failed’ and that governments who once embraced a multicultural approach to diversity are turning away, adopting a strong emphasis on civic integration. This reaction, we are told, “reflects a seismic shift not just in the Netherlands, but in other European countries as well” (JOPPKE 2007). This paper challenges this view. Drawing on an updated version of the Multiculturalism Policy Index introduced earlier (BANTING and KYMLICKA 2006), the paper presents an index of the strength of multicultural policies for European countries and several traditional countries of immigration at three points in time (1980, 2000 and 2010). The results paint a different picture of contemporary experience in Europe. While a small number of countries, including most notably the Netherlands, have weakened established multicultural policies during the 2000s, such a shift is the exception. Most countries that adopted multicultural approaches in the later part of the twentieth century have maintained their programs in the first decade of the new century; and a significant number of countries have added new ones. In much of Europe, multicultural policies are not in general retreat. As a result, the turn to civic integration is often being layered on top of existing multicultural programs, leading to a blended approach to diversity. The paper reflects on the compatibility of multiculturalism policies and civic integration, arguing that more liberal forms of civic integration can be combined with multiculturalism but that more illiberal or coercive forms are incompatible with a multicultural approach.

Disseny d'una màquina carregadora de planxa a l'empresa Serralleria i Alumini Vilaró (S.A.V)

Les empreses sempre han buscat com optimitzar el màxim els seus recursos i ser més eficients a la hora de realitzar les tasques que li han estat encomanades. És per aquest motiu que constantment les empreses realitzen estudis i valoracions de com poder millorar dia a dia. Aquest fet no és diferenciador a l’empresa Serralleria i Alumini Vilaró (S.A.V), que dia a dia estudia com optimitzar els seus processos o de vegades introduir-ne de nous per tal d’expandir la seva oferta de serveis. L’empresa és dedica a la fabricació de peces metàl•liques el procés ja sigui només de tall i mecanitzat, plegat, soldadura, acabats en inoxidable, pintura i fins i tot embalatge pel que fa a la part productiva, respecte a la part d’oficina tècnica també ofereix serveis de desenvolupament de productes segons especificacions del client i reenginyeria de qualsevol producte, analitzant la part que és vol millorar. En l’actualitat l’empresa ha detectat una mancança que creu que es podria solucionar, el problema és que l’empresa disposa de varies màquines de tall, entre les quals hi ha una màquina de tall làser i el problema principal és que la càrrega de les planxes del calaix de magatzem a la bancada de la màquina es realitza o bé manualment o a través d’un gripper sostingut al pont grua, depenent del pes de la planxa a transportar. L’objectiu principal d’aquest treball és fer el disseny d’una màquina que permeti automatitzar el procés de transportar la planxa metàl•lica del calaix de magatzem dipositat sobre una taula mòbil a la bancada de la màquina de tall. El disseny que pretenem fer és complet començant per fer un disseny estructural de la màquina més els seus respectius càlculs, moviments que volem aconseguir, tria de components ( motors, sensors ...), elaboració d’un pressupost per poder fer una estimació i finalment la elaboració del programa de control de tota la màquina més la interacció amb la màquina a través d’una pantalla tàctil. Es a dir, el que pretenem és realitzar un projecte que puguem fabricar en la realitat utilitzant tota la informació continguda dins del mateix

A study of the effects of PVAC on works of art on paper and wood: pH and colour change

This paper presents the preliminary findings of pH and colour measurements carried out on artworks on paperand on wood that had been treated with a poly(vinyl acetate) (PVAC) based adhesive in the 1980s. In both cases, areas treated with PVAC proved to be less acidic than untreated areas. Contrary to expectations, the conservation treatments have not, as yet, increased acidity levels in the objects under study. Colour measurements of the works on paper showed that those that had been backed with a cotton fabric using a mixture of methylcellulose and PVAC were less yellow than those from the same print run that had not been backed. This finding suggests that the backing somehow prevented the natural degradation of the support. In view of these preliminary results, further research is clearly needed. This study forms part of a broader ongoing project to assess the role of PVAC in the conservation of a range of cultural assets.

A study of the effects of PVAC on works of art on paper and wood: pH and colour change

This paper presents the preliminary findings of pH and colour measurements carried out on artworks on paperand on wood that had been treated with a poly(vinyl acetate) (PVAC) based adhesive in the 1980s. In both cases, areas treated with PVAC proved to be less acidic than untreated areas. Contrary to expectations, the conservation treatments have not, as yet, increased acidity levels in the objects under study. Colour measurements of the works on paper showed that those that had been backed with a cotton fabric using a mixture of methylcellulose and PVAC were less yellow than those from the same print run that had not been backed. This finding suggests that the backing somehow prevented the natural degradation of the support. In view of these preliminary results, further research is clearly needed. This study forms part of a broader ongoing project to assess the role of PVAC in the conservation of a range of cultural assets.

A study of the effects of PVAC on works of art on paper and wood: pH and colour change

This paper presents the preliminary findings of pH and colour measurements carried out on artworks on paperand on wood that had been treated with a poly(vinyl acetate) (PVAC) based adhesive in the 1980s. In both cases, areas treated with PVAC proved to be less acidic than untreated areas. Contrary to expectations, the conservation treatments have not, as yet, increased acidity levels in the objects under study. Colour measurements of the works on paper showed that those that had been backed with a cotton fabric using a mixture of methylcellulose and PVAC were less yellow than those from the same print run that had not been backed. This finding suggests that the backing somehow prevented the natural degradation of the support. In view of these preliminary results, further research is clearly needed. This study forms part of a broader ongoing project to assess the role of PVAC in the conservation of a range of cultural assets.

A study of the effects of PVAC on works of art on paper and wood: pH and colour change

This paper presents the preliminary findings of pH and colour measurements carried out on artworks on paperand on wood that had been treated with a poly(vinyl acetate) (PVAC) based adhesive in the 1980s. In both cases, areas treated with PVAC proved to be less acidic than untreated areas. Contrary to expectations, the conservation treatments have not, as yet, increased acidity levels in the objects under study. Colour measurements of the works on paper showed that those that had been backed with a cotton fabric using a mixture of methylcellulose and PVAC were less yellow than those from the same print run that had not been backed. This finding suggests that the backing somehow prevented the natural degradation of the support. In view of these preliminary results, further research is clearly needed. This study forms part of a broader ongoing project to assess the role of PVAC in the conservation of a range of cultural assets.

Contemporary engagements within corridors of the past: temporal elasticity, graffiti, and the materiality of St. Rock Street, Barcelona

In a medieval Barcelonan side-street, urine, rubbish, and a bewildering array of graphic imagery splatters the narrowing walls between two major thoroughfares. A contemporary conflict between residents, unknown artists and others is played out using banners, bottles, stickers, posters, stencils, spray paint, and bodily substances. In this shadowed liminality, local and global debates are superimposed upon substructures constructed from disease, prostitution, and the Saint of the Plague. The continuing urban struggle constitutes temporal statements of dirt and purity, violence and humour, dominance and resistance, death and salvation. Like the renovated facades masking the crumbling remains of structures long neglected, the government’s literal whitewashing of the art is a temporal cover-up of a discursive symptom stretching from deeply embedded preconditions. However, from his niche in the angular bend of the alley bearing his name, the statue of St. Rock remains unblinkingly staring, raised above the contestations expressed below.

Identificación de patologías causadas por el PVAc en Bienes Culturales

Esta contribución presenta el Proyecto de investigación que se está llevando a cabo en la Sección de Conservación¿Restauración de la Facultad de Bellas Artes de la Universidad de Barcelona desde el año 2006. El proyecto tiene por objetivo identificar los problemas que generan los tratamientos con PVAc, poliacetato de vinilo, en diversos bienes patrimoniales, así como el establecimiento de protocolos para la reversibilización del adhesivo. El trabajo se centra en los materiales de archivo, los materiales arqueológicos, la pinturasobre tela, sobre madera y la pintura mural por ser casos especialmente representativos de patrimonio en los que se ha utilizado este adhesivo y en los que se pueden detectar problemas derivados de su utilización. El estudio parte de la selección de obras originales procedentes de museos e instituciones colaboradoras que fueron tratadas con poliacetato de vinilo. De éstas obras se extrajeron muestras para caracterizar su composición y estado conservación. Una vez conocida la estructura de las obras se prepararon muestras probeta simulando las obras originales y se sometieron a un proceso de envejecimiento acelerado. A partir de estos simulacros se realizaron análisis para conocer los efectos derivados del uso del PVAc en tratamientos de conservación-restauración. Las técnicas de análisis empleadas fueron: medición de pH, espectroscopía de IR por transformada de Fourier (FTIR), análisis de pirolisis-cromatografía de gases / espectrometría de masas (Py-GC-MS), espectroscopia Raman por transformada de Fourier (FT-Raman), análisis de color, microscopía electrónica de barrido, espectroscopia de dispersión de rayos X (SEM-EDX) y microscopía óptica. Con la divulgación de los resultados acerca de la composición, pH, color, efectos del adhesivo sobre los soportes, propiedades mecánicas y reversibilización del adhesivo, obtenidos de las muestras probeta antes y después de la primera fase de envejecimiento acelerado, así como en unas muestras de adhesivos envejecidas de forma natural durante 10 años, se pretende fomentar la difusión y el intercambio de información entre los centros dedicados a la Conservación-Restauración del patrimonio.

Identificación de patologías causadas por el PVAc en Bienes Culturales

Esta contribución presenta el Proyecto de investigación que se está llevando a cabo en la Sección de Conservación¿Restauración de la Facultad de Bellas Artes de la Universidad de Barcelona desde el año 2006. El proyecto tiene por objetivo identificar los problemas que generan los tratamientos con PVAc, poliacetato de vinilo, en diversos bienes patrimoniales, así como el establecimiento de protocolos para la reversibilización del adhesivo. El trabajo se centra en los materiales de archivo, los materiales arqueológicos, la pinturasobre tela, sobre madera y la pintura mural por ser casos especialmente representativos de patrimonio en los que se ha utilizado este adhesivo y en los que se pueden detectar problemas derivados de su utilización. El estudio parte de la selección de obras originales procedentes de museos e instituciones colaboradoras que fueron tratadas con poliacetato de vinilo. De éstas obras se extrajeron muestras para caracterizar su composición y estado conservación. Una vez conocida la estructura de las obras se prepararon muestras probeta simulando las obras originales y se sometieron a un proceso de envejecimiento acelerado. A partir de estos simulacros se realizaron análisis para conocer los efectos derivados del uso del PVAc en tratamientos de conservación-restauración. Las técnicas de análisis empleadas fueron: medición de pH, espectroscopía de IR por transformada de Fourier (FTIR), análisis de pirolisis-cromatografía de gases / espectrometría de masas (Py-GC-MS), espectroscopia Raman por transformada de Fourier (FT-Raman), análisis de color, microscopía electrónica de barrido, espectroscopia de dispersión de rayos X (SEM-EDX) y microscopía óptica. Con la divulgación de los resultados acerca de la composición, pH, color, efectos del adhesivo sobre los soportes, propiedades mecánicas y reversibilización del adhesivo, obtenidos de las muestras probeta antes y después de la primera fase de envejecimiento acelerado, así como en unas muestras de adhesivos envejecidas de forma natural durante 10 años, se pretende fomentar la difusión y el intercambio de información entre los centros dedicados a la Conservación-Restauración del patrimonio.