Considerations on the Diffraction Limitations to the Spatial Resolution of Optical Transition Radiation

The interest in using optical transition radiation (OTR) in high energy (multiGeV) beam diagnostics has motivated theoretical and experimental investigations on the limitations brought by diffraction on the attainable resolution. This paper presents calculations of the diffraction effects in an optical set-up using OTR. The OTR diffraction pattern in a telescopic system is calculated taking into account the radial polarization of OTR. The obtained diffraction pattern is compared to the patterns obtained by other authors and the effects of different parameters on the shape and on the size of the OTR diffraction pattern are studied. The major role played by the radial polarization on the shape of the diffraction pattern is outlined. An alternative method to calculate the OTR diffraction pattern is also sketchedComment: Submitted to Particle Accelerator

“Wow, they took turns”: Evaluation in the US and UK press coverage of the final US presidential debate of 2020

This thesis explores press bias in the US and UK news coverage of the final 2020 US presidential debate between Joe Biden and Donald Trump. An integral part of the US presidential election campaigns, the debates are televised events where the presidential candidates discuss controversial topics, and the press reports about the debates in real time. The goal of this thesis is to analyse whether a bias towards one of the candidates can be identified in the press coverage, and whether there is a difference between the coverage in the two countries. While the topic of press bias in elections has evoked academic interest in other fields, linguistic research has been minimal. Previous studies have found that the press coverage of presidential debates is sometimes biased or inaccurate, which might have the potential to influence voter behaviour. In this thesis I analyse whether a linguistic approach can offer new insight on how these biases manifest. The data comes from 8 US and 10 UK newspapers and consists of 69 newspaper articles. These countries were chosen, because their media systems have been found to share many similarities in the past, and they can give a general idea of the press coverage in the English-speaking world. More than just bias, this study analyses something called evaluation, an area of linguistics that deals with how writers express their views, how they build discourse with the readers and how they reflect the values of their community. Appraisal Framework (Martin and White, 2005) was used in the analysis, as it has been specifically designed for analysing evaluation and has been applauded for its ability to recognise implicit attitudes of the writers. The framework consists of three categories: ATTITUDES of the writer, ENGAGEMENT with the reader and GRADUATION, the degree of the attitudes. The collected data was analysed and classified manually in a close reading. The differences between the countries were found to be small, and a consistent bias favouring Biden was identified in the press coverage of both countries. In the ATTITUDE category, Trump was more often evaluated negatively than positively in both countries, especially regarding his moral standing (PROPRIETY) and his skills and capabilities (CAPACITY). Biden, on the other hand, was not evaluated negatively as much as Trump, and in the US, there were more positive than negative evaluations of him. He was most often applauded for his successes in the debate (CAPACITY). ENGAGEMENT was most often used by the journalists to oppose Trump’s views and to support Biden’s. The framework made it possible to build a more detailed description of how the biases manifest in the presidential debate news coverage and especially excelled in recognising implicit attitudes. At the same time, the framework had some issues regarding replicability of the study due to the subjectivity in identifying implicit attitudes. Some of these issues have been brought up by researchers in the past and adjustments for the framework have been suggested. Future studies using the Appraisal Framework could benefit from using one of these adjustments and seeing how that affects the results

Modelling and automated calibration of a general multi-projective camera

Recently, multi-projective cameras (MPCs), often based on frame-mounted multiple cameras with a small baseline and arbitrary overlap, have found a remarkable place in geomatics and vision-based applications. This paper outlines the geometric calibration of a general MPC by presenting a mathematical model that describes its unknown generic geometry. A modified bundle block adjustment is employed to calibrate an industrial-level 360° non-metric camera. The structure of any MPC can be retrieved as a calibration set of relative and interior orientation parameters (as well as the pose of the MPC shots) using a calibration room which has been accurately determined by close range photogrammetry. To demonstrate the efficiency and precision of the model, a Panono camera (an MPC with 36 individual cameras) was calibrated. After the adjustment, sub-pixel image residuals and acceptable object-space errors were observed.Peer reviewe

Performance and beef quality of growing bulls offered whole crop legume-cereal and alsike clover silages

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Palkokasvisäilörehujen vaikutukset sonnien kasvu- ja teurastuloksiin sekä lihan laatuun

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Effects of silage plant species and breed on carcass and meat quality of finishing bulls using forage-based beef production systems

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Bunch length measurements at the TESLA Test Facility using a streak camera

A streak camera provides a direct and convenient way to measure bunch lengths in the millimeter and submillimeter range. At the TESLA Test Facility (TTF) a streak camera with a subpicosecond resolution is in operation. A bunch compressor is used to produce bunch lengths down to 250$\mu$m for the operation of the TTF Free Electron Laser. Bunch length measurements are presented and compared with simulations