The incumbent German power companies in a changing environment: A comparison of E.ON, RWE, EnBW and Vattenfall from 1998 to 2013

This paper examines the actions and strategies of Germany´s leading energy companies - E.ON, RWE, EnBW and Vattenfall - in the light of a changing regulatory framework and other circumstances. The liberalization of the German electricity market, measures to promote renewable energies, market developments as well as exogenous shocks such as the Fukushima nuclear disaster and the fiscal crisis all had far-reaching consequences for these companies. A comparative analysis of these companies from 1998 to 2013 shows their development from thriving growth at the start of liberalization up to the current state of crisis. Conducted with a focus on the context of the Energiewende - Germany´s commitment to shift towards sustainable energy production - this article contributes to the current debate on the sustainable transformation of energy supply. The theory of strategic action fields by Fligstein and McAdam serves as a theoretical framework.Dieser Beitrag untersucht die Strategien der etablierten deutschen Stromkonzerne E.ON, RWE, EnBW und Vattenfall vor dem Hintergrund sich verändernder Rahmenbedingungen. Regulatorische Eingriffe wie etwa die Liberalisierung des deutschen Elektrizitätsmarktes oder Maßnahmen zur Förderung erneuerbarer Energien, Marktentwicklungen sowie exogene Schocks in Form der Nuklearkatastrophe von Fukushima und der Finanzkrise hatten weitreichende Folgen für die Stromkonzerne. Um die Entwicklung der Unternehmen - von einem florierenden Wachstum zu Beginn der Liberalisierung bis hin zur aktuellen Krise - verständlich zu machen, werden die Aktivitäten der Unternehmen in der Zeit von 1998 bis 2013 einer vergleichenden Analyse unterzogen. Den theoretischen Rahmen hierfür bildet die Theorie strategischer Handlungsfelder von Fligstein und McAdam. Ein analytischer Schwerpunkt liegt auf den Entwicklungen des deutschen Strommarktes im Zuge der Energiewende. Damit leistet der Artikel einen Beitrag zur aktuellen Diskussion über den nachhaltigen Umbau der Energieversorgung

Using EBSD and TEM-Kikuchi patterns to study local crystallography at the domain boundaries of lead zirconate titanate

Reliable EBSD mapping of 90° domains in a tetragonal ferroelectric perovskite has been achieved for the first time, together with reliable automated orientation determination from TEM-Kikuchi patterns. This has been used to determine misorientation angles at 90° domain boundaries and thus local <i>c</i>/<i>a</i> ratios. The sources of orientation noise/error and their effects on the misorientation angle data have been thoroughly analyzed and it is found that this gives a cosine distribution of misorientation angles about the mean with a characteristic width related to the width of the orientation noise distribution. In most cases, a good agreement is found between local <i>c</i>/<i>a</i> ratios and global measurements by X-ray diffraction, but some clear discrepancies have also been found suggesting that real local variations are present, perhaps as a consequence of compositional inhomogeneities

The destabilisation of the German electricity industry (1998-2015): Application and extension of a multi-dimensional framework

This article aims to explain the rapid destabilisation of the German electricity industry between 1998 and 2015. The longitudinal case study uses analytical categories from a multi-dimensional framework, which emphasises the importance of external pressures on the industry (both techno-economic and socio-political) and firm-level response strategies (technical innovation, economic positioning, cultural framing, corporate political strategies). We also extend the framework by investigating the effects of different kinds and temporal sequence of external pressures, and the role of industry heterogeneity in shaping response strategies. The case study uses a wide range of primary sources (interviews with high-level managers, press releases, annual reports, newspapers) and secondary sources (quantitative statistics, academic articles, books) to develop a comprehensive, multi-dimensional explanation of the destabilisation process.Dieser Artikel will die rapide Destabilisierung der deutschen Elektrizitätsindustrie im Zeitraum zwischen 1998 und 2015 erklären. Hierfür wird eine multidimensionale Forschungsheuristik - das Triple Embeddedness Framework (Geels 2014) - angelegt, welches die Bedeutung von externen (sozio-politischen und ökonomischen) Veränderungen sowie von Anpassungsstrategien der Unternehmen (technologische Innovationen, Öffentlichkeitsarbeit oder politische Strategien) gleichermaßen in Rechnung stellt. Wir erweitern dieses Framework, indem wir die Rolle verschiedener Arten von externen Veränderungen sowie deren temporale Sequenzen berücksichtigen und außerdem die Rolle von Heterogenität innerhalb einer Industrie untersuchen. Die Fallstudie greift auf einen breiten Fundus an primären Datenquellen (Interviews mit Managern, Pressemitteilungen, Geschäftsberichte, Zeitungsartikel) sowie Sekundärquellen (quantitative Statistiken, wissenschaftliche Artikel und Bücher) zurück, um so eine umfassende, multi-dimensionale Analyse des Destabilisierungsprozesses zu bieten

Adaptive capacities, path creation and variants of sectoral change: The case of the transformation of the German energy supply system

Since the proclamation of the German 'Energiewende' by the Federal Government in 2011, the transition of the energy supply system has accelerated. In 2011, the Helmholtz-Alliance - ENERGY TRANS - Future Infrastructures for Meeting Energy Demands. Towards Sustainability and Social Compatibility - was launched to perform an interdisciplinary analysis of the social challenges presented by the energy transition. The study presented here, Adaptive Capacities, Path Creation, and Variants of Sectoral Change is embedded within the Helmholtz-Alliance and analyses the organizational changes within the German energy system from a sociological perspective. ...Die Liberalisierung der Energiemärkte, die sukzessive Zunahme des Anteils regenerativer Energien am Strommix und das Auftreten neuer Marktakteure verändern das deutsche Stromversorgungssystem. Nach dem Atomunfall in Fukushima von 2011 hat die Bundesregierung beschlossen, aus der Atomkraft auszusteigen. Gleichzeitig rief sie die Energiewende aus und kündigte an, den Wechsel zu erneuerbaren Energien zu beschleunigen. Die im selben Jahr ins Leben gerufene Helmholtz-Allianz ENERGY TRANS - Zukünftige Infrastrukturen der Energieversorgung. Auf dem Weg zur Nachhaltigkeit und Sozialverträglichkeit untersucht in interdisziplinärer Zusammenarbeit die gesellschaftlichen Herausforderungen der Energiewende. Das hier vorgestellte Projekt Adaptive Capacities, Path Creation and Variants of Sectoral Change ist in diese Forschungsallianz eingebunden und untersucht aus organisationssoziologischer Perspektive den Wandel des deutschen Energiesystems. ..

Figure-Ground Segmentation Using Multiple Cues

The theme of this thesis is figure-ground segmentation. We address the problem in the context of a visual observer, e.g. a mobile robot, moving around in the world and capable of shifting its gaze to and fixating on objects in its environment. We are only considering bottom-up processes, how the system can detect and segment out objects because they stand out from their immediate background in some feature dimension. Since that implies that the distinguishing cues can not be predicted, but depend on the scene, the system must rely on multiple cues. The integrated use of multiple cues forms a major theme of the thesis. In particular, we note that an observer in our real environment has access to 3-D cues. Inspired by psychophysical findings about human vision we try to demonstrate their effectiveness in figure-ground segmentation and grouping also in machine vision

Reversible Oxidation of a Conserved Methionine in the Nuclear Export Sequence Determines Subcellular Distribution and Activity of the Fungal Nitrate Regulator NirA

The assimilation of nitrate, a most important soil nitrogen source, is tightly regulated in microorganisms and plants. In Aspergillus nidulans, during the transcriptional activation process of nitrate assimilatory genes, the interaction between the pathway-specific transcription factor NirA and the exportin KapK/CRM1 is disrupted, and this leads to rapid nuclear accumulation and transcriptional activity of NirA. In this work by mass spectrometry, we found that in the absence of nitrate, when NirA is inactive and predominantly cytosolic, methionine 169 in the nuclear export sequence (NES) is oxidized to methionine sulfoxide (Metox169). This oxidation depends on FmoB, a flavin-containing monooxygenase which in vitro uses methionine and cysteine, but not glutathione, as oxidation substrates. The function of FmoB cannot be replaced by alternative Fmo proteins present in A. nidulans. Exposure of A. nidulans cells to nitrate led to rapid reduction of NirA-Metox169 to Met169; this reduction being independent from thioredoxin and classical methionine sulfoxide reductases. Replacement of Met169 by isoleucine, a sterically similar but not oxidizable residue, led to partial loss of NirA activity and insensitivity to FmoB-mediated nuclear export. In contrast, replacement of Met169 by alanine transformed the protein into a permanently nuclear and active transcription factor. Co-immunoprecipitation analysis of NirA-KapK interactions and subcellular localization studies of NirA mutants lacking different parts of the protein provided evidence that Met169 oxidation leads to a change in NirA conformation. Based on these results we propose that in the presence of nitrate the activation domain is exposed, but the NES is masked by a central portion of the protein (termed nitrate responsive domain, NiRD), thus restricting active NirA molecules to the nucleus. In the absence of nitrate, Met169 in the NES is oxidized by an FmoB-dependent process leading to loss of protection by the NiRD, NES exposure, and relocation of the inactive NirA to the cytosol

Stochasticity from function -- why the Bayesian brain may need no noise

An increasing body of evidence suggests that the trial-to-trial variability of spiking activity in the brain is not mere noise, but rather the reflection of a sampling-based encoding scheme for probabilistic computing. Since the precise statistical properties of neural activity are important in this context, many models assume an ad-hoc source of well-behaved, explicit noise, either on the input or on the output side of single neuron dynamics, most often assuming an independent Poisson process in either case. However, these assumptions are somewhat problematic: neighboring neurons tend to share receptive fields, rendering both their input and their output correlated; at the same time, neurons are known to behave largely deterministically, as a function of their membrane potential and conductance. We suggest that spiking neural networks may, in fact, have no need for noise to perform sampling-based Bayesian inference. We study analytically the effect of auto- and cross-correlations in functionally Bayesian spiking networks and demonstrate how their effect translates to synaptic interaction strengths, rendering them controllable through synaptic plasticity. This allows even small ensembles of interconnected deterministic spiking networks to simultaneously and co-dependently shape their output activity through learning, enabling them to perform complex Bayesian computation without any need for noise, which we demonstrate in silico, both in classical simulation and in neuromorphic emulation. These results close a gap between the abstract models and the biology of functionally Bayesian spiking networks, effectively reducing the architectural constraints imposed on physical neural substrates required to perform probabilistic computing, be they biological or artificial

Experimental measurement of stress at a four-domain junction in lead zirconate titanate

A junction between two lamellar bands of ferroelectric domains in a lead zirconate titanate (PZT) ceramic is analysed using Kikuchi diffraction patterns in the transmission electron microscope. Indexing of the diffraction patterns allowed the determination of the 3D relative orientation of the 4 different domains at the junction and thus the characterisation of the domain boundaries. The local c/a ratio could also be determined from the misorientations at the domain boundaries. Analysis of the data showed that large stresses were concentrated at the junction, and that this is inevitable at such band junctions. Such stress concentrations could act as nuclei for cracking of the ceramic under additional loading in service, perhaps particularly as a consequence of extended electromechanical cycling. Moreover, the stresses would increase with increasing c/a making the issues all the more serious for Ti-rich compositions having larger c/a ratios

Aging of poled ferroelectric ceramics due to relaxation of random depolarization fields by space-charge accumulation near grain boundaries

Migration of charged point defects triggered by the local random depolarization field is shown to plausibly explain aging of poled ferroelectric ceramics providing reasonable time and acceptor concentration dependences of the emerging internal bias field. The theory is based on the evaluation of the energy of the local depolarization field caused by mismatch of the polarizations of neighbor grains. The kinetics of charge migration assumes presence of mobile oxygen vacancies in the material due to the intentional or unintentional acceptor doping. Satisfactory agreement of the theory with experiment on the Fe-doped lead zirconate titanate is demonstrated.Comment: theory and experiment, 22 pages, 3 figure

Peroxisomal dysfunctions cause lysosomal storage and axonal Kv1 channel redistribution in peripheral neuropathy

Impairment of peripheral nerve function is frequent in neurometabolic diseases, but mechanistically not well understood. Here, we report a novel disease mechanism and the finding that glial lipid metabolism is critical for axon function, independent of myelin itself. Surprisingly, nerves of Schwann cell-specific Pex5 mutant mice were unaltered regarding axon numbers, axonal calibers, and myelin sheath thickness by electron microscopy. In search for a molecular mechanism, we revealed enhanced abundance and internodal expression of axonal membrane proteins normally restricted to juxtaparanodal lipid-rafts. Gangliosides were altered and enriched within an expanded lysosomal compartment of paranodal loops. We revealed the same pathological features in a mouse model of human Adrenomyeloneuropathy, preceding disease-onset by one year. Thus, peroxisomal dysfunction causes secondary failure of local lysosomes, thereby impairing the turnover of gangliosides in myelin. This reveals a new aspect of axon-glia interactions, with Schwann cell lipid metabolism regulating the anchorage of juxtaparanodal Kv1-channels