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We explore a specific small geometry containing a single thin bounded grain on a substrate with a hole at its center. By employing a mathematical model based on surface diffusion, no flux boundary conditions, and prescribed contact angles, we study the evolution of the hole as well as the exterior surface of the grain, based on energetic considerations and dynamic simulations. Our results regarding the formation and evolution of holes in thin films in small geometries shed light on various nonlinear phenomena associated with wetting and dewetting.

Today, thin film based devices are found in a wide field of applications. The main reasons are that thin film technology enables access to unique physical properties and possibilities to miniaturize devices. Thin film devices are generally described in terms such as electrical, optical and magnetical properties. However, the lifetime of these devices is often limited by mechanical stresses causing plastic deformation. An effect of the plastic deformation is hillocking where isolated features are created on the film surface. The continual need to improve performance, reduce size as well as cost is pushing thin film structures close to or beyond present fundamental understanding. Further progress requires better understanding of basic phenomena where analytical methods for characterization of thin film deformation play a crucial role. To follow the initial hillock formation during thermal treatments it is essential to have a suitable tool for achieving real-time measurements with high sensitivity over a relatively large area that does not considerably affect the film surface. Methods based on light scattering are generally very sensitive to changes in the surface topography and allow contact free measurements at high speed. In this thesis light scattering methods are investigated as tools for stress analysis of thin metal films. Detection and characterization of isolated surface features using angular resolved scattering has been investigated by simulations. Results were used in development of an optical instrument for simultaneous measurements of initial hillocking and changes in overall film stress. The instrument combines light scattering and laser beam deflection techniques. It is shown how the onset of initial hillocking in aluminum films is accompanied by stress relaxation. Real-time dark field microscopy was demonstrated as a technique for analysis of the lateral hillock distribution. Analysis of the distribution show clustering of hillocks which is supposed to be related to the microstructure of the film. It is demonstrated that copper inclusion can be used to strengthen aluminum films to withstand higher stress before hillocking occurs. The copper content also reduces the grain size and thereby the surface roughness, which results in good or even better optical performance than for pure aluminum films. / <p>NR 20140805</p>

The aim of this study is to develop a theoretical basis and to perform computational experiments for understanding the grain boundary (GB) grooving in polycrystalline thin film metallic conductors (interconnects) by anisotropic surface diffusion due to capillary, electromigration and elastostatic forces. To this end, irreversible thermo&ndash / kinetics of surfaces and interfaces with triple junction singularities is elaborated, and the resulting well-posed moving boundary value problem is solved using the front&ndash / tracking method. To simulate the strain conditions of the interconnects during service, the problem is addressed within the framework of isotropic linear elasticity in two dimensions (plane strain condition). In the formulation of stress induced surface diffusion, not only the contribution due to elastic strain energy density (ESED) but also that of the elastic dipole tensor interactions (EDTI) between the stress field and the mobile atomic species (monovacancies) is considered. In computation of the elastostatic and electrostatic fields the indirect boundary element method (IBEM) with constant and straight boundary elements is utilized. The resulted non&ndash / linear partial differential equation is solved numerically by Euler&rsquo / s method of finite differences. The dynamic computer simulation experiments identify well known GB groove shapes and shed light on their growing kinetics. They also allow generating some scenarios under several conditions regarding to the applied force fields and/or physicochemical parameters. The destruction of groove symmetry, termination of the groove penetration with isotropic surface diffusivity, ridge/slit formations with anisotropic diffusivity and the role played by the wetting parameter are all identified for electromigration conditions. The kinetics of accelerated groove deepening with an applied tensile stress is examined in connection with GB cavity growth models in the literature and a diffusive micro-crack formation is reported at the groove tip for high stresses. On the other hand, the use of EDTI provided a means to dynamically simulate GB ridges under compressive stress fields with surface diffusion. An incubation time for hillock growth and a crossover depth over which GB migration becomes energetically favorable is defined and discussed in this context.

Introdução: A epilepsia do lobo temporal mesial (ELTM) é a forma mais comum de epilepsia na população adulta, tendo a esclerose hipocampal como principal substrato neuropatológico. Uma elevada proporção dos pacientes com ELTM apresentam história familiar positiva para a epilepsia, sugerindo a participação de fatores genéticos nesta síndrome. O citoesqueleto neuronal é essencial para os processos fisiológicos das células nervosas e crises epilépticas parecem afetar esta estrutura. O citoesqueleto neuronal possui importantes componentes regulatórios, dentre eles as proteínas associadas aos microtúbulos do tipo 2 (MAP2) e tau. Objetivos: Avaliar a densidade neuronal (células imunomarcadas com NeuN), neobrotamento das fibras musgosas (por histoquímica de neo-Timm) e a expressão imunohistoquímica das proteínas MAP2 e tau no hipocampo de casos cirúrgicos de ELTM (subtipos familiar e esporádico) e controles. As mesmas análises foram conduzidas no modelo animal de lítiopilocarpina. Métodos: Casos ELTM (n=38) foram divididos em ELTM familiar (n=20) e ETLM esporádica (n=18). Hipocampos controles (n=10) foram provenientes de necrópsias de sujeitos sem histórico de problemas neurológicos. No modelo animal de lítio-pilocarpina, animais submetidos ao status epilepticus (SE) foram sacrificados nos seguintes tempos pós-SE: 1, 7, 15 e 60 dias e classificados como grupos SE1, SE7, SE15 e SE60. Animais controle foram injetados com salina. Resultados: O grupo ELTM apresentou menor densidade neuronal que o controle nas regiões da camada granular, hilo, CA4, CA3, CA1 e prosubículo. O grupo ELTM mostrou maior valor de cinza da histoquímica de neo-Timm na camada granular, molecular interna e molecular externa e maior espessura do neobrotamento axonal na camada molecular interna em relação ao grupo controle. O grupo ELTM esporádica teve maior valor de cinza da histoquímica de neo-Timm e tendência à maior espessura do neobrotamento que o grupo ELTM familiar na camada molecular interna. O grupo ELTM apresentou menor expressão de MAP2 que o grupo controle no hilo, CA4, CA3, CA1 e prosubículo e maior expressão que o controle na camada granular, CA2 e parasubículo. O grupo ELTM esporádica teve maior expressão de MAP2 que o grupo ELTM familiar em CA1 e córtex entorrinal. O grupo ELTM apresentou maior expressão de tau que o grupo controle nas regiões da camada granular, hilo, CA3, CA2 e córtex entorrinal. O grupo ELTM esporádica demonstrou menor imunorreatividade para tau que o grupo ELTM familiar no córtex entorrinal. No modelo de lítio-pilocarpina, os grupos submetidos ao SE apresentaram menor densidade neuronal e maior neobrotamento que o grupo salina. Quanto à expressão de MAP2, os grupos SE60 e SE15 apresentaram maiores valores de expressão que os demais grupos em todas as regiões analisadas. A expressão de tau em CA3 não foi diferente entre os grupos animais analisados. Conclusão: Nossos resultados existem perda neuronal, reorganização sináptica das fibras musgosas e alterações na expressão de proteínas MAP2 e tau no hipocampo de pacientes com ELTM. Dentre os casos ELTM, encontramos diferenças no neobrotamento de fibras musgosas e na expressão de MAP2 e tau entre os grupos ELTM familiar e esporádica, indicando que estes grupos se apresentam de forma distinta em relação à epilepsia. Encontramos resultados II semelhantes em relação à densidade neuronal e o neobrotamento de fibras musgosas entre pacientes com ELTM e no modelo experimental. Porém, em relação à expressão das proteínas MAP2 e tau, encontramos algumas diferenças entre humanos e animais com ELTM. Nossos resultados sugerem que apesar do modelo de epilepsia induzida por lítio-pilocarpina ser relevante para o estudo da ELTM humana e mimetizar importantes aspectos neuropatológicos, a correspondência quanto à expressão de algumas proteínas estruturais não é completa. Estudos adicionais de expressão de proteínas do citoesqueleto em outros modelos animais de ELTM serão de grande importância para o melhor entendimento do processo epileptogênco. / Introduction: Mesial temporal lobe epilepsy (MTLE) is the most common form of epilepsy in adults and has hippocampal sclerosis as the main pathological substrate. A high proportion of patients with MTLE have positive familial history for epilepsy, suggesting the involvement of genetic factors in this syndrome. Seizures may affect the neuronal cytoskeleton, an structure that is essential in the physiological processes of nerve cells. Components of the neuronal cytoskeleton include microtubule-associated protein type 2 (MAP2) and tau. Objectives: Our aim was to evaluate neuronal density, mossy fiber sprouting and immunohistochemical expression of MAP2 and tau in the hippocampus of surgical cases of MTLE (familial and sporadic subtypes) and controls. The same analysis were conducted in the MTLE lithiumpilocarpine animal model.Methods: MTLE cases (n = 38) were divided into familial MTLE (n = 20) and sporadic MTLE (n = 18). Control hippocampi (n = 10) were obtained from autopsies of subjects without history of epilepsy. In the lithium-pilocarpine animal model, male Wistar rats were submitted to status epilepticus (SE) and were killed at the following post-SE days: 1, 7, 15 and 60, and were further classified SE1, SE7, SE15 and SE60. Control animals were injected with saline. Results: MTLE showed decreased neuronal density than controls in the granular layer, hilus, CA4, CA3, CA1 and prosubiculum. MTLE group showed increased neo-Timm gray value in the granular layer, inner and outer molecular layer, as well as increased mossy fiber length of mossy fiber in the inner molecular layer when compared to controls. Sporadic MTLE specimens exhibited increased inner molecular layer gray value than familial MTLE. MTLE hihppocampi showed decreased MAP2 expression in the hilus, CA4, CA3, CA1 and prosubiculum. In the granular layer, CA2 and parasubiculum, MAP2 expression was higher in MTLE specimens than in controls. CA1 and entorhinal cortex from sporadic MTLE hippocampi showed increased MAP2 expression than familial MTLE. Tau expression was increased in the granular layer, hilus, CA3, CA2 and entorhinal cortex of MTLE specimens. Sporadic MTLE exhibited lower tau immunoreactivity in the entorhinal cortex than familial MTLE. In the lithiumpilocarpine animal model, rats submitted to SE presented lower values of neuronal density and mossy fiber sprouting than controls. SE15 and SE60 showed increased MAP2 expression in all hippocampal subfields. Tau expression in CA3 was not different among the groups. Conclusion: Our results indicate that besides neuronal loss and axonal sprouting, MTLE specimens also exhibit dendritic abnormalities related to MAP2 expression. Increased tau immunoreactivity in epileptogenic hippocampi indicates possible abnormal expression related to mossy fiber sprouting in chronic MTLE. We found differential sprouting, MAP2 and tau expression between sporadic and familial MTLE. It is possible that different genetic background might result in somehow distinct neuropathological substrates between the two MTLE subtypes, although their clinical manifestation is quite similar. While neuronal loss and axonal sprouting profiles in human MTLE and chronic phase of the lithium-pilocarpine animal model are comparable, we could not find corresponding results regarding MAP2 and tau expression. IV Several studies have shown that chemo-convulsant as pilocarpine and kainic acid result in widespread brain epileptic discharges, which are different from the more focal hippocampal discharges seen in human MTLE. Despite its limitations, the lithium-pilocarpine model stands as an important and widely used animal model of epilepsy. Besides that, other animal models in which ictal discharges and lesions are more limited to the hippocampal formation might better mimic what we see in human MTLE.

Introdução: A epilepsia do lobo temporal mesial (ELTM) é a forma mais comum de epilepsia na população adulta, tendo a esclerose hipocampal como principal substrato neuropatológico. Uma elevada proporção dos pacientes com ELTM apresentam história familiar positiva para a epilepsia, sugerindo a participação de fatores genéticos nesta síndrome. O citoesqueleto neuronal é essencial para os processos fisiológicos das células nervosas e crises epilépticas parecem afetar esta estrutura. O citoesqueleto neuronal possui importantes componentes regulatórios, dentre eles as proteínas associadas aos microtúbulos do tipo 2 (MAP2) e tau. Objetivos: Avaliar a densidade neuronal (células imunomarcadas com NeuN), neobrotamento das fibras musgosas (por histoquímica de neo-Timm) e a expressão imunohistoquímica das proteínas MAP2 e tau no hipocampo de casos cirúrgicos de ELTM (subtipos familiar e esporádico) e controles. As mesmas análises foram conduzidas no modelo animal de lítiopilocarpina. Métodos: Casos ELTM (n=38) foram divididos em ELTM familiar (n=20) e ETLM esporádica (n=18). Hipocampos controles (n=10) foram provenientes de necrópsias de sujeitos sem histórico de problemas neurológicos. No modelo animal de lítio-pilocarpina, animais submetidos ao status epilepticus (SE) foram sacrificados nos seguintes tempos pós-SE: 1, 7, 15 e 60 dias e classificados como grupos SE1, SE7, SE15 e SE60. Animais controle foram injetados com salina. Resultados: O grupo ELTM apresentou menor densidade neuronal que o controle nas regiões da camada granular, hilo, CA4, CA3, CA1 e prosubículo. O grupo ELTM mostrou maior valor de cinza da histoquímica de neo-Timm na camada granular, molecular interna e molecular externa e maior espessura do neobrotamento axonal na camada molecular interna em relação ao grupo controle. O grupo ELTM esporádica teve maior valor de cinza da histoquímica de neo-Timm e tendência à maior espessura do neobrotamento que o grupo ELTM familiar na camada molecular interna. O grupo ELTM apresentou menor expressão de MAP2 que o grupo controle no hilo, CA4, CA3, CA1 e prosubículo e maior expressão que o controle na camada granular, CA2 e parasubículo. O grupo ELTM esporádica teve maior expressão de MAP2 que o grupo ELTM familiar em CA1 e córtex entorrinal. O grupo ELTM apresentou maior expressão de tau que o grupo controle nas regiões da camada granular, hilo, CA3, CA2 e córtex entorrinal. O grupo ELTM esporádica demonstrou menor imunorreatividade para tau que o grupo ELTM familiar no córtex entorrinal. No modelo de lítio-pilocarpina, os grupos submetidos ao SE apresentaram menor densidade neuronal e maior neobrotamento que o grupo salina. Quanto à expressão de MAP2, os grupos SE60 e SE15 apresentaram maiores valores de expressão que os demais grupos em todas as regiões analisadas. A expressão de tau em CA3 não foi diferente entre os grupos animais analisados. Conclusão: Nossos resultados existem perda neuronal, reorganização sináptica das fibras musgosas e alterações na expressão de proteínas MAP2 e tau no hipocampo de pacientes com ELTM. Dentre os casos ELTM, encontramos diferenças no neobrotamento de fibras musgosas e na expressão de MAP2 e tau entre os grupos ELTM familiar e esporádica, indicando que estes grupos se apresentam de forma distinta em relação à epilepsia. Encontramos resultados II semelhantes em relação à densidade neuronal e o neobrotamento de fibras musgosas entre pacientes com ELTM e no modelo experimental. Porém, em relação à expressão das proteínas MAP2 e tau, encontramos algumas diferenças entre humanos e animais com ELTM. Nossos resultados sugerem que apesar do modelo de epilepsia induzida por lítio-pilocarpina ser relevante para o estudo da ELTM humana e mimetizar importantes aspectos neuropatológicos, a correspondência quanto à expressão de algumas proteínas estruturais não é completa. Estudos adicionais de expressão de proteínas do citoesqueleto em outros modelos animais de ELTM serão de grande importância para o melhor entendimento do processo epileptogênco. / Introduction: Mesial temporal lobe epilepsy (MTLE) is the most common form of epilepsy in adults and has hippocampal sclerosis as the main pathological substrate. A high proportion of patients with MTLE have positive familial history for epilepsy, suggesting the involvement of genetic factors in this syndrome. Seizures may affect the neuronal cytoskeleton, an structure that is essential in the physiological processes of nerve cells. Components of the neuronal cytoskeleton include microtubule-associated protein type 2 (MAP2) and tau. Objectives: Our aim was to evaluate neuronal density, mossy fiber sprouting and immunohistochemical expression of MAP2 and tau in the hippocampus of surgical cases of MTLE (familial and sporadic subtypes) and controls. The same analysis were conducted in the MTLE lithiumpilocarpine animal model.Methods: MTLE cases (n = 38) were divided into familial MTLE (n = 20) and sporadic MTLE (n = 18). Control hippocampi (n = 10) were obtained from autopsies of subjects without history of epilepsy. In the lithium-pilocarpine animal model, male Wistar rats were submitted to status epilepticus (SE) and were killed at the following post-SE days: 1, 7, 15 and 60, and were further classified SE1, SE7, SE15 and SE60. Control animals were injected with saline. Results: MTLE showed decreased neuronal density than controls in the granular layer, hilus, CA4, CA3, CA1 and prosubiculum. MTLE group showed increased neo-Timm gray value in the granular layer, inner and outer molecular layer, as well as increased mossy fiber length of mossy fiber in the inner molecular layer when compared to controls. Sporadic MTLE specimens exhibited increased inner molecular layer gray value than familial MTLE. MTLE hihppocampi showed decreased MAP2 expression in the hilus, CA4, CA3, CA1 and prosubiculum. In the granular layer, CA2 and parasubiculum, MAP2 expression was higher in MTLE specimens than in controls. CA1 and entorhinal cortex from sporadic MTLE hippocampi showed increased MAP2 expression than familial MTLE. Tau expression was increased in the granular layer, hilus, CA3, CA2 and entorhinal cortex of MTLE specimens. Sporadic MTLE exhibited lower tau immunoreactivity in the entorhinal cortex than familial MTLE. In the lithiumpilocarpine animal model, rats submitted to SE presented lower values of neuronal density and mossy fiber sprouting than controls. SE15 and SE60 showed increased MAP2 expression in all hippocampal subfields. Tau expression in CA3 was not different among the groups. Conclusion: Our results indicate that besides neuronal loss and axonal sprouting, MTLE specimens also exhibit dendritic abnormalities related to MAP2 expression. Increased tau immunoreactivity in epileptogenic hippocampi indicates possible abnormal expression related to mossy fiber sprouting in chronic MTLE. We found differential sprouting, MAP2 and tau expression between sporadic and familial MTLE. It is possible that different genetic background might result in somehow distinct neuropathological substrates between the two MTLE subtypes, although their clinical manifestation is quite similar. While neuronal loss and axonal sprouting profiles in human MTLE and chronic phase of the lithium-pilocarpine animal model are comparable, we could not find corresponding results regarding MAP2 and tau expression. IV Several studies have shown that chemo-convulsant as pilocarpine and kainic acid result in widespread brain epileptic discharges, which are different from the more focal hippocampal discharges seen in human MTLE. Despite its limitations, the lithium-pilocarpine model stands as an important and widely used animal model of epilepsy. Besides that, other animal models in which ictal discharges and lesions are more limited to the hippocampal formation might better mimic what we see in human MTLE.

Im Rahmen dieser Arbeit wurde die Akustomigrationsresistenz von in Kupfertechnologie hergestellten SAW-Strukturen charakterisiert und diese mit dem Schädigungsverhalten von Al-basierten SAW-Strukturen unter gleichen Belastungsbedingungen verglichen. Dies wurde durch die Anwendung einer speziellen Power-SAW-Teststruktur ermöglicht. Das Schädigungsniveau wurde hierbei über die irreversible Verschiebung der Peakfrequenz bzw. durch Änderungen im elektrischen Widerstand sowie durch mikroskopische Untersuchung der Mikrostruktur beurteilt. Die durchgeführten SAW-Belastungsexperimente mit HF-Leistungen bis zu 4,5 W zeigten, dass das entwickelte Ta-Si-N/Cu/Ta-Si-N-System im Vergleich zur Al/Ti-Metallisierung eine Akustomigrationsresistenz besitzt, die um mehr als drei Größenordnungen höher ist als jene der Al/Ti-Metallisierung. Hohe SAW-Belastungen verursachten sowohl im Al- als auch im Cu-Testwandler Hügel- und Lochbildung. Während die Hügel in der Al/Ti-Metallisierung senkrecht zur Oberfläche bis zu einer Höhe von 1 µm und die Löcher bis hinab an die Ti-Schicht wuchsen, bildeten sich in den extrem belasteten Cu-basierten Wandlern nur flache Hügel und schmale Löcher aus, welche noch mit der Deckschicht vollständig bedeckt waren. Anhand von REM/EBSD, TEM sowie FIB-Untersuchungen konnte ein relevanter Zusammenhang zwischen der Mikrostruktur und dem Schädigungsverhalten aufgezeigt werden.

The goal of this thesis is to describe the methods of visualization of the terrain relief, ranging from historical ways to current means, which employ software devices. It´s also to gather all available charts for the selected locality and perform an analysis of development of visualization of the terrain relief, which will be based on the collected data. Another goal was to compare the accuracy of the height scripts with the help of designed longitudinal profiles from obtained height script plans, the derived. State map in the scope of 1: 5000 and various map sources. Last at not least to explain the process of creation of the digital terrain model in ArcGIS software ? program.

<p>Neuromorphic computing endeavors to develop computational systems capable of emulating the brain’s capacity to execute intricate tasks concurrently and with remarkable energy efficiency. By utilizing new bioinspired computing architectures, these systems have the potential to revolutionize high-performance computing and enable local, low-energy computing for sensors and robots. Organic and soft materials are particularly attractive for neuromorphic computing as they offer biocompatibility, low-energy switching, and excellent tunability at a relatively low cost. Additionally, organic materials provide physical flexibility, large-area fabrication, and printability.</p><p>This doctoral dissertation showcases the research conducted in fabricating a comprehensive spiking organic neuron, which serves as the fundamental constituent of a circuit system for neuromorphic computing. The major contribution of this dissertation is the development of the organic, flexible neuron composed of spiking synapses and somas utilizing ultra-low voltage organic field-effect transistors (OFETs) for information processing. The synaptic and somatic circuits are implemented using physically flexible and biocompatible organic electronics necessary to realize the Polymer Neuromorphic Circuitry. An Axon-Hillock (AH) somatic circuit was fabricated and analyzed, followed by the adaptation of a log-domain integrator (LDI) synaptic circuit and the fabrication and analysis of a differential-pair integrator (DPI). Finally, a spiking organic neuron was formed by combining two LDI synaptic circuits and one AH synaptic circuit, and its characteristics were thoroughly examined. This is the first demonstration of the fabrication of an entire neuron using solid-state organic materials over a flexible substrate with integrated complementary OFETs and capacitors.</p>