Under de senaste tre decennierna har populära managementböcker erbjudit snabba och enkla recept för hur ledare ska leda personal på ett effektivt sätt. Dessa böcker har blivit bästsäljare och har inspirerat många ledare inför nya utmaningar angående personalfrågor. Kända managementförfattare har alltså stor påverkan för hur individ och ledarskap uppfattas i samhället, samt för att förstärka en viss vision om hur människors beteende borde utformas för att företagsmässiga mål skall kunna uppnås. Denna studies syfte var att öka förståelsen för populär managementlitteraturs maktdimensioner. Tre bästsäljande managementböcker från sekelskiftet analyserades genom en foucaultinspirerad diskursanalys, med fokus på styrningsmentalitet, disciplin och människosyn. I analysen visas hur de utvalda böckerna innebär en styrningsmentalitet som präglas av interna kontroll- och utvärderingsformer, samt en disciplinär dimension som kristalliseras ut i definitioner av vad norm och avvikelse är i dagens organisation. / Over the past three decades, popular management books have offered quick and easy recipes for how leaders have to lead staff in an effective manner. These books have become bestsellers and they have inspired many leaders to face challenges regarding management of people. Famous management writers have thus a big influence on how individuals and leadership are perceived in society, as well as a big influence to reinforce a certain vision of how human behavior should be designed in order for that entrepreneurial goals will be achieved. The study's aim is to increase understanding about the power dimensions in popular management literature. Three best-selling management books from the turn of the century were analyzed using a Foucault-inspired discourse analysis, focusing on management mentality, discipline and view of human beings. The analysis shows how the selected books implies a management mentality  that is characterized by internal monitoring and evaluation, as well as a disciplinary dimension that crystallizes in the definitions of what norm and deviation are in today's organization.

This work resulted in the development of multiple distinct and novel methods of cheaply producing large numbers of biologically derived, complex, 3-dimensional microstructures in a multitude of possible compositions. The biologically derived structures employed in this work were diatoms, a type of single celled algae, which grow complex silica shells in species-specific shapes. Due to the wide diversity of naturally occurring diatom shapes (on the order of 105), and the flexibility in tailoring chemical compositions using the methods developed here, real potential exists for cheaply mass-producing industrially relevant quantities of controlled shape and size 3-d particles for the first time. The central theme of this research is the use of diatoms as a transient scaffold onto which a coating is applied. After curing the coating, and in some cases firing the coating to form ceramic, the diatom can be selectively etched away leaving a free standing replica of the original structure with the salient features of the pre-form intact, but now composed of a completely different material. Using this concept, specific methods were developed to suit various precursors. Dip coating techniques were used to create epoxy diatoms, and silicon carbide diatoms. The Sol-Gel method was used to synthesize zirconia diatoms in both the tetragonal and monoclinic phases. A multi step method was developed in which previously synthesized epoxy diatoms were used as a template for deposition of a silicon carbide precursor and then heat treated to produce a silicon carbide/carbon multi-component ceramic. A hydrothermal reaction was also developed to convert Titania diatoms to barium titanate by reaction with barium hydroxide. Finally, the device potential of diatom-derived structures was conclusively demonstrated by constructing a gas sensor from a single Titania diatom. Under suitable conditions, the sensor was found to have the fastest response and recovery time of any sensor of this type reported in the literature. Furthermore, this work has laid the groundwork for the synthesis of many other tailored compositions of diatoms, and provided several compositions for device creation.

Pronking is a legged locomotory gait in which all legs are used in synchrony, usually resulting in slow speeds but long flight phases and large jumping heights that may potentially be useful for mobile robots locomoting in cluttered natural environments. Instantiations of this gait for robotic systems suffer from severe pitch instability either due to underactuated leg designs, or the open-loop nature of proposed controllers. Nevertheless, both the kinematic simplicity of this gait and its dynamic nature suggest that the Spring-Loaded Inverted Pendulum Model (SLIP), a very successful predictive model for both natural and robotic runners, would be a good basis for more robust and maneuverable robotic pronking. In the scope of thesis, we describe a novel controller to achieve stable and controllable pronking for a planar, underactuated hexapod model, based on the idea of &ldquo / template-based control&rdquo / , a controller structure based on the embedding of a simple dynamical template within a more complex anchor system. In this context, high-level control of the gait is regulated through speed and height commands to the SLIP template, while the embedding controller based on approximate inverse-dynamics and carefully designed passive robot morphology ensures the stability of the remaining degrees of freedom. We show through extensive simulation experiments that unlike existing open-loop alternatives, the resulting control structure provides stability, explicit maneuverability and significant robustness against sensor noise.

Proclus is part of a long exegetical tradition that understands Plato and Homer to be in agreement. The Sixth Essay of his Commentary on Plato’s Republic particularly significant because it is the only extant ancient text that attempts to prove the concord of Plato and Homer philosophically. Yet, despite his uniquely reasoned approach, this endeavour suffers from charges of irrationalism. The necessity that drives him to seek this conciliation is thought to come from the pious attachment he has to Homer as an authority rather than the properly philosophical demands of his rational system. The aim of this thesis is to show that Proclus’ need to show Plato and Homer’s agreement is not an irrational adjunct to an otherwise rational outlook, but that it follows from the central doctrines of his philosophy. This will be accomplished through a detailed consideration of Proclus’ doctrine of the poetic ????????. In looking at how Proclus’ reading of Plato in the Sixth Essay is informed by his understanding of ????????, we will see how Homer becomes the means, both of taking the traditional criticisms of Plato’s apparent self-contradiction seriously and also of defending him against them. In looking in turn at how the soul actually experiences the ??????? of Homer’s inspired poetry, it shall become apparent that Homer does not just save the coherence of rational thought in this exterior way, but that his poetry operates as both the possibility and perfection of the rational soul’s various powers.

No description available.

This study focuses on fabrication of dry adhesives mimicking gecko adhesion. We also look into the origin of the supreme adhesion of geckos, which have inspired the fabrication of fibrillar dry adhesives during the last decade or so. In principle, the superior material properties of ??-keratin (the main material comprising the fibrillar feature on gecko toe pads) along with the hierarchical high aspect-ratio fibrillar structure of geckos??? foot pad have enabled geckos to stick readily and rapidly to almost any surface in both dry and wet conditions. In this research, non-sticky fluoropolymer (Teflon AF) resembling ??-keratin rigidity and having an extremely low surface energy and dielectric constant was applied to fabricate a novel dry adhesive consisting of extremely high aspect-ratio nanopillars (200 nm in diameter) terminated with a fluffy top nanolayer. Both the nanopillars and the terminating layer were fabricated concurrently by replica-molding using a nanoporous anodic aluminum oxide membrane as the mold. In particular, upon infiltration of Teflon AF melt into the anodic aluminum oxide nanopores, the polymer melt fingered over the pore walls. The fingerlike structure formed during infiltration, subsequently collapsed after removal of the mold, developing a unique sheet-like nanostructure on top of the base nanopillars. Concurrent fabrication of the terminating nanostructure helps the fabrication of extremely high aspect-ratio (27.5???225) nanopillars which, up to an aspect-ratio of 185, neither collapse at the tip nor bundle. In order to fabricate nanopillars of different topographical properties, in our first approach, the height of the nanopillars as well as the size and density of the terminating nanostructure are carefully controlled by adjusting the processing temperature. Following that, a novel replica-molding technique for fabrication of bi-level Teflon AF nanopillars is reported. The developed technique relies on the concurrent heating and cooling of the Teflon AF melt which filled vertically-aligned alumina nanochannels. Unlike conventional polymer infiltration methods which consist of filling the mold by only heating the polymer above its glass transition temperature, in our novel method, the polymer melt is also simultaneously cooled down during the infiltration process. Concurrent cooling of the Teflon AF melt allows control over the interfacial instabilities of the polymer thin film, which forms ahead of the polymer melt upon its infiltration into the alumina nanochannels. Doing so, the geometrical properties of the subsequently developed peculiar fluffy nanostructure ??? after removal of the mold ??? on top of the extremely high aspect-ratio Teflon AF nanopillars (~25 ??m tall) are modified. In this project, we have also shown that the adhesion of the fabricated dry adhesives for the most part arises from electrostatic interactions of the applied polymer. In other words, Teflon AF, having an exceptional potential for developing electric charges at its surface upon contact with other materials via the so-called contact electrification phenomenon, can develop significant electrostatic interactions at its surface upon contact. In the current thesis, tribological results were discussed in detail to clarify the contribution of the structural properties of the fabricated dry adhesives toward their remarkable adhesion and friction forces generated via contact electrification. Nanopillars of specific geometrical properties have achieved remarkable adhesion and friction strengths, up to ~2.1 N/cm2 and 17 N/cm2, respectively (up to ~2.1 and 1.7 times larger than those of a gecko toe pad). It is commonly accepted that the adhesive performance of other synthetic bio-inspired dry adhesives is due to the formation of van der Waals interactions at the tip or side of the dry adhesives fibrils with the substrate they are brought into contact with. However, what has been usually neglected in this connection is that electrostatic interactions may also be developed at the contact between any two materials via the familiar contact electrification phenomenon. Although contact electrification is common and can have a large influence on interfacial interaction forces, its impact on adhesive properties of synthetic dry adhesives has been overlooked. Our results on adhesion of bi-level Teflon AF nanopillars, which can generate strong adhesion forces relying on electrostatic interactions arising from contact electrification, have brought to light again the idea that charging the surface of dry adhesives, specifically polymeric ones, can play a very crucial role in their adhesive behavior. From this perspective, the main reasons that have caused this lack of attention to this concept and the possible contributions of contact electrification to interfacial interactions of polymeric dry adhesives, other than bi-level Teflon AF nanopillars, are also thoroughly discussed in this thesis. Besides synthetic fibrillar dry adhesives, the possibility of the occurrence of contact electrification and its contribution to the supreme dry adhesion of geckos have also been overlooked for several decades. In this research, by the simultaneous measurement of electric charges and adhesion forces that gecko toe pads develop on two distinct substrates (a sticky and a non-sticky one), we have shown that the toe pads generate significantly large amounts of electric charge on both substrates. More importantly, we have found that there is a direct correlation between the contact electrification-driven electrostatic forces and the measured adhesion forces. Otherwise stated, we have shown that what makes the difference that geckos stick strongly to one surface and not to the other are the electrostatic interactions arising from contact electrification, and not van der Waals interactions, which have been considered as the prime source of adhesion of geckos for many years.

Metamaterials are humanly engineered artificial electromagnetic materials which produce electromagnetic properties that are unusual, yet can be observed readily in nature. These unconventional properties are not a result of the material composition but rather of the structure formed. The objective of this thesis is to investigate and design smaller and wideband metamaterial-inspired antennas for personal communication applications, especially for WiMAX, lower band and higher band WLAN applications. These antennas have been simulated using HFSS Structure Simulator and CST Microwave Studio software. The first design to be analysed is a low-profile metamaterial-inspired CPW-Fed monopole antenna for WLAN applications. The antenna is based on a simple strip loaded with a rectangular patch incorporating a zigzag E-shape metamaterial-inspired unit cell to enable miniaturization effect. Secondly, a physically compact, CSRR loaded monopole antenna with DGS has been proposed for WiMAX/WLAN operations. The introduction of CSRR induces frequency at lower WLAN 2.45 GHz band while the DGS has provided bandwidth enhancement in WiMAX and upper WLAN frequency bands, keeping the radiation pattern stable. The next class of antenna is a compact cloud-shaped monopole antenna consisting of a staircase-shaped DGS has been proposed for UWB operation ranges from 3.1 GHz to 10.6 GHz. The novel shaped antenna along with carefully designed DGS has resulted in a positive gain throughout the operational bandwidth. Finally, a quad-band, CPW-Fed metamaterial-inspired antenna with CRLH-TL and EBG is designed for multi-band: Satellite, LTE, WiMAX and WLAN.

Sistemas de vigilância são geralmente empregados no monitoramento de áreas de grandes dimensões nas quais seus usuários visam detectar ou observar fenômenos de seu interesse. O uso de redes de sensores sem fio nesses sistemas apresenta especial interesse, uma vez que essas redes podem apresentar soluções de baixo custo e robustas para cobrir áreas extensas. Neste contexto, novas aplicações têm surgido propondo o uso de redes de sensores sem fio compostas por nós sensores estáticos e móveis. Uma das motivações para esta tendência é a redução do custo de implantação e operação do sistema, além da possibilidade de proporcionar incremento em suas funcionalidades. O foco desta tese se concentra na proposta de soluções para redes de sensores sem fio com uso cooperativo de sensores estáticos e móveis, com particular atenção a sensibilidade ao contexto na configuração e execução de missões de sensoriamento. O objetivo é manter um baixo custo de comunicação associado às soluções propostas. Esta preocupação se dá pelo fato da comunicação aumentar o consumo de energia em redes de sensores, o que é um problema importante para nós sensores com limitada fonte de energia, i.e. baterias. No caso de nós sensores móveis, esta limitação pode não ser relevante, uma vez que seu movimento deve consumir uma quantidade muito mais expressiva de energia do que a comunicação. Neste caso, o problema se relaciona à estabilidade dos enlaces, bem como ao curto intervalo de tempo disponível para transmitir e receber dados. Logo, o melhor é comunicar o menos possível. Com relação à interação entre nós sensores estáticos, os problemas de disseminação e alocação de missões de sensoriamento são estudados e uma solução que explora o uso de informações locais é proposta e avaliada. Esta solução emprega agentes de software móveis que têm a capacidade de tomar decisões autônomas através do uso de informações de contexto local. Para redes de sensores móveis, o problema estudado se refere a como transferir missões entre os nós sensores de acordo com seu movimento e localização em relação aos locais onde as missões devem ser executadas. Para tratar este problema, uma abordagem baseada em agentes móveis é proposta, na qual os agentes implementam a migração das missões de sensoriamento usando informações de contexto geográfico para decidir a respeito de suas migrações. Para redes de sensores com sensores estáticos e móveis, a cooperação entre eles é abordada através de um mecanismo com inspiração biológica para realizar a realizar a entrega de dados emitidos pelos sensores estáticos aos sensores móveis. Para isto, explora-se uma analogia baseada no comportamento de formigas na construção e seguimento de trilhas. As soluções propostas são flexíveis, sendo aplicáveis a diferentes domínios de aplicação. Resultados experimentais evidenciam sua escalabilidade, avaliando, por exemplo, seu custo em termos de comunicação, além de outras métricas de interesse para cada uma das soluções. Estes resultados são comparados aos atingidos por soluções de referência (solução ótima teórica e baseada em inundação), indicando sua eficiência. Estes resultados são próximos do ótimo teórico e significativamente melhores que aqueles atingidos por soluções baseadas em técnicas de inundação. / Surveillance systems are usually employed to monitor wide areas in which their users are interested in detecting and/or observing events or phenomena of their interest. The use of wireless sensor networks in such systems is of particular interest as these networks can provide a relative low cost and robust solution to cover large areas. Emerging applications in this context are proposing the use of wireless sensor networks composed of both static and mobile sensor nodes. Motivation for this trend is to reduce deployment and operating costs, besides providing enhanced functionalities. This work focuses on the proposal of solutions for wireless sensor networks including static and mobile sensor nodes specifically regarding cooperative and context aware mission setup and performance. The goal is to keep the communication costs as low as possible in the execution of the proposed solutions. This concern comes from the fact that communication increases energy consumption, which is a particular issue for energy constrained sensor nodes often used in wireless sensor networks, especially if battery supplied. In the case of the mobile nodes, this energy constraint may not be valid, since their motion might need much more energy, but links instabilities and short time windows available to receive and transmit data. Therefore, it is better to communicate as little as possible. For the interaction among static sensor nodes, the problems of dissemination and allocation of sensing missions are studied and a solution that explores local information is proposed and evaluated. This solution uses mobile software agents that have capabilities to take autonomous decisions about the mission dissemination and allocation using local context information. For mobile wireless sensor networks, the problem studied is how to perform handover of missions among the nodes according to their movements and locations in relation to the place where the missions have to be performed. To handle this problem, a mobile agent approach is proposed in which the agents implement the sensing missions’ migration from node to node using geographical context information to decide about their migrations. For the networks combining static and mobile sensor nodes, the cooperation among them is approached by a biologically-inspired mechanism to deliver data from the static to the mobile nodes. The data delivery mechanism explores an analogy based on the behaviour of ants building and following trails, inspired by the ant colony algorithm. The proposed solutions are flexible, being able to be applied to different application domains. Obtained experimental results provide evidence of the scalability of these proposed solutions, for example by evaluating their cost in terms of communication, among other metrics of interest for each solution. These results are compared to those achieved by reference solutions (theoretical optimum and floodingbased), providing indications of the proposed solutions’ efficiency. These results are considered close to the theoretical optimum one and significantly better than the ones achieved by flooding-based solutions.

Sistemas de vigilância são geralmente empregados no monitoramento de áreas de grandes dimensões nas quais seus usuários visam detectar ou observar fenômenos de seu interesse. O uso de redes de sensores sem fio nesses sistemas apresenta especial interesse, uma vez que essas redes podem apresentar soluções de baixo custo e robustas para cobrir áreas extensas. Neste contexto, novas aplicações têm surgido propondo o uso de redes de sensores sem fio compostas por nós sensores estáticos e móveis. Uma das motivações para esta tendência é a redução do custo de implantação e operação do sistema, além da possibilidade de proporcionar incremento em suas funcionalidades. O foco desta tese se concentra na proposta de soluções para redes de sensores sem fio com uso cooperativo de sensores estáticos e móveis, com particular atenção a sensibilidade ao contexto na configuração e execução de missões de sensoriamento. O objetivo é manter um baixo custo de comunicação associado às soluções propostas. Esta preocupação se dá pelo fato da comunicação aumentar o consumo de energia em redes de sensores, o que é um problema importante para nós sensores com limitada fonte de energia, i.e. baterias. No caso de nós sensores móveis, esta limitação pode não ser relevante, uma vez que seu movimento deve consumir uma quantidade muito mais expressiva de energia do que a comunicação. Neste caso, o problema se relaciona à estabilidade dos enlaces, bem como ao curto intervalo de tempo disponível para transmitir e receber dados. Logo, o melhor é comunicar o menos possível. Com relação à interação entre nós sensores estáticos, os problemas de disseminação e alocação de missões de sensoriamento são estudados e uma solução que explora o uso de informações locais é proposta e avaliada. Esta solução emprega agentes de software móveis que têm a capacidade de tomar decisões autônomas através do uso de informações de contexto local. Para redes de sensores móveis, o problema estudado se refere a como transferir missões entre os nós sensores de acordo com seu movimento e localização em relação aos locais onde as missões devem ser executadas. Para tratar este problema, uma abordagem baseada em agentes móveis é proposta, na qual os agentes implementam a migração das missões de sensoriamento usando informações de contexto geográfico para decidir a respeito de suas migrações. Para redes de sensores com sensores estáticos e móveis, a cooperação entre eles é abordada através de um mecanismo com inspiração biológica para realizar a realizar a entrega de dados emitidos pelos sensores estáticos aos sensores móveis. Para isto, explora-se uma analogia baseada no comportamento de formigas na construção e seguimento de trilhas. As soluções propostas são flexíveis, sendo aplicáveis a diferentes domínios de aplicação. Resultados experimentais evidenciam sua escalabilidade, avaliando, por exemplo, seu custo em termos de comunicação, além de outras métricas de interesse para cada uma das soluções. Estes resultados são comparados aos atingidos por soluções de referência (solução ótima teórica e baseada em inundação), indicando sua eficiência. Estes resultados são próximos do ótimo teórico e significativamente melhores que aqueles atingidos por soluções baseadas em técnicas de inundação. / Surveillance systems are usually employed to monitor wide areas in which their users are interested in detecting and/or observing events or phenomena of their interest. The use of wireless sensor networks in such systems is of particular interest as these networks can provide a relative low cost and robust solution to cover large areas. Emerging applications in this context are proposing the use of wireless sensor networks composed of both static and mobile sensor nodes. Motivation for this trend is to reduce deployment and operating costs, besides providing enhanced functionalities. This work focuses on the proposal of solutions for wireless sensor networks including static and mobile sensor nodes specifically regarding cooperative and context aware mission setup and performance. The goal is to keep the communication costs as low as possible in the execution of the proposed solutions. This concern comes from the fact that communication increases energy consumption, which is a particular issue for energy constrained sensor nodes often used in wireless sensor networks, especially if battery supplied. In the case of the mobile nodes, this energy constraint may not be valid, since their motion might need much more energy, but links instabilities and short time windows available to receive and transmit data. Therefore, it is better to communicate as little as possible. For the interaction among static sensor nodes, the problems of dissemination and allocation of sensing missions are studied and a solution that explores local information is proposed and evaluated. This solution uses mobile software agents that have capabilities to take autonomous decisions about the mission dissemination and allocation using local context information. For mobile wireless sensor networks, the problem studied is how to perform handover of missions among the nodes according to their movements and locations in relation to the place where the missions have to be performed. To handle this problem, a mobile agent approach is proposed in which the agents implement the sensing missions’ migration from node to node using geographical context information to decide about their migrations. For the networks combining static and mobile sensor nodes, the cooperation among them is approached by a biologically-inspired mechanism to deliver data from the static to the mobile nodes. The data delivery mechanism explores an analogy based on the behaviour of ants building and following trails, inspired by the ant colony algorithm. The proposed solutions are flexible, being able to be applied to different application domains. Obtained experimental results provide evidence of the scalability of these proposed solutions, for example by evaluating their cost in terms of communication, among other metrics of interest for each solution. These results are compared to those achieved by reference solutions (theoretical optimum and floodingbased), providing indications of the proposed solutions’ efficiency. These results are considered close to the theoretical optimum one and significantly better than the ones achieved by flooding-based solutions.

Orientador: Douglas Soares Galvão / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica "Gleb Wataghin" / Made available in DSpace on 2018-08-14T05:39:30Z (GMT). No. of bitstreams: 1 Brunetto_Gustavo_M.pdf: 28278571 bytes, checksum: 7cba216c6b133f4a224e2155791937f4 (MD5) Previous issue date: 2009 / Resumo: Recentemente, a primeira nanoroda molecular foi caracterizada a partir de experimentos com o microscópio de tunelamento eletrônico (STM). Foi demonstrado que a molécula de hidrocarboneto (C44H24) especificamente desenhada poderia rolar sobre a superfície de cobre ao longo da direção [110] da superfície. A molécula consiste em duas rodas baseadas no grupo triptycene as quais são conectadas por um eixo. Nós reportamos um estudo teórico da simulação desse processo. Usamos métodos ab initio (DMol 3) e de dinâmica molecular clássica (UFF). Consideramos diferentes orientações cristalográficas ([111], [110], e [100]) para a superfície de cobre, a fim de determinar como estas diferentes orientações afetam o processo de rolamento molecular. Nossos resultados estão em boa acordância com os dados experimentais disponíveis. As simulações mostraram que o mecanismo de rolamento só é possível para a direção [110]. Para as outras direções ([111] e [100]) a superfície é muito suave e não pode prover o torque necessário para o processo de rolamento. Para estes casos a molécula somente desliza (movimento de translação), sem rolar quando interage com a ponta do microscópio. Para a direção [110] a separação espacial entre as colunas de cobre é suficiente para travar a molécula e criar um torque. Além da superfície correta, a posição relativa da molécula sobre a superfície é muito importante. A molécula deve estar com seu eixo principal paralelo à direção [110]. Este efeito de comensurabilidade, entre a molécula e a superfície, é similar a difusão seletiva na superfície recentemente observada para outras classes de moléculas orgânicas. Os perfis experimentais observados para o empuramento, puxamento e rolamento também podem ser explicados em termos destas características geométricas entre a molécula e as diferentes direções cristalográficas do cobre / Abstract: Recently, the first molecular nanowheel was characterized with scanning tunneling micro-scope experiments. It was demonstrated that a specifically designed hydrocarbon molecule (C44H24) could roll over a copper substrate along the [110] direction of a surface. The molecule consists in two wheels based on two triptycene groups which are connected by an axle. We report a theoretical study of the simulations of this process. We used ab initio (DMol 3) and classical molecular dynamics methods (UFF). We have considered different crystallographic orientations ([111], [110], and [100]) for the copper surface, in order to determine how these different orientations affect the molecular rolling processes. Our results are in good agreement with the available experimentally data. The simulations showed that the rolling mechanism is only possible for the [110] direction. For the others directions ([111] and [100]) the surfaces are too smooth and cannot provide the necessary torque to the rolling process. For these cases the molecule just slides (translational movement), without rolling when interact with the STM tip. For the [110] direction the spatial separation among rows of copper atoms is enough to trap the molecule and to create a torque. Besides the correct surface the relative position of the molecule on the surface is very important. The molecule should be with its main axis in the parallel direction to [110]. This commensurability effect, between the molecule and the surface, is similar to the surface selective diffusion recently observed for other classes of organic molecules. The experimental observed pushing, pulling, and rolling profiles can also be explained in terms of these geometrical features between the molecule and the different Cu crystallographic directions / Mestrado / Mestre em Física