No description available.

Made available in DSpace on 2015-03-26T13:35:20Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4132930 bytes, checksum: 1169203ed33a5e53252821abccd6cf81 (MD5) Previous issue date: 2013-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work, ultra-thin layers of oxides grown using the technique of atomic layer deposition were characterized by measurements of x-ray reflectivity. TiO2:Al2O3 samples were grown using titanium isopropoxide (Ti(Hi-Pr)4), trimethylaluminum (Al(CH3)3) and water. The proportion of alumina was changed from 8 to 44% by varying the number of cycles of each precursor. TiO2:NiO samples were also grown using nickelocene (NiCp2) and water as precursors for NiO. The x-ray reflectivity measurements were performed at the Brazilian Synchrotron Light Laboratory and showed a reduction in deposition rate during growth of the TiO2:NiO series of samples, which prevented its use in the remainder of the study. The experimental data of TiO2:Al2O3 samples were analyzed using 03 simulation software: MOTOFIT, a free package designed to run on the IGOR Pro platform, and two MATHEMATICA codes; a first one based on kinematic approximation and another based in the Parrat recursion s method. The fitting procedure was based on two models: single layer, considering alumina as dopant, and multilayer, with sample composed of alternate layers of TiO2 and Al2O3. We conducted a detailed comparison of the results obtained from the softwares and models used and analyzed the influence of various parameters on the fits obtained. The fittings allowed the determination of various sample parameters, such as electron density and thickness of each layer and the roughness of the various interfaces. Comparing the software, we found that the best fits to the experimental data were obtained using the Parrat recursion s method. The multilayer model resulted in a better fit, reflecting the repetitive nature of the growth process, although the interface roughness values obtained were too large compared to layer thickness. Irrespective of software and the model used, the results show that atomic layer deposition can be used to obtain layers with controlled thickness and roughness less than 1 nm, independent of the number of cycles used in the deposition process. / Neste trabalho, camadas ultra-finas de óxidos, crescidas pela técnica de deposição por camada atômica, foram caracterizadas através de medidas de refletividade de raios-x. As amostras de TiO2:Al2O3 foram crescidas utilizando a técnica de deposição por camada atômica (ALD) usando como precursores isopropóxido de titânio (Ti(O-i-Pr)4), trimetilalumínio (Al(CH3)3) e água. A proporção de alumina foi modificada de 8 á 44%, variando a quantidade de ciclos de cada um dos precursores. Foram crescidas, também, amostras de TiO2:NiO, utilizando Niqueloceno (NiCp2) e água como precursores para NiO. As medidas de refletividade de raios-x foram realizadas nas instalações do Laboratório Nacional de Luz Síncrotron e mostraram uma redução na taxa de deposição durante o crescimento da série de amostras de TiO2:NiO, que impediu a sua utilização no restante do estudo. Os resultados experimentais das amostras de TiO2:Al2O3 foram analisados utilizando 03 softwares de simulação: MOTOFIT, um pacote livre desenvolvido para rodar na plataforma IGOR Pro, e dois códigos desenvolvidos para rodar na plataforma MATHEMATICA, o primeiro baseado na aproximação cinemática e o segundo no método de recursão de Parrat. Os ajustes das curvas experimentais foram feitos utilizando dois modelos: o de camada simples, considerando a alumina e o óxido de níquel como dopantes, e o de multicamada. Foi feita uma comparação detalhada entre os softwares e os modelos utilizados, analisando a influência dos vários parâmetros nos ajustes obtidos. Estes ajustes permitiram a determinação de diversos parâmetros característicos das amostras, tais como a espessura e a densidade eletrônica de cada camada e a rugosidade das várias interfaces. Na comparação entre os softwares, observou-se que o melhor ajuste aos dados experimentais foi obtido utilizando o método de recursão de Parrat. Em relação aos dois modelos utilizados, o de multicamada foi o que permitiu um melhor ajuste, refletindo a natureza repetitiva do processo de crescimento, apesar de fornecer valores de rugosidade das interfaces muito grande, comparados à espessura das camadas. Independente do software e do modelo utilizado, os ajustes permitem afirmar que a técnica de deposição por camada atômica permite a obtenção de camadas com espessura controlada e rugosidade menor que 1 nm, independente do número de ciclos utilizados na deposição.

Orientador: Lourenço Correr Sobrinho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-27T00:03:33Z (GMT). No. of bitstreams: 1 Brisolara_PauloGilbertodaSilveira_M.pdf: 2380503 bytes, checksum: edcc34fb503e863b41cb601c8ce011ef (MD5) Previous issue date: 2000 / Resumo: o propósito deste estudo foi avaliar o ajuste cervical antes e após a cimentação de coroas totais metálicas confeccionadas com liga de níquel-cromo (Verabond 11), em preparos sobre dentes bovinos com diferentes términos cervicais: chanfro em 45° , ombro biselado em 20° e ombro reto, com os cimentos de fosfato de zinco, ionômero de vidro e resinoso. Noventa coroas totais metálicas foram fundidas com a liga de níquel-cromo (Verabond 11) utilizando o maçarico gás-oxigênio. Após a fundição, as coroas foram adaptadas sobre os preparos com carga estática de 9 kg. A discrepância marginal foi medida com micrômetro digital (Mitutoyo) e as coroas metálicas foram fixadas sobre os dentes com os cimentos de fosfato de zinco, ionômero de vidro e resinoso, manipulados de acordo com as recomendações dos fabricantes. Em seguida, a discrepância marginal foi medida novamente. Os resultados submetidos à análise de variância e ao teste de Tukey (5%) e indicaram que: antes da cimentação, o término cervical em ombro biselado em 20° mostrou a maior média de desajuste cervical, sendo diferente estatisticamente do chanfro em 45° e ombro reto, também diferentes entre si; após a cimentação, para cada tipo de cimento, o melhor ajuste cervical foi obtido com o término cervical em ombro reto, seguido pelo chanfro em 45° e ombro biselado em 20°; independente do término cervical, as coroas metálicas fixadas com o cimento de ionômero de vidro apresentaram os melhores resultados, seguido pelo cimento de fosfato de zinco e cimento resinoso / Abstract: The purpose of this study was to analyse the cervical fits before and after cementation of full cast crowns made with nickel-chromium alloy (Verabond 11), with three different marginal designs: 45-degree chamfered, 20-degree bevel shoulder and right shoulder, on the bovino teeth with zinc phosphate, glass ionomer and resin cements. Ninety crowns were cast with nickel-chromium (Verabond 11) melted by gas-oxygen torch. After casting the crowns were seated on different marginal configurations with a static load of 9 kg. The marginal discrepancy was measured before cementation using a digital micrometer (Mitutoyo). Afterwards, the crowns were luted onto the tooth with zinc phosphate, glass ionomer and resin cements mixed with standardized proportions and procedures, the marginal discrepancy was measured again. The results were submitted to analysis of variance and Tukey's test (5%) and indicated that before cementation the marginal designs: 20-degree bevel shoulder showed the most average cervical fits, being statistically different in relation to 45-degree chamfered and right shoulder, also different between them. After cementation, for each cement, the better fits were obtained with right shoulder in relation to 45-degree chamfered and 20 degree bevel shoulder. Independent of marginal configurations, the full cast crowns luted with glass ionomer cement showed the better cervical fits in relation to zinc phosphate and resin cements / Mestrado / Mestre em Materiais Dentários

Bekanntlich gibt es für fast jede erdenkliche Aufgabe ein Open-Source-Programm. Bis auf einige Ausnahmen ist das Angebot an Software für Amateurastronomen allerdings recht unübersichtlich. Der Vortrag soll deshalb eine Übersicht über verschiedene Software-Projekte geben, die für Astrofotografie und astronomische Beobachtungen nützlich sind. Einfache Demonstrationen werden die Einsatzmöglichkeiten dieser Programme verdeutlichen und sollen dazu anregen, den Nachtimmel selbst mit Feldstecher und Kamera zu erkunden.

No description available.

Bekanntlich gibt es für fast jede erdenkliche Aufgabe ein Open-Source-Programm. Bis auf einige Ausnahmen ist das Angebot an Software für Amateurastronomen allerdings recht unübersichtlich. Der Vortrag soll deshalb eine Übersicht über verschiedene Software-Projekte geben, die für Astrofotografie und astronomische Beobachtungen nützlich sind. Einfache Demonstrationen werden die Einsatzmöglichkeiten dieser Programme verdeutlichen und sollen dazu anregen, den Nachtimmel selbst mit Feldstecher und Kamera zu erkunden.

Nowadays, the use of robots in industrial tasks is growing constantly. However, manual assembly is one area that is hard to make fully automated since manual assembly operations work with different shapes and products that require human finesse to do some operations. Humans, on the other hand, have a lot of limitations since this kind of task can be unergonomic and repetitive for operators, which can cause them stress, fatigue, repetitive stress injuries(RSI), and repetitive motion injuries. This project involved designing an insert for the gripper 2F-85 (version 3) that would allow the collaborative robot (UR5) to carry out more assembly tasks in order to relieve human workers of repetitive tasks. The insert has to handle cylindrical shapes in addition to bigger parts that the actual insert cannot handle due to its parallel stroke. For that, a detailed market analysis and insert research were conducted in the initial study. The new insert was then developed using a double-diamond design process. The needs were ranked using the Moscow prioritization method, and ideas were then generated using the brainstorming technique. The final concept was chosen using the weighted decision matrix method. After the final concept selection, computer-aided design (CAD) technology was employed to create the new insert's 3D model and its technical specifications. The mechanical behaviour of the new insert was analysed to reflect its range of workability, expressing the maximum force that it can withstand on each of its grip work surfaces without presenting plastic deformation. For this study, finite element analyses were conducted following the general method for linear structural analysis using Abaqus. Achieving an insert that can reach, transport, and assemble different shapes will help integrate collaborative robots into manual assembly processes, avoiding the cost of a new gripper.

No description available.

Die vorliegende Dissertation beschäftigt sich mit analytischen, numerischen und experimentellen Grundlagenuntersuchungen zum Füge- und zum Übertragungsverhalten einer reibformschlüssigen Stahl-Aluminium-Rändelpressverbindung. Die Besonderheit dieser Verbindung besteht darin, dass eine mit einer Rändelung und Übermaß versehene harte Stahlwelle in eine weiche Aluminiumnabe mit kreisrunder Bohrung längseingepresst wird. Die maßgebende Größe für den Fügevorgang ist der Fasenwinkel der Welle φ. Der Nabenwerkstoff wird hierbei in Abhängigkeit des Fasenwinkels der Welle φ umgeformt beziehungsweise herausgeschnitten. Mit Hilfe der relativen Festigkeit R F , welche das Verhältnis von maximaler Lösekraft F l, max zu maximaler Fügekraft F f, max repräsentiert, wurde ein Gütekennwert zur gezielten Auswahl von Stahl-Aluminium-Rändelpressverbindungen hinsichtlich der axialen Übertragungsfähigkeit abgeleitet. Die Charakterisierung der experimentell ermittelten Torsionsmoment - Verdrehwinkel - Kurven ergab zur Auslegung die Bereiche Auslegungs- und Versagenskriterium. Das maximal übertragbare Torsionsmoment wird beim sogenannten Versagenskriterium τ S durch das Abscheren der Rändel in der Nabe erreicht. In Analogie zum Füge- und zum Löseverhalten zeigt sich der positive Einfluss des Fasenwinkels φ auf das übertragbare Torsionsmoment. So können formend gefügte Stahl-Aluminium- Rändelpressverbindungen ein um bis zu ca. 40% größeres statisches Torsionsmoment als vergleichbare schneidend gefügte Rändelpressverbindungen übertragen. Das mechanisch-physikalische Berechnungsmodell zur Berechnung des statisch übertragbarenTorsionsmomentes basiert auf der Kerbzahnverbindung. Damit kann das Torsionsmoment am Auslegungskriterium T pF sowie das maximal übertragbare Torsionsmoment bei Abscherung Tτ S ermittelt werden. Die Berücksichtigung des formenden beziehungsweise schneidenden Fügevorgangs wird in Abhängigkeit des Fasenwinkels φ mit Hilfe des sogenannten winkelbasierten Umformgrades ε plRPV beschrieben. / The present thesis provides analytical, numerical and experimental fundamental studies for the joining behaviour and the transmission behaviour of a friction and form closure steel-aluminum knurled interference fit. The special feature of this connection is a knurled and oversize hard steel shaft, longitudinally pressed in a soft aluminum hub with a circular bore. The most important parameter for the joining process is the shaft chamfer angle φ. Due to the shaft chamfer angle φ the material of the hub will be formed or cutted during the joining process. By using the relative strength, the quotient of push out force and joining force who describes the joint strength, a first quality parameter for a precise selection of steel-aluminum knurled interference fit has been derived. The description of the experimentally determined torque - twisting angle – curves has shown areas of design criterion and mechanical breakdown. The maximum transmittable torque is achieved by reaching the shearing stress of the knurls in the hub - mechanical breakdown τ S. Similar to the joining and the push out behaviour, the positive influence of the shaft chamfer angle φ is also shown at the transmittable torque. Furthermore, knurled interference fits joined by forming can transmit higher torques of about 40% than interference fits joined by cutting due to the material hardening. The mechanical-physical model for calculating the static transmittable torque is based on the serration connection. Thus, the torque at the design criterion and the maximum transmittable torque at the mechanical breakdown can be found. The consideration of the forming or cutting joining process is described as a function of the shaft chamfer angle φ using the so-called angle-based plastic strain ε plRPV.

Die vorliegende Dissertation beschäftigt sich mit analytischen, numerischen und experimentellen Grundlagenuntersuchungen zum Füge- und zum Übertragungsverhalten einer reibformschlüssigen Stahl-Aluminium-Rändelpressverbindung. Die Besonderheit dieser Verbindung besteht darin, dass eine mit einer Rändelung und Übermaß versehene harte Stahlwelle in eine weiche Aluminiumnabe mit kreisrunder Bohrung längseingepresst wird. Die maßgebende Größe für den Fügevorgang ist der Fasenwinkel der Welle φ. Der Nabenwerkstoff wird hierbei in Abhängigkeit des Fasenwinkels der Welle φ umgeformt beziehungsweise herausgeschnitten. Mit Hilfe der relativen Festigkeit R F , welche das Verhältnis von maximaler Lösekraft F l, max zu maximaler Fügekraft F f, max repräsentiert, wurde ein Gütekennwert zur gezielten Auswahl von Stahl-Aluminium-Rändelpressverbindungen hinsichtlich der axialen Übertragungsfähigkeit abgeleitet. Die Charakterisierung der experimentell ermittelten Torsionsmoment - Verdrehwinkel - Kurven ergab zur Auslegung die Bereiche Auslegungs- und Versagenskriterium. Das maximal übertragbare Torsionsmoment wird beim sogenannten Versagenskriterium τ S durch das Abscheren der Rändel in der Nabe erreicht. In Analogie zum Füge- und zum Löseverhalten zeigt sich der positive Einfluss des Fasenwinkels φ auf das übertragbare Torsionsmoment. So können formend gefügte Stahl-Aluminium- Rändelpressverbindungen ein um bis zu ca. 40% größeres statisches Torsionsmoment als vergleichbare schneidend gefügte Rändelpressverbindungen übertragen. Das mechanisch-physikalische Berechnungsmodell zur Berechnung des statisch übertragbarenTorsionsmomentes basiert auf der Kerbzahnverbindung. Damit kann das Torsionsmoment am Auslegungskriterium T pF sowie das maximal übertragbare Torsionsmoment bei Abscherung Tτ S ermittelt werden. Die Berücksichtigung des formenden beziehungsweise schneidenden Fügevorgangs wird in Abhängigkeit des Fasenwinkels φ mit Hilfe des sogenannten winkelbasierten Umformgrades ε plRPV beschrieben. / The present thesis provides analytical, numerical and experimental fundamental studies for the joining behaviour and the transmission behaviour of a friction and form closure steel-aluminum knurled interference fit. The special feature of this connection is a knurled and oversize hard steel shaft, longitudinally pressed in a soft aluminum hub with a circular bore. The most important parameter for the joining process is the shaft chamfer angle φ. Due to the shaft chamfer angle φ the material of the hub will be formed or cutted during the joining process. By using the relative strength, the quotient of push out force and joining force who describes the joint strength, a first quality parameter for a precise selection of steel-aluminum knurled interference fit has been derived. The description of the experimentally determined torque - twisting angle – curves has shown areas of design criterion and mechanical breakdown. The maximum transmittable torque is achieved by reaching the shearing stress of the knurls in the hub - mechanical breakdown τ S. Similar to the joining and the push out behaviour, the positive influence of the shaft chamfer angle φ is also shown at the transmittable torque. Furthermore, knurled interference fits joined by forming can transmit higher torques of about 40% than interference fits joined by cutting due to the material hardening. The mechanical-physical model for calculating the static transmittable torque is based on the serration connection. Thus, the torque at the design criterion and the maximum transmittable torque at the mechanical breakdown can be found. The consideration of the forming or cutting joining process is described as a function of the shaft chamfer angle φ using the so-called angle-based plastic strain ε plRPV.