No description available.

Inhalation of respirable coal mine dust (RCMD) can lead to chronic lung diseases, including coal worker’s pneumoconiosis (CWP) and more severe forms such as progressive massive fibrosis. After the Federal Coal Mine Health and Safety Act was passed in 1969, limits on exposure to respirable dust were set, and the prevalence of CWP abruptly decreased. However, during the last two decades, a resurgence of the disease has been reported. Many authors have argued that the increasing numbers might be related to mining practices, including the extraction of thinner coal seams, characteristics of the mineral deposits, and more powerful cutting machines. Dust particles in coal mines are usually associated with three main sources: Coal particles are produced when the coal seam is being actively extracted. Silica and silicates are generated while cutting the rock strata surrounding the coal or during roof-bolting activities. Finally, rock dust application is the primary source of highly pure carbonates. Timely information about dust composition would allow the identification of potential dust sources and pursue efforts to control dust exposure efficiently. However, this information needs to be provided promptly since dust levels are dynamically changing through the shift. Currently, monitoring technologies such as the continuous personal dust monitor allow real-time measurements, but they are limited to total dust concentration and provide no information about dust composition. More recently, the National Institute for Occupational Safety and Health (NIOSH) has been developing an end-of-shift silica monitor. Still, technologies that offer information on dust composition in a semi-continuous manner are needed. In this work, a new monitoring concept is explored that has the potential to provide near real time data on RCMD constituents. The possible use of a portable optical microscopy (OM) combined with image processing techniques is explored as the basis for a novel RCDM monitoring device. The use of OM in different fields and the rapid development of automated image analysis reveals a clear opportunity that has not been yet exploited for mine dust monitoring applications. This thesis research consisted of two primary studies. The first was an analysis of lab-generated respirable dust samples containing the main mineralogical classes in RCMD (i.e., coal, silica, kaolinite as a proxy for silicate minerals, and a real rock dust product). Samples were imaged using a polarizing microscope and analyzed using an image processing routine to identify and classify particles based on optical characteristics. Specifically, birefringence of particles was exploited to separate coal particles form mineral particles. This is an exciting result since even such a basic fractionation of RCMD would be valuable to track changing conditions at the mine production face and enable rapid decision making. The second study was conducted to explore subclassification of the mineral fraction. A model was built to explore multiple particle features, including particle size, shape, color, texture, and optical properties. However, a simple stepwise method that uses birefringence for separating coal particles first and then classifying silica particles proved most effective. One particular challenge to the silica classification was determined to be the particle loading density. Future work to further enhance the output of the algorithm and next steps were depicted. This thesis research demonstrated that OM and image processing can be used to separate mineral and coal fractions. Subclassification of silica and other minerals using optical properties such as birefringence of particles alone was successful, but showed less accuracy. A robust sampling method that accounts for particle loading density and a more complex model with additional differentiating features might enhance the results. This approach should be considered as a potential candidate for the development of new RCMD monitoring technologies. This tool could enable better tracking of dust conditions and thus better decision-making regarding ventilation, dust controls, and operator position to reduce exposure hazards. / M.S. / Inhalation of fine particles in underground coal environments can lead to chronic lung diseases, such as coal worker’s pneumoconiosis or progressive massive fibrosis (PMF), which is the most severe form of disease. During the last two decades, the rates of reported cases of PMF in underground coal miners have more than doubled. Many authors have suggested different reasons to explain this trend, including the extraction of thinner coal deposits, mining techniques, changes in mineral content, and the use of high-powered cutting equipment. However, detailed information of specific dust constituents and monitoring the variability of dust concentrations during work shifts are needed to determine possible dust sources and comprehend the more recent changing disease patterns. A dust-monitoring system that provides accurate and timely data on specific respirable coal mine dust (RCMD) constituents would enable the deployment of effective control strategies to mitigate exposure to respirable hazards. Optical microscopy (OM) has been used for a long time to analyze and identify dust particles. More recent advances in portable microscopy have allowed the microscope analysis to be implemented in the field. On the other hand, automated image processing techniques are rapidly progressing and powerful imaging hardware has become a reality in handy small devices. OM and image processing technologies offer a path for near real-time applications that have not been explored for RCMD monitoring yet. In this work, a novel monitoring concept is explored using OM and image processing to classify RCMD particles. Images from dust samples captured with a polarizing microscope were used to build a classification model based on optical properties. The method herein described showed outstanding accuracy for separating coal and mineral fractions. Additionally, the Identification of silica particles in the mineral fraction was investigated and has proved more challenging. A particular finding suggests that particle loading density in the images plays an important role in classification accuracy.

L’imagerie de filtrage en polarisation est une technique populaire largement utilisée en optique pour le biomédical pour le sondage des tissus superficiels, pour le sondage de volumes plus profonds, mais aussi pour l’examen sélectif de volumes sub-surfaciques. Du fait de l’effet de ’mémoire de polarisation’ de la lumière polarisée, l’imagerie de filtrage en polarisation elliptique est sensible á des épaisseurs de tissus différentes, depuis la surface, accessible avec la polarisation linéaire, jusqu’á une épaisseur critique accessible par la polarisation circulaire. Nous nous concentrons sur des méthodes utilisant des combinaisons de polarisations elliptiques afin de sélectionner la portion de lumière ayant maintenu son état de polarisation et éliminer le fond pour un meilleur contraste avec de plus une information sur la profondeur. Avec ce type de filtrage, il est possible d’accéder á des profondeurs de tissus biologiques bien définies selon l’ellipticité de polarisation. De plus, ces travaux ont permis d’étendre la méthode á la spectroscopie pour quantifier la concentration en chromophores á une profondeur spécifique. Les méthodes développées ont été validées in vivo á l’aide d’expériences réalisées sur des anomalies de la peau et aussi sur le cortex exposé d’un rat anesthésié. Enfin, une étude préliminaire a été réalisée pour examiner la possibilité d’étendre la méthode á l’imagerie de 'speckle'. Des tests préliminaires réalises sur fantômes montrent l’influence de l’ellipticité de polarisation sur la formation et le comportement du speckle, ce qui offre la possibilité d’accéder á des informations sur le flux sanguin á des profondeurs spécifiques dans les tissus. / Polarization gating imaging is a popular and widely used imaging technique in biomedical optics to sense tissues, deeper volumes, and also selectively probe sub-superficial volumes. Due to the ‘polarization memory’ effect of polarized light, elliptical polarization gating allows access to tissue layers between those of accessible by linear or circular polarizations. As opposed to the conventional linearly polarized illumination, we focus on polarization gating methods that combine the use of elliptically polarized light to select polarization-maintaining photons and eliminate the background while providing superior contrast and depth information. With gating, it has also become possible to access user-defined depths (dependent on optical properties) in biological tissues with the use of images at different ellipticities. Furthermore, this investigation allowed the application of polarization gating in spectroscopy to selectively quantify the concentration of tissue chromophores at user-desired depths. Polarization gating methods have been validated and demonstrated with in vivo experiments on abnormalities of human skin (nevus, burn scar) and also on the exposed cortex of an anaesthetized rat. Finally, as a first step towards the use of coherent illumination, adding the concept of polarimetry to laser-speckle imaging was demonstrated. Preliminary tests on phantoms (solid and liquid) suggested evidence of the influence of polarization ellipticity on the formation and behaviour of speckles, which could pave the way for more insight in the study of blood flow in tissues.

La transferencia nuclear de células somáticas (SCNT) en la especie porcina se ha convertido en una herramienta muy útil para para la elaboración de modelos genéticos de enfermedades humanas y para el uso en xenotransplantes. Aunque el número de cerdos clonados aumenta cada año, la eficiencia total de esta tecnología es todavía muy baja. Uno de los pasos más difíciles de la SCNT en porcino es la enucleación del ovocito, principalmente debido a que su citoplasma contiene numerosas gotas lipídicas. El principal objetivo de la tesis fue evaluar el efecto de diversas técnicas para visualizar la placa metafásica y el corpúsculo polar sobre la capacidad de desarrollo de ovocitos porcinos madurados in vitro. / Somatic cell nuclear transfer (SCNT) technology in porcine has become a very useful tool for the elaboration of genetic models for human diseases and the use in xenotransplantation. The efficiency of SCNT is still very low, although the number of cloned pigs increases each year. One of the hardest steps of porcine SCNT is the enucleation of the oocyte because its cytoplasm contains many lipid droplets. The main objective of this thesis was to assess the effect of several approaches to visualize the metaphase II plate and the first polar body on the developmental ability of in vitro mature porcine oocytes.

No description available.

The purpose of this work was to explore the use of fractional evaporative crystallization as a technology that can be used to separate medium-curie waste from the Hanford Site tank farms into a high-curie waste stream, which can be sent to a Waste Treatment and Immobilization Plant (WTP), and a low-curie waste stream, which can be sent to Bulk Vitrification. Experimental semi-batch crystallizations of sodium salts from simulant solutions of double-shell tank (DST) feed demonstrated that the recovered crystalline product met the purity requirement for exclusion of cesium and nearly met the requirement on sodium recovery. Batch fractional evaporative crystallization involves the removal of multiple solutes from a feed solution by the progressive achievement of supersaturation (through evaporation) and concomitant nucleation and growth of each species. The slurry collected from each of these crystallization stages was collected and introduced to filtration and washing steps. The product crystals obtained after washing were sampled for analysis by polarized light microscopy (PLM), dried, and sieved. The PLM results aided in identification of species crystallized in each stage. Carbonation was used as a supplemental method to evaporative crystallization in order to increase the sodium recovery in DST experiments. Carbonation was necessary due to the high aluminum ion concentration in the solution, which leads to formation of a viscous gel during evaporation. This gel was avoided by reacting carbon dioxide with hydroxyl ions, which modified the system behavior. Through two stages of carbonation, each followed by evaporation, the effect of carbonation on sodium recovery was demonstrated.

Made available in DSpace on 2015-05-14T12:56:05Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2455029 bytes, checksum: 0889fcfcf64d79338e5014d0a4360899 (MD5) Previous issue date: 2009-12-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main effect of the microabrasion in the enamel is significant erosion. However, there is a gap in the literature about validated and reproducible assessment of the depth of erosion in the enamel surface which is originally curve. AIMS: Evaluate depth of erosion and mineral loss of enamel produced by microabrasion technique in original coronary surface of human teeth. METHODS AND MATERIALS: 40 extracted human molars were randomly spited in four groups, with 10 specimens each, in accordance with the microabrasive treatment: AC- 18% hydrochloric acid and pumice, AF 37% phosphoric acid and pumice, OP Opalustre and WRM Whiteness RM. Each specimens had buccal surface´s laterals isolated so that the central area received the microabrasion treatment. After this procedure, transverse slices not demineralized were prepared and submitted to microradiography and analysis in Polarized Light Microscope. One own terminology had created for the morphology of the interface enamel normal-microabrasioned. This served as base to introduction of a profilometry technique with analysis of digital images, in order to get the depth of erosion on microabrasion´s area. The Intraclass Correlation Test was applied to test technique´s reproducibility. The mineral loss and the depth which it happened had analyzed by transverses plotted at equidistant points of the limit enamel normal-microabrasioned. The dates were analyzed with ANOVA test (p < 0.05). RESULTS: The profilometry technique achieved a good reproducibility (Intraclass Correlation Test of 0,9998) and was validated internally. The AC group was the most aggressive, with a greater depth of erosion (110,51 ± 41,21 &#956;m), and a greater mineral loss (13 ± 3 peso %), with significant difference between WRM group (p < 0,05; 9,41± 4,4 peso %) and OP group (p < 0,05; 9,0 ± 3,8 peso %). The OP group, on the other hand, was the less aggressive, with the lowest values in all parameters analyzed, presenting depth of erosion less than AC group (p < 0,0001), WRM group (p < 0,001; 86,24 ± 27,99 &#956;m) and AF group (p < 0,05; 74,46 ± 42,06 &#956;m). The others two groups achieved intermediate results for depth of erosion and mineral loss. The depth of mineral loss was greater than on AF group (31,38 ± 20,30 &#956;m), however, there wasn´t statistical difference between the groups. CONCLUSIONS: Based on own terminology for the interface enamel normalmicroabrasioned and on the implementation of new technique of profilometry, the agents tested showed a significant difference in the depth of erosion, which was consistent with the mineral loss. However, there wasn´t difference in the depth of mineral loss. Furthermore the new technique of profilometry is proposed to fill a gap in the literature, allowing the determination of physical depth of erosion in areas naturally curves of hard biological tissues. / O principal efeito da microabrasão no esmalte dental é uma erosão significativa. Porém, existe uma lacuna na literatura no que concerne à avaliação validada e reprodutível da profundidade de desgaste na superfície dental natural. OBJETIVOS: Avaliar a profundidade de desgaste e a perda mineral do esmalte dentário resultante da técnica de microabrasão na superfície coronária original de dentes humanos. MATERIAIS E MÉTODOS: 40 terceiros molares humanos extraídos foram divididos aleatoriamente em 4 grupos, de 10 espécimes cada, de acordo com o material microabrasivo utilizado: AC - ácido clorídrico a 18% e pedra-pomes, AF - ácido fosfórico a 37% e pedra-pomes, OP - Opalustre® e WRM - Whiteness RM®. Cada elemento teve as laterais da face vestibular protegidas para que apenas a área central fosse exposta aos agentes microabrasivos. Após o procedimento de microabrasão, cortes transversais não desmineralizados foram preparados e submetidos à radiomicrografia e análise em Microscopia de Luz Polarizada. Uma terminologia própria foi formulada para a morfologia da interface esmalte normalmicroabrasionado. Esta serviu de base à introdução de uma Técnica de Perfilometria com Análise de Imagens Digitais, com o intuito de obter a profundidade de desgaste ao longo da área microabrasionada. O teste de correlação intraclasse foi aplicado para testar a reprodutibilidade da técnica. A quantidade da perda mineral e a profundidade em que esta ocorreu foram analisadas em transversais traçadas em pontos eqüidistantes do limite esmalte normal-microabrasionado. Os dados obtidos foram analisados com o teste ANOVA (p < 0,05). RESULTADOS: A Técnica de Perfilometria obteve uma boa reprodutibilidade (coeficiente de correlação intraclasse de 0,9998) e foi validada internamente. O grupo AC foi o mais agressivo, apresentando a maior profundidade de desgaste (110,51 ± 41,21 &#956;m), e a maior perda mineral (13 ± 3 peso %), com diferenças significantes em relação aos grupos WRM (p < 0,05; 9,41± 4,4 peso %) e OP (p < 0,05; 9,0 ± 3,8 peso %). O grupo OP, por outro lado, foi o menos agressivo com os menores valores para todos os parâmetros analisados, apresentando uma profundidade de desgaste menor em relação aos grupos AC (p < 0,0001), WRM (p < 0,001; 86,24 ± 27,99 &#956;m) e AF (p < 0,05; 74,46 ± 42,06 &#956;m). Os outros dois grupos apresentaram resultados intermediários para profundidade de desgaste e quantidade de perda mineral. Não houve diferença quanto à profundidade de perda mineral CONCLUSÃO: Com base em uma terminologia própria para a interface esmalte normal-microabrasionado e na aplicação de uma nova Técnica de Perfilometria, os agentes testados mostraram uma significativa diferença quanto à profundidade de desgaste, que foi condizente com a perda mineral. A nova Técnica de Perfilometria propõe o preenchimento de uma lacuna na literatura, permitindo a determinação física de profundidade de desgaste em superfícies naturalmente curvas de tecidos biológicos duros.

L’architecture des cellules myocardiques en trois dimensions du cœur normal et malformé est un sujet de recherche initié depuis plusieurs siècles, mais il existe encore des questions non résolues. Cette thèse apporte de nouveaux éléments de réponse grâce à l'utilisation d'une technique originale d'Imagerie en Lumière Polarisée et l'étude d'une période précise du développement des tissus cardiaques, celle de l'adaptation postnatale. Dans cette thèse, nous introduisons deux nouvelles représentations de l'information : un paramètre d'Isotropie régional et la dissection virtuelle à la base de représentation en LIC-3D qui permet l'exploration à volonté des masse ventriculaires selon des angles de coupes arbitraires.Le remodelage ventriculaire physiologique postnatal (étudié sur 16 cœurs) s'accompagne globalement d'une diminution de l'isotropie régionale et localement par l'apparition de zones fortement isotropes dont la topologie est identique aux plans de clivage décrits dans le modèle de Torrent - Guasp. Cette étude apporte pour la première fois des éléments complémentaires pour la description des composantes profondes de la voie de sortie du ventricule droit. L'architecture 3D du septum de sortie, du repli ventriculo-infundibulaire et des « fibres » latitudinales de la paroi de deux ventricules est documentée et précisée dans dix cœurs normaux. Dans une étude de 11 cœurs malformés représentant 7 pathologies différentes, 3 patrons topologiques ont été décrits : 1) le patron normal : Alignement du repli ventriculo-infundibulaire et du septum de sortie, dans les malformations de type de communication interventriculaire ou canal atrio-ventriculaire ; 2) le patron parallèle : le repli ventriculo-infundibulaire et septum de sortie sont parallèles dans la Tétralogie de Fallot ; 3) le patron en V : le repli ventriculo-infundibulaire dans les cœurs avec discontinuité musculaire mitro-artérielle.En conclusion, nous apportons des nouveaux éléments de compréhension de la mise en place de l'architecture du myocarde en situation normale et pathologique. Cependant, ces données nouvelles devront être consolidées statistiquement sur un plus grand nombre de cas. Elle devront être confrontées aux données physiologiques observables grâce au méthodes d'imagerie fonctionnelle. / The 3D architecture of the ventricular mass is poorly known, although in vivo imaging techniques show the physiological inhomogeneity of transmural myocardial mechanics. Polarized light imaging makes it possible to quantitatively analyse the myocardial cell orientation to study the regional isotropy of myosin filaments (a new parameter) and to provide virtual dissection (a new tool) of the myocardial ventricular mesh. This deep inside is complementary of superficial anatomical description.Sixteen normal hearts of human term stillbirths, newborns and infants were studied. During the first months of postnatal age, the median regional isotropy values decreased in the ventricular three-dimensional mesh. There was a progressive appearance of a particularly inhomogeneous secondary arrangement of myocardial cells with alternation of thick low-RI and thin high-RI areas. The topology of Torrent-Guasp' cleavage plans and intercalated high RI areas were identical. The outlet septum was constantly identified.Eleven malformed hearts were studied. The deep components of the ventriculo-infundibular fold, the outlet septum and the latitudinal fibres of the ventricular walls were described and 3 different patterns could be portrayed : 1) a normal aligned pattern ; 2) a parallel pattern of the ventriculo-infundibular fold and the outlet septum in Tetralogy of Fallot ; 3) a V pattern of the ventriculo-infundibular fold in heart with mitro-arterial muscular discontinuity.To conclude, we uncover new elements to understand the onset of the myocardial architecture in normal and pathological hearts. However, this new data need to be statistically consolidated by studying a greater numbers of cases. As a perspective, these observations will be confronted to physiological data provided by functional imaging technique.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-08-11T12:22:28Z No. of bitstreams: 1 robertosottomaiorfortesdeoliveira.pdf: 16646767 bytes, checksum: fbcd339691975b226d2d9a290fdd5b18 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-11T12:57:06Z (GMT) No. of bitstreams: 1 robertosottomaiorfortesdeoliveira.pdf: 16646767 bytes, checksum: fbcd339691975b226d2d9a290fdd5b18 (MD5) / Made available in DSpace on 2017-08-11T12:57:06Z (GMT). No. of bitstreams: 1 robertosottomaiorfortesdeoliveira.pdf: 16646767 bytes, checksum: fbcd339691975b226d2d9a290fdd5b18 (MD5) Previous issue date: 2010-02-03 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / As fibras transeptais situam-se na lâmina própria da gengiva entre dois dentes adjacentes. São comumente descritas como um grupo de fibras colágenas inseridas no cemento de um dente que seguem diretamente por sobre a crista óssea alveolar inserindo-se em uma região correspondente no cemento do dente adjacente. De maneira distinta, relatou-se na literatura que as fibras transeptais não são contínuas ao longo de toda sua extensão; são originadas dos dentes adjacentes, entrelaçando-se na região central do espaço interproximal. Com o presente estudo, objetivou-se avaliar e quantificar o arranjo das fibras gengivais transeptais empregando-se análise histomorfométrica e histoquímica em cortes histológicos sagitais da região entre primeiro e segundo molares da maxila de 12 ratos Wistar machos. As fibras colágenas foram coradas pelo método de picro-sirius e analisadas por microscopia de luz polarizada linear, processamento e análise digital de imagem baseados em métodos de filtragem e medição por transformada de Fourier. Foram realizadas medidas histomorfométricas de orientação, densidade e dimensão fractal das fibras. O brilho máximo apresentado pelas fibras foi mensurado pelo histograma de intensidade. Os parâmetros quantitativos foram comparados entre três regiões de interesse ao longo da extensão da gengiva interproximal ocupada pelas fibras transeptais utilizando-se análise de variância (ANOVA) seguida de testes post hoc de Bonferroni ou Tamhane T2. Houve um aumento significativo (p < 0,05) nos parâmetros de densidade de ocupação e dimensão fractal das fibras pertencentes à região central quando comparada às regiões próximas aos dentes, sem haver diferença na orientação e na intensidade de brilho das fibras. Os resultados demonstraram quantitativamente um arranjo mais denso de fibras na região central, reforçando o conceito de que as fibras transeptais entrelaçam-se nesta região. / The transeptal fibers are located in the lamina propria of the gingiva between adjacent teeth. They are often described as a group of collagen fibers embedded in the cementum of one tooth that follows a straight path over the alveolar bone crest and embeds itself in the cementum of the adjacent tooth. In a distinct way, it was reported in the literature that the transeptal fibers are not continuous over its full length but originates from the adjacent teeth interlacing in the central area of the interproximal gingiva. The present study aimed to evaluate and quantitate the gingival transseptal fibers arrangement by histomorphometry and histochemistry of sagittally cut tissue sections of the interdental region between first and second maxilar molar teeth of 12 male Wistar rat. The collagen fibers were stained with Picrosirius red staining and assessed with linear polarized light microscopy, digital image processing and analysis based on Fourier transform measurements and filtering techniques. Histomorphometrical parameters like fiber orientation, area fraction and fractal dimension were measured. The maximal brilliance presented by the fibers was evaluated using intensity histogram measurements. These quantitative parameters were compared among three different regions of interest along the length of the interdental gingiva using one-way analysis of variance (ANOVA) and Bonferroni’s or Tamhane’s T2 post hoc tests. There was an increase (p < 0.05) in area fraction and fractal dimension parameters in the central region compared to regions near the teeth, and no difference in the orientation and maximal brilliance of fibers among the tree regions. Our results quantitative demonstrated a denser arrangement of the fibers in the central region reinforcing the model of an interlacement of the transseptal fibers in that region.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of the present work is to classify co-registered pixels of stacks of polarized light images of iron ore into their respective crystalline grains or pores, thus producing grain segmented images that can be analyzed by their size, shape and orientation distributions, as well as their porosity and the size and morphology of the pores. Polished sections of samples of hematite-rich ore are digitally imaged in a rotating polarizer microscope at varying planepolarization angles. An image stack is produced for every field of view, where each image corresponds to a polarizer position. Any point in the sample is registered to the same pixel coordinates at all images in the stack. The resulting set of intensities for each pixel is directly related to the orientation of the crystal sampled at the corresponding position. Multivariate analysis of the sets of intensities leads to the classification of the pixels into their respective crystalline grains. Individual hematite grains of iron ore, as well as their pores, are segmented. The results are compared to those obtained by visual point counting methods. / O objetivo do presente trabalho é classificar pixels co-registrados de pilhas de imagens de luz polarizada de minério de ferro nos seus respectivos grãos cristalinos ou poros, produzindo assim imagens segmentadas por grãos que podem ser analisados quanto às suas distribuições de tamanho, forma e orientação, bem como sua porosidade, tamanho e forma dos poros. Seções polidas de amostras de minério de ferro rico em hematita foram imageadas difratalmente em um microscópio com polarizador giratório em ângulos variados de polarização. Uma pilha de imagens foi produzida para cada campo na qual cada imagem corresponde a uma orientação do polarizador. Cada ponto na amostra foi registrado nas mesmas coordenadas em todas as imagens da pilha. O conjunto resultante de intensidades de cada pixel está diretamente relacionado com a orientação do cristal amostrado na posição correspondente. A análise multivariada dos conjuntos de intensidades leva à classificação dos pixels nos seus respectivos grãos cristalinos. Grãos individuais de hematita do minério de ferro, bem como os seus poros foram segmentados. Os resultados foram comparados com aqueles obtidos pelo método de contagem dos pontos, ou seja, por inspeção visual.