Multicolour far infrared photometry of galactic H2 regions

Results are presented of far infrared photometric measurements of H2 regions in the galactic plane between longitudes 350 and 40 degrees. The results are combined from balloon flights in 1972 and 1973 carried out in cooperation with CNES in the south of France

Photoelectron Spectroscopy on Doped Organic Semiconductors and Related Interfaces

Using photoelectron spectroscopy, we show measurements of energy level alignment of organic semiconducting layers. The main focus is on the properties and the influence of doped layers. The investigations on the p-doping process in organic semiconductors show typical charge carrier concentrations up to 2*10E20 cm-3. By a variation of the doping concentration, an over proportional influence on the position of the Fermi energy is observed. Comparing the number of charge carriers with the amount of dopants present in the layer, it is found that only 5% of the dopants undergo a full charge transfer. Furthermore, a detailed investigation of the density of states beyond the HOMO onset reveals that an exponentially decaying density of states reaches further into the band gap than commonly assumed. For an increasing amount of doping, the Fermi energy gets pinned on these states which suggests that a significant amount of charge carriers is present there. The investigation of metal top and bottom contacts aims at understanding the asymmetric current-voltage characteristics found for some symmetrically built device stacks. It can be shown that a reaction between the atoms from the top contact with the molecules of the layer leads to a change in energy level alignment that produces a 1.16eV lower electron injection barrier from the top. Further detailed investigations on such contacts show that the formation of a silver top contact is dominated by diffusion processes, leading to a broadened interface. However, upon insertion of a thin aluminum interlayer this diffusion can be stopped and an abrupt interface is achieved. Furthermore, in the case of a thick silver top contact, a monolayer of molecules is found to float on top of the metal layer, almost independent on the metal layer thickness. Finally, several device stacks are investigated, regarding interface dipoles, formation of depletion regions, energy alignment in mixed layers, and the influence of the built-in voltage. We show schematic energy level alignments of pn junctions, pin homojunctions, more complex pin heterojunctions with Zener-diode characteristics, as well as a complete OLED stack. The results allow a deeper insight in the working principle of such devices.Mit Hilfe der Photoelektronenspektroskopie werden in der vorliegenden Arbeit Energieniveaus an Grenzflächen von organischen Halbleitern untersucht, wobei ein Hauptaugenmerk auf dem Einfluss und den Eigenschaften dotierter Schichten liegt. Bei der Untersuchung grundlegender Eigenschaften eines p-dotierten organischen Halbleiters können Ladungsträgerkonzentrationen bis zu 2*10E20 cm-3 nachgewiesen werden. Eine Variation der Dotierkonzentration zeigt einen überproportionalen Einfluss der Ladungsträger auf die Position des Ferminiveaus verglichen mit Experimenten an anorganischen Schichten. Durch den Vergleich mit der Anzahl Dotanden in der Schicht kann gezeigt werden, dass dabei nur etwa 5% der Dotanden einen vollständigen Ladungstransfer eingehen. Eine detaillierte Untersuchungen der Zustandsdichte jenseits des HOMOs (Highest Occupied Molecular Orbital) zeigt, dass die exponentiell abfallende Flanke der Zustandsdichte weiter in die Bandlücke hineinreicht als üblicherweise angenommen. Das Ferminiveau erfährt bei steigender Dotierung ein Pinning an diesen Zuständen, was für eine signifikante Ladungsträgerkonzentration spricht. Weiterhin wurden Untersuchungen zu Metal Top- und Grundkontakten durchgeführt. Es kann gezeigt werden, dass die Ursache für die Entstehung unsymmetrischer Strom-Spannungskurven, trotz eines symmetrischen Probenaufbaus, an einer Reaktion zwischen dem Molekül und den Metallatomen liegt. Dadurch entsteht eine um 1.16eV reduzierte Injektionsbarriere für Elektronen am Topkontakt. Weitere detaillierte Untersuchungen an diesen Topkontakten zeigen, dass im Falle von Silber als Metall diese Grenzfläche von Diffusionsprozessen dominiert ist. Im Gegensatz dazu zeigt das unedle Metall Aluminium keine Diffusion und führt zu abrupten Grenzflächen. Im ersten Fall kann zudem eine Monolage vom Molekül auf dem Metallkontakt nachgewiesen werden, die unabhängig von der Metalldicke aufschwimmt. Zuletzt werden Bauelemente oder Teile solcher mit Photoelektronenspektroskopie vermessen. Hierbei werden die Grenzflächendipole, die Ausbildung von Verarmungszonen, die Energieangleichung in Mischschichten und der Einfluss der Eingebauten Spannung untersucht. Es können die Banddiagramme von pn-Übergängen, einfachen pin Homoübergängen, komplexeren pin Heteroübergänge mit Zener-Dioden Verhalten sowie eine gesamte OLED gezeigt werden. Die Ergebnisse erlauben einen tieferen Einblick in die Arbeitsweise solcher Bauelemente

Quality improvement in radiology reporting by imaging informatics and machine learning

This thesis aims to explore the application of imaging informatics and machine learning to improve the quality of radiology reporting. Feedback contributes to the identification of potential areas of improvement. Therefore, quality management in radiology could benefit from the implementation of feedback systems. Chapter 2 studies feedback from referring physicians, and chapter 3 demonstrates the implementation of a peer feedback system among radiologists. Structured reporting results in less variation among radiologists, and it encourages them to follow guidelines. The studies of chapters 4 and 5 demonstrate the successful application of structured reporting in oncological CT reports and critical findings communication. The branch of AI that deals with text is natural language processing (NLP). In chapters 6, 7, and 8, different NLP methods are compared, resulting in a pipeline to classify radiology reports on a large scale. The extracted information can be used for quality assurance and scientific research. In chapter 9, AI applications in the field of neuroradiology are systematically assessed. The results demonstrate that these new tools mainly support the radiologist and extend the radiologist's possibilities by providing quantitative analysis of radiological examinations. In conclusion, improved insight by human feedback or automatically extracted data provides radiologists with opportunities to improve reporting and the information quality delivered by radiology reporting. Structured reporting and AI applications allow radiologists to enhance their reports further and increase the positive impact on patient care

“Playing on Relations”: Practices of Local-Level Citizenship and Inter-Ethnic Estrangement in a Southern Thai Village (SWP 49)

Since its formal incorporation into the Thai nation state in the early 20th century, the Malay-Muslim majority region of southernmost Thailand has chafed under the rule of a culturally and linguistically alien Thai state. Beginning at the turn of the 21st century, Thailand’s program of administrative decentralization may have offered a salve to this condition by empowering locally elected representatives to address the needs and solve the problems of the people. This article argues, however, that decentralized government in Thailand suffers from a number of shortcomings that limit the efficacy of “bringing the state closer to the people.” Among these shortcomings is a tendency to produce dominant chief executives (“mayors”) capable of directing the flow of power and resources through informal networks that readily bypass formal representative institutions and participatory mechanisms. In the context of ethnically diverse villages and administrative subdistricts (Tambon), the ability to participate in such informal networks can be conditioned by ethnic or religious identity. This can result in the politicization of ethnic identity following dynamics that are independent of those typically highlighted in relation to the Malay-Muslim majority south and the Thai polity in general. &nbsp

Small-sided games in youth soccer:performance and behavior compared to the official match

A small-sided game is a widely used training format in soccer. The purpose is to replicate (situations from) an official match. Adaptations in pitch size, number of players, and rules affect players’ physical, technical, and tactical performance in these games and the representation for the match. Therefore, this thesis aimed to determine the relation between performance in small-sided games and the official match for elite youth soccer players. A series of small-sided games were played utilizing a variety in number of players and two pitch sizes: a smaller pitch area, typically used in practice, and a larger pitch area, with an equivalent area per player to that of a match. Performance during small-sided games was compared with official matches for different age groups. A large pitch afforded players to adopt a greater dispersion resulting in greater distances between players and teams. Likewise, these distances varied more and players’ physical performance increased. In general, distances between players in these small-sided games were comparable to those during matches, i.e. 9-12 meters, regardless of the number of players per team. However, age-related differences were present in the relation between small-sided games and matches. Also, a lack of match-related pressure in small-sided games mostly affected physical and technical performance, but is less apparent in tactical behavior. Concluding, a similar area per player as the match afforded more space which resulted in comparable distances between players as the match. Such small-sided games better represent the demands of the official match, especially in the tactical domain

Multicolour Far Infrared Photometry of Galactic H II Regions

Results are presented of far infrared photometric measurements of some galactic H II regions in the galactic plane between longitudes 350° and 40°