Para melhorar a visualização das pequenas estruturas anatômicas importantes para o diagnóstico do câncer de mama e otimizar o processamento das mamografias pelos sistemas computadorizados de auxílio ao diagnóstico (CAD), foi desenvolvido um dispositivo, baseado na tecnologia slit, que melhora a aquisição dos mamogramas. Este dispositivo reduz a radiação espalhada e o tamanho do foco e foi projetado a partir de um modelo computacional. O modelo adotado permite quantificar o valor desses parâmetros para qualquer sistema radiológico, qualquer espessura de tecidos moles radiografada e qualquer tensão aplicada ao tubo de raios-X. O dispositivo foi implementado e testado, quantificando as melhorias obtidas. As imagens geradas foram comparadas com as fornecidas pelos sistemas mamográficos convencionais. O modelo serviu para estudar também a interferência do espalhamento sobre o desempenho dos algoritmos usados nos sistemas de diagnóstico auxiliado por computador (CAD). / In order to improve the visualization of the small and important anatomical structures for breast cancer diagnosis and to optimize the image processing of mammograms by the computer aided diagnosis systems (CAD), a device that comes from slit technology was developed to improve the acquisition of mammograms. This device reduces the amount of scattered radiation and the focus size and it can be projected from a computational model. This model allows quantifying the value of those parameters, scattered radiation and the focus size, for any radiological system, any X-rayed soft tissue thickness and any tension applied to the X-ray tube. The device was implemented and tested quantifying the obtained improvements. The generated images were compared to the supplied for conventional mammography systems. The model was also good for studying interference on the algorithms used in the computer aided diagnosis systems (CAD).

In this thesis was designed, manufactured and tested the fourth evolution of a slit-flow rheometer with another necessary parts, eg. rheometer`s holder, drive frame and important jig tools. The rheometer is able to measure rheological properties of magnetic and non-magnetic fluids at very high shear rates, which commercial rheometers can not reach. It is designed for 200 bar pressure and maximum load 15 kN. The construction of the slit-flow rheometer with it`s holder and drive frame improves user friendliness, accelerates change of the fluid sample and expands research opportunities thanks to a big space for additional adjustments. It is possible to use different length of the slit and thanks to a changeable inserts it is possible to change parameters of the slit (roughness of the walls, wall material, thickness of the slit). A part of this thesis was focused on illation of necessary equations for planning calibration measurements. Aim of these measurements is to obtain minor pressure losses dependence on Reynolds number for specific slit.

In this dissertation, imaging characteristics of a nano-slit are investigated. Applications of a scanning and rotating nano-slit in measuring sub-micron aerial features are demonstrated. Coherent sub-micron spot distributions are reconstructed with a very high contrast. Finally, high NA partially coherent images with features as small as 210 nm half-pitch are reconstructed and the ultimate resolution of the system is determined.A nano-slit is characterized as a sensor for coherent line-and-space features. Experiments and simulation verify image detection with contrasts greater than 0.9. Effects of polarization on imaging performance are reported. A scanning and rotating nano-slit in conjunction with a filtered back-projection technique is used to reconstruct sub-micron coherent spot distributions. Simulation results show very good agreement with the experiment. Further, it is shown that the reconstruction is very resilient to some common random experimental errors.Imaging characteristics of a scanning nano-slit sensor are determined for high NA partially coherent images. Good imaging performance (contrast > 0.8) is demonstrated with line-and-space images up to a spatial frequency of 2.38 lp / micron. Sub-micron features in a high NA partially coherent image are measured with a scanning and rotating nano-slit. A modified microscope is used to create the measured features, including 210 nm half-pitch features that cannot be imaged using the microscope in a conventional imaging mode. Using the filtered back projection technique, two-dimensional sub-micron features are reconstructed by the nano-slit sensor. It is determined that the resolution limit of ~ 200 nm is determined by the reconstruction technique and not by the width of the nano-slit.

Resumo: Esta pesquisa é fruto do desenvolvimento de uma sequência didática sobre o comportamento das entidades físicas: partícula, onde e partícula-onda no Experimento da Supla Fenda, numa versão adaptada de Feynman e colaboradores e foi desenvolvida com estudantes de terceira série do ensino superior do curso de Química, disciplina Química Quântica, de uma universidade pública estadual. O objetivo geral do estudo foi discutir os fundamentos e práticas de experimentos mentais, tendo como parâmetro a utilização de diversas alternativas didáticas e seus desdobramentos para o ensino nas disciplinas científicas. A pesquisa de cunho qualitativo ancora-se nos fundamentos dos experimentos mentais e tem por base as teorias que visam promover a comunicação verbal e escrita dos conhecimentos científicos. O problema de pesquisa originou-se das dificuldades que os estudantes demonstravam em sala de aula para explicar e debater suas idéias, de maneira significativa, inteligível e dinâmica, quando estas exigiam deles o domínio da verbalização de conhecimentos científicos sobre o experimento da dupla fenda. Para interpretação e análise dos dados, utilizou-se a vertente interpretativa por meio de instrumentos e técnicas que permitem, principalmente, a descrição e interpretação de fatos e fenômenos, a recuperação de sentidos, tendo como base a investigação interpretativa do conjunto de materiais empíricos que se transformaram em textos. Os resultados revelam que os procedimentos didáticos utilizados são relevantes por possibilitarem a problematização, a discussão, o uso da imaginação e da linguagem verbal e escrita, pouco usuais em contextos de aulas de Química Quântica. Com relação aos textos, tanto aqueles transcritos das discussões e das falas dos estudantes quanto os que foram produzidos durante o desenvolvimento da pesquisa, por solicitação do professor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This research is the result of the development of a didactic sequence on the behavior of physical entities: particle, wave and wave-particle in the Double-Slit Experiment, in an adapted version from Feynman and assistants, which was developed with university students from the third grade of the Chemistry course, in the discipline of Quantum Chemistry, at a Brazilian public state university. The study aimed to discuss the fundaments and practices of thought experiments by using several didactic alternatives and its unfoldings to the teaching of scientific disciplines. The research, of qualitative basis, is anchored to the fundaments of thought experiments grounded on theories aiming to promote verbal and written communication of scientific knowledge. The research problem focuses on the difficulties that the students show in the classroom in order to explain and discuss their ideas when theses require that they master verbalization of scientific knowledge on the double-slit experiment in a meaningful, significant and dynamic manner. To the purpose of data interpretation and analysis, we used the interpretative perspective by means of the methodological and theoretical. Results revealed that the didactic procedures used are relevant since they allow problematization, discussion, the use of imagination and of verbal and written language, quite rare in classroom contexts of Quantum Chemistry. Regarding the texts, both the ones transcribed during the discussions and the students' speeches and those produced during the development of the research, required by the teacher, deserve attention. The text productions were found considerably reduced, fragmented, lacking progression and continuity of ideas, and also lacking the interconnected sequence of the parts that constitute an articulated whole. By means of discourse analysis, we detected loss of the line of unity that assures its interpretability... (Complete abstract click electronic access below) / Orientador: Aguinaldo Robinson de Souza / Coorientador: Ourides Santin Filho / Banca: Luiz Carlos de Menezes / Banca: Luiz Henrique Ferreira / Banca: João José Caluzi / Banca: Eduardo Adolfo Terrazzan / Doutor

Neste trabalho apresentamos um estudo sistemático da transmissão da radiação eletromagnética em um conjunto de fendas metálicas individuais depositadas em substratos de vidro BK7 com larguras abaixo do comprimento de onda da luz incidente. As fendas foram obtidas através da evaporação térmica de prata e ouro sobre um substrato dielétrico (vidro BK7). A fabricação das fendas foi feita de forma direta através de um equipamento de feixe de íons de Gálio (FEI Quanta 3D). A transmissão óptica das fendas foi estudada com radiação laser para os comprimentos de onda de 488 nm e 632.8 nm. Observouse uma oscilação de intensidade na transmissão devido ao efeito de interferência dos surface plasmon polariton (SPP) gerados na superfície metálica como função da espessura do filme metálico. Os resultados experimentais obtidos foram confrontados com simulações computacionais, via método de elementos finitos, a partir das quais pode se compreender os mecanismos de propagação da radiação na estrutura em questão, e compará-los com detalhes da fabricação de fendas. Procedimento similar foi realizado ao variar a largura das mesmas. Também foi feita a análise da transmissão óptica em fendas fabricadas em filmes constituídos por camadas alternadas de prata e ouro, a fim de comparar como tal mudança na configuração da estrutura afeta os resultados anteriores. O trabalho serviu para mostrar que as dimensões dos filmes metálicos, assim como das fendas, apresentavam grande influência nas propriedades de transmissão e, além do que foi possível conferir diversos conceitos básicos da teoria eletromagnética num sistema relativamente simples. A compreensão dessas propriedades é fundamental para o desenvolvimento de futuros dispositivos que utilizam efeitos plasmônicos. / This work presents a systematic study of the transmission of electromagnetic radiation on a set of single metallic slits metallic with widths below the wavelength of incident light, deposited on BK7 glass substrates. The slits were obtained by thermal evaporation of silver and gold on a dielectric (BK7 glass). The fabrication of the slits was performed directly through a gallium ion beam equipment (FEI Quanta 3D). The optical transmission of the slits was studied by laser radiation for the wavelengths of 488 nm and 632.8 nm. An oscillation in the transmission intensity was observed due to the interference effect of the surface plasmon polariton (SPP) generated on the metallic surface as a function of the metal film thickness. The experimental results were compared with computational simulations, via finite element method, in order to comprehend the mechanisms of radiation propagation in the structure and compare them with details of slits fabrication. A similar procedure was performed by varying the width of the slits. An analagous analysis of the optical transmission in slits fabricated in films consisting of alternating layers of silver and gold was performed in order to compare how this change in structure configuration affects the previous results. The work served to show that the dimensions of the metal films, as well as of the slits, have a significant influence on the properties of transmission, and, moreover it was possible to confer different basic concepts of electromagnetic theory in a relatively simple system. Understanding these properties is fundamental for the development of future devices that make use of plasmonics effects.

Soft matter, self-assembled 3D photonic structures such as blue phase liquid crystals have of great interest to the displays industry and are highly desirable as spatial light modulators because of their polarisation independence and fast switching. However, these types of devices suffer from multistep fabrication conditions and require high threshold voltages. To overcome these limitations, two key points were considered: High flexoelectric liquid crystals are capable of uniform 3D self-assembly, with a wide temperature range but have high threshold voltages, whereas, other classes of high dielectric liquid crystals have fast electro-optic response times with low threshold voltages but show poor 3D self-assembly. In this work, new mixture formulations have been devised having both properties in moderation in order to achieve simple yet stable 3D self-assembled blue phases with fast response times at as low as possible applied fields. Dielectric materials were considered from a commercial source whereas, miscible flexoelectric soft materials were synthesised in-house. These synthesised materials were fully characterised. Then mixtures were formulated in commercial high dielectric hosts to study their miscibility, new mesogenic transitions and electro-optic responses in terms of flexoelectric and dielectric properties. The selected mixtures were further investigated for the rapid growth of blue phases and their compatibility with reactive mesogens to form stable blue phases at room temperature. This new formulation of materials has given rise to mixtures and devices which are inherently easy to fabricate allowing the robust and resilient growth of blue phases under an hour in standard laboratory conditions. Furthermore, polarisation independent electro-optic switching has been characterised at fields < 1V micron m-1. For phase modulation studies of these stabilised blue phase devices, phase shift was measured using a modified Young's slit interferometer. The observed results were very promising, with a full 2.5 pi phase shift observed at a field of 9.25 V micron m-1 when compared to earlier reported devices (which required complicated multistep fabrication processes) giving values of full 1.8 pi phase shifts at 20 V micron m-1.

Des recherches menées chez les invertébrés ont conduit à la découverte de plusieurs molécules contrôlant le comportement des axones vis-à-vis de la ligne médiane, dont les molécules sécrétées Slits et leurs récepteurs membranaires Roundabouts (Robos). Nos travaux contribuent à confirmer in vivo la conservation de la fonction de ce système de guidage chez les vertébrés. Ce travail de thèse porte essentiellement sur l'analyse du développement de plusieurs systèmes neuronaux chez les souris déficientes pour un ou plusieurs des gènes slits ou robos. Il confirme que Robo1 et Robo2 sont essentiels au contrôle exercé par les Slits sur le croisement de la ligne médiane par plusieurs faisceaux d'axones du télencéphale. Nous avons également analysé le développement de plusieurs populations de neurones précérebelleux (NPC) du tronc cérébral. Nos résultats démontrent, pour la première fois, que le système Slit/Robo contrôle la capacité des neurones à migration tangentielle de croiser ou non la ligne médiane

The interest in creating and detecting electromagnetic waves carryingangular momentum in such a way that they form helical wavefronts,so called "twisted light'', has increased in recent decades.One possible way of generating such waves at radio frequenciesis to use a circular phased antenna array, where a larger relativephasing of the antenna elements corresponds to more twist of thewavefront per wavelength.However, analytical computations of the radiated power, and in turn theamountof emitted angular momentum, displays a quite rapid decrease with increasedphasing. This decrease in intensity may cause problems when alarge range of twisting is desired; for instance, as a means to encodeand transmit information. We have found that the decrease in radiatedpower does not haveany explicit relation to the beam being endowed with angular momentum.Instead, the decrease in emitted power can be explained byelectromagnetic couplingof the antenna elements in the array and that energy conservationholds, because an equal decrease in power is seen at the input of the array.We also show that a similar discrepancy is seen between the incomingand the total diffracted power in Young's classic double slit experiment,which, having only two slits, cannot provide any twisted light.The source of that discrepancy should be of a different origin.Although an explanation in terms of surface plasmons was recently givenin the literature, that is only applicable to metal screens. A general explanation of the problem therefore remains to be found.

Inom dagens byggande i Sverige ställs allt högre krav på den värmeisolerande förmågan hos klimatskärmen i de hus som byggs. Detta ställer i sin tur högre krav på konstruktionerna och medför även ny problematik. Standardlösningar som tidigare fungerat bra byts ut mot nya, ibland obeprövade, lösningar. De hårdare kraven på energi- och fuktdimensionering innebär alltså att vikten av val av stommaterial ökar vid en projektering. Vi har här försökt ge en realistisk bild av hur valet av reglar kan påverka energi och fukttillståndet hos en byggnad med utfackningsväggar, med fokus på reglar i fält. Till undersökningen användes referensobjekt i form av ritningar som tillhandahölls av handledaren på Clarus arkitekter. Med hjälp av dessa gjordes tredimensionella energiberäkningar som visade dels att valet av material kan ha mycket stor betydelse både för energiförluster och fukttillstånd, samt att sambanden inte nödvändigtvis behöver vara enkla. Valet av reglar har mycket varierande betydelse beroende på hur väggen är uppbyggd. Genom en laboration undersöktes skillnaden mellan slitsade och oslitsade ytterväggsreglar för att ge ökad förståelse och verifiera noggrannheten av beräkningarna jämfört med en verklig vägg. Det sista visade sig svårt att uppnå, men det var tydligt att slitsarna hade mycket stor betydelse för temperaturfördelningen i en vägg. / Construction of Swedish buildings today places higher demands on the heat-insulating capacity of the building envelope in the house built. This in turn places higher demands on the structures and also creates new problems. Standard solutions that previously worked well are being replaced by new, sometimes untested, solutions. The tougher demands on energy and moisture design means that the choice of substrate material is of greater importance than before when designing buildings.Here we have tried to give a realistic view of how the choice of studs can affect energy and humidity conditions of a building with curtain walls, focusing on studs in the field. The survey used reference objects projects in the form of drawings provided by the supervisor at Clarus Architects. Using these, three-dimensional calculations were made showing firstly that the choice of material can be of great importance both for the energy and moisture, and secondly, that the relationship is not necessarily simple. The importance of the choice of studs varies depending on how the wall is built. By a laboratory experiment, the correlation between slotted and unslotted outer wall studs was examined to provide greater understanding and verifying the accuracy of the calculations compared to a real wall. The last task proved difficult to achieve, but it was clear that the studs had great significance for the temperature distribution in a wall.

<p>This thesis investigates possibilities to perform image interpolation on an FPGA instead of on a graphics card. The images will be used for 3D display on Setred AB’s screen and an implementation in firmware will hopefully give two major advantages over the existing rendering methods. First, an FPGA can handle big amounts of data and perform a lot of calculations in parallel. Secondly, the amount of data to transfer is drastically increased after the interpolation and with this, a higher bandwith is required to transfer the data at a high speed. By moving the interpolation as close to the projector as possible, the bandwidth requirements can be lowered. Both these points will hopefully be improved, giving a higher frame rate on the screen.</p><p>The thesis consists of three major parts, where the first handles methods to increase the resolution of images. Especially nearest neighbour, bilinear and bicubic interpolation is investigated. Bilinear interpolation was considered to give a good trade off between image quality and calculation cost and was therefore implemented. The second part discusses how a number of perspectives can be interpolated from one or a few captured images and the corresponding depth or disparity maps. Two methods were tested and one was chosen for a final implementation. The last part of the thesis handles Multi Video, a method that can be used to slice the perspectives into a form that is needed for the Scanning Slit display to show them correctly.</p><p>The quality of the images scaled with bilinear interpolation is satisfactory if the scale factor is kept reasonably low. The perspectives interpolated in the second part show good quality with lots of details but suffers from some empty areas. Further improvements of this function is not necessary but would increase the image quality further. An acceptable frame rate has been achieved but further improvements of the speed can be performed. The most important continuation of this thesis is to integrate the implemented parts with the existing firmware and with that enable a real test of the performance.</p>