Master of Arts / Department of Communications Studies / Soo-Hye Han / The rise of partisan political news over the past two decades has influenced how political candidates discursively construct their image. While there is an extensive literature devote to presidential discourse, little is known about what gubernatorial discourse looks like and how they construct their image. This study examines how gubernatorial candidates discursively construct their image in a hyperpolarized electoral environment. An extensive content analysis of gubernatorial political interviews (n = 94), and specifically the utterances arising from those interviews (n = 1,524), was conducted. Findings show that gubernatorial candidates discursively construct their own image as a savior to the state, while creating their opponent’s and the DC elite’s image as a villain. Additionally, gubernatorial candidates do not adhere to the image bound by their party, and construct an image that is unique to their environment. Consequently, the environment that a gubernatorial candidate is situated influences how they communicate and construct their image and their opponent’s image. By examining gubernatorial discourse through political interviews, this study offers theoretical implications into understanding the influence of polarization, issue ownership, and tone in gubernatorial discourse. Practical implications examine the role of media outlets in gubernatorial discourse. This study contributes to scholarly understanding of gubernatorial discourse in a changing and polarizing political environment.

A pair of light beams that have orthogonal polarizations and equal intensity can be generated through reflection and refraction of a monochromatic light at a dielectric surface. Sytematic procedures to design beam splitters which can produce such output light beams are described in this thesis. Two designs that are of particular interest are prismatic substrates coated by a single layer and a double layer of thin films. Specific examples of each beam splitter in the visible and infrared are included. The performance of each beam splitter as a function of incidence angle, film thickness, and wavelength is also discussed.

The Polarizer-Sample-Analyzer (PSA) arrangement with the optical components P and A rotating with a fixed speed ratio (3:1) was originally introduced to determine nine Mueller matrix elements from Fourier analysis of the output signal of a photodetector. The arrangement is modified to the P'PSAA' arrangement where P' and A' represent fixed polarizers that are added at both ends with the speed ratio of the rotating components (P and A) remaining the same as before. After determination of the partial Mueller matrix in the ideal case, azimuthal offsets and imperfection parameters are introduced in the straight-through configuration and the imperfection parameters are determined from the Fourier coefficients. Finally, the sample is reintroduced and the full Mueller matrix elements are calculated to show the deviation from the ideal case and their dependency on the offsets and imperfection parameters.

This dissertation aims to investigate the bases of partisan differentiation and degree of polarization since Taiwan's 2000 presidential election. By employing American concepts and theories of partisan polarization, I analyze Taiwan's party politics at both the elite and mass levels. At the elite level, I examine whether inter‐party antagonism has become more intense in Taiwan's legislature and what types of issues contribute most to party conflict since 2000. At the mass level, I examine public perceptions of the parties, analyze whether any political issues divide the Taiwanese public along partisan lines, and explore the social and demographic bases of partisan divisions. The findings suggest that political elites became polarized along partisan lines after 2000, as observed in roll‐call voting behavior in the Legislative Yuan. This resulted from the formation of a divided government and the confrontation of two party coalitions after the 2000 presidential election. Furthermore, this polarization is mainly due to the opposite positions of the two party coalitions on the issue of the relationship with China. The pan‐blue party coalition favors reunification and closer interaction with China, whereas its counterpart, the pan‐green party coalition, favors Taiwanese independence and limited interaction with China. The issues of social reform vs. stability, social welfare vs. lower taxes, and environmental protection vs. economic development are less polarizing and less consistently divisive than the issue of Taiwan's relations with China. Partisan polarization is less evident among ordinary citizens than among political elites. The only issue dividing Taiwanese significantly is the China relationship issue (independence or unification with China). In addition, demographic factors may lead to partisan division among citizens. Nevertheless, this polarization is more moderate than that of political elites because the number of partisan independents is high and has not decreased significantly. In short, partisan polarization in Taiwan is not as intense as some political scientists claim. Taiwan's partisan polarization at the mass level is closer to the concept of "sorting", referring to the process of people gradually affiliating with the party that best reflects their policy preferences, even if those preferences are more moderate than extreme.

<p>The Duke Free-electron laser (FEL) system, driven by the Duke electron storage ring, has been at the forefront of developing new light source capabilities over the past two decades. In 1999, the Duke FEL demonstrated the first lasing of a storage ring FEL in the vacuum ultraviolet (VUV) region at $194$ nm using two planar OK-4 undulators. With two helical undulators added to the outboard sides of the planar undulators, in 2005 the highest FEL gain ($47.8\%$) of a storage ring FEL was achieved using the Duke FEL system with a four-undulator configuration. In addition, the Duke FEL has been used as the photon source to drive the High Intensity $\gamma$-ray Source (HIGS) via Compton scattering of the FEL beam and electron beam inside the FEL cavity. Taking advantage of FEL's wavelength tunability as well as the adjustability of the energy of the electron beam in the storage ring, the nearly monochromatic $\gamma$-ray beam has been produced in a wide energy range from $1$ to $100$ MeV at the HIGS. To further push the FEL short wavelength limit and enhance the FEL gain in the VUV regime for high energy $\gamma$-ray production, two additional helical undulators were installed in 2012 using an undulator switchyard system to allow switching between the two planar and two helical undulators in the middle section of the FEL system. Using different undulator configurations made possible by the switchyard, a number of novel capabilities of the storage ring FEL have been developed and exploited for a wide FEL wavelength range from infrared (IR) to VUV. These new capabilities will eventually be made available to the $\gamma$-ray operation, which will greatly enhance the $\gamma$-ray user research program, creating new opportunities for certain types of nuclear physics research.</p><p>With the wide wavelength tuning range, the FEL is an intrinsically well-suited device to produce lasing with multiple colors. Taking advantage of the availability of an undulator system with multiple undulators, we have demonstrated the first two-color lasing of a storage ring FEL. Using either a three- or four-undulator configuration with a pair of dual-band high reflectivity mirrors, we have achieved simultaneous lasing in the IR and UV spectral regions. With the low-gain feature of the storage ring FEL, the power generated at the two wavelengths can be equally built up and precisely balanced to reach FEL saturation. A systematic experimental program to characterize this two-color FEL has been carried out, including precise power control, a study of the power stability of two-color lasing, wavelength tuning, and the impact of the FEL mirror degradation. Using this two-color laser, we have started to develop a new two-color $\gamma$-ray beam for scientific research at the HIGS.</p><p>Using the undulator switchyard, four helical undulators installed in the beamline can be configured to not only enhance the FEL gain in the VUV regime, but also allow for the full polarization control of the FEL beams. For the accelerator operation, the use of helical undulators is essential to extend the FEL mirror lifetime by reducing radiation damage from harmonic undulator radiation. Using a pair of helical undulators with opposite helicities, we have realized (1) fast helicity switching between left- and right-circular polarizations, and (2) the generation of fully controllable linear polarization. In order to extend these new capabilities of polarization control to the $\gamma$-ray operation in a wide energy range at the HIGS, a set of FEL polarization diagnostic systems need to be developed to cover the entire FEL wavelength range. The preliminary development of the polarization diagnostics for the wavelength range from IR to UV has been carried out.</p> / Dissertation

Alors que la microscopie super-résolue a apporté une amélioration considérable en imagerie des assemblages moléculaires dans les milieux biologiques à l'échelle nanométrique, son extension à l'imagerie de l'orientation moléculaire, utilisant l'anisotropie de fluorescence, n'a pas encore été complètement explorée. Apporter une information sur l'orientation moléculaire à l'échelle nanométrique aurait un intérêt considérable pour la compréhension des fonctions biologiques. Dans cette thèse, nous proposons une technique de microscopie super-résolution résolue en polarisation, capable d'imager les comportements d'orientation moléculaire dans des environnements statiques et dynamiques, dans le but de rapporter une information structurale à l'échelle de la molécule unique et à des échelles spatiales nanométriques. En utilisant la microscopie par reconstruction stochastique (dSTORM) en combinaison avec une détection polarisée, des images d'anisotropie de fluorescence sont reconstruites avec une résolution spatiale de quelques dizaines de nanomètres. Nous analysons numériquement le principe de la méthode en combinaison avec des modèles des mécanismes d'orientation moléculaire. Enfin, nous proposons une technique alternative basée sur l'émission de molécules uniques en fluctuations stochastiques: l'imagerie super-résolue polarisée par fluctuations (polar-SOFI), et comparons cette approche avec la précédente. Nous illustrons les deux techniques pour l'imagerie de l'ordre moléculaire dans des fibres de stress d'actine et de tubuline dans des cellules fixées, des fibres d'ADN et des fibrilles d'amyloïde à base d'insuline. / While super-resolution microscopy has brought a significant improvement in nanoscale imaging of molecular assemblies in biological media, its extension to imaging molecular orientation using fluorescence anisotropy has not yet been fully explored. Providing orientational order information at the nanoscale would be of considerable interest for the understanding of biological functions since they are intrinsically related to structural fundamental processes such as in protein clustering in cell membranes, supra-molecular polymerization or aggregation. In this thesis, we propose a super-resolution polarization-resolved microscopy technique able to image molecular orientation behaviors in static and dynamic environments, in order to report structural information at the single molecule level and at nanometric spatial scale. Using direct Stochastic Optical Reconstruction Microscopy (dSTORM) in combination with polarized detection, fluorescence anisotropy images are reconstructed at a spatial resolution of a few tens of nanometers. We analyze numerically the principle of the method in combination with models for orientational order mechanisms, and provide conditions for which this information can be retrieved with high precision in biological samples based on fibrillar structures. Finally, we propose an alternative technique based on stochastic fluctuations of single molecules: polarized super-resolution optical fluctuation imaging (polar-SOFI), and compare this approach with the previous one. We illustrate both techniques on molecular order imaging in actin stress fibers and tubulin fibers in fixed cells, DNA fibers and insulin amyloid fibrils.

Thesis advisor: Hideo Konishi / Thesis advisor: Alberto Alesina / This dissertation studies the interaction of politicians’ and voters’ incentives and its effect on redistributive and immigration policies. The first chapter ``Redistribution, Polarization, and Ideology'' focuses on the effect of income inequality and party polarization on redistributive policy, both theoretically and empirically. I demonstrate that income inequality and party polarization on social issues push redistributive policy in opposite directions. In particular, when the importance of ideology for the voters rises with their income, polarization discourages redistribution. Using data from the American National Election Study and the Census, I verify that it is indeed the case that the importance attached to ideological issues is increasing in the voters' income. Effects of ``income elastic'' ideology can account for the observed stability of redistribution policy in the U.S. The second chapter, ``Foreign Born U.S. Citizens and Immigration Policy'', studies the impact of immigration on immigration reforms, and decomposes the effects of naturalized and non-naturalized immigrants. Using Census data and roll call votes for the House on 2005 and 2006 immigration bills, we find that immigration affects Democratic and Republican parties differently. While the effect of non-naturalized immigrants can be explained by congressional district's socio-economic characteristics, naturalized immigrants exert an additional effect linked to their ability to vote in congressional elections. Higher naturalized immigrant population increases the probability that Democrats vote in favor of immigration, and decreases it for Republicans, suggesting opposite electoral incentives for the two parties, that can be interpreted in a framework of rational office-motivated incumbents seeking reelection. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

As curvas de polarização potenciodinâmicas cíclicas da liga de níquel Inconel 625, em solução de NaCl 3,56 %, pH 7,5, desaerada e a temperatura ambiente, obtidas com base na metodologia descrita na norma ASTM G61, foram estudadas com o objetivo de interpretá-las, especialmente no trecho após a reversão da polarização. Para esse estudo, foram realizadas análises complementares por MEV/EDS e por espctroscopia Raman da superfície do eletrodo de trabalho e determinação qualitativa por EDS da composição do eletrólito coletado nas vizinhas do eletrodo de trabalho. Medidas de pH e determinação do teor de O2 do eletrólito junto ao eletrodo de trabalho também foram feitas. Os resultados obtidos mostraram que, entre o potencial de circuito aberto até potencial de quebra (Eb), da ordem de 0,600 V (ECS), a curva de polarização apresenta um comportamento passivo com tendência a atingir a densidade de corrente da ordem de 10-6 A/cm². Nessa região, ocorre o espessamento da camada devido à formação principalmente de Cr2O3. Após Eb, ocorre a mudança na inclinação da curva, devido à ocorrência da reação de oxidação da água, comprovada pela acidificação do eletrólito. No potencial de 0,750 V (ECS) ocorre uma inflexão na curva, causando a diminuição discreta da corrente, atribuída à formação de MoO42- (gel) que evita a incorporação de ânions como Cl- ou OH-, dificultando, porém não evitando, a oxidação/dissolução da camada passiva, comprovada pela presença de íons de Cr e de Ni no eletrólito, caracterizando uma região transpassiva. Após a reversão da polarização no potencial de 1,130 V (ECS), a curva apresenta uma histerese positiva, com valores de densidades de correntes menores em relação ao mesmo potencial aplicado durante a polarização direta, indicando a ocorrência de repassivação devido principalmente à formação de uma camada rica em Mo sobre a liga, cuja formação pode ser atribuída à transformação do molibdato para o óxido MoO3 decorrente da forte acidificação do eletrólito verificado nesse trecho da curva. Ainda, após a inversão da polarização, ocorre a transição da corrente anódica para catódica em um potencial próximo de 0,720 V (ECS). Do potencial de 0,600 V (ECS) até 0,200 V (ECS), observa-se uma região de passivação secundária, atribuída à formação do MoO3 de maneira mais significativa. Ao final a densidade de corrente volta a aumentar, indicando o início da oxidação/dissolução do MoO3 para Mo3+. / Cyclic potentiodynamic polarization curves of the nickel alloy Inconel 625 in 3.56 % NaCl solution, pH 7.5, deaerated and at ambient temperature, obtained according to the ASTM G61, were studied in order to interpret them, especially after the reversion of the scanning direction. For this study, complementary analyzes by MEV/EDS and by Raman spectroscopy of the working electrode surfaces as well as EDS analyses of the electrolyte collected near the working electrode were carried out. The pH values and O2 content of the electrolyte near the working electrode were also obtained. From the open circuit potential (OPC) up to breakdown potential (Eb), at about 0,600 V (ECS), the polarization curve presents a passive behavior with a tendency to reach the current density of 10-6 A/cm². In this region, the thickening of the passive film takes place mainly due to the formation of Cr2O3. After Eb, a change of the curve slope occurs due to the oxygen evolution reaction which is confirmed by the acidification of the electrolyte. At the 0,750 V (ECS) potential, an inflection of the curve is observed causing a discrete decrease in the current which was attributed to the formation of MoO42- (gel) which, in turn, avoids the incorporation of anions as Cl- or OH- in the passive film. This fact makes the oxidation/dissolution of the passive film difficult but does not avoid it since Cr and Ni ions were detected in the electrolyte after the inflection, characterizing a transpassive region. After the reversion of the scanning direction at the potential 1,130 V (ECS), the curve shows a positive hysteresis with lower current densities than the values obtained at the same potential applied during the direct polarization. This indicates the occurrence of repassivation mainly due to the formation of a Mo rich layer on the alloy whose formation can be attributed to the transformation of the molybdate to the MoO3 because of the strong acidification of the electrolyte. After the reversion of the polarization, a transition from the anodic current to cathodic occurs at a potential close to 0,720 V (ECS). From the potential of 0,600 V (ECS) up to 0,200 V (ECS), a secondary passivation region is observed which was attributed to the significant formation of MoO3. At the end of the reverse polarization, the current increases again, indicating the initiation of the oxidation/dissolution of MoO3 to Mo3+.

Este trabalho estima o efeito da polarização de renda sobre os índices de criminalidade para avaliar se a polarização é mais relevante que as medidas de desigualdade tradicionais na explicação da criminalidade. Para o cálculo da polarização foi utilizada a medida proposta por Duclos et al. (2004). Foram estimados modelos com dados de corte transversal e em painel, utilizando dados dos municípios paulistas, empregando-se modelos de auto-correlação espacial e System GMM. A principal conclusão deste trabalho é que a medida de polarização de renda tem efeito positivo e significativo sobre a taxa de crimes contra o patrimônio, assim como esperado inicialmente. Este resultado é robusto a alterações no peso do sentimento de identificação entre os indivíduos, &alpha;, e aos diferentes métodos econométricos e variáveis de renda utilizadas para calcular as medidas de desigualdade. / This paper estimates the effect of polarization of income on crime rates to assessing whether the polarization is more relevant than traditional measures of inequality in the explanation of crime. To calculate the polarization was used to measure proposed by Duclos et al. (2004). Models were estimated with cross-sectional and panel datas using models of spatial autocorrelation and System GMM. The main conclusion of this study is that the measure of income polarization has positive and significant effect on the rate of property crimes, as originally hoped. This result is robust to weight changes the feeling of identification among individuals, &alpha;, and different econometric methods and income variables used for calculate measures of inequality.

Neste trabalho, foram desenvolvidos e implementados três métodos experimentais, o método de corrente constante - CC (adaptado a partir do triodo de corona à corrente constante), o método de rampa de tensão - RT (adaptado a partir do método bipolar de medida de histerese elétrica) e o método para medida do coeficiente piroelémco pela técnica da temperatura oscilante (função senoidal). Os métodos foram empregados no estudo das polarizações elétricas apresentadas pelo PVDF, PVF, o copolímero P(VDF-TrFE) e a blenda P(VDF-TrFE) - PMMA. Verificou-se através de medidas de difratometia de raios-x, medida da polarização ferroelétrica (obtida pelos métodos CC e RT) e medida do coeficiente piroelétrico que parte da polarização elétrica relaxa após a remoção do campo elétrico e está associada a efeitos não hereditários. Foi estudada a dependência desta polarização com o campo elétrico aplicado (taxa de subida do campo e campo máximo), com o tempo de curto circuito que a amostra foi submetida entre processos de polarização consecutivos e o tipo de amostra. Foram determinados e comparados a polarização remanescente e o campo coercitivo dos materiais citados, obtidos pelos métodos CC e RT. / In this work three experimental setups were developed, the constant current method (CC) (derived from the corona mode with constant current), the ramp voltage method (RT) (derived from the bipolar hysteresis measurements) and measurement of the pyroeletric coefficient employing a sinusoidal temperature variation. These methods were used to study the ferroelectric polarization in polymers such as PVDF, PVF, copolymer of P(VDF-TrFE) and P(VDF-TrFE) - PMMA blend. From x-ray, electric polarization and pyroelectric measurements it was found that part of the total polarization decays after removing the electric field. The dependence of such decaying polarization on the rate of increasing of the electric field, on the maximum field applied to the sample and the time interval of short-circuit between successive measurements was investigated. The value of the remanent polarization and the coercive field was determined for polymeric materials listed above and a comparison of the results obtained using the CC and RT method was performed.