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Trends, Discourses and Representations in Religions in Africa (2012)

Meron Zeleke Halkano Abdi Wario

Religion in Africa has for long been a woven cultural fabric of life, a great moving force that guided people’s behavior, interaction and action since time immemorial. A decade after the United States experience of the 9/11, the unfortunate event has set the landmark for a geopolitics in contemporary Africa that securitizes religious movements and that identify them with the so-called global war on terror, a phenomenon within which most African nations play a significant regional role. The current wave of developments related to religion in the contingent became fossilized through religious manipulation and politicization in the post-colonial era. Three thematic concepts have been identified, i.e., religious trends, cultural discourses and representation, in order to capture some of the most contemporary issues of concern to Muslim, Christian and indigenous religious communities in Africa. Nine papers in this second issue of BIGSAS Works! hence targeted current doctoral researches from a wide range of disciplines and successfully integrated a cross-disciplinary approach to appreciate the complexity of faith matters in the continent.

Daniela Schulz, Wenn die Musik spielt... Der deutsche Schlagerfilm der 1950er bis 1970er Jahre, Bielefeld: Transcript 2012 (2012)

Hans J. Wulff

In vielen Geschichten des deutschen Films steht der Schlagerfilm als lebendiger Beweis für das Zurücktreten jedweden ästhetischen Anspruchs, den Film erfüllen könnte. Stattdessen trete ein flaches Unterhaltungskonzept in den Vordergrund, durchsetzt mit restaurativen Elementen, ablenkend von den Realitäten der Zeit, eskapistischen Neigungen eines kleinbürgerlichen Publikums Vorschub leistend. Es besteht allerdings kein Zweifel daran, dass der Schlagerfilm eines der größten und erfolgreichsten Genres der deutschen Filmproduktion der 1950er bis Mitte der 1970er Jahre gewesen ist. Und doch ist eine Untersuchung des mehrere hundert Filme umfassenden Korpus bis heute ausgeblieben1. Schulz' Kölner Dissertation aus dem Jahre 2011 betritt also Neuland, allein der Mut, sich der so missachteten Gattung anzunehmen, verdient Respekt.

Zur so genannten gegengeschlechtlichen Besetzungspraxis. Nebst einer Besprechung der aktuellen Publikationen von Knaus sowie Beghelli und Talmelli (2012)

Saskia Maria Woyke

Das Thema der Singstimmen beschäftigt die Musikwissenschaft spätestens seit dem so genannten "performative turn" der Geisteswissenschaften vor nunmehr fast zwei Jahrzehnten intensiver denn je. Positiverweise aber verlagert sich das Interesse auf die Stimmen, die Vokalprofile selbst, in Verbindung mit den Rollenprofilen, ebenso wie auf die Frage der Geschlechterbilder, die in ihnen übertragen werden, statt in vornehmlich biographisch orientierten Angaben über die Sängerinnen und Sänger zu verharren. Diese eher späte Entwicklung hat mit der Schwierigkeit der allgemeinen wie wissenschaftlichen Beschreibung einer aufgezeichneten oder gar verklungenen Stimme zu tun. Gleichzeitig sind die Geschlechterdiskurse im Umfeld der Stimmaufführungen verschiedener Epochen, Jahrzehnte und Orte, jedenfalls bis ca. 1750 trotz bemerkenswerter Ansätze seitens der Geschlechterforschung noch nicht gänzlich aufgearbeitet, was zur Folge hat, dass die Stimmforschung, die die Kategorie des Geschlechts einbeziehen will, hier oft nicht nur mit einer, sondern zwei nahezu Unbekannten operieren muss. Eine Aufzählung der entsprechenden neuesten Literatur zum Thema wird im Folgenden unterlassen, würde sie doch den Raum überschreiten oder aber als exemplarische Auswahl Wertvolles auslassen.

Measurement of emotional reactions to television advertisements – A state of the art review (2012)

Christian Wolterink

Human emotions and their measurement present a complex and intricate affair which perpetuates an ongoing discourse in marketing research. Since emotions play a pivotal role in the success of advertisements, the exploitation of tools for their precise measurement is crucial to researchers and practitioners alike. Yet, there is no single gold standard instrument existent that enables a comprehensive detection of all emotion facets at once. This thesis therefore focuses on the theoretical conceptualization of emotion, and afterwards presents a variety of measurement methods that address different emotion components. Thereby, particular emphasis is placed on their applicability as regards television commercials.

Novel microemulsions with an anionic/non-ionic surfactant mixture (2012)

Lukas Wolf

Mikroemulsionen bestehen im einfachsten Fall aus Wasser, Öl und Tensid(en). Es handelt sich dabei im Gegensatz zu normalen Emulsionen um transparente, thermodynamisch stabile Phasen. Diesen makroskopisch einphasig erscheinenden Systemen liegen jedoch hoch komplexe Nanostrukturen zu Grunde. Die in wissenschaftlicher Hinsicht bislang am besten untersuchten und verstandenen Mikroemulsionssysteme bestehen entweder aus Wasser, Öl und einem einzigen elektrisch ungeladenen nicht-ionischen Tensid oder einem elektrisch geladenen ionischen Tensid. Beide Systeme unterscheiden sich grundlegend, unter anderem in ihrem Phasenverhalten, ihrer Temperaturstabilität oder ihren Nanostrukturen. Systeme mit Mischungen aus ionischen und nichtionischen Tensiden dagegen wurden bisher kaum untersucht. Im Rahmen dieser Arbeit wurde das Phasenverhalten einer anionischen/nichtionischen Tensidmischung mit verschiedenen Ölen bei konstanter Temperatur und konstantem Tensidgehalt untersucht. Die Phasendiagramme weisen jeweils zwei optisch isotrope Phasengebiete, so genannte Einphasenkanäle, mit steigendem Öl-Gehalt auf. Die beiden Mikroemulsions-Einphasenkanäle sind voneinander durch ein optisch anisotropes Phasengebiet getrennt. Der Mikroemulsionskanal unterhalb des anisotropen Bereichs erstreckt sich von der wässrigen Phase ausgehend mit wachsendem Öl- und nichtionischen Co-Tensid-Anteil bis in die Mitte des Phasendiagramms und endet dort. Der obere Einphasenkanal verläuft durch ein steiles Minimum, in Bezug auf das Tensid/Co-Tensidverhältnis, durchgehend von der wässrigen zur ölreichen Seite des Phasendiagramms. Im Gegensatz zu Mikroemulsionen mit nichtionischen Tensiden handelt es sich um isotherme Einphasenkanäle. Die einphasigen Gebiete wurden mit diversen physikalisch-chemischen Methoden untersucht. Mittels Leitfähigkeits-, SANS-, PFG-NMR-Messungen und elektronenmikroskopischen cryo-TEM Aufnahmen konnten die Nanostrukturen identifiziert werden. Während im unteren Einphasenkanal die Strukturen aus kleinen Öl-Tröpfchen in einer kontinuierlichen Wasserphase bestehen, welche mit zunehmendem Öl-Gehalt anschwellen, kommt es im oberen Einphasenkanal zu einer komplexen Strukturänderung. Während der ölfreien Probe eine bikontinuierliche Schwammstruktur zu Grunde liegt, wandelt sich diese mit bereits wenigen Prozent an Öl zu einer polyedrischen Wasser-in-Öl Schaumstruktur. Für diese, in Mikroemulsionen bislang unbekannten, Struktur wurde der Begriff High Internal Phase Microemulsion (HIPME) eingeführt, aufgrund ihrer strukturellen Parallelen zu bereits bekannten High Internal Phase Emulsionen (HIPE). Mittels transienter Elektrodoppelbrechung konnte dieser komplexe strukturelle Übergang nachvollzogen werden. Die ermittelten strukturellen Relaxationszeiten, welche zudem die Viskosität der Mikroemulsionen bestimmen, weisen ein deutliches Maximum am Übergangspunkt von der bikontinuierlichen zur HIPME-Struktur auf. Grund für die beobachtete HIPME-Struktur ist vermutlich der Anteil der elektrischen Ladung des anionischen Tensids. Diese sorgt für eine vergleichbar hohe Grenzflächenspannung zwischen der wässrigen verdünnten Tensid-Phase und des Öls. Konsequenz dieser hohen Grenzflächenspannung sind ölkontinuierliche Schaumstrukturen anstatt bikontinuierlicher Strukturen, welche man in vergleichbaren Mikroemulsionen mit rein nichtionischen Tensiden erhält. Durch Abschirmen der elektrischen Ladungen mit Salz werden die HIPME-Strukturen gestört, was sich in einem Ansteigen der Leitfähigkeit und einer erhöhten Mobilität der Wasserphase äußert, welche mit NMR beobachtet wurde.

Synthesis and Combinatorial Optimization of Novel Star-Shaped Resist Materials for Lithographic Applications (2012)

Florian Wieberger

Gordon Earle Moore predicted in the mid-1960s the cost-efficient doubling of transistors’ number on integrated circuits every two years – known as Moore’s Law. Leading companies orientates by the development of integrated circuits on this Moore’s Law and contributed to this prediction to come true up to the present. In so doing, the semiconductor industry drafts every two years aims to fulfill this prediction summarized in the so-called International Technology Roadmap for Semiconductors (ITRS). The ITRS lists guidelines for cost-effective progresses in performance of integrated circuits, e.g. design of integrated circuits, advancements of exposure tools and exposure techniques, and closely correlated resist materials. This thesis deals with the development of new resist materials and their combinatorial investigation concerning the performance in lithographic patterning. The lithographic patterning procedure is a sequence of multiple processing steps and thus this procedure involves many processing variables interacting strongly with each other. For understanding and comprehensive investigation of such multi-variable dependent systems the development and implementation of combinatorial approaches were in the focus of this thesis. Furthermore this thesis is focused on the synthesis of new tailored resist materials for lithographic patterning. Star topology was the selected polymer architecture of this new resist material realized via the core-first atom transfer radical polymerization (ATRP) technique. The lithographic performance of electron beam lithography patterning was investigated for the resulting randomly distributed star terpolymers and star block copolymers by combinatorial libraries in view of features’ quality. The first chapter deals with developed, adapted, and improved combinatorial techniques for thin film investigations in general and utilized for lithographic patterning investigations in particular. The lithographic patterning procedure of chemically amplified resist systems consists of various steps: film preparation, post apply bake (PAB) to remove residual solvent, exposure, post exposure bake (PEB) to activate the catalytic reaction, and development. For this rather complex process variable gradients were developed and adapted for each processing step to investigate and optimize the performance of especially new resist systems. For the film preparation a method was developed to prepare an internal material composition gradient. This was realized by a gradient extrudate prepared using two individual controllable syringe pumps and subsequent doctor-blading. The material composition gradient was verified by high performance liquid chromatography. The second (PAB) and also the fourth (PEB) processing step are both annealing processes of the resist film although they serve different purposes. For the investigation of such annealing processes temperature gradients were prepared adjustable in temperature range and temperature slope. This adjustability is ensured by the active heating and the active cooling source and also by the gap and the type of metal plate. For the third step exposure methods were developed to realize defined exposure dose gradients in very small areas of the resist film. Different exposure dose gradients were designed for photolithography as well as for electron beam lithography. For the latter case this dose gradient was programmed in the pattern design using the software which controls the electron beam during the exposure process. The dose gradient for photolithography investigations was realized by a special designed shadow mask. For the last processing step development a preliminary screening of the dissolubility conditions of the resist film was established utilizing quartz crystal microbalances. Based on this measured dissolubility behavior the time frame was set for development time gradients performed by a stepwise or continuously immersion of the resist films. Lastly two to three variable gradients were combined to binary or ternary combinatorial libraries, respectively. The ternary combinatorial libraries allow the investigation of three variables of the lithographic patterning process in one experiment. Thus it is possible to optimize a resist material system fast and efficiently in respect to resist performance. In the second chapter a star-shaped teroligomer is reported as new high potential resist type for lithographic patterning purposes. The polymerization was carried out via the core-first ATRP route using a functionalized saccharose with eight initiating sites as core. Four star-shaped teroligomers were synthesized with varying target arm lengths. In addition a saccharose molecule was synthesized with an average number of 3.5 initiating sites and thus a star oligomer was realized with a reduced arm number but an identical core and similar arm length. As reference resist material a linear model oligomer was synthesized using ethyl 2-bromoisobutyrate as initiator. For all polymers narrow monomodal distributions were detected with polydispersity index values of lower than 1.1. Based on calibration polymerizations runs the monomer feed of the three used monomers was adapted to achieve targeted monomer incorporations for all teroligomers. The targeted monomer incorporation was copied from a currently industrially used linear teroligomer. One star oligomer was selected as proof of principle for the utilization of the star architecture for lithographic purposes. This new resist material was combinatorial investigated in a ternary library and thus optimized in one experiment concerning exposure dose, PEB temperature, and development time. The optimized patterns with a feature size of 100 nm and an excellent line edge roughness (LER) value of 3.1 nm were observed. The last chapter of this thesis demonstrates the straight forward advancement of the star-shaped resist material reported in chapter two. The statistical monomer incorporation was exchanged by the introduction of the tailored star block copolymer architecture. This architecture was synthesized for the first time via the core-first ATRP route by full conversion of a first polar monomer and in-situ polymerization of additionally added nonpolar monomer. The successful syntheses were indicated by contact angle measurements showing increased hydrophobicity of star block copolymers in contrast to random star copolymers with the same monomer incorporation. The star block copolymers exhibited also enhanced dissolubility behavior characterized by quartz crystal microbalance measurements. Furthermore they demonstrated an up to eight times increased sensitivity at their lithographic application in contrast to the synthesized reference linear copolymer. The most promising star block copolymer was selected to investigate its lithographic performance. The optimization was performed in a ternary combinatorial library based on the gradient variables exposure dose and feature size, PEB temperature, and development time. The optimized pattern of clear lines and a feature size of 66 nm was observed with a LER value of 6 nm. To conclude, different tailored star-shaped terpolymers were synthesized using the ATRP core-first route and successfully applied in the lithographic patterning process for the first time. In addition the combinatorial optimization offers the absolutely promising potential of utilizing these star shaped resist materials by the demonstrated brilliant LER values, the achieved extremely high sensitivity, and the fast and efficient development of clear 66 nm lines.

The service-productivity learning cockpit – a business intelligence tool for service enterprises (2012)

Sebastian Walther Gaurang Phadke Torsten Eymann

The paper describes the development of an agent-based simulation tool for hospital managers to manage their productivity of services, especially in the context of supporting services like patient transport logistics. The learning cockpit allows hospital managers to see how the change of inputs changes the overall perceived customer values of all stakeholders and therefore to get a visualization of the impacts their decisions cause. The paper introduces the general research domain service-productivity, followed by a description of the development steps of artefact creation. The learning cockpit is part of a research project called BELOUGA, which is funded by the German government.

Beyond productivity- Effects of extreme weather events on ecosystem processes and biotic interactions (2012)

Julia Walter

Under global climate change, extreme weather events, such as heat waves, drought or heavy rain spells, are projected to increase in magnitude and frequency. As these may affect vegetation and ecosystems more than gradual shifts in mean climatic parameters, investigating the consequences of extreme weather events recently became an important issue in climate change research. The main focus of most experiments investigating effects of extreme weather events on vegetation is on primary productivity. In our experiment in artificially planted communities, even an extreme drought of 1000-year recurrence did not have effects on above- or below-ground biomass production from 2005-2010. Thus, the main objectives of this thesis were (1) to investigate if extreme weather events have an effect on ecosystem functions beyond productivity, (2) to test if such a high resistance or resilience in response to drought regarding productivity also exists in more naturally grown plant communities and (3) to further elucidate possible mechanisms of the surprisingly large stability of the plant communities. To investigate these objectives, several experimental studies were conducted in artificially planted, as well as in naturally grown grassland communities and consequences of extreme weather events for ecosystem processes, such as decomposition and herbivory were investigated. In a pot experiment, it was studied, if grass plants react improved towards repeated drought when compared to a first drought and thus reveal a kind of drought memory. Such a memory might be one possible, but up until now widely neglected mechanism of resilience. Even though biomass production remained stable in our experiment in artificially planted communities, biomass quality was severely affected by extreme drought, thereby strongly affecting the development of a herbivore caterpillar feeding on drought-exposed leaves. Further, plant compounds of the host plant depended on the composition of the plant community it was grown in. This in turn resulted in strong effects on the larval mortality of herbivores feeding on such plants. In contrast to the study in artificially planted communities, aboveground net primary productivity (ANPP) was reduced in naturally composed grassland in response to extreme rainfall variability, including an extreme drought followed by heavy rainfall. Forage quality was altered by drought. Furthermore, mowing frequency strongly altered forage quality and biomass production, but did not interact with rainfall variability and thus did neither buffer, nor amplify effects of extreme rainfall variability. Despite effects of rainfall variability on ANPP, grassland showed high resilience after drought followed by heavy rain, as effects were large shortly after the extreme event, but did not persist until a second harvest later in the year. In natural grassland, rainfall variability and drought also affected ecosystem processes, here litter decomposition, beyond productivity. Drought followed by heavy rain pulses decreased decomposition rates. Decomposition in more frequently mown meadows was more vulnerable towards drought exposure. Winter warming and additional winter rain had no long-term effect on decomposition. To conclude, projected increases in drought frequency under climate change may inhibit decomposition and alter nutrient and carbon cycling along with soil quality in temperate grassland, whereas a reduction of snow cover leading to more variable soil surface temperatures may counteract increased decomposition under winter warming. In this thesis, an ecological stress memory as one possible mechanism of resilience is defined as any response of a single plant after a stress experience that improves the reaction of the plant towards future stress experience and which is assessed on a whole plant level. This thesis further provides evidence of a drought memory in grass plants: Plants repeatedly subjected to drought showed improved photo-protection and a higher rate of living biomass when compared to plants faced with their first drought. Similarly, tree seedlings exposed to drought in summer revealed higher frost resistance during winter, providing evidence of a long-lasting “cross-stress-memory” . To sum up, the thesis shows that extreme weather events, even though neither severely affecting biomass production in artificially composed, nor in naturally growing communities in the long-term, exert strong influence on physiological or biogeochemical parameters, such as plant compounds or soil biotic activity. These changes in turn modify ecosystem functions beyond productivity, for example herbivory or decomposition, possibly altering biotic interactions and nutrient cycling. Furthermore, the findings imply that plants exhibit a stress memory after stress exposure, which may be one mechanisms leading to a high stability and resilience upon frequent stress.

Kinetics and Reaction Engineering Aspects of Syngas Production by the Heterogeneously Catalysed Reverse Water Gas Shift Reaction (2012)

Rajabhau Bajirao Unde

As a contribution to the development of a process for CO2 utilisation and/or syngas production, the catalytic hydrogenation of CO2 using commercial Ni/Al12O19 and Al2O3 catalysts was studied. The experiments were performed in a down-flow fixed bed quartz reactor at atmospheric pressure. The reverse water gas shift (RWGS) reaction was examined in both the forward and reverse direction. In addition to these experiments, the consecutive reaction of CO to CH4 was also studied. The results indicate that the Ni/Al12O19 and the Al2O3 catalyst used are suitable to convert CO2 with H2 to CO and H2O at temperatures higher than 800 °C where no CH4 formation was observed. Kinetic data was obtained by systematic variation of the reaction conditions. These data were used to develop a model which explains the intrinsic and the effective kinetics (influence of internal and external diffusion) of the respective reaction. Based on the kinetic data of the RWGS reaction over the Ni/Al12O19 and the Al2O3 catalysts, technical fixed-bed reactors were simulated for the production of syngas, using a one-dimensional reactor model. The model takes into account the intrinsic kinetics, the internal and external mass transfer and the concentration and temperature gradients only in axial but not in radial direction. Two cases were considered as attractive for a technical RWGS process, isothermal and adiabatic operation in a fixed-bed tubular reactor. The differential equations for mass and heat transfer were solved by using the program Berkeley Madonna. The simulated temperature and conversion profiles within the reactor are presented. Pressure drop as well as reactor size required in a technical adiabatic fixed bed RWGS reactors were also estimated for both catalysts.

Monte Carlo Simulation Methods for Studying the Thermodynamics of Ligand Binding & Transfer Processes in Biomolecules (2012)

R. Thomas Ullmann

The binding and transfer of ligands is of central importance for the function of many biomolecular systems. The main topic of this thesis is the development and application of Monte Carlo (MC) simulation methods for studying complex ligand binding equilibria which can also involve conformational changes. The simulated systems were described by microstates within a continuum electrostatics/molecular mechanics (CE/MM) model of the receptor-ligand system. The CE/MM modeling methodology was improved. The improvements led to more detailed molecular models that enable a more realistic reproduction of system properties and environmental conditions. The developed simulation methods were applied to biomolecular systems whose function involves aspects that are important for the understanding of bioenergetic energy transduction. The results of this thesis are presented in five articles that are published in peer reviewed scientific journals. Manuscript A presents the Monte Carlo simulation software GMCT which was largely developed in this thesis. The software offers a variety of different simulation methods that allow the user to harness the full potential of CE/MM models in the simulation of complex receptor systems. Manuscript B presents a novel theoretical framework for free energy calculations with the free energy perturbation method. The novel framework is more broadly applicable and can lead to more efficient simulations than previous formulations. The derivation of the formalism also led to interesting insights into general statistical mechanics. The formalism was implemented in GMCT and could already be used fruitfully for the free energy calculations presented in Manuscripts C and D. Manuscript C demonstrates the application of free energy measures of cooperativity to study the coupling of protonation, reduction and conformational change in azurin from Pseudomonas aeruginosa (PaAz). Such a coupling is prototypic for bioenergetic systems because it forms the thermodynamic basis of their energy transducing function. PaAz is an experimentally well characterized, small electron transport protein. For this reason, PaAz was used here as model system to demonstrate the usefulness of cooperativity free energies in detecting and quantifying thermodynamic coupling between events in complex biomolecular systems. The results of this study led to new insight that could help to determine the still enigmatic physiological role of PaAz. In Manuscript D, free energy calculations were applied to study the thermodynamics of transport through the ammonium transporter Amt-1 from Archaeoglobus fulgidus (AfAmt-1). Ammonium is the most directly utilizable nitrogen source for plants and microorganisms. AfAmt-1 and its homologues facilitate the transport of ammonia/ammonium across biological membranes in living beings from all domains of life. It is intensely debated how these proteins perform their function and whether ammonia or its protonated form ammonium is actually transported. The study extended upon previous theoretical studies by including the effects of substrate concentration, electrochemical transmembrane gradients, proton-coupled binding equilibria and competitive binding of different ligand species. It was found that the transported species is most likely the ammonium ion. An ammonia/proton symport mechanism that involves a pair of coplanar histidine residues at the center of the transmembrane pore as transient proton acceptor is made plausible by the high genetic conservation of these residues. Manuscript E presents a first application of the microstate description within a CE/MM model to the simulation of the non-equilibrium dynamics of a molecular system. We simulated the re-reduction kinetics of the primary electron donor in the photocycle of the bacterial photosynthetic reaction center from Blastochloris viridis. The simulation results are in very good agreement with experimentally measured data.

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