Dissertations / Theses: 'Polarized light microscope'

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Santa, Nestor. "Demonstration of Optical Microscopy and Image Processing to Classify Respirable Coal Mine Dust Particles." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103919.

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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.
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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.

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Cao, Shuiyan. "Using plasmonic nanostructures to control electrically excited light emission." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS042/document.

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Dans cette thèse, nous utilisons différentes nanostructures plasmoniques pour contrôler l'émission de lumière excitée électriquement. Notre émission électrique provient d'une "nanosource STM" qui utilise le courant tunnel inélastique entre la pointe d'un microscope à effet tunnel (STM) et un échantillon métallique, pour exciter localement les plasmons polaritons de surface localisés et propagatifs. L’interaction de notre nanosource STM et d'une lentille plasmonique circulaire (une série de fentes concentriques gravées dans un film d'or épais) produit une microsource radialement polarisée de faible dispersion angulaire (≈ ± 4 °). L'influence des paramètres structuraux sur la propagation angulaire de la microsource résultante est également étudiée. En outre, une faible dispersion angulaire (<± 7 °) pour une grande plage de longueurs d'onde (650-850 nm) est obtenue. Ainsi, cette microsource électrique de lumière presque collimatée a une réponse spectrale large et est optimale sur une large plage d'énergie, en particulier en comparaison avec d'autres structures plasmoniques résonantes telles que les nanoantennes Yagi-Uda. L'interaction de notre nanosource STM et d'une lentille plasmonique elliptique (une seule fente elliptique gravée dans un film d'or épais) est également étudiée. Lorsque l'excitation STM est située au point focal de la lentille plasmonique elliptique, un faisceau lumineux directionnel à faible divergence est acquis. De plus, expérimentalement, nous trouvons qu'en changeant l'excentricité de la lentille plasmique elliptique, l'angle d'émission varie. On constate que plus l'excentricité de la lentille elliptique est grande, plus l'angle d'émission est élevé. Cette étude permet de mieux comprendre comment les nanostructures plasmoniques façonnent l'émission de lumière. L'interaction de SPP excités par STM et d'une structure de pile multicouche planaire plasmonique est également étudiée. Il est démontré qu'en utilisant l'excitation STM, nous pouvons sonder la structure de bande optique de la pile Au-SiO₂-Au. Nous trouvons que l'épaisseur du diélectrique joue un rôle important dans la modification du couplage entre les modes. Nous comparons également les résultats obtenus par excitation laser et STM de la même structure de pile. Les résultats indiquent que la technique STM est supérieure en sensibilité. Ces résultats mettent en évidence le potentiel de la STM en tant que technique de nanoscopie optique sensible pour sonder les bandes optiques des nanostructures plasmoniques. Enfin, l'interaction d'une nanosource STM et d'une plaque triangulaire individuelle est également étudiée. Nous trouvons que lorsque l'excitation STM est centrée sur la plaque triangulaire, il n'y a pas d'émission de lumière directionnelle. Cependant, lorsque la nanosource STM est située sur le bord du triangle, on obtient une émission de lumière directionnelle. Cette étude nous fournit une nouvelle voie pour atteindre l'émission de lumière directionnelle. Nous étudions également l'exploration du LDOS optique du triangle avec la nanosource STM. Ainsi, nos résultats montrent que la manipulation de la lumière est réalisée par des interactions SPP-matière. En utilisant des nanostructures plasmoniques, nous contrôlons la collimation, la polarisation et la direction de la lumière provenant de la nanosource STM
In this thesis, we use different plasmonic nanostructures to control the emission of electrically-excited light. Our electrical emission is from an “STM-nanosource” which uses the inelastic tunnel current between the tip of a scanning tunneling microscope (STM) and a metallic sample, to locally excite both localized and propagating surface plasmon polaritons. The interaction of our STM-nanosource and a circular plasmonic lens (a series of concentric slits etched in a thick gold film) produces a radially polarized microsource of low angular spread (≈±4°). The influence of the structural parameters on the angular spread of the resulting microsource is also investigated. In addition, a low angular spread (<±7°) for a large wavelength range (650-850 nm) is achieved. Thus this electrically-driven microsource of nearly collimated light has a broad spectral response and is optimal over a wide energy range, especially in comparison with other resonant plasmonic structures such as Yagi-Uda nanoantennas. The interaction of our STM-nanosource and an elliptical plasmonic lens (a single elliptical slit etched in a thick gold film) is also studied. When the STM excitation is located at the focal point position of the elliptical plasmonic lens, a directional light beam of low angular spread is acquired. Moreover, in the experiment we find that by changing the eccentricity of the elliptical plasmonic lens, the emission angle is varied. It is found that the larger the eccentricity of the elliptical lens, the higher the emission angle. This study provides a better understanding of how plasmonic nanostructures shape the emission of light. The interaction of STM-excited SPPs and a planar plasmonic multi-layer stack structure is also investigated. It is demonstrated that using STM excitation we can probe the optical band structure of the Au-SiO₂-Au stack. We find that the thickness of the dielectric plays an important role in changing the coupling between the modes. We also compare the results obtained by both laser and STM excitation of the same stack structure. The results indicate that the STM technique is superior in sensitivity. These findings highlight the potential of the STM as a sensitive optical nanoscopic technique to probe the optical bands of plasmonic nanostructures. Finally, the interaction of an STM-nanosource and an individual triangular plate is also studied. We find that when the STM excitation is centered on the triangular plate, there is no directional light emission. However, when the STM-nanosource is located on the edge of the triangle, directional light emission is obtained. This study provides us a novel avenue to achieve directional light emission. We also study probing the optical LDOS of the triangle with the STM-nanosource. Thus, our results show that the manipulation of light is achieved through SPP-matter interactions. Using plasmonic nanostructures, we control the collimation, polarization, and direction of the light originating from the STM-nanosource

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Gomes, Claudia Messias. "Influência da diminuição da temperatura sobre o fuso meiótico de oócitos de camundongas e de mulheres maturados in vitro." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/5/5139/tde-22072011-132252/.

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Introdução: O fuso meiótico dos oócitos de mamíferos pode se despolimerizar quando exposto a pequenas variações de temperatura. Este fato já está bem estabelecido e estudado em oócitos maduros em metáfase II (MII). No entanto, pouco se sabe a respeito da influência da diminuição da temperatura sobre o fuso meiótico dos oócitos imaturos. Desse modo, este estudo tem como objetivos: 1) avaliar a influência da diminuição da temperatura sobre o fuso meiótico de oócitos de camundongas maturados in vitro e 2) avaliar o fuso meiótico em oócitos humanos maturados in vitro submetidos à criopreservação pela técnica de congelação lenta ou por vitrificação quando em estágio de vesícula germinativa. Métodos: Realizaram-se dois experimentos, denominados 1 e 2, sendo o primeiro em oócitos de camundongas e o segundo em oócitos humanos. No experimento 1 oócitos imaturos de camundongas nos estágios de metáfase I (MI), telófase I(TI) e MII foram cultivados nas seguintes temperaturas: 37º C (controle), temperatura ambiente (22oC) e 4º C por 0, 10, 30 e 60 minutos. Após este período de tempo o fuso meiótico oocitário foi avaliado por meio de microscopia de luz polarizada (MLP) (LC-Polscope-Oosight image software) e imunocitoquímica (IC). No experimento 2 oócitos em estágio de vesícula germinativa (GV) coletados de pacientes submetidas à indução da ovulação e fertilização in vitro, foram divididos de forma randômica em três grupos: oócitos a fresco (A), oócitos congelados pela técnica de congelação lenta (B) e oócitos congelados pela técnica de vitrificação (C). Os oócitos a fresco, os descongelados e os aquecidos foram maturados in vitro até estágio de (MII). A análise do fuso meiótico foi realizada por microscópio invertido equipado com uma câmera de vídeo analógica e um sistema de imagens que combina luz polarizada em cristal líquido (ICSI Guard Octax). Resultados: Experimento 1: No tempo 0 e à 37º C, todos os oócitos apresentavam o fuso meiótico visível tanto pela MLP quanto pela IC. À 4º C, o número de oócitos em MI com fuso meiótico visível por meio da MLP foi menor do que com a IC, e descresceu com o tempo, fato que também ocorreu, em menor proporção, com os oócitos em TI. No entanto, a 4º C, o reconhecimento do fuso meiótico dos oócitos em TI foi semelhante tanto para MLP como para IC. Quando os oócitos MII foram expostos à 4º C, a detecção do fuso meiótico teve descréscimo diretamente proporcional ao tempo de cultura quando foi utilizada a MLP, sendo que o mesmo ocorreu para a IC, porém de forma menos pronunciada. À temperatura ambiente houve um pequeno descéscimo na visualização do fuso meiótico tanto por MLP quanto por IC, porém este não foi estatisticamente significativo para os oócitos em TI. Experimento 2: A taxa de sobrevivência imediatamente após o descongelamento/ aquecimento foi de 44,6% para o grupo B e de 79% para o grupo C. Após 24 horas em cultura , estas taxas passaram para 29,2% e 69%, respectivamente. A mediana de tempo para maturação foi de 26 horas para os grupos A e C, e de 27 horas para o grupo B. Ao final da maturação in vitro a porcentagem de oócitos em MII foi menor no grupo B e semelhante nos grupos A e C. Assim como para a detecção do fuso meiótico que foi menor no grupo B e similar nos grupos A e C. Conclusões: Houve diferença na porcentagem de despolimerização do fuso meiótico em resposta à baixa temperatura entre os oócitos de camundongas nos diferentes estágios da divisão meiótica, sendo menor nos oócitos em TI. A porcentagem de despolimerização do fuso meiótico foi diretamente proporcional ao tempo de cultivo, à exceção dos oócitos em TI à temperatura ambiente. Os oócitos hmanos em GV vitrificados apresentaram melhores taxas de sobrevivência quando comparados com oócitos humanos em GV criopreservados pelo congelamento lento. Os oócitos humanos em GV vitrificados apresentaram taxas semelhantes de maturação in vitro e detecção do fuso meiótico polimerizado quando comparados a oócitos a fresco
Introduction: The meiotic spindle of most mammals is sensitive to cooling and depolymerizes even after a slight reduction in temperature. This is well described and studied on matured oocytes at metaphase II (MII). However, little is known about the influence of low temperatures under meiotic spindle of imature oocytes. In this way, we sougth to evaluate: 1) the influence of low temperatures on mice oocyte meiotic spindle matured in vitro e 2) the oocyte meiotic spindle from human oocytes matured in vitro and cryopreserved by slow-rate freezing or vitrification at GV stage. Methods: Two experiments were done: the first one on mice and the second one on women.At experiment 1, immature mice oocytes at metaphase I (MI), telophase I (TI) and MII were cultured at 37º C (control), room temperature (22oC) and 4º C for 0, 10, 30 and 60 minutes and then spindle analysis was made with polarized light microscopy (PLM) (LC-Polscope-Oosight image software) or immunocytochemistry (ICC). At experiment 2, GV oocytes retrieved from women submitted to ovulation induction and in vitro fertilization were randomly divided in three groups: fresh oocytes (A), cryopreserved by slow-freezing (B) and cryopreserved by vitrification (C). Fresh, thawed and warmed oocytes were matured in vitro to metaphase II oocytes (MII). A meiotic spindle analysis was done by polarized light microscopy (ICSI Guard Octax). Results: Experiment 1: At time 0 min and 37º C, all oocytes had polymerized spindles both at PLM or ICC. At 4º C, the number of MI oocytes with detectable spindles at PLM was smaller than those analysed by ICC, and it decreased with time, which had also occured with TI oocytes at a smaller proportion. However, at 4º C, TI meiotic spindle recognition with polarized light microscopy and ICC was comparable. When MII oocytes were cultured at 4º C, the spindle visualization decreased proportionally in correlation with culture time at PLM, and the same happened with ICC in a less pronounced manner. At room temperature there was a little descrease regarding visualization of meiotic spindle, both at PLM and ICC, altought it was not significant for TI oocytes. Experiment 2: Oocyte survival immediately after thawing/warming were 44.6% for group B and 79% for group C. After 24 hours of culture, oocyte survival was 29.2% and 69%, respectively. The median time for maturation was 26 hours for groups A and C, and 27 hours for group B. The percentage of MII after maturation in vitro were smaller in group B and similar between groups A and C. The same oocured for spindle visualization which were lower in group B and similar between groups A and C. Conclusions: There was a difference on the percentages of meiotic spindle depolymerization in response to cooling in mice oocytes at different stages of meiotic division. Spindle depolymerization was lower in TI. Also, meiotic spindle depolimerization was proportional to culture time, except for TI oocytes at room temperature.Vitrified GV oocytes had a better survival when warmed, compared to slow-rate frozen oocytes. Vitrified GV oocytes had similar maturation in vitro rates and polymerized spindles detection when compared to fresh oocytes

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MacDonald, Donia J. "Wall characteristics of saccular aneurysms from polarized light microscopy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0006/MQ42172.pdf.

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Москаленко, Роман Андрійович, Роман Андреевич Москаленко, Roman Andriiovych Moskalenko, I. Iashchіchyn, M. Fallah, and Artem Mykhailovych Piddubnyi. "Verification of corpora amylacea amyloid nature via polarized light microscopy." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41281.

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Baba, Justin Shekwoga. "The use of polarized light for biomedical applications." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1206.

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Polarized light has the ability to increase the specificity of the investigation of biomedical samples and is finding greater utilization in the fields of medical diagnostics, sensing, and measurement. In particular, this dissertation focuses on the application of polarized light to address a major obstacle in the development of an optical based polarimetric non-invasive glucose detector that has the potential to improve the quality of life and prolong the life expectancy of the millions of people afflicted with the disease diabetes mellitus. By achieving the mapping of the relative variations in rabbit corneal birefringence, it is hoped that the understanding of the results contained herein will facilitate the development of techniques to eliminate the effects of changing corneal birefringence on polarimetric glucose measurement through the aqueous humor of the eye. This dissertation also focuses on the application of polarized light to address a major downside of cardiovascular biomechanics research, which is the utilization of toxic chemicals to prepare samples for histological examination. To this end, a polarization microscopy image processing technique is applied to non-stained cardiovascular samples as a means to eliminate, for certain cardiac samples, the necessity for staining using toxic chemicals. The results from this work have the potential to encourage more investigators to join the field of cardiac biomechanics, which studies the remodeling processes responsible for cardiovascular diseases such as myocardial infarct (heart attacks) and congestive heart failure. Cardiovascular disease is epidemic, particularly amongst the population group older than 65 years, and the number of people affected by this disease is expected to increase appreciably as the baby boomer generation transitions into this older, high risk population group. A better understanding of the responsible mechanisms for cardiac tissue remodeling will facilitate the development of better prevention and treatment regimens by improving the early detection and diagnosis of this disease.

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Burgio, Lucia. "Analysis of pigments on art objects by Raman microscopy and other techniques." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369123.

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Li, Yanfang. "A study on the use of polarized light in application to noninvasive tissue diagnoistics /." See Full Text at OhioLINK ETD Center (Requires Adobe Acrobat Reader for viewing), 2005. http://www.ohiolink.edu/etd/view.cgi?toledo1134596719.

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Dissertation (Ph.D.)--University of Toledo, 2005.
Typescript. "A dissertation [submitted] as partial fulfillment of the requirements of the Doctor of Philosophy degree in Engineering." Bibliography: leaves 106-120.

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Lima, Júlia Magalhães da Costa. "Análise da profundidade de desgaste e da perda mineral no esmalte subjacente à microabrasão após técnica microabrasiva." Universidade Federal da Paraíba, 2009. http://tede.biblioteca.ufpb.br:8080/handle/tede/6669.

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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 μm), 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 μm) and AF group (p < 0,05; 74,46 ± 42,06 μm). 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 μm), 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 μm), 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 μm) e AF (p < 0,05; 74,46 ± 42,06 μm). 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.

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Lucisano, Marília Pacifico. "Efeito do uso sistêmico de alendronato sódico no tecido ósseo e nas estruturas dentárias mineralizadas: estudo químico, mecânico e morfológico, em modelo murino." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/58/58135/tde-04022011-114321/.

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Os bisfosfonatos representam uma classe de drogas que agem sobre o metabolismo ósseo e são amplamente utilizadas na prevenção e tratamento de estados osteopênicos e osteoporóticos. Os objetivos do presente estudo foram avaliar, in vivo, o efeito do uso sistêmico de alendronato sódico: na densidade mineral óssea de ratos, por meio da densitometria óptica radiográfica e da técnica de absortometria radiológica de dupla energia (DXA); e nas estruturas dentárias mineralizadas de incisivos murinos, por meio da espectrometria na região do infravermelho, espectroscopia de fluorescência, microdureza transversal, microscopia eletrônica de varredura e microscopia de luz polarizada. Foram utilizados 45 ratos Wistar, com 36-42 dias de idade, pesando em média 200-230g, os quais foram divididos em dois grupos: experimental (n= 25) e controle (n= 20). No grupo experimental foram administradas duas doses semanais de 1mg/Kg de alendronato de sódio quimicamente puro diluído em água destilada, via gavagem, enquanto que os animais do grupo controle receberam apenas água destilada. Decorrido o período de 60 dias, os animais foram mortos por sobredose anestésica e, em seguida, foram extraídos os incisivos superiores e removidas as tíbias. As tíbias foram submetidas à avaliação da densidade mineral óssea por meio de análise radiográfica e da técnica de absortometria radiológica de dupla energia (DXA). Os incisivos superiores foram submetidos às seguintes avaliações: análise química por espectrometria na região do infravermelho e espectroscopia de fluorescência, microdureza transversal do esmalte e da dentina; microscopia eletrônica de varredura e microscopia de luz polarizada. Os resultados numéricos obtidos foram submetidos à análise estatística por meio do teste não-paramétrico de Kruskal-Wallis, utilizando o software SAS (Statistical Analysis System) for Windows versão 9.1.3. O nível de significância adotado foi de 5%. O grupo experimental apresentou valores de densidade mineral óssea superiores (p<0,05) em relação ao grupo controle, pelos métodos da densitometria óptica radiográfica e DXA. A análise química pelos métodos de espectrometria na região do infravermelho e espectroscopia de fluorescência permitiu detectar a presença do alendronato na estrutura dentária mineralizada do grupo experimental e que a porcentagem dessa incorporação foi de 0,0018% por elemento dental. Os resultados da microdureza transversal do esmalte e da dentina não revelaram diferença estatisticamente significante entre os grupos experimental e controle (p>0,05). Não foram observadas diferenças morfológicas significativas entre as amostras de ambos os grupos por meio da análise por microscopia eletrônica de varredura e microscopia de luz polarizada. Com base nos resultados obtidos, conclui-se que o tratamento com alendronato sódico provocou aumento na densidade mineral óssea da metáfise proximal da tíbia e que o alendronato incorporou-se nas estruturas dentárias mineralizadas, porém sem provocar efeitos significativos na microdureza e na morfologia do esmalte e da dentina de incisivos de ratos.
Bisphosphonates represent a class of drugs that act on bone metabolism and are widely used in the prevention and treatment of osteopenic and osteoporotic states. The objectives of this study were to evaluate, in vivo, the effect of the systemic use of sodium alendronate on: the mineral bone density of rats, by radiographic optical densitometry and dual-energy x-ray absorptiometry (DXA); the mineralized dental structures of murine incisors, by analysis of infrared (IR) spectrometry, fluorescence spectroscopy, cross-sectional microhardness (CSMH), scanning electron microscopy (SEM) and polarized light microscopy (PLM). Forty-five Wistar rats aged 36-42 days and weighing 200-230 g were assigned to two groups: experimental (n= 25) and control (n= 20). The experimental group received two weekly doses of 1 mg/kg of chemically pure sodium alendronate diluted in distilled water, via gavage, while the animals of the control group received only distilled water. After 60 days, the animals were killed by anesthetic overdose, and the maxillary incisors were extracted and the tibias were removed. The mineral bone density of the tibias was analyzed radiographically and by DXA. The maxillary incisors were subjected to the following evaluations: chemical analysis by IR spectrometry and fluorescence spectroscopy, enamel and dentin CSMH, SEM and PLM. The results were subjected to statistical analysis by the Kruskal-Wallis non-parametric test, using the SAS (Statistical Analysis System) software for Windows version 9.1.3. The significance level was set at 5%. The experimental group presented higher mineral bone density (p<0.05) than the control group, by radiographic optical densitometry and DXA. The chemical analysis by IR spectrometry and fluorescence spectroscopy revealed the presence of alendronate in the mineralized dental structure of the specimens of the experimental group, with a percentage of incorporation of 0.0018% per tooth. The results of enamel and dentin CSMH did not show statistically significant difference between the experimental and control groups (p>0.05). There were no significant morphological differences among the specimens of the groups by SEM and PLM. Based on the obtained results, it may be concluded that the treatment with sodium alendronate caused an increase in the mineral bone density of the proximal tibial metaphysis, and that alendronate was incorporated in the mineralized dental structures without causing significant effects in the enamel and dentin microhardness and morphology of rat incisors.

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11

Scott, Michael L. "Determining the Air Void Parameters of Concrete Using Digital Image Analysis of Polarized Light Micrographs." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/30547.

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The ASTM C457 test has long been a standard used to obtain the air void parameters of concrete materials. These air void parameters provide valuable information that has been linked to the performance of concrete under conditions such as freezing and thawing cycles. The standard test procedure involves linearly traversing a cut and polished section of a concrete specimen while a technician observes it under a microscope. Chord lengths of material constituents that the technician observes along the linear traverse are recorded and later used to calculate air void parameters statistically. This procedure is long and tedious, which makes it susceptible to human error due to operator fatigue. This study proposes and implements a new test method for evaluating concrete air void parameters using an image analysis method. A polishing procedure along with a differential interference contrast microscope are used to obtain high contrast images of material constituents, which provide raw data for the image analysis method. Because of the high contrast that can be obtained, cement paste, air voids in the cement paste, and aggregate materials in the concrete can be distinguished from one another based on these images. An image analysis program has been written for this study which linearly traverses these images and records the chord lengths of material constituents in a similar way to the standard ASTM C457 test. The chord length data must be processed further, however, because features in the images can be truncated by the edge of the image. Correction calculations for this problem are implemented in the image analysis algorithm. Two specimens which have been previously tested using the standard ASTM C457 method by the Virginia Transportation Research Council, (VTRC), are used in this study. The air void parameters obtained using the new test are compared directly with the results obtained by VTRC for the two specimens. Statistical comparisons indicate that the results of the new test are indeed significant, showing the potential it has for practical implementation. There are drawbacks to the test including a long polishing procedure, but this process can be automated. The new test appears to have excellent potential for practical application, but it should be emphasized that the test has only been implemented using materials in two concrete specimens. Further study on a variety of other concrete materials would be required for implementation in a standard procedure.
Master of Science

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12

Henderson, John J. "Microhistology of moose browse using polarized light microscopy and age & sex-determination using moose scat." University of Nebraska at Kearney, 2013.

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13

Moody, Hannah Leigh. "Detection of condom lubricants and starches in the presence of biologicals by diffuse reflectance infrared fourier transform spectroscopy and polarized light microscopy." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21221.

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Thesis (M.S.F.S.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
Condoms have been used in sexual assaults as a means of preventing the transmission of biological fluids. Current sexual assault evidence collection kit processing protocols do not regularly take advantage of the information that can be gathered by examining residues left by condoms during intercourse. A biphasic liquid-liquid extraction technique was developed to separate polar and non-polar condom residues, which had been collected on cotton tipped swabs. This research involved the examination of twenty condom brands by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. Five brands were selected to examine the consistency of this technique when the lubricants were exposed to body and storage temperature conditions for various times and in the presence of oral, vaginal, and blood samples. Additionally, starches collected from the condoms under each of the above conditions were examined. Although all lubricants were identifiable using this IR technique, the nonoxynol-9 (spermicide) containing samples produced spectra which were not identical to those produced by nonoxynol-9 standards. Although there was a decrease in the percent transmittance within IR spectra as the time between the collection and the extraction of the swabs increased, the condom residues of interest remained identifiable at all time points examined. The use of vaginal and oral swabs in the collection caused a negligible amount of background interference, which could be eliminated through spectral subtraction of the swab.
2031-01-01

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14

Hao, Alvin Chua Sern. "Miróbriga: study of roman mortars." Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/24466.

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Mirobriga is a Roman site located in the municipality of Santiago do Cacém, in Setúbal, a district in the southwest of Portugal. This settlement is mentioned in the ancient literature, and the archaeological evidence suggests that the city was developed by the Romans as an urban centre around the 1st century AD. For this study, 17 mortar samples were collected from various buildings – the Western Thermae, Domus 3, Domus 4, Taberna 1, Taberna 2, the ‘Hospedaria’, the macellum, and the forum. The chemical, mineralogical, and microstructural characterisation of the samples was performed using a number of complementary techniques – stereomicroscopy, polarised light microscopy, chemical and granulometric analysis, thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), and variable pressure scanning electron microscopy-energy dispersive spectrometry (SEM-EDS). The results show that the aggregates consist mainly of quartz, whereas the binder was lime-based. The sand for the aggregates was sourced locally (within a 20 km radius), whilst the limestone for the binder may have been obtained from local quarries (within a 20 km radius), or imported from further afield (possibly from São Brissos). Most of the samples have a binder to aggregate ratio of 1 : 3, and display some degree of hydraulicity. From the results, it may be said that most of the samples are similar, indicating the contemporaneity of the buildings. Nevertheless, several samples (MRBT-1E, MRBT-2E, MRBH7-12E, MRBH7-13BE, MRBH7- 13VE, and MRBF-16E) are different, which may be attributed to their function. Keywords: Mirobriga, Roman mortars, stereomicroscopy, polarised light microscopy, SEM-EDS, TGA, XRD, raw materials, provenance; Resumo: O sítio arqueológico de Mirobriga localiza-se junto à cidade de Santigo do Cacém (distrito de Setúbal) no sudoeste de Portugal. Este sítio é mencionado na literatura antiga e as evidências arqueológicas sugerem que a cidade foi desenvolvida pelos romanos, como um centro urbano, por volta do século I dC. Para este estudo, foram recolhidas 17 amostras de argamassa de vários edifícios, nomeadamente, Termas Ocidentais, Domus 3 e 4, Taberna 1 e 2, a Hospedaria, macellum e fórum. A caracterização química, mineralógica e microestrutural das amostras foi realizada por recurso a técnicas complementares – estereomicroscopia, microscopia de luz polarizada, análise química e granulométrica, análise termogravimétrica (ATG), difração de raios-X (DRX), microscopia eletrónica de varrimento com espectroscopia de raios X por dispersão de energias (MEV-EDS). Os resultados mostram que a maioria das amostras são similares, nomeadamente, no que respeita ao tipo de agregados, com predomínio de quartzo e ao tipo de ligante, cal calcítica. A areia para os agregados era de proveniência local (num raio de 20 km) enquanto que o calcário para o ligante pode ter sido obtido em pedreiras locais (num raio de 20 km) ou transportado de mais longe (provavelmente de São Brissos). A maioria das amostras apresenta uma razão ligante agregado de 1:3 e um grau de hidraulicidade análogo., indicando a contemporaneidade dos diferentes edifícios estudados. As diferenças observadas em algumas amostras (MRBT-1E, MRBT-2E, MRBH7-12E, MRBH7-13BE, MRBH7-13VE, and MRBF-16E) podem ser atribuídas à função desempenhada pelas mesmas.

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15

Oliveira, Roberto Sotto-Maior Fortes de. "Arranjo das fibras gengivais transeptais de ratos Wistar: estudo histomorfométrico e histoquímico." Universidade Federal de Juiz de Fora (UFJF), 2010. https://repositorio.ufjf.br/jspui/handle/ufjf/5549.

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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.

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16

Kilani, Suha School of Medicine UNSW. "The use of polarised light microscopy as a non-invasive tool for early assessment of human oocytes and embryos." Awarded by:University of New South Wales. School of Medicine, 2007. http://handle.unsw.edu.au/1959.4/35247.

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The overall aim was to evaluate a non-invasive technique for the assessment of oocytes and embryos using polarized light microscopy (PolScope-LC) with the goal of improving success rates in IVF. A literature review revealed little validation of the PolScope techniques in published work. A reproducible and accurate method for measuring the zona pellucida (ZP) thickness and density involving the PolScope computer software was validated by achieving low coefficient of variance and small inter/intra observer errors. Utilizing this method, 1477 oocytes from 211 stimulated cycles were analysed in this thesis. Results showed that increasing age has an adverse effect on the ZP thickness and density. Study of extended culturing of embryos showed that the ZP starts thinning as early as day 3 and embryos tend to have denser zonas over time. Standardisation of timing of PolScope observations in relation to the meiotic spindle was studied. Metaphase II oocytes were examined sequentially in culture from aspiration until microinjection using the PolScope The spindle is a highly dynamic structure that can appear and disappear over time in culture. A visible spindle was detected in 58% of the oocytes immediately after aspiration. This percentage increased until it stabilised at 39-40hrs post hCG and then declined significantly. Average spindle signal intensity increased over time reaching its peak at 39-40hrs post hCG, then declined significantly by 40.5hrs post hCG. The importance of spindle presence and morphology was investigated by following up embryos created after sperm injection at 39-40hrs post hCG. There was a significant relationship between normal meiotic spindle shape and density and embryo quality. A higher percentage of ???usable??? embryos, and all of pregnancies, arose from oocytes with a normal barrel shaped spindle. Finally, the impact of two issues related to spindle formation - the type of hCG used to trigger oocyte maturation and the site of microinjection during ICSI were assessed using the PolScope. The results showed a biological difference in spindle formation and embryo quality between rhCG and uhCG. In a separate randomised trial embryo quality was better when injecting the sperm in the vegetal pole away from the spindle during ICSI. The results from this thesis suggest that PolScope, if appropriately applied, may assist in improving IVF outcome.

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17

Truong, Ba Luu. "Organisation tri-dimensionnelle des cellules myocardiques au cours du développement ventriculaire fœtal et postnatal." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAS011/document.

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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

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18

Rosa, Marlise. "SEGMENTAÇÃO DE GRÃOS DE HEMATITA EM AMOSTRAS DE MINÉRIO DE FERRO POR ANÁLISE DE IMAGENS DE LUZ POLARIZADA." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/8064.

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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.

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19

Georgiev, Georgi Yordanov. "Structural studies of polymers and polymer liquid crystals by X-ray scattering, thermal analysis and ellipsometric studies through polarized light microscopy /." Thesis, Connect to Dissertations & Theses @ Tufts University, 2002.

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Thesis (Ph.D.)--Tufts University, 2002.
Adviser: Peggy Cebe. Submitted to the Dept. of Physics. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;

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20

Polowsky, Patrick. "Analysis of surface crystals on soft washed rind cheeses using polarized light microscopy and their effect on the sensory perception of grittiness." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/864.

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With the rising popularity of artisanal cheese in the United States, the soft washed rind category has emerged as a fast-growing segment of the marketplace. There is much anecdotal evidence to suggest a common sensorial defect in soft washed rind cheese is a gritty/sandy texture attributed to crystal growth on the rind of these cheeses A preliminary study was undertaken to develop a set of criteria to visually identify crystals found on soft washed rind cheeses. Single crystal identities were presumptively determined using polarized light microscopy (PLM), and cross-checked using powder x-ray diffractometry (PXRD). Two distinct crystal groupings were determined based on these metrics. Group 1 crystals had high birefringent coloring, angle of extinction (AE) ≈ 90°, and were smaller and less circular than Group 2 crystals (P<0.05). Group 2 crystals had no birefringent coloring and AE ≈ 18°. Using established mineralogical data, Group 1 and Group 2 crystals were identified to be struvite and ikaite, respectively. These crystalline bodies are situated in an amorphous cheese matrix (i.e. smear), which create difficulties when examining via PLM and PXRD, leading to high background noise. To remedy these issues, a novel method for harvesting crystals was developed. Smear scrapings were immersed in NaOH (pH=10) to dissolve smear material, which resulted in improved PLM and PXRD performance. A subsequent observational study was conducted to understand the prevalence of surface crystals and grittiness associated with washed rind cheeses sourced from the U.S.A. and Europe. Crystal types were identified via PXRD and PLM. Crystal size and shape (circularity) metrics were determined via PLM and image analysis. A descriptive sensory panel (n=12) was used to evaluate grittiness presence and intensity. Identified crystal types included ikaite, struvite, calcite, and brushite. Mean crystal length and area ranged from ~30μm to ~1100μm, and ~500μm2 to ~200,000μm2, respectively. Sensory perception threshold for grittiness occurred at a mean crystal length of ~70μm and mean crystal area of ~2900μm2. Below these threshold levels, cheeses presented with negligible grittiness. Above these threshold levels, grittiness was highly correlated with crystal length and area (r=0.93 and 0.96, respectively; P<0.001). These results indicate surface crystals have a direct impact on the sensorial quality of soft washed rind cheeses.

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21

Martinek, Radomír. "Analýza metod pro hodnocení submikrostruktury buněčné stěny dřeva." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372274.

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The content of this study is focused on the influence of the structure of wood at microscopic and submicroscopic level on its mechanical properties. The wood cell wall consists of several layers, the dominant layer being layer S2, which occupies up to 80 % of the total thickness of the wood cell wall. Unique feature of this layer is that cellulose microfibrils placed in this layer are highly aligned and spirally wound around the cell axis. The inclination of these microfibrils is called microfibril angle (MFA) and is the key feature that affects mechanical properties of wood and its shrinkage. In theoretical part of this thesis methods for measuring microfibril angle are described. A method for measuring mechanical properties of the wood cell wall called nanoindentation is discussed in detail. In the practical part of this thesis, microfibril angle is measured by means of polarized light microscopy and mechanical properties of wood cell wall is determined by means of nanoindentation.

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Thomas, Jimmy. "An investigation on the formation and occurrence of spiral grain and compression wood in radiata pine (Pinus radiata D. Don.)." Thesis, University of Canterbury. Biological Sciences, 2014. http://hdl.handle.net/10092/9654.

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Radiata pine (Pinus radiata) is the most important plantation tree in New Zealand forestry, and factors that reduce the quality of wood cause significant economic loss. Two of the most important of these issues are compression wood and spiral grain. Compression wood is a type of reaction wood, formed when a tree moves away from the vertical, and is characterised by biochemical and structural changes within the wood that reduce its quality and value. Spiral grain, however, is the alignment of the wood grain in a helix around the tree’s axis and away from the vertical. Again, this reduces the structural qualities of the wood and thus its value. Spiral grain and compression wood are notorious for their deleterious effect on the quality of wood produced and are very important for the forest industry due to the huge economic loss they cause. The demand for reliable tools to evaluate these wood quality issues in clonal planting material at an early stage, within 3 years of germination rather than at 8 to 15 years as in current practise, is of ever increasing importance from plant breeders and other industry stake holders. Therefore this research was undertaken with an overall aim to develop quick, easy and reproducible techniques to evaluate young radiata pine clones (up to 3 years old) based on compression wood content and presence of spiral grain. This is important because a shortened breeding cycle could provide significant economic benefits to the forest industry. The incidence of these commercially important wood quality parameters has been studied in this thesis in research conducted on young trees (1 to 3 years old). The research described in this thesis used a variety of different imaging approaches to investigate wood structure, including polarised light and confocal microscopy, and X-ray tomography and circular polarised light scanning. The images achieved have been analysed using a range of different software, including Photoshop, ImageJ and Matlab bringing a quantification approach to the imaging. Compression wood was quantified in young clonal material using images collected with a commercial document scanner, and processed using image analysis tools available in Photoshop. An easy, reliable and robust, automatic image analysis protocol was successfully developed and tested for the detection and quantification of compression wood in these young trees. This new technique to detect and quantify compression wood was based on the thresholding of the blue channel of the scanned RGB image as this was demonstrated to contain the greatest image contrast. Development of this new technique may reduce the waiting time for screening clonal planting materials based on compression wood content. To understand the organisation of the grain at a cellular level within these young trees, confocal microscopy techniques were utilised. The cell wall characteristics and fluorescence properties of compression wood in comparison with normal wood were investigated using a new cellulose specific dye, pontamine fast scarlet 4B. Staining protocols for this dye for confocal microscopy were optimised, and the potential of measuring the microfibril angle of the S1 and S3 layers of the pontamine treated opposite wood was demonstrated through either direct observations of these layers, or through the property of bifluorescence where the dye is excited only when aligned parallel to the polarisation of the incident light. Despite extensive work with confocal microscopy, this technique proved to be unsuitable for investigations of spiral grain because although it provided cellular detail, imaging was limited to the surface layers of sections, and the area over which observations were required was prohibitive. Instead of confocal microscopy, the incidence of spiral grain in young stems was investigated in two completely new ways. Resin canals, which are formed from the same cambial initials as the tracheids and which align with the grain, were used as a proxy to demonstrate the grain changes. A novel technique, using circular polarised light and a professional flatbed scanner, was developed to image whole serial transverse sections of the young stems to detect the resin canals. Using ImageJ, the number and location of resin canals was measured on vertical controls, and trees that had been rocked and leaned. The number and frequency of resin canals were less in tilted trees, especially in compression wood, compared to the higher number of canals formed in the rocked trees. More importantly, a combination of serial sectioning and this approach allowed a 3-dimensional view of the orientation of resin canals inside a stem to be generated with ImageJ, and the angles of these canals could be measured using Matlab. The resin canals were oriented with a left-handed spiralling near the stem surface whereas the canals near to the pith were nearly straight, consistent with previous observations of the development of spiral grain in radiata pine. However, it was observed that while vertical trees had a symmetric pattern of grain and grain changes around the stem, this was not the case in tilted trees. In these, the opposite wood often had severe spiral grain visible through formation of twist whereas the compression wood formed on the lower side had bending. Consistent with this, grain associated with compression wood was significantly straighter than in opposite wood. This hitherto unknown link between the incidence of compression wood and spiral grain was investigated and explained on the basis of the characteristics of resin canals in these types of wood. X-ray micro-tomography was also used to investigate resin canals in the stubs from which serial sections were collected. The 3D reconstructions of the resin canals showed exactly the same patterns as observed by polarised light scanning.

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23

Gwinnett, Claire M. B. "The Use of Inexperienced Personnel in the Analysis of Synthetic Textile Fibres using Polarized Light Microscopy for the Generation of Data Suitable for the Production of a Synthetic Fibres Database." Thesis, Staffordshire University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522253.

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24

Devaki, Sudha J., Neethu K. Sadanandhan, Renjith Sasi, Hans-Juergen P. Adler, and Andrij Pich. "Water dispersible electrically conductive poly(3,4- ethylenedioxythiophene) nanospindles by liquid crystalline template assisted polymerization." Royal Society of Chemistry, 2014. https://tud.qucosa.de/id/qucosa%3A36259.

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In this work, we demonstrate an inimitable liquid crystalline template strategy for the preparation of water dispersible electrically conducting poly(3,4-ethylenedioxythiophene) nanospindles (PEDOTSs). PEDOTSs were formed during the polymerization of the spindle shaped liquid crystalline phase of “EDOT–PDPSA” which was formed by the specific interactions of 3,4-ethylenedioxythiophene (EDOT) with 3-pentadecyl phenol-4-sulphonic acid (PDPSA). Liquid crystalline phases were characterized by Polarized Light Microscopic (PLM) analyses, rheology and XRD. Morphology and solid state ordering of conducting nanospindles were characterized by SEM, TEM and XRD. PEDOTSs exhibited an electrical conductivity of ~2.79 S cm⁻¹ and a good thermal stability (~300 °C), which suggests their applicability in fabricating high temperature electronic devices. Furthermore, electrochemical studies of PEDOTS modified glassy carbon electrodes (GCEs) showed an oxidation peak of ascorbic acid at a lower potential of 0.046 V with a peak current about 10 times (91.68 µA) higher than that of the bare GCE with excellent electrode stability, proposing that it can be used as a steady electrode for the electro-catalytic oxidation of similar molecules.

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25

Maside, Mielgo Carolina. "Efecto de diversas técnicas para visualizar la placa metafásica y el corpúsculo polar sobre la capacidad de desarrollo de ovocitos porcinos madurados in vitro." Doctoral thesis, Universidad de Murcia, 2012. http://hdl.handle.net/10803/104603.

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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.

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26

Novák, Kamil. "Analýza vlivu uspořádání kolagenu na mechanické vlastnosti tepen." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-383532.

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This dissertation thesis concerns with Analysis of Influence of Collagen Organization on Mechanical Properties of Arteries and it is divided into three main parts. Motivation for this dissertation thesis was in a study reviewing effect of material model upon resulting stresses in AAA. The effect was calculated in 70 patient-specific geometries of AAA, which exceeds the number of geometries in other scientific papers by one order. Within this study, two material models were used, i.e. real one and 100× stiffer, and obtained stresses were mutually compared. It was quantified that peak stress difference can be higher than 20 % in 10% of patients and therefore the real material model should be preferred over the artificial one although operation with this model is more demanding. The second part of this thesis deals with an identification of structural parameters (orientation and dispersion of collagen fibres) of porcine aortic tissue by using adjusted Fast Fourier Transform based algorithm. The extracted structural parameters were inserted into two-layer structure-motivated constitutive model Martufi-Gasser. This model was validated and its predictive capabilities were also tested with fine results. The most important information obtained from the digital image processing of ~9000 micrographs is existence of only one family of dispersed collagen fibres which breaks the current dogma present in many scientific papers about two families of collagen fibres. The third part concerns with a proposal of an automated phase-correlation based algorithm for obtaining collagen fibre direction from polarized light microscopy images. The proposed algorithm was verified and validated and it yields histograms of collagen fibre directions with overall number of measured points larger than it would be possible to get from any manual measurement. The limitation of the original proposed algorithm is in 90° period of polarized light intensity, thus the method results in angles in the range of 0°–90. Therefore the end of the thesis is dedicated resolving this problem and obtaining real angles in a span of 0°–180°. To this end, the microscope set-up was changed and the algorithm was adjusted accordingly. The original and the adjusted algorithms are collagen-specific, fast and an operator independent. Despite all the author´s effort put into collagen fibre waviness quantification directly from the histograms, the waviness has not been quantified yet in this way and it remains at the stage of research.

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27

van, Dijk Jeroen. "Size and Abundance of Late Pleistocene Reticulofenestrid Coccoliths from the Eastern Indian Ocean in Relation to Temperature and Aridity." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325273.

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Measurements on coccolith abundance and mass can be used as a signal of primary productivity and pelagic calcification in response to environmental change. The Leeuwin Current (LC) is known to transport warm and low-salinity waters from the Indo-Pacific Warm Pool (IPWP) southwards along the coast of West Australia. Along with the onset of continental aridity during late Neogene, increased strength of the LC may have played a role in reef expansion on the Northwest Shelf. In this study the morphological variation in size and mass of reticulofenestrid coccoliths was assessed in material from IODP Site U1461 in the eastern Indian Ocean spanning the past 500 ka. Both the absolute abundance of all reticulofenstrid coccoliths (Emiliania huxleyi, Reticulofenestra spp., Gephyrocapsa spp. and Pseudoemiliania spp.) was determined, as well as the relative abundance of large versus small coccoliths. Coccolith size and mass were measured quantitatively under circularly polarized light. The data was compared to variations in sea surface temperatures (SST) of the LC, and to continental aridity of Australia. SST fluctuations could influence coccolithophore productivity by affecting their metabolic rate, whereas continental aridity may influence the influx of terrestrial matter by wind. The investigated interval is dominated by small species of Gephyrocapsa. Peak values of absolute abundance and mass were observed during Marine Isotope Stage (MIS) 11, an interglacial period of extended warmth and humidity. These results coupled with high densities of aragonite needles in the same samples indicate the sediments were diluted by material overflowing from the adjacent shallow- water carbonate platform, analogous to the whiting events observed in the modern-day Bahamas. A decrease in abundance of Gephyrocapsa caribbeanica at 240 ka can be linked to the timing of their last common occurrence (LCO), within MIS 7. The subsequent shift to Gephyrocapsa oceanica as the dominant large species may indicate an ecological replacement of G. caribbeanica, or signify warm and low-salinity waters.
Mätningar av abundans och massa hos coccoliter kan användas som en signal för primärproduktion och pelagisk förkalkning som resultat av miljöförändringar. Leeuwin Current (LC) är känd för att transportera varmt vatten och vatten med låg salthalt från Indo-Pacific Warm Pool (IPWP) söderut längs kusten i västra Australien. Tillsammans med början av kontinental torka under sen Neogen kan ökad styrka hos LC ha spelat en roll i expansionen av rev på nordvästsockeln. I denna studie bedömdes den morfologiska variationen i storlek och massa hos coccoliter i material från IODP plats U1461 i östra Indiska oceanen från de senaste 500 000 åren. Både den absoluta abundansen av alla reticulofenstridcoccoliter (Emiliania huxleyi, Reticulofenestra spp., Gephyrocapsa spp. och Pseudoemiliania spp.) bestämdes, liksom den relativa abundansen av stora jämfört med små coccoliter. Storlek och massa av coccoliter mättes kvantitativt under cirkulärt polariserat ljus. Uppgifterna jämfördes med variationer i havsytans temperatur (SST) hos LC, och med kontinental torrhet i Australien. SST-fluktuationer kan påverka produktiviteten hos coccolitoforider genom att påverka deras metabolism, medan kontinental torrhet kan påverka inflödet av markmaterial med vind. Det undersökta intervallet domineras av små arter av Gephyrocapsa. Toppvärden av absolut abundans och massa observerades under marinisotopsteget (MIS) 11, en interglacial period med förlängd värme och fuktighet. Dessa resultat kombinerat med hög densitet av aragonitnålar i samma prover indikerar att sedimenten späddes ut med material som svämmade över från den intilliggande grunda karbonatplattformen, vilket är jämförligt med de vitningshändelser som har observerats i dagens Bahamas. En minskning i abundans av Gephyrocapsa caribbeanica vid 240 ka kan kopplas till tidpunkten för deras senaste gemensamma förekomst (LCO) inom MIS 7. Den efterföljande övergången till Gephyrocapsa oceanica som den dominerande stora arten kan indikera en ekologisk ersättning av G. caribbeanica, eller indikera varmt vatten med låg salthalt.

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28

Dumont, George Pierre Jr. "The use of carbonation and fractional evaporative crystallization in the pretreatment of Hanford nuclear wastes." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/24716.

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Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2007.
Committee Chair: Dr. Ronald W. Rousseau; Committee Member: Dr. Amyn S, Teja; Committee Member: Dr. Wm. James Frederick Jr.

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29

Relaix, Sabrina. "Cristaux liquides cholestériques en conditions non usuelles de photogélification : modulation du profil de réflexion de la lumière." Phd thesis, Université Paul Sabatier - Toulouse III, 2007. http://tel.archives-ouvertes.fr/tel-00179999.

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De part sa structuration en hélice, un Cristal Liquide Cholestérique (CLC) possède des propriétés optiques singulières. La lumière incidente sur un CLC est réfléchie sélectivement, avec une longueur d'onde λ0 associée proportionnelle au pas hélicoïdal et ceci sur une largeur spectrale de quelques dizaines de nm autour de λ0. La quantité de lumière réfléchie est par ailleurs limitée à 50% de la lumière ambiante (non polarisée).

Les travaux de thèse se sont focalisés sur l'obtention de propriétés de réflexion de cholestériques gélifiés atypiques, avec deux objectifs de recherche: l'élargissement de la bande de réflexion et l'accroissement de la quantité de lumière réfléchie.

La première partie du manuscrit de thèse propose un procédé d'élaboration permettant un élargissement de la bande de réflexion de gels de CLC. Cet objectif est atteint par l'utilisation d'un CLC absorbant la lumière UV, à l'origine d'un gradient d'intensité lors de la gélification. Des études par microscopie optique, spectrophotométrie et microscopie électronique en transmission ont permis de déterminer la distribution structurale à l'origine de la distribution des longueurs d'onde de réflexion observée.

La seconde partie du manuscrit se focalise sur l'augmentation de la quantité de lumière réfléchie par un gel réalisé à partir d'un mélange cholestérique qui voit son sens d'hélicité changer avec la température. L'impact de l'histoire de la polymérisation et du parcours en température après gélification sur les propriétés du profil de réflexion sera analysé avec une attention particulière sur la nature et la quantité de la polarisation du faisceau réfléchi.

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30

Woldemichael, Michael Haile. "The Mineralogical Composition of House Dust in Ontario, Canada." Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20664.

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Despite increasing concern about the presence of heavy metals, pesticides and other toxins in indoor environments, very little is known about the physical and chemical composition of ordinary household dust. This study represents the first systematic investigation of the mineralogical composition of indoor dust in residential housing in Canada. Specimens of dust were obtained from homes in six geographically separate cities in the Province of Ontario: two located on the metamorphic and igneous rocks of the Precambrian Canadian Shield (Thunder Bay and Sudbury), the other four located on Palaeozoic limestone and shale dominated bedrock (Barrie, Burlington, Cambridge, and Hamilton). Forty samples of household vacuum dust were obtained. The coarse fraction (80 – 300 µm) of this dust was subjected to flotation (using water) to separate the organic components (e.g. insect fragments, dander), natural and synthetic materials (e.g. fibres, plastics) from the mineral residue. The mineral fraction was then analyzed using quantitative point counting, polarizing light microscopy, powder X-ray diffraction and scanning electron microscopy methods. Despite the great distances between the sampling localities and the distinct differences in bedrock geology, the mineral fraction of dust from all six cities is remarkably similar and dominated by quartz and feldspar, followed by lithic fragments, calcite, and amphibole. Some evidence of the influence of local geology can nevertheless be found. For example, a relatively higher proportion of sulphide minerals is observed in the two cities on the Canadian Shield where these minerals are clearly more abundant in the bedrock. Specimens from Sudbury, Canada’s largest mining centre located atop a nickel-sulphide mineral deposit, showed the highest sulphide contents. Quartz is the dominant mineral in all cities. All quartz grains have internal strain features and fluid inclusions that are indicative of a metamorphic-igneous provenance. In all cities, sand is used on the streets as an abrasive for traction during the icy winter season. This sand is obtained in all cases from local glaciofluvial deposits that were ultimately derived principally from the rocks of the Canadian Shield in the last Pleistocene glaciations that affected all of Ontario. Thus, tracking in sand is the most plausible mechanism by which quartz was introduced into these homes since sampling was done, in all cases, in the winter season. The results indicate that glacial deposits dominate the mineral composition of indoor dust in Ontario cities and that nature of the bedrock immediately underlying the sampling sites is relatively of minor importance.

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31

Bayuadri, Cosmas. "Stability of sodium sulfate dicarbonate (~2Na₂CO₃• Na₂SO₄) crystals." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11507.

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Research on salts species formed by evaporation of aqueous solution of Na2 in the early 1930s. The thermodynamic, crystallographic and many other physical and chemical properties of most of the species formed from this solution has been known for decades. However, there was no complete information or reliable data to confirm the existence of a unique double salt that is rich in sodium carbonate, up until five years ago when a research identified the double salt (~2Na ₂ CO ₃ • Na ₂ SO ₄) from the ternary system Na₂CO ₃Na₂SO ₄ H₂O. Crystallization of this double salt so called sodium sulfate dicarbonate (~2Na ₂ CO ₃ • Na ₂ SO ₄) is known to be a primary contributor to fouling heat transfer equipment in spent-liquor concentrators used in the pulp and paper industry. Therefore, understanding the conditions leading to formation of this double salt is crucial to the elimination or reduction of an industrial scaling problem. In this work, double salts were generated in a batch crystallizer at close to industrial process conditions. X-ray diffraction, calorimetry, and microscopic observation were used to investigate the stability of the salts to in-process aging, isolation and storage, and exposure to high temperature. The results show that care must be taken during sampling on evaporative crystallization. Two apparent crystal habits were detected in the formation of sodium sulfate dicarbonate; the favored habit may be determined by calcium ion impurities in the system. The results also verify that sodium sulfate dicarbonate exists as a unique phase in this system and that remains stable at process conditions of 115-200℃

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Seltmann, Jens. "Struktur-Eigenschaftsbeziehungen V-förmiger Mesogene zur Realisierung biaxial nematischer Mesophasen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-67693.

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Die vorliegende Arbeit befasst sich mit der Synthese und der Untersuchung von Struktur-Eigenschaftsbeziehungen neuartiger V-förmiger, formstabiler Mesogene zur Realisierung biaxial nematischer Mesophasen (Nb). Alle synthetisierten Verbindungen besitzen ein formtreues Oligo(phenylenethinylen)-Grundgerüst, an welches laterale Alkyloxyketten und verschiedene terminale Substituenten (z. B. -CN, O(CH2)nCOOEt, Pyridyle) angebunden wurden. Durch dieses spezielle Design erhält man ausschließlich nematische und keine höher geordneten flüssigkristallinen Phasen. Durch den Einsatz verschiedener zentraler heterozyklischer Kernbausteine konnten erfolgreich Öffnungswinkel zwischen 108.9° und 160° realisiert werden. Dabei zeigen Thiadiazolderivate stets enantiotrope Mesophasen, wobei im Hochtemperaturbereich eine uniaxiale Phase mit biaxialen Aggregaten vorliegt. Beim Abkühlen konnte bei etwa 50 °C mittels Polarisationsmikroskopie und dielektrischer Spektroskopie ein Übergang in die Nb-Phase nachgewiesen werden. Die erstmalige Beobachtung eines direkten Übergangs von der isotropen Phase in die Nb-Phase gelang durch den Einsatz von Benzo[1,2-b:4,3-b]dithiophen als Kernbaustein.

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Huang, Yung-Kuo, and 黃永國. "Inspection of 3D Profile and Internal Structure with Polarized Low Coherent Light Interference Microscope." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/93011580853076290987.

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博士
國立中正大學
機械工程所
94
Abstract In this paper, we set up a polarized sensitivity optical coherence tomography microscope (PS-OCM) of Linnik type. This PS-OCM was modified mechanism of the reference arm in order to compensate the difference of optical path. So the microscope can achieve the function of white light interference microscope (WLI), virtual confocal microscope and the PS-OCM. The resolution of WLI reached to nanometers scale. So it is indispensable to MENS or semiconductor manufacture procedure. The optical tomography had the functions which was transparent material internal structure measured and bio-tissue internal imaging. Therefore, it was increasingly attach importance to field of optical inspection except field of biotechnology. Additionally, OCM will inspect the birefringence, when the OCM used the polarization light source. Inspection of 3D profile with this PS-OCM, we developed a new scanning algorithm. This algorithm combined Hilbert transform to search the zero order fringe of the interferogram. And measure a 3D profile standard to prove the correctness of the algorithm. The PS-OCM can execute the function of microscope, and this paper develops a virtual confocal algorithm. Use this algorithm, the PS-OCM except inspected 3D profile and provide the full depth of field image of the sample. The PS-OCM can measure the internal structure of transparent material which operated with the mechanism of optical difference compensated. And the paper drove an equation of optical difference compensated which regulated the displacement of the compensation mechanism. Because, the sample arm of the PS-OCM would be longer when focus fall in transparent material internal. So, this PS-OCM is unrestricted with the depth of field of objective on the depth of measurement. Finally, we demonstrate a measurement of the stress induce birefringence with the PS-OCM.

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Chen, Yueh-Hsiang, and 陳躍翔. "Collection and Polarized Light Microscopy Analysis of Textile Fiber Evidence in Traffic Accidents." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/h82xhk.

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碩士
中央警察大學
鑑識科學研究所
99
Crime scene investigators collect and preserve evidences in major criminal cases, except for homicide, robbery, and sexual assault cases attracting public attention, also playing important roles in traffic accidents investigation, especially in traffic homicide cases. To effectively collect accident evidence, investigators must thoroughly understand the dynamic relationships from pre-accident to post-accident between the vehicle and the victim, vehicle damage, evidence left patterns and locations, victim’s traumatic injuries, and clothes abrasions and lacerations. In this study, 22 cases were studied to get a better strategy for forensic traffic accident textile fiber evidence search and collection. Traffic accidents involved pedestrians and scooter riders can be classified into 4 categories. Forensic fiber analysis by polarized light microscopy (PLM) usually re-fers to observation refractive index, extinction, interference colors, birefringence and other physical properties under the polarized light micro-scope to determine fiber generic types. In this study, retardations of textile fiber specimens were measured with Berek compensator under the polarized light microscope. This method improves the accuracy and digitalizes the result of interference colors observation with true retardation. A datasheet for forensic textile fiber identification with polarized light microscopy is proposed, and the flowchart system is theorized. The datasheet and flowchart system allow forensic textile fiber examiners to distinguish and identify common synthetic fibers encountered in caseworks.

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Quackenbush, Brett Michael 1969. "A comparison of a 2.26% fluoride varnish versus a 1.23% APF foam using polarized light microscopy, confocal microscopy and quantitative light fluorescence." Thesis, 2000. http://hdl.handle.net/1805/3712.

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Indiana University-Purdue University Indianapolis (IUPUI)
Secondary caries and the replacement of existing restorations account for 50 to 70 percent of operative dentistry today. Quantitative Light Fluorescence (QLF) has been shown to be effective at diagnosing very early tooth demineralization on smooth surfaces (less than 50 μ in depth); however, QLF has never been utilized to evaluate secondary caries in dentin. The objective of this study was to validate the accuracy of QLF in diagnosing early secondary caries and then verify the results using confocal microscopy and polarized light microscopy. Seventy-five mandibular molar teeth were prepared with Class V amalgam preparations on the mesial surface. A fluoridated varnish and 1.23- percent acidulated phosphate fluoride (APF) were introduced to this evaluation system, two agents known to effectively inhibit tooth demineralization. The artificial caries system utilized was adjusted to ensure that secondary caries would occur at restoration/tooth surface interfaces. The teeth were exposed to this artificial caries challenge for five days and following lesion formation, QLF was used to determine if incipient demineralization could be detected. The results of the QLF analysis were then compared with the data gathered using confocal microscopy and polarized light microscopy. Our results demonstrate that QLF detected 100 percent of the lesions seen with confocal microscopy and polarized light microscopy; however, no sound specimens were analyzed with any of the three techniques. There were no consistent significant differences between the fluoridated varnish and APF (p < 0.05) with any of the three methods utilized. We conclude that QLF can be used in early caries diagnosis and that emphasis should now be focused on treatment of the early lesion.

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Godinho, Isabel Ribeiro. "Structure and stability of creams containing ectoine: liquid crystalline states." Master's thesis, 2016. http://hdl.handle.net/10451/35849.

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Abstract:

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2016
Ectoine is a low molecular organic osmolyte, produced by various extremolytes, which have a large range of applications, such as medical devices, cosmetics, and life science products, due to their ability to protect biological macromolecules and cells from damage by external stresses. The aim of this project was to study the influence that ectoine can have on the properties of creams. This substance has several positive effects when used in dermocosmetic products, however it is thought that ectoine can possibly change the stability of creams. To study this possibility, simple creams constituted by different lyotropic liquid crystalline phases, such as lamellar, hexagonal and cubic phase; and more complex creams, such as anionic and non-ionic hydrophilic creams, were used. During the project, it was shown that ectoine added on creams could provoke various alterations in lyotropic liquid crystalline phases, such as the transition between mesophases and the change of the creams’ viscosity. Therefore, it was proved, by using the polarized light microscopy and rheological measurements, that ectoine could change the structure and stability of creams to a certain extent, as expected.
A ectoina é um osmólito orgânico de baixo peso molecular, produzido por diversos extremólitos, os quais têm uma grande variedade de aplicações, tais como dispositivos médicos, cosméticos e produtos de científicos, devido ao seu mecanismo de autoproteção, protegendo as células e as macromoléculas biológicas das condições ambientais extremas. O objetivo deste trabalho foi estudar a influência que a ectoina poderia ter nas propriedades dos cremes. Esta substância tem vários efeitos positivos quando utilizada em produtos de dermocosmética, no entanto pensa-se que a ectoina pode, possivelmente, mudar a estabilidade de cremes. Para estudar esta possibilidade foram usados cremes simples constituídos por diferentes fases de cristais líquidos liotrópicos, fase lamelar, hexagonal e cúbica; e cremes mais complexos, tais como, cremes hidrofílicos aniónicos e não-iónicos. Durante o projeto, foi demonstrado que a ectoina ao ser adicionada em cremes, pode provocar várias alterações nas fases de cristais líquidos liotrópicos, tais como a transição entre mesofases e a alteração da viscosidade dos cremes. Assim, provou-se, utilizando a microscopia de luz polarizada e medições reológicas, que a ectoina poderia alterar a estrutura e estabilidade de cremes, em certa medida, como esperado.

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37

Raguin, Emeline. "Histomorphometric assessment of double-zonal osteons in human cortical bone." Thèse, 2018. http://hdl.handle.net/1866/21121.

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