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Background: The engagement in aggressive behavior in middle childhood is linked to the development of severe problems in later life. Thus, identifying factors and processes that con-tribute to the continuity and increase of aggression in middle childhood is essential in order to facilitate the development of intervention programs. The present PhD thesis aimed at expand-ing the understanding of the development of aggression in middle childhood by examining risk factors in the intrapersonal and interpersonal domains as well as the interplay between these factors: Maladaptive anger regulation was examined as an intrapersonal risk factor; processes that occur in the peer context (social rejection and peer socialization) were included as interpersonal risk factors. In addition, in order to facilitate the in situ assessment of anger regulation strategies, an observational measure of anger regulation was developed and validated.
Method: The research aims were addressed within the scope of four articles. Data from two measurement time points about ten months apart were available for the analyses. Participants were elementary school children aged from 6 to 10 years at T1 and 7 to 11 years at T2. The first article was based on cross-sectional analyses including only the first time point; in the remaining three articles longitudinal associations across the two time points were analyzed. The first two articles were concerned with the development and cross-sectional as well as longitudinal validation of observational measure of anger regulation in middle childhood in a sample of 599 children. Using the same sample, the third article investigated the longitudinal link between maladaptive anger regulation and aggression considering social rejection as a mediating variable. The frequency as well as different functions of aggression (reactive and proactive) were included as outcomes measures. The fourth article examined the influence of class-level aggression on the development of different forms of aggression (relational and physical) over time under consideration of differences in initial individual aggression in a sample of 1,284 children. In addition, it was analyzed if the path from aggression to social rejection varies as a function of class-level aggression.
Results: The first two articles revealed that the observational measure of anger regulation developed for the purpose of this research was cross-sectionally related to anger reactivity, aggression and social rejection as well as longitudinally related to self-reported anger regula-tion. In the third article it was found that T1 maladaptive anger regulation showed no direct link to T2 aggression, but an indirect link through T1 social rejection. This indirect link was found for the frequency of aggression as well as for reactive and proactive aggression. The fourth article revealed that with regard to relational aggression, a high level of classroom ag-gression predicted an increase of individual aggression only among children with initially low levels of aggression. For physical aggression, it was found that the overall level of aggression in the class affected all children equally. In addition, physical aggression increased the likelihood of social rejection irrespective of the class-level of aggression whereas relational aggression caused social rejection only in classes with a generally low level of relational aggression. The analyses of gender-specific effects showed that children were mainly influenced by their same-gender peers and that the effect on the opposite gender was higher if children engaged in gender-atypical forms of aggressive behavior.
Conclusion: The results provided evidence for the construct and criterion validity of the observational measure of maladaptive anger regulation that was developed within the scope of this research. Furthermore, the findings indicated that maladaptive anger regulation constitutes an important risk factor of aggression through the influence of social rejection. Finally, the results demonstrated that the level of aggression among classmates is relevant for the development of individual aggression over time and that the children´s evaluation of relationally aggressive behavior varies as a function of the normativity of relational aggression in the class. The study findings have implications for the measurement of anger regulation in middle childhood as well as for the prevention of aggression and social rejection.
This publications-based thesis summarizes my contribution to the scientific field of ultrafast structural dynamics. It consists of 16 publications, about the generation, detection and coupling of coherent gigahertz longitudinal acoustic phonons, also called hypersonic waves. To generate such high frequency phonons, femtosecond near infrared laser pulses were used to heat nanostructures composed of perovskite oxides on an ultrashort timescale. As a consequence the heated regions of such a nanostructure expand and a high frequency acoustic phonon pulse is generated. To detect such coherent acoustic sound pulses I use ultrafast variants of optical Brillouin and x-ray scattering. Here an incident optical or x-ray photon is scattered by the excited sound wave in the sample. The scattered light intensity measures the occupation of the phonon modes.
The central part of this work is the investigation of coherent high amplitude phonon wave packets which can behave nonlinearly, quite similar to shallow water waves which show a steepening of wave fronts or solitons well known as tsunamis. Due to the high amplitude of the acoustic wave packets in the solid, the acoustic properties can change significantly in the vicinity of the sound pulse. This may lead to a shape change of the pulse. I have observed by time-resolved Brillouin scattering, that a single cycle hypersound pulse shows a wavefront steepening. I excited hypersound pulses with strain amplitudes until 1% which I have calibrated by ultrafast x-ray diffraction (UXRD).
On the basis of this first experiment we developed the idea of the nonlinear mixing of narrowband phonon wave packets which we call "nonlinear phononics" in analogy with the nonlinear optics, which summarizes a kaleidoscope of surprising optical phenomena showing up at very high electric fields. Such phenomena are for instance Second Harmonic Generation, four-wave-mixing or solitons. But in case of excited coherent phonons the wave packets have usually very broad spectra which make it nearly impossible to look at elementary scattering processes between phonons with certain momentum and energy.
For that purpose I tested different techniques to excite narrowband phonon wave packets which mainly consist of phonons with a certain momentum and frequency. To this end epitaxially grown metal films on a dielectric substrate were excited with a train of laser pulses. These excitation pulses drive the metal film to oscillate with the frequency given by their inverse temporal displacement and send a hypersonic wave of this frequency into the substrate. The monochromaticity of these wave packets was proven by ultrafast optical Brillouin and x-ray scattering.
Using the excitation of such narrowband phonon wave packets I was able to observe the Second Harmonic Generation (SHG) of coherent phonons as a first example of nonlinear wave mixing of nanometric phonon wave packets.
The aim of this thesis was the elucidation of different ionization methods (resonance-enhanced multiphoton ionization – REMPI, electrospray ionization – ESI, atmospheric pressure chemical ionization – APCI) in ion mobility (IM) spectrometry. In order to gain a better understanding of the ionization processes, several spectroscopic, mass spectrometric and theoretical methods were also used. Another focus was the development of experimental techniques, including a high resolution spectrograph and various combinations of IM and mass spectrometry.
The novel high resolution 2D spectrograph facilitates spectroscopic resolutions in the range of commercial echelle spectrographs. The lowest full width at half maximum of a peak achieved was 25 pm. The 2D spectrograph is based on the wavelength separation of light by the combination of a prism and a grating in one dimension, and an etalon in the second dimension. This instrument was successfully employed for the acquisition of Raman and laser-induced breakdown spectra.
Different spectroscopic methods (light scattering and fluorescence spectroscopy) permitting a spatial as well as spectral resolution, were used to investigate the release of ions in the electrospray. The investigation is based on the 50 nm shift of the fluorescence band of rhodamine 6G ions of during the transfer from the electrospray droplets to the gas phase.
A newly developed ionization chamber operating at reduced pressure (0.5 mbar) was coupled to a time-of-flight mass spectrometer. After REMPI of H2S, an ionization chemistry analogous to H2O was observed with this instrument. Besides H2S+ and its fragments, H3S+ and protonated analyte ions could be observed as a result of proton-transfer reactions.
For the elucidation of the peaks in IM spectra, a combination of IM spectrometer and linear quadrupole ion trap mass spectrometer was developed. The instrument can be equipped with various ionization sources (ESI, REMPI, APCI) and was used for the characterization of the peptide bradykinin and the neuroleptic promazine.
The ionization of explosive compounds in an APCI source based on soft x-radiation was investigated in a newly developed ionization chamber attached to the ion trap mass spectrometer. The major primary and secondary reactions could be characterized and explosive compound ions could be identified and assigned to the peaks in IM spectra. The assignment is based on the comparison of experimentally determined and calculated IM. The methods of calculation currently available exhibit large deviations, especially in the case of anions. Therefore, on the basis of an assessment of available methods, a novel hybrid method was developed and characterized.
Understanding the rates and processes of denudation is key to unraveling the dynamic processes that shape active orogens. This includes decoding the roles of tectonic and climate-driven processes in the long-term evolution of high- mountain landscapes in regions with pronounced tectonic activity and steep climatic and surface-process gradients. Well-constrained denudation rates can be used to address a wide range of geologic problems. In steady-state landscapes, denudation rates are argued to be proportional to tectonic or isostatic uplift rates and provide valuable insight into the tectonic regimes underlying surface denudation. The use of denudation rates based on terrestrial cosmogenic nuclide (TCN) such as 10Beryllium has become a widely-used method to quantify catchment-mean denudation rates. Because such measurements are averaged over timescales of 102 to 105 years, they are not as susceptible to stochastic changes as shorter-term denudation rate estimates (e.g., from suspended sediment measurements) and are therefore considered more reliable for a comparison to long-term processes that operate on geologic timescales. However, the impact of various climatic, biotic, and surface processes on 10Be concentrations and the resultant denudation rates remains unclear and is subject to ongoing discussion. In this thesis, I explore the interaction of climate, the biosphere, topography, and geology in forcing and modulating denudation rates on catchment to orogen scales.
There are many processes in highly dynamic active orogens that may effect 10Be concentrations in modern river sands and therefore impact 10Be-derived denudation rates. The calculation of denudation rates from 10Be concentrations, however, requires a suite of simplifying assumptions that may not be valid or applicable in many orogens. I investigate how these processes affect 10Be concentrations in the Arun Valley of Eastern Nepal using 34 new 10Be measurements from the main stem Arun River and its tributaries. The Arun Valley is characterized by steep gradients in climate and topography, with elevations ranging from <100 m asl in the foreland basin to >8,000 asl in the high sectors to the north. This is coupled with a five-fold increase in mean annual rainfall across strike of the orogen. Denudation rates from tributary samples increase toward the core of the orogen, from <0.2 to >5 mm/yr from the Lesser to Higher Himalaya. Very high denudation rates (>2 mm/yr), however, are likely the result of 10Be TCN dilution by surface and climatic processes, such as large landsliding and glaciation, and thus may not be representative of long-term denudation rates. Mainstem Arun denudation rates increase downstream from ~0.2 mm/yr at the border with Tibet to 0.91 mm/yr at its outlet into the Sapt Kosi. However, the downstream 10Be concentrations may not be representative of the entire upstream catchment. Instead, I document evidence for downstream fining of grains from the Tibetan Plateau, resulting in an order-of-magnitude apparent decrease in the measured 10Be concentration.
In the Arun Valley and across the Himalaya, topography, climate, and vegetation are strongly interrelated. The observed increase in denudation rates at the transition from the Lesser to Higher Himalaya corresponds to abrupt increases in elevation, hillslope gradient, and mean annual rainfall. Thus, across strike (N-S), it is difficult to decipher the potential impacts of climate and vegetation cover on denudation rates. To further evaluate these relationships I instead took advantage of an along-strike west-to-east increase of mean annual rainfall and vegetation density in the Himalaya. An analysis of 136 published 10Be denudation rates from along strike of the revealed that median denudation rates do not vary considerably along strike of the Himalaya, ~1500 km E-W. However, the range of denudation rates generally decreases from west to east, with more variable denudation rates in the northwestern regions of the orogen than in the eastern regions. This denudation rate variability decreases as vegetation density increases (R=- 0.90), and increases proportionately to the annual seasonality of vegetation (R=0.99). Moreover, rainfall and vegetation modulate the relationship between topographic steepness and denudation rates such that in the wet, densely vegetated regions of the Himalaya, topography responds more linearly to changes in denudation rates than in dry, sparsely vegetated regions, where the response of topographic steepness to denudation rates is highly nonlinear. Understanding the relationships between denudation rates, topography, and climate is also critical for interpreting sedimentary archives. However, there is a lack of understanding of how terrestrial organic matter is transported out of orogens and into sedimentary archives. Plant wax lipid biomarkers derived from terrestrial and marine sedimentary records are commonly used as paleo- hydrologic proxy to help elucidate these problems. I address the issue of how to interpret the biomarker record by using the plant wax isotopic composition of modern suspended and riverbank organic matter to identify and quantify organic matter source regions in the Arun Valley. Topographic and geomorphic analysis, provided by the 10Be catchment-mean denudation rates, reveals that a combination of topographic steepness (as a proxy for denudation) and vegetation density is required to capture organic matter sourcing in the Arun River.
My studies highlight the importance of a rigorous and careful interpretation of denudation rates in tectonically active orogens that are furthermore characterized by strong climatic and biotic gradients. Unambiguous information about these issues is critical for correctly decoding and interpreting the possible tectonic and climatic forces that drive erosion and denudation, and the manifestation of the erosion products in sedimentary archives.
It is the intention of this study to contribute to further rethinking and innovating in the Microcredit business which stands at a turning point – after around 40 years of practice it is endangered to fail as a tool for economic development and to become a doubtful finance product with a random scope instead. So far, a positive impact of Microfinance on the improvement of the lives of the poor could not be confirmed. Over-indebtment of borrowers due to the pre-dominance of consumption Microcredits has become a widespread problem. Furthermore, a rising number of abusive and commercially excessive practices have been reported.
In fact, the Microfinance sector appears to suffer from a major underlying deficit: there does not exist a coherent and transparent understanding of its meaning and objectives so that Microfinance providers worldwide follow their own approaches of Microfinance which tend to differ considerably from each other.
In this sense the study aims at consolidating the multi-faced and very often confusingly different Microcredit profiles that exist nowadays. Subsequently, in this study, the Microfinance spectrum will be narrowed to one clear-cut objective, in fact away from the mere monetary business transactions to poor people it has gradually been reduced to back towards a tool for economic development as originally envisaged by its pioneers.
Hence, the fundamental research question of this study is whether, and under which conditions, Microfinance may attain a positive economic impact leading to an improvement of the living of the poor.
The study is structured in five parts: the three main parts (II.-IV.) are surrounded by an introduction (I.) and conclusion (V.). In part II., the Microfinance sector is analysed critically aiming to identify the challenges persisting as well as their root causes. In the third part, a change to the macroeconomic perspective is undertaken in oder to learn about the potential and requirements of small-scale finance to enhance economic development, particularly within the economic context of less developed countries. By consolidating the insights gained in part IV., the elements of a new concept of Microfinance with the objecitve to achieve economic development of its borrowers are elaborated.
Microfinance is a rather sensitive business the great fundamental idea of which is easily corruptible and, additionally, the recipients of which are predestined victims of abuse due to their limited knowledge in finance. It therefore needs to be practiced responsibly, but also according to clear cut definitions of its meaning and objectives all institutions active in the sector should be devoted to comply with. This is especially relevant as the demand for Microfinance services is expected to rise further within the years coming. For example, the recent refugee migration movement towards Europe entails a vast potential for Microfinance to enable these people to make a new start into economic life. This goes to show that Microfinance may no longer mainly be associated with a less developed economic context, but that it will gain importance as a financial instrument in the developed economies, too.
Flood generation at the scale of large river basins is triggered by the interaction of the hydrological pre-conditions and the meteorological event conditions at different spatial and temporal scales. This interaction controls diverse flood generating processes and results in floods varying in magnitude and extent, duration as well as socio-economic consequences. For a process-based understanding of the underlying cause-effect relationships, systematic approaches are required. These approaches have to cover the complete causal flood chain, including the flood triggering meteorological event in combination with the hydrological (pre-)conditions in the catchment, runoff generation, flood routing, possible floodplain inundation and finally flood losses.
In this thesis, a comprehensive probabilistic process-based understanding of the causes and effects of floods is advanced. The spatial and temporal dynamics of flood events as well as the geophysical processes involved in the causal flood chain are revealed and the systematic interconnections within the flood chain are deciphered by means of the classification of their associated causes and effects. This is achieved by investigating the role of the hydrological pre-conditions and the meteorological event conditions with respect to flood occurrence, flood processes and flood characteristics as well as their interconnections at the river basin scale.
Broadening the knowledge about flood triggers, which up to now has been limited to linking large-scale meteorological conditions to flood occurrence, the influence of large-scale pre-event hydrological conditions on flood initiation is investigated. Using the Elbe River basin as an example, a classification of soil moisture, a key variable of pre-event conditions, is developed and a probabilistic link between patterns of soil moisture and flood occurrence is established. The soil moisture classification is applied to continuously simulated soil moisture data which is generated using the semi-distributed conceptual rainfall-runoff model SWIM. Applying successively a principal component analysis and a cluster analysis, days of similar soil moisture patterns are identified in the period November 1951 to October 2003.
The investigation of flood triggers is complemented by including meteorological conditions described by a common weather pattern classification that represents the main modes of atmospheric state variability. The newly developed soil moisture classification thereby provides the basis to study the combined impact of hydrological pre-conditions and large-scale meteorological event conditions on flood occurrence at the river basin scale.
A process-based understanding of flood generation and its associated probabilities is attained by classifying observed flood events into process-based flood types such as snowmelt floods or long-rain floods. Subsequently, the flood types are linked to the soil moisture and weather patterns. Further understanding of the processes is gained by modeling of the complete causal flood chain, incorporating a rainfall-runoff model, a 1D/2D hydrodynamic model and a flood loss model. A reshuffling approach based on weather patterns and the month of their occurrence is developed to generate synthetic data fields of meteorological conditions, which drive the model chain, in order to increase the flood sample size. From the large number of simulated flood events, the impact of hydro-meteorological conditions on various flood characteristics is detected through the analysis of conditional cumulative distribution functions and regression trees.
The results show the existence of catchment-scale soil moisture patterns, which comprise of large-scale seasonal wetting and drying components as well as of smaller-scale variations related to spatially heterogeneous catchment processes. Soil moisture patterns frequently occurring before the onset of floods are identified. In winter, floods are initiated by catchment-wide high soil moisture, whereas in summer the flood-initiating soil moisture patterns are diverse and the soil moisture conditions are less stable in time. The combined study of both soil moisture and weather patterns shows that the flood favoring hydro-meteorological patterns as well as their interactions vary seasonally. In the analysis period, 18 % of the weather patterns only result in a flood in the case of preceding soil saturation. The classification of 82 past events into flood types reveals seasonally varying flood processes that can be linked to hydro-meteorological patterns. For instance, the highest flood potential for long-rain floods is associated with a weather pattern that is often detected in the presence of so-called ‘Vb’ cyclones. Rain-on-snow and snowmelt floods are associated with westerly and north-westerly wind directions. The flood characteristics vary among the flood types and can be reproduced by the applied model chain. In total, 5970 events are simulated. They reproduce the observed event characteristics between September 1957 and August 2002 and provide information on flood losses. A regression tree analysis relates the flood processes of the simulated events to the hydro-meteorological (pre-)event conditions and highlights the fact that flood magnitude is primarily controlled by the meteorological event, whereas flood extent is primarily controlled by the soil moisture conditions.
Describing flood occurrence, processes and characteristics as a function of hydro-meteorological patterns, this thesis is part of a paradigm shift towards a process-based understanding of floods. The results highlight that soil moisture patterns as well as weather patterns are not only beneficial to a probabilistic conception of flood initiation but also provide information on the involved flood processes and the resulting flood characteristics.
Foam fractionation of surfactant and protein solutions is a process dedicated to separate surface active molecules from each other due to their differences in surface activities. The process is based on forming bubbles in a certain mixed solution followed by detachment and rising of bubbles through a certain volume of this solution, and consequently on the formation of a foam layer on top of the solution column. Therefore, systematic analysis of this whole process comprises of at first investigations dedicated to the formation and growth of single bubbles in solutions, which is equivalent to the main principles of the well-known bubble pressure tensiometry. The second stage of the fractionation process includes the detachment of a single bubble from a pore or capillary tip and its rising in a respective aqueous solution. The third and final stage of the process is the formation and stabilization of the foam created by these bubbles, which contains the adsorption layers formed at the growing bubble surface, carried up and gets modified during the bubble rising and finally ends up as part of the foam layer.
Bubble pressure tensiometry and bubble profile analysis tensiometry experiments were performed with protein solutions at different bulk concentrations, solution pH and ionic strength in order to describe the process of accumulation of protein and surfactant molecules at the bubble surface. The results obtained from the two complementary methods allow understanding the mechanism of adsorption, which is mainly governed by the diffusional transport of the adsorbing protein molecules to the bubble surface. This mechanism is the same as generally discussed for surfactant molecules. However, interesting peculiarities have been observed for protein adsorption kinetics at sufficiently short adsorption times. First of all, at short adsorption times the surface tension remains constant for a while before it decreases as expected due to the adsorption of proteins at the surface. This time interval is called induction time and it becomes shorter with increasing protein bulk concentration. Moreover, under special conditions, the surface tension does not stay constant but even increases over a certain period of time. This so-called negative surface pressure was observed for BCS and BLG and discussed for the first time in terms of changes in the surface conformation of the adsorbing protein molecules. Usually, a negative surface pressure would correspond to a negative adsorption, which is of course impossible for the studied protein solutions. The phenomenon, which amounts to some mN/m, was rather explained by simultaneous changes in the molar area required by the adsorbed proteins and the non-ideality of entropy of the interfacial layer. It is a transient phenomenon and exists only under dynamic conditions.
The experiments dedicated to the local velocity of rising air bubbles in solutions were performed in a broad range of BLG concentration, pH and ionic strength. Additionally, rising bubble experiments were done for surfactant solutions in order to validate the functionality of the instrument. It turns out that the velocity of a rising bubble is much more sensitive to adsorbing molecules than classical dynamic surface tension measurements. At very low BLG or surfactant concentrations, for example, the measured local velocity profile of an air bubble is changing dramatically in time scales of seconds while dynamic surface tensions still do not show any measurable changes at this time scale. The solution’s pH and ionic strength are important parameters that govern the measured rising velocity for protein solutions. A general theoretical description of rising bubbles in surfactant and protein solutions is not available at present due to the complex situation of the adsorption process at a bubble surface in a liquid flow field with simultaneous Marangoni effects. However, instead of modelling the complete velocity profile, new theoretical work has been started to evaluate the maximum values in the profile as characteristic parameter for dynamic adsorption layers at the bubble surface more quantitatively.
The studies with protein-surfactant mixtures demonstrate in an impressive way that the complexes formed by the two compounds change the surface activity as compared to the original native protein molecules and therefore lead to a completely different retardation behavior of rising bubbles. Changes in the velocity profile can be interpreted qualitatively in terms of increased or decreased surface activity of the formed protein-surfactant complexes. It was also observed that the pH and ionic strength of a protein solution have strong effects on the surface activity of the protein molecules, which however, could be different on the rising bubble velocity and the equilibrium adsorption isotherms. These differences are not fully understood yet but give rise to discussions about the structure of protein adsorption layer under dynamic conditions or in the equilibrium state.
The third main stage of the discussed process of fractionation is the formation and characterization of protein foams from BLG solutions at different pH and ionic strength. Of course a minimum BLG concentration is required to form foams. This minimum protein concentration is a function again of solution pH and ionic strength, i.e. of the surface activity of the protein molecules. Although at the isoelectric point, at about pH 5 for BLG, the hydrophobicity and hence the surface activity should be the highest, the concentration and ionic strength effects on the rising velocity profile as well as on the foamability and foam stability do not show a maximum. This is another remarkable argument for the fact that the interfacial structure and behavior of BLG layers under dynamic conditions and at equilibrium are rather different. These differences are probably caused by the time required for BLG molecules to adapt respective conformations once they are adsorbed at the surface.
All bubble studies described in this work refer to stages of the foam fractionation process. Experiments with different systems, mainly surfactant and protein solutions, were performed in order to form foams and finally recover a solution representing the foamed material. As foam consists to a large extent of foam lamella – two adsorption layers with a liquid core – the concentration in a foamate taken from foaming experiments should be enriched in the stabilizing molecules. For determining the concentration of the foamate, again the very sensitive bubble rising velocity profile method was applied, which works for any type of surface active materials. This also includes technical surfactants or protein isolates for which an accurate composition is unknown.
Changes in extratropical storm track activity and their implications for extreme weather events
(2016)
In this thesis, the two prototype catalysts Fe(CO)₅ and Cr(CO)₆ are investigated with time-resolved photoelectron spectroscopy at a high harmonic setup. In both of these metal carbonyls, a UV photon can induce the dissociation of one or more ligands of the complex. The mechanism of the dissociation has been debated over the last decades. The electronic dynamics of the first dissociation occur on the femtosecond timescale.
For the experiment, an existing high harmonic setup was moved to a new location, was extended, and characterized. The modified setup can induce dynamics in gas phase samples with photon energies of 1.55eV, 3.10eV, and 4.65eV. The valence electronic structure of the samples can be probed with photon energies between 20eV and 40eV. The temporal resolution is 111fs to 262fs, depending on the combination of the two photon energies.
The electronically excited intermediates of the two complexes, as well as of the reaction product Fe(CO)₄, could be observed with photoelectron spectroscopy in the gas phase for the first time. However, photoelectron spectroscopy gives access only to the final ionic states. Corresponding calculations to simulate these spectra are still in development. The peak energies and their evolution in time with respect to the initiation pump pulse have been determined, these peaks have been assigned based on literature data. The spectra of the two complexes show clear differences. The dynamics have been interpreted with the assumption that the motion of peaks in the spectra relates to the movement of the wave packet in the multidimensional energy landscape. The results largely confirm existing models for the reaction pathways. In both metal carbonyls, this pathway involves a direct excitation of the wave packet to a metal-to-ligand charge transfer state and the subsequent crossing to a dissociative ligand field state. The coupling of the electronic dynamics to the nuclear dynamics could explain the slower dissociation in Fe(CO)₅ as compared to Cr(CO)₆.
This dissertation uses a common grammatical phenomenon, light verb constructions (LVCs) in English and German, to investigate how syntax-semantics mapping defaults influence the relationships between language processing, representation and conceptualization. LVCs are analyzed as a phenomenon of mismatch in the argument structure. The processing implication of this mismatch are experimentally investigated, using ERPs and a dual task. Data from these experiments point to an increase in working memory. Representational questions are investigated using structural priming. Data from this study suggest that while the syntax of LVCs is not different from other structures’, the semantics and mapping are represented differently. This hypothesis is tested with a new categorization paradigm, which reveals that the conceptual structure that LVC evoke differ in interesting, and predictable, ways from non-mismatching structures’.
The cell interior is a highly packed environment in which biological macromolecules evolve and function. This crowded media has effects in many biological processes such as protein-protein binding, gene regulation, and protein folding. Thus, biochemical reactions that take place in such crowded conditions differ from diluted test tube conditions, and a considerable effort has been invested in order to understand such differences.
In this work, we combine different computationally tools to disentangle the effects of molecular crowding on biochemical processes. First, we propose a lattice model to study the implications of molecular crowding on enzymatic reactions. We provide a detailed picture of how crowding affects binding and unbinding events and how the separate effects of crowding on binding equilibrium act together. Then, we implement a lattice model to study the effects of molecular crowding on facilitated diffusion. We find that obstacles on the DNA impair facilitated diffusion. However, the extent of this effect depends on how dynamic obstacles are on the DNA. For the scenario in which crowders are only present in the bulk solution, we find that at some conditions presence of crowding agents can enhance specific-DNA binding. Finally, we make use of structure-based techniques to look at the impact of the presence of crowders on the folding a protein. We find that polymeric crowders have stronger effects on protein stability than spherical crowders. The strength of this effect increases as the polymeric crowders become longer. The methods we propose here are general and can also be applied to more complicated systems.
Changing the perspective sometimes offers completely new insights to an already well-known phenomenon. Exercising behavior, defined as planned, structured and repeated bodily movements with the intention to maintain or increase the physical fitness (Caspersen, Powell, & Christenson, 1985), can be thought of as such a well-known phenomenon that has been in the scientific focus for many decades (Dishman & O’Connor, 2005). Within these decades a perspective that assumes rational and controlled evaluations as the basis for decision making, was predominantly used to understand why some people engage in physical activity and others do not (Ekkekakis & Zenko, 2015).
Dual-process theories (Ekkekakis & Zenko, 2015; Payne & Gawronski, 2010) provide another perspective, that is not exclusively influenced by rational reasoning. These theories differentiate two different processes that guide behavior “depending on whether they operate automatically or in a controlled fashion“ (Gawronski & Creighton, 2012, p. 282). Following this line of thought, exercise behavior is not solely influenced by thoughtful deliberations (e.g. concluding that exercising is healthy) but also by spontaneous affective reactions (e.g. disliking being sweaty while exercising). The theoretical frameworks of dual-process models are not new in psychology (Chaiken & Trope, 1999) and have already been used for the explanation of numerous behaviors (e.g. Hofmann, Friese, & Wiers, 2008; Huijding, de Jong, Wiers, & Verkooijen, 2005). However, they have only rarely been used for the explanation of exercise behavior (e.g. Bluemke, Brand, Schweizer, & Kahlert, 2010; Conroy, Hyde, Doerksen, & Ribeiro, 2010; Hyde, Doerksen, Ribeiro, & Conroy, 2010). The assumption of two dissimilar behavior influencing processes, differs fundamentally from previous theories and thus from the research that has been conducted in the last decades in exercise psychology. Research mainly concentrated on predictors of the controlled processes and addressed the identified predictors in exercise interventions (Ekkekakis & Zenko, 2015; Hagger, Chatzisarantis, & Biddle, 2002).
Predictors arising from the described automatic processes, for example automatic evaluations for exercising (AEE), have been neglected in exercise psychology for many years. Until now, only a few researchers investigated the influence of these AEE for exercising behavior (Bluemke et al., 2010; Brand & Schweizer, 2015; Markland, Hall, Duncan, & Simatovic, 2015). Marginally more researchers focused on the impact of AEE for physical activity behavior (Calitri, Lowe, Eves, & Bennett, 2009; Conroy et al., 2010; Hyde et al., 2010; Hyde, Elavsky, Doerksen, & Conroy, 2012). The extant studies mainly focused on the quality of AEE and the associated quantity of exercise (exercise much or little; Bluemke et al., 2010; Calitri et al., 2009; Conroy et al., 2010; Hyde et al., 2012). In sum, there is still a dramatic lack of empirical knowledge, when applying dual-process theories to exercising behavior, even though these theories have proven to be successful in explaining behavior in many other health-relevant domains like eating, drinking or smoking behavior (e.g. Hofmann et al., 2008).
The main goal of the present dissertation was to collect empirical evidence for the influence of AEE on exercise behavior and to expand the so far exclusively correlational studies by experimentally controlled studies. By doing so, the ongoing debate on a paradigm shift from controlled and deliberative influences of exercise behavior towards approaches that consider automatic and affective influences (Ekkekakis & Zenko, 2015) should be encouraged. All three conducted publications are embedded in dual-process theorizing (Gawronski & Bodenhausen, 2006, 2014; Strack & Deutsch, 2004). These theories offer a theoretical framework that could integrate the established controlled variables of exercise behavior explanation and additionally consider automatic factors for exercise behavior like AEE.
Taken together, the empirical findings collected suggest that AEE play an important and diverse role for exercise behavior. They represent exercise setting preferences, are a cause for short-term exercise decisions and are decisive for long-term exercise adherence. Adding to the few already present studies in this field, the influence of (positive) AEE for exercise behavior was confirmed in all three presented publications. Even though the available set of studies needs to be extended in prospectively studies, first steps towards a more complete picture have been taken. Closing with the beginning of the synopsis: I think that time is right for a change of perspectives! This means a careful extension of the present theories with controlled evaluations explaining exercise behavior. Dual-process theories including controlled and automatic evaluations could provide such a basis for future research endeavors in exercise psychology.
It is "scientific folklore" coming from physical heuristics that solutions to the heat equation on a Riemannian manifold can be represented by a path integral. However, the problem with such path integrals is that they are notoriously ill-defined. One way to make them rigorous (which is often applied in physics) is finite-dimensional approximation, or time-slicing approximation: Given a fine partition of the time interval into small subintervals, one restricts the integration domain to paths that are geodesic on each subinterval of the partition. These finite-dimensional integrals are well-defined, and the (infinite-dimensional) path integral then is defined as the limit of these (suitably normalized) integrals, as the mesh of the partition tends to zero.
In this thesis, we show that indeed, solutions to the heat equation on a general compact Riemannian manifold with boundary are given by such time-slicing path integrals. Here we consider the heat equation for general Laplace type operators, acting on sections of a vector bundle. We also obtain similar results for the heat kernel, although in this case, one has to restrict to metrics satisfying a certain smoothness condition at the boundary. One of the most important manipulations one would like to do with path integrals is taking their asymptotic expansions; in the case of the heat kernel, this is the short time asymptotic expansion. In order to use time-slicing approximation here, one needs the approximation to be uniform in the time parameter. We show that this is possible by giving strong error estimates.
Finally, we apply these results to obtain short time asymptotic expansions of the heat kernel also in degenerate cases (i.e. at the cut locus). Furthermore, our results allow to relate the asymptotic expansion of the heat kernel to a formal asymptotic expansion of the infinite-dimensional path integral, which gives relations between geometric quantities on the manifold and on the loop space. In particular, we show that the lowest order term in the asymptotic expansion of the heat kernel is essentially given by the Fredholm determinant of the Hessian of the energy functional. We also investigate how this relates to the zeta-regularized determinant of the Jacobi operator along minimizing geodesics.
The cytoskeleton is an essential component of living cells. It is composed of different types of protein filaments that form complex, dynamically rearranging, and interconnected networks. The cytoskeleton serves a multitude of cellular functions which further depend on the cell context. In animal cells, the cytoskeleton prominently shapes the cell's mechanical properties and movement. In plant cells, in contrast, the presence of a rigid cell wall as well as their larger sizes highlight the role of the cytoskeleton in long-distance intracellular transport. As it provides the basis for cell growth and biomass production, cytoskeletal transport in plant cells is of direct environmental and economical relevance. However, while knowledge about the molecular details of the cytoskeletal transport is growing rapidly, the organizational principles that shape these processes on a whole-cell level remain elusive.
This thesis is devoted to the following question: How does the complex architecture of the plant cytoskeleton relate to its transport functionality? The answer requires a systems level perspective of plant cytoskeletal structure and transport. To this end, I combined state-of-the-art confocal microscopy, quantitative digital image analysis, and mathematically powerful, intuitively accessible graph-theoretical approaches.
This thesis summarizes five of my publications that shed light on the plant cytoskeleton as a transportation network: (1) I developed network-based frameworks for accurate, automated quantification of cytoskeletal structures, applicable in, e.g., genetic or chemical screens; (2) I showed that the actin cytoskeleton displays properties of efficient transport networks, hinting at its biological design principles; (3) Using multi-objective optimization, I demonstrated that different plant cell types sustain cytoskeletal networks with cell-type specific and near-optimal organization; (4) By investigating actual transport of organelles through the cell, I showed that properties of the actin cytoskeleton are predictive of organelle flow and provided quantitative evidence for a coordination of transport at a cellular level; (5) I devised a robust, optimization-based method to identify individual cytoskeletal filaments from a given network representation, allowing the investigation of single filament properties in the network context. The developed methods were made publicly available as open-source software tools.
Altogether, my findings and proposed frameworks provide quantitative, system-level insights into intracellular transport in living cells. Despite my focus on the plant cytoskeleton, the established combination of experimental and theoretical approaches is readily applicable to different organisms. Despite the necessity of detailed molecular studies, only a complementary, systemic perspective, as presented here, enables both understanding of cytoskeletal function in its evolutionary context as well as its future technological control and utilization.
Among the bloom-forming and potentially harmful cyanobacteria, the genus Microcystis represents a most diverse taxon, on the genomic as well as on morphological and secondary metabolite levels. Microcystis communities are composed of a variety of diversified strains. The focus of this study lies on potential interactions between Microcystis representatives and the roles of secondary metabolites in these interaction processes.
The role of secondary metabolites functioning as signaling molecules in the investigated interactions is demonstrated exemplary for the prevalent hepatotoxin microcystin. The extracellular and intracellular roles of microcystin are tested in microarray-based transcriptomic approaches. While an extracellular effect of microcystin on Microcystis transcription is confirmed and connected to a specific gene cluster of another secondary metabolite in this study, the intracellularly occurring microcystin is related with several pathways of the primary metabolism. A clear correlation of a microcystin knockout and the SigE-mediated regulation of carbon metabolism is found. According to the acquired transcriptional data, a model is proposed that postulates the regulating effect of microcystin on transcriptional regulators such as the alternative sigma factor SigE, which in return captures an essential role in sugar catabolism and redox-state regulation.
For the purpose of simulating community conditions as found in the field, Microcystis colonies are isolated from the eutrophic lakes near Potsdam, Germany and established as stably growing under laboratory conditions. In co-habitation simulations, the recently isolated field strain FS2 is shown to specifically induce nearly immediate aggregation reactions in the axenic lab strain Microcystis aeruginosa PCC 7806. In transcriptional studies via microarrays, the induced expression program in PCC 7806 after aggregation induction is shown to involve the reorganization of cell envelope structures, a highly altered nutrient uptake balance and the reorientation of the aggregating cells to a heterotrophic carbon utilization, e.g. via glycolysis. These transcriptional changes are discussed as mechanisms of niche adaptation and acclimation in order to prevent competition for resources.
This cumulative dissertation contains four self-contained articles which are related to EU regional policy and its structural funds as the overall research topic. In particular, the thesis addresses the question if EU regional policy interventions can at all be scientifically justified and legitimated on theoretical and empirical grounds from an economics point of view. The first two articles of the thesis (“The EU structural funds as a means to hamper migration” and “Internal migration and EU regional policy transfer payments: a panel data analysis for 28 EU member countries”) enter into one particular aspect of the debate regarding the justification and legitimisation of EU regional policy. They theoretically and empirically analyse as to whether regional policy or the market force of the free flow of labour (migration) in the internal European market is the better instrument to improve and harmonise the living and working conditions of EU citizens. Based on neoclassical market failure theory, the first paper argues that the structural funds of the EU are inhibiting internal migration, which is one of the key measures in achieving convergence among the nations in the single European market. It becomes clear that European regional policy aiming at economic growth and cohesion among the member states cannot be justified and legitimated if the structural funds hamper instead of promote migration. The second paper, however, shows that the empirical evidence on the migration and regional policy nexus is not unambiguous, i.e. different empirical investigations show that EU structural funds hamper and promote EU internal migration. Hence, the question of the scientific justification and legitimisation of EU regional policy cannot be readily and unambiguously answered on empirical grounds. This finding is unsatisfying but is in line with previous theoretical and empirical literature. That is why, I take a step back and reconsider the theoretical beginnings of the thesis, which took for granted neoclassical market failure theory as the starting point for the positive explanation as well as the normative justification and legitimisation of EU regional policy. The third article of the thesis (“EU regional policy: theoretical foundations and policy conclusions revisited”) deals with the theoretical explanation and legitimisation of EU regional policy as well as the policy recommendations given to EU regional policymakers deduced from neoclassical market failure theory. The article elucidates that neoclassical market failure is a normative concept, which justifies and legitimates EU regional policy based on a political and thus subjective goal or value-judgement. It can neither be used, therefore, to give a scientifically positive explanation of the structural funds nor to obtain objective and practically applicable policy instruments. Given this critique of neoclassical market failure theory, the third paper consequently calls into question the widely prevalent explanation and justification of EU regional policy given in static neoclassical equilibrium economics. It argues that an evolutionary non-equilibrium economics perspective on EU regional policy is much more appropriate to provide a realistic understanding of one of the largest policies conducted by the EU. However, this does neither mean that evolutionary economic theory can be unreservedly seen as the panacea to positively explain EU regional policy nor to derive objective policy instruments for EU regional policymakers. This issue is discussed in the fourth article of the thesis (“Market failure vs. system failure as a rationale for economic policy? A critique from an evolutionary perspective”). This article reconsiders the explanation of economic policy from an evolutionary economics perspective. It contrasts the neoclassical equilibrium notions of market and government failure with the dominant evolutionary neo-Schumpeterian and Austrian-Hayekian perceptions. Based on this comparison, the paper criticises the fact that neoclassical failure reasoning still prevails in non-equilibrium evolutionary economics when economic policy issues are examined. This is surprising, since proponents of evolutionary economics usually view their approach as incompatible with its neoclassical counterpart. The paper therefore argues that in order to prevent the otherwise fruitful and more realistic evolutionary approach from undermining its own criticism of neoclassical economics and to create a consistent as well as objective evolutionary policy framework, it is necessary to eliminate the equilibrium spirit. Taken together, the main finding of this thesis is that European regional policy and its structural funds can neither theoretically nor empirically be justified and legitimated from an economics point of view. Moreover, the thesis finds that the prevalent positive and instrumental explanation of EU regional policy given in the literature needs to be reconsidered, because these theories can neither scientifically explain the emergence and development of this policy nor are they appropriate to derive objective and scientific policy instruments for EU regional policymakers.
En route towards advanced catalyst materials for the electrocatalytic water splitting reaction
(2016)
The thesis on hand deals with the development of new types of catalysts based on pristine metals and ceramic materials and their application as catalysts for the electrocatalytic water splitting reaction. In order to breathe life into this technology, cost-efficient, stable and efficient catalysts are imploringly desired. In this manner, the preparation of Mn-, N-, S-, P-, and C-containing nickel materials has been investigated together with the theoretical and electrochemical elucidation of their activity towards the hydrogen (and oxygen) evolution reaction. The Sabatier principle has been used as the principal guideline towards successful tuning of catalytic sites. Furthermore, two pathways have been chosen to ameliorate the electrocatalytic performance, namely, the direct improvement of intrinsic properties through appropriate material selection and secondly the increase of surface area of the catalytic material with an increased amount of active sites. In this manner, bringing materials with optimized hydrogen adsorption free energy onto high surface area support, catalytic performances approaching the golden standards of noble metals were feasible. Despite varying applied synthesis strategies (wet chemistry in organic solvents, ionothermal reaction, gas phase reaction), one goal has been systematically pursued: to understand the driving mechanism of the growth. Moreover, deeper understanding of inherent properties and kinetic parameters of the catalytic materials has been gained.
Over the past decades, rapid and constant advances have motivated GNSS technology to approach the ability to monitor transient ground motions with mm to cm accuracy in real-time. As a result, the potential of using real-time GNSS for natural hazards prediction and early warning has been exploited intensively in recent years, e.g., landslides and volcanic eruptions monitoring. Of particular note, compared with traditional seismic instruments, GNSS does not saturate or tilt in terms of co-seismic displacement retrieving, which makes it especially valuable for earthquake and earthquake induced tsunami early warning. In this thesis, we focus on the application of real-time GNSS to fast seismic source inversion and tsunami early warning.
Firstly, we present a new approach to get precise co-seismic displacements using cost effective single-frequency receivers. As is well known, with regard to high precision positioning, the main obstacle for single-frequency GPS receiver is ionospheric delay. Considering that over a few minutes, the change of ionospheric delay is almost linear, we constructed a linear model for each satellite to predict ionospheric delay. The effectiveness of this method has been validated by an out-door experiment and 2011 Tohoku event, which confirms feasibility of using dense GPS networks for geo-hazard early warning at an affordable cost.
Secondly, we extended temporal point positioning from GPS-only to GPS/GLONASS and assessed the potential benefits of multi-GNSS for co-seismic displacement determination. Out-door experiments reveal that when observations are conducted in an adversary environment, adding a couple of GLONASS satellites could provide more reliable results. The case study of 2015 Illapel Mw 8.3 earthquake shows that the biases between co-seismic displacements derived from GPS-only and GPS/GLONASS vary from station to station, and could be up to 2 cm in horizontal direction and almost 3 cm in vertical direction. Furthermore, slips inverted from GPS/GLONASS co-seismic displacements using a layered crust structure on a curved plane are shallower and larger for the Illapel event.
Thirdly, we tested different inversion tools and discussed the uncertainties of using real-time GNSS for tsunami early warning. To be exact, centroid moment tensor inversion, uniform slip inversion using a single Okada fault and distributed slip inversion in layered crust on a curved plane were conducted using co-seismic displacements recorded during 2014 Pisagua earthquake. While the inversion results give similar magnitude and the rupture center, there are significant differences in depth, strike, dip and rake angles, which lead to different tsunami propagation scenarios. Even though, resulting tsunami forecasting along the Chilean coast is close to each other for all three models.
Finally, based on the fact that the positioning performance of BDS is now equivalent to GPS in Asia-Pacific area and Manila subduction zone has been identified as a zone of potential tsunami hazard, we suggested a conceptual BDS/GPS network for tsunami early warning in South China Sea. Numerical simulations with two earthquakes (Mw 8.0 and Mw 7.5) and induced tsunamis demonstrate the viability of this network. In addition, the advantage of BDS/GPS over a single GNSS system by source inversion grows with decreasing earthquake magnitudes.
In this thesis sentence processing was investigated using a psychophysiological measure known as pupillometry as well as Event-Related Potentials (ERP). The scope of the the- sis was broad, investigating the processing of several different movement constructions with native speakers of English and second language learners of English, as well as word order and case marking in German speaking adults and children. Pupillometry and ERP allowed us to test competing linguistic theories and use novel methodologies to investigate the processing of word order. In doing so we also aimed to establish pupillometry as an effective way to investigate the processing of word order thus broadening the methodological spectrum.
This volume is a novel approach to the corpus-based variationist sociolinguistic study of contemporary urban western Irish English. Based on qualitative data as well as on linguistic features extracted from the Corpus of Galway City Spoken English, this study approaches the major sociolinguistic characteristics of (th) and (dh) variability in Galway City English. It demonstrates the diverse local patterns of variability and change in the phonetic realisation of the dental fricatives and establishes a considerable degree of divergence from traditional accounts on Irish English. This volume suggests that the linguistic stratification of variants of (th) and (dh) in Galway correlates both with the social stratification of the city itself and with the stratification of speakers by social status, sex/gender and age group.
Dynamics of mantle plumes
(2016)
Mantle plumes are a link between different scales in the Earth’s mantle: They are an important part of large-scale mantle convection, transporting material and heat from the core-mantle boundary to the surface, but also affect processes on a smaller scale, such as melt generation and transport and surface magmatism. When they reach the base of the lithosphere, they cause massive magmatism associated with the generation of large igneous provinces, and they can be related to mass extinction events (Wignall, 2001) and continental breakup (White and McKenzie, 1989).
Thus, mantle plumes have been the subject of many previous numerical modelling studies (e.g. Farnetani and Richards, 1995; d’Acremont et al., 2003; Lin and van Keken, 2005; Sobolev et al., 2011; Ballmer et al., 2013). However, complex mechanisms, such as the development and implications of chemical heterogeneities in plumes, their interaction with mid-ocean ridges and global mantle flow, and melt ascent from the source region to the surface are still not very well understood; and disagreements between observations and the predictions of classical plume models have led to a challenge of the plume concept in general (Czamanske et al., 1998; Anderson, 2000; Foulger, 2011). Hence, there is a need for more sophisticated models that can explain the underlying physics, assess which properties and processes are important, explain how they cause the observations visible at the Earth’s surface and provide a link between the different scales.
In this work, integrated plume models are developed that investigate the effect of dense recycled oceanic crust on the development of mantle plumes, plume–ridge interaction under the influence of global mantle flow and melting and melt migration in form of two-phase flow.
The presented analysis of these models leads to a new, updated picture of mantle plumes: Models considering a realistic depth-dependent density of recycled oceanic crust and peridotitic mantle material show that plumes with excess temperatures of up to 300 K can transport up to 15% of recycled oceanic crust through the whole mantle. However, due to the high density of recycled crust, plumes can only advance to the base of the lithosphere directly if they have high excess temperatures, high plume volumes and the lowermost mantle is subadiabatic, or plumes rise from the top or edges of thermo-chemical piles. They might only cause minor surface uplift, and instead of the classical head–tail structure, these low-buoyancy plumes are predicted to be broad features in the lower mantle with much less pronounced plume heads. They can form a variety of shapes and regimes, including primary plumes directly advancing to the base of the lithosphere, stagnating plumes, secondary plumes rising from the core–mantle boundary or a pool of eclogitic material in the upper mantle and failing plumes. In the upper mantle, plumes are tilted and deflected by global mantle flow, and the shape, size and stability of the melting region is influenced by the distance from nearby plate boundaries, the speed of the overlying plate and the movement of the plume tail arriving from the lower mantle. Furthermore, the structure of the lithosphere controls where hot material is accumulated and melt is generated. In addition to melting in the plume tail at the plume arrival position, hot plume material flows upwards towards opening rifts, towards mid-ocean ridges and towards other regions of thinner lithosphere, where it produces additional melt due to decompression. This leads to the generation of either broad ridges of thickened magmatic crust or the separation into multiple thinner lines of sea mount chains at the surface. Once melt is generated within the plume, it influences its dynamics, lowering the viscosity and density, and while it rises the melt volume is increased up to 20% due to decompression. Melt has the tendency to accumulate at the top of the plume head, forming diapirs and initiating small-scale convection when the plume reaches the base of the lithosphere. Together with the introduced unstable, high-density material produced by freezing of melt, this provides an efficient mechanism to thin the lithosphere above plume heads.
In summary, this thesis shows that mantle plumes are more complex than previously considered, and linking the scales and coupling the physics of different processes occurring in mantle plumes can provide insights into how mantle plumes are influenced by chemical heterogeneities, interact with the lithosphere and global mantle flow, and are affected by melting and melt migration. Including these complexities in geodynamic models shows that plumes can also have broad plume tails, might produce only negligible surface uplift, can generate one or several volcanic island chains in interaction with a mid–ocean ridge, and can magmatically thin the lithosphere.
Porous Membranes from Imidazolium- and Pyridinium-based Poly(ionic liquid)s with Targeted Properties
(2016)
This study presents new insights into null subjects, topic drop and the interpretation of topic-dropped elements. Besides providing an empirical data survey, it offers explanations to well-known problems, e.g. syncretisms in the context of null-subject licensing or the marginality of dropping an element which carries oblique case. The book constitutes a valuable source for both empirically and theoretically interested (generative) linguists.
In recent years, entire industries and their participants have been affected by disruptive technologies, resulting in dramatic market changes and challenges to firm’s business logic and thus their business models (BMs). Firms from mature industries are increasingly realizing that BMs that worked successfully for years have become insufficient to stay on track in today’s “move fast and break things” economy. Firms must scrutinize the core logic that informs how they do business, which means exploring novel ways to engage customers and get them to pay. This can lead to a complete renewal of existing BMs or innovating completely new BMs.
BMs have emerged as a popular object of research within the last decade. Despite the popularity of the BM, the theoretical and empirical foundation underlying the concept is still weak. In particular, the innovation process for BMs has been developed and implemented in firms, but understanding of the mechanisms behind it is still lacking. Business model innovation (BMI) is a complex and challenging management task that requires more than just novel ideas. Systematic studies to generate a better understanding of BMI and support incumbents with appropriate concepts to improve BMI development are in short supply. Further, there is a lack of knowledge about appropriate research practices for studying BMI and generating valid data sets in order to meet expectations in both practice and academia.
This paper-based dissertation aims to contribute to research practice in the field of BM and BMI and foster better understanding of the BM concept and BMI processes in incumbent firms from mature industries. The overall dissertation presents three main results. The first result is a new perspective, or the systems thinking view, on the BM and BMI. With the systems thinking view, the fuzzy BM concept is clearly structured and a BMI framework is proposed. The second result is a new research strategy for studying BMI. After analyzing current research practice in the areas of BMs and BMI, it is obvious that there is a need for better research on BMs and BMI in terms of accuracy, transparency, and practical orientation. Thus, the action case study approach combined with abductive methodology is proposed and proven in the research setting of this thesis. The third result stems from three action case studies in incumbent firms from mature industries employed to study how BMI occurs in practice. The new insights and knowledge gained from the action case studies help to explain BMI in such industries and increase understanding of the core of these processes.
By studying these issues, the articles complied in this thesis contribute conceptually and empirically to the recently consolidated but still increasing literature on the BM and BMI. The conclusions and implications made are intended to foster further research and improve managerial practices for achieving BMI in a dramatically changing business environment.
In the past, floods were basically managed by flood control mechanisms. The focus was set on the reduction of flood hazard. The potential consequences were of minor interest. Nowadays river flooding is increasingly seen from the risk perspective, including possible consequences. Moreover, the large-scale picture of flood risk became increasingly important for disaster management planning, national risk developments and the (re-) insurance industry. Therefore, it is widely accepted that risk-orientated flood management ap-proaches at the basin-scale are needed. However, large-scale flood risk assessment methods for areas of several 10,000 km² are still in early stages. Traditional flood risk assessments are performed reach wise, assuming constant probabilities for the entire reach or basin. This might be helpful on a local basis, but where large-scale patterns are important this approach is of limited use. Assuming a T-year flood (e.g. 100 years) for the entire river network is unrealistic and would lead to an overestimation of flood risk at the large scale. Due to the lack of damage data, additionally, the probability of peak discharge or rainfall is usually used as proxy for damage probability to derive flood risk. With a continuous and long term simulation of the entire flood risk chain, the spatial variability of probabilities could be consider and flood risk could be directly derived from damage data in a consistent way.
The objective of this study is the development and application of a full flood risk chain, appropriate for the large scale and based on long term and continuous simulation. The novel approach of ‘derived flood risk based on continuous simulations’ is introduced, where the synthetic discharge time series is used as input into flood impact models and flood risk is directly derived from the resulting synthetic damage time series.
The bottleneck at this scale is the hydrodynamic simu-lation. To find suitable hydrodynamic approaches for the large-scale a benchmark study with simplified 2D hydrodynamic models was performed. A raster-based approach with inertia formulation and a relatively high resolution of 100 m in combination with a fast 1D channel routing model was chosen.
To investigate the suitability of the continuous simulation of a full flood risk chain for the large scale, all model parts were integrated into a new framework, the Regional Flood Model (RFM). RFM consists of the hydrological model SWIM, a 1D hydrodynamic river network model, a 2D raster based inundation model and the flood loss model FELMOps+r. Subsequently, the model chain was applied to the Elbe catchment, one of the largest catchments in Germany. For the proof-of-concept, a continuous simulation was per-formed for the period of 1990-2003. Results were evaluated / validated as far as possible with available observed data in this period. Although each model part introduced its own uncertainties, results and runtime were generally found to be adequate for the purpose of continuous simulation at the large catchment scale.
Finally, RFM was applied to a meso-scale catchment in the east of Germany to firstly perform a flood risk assessment with the novel approach of ‘derived flood risk assessment based on continuous simulations’. Therefore, RFM was driven by long term synthetic meteorological input data generated by a weather generator. Thereby, a virtual time series of climate data of 100 x 100 years was generated and served as input to RFM providing subsequent 100 x 100 years of spatially consistent river discharge series, inundation patterns and damage values. On this basis, flood risk curves and expected annual damage could be derived directly from damage data, providing a large-scale picture of flood risk. In contrast to traditional flood risk analysis, where homogenous return periods are assumed for the entire basin, the presented approach provides a coherent large-scale picture of flood risk. The spatial variability of occurrence probability is respected. Additionally, data and methods are consistent. Catchment and floodplain processes are repre-sented in a holistic way. Antecedent catchment conditions are implicitly taken into account, as well as physical processes like storage effects, flood attenuation or channel–floodplain interactions and related damage influencing effects. Finally, the simulation of a virtual period of 100 x 100 years and consequently large data set on flood loss events enabled the calculation of flood risk directly from damage distributions. Problems associated with the transfer of probabilities in rainfall or peak runoff to probabilities in damage, as often used in traditional approaches, are bypassed.
RFM and the ‘derived flood risk approach based on continuous simulations’ has the potential to provide flood risk statements for national planning, re-insurance aspects or other questions where spatially consistent, large-scale assessments are required.
In this dissertation, an electric field-assisted method was developed and applied to achieve immobilization and alignment of biomolecules on metal electrodes in a simple one-step experiment. Neither modifications of the biomolecule nor of the electrodes were needed. The two major electrokinetic effects that lead to molecule motion in the chosen electrode configurations used were identified as dielectrophoresis and AC electroosmotic flow. To minimize AC electroosmotic flow, a new 3D electrode configuration was designed. Thus, the influence of experimental parameters on the dielectrophoretic force and the associated molecule movement could be studied. Permanent immobilization of proteins was examined and quantified absolutely using an atomic force microscope. By measuring the volumes of the immobilized protein deposits, a maximal number of proteins contained therein was calculated. This was possible since the proteins adhered to the tungsten electrodes even after switching off the electric field. The permanent immobilization of functional proteins on surfaces or electrodes is one crucial prerequisite for the fabrication of biosensors.
Furthermore, the biofunctionality of the proteins must be retained after immobilization. Due to the chemical or physical modifications on the proteins caused by immobilization, their biofunctionality is sometimes hampered. The activity of dielectrophoretically immobilized proteins, however, was proven here for an enzyme for the first time. The enzyme horseradish peroxidase was used exemplarily, and its activity was demonstrated with the oxidation of dihydrorhodamine 123, a non-fluorescent precursor of the fluorescence dye rhodamine 123.
Molecular alignment and immobilization - reversible and permanent - was achieved under the influence of inhomogeneous AC electric fields. For orientational investigations, a fluorescence microscope setup, a reliable experimental procedure and an evaluation protocol were developed and validated using self-made control samples of aligned acridine orange molecules in a liquid crystal.
Lambda-DNA strands were stretched and aligned temporarily between adjacent interdigitated electrodes, and the orientation of PicoGreen molecules, which intercalate into the DNA strands, was determined. Similarly, the aligned immobilization of enhanced Green Fluorescent Protein was demonstrated exploiting the protein's fluorescence and structural properties. For this protein, the angle of the chromophore with respect to the protein's geometrical axis was determined in good agreement with X-ray crystallographic data. Permanent immobilization with simultaneous alignment of the proteins was achieved along the edges, tips and on the surface of interdigitated electrodes. This was the first demonstration of aligned immobilization of proteins by electric fields.
Thus, the presented electric field-assisted immobilization method is promising with regard to enhanced antibody binding capacities and enzymatic activities, which is a requirement for industrial biosensor production, as well as for general interaction studies of proteins.
Software-as-a-Service (SaaS) offers several advantages to both service providers and users. Service providers can benefit from the reduction of Total Cost of Ownership (TCO), better scalability, and better resource utilization. On the other hand, users can use the service anywhere and anytime, and minimize upfront investment by following the pay-as-you-go model. Despite the benefits of SaaS, users still have concerns about the security and privacy of their data. Due to the nature of SaaS and the Cloud in general, the data and the computation are beyond the users' control, and hence data security becomes a vital factor in this new paradigm. Furthermore, in multi-tenant SaaS applications, the tenants become more concerned about the confidentiality of their data since several tenants are co-located onto a shared infrastructure.
To address those concerns, we start protecting the data from the provisioning process by controlling how tenants are being placed in the infrastructure. We present a resource allocation algorithm designed to minimize the risk of co-resident tenants called SecPlace. It enables the SaaS provider to control the resource (i.e., database instance) allocation process while taking into account the security of tenants as a requirement.
Due to the design principles of the multi-tenancy model, tenants follow some degree of sharing on both application and infrastructure levels. Thus, strong security-isolation should be present. Therefore, we develop SignedQuery, a technique that prevents one tenant from accessing others' data. We use the Signing Concept to create a signature that is used to sign the tenant's request, then the server can verifies the signature and recognizes the requesting tenant, and hence ensures that the data to be accessed is belonging to the legitimate tenant.
Finally, Data confidentiality remains a critical concern due to the fact that data in the Cloud is out of users' premises, and hence beyond their control. Cryptography is increasingly proposed as a potential approach to address such a challenge. Therefore, we present SecureDB, a system designed to run SQL-based applications over an encrypted database. SecureDB captures the schema design and analyzes it to understand the internal structure of the data (i.e., relationships between the tables and their attributes). Moreover, we determine the appropriate partialhomomorphic encryption scheme for each attribute where computation is possible even when the data is encrypted.
To evaluate our work, we conduct extensive experiments with di↵erent settings. The main use case in our work is a popular open source HRM application, called OrangeHRM. The results show that our multi-layered approach is practical, provides enhanced security and isolation among tenants, and have a moderate complexity in terms of processing encrypted data.
In many statistical applications, the aim is to model the relationship between covariates and some outcomes. A choice of the appropriate model depends on the outcome and the research objectives, such as linear models for continuous outcomes, logistic models for binary outcomes and the Cox model for time-to-event data. In epidemiological, medical, biological, societal and economic studies, the logistic regression is widely used to describe the relationship between a response variable as binary outcome and explanatory variables as a set of covariates. However, epidemiologic cohort studies are quite expensive regarding data management since following up a large number of individuals takes long time. Therefore, the case-cohort design is applied to reduce cost and time for data collection. The case-cohort sampling collects a small random sample from the entire cohort, which is called subcohort. The advantage of this design is that the covariate and follow-up data are recorded only on the subcohort and all cases (all members of the cohort who develop the event of interest during the follow-up process).
In this thesis, we investigate the estimation in the logistic model for case-cohort design. First, a model with a binary response and a binary covariate is considered. The maximum likelihood estimator (MLE) is described and its asymptotic properties are established. An estimator for the asymptotic variance of the estimator based on the maximum likelihood approach is proposed; this estimator differs slightly from the estimator introduced by Prentice (1986). Simulation results for several proportions of the subcohort show that the proposed estimator gives lower empirical bias and empirical variance than Prentice's estimator.
Then the MLE in the logistic regression with discrete covariate under case-cohort design is studied. Here the approach of the binary covariate model is extended. Proving asymptotic normality of estimators, standard errors for the estimators can be derived. The simulation study demonstrates the estimation procedure of the logistic regression model with a one-dimensional discrete covariate. Simulation results for several proportions of the subcohort and different choices of the underlying parameters indicate that the estimator developed here performs reasonably well. Moreover, the comparison between theoretical values and simulation results of the asymptotic variance of estimator is presented.
Clearly, the logistic regression is sufficient for the binary outcome refers to be available for all subjects and for a fixed time interval. Nevertheless, in practice, the observations in clinical trials are frequently collected for different time periods and subjects may drop out or relapse from other causes during follow-up. Hence, the logistic regression is not appropriate for incomplete follow-up data; for example, an individual drops out of the study before the end of data collection or an individual has not occurred the event of interest for the duration of the study. These observations are called censored observations. The survival analysis is necessary to solve these problems. Moreover, the time to the occurence of the event of interest is taken into account. The Cox model has been widely used in survival analysis, which can effectively handle the censored data. Cox (1972) proposed the model which is focused on the hazard function. The Cox model is assumed to be
λ(t|x) = λ0(t) exp(β^Tx)
where λ0(t) is an unspecified baseline hazard at time t and X is the vector of covariates, β is a p-dimensional vector of coefficient.
In this thesis, the Cox model is considered under the view point of experimental design. The estimability of the parameter β0 in the Cox model, where β0 denotes the true value of β, and the choice of optimal covariates are investigated. We give new representations of the observed information matrix In(β) and extend results for the Cox model of Andersen and Gill (1982). In this way conditions for the estimability of β0 are formulated. Under some regularity conditions, ∑ is the inverse of the asymptotic variance matrix of the MPLE of β0 in the Cox model and then some properties of the asymptotic variance matrix of the MPLE are highlighted. Based on the results of asymptotic estimability, the calculation of local optimal covariates is considered and shown in examples. In a sensitivity analysis, the efficiency of given covariates is calculated. For neighborhoods of the exponential models, the efficiencies have then been found. It is appeared that for fixed parameters β0, the efficiencies do not change very much for different baseline hazard functions. Some proposals for applicable optimal covariates and a calculation procedure for finding optimal covariates are discussed.
Furthermore, the extension of the Cox model where time-dependent coefficient are allowed, is investigated. In this situation, the maximum local partial likelihood estimator for estimating the coefficient function β(·) is described. Based on this estimator, we formulate a new test procedure for testing, whether a one-dimensional coefficient function β(·) has a prespecified parametric form, say β(·; ϑ). The score function derived from the local constant partial likelihood function at d distinct grid points is considered. It is shown that the distribution of the properly standardized quadratic form of this d-dimensional vector under the null hypothesis tends to a Chi-squared distribution. Moreover, the limit statement remains true when replacing the unknown ϑ0 by the MPLE in the hypothetical model and an asymptotic α-test is given by the quantiles or p-values of the limiting Chi-squared distribution. Finally, we propose a bootstrap version of this test. The bootstrap test is only defined for the special case of testing whether the coefficient function is constant. A simulation study illustrates the behavior of the bootstrap test under the null hypothesis and a special alternative. It gives quite good results for the chosen underlying model.
References
P. K. Andersen and R. D. Gill. Cox's regression model for counting processes: a large samplestudy. Ann. Statist., 10(4):1100{1120, 1982.
D. R. Cox. Regression models and life-tables. J. Roy. Statist. Soc. Ser. B, 34:187{220, 1972.
R. L. Prentice. A case-cohort design for epidemiologic cohort studies and disease prevention trials. Biometrika, 73(1):1{11, 1986.
Buyer-seller negotiations have significant impact on a company’s profitability, which makes practitioners aim at maximizing their performance. One lever for increasing bargaining performance is to pursue a clearly defined aspiration, i.e. one’s most desired outcome. In this context, the author explores the role of such aspirations in the three negotiation phases: preparation, bargaining, and striking a deal. She investigates determinants of aspirations, unintended consequences such as unethical bargaining behavior, and the consequences of overly ambitious aspirations. As a result, she does not only close existing gaps in negotiation research, but also derives valuable implications for practitioners
The author examines the cultural identity development of Oromo-Americans in Minnesota, an ethnic group originally located within the national borders of Ethiopia. Earlier studies on language and cultural identity have shown that the degree of ethnic orientation of minorities commonly decreases from generation to generation. Yet oppression and a visible minority status were identified as factors delaying the process of de-ethnicization. Given that Oromos fled persecution in Ethiopia and are confronted with the ramifications of a visible minority status in the U.S., it can be expected that they have retained strong ties to their ethnic culture. This study, however, came to a more complex and theory-building result.
Exhaustivity
(2016)
The dissertation proposes an answer to the question of how to model exhaustive inferences and what the meaning of the linguistic material that triggers these inferences is. In particular, it deals with the semantics of exclusive particles, clefts, and progressive aspect in Ga, an under-researched language spoken in Ghana. Based on new data coming from the author’s original fieldwork in Accra, the thesis points to a previously unattested variation in the semantics of exclusives in a cross-linguistic perspective, analyzes the connections between exhaustive interpretation triggered by clefts and the aspectual interpretation of the sentence, and identifies a cross-categorial definite determiner. By that it sheds new light on several exhaustivity-related phenomena in both the nominal and the verbal domain and shows that both domains are closely connected.
While children acquire new words and simple sentence structures extremely fast and without much effort, the ability to process complex sentences develops rather late in life. Although the conjoint occurrence between brain-structural and brain-functional changes, the decrease of plasticity, and changes in cognitive abilities suggests a certain causality between these processes, concrete evidence for the relation between brain development, language processing, and language performance is rare. Therefore, the current dissertation investigates the tripartite relationship between behavior (in the form of language performance and cognitive maturation as prerequisite for language processing), brain structure (in the form of gray matter maturation), and brain function (in the form of brain activation evoked by complex sentence processing). Previous developmental studies indicate a missing increase of activation in accordance to sentence complexity (functional selectivity) in language-relevant brain areas in children. To determine the factors contributing to the functional development of language-relevant brain areas, different methodologies and data acquisition techniques were used to investigate the processing of center-embedded sentences in 5- and 6-year-old children, 7- and 8-year-old children, and adults. Behavioral results indicate that children between 5 and 8 years show difficulties in processing double embedded sentences and that their performance for these type of sentences is positively correlated with digit span. In 7- and 8-year-old children, it was found that especially the processing of long-distance relations between the initial phrase and its corresponding verb appears to be associated with the subject’s verbal working memory capacity. In contrast, children’s performance for double embedded sentences in the younger age group positively correlated with their performance in a standardized sentence comprehension test. This finding supports the hypothesis that processing difficulties in this age group may be mainly attributed to difficulties in processing case marking information. These findings are discussed with respect to current accounts of language and working memory development. A second study aimed at investigating the structural maturation of brain areas involved in sentence comprehension. To do this, whole-brain magnetic resonance images from 59 children between 5 and 8 years were collected and children’s gray matter was analyzed by using voxel-based morphometry. Children’s grammatical proficiency was assessed by a standardized sentence comprehension test. A confirmatory factory analysis corroborated a grammar-relevant and a verbal working memory-relevant factor underlying the measured performance. While children’s ability to assign thematic roles is positively correlated with gray matter probability (GMP) in the left inferior temporal gyrus and the left inferior frontal gyrus, verbal working memory-related performance is positively correlated with GMP in the left parietal operculum extending into the posterior superior temporal gyrus. These areas have been previously shown to be differentially engaged in adults’ complex sentence processing. Thus, the findings of the second study suggest a specific correspondence between children’s GMP in language-relevant brain regions and differential cognitive abilities which underlie complex sentence comprehension. In a third study, functional brain activity during the processing of center-embedded sentences was investigated in three different age groups (5–6 years, 7–8 years, and adults). Although all age groups engage a qualitatively comparable network of the left pars opercularis (PO), the left inferior parietal lobe extending into the posterior superior temporal gyrus (IPL/pSTG), the supplementary motor area (SMA) and the cerebellum, functional selectivity of these regions was only observable in adults. However, functional activation of the language-related regions (PO and IPL/pSTG) predicted sentence comprehension performance for all age groups. To solve the question of the complex interplay between different maturational factors, a fourth study analyzed the predictive power of gray matter probability, verbal working memory capacity, and behavioral differences in performance for simple and complex sentence for the functional selectivity of each activated region. These analyses revealed that the establishment of the adult-like functional selectivity for complex sentences is predicted by a reduction of the left PO’s gray matter probability across age groups while that of the IPL/pSTG is additionally predicted by verbal working memory capacity. Taken all findings together, the current thesis provides evidence that both structural brain maturation and verbal working memory expansion provide the basis for the emergence of functional selectivity in language-related brain regions leading to more efficient sentence processing during development.
The aim of this work is the evaluation of the geothermal potential of Luxembourg. The approach consists in a joint interpretation of different types of information necessary for a first rather qualitative assessment of deep geothermal reservoirs in Luxembourg and the adjoining regions in the surrounding countries of Belgium, France and Germany. For the identification of geothermal reservoirs by exploration, geological, thermal, hydrogeological and structural data are necessary. Until recently, however, reliable information about the thermal field and the regional geology, and thus about potential geothermal reservoirs, was lacking. Before a proper evaluation of the geothermal potential can be performed, a comprehensive survey of the geology and an assessment of the thermal field are required.
As a first step, the geology and basin structure of the Mesozoic Trier–Luxembourg Basin (TLB) is reviewed and updated using recently published information on the geology and structures as well as borehole data available in Luxembourg and the adjoining regions. A Bouguer map is used to get insight in the depth, morphology and structures in the Variscan basement buried beneath the Trier–Luxembourg Basin. The geological section of the old Cessange borehole is reinterpreted and provides, in combination with the available borehole data, consistent information for the production of isopach maps. The latter visualize the synsedimentary evolution of the Trier–Luxembourg Basin. Complementary, basin-wide cross sections illustrate the evolution and structure of the Trier–Luxembourg Basin. The knowledge gained does not support the old concept of the Weilerbach Mulde. The basin-wide cross sections, as well as the structural and sedimentological observations in the Trier–Luxembourg Basin suggest that the latter probably formed above a zone of weakness related to a buried Rotliegend graben. The inferred graben structure designated by SE-Luxembourg Graben (SELG) is located in direct southwestern continuation of the Wittlicher Rotliegend-Senke.
The lack of deep boreholes and subsurface temperature prognosis at depth is circumnavigated by using thermal modelling for inferring the geothermal resource at depth. For this approach, profound structural, geological and petrophysical input data are required. Conceptual geological cross sections encompassing the entire crust are constructed and further simplified and extended to lithospheric scale for their utilization as thermal models. The 2-D steady state and conductive models are parameterized by means of measured petrophysical properties including thermal conductivity, radiogenic heat production and density. A surface heat flow of 75 ∓ 7 (2δ) mW m–2 for verification of the thermal models could be determined in the area. The models are further constrained by the geophysically-estimated depth of the lithosphere–asthenosphere boundary (LAB) defined by the 1300 °C isotherm. A LAB depth of 100 km, as seismically derived for the Ardennes, provides the best fit with the measured surface heat flow. The resulting mantle heat flow amounts to ∼40 mW m–2. Modelled temperatures are in the range of 120–125 °C at 5 km depth and of 600–650 °C at the crust/mantle discontinuity (Moho). Possible thermal consequences of the 10–20 Ma old Eifel plume, which apparently caused upwelling of the asthenospheric mantle to 50–60 km depth, were modelled in a steady-state thermal scenario resulting in a surface heat flow of at least 91 mW m–2 (for the plume top at 60 km) in the Eifel region. Available surface heat-flow values are significantly lower (65–80 mW m–2) and indicate that the plume-related heating has not yet entirely reached the surface.
Once conceptual geological models are established and the thermal regime is assessed, the geothermal potential of Luxembourg and the surrounding areas is evaluated by additional consideration of the hydrogeology, the stress field and tectonically active regions. On the one hand, low-enthalpy hydrothermal reservoirs in Mesozoic reservoirs in the Trier–Luxembourg Embayment (TLE) are considered. On the other hand, petrothermal reservoirs in the Lower Devonian basement of the Ardennes and Eifel regions are considered for exploitation by Enhanced/Engineered Geothermal Systems (EGS). Among the Mesozoic aquifers, the Buntsandstein aquifer characterized by temperatures of up to 50 °C is a suitable hydrothermal reservoir that may be exploited by means of heat pumps or provide direct heat for various applications. The most promising area is the zone of the SE–Luxembourg Graben. The aquifer is warmest underneath the upper Alzette River valley and the limestone plateau in Lorraine, where the Buntsandstein aquifer lies below a thick Mesozoic cover. At the base of an inferred Rotliegend graben in the same area, temperatures of up to 75 °C are expected. However, geological and hydraulic conditions are uncertain. In the Lower Devonian basement, thick sandstone-/quartzite-rich formations with temperatures >90 °C are expected at depths >3.5 km and likely offer the possibility of direct heat use. The setting of the Südeifel (South Eifel) region, including the Müllerthal region near Echternach, as a tectonically active zone may offer the possibility of deep hydrothermal reservoirs in the fractured Lower Devonian basement. Based on the recent findings about the structure of the Trier–Luxembourg Basin, the new concept presents the Müllerthal–Südeifel Depression (MSD) as a Cenozoic structure that remains tectonically active and subsiding, and therefore is relevant for geothermal exploration. Beyond direct use of geothermal heat, the expected modest temperatures at 5 km depth (about 120 °C) and increased permeability by EGS in the quartzite-rich Lochkovian could prospectively enable combined geothermal heat production and power generation in Luxembourg and the western realm of the Eifel region.
Food and fear
(2016)