Caracterização material e microbiológica de espécimes fotográficos

Neste trabalho foram estudadas quatro espécies fotográficas, dois ambrótipos do séc. XIX e dois negativos de gelatina do séc. XX. Estas espécies são suscetiveis a degradações, físicas, químicas e microbiológicas. Técnicas de análise não destrutivas como, a fotografia, a microscopia ótica, a microscopia eletrónica de varrimento e espetroscopia de raios-X por dispersão em energias, a micro-espetroscopia de infravermelho em modo de reflexão total atenuada, a micro-espetroscopia de Raman e a micro-difração de raios-X foram utilizadas na caracterização material. A colonização microbiológica das amostras foi estudada através do isolamento e caracterização dos microrganismos contaminantes. Foram ainda realizados estudos de determinação de atividade celulolítica para os isolados fúngicos provenientes dos ambrótipos bem como ensaios de simulação, nos quais se utilizaram estes isolados para induzir contaminação em ambrótipos contemporâneos e assim avaliar o seu potencial biodeteriogénico. Foi ainda avaliado o potencial biodeteriogénico de isolados bacterianos em negativos de gelatina contemporâneos; Abstract: Material and microbiological characterization of photographic specimens This work presents a scientific study of four photographic specimens, two ambrotypes and two gelatin-silver negative plates from 19th and 20th century, respectively. These specimens are susceptible to physical, chemical and microbiological degradations. A non-destructive approach was used based on techniques such as technical photography, optical microscopy, scanning electron microscopy, infrared micro-spectroscopy, micro-Raman spectroscopy and X-rays micro-diffraction. Microbiological colonization of the samples was studied by isolation and characterization of the contaminating microorganisms. Studies to evaluate cellulolytic activity of fungal isolates from the ambrotypes were carried out and also simulation assays in which were used these isolated to induce contamination in contemporary ambrotypes were done to evaluate their biodeteriogenic potential. It was also studied the biodeteriogenic potential of the bacterial isolates from gelatin-silver negative plates which were subsequently inoculated in contemporary gelatin-silver negatives.

The fingerprinting of the materials used in portuguese illuminated manuscripts: origin, production and specificities of the 16th century Anttiphonary paints from the Biblioteca Pública de Évora

This thesis focuses on the characterization of materials utilized within the illuminations of Codex 116c of Manizola, a large 16th century antiphonal housed in the Biblioteca Pública de Évora (BPE). Using various spectroscopic techniques (XRF, FTIR, Raman and SEM-EDS), a selection of illuminations were analyzed for pigment and binder identification. The manuscript was further analyzed using fiber optic reflectance spectroscopy (FORS), a non-invasive and portable analysis method ideal for use in illuminations. Using historical documentation and results gained from more extensive analysis of the manuscript, a collection of reference paint samples were created to be analyzed using this method. These samples serve as a reference not only to assist in the identification of pigments used within the manuscript, but also for future studies on similar materials allowing for a better understanding of manuscript production during the 16th century; RESUMO: O presente trabalho é dedicado à caracterização dos materiais utilizados na produção das iluminuras do Codex 116c da Manziola do espólio da Biblioteca Pública de Évora (BPE). Trata-se de um antifonário de grandes dimensões produzido no séc XVI que deverá ter pertencido à Livraria de São Bento de Cástris. A identificação dos materiais utilizados na produção das iluminuras pode ser feita através de análises científicas. No entanto, alguns dos componentes das tintas utilizadas, especialmente os pigmentos orgânicos (lacas) e algumas misturas, apresentam obstáculos à sua identificação por métodos não invasivos. Através de várias técnicas espectroscópicas (XRF, FTIR, Raman e SEM-EDS), foi analisado um conjunto representativo de iluminuras, de modo a identificar os pigmentos e os ligantes presentes nas tintas. O manuscrito foi também analisado por FORS, um método portátil e não invasivo, ideal para a análise de iluminuras. Com base em documentos históricos e nos resultados analíticos, foi criado um conjunto de amostras de referência para ser analisado com FORS. Com esta abordagem, pretende-se que estas amostras, especialmente as de lacas, sirvam de referência não só na identificação dos pigmentos no manuscrito como em estudos sobre materiais semelhantes, contribuindo para um conhecimento mais aprofundado sobre a produção de manuscritos no séc XVI.

QUANTIFICATION OF CALCIUM IN SPARKLING WINES BY INFRARED SPECTROSCOPY

Markets are increasingly competitive and the companies feel the urge to improve their manufacturing processes. Blending that with a larger control of quality and safety it was created a need to develop new methods of analysis each time more accurate, faster and with lower costs. Alentejo is a region with a wide variety of soils, most of them are rich in calcium and potassium. In the production of sparkling wine many wineries use encapsulated yeast in alginate beads, instead of the traditional method, champenoise. The first method is faster, allowing a more versatile production, reducing the risk of contamination and features organoleptic characteristics similar to the traditional method (yeast free). However, encapsulated yeast spheres should be only used if the base wine matches a number of features, among them calcium content. In this study the calcium content in the wine was determined by atomic absorption spectroscopy (AAS) and by near-infrared spectroscopy. The AAS is a high sensitivity method clearly produces a reliable result, however it is very time consuming and produces great quantities of environmental waste, therefore the possibility of using near-infrared spectroscopy as a method was studied to be a fast, simple and clean alternative to the AAS. It was obtained a calibration model with a variation coefficient higher than 0.80 which indicates that the near-infrared spectroscopy as an adequately alternative the ASS.

A new look into the archaeological materials from the Museum of Évora, Portugal – the case study of the Zambujeiro Dolmen

This paper presents the results of a multidisciplinary and multi-analytical study of the amber beads, red pigments, lithic arrowheads and selected ceramics from the Museum of Évora’s collection of the Zambujeiro Dolmen. Amber beads were studied by Attenuated Total Reflectance Fourier Transformed Infrared Spectroscopy (ATR-FTIR) and Pyrolysis coupled to Gas Chromatography and Mass Spectrometry (Py-GC/MS) to confirm their chemical nature and provenance. The red pigments, frequently found in funerary Neolithic context of the Iberian Peninsula, were studied with micro-Raman, and Scanning Electron Microscopy coupled to Energy Dispersive X-Ray Spectroscopy (SEM-EDS) to identify their chemical nature and provenance. The lithic arrowheads were analysed by portable X-Ray Fluorescence (p-XRF), micro X-Ray Diffraction (XRD), SEM-EDS, and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The ceramic materials were studied to infer provenance and production technology by p-XRF, XRD and SEM-EDS; ceramic contents were evaluated by GC/MS. The studies have shown that while some materials travel hundreds or thousands of kilometres to arrive to the Zambujeiro Dolmen, local materials were also used in the items selected by the communities to honour their deceased.

Comparative Study of Four Portuguese 16th Century Illuminated Manueline Charters based on Spectroscopy and Chemometrics Analysis

The comparative study based on spectroscopic analysis of the materials used to produce four sixteenth-century Manueline Charters (the Charters of Alcochete, Terena, Alandroal and Evora) was performed following a systematic analytical approach. SEM–EDS, l-Raman and l-FTIR analysis highlighted interesting features between them, namely the use of different pigments and colourants (such as different green and yellow pigments), the presence of pigments alterations and the use of a non-expected extemporaneous material (with the presence of titanium white in the Charter of Alcochete). Principal component analysis restricted to the C–H absorption region (3000–2840 cm-1) was applied to 36 infrared spectra of blue historical samples from the Charters of Alcochete,Terena, Alandroal and Évora, suggesting the use of a mixture of a triglyceride and polysaccharide as binder.

Liquid Mixtures Involving Hydrogenated and Fluorinated Alcohols: Thermodynamics, Spectroscopy, and Simulation

This article reports a combined thermodynamic, spectroscopic, and computational study on the interactions and structure of binary mixtures of hydrogenated and fluorinated substances that simultaneously interact through strong hydrogen bonding. Four binary mixtures of hydrogenated and fluorinated alcohols have been studied, namely, (ethanol + 2,2,2-trifluoroethanol (TFE)), (ethanol + 2,2,3,3,4,4,4-heptafluoro-1-butanol), (1-butanol (BuOH) + TFE), and (BuOH + 2,2,3,3,4,4,4-heptafluoro-1-butanol). Excess molar volumes and vibrational spectra of all four binary mixtures have been measured as a function of composition at 298 K, and molecular dynamics simulations have been performed. The systems display a complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The combined analysis of the results from different approaches indicates that this results from a balance between preferential hydrogen bonding between the hydrogenated and fluorinated alcohols and the unfavorable dispersion forces between the hydrogenated and fluorinated chains. As the chain length increases, the contribution of dispersion increases and overcomes the contribution of H-bonds. In terms of the liquid structure, the simulations suggest the possibility of segregation between the hydrogenated and fluorinated segments, a hypothesis corroborated by the spectroscopic results. Furthermore, a quantitative analysis of the infrared spectra reveals that the presence of fluorinated groups induces conformational changes in the hydrogenated chains from the usually preferred all-trans to more globular arrangements involving gauche conformations. Conformational rearrangements at the CCOH dihedral angle upon mixing are also disclosed by the spectra.

PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper

PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high res- olution, high sensitivity, full-sky observations of the sky emission at wavelengths ranging from millimeter-wave to the far-infrared. PRISM’s main objective is to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume. PRISM will survey the full sky in a large number of frequency bands in both intensity and polarization and will measure the absolute spectrum of sky emission more than three orders of magnitude bet- ter than COBE FIRAS. The data obtained will allow us to precisely measure the absolute sky brightness and polarization of all the components of the sky emission in the observed frequency range, separating the primordial and extragalactic components cleanly from the galactic and zodiacal light emissions. The aim of this Extended White Paper is to provide a more detailed overview of the highlights of the new science that will be made possible by PRISM, which include: (1) the ultimate galaxy cluster survey using the Sunyaev-Zeldovich (SZ) e↵ect, detecting approximately 106 clusters extending to large redshift, including a char- acterization of the gas temperature of the brightest ones (through the relativistic corrections to the classic SZ template) as well as a peculiar velocity survey using the kinetic SZ e↵ect that comprises our entire Hubble volume; (2) a detailed characterization of the properties and evolution of dusty galaxies, where the most of the star formation in the universe took place, the faintest population of which constitute the di↵use CIB (Cosmic Infrared Background); (3) a characterization of the B modes from primordial gravity waves generated during inflation and from gravitational lensing, as well as the ultimate search for primordial non-Gaussianity using CMB polarization, which is less contaminated by foregrounds on small scales than thetemperature anisotropies; (4) a search for distortions from a perfect blackbody spectrum, which include some nearly certain signals and others that are more speculative but more informative; and (5) a study of the role of the magnetic field in star formation and its inter- action with other components of the interstellar medium of our Galaxy. These are but a few of the highlights presented here along with a description of the proposed instrument.