Research concerning the formation and removal of black crusts on various historical objects is approached from many different angles. The so-called “yellowing effect”, observed after laser treatment for cleaning purposes, has also received a lot of attention. Evidence regarding this phenomenon differs considerably and the actual mechanisms are still speculated on by researchers. In an attempt to elucidate the processes involved in the yellowing effect associated with laser cleaning, a new analytical technique has been used to investigate the black crust, a region of the sample cleaned by laser irradiation at 1064 nm and another region of the same sample subjected to further laser irradiation at 355 nm, on a limestone sample from the cathedral of Seville in Spain. Micro-Raman spectrometry offers the advantage of spatial chemical characterization of the stone, based upon its molecular makeup and was performed on the bulk body of the stone. Raman and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDXS) results indicate that the surfaces cleaned by irradiation at 1064 nm and by double irradiation at 1064 and 355 nm differed in terms of their calcium sulphate, calcium oxalate and iron oxide content, and that this could contribute to the difference in colour observed.

This thesis was focused on testing of portable Raman spectrometer for detection of components in model mixtures of five different biomolecules in a gypsum matrix. The main goal was to test the ability of the instrument to detect amino acids glycine, L-proline, L-alanine and nucleobase thymine in samples containing UV protective pigment -carotene. Other measurements were taken using the laboratory inVia Reflex instrument to comapare the results gained from the portable Raman spectrometer. Both instruments were equipped with the excitation laser working at 785 nm wavelength. It was found out that it is possible to detect amino acid in mixtures containing -carotene at the lowest concentration of amino acid 100 g/kg and the maximum concentration of -carotene 1 g/kg. Thymine could be identified at the concentration of 100 g/kg in mixtures with higher concentration of -carotene (10 g/kg). In mixtures of -carotene at the concentration of 1 g/kg and only one of the studied nitrogen containg compounds (at the concentration of 100 g/kg) in the gypsum matrix, it was possible to detect all present components. In mixtures containing two nitrogen compounds with -carotene at the concentration of 1 g/kg in the gypsum matrix, both nitrogenous compounds could be detected. When measuring the samples of the three nitrogen...

In this thesis Raman spectroscopy is evaluated as a tool of identification and discrimination of carotenoids from microbial biomass. Microorganisms, halophilic or nonhalophilic, belong to Cyanobacteria, Proteobacteria, Chlorophyta, Rhodophyta and to others. Biomass was cultiveted under laboratory conditions and yielded varied colours. Raman spectra were recorded succesfully from lyophilized biomass by excitation wavelenth 514.5 nm (dispersive Raman microspectrometr) and 1064 nm (FT Raman spectrometer). Results were compared with Raman spectroscopic data from pigment extracts. Spectra of carotenoids are characterized by the main Raman bands υ1, υ2 a υ3 due to C=C stretching, C-C stretching and C-CH3 deformation. HPLC/UV-VIS allows effective pigment separation from extracts and detection of separated pigments by UV-VIS analyzator. Assessment of Raman analysis and its potential to detect microbial carotenoids are discused. Sarcinaxantin is an unusual carotenoid identified together with more common β - carotene. Raman spectroscopic results obtained on carotenoids recorded from colonies which accumulated more than one carotenoid need to be interpreted carefully. Powered by TCPDF (www.tcpdf.org)

Summary: Raman spectroscopy is a widely used method in geoscience fields. Using a portable Raman spectrometer is possible to identify different materials, Raman spectrometer will participate in the survey the Martian surface. Its use is widely applied in mineralogy. There was measured a set of dark, green and some bright minerals of different mineralogical system groups that have been assessed the applicability of the chosen detector excitation at 785 nm mainly off-road equipment. The obtained spectra were measured off-road equipment ahura and delta nu at excitation 785 nm and laboratory equipment InVia Renishaw and there were used lasers at excitaion of 785 nm and 514 nm. It was set of these minerals: Prehnite, Sulphur, Tyrkenit (howlit), Pyroxene (diopside), Libethenite, Toutmaline (verdelite), Dioptas, Klinoklas, Langit, Jadeit, Pseudomalachit (ehlit), Actinolite, Epidote, Augite. Some minerals were measured off-road equipment acquired spectrum, witch corresponded with laboratory measurements, the spectra of other optical properties due to their ambiguous. Keywords: Raman spektroscopy, portable Raman spectrometer, mineralogy, dark and green minerals

The multidisciplinary field of astrobiology has grown rapidly in recent years. The major goals of research in the field have been the search for habitable environments both within and outside our solar system, the search for evidence of prebiotic chemistry and life on Mars and other bodies in our solar system, laboratory and field research into the origins and early evolution of life on Earth, and studies of the potential for life to adapt to challenges on Earth and in space. NASA and ESA are heavily focused on a number of upcoming exploratory missions (e.g., the Mars Science Laboratory, with its planned launch in the fall 2011; ExoMars 2018; and the follow-up Mars Sample Return missions beyond 2020). A Raman spectrometer is now being miniaturized for the ExoMars Rover Instrument Suite. This Raman instrument is expected to be used to identify organic compounds and mineral products that could be related to signatures of life, as well as provide a general mineralogical overview, especially those minerals produced by water- related processes. This thesis describes the results of laboratory investigation into the feasibility of Raman spectroscopy to detect different types of biomarkers (pigments, carboxylic acids, and aminoacids) first mixed in the mineral matrices and...

This work deals with the possibility of Raman spectroscopical identification of selected biomarkers of extremophile species. It focuses mainly on selected cyanobacteria, algae and lichens with an emphasis on the ability to detect carotenoids. These pigments exhibit three characteristic bands of Raman spectra which represent stretching vibrations C=C; C-C and bending vibration C-CH3 in molecules of carotenoids. Raman spectra were measured not only by laboratory microspectrometers (λ - 514 nm and 532 nm), but also by portable and handheld spectrometers (λ - 532 nm, 785 nm and 700 - 1100 nm). In the case of cyanobacteria, the spectroscopical analysis was performed also on the fractions obtained by high performance liquid chromatography (HPLC). This work critically evaluates the possibilities of Raman spectroscopy to identify the carotenoids of cyanobacteria, algae and lichens. Besides the signal of carotenoids, interpretation of other bands in the Raman spectra corresponding to the presence of other biomarkers is given here for selected samples. The obtained Raman spectra of carotenoids should be interpreted with great caution, because of the ifluence of several factors, which potentially cause unsystematic shifts in the positions of Raman bands (carotenoids bond in biological tissue, interactions with...

L’objectif de ce travail de recherche est d’étudier la possibilité d’utiliser la spectrométrie Raman dite "conventionnelle" pour l’analyse, voire le contrôle in situ de solutions ioniques et d'en déterminer les limites. Nous avons étudié différentes solutions salines, composées d'ions polyatomiques comme le nitrate (NO3-) donnant des raies Raman autour de 1000 cm-1, et d'ions halogénures (F-, Cl-, Br-, I-) qui ne possèdent pas de signature directe mais influencent de manière indirecte le spectre de l’eau. Les méthodologies proposées dans ce travail permettent une identification et une quantification des solutions salines et sont basées sur des analyses classiques de spectres à l'aide de pré-traitements (normalisation, correction de ligne de base). Les limites de détection des ions étudiés correspondent pour certains ions aux limites de potabilité de l’eau (nitrates et sulfates par exemple). D’autres substances restent impossibles à quantifier (nitrite, ammonium). Des méthodes statistiques ont ensuite été employées. Ainsi, l’analyse en composante principale (ACP) permet d’identifier la nature d’une solution saline, que l’ion présente une signature directe ou indirecte, et d'accéder aux arrangements moléculaires des ions avec l’eau. La régression PLS permet de quantifier les ions en solution à travers des modèles de prédiction. Cette méthode a été utilisée sur des solutions pures de nitrate et de chlorure avec des erreurs sur les prédictions en concentration 4 à 5 fois plus faibles que celles trouvées par les méthodes classiques. Ces méthodes statistiques ont également permis de descendre à des gammes de concentrations en ion Cl- beaucoup plus faibles (10-100 mM) / The objective of this research is to study the possibility of using conventional Raman spectroscopy for analysis, or in situ control of substances dissolved in water and to determine the limits of this technique. Several salt solutions were studied. Polyatomic ions such as nitrate (NO3-) give intense Raman lines around 1000 cm-1. Halide ions (F-, Cl-, Br-, I-) have no direct signature but indirectly affect the water spectrum. The methodology proposed in this work for identification and quantification of salt solutions is based on classical analysis of spectra using pre-treatment methods (normalization, baseline correction). The limits of detection of the studied ions correspond to the water potability limits. It is possible to go below the potability limits for nitrates and sulfates for example but it is impossible to reach them for some other substances (nitrite, ammonium). Then, statistical methods were used. Thus, the principal component analysis (PCA) allows to identify the nature of a salt solution (with direct or indirect signatures) and to acces to the molecular arrangements of ions with water. PLS regression quantifies the ions through predictive models. This method was used on pure solutions of nitrate and chloride with errors on the concentration predictions 4 to 5 times lower than those found by classical methods. Lower concentration ranges (10-100 mM) for the Cl- ion are reachable using these statistical methods

En cas d'accident grave sur un réacteur à eau sous pression, l'évaluation de la quantité d'iode susceptible d'être rejetée dans l'environnement revêt une grande importance du fait de la radiotoxicité et du caractère volatil de cet élément. Le rejet d'iode du cœur du réacteur endommagé et son transport dans les différentes parties du réacteur jusqu'à l'enceinte de confinement, ont été largement étudiés, en particulier dans les expériences Phébus-FB. A ce jour, les connaissances acquises et les modèles utilisés ne permettent pas de rendre compte complètement du comportement de l'iode observé lors d'essais à grande échelle. Une hypothèse est que l'iode gazeux proviendrait du circuit primaire à cause de processus qui limiteraient la formation d'iodure de césium. La formation d'iodure de césium pourrait être limitée à cause de limitations cinétiques ou à la présence d'éléments qui piégeraient le césium (molybdène, bore). Des expériences de laboratoire dans un montage spécialement conçu reproduisent la chimie de mélanges CsI/MoO3 et CsI/H3BO3 sous vapeur d'eau entre 1600°C (température et 150°C. Les aérosols et les gaz présents à 150°C sont piégés séparément. Les analyses des phases condensées et aérosols par MEBE-EDX, microspectrométrie Raman, ICP-MS et XPS ont permis d'identifier des particules d'aérosols submicroniques collectés à 150°C. Les analyses des gaz piégés en solution par ICP-MS et spectroscopie UV-visible traduisent l'existence d'iode gazeux pour les deux systèmes étudiés {Cs, I, Mo, O, H} et {Cs, I, B, O, H}. La modélisation de la chimie et du transport des espèces gazeuses et particulaires pour les deux systèmes dans la ligne expérimentale a été réalisée à l'aide du code de calcul SOPHAEROS développé à l'IRSN. Les résultats expérimentaux ont ainsi pu être comparés aux résultats des simulations. / In case of a severe accident on a nuclear reactor, radioactive iodine may be released into the environment, impacting significantly the radiological consequences. Determination of the amount released, and of the physical state of iodine (gaseous form or solid aerosol form), is thus a major issue. The release of iodine from the damaged reactor core and its transport in the different parts of the reactor up to the reactor containment, have been extensively studied, particularly in the Phébus-FP large scale experiments. Phébus-FP results notably showed that a significant fraction of iodine under gaseous form can reach the containment. The models used in severe accident codes did not (and still does not) fully account for this iodine speciation. A likely explanation is that iodine keeps a gaseous form up to the containment due to some processes that limit the formation of caesium iodide in the reactor coolant system (RCS) (caesium iodide was assumed to be the dominant form of iodine in the RCS). Caesium iodide formation would be limited due to chemical kinetic limitations and due to the presence of other elements (molybdenum or boron) responsible for “trapping” the caesium. An experimental research program has been developed with the aim to study the chemical behaviour of iodine during its transport in the RCS, with presence of steam, caesium and molybdenum or boron. Experiments are compared to calculations performed with the IRSN severe accident code ASTEC where a chemical kinetic model has been implemented

Raman spectroscopy is an irreplaceable method for chemical and structural characterization of many substances. This is especially true for carbonaceous matter. It is non-destructive and capable of determining the crystallinity of the studied carbonaceous phase, and subsequently, with the aid of empirical relations, also the temperature of formation of the rock under study. Until very recently, the most of the Raman spectroscopy measurements was conducted only single point-wise on grains chosen on purpose, e.g., in an optical microscope. Alongside with the evolution and affordability of the Raman spectroscopic technique it is now very appealing to utilize the possibility of Raman mapping coupled to the automated analysis of large quantities of acquired spectra. The aim of this study was to critically evaluate the pros and cons of such an approach on selected rocks with varying carbon content and crystallinity of the carbonaceous phase. The samples range from graphite, Karelian shungite, elemental carbon-rich carbonates, alpine schist to eclogite. In general, we can rate the large area mapping as suitable in many cases, however, there are certain issues associated with the method, especially concerning the sample preparation and automated analysis. Several actions are proposed to limit the pitfalls...

Results of ab initio and density functional theory calculations on the structure and vibrational frequencies of hypophosphite anion indicate earlier experimental assignments of the fundamental vibrational modes are correct while the recent reassignments of several modes proposed by Bickley et al. are inconsistent with the calculated results.