Study aim: To find out, without relying on gait-specific assumptions or prior knowledge, which parameters are most important for the description of asymmetrical gait in patients after total hip arthroplasty (THA). Material and methods: The gait of 22 patients after THA was recorded using an optical motion capture system. The waveform data of the marker positions, velocities, and accelerations, as well as joint and segment angles, were used as initial features. The random forest (RF) and minimum-redundancy maximum-relevance (mRMR) algorithms were chosen for feature selection. The results were compared with those obtained from the use of different dimensionality reduction methods. Results: Hip movement in the sagittal plane, knee kinematics in the frontal and sagittal planes, marker position data of the anterior and posterior superior iliac spine, and acceleration data for markers placed at the proximal end of the fibula are highly important for classification (accuracy: 91.09%). With feature selection, better results were obtained compared to dimensionality reduction. Conclusion: The proposed approaches can be used to identify and individually address abnormal gait patterns during the rehabilitation process via waveform data. The results indicate that position and acceleration data also provide significant information for this task.

Deligne-Lusztig theory allows the parametrization of generic character tables of finite groups of Lie type in terms of families of conjugacy classes and families of irreducible characters "independently" of \(q\). Only in small cases the theory also gives all the values of the table. For most of the groups the completion of the table must be carried out with ad-hoc methods. The aim of the present work is to describe one possible computation which avoids Lusztig's theory of "character sheaves". In particular, the theory of Gel'fand-Graev characters and Clifford theory is used to complete the generic character table of \(G={\rm Spin}_8^+(q)\) for \(q\) odd. As an example of the computations, we also determine the character table of \({\rm SL}_4(q)\), for \(q\) odd. In the process of finding character values, the following tools are developed. By explicit use of the Bruhat decomposition of elements, the fusion of the unipotent classes of \(G\) is determined. Among others, this is used to compute the 2-parameter Green functions of every Levi subgroup with disconnected centre of \(G\). Furthermore, thanks to a certain action of the centre \(Z(G)\) on the characters of \(G\), it is shown how, in principle, the values of any character depend on its values at the unipotent elements. It is important to consider \({\rm Spin}_8^+(q)\) as it is one of the "smallest" interesting examples for which Deligne--Lusztig theory is not sufficient to construct the whole character table. The reasons is related to the structure of \({\mathbf G}={\rm Spin}_8\), from which \(G\) is constructed. Firstly, \({\mathbf G}\) has disconnected centre. Secondly, \({\mathbf G}\) is the only simple algebraic group which has an outer group automorphism of order 3. And finally, \(G\) can be realized as a subgroup of bigger groups, like \(E_6(q)\), \(E_7(q)\) or \(E_8(q)\). The computation on \({\rm Spin}_8^+(q)\) serves as preparation for those cases.

Künstliche Intelligenz in Mittelstädten – mittendrin oder außen vor? 1/2020 – 03/2021 Mittelstädte stehen nur selten im Fokus beim Einsatz von Künstlicher Intelligenz. Dies ist das zentrale Ergebnis der Studie aus dem Jahr 2020. Das Ziel bestand darin, Hemmnisse der digitalen Transformation in Politik und Verwaltung zu identifizieren, technologische Varianten zu untersuchen und gute Beispiele aus Mittelstädten vorzustellen. Autor*innen des Fachgebiets Stadtsoziologie der TU Kaiserslautern, des Deutschen Forschungszentrums für Künstliche Intelligenz (DFKI) und des Fraunhofer-Institut für Experimentelles Software Engineering (IESE) stellen in der Studie Interviews mit Vertreter*innen aus Kommunen und Anbieter*innn von KI-Verwaltungsdienstleistungen. Die Studie wurde von der Entwicklungsagentur Rheinland-Pfalz gefördert und hat folgende Fragen beantwortet: • Welche Kompetenzen und Stellen sind in den Rathäusern von Mittelstädten verfügbar, um die digitale Transformation zu gestalten? Wie sind die Prozesse gestaltet? Wie sehen Personalstrategien für die Digitalisierung der Verwaltung aus? • Gibt es nationale und internationale kreative Beispiele von KI-Nutzungsmöglichkeiten und Vorgehensweisen? • Gibt es Unterschiede in der Nachfrage nach bestimmten Diensten, Beratungen, Kompetenzen, Infrastrukturen zwischen Großstädten und Mittelstädten, insbesondere kleinen Mittelstädten? • Kann das Land eine relevante Rolle zur Unterstützung von Städten und Gemeinden einnehmen (zum Beispiel, wenn die vom Bund angekündigte Unterstützung zur Umsetzung des Onlinezugangsgesetzes ausbleibt)? Mittelstädte sind neben den Kleinstädten die typischen Städte des bundesdeutschen Siedlungssystems. Es gibt dabei lediglich eine quantitative Bestimmung von Mittelstädten, die eine Spanne von 20.000 bis 100.000 Einwohner umfasst. Ein Drittel der deutschen Bevölkerung lebt in Mittelstädten, in Rheinland-Pfalz sind es rund 720.000 Personen.

We present a study of optoelectronically active Ga(As)As quantum dots (QDs) on Al-rich AlxGa1-xAs layers with Al concentrations up to x=90%. So far, however, it has not been possible to grow optoelectronically active Ga(As)As QDs epitaxially directly on and in between Al-rich barrier layers in the AlGaInAsSb material system. A QD morphology might appear on the growth front, but the QD-like entities will not luminesce. Here, we use photoluminescence (PL) measurements to show that thin Al-free capsule layers between Al-rich barrier layers and the QD layers can solve this problem; this way, the QDs become optoelectronically active; that is, the dots become QDs. We consider antimonide QDs, that is, Ga(As)Sb QDs, either on GaAs for comparison or on AlxGa1-xAs barriers (x >10%) with GaAs capsule layers in between. We also discuss the influence of QD coupling both due to stress/strain from neighboring QDs and quantum-mechanically on the wavelength of the photoluminescence peak. Due to their mere existence, the capsule layers alter the barriers by becoming part of them. Quantum dots applications such as QD semiconductor lasers for spectroscopy or QDs as binary storage cells will profit from this additional degree of design freedom.

Local thermal comfort plays a growing role in terms of occupant satisfaction and in the energy performance of a building. To improve thermal comfort of occupants, decentralized heating and cooling systems are getting more interest in the research community but also in the market. Some studies have also shown that they can reduce the heating and cooling demand of buildings. These systems can be for example, an office chair with heating and cooling function, a thermoelectric heating and cooling wall or even a table fan. Building simulation software is used to optimize the energy performance of buildings during the planning process, but just a few programs enable detailed comfort calculations. Programs which allow the usage of decentralized heating and cooling systems are totally missing. This dissertation presents a newly developed adaptive building controller for combined, central and decentralized systems inside the building simulation software ESP‐r. The building controller adapts the setpoint‐temperatures of the central heating and cooling system and regulates the usage of decentralized systems, based on the thermal sensation and comfort values of a virtual thermal manikin in the considered building zone. This work shall contribute to the application of detailed comfort values within building simulation, which is also necessary to consider decentralized heating and cooling systems like the thermoelectric movable partition or the office chair with heating and cooling function. The first step by the development of the adaptive controller, was the coupling of PhySCo, a "Physiology, Sensation and Comfort" model with the building simulation software Esp-r. The physiology model within PhySCo uses the values of room temperature, mean radiant temperature, air velocity, relative humidity, solar radiation as well as personal parameters such as clothing and activity level. The model calculates skin and core temperatures for 16 individual body parts under consideration of thermophysiological control mechanisms such as sweating, shivering, vasodilatation and vasoconstriction of the blood vessels. These values are used to calculate local and overall sensation and comfort values. Within the adaptive building controller, the local and overall sensation and comfort values are used to control the setpoint‐temperatures of the central heating and cooling system, as well as to regulate the decentralized heating and cooling systems. The adaptive building controller with a wide deadband, with setpoints of 18 to 26 °C was in simulation studies compared with a basic controller with a fixed and narrow setpoint range of 21 to 24 °C. The evaluation focused on the overall comfort values and on a possible reduction of the heating and cooling energy demand of the central system. The results showed, that the adaptive controller could keep the comfort values at the same level as the basic controller and reduced the heating demand at the same time noticeably. The cooling load could also be reduced compared to the basic controller, but the reduction was much smaller compared to the heating load.In the next step, the decentralized heating and cooling systems were added to the adaptive building controller. First the thermoelectric heating and cooling wall, followed by the office chair with heating and cooling function, then both systems were added to the adaptive controller and tested together. The results show clearly that by adding the decentralized heating and cooling systems, the comfort could get further improved and at the same time, the heating and cooling energy demand could get reduced. It was noticeable that during the summer simulation period, comfort was increased, though the increase was rather small. As an additional support, a fan was simulated, which increased the air velocity for the heat‐sensitive head. Thereby, the comfort could be further increased, thus the cooling of the central system was also reduced. In addition, an increase of the upper set point to 30 °C was possible without reducing the comfort level. The adaptive building controller enables a detailed comfort analysis within the building simulation software. It can also be used for the planning of decentralized heating and cooling systems and their effect on thermal comfort.

The present work investigates the role of higher education experience in the process of students’ adult identity formation. In the broadest sense, adult identity is “seeing oneself as an adult” (Macmillan, 2007: 20), and it lays in the core of intensive processes of personal identity formation in the years following adolescence, which are for an increasing number of youth over the past decades spent in higher education. Approaches to adulthood in prior studies reveal ongoing discussions and attempts at re-conceptualisation against changing conditions and regimes of transition to adulthood. Traditionally, the so-called “objective markers” of adulthood have dominated the discourses for a long time, emphasising role transitions and demographic features as criteria for adulthood. The new research venues adding biographical approaches and subjective experiences reveal significance of inner, psychological processes of becoming an adult. However, the problem of the role of higher education in the process of students’ adult identity has not been fully illuminated thus far. The reason for this might be sought within the domain of disciplinary orientation of the field of higher education and Educational Sciences. Higher education research focuses on the overall, “grand” effects of education, while traditional Educational Sciences have not been showing much interest in higher education topics. Substantial work has been produced from developmental sciences, psychology in particular, which has revealed an intricate forest of today’s adulthood and conditions for its attainment, leaving open a whole set of educational, social, economic, cultural antecedents, correlates and experiences affecting transition to adulthood. Besides, as analyses presented in Chapter 2 show, students’ position in dominant discourses marked by political and economic imperatives is marginal. Their experiences and voices are in a sense excluded, making it almost impossible to infer on actual students’ personal benefits of the higher education process. The theoretical framework for this research consists of Erikson’s (Erikson, 1959; 1963; 1968) positions on human development in post-adolescent years, and McAdams’s model of narrative identity (1988; 2011; 2018), which also arose from Eriksonian tradition. Psychosocial theory (Erikson, 1959; 1963; 1968) assumes that social institutions provide structure and guidance to personal development, whereby they create a niche for psychosocial moratorium enabling youth a period of “identity work” before taking on long-term adult commitments. Research over recent decades reporting that higher education provides opportunities for students’ self-growth, exploration and resolving key identity questions in a variety of fields (e.g., Adams and Fitch, 1983; Arnett, 2004a; Berman, Kennerley, Kennerley, 2008; Mayhew, Rockenbach, Bowman, Seifert, Wolniak, Pascarella, Terenzin, 2016) supports such theoretical stances. The present research intends to extend existing knowledge raising the central question: What role of higher education experience students perceive in their adult identity formation? The empirical part reports on biographical research into senior year students’ lived experiences of their developmental path and their meaning to the higher education process. Students’ experiences are approached using the qualitative technique of problem-centred interviewing (PCI), which helps focus participants’ narration on the researcher’s interest and subsequent in-depth analysis of collected experiences. In total, 40 senior year students coming from diverse backgrounds were interviewed. Data were analysed in Atlas.ti software, which enabled the coding system’s better organization and browsing through transcripts. The qualitative analysis process consisted of both inductive and deductive approaches, wherein open and thematic coding techniques were performed interchangeably. Research findings indicate that in certain groups of students – but not in all – higher education experience facilitates and enriches the process of adult identity formation granting orientation and guidelines. Students identify experiences with the highest adult identity formational potential organised in the four broad categories: relationships with teachers and peers, respectively, teaching approach and study material, and extra-curricular activities. Based on the obtained findings, four patterns of thinking about the role of higher education in students’ adult identity formation have been identified: generator of adult identity formation, a safe-zone for exploration processes, interim phase leading to adulthood, and higher education suspending adult identity formation. This formed the basis for constructing the four student types; proactive, explorer, comfort-zone and atypical student. Research findings give the rationale for rethinking the educative potential of higher education in terms of its relevance for diverse students personally – for their self-growth and forming their personal identities, in addition to the professional ones.

The subject of this thesis is the probabilistic reliability assessment of notched metallic components under periodic constant-amplitude loads with respect to the failure mode of high-cycle fatigue. The latter refers to the crack initiation within the considered component caused by a high number, typically millions, of load cycles characterized by their small magnitude in terms of the material's static strength. In order to estimate the probability of failure due to high-cycle fatigue for a specified component under given loads, a new empirical model based on weakest-link theory is developed which describes a probabilistic and component specific constant-life diagram with respect to the anticipated design life. A conventional, non-probabilistic constant-life diagram reflects a discrete design boundary in terms of mean stress and stress amplitude, typically based on test results with respect to unnotched coupons made from the material of interest. Its application to the design of a notched component is established by identifying the stress conditions at the component's hot spot with those acting in the smooth coupons during the tests, and comparing those hot-spot conditions with the design boundary described in the constant-life diagram. Disregarded influences, such as notch and statistical size effect have to be incorporated by respective correction factors. The proposed probabilistic model on the other hand describes a continuous field of failure probabilities in the design stress plane, taking into account not only the hot-spot stresses, but the entire cyclic stress field acting throughout the component. In this way, the methodology directly accounts for notch and statistical size effects. Responsible for providing this greater scope is the weakest-link concept, which represents a non-local stochastic approach for quantifying the failure probability of loaded solids. The four model parameters can be calibrated with fatigue test data sets containing entirely unrelated test results on arbitrary specimen geometries, obliterating the constraining need for test data following staircase or probit schemes. This work contains the formulation, analysis, validation and application of the proposed model. After its introduction and a comparison with existing methods, it is analyzed in terms of its numerical properties when applied to finite element models, its efficient calibration and the corresponding model uncertainty. The validation is split into two parts. In a first analysis, the model is fitted to test data, containing results on several types of notched specimens, reflecting predominantly elastic material behavior. In a second step, this restriction is lifted and the model is used in order to predict the failure behavior of notched test specimens experiencing notch root plasticity due to high mean stresses. In both validation studies, the derived model predictions are, for the most part, well in line with the experimentally observed failure behavior of the test specimens. Finally, the applicability of the proposed probabilistic methodology in a design context is demonstrated on the example of a gas turbine compressor blade and the corresponding compressor stage.

Die Arbeit beschäftigt sich mit dem Einfluss des Völkerrechts auf das deutsche Genehmigungsverfahren für den Export von Kriegswaffen und Rüstungsgütern. Der Handel mit Waffen und Rüstungsgütern ist ein Milliardengeschäft, mit weitreichenden politischen Konsequenzen. Wie sämtliche militärische Fragen bildet der internationale Waffenhandel einen sensiblen und schwer zu regulierenden Rechtsbereich, da viele Nationen schnell einen Eingriff in ihre staatliche Souveränität befürchten. Der internationale Waffenhandel ist jedoch mit vielen Problemen behaftet – so erscheint insbesondere die Lieferung von Waffen in Krisengebiete als kritisch, weil diese die Eskalation von Konflikten und Gewalt bewirken können. Ebenfalls können die Waffen von autoritären Regimen zur Unterdrückung der eigenen Bevölkerung missbraucht werden. Insgesamt ergaben sich aus dem Fehlen von internationalen Standards und Regularien für den globalen Handel mit konventionellen Rüstungsgütern bisher gravierende negative Folgen. So entstehen aus den nicht oder lediglich rudimentär vorliegenden Exportkontrollsystemen, namentlich bei Kleinwaffen, Leichtwaffen und Landminen, u.a. eine intensivere und schnellere Eskalation von Konflikten, anwachsende und ausufernde illegale Waffenmärkte sowie die Erhöhung des Risikos des Missbrauchs von Waffen gegen die Zivilbevölkerung. In diesem Kontext sollen idealerweise die internationalen und die nationalen juristischen Gestaltungsmittel der Kontrolle der Rüstung und des internationalen Waffenhandels ein übergreifendes politisches Konzept zur Herstellung von stabilen zwischenstaatlichen Beziehungen und zur Gewährleistung der internationalen Sicherheit bilden. Im Spannungsfeld zwischen den internationalen und den nationalen Interessen und Bestimmungen wird hier die Bedeutung des deutschen Grundgesetzes und des internationalen Rechts im Bereich des Waffenhandels für das deutsche Genehmigungsverfahren für Rüstungsexporte relevant.

Laser-induced interstitial thermotherapy (LITT) is a minimally invasive procedure to destroy liver tumors through thermal ablation. Mathematical models are the basis for computer simulations of LITT, which support the practitioner in planning and monitoring the therapy. In this thesis, we propose three potential extensions of an established mathematical model of LITT, which is based on two nonlinearly coupled partial differential equations (PDEs) modeling the distribution of the temperature and the laser radiation in the liver. First, we introduce the Cattaneo–LITT model for delayed heat transfer in this context, prove its well-posedness and study the effect of an inherent delay parameter numerically. Second, we model the influence of large blood vessels in the heat-transfer model by means of a spatially varying blood-perfusion rate. This parameter is unknown at the beginning of each therapy because it depends on the individual patient and the placement of the LITT applicator relative to the liver. We propose a PDE-constrained optimal-control problem for the identification of the blood-perfusion rate, prove the existence of an optimal control and prove necessary first-order optimality conditions. Furthermore, we introduce a numerical example based on which we demonstrate the algorithmic solution of this problem. Third, we propose a reformulation of the well-known PN model hierarchy with Marshak boundary conditions as a coupled system of second-order PDEs to approximate the radiative-transfer equation. The new model hierarchy is derived in a general context and is applicable to a wide range of applications other than LITT. It can be generated in an automated way by means of algebraic transformations and allows the solution with standard finite-element tools. We validate our formulation in a general context by means of various numerical experiments. Finally, we investigate the coupling of this new model hierarchy with the LITT model numerically.

To improve efficiency of memory accesses, modern multiprocessor architectures implement a whole range of different weak memory models. The behavior of performance-critical code depends on the underlying hardware. There is a rising demand for verification tools that take the underlying memory model into account. This work examines a variety of prevalent problems in the field of program verification of increasing complexities: testing, reachability, portability and memory model synthesis. We give efficient tools to solve these problems. What sets the presented methods apart is that they are not limited to some few given architectures. They are universal: The memory model is given as part of the input. We make use of the CAT language to succinctly describe axiomatic memory models. CAT has been used to define the semantics of assembly for x86/TSO, ARMv7, ARMv8, and POWER but also the semantics of programming languages such as C/C++, including the Linux kernel concurrency primitives. This work shows that even the simple testing problem is NP-hard for most memory models. It does so using a general reduction technique that applies to a range of models. It examines the more difficult program verification under a memory model and introduces Dartagnan, a bounded model checker (BMC) that encodes the problem as an SMT-query and makes use of advanced encoding techniques. The program portability problem is shown to be even harder. Despite this, it is solved efficiently by the tool Porthos which uses a guided search to produce fast results for most practical instances. A memory model is synthesized by Aramis for a given set of reachability results. Concurrent program verification is generally undecidable even for sequential consistency. As an alternative to BMC, we propose a new CEGAR method for Petri net invariant synthesis. We again use SMT-queries as a back-end.

This paper presents a method for simultaneous classification and robust tracking of traffic participants based on the labeled random finite set (RFS) tracking framework. Specifically, a method to integrate the object class information into the tracking loop of the multiple model labeled multi-Bernoulli (MMLMB) filter, using Dempster-Shafer evidence theory is presented. The multi-object state is estimated using the detections from the sensors and by propagation of multi-object density in a Bayesian fashion. Parallelly, the object class information is also predicted and updated recursively. The underlying object class information required for this could typically be obtained from different types of sensor such as radar, lidar and camera, using classical perception or more recent deep learning methods. On one hand, this enables an unified classification and tracking of traffic participants. On the other hand, it also increases the robustness of multi-object tracking, as the parameters of the tracking algorithm could be adapted using the class information. Moreover, using the Dempster-Shafer method for fusing class information from different sensor sources improves the overall performance, especially when the sensors have contradicting classification.

Die zunehmende Urbanisierung und wachsende Population erschweren die Gewährleis-tung einer konstanten Lebensmittelversorgung weltweit. Dies spiegelt sich vor allem in Städten wider, da diese oftmals über keine eigenständige und unabhängige Lebensmit-telproduktion verfügen. Die Lebensmittelnachfrage steigt kontinuierlich, jedoch stößt die Landwirtschaft im ländlichen Raum aufgrund knapper werdender Ressourcen an ihre Grenzen. Zudem gelten landwirtschaftliche Prozesse aufgrund eines hohen Was-serverbrauchs, Treibhausgasemissionen und Bodenverlusten als Treiber des Klima-wandels. In dieser konzeptionellen Bachelorarbeit untersuche ich die Erfolgs- und Ge-fahrenfaktoren des Urban Farmings und beurteile, inwiefern die urbane Agrikultur die Realisierung der Sustainable Development Goals beeinflusst. Im Zuge dessen identifi-ziere ich die Akteure des Urban Farmings und untersuche das Start-up Infarm, um Ur-ban Farming als Geschäftsmodell in einen greifbaren Kontext zu versetzen. Urban Farming stellt durch die Verlagerung landwirtschaftlicher Produktionsprozesse ein Mittel zur nachhaltigen Entwicklung dar. Die Implikation von Urban Farming schafft durch die Verkürzung von Lieferketten ein sicheres Versorgungsnetz für Städte und wirkt durch den Einsatz disruptiver Technologien und Smart Farming den Folgen des Klimawandels entgegen. Außerdem kurbelt Urban Farming durch die Generierung von Arbeitsplätzen das Wirtschaftswachstum an, unterstützt die Biodiversität und macht Städte langfristig nachhaltiger. Allerdings birgt Urban Farming ebenfalls Gefahrenpo-tentiale, die die Realisierung der SDGs hemmen könnten. Urban Farming benötigt ein hohes Maß an Planung, Knowhow und Expertise in der Planung und Umsetzung, um als erfolgreiches Mittel zur nachhaltigen Entwicklung zu dienen. Relevant für die zu-künftige Forschung ist die Identifikation und Reduktion potenzieller Risikofaktoren, um Urban Farming als Teil des landwirtschaftlichen Sektors zu etablieren und sein volles Potential auszuschöpfen.

Durch den zunehmenden Anteil erneuerbarer Erzeugung und die voranschreitende Elektrifizierung von Verkehrs- und Wärmesektor gewinnt die Möglichkeit, den Netzzustand im Verteilnetz zu kennen und steuern zu können, für die Netzbetreiber immer mehr an Bedeutung. Im Forschungsprojekt "SmartAPO" wurde ein Netzautomatisierungssystem entwickelt, das den Zustand im Niederspannungsnetz auf Basis von Smart-Meter-Daten schätzen und regeln kann. Ziel dieser Arbeit ist die Analyse und Bewertung des Systems im Vorlauf eines Feldtests durch die Implementierung im Labor. Die Untersuchungen leisten einen Beitrag zu den Forschungsaktivitäten im Bereich intelligenter Verteilnetze. Nach der Darstellung der im Netzautomatisierungssystem verwendeten Funktionen werden für die Laboruntersuchungen geeignete Anwendungsfälle entwickelt und qualitative Bewertungskriterien formuliert. Die Anwendungsfälle orientieren sich an realistischen Begebenheiten und beinhalten Tages- und Echtzeitprofile. Neben Haushaltslasten wird die Last durch Ladevorgänge von Elektrofahrzeugen und durch Wärmepumpen einbezogen. Es kommen verschiedene Konfigurationen der Netznachbildung zum Einsatz, um die Regelung in unterschiedlichen Netztopologien zu testen. Auch der Umgang mit Störeinflüssen, wie langen Messzyklen und fehlenden Messdaten, wird betrachtet. Durch die Auswertung der durchgeführten Untersuchungen und die Anwendung der angesetzten Kriterien wird die Spannungsregelung mit einem regelbaren Ortsnetztransformator und die Stromregelung mit einem Maschenstromregler validiert. Die betrachteten internen Funktionen werden verifiziert. Die Verifizierung des Umgangs mit Störeinflüssen erfolgt mit Einschränkungen, die den Bedarf an weiteren Untersuchungen aufzeigen. Die gemachte Arbeit ist wichtiger Bestandteil des Forschungsprojektes und trägt dazu bei, die Netzautomatisierung im Niederspannungsnetz, die für die erfolgreiche Umsetzung der Energiewende in Deutschland erforderlich ist, voranzubringen.

Glycine constitutes the major neurotransmitter at inhibitory synapses of lower brain regions. A rapid removal of glycine from the synaptic cleft and consequent recycling is crucial for synaptic transmission in systems with high effort on temporal precision. This is mainly achieved by glycine translocation via two glycine transporters (GlyTs), namely GlyT1 and GlyT2. At inhibitory synapses, GlyT2 was found to be specifically expressed by neurons, supplying the presynapse with glycine needed for vesicle filling. In contrast, GlyT1 is attributed to astrocytes and primarily mediates the termination of synaptic transmission by glycine removal from the synaptic cleft. Employing patch-clamp recordings from principal neurons of the lateral superior olive (LSO) in acute brainstem slices of GlyT1b/c knockout (KO) mice and wildtype (WT) littermates at postnatal day 20, I analyzed how postsynaptic responses are changed in a GlyT1-depleted environment. During spontaneous vesicle release I found no change of postsynaptic responses, contradicting my initial hypothesis of prolonged decay times. Electrical stimulation of fibers of the medial nucleus of the trapezoid body (MNTB), which are known to form fast, reliable and highly precise synapses with LSO principal neurons, revealed that GlyT1 is involved in proper synaptic function during sustained, high frequent synaptic transmission. Stimulation with 50 Hz led to a stronger decay time and latency prolongation in GlyT1b/c KO, accelerating to 60% longer decay times and 30% longer latencies. Additionally, a more pronounced frequency-dependent depression and fidelity decrease was observed during stimulation with 200 Hz in GlyT1b/c KO, resulting in 67% smaller amplitudes and only 25% of WT fidelity at the end of the challenge. Basic properties like readily releasable pool, release probability, and quantal size (q) were not altered in GlyT1b/c KO, but interestingly q decreased during 50 Hz and 100 Hz challenges to about 84%, which was not observed in WT. I conclude that stronger accumulation of extracellular glycine due to GlyT1 loss leads to prolonged activation of postsynaptic glycine receptors (GlyRs). As a further consequence, activation of presynaptic GlyRs in the vicinity of the synaptic cleft might be enhanced, accompanied by a stronger occurrence of shunting inhibition. Furthermore, I assume a GlyT1-dependent glycine shuttle, which is absent at GlyT1b/c KO synapses. This could result in a diminished glycine supply to GlyT2 located at more distant sites, causing a disturbed replenishment during periods with excess release of glycine. Conclusively, my study reveals a contribution of astrocytes in fast and reliable synaptic transmission at the MNTB-LSO synapse, which in turn is crucial for proper sound source localization.

Background: The positive effect of carbohydrates from commercial beverages on soccer-specific exercise has been clearly demonstrated. However, no study is available that uses a home-mixed beverage in a test where technical skills were required. Methods: Nine subjects participated vol-untarily in this double-blind, randomized, placebo-controlled crossover study. On three testing days, the subjects performed six Hoff tests with a 3-min active break as a preload and then the Yo-Yo Intermittent Running Test Level 1 (Yo-Yo IR1) until exhaustion. On test days 2 and 3, the subjects received either a 69 g carbohydrate-containing drink (syrup–water mixture) or a carbo-hydrate-free drink (aromatic water). Beverages were given in several doses of 250 mL each: 30 min before and immediately before the exercise and after 18 and 39 min of exercise. The primary target parameters were the running performance in the Hoff test and Yo-Yo IR1, body mass and heart rate. Statistical differences between the variables of both conditions were analyzed using paired samples t-tests. Results: The maximum heart rate in Yo-Yo IR1 showed significant differ-ences (syrup: 191.1 ± 6.2 bpm; placebo: 188.0 ± 6.89 bpm; t(6) = −2.556; p = 0.043; dz = 0.97). The running performance in Yo-Yo IR1 under the condition syrup significantly increased by 93.33 ± 84.85 m (0–240 m) on average (p = 0.011). Conclusions: The intake of a syrup–water mixture with a total of 69 g carbohydrates leads to an increase in high-intensive running performance after soccer specific loads. Therefore, the intake of carbohydrate solutions is recommended for intermit-tent loads and should be increasingly considered by coaches and players.

International talent management, public management and policy

Diese Arbeit beschäftigt sich mit dem elektronischen Einfluss des Substitutionsmusters auf die Eigenschaften des angeregten Zustands von Bis(2,2'-bipyridin)ruthenium(II)- komplexen. Dazu wurde eine Funktionalisierung der 2,2'-Bipyridin- (X2bpy) und Pyridinliganden (Ypy) para-Position zum Stickstoffdonoratom untersucht. Grundlegende Änderungen, beschrieben durch die Hammett-Parameter, führten zu einer Variation der elektronischen Konfiguration der Liganden und des Metallions. Die funktionalisierten Liganden wurden ausgehend von den Vorstufen [(PhCOOR)RuCl2]2 (R = Me, iPr) durch ein Ruthenium(II)ion komplexiert. Die Bis(X2bpy)ruthenium(II)- dichloridverbindungen wurden mit Acetylacetonat (acac), Hexafluoroacetylacetonat (F6acac) und funktionalisiertem Pyridin (Ypy) umgesetzt, um die Komplexe [(acac)(X2bpy)2Ru], [(F6acac)(X2bpy)2Ru] und [(Ypy)2(X2bpy)2Ru] darzustellen, die alle PF6 als Gegenion besitzen. Die folgenden Komplexreihen vom Typ [(Ypy)2(X2bpy)2Ru] wurden in zwei Kategorien unterteilt. Der erste Teil beinhaltete die Funktionalisierung des X2bpy mit N-Nicotinoylpyrrolidin (m-pyCON(C4H8)) als zweitem Liganden. Dieser Pyridin-Ligand wurde ausgewählt, weil der Ligand eine IR-Markierung und die Pyrrolidin-Einheit trägt, welche eine gute Löslichkeit in organischen Lösungsmitteln gewährleistet. In der zweiten Serie wurden ausschließlich die Pyridinliganden funktionalisiert, um den direkten Einfluss der Substituenten auf die Stickstoff-Ruthenium-Bindung zu untersuchen. Sowohl py als auch bpy konnten mit elektronenschiebenden und -ziehenden Gruppen versehen werden, die durch ihre elektronischen Effekte (I-Effekt, M-Effekt) die Elektronenkonfiguration des Liganden, des Rutheniums und damit des gesamten Komplexes beeinflussen. Hierzu sollen IR und UV/Vis-Messungen in der Gasphase und in der Lösung durchgeführt werden. Ergänzend wurden diese Effekte mittels 1H- and 15N-NMR-Spektroskopie untersucht, wodurch der elektronische Einfluss auf die Liganden und auf das Stickstoffdonoratom gezeigt werden konnte, da die Ergebnisse mit den Hammett-Parametern σp+ korrelieren. Die Komplexe mit elektronenziehenden Substituenten werden dabei reaktionsträge, was auf eine Stabilisierung des MLCT-Zustands hinweist, während elektronenziehende Gruppen eine Ligandendissoziation und daher eine Stabilisierung des MC-Zustands hervorrufen. Zusammenfassend lässt sich sagen, dass durch die Nutzung elektronischer Effekte die Komplexe gezielt manipuliert werden konnten, was die Realisierung von maßgeschneiderten Komplexen ermöglicht.

Entscheidungen und Entscheidungsprozesse der Legislative der Vereinigten Staaten von Amerika

To foster sustainability pursuits, regulation by state-imposed legislation is often crucial, but self-regulation by corporations, associations, and other non-state actors increasingly exerts pressures and provides incentives for sustainable practices. In order to shed more light on the complex interplay among sustainability regulations and self-regulation, this study focused on a highly regulated field: the German wine industry. Using a social network analysis, this study identified the most central actors (e.g., associations, regulatory institutions) that need to be addressed in order to ensure the enforcement of sustainability. By analyzing 15 semi-structured interviews with the key actors, we outlined their understanding of sustainability, and classified three distinctive governance patterns. These mixed methods and in-depth analyses revealed that self-regulation by associations plays a crucial role in terms of enhancing sustainability, but regulation remains an important trigger in this context. This article concludes with some lessons for regulation and self-regulation policies that can ensure sustainability within an organizational field.

Structural resilience describes urban drainage systems’ (UDSs) ability to minimize the frequency and magnitude of failure due to common structural issues such as pipe clogging and cracking or pump failure. Structural resilience is often neglected in the design of UDSs. The current literature supports structural decentralization as a way to introduce structural resilience into UDSs. Although there are promising methods in the literature for generating and optimizing decentralized separate stormwater collection systems, incorporating hydraulic simulations in unsteady flow, these approaches sometimes require high computational effort, especially for flat areas. This may hamper their integration into ordinary commercially designed UDS software due to their predominantly scientific purposes. As a response, this paper introduces simplified cost and structural resilience indices that can be used as heuristic parameters for optimizing the UDS layout. These indices only use graph connectivity information, which is computationally much less expensive than hydraulic simulation. The use of simplified objective functions significantly simplifies the feasible search space and reduces blind searches by optimization. To demonstrate the application and advantages of the proposed model, a real case study in the southwest city of Ahvaz, Iran was explored. The proposed framework was proven to be promising for reducing the computational effort and for delivering realistic cost-wise and resilient UDSs.

In order to exploit the full lightweight potential of fibre-reinforced plastics (FRP), a detailed knowledge of their progressive failure behaviour under load is required. In this context, acoustic emission analysis offers a method to characterize the underlying mechanisms in more detail. By detecting and analszing acoustic waves emitted during crack initiation and growth, the location and type of damage can be described over the course of the test. A major challenge thereby is the differentiation between FRP specific damaging events, such as fibre and matrix fractures, on the basis of their acoustic emissions. The present work deals with the influence of two parameters which can have a significant impact on the acoustic characteristics of damaging events. These include the depth in which the damaging event occurs (source depth) and the lateral distance the acoustic wave has to travel from the source to the sensor (source-to-sensor distance). In order to gain an understanding of the effects of both parameters, the work highlights the properties of guided waves in fibre- reinforced plastics as crucial. By analysing artificial acoustic emission sources as well as acoustic emissions from real damaging events, the work demonstrates that changes in source depth and source-to-sensor distance can be accompanied by strong changes in the modal and frequency content of the acoustic emissions. These changes can even lead to a fibre break being mistakenly classified as a matrix break and vice versa. Consequently, for more reliable results in source identification, the influence of source depth and source-to-sensor distance must be considered. In this context, the use of modal acoustic emission analysis can be of great benefit in understanding the underlying phenomena and developing more robust evaluation methods.

Der Beruf schulischer Lehrkräfte ist starken Spannungsverhältnissen und Antinomien ausgesetzt, die es gerade in der unterrichtlichen Gestaltung zu bewerkstelligen gilt. Durch aktuelle bildungspolitische Forderungen, die eine Medienkompetenzförderung und die Einbindung digitaler Medien in den Unterricht fordern, wachsen auch die Erwartungen an den Lehrer*innenberuf sowie seine Aufgaben. Da es gilt, Schülerinnen und Schüler auf eine selbst- und eigenverantwortliche Teilhabe in der Gesellschaft vorzubereiten, braucht es daher geeignete Lehr- und Lernkonzepte, um digital gestützte Veränderungs- und Arbeitsprozesse zu berücksichtigen. Das fordert zuweilen ein Umdenken bewährter Unterrichtskonzepte und Rollenwahrnehmungen von Lehrkräften. In der Arbeit steht daher die Rollenwahrnehmung schulischer Lehrkräfte unter der Perspektive eines digitalen Medieneinsatzes im Fokus. Dazu wurde in einem zweistufigen qualitativen Analyseverfahren Rollenwahrnehmungen von Lehrerinnen und Lehrern erhoben und diese vor dem Hintergrund der sozialen Rollentheorie von Parsons diskutiert.

Glasfaserverstärktes Sheet Molding Compound (G-SMC) wird seit mehreren Jahrzehnten vorrangig in der Automobilindustrie zur Herstellung von Außenhaut- und Verkleidungsbauteilen verwendet. Es handelt sich dabei hauptsächlich um ebene und großflächige Bauteile mit niedrigen oder semistrukturellen Anforderungen. Aufgrund der hohen Designfreiheit von Bauteilen dieser Werkstoff-klasse wird seit einigen Jahren versucht diese durch die Steigerung der mechanischen Kennwerte als strukturelle Komponenten zu befähigen und in Fahrzeugstrukturen zu integrieren. Die beiden wichtigsten Stellgrößenen sind hierbei die Verwendung von Kohlenstofffasern (C-Fasern) zusammen mit einem hohen Faservolumengehalt (über 40 Vol-%). Mit dem Einsatz teurer C-Fasern und dem Wunsch nach effzientem Materialeinsatz steigt der Bedarf nach Simulationswerkzeugen, um die Formfüllung bzw. Bauteilherstellung zu beschreiben. Für G-SMC wurden bisher DProzesssimulationen entwickelt und validiert. Trotz allem ist der Einsatz in der industriellen Praxis bisher kaum verbreitet. Insbesondere lassen sie sich auf den Einsatz von Kohlenstofffaserverstärkten Sheet Molding Compounds (C-SMC) nicht anwenden, da hierbei komplexe, teilweise verripte 3D-Bauteile vorliegen. Um die Material- und Produktkosten bei C-SMC zu senken, werden mittlerweile auch rezyklierte Halbzeuge angeboten und industriell eingesetzt. Diese Halbzeuge weisen in ihrem Umform- und Fließverhalten deutliche Unterschiede zu Neufasermaterialien auf. Hier setzt die vorliegende Arbeit an. Sie leistet einen Beitrag zur Charakterisierung und phänomenologischen Beschreibung von C-SMC mit neuen und rezyklierten C-Fasern. Dabei stehen Methoden zur Erzeugung von Eingangs- und Validierungsdaten für die 3D-Prozesssimulation im Vordergrund. Zur Bestimmung der Faserorientierungen als wichtigste Kenngröße wird das Wirbelstromverfahren in Transmission verwendet. Dabei wird erstmalig eine Methode zur Messung von komplexeren 3D-Bauteilen gezeigt und eine Übertragung auf Finite-Elemente-Netze (FE-Netze) entwickelt. Auf Basis der Materialcharakterisierung wird eine durchgängige, virtuelle 3D-Prozesskette (VPK) für den Pressvorgang bereitgestellt. Für die 3D-Simulation des Pressvorgangs wird der gekoppelte Euler-Lagrange-Ansatz (CEL) verwendet. Ein wichtiges Unterscheidungsmerkmal gegenüber der bisherigen Modellierung von G-SMC ist der festkörpermechanische Betrachtungsansatz des C-SMC beim Pressen. Insbesondere für rezykliertes C-SMC mit einer Wirrfaserstruktur und starken Kompaktierung kommen die bisher verwendeten uidmechanischen Anäatze an die Grenzen ihrer Gültigkeit. Für die Simulation der Bauteilabkühlung nach dem Pressvorgang wird eine linearelastische, orthotrope 3D-Verzugssimulation entwickelt. Für die Verknüpfung der Presssimulation mit der anschließenden Verzugssimulation wird eine modulare Schnittstellenlösung bereitgestellt. Ein Fokus der Entwicklung ist die industrielle Einsetzbarkeit der VPK, weshalb Werkzeuge und Methoden bereitgestellt werden, um komplexere Modelle zu erstellen und diese zu verknüpfen. Die Anwendbarkeit und Prognosegüte der entwickelten VPK wird abschließend an einem Vorserienbauteil einer PKW-Stütze C-Säule ausführlich untersucht.

This work deals with the simulation of the micro-cutting process of titanium. For this purpose, a suitable crystal-plastic material model is developed and efficient implemen- tations are investigated to simulate the micro-cutting process. Several challenges arise for the material model. On the one hand, the low symmetry hexagonal close-packed crystal structure of titanium has to be considered. On the other hand, large defor- mations and strains occur during the machining process. Another important part is the algorithm for the determination of the active slip systems, which has a significant influence on the stability of the simulation. In order to obtain a robust implemen- tation, different aspects, such as the algorithm for the determination of the active slip systems, the method for mesh separation between chip and workpiece as well as the hardening process are investigated, and different approaches are compared. The developed crystal-plastic material model and the selected implementations are first validated and investigated using illustrative examples. The presented simulations of the micro-cutting process show the influence of different machining parameters on the process. Finally, the influence of a real microstructure on the plastic deformation and the cutting force during the process is shown.

Simulating the flow of water in district heating networks requires numerical methods which are independent of the CFL condition. We develop a high order scheme for networks of advection equations allowing large time steps. With the MOOD technique unphysical oscillations of non smooth solutions are avoided. In numerical tests the applicability to real networks is shown.