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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Physical and computational models of the gloss exhibited by the human hair tress : a study of conventional and novel approaches to the gloss evaluation of human hair

Rizvi, Syed January 2013 (has links)
The evaluation of the gloss of human hair, following wet/dry chemical treatments such as bleaching, dyeing and perming, has received much scientific and commercial attention. Current gloss analysis techniques use constrained viewing conditions where the hair tresses are observed under directional lighting, within a calibrated presentation environment. The hair tresses are classified by applying computational models of the fibres' physical and optical attributes and evaluated by either a panel of human observers, or the computational modelling of gloss intensity distributions processed from captured digital images. The most popular technique used in industry for automatically assessing hair gloss is to digitally capture images of the hair tresses and produce a classification based upon the average gloss intensity distribution. Unfortunately, the results from current computational modelling techniques are often found to be inconsistent when compared to the panel discriminations of human observers. In order to develop a Gloss Evaluation System that produces the same judgements as those produced from both computational models and human psychophysical panel assessments, the human visual system has to be considered. An image based Gloss Evaluation System with gonio-capture capability has been developed, characterised and tested. A new interpretation of the interaction between reflection bands has been identified on the hair tress images and a novel method was developed to segment the diffuse, chroma and specular regions from the image of the hair tress. A new model has been developed, based on Hunter's contrast gloss approach, to quantify the gloss of the human hair tress. Furthermore, a large number of hair tresses have been treated with a range of hair products to simulate different levels of hair shine. The Tresses have been treated with different commercial products. To conduct a psychophysical experiment, one-dimensional scaling paired comparison test, a MATLAB GUI (Graphical user interface) was developed to display images of the hair tress on calibrated screen. Participants were asked to select the image that demonstrated the greatest gloss. To understand what users were attending to and how they used the different reflection bands in their quantification of the gloss of the human hair tress, the GUI was run on an Eye-Tracking System. The results of several gloss evaluation models were compared with the participants' choices from the psychophysical experiment. The novel gloss assessment models developed during this research correlated more closely with the participants' choices and were more sensitive to changes in gloss than the conventional models used in the study.
12

Efeito do peróxido de carbamida em diferentes concentrações sobre a rugosidade superficial e brilho de uma cerâmica odontológica / The effect of carbamide peroxide in different concentrations on the surface roughness and gloss using dental ceramics

Ana Carolina Cabral Roque 22 January 2016 (has links)
O gel de peróxido de carbamida é utilizado em concentrações que variam de 10 a 35%, por períodos de 2 a 8 horas diárias e seu efeito sobre os materiais restauradores ainda não está totalmente elucidado. Assim, o objetivo desse estudo foi avaliar a ação do peróxido de carbamida, 10 e 16%, sobre a rugosidade superficial e o brilho de uma cerâmica odontológica feldspática. Foram confeccionados espécimes (n=10), com a cerâmica IPS d.SIGN , que foram submetidos a protocolos de aplicação de gel de peróxido de carbamida a 10 e 16%, nos tempos de 4 ou 3 horas diárias respectivamente, pelo período de 14 dias. A determinação da rugosidade e da alteração de brilho foi realizada no início do tratamento, após 07 e após 14 dias. A rugosidade superficial foi determinada pelo microscópio, LEXT 3D Measuring Laser Microscope OLS4000, OLYMPUS, e a leitura do brilho foi feita pelo aparelho Micro Gloss. Após a obtenção dos dados, foi realizada a análise TwoWay ANOVA, verificou-se que o resultado obtido foi estatisticamente significante para a variável de rugosidade, tanto para os fatores de variação de tempo (p = 0,004), concentração do peróxido de carbamida (p = 0,007) e para a interação entre ambos (p = 0,013). Foi feito o teste de múltiplas comparações com ajustes de Bonferroni, para análise dos resultados obtidos. Na análise do brilho, para os resultados encontrados, não houve diferença estatisticamente significante. Assim, pode-se concluir que o peróxido de carbamida 10% não provocou alterações significativas na rugosidade da cerâmica, mas o peróxido de carbamida a 16% provocou aumento da rugosidade após o período de 14 dias de aplicação, com médias em torno de 4,0 μm. Conclui-se, então, que as restaurações cerâmicas devem ser protegidas antes da aplicação de agentes clareadores à base de peróxido de carbamida 10 ou 16%. / The carbamide peroxide gel is used in concentrations ranging from 10 to 35% for periods from 2 to 8 hours daily and its effect on the restorative material isnt yet fully elucidated. The objective of this study was to evaluate the action of carbamide peroxide, 10 and 16%, on the surface roughness and the gloss of a feldspathic dental ceramics. Specimens were prepared (n = 10), IPS d.SIGN ceramics and submitted to carbamide peroxide gel application protocols 10 and 16% at 4 or 3 hours, respectively, at time 14 days. The determination of roughness and gloss was made at baseline, after 07 and after 14 days. The surface roughness was determined by microscope, 3D Measuring Laser Microscope OLS4000 LEXT, OLYMPUS, and the reading of the gloss was taken by Micro Gloss device. After obtaining the data, the TwoWay ANOVA analysis was performed, it was found that the obtained result was statistically significant roughness variable, both for time-variant factor (p = 0.004), concentration of the carbamide peroxide (p = 0.007) and the interaction between both (p = 0.013). It was made for multiple comparisons test with Bonferroni adjustments, for analysis of the results.There was no statistically significant difference in gloss. Thus, it can be concluded that the carbamide peroxide 10% did not cause significant changes in roughness ceramic, but the carbamide peroxide at 16% caused an increased roughness after 14 days of application, averaging around 4, 0 micrometers. Therefore, the ceramic restorations must be protected before the application of bleaching agents based on carbamide peroxide 10 or 16%.
13

Efeito do peróxido de carbamida em diferentes concentrações sobre a rugosidade superficial e brilho de uma cerâmica odontológica / The effect of carbamide peroxide in different concentrations on the surface roughness and gloss using dental ceramics

Roque, Ana Carolina Cabral 22 January 2016 (has links)
O gel de peróxido de carbamida é utilizado em concentrações que variam de 10 a 35%, por períodos de 2 a 8 horas diárias e seu efeito sobre os materiais restauradores ainda não está totalmente elucidado. Assim, o objetivo desse estudo foi avaliar a ação do peróxido de carbamida, 10 e 16%, sobre a rugosidade superficial e o brilho de uma cerâmica odontológica feldspática. Foram confeccionados espécimes (n=10), com a cerâmica IPS d.SIGN , que foram submetidos a protocolos de aplicação de gel de peróxido de carbamida a 10 e 16%, nos tempos de 4 ou 3 horas diárias respectivamente, pelo período de 14 dias. A determinação da rugosidade e da alteração de brilho foi realizada no início do tratamento, após 07 e após 14 dias. A rugosidade superficial foi determinada pelo microscópio, LEXT 3D Measuring Laser Microscope OLS4000, OLYMPUS, e a leitura do brilho foi feita pelo aparelho Micro Gloss. Após a obtenção dos dados, foi realizada a análise TwoWay ANOVA, verificou-se que o resultado obtido foi estatisticamente significante para a variável de rugosidade, tanto para os fatores de variação de tempo (p = 0,004), concentração do peróxido de carbamida (p = 0,007) e para a interação entre ambos (p = 0,013). Foi feito o teste de múltiplas comparações com ajustes de Bonferroni, para análise dos resultados obtidos. Na análise do brilho, para os resultados encontrados, não houve diferença estatisticamente significante. Assim, pode-se concluir que o peróxido de carbamida 10% não provocou alterações significativas na rugosidade da cerâmica, mas o peróxido de carbamida a 16% provocou aumento da rugosidade após o período de 14 dias de aplicação, com médias em torno de 4,0 μm. Conclui-se, então, que as restaurações cerâmicas devem ser protegidas antes da aplicação de agentes clareadores à base de peróxido de carbamida 10 ou 16%. / The carbamide peroxide gel is used in concentrations ranging from 10 to 35% for periods from 2 to 8 hours daily and its effect on the restorative material isnt yet fully elucidated. The objective of this study was to evaluate the action of carbamide peroxide, 10 and 16%, on the surface roughness and the gloss of a feldspathic dental ceramics. Specimens were prepared (n = 10), IPS d.SIGN ceramics and submitted to carbamide peroxide gel application protocols 10 and 16% at 4 or 3 hours, respectively, at time 14 days. The determination of roughness and gloss was made at baseline, after 07 and after 14 days. The surface roughness was determined by microscope, 3D Measuring Laser Microscope OLS4000 LEXT, OLYMPUS, and the reading of the gloss was taken by Micro Gloss device. After obtaining the data, the TwoWay ANOVA analysis was performed, it was found that the obtained result was statistically significant roughness variable, both for time-variant factor (p = 0.004), concentration of the carbamide peroxide (p = 0.007) and the interaction between both (p = 0.013). It was made for multiple comparisons test with Bonferroni adjustments, for analysis of the results.There was no statistically significant difference in gloss. Thus, it can be concluded that the carbamide peroxide 10% did not cause significant changes in roughness ceramic, but the carbamide peroxide at 16% caused an increased roughness after 14 days of application, averaging around 4, 0 micrometers. Therefore, the ceramic restorations must be protected before the application of bleaching agents based on carbamide peroxide 10 or 16%.
14

The Effect of Various Word Treatments on Chinese Vocabulary Comprehension During Multimedia Language Learning

Kim, Jeongwoon 01 July 2015 (has links)
The current study investigated the effect of viewing various types of word definitions-dictionary, glossed, and annotated definitions-on Chinese learners' vocabulary comprehension during video-based language learning. A total of 53 advanced Chinese learner participants were given access to various randomized word definitions while viewing the subtitled videos used in the experiment. Results showed that learners recalled words for which they viewed definitions significantly better after the experiment than before. The viewing of dictionary, glossed, or annotated definitions yielded comparable levels of word comprehension. In situations where learners did not view word definitions; however, word comprehension was not significantly higher on the posttest measures of recall. Attrition occurred whether participants viewed word definitions or not, but it occurred more severely for those words that learners chose not to look up definitions. The more a target word occurred, the better the word was comprehended. Survey results showed that participants preferred dictionary and annotated definitions more than glossed definitions. The results from this study suggest that word treatment is an effective way to comprehend vocabulary. If language learners and teachers lack resources to afford cost-intensive glosses and annotations, they can consider taking advantage of free, automatic online dictionaries, which are as effective as glosses and annotations.
15

Mikalojaus Daukšos Postilės marginalijos / Marginalia in Mikalojus Daukša‘s Postilla

Jankauskas, Benas 20 June 2012 (has links)
Marginalijos – vienas įdomiausių knygos elementų tiek M. Daukšos Postilėje, tiek ir visose kitose senosiose knygose visame pasaulyje. Šiuo metu jų tyrimams skiriama vis daugiau dėmesio. Bakalauro darbe aptariamos marginalijų klasifikavimo galimybės, tyrimo istorija ir raida, tyrimo kryptys siejant teorinę medžiagą su darbo šaltiniu. Kadangi marginalijos Lietuvoje dar tik pradedamos tirti, darbas iš dalies skirtas supažindinimui su šiuo knygos elementu. Darbe analizuojamos Postilės pirmosios dalies marginalijos, skirstomos į tris pagrindines grupes: glosas, rubrikas ir scholijas. Pagal specialiai susidarytą marginalijų klasifikaciją šios grupės dar skirstomos į pogrupius pagal atliekamas funkcijas. Atlikus tyrimą, daroma išvada, kad marginalijos Daukšos Postilėje dažniausiai atlieka pagalbinę funkciją – nurodo, kas pasakojama tam tikroje pastraipoje, paaiškina kitos kalbos, neaiškios tarmės žodį, informuoja, iš kurio šaltinio yra cituojama. Kita marginalijų paskirtis – tai galimybė Postilės vertėjui M. Daukšai knygos paraštėse parodyti skaitytojui lietuvių kalbos grožį, jos žodyno turtingumą. Darbo priede pateikiama 120 įdomiausių marginalijų – glosų – pavyzdžių, kuriuose matomas tiesioginis ryšys su pagrindiniu tekstu. / Marginalia are one of the most interesting elements of the book not only in Postilla by Mikalojus Daukša, but also in books worldwide. Currently, researches based on marginalija attract even more attention. Research of the final work contains theory of classification and development of similar researches. As this work is fresh in Lithuania, the goal of introducing marginalia should be considered too. Analyzed marginalia are divided into three main groups: glosses, rubrics and scholias. By special classification of marginalia of this book, groups are divided into subgroups. Analysis shows that marginalia in Postilla by M. Daukša help reader to understand the text easily. Other function of marginalia of this book is that the author can show the beauty and riches of his language. In the appendix of the work there are 120 most interesting examples of glosses, where the relation between text and marginalia is shown.
16

Influência do observador, do iluminante e do ângulo de visualização na perceptibilidade e aceitabilidade de diferenças de brilho superficial de resinas compostas / Influence of observer, illuminant and visualization field on perception and acceptability the difference of surface gloss of resin composites

Rocha, Rafael Santos 13 December 2017 (has links)
Submitted by Rafael Santos Rocha null (rafaelrocha_ss@hotmail.com) on 2017-12-21T01:55:24Z No. of bitstreams: 1 Dissertação mestrado - Rafael.pdf: 2092949 bytes, checksum: 7ff26a28718621a3aac72898b8ba2eb3 (MD5) / Submitted by Rafael Santos Rocha null (rafaelrocha_ss@hotmail.com) on 2017-12-21T12:31:26Z No. of bitstreams: 1 Dissertação mestrado - Rafael.pdf: 2092949 bytes, checksum: 7ff26a28718621a3aac72898b8ba2eb3 (MD5) / Approved for entry into archive by Silvana Alvarez null (silvana@ict.unesp.br) on 2018-01-04T15:18:48Z (GMT) No. of bitstreams: 1 rocha_rs_me_sjc.pdf: 2002864 bytes, checksum: 354dae44b5fb5e16adc9be584300a8eb (MD5) / Made available in DSpace on 2018-01-04T15:18:48Z (GMT). No. of bitstreams: 1 rocha_rs_me_sjc.pdf: 2002864 bytes, checksum: 354dae44b5fb5e16adc9be584300a8eb (MD5) Previous issue date: 2017-12-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi avaliar a influência de observadores sobre a percepção e aceitabilidade de brilho superficial de resinas compostas, sob diferentes iluminantes, em angulação livre e pré-determina em 60°. E ainda, determinar o limite de perceptibilidade e aceitabilidade da variação de unidade de brilho (∆UB) entre os espécimes. Foram confeccionados 8 espécimes cilíndricos de 6 mm de diâmetro e 1,5 mm de espessura de resina composta, bem como um espécime padrão de dente humano, com 0,5 mm de espessura em esmalte e 1 mm em dentina. Os espécimes receberam polimento a fim de que se obtivesse ao final do processo amostras com 10 UB, 20 UB, 30 UB, 40 UB, 50 UB, 60 UB, 70 UB e 80 UB e um padrão de dente humano de 80 UB. Foram selecionados 60 observadores (20 leigos, 20 alunos de graduação e 20 cirurgiões-dentistas). O estudo foi submetido e aprovado pelo comitê de ética local. Os participantes fizeram a qualificação do brilho superficial de resina composta em cabine de luz (Gti – Newburgh,NJ). Para tanto, as amostras foram posicionadas no interior da cabine, duas a duas de forma aleatória, de forma com que a luz incidisse sua superfície em um ângulo de 60°. Os observadores responderam perguntas específicas para se determinar o nível e limite de perceptibilidade das variações de brilho. Todas as análises foram realizadas em duas condições de iluminação, com iluminantes D65 e luz fluorescente. Cinquenta por cento dos observadores iniciaram as análises com ângulo de visualização livre, seguido da qualificação em angulação pré-definida em 60° e, os demais observadores fizeram as observações de forma oposta. Para o nível e limite de aceitabilidade da variação do brilho, as amostras foram individualmente comparadas com o padrão de dente humano. Os dados foram analisados pelo teste Modelo Generalizado Linear/Não-Linear PROBIT e regressão não-linear PROBIT (5%). Para a perceptibilidade, foram encontradas diferenças significantes para a variação de brilho (Δ UB) (p<0,001), para os observadores (p=0,043) e para os iluminantes (p<0,001), no entanto, não houve diferença entre o ângulo de visualização livre e fixo em 60° (p=0,303). Em relação à aceitabilidade, foram observadas diferenças significantes para a variação de brilho (Δ UB) (p<0,001), para os observadores (p=0,003), para os iluminantes (p=0,045) e no ângulo de visualização livre e fixo em 60° (p<0,001). Os limites de perceptibilidade e aceitabilidade, levando em consideração todos os fatores foi de 6,4 UB e 35,7 UB, respectivamente. Conclui-se que fatores rotineiramente encontrados em situações clínicas influenciam a perceptibilidade e aceitabilidade de diferenças de brilho superficial de resinas compostas e que apesar de perceberem limites menores de diferença de brilho, os observadores aceitam clinicamente diferenças cinco vezes maiores.
17

Conception de la détection d'un gonioreflectomètre métrologique pour mesurer la BRDF des surfaces / Design of the detection of metrological gonioreflectometer for measuring the BRDF of surface

Ouarets, Shiraz 03 June 2015 (has links)
Le but de ce travail de thèse est de doter la métrologie française d'un instrument de référence dédié à la caractérisation métrologique des propriétés réflectives des objets qui, du point de vue de l'apparence, sont à l'origine des sensations de couleur, de brillant, de texture, de translucidité…etc. Ce mémoire décrit la conception, réalisation et mise au point d'un dispositif de mesure de la fonction de distribution bidirectionnelle du facteur de luminance d'une surface plane (BRDF). La BRDF est la grandeur physique qui caractérise intégralement la réflexion lumineuse à la surface d'un matériau. En cela, sa mesure s'inscrit comme un outil indispensable pour la mesure de l'apparence car elle permet de connaître en détail le signal qui entre dans l'œil.Certaines surfaces présentent une apparence pigmentée, métallisée, nacrée ou encore interférentielle, ces surfaces, dites "goniochromatiques", ont la capacité de changer d'apparence en fonction de l'angle d'observation. Pour les caractériser, il est impératif d'effectuer une mesure de BRDF sous plusieurs conditions d'observation et d'illumination. L'outil de mesure de la BRDF est un gonioréflectomètre, dédié à des mesures dans le domaine UV - Visible (250 nm – 900 nm).Le montage expérimental consiste en deux lignes distinctes. La première, appelée voie spectrale, est dédiée à l'étude de la couleur. Elle est constituée d'une illumination fixe assurée par une lampe à décharge de xénon filtrée par un monochromateur puis focalisée sur la surface étudiée. La détection, mobile, est assurée par un système optique constitué de lentilles et de miroirs qui servent à renvoyer la lumière réfléchie par la surface sur la photodiode.La deuxième ligne, appelée voie spatiale, est la dédiée à l'étude du brillant. Elle requière une résolution angulaire qui égale l'acuité visuelle de l'œil humain (0,03°) c'est cette partie qui introduit l'originalité de notre instrument. Sur cette voie, la détection est fixe et est basée sur la combinaison d'une optique de Fourier et d'une caméra CCD (512x512 pixels). L'illumination est mobile et est assurée par une lampe incandescente à filament de tungstène collimatée sur l'échantillon.Les deux lignes partagent un robot porte-échantillon qui offre six dégrées de liberté qui sert à reproduire toutes les directions d'illumination et d'observation au-dessus de l'échantillon.Mots clés : Couleur, Brillant, BRDF, Goniochromatisme, Pic spéculaire. / The aim of this thesis is to provide the French Metrology with a reference instrument that can be used for measuring the appearance of objects. Several physical properties of object appearance are used not only to identify the object itself but also determine its quality. These include color, gloss, texture and translucency. This work describes the design, characterization and the implementation of an instrument that has been built particularly to measure the bidirectional reflectance distribution function (BRDF) of planar surfaces. BRDF is a physical quantity that enables measuring the surface color and gloss. Accordingly it is important to ensure accurate and traceable measurements of such a quantity in order for a comprehensive understanding of surface properties to be fulfilled.Some surfaces show pigmented, metallic, sparkling or pearlescent appearance. These surfaces, called goniochromatic surfaces, have the ability to change their appearance depending on the viewing angle. To characterize them, it is necessary to deliver surface reflectance measurements at several directions and under different illumination conditions. The instrument that enables these measurements is called gonioreflectometer.The experimental setup we have designed consists of two separate detection lines. The first line, called "color line", is used to study the color. It consists of a stationary illumination source that uses a xenon lamp spectrally resolved by a monochromator. The light coming out from the source is focused on the surface under investigation. The reflected light by the surface is collected by using a lens and directed onto a photodiode by a mirror. This detection system can be moved over a wide angular range so as to measure the BRDF.The second line, called "gloss line", is used to measure the gloss of the surface. In order to be very close to the average human observer, high angular resolution is required. In this line the detection part is stationary. It consists of a Charged Coupled Device (CCD) camera of 512 x 512 pixels. The source used to illuminate the surface is an incandescent tungsten lamp. Angular measurements in this line are provided by the movement of the illumination source itself. Both color and gloss lines share a robot sample-holder that provides six degrees of freedom. This of course facilitates measurements over varies detection and illumination directions of the sample.Key words: Color, Gloss, BRDF, Goniochromatisme, Specular pic.
18

Comportement des aciers inoxydables ferritiques stabilisés lors des étapes de recuit et décapage / Behaviour of stabilised ferritic stainless steels during the annealing and the pickling stage - Influence of the stabilizer elements (Nb, Ti)

Issartel, Jérôme 10 February 2012 (has links)
Lors de l’élaboration des aciers plats inoxydables, un recuit haute température de courte durée (60 s environ), sous atmosphère oxydante (O2/H2O/CO2/N2) est mis en place après laminage à froid. Ce recuit entraîne la formation d’une couche d’oxyde de faible épaisseur qui est éliminée par un décapage. Ces étapes de recuit et décapage peuvent entraîner une perte de qualité du produit fini, se traduisant par une perte de brillance. L’acier bistabilisé Ti, Nb (AISI 441) est sensible à la dégradation de surface. L’objectif de la thèse est d’identifier les phénomènes à l’origine de la perte de brillance. Les travaux menés consistent à étudier les couches d’oxyde et le comportement de l’acier lors du décapage. Une morphologie originale de l’interface interne avec la présence de protrusions métalliques a été observée. L’étude des protrusions par la microscopie électronique à balayage couplée à une sonde ionique focalisée : MEB-FEG/FIB, a permis de proposer un mécanisme décrivant leur formation. Ce mécanisme s’appuie sur la précipitation de la silice qui semble également être un élément clé pour comprendre la dégradation de surface. Un lien entre perte de brillance et teneur en chrome dans le substrat a été établi. La déchromisation de l’acier liée au recuit est susceptible d’être facilitée par les protrusions. / During the industrial processing line of stainless steel flat products, a short annealing (60 s) at high temperature in a gas furnace-oxidizing atmosphere (O2/H2O/CO2/N2) takes place after cold rolling. This annealing leads to the formation of a thin oxide film which is then removed by a pickling step at the end of the process. The annealing and pickling stages may cause a loss of gloss, resulting in a loss of product quality. The steel bistabilizied Ti, Nb (AISI 441) is sensitive to this surface degradation. The aim of this thesis is to identify the phenomena leading to the loss of gloss. Our work consists in studying the oxide layers and the behavior of steel during pickling. A peculiar morphology of the internal interface with the presence of metallic protrusions was observed. The protrusions investigation using a scanning electron microscopy coupled with a focused ion beam: MEB-FEG/FIB, allowed us to propose a mechanism of their formation. This mechanism is based on the precipitation of silica which also appears to be a key point to understand the surface degradation. A link between the loss of gloss and the chromium content in the substrate was established and the chromium depletion related to the annealing is likely to be facilitated by protrusions.
19

Du texte à l'œuvre : L'édition commentée du Livre-oreiller de Sei Shônagon par Kitamura Kigin (1674) / From text to literary work : The commentary edition by Kitamura Kigin of Sei Shônagon's ’Pillow Book’ (1674)

Lesigne-Audoly, Evelyne 04 December 2013 (has links)
Cette thèse porte sur une édition commentée du Livre-oreiller (Makura no sôshi枕草子 ; c. 1000), réalisée par Kitamura Kigin 北村季吟 en 1674 et intitulée Commentaire de l’aurore au printemps (Shunshoshô 春曙抄). Le Livre-oreiller est atypique et hétérogène. Atypique, il ne ressemble à aucune autre œuvre japonaise de la même époque. Hétérogène, il est difficile d’enfermer la diversité de ce qui le compose dans une définition unique, ou de caractériser ce qui pourrait assurer sa cohérence. La biographie de son auteur, désignée par le surnom de « Sei Shônagon » 清少納言, est incertaine. Enfin, les différents manuscrits présentent entre eux des différences profondes.L’objectif de ce travail est de reconstituer la trajectoire qu’a suivie Le Livre-oreiller pour passer du texte — objet écrit se manifestant comme multiple, instable, indéterminé, non interprété — à l’œuvre — entité unique, stable, signifiante et interprétable. Notre postulat est que le Commentaire de l’aurore au printemps constitue un moment décisif dans cette évolution. Le poète Kitamura Kigin, auteur de cette édition commentée, fut un influent commentateur de textes anciens, à une époque caractérisée par le développement du livre imprimé et la démocratisation de l’accès à la connaissance lettrée. Notre travail se situe à la croisée de l’étude littéraire, des études de la réception, et de l’histoire matérielle du livre. / This research is about The Spring Dawn Commentary, a commentary edition of The Pillow Book (Makura no sôshi 枕草子 ; c. 1000), written by Kitamura Kigin 北村季吟 in 1674.The Pillow Book is both atypical and heterogeneous. Atypical in that it is not readily comparable to other texts of the same era. Being heterogeneous, it evades attempts to characterize in one single definition all what it is composed of. The life of the author, known as “Sei Shônagon” 清少納言, remains obscure, and ancient manuscripts are extremely diverse in the text they present. The purpose of this study is to observe the course by which The Pillow Book has changed from “text” to “ literary work”. That is, how what was plural, inconstant and uncertain in its meaning became one, constant, meaningful and thus suitable for interpretation. The argument of this research is that The Spring Dawn Commentary played a major role in this process.17th century in Japan was characterized by a rapid development in book printing technology and the book trade, thus enabling the spread of knowledge. In this context, the poet Kitamura Kigin was one of the most respected commentators of ancient literature.
20

Physical, mechanical and surface properties of dental resin-composites

Alrahlah, Ali Awad January 2013 (has links)
Since resin composites were first presented to dentistry more than half a century ago, the composition of resin composites has developed significantly. One major change was that the reinforcing filler particles were reduced in size to generate materials of a given filler content that display better physical and mechanical properties. Resin composites may absorb water and chemicals from the surrounding environment but at the same time, composites may release constituents to their surroundings. The physical/mechanical properties of a restorative material provide an indication of how the material will function under stress in the oral environment. The aims of this research were to examine the effects of water at 37°C on the physical and mechanical properties, and the effect of food-simulating solvents of a variety of experimental and contemporary resin composites, on the surface properties. Eight representative resin composites were selected (Exp. VT, BL, NCB, TEC, GSO, XB, VDF and CXD). Due to the recent development of bulk fill materials on the market during the course of this research, the post-cure depth of cure of new bulk fill materials was also investigated. Five representative resin composites were selected: TBF, XB, FBF, VBF and SF. Water sorption and solubility were investigated at 37°C for 150 days. Sorption and solubility are affected by the degree of hydrophilicity of the resin matrix. The bulk fill materials examined showed the lowest water sorption and solubility. Laser scan micrometer (LSM) was used to investigate hygroscopic expansion. The extent of the hygroscopic expansion positively correlated with the amount of water sorption. The effect of water on fracture toughness was also examined. A self-adhesive hydrophilic resin matrix decreased in fracture toughness after 7 days of storage at 37°C. By contrast, the least water absorbed bulk fill material increased in fracture toughness over time. The effect of food-simulating solvents (distilled water, 75% ethanol/water and MEK) on surface micro-hardness, colour stability and gloss retention were investigated. The MEK solvent resulted in the lowest micro-hardness and the greatest colour change (ΔE) for most of the examined composites, while the 75% ethanol/water solution caused the greatest loss in gloss for most of the examined composites. A highly filled nano-composite showed the best result over time, regardless of the condition of storage. Surface micro-hardness profiles were used as an indirect method to assess the depth of cure of bulk fill resin composites. The examined bulk fill resin composites can be cured to an acceptable depth (4 mm).

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