This thesis firstly theoretically describes phenomena which appear in optical fiber transmission. The theoretical part of the thesis deals with linear and non-linear phenomena, and later on proceeds to dispersions with a more significant effect on the optical transmission quality. It puts polarization to the centre of the phenomenon called Polarization mode dispersion (PMD), which is the main object of our interest. It leads to a deep PMD description from the point of view of polarization states, limit values, compensation methods, and methods of measurement. The practical part of this thesis deals with a draft of PMD measurement via Fixed Analyzer method. For the purposes of this measurement, we used the optical spectral analyzer MS9740A. In order to compare measured values, the proposed idea then proceeds to the reference measurement by using a modular platform EXFO FTB--200 in combination with CD/PMD module EXFO FTB-5700. Results of measurements have been evaluated for the limit values defined by the standard. In the last chapter of this thesis, the reference measurements are compared to the Fixed Analyzer method. All the advantages and disadvantages of individual measurement methods are identified at the end of this chapter too.

The field of metabolic engineering focuses on using molecular biology tools to genetically modify the metabolic pathways of cells for the production of chemical compounds. The field of directed evolution can alter the native abilities of proteins by taking inspiration from natural evolution. Both fields bring novel solutions to current problems in energy, the environment, and medicine. However, there is still no general higher throughput screening method for both of these fields. In this dissertation, we apply our designed fluorescence polarization assay to fill this need in the fields of metabolic engineering and directed evolution. Chapter 0 gives background information related to metabolic engineering, directed evolution, tetracyclines, the Tetracycline Repressor protein (TetR), TAN-1612, and fluorescence polarization. Chapter 1 describes our development of a quantitive, sensitive, and fast fluorescence polarization assay which uses the TetR protein to detect the binding of the small molecule tetracycline TAN-1612. Chapter 2 demonstrates that the binding affinity of the TetR protein for TAN-1612 can be improved using directed evolution and by incorporating our assay to screen TetR mutants. Finally, in Chapter 3 we apply our fluorescence polarization assay to the screening of yeast strains biosynthesizing TAN-1612, without the need of time and labor intensive extraction and purification steps.

This investigation is an examination of the behavior of dual coated reinforcing steel (DCR) with defects in the polymer coating exposing the only zinc layer in simulated concrete pore solution with and without chlorides. The intentional defects simulated the condition typically experienced by the rebar in service. Specimens were tested at open circuit potential, +100 mV, -500 mV, and -1000 mV for 30 to 100 days. The results were compared with that from previous DCR investigation with to-steel defects and epoxy-coated rebar (ECR). DCR with to-zinc defects had extensive corrosion damage when under strong anodic polarization and exposed to chlorides and was similar to that seen for DCR with to steel defects. The freely corroding (OCP) to-zinc DCR specimens in solutions both with and with no-chlorides experienced initially very active dissolution which ended after ~1 day. The zinc exposed at the coating breaks was not completely consumed even after 100 days and there was no visible corrosion product accumulation. This may be due to the formation of a calcium hydroxyzincate passive film and shows that the zinc passivates in alkaline solutions without the benefit of a crevice environment. The DCR with to-steel defects and the DCR with to-zinc defects had similar amounts of disbondment for all test conditions. Notable disbondment was seen only in highly anodic polarization regime with chlorides and was due to large amounts of solid corrosion product formation. These results suggest then that the overall process of zinc wastage in DCR in concrete pore water is not likely to be rapid, which would be beneficial to extending the period in which the barrier and galvanic properties of the zinc are maintained.

Affective polarization is a relatively new concept that refers to feelings of sympathy towards partisans of a person's own political party preference and antipathy towards those who vote for and identify with opposing parties. This thesis aims to answer the questions if those who know more about politics also are more affectively polarized, and whether there is a difference between knowing about different types of political facts, and the predicted level of affective polarization. Using panel data from 35 different countries from Module 4 of the Comparative Study of Election Systems, I measure the affective polarization on an individual level, and whether answering correctly to different types of knowledge questions predict the respondents to be more or less affectively polarized. The results show that political knowledge significantly predicts higher levels of affective polarization, but that there is a difference between different types of political knowledge. Political knowledge typically learned from the media has a stronger factor in predicting affective polarization.

The MeToo movement, which sought to combat sexual violence, evolved into a partisan problem, where support for or against the movement fell across party lines. This polarization negatively impacted the progress of the MeToo movement, fitting the larger pattern of increasing polarization in the United States. My thesis seeks to understand the politicized nature of sexual violence and to explore what language and themes are drawn on to politicize conversations around sexual violence by using the MeToo movement as a case study. My thesis found that the political polarization of sexual violence increased during the MeToo movement (and especially during and after the Kavanaugh hearing) primarily through detractors' language and framing of the issue. #MeToo detractors employed legalistic, violent, and misogynistic language to victimize the accused and villainize victims and supporters. In contrast, #MeToo supporters consistently used legalistic language to advocate for survivors' rights to state support in the face of actual violence. Insight on these politicizing discourses reveals a need for Democrats and Republicans to take on #MeToo policy reforms that both address due process and human rights while refraining from a victim/villain dichotomy.

Polarization is detected at early times for all types of supernovae, indicating that all such systems are, or quickly become, asymmetric. Spectropolarimetric observations also show that the asymmetry varies in both magnitude and orientation for different elements in the ejecta. One explanation for these observations is that local chemical inhomogeneities (called clumps) exist in the ejecta above the region where the continuum forms. To examine the effects of clumpiness on observations, I will present results of a comparison between a fast, flexible, approximate semi-analytic code for modeling polarized line radiative transfer within three-dimensional inhomogeneous rapidly expanding atmospheres; and VLT spectropolarimetric observations of SN2006X.

New results are described for the use of the Hanle effect in the photospheres of oblique magnetic rotators and of the Zeeman effect in stellar wind emission lines.

Wolf-Rayet (WR) stars are understood to have clumpy winds [1]. Robert et al. [2] found a statistical relation between the variations of the polarization and the scattering light intensity, R = σ p/σ phot ≈ 0.05. To explain this result, we propose a model in which clumps are ejected from the surface of WR stars uniformly in space with a Gaussian time interval distribution. According to the observed R along with the subpeaks on the emission lines of WR stars, we can obtain the parameters of the velocity law index β, and of the clump ejection rate in a flow time N. Also, the fraction η of the total mass loss rate contained in the clumps can be found from the observed polarization.

Polarization has been detected at early times for all types of supernovae (SNe), indicating that all such systems result from or quickly develop some form of asymmetry. In addition, the detection of strong line polarization in SNe is suggestive of chemical inhomogeneities ("clumps") in the layers above the photosphere, which may reflect hydrodynamical instabilities during the explosion. We have developed a fast, flexible, approximate semi-analytic code for modeling polarized line radiative transfer within three-dimensional inhomogeneous rapidly expanding atmospheres. Given a range of model parameters, the code generates random sets of clumps in the expanding ejecta and calculates the emergent line profile and Stokes parameters for each configuration. The ensemble of these configurations represents the effects both of various host geometries and of different viewing angles. We present results for the first part of our survey of model geometries, specifically the effects of the number and size of clumps (and the related effect of filling factor) on the emergent spectrum and Stokes parameters. Our simulations show that random clumpiness can produce line polarization in the range observed in SNe Ia, as well as the Q-U loops that are frequently seen in all SNe. We have also developed a method to connect the results of our simulations to robust observational parameters such as maximum polarization and polarized equivalent width in the line. Our models, in connection with spectropolarimetric observations, can constrain the three-dimensional structure of SN ejecta and offer important insight into the SN explosion physics and the nature of their progenitor systems.

The Hanle effect has been proposed as a new diagnostic of circumstellar magnetic fields for early-type stars, for which it is sensitive to field strengths in the 1-300 G range. In this paper we compute the polarized P Cygni line profiles that result from the Hanle effect. For modeling the polarization, we employ a variant of the "last scattering approximation." For cases in which the Sobolev optical depths are greater than unity, the emergent line intensity is assumed to be unpolarized, while for smaller optical depths, the Stokes source functions for the Hanle effect with optically thin line scattering are used. For a typical P Cygni line, the polarized emission forms in the outer wind, because the Sobolev optical depth is large at the inner wind. For low surface field strengths, weak P Cygni lines are needed to measure the circumstellar field. For high values of the surface fields, both the Zeeman and Hanle diagnostics can be used, with the Zeeman effect probing the photospheric magnetic fields and the Hanle effect measuring the magnetic field in the wind flow. Polarized line profiles are calculated for a self-consistent structure of the flow and the magnetic geometry based on the WCFields model, which is applicable to slowly rotating stellar winds with magnetic fields drawn out by the gas flow. For surface fields of a few hundred gauss, we find that the Hanle effect can produce line polarizations in the range of a few tenths of a percent up to about 2%.