No presente trabalho descrevemos nossos resultados relativos à investigação da dinâmica de solvatação mecânica por meio de simulações por dinâmica molecular, respeitando o regime da resposta linear, em sistemas-modelo de argônio líquido com um soluto monoatômico ou diatômico dissolvido. Estudamos sistematicamente a influência dos parâmetros moleculares dos solutos (tamanho, polarizabilidade) e da densidade frente a vários modelos de solvatação. Funções de Correlação Temporal da Energia de Solvatação foram calculadas com relação à correlações de n-corpos (n = 2; 3) distinguindo interações repulsivas e atrativas para ambos os sistemas líquidos. Também obtivemos segundas derivadas temporais dessas funções referindo-se à parcelas translacionais, rotacionais e roto-translacionais na solução do diatômico. Encontramos que funções de correlação temporal coletivas podem ser razoavelmente bem aproximadas por correlações binárias a densidades baixas e, a densidades altas, correlações ternárias tornam-se mais importantes produzindo um descorrelacionamento mais rápido das funções coletivas devido a efeitos de cancelamento parciais. As funções de correlação para interações repulsivas e atrativas exibem comportamentos dinâmicos independentes do modelo de solvatação devido a fatores de escalonamento linear que afetam apenas as amplitudes das dessas funções de correlação temporal. Em geral, os sistemas com grau de liberdade rotacional apresentam tempos de correlação mais curtos para a dinâmica coletiva e tempos de correlação mais longos para as funções binárias e ternárias. Finalmente, esse estudo mostra que os sistemas contendo o diatômico relaxam-se predominantemente por mecanismos translacionais binários em modelos de solvatação envolvendo alterações apenas na polarizabilidade do soluto, e por mecanismos rotacionais atrativos binários em modelos envolvendo alterações no comprimento de ligação. / In the present work, we describe our results concerning our molecular dynamics investigation of the mechanical solvation dynamics within the linear response regime in model systems composed by liquid argon with a monoatomic or diatomic solute. The effect of molecular parameters (size, polarizability) and density has been elucidated for various solvation models. Time Correlation Functions for the solvation energy were calculated and separated into n-body (n = 2; 3) contributions distinguishing repulsive and attractive interactions in both liquid systems. In addition, we computed second time derivatives of these functions in order to describe translational, rotational, and roto-translational portions in the solutions containing the diatomics. We found that collective time correlation functions are well described by binary correlations at low liquid densities and, at high densities, ternary correlations become more important producing faster decaying collective time correlation functions due to partial cancellation effects. The repulsive and attractive time correlation functions exhibit a dynamic behavior that is independent on the solvation model due to linear scaling factors that only affect the absolute amplitudes of these functions. In general, the systems involving a rotational degree of freedom furnish smaller correlation times for the collective solvation dynamics, but stronger correlated two-body and three-body terms. Finally, this study shows that the solvation dynamics for the solution containing the diatomics relaxes predominatly by binary translational mechanisms when solvation models involving changes only in the polarizability parameter are considered. Binary attractive rotational mechanism become important in models with changes in the bond length.

No presente trabalho descrevemos nossos resultados relativos à investigação da dinâmica de solvatação mecânica por meio de simulações por dinâmica molecular, respeitando o regime da resposta linear, em sistemas-modelo de argônio líquido com um soluto monoatômico ou diatômico dissolvido. Estudamos sistematicamente a influência dos parâmetros moleculares dos solutos (tamanho, polarizabilidade) e da densidade frente a vários modelos de solvatação. Funções de Correlação Temporal da Energia de Solvatação foram calculadas com relação à correlações de n-corpos (n = 2; 3) distinguindo interações repulsivas e atrativas para ambos os sistemas líquidos. Também obtivemos segundas derivadas temporais dessas funções referindo-se à parcelas translacionais, rotacionais e roto-translacionais na solução do diatômico. Encontramos que funções de correlação temporal coletivas podem ser razoavelmente bem aproximadas por correlações binárias a densidades baixas e, a densidades altas, correlações ternárias tornam-se mais importantes produzindo um descorrelacionamento mais rápido das funções coletivas devido a efeitos de cancelamento parciais. As funções de correlação para interações repulsivas e atrativas exibem comportamentos dinâmicos independentes do modelo de solvatação devido a fatores de escalonamento linear que afetam apenas as amplitudes das dessas funções de correlação temporal. Em geral, os sistemas com grau de liberdade rotacional apresentam tempos de correlação mais curtos para a dinâmica coletiva e tempos de correlação mais longos para as funções binárias e ternárias. Finalmente, esse estudo mostra que os sistemas contendo o diatômico relaxam-se predominantemente por mecanismos translacionais binários em modelos de solvatação envolvendo alterações apenas na polarizabilidade do soluto, e por mecanismos rotacionais atrativos binários em modelos envolvendo alterações no comprimento de ligação. / In the present work, we describe our results concerning our molecular dynamics investigation of the mechanical solvation dynamics within the linear response regime in model systems composed by liquid argon with a monoatomic or diatomic solute. The effect of molecular parameters (size, polarizability) and density has been elucidated for various solvation models. Time Correlation Functions for the solvation energy were calculated and separated into n-body (n = 2; 3) contributions distinguishing repulsive and attractive interactions in both liquid systems. In addition, we computed second time derivatives of these functions in order to describe translational, rotational, and roto-translational portions in the solutions containing the diatomics. We found that collective time correlation functions are well described by binary correlations at low liquid densities and, at high densities, ternary correlations become more important producing faster decaying collective time correlation functions due to partial cancellation effects. The repulsive and attractive time correlation functions exhibit a dynamic behavior that is independent on the solvation model due to linear scaling factors that only affect the absolute amplitudes of these functions. In general, the systems involving a rotational degree of freedom furnish smaller correlation times for the collective solvation dynamics, but stronger correlated two-body and three-body terms. Finally, this study shows that the solvation dynamics for the solution containing the diatomics relaxes predominatly by binary translational mechanisms when solvation models involving changes only in the polarizability parameter are considered. Binary attractive rotational mechanism become important in models with changes in the bond length.

Neste trabalho estudamos o processo de foto-ionização associativa(PAI) em uma amostra fria de átomos de sódio com o objetivo entender os efeitos dos estados repulsivos e dimensão da colisão. Realizamos experimentos de PAI com duas cores em uma armadilha magneto-óptica adicionando um feixe de prova com intensidade, frequências e polarização ajustáveis. O formato dos átomos aprisionados também foi uma das variáveis no estudo da PAI. Para os átomos em formação esférica, observamos uma mudança marcante no comportamento da constante de taxa de formação da foto-ionização associativa(K) para um determinado domínio de frequências, e essa mudança no comportamento pode ser atribuída a participação de estados moleculares repulsivos na PAI e a formação de um possível cruzamento evitado entre os níveis moleculares. No atomotron ,armadilha atômica em forma de anel, variamos a polarização do laser de prova e constatamos que a razão entre K das polarizações paralela e perpendicular ao movimento dos átomos é igual a 4. Uma comparação entre K do atomotron e o da armadilha esférica em função da intensidade do feixe de prova, nos mostrou uma diferença no comportamento e no valor da constante de taxa. / Photoassociative ionization (PAI) in a cold sample of sodium atoms was the main subject of our studies as a way to understand the effects of repulsive states and collision dimensions. Two-color PAI experiment were preformed in a magneto-optical trap (MOT) trough the addition of a probe laser beam, the intensity, polarization and frequency of that probe laser were tunable. The shape of the trapped atoms also could be changed. In a spherical shape MOT, we observed a marked change in the PAI rate constant (K) for a definite frequency range, and that change can be attributed to the influence of repulsive molecular states and the a possible formation of an avoided crossing between molecular levels. In atomotron, ring shaped mot, we changed the polarization of the probe beam, and saw that the ratio between K for a polarization parallel to the atoms motion and a perpendicular one is 4. Comparing the K as a function of the intensity between a spherical shaped mot and atomotron showed us a difference in the behavior and the value of the rate constant.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-03-03T15:39:30Z No. of bitstreams: 1 josehenriquesilva.pdf: 38531594 bytes, checksum: c78eae9aa6726299a310f26bfa565039 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-06T20:17:02Z (GMT) No. of bitstreams: 1 josehenriquesilva.pdf: 38531594 bytes, checksum: c78eae9aa6726299a310f26bfa565039 (MD5) / Made available in DSpace on 2017-03-06T20:17:02Z (GMT). No. of bitstreams: 1 josehenriquesilva.pdf: 38531594 bytes, checksum: c78eae9aa6726299a310f26bfa565039 (MD5) Previous issue date: 2011-11-09 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nos últimos anos, o estudo do comportamento da magnetização em nanodiscos magnéticos tem atraído à atenção de muitos pesquisadores da área de nanomagnetismo. Devido a possibilidade dos nanodiscos apresentarem um estado de magnetização em forma de vórtice com componente fora-do-plano no seu centro, estes podem ser os possíveis substitutos dos dispositivos de armazenamento magnético utilizados atualmente. Para que os nano discos possam ser utilizados para fins de armazenamento,precisa-se conhecer com detalhes o comportamento do vórtice em diversas situações. Em trabalho recente verificou-se experimentalmente que a frequência do modo girotrópico na presença de impureza é maior que a frequência caso não houvesse impureza no nanodisco e que a frequência diminui com o aumento do diâmetro. No presente trabalho estudamos o comportamento do modo girotrópico, quando colocamos a impureza numa distância, em relação ao centro do nanodisco, menor que o raio do Modo Girotrópico e também quando colocamos a impureza numa distância maior que o raio do modo girotrópico. A impureza magnética é definida a partir da constante de acoplamento J da interação de troca entre Spin-Spin. Se a constante de acoplamento J' da interação entre impureza-Spin vizinho for maior que J(J' > J), temos uma impureza repulsiva e para J' < J a impureza é atrativa. Para estudar a influência de impurezas na frequência do modo girotrópico foram feitas simulações micromagnéticas em nanodiscos magnéticos usando valores conhecidos das constantes do Permalloy-79. Foram feitas simulações em nanodiscos com diversos diâmetros (125nm, 145nm, 175nm, 195nm, 225nm e 275nm), todos com 10nm de espessura. Nossos resultados mostram que existe uma flutuação na frequência do modo girotrópico na presença de impurezas magnéticas, o que está de acordo com resultados experimentais recentes. / In recent years, to study the behavior of magnetization in magnetic nanodisks has attracted the attention of many researchers in nanomagnetism. Due to the possibility of nanodisks to present a state of magnetization with vortex-shaped component out-of-plane at its center, this can substitute the magnetic storage devices used today. For nanodisks that can be used for storage purposes, one needs to know in detail the behavior of the vortex in many situations. In a recent study, it was experimentally found that the frequency of the gyrotropic mode in the presence of impurities is greater than the frequency, if there were no impurity in nanodisks, so that the frequency decreases with increasing the diameter. In this paper we study the behavior of gyrotropic mode when we place the impurity at a distance from the center of the nanodisks, smaller than the gyrotropic radius mode and also when the impurity placed at a distance greater than the radius of the gyrotropic mode. The magnetic impurity is defined as the coupling constant J of the exchange interaction between the Spin-Spin interaction. If the coupling constant J' from the interaction between impurity-neighbor spin is greater than J (J0 > J), we have a repulsive impurity and if J' <J the impurity is attractive. To study the influence of impuritiesin the gyrotropic frequency mode, micromagnetic simulations were made in magnetic nanodisks using known values of constants of the Permalloy-79. Nanodisks simulations were made with different diameters (125nm,145nm,175nm,195nm,225nmand275nm), all of with10nm thick. Our results show that there is a fluctuation in the gyrotropic frequency mode in the presence of magnetic impurities, which is in agreement with recent experimental results.

A análise de texturas dinâmicas tem se apresentado como uma área de pesquisa crescente e em potencial nos últimos anos em visão computacional. As texturas dinâmicas são sequências de imagens de textura (i.e. vídeo) que representam objetos dinâmicos. Exemplos de texturas dinâmicas são: evolução de colônia de bactérias, crescimento de tecidos do corpo humano, escada rolante em movimento, cachoeiras, fumaça, processo de corrosão de metal, entre outros. Apesar de existirem pesquisas relacionadas com o tema e de resultados promissores, a maioria dos métodos da literatura possui limitações. Além disso, em muitos casos as texturas dinâmicas são resultado de fenômenos complexos, tornando a tarefa de caracterização um desafio ainda maior. Esse cenário requer o desenvolvimento de um paradigma de métodos baseados em complexidade. A complexidade pode ser compreendida como uma medida de irregularidade das texturas dinâmicas, permitindo medir a estrutura dos pixels e quantificar os aspectos espaciais e temporais. Neste contexto, o objetivo deste mestrado é estudar e desenvolver métodos para caracterização de texturas dinâmicas baseado em metodologias de complexidade advindas da área de sistemas complexos. Em particular, duas metodologias já utilizadas em problemas de visão computacional são consideradas: redes complexas e caminhada determinística parcialmente auto-repulsiva. A partir dessas metodologias, três métodos de caracterização de texturas dinâmicas foram desenvolvidos: (i) baseado em difusão em redes - (ii) baseado em caminhada determinística parcialmente auto-repulsiva - (iii) baseado em redes geradas por caminhada determinística parcialmente auto-repulsiva. Os métodos desenvolvidos foram aplicados em problemas de nanotecnologia e tráfego de veículos, apresentando resultados potenciais e contribuindo para o desenvolvimento de ambas áreas. / Dynamic texture analysis has been an area of research increasing and in potential in recent years in computer vision. Dynamic textures are sequences of texture images (i.e. video) that represent dynamic objects. Examples of dynamic textures are: evolution of the colony of bacteria, growth of body tissues, moving escalator, waterfalls, smoke, process of metal corrosion, among others. Although there are researches related to the topic and promising results, most literature methods have limitations. Moreover, in many cases the dynamic textures are the result of complex phenomena, making a characterization task even more challenging. This scenario requires the development of a paradigm of methods based on complexity. The complexity can be understood as a measure of irregularity of the dynamic textures, allowing to measure the structure of the pixels and to quantify the spatial and temporal aspects. In this context, this masters aims to study and develop methods for the characterization of dynamic textures based on methodologies of complexity from the area of complex systems. In particular, two methodologies already used in computer vision problems are considered: complex networks and deterministic walk partially self-repulsive. Based on these methodologies, three methods of characterization of dynamic textures were developed: (i) based on diffusion in networks - (ii) based on deterministic walk partially self-repulsive - (iii) based on networks generated by deterministic walk partially self-repulsive. The developed methods were applied in problems of nanotechnology and vehicle traffic, presenting potencial results and contribuing to the development of both areas.

The thesis is focused on the calculation of electrodynamic forces that counterwork on moving contacts of compact circuit breaker BL1600 from the company OEZ Letohrad. The thesis is divided into separates chapters that build on themselves. In the introduction the reason why we deal with calculation of dynamic forces and structural arrangement of current carrying path is described. In the following chapter there is a theoretical analysis of electrodynamic forces that conterwork on individual parts of circuit breaker´s element. The third part is devoted to structural arrangement of the circuit breaker BL1600. In this part we can find an example of using the circuit broker Modeion in practice. Two next chaptures deal with adjustment of the model of current carrying path which then serves for the calculation of electrodynamic forces. The rest of the thesis is devoted to my own calculations. These calculations are mainly stationary where we try to find the forces that conterwork on the contacts in a steady current and in a point in time. There are also dynamics calculation when we can watch the forces that counterwork on contacts in a certain time interval. The last chapter is devoted to a stationary calculation of forces that counterwork on the electrical arc which arises while turning the short-circuit current off. The obtained results are evaluated in partial conclusions of this thesis.

In der vorliegenden Arbeit wird die Entwicklung von ausschließlich elektrostatisch arbeitenden Sensor-Aktor-Arrays zur Oberflächenprofilbestimmung an Mikroteilen beschrieben. Ein wesentliches Merkmal der Strukturen ist ihr großer Eigenzustellbereich von bis zu 20 Mikrometer. Die Auswertung atomarer Kräfte ermöglicht Wegauflösungen im Nanometerbereich. Auf Grund der geringen Abmessungen durch die mikromechanische Fertigung des Sensorelements und der integrierten Sensor-Aktorfunktion sind Anordnungen als Zeilenarray möglich. Die Entwicklung richtet sich auf Strukturen, welche in klassischer Oberflächentechnologie gefertigt werden können. Durchgeführte experimentelle Tests wurden mit Sensoren in Silizium-bulk-Mikromechanik (SCREAM) realisiert. Der Schwerpunkt der Arbeit behandelt die Charakterisierung der Sensorelemente und damit verbundene Layoutverbesserungen, wie das Einbringen von Feldstoppern und die Nutzbarkeit des Sensors zur Profilbestimmung von Oberflächen unter Beachtung industrieller Anforderungen. Vorteile des Einsatzes eines solchen Sensor-Aktor-Arrays liegen in der Miniaturisierung und dem vergleichsweise großen Eigenzustellbereich jedes einzelnen Sensors. Dadurch ist es möglich, technische Oberflächen, welche im Eigenzustellbereich des Sensorarrays liegen, ohne das Nachregeln einer übergeordneten Positioniereinheit im Profil zu bestimmen. Es wird gezeigt, wie die angewandte kapazitive Wirkungsweise des Sensors mit den sehr kleinen Nutzkapazitäten im Beisein von großen Parasitärkapazitäten zur Signalauswertung genutzt werden kann.

Force fields of 3d objects are used for different purposes in computer graphics as skeletonization and collision detection. In this paper we present a novel method to approximate the force field of a discrete 3d object in linear time. Similar to the distance transformation we define a rule that describe how the forces associated with boundary points are propagated into the interior of the object. The result of this propagation depends on the order in which the points of the object are processed. Therefore we analyze how to obtain an order-invariant approximation formula. For a chosen iteration order (i, j, k) the set of boundary points that influence the force of a particular point p of the object can be described by a spatial region Rijk. The geometries of these regions are characterized both for the Cartesian and the body-centered cubic grid (bcc grid). We show that in the case of the bcc grid these regions can be combined in such a way that E3 is uniformly covered which basically means that each boundary point is contained in the same number of regions. Based on the covering an approximation formula for the force field is proposed that has linear complexity and gives good results for standard objects. We also show that such a uniform covering can not be built from the regions of influence of the Cartesian grid. With our method it becomes possible to use features of the force field for a fast and topology preserving skeletonization. We use a thinning strategy on the bcc grid to compute the skeleton and ensure that critical points of the force field are not removed. This leads to improved skeletons with respect to the properties of centeredness and rotational invariance.

This essay explores and examines disgust in five literary figures and books based on scent, bodyfluids and abjection. Together with Julia Kristeva's Powers of Horror: An Essay on Abjection and Sara Ahmed's "The Performativity of Disgust" in The Cultural Politics of Emotion, I analyze these books, and my position as a researchsubject. The questions I ask are: What does disgust mean? How do the subject's boundaries shift when things penetrate the body? How are scents, body fluids and disgust expressed in relation to power and the female body? And what does it mean that I stick my reading experiences on the texts I read?   The analysis begins in Mare Kandre's novel Aliide, Aliide and how gaze, power and girlhood are made, as well as how abjection takes place in the intake of milk and larvae. Body in body and body against body are analyzed based on Aliide's disgust in the novel. I discuss how something growing inside is experienced as disgusting and frightening and connect it to the pregnant body and the fetus as abjection. In the second chapter of the analyze, it is Parfymen: berättelsen om en mördare by Patrick Süskind that focuses on the scent of the female body that Grenouille, the main character tries to extract and master. The gaze on the female body and the extraction of fragrance is in focus here and in Nekrofilen by Gabrielle Wittkop, Lucien's desire for the dead body is examined. The body fluids, such as the vomit that the bodies excrete can be read as limits to life and death. In the third and final analysis section, I read these books with affect. I reconnect to my introduction where Ulf Lundell's poems made me feel disgusted. I use Ahmed's concept of performativity to discuss how cannibalism - reading - eating body fluids are connected, and how writing about disgust, is a form om vomiting. I examine my own writing subject and what an affective reading does to literary studies and the research position. In conclusion, I discuss how the universal and the subjective making of disgust effect research.

<p>In this thesis, we present novel computational methods and frameworks to address the challenges associated with the determination of free energy profiles for condensed-phase chemical reactions using combined quantum mechanical and molecular mechanical (QM/MM) approaches. We focus on overcoming issues related to force matching, molecular polarizability, and convergence of free energy profiles. First, we introduce a method called Reaction Path-Force Matching in Collective Variables (RP-FM-CV) that efficiently carries out ab initio QM/MM free energy simulations through mean force fitting. This method provides accurate and robust simulations of solution-phase chemical reactions by significantly reducing deviations on the collective variables forces, thereby bringing simulated free energy profiles closer to experimental and benchmark AI/MM results. Second, we explore the role of pairwise repulsive correcting potentials in generating converged free energy profiles for chemical reactions using QM/MM simulations. We develop a free energy correcting model that sheds light on the behavior of repulsive pairwise potentials with large force deviations in collective variables. Our findings contribute to a deeper understanding of force matching models, paving the way for more accurate predictions of free energy profiles in chemical reactions. Next, we address the underpolarization problem in semiempirical (SE) molecular orbital methods by introducing a hybrid framework called doubly polarized QM/MM (dp-QM/MM). This framework improves the response property of SE/MM methods through high-level molecular polarizability fitting using machine learning (ML)-derived corrective polarizabilities, referred to as chaperone polarizabilities. We demonstrate the effectiveness of the dp-QM/MM method in simulating the Menshutkin reaction in water, showing that ML chaperones significantly reduce the error in solute molecular polarizability, bringing simulated free energy profiles closer to experimental results. In summary, this thesis presents a series of novel methods and frameworks that improve the accuracy and reliability of free energy profile estimations in condensed-phase chemical reactions using QM/MM simulations. By addressing the challenges of force matching, molecular polarizability, and convergence, these advancements have the potential to impact various fields, including computational chemistry, materials science, and drug design.</p>