O objetivo deste trabalho foi implementar um sistema para a determinação do coeficiente piroelétrico em materiais poliméricos. O método consiste em variar a temperatura da amostra de forma senoidal e medir a corrente em função do tempo. Através do sinal da corrente elétrica e da sua diferença de fase com a temperatura, separa-se a corrente elétrica de origem piroelétrica, a partir da qual se determina o coeficiente piroelétrico. Apresenta-se a caracterização do sistema abrangendo aspectos como o intervalo de temperatura das medidas e amplitude e freqüência da oscilação da temperatura. O método foi empregado para realizar medidas exploratórias com o polímero ferroelétrico poli(fluoreto de vinilideno), PVDF, polarizado pela aplicação de uma rampa de tensão, e com o polímero poli(metacrilato de metila), PMMA, com corante polar, polarizado com o triodo de corona. Nas medidas foram variados os parâmetros do processo de polarização elétrica tais como o campo elétrico máximo e a temperatura / An experimental setup to measure the pyroelectric coefficient of polymers was implemented. The method is based on the measurement of the electric current generated by the sample when its temperature was set to oscillate sinusoidally. Using the measured current and its phase difference related with the temperature thepyroelectric current was obtained, from that the pyroelectric coefficient was determined. It is shown the characterization of the experimental system such as the temperature amplitude and frequency interval of operation. The method was applied in exploratory measurements employing the ferroelectric polymer poly(vynilidene fIuoride), PVDF, poled by a ramp voltage, and the poly(methyl metacrylate), PMMA, having a polar dye, poled with the carona triode. Measurements were performed far different poling conditions such as the maximum applied field and temperature

Nesta dissertação relatamos os resultados de medidas elétricas realizadas, a maioria delas, em folhas de 25&#956m de polivinilidene de flúor (PVDF), e em menor número em folhas de tetrafluoretileno-hexafluorpropileno (Teflon FEP). Correntes de polarização sob variadas tensões e de despolarização foram medidas a várias temperaturas e com temperatura variável. O PVDF sofre modificações, possivelmente estruturais, sob aquecimento acima de 100&#176C quando um campo elétrico parece produzir uma limpeza elétrica, resultando uma condutividade menor. As polarizações são do tipo t-n, indicando, no caso do PVDF uma distribuição em freqüências e para o FEP tratado termicamente a 200&#176C, uma em energia. Apesar das amostras de PVDF fornecerem resultados pouco reprodutíveis, pode-se concluir que para os campos empregados o comportamento é razoavelmente linear na polarização e superlinear para a condutividade. Observou-se também um comportamento anômalo da corrente, no PVDF, sob a ação prolongada de campo aplicado, mesmo para as menores tensões. Para o FEP o comportamento da corrente para os diversos campos usados foi bastante irregular embora as polarizações e as subseqüentes despolarizações coincidissem na maioria dos casos / We present here the results of electrical measurements performed, most of them, in 25&#956m foils of polyvinylidene fluoride (PVDF), and fewer in flois of tetrafluorethilene-hexafluorpropilene (Teflon FEP). Polarization currents under varied applied voltages and the corresponding depolarizations were measured at constante temperature and during heating and cooling. The PVDF exhibits modifications, possibly its structure changes, if heated above 100&#176C; in this case an electric field seems to clean the sample since its conductivity strongly decreases thereafter. The polarizations are of the t-n type, poiting to a distribution of frequencies inPVDF and of energies in FEP previously annealed at 200&#C. Although the results are poorly reproducible, some conclusions could be drawn for the PVDF: the polarization is nearly linear with the field but the conductivity shows a super linear dependence. An anomalous behavior of the current was observed at long time under tension, even the smallest use here. In the case of FEP, the magnitude of the current in relation with the voltage hás shown an irregular behavior, although polarization and the corresponding depolarization do indeed coincide in most cases

A Microscopia Holográfica Digital (MHD) é uma poderosa ferramenta para análise não destrutiva de superfícies e caracterização morfológica e estrutural de materiais. Várias técnicas microscópicas têm sido utilizadas com esses objetivos, mas, em todas elas, a visualização de campo completo não é permitida em uma única aquisição da informação do sistema analisado, além disso, a necessidade de uso de corantes, o processo de varredura, entre outros fatores, dificulta a aquisição das imagens. A Microscopia Holográfica Digital permite contornar essas dificuldades através de um método simples e rápido. Com uma modificação em seu arranjo original, é possível revelar as diferenças na absorção e nos índices de refração experimentados por um campo transmitido por um material anisotrópico. Este método, neste trabalho, foi nomeado como Microscopia Holográfica de Polarização, o qual permite medir as diferenças de fase e de intensidade relacionadas com a birrefringência e com o dicroísmo do material, respectivamente. Dessa forma, A MHD se mostra uma ferramenta promissora na análise de problemas em diversas áreas, pois possibilita, através de uma única captura, obter informações sobre as propriedades ópticas e estruturais dos sistemas de interesse. O objetivo desse trabalho foi, além do desenvolvimento instrumental, analisar variações nas propriedades ópticas e morfológicas de eritrócitos através da quantificação dos índices de refração e perfis topográficos destes quando submetidos aos principais agentes de fixação de amostras. Essas variações são determinantes na escolha do método de análise, já que estes podem alterar significativamente os resultados, assim como a sua interpretação. Também foi descrito um novo método, baseado na técnica holográfica, de análise do dicroísmo linear através de uma varredura executada sobre os padrões de difração das componentes ortogonais do campo transmitido pela amostra. A aplicação da MHD ao estudo de processos dinâmicos também foi realizada, utilizando células cardíacas vivas e proteínas em solução. Somados, estes resultados demonstraram a possibilidade de se utilizar as técnicas holográficas como métodos de estudo amplo de microssistemas biológicos. / The Digital Holographic Microscopy (DHM) is a powerful tool for nondestructive analysis of surfaces and for morphological and structural characterization of materials. Several microscopic techniques have been used with these purposes, but in all cases, the complete field reconstruction is not allowed in a single acquisition of information of the analyzed system, moreover, the requirements of staining and scanning procedures, among other factors, difficult the image acquisition. Digital Holographic Microscopy allows to overcome these difficulties through a simple and quick method. With a modification in its original setup, is possible to reveal the differences in absorption and refractive index experienced by a wavefield transmitted by an anisotropic material. This method, in this thesis, is named Polarization Holographic Microscopy, which allows to measure differences in phase and intensity related to the birefringence and the dichroism of the material, respectively. Thereby, the DHM is shown as a promising tool for the study of problems in several fields, because it allows, through a single capture, to obtain information related to optical and morphological properties of the systems of interest. The objective of this work was, besides instrumental development, to evaluate changes in optical and morphological properties of erythrocytes through quantification of their refractive index and topographic profiles when submitted to the main fixating agents. These changes are crucial once the method of analysis is chosen, as they can significantly alter the results, as well as their interpretation. A new method was also described based on the holographic technique, for analysis of linear dichroism, through scans performed on the diffraction patterns of the orthogonal components of the field transmitted by the sample. The application of the DHM to the study of dynamic processes was also performed, using live cardiac cells and proteins in solution. Together, these results demonstrate the possibility of using holographic techniques such as extensive methods for studying biological microsystems.

Over the past decade, research into computer vision has proliferated with the goal to incorporate artificial intelligence into a wide range of applications. These applications can be as sophisticated as intelligent assistants in smartphones and self-driving cars or as mundane as text and face recognition. While most of these applications are software based, they represent unique challenges when it comes to industrial implementation. This thesis concentrates on an optical non-destructive testing (NDT) and automatic classification methodology using customized image processing techniques. In contrast to conventional spatial analyses, which are highly susceptible to noise and human perception, our proposed transform domain approach provides a high degree of robustness and flexibility in feature selection and hence a better classification efficiency. Our presented algorithm classifies the Part-Under-Test (PUT) into two bins of either acceptable or faulty using transform domain techniques in conjunction with a classifier. Because the classification is critically dependent on the features extracted from these images, a sophisticated scalable database was created. This thesis applies transform domain techniques such as Discrete Wavelet Transform (DWT) and Rotated Wavelet Transform (RWT) for feature extraction and then classifies the PUT based on those features. Although, this approach achieves promising classification efficiency, it does not meet industrial standards. It was concluded that in order to achieve those standards, the effect of emissivity fluctuations of the PUT should be negated. The research was then extended to apply an image acquisition algorithm in the form of shape from polarization. The approach exploits the partially linearly polarization of reflected light from the PUT surface. It was observed that this method could not only detect if the PUT is faulty or fault free, but also highlight the locations of the flaws.

A disfunção do sistema imune inato e a neuroinflamação tem sido cada vez mais reconhecidas como elementos importantes na fisiopatologia do transtorno bipolar (TB). Como componentes essenciais da imunidade inata, os macrófagos tem múltiplas funções tanto na inibição como na promoção da proliferação celular e na reparação tecidual, sendo a diversidade e a plasticidade características marcantes deste tipo celular. A polarização M1 clássica e a polarização alternativa M2 de macrófagos representam dois extremos de um estado dinâmico na mudança da ativação dos mesmos. Os macrófagos do tipo M1 sintetizam citocinas próinflamatórias que inibem a proliferação de células circundantes e danificam tecidos, enquanto os macrófagos do fenótipo M2 liberam citocinas antiinflamatórias que podem promover reparo tecidual. Um desequilíbrio da polarização M1-M2 dos macrófagos é frequentemente associado a várias doenças ou condições inflamatórias. O objetivo desta tese foi, além de revisar a importância da inflamação sistêmica na modulação da resposta inflamatória da microglia/macrófagos e consequentemente seu potencial envolvimento na fisiopatologia do TB, avaliar o perfil de polarização M1/M2 em cultura de macrófagos de sujeitos com TB comparados a indivíduos saudáveis. Monócitos foram isolados a partir de sangue periférico de dez sujeitos com TB e dez indivíduos saudáveis e diferenciados em macrófagos através da adição de fator estimulante de colônia de macrófagos (MCSF) ao meio de cultura. Para induzir a polarização M1 ou M2, as culturas foram incubadas com IFN-y e LPS ou IL-4 respectivamente. Após a incubação, recolheram-se os sobrenadantes e mediram-se as citocinas (IL-1β, IL-6, IL-10 e TNF-α) por ensaio multiplex. A secreção das citocinas IL-1β, TNF-α e IL-6 características do protótipo M1 e citocinas IL-10 do protótipo M2 foram semelhantes entre os pacientes e os controles. Utilizou-se a razão TNF-α / IL-10 do fenótipo M1 para refletir o estado inflamatório dos participantes. Não foi observada diferença entre os grupos (p=0,627). Duas hipóteses diferentes poderiam explicar esses resultados: todos os pacientes incluídos neste estudo representam um estágio inicial da doença como evidenciado pela pontuação FAST total inferior a 11. De acordo com o modelo de estadiamento em TB, as alterações biológicas (incluindo a inflamação) parecem estar relacionadas com os episódios de humor e progressão da doença. Juntamente com estudos anteriores, os nossos dados sugerem que os pacientes nos estágios iniciais ainda preservam a função do sistema imunológico sem apresentar um desequilíbrio a favor do perfil de macrófagos M1 como tem sido observado em pacientes no estágio tardio, destacando a relevância da intervenção precoce no TB. Ainda, estes pacientes estavam em tratamento com estabilizadores de humor e é plausível especular que esses fármacos exerçam efeitos sobre a polarização de macrófagos. Estudos futuros em pacientes drug-free são essenciais para avaliar esta questão. Em conclusão, nossos achados sugerem que os pacientes TB não apresentam desequilíbrio na polarização dos macrófagos em favor do fenótipo pró-inflamatório M1. O fato de todos estes pacientes estarem em estágios iniciais da doença reforça os efeitos protetores da intervenção precoce no TB na prevenção de alterações do sistema imune e, consequentemente, na progressão da doença. / Innate immune system dysfunction and neuroinflammation have been recognized as important elements in the pathophysiology of bipolar disorder (BD). As essential players of innate immunity, macrophages have multiple roles in inhibition and promotion of cell proliferation and tissue repair. The classical M1 polarization and the M2 alternative polarization of macrophages represent two extremes of a dynamic state in their change of activation. M1 macrophages synthesize proinflammatory cytokines that inhibit the proliferation of surrounding cells and damage tissues, whereas macrophages of the M2 phenotype release antiinflammatory cytokines that may promote tissue repair. An imbalance of the M1-M2 polarization of macrophages is often associated with various diseases or inflammatory conditions. The aim of this thesis was to review the importance of systemic inflammation in modulating the inflammatory response of microglia/ macrophages and consequently their potential involvement in the pathophysiology of BD, and also evaluate the M1/M2 polarization profile in macrophages of patients with BD compared to healthy individuals. Blood monocytes were obtained from ten BD patients and ten healthy controls. These cells were activated/polarized into the M1 (IFNγ + LPS) or M2(IL-4) phenotype. Supernatants were collected and the cytokines (IL-1β, IL-6, IL-10 and TNF-α) were measured by multiplex assay. Secretion of the IL- 1β, TNF-α, IL-6 and IL-10 were similar between patients and controls. The TNF-α/IL- 10 ratio of the M1 phenotype was used to reflect the inflammatory state of the participants. There was no difference between groups (p = 0.627). Two hypotheses could explain these results: all patients included in this study represent an early stage of disease as evidenced by the FAST score below 11. According to the BD staging model, biological changes (including inflammation) appear to be related to mood episodes and disease progression. Together with previous studies, our data suggest that patients in early stages of BD still preserve immune system function without presenting an imbalance in favor of M1 macrophages as has been observed in latestage patients, highlighting the relevance of early intervention. Moreover, these patients were under treatment with mood stabilizers and it is plausible to speculate that these drugs have effects on macrophage polarization. Future studies in drug-free patients are essential to assess this issue. In conclusion, our findings suggest that BD patients do not present imbalance in macrophage polarization in favor of the M1 proinflammatory phenotype. The fact that all these patients are in the early stages of the disease reinforces the protective effects of early intervention in BD to prevent changes in the immune system and, consequently, prevent the progression of the disease.

Previously, the rich customers bought expensive luxury goods, the impoverished customers bought cheap low quality merchandise and the middle class customers stayed true and loyal to the middle market. However, today there has been a change in the customer shopping behaviour, especially among the middle class customers who no longer want to be stuck in mediocrity. Either the customers “trade up”, which means that they buy goods with higher price and quality; or they “trade down”, which means that they buy cheaper low quality goods. This has created a change, which means that around the world, premium and no-frills products are squeezing middle-of-the-road products and services. Sales in the middle market are pressed while sales on both the top end and the bottom end of the market are rapidly growing. The market conditions are changing and this thesis is written with the purpose to analyse the given market situation - giving companies, primarily in the fashion industry, an opportunity to overview the possibilities for positioning on a market where the gap between discount and premium brands is getting bigger. Obviously, the phenomenon of market polarization will continue and the pressure on the companies to change will increase. This thesis discus therefore how a company can position and reposition itself in the emerging and ever changing environment. Three companies have been researched – Helly Hansen, Pennyblack and Nova Star. The choice of the companies have been made on the basis of all being active on the Scandinavian middle market practicing in three different parts of the fashion industry, which gives this study a broader approach. The study is qualitative and based on interviews with representatives from each company. After conducting the interviews and analysing the empirical framework, the conclusions suggest that the most beneficial way for a company to position itself on the current saturated market is by differentiating themselves, providing something that the competitors cannot offer. Nevertheless, the differentiation has nowadays become more complex and convoluted. This happened since the saturation has made attributes that previously have been seen as unique - such as for example, superior quality and design, to be mainly common. The saturated market leads to more and more tough competition between the companies. The study shows that this actually is the reason making the companies to try to make profit everywhere, attempting to reach people that should not fall within their targeted segment. On the contrary, it is more beneficial to target as narrowly as possible, specifically aiming at the consumers that would actually benefit form the products a company offers. Lastly, the results indicate that the International brands attempting to enter the Scandinavian market should be prepared to adjust their strategies, since the Scandinavian market seems to be different from the rest of the world. / Program: Master in Fashion Management with specialisation in Fashion Marketing and Retailing

The E and B EXperiment (EBEX) is a pointed balloon-borne telescope designed to measure the polarization of the cosmic microwave background (CMB) as well as that from Galactic dust. The instrument is equipped with a 1.5 meter aperture Gregorian-Dragone telescope, providing an 8' beam at three frequency bands centered on 150, 250 and 410 GHz. The telescope is designed to measure or place an upper limit on inflationary B-mode signals and to probe B-modes originating from gravitationnal lensing of the CMB. The higher EBEX frequencies are designed to enable the measurement and removal of polarized Galactic dust foregrounds which currently limit the measurement of inflationary B-modes. Polarimetry is achieved by rotating an achromatic half-wave plate (HWP) on a superconducting magnetic bearing. In January 2013, EBEX completed 11 days of observations in a flight over Antarctica covering 6,000 square degrees of the southern sky. This marks the first time that kilo-pixel TES bolometer arrays have made science observations on a balloon-borne platform. In this thesis we report on the construction, deployment and data analysis of EBEX. We review the development of the pointing sensors and software used for real-time attitude determination and control, including pre-flight testing and calibration. We then report on the 2013 long duration flight (LD2013) and review all the major stages of the analysis pipeline used to transform the ~1 TB of raw data into polarized sky maps. We review "LEAP", the software framework developed to support the analysis pipeline. We discuss in detail the novel program developed to reconstruct the attitude post-flight and estimate the effect of attitude errors on measured B-mode signals. We describe the bolometer time-stream cleaning procedure including removing the HWP-synchronous signal, and we detail the map making procedure. Finally we present a novel method to measure and subtract instrumental polarization, after which we show Galaxy and CMB maps.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1970. / Includes bibliographical references (leaves 327-332). / by John David Ramshaw. / Ph.D.

Yuen Chi Yan = 有關光折變晶體中空間孤子、偏振轉動以及霍爾效應的研究 / 阮志仁. / Thesis submitted in: July 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 81-82). / Text in English; abstracts in English and Chinese. / Yuen Chi Yan = You guan guang zhe bian jing ti zhong kong jian gu zi, pian zhen zhuan dong yi ji Huoer xiao ying de yan jiu / Ruan Zhiren. / Acknowledgments --- p.i / Abstract --- p.ii / Table of Contents --- p.v / Chapter Chapter 1 --- Photorefractive Spatial Soliton --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Bright Spatial Soliton --- p.3 / Chapter 1.2.1 --- Experiment --- p.4 / Chapter 1.2.2 --- Results and Discussion --- p.6 / Chapter 1.2.2.1 --- Expansion --- p.6 / Chapter 1.2.2.2 --- Contraction --- p.10 / Chapter 1.3 --- Dark Spatial Soliton --- p.15 / Chapter 1.3.1 --- Experiment --- p.15 / Chapter 1.3.2 --- Results and Discussion --- p.20 / Chapter Chapter 2 --- Polarization Rotation --- p.23 / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.2 --- Experiment --- p.24 / Chapter 2.3 --- Results and Discussion --- p.30 / Chapter 2.3.1 --- Effect of varying pump beam power --- p.30 / Chapter 2.3.2 --- Effect of different polarizations of signal beam --- p.41 / Chapter 2.3.3 --- Effect of signal beam size --- p.43 / Chapter 2.3.4 --- Effect of applied E-field --- p.46 / Chapter 2.3.5 --- Effect of signal beam and pump beam separation and perpendicularly --- p.52 / Chapter 2.3.6 --- Investigation of Δne using interferometer --- p.60 / Chapter 2.3.7 --- Computer Simulation --- p.69 / Chapter Chapter 3 --- Hall Effect --- p.72 / Chapter 3.1 --- Introduction --- p.72 / Chapter 3.2 --- Experiment --- p.75 / Chapter 3.3 --- Results and Discussion --- p.76 / Conclusion and Possible Further Works --- p.79 / References --- p.81

Chan Po Shan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 79). / Text in English; abstracts in English and Chinese. / Chan Po Shan. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Application of Optical Waveguides --- p.1 / Chapter 1.2 --- Planar Waveguide Characterizations --- p.2 / Chapter 1.3 --- Silicon-On-Insulator Rib Waveguides --- p.3 / Chapter 1.4 --- Polarization compensation schemes --- p.4 / Chapter 1.5 --- Objectives --- p.6 / Chapter 2 --- Silicon-On-Insuiator Rib Waveguides --- p.9 / Chapter 2.1 --- Properties of Silicon Waveguides --- p.9 / Chapter 2.2 --- Single Mode Rib Waveguides Simulations --- p.11 / Chapter 2.3 --- Special design optimisations --- p.14 / Chapter 2.4 --- Fabrications and Results --- p.16 / Chapter 3 --- Polarization Characteristics of SOI Rib Waveguides --- p.20 / Chapter 3.1 --- Properties of silicon and effect of rib structure --- p.20 / Chapter 3.2 --- Polarization affected by Form Birefringence --- p.21 / Chapter 3.3 --- Case Study: Arrayed Waveguide Grating --- p.23 / Chapter 3.4 --- Possibility of polarization Compensation in planar waveguides --- p.26 / Chapter 4 --- Fixed Polarization Compensation Techniques --- p.30 / Chapter 4.1 --- Theoretical analysis of slant rib waveguides on polarization --- p.30 / Chapter 4.2 --- Focused Ion Beam Trimming of SOI waveguides --- p.31 / Chapter 4.3 --- Possible applications --- p.36 / Chapter 5 --- Tuneable Polarization Compensation Techniques --- p.41 / Chapter 5.1 --- stress on rib waveguide for polarization compensation --- p.41 / Chapter 5.2 --- Magnetostriction and Magnetostrictive Materials --- p.42 / Chapter 5.3 --- Sputtering of soft magnetic layer on SOI rib waveguides --- p.46 / Chapter 5.4 --- Test results and Analysis --- p.47 / Chapter 6 --- Advanced SOI Devices --- p.55 / Chapter 6.1 --- Unique planar optoelectronics devices --- p.55 / Chapter 6.2 --- Simulation and Fabrications --- p.57 / Chapter 6.3 --- Test Results and Discussion --- p.58 / Chapter 7 --- Conclusion --- p.62 / Chapter 7.1 --- Summary --- p.62 / Chapter 7.2 --- Future work --- p.63 / Appendices / Chapter A1 --- Effective Index Method --- p.66 / Chapter A2 --- Beam Propagation Method --- p.70 / Chapter A3 --- SOI Rib Waveguide Fabrication --- p.72 / Chapter A4 --- Focused Ion Beam --- p.74 / Chapter A5 --- Polarization Optics --- p.76 / List of Publications --- p.79