Dissertations / Theses on the topic 'Colorimetric analysis'

The trichromatic principle of representing color has for a long time been dominating in color imaging. The reason is the trichromatic nature of human color vision, but as the characteristics of typical color imaging devices are different from those of human eyes, there is a need to go beyond the trichromatic approach. The interest for multi-channel imaging, i.e. increasing the number of color channels, has made it an active research topic with a substantial potential of application.

To achieve consistent color imaging, one needs to map the imaging-device data to the device-independent colorimetric representations CIEXYZ or CIELAB, the key concept of color management. As the color coordinates depend not only on the reflective spectrum of the object but also on the spectral properties of the illuminant, the colorimetric representation suffers from metamerism, i.e. objects of the same color under a specific illumination may appear different when they are illuminated by other light sources. Furthermore, when the sensitivities of the imaging device differ from the CIE color matching functions, two spectra that appear different for human observers may result in identical device response. On contrary, in multispectral imaging, color is represented by the object’s physical characteristics namely the spectrum which is illuminant independent. With multispectral imaging, different spectra are readily distinguishable, no matter they are metameric or not. The spectrum can then be transformed to any color space and be rendered under any illumination.

The focus of the thesis is high quality image-acquisition in colorimetric and multispectral formats. The image acquisition system used is an experimental system with great flexibility in illumination and image acquisition setup. Besides the conventional trichromatic RGB filters, the system also provides the possibility of acquiring multi-channel images, using 7 narrowband filters. A thorough calibration and characterization of all the components involved in the image acquisition system is carried out. The spectral sensitivity of the CCD camera, which can not be derived by direct measurements, is estimated using least squares regression, optimizing the camera response to measured spectral reflectance of carefully selected color samples.

To derive mappings to colorimetric and multispectral representations, two conceptually different approaches are used. In the model-based approach, the physical model describing the image acquisition process is inverted, to reconstruct spectral reflectance from the recorded device response. In the empirical approach, the characteristics of the individual components are ignored, and the functions are derived by relating the device response for a set of test colors to the corresponding colorimetric and spectral measurements, using linear and polynomial least squares regression.

The results indicate that for trichromatic imaging, accurate colorimetric mappings can be derived by the empirical approach, using polynomial regression to CIEXYZ and CIELAB. Because of the media-dependency, the characterization functions should be derived for each combination of media and colorants. However, accurate spectral data reconstruction requires for multi-channel imaging, using the model-based approach. Moreover, the model-based approach is general, since it is based on the spectral characteristics of the image acquisition system, rather than the characteristics of a set of color samples.

Report code: LiU-TEK-LIC- 2006:70

To reproduce color images in print, the continuous tone image is first transformed into a binary halftone image, producing various colors by discrete dots with varying area coverage. In halftone prints on paper, physical and optical dot gains generally occur, making the print look darker than expected, and making the modeling of halftone color reproduction a challenge. Most available models are based on macroscopic color measurements, averaging the reflectance over an area that is large in relation to the halftone dots. The aim of this study is to go beyond the macroscopic approach, and study halftone color reproduction on a micro-scale level, using high resolution images of halftone prints. An experimental imaging system, combining the accuracy of color measurement instruments with a high spatial resolution, opens up new possibilities to study and analyze halftone color prints. The experimental image acquisition offers a great flexibility in the image acquisition setup. Besides trichromatic RGB filters, the system is also equipped with a set of 7 narrowband filters, for multi-channel images. A thorough calibration and characterization of all the components in the imaging system is described. The spectral sensitivity of the CCD camera, which can not be derived by direct measurements, is estimated using least squares regression. To reconstruct spectral reflectance and colorimetric values from the device response, two conceptually different approaches are used. In the model-based characterization, the physical model describing the image acquisition process is inverted, to reconstruct spectral reflectance from the recorded device response. In the empirical characterization, the characteristics of the individual components are ignored, and the functions are derived by relating the device response for a set of test colors to the corresponding colorimetric and spectral measurements, using linear and polynomial least squares regression techniques. Micro-scale images, referring to images whose resolution is high in relation to the resolution of the halftone, allow for measurements of the individual halftone dots, as well as the paper between them. To capture the characteristics of large populations of halftone dots, reflectance histograms are computed as well as 3D histograms in CIEXYZ color space. The micro-scale measurements reveal that the reflectance for the halftone dots, as well as the paper between the dots, is not constant, but varies with the dot area coverage. By incorporating the varying micro-reflectance in an expanded Murray-Davies model, the nonlinearity caused by optical dot gain can be accounted for without applying the nonphysical exponentiation of the reflectance values, as in the commonly used Yule-Nielsen model. Due to their different intrinsic nature, physical and optical dot gains need to be treated separately when modeling the outcome of halftone prints. However, in measurements of reflection colors, physical and optical dot gains always co-exist, making the separation a difficult task. Different methods to separate the physical and optical dot gain are evaluated, using spectral reflectance measurements, transmission scans and micro-scale images. Further, the relation between the physical dot gain and the halftone dot size is investigated, demonstrated with FM halftones of various print resolutions. The physical dot gain exhibits a clear correlation with the dot size and the dot gain increase is proportional to the increase in print resolution. The experimental observations are followed by discussions and a theoretical explanation.

This dissertation concerns the task of classifying objects by methods of morpho-colorimetric and non-parametric statistical analysis. The study can be applied in botany where manual classification of seeds is still a common practice. It is labor-intensive, subjective, and suffers from contradiction, as well as it is a time-consuming task even for highly specialized botanists. Starting from this problem, automated, consistent, and efficient algorithms of classification of seeds have been developed allowing the researcher to have a valid support for reducing drastically time for classification and, at the same time, an exploratory tool that detects latent patterns in data that human eye cannot identify. Firstly an approach called Background Subtraction, that enhances the quality of segmentation process output of an image, has been proposed. From RGB images it allows to get more precise binary images which need of a reduced intervention of manual correction. Then for each object data concern size, texture, color and shape have been extracted. These have been used as input for classification process, in which four classifiers have been performed: Linear Discriminant Analysis (LDA), Classification And Regression Trees (CART), Support Vector Machines (SVM) and Naïve Bayes (NB). In order to enhance the classification accuracy an approach of classifier combination, indicated as CA, has been developed. It consists in spliting the complex problem of classifying among D classes into D−1 sub problems less complex than the original one, each of them classifying between only two classes. Combining the four classifiers considered, CA allowed to reduce of 25% the misclassification error obtained by the best of the four classifiers. Finally, approach aimed at evaluating the reliability of a classification rule has been proposed. The algorithms proposed are developed and optimized for botanical seeds, but they are suitable to a larger class of morphological classification problems. In order to make these algorithms usable and executable, functions have been created in R language and published.

The thesis presents the development of polymer based electrospun nanofibers as diagnostic probes for the selective detection of toxic metal ions in water. Through modification of the chemical characteristics of nanofibers by pre- and post-electrospinning treatments, three different diagnostic probes were successfully developed. These were the fluorescent pyridylazo-2-naphthol-poly(acrylic acid) nanofiber probe, the colorimetric probe based on glutathione-stabilized silver/copper alloy nanoparticles and the colorimetric probe based on 2-(2’-Pyridyl)-imidazole functionalized nanofibers. The probes were characterized by Fourier transform infrared spectroscopy (FTIR), Energy dispersive x-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The fluorescent nanofiber probe was developed towards the determination of Ni²⁺. Covalently functionalized pyridylazo-2-naphthol-poly(acrylic acid) polymeric nanofibers were employed. The solid state Ni²⁺ probe exhibited a good correlation between the fluorescence intensity and nickel concentration up to 1.0 mg/mL based on the Stern-Volmer mechanism. The detection limit of the nanofiber probe was found to be 0.07 ng/mL. The versatility of the fluorescent probe was demonstrated by affording a simple, rapid and selective detection of Ni²⁺ in the presence of other competing metal ions by direct analysis without employing any sample handling steps. For the second part of the study, a simple strategy based on the in-situ synthesis of the glutathione stabilized silver/copper alloy nanoparticles (Ag/Cu alloy NPs) in nylon 6 provided a fast procedure for fabricating a colorimetric probe for the detection of Ni²⁺ in water samples. The electrospun nanofiber composites responded to Ni²⁺ ions but did not suffer any interference from the other metal ions. The effect of Ni²⁺ concentration on the nanocomposite fibers was considered and the “eye-ball” limit of detection was found to be 5.8 μg/mL. Lastly, the third probe was developed by covalently linking an imidazole derivative; 2-(2′-Pyridyl)-imidazole (PIMH) to Poly(vinylbenzyl chloride) (PVBC) and nylon 6 nanofibers by post-electrospinning treatments using a wet chemical method and graft copolymerization technique, respectively. The post-electrospinning modifications of the nanofibers were achieved without altering their fibrous morphology. The color change to red-orange in the presence of Fe²⁺ for both the grafted nylon 6 (white) and the chemically modified PVBC (yellow) nanofibers was instantaneous. The developed diagnostic probes exhibited the desired selectivity towards the targeted metal ions.

Access to safe water is a basic human right recognized by the United Nations General Assembly in 2010 (WHO, 2020). However, a least 2.2 billion people globally still are without safely managed water services meaning they use a drinking water source that can be contaminated with faeces (WHO, 2020). With such a pressing global health issue, it is clear that improvement to water systems is important and required in the Agenda 2030 Sustainable Development Goals (SDGs). However, to improve water systems and prove they are safe water sources, water quality testing must occur. A solution to this issue is the development of rapid detection sensors for pathogens in water. The first chapter of this thesis aims to create an informed list of rapid detection sensors that should be focused on for future development. This is achieved by using multicriteria decision analysis techniques based on using two consecutive processes. The first is the Analytic Hierarchy Process (AHP), which was used to develop weightings for criteria being measured for different sensor alternatives. The second process is the Technique of Order Preference Similarity to the Ideal Solution (TOPSIS), which was used to perform the ranking of the sensors being reviewed based on the weighted criteria. The outcome of the multicriteria decision analysis was identifying the top 5 rapid detection nanosensors for future development. They can be further improved to include field scale applications while also achieving lower detection limits and shorter detection times. The cost for these sensors could possibly be reduced by changing the nanoparticles that the sensor is composed of. Through improved methods, the goal of creating a cost effective, rapid-detection nanosensor for bacteria (e.g., Shiga-toxin producing E. coli) in drinking water can be achieved by prioritization of research on these promising nanosensors. The second chapter of the thesis focuses on optimizing a gold nanosensor developed in 2015 by Raweewab T. and Rawiwan L, hereafter called the “Original Method.” The goal was to reduce the cost and improve the reusability of their indirect colorimetric gold nanosensor without compromising the simplicity of the detection platform. With a reusable and more cost-effective sensor, field applications for water quality testing in water system projects in impoverished areas can be more obtainable. The nanoparticle itself was the target of optimization in this study. The hypothesis was that the polyethylenimine (PEI) coating on the gold nanoparticle surface is the governing factor of how the sensor functions, meaning the core nanomaterial does not affect the function of the sensor. In this study, the results showed that sensor still maintained its function after replacing the PEI coated gold nanoparticle used in the Original Method with PEI coated silver nanoparticles. These findings indicated that with further development and future research, it will be possible to use less expensive nanoparticles for making the nanosensor. It will also be possible to make this sensor reusable through the development of PEI coated magnetite nanoparticles. Their magnetic quality could allow for recovering the nanosensors from the test media, then re-conditioned and used again.

A avaliação de uma estrutura danificada por incêndios usualmente inicia por observações visuais do concreto, incluindo sua mudança de cor. A mudança de cor observada no concreto exposto a altas temperaturas persiste após seu resfriamento, constituindo-se em uma ferramenta importante para uma avaliação preliminar do nível de deterioração do concreto, pois essas mudanças podem ser relacionadas com as temperaturas as quais o mesmo foi exposto. Com o objetivo de avaliar as mudanças de cor e a degradação térmica de concretos potencialmente encontrados em estruturas no estado, foram estudados concretos de resistência convencional, moldados com materiais usualmente empregados no RS. Foram utilizadas três relações água/cimento, empregando-se o cimento CPIV, agregado graúdo granítico e basáltico. Os espécimes moldados foram submetidos às temperaturas de 200°C, 400°C, 600°C e 900°C, utilizando-se como base uma taxa de aquecimento baseada na curva padrão “Temperatura-Tempo”. Após o aquecimento, os espécimes foram resfriados lentamente, no interior do forno, e bruscamente, com aspersão de água. A degradação térmica do concreto foi avaliada através de ensaios de resistência à compressão, módulo de elasticidade e ultra-som. Para a avaliação das mudanças de cor foi utilizada metodologia colorimétrica, método mais consistente do que uma avaliação visual subjetiva. Observou-se queda de resistência à compressão e do módulo de elasticidade do concreto, conforme o aumento da temperatura de exposição. O ensaio de ultra-som mostrou-se bastante efetivo para detectar micro-fissuração do concreto, apresentando fatores de redução da velocidade de propagação mais semelhantes aos fatores de redução do módulo de elasticidade do que da resistência à compressão, mostrando a sensibilidade e potencialidade do método. As maiores diferenças colorimétricas foram obtidas nos concretos expostos às temperaturas mais altas, acima de 600°C, cujos níveis de percepção podem ser classificados como facilmente distinguíveis e muito grandes, o que pôde ser confirmado pela análise visual dos concretos, na qual foi observado o surgimento de uma cor amarelada. Considera-se, portanto, viável a identificação dos níveis de temperatura de exposição do concreto através das diferenças colorimétricas, especialmente para altas temperaturas de exposição, e, portanto, de maior interesse, já que levam a níveis de degradação mais acentuados.
The assessment of fire damaged concrete structures usually starts with visual observation of concrete, including his color change. The observed color change in high temperatures exposed concrete remains after cooling, consisting in a important tool for a preliminar assessment of concrete deterioration degree, therefore this changes could be related with the exposed temperatures. With the objective of assessing the color changes and thermal degradation of concretes potentially finding out in state’s structures, it was studied in this work normal-strength concretes made with materials usually finding in RS state. The concretes were made with three w/c ratio, with Pozzolanic cement (CPIV), granitic e basaltic coarse aggregate. The molded specimens were subjected to temperatures of 200°C, 400°C, 600°C e 900°C, with utilization of the standard fire curve (ISO 834). After heating, the specimens were allowed to a slow cool in the furnace, and quickly with water spread. The concrete thermal degradation was assessed with compressive strength test, elasticity modulus and pulse velocity measurements. The color changes was assessed by colorimetric methodology, a more consistent method than a subjective visual assessment. It was observed concrete loss of compressive strength and elasticity modulus with de increment of the exposure temperature. The pulse velocity test showed itself as a very effective for detecting concrete micro-cracks, showing reducing factors, as exposure temperature, more likely the elasticity modulus reducing factors than the compressive strength, indicating method sensibility and potentiality. The larger colorimetric differences were obtained on concretes exposed at higher temperatures, above 600°C, witch perceptions levels can be confirmed by concretes visual analyses, where was observed the appeared of a buff color. Can be consider, thus, viable to make the identification of concrete exposed temperatures levels through colorimetric differences, specially for higher exposure temperatures, end, thus, of major interest, since they conduce to more accentuated degradation levels.

[ES] Las labores de documentación de arte rupestre son arduas y delicadas, donde el color desempeña un papel fundamental, proporcionando información vital a nivel descriptivo, técnico y cuantitativo . Tradicionalmente los métodos de documentación en arqueología quedaban restringidos a procedimientos estrictamente subjetivos. Sin embargo, esta metodología conlleva limitaciones prácticas y técnicas, afectando a los resultados obtenidos en la determinación del color. El empleo combinado de técnicas geomáticas, como la fotogrametría o el láser escáner, junto con técnicas de procesamiento de imágenes digitales, ha supuesto un notable avance. El problema es que, aunque las imágenes digitales permiten capturar el color de forma rápida, sencilla, y no invasiva, los datos RGB registrados por la cámara no tienen un sentido colorimétrico riguroso. Se requiere la aplicación de un proceso riguroso de tranformación que permita obtener datos fidedignos del color a través de imágenes digitales. En esta tesis se propone una solución científica novedosa y de vanguardia, en la que se persigue integrar el análisis espectrofotométrico y colorimétrico como complemento a técnicas fotogramétricas que permitan una mejora en la identificación del color y representación de pigmentos con máxima fiabilidad en levantamientos, modelos y reconstrucciones tridimensionales (3D). La metodología propuesta se basa en la caracterización colorimétrica de sensores digitales, que es de novel aplicación en pinturas rupestres. La caracterización pretende obtener las ecuaciones de transformación entre los datos de color registrados por la cámara, dependientes del dispositivo, y espacios de color independientes, de base física, como los establecidos por la Commission Internationale de l'Éclairage (CIE). Para el tratamiento de datos colorimétricos y espectrales se requiere disponer de un software de características técnicas muy específicas. Aunque existe software comercial, lo cierto es que realizan por separado el tratamiento digital de imágenes y las operaciones colorimétricas. No existe software que integre ambas, ni que además permita llevar a cabo la caracterización. Como aspecto fundamental, presentamos en esta tesis el software propio desarrollado, denominado pyColourimetry, siguiendo las recomendaciones publicadas por la CIE, de código abierto, y adaptado al flujo metodológico propuesto, de modo que facilite la independencia y el progreso científico sin ataduras comerciales, permitiendo el tratamiento de datos colorimétricos y espectrales, y confiriendo al usuario pleno control del proceso y la gestión de los datos obtenidos. Adicinalmente, en este estudio se expone el análisis de los principales factores que afectan a la caracterización tales como el sensor empleado, los parámetros de la cámara durante la toma, la iluminación, el modelo de regresión, y el conjunto de datos empleados como entrenamiento del modelo. Se ha aplicado un modelo de regresión basado en procesos Gaussianos, y se ha comparado con los resultados obtenidos mediante polinomios. También presentamos un nuevo esquema de trabajo que permite la selección automática de muestras de color, adaptado al rango cromático de la escena, que se ha denominado P-ASK, basado en el algoritmo de clasificación K-means. Los resultados obtenidos en esta tesis demuestran que el proceso metodológico de caracterización propuesto es altamente aplicable en tareas de documentación y preservación del patrimonio cultural en general, y en arte rupestre en particular. Se trata de una metodología de bajo coste, no invasiva, que permite obtener el registro colorimétrico de escenas completas. Una vez caracterizada, una cámara digital convencional puede emplearse para la determinación del color de forma rigurosa, simulando un colorímetro, lo que permitirá trabajar en un espacio de color de base física, independiente del dispositivo y comparable con
[CA] Les tasques de documentació gràfica d'art rupestre són àrdues i delicades, on el color compleix un paper fonamental, proporcionant informació vital a nivell descriptiu, t\`ecnic i quantitatiu.Tradicionalment els mètodes de documentació en arqueologia quedaven restringits a procediments estrictament subjectius, comportant limitacions pràctiques i tècniques, afectant els resultats obtinguts en la determinació de la color. L'ús combinat de tècniques geomàtiques, com la fotogrametria o el làser escàner, juntament amb tècniques de processament i realç d'imatges digitals, ha suposat un notable avanç. Tot i que les imatges digitals permeten capturar el color de forma ràpida, senzilla, i no invasiva, les dades RGB proporcionades per la càmera no tenen un sentit colorimètric rigorós. Es requereix l'aplicació d'un procés rigorós de transformació que permeti obtenir dades fidedignes de la color a través d'imatges digitals. En aquesta tesi es proposa una solució científica innovadora i d'avantguarda, en la qual es persegueix integrar l'anàlisi espectrofotomètric i colorimètric com a complement a tècniques fotogramètriques que permetin una millora en la identificació de la color i representació de pigments amb màxima fiabilitat en aixecaments, models i reconstruccions tridimensionals 3D. La metodologia proposada es basa en la caracterització colorimètrica de sensors digitals, que és de novell aplicació en pintures rupestres. La caracterització pretén obtenir les equacions de transformació entre les dades de color registrats per la càmera, dependents d'el dispositiu, i espais de color independents, de base física, com els establerts per la Commission Internationale de l'Éclairage (CIE). Per al tractament de dades colorimètriques i espectrals de forma rigorosa es requereix disposar d'un programari de característiques tècniques molt específiques. Encara que hi ha programari comercial, fan per separat el tractament digital d'imatges i les operacions colorimètriques. No hi ha programari que integri totes dues, ni que permeti dur a terme la caracterització. Com a aspecte addicional i fonamental, vam presentar el programari propi que s'ha desenvolupat, denominat pyColourimetry, segons les recomanacions publicades per la CIE, de codi obert, i adaptat al flux metodológic proposat, de manera que faciliti la independència i el progrés científic sense lligams comercials, permetent el tractament de dades colorimètriques i espectrals, i conferint a l'usuari ple control del procés i la gestió de les dades obtingudes. A més, s'exposa l'anàlisi dels principals factors que afecten la caracterització tals com el sensor emprat, els paràmetres de la càmera durant la presa, il¿luminació, el model de regressió, i el conjunt de dades emprades com a entrenament d'el model. S'ha aplicat un model de regressió basat en processos Gaussians, i s'han comparat els resultats obtinguts mitjançant polinomis. També vam presentar un nou esquema de treball que permet la selecció automàtica de mostres de color, adaptat a la franja cromàtica de l'escena, que s'ha anomenat P-ASK, basat en l'algoritme de classificació K-means. Els resultats obtinguts en aquesta tesi demostren que el procés metodològic de caracterització proposat és altament aplicable en tasques de documentació i preservació de el patrimoni cultural en general, i en art rupestre en particular. Es tracta d'una metodologia de baix cost, no invasiva, que permet obtenir el registre colorimètric d'escenes completes. Un cop caracteritzada, una càmera digital convencional pot emprar-se per a la determinació de la color de forma rigorosa, simulant un colorímetre, el que permetrà treballar en un espai de color de base física, independent d'el dispositiu i comparable amb dades obtingudes mitjançant altres càmeres que tambè estiguin caracteritzades.
[EN] Cultural heritage documentation and preservation is an arduous and delicate task in which color plays a fundamental role. The correct determination of color provides vital information on a descriptive, technical and quantitative level. Classical color documentation methods in archaeology were usually restricted to strictly subjective procedures. However, this methodology has practical and technical limitations, affecting the results obtained in the determination of color. Nowadays, it is frequent to support classical methods with geomatics techniques, such as photogrammetry or laser scanning, together with digital image processing. Although digital images allow color to be captured quickly, easily, and in a non-invasive way, the RGB data provided by the camera does not itself have a rigorous colorimetric sense. Therefore, a rigorous transformation process to obtain reliable color data from digital images is required. This thesis proposes a novel technical solution, in which the integration of spectrophotometric and colorimetric analysis is intended as a complement to photogrammetric techniques that allow an improvement in color identification and representation of pigments with maximum reliability in 3D surveys, models and reconstructions. The proposed methodology is based on the colorimetric characterization of digital sensors, which is of novel application in cave paintings. The characterization aims to obtain the transformation equations between the device-dependent color data recorded by the camera and the independent, physically-based color spaces, such as those established by the Commission Internationale de l'Éclairage (CIE). The rigorous processing of color and spectral data requires software packages with specific colorimetric functionalities. Although there are different commercial software options, they do not integrate the digital image processing and colorimetric computations together. And more importantly, they do not allow the camera characterization to be carried out. Therefore, as a key aspect in this thesis is our in-house pyColourimetry software that was developed and tested taking into account the recommendations published by the CIE. pyColourimetry is an open-source code, independent without commercial ties; it allows the treatment of colorimetric and spectral data and the digital image processing, and gives full control of the characterization process and the management of the obtained data to the user. On the other hand, this study presents a further analysis of the main factors affecting the characterization, such as the camera built-in sensor, the camera parameters, the illuminant, the regression model, and the data set used for model training. For computing the transformation equations, the literature recommends the use of polynomial equations as a regression model. Thus, polynomial models are considered as a starting point in this thesis. Additionally, a regression model based on Gaussian processes has been applied, and the results obtained by means of polynomials have been compared. Also, a new working scheme was reported which allows the automatic selection of color samples, adapted to the chromatic range of the scene. This scheme is called P-ASK, based on the K-means classification algorithm. The results achieved in this thesis show that the proposed framework for camera characterization is highly applicable in documentation and conservation tasks in general cultural heritage applications, and particularly in rock art painting. It is a low-cost and non-invasive methodology that allows for the colorimetric recording from complete image scenes. Once characterized, a conventional digital camera can be used for rigorous color determination, simulating a colorimeter. Thus, it is possible to work in a physical color space, independent of the device used, and comparable with data obtained from other cameras that are also characterized.
Thanks to the Universitat Politècnica de València for the FPI scholarship
Molada Tebar, A. (2020). Colorimetric and spectral analysis of rock art by means of the characterization of digital sensors [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160386
TESIS

DNA methylation naturally happens at the fifth carbon position of cytosine base within the CpG dinucleotides, plays a significant role in the numerous biological events, such as gene expression, cellular proliferation, embryonic developments, and chromosome instability. Aberrancies in DNA methylation pattern can lead to the genomic instability, resulting in the development of various human diseases including cancer, considered as one of the promising epigenetic (diagnostic and prognostic) biomarkers. Current research shows that abnormality in DNA methylation pattern presents a signature for disease diagnosis, therapeutic interventions, and prognosis of outcome. Therefore, current DNA methylation research has a major focus and needs for the development of easy, reliable and sensitive detection strategies. Throughout the last few decades, extensive research has been reported towards the quantification of DNA methylation in the mammalian genome. However, having their respective advantages in analytical performance and reliability, most of these strategies are confined to laboratory-based molecular biology techniques, such as real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), microarrays, and sequence-based methods. These methods largely require either bisulfite treatment (BT) or specific restriction enzyme digestion followed by a subsequence DNA amplification or sequencing. BT converts unmethylated cytosine to uracils leaving methylated cytosine unchanged, leveraging the methylated fragments distinguishable for detection. Low conversion, non-specific responses, false reading, longer assay time, amplification biased and complex chemistries significantly reducing the practice of BT and PCR amplification in current DNA methylation analysis. Hence, development of new analytical techniques without the BT steps and PCR amplification could be a valuable and out-of-bench tool for sensitive, low-cost and rapid platform to accomplish the emerging demand in genome-wide DNA methylation analysis in clinics. In this regard, bisulfite-free electrochemical biosensors have gained much attention in recent years as electrochemistry offers sensitive, cost-effective, portable, and simple biomolecules recognition readout. Parallel with electrochemistry, biosensors with optical readout enable direct real-time detection of biological molecules and are easily adaptable to multiplexing. Incorporation of electrochemical and optical readouts to bisulfite-free DNA methylation analysis is paving the way for translation of this important biomarker to standard patient care even resource-poor settings. This PhD thesis explores various electrochemistry along with colorimetric approach based sensitive, specific, rapid and inexpensive biosensor platform for bisulfitefree global DNA methylation analysis. Moreover, a series of commercial and in-house synthesised novel superparamagnetic nanomaterials were integrated to enhance the sensitivity and portability of the detection platform. A comprehensive literature review entailing detailed mechanism in DNA methylation pattern, association of DNA methylation with various human diseases, progress in DNA methylation biosensors techniques with a special emphasis on electrochemical and optical detection platforms have been reported. The challenges associated with current strategies have been outlined, and a great deal of recommendations also addressed to overcome the existing techniques. In the following chapters, four novel DNA methylation analysis strategies have reported based on colorimetry, electrochemistry and engineered nanostructures based inorganic enzymes (nanozymes) for the sensitive, rapid, and inexpensive analysis of global DNA methylation. First, based on the nucleic-acid affinity with the gold surface and methylation site-specific 5-mC antibody conjugated with horseradish peroxidase (HRP, natural enzyme), an amplification-free electrochemical and colorimetric assay was developed for the detection of global DNA methylation. In this strategy, the methylationsites to 5-mC antibody recognition were carried out on a screen-printed electrode surface and HRP catalysed 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation were employed to read out the recognition event. The widely used colorimetry and ultra-sensitive chronoamperometry (i-t) were used to readout the DNA methylation pattern. Subsequent to the development of this proof-of-concept sensor, we replaced the commercial HRP enzyme with an in-house specially designed mesoporous iron-oxide for reading the methylation site recognition events in genomic DNA obtained from the oesophageal cancer cell lines. In this DNA biosensor, both the BT and PCR amplification were avoided to overcome the challenges associated with them and to achieve relatively simple and rapid DNA methylation detection. Prior to integration of mesoporous iron-oxides into the sensor platform, the peroxidase-like activity was explored and a colorimetric glucose sensor was developed. This intrinsic property was then combined with DNA methylation site-5-mC antibody immunocomplex and hence a sensitive colorimetric and electrochemical readout were reported for global DNA methylations. In the following chapter, a more sensitive assay was stated by utilising the coupling of enzymatic and electrocatalytic strengths of another natural (glucose oxidase) enzyme. In this assay, chronocoulometric (CC) charge measurement from redox mediator [Ru(NH3)6]3+ in the presence of glucose subtract via glucose oxidase enzyme was used for DNA methylation analysis. In our final readout strategies, we extended our approach towards an inexpensive and portable assay platform which enabled naked-eye, colorimetric and electrochemical interrogation of in-house synthesised porous graphene oxide-loaded iron oxide (GOFe2O3) via (TMB)/Nanozyme)-based colorimetric assay. All the readout platforms reported herein have shown excellent analytical performance with high sensitivity (limit of detection-LOD for global DNA methylation 5%) and specificity. The applicability of the assays was also demonstrated in different cancer cell line samples with high reproducibility. We envisage that this research efforts will contribute to the on-going development of simple, inexpensive and sensitive technology for global DNA methylation analysis towards commercial aspect of both the laboratory settings and resource-poor clinical settings.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text

Epidemiological studies have linked exposure to elevated levels of airborne particulate matter with increased incidences of several types of respiratory disease, hospital admissions and morbidity. Millions of tons of airborne particulate matter are generated and released into the atmosphere each year. However, particulate matter resulting from the combustion of fuel oil and coal are of particular concern, because they are generally composed of small particles that can easily penetrate deep into the lungs, and can contain significant concentrations of toxic transition metals, such as zinc, iron and vanadium. Pulmonary toxicity (i.e. damage caused to lung tissues) of particulate matter is currently evaluated via time-consuming in-vivo testing, or via in-vitro testing. Compared to in-vivo testing, in-vitro testing offers significant advantages in terms of time savings and sample throughput. Unfortunately, the number of in-vitro testing methods are currently very limited, and do not allow a thorough investigation of the mechanisms of particulate matter toxicity. In light of these issues, the goals of the study described here were three-fold: *To adapt several in-vitro toxicity assays currently used in other applications to use in measuring particulate matter toxicity on lung cell layers; *To use these adapted assays to quantify the toxicity of numerous types of oil and coal ashes with varying particle sizes and transition metal concentrations, and; *To use the same assays to quantify the toxicities of several transition metals found in coal and oil ashes to better understand their relative contributions to overall particulate matter toxicity. Three colorimetric in-vitro assays were chosen for adaptation, and proved effective in measuring adverse cellular response to particulate matter exposure. Particle size was shown to have a large effect on the overall cytotoxicity of particulate matter; fine (less than 2.5 μm aerodynamic diameter) particles proved substantially more toxic than coarse (larger than 2.5 μm aerodynamic diameter) particles. Dose-response experiments measuring the toxic effects of the transition metals zinc, vanadium and iron revealed that zinc was the most toxic; a concentration of 0.6 mM caused a 50% drop in cellular metabolism, compared to 3 mM and 4 mM for vanadium and iron respectively.

Problems associated with instruments used to measure low levels of NO₂ include non-specificity, low sensitivity, and an uncharacterized dependence on environmental conditions. MDA Scientific has recently introduced a continuous colorimetric tape technique (chemcassette) to monitor for pollutant gases. Advantages of this technology include ease of use, fast-response alarm capability, and adaptability to measure different pollutants. This research characterized and compared chemcassette performance for NO₂ with other low-level NO₂ monitoring technologies including the luminox LMA-3 monitor and the EPA reference CSI chemiluminescnt monitor. The test protocol was based on EPA procedures. The chemcassette was found to be sensitive to temperature and relative humidity effects. The chemiluminescent monitor had the best overall performance. The luminox monitor displayed temperature dependence. Variation in stability of the chemcassette optical system, tape paper uniformity, and possible interference from ozone were characterized. (Abstract shortened with permission of author.)

Sardinia, with a surface of 24.084 Km2, is the second largest island in the Mediterranean Sea and represents an interesting laboratory, from biological, historical and cultural perspectives, where studies on ecology, ecophysiology and morpho-colorimetric analysis of wild grapevines populations and relationships with some autochthonous cultivars can be carried out. The peculiar insular condition of Sardinia and the large population of wild grapevine coenosis distributed in the whole island, allowed the local inhabitants to develop independent domestication processes. Infact, the wine heritage in Sardinia consists of 210 cultivars. Among these cultivars, 151 are considered as local true varieties and the result of different events, such as the direct domestication of wild grape, crosses between local varieties and the importation of agricultural techniques and cultivars from different ethnic groups that colonised the Island. The remaining 69 varieties can be considered as false attributions (synonyms and/or homonyms) due to the existence of different dialects within the same territory. The observations made in the field in order to detect the presence of young seedlings in the various island populations confirm that the germination period ranges from February to May and at the same time, the germination phenology limits the species distribution, in Sardinia, along riverbanks or colluvial sites of hilly humid slopes (as in most wild grapevine populations found in Europe) where seedlings can grow even during the dry summer conditions, suggesting a phenotypic adaptation to different microclimates. Through the measurement of 113 morpho-colorimetric discriminant parameters on seeds, of which: 33 coming from morpho-colorimetric measurements and 80 coming from the EFDs method we have obtained some statistical classifiers capable to identify, classify the studied cultivars of Vitis vinifera L. subsp. vinifera and to compare them with some wild populations of Vitis vinifera L. subsp. sylvestris (C.C. Gmel) Hegi and some archaeological remains of seeds founded in Sardinia. The use of 93 morphological parameters in the study of the archaeological seeds found in the prenuragic and nuragic site of Sa Osa has permitted their classification as white grapes for dessert wine, still today cultivated under the name of Vernaccia. Moreover, the image analysis technique has been used to investigate the various groups of synonymy and homonymy previously proposed on the basis of the Simple Sequence Repeat (SSR) marker providing high percentage values of correct identification of each group and showing a certain correspondence to the phenotypic seed characters- This results simultaneously suggests some potential modifications to the proposed groupings.

La adopción de tecnologías automatizadas de análisis de imagen va en aumento en los laboratorios de microbiología, éstas suponen un medio para incrementar la productividad, la objetividad y la trazabilidad de los resultados de las pruebas. Específicamente, la enumeración de colonias y la detección del desarrollo de color en éstas constituyen las dos aplicaciones más comunes de la visión artificial en el laboratorio microbiológico. En el albor de la era de la visión computarizada, el contaje y análisis de colonias se posiciona como una tarea más que automatizar mediante la inteligencia artificial aplicada al análisis de imagen. La presente tesis evalúa la capacidad de los escáneres flatbed para capturar imágenes para la detección y medida del desarrollo de color en colonias. Así mismo, se evalúa la incidencia que distintas concentraciones de cromógenos tienen sobre el desarrollo de color a lo largo del tiempo. Se sugieren aproximaciones asequibles para interpretar los datos obtenidos y se profundiza en el análisis del desarrollo de color. Los aspectos metrológicos de la técnica presentada son debidamente abordados. Se presta particular atención a la caracterización de la técnica empleada, a resaltar sus limitaciones y a evaluar la reproducibilidad de los resultados obtenidos en distintos dispositivos. Se aportan los primeros datos en relación a la enumeración de colonias aplicando técnicas cinéticas de toma de imagen en medios de cultivo alternativos. Así mismo, se evalúa el tiempo hasta detección de las colonias, junto con la recuperación de estas como medios para estudiar la inducción de estrés vinculada a la presencia de matrices potencialmente tóxicas.
Microbiology laboratories are increasingly adopting automated imaging technologies as means to leverage their productivity and increase traceability and objectivity of test results. Specifically, colony enumeration and detection of color development in these stand as the two most common applications of machine vision in microbiology laboratories. In the advent of the age of computer vision, colony counting and analysis stands as yet another process that can be automated by means of image-driven artificial intelligence. The present work assesses the capacity of flatbed scanners to capture images for the detection and measurement of color development in colonies. Effects of different concentrations of chromogens and the differences in color development over time are evaluated. Affordable approaches to interpret derived data are suggested and insights related to the analysis of color development are supplied. Metrological aspects of the measurement technique are duly addressed. Thus, particular care is devoted to characterize the measurement technique employed, to highlight its limitations, and to assess the cross-device reproducibility of obtained results. First-in-class accounts of enumeration of colonies in alternative culture media, based on kinetic imaging of their growth, are also reported. Furthermore, time to the earliest detection of colonies is evaluated, along with colony recovery evaluation, as a means to assess stress induction related to the presence of potentially toxic matrices.

Cavity enhanced spectroscopies (CES) are currently amongst the most sensitive spectroscopic techniques available for probing gas-phase samples, however their application to the liquid-phase has been more limited. Sensitive analysis of submicrolitre liquid samples is highly desirable, as miniaturisation allows for the reaction and analysis of scarce or expensive reagents, produces less waste, and can increase the speed of separations and reactions, whilst having a small footprint and high throughput. Absorption spectroscopy is a particularly desirable technique due to its universal, label-free nature, however its application to small volume liquid samples is hampered by the associated short absorption pathlengths, which limit sensitivity. CES improve sensitivity by trapping light within a confined region, increasing the effective pathlength through the sample. Three distinct types of optical cavity were constructed and evaluated for the purposes of making optical absorption measurements on liquid samples. The first incorporated a high optical quality flow cell into a "macrocavity" formed from two dielectric mirrors separated by 51.3 cm. Cavity losses were minimised by positioning the flow cell at Brewster's angle to the optical axis, and the setup was used to perform a single-wavelength cavity ringdown spectroscopy experiment to detect and quantify nitrite within aqueous samples. The detection limit was determined to be 8.83 nM nitrite in an illuminated volume of only 74.6 nL. Scattering and reflective losses from the flow cell surfaces were found to be the largest barrier to increased sensitivity, leading us to focus on the integration of cavity mirrors within a microfluidic flow system in the work that followed. In the second set of experiments, cavity enhanced absorption spectroscopy (CEAS) measurements were performed on Thymol Blue using custom-made microfluidic chips with integrated cavity mirrors. Unfortunately, due to the plane-parallel configuration of the mirrors and the corresponding difficulty in sustaining stable cavity modes, the results were underwhelming, with a maximum cavity enhancement factor (CEF) of only 2.68. At this point, attention was focussed toward a more well-defined cavity geometry: open-access plano-concave microcavities. The microcavities consist of an array of micron-scale concave mirrors opposed by a planar mirror, with a pathlength that is tunable to sub-nanometer precision using piezoelectric actuators. In contrast to the other experimental setups described, themicrocavities allow for optical measurements to be performed in which we monitor the change of wavelength and/or amplitude of a single well-defined cavity mode in response to a liquid sample introduced between the mirrors. In the first microcavity experiment, we used 10 μm diameter mirrors with cavity lengths from 2.238 μm to 10.318 μm to demonstrate refractive index sensing in glucose solutions with a limit of detection of 3.5 x 10^-4 RIU. The total volume of detection in our setup was 54 fL. Thus, at the limit of detection, the setup can detect the change of refractive index that results from the introduction of 900 zeptomoles (500,000 molecules) of glucose into the device. The microcavity sensor was then adapted to enable broadband absorption measurements of methylene blue via CEAS. By recording data simultaneously from multiple cavities of differing lengths, absorption data is obtained at a number of wavelengths. Using 10 μm diameter mirrors with cavity pathlengths from 476 nm to 728 nm, a limit of detection, expressed as minimum detectable absorption per unit pathlength, of 1.71 cm^-1 was achieved within a volume of 580 attolitres, corresponding to less than 2000 molecules within the mode volume of the cavity. Finally, a new prototype was developed with improved cavity finesse, a much more intense and stable light source, and improved flow design. Using a single plano-concave microcavity within the array with a cavity pathlength of 839.7 nm, and 4 μm radius of curvature mirror, absorption measurements were performed on Methylene Blue. Analysis of this data indicated a CEF of around 9270, and a limit of detection based on the measured signal-to-noise ratio of 0.0146 cm^-1. This corresponds to a minimum detectable concentration of 104 nM Methylene Blue, which given the mode volume of 219 aL, suggests a theoretical minimum detectable number of molecules of 14.

This dissertation examined the relationships between color contrast and legibility for digital raster video imagery. CIE colorimetric components were combined into three-dimensional color coordinate systems whose coordinates map one-to-one with the physical energy parameters of all colors. The distance between any two colors' coordinates in these 3-spaces is termed Color-Difference (ΔE). ΔE was hypothesized as a metric of the speed (RS) with which observers possessing normal vision could accurately read random numeral strings of one color displayed against backgrounds of another color. Two studies totaling 32064 practice and experimental trials were conducted. The first study determined that the CIE Uniform Color Spaces are inappropriate for the modeling of RS. Subsequently, a different 3-space geometry and colorimetric component scaling were empirically derived from the Study 1 data to produce a one-dimensional ΔE scale which ” approximates an interval scale of RS. This ΔE scale and others were then applied to the different stimulus conditions in Study 2 to determine the generalizability of such ΔE metrics. The pair of studies is conclusive: several ΔE scales exist which serve equally well to describe or prescribe RS with multicolor CRT raster imagery for a range of character luminances in both positive and negative presentation polarities. These are the Y,u',v', logY,u',v', L*,u',v', and L*,u*,v* rescaled color spaces. Because of its predictive accuracy and simplicity, a luminance—generalized, ΔE—standardized Y,u',v' metric, accounting for 71% and 75% of the RS variability in Studies 1 and 2, respectively, is recommended as the most appropriate metric of emissive display legibility to be tested in these studies.
Ph. D.

A Physalis peruviana Linnaeus é uma fruta considerada exótica que possui elevado custo de comercialização, principalmente nos mercados internacionais. Suas propriedades nutracêuticas e o aumento da sua produtividade no Estado do Rio Grande do Sul, associados à sua elevada perecibilidade definiram o objetivo deste trabalho: estudar o processo de transferência de massa durante a desidratação osmótica de physalis. Diversos trabalhos que avaliam as propriedades dos compostos bioativos da physalis através de ensaios in vitro e in vivo estão disponíveis na literatura, no entanto, há uma carência de informações a respeito de processos de industrialização desta fruta. Neste trabalho foi realizada a desidratação osmótica da physalis avaliando os efeitos da temperatura (variando de 40 a 70 C), da concentração da solução osmótica de sacarose (variando de 40 a 70 g por 100 g de solução) e da interação dessas variáveis através de planejamento experimental 22 com três repetições no ponto central (em duplicata). Análises de umidade (método gravimétrico), sólidos solúveis (refratômetro), açúcares totais (cromatografia líquida de alta eficiência) foram realizadas ao longo do processo de desidratação osmótica, enquanto que, as análises de carotenoides totais (espectrofotômetro), atividade de água (método higrométrico) e cor (escala CIELAB) foram realizadas para a fruta in natura e após 10 horas de processamento. Adicionalmente, testes utilizando uma sonda de ultrassom (frequência de 20 KHz, amplitude de 80 % durante 30 minutos) como pré-tratamento ao processo de desidratação osmótica foram realizados, a fim de aumentar a permeabilidade da casca cerosa desta fruta. Além disso, foram realizadas análises de atividade de água e da viscosidade das soluções osmóticas utilizadas neste trabalho. Os resultados mostraram que a utilização da sonda de ultrassom como pré-tratamento não apresentou diferenças estatisticamente significativas para nenhum dos parâmetros estudados, dentro da faixa de temperatura e concentração avaliadas. O modelo de Rastogi & Raghavarao mostrou-se adequado para a determinação do conteúdo de umidade e de sacarose no equilíbrio, assim como a utilização do modelo de difusão da Segunda Lei de Fick para a determinação da difusividade mássica efetiva da água e da sacarose na physalis usando os cinco primeiros termos da série. A difusividade mássica efetiva da água variou de 2,44 - 7,60 x 10-10 m2 s-1, enquanto que a da sacarose variou de 2,13 - 3,20 x 10-10 m2 s-1. Dentre todas as condições estudadas no planejamento experimental, o processo de desidratação osmótica mostrou-se mais eficiente quando realizado na temperatura de 70 C e concentração da solução osmótica de 70 g por 100 g de solução. Nessa condição experimental houve uma elevada perda de água (aproximadamente 83 %), além de uma redução estatisticamente significativa na atividade de água da fruta (passando de 0,979 para 0,872 após 10 horas), no entanto, ocorreu a maior perda de carotenoides totais (aproximadamente 50 %). Nessa condição experimental, a matriz do tecido da physalis sofreu alterações que foram comprovadas através da análise microestrutural realizada por Microscopia Eletrônica de Varredura (MEV). Adicionalmente, verificou-se que nenhum dos tratamentos realizados promoveu modificações visualmente perceptíveis na diferença global de cor (ΔE*) devido ao processo de desidratação osmótica.
Physalis peruviana Linnaeus is considered to be an exotic fruit, with a high cost of commercialization, especially in international markets. Its nutraceutical properties and increased productivity in the state of Rio Grande do Sul, associated with its high perishability defined the goal of this work is the following: to study the process of mass transfer during the osmotic dehydration of physalis. It is noteworthy that several studies have evaluated the properties of the bioactive compounds of physalis both in vitro and in vivo; however, there is a shortage of information in the literature regarding the industrialization of physalis. In this work the osmotic dehydration of physalis was carried out evaluating the effects of temperature (ranging from 40 to 70 °C), osmotic sucrose solution concentration (ranging from 40 to 70 g per 100 g solution) and the interaction of these variables by a 22 experimental design, with three replicates at the center point (in duplicate). Analyses of moisture content (gravimetric method), soluble solids (refractometer) and total sugars (high performance liquid chromatography - HPLC) were performed along the osmotic dehydration process. Content of total carotenoids (spectrophotometer), water activity (hygrometric method) and color (CIELAB scale) were analyzed for the fresh fruit and after 10 hours of processing. In addition, tests using an ultrasound probe (frequency 20 kHz, amplitude of 80 % for 30 minutes) as a pretreatment for the process of osmotic dehydration were performed to increase the permeability of the waxy skin of this fruit. Furthermore, analyses of the water activity and viscosity of the osmotic solutions used were carried out. The results show that the use of the ultrasound probe as a pre-treatment did not yield statistically significant differences for any of the parameters studied within the temperature range at the concentrations assessed. The model of Rastogi & Raghavarao proved to be suitable for the determination of equilibrium content; Fick's Second Law was satisfactorily used to determine the effective diffusivity of water and sucrose for a spherical geometry. Thus, the effective diffusivity of water was calculated and ranged from 2.44 to 7.60 x 10-10 m2 s-1, while that of sucrose ranged from 2.13 to 3.20 x 10-10 m2 s-1. Among all conditions studied in the experimental design, the osmotic dehydration process was more efficient when performed at a temperature of 70 °C and an osmotic solution concentration of 70 g per 100 g of solution. In these conditions, there was a high water loss (approximately 83 %) and a statistically significant reduction in the water activity of this fruit (from 0.979 to 0.872 after 10 hours); however, the greatest loss of total carotenoids (approximately 50 %) was observed. Under this experimental condition, the tissue matrix of physalis suffered structural changes, as proven through Scanning Electron Microscopy (SEM) analysis. Additionally, it was found that none of the treatments performed promoted visually perceptible changes in the overall color difference (ΔE*) due to processing.

The one-humped or the dromedarian camel is a pseudo-ruminant mammal, well adapted to the hot and dry climates of the desert. Its ability to withstand torrid heat and extreme desiccation is of paramount importance to its survival. The studies presented in this thesis were designed to investigate and document the effect of dehydration in the presence or absence of angiotensin II (Ang II) AT1 receptor blocker (losartan) on blood constituents, electrolytes, hormones, neurotransmitters as well as liver and kidney enzymes in a subset of dehydrated camels and to compare them with hydrated camels. Additionally, we studied the response of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) and revealed for the first time the cardiac storage form of BNP in the camel heart. Dehydration induced significant increments in packed cell volume (PCV), white blood cells (WBC), gamma glutamyl-transferase (GGT), serum sodium, creatinine and urea levels, and a doubling in plasma cortisol and arginine vasopressin (AVP) levels. At the same time dehydration caused significant decrease in body weights, plasma insulin like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3), and a 50% decrement in ANP and BNP levels. Moreover, dehydration with and without losartan resulted in significant changes in stress hormones and anti-oxidants in plasma, liver and kidney homogenates. Losartan on one hand enhanced the effect of dehydration resulting in significant increases in sodium, creatinine and urea levels. In addition losartan raised the  binding affinity of Ang II AT2 receptors in the small intestine with 8-fold and with 16-fold for liver AT1 receptors, indicating that Ang II AT1 and AT2 receptor binding sites were present in camel's small intestine while only AT1 receptor binding sites were found in the camel liver. One the other hand losartan resulted in significant decrease in body weights impaired the rise in anti-diuretic hormone and reduced aldosterone level. Finally, we showed that the proBNP is the storage form of BNP in the camel heart.

This research is divided in five chapters: [CHAPTER 1] describes the research carried out on waterlogged plant remains from a Late Bronze Age well found near Cabras, in Sa Osa area (Central-West Sardinia). The combination of macro-remain and pollen analyses in this unique context provided important information for exploring not only local subsistence systems but also human impact on the surrounding environment. Grapes and figs were the most abundant remains together with other fruits and edible vascular plants. Remains of melon and mulberry were identified being the earliest remains of these two species for Western Europe. [CHAPTER 2] concerns the plant remains contained in some Phoenician-Punic amphorae dated to the 6th-5th and the 3rd-2nd century BC century BC found at the bottom of Santa Giusta lagoon (Central-West Sardinia). Many of these amphorae contained ovine/caprine bones with butchery marks associated with grapes and other fruits, as plums, sloes, and junipers, which may have played a role in meat preservation. Other fruits and nuts found in the same contexts, such as watermelon, bottle gourd, hazelnuts, walnuts, pine nuts, almonds and olives were probably related to food trade. [CHAPTER 3] describes the phenotypic characterization achieved by seed features compared with molecular analysis on modern Cucumis melo genotypes. A set of 124 accessions of Cucumis melo has been selected for molecular and morpho-colourimetric analyses plus an additional selection of accessions of C. sativus, Citrullus lanatus and C. colocynthis used to highlight seed morphology distances among genus and species. A strong correlation has been found between the two characters. Both molecular and seed morpho-colorimetrical analyses confirm the existence of two melon subspecies while an intermediate group has also found. [CHAPTER 4] describes the comparison of molecular and morphological seed features of Late Bronze Age melon seeds found in Sa Osa (Chapter 1) with a set of 172 accessions of melon landraces. Both molecular and morphological analyses confirmed that these archaeological seeds did not belong to a wild species, but to a cultivated melon, likely to be an intermediate form between the two melon subspecies. Reasonably, this primitive melon could be attributed to an ancestral non-sweet or low sugar form of chate, flexuosus or ameri varieties. [CHAPTER 5] describes de comparison of molecular and morphological seed features of Medieval melon and watermelon seeds discovered in a well in via Satta, in the centre of Sassari. Molecular characterization has been carried out on the same reference set described in Chapter 4 while the morphological comparison of watermelon seeds was based on 36 Citrullus lanatus and C. colocynthis landraces. Molecular and morphological analyses matched with both sweet and non-sweet melon accessions. Data suggests that several types of melon were already cultivated in Medieval Age. Morphological characterization of watermelon seeds evidenced a close relation with Sardinian, Spanish and Asian landraces, suggesting that watermelons were already close to modern varieties.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The Camembert is considered one of the finest cheeses. Presents as main characteristic the surface covered with a white mycelium of the fungus Penicillium candidum, which provides peculiar sensory characteristics greatly appreciated. In Brazil, little has been studied about this cheese, in this way, in order to generate scientific technical knowledge about factors that may influence the standard of quality cheeses such as Camembert, this work was divided into two parts. In the first (Chapter II), the objective was to evaluate the application of different primary cultures, and different concentrations of salt in the curing process. In the second (Chapter III), the objective was to develop and evaluate a protocol for obtaining fresh biomass of Penicillium candidum for use as a catch crop. Were used as primary cultures mesophilic homofermentative, heterofermentative mesophilic and thermophilic. The concentration of the brine used was 15, 20, 25 and 29º Brix. The biomass of P. candidum obtained in synthetic medium was recovered, and micro fragmented sprayed onto cheeses, with score of 2.106 spores / cheese. Of physical and chemical composition analyzes were performed, maturation index, colorimetric analysis and texture profile in the samples during maturation. The mycelia growth was established by the whiteness index (WI), which proved effective for this purpose, it is fast and inexpensive. Although the texture profile parameters were similar during maturation with different primary cultures, resilience showed lower value for processed cheeses with thermophilic culture, and was the only parameter that showed significant differences between cultures. Another positive factor for cheeses with this culture was superficial development of white mold mycelium with one-day gain, compared to mesophilic. Samples with different salt concentrations, showed significant differences (p <0.05) between the moisture, protein, dry matter, ash, sodium and sodium chloride, and did not affect the growth of the fungus P. candidum. The physical and chemical composition of cheeses matured with biomass was similar to cheeses matured with spores, but proteolysis of cheeses matured with biomass was more intense, with the end of 15 days of aging, free amino acid content of 14% more, compared with samples containing only spores. Among the samples with the application of the inoculums, the tyrosine levels and fat, as well as the cohesiveness of the texture profile parameter showed significant difference. The mycelium overlaid cheese with a day in advance when compared only with the inoculums of spores and showed greater height. This work demonstrates ways to monitor and speed up the mycelium closing within two days, using colorimetric analysis, thermophilic culture and micro fragmented biomass. These results can be readily used by companies to establish quality standards for cheese like Camembert.
O Camembert é considerado um dos principais queijos finos. Apresenta como principal característica a superfície recoberta por um micélio branco do fungo Penicillium candidum, que proporciona características sensoriais peculiares muito apreciadas. No Brasil pouco foi estudado sobre este queijo, desta forma com o propósito de gerar conhecimento técnico científico sobre fatores que podem influenciar o padrão de qualidade de queijos tipo Camembert, esta dissertação foi dividida em duas partes. Na primeira (Capítulo II) o objetivo foi avaliar a aplicação de diferentes culturas primárias, e diferentes concentrações de sal no processo de salga. Na segunda (Capítulo III) o objetivo foi desenvolver e avaliar um protocolo de obtenção de biomassa fresca de Penicillium candidum para utilização como cultura secundária. As culturas primárias utilizadas foram mesofílica homofermentativa, mesofílica heterofermentativa e termofílica. As concentrações das salmouras foram de 15, 20, 25 e 29º Brix. A biomassa de P. candidum obtida em meio sintético foi recuperada, microfragmentada e aspergida sobre os queijos, com contagem de 2.106 de esporos/queijo. Foram realizadas análises de composição físico-química, índice de maturação, análise colorimétrica e perfil de textura nas amostras durante a maturação. O crescimento do micélio foi estabelecido pelo índice de brancura (WI) o qual se mostrou eficiente para este propósito, sendo rápido e de baixo custo. Embora os parâmetros do perfil de textura tenham sido semelhantes durante a maturação com diferentes culturas primárias, a resiliência apresentou menor valor para os queijos processados com cultura termofílica, e foi o único parâmetro que apresentou diferença significativa entre as culturas. Outro fator positivo para os queijos com esta cultura, foi o desenvolvimento superficial do micélio do mofo branco com ganho de um dia, em comparação às mesofílicas. As amostras com diferentes concentrações de sal, apresentaram diferença significativa (p< 0,05) entre os teores de umidade, proteína, extrato seco, cinzas, cloreto de sódio e sódio, e não interferiram no crescimento do fungo P. candidum. A composição físico-química dos queijos maturados com biomassa foi semelhante aos queijos maturados com esporos, porém a proteólise dos queijos maturados com biomassa foi mais intensa, apresentando ao final de 15 dias de maturação, teor de aminoácidos livres de 14% a mais, comparado com amostras contendo apenas esporos. Entre as amostras com as aplicações dos inóculos, os teores de tirosina e gordura, assim como o parâmetro coesividade do perfil de textura, apresentaram diferença significativa. O micélio recobriu o queijo com um dia de antecedência quando comparado apenas com o inóculo de esporos e apresentou maior altura. Este trabalho demonstra formas de monitorar e acelerar o fechamento do micélio em até dois dias, utilizando análise colorimétrica, cultura termofílica e biomassa microfragmentada. Estes resultados podem ser prontamente utilizados por empresas a fim de estabelecer padrões de qualidade para queijos tipo Camembert.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This thesis describes the development of colorimetric sensors in polymeric materials for the biomarkers detection for clinical diagnostics. The devices were manufactured with 96 microzones from the direct printing technology, using transparency film. The printed microplates were used to detect dengue, glucose and total proteins. Dengue detection in patient serum samples was performed with the capture and indirect ELISA assay for the detection of immunoglobulin M and immunoglobulin G, respectively. After the acquisition of the images with a cellular camera, a color histogram analysis and the principal component analysis (PCA) were performed. The results of these analyzes allowed to easily differentiate the groups of serum samples from patients who were infected and non-infected with the dengue virus. In order to promote carboxyl groups on the surface of the polyester film, this was modified by two methodologies: alkaline hydrolysis and adsorption of a polymer. The glucose assay was performed on the films modified by both methodologies and detected by a cellular camera, and the detection limits found were 0.70 mM and 0.93 mM for the polymer and hydrolyzed film, respectively. In addition, the biuret assay was performed on the microplates for the analysis of total proteins in canine serum samples using a bench scanner as the detection system. The limit of detection was 9.7 μM for the analytical curve ranging from 0 to 200 μM albumin.
Essa tese descreve o desenvolvimento de sensores colorimétricos em materiais poliméricos para detecção de biomarcadores para diagnósticos clínicos. Os dispositivos foram fabricados com 96 zonas a partir da tecnologia de impressão direta, utilizando filme de transparência. As microplacas impressas foram utilizadas para realizar a detecção de dengue, glicose e proteínas totais. A detecção de dengue em amostras de soros de pacientes foi realizada com o ensaio imunoenzimático (ELISA) captura e indireto para a detecção da imunoglobulina M e imunoglobulina G, respectivamente. Após a aquisição das imagens com uma câmera de celular foi realizada uma análise por histogramas de cores e pela ferramenta multivariada de análise de componentes principais (PCA). Os resultados dessas análises permitiram diferenciar facilmente os grupos de amostras de soro de pacientes contaminados e não contaminados com o vírus da dengue. A fim de promover grupos carboxílicos na superfície do filme de poliéster, este foi modificado por duas metodologias: hidrólise alcalina e adsorção de um polímero. O ensaio de glicose foi realizado nos filmes modificados por ambas as metodologias e detectados por uma câmera de celular, e os limites de detecção encontrados foram 0,70 mM e 0,93 mM, para o filme com polímero e hidrolisado, respectivamente. Além disso, foi realizado nas microplacas o ensaio do biureto para a análise de proteínas totais em amostras de soro canino utilizando como sistema de detecção um scanner de bancada. O limite de detecção encontrado foi igual a 9,7 µM através da curva analítica variando de 0 a 200 µM de albumina.

A falta de acesso à água potável ainda é um problema de saúde pública no Brasil. O desenvolvimento de novos métodos analíticos de baixo custo para o reconhecimento de amostras contaminadas é uma necessidade, pois análises laboratoriais estão fora da realidade socioeconômica da população mais vulnerável. Visando contribuir para a resolução deste problema, esta tese apresenta esforços para o desenvolvimento de métodos de baixo custo para a análise de qualidade de águas ambientais. Foi estudada a associação de ferramentas quimiométricas com sensores voltamétricos para tentar discriminar amostras de águas contaminadas com espécies eletroativas. O modelo desenvolvido foi capaz de discriminar de forma satisfatória amostras contaminadas contendo chumbo(II), cobre(II), zinco(II) e nitrito. Os esforços para a redução do custo das análises também focaram no desenvolvimento de sensores com materiais de baixo custo. Um dos dispositivos voltamétricos propostos foi capaz de quantificar metais tóxicos e pesticidas, utilizando papel, grafite e cera. Foi desenvolvido também um sistema de agitação por som que resultou em um aumento significativo da sensibilidade dos dispositivos voltamétricos portáteis permitindo a quantificação de chumbo(II) até 48 nmol L-1, cádmio(II) até 370 nmol L-1 e zinco(II) até 340 nmol L-1. Outro sensor voltamétrico foi confeccionado utilizando apenas papelão como matéria prima, para o qual um laser de CO2 foi utilizado pela primeira vez com o intuito de pirolisar a superfície do papelão gerando estruturas de carbono condutoras. Sensores colorimétricos em papel foram testados com sucesso para a quantificação de fluoreto até 500 µmol L-1 em amostras de água mineral utilizando fotografias retiradas por um telefone celular para a construção de modelos12 de calibração. Com outro sistema colorimétrico em papel foi possível medir o pH de amostras utilizando um método de calibração multivariada. Como mostrado neste trabalho, o desenvolvimento e a integração dos dispositivos analíticos em papel é uma alternativa abrangente, confiável e de baixo custo para a análise da qualidade de águas ambientais.
The lack of access to safe water remains as a public health problem in Brazil. The development of new analytical methods for low cost contaminated samples recognition is necessary since the complete laboratorial procedures are away from the reality of the most socioeconomic vulnerable population. In order to contribute to solve this problem, this thesis shows our efforts to develop new low-cost analytical methods to evaluate environmental waters quality. The combination of chemometric tools with voltammetric sensors was studied to discriminate contaminated water samples with electroactive species. The proposed model was able to discriminate potable and contaminated samples containing lead(II), copper(II), zinc(II) and nitrite species. Efforts to reduce the analysis cost have also focused on the development of sensors using low-cost materials. A proposed voltammetric device fabricated with paper, graphite and wax was able to quantify heavy metals and pesticides. The use of a sound agitation system for the portable voltammetric devices resulted in a significant increase in the sensitivity allowing the quantification of lead(II) above 48 nmol L-1, cadmium(II) above 370 nmol L-1 e and zinc(II) above 340 nmol L-1 . Another voltammetric sensor was made for the first time using only cardboard as material and a CO2 laser to pyrolyze the cardboard surface generating conductive carbon structures. Paper colorimetric sensors were successfully tested for fluoride quantification in spring water samples based on photographs taken by a smartphone with a LOQ of 500 µmol L-1. Another paper colorimetric system was capable to measure the pH of samples using a multivariate calibration method. As shown in this thesis, the development and integration of analytical paper-based devices is a reliable and low-cost alternative for water quality analysis

A proposta da presente tese foi desenvolver dispositivos inteligentes (língua e nariz eletrônicos/ colorimétrico) de baixo custo para discriminar amostras de alimentos contaminados quimicamente e biologicamente. Um dispositivo \"optoeletrônico\" à base de membranas poliméricas coloridas com indicadores de pH foi utilizado para discriminar compostos voláteis emitidos por micro-organismos (aminas liberadas pelos processos de deterioração dos alimentos e que são produto da descarboxilação de aminoácidos em alimentos predominantemente proteicos). As aminas avaliadas nesse estudo foram: isobutilamina, isopentilamina e trietilamina. O limite de detecção de 5 ppm das aminas foi alcançado utilizando o dispositivo \"optoeletrônico\" e, esse sistema, também foi testado em amostras reais de carne contaminadas obtendo uma boa discriminação das amostras com e sem as aminas. Aminas biogênicas (cadaverina, tiramina e putrescina) também foram testadas obtendo uma separação pelo gráfico de escores. Em uma segunda etapa o dispositivo também foi avaliado para discriminar quatro espécies de bactérias (Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis e Escherichia coli) incubadas a 37°C e 25°C. Em ambos os casos o dispositivo inteligente utilizou um smartphone para registrar as imagens que atuou como detector para extração dos dados de RGB das imagens. A partir dessas informações (valores de RGB), as ferramentas quimiométricas PCA (do inglês Principal Component Analysis, Análise de Componentes Principais) e HCA (do inglês Hierarchical Cluster Analysis, Análise de Agrupamentos Hierárquicos) foram utilizadas para discriminar as amostras e a k-NN (do inglês kth Nearest Neighbor, k- vizinhos mais próximos) para validar o método. Em uma terceira etapa, uma língua eletrônica voltamétrica foi fabricada para discriminar amostras de leite adulteradas com melamina, ureia e formaldeído contendo concentrações finais de 0,95; 4,16 e 10,0 mmol L-1, respectivamente. Essa língua voltamétrica foi composta por três eletrodos metálicos: platina, ouro e cobre e dados voltamétricos foram utilizados como dados de entrada para as ferramentas quimiométricas (PCA e HCA). Foram testados três tipos de leite (integral, desnatado e semidesnatado) de três diferentes marcas e todos eles puderam ser discriminados com sucesso. O trabalho também apresenta a utilização de MIPs (polímeros molecularmente impressos - do inglês, molecularly imprinted polymers) como alternativa para detecção e discriminação de alimentos contaminados fazendo uso da impressão (cavidades) de substâncias químicas contaminantes ou das proteínas específicas de cada micro-organismo presente no processo de deterioração dos alimentos
The present thesis aimed at development of low cost smart devices (electronic tongue and colorimetric nose) to discriminate chemically and biologically contamination in food samples. An \"optoelectronic\" plastic-based device with colored membranes contained pH indicator was used to discriminate volatile compounds released by microorganisms, due to the deterioration process of protein in food by the organisms. The amines evaluated in this study were: isobutylamine, isopentylamine and triethylamine, achieving a detection limit of 5 ppm. Such system was also tested in real meat samples contaminated with individual amines obtained a good discrimination of samples with and without studied compounds. Biogenic amines (cadaverine, tyramine and putrescine) were also tested and discriminated. In a second step, the device was also evaluated to discriminate four bacteria species (Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis and Escherichia coli) incubated at 37 ° C and 25 ° C. In both cases, a smartphone was used as detector to extract RGB values of the samples. From extracted information (RGB values), the chemometric tools PCA (Principal Component Analysis) and HCA (Hierarchical Cluster Analysis) were used to discriminate samples and k-NN (kth Nearest Neighbor) was evaluated to validate the method. In a third stage, a voltammetric electronic tongue was developed to discriminate adulterated milk samples with melamine, urea and formaldehyde. This voltammetric electronic tongue was fabricated using three working electrodes: platinum, gold and copper and the voltammetric data was used as input data for chemometric tools (PCA and HCA). Three types of milk (whole, skimmed and semi-skimmed) from three different brands were tested and all of them could be successfully discriminated

Ceramics are among the most useful artifact types in historical archaeology. Identifying different earthenware types is often difficult, especially when the sherds lack diagnostic features. The purpose of this study was to determine if the colors of ceramics can be used to identify pearlware, creamware, and whiteware sherds that lack diagnostic features. A colorimeter was used measure the color of the glazes and pastes from 1929 scans of sherds categorized by experts in museum collections. Several statistical tests were performed on the data set, including ANOVA, multiple comparison, and discriminate analysis. Results from ANOVA indicated that creamware, pearlware and whiteware had different mean color values. Multivariate analysis was used to group the observations and indicated that color can be used to identify creamware, pearlware, and whiteware, but only if a color standard can be generated to compare against because colorimetric analysis can roughly duplicate the results of a single expert.

Alfredo Volpi (1896 - 1988) é um dos mais importantes pintores brasileiros contemporâneos. Sua extensa obra foi marcada, principalmente, por composições cromáticas e abstrações geométricas. Foi um artista que dava importância muito grande à técnica e aos materiais, tendo desenvolvido uma maneira própria e sistemática de trabalhar: confeccionava suas próprias telas, tintas e até pigmentos, com terras naturais. Analisou-se ao todo 11 pinturas a têmpera em diversos suportes (tela, aglomerado de madeira e mural), 10 delas realizadas na década de 1950, período em que a obra do artista passou por uma grande transformação, do figurativismo ao abstracionismo e do uso de tintas industriais à base de óleo para a técnica medieval da têmpera. As características de opacidade, saturação cromática e presença material do pigmento sobre a superfície da tela, inerentes a esta técnica pictórica, tornam-se elementos tão importantes em sua obra, quanto o uso da cor na formação do espaço. Foram realizados estudos de cor e composição química dos materiais e levantamentos de informações sobre seus procedimentos técnico-artísticos a partir de métodos analíticos complementares não destrutivos e pesquisa em diversas fontes, pois entende-se que estes elementos são chaves importantes para o entendimento mais profundo de sua obra. O espectrofotômetro foi utilizado para medição da cor com base em curvas espectrais e coordenadas numéricas de referência dentro de um espaço de cor uniforme. Técnicas de imageamento por luz visível, fluorescência visível por radiação ultravioleta e reflectografia de infravermelho próximo foram utilizadas para levantar informações sobre o processo criativo do artista, detectar locais de intervenções de restauro e observar o grau de fluorescência de cada área cromática das pinturas como auxiliar na identificação de pigmentos. A técnica de EDXRF (Espectroscopia de Fluorescência de Raios X por Energia Dispersiva) foi importante para caracterização química dos materiais. O MEV-EDS (Microscópio Eletrônico de Varredura com Espectroscopia por Dispersão de Energia de Raios X) forneceu informações sobre composição química e imagens da superfície dos materiais presentes nas pinturas murais. A partir da integração destas informações pôde-se identificar uma parte da rica paleta deste pintor, documentar as cores das pinturas no presente, identificar ou dar indicações da composição dos pigmentos e da base de preparação das pinturas e iluminar partes da história de cada uma das obras, como presença de esboços feitos à grafite, pinturas anteriores encobertas, pinceladas e maneiras de misturar a tinta e documentar seu estado atual de conservação. As ferramentas utilizadas se mostraram úteis na caracterização das pinturas, revelaram informações inéditas sobre a obra deste artista e levantaram novas indagações. As informações obtidas podem ser o início de um banco de dados sobre sua obra.
Painter Alfredo Volpi (1896 - 1988) is one of the most important contemporary Brazilian artists. His extensive work, mostly characterised by chromatic compositions and geometric abstractions, is technically unique. The artist attributed great importance to craft and materials, developing his own systematic way of working. Among the paintings analysed were 11 temperasin various supports (canvas, hardboard panel and mortar). Of the selection, 10 paintings were made around 1950, when the artist\'s work underwent a major transformation, from figuration to abstraction, from the use of industrial oil-based paints to the medieval technique of tempera. This technique, known for its opacity, colour saturation and material presence of pigments on the canvas,became as important as the colour itself in the shaping of the artist\'s new spatial relation. It is understood that these elements are important keys to a deeper understanding of his work, both technically and artistically. The present investigation was carried out making use of non-destructive complementary analytical techniques. The aim was to study the chromatic and chemical composition characteristics of his paintings and gather information on the technical procedures the artist may have used. The spectrophotometer was used to measure the colour based on the spectral curves and numerical reference coordinates within a uniform colour space. Techniques of visual examination with visible light, visible fluorescence by ultraviolet radiation and near-infrared reflectography were used to gather information about the artist\'s creative process. These techniques also helped detect restoration patches and identify pigments. The EDXRF (Energy Dispersive X-Ray Fluorescence) technique was important for chemical characterization of materials, while the SEM-EDS (Scanning Electron Microscope with Energy Dispersive X-Ray Spectroscopy) provided surface images and information on the chemical composition of the material present in the murals. From the integration of these techniques it was possible to identify a part of the rich palette of Volpi´s paintings; to document the present aspects of the colours; to recognize or give indications of pigment and ground compositions and to shed light on parts of each of the works background, such as the presence of graphite sketches, covered earlier paintings and brushstrokes as well as to document the current condition of the works under study. The tools used have proven useful in characterizing the paintings, revealing new information about the work of the artist and raising new questions. The information obtained may be the beginning of a database on his oeuvre.

To works of art is often assigned a specific value of cultural and expressive testimony of an artist or, more generally, of a culture. Preserve this value means keeping intact the appearance of the work and its component material in order for the message to reach the public, without alteration. A good knowledge of the materials constituting the work is needed to preserve them appropriately. My research work is focused on the study of modern and contemporary paintings and of materials used, which are not well known compared to traditional materials. The main goal of this work was to investigate some of the most popular art materials to track even the weakest changes, which are index of degradation and occur in the form of chromatic alterations. Image spectroscopy (IS) was the scientific technique on which we focused the attention, since it helps to reveal early alterations using imaging, in a complete non-invasive way. Spectral data in the VIS-NIR range were processed by multivariate statistical analysis. The use of Principal Component Analysis (PCA) on IS spectra was applied to modern painting materials, as Titanium White, Artificial Ultramarine Blue in acrylic and oil binders in a test panel. IS + PCA has proven to be an effective method for the early identification of chromatic alterations, although of faint amounts. Moreover, colorimetric data have provided useful and complementary information, recognizing the alterations trends. Unexpectedly, IS has also demonstrated a discriminant power for some materials. The most striking case was the identification of white Lithopone for an absorption band in the visible range, due to the presence of cobalt as vicariant element of Zinc. The knowledge of changes in the chemical composition of this pigment in a specific time period has allowed the recognition of a fake in contemporary artwork. Other scientific methodologies have been used. X-ray fluorescence was used to collect more detailed information about the materials. This can be the case of examinations on Jean Metzinger’s work, present in the Peggy Guggenheim Collection (Venice). Image diagnostics, as Ultraviolet fluorescence, Wide band infrared reflectography, have proved useful to collect information on the state of conservation of works in non-quantitative way. The common features of such techniques are to be non-invasive, non-destructive, to be used in situ.

This research aims to understand the organization of activities across a prehispanic urban center at the Formative period site of Tlalancaleca (800 BC- AD 100), located in Puebla, Mexico. This study analyzes soil samples at the central civic-ceremonial complex of Cerro Grande in an attempt to understand the use of space. This work is a part of the larger Proyecto Arqueológico Tlalancaleca, Puebla (PATP), which is focused on understanding the socio-political organization at Tlalancaleca that led to this site of early urbanism. Soil samples from Tlalancaleca are analyzed using three chemical methods to perform a cross-comparison of analytical methods. These three methods are inductively coupled plasma-optical emission spectrometry (ICP-OES), Mehlich 3 soil phosphorus colorimetry, and portable X-ray fluorescence (pXRF) spectrometry. The final results of this soil analysis confirm that the Cerro Grande Complex was an actively used space, with areas maintained for specific uses and areas where activities changed over time. In the comparison of methods, ICP-OES was found to be the most comprehensive, precise, and accurate method to use, while pXRF and Mehlich colorimetry were found to show differing information with regards to available and natural concentrations of the different elements. An analytical examination of phosphorus, strontium, calcium, and barium revealed evidence of construction of monumental buildings, a cache, and possible separate feasting areas, indicating that physical spaces and constructions were likely attached to social and political organizations.

Orientadores: Pedro Eduardo de Felicio, Expedito Tadeu Facco Silveira
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O presunto cru é um produto fermentado tradicional e com longo período de maturação, apreciado particularmente nos países da Península Ibérica e Itália. No Brasil seu consumo é pequeno, devido ao preço relativamente elevado. Assim, foi realizado um trabalho visando o desenvolvimento de um produto com características similares aos presuntos crus tradicionais, mas com um tempo de processo menor e com provável redução de custos de produção. Através de avaliações sensoriais e instrumentais foram analisados 4 produtos tradicionais e 2 produtos elaborados no presente trabalho de pesquisa com 3,5% ou 5,0% de sal, denominados CTC 3,5% e CTC 5,0%. Foram realizadas medidas de cor do sistema Hunter Lab. As amostras se dividiram em dois grupos com relação à luminosidade e teor de vermelho: luminosidade - produtos mais claros (presuntos CTC) e produtos mais escuros (Serrano, Tipo Serrano, Italiano e Tipo Parma), e cor vermelha - presuntos com maior teor de vermelho (Italiano e Tipo Serrano) e presuntos com menor teor (CTC 3,5%, CTC 5,0%, Serrano e Tipo Parma). Na avaliação instrumental de textura através de TPA - Análise de Perfil de Textura, os produtos que mostraram perfis texturais mais distintos foram os presuntos do CTC em relação ao Italiano. Os presuntos CTC obtiveram os maiores valores de dureza, elasticidade, coesividade e mastigabilidade, enquanto o presunto Italiano apresentou os menores valores. Análise Descritiva Quantitativa (ADQ) foi aplicada para definição de atributos sensoriais de presuntos crus. Os dados foram analisados utilizando análise de variância, teste de Tukey e Análise de Componentes Principais (ACP). Na ADQ, 18 descritores foram utilizados para caracterizar as amostras. Os produtos se diferenciaram pelos seguintes atributos: CTC 3,5% - sabor mais ácido e menor intensidade de aroma e sabor de ranço, vermelho e suculência; CTC 5,0% - maior fibrosidade e menores notas de intensidade e persistência de sabor, e maciez; Serrano - maiores intensidades de aroma de ranço, vermelho, intensidade e persistência de sabor e menor sabor salgado; Tipo Serrano - maior intensidade de sabor de ranço e menor intensidade de sabor doce; Italiano - maiores intensidades de sabor salgado e maciez; Tipo Parma - sabor de carne, marmoreado e amarelo da gordura mais intensos. A ACP separou as amostras em dois grupos: (1) um formado pelos presuntos CTC 3,5%, Serrano e Italiano, caracterizado principalmente pelos atributos aroma e sabor de carne, aroma e sabor ácido, aroma e sabor doce e fibrosidade, e (2) outro formado pelos presuntos CTC 5,0%, Tipo Serrano e Tipo Parma, que se diferenciou do primeiro principalmente pelos descritores sabor salgado, marmoreado e maciez. As mesmas amostras foram avaliadas com relação a sua aceitação, utilizando escalas hedônicas de 9 pontos, e preferência pelos consumidores. Foram realizados dois testes afetivos: (1) um teste de aceitação onde as 6 amostras foram avaliadas e (2) um teste de aceitação e de preferência onde apenas os dois produtos elaborados no CTC foram avaliados. Os dados dos dois testes foram analisados utilizando análise de variância e teste de Tukey. Além disso, os dados de aceitação global do primeiro teste foram analisados através do Mapa de Preferência Interno (MDPREF). Os resultados dos testes afetivos mostraram que todos os tipos de presunto cru analisados obtiveram a maioria de suas notas da avaliação pelos consumidores entre gostei ligeiramente e gostei muitíssimo. De maneira geral, o presunto Tipo Serrano foi o produto que obteve o maior percentual de notas na faixa de aceitação da escala e o Serrano foi o que obteve o menor percentual. O MDPREF evidenciou quatro segmentações das amostras, em ordem decrescente de aceitação pelos consumidores: (1) um composto pelas amostras de presunto cru Italiano e Tipo Serrano, (2) um referente às duas amostras do CTC, (3) um formado pelo presunto Tipo Parma e (4) o último representado pelo presunto Serrano. Os dois produtos CTC (3,5 e 5,0%) apresentaram níveis similares de aceitação pelo consumidor e não diferiram (p>0,05) no teste de preferência pelos consumidores
Abstract: The dry cured ham is a traditional fermented product with a long period of maturation, appreciated particularly in countries of the Iberian peninsula and Italy. In Brazil its consumption is small, because of the price relatively raised. Thus, the development of a product with similar characteristics was carried aiming at the traditional dry cured hams, but with a reduced process time and probable reduction of production costs. Through sensorial and instrumental evaluations 4 traditional products and 2 products elaborated in this present work of research with 3.5 or 5.0% of salt, named CTC 3,5% and CTC 5,0%, had been analyzed. Color was measured by Hunter Lab Color System. The samples were divided in two groups with regard to luminosity and red content: luminosity - clearer products (CTC hams) and darker products (Serrano, Type Italian and Parma Type), and red color - (Italian and Parma Type) and hams with less content (CTC 3,5%, CTC 5,0%, Serrano and Parma Type). In the instrumental evaluation of texture through TPA ¿ Texture Profile Analysis, the products that have shown more distinct texture profiles were the hams of the CTC in relation to the Italian. The CTC dry cured hams had the biggest values of hardness, springiness, cohesiveness and chewiness, while the Italian ham presented the smaller values. Quantitative Descriptive Analysis (DQA) was applied for definition of sensorial attributes of dry cured ham. The data were analyzed using analysis of variance, Tukey Test and Principal Components Analysis (PCA). In the ADQ, 18 descriptors had been used to characterize the samples. The products were differentiated for the following attributes: CTC 3,5% - more acid flavor and less intensity of rancid odour and flavor, redness and juiciness; CTC 5,0% - higher fibrousness and lower scores of flavor intensity and persistence, and softness; Serrano - bigger intensities rancid flavor, redness, flavor intensity and persistence and minor salty flavor; Serrano Type - highest intensities rancid flavor and less sweet intensity flavor; Italian - highest salty flavor and softness; Parma Type - highest meaty flavor, marbling and fat yellowness. PCA separated the samples in two groups: (1) one formed for CTC 3,5%, Serrano and Italian dry cured hams, mainly characterized for the attributes meaty odour and flavor, acid odour and flavor, sweet odour and flavor and fibrousness, and (2) other formed by the CTC 5,0%, Serrano Type and Parma Type hams, that was differentiated mainly of first group for the descritors the salty flavor, marbling and softness. The same samples were evaluated with regard to its acceptance, using hedonic scales of 9 points, and preference of the consumers. Two affective tests were carried through: (1) one was tested of acceptance where the 6 samples were evaluated and (2) one was tested of acceptance and preference where only the two products elaborated in the CTC were evaluated. The data of the two tests were analyzed using variance analysis and Tukey Test. Moreover, the data of global acceptance of the first test was analyzed through the Internal Preference Map (MDPREF). The results of the affective tests had shown that all the types of dry cured ham analyzed had the majority of its notes of the evaluation for the consumers between I liked slightly and I liked very much. In general way, the ham Serrano Type was the product that got the percentile greater of notes in the region of acceptance of the scale and Serrano was what it got the percentile minor. The MDPREF evidenced four segmentation of the samples, orderly decreasing of acceptance for the consumers: (1) a composition for the samples of Italian and Serrano Type dry cured hams, (2) a referring one to two samples CTC, (3) one formed for Parma Type ham and (4) the last one represented for the Serrano ham. The two products elaborated in the CTC had presented similar levels of acceptance for the consumer. They don¿t differ (p>0.05) in the preference test with consumers
Mestrado
Tecnologia de Alimentos
Mestre em Tecnologia de Alimentos

Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007.
Committee Chair: Sheldon May; Committee Members: Nicholas Hud, Stanley Pollock, James Powers, and Gerald Pullman. Part of the SMARTech Electronic Thesis and Dissertation Collection.

This master’s thesis studies the effect of weathering on thermally modified Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) with different surface treatments. Most importantly colour changes were analysed, especially, the greying. However, other aspects of appearance changes, like cracks, mould and chemical changes on the surface were included. Special emphasis was on analysing the influence of tree species, type of thermal modification and surface treatment on these properties. Furthermore, it was tested if near infra-red (NIR) spectroscopy allows to estimate the colour, in addition, to measuring chemical changes. The whole study was set up as a decking of a gangway in Northern Sweden and evaluated after the first year of exposure. With the help of colorimetry, changes in colour based on the CIE L*C*hab colour space were measured. Test results showed that within one year all surfaces turned greyer significantly due to changes in content of lignin and cellulose measured with NIR spectroscopy. Differences could neither be observed between the uses of the two tree species nor between the uses of the thermal modifications, pressurised saturated steam at a temperature of 180 °C and superheated steam at a temperature of 212 °C. However, the surface treatment affects the colour change. Timber treated with a silicon based treatment had from the beginning a greyer colour and turned greyest after one year, while oil and pigmented oil stain slowed down the greying compared to untreated and iron vitriol treated timber. After one year of exposure for none of the treatments the colour had stabilised. Qualitative analysis of cracks and mould growth on the surface indicated some dependence on thermal modification and surface treatment. The PLS model for the prediction was not good, so no universally valid conclusions could be drawn of them. Timber with silicon based treatment showed a tendency for mould growth and timber thermally modified with pressurised saturated steam at a temperature of 180 °C tends to have cracks more often. It was possible to estimate the colour from NIR spectroscopy. Best estimations were achieved for the Chroma, followed by lightness and hue. Even better prediction of the Chroma could be achieved by fitting different models based on the surface treatments.  Hence, NIR spectroscopy allows a good estimation of the greying without needing a further measurement instrument, like a colorimeter.

La coloration d'un béton, matériau faiblement chromatique, est obtenue soit par introduction de pigments dans son volume, soit par application d'un revêtement coloré sur sa surface. Ces travaux de thèse s'intéressent à une voie de coloration alternative innovante, qui consiste à introduire les pigments dans l'agent de décoffrage afin qu'ils soient transférés durablement vers la surface du béton frais au moment où celui-ci est coulé dans le coffrage. Cette méthode s'apparente beaucoup à la technique de peinture à fresque, qui a largement fait ses preuves en terme de durabilité. Dans un premier temps, l'étude de fresques sur chaux et sur ciment anciennes, ainsi que de reconstitutions, a permis d'identifier les principaux paramètres qui régissent le dépôt des pigments et leur adhésion durable au support : compatibilité du liant avec l'eau capillaire de l'enduit, granulométrie des pigments,cisaillement du pinceau à la surface de la fresque. Dans un second temps, la transposition de ces paramètres au cas du béton a conduit à l'identification de solutions satisfaisantes en terme de transfert et de durabilité de la couleur, mais aussi d'état de surface du béton (rugosité, porosité, homogénéité) : remplacement de l'huile de décoffrage par des tensioactifs non ioniques de faible viscosité et emploi de pigments correctement dispersés dans l'agent décoffrant. Finalement, l'étude des interfaces béton- agent décoffrant - coffrage a montré que le transfert durable des pigments repose sur un double mécanisme de démouillage de l'agent décoffrant par le béton en écoulement et de mélange des deux phases au niveau du front de la coulée, qui aboutit à la formation d'une inter phase pigments - béton de plusieurs dizaines de micromètres d'épaisseur. La profondeur de pénétration des pigments sous la surface a pu être quantifiée grâce à la combinaison d'observations en microscopie électronique à balayage et d'analyses en spectroscopie de rétrodiffusion Rutherford. La durabilité de la coloration a été évaluée par des mesures colorimétriques dans l'espace CIELab.