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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.
61

Tratamento do ectrópio cicatricial da pálpebra com aplicação de substâncias injetáveis. / Injectable substances to treat eyelid cicatricial ectropion.

Veloso, Laryssa Kataki de Oliveira 30 May 2018 (has links)
Submitted by Laryssa Kataki De Oliveira Veloso (laryssakataki@hotmail.com) on 2018-06-15T13:25:57Z No. of bitstreams: 1 DISSERTAÇÃO LARYSSA FINAL.pdf: 1251310 bytes, checksum: 43a08fca6a961ece3b6833de3671f737 (MD5) / Approved for entry into archive by ROSANGELA APARECIDA LOBO null (rosangelalobo@btu.unesp.br) on 2018-06-18T20:28:55Z (GMT) No. of bitstreams: 1 veloso_lko_me_bot.pdf: 1251310 bytes, checksum: 43a08fca6a961ece3b6833de3671f737 (MD5) / Made available in DSpace on 2018-06-18T20:28:55Z (GMT). No. of bitstreams: 1 veloso_lko_me_bot.pdf: 1251310 bytes, checksum: 43a08fca6a961ece3b6833de3671f737 (MD5) Previous issue date: 2018-05-30 / OBJETIVO: Avaliar a eficiência da injeção de ácido hialurônico (AH) ou de soro fisiológico (SF), aplicados no subcutâneo da pálpebra inferior de portadores de ectrópio cicatricial, visando à correção não cirúrgica do mal posicionamento palpebral. MÉTODOS: este foi um estudo prospectivo, intervencionista, envolvendo 23 pálpebras de 15 portadores de ectrópio cicatricial, divididos aleatoriamente em dois grupos: G1 (13 pálpebras) no qual foram feitas quatro aplicações de 4ml de SF (Cloreto de Sódio 0,9%, Equiplex, Goiás, Brasil), associado a 1ml de cloridrato de lidocaína a 2,0% sem vasoconstritor (Xylestesin®, Cristália, São Paulo, Brasil), em intervalos de uma semana entre as aplicações; e G2 (10 pálpebras) que receberam aplicação de 1 ml de AH (Restylane® Lidocaine, Q med, Uppsala, Suécia) em aplicação única. Foram avaliadas as variáveis demográficas dos participantes, as queixas, o grau do ectrópio, o grau de flacidez palpebral, a localização do ectrópio, além de avaliações quantitativas realizadas utilizando-se a fotodocumentação sistematizada dos olhos dos pacientes, 30 dias após a primeira aplicação no G1 e 7 e 30 dias após as aplicações do G2. As imagens obtidas foram transferidas para um computador e avaliadas utilizando-se o programa Image J, avaliando-se a distância da pálpebra inferior até o reflexo corneano (DMR2), distância limbo-margem (LM), ângulo da comissura interna (AI) e externa (AE), área total (AT), lateral (AL) e medial (AM). As áreas a serem avaliadas foram delimitadas por uma linha que une as duas comissuras e outra linha que coincide com a margem da pálpebra inferior. As avaliações foram feitas sem tração e com tração da pálpebra inferior para baixo. Todos os dados foram transferidos para a planilha Excel, sendo realizada a análise comparativa antes e após as aplicações nos dois grupos. RESULTADOS: Os grupos foram semelhantes quanto a idade, sexo, cor da pele e grau do ectrópio. Houve melhora signficativa dos sintomas nos indivíduos de G2 após a aplicação de AH. Apos a injeção, o G1 apresentou redução significativa de AI com e sem tração, AE com tração, LM sem tração e AM com tração. No G2, após as injeções as medidas AI sem tração, AE, DMR2, AT e AM com e sem tração, LM e AL com tração apresentaram alterações significativas (p<0,05). A comparação das medidas realizadas no G2 após sete e 30 dias mostrou estabilidade dos resultados obtidos com a injeção de AH. CONCLUSÃO: A aplicação de AH na pálpebra inferior de portadores de ectrópio cicatricial mostrou melhora parcial do mal posicionamento palpebral. A aplicação de SF não foi efetiva no tratamento do ectrópio cicatricial. / PURPOSE: Evaluate the efficiency of injection of hyaluronic acid (HA) or saline solution (SF) applied to the lower eyelid subcutaneous, aiming at the non-surgical correction of cicatricial ectropion. METHODS: This was a prospective study involving 23 eyelids of 15 patients with cicatricial ectropion, randomly divided into two groups: G1 (13 eyelids) with four applications of 4ml of SF (Sodium Chloride 0.9%, Equiplex, Goiás , Brazil), associated to 1ml of lidocaine hydrochloride 2% without vasoconstrictor (Xylestesin®, Cristália, São Paulo, Brazil), with a one-week interval between applications; and G2 (10 eyelids) which received single application of 1 ml of AH (Restylane® Lidocaine, Q med, Uppsala, Sweden). Demographic variables, complaints, ectropion degree, eyelid flaccidity degree, ectropion location, and quantitative assessments using the systematized photodocumentation of patients eyelids 30 days after the first application in G1 and 7 and 30 days after applications in G2 were studied. The images were transferred to a computer and evaluated using the Image J program and the distance between the lower eyelid margin to corneal reflex (DMR2), limbus margin distance (LM), internal angle (IA) and external angle (EA), total (TA), lateral (LA) and medial areas (MA) were analyzed. The area measurements were delimited by a line between the two commissures and along the lid margin of the lower eyelid. The evaluations were done without traction and with traction downward of the lower eyelid. All data were transferred to the Excel spreadsheet and comparative analysis was performed before and after the applications in the two groups. RESULTS The groups were similar according to age, sex, skin color and degree of ectropion. There was a significant improvement in G2 individuals after the application of AH. After injections G1 presented a significant reduction of AI with and without traction, EA with traction, LM without traction and AM with traction. The G2 after injections showed AI measurements without traction, EA, DMR2, TA and MA with and without traction, LM and LA with traction with significant alterations (p <0.05). The comparison of the G2 measurements obtained after 7 and 30 days showed stability of the results obtained with the AH injection. CONCLUSION: The application of AH in the lower eyelid of patients with cicatricial ectropion resulted in partial improvement of palpebral malposition. The application of SF was not effective in the treatment of cicatricial ectropion.
62

Obtencao e caracterizacao de ceramicas no sistema Si-Al-O-N-C empregando pirolise de misturas de polissiloxano e cargas

ROCHA, ROSA M. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:49:18Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:20Z (GMT). No. of bitstreams: 1 09621.pdf: 29120771 bytes, checksum: 09052cbfc1e575071c4639bed85d4176 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
63

Avalia??o mec?nica e microestrutural de comp?sitos de poli?ster com adi??o de cargas minerais e res?duos industriais

Santos, Eylisson Andr? dos 26 July 2007 (has links)
Made available in DSpace on 2014-12-17T14:58:25Z (GMT). No. of bitstreams: 1 EylissonAS.pdf: 1489335 bytes, checksum: 8fcffdaaafca0f8691545bd2bc5dd5fc (MD5) Previous issue date: 2007-07-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / With the current growth in consumption of industrialized products and the resulting increase in garbage production, their adequate disposal has become one of the greatest challenges of modern society. The use of industrial solid residues as fillers in composite materials is an idea that emerges aiming at investigating alternatives for reusing these residues, and, at the same time, developing materials with superior properties. In this work, the influence of the addition of sand, diatomite, and industrial residues of polyester and EVA (ethylene vinyl acetate), on the mechanical properties of polymer matrix composites, was studied. The main objective was to evaluate the mechanical properties of the materials with the addition of recycled residue fillers, and compare to those of the pure polyester resin. Composite specimens were fabricated and tested for the evaluation of the flexural properties and Charpy impact resistance. After the mechanical tests, the fracture surface of the specimens was analyzed by scanning electron microscopy (SEM). The results indicate that some of the composites with fillers presented greater Young s modulus than the pure resin; in particular composites made with sand and diatomite, where the increase in modulus was about 168 %. The composites with polyester and EVA presented Young s modulus lower than the resin. Both strength and maximum strain were reduced when fillers were added. The impact resistance was reduced in all composites with fillers when compared to the pure resin, with the exception of the composites with EVA, where an increase of about 6 % was observed. Based on the mechanical tests, microscopy analyses and the compatibility of fillers with the polyester resin, the use of industrial solid residues in composites may be viable, considering that for each type of filler there will be a specific application / Com o crescimento acelerado do consumo de produtos industrializados, principalmente de produtos descart?veis, o aumento excessivo de lixo e sua disposi??o em lugares inadequados tornaramse um dos grandes problemas da sociedade moderna. A utiliza??o de res?duos s?lidos industriais como carga em comp?sitos ? uma id?ia que surge com o intuito de buscar alternativas adequadas para o reaproveitamento desses res?duos, visando tamb?m o desenvolvimento de materiais com propriedades superiores ?quelas dos materiais convencionais. Neste trabalho, estudouse a influ?ncia da adi??o de res?duos industriais de poli?ster e EVA (Etileno Acetato de Vinila), al?m de cargas de areia e diatomita, nas propriedades mec?nicas de comp?sitos de matriz poli?ster. O principal objetivo foi avaliar o comportamento mec?nico desses materiais com a adi??o de cargas de res?duo industrial, comparandoos com as propriedades da resina pura. Corposdeprova foram confeccionados e as propriedades mec?nicas dos comp?sitos obtidos foram analisadas, atrav?s de testes de flex?o e de impacto. Ap?s os ensaios mec?nicos, a superf?cie de fratura dos corposdeprova foi analisada por microscopia eletr?nica de varredura (MEV). Os resultados dos ensaios de flex?o mostraram que alguns comp?sitos apresentaram maior m?dulo, quando comparados com os resultados da resina pura; com destaque para os confeccionados com areia e diatomita, em que o aumento do m?dulo chegou a 168 %. Os comp?sitos confeccionados com adi??o de poli?ster e de EVA apresentaram m?dulo mais baixo que o da resina pura. Tanto o limite de resist?ncia quanto ? deforma??o m?xima, apresentaram redu??o nos seus valores, quando da adi??o de cargas. A resist?ncia ao impacto, em rela??o ? resina pura, foi reduzida em todos os comp?sitos com adi??o de cargas, exceto nos comp?sitos com a adi??o de EVA, onde houve um aumento de aproximadamente 6 %. Com base nos ensaios mec?nicos realizados, nas an?lises microsc?picas e na compatibilidade das cargas com a resina poli?ster, a utiliza??o das cargas de res?duos s?lidos industriais em comp?sitos mostrouse vi?vel, considerando que para cada tipo de carga haver? uma aplica??o espec?fica
64

Obtencao e caracterizacao de ceramicas no sistema Si-Al-O-N-C empregando pirolise de misturas de polissiloxano e cargas

ROCHA, ROSA M. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:49:18Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:20Z (GMT). No. of bitstreams: 1 09621.pdf: 29120771 bytes, checksum: 09052cbfc1e575071c4639bed85d4176 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
65

Dispersion de charges d'oxydes de terres rares, Er2O3 et Pr6O11, dans une matrice polymère / Dispersion of rare earth oxide fillers, Er2O3 et Pr6O11, in a polymer matrix

De Rancourt, Yoann 18 December 2013 (has links)
Ce travail de thèse porte sur l'incorporation de charges minérales d'oxyde d'erbium, Er2O3, et d'oxyde de praséodyme, Pr6O11, dans une matrice polymère de type élastomère, ceci dans le cadre d'un projet industriel de remplacement du plomb dans des équipements de radioprotection. L'objet de cette thèse était d'améliorer la dispersion des charges au sein de la matrice par le biais de procédés de traitements chimiques de ces particules. Divers types de fonctionnalisations de surface ont été employés afin de compatibiliser celles-ci avec une matrice organique, notamment par greffage de composés de type acides phosphoniques. Plusieurs acides phosphoniques ont ainsi pu être utilisés avec succès pour la fonctionnalisation des deux types de charges. La caractérisation de ces différentes fonctionnalisations représente une part importante de ce projet. Des techniques d'analyse innovantes, aussi bien directes qu'indirectes ont été employées dans ce but, à savoir de la Py-GC/MS pour la détection des composés ancrés à la surface des charges, de la fluorescence X et de la spectroscopie infrarouge dans un objectif de quantification, mais aussi des études cinétiques de sédimentation des charges dans un milieu liquide organique. Finalement, des composites ont pu être obtenus par mélange des charges, traitées et non traitées, avec une matrice polyuréthane. Des essais de traction ont permis de montrer clairement une amélioration des propriétés mécaniques de certains des composites, grâce à la fonctionnalisation des charges par les acides phosphoniques. / This thesis focuses on the incorporation of mineral fillers of erbium oxide, Er2O3, and praseodymium oxide, Pr6O11, in an elastomeric polymer matrix, in the context of an industrial project to replace the lead in radiation protection equipment. The actual purpose of this thesis was to improve the dispersion of the fillers in the matrix through chemical treatment processes of these particles. Various types of surface functionalization were used to compatibilize them with an organic matrix, in particular by grafting compounds such as phosphonic acids. Hence, several phosphonic acids have been successfully used for the functionalization of both types of fillers. The characterization of these functionalizations is an important part of this project. Innovative analysis techniques, both direct and indirect have been used for this purpose, namely Py-GC/MS to detect the chemical compounds anchored to the surface of the fillers, X-ray fluorescence and FTIR spectroscopy with a quantification target, but also a study of sedimentation kinetics of the fillers in an organic medium. Finally, composites were obtained by mixing the fillers, untreated and treated, with a polyurethane matrix. Tensile tests have clearly shown an improvement of mechanical properties for some of the composites, due to the functionalization of the fillers by phosphonic acids.
66

Transfert métallique lors des opérations de toilage à sec des aciers : effet des charges actives

Vernhet, Laura 09 July 2015 (has links)
Dans les industries automobile et aéronautique, les opérations de finition des pièces métalliques sont souvent réalisées avec des bandes abrasives ; on parle alors de « toilage ». Lors des opérations de toilage à sec des aciers, les conditions à l’interface entre l’outil abrasif et la pièce métallique usinée sont très sévères en termes de pression et de température. Un transfert métallique, communément appelé « chargement métallique » est observé à la surface des grains abrasifs en céramique de la bande abrasive, entrainant une chute de ses performances de coupe. L’objectif de ce travail est de comprendre ce phénomène de chargement métallique et notamment de mettre en évidence les paramètres l’influençant. L’effet de la nature des grains, de la nature des aciers ou encore de la présence de charges actives dans la bande abrasive ont donc été étudié. Une étude a donc été réalisée à différentes échelles : à l’échelle globale du contact bande abrasive / métal sur un dispositif industriel de toilage, puis à l’échelle plus locale du contact entre la céramique (du grain abrasif) et du métal, grâce à un dispositif tribologique adapté. Des caractérisations physico-chimiques par XPS (X-Ray Photoelectron Spectroscopy) et TEM-EDX (Transmission Electron Microscopy couplée avec la spectroscopie Energy Dispersive X-ray) des bandes abrasives ont également été réalisées. L’influence des charges actives, produits fluorés ajoutés à la résine de la bande abrasive, sur l’adhésion du métal sur le grain céramique a ainsi été mise en évidence, notamment dans le cas de l’acier inoxydable 304 où le chargement métallique a été fortement limité. Les mécanismes d’action de ces charges actives sont ensuite discutés. / In automotive and aeronautic industries, grinding operations can sometimes be done with abrasive belts. During dry metal grinding, conditions at the interface between the abrasive tool and the metal workpiece are very hard in terms of pressure and temperature. Metal transfer, known as “metal capping”, is observed at the surface of the abrasive ceramic grain inducing a drop in the cutting efficiency. The objective of this work is to understand this metal capping phenomenon and to highlight the parameters which have an influence on it. The effects of abrasive grain nature, metal nature or active filler presence in the abrasive belt are then studied. A study has been done at different scales: at the global scale of the abrasive belt / metal contact thanks to an industrial grinding test, and then at the more local scale of the contact between ceramic (from the abrasive grain) and metal, thanks to a suitable tribological device. Physicochemical characterizations by XPS (X-Ray Photoelectron Spectroscopy) and TEM-EDX (Transmission Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy) were carried out on worn abrasive belts. The influence of the active fillers – fluorinated products added in the resin of the abrasive belt – on metal adhesion on the ceramic grain was then observed, especially in the case of the 304 stainless steel grinding where metal capping was significantly reduced. Action mechanisms of these active fillers were finally discussed.
67

Fabrication Of Epoxy Composites With CTBN And Fly Ash As Individual And Hybrid Fillers : Studies On Curing Schedule And Mechanical Properties Under Static And Dynamic Loading Conditions

Santra, Sanjitarani 01 1900 (has links) (PDF)
No description available.
68

Modified epoxy coatings on mild steel: A study of tribology and surface energy.

Dutta, Madhuri 08 1900 (has links)
A commercial epoxy was modified by adding fluorinated poly (aryl ether ketone) and in turn metal micro powders (Ni, Al, Zn, and Ag) and coated on mild steel. Two curing agents were used; triethylenetetramine (curing temperatures: 30 oC and 70 oC) and hexamethylenediamine (curing temperature: 80 oC). Variation in tribological properties (dynamic friction and wear) and surface energies with varying metal powders and curing agents was evaluated. When cured at 30 oC, friction and wear decreased significantly due to phase separation reaction being favored but increased when cured at 70 oC and 80 oC due to cross linking reaction being favored. There was a significant decrease in surface energies with the addition of modifiers.
69

The effect of filler type and shape on HMA energy dissipation performance.

Gebremeskel Kiflat, Yohannes January 2013 (has links)
Hot mix asphalt pavements require adequate compaction to achieve the required density to resist rutting. The amount of energy required to achieve the optimum degree of compaction depends on the type of gradation, bitumen content, filler type and shape, type of compaction equipment etc. In this study, the net energy required to reduce the specimen volume (size) after each gyration of the superpave gyratory compactor is used as the compaction energy index (CEI) to measure the compactability of the samples. Samples with different filler types and content are used for the analysis. Effect of fillers on the viscosity of the mastic has been studied previously. Viscosity of mastics in return affects the compactability of the mix in general. In this regard this paper tries to study the effect of fillers on the compaction of hot mix asphalt with the help of the superpave gyratory compactor. Moreover, resistance of the asphalt mix samples against rutting is evaluated using the simple performance test. In this test, the sample is subjected to a hydraulic loading while strain transducers attached to the sample measure the displacement. A computer program receives the displacement data at various frequencies and calculates the dynamic modulus and flow number which are used for the evaluation of the pavement performance.     :
70

Rhéologie et mise en oeuvre de formulations polymères hautement chargées / Rheology and processing of highly filled materials

Rueda, Martha Margarita 23 March 2017 (has links)
Nous présentons dans ce travail une étude approfondie de la rhéologie à l'état fondu de composites très chargés en particules inorganiques. Les systèmes modèles étudiés sont composés de particules de ferrites ou de fibres de verre dispersées dans une matrice polypropylène. Le comportement rhéologique linéaire et non-linéaire ainsi que la morphologie des composants du mélange ont été étudiés. Sous différentes conditions d'écoulement, nous avons pu mettre en évidence la relation étroite qu'il existe entre la microstructure du matériau, sa formulation et ses propriétés rhéologiques. Nous avons ainsi évalué les principaux paramètres liés à la charge (e.g., distribution de taille, facteur de forme, chimie de surface) sur la viscosité du mélange. Ces travaux ont montré que l'ajout de charges dans une matrice thermoplastique change fondamentalement la rhéologie linéaire et non-linéaire du mélange. Sous écoulement dynamique, nous avons pu quantifier les interactions entre les charges (force de contact) et charges-polymère. D'une part, les systèmes ferrites/polypropylène ont montré une forte structuration dans le temps, ce qui se traduit par un comportement type réseaux à très faibles déformation. D'autre part, les systèmes fibres/polypropylène ont montré qu'un facteur de forme plus élevé et de meilleures interactions fibre-fibre favorisaient la création du réseau de particules. Sous écoulement permanent, les phénomènes non-linéaires ont été également étudiés. Nous n'avons pas mis en évidence de phénomènes de glissement pour l'ensemble de ces systèmes. Plus particulièrement, le système ferrites/polypropylène a montré une atténuation du comportement pseudo-plastique à haute vitesse de cisaillement. Ainsi, ce travail expérimental a contribué à la compréhension des propriétés d'écoulement de ces systèmes complexes / We present in this work a complete study of the melt rheological behavior of highly filled polymers. We study the rheological behavior of two model systems, ferrite particles and short-glass fibers dispersed in polypropylene. We investigate the structural features of such complex materials by linear and non-linear rheological behavior. Under different flow conditions, we show the close relationship between the variation in the microstructure, the formulation and the flow properties. We evaluate the effect of the main parameters related to the filler (e.g., particle size distribution, aspect ratio, surface chemistry) on the viscosity of the mixture. This work shows that the addition of fillers fundamentally changes the linear and non-linear viscoelasticity of the molten composite. Under dynamic flow, we are able to quantify the particle-particle and matrix-particle interactions. Therefore, we study the creation of the filler network with increasing the particulate phase. On the one hand, ferrite/polypropylene systems presented a network structure that evolves over time which manifest by a solid-like behavior accentuation at very low deformations. On the other hand, fibers/polypropylene composites showed that the higher the aspect ratio and the interparticle interactions, the higher is the probability to create a network structure. Under steady state flow, the non-linear behavior is studied. Wall slip effects were found to be negligible under the flow conditions studied in this work. In particular, ferrite/polypropylene showed an attenuation of the shear-thinning behavior at low shear rates. Thus, this experimental work has contributed to the understanding of the flow properties of these complex materials

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