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Modern physics is based on Newton’s laws of motion, which describe interaction via forces. In this paper, we argue that interaction needs to be described in terms of processes. By introducing the momentum work and the associated momentum energy in mechanics, we present a coherent formulation of the process equations for mechanics and thermodynamics. This naturally leads to a simple derivation of the Lorentz-transformed mass, according to which any object changes its mass in real terms when its velocity is changed. Momentum work requires a revision of Newton’s laws of motion. For the first time in the history of physics, the elastic collision between objects, such as particles, can be described as a temporal process, not as interaction via force = counter-force. The mechanism of energy conversion during the elastic collision and other mechanical processes, such as free fall, becomes clear and demonstrates the validity of the principle of energy conservation on microscale at any point in time. The results suggest that physics can be rebuilt on a more coherent footing of dynamic processes up to quantum-process thermodynamics.

Ziel dieser Arbeit war es, die Morphologie und mechanischen Eigenschaften von einzelnen nativen Typ-I-Kollagenfibrillen bei verschiedenen Umgebungsbedingungen zu untersuchen. Um auf der Nanometerskala die mechanischen Eigenschaften der Fibrillenoberfläche und des Fibrillenvolumens bestimmen zu können, wurde die dynamische (MUSIC-Mode) und statische (FD) Rasterkraftmikroskopie (engl.: Atomic-Force-Microscopy – AFM) genutzt. Die dynamische Spektroskopie erlaubte Rückschlüsse auf die Änderung der mechanischen Eigenschaften von Oberflächen (unter Einbeziehung der ersten 10 nm) bei Variation der Umgebungsbedingungen, wohingegen die statische Kraftspektroskopie Einblicke in das mechanische Verhalten der Volumenphase des Materials (Bulk) gestattete. Es wurden einzelne ovine (vom Schaf stammende) Kollagenfibrillen hinsichtlich ihrer mechanischen und morphologischen Veränderung als Folge von variierten Umwelteinflüssen (Salzkonzentrations-änderung des umgebenden Mediums sowie beim Durchlaufen des Peroxo-essigsäure/Ethanol-Sterilisationsprozesses) untersucht. Im Einzelnen konnte mit dem MUSIC-Mode-AFM und der FD-Spektroskopie die Denaturierung einer Kollagenfibrille in Abhängigkeit der Salzkonzentration beobachtet werden. Ebenfalls konnte mittels der MUSIC-Mode und der FD-Spektroskopie für mehrere Fibrillen unterschiedlichen Durchmessers nachgewiesen werden, dass während des Entfettungsschrittes des Peroxoessigsäure/Ethanol-Sterilisationsprozesses irreversible Veränderungen ihres Quellverhaltens sowie ihrer mechanischen Eigenschaften auftreten.:1 Einleitung ...................................................................................... 8 2 Zielstellungen dieser Arbeit .......................................................... 9 3 Kollagen ...................................................................................... 10 3.1 Aufbau und Struktur .......................................................................... 10 3.2 Die Rolle des Wassers und der Einfluss

This thesis presents significant advancements in the field of driver’s chest localization and breathing detection using FMCW radar. It introduces a neural network model for predicting the 3D location of the driver’s chest and a novel algorithm for detecting breathing patterns and localizing the chest position. These scientific breakthroughs contribute to the development of an adaptive safety system for level 3 and above autonomous driving within the IFAS project (FKZ 19A19009E).

Die dreidimensionale Mikrostruktur, welche bei der Oberflächenkristallisation von Glaskeramiken entsteht, wird mittels einer neuartigen Methode zur Präparation von abgesenkten Probenoberflächen untersucht. Diese Initialkantensektionierungsmethode, welche auf der Erzeugung von Scharten in der Probenoberfläche und anschließender Glanzwinkelionenstrahlerosion basiert, erlaubt das rapide Freilegen von großflächigen Schichten in wohldefinierten Tiefen unterhalb der ursprünglichen Probenoberfläche. In dieser Dissertation werden mehrere Variationen der Technik durch Kombination von Laserablation, Ionenbreit- sowie Ionenfeinstrahlerosion untersucht und miteinander verglichen. Die in Bezug auf Schnittgeometrie und Probengüte relevanten, experimentellen Parameter werden bestimmt und bewertet. Ein Modell zur Beschreibung der zeitlichen Evolution der Probengeometrie während des Erosionsvorgangs wird auf Grundlage von Simulationen und analytischen Näherungen aufgestellt und mit experimentellen Ergebnissen verglichen. Schließlich wird die Initialkantensektionierungsmethode mit Elektronenrückstreubeugung kombiniert um Wachstumseffekte bei der Oberflächenkristallisation von Diopsid- und Ba2TiSi2O8-Fresnoitglaskeramiken zu untersuchen.:1 Introduction 1.1 Motivation 1.2 Aims and Objectives 2 Literature Review 2.1 Sample Preparation for Electron Backscatter Diffraction Studies 2.2 Serial Sectioning Methods 2.3 Microstructure Characterization of Glass Ceramics using EBSD 2.4 Interim Conclusion 3 Theory 3.1 Erosion of a Surface Under Ion Bombardment 3.1.1 Sputtering 3.1.2 Kinetic Theory of Surface Evolution 3.1.3 Numerical Simulation of Surface Erosion 3.1.4 Erosion of a Surface With Initial Notches 3.2 Electron Backscatter Diffraction 3.2.1 Measurement Principle 3.2.2 Representation of Orientations and Texture 4 Methods and Materials 4.1 Sample Preparation and Processing 4.2 Surface Metrology 4.3 Microstructure Analysis 4.4 Materials 5 Erosion of Surfaces With Initial Notches 5.1 Evalu, Three-dimensional microstructures resulting from surface crystallization of glass ceramics are studied using a novel sample sectioning method. Based on the creation of notches on the sample surface and subsequent glancing-angle ion beam erosion, initial notch sectioning enables the rapid excavation of large subsurface layers at well-defined depths. In this thesis, several variations of this technique using different combinations of laser ablation, broad and focused ion beam erosion are realized and compared to each other. Relevant parameters controlling the section geometry and quality are determined. A model of the surface evolution kinetics is developed using simulations and analytical estimates, which is compared to experimental results. Finally, initial notch sectioning in combination with electron backscatter diffraction is applied to elucidate growth phenomena in the surface crystallization of diopside and Ba2TiSi2O8 fresnoite glass ceramics.:1 Introduction 1.1 Motivation 1.2 Aims and Objectives 2 Literature Review 2.1 Sample Preparation for Electron Backscatter Diffraction Studies 2.2 Serial Sectioning Methods 2.3 Microstructure Characterization of Glass Ceramics using EBSD 2.4 Interim Conclusion 3 Theory 3.1 Erosion of a Surface Under Ion Bombardment 3.1.1 Sputtering 3.1.2 Kinetic Theory of Surface Evolution 3.1.3 Numerical Simulation of Surface Erosion 3.1.4 Erosion of a Surface With Initial Notches 3.2 Electron Backscatter Diffraction 3.2.1 Measurement Principle 3.2.2 Representation of Orientations and Texture 4 Methods and Materials 4.1 Sample Preparation and Processing 4.2 Surface Metrology 4.3 Microstructure Analysis 4.4 Materials 5 Erosion of Surfaces With Initial Notches 5.1 Evaluation of Surface Processing Methods 5.1.1 Notch Creation 5.1.2 Terrace Formation by Glancing-Angle Ion Beam Erosion 5.2 Surface Properties in the Terrace Region 5.2.1 Terrace Roughness 5.2.2 Ion Beam Induced Amorphization 5.3 Evolution of Surface Geometry 5.3.1 Linear Model 5

Steigende Zahlen von Patienten mit neurodegenerativen Erkrankungen sind ein überzeugender Grund, das menschliche Gehirn und seinen fortschreitenden Verfall zu untersuchen, wobei aber viele essenzielle biochemische Funktionen bisher noch nicht vollends geklärt sind. In vitro Forschung zur Hirnfunktion auf geeigneten Plattformen ist ein vielversprechender Weg, diese Lücke zu schließen. Eigenschaften der brain-machine Grenzfläche müssen erforscht werden, um neue Biomaterialien effektiv für lab-on-a-chip Anwendungen wie bspw. Multielektrodenarrays (MEAs) einzusetzen. Diese brain-on-a-chip Anwendungen können dazu dienen, die Zahl der Tierexperimente zu reduzieren, damit Forschung zu beschleunigen und Kosten zu senken. In dieser Hinsicht erfordert die Miniaturisierung von MEAs für eine detailliertere Messung von neuronalen Funktionen die Entwicklung von neuen Biomaterialien mit vorteilhaften elektrischen Eigenschaften. Die Wechselwirkung dieser Biomaterialien mit Zellen muss untersucht werden, um gute Zelladhäsion, Proliferation und elektrische Kopplung zu gewährleisten. Die vorliegende Arbeit dient der Charakterisierung der Wechselwirkung von humanen neuronalen Zellen und Gliazellen (neuronenartige SH-SY5Y und gliaartige U-87 MG Zellen) mit dem Elektrodenmaterial Titannitrid mit nanokolumnarer Oberfläche (TiN nano) und dessen Vorteile bezüglich elektrischer und bioaktiver Eigenschaften im Vergleich mit Gold (Au) und Indiumzinnoxid (ITO), welche derzeit für MEAs und Neuroelektroden verwendet werden. Das Ziel der Arbeit ist die Implementierung neuer aus der theoretischen Physik, Mathematik und Computerwissenschaft entlehnten Techniken, um eine bildbasierte Methode zu entwickeln, die auf minimalen Experimenten beruht und trotzdem wichtige Hinweise zur Biokompatibiliät eines Materials liefert. Das schließt die Analyse von Zellnetzwerken, Zellverteilung, Adhäsion und elektrochemischer Eigenschaften in mono- und co-Kultur ein. Dazu werden Autokorrelation, selbstlernende Algori, Rising numbers of patients with neurodegenerative diseases are a compelling reason to study the human brain and its progressive deterioration but many essential biochemical functions are still under investigation. Conducting research on brain function in vitro with suitable platforms is a promising solution to close these gaps. Characteristics of the brain-machine interface need to be investigated to effectively employ new biomaterials for lab-on-a-chip devices, such as multielectrode arrays (MEAs) for example. These brain-on-a-chip devices will potentially reduce the number of conducted animal experiments and therewith accelerate future research and reduce costs. In this context, miniaturization of MEAs for more detailed measurements of neuronal function calls for new biomaterials with advantageous electrical characteristics. The interaction of these biomaterials with cells needs to be investigated to ensure good cell adhesion, proliferation, and electrical coupling. This thesis aims to study and characterize the interaction of human neuronal and glial cells (neuron-like SH-SY5Y and glia-like U-87 MG cells) with the electrode material titanium nitride with nanocolumnar surface topography (TiN nano) and its advantages in terms of electric and bioactive properties compared to gold (Au) and indium tin oxide (ITO) which are currently employed for MEAs and neuroelectrodes. The overall goal of this study is the implementation of new techniques drawn from theoretical physics, mathematics, and computer science to establish an image-based method that relies on minimal experimental effort but nevertheless yields important evidence of biocompatibility of the material. Analysis includes the investigation of cellular networks, cell distribution, adhesion, and electrochemical properties in mono- and co-culture experiments. To this end, autocorrelation function, self-learning algorithms, and nearest neighbor analysis are deployed to move away from classical biochemical assays tow

An investigation into open problems related to black hole evaporation in the semi-classical framework, concerning the existence of quantum field theories on spacetimes modelling evaporating black holes as well as the existence of black hole solutions to the semi-classical Einstein equations., Eine Untersuchung offener Probleme zur Verdampfung schwarzer Löcher im semi-klassischen Modell, bezüglich der Existenz von Quantenfeldtheorien auf Raumzeiten, die verdampfende schwarze Löcher beschreiben, sowie der Existenz von Lösungen der semi-klassischen Einstein Gleichungen, welche schwarze Löcher darstellen.

Charged or rotating black holes possess an inner horizon beyond which determinism is lost. However, the strong cosmic censorship conjecture claims that even small perturbations will turn the horizon into a singularity beyond which the spacetime is inextendible, preventing the loss of determinism. Motivated by this conjecture, this dissertation studies free scalar quantum fields on various black-hole spacetimes to test whether quantum effects can lead to the formation of a singularity at the inner horizon in cases where classical perturbations cannot. The starting point is the investigation of the behaviour of real-scalar-field observables near the inner horizon of Reissner-Nordström-de Sitter spacetimes. Using semi-analytical methods, we find that quantum effects can indeed uphold the censorship conjecture. Subsequently, we consider charged scalar fields on the same spacetime and observe that a first-principle calculation is essential to accurately describe the quantum effects at the inner horizon. As a first step towards an extension of these results to rotating black holes, we rigorously construct the Unruh state for the real scalar field on slowly rotating Kerr-de Sitter spacetimes. We show that it is a well-defined Hadamard state and can therefore be used to compute expectation values of the stressenergy tensor and other non-linear observables.:1 Introduction 7 2 An introduction to quantum fields and black holes 13 2.1 Notations and conventions . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.2 A brief introduction to AQFT . . . . . . . . . . . . . . . . . . . . . . . . 15 2.3 An introduction to microlocal analysis . . . . . . . . . . . . . . . . . . . 24 2.4 An introduction to black-hole spacetimes . . . . . . . . . . . . . . . . . 28 2.4.1 The Reissner-Nordström-de Sitter spacetime . . . . . . . . . . . 28 2.4.2 The Kerr-de Sitter spacetime . . . . . . . . . . . . . . . . . . . . 32 2.5 Free scalar fields in black-hole spacetimes . . . . . . . . . . . .

In Paper I of this series, the elastic collision was described via simultaneous processes, where the energy is conserved at any moment. In this paper, we critically review the kinetic theory of gases, which was developed based on Newtonian mechanics, and show that it violates the principle of the conservation of energy. By placing the energy conservation at the beginning of the deductive formalism, we derive the ideal gas law via equally strong simultaneous counter-processes at the walls, namely, momentum work and volume work. Several new insights into the state variables of an ideal gas are obtained: (i) pressure cannot be expressed via the kinetic energy of an ideal gas, and (ii) temperature can be interpreted as a particle-related (microscopic) state variable. The historical choice to set a zero point of the potential energy for a confined ideal gas needs to be corrected, and the internal energy of an ideal gas turns out to include more forms of energy than specified in the kinetic theory of gases. Finally, and importantly, we show that the process approach to an ideal gas and thus to collisions is experimentally confirmed.

This document is Sajad Azizi's doctoral thesis titled 'Three Aspects of Photoionization in Ultrashort Pulses.' The research was conducted under the supervision of Prof. Dr. Jan Michael Rost at the Max Planck Institute for the Physics of Complex Systems.:Contents 1 Introduction 1 1.1 Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Thesis outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Fundamental Concepts 5 2.1 Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2 Introduction to strong field ionization . . . . . . . . . . . . . . . . . . . . . . 6 2.2.1 From the photoelectric effect to strong-field ionization . . . . . . . . . 6 2.3 Non-relativistic time-dependent Hamiltonian . . . . . . . . . . . . . . . . . . 10 2.3.1 Dipole approximation and choice of gauges . . . . . . . . . . . . . . . 11 2.3.2 Interaction of an electron with a classical field . . . . . . . . . . . . . 12 2.4 Ultrashort laser pulse shaping . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.4.1 Fourier-limited pulse: Gaussian envelope . . . . . . . . . . . . . . . . . 17 2.4.2 Modulated pulse: sinusoidal phase modulation . . . . . . . . . . . . . 18 2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3 Controlling Non-adiabatic Photoionization with Ultrashort Pulses 20 3.1 Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.2 Introduction to non-adiabatic ionization . . . . . . . . . . . . . . . . . . . . . 21 3.2.1 Intuitive picture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.2.2 Mathematical picture . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.3 Non-adiabatic ionization with tailored laser pulses . . . . . . . . . . . . . . . 25 3.3.1 Ionization by single Gaussian pulses . . . . . . . . . . . . . . . . . . . 26 3.3.2 Sensitivity of non-adiabatic photoionization

Carbon-bonded alumina filters and their binders, lactose, tannin and CarboresP, were investigated by Raman spectroscopy. Special emphasis was placed on the pyrolysis study of the binders. In situ measurements were performed on the tannins gallic acid, ellagic acid and tannic acid to determine the pyrolysis temperatures and products. Furthermore, the binder samples fired in a reducing atmosphere in a coke bed were analyzed by Raman spectroscopy and their transition from an amorphous carbon system to nanocrystalline graphite was observed. The influence of different binders on the carbon-bound alumina filters was studied, as well as the influence of different additives. However, no significant difference was observed between samples with different binder compositions or with additives. In addition, Raman measurements on the spinel MgAlON indicate an increased disorder of the structure due to the incorporated nitrogen.

Viele Länder des globalen Südens erleben aktuell die doppelte Dynamik von rasanter Urbanisierung und globaler Umweltveränderung. Die Schaffung nachhaltiger und widerstandsfähiger Städte ist ein globales Ziel der UN (SDG11). Die Urbanisierung wird mit zahlreichen Vorteilen auf gesellschaftlicher und individueller Ebene in Verbindung gebracht. Gleichzeitig birgt sie jedoch negative Auswirkungen auf die natürlichen Ressourcen, kann städtische Versorgungssysteme überfordern und neue Verwundbarkeiten schaffen. Da die verschiedenen Herausforderungen miteinander verknüpft sind, bedarf es eines interdisziplinären Forschungsansatzes. Im Laufe des letzten Jahrzehnts hat sich der Food-Water-Energy (FWE)-Nexus für sektorübergreifende Analysen etabliert. In dieser Dissertation wird ein Beitrag zum Verständnis des FWE-Nexus in schnell urbanisierenden Regionen des globalen Südens geleistet und es werden Defizite in der aktuellen Debatte adressiert. Im Mittelpunkt der Arbeit steht die Millionenstadt Pune in Indien. Um ein umfassendes Systemverständnis zu erlangen, wird in Zusammenarbeit mit lokalen Stakeholdern zunächst eine Sammlung von 22 FWE-Herausforderungen auf verschiedenen Ebenen erstellt. In den anschließenden vertieften Analysen werden ausgewählte urbanisierungsbezogene Herausforderungen untersucht, insbesondere die zukünftige Entwicklung des Stadtwachstums und die Zuwanderung nach Pune. Letztere ist einer der wichtigsten Wachstumstreiber. Zu diesem Zweck wird ein neuartiger Modellierungsansatz vorgestellt, bei dem nationale sozioökonomische Szenarien auf die Stadtebene herunterskaliert, und in räumlich explizite Darstellungen von bebauter Fläche und Bevölkerungsdichte übersetzt werden. Diese erlauben Analysen potenzieller FWE-Nexus-Herausforderungen in Zukunft. Die Untersuchung der Zuwanderung nach Pune basiert auf qualitativen und quantitativen Datenquellen mittels Mixed-Methods-Verfahren. Das in allen Szenarien erwartete signifikante Stadtwachstum ist mit einer Konzentr, Many countries in the global South are experiencing the combined dynamics of rapid urbanization and global environmental change. The provision of sustainable and resilient cities is a declared global goal (SDG11). Urbanization has been associated with multiple benefits on societal and individual level. However, it can also entail adverse impacts on natural resources, overstrain supply systems, and create new vulnerabilities. The interlinked nature of challenges requires an interdisciplinary research approach. Over the last decade, the Food-Water-Energy (FWE) nexus has been popularized for inter-sectoral analyses. This thesis attempts to add to the understanding of the FWE nexus in rapidly urbanizing regions of the global South and to address shortcomings in the current debate. The work is centered around the emerging megacity of Pune in India. For a comprehensive understanding of the system under investigation, a set of 22 FWE challenges on various levels is co-produced with local stakeholders. Subsequent analyses investigate selected urbanization-related challenges in-depth, namely future trajectories of the city’s growth and in-migration as one of its main drivers. To that end, a novel modeling approach is presented, downscaling established high-level socioeconomic scenarios to the city level and translating them into built-up area mapped by a cellular automaton. Population surfaces are then generated via dasymetric mapping. The resulting spatial configurations of built-up and population scenarios are analyzed in terms of potential FWE nexus challenges. The analysis of in-migration to Pune is based on qualitative and quantitative data sources and their mixed methods analysis. The significant demographic, economic, and spatial growth expected in all scenarios is associated with a concentration of resource demands in the city, significant loss of fertile land, and an increase in flood-affected population and infrastructure. As to in-migration, climate change has pla

Broadband Coherent Anti-Stokes Raman scattering (B-CARS) is an advanced Raman spectroscopy technique used to investigate the vibrational properties of materials. B-CARS combines the spectral sensitivity of spontaneous Raman scattering with the enhanced signal intensity of coherent Raman techniques. While B-CARS has been successfully applied in biomedicine for ultra-fast imaging of biological tissue, its potential in solid-state physics remains largely unexplored. This work delves into the challenges and adaptations necessary to apply B-CARS to crystalline materials and shows its potential as a powerful tool for high-speed, hyperspectral investigations. The theoretical part of this work covers inelastic light-matter scattering fundamentals and the signal generation process of B-CARS, with special attention given to the so-called Non-Resonant Background (NRB). This sample-unspecific signal amplifies the B-CARS intensity but also distorts the shape and position of the measured spectral peaks. A reliable NRB correction becomes crucial to retrieve precise spectral parameters containing information on the investigated material's crystallographic structure, defect density, and stress distribution. The first results chapter presents a practical guideline for an optimized workflow of sample preparation, measurement procedure, and data analysis. The influences of sample surfaces, focus positioning, and polarization sensitivity are discussed. The successful NRB removal is achieved by adapting an algorithm initially designed for biomedical purposes. The second chapter involves a transnational Round Robin investigating the same set of materials using different experimental setups. The influences of laser source, detection range, and transmission vs. epi detection are explored to optimize the experimental parameters. This work showcases applications such as high-speed, hyperspectral imaging of ferroelectric domain walls in LiNbO3, demonstrating the potential of B-CARS in the cutt

Aerosol-cloud and aerosol-radiation interactions depend on several factors such as the physico-chemical properties, geographical and temporal variability, and vertical distribution of atmospheric aerosols. Of particular importance are cloud condensation nuclei (CCN) and black carbon (BC) particles as a subset of the atmospheric aerosol population. CCN are a prerequisite for cloud droplet formation, and variations in CCN loading can modify cloud properties. BC can efficiently absorb solar radiation, induce local heating and inhibit cloud formation. In order to determine the effects of CCN and BC on clouds, precipitation, radiation and the Earth’s energy budget, atmospheric loading and spatio-temporal distribution of aerosols are highly relevant. Thus this dissertation addresses and helps to elucidate the spatio-temporal variation and co-variability of CCN and BC with extensive field measurement data from aircraft and ground-based measurements. The data analyses focus on anthropogenic pollution, wildfire emissions and volcanic aerosols. In the Anthropocene, the distribution and abundance of atmospheric aerosols have changed drastically. Major sources of anthropogenic particulate pollution are the combustion of fossil fuels and biofuels as well as emissions from open biomass burning. The ubiquitous presence of anthropogenic air pollution, especially over continental regions in the Northern Hemisphere, hampers the assessment of anthropogenic influence on aerosol and climate due to a lack of unperturbed reference measurements. The abrupt reduction in human activities during the first COVID-19 lockdown created unprecedented atmospheric conditions that allowed us to investigate and quantify changes in the tropospheric composition in response to changes in anthropogenic emissions. The results reflect a strong and immediate influence of human activities on air quality, the role of BC as a major air pollutant in the Anthropocene, and close links between the atmospher

Manganese-based Heusler compounds display intriguing fundamental physical properties, determined by the delicate balance of magnetic interactions that give rise to real and reciprocal-space topology, sparking the interest in their potential application in the spin-based technology of the future. In this thesis, a thorough study of thin films of two Mn-based Heusler compounds, the hexagonal MnPtGa and inverse tetragonal Mn2Rh(1-x)Ir(x)Sn (0 < x < 0.4) system, was performed. The observation of Néel-type skyrmions in single-crystalline MnPtGa motivated our interest in the growth and characterization of thin films of this compound. The films were deposited by magnetron sputtering on (0001)-Al2O3 single crystalline substrates, achieving the epitaxial growth of the Ni2In-type hexagonal crystal structure (P6_3/mmc space group, no. 194). Two thermally-induced magnetic transitions were identified in MnPtGa thin films: below the ordering temperature (T_C=273 K) the system becomes ferromagnetic, followed by a spin-reorientation transition at T_sr=160 K, adopting a spin-canted magnetic structure. Resorting to single-crystal neutron diffraction (SCND), we were able to resolve the magnetic ground state of our MnPtGa thin films. The Mn magnetic moments were found to tilt 20 degrees away from the c-axis, forming a commensurate magnetic structure with a ferromagnetic component along the crystallographic c-axis and a staggered antiferromagnetic one in the basal plane. This further demonstrated the applicability of a bulk technique, such as SCND, to the study of magnetic structures in thin films. Additionally, the perpendicular magnetic anisotropy (PMA) in the system was determined by magnetometry technique. Electrical magnetotransport measurements were performed in a thickness series of MnPtGa thin films. A non-monotonous anomalous Hall conductivity (AHC) was observed, whose intrinsic Berry-curvature origin was elucidated by means of first-principle calculations. We further observed

In the context of the search and tuning for novel magnetic materials, transition metal compounds exhibit remarkable features where the spin-orbit interaction is crucial. The collective interactions between various effects, like spins and charges, create different classes of unique magnetic systems. For heavy transition-metal compounds, the strength of spin-orbital coupling is enhanced. The jeff. = 1/2 Mott insulating state emerges from the combination of the spin-orbit interaction and the electronic correlations. The quantum-chemistry methods are employed in this thesis to investigate single- and two-site magnetic interactions of the selected transition-metal compounds. We also provide different estimations for the single- and two-site magnetic interactions based on the level of calculation accuracy. In this thesis, we apply ab initio quantum-chemistry methods to explore the electronic and magnetic properties of several d/f compounds. The thesis structure is as follows: In Chapter 1, the introduction of the thesis provides a short discussion of the electronic correlations and magnetism in transition metal compounds. In Chapter 2, the fundamentals of the quantum chemistry wavefunction-based approach are covered. This chapter gives an overview of the applied methods in this thesis. In Chapter 3, we discuss the quantum chemistry approach to investigate the material candidates to host Kitaev physics. The technique to obtain the strength of two-site magnetic couplings, including the Kitaev coupling, is discussed in-depth. In Chapter 4, we apply the technique, which is described in Chapter 3, to investigate the two-site magnetic interactions in the H3LiIr2O6, and Cu2IrO2 compounds as Kitaev candidates. The two-site magnetic couplings are reported in these compounds. In Chapter 5, we use quantum chemistry methods to investigate the on-site electronic and magnetic properties in the KCeO2 compound where 4f1 Ce3+ ions form a triangular two-dimensional lattice with sites of ef

In dieser Arbeit berichte ich von meinen Untersuchungen der Fermiflächen der topologischer Semimetalle PtGa, CoSi, CaAuAs und CaCdGe. Dazu habe ich die Quantenoszillationen der einkristallinen Proben mittels Drehmomentmagnetometrie gemessen und vergleiche die Resultate mit denen von Dichtefunktionaltheorie-Rechnungen. Aus diesem Vergleich lassen sich die Bandstruktur und Fermiflächen verlässlich bestimmen und damit deren Topologie verifizieren. PtGa und CoSi kristallisieren in der Raumgruppe P213 (198) und sind damit chiral und nicht zentrosymmetrisch. Sie besitzen eine außergewöhnliche Bandstruktur-Topologie mit hochgradig entarteten Bandberührungspunkten und Bandberührungsflächen, welche empfindlich von der Spin-Bahn-Kopplung abhängt. PtGa unterliegt einer sehr starken Spin-Bahn-Kopplung, welche den experimentellen Nachweis der topologischen Ladung der Bandberührungspunkte ermöglichte. In CoSi ist die Spin-Bahn-Kopplung schwach, sodass ihre experimentelle Signifikanz bisher umstritten ist. In meinen Messungen zeigen beide Materialien eine deutliche Spinaufspaltung der Quantenoszillationsfrequenzen, welche die Auswirkung Spin-Bahn-Kopplung auch für CoSi nachweist. Die Übereinstimmungen der Resultate der Messungen mit denen der Bandstruktur-Rechnungen bestätigen zudem Bandstrukturen und ihre Topologie. CaAuAs und CaCdGe weisen gemäß Bandstruktur-Rechnungen ohne Berücksichtigung der Spin-Bahn-Kopplung Bandberührungslinien auf, welche durch die Spin-Bahn-Kopplung aufgespalten werden. Bei CaAuAs stimmen die Quantenoszillationsfrequenzen sehr gut mit den berechneten Frequenzen unter Beachtung der Spin-Bahn-Kopplung überein. Dies spricht gegen die Existenz von Bandberührungslinien und für ihre Aufspaltung zu Dirac-Punkten. CaCdGe weichen die berechneten und die gemessenen Ergebnisse zum Teil stark von einander ab, sodass Bandstruktur nicht klar bestimmt ist und weitere Untersuchungen notwendig sind.

Increased anthropogenic aerosols result in an enhancement in cloud droplet number concentration (Nd), which consequently modifies cloud and precipitation processes. It is unclear how exactly cloud liquid water path (LWP) and cloud fraction respond to aerosol perturbations. A volcanic eruption may help to better understand and quantify the cloud response to external perturbations, with a focus on short-term cloud adjustments. The goal of the present study is to understand and quantify the response of clouds to a se- lected volcanic eruption and to thereby advance the fundamental understanding of the cloud response to external forcing. In this study we used the ICON (ICOsahedral Non-hydrostatic) model in its numerical weather prediction setup at a cloud-system-resolving resolution of 2.5 km horizontally, to simulate the region around the Holuhraun volcano for one week (1 – 7 September 2014). The ICON-NWP version employed in this study does not include an interactive aerosol model. Therefore a new method for cloud condensation nuclei (CCN) activation in a mi- crophysics scheme that was developed specifically for this study is introduced. The CCN values were determined by interpolating from look-up tables and considering the corresponding pressure (p) and vertical velocity (w) values within each grid-box of the atmospheric model. Moreover, in order to improve the comparison between cloud microphysical variables and satellite retrievals, the MODIS simulator from the COSP (CFMIP Observation Simulator Package) framework was implemented into the source code of ICON-NWP. A pair of simulations, with and without the volcanic aerosol plume, allowed us to as- sess the simulated effective radiative forcing and its mechanisms, as well as its impact on adjustments of LWP and cloud fraction to the perturbations of Nd. In comparison to MODIS (Moderate Resolution Imaging Spectroradiometer) satellite retrievals, a clear enhancement of Nd due to the volcanic aerosol is detected and attr

Die vorliegende Doktorarbeit beschäftigt sich mit der numerischen Ausbreitungssimulation von Luftschadstoffen im urbanen Raum. Als Strömungshindernisse prägen Gebäude maßgeblich das kleinskalige Windfeld und damit den horizontalen Transport und die Verteilung von urbanen Luftschadstoffen. Die häufig im Rahmen von Großwirbelsimulationen (engl.: Large Eddy Simulation, LES) zur expliziten Darstellung von Gebäuden verwendeten hohen räumlichen Auflösungen in Bereich von wenigen Metern erforden einen hohen Rechenaufwand und beschränken daher die Anwendung meist auf wenige Gebäudeblöcke. Mittels eines neuen Diskretisierungsansatzes können Gebäude auch bei deutlich geringeren Auflösungen in Bereich der sogenannten urbanen Grauzone (horizontale Gitterweite > 10m) mittels diffuser Gebäudekanten explizit dargestellt werden. Im Rahmen dieser Arbeit wurde das urbane Dispersionsmodells CAIRDIO (v1.0) mit diesem neuen Diskretisierungsansatz entwickelt. Das Modell wurde zunächst mit einem Windkanalexperiment, welches die turbulente Ausbreitung eines Test-Tracers in einer Modellstadt beinhaltet, validiert. Dabei konnte bis zu einer horizontalen Auflösung von 40m noch eine hinreichend gute Übereinstimmung des Modells mit Konzentrationsmessungen erzielt werden, es wurde jedoch nur ein Bruchteil der Rechenzeit einer Referenzsimulation mit 5m Gitterweite benötigt. Der Ansatz mit diffusen Gebäuden erlaubt daher den Anwendungsbereich mikroskaliger Simulationen im Vergleich zu klassischen LES Simulationen erheblich zu erweitern, z.B. auf die Simulation ganzer Städte. In einer ersten realistischen Fallstudie wurde das Modell CAIRDIO auf die Stadt Leipzig in Mitteldeutschland angewandt. Dabei wurde die Ausbreitung von realistischen Feinstaub und Ruß-Emissionen bei einer horizontalen Auflösung von 40m für das gesamte Stadtgebiet über einen Zeitraum von 2 Tagen (Anfang März 2020) berechnet und mit Messungen validiert. Es konnten die Auswirkungen der variablen Grenzschichtdynamik auf den urbane

The Arctic region shows a particularly high susceptibility to climate change, which historically manifests in an amplification of the near-surface warming in the Arctic relative to the global mean. This Arctic amplification (AA) has impacts on the climate system also beyond the northern polar regions, which highlights the importance to adequately represent it in numerical models. While state-of-the-art climate models widely agree on the presence of AA, they simulate a large spread in the magnitude of Arctic-amplified warming. This thesis addresses the need to evaluate the performance of global climate models in projecting AA and its most important drivers. For the latter, the focus is on the three amplifying climate feedbacks (ACFs) that largely drive the meridional warming structure leading to AA. The ACFs include the sea-ice-albedo feedback (SIAF), the Planck feedback, and the lapse-rate feedback (LRF). These feedbacks arise from the relevant changes in Arctic sea ice, near-surface temperatures, and the deviation from the near-surface temperature change through the atmosphere, respectively. In the thesis, two observational constraints are presented to narrow the range of climate models of the sixth Coupled Model Intercomparison Project (CMIP6) regarding their projection of AA and the ACFs in both past and future climate. While for the past, the models representation of near-surface processes can often be directly evaluated against observations, it is particularly the LRF that is difficult to constrain as it incorporates the entire atmospheric warming structure. As a consequence, the historical constraint focuses on the LRF, while the future constraint gives a prediction range for the evolution of AA and all three ACFs through the 21st century. The main results are highlighted in the view of the changing atmospheric energy budget (AEB) of the Arctic under anthropogenic climate forcing. The AEB provides a framework to address Arctic climate change at large scales, a

Recent developments in functional magnetic resonance imaging (fMRI) methods at high magnetic field strengths (≥7 T) promise the non-invasive indirect measurement of neural activation at the spatial scale of cortical columns and layers. However, the achievable spatial specificity of fMRI, which is ultimately limited by the spatio-temporal properties of the hemodynamic response, is still waiting to be fully characterized. To examine the spatial specificity of the blood oxygenation level dependent (BOLD) contrast exploited by fMRI, the spatial point spread function (PSF) of the gradient echo (GE) and the spin echo (SE) BOLD signal tangential to the cortical surface was determined at different cortical depths. Both GE- and SE-BOLD showed a loss in spatial specificity toward the pial surface, demonstrating the impact of unspecific macrovascular contributions to both contrasts and only a minor advantage of the SE-BOLD signal for high-resolution fMRI applications. However, unidirectional draining of deoxygenated blood mainly limits spatial specificity in the radial direction. To examine the discriminability of laminar information, ocular dominance columns (ODCs) in the primary visual cortex (V1) were mapped using fMRI sensitive to either the BOLD contrast or cerebral blood volume (CBV) changes, and the stimulated eye was decoded using a machine learning classifier at different cortical depths. Only CBV-fMRI showed increased prediction accuracies at the cortical depth that matched neurophysiological expectations, showing its improved spatial specificity and potential for layer-specific fMRI in humans. Furthermore, the thin-thick-pale stripe pattern in the secondary visual cortex (V2) was targeted, exploiting the sensitivity to color and binocular disparity of thin and thick stripes, respectively. The structure-function relationship of the stripe architecture to cortical myelin was studied, which so far has shown inconsistent findings in multiple histological experiments. Hi

The investigation into topological phases on non-periodic lattices has recently gained wide interest because of the discovery of never-before seen phenomena lacking a counterpart in periodic lattices. In this thesis, I present the results of my work on the lattice Laughlin state on fractal lattices and that of the BHZ model on quasicrystals. I show that the entanglement spectrum has the same topological fingerprint as in periodic lattices, and thus can be used as a probe of topological order in these new environments, where such probes are severely lacking, especially for interacting topological phases. I also show how the entanglement entropy displays precise oscillations as a function of lattice filling in fractal lattices, and is smooth for periodic lattices. I study the on-site particle densities, and anyonic excitations on different kinds of fractal lattices and show how radically different they are from the 2D case. Finally, I study the BHZ model on the Amman-Beenker tiling and show the different kinds of Bulk Localized Transport(BLT) states, the edge states, and how the latter can be used to pump charge between different kind of BLT states. I couple two layers of the half-BHZ, which are time-reversed partners of each other, with a simple time-reversal symmetric hopping, and show that the BLT and edge states still survive.

Epigenetics comprises chemical modifications of the DNA and the proteins that the DNA is wrapped around them. These modifications play key roles in establishing and maintaining cellular identity throughout development and adulthood. In recent years, it has become increasingly clear that these actions are more dynamic than initially believed. The alteration of cellular identities during regeneration, ageing, and the formation of tumors is closely linked to systematic changes in epigenetic modifiers. The emergence of cutting-edge single-cell sequencing technologies has enabled thorough explorations of biological processes with high molecular precision. Nevertheless, the regulation of cellular behavior is intricately tied to collective processes occurring in both spatial and temporal dimensions, operating on the mesoscopic and macroscopic scales. However, these larger scales cannot be straightforwardly deduced from microscopic measurements along the DNA sequence. Consequently, the findings obtained from sequencing experiments stay at the descriptive level until they are coupled with methodologies capable of discerning collective degrees of freedom. Here, using statistical physics tools and sequencing technologies, we study the collective processes underlying epigenetic dynamics in cells that change their identity over time. Specifically, we investigate collective epigenetic processes during ageing and the reprogramming of cells after injury. In the first part of this thesis, we study the mechanistic basis of epigenetic modifications during ageing. Despite the accuracy of machine learning models in predicting the biological age based on epigenetic DNA methylation marks, these tools do not inform about the mechanistic basis of epigenetic ageing. We show that epigenetic ageing is reflected in systematic and collective changes in DNA methylation marks during ageing, which manifests in the stereotypical behavior of two-point correlation functions. We devise a stochastic the

Spin-orbit coupling (SOC) is a relativistic effect whose origin lies in the Dirac’s equation – a relativistic analogue of Schrödinger’s equation. SOC corrects the electronic states of a quantum mechanical system up to ~1 eV in case of semiconductors and ~ 2 – 3.6 eV in case of actinides and heavy elements by considering not only the coordinates but also the spin of the electrons in the system. Most of the applications of the present day technology are based on manipulating the electronic structure of a system with very high accuracy and precision. This demands availability of correct electronic structure of a material or molecule within a feasible computational time. Some direct consequences of SOC in materials can be noticed in analyzing the charge-transport properties of a semiconductor, evaluating the candidature of transition metal dichalcogenides (TMDCs) for spintronic, twistronic and valleytronic applications, and in the origin of topological properties of a material. Not only in materials but also in molecules the SOC effects can be observed. Fine-structure of atomic spectra was explained on the account of SOC. Several additional peaks and wavelength shift in UV-vis spectroscopy of Gold Superatoms can only be explained by correctly considering the energy level splittings caused by SOC. SOC allows intersystem and reverse intersystem crossing by mixing the spin states, ultimately opening various chemical reaction pathways which were spin forbidden before. Current advancements in computational power enrich us to work shoulder to shoulder with experiments where one can simulate the synthesized structures containing thousands of atoms using semi-empirical methods as in DFTB, GFN-XTB. These methods so far considered SOC effects but only as case studies in testing the implementation of SOC Hamiltonian rather than a systemic extension of SOC parameters to most part of the periodic table and studying SOC effects for different categories of materials and molecules. Thi

Während der Tumorprogression unterliegen Zellen und Gewebe mechanischen Veränderungen. Mittels Magnetresonanz-Elastographie (MRE) kann die Mechanik von Geweben in vivo untersucht werden. In der Klinik wird diese Technik jedoch bisher hauptsächlich als zusätzlicher Bildkontrast verwendet, wobei eine Verknüpfung mit der zugrunde liegenden Physik des Krebses bisher weitgehend fehlt. In meiner Arbeit skizziere ich einen in vivo Tumor-Marker, der auf biophysikalische Parametern beruht. Dazu liefere ich eine breite experimentelle Basis, die von der mechanischen Charakterisierung von Kollagen als Hauptbestandteil der extrazellulären Matrix bis zum Tracking lebender Zellen und ex vivo MRE in vitalen menschlichen Tumorexplantaten reicht. Eine anschließende Analyse der mechanischen Fingerabdrücke von Tumoren in vivo zeigt robuste Trends. Diese werden durch ein Gedankenexperiment zu den grundlegenden mechanischen Voraussetzungen für das Tumorwachstum weiter erläutert. Darauf aufbauend leite ich ein auf biophysikalischen Parametern basierendes Tumor-Klassifikationsschema ab. Abschließend fasse ich zusammen, wie tumorassoziierte Mechanismen die Mechanik von Gewebe beeinflussen, wobei ich auch emergente Effekte berücksichtige.:Contents iv List of Figures viii 1 Introduction 1 2 Background 5 2.1 Tissue architecture 5 2.1.1 The extracellular matrix 5 2.1.2 ECM in tumors 6 2.1.3 Focus: collagen 7 2.1.4 The neural ECM in the brain 9 2.1.5 Breast tissue 10 2.1.6 Cervix and uterus tissue 11 2.2 Cancer 13 2.2.1 Development and spreading 13 2.2.2 Clinical grading and staging 15 2.3 Cell mechanics 17 2.3.1 Contractility17 2.3.2 Unjamming and tissue Fluidization in cancer 19 2.4 Applied Magnetic Resonance Imaging 20 2.4.1 The necessary basics 20 2.4.2 Diffusion weighted imaging 24 2.4.3 MR Elastogprahy 25 2.5 Viscoelasticity and rheological models 28 2.5.1 Deformation and material response 28 2.5.2 Basic viscoelastic model components 30 2.5.3 Fractional element model 32 2.5.4 Kelvin-Voigt, During cancer progression, cells and tissues undergo mechanical changes. Magnetic Resonance Elastography (MRE) can probe tissue mechanics in vivo, but currently, it is predominantly used as an additional contrast mode in clinical settings and the connection to the underlying physics of cancer is mostly lacking. In my thesis, I outline a roadmap towards an in vivo tumor marker that focuses on biophysical properties. I provide a diverse experimental background, which spans from the mechanical characterization of extracellular matrix surrogates to live cell tracking and ex vivo MRE in vital human tumor explants. A subsequent analysis of the mechanical Fingerprints of tumors in vivo reveals robust trends. These trends are elucidated further through a gedankenexperiment on the fundamental mechanical prerequisites for tumor growth. I propose a biophysics-based tumor classification scheme rooted in mechanical parameters. In conclusion, I consolidate how tumorassociated mechanisms impact bulk tissue mechanics, emphasizing emergent effects.:Contents iv List of Figures viii 1 Introduction 1 2 Background 5 2.1 Tissue architecture 5 2.1.1 The extracellular matrix 5 2.1.2 ECM in tumors 6 2.1.3 Focus: collagen 7 2.1.4 The neural ECM in the brain 9 2.1.5 Breast tissue 10 2.1.6 Cervix and uterus tissue 11 2.2 Cancer 13 2.2.1 Development and spreading 13 2.2.2 Clinical grading and staging 15 2.3 Cell mechanics 17 2.3.1 Contractility17 2.3.2 Unjamming and tissue Fluidization in cancer 19 2.4 Applied Magnetic Resonance Imaging 20 2.4.1 The necessary basics 20 2.4.2 Diffusion weighted imaging 24 2.4.3 MR Elastogprahy 25 2.5 Viscoelasticity and rheological models 28 2.5.1 Deformation and material response 28 2.5.2 Basic viscoelastic model components 30 2.5.3 Fractional element model 32 2.5.4 Kelvin-Voigt model 33 2.6 Stiffness and Fluidity 34 2.6.1 Stiffness and Fluidity in clinical in vivo MRE 35 3 Materials and Methods 36 3.1 Collagen Gels 36 3.1.1 Collagen preparation 36 3.1.2 Collag

Current commercial intercalation cathodes are approaching their theoretical capacity edges, which limits further improvement of the energy density in Li-ion batteries. To overcome this limitation, Li-rich antiperovskite cathodes were developed, utilizing both cationic and anionic redox activities. This class of materials has the general formula (Li2TM)ChO, where TM and Ch represent a transition metal (Fe, Mn, Co) and chalcogen ion (S, Se), respectively. This work focuses on understanding the reaction mechanism, exploring novel approaches for optimizing the electrochemical performance, and developing a scalable synthesis method for the antiperovskite cathodes. Firstly, the effect of substituting S by Se in the solid-state synthesized (Li2Fe)SO on the structural and electrochemical performance is thoroughly investigated. The anionic substitution was found to improve the structural and thermal stabilities of (Li2Fe)SO material. The cyclic voltammetry data confirmed both the cationic (Fe) and anionic (S/Se) redox activities, with possibility of controlling the anionic redox potential through the anionic substitution. It was observed that the electrochemical performance exhibits a non-linear dependence on the degree of anionic substitution. Among the prepared (Li2Fe)S1-xSexO (x = 0.1-0.9) compositions, (Li2Fe)S0.7Se0.3O exhibited the best electrochemical performance with a specific capacity 245 mAhg-1 and good cycling stability at low current rate. Ex-situ and in-situ measurements suggested an enhanced structural stability of (Li2Fe)S0.7Se0.3O during electrochemical cycling compared to (Li2Fe)SO, which could be one of the reasons for its superior performance at low current rates. The second part of this work focuses on understanding the reaction mechanism of (Li2Fe)SeO prepared by solid-state reaction (SSR) method and exploring the impact of cationic substitution of Fe by Mn on its structural and electrochemical properties. Electrochemical investigations showed that the

Im Jahr 2026 beginnt im Rahmen der Phase-II Erweiterung der Ausbau des Large Hadron Colliders, damit dieser zukünftig mit dem bis zu 7.5-fachen seiner nominellen Luminosität betrieben werden kann. Der Beginn der Datenaufnahme für den sogenannten High-Luminosity Large Hadron Collider ist für 2029 vorgesehen. Durch die Erweiterung wird eine wesentliche Zunahme der Kollisionsrate und damit der Kollisionsdaten erwartet, welche die heutige Auffassung von Theorien jenseits des Standardmodells der Teilchenphysik verbessern wird. Zusammen mit der Steigerung interessanter Ereignisse werden jedoch auch Proton-Proton-Kollisionen mit meist niederenergetischen hadronischen Teilchen im Endzustand und damit Signalüberlappungen zunehmen. Am ATLAS-Experiment führt dies zu höheren Anforderungen an die Detektorelektronik und die Echtzeit-Datenverarbeitung. Für die Flüssig-Argon-Kalorimeter ist ein Austausch der gesamten Elektronik vorgesehen. Studien konnten zeigen, dass der Optimalfilter, der derzeit zur Energierekonstruktion eingesetzt wird, einen erheblichen Leistungsabfall verzeichnen wird. Eine zuverlässige Energieinformation ist jedoch essentiell, insbesondere auch für das Triggersystem. Im Rahmen dieser Arbeit wurden sogenannte Faltungsnetzwerke für die Rekonstruktion von Energiedepositionen in Flüssig-Argon-Kalorimeterzellen entwickelt. Da diese auf Field Programmable Gate Arrays (FPGAs) mit strengen Ressourcenbeschränkungen implementiert werden sollen, müssen diese nicht nur eine hohe Rekonstruktionsgenauigkeit zeigen, sondern auch einen geringen Ressourcenverbrauch haben. Eine Hyperparametersuche wird präsentiert, die das Bestimmen geeigneter Netzwerkarchitekturen ermöglicht. Für das Trainieren und Testen von Faltungsnetzwerken wurden Daten mit realistischen Signalszenarien anhand der AREUS-Simulationssoftware generiert. Die verschiedenartigen Signalbedingungen und Leistungsanforderungen machen eine umfassende Untersuchung des Energierekonstruktionsalgorithmus erforderlich., In 2026, the expansion of the Large Hadron Collider will begin as part of the Phase II extension so that it can be operated at up to 7.5 times its nominal luminosity in future. The start of data acquisition for the so-called High-Luminosity Large Hadron Collider is scheduled for 2029. The expansion is expected to significantly increase the collision rate and thus the collision data, which will improve the current understanding of theories beyond the standard model of particle physics. However, together with the increase in interesting events, proton-proton collisions with mostly low-energy hadronic particles in the final state and thus signal overlaps will also increase. At the ATLAS experiment, this will lead to higher demands on the detector electronics and real-time data processing. The entire electronics for the liquid argon calorimeters will be replaced. Studies have shown that the optimal filter, which is currently used for energy reconstruction, will experience a considerable drop in performance. However, reliable energy information is essential, especially for the trigger system. As part of this work, so-called convolutional networks were developed for the reconstruction of energy depositions in liquid argon calorimeter cells. Since these are to be implemented on field programmable gate arrays (FPGAs) with strict resource constraints, they must not only show a high reconstruction accuracy but also have a low resource consumption. A hyperparameter search is presented, which enables the determination of suitable network architectures. For the training and testing of convolutional networks, data with realistic signal scenarios were generated using the AREUS simulation software. The different signal conditions and performance requirements necessitate a comprehensive investigation of the energy reconstruction algorithm. The reproducibility of the training results of the convolutional networks is a further application requirement. Consequently, this thesis describ

The growing concern about climate change is pushing the global community towards greener solutions to cut down the greenhouse gases emissions. As such, producing energy from sustainable sources becomes mandatory to achieve the net zero emissions goal by 2050, as set by the United Nations. Solar panels offer the possibility to generate power from light harvesting, but it’s the use of organic materials that offers great advantages in terms of functionality and life-cycle. In particular, organic semiconductors properties such as their tunable colours, lightweight, flexibility, and semi-transparency enable the use of Organic Photovoltaics (OPV) in building façades and contribute to the realisation of Net Zero Energy Buildings (NZEB). However, the OPV scalability to terawatts of installed capacity is still non competitive with respect to its cost when compared to the conventional inorganic silicon-based technologies. One of the reasons is the lower performance achieved by the state-of-the-art OPV devices, whose active layer (the film where the light is absorbed and converted into free charges, electrons and holes, i.e. electricity) is typically composed of a blend made of an electron donor material (conjugated polymer) and a smaller compound as electron acceptor (Non-Fullerene Acceptor, NFA). A crucial factor determining the low performance of OPVs made with NFAs is related to their poor charge transport properties (e.g. low electron mobility and high recombination), which are intimately related to how these molecules are arranged in the solid film, i.e. their molecular organisation. Great progress was made in the field of organic electronics to obtain higher mobility by understanding the crystalline behaviour of organic molecules from their single crystals, and using these knowledge in the design of new compounds with the desired properties. At the beginning of this thesis project, little was known about the solid-state organisation of NFAs as very few single crystal st

Laser-plasma-based ion accelerators are becoming a versatile platform to drive different fields of applied research and life sciences, for example translational research in radiation oncology. To ensure stable accelerator performance, complete control over the ion source, i.e., the high-intensity laser-solid interaction, is required. However, idealized interaction conditions are almost impossible to reach, as the utilized high-power lasers always feature a non-negligible amount of light preceding the laser peak. This leading edge of the laser pulse usually exceeds the ionization potential of bound electrons much earlier than the arrival of the high-power laser peak and the solid-density target undergoes significant modifications even before the actual high-intensity laser-plasma interaction starts. Control over this so-called target pre-expansion is a key requirement to achieve quantitative agreement between numerical simulations and experiments of high-intensity laser-solid interactions. This thesis investigates several aspects that are relevant to improve the capability of simulations to model realistic experimental scenarios. The corresponding experiments are conducted with cryogenic hydrogen-jet targets and the DRACO-PW laser at peak intensities between 10^12 W/cm^2 and 10^21 W/cm^2 . The experimental implementation of time-resolved optical-probing diagnostics and technical innovations with respect to the technique of off-harmonic optical probing overcome the disturbances by parasitic plasma self-emission and allow for unprecedented observations of the target evolution during the laser-target interactions. The laser-induced breakdown of solids, i.e., the phase transition from the solid to the plasma state, can be considered as an heuristic starting point of high-intensity laser-solid interactions. As it is highly relevant to simulations of target pre-expansion, Chapter 3 of this thesis presents time-resolved measurements of laser-induced breakdown in laser-targe, Laser-Plasma-basierte Ionenbeschleuniger stellen einer vielseitigen Plattform für verschiedene Bereiche der angewandten Forschung und der Biowissenschaften dar, z. B. für die translationale Forschung in der Strahlentherapie. Um eine stabile Beschleunigerleistung zu gewährleisten, muss die Ionenquelle, d. h. die Wechselwirkung zwischen dem Hochintensitätslaser und einem Festkörper, vollständig kontrolliert sein. Idealisierte Wechselwirkungsbedingungen können jedoch fast nie erreicht werden, da die verwendeten Hochleistungslaser immer eine nicht zu vernachlässigende Lichtmenge vor der Spitze des Laserpulses aufweisen. Diese vorangehende Flanke des Laserpulses überschreitet Intensitäten, welche zur Ionisation gebundener Elektronen führen, in der Regel schon wesentlich eher als das die Spitze des Hochleistungslaserpulses eintrifft. Der Festkörper unterliegt deshalb noch vor der eigentlichen hochintensiven Wechselwirkung erheblichen Modifikationenen durch die vorangehende Flanke. Die Kontrolle dieser so genannten Vorexpansion ist eine wichtige Voraussetzung für die quantitative Übereinstimmung zwischen numerischen Simulationen und Experimenten von Wechselwirkungen zwischen hochintensiven Lasern und Festkörpern. Diese Arbeit untersucht mehrere Aspekte, welche für die Verbesserung von Simulationen realistischer experimenteller Szenarien relevant sind. Die entsprechenden Experimente werden mit Festkörpern aus kryogenen Wasserstoff und dem DRACO PW Laser mit Intensitäten zwischen 10^12 W/cm^2 und 10^21 W/cm^2 durchgeführt. Die experimentelle Implementierung zeitaufgelöster optischer Mikroskopie und technische Innovationen für die Technik der optischen Untersuchung abseits der Harmonischen des Lasers (off-harmonic optical probing) überwinden Störungen durch parasitäre Selbstemission des Plasmas und ermöglichen bisher unerreichte Beobachtungen der Evolution des Plasmas. Die laserinduzierte Zerstörschwelle des Festkörpers, d.h. der Phasenübergang vom

The transition-metal oxides (TMOs) are a material class host to a number of intriguing and potentially technologically useful phenomena as a result of many-body correlation effects, from superconductivity, magnetic and orbital ordering, to ferroelectricity and metal-insulator transitions. Here, materials with similar structures and seemingly equivalent electronic configuration often exhibit wildly different properties as a result of strong competition between different ground states from the many degrees of freedom, whose balance can be further tuned through the use of pressure, doping, magnetic fields or temperature. To investigate these materials, we make use of photoelectron spectroscopy (PES), probing elementary excitations possible in the material and thus providing linked information both about the ground state and possible excited states, closely related to the physical properties of a material such as its response to external fields. Angle-resolved PES (ARPES) provides additional momentum information and as a result, it is uniquely suited to investigate the character of the electronic structure of solids as it resolves the dispersion, meaningful in the independent-electron view where crystal momentum is a well-defined quantum number, but which can retain validity even in strongly correlated systems through the concept of quasiparticles. While ARPES is a well-established technique, it is rarely used in the soft X-ray regime (SX-ARPES) due to significant experimental challenges posed. However, the higher energies in SX-ARPES allow it to be significantly more bulk-sensitive, an extremely important fact since the properties of the bulk material and its surface are often extremely, or worse, subtly different. Critically, this permits measurements on single crystals of TMOs, whose surfaces may show roughness or reconstruction, for example as a result of a polar surface compensation, but whose bulk properties are well-defined in contrast to thin films which are add

In strongly correlated electron systems the intricate interplay between electronic correlation effects and the tendency to form bands leads to a wealth of fascinating physical phenomena. The theoretical description of such systems is extremely complex and cannot be tackled exactly, so that ingenious modelling based on approximations must be utilized. Experiments are of utmost importance in this regard, since they provide a way to test and verify models, or to help devise better ones. This Dissertation deals with strongly correlated uranium intermetallic systems. The interesting phases they can adopt include heavy fermion behaviour, unconventional superconductivity, hidden and multipolar order, and exotic induced magnetism. Here the hybridization between the 5f states and the conduction electrons drives the physics. The description of the 5f states is therefore of utmost importance. However, since there is no clear hierarchy of interactions like Coulomb repulsion, spin-orbit coupling, hopping and crystal-field, the modelling is difficult. This is in strong contrast to the more spatially localized 4f states of, e.g., cerium compounds. It is far from clear how to quantitatively describe the electronic structure of uranium intermetallics and whether, for example, an itinerant band approach or an impurity-type model, taking local degrees of freedom explicitly into account, would be a better starting point. In intermetallics, the situation is aggravated by the fact that the modelling lacks important pieces of information. This is not least due to the fact that understanding the formal valence, the filling of the 5f shell, and the relevant symmetries of the $5f$ electrons are experimentally demanding tasks. This Dissertation, therefore, aims at developing new methods and Ans\'atze in this direction. We use x-ray spectroscopy to investigate the electronic structure, and in particular element-specific Inelastic X-ray Scattering (IXS); resonant (RIXS) at the U M(5) edge and n

The new generation of non-linear optical devices, based on periodically-poled lithium niobate thin film platforms, aims at achieving record-high conversion efficiencies and a formerly unknown capability for integration into modern quantum optical systems. It thus not only suits the demands of high-end telecommunication applications, but also provides striking potential for further performance enhancement. However, most of these record-setting new developments lack in in-depth analysis of their domain grid structures to determine whether the key requirements for efficient non-linear optical conversion are ideally fulfilled. Established analysis techniques for the exploration of bulk lithium niobate, like Raman spectroscopy, have not been adapted for these thin film structures, because the low interaction volumes require long acquisition times. In this work, the importance of Raman spectroscopy analysis for thin film lithium niobate device optimization is demonstrated in cross-correlated co-imaging with second-harmonic imaging and piezoresponse force microscopy. Key performance indicators of quasi-phase matching are identified and specifically investigated. The experiments show that Raman spectroscopy is capable of detecting all these indicators and is unique in its ability to identify performance-inhibiting mechanical and electrical stress fields. In an attempt to establish high-speed Raman imaging on lithium niobate structures, the coherent four-wave mixing method of broadband coherent anti-Stokes Raman scattering (B-CARS) is, for the first time, systematically introduced for fundamental solid state analysis by theoretically and experimentally addressing all special implications of crystalline material systems via the model material lithium niobate, e.g. phase matching conditions, phase retrieval, and complex selection rules. It is shown that the resonant B-CARS signal can be retrieved in post-processing and allows a direct comparison with spontaneous Raman spectros

In der perkutanen Strahlentherapie wird seit einiger Zeit am sogenannten FLASH-Effekt geforscht, bei welchem sich durch die Dosisapplikation in sehr kurzer Zeit bei ultrahohen Dosisleistungen verschiedene positive Effekte zeigten. In der Qualitätssicherung sind dafür präzise Dosismessgeräte nötig. Bisher verwendete Ionisationskammern zeigen jedoch bei ultrahohen Dosisleistungen Sättigungseffekte. Als Alternative wird eine faseroptische Sonde aus Berylliumoxid untersucht. Im Berylliumoxid werden durch ionisierende Strahlung über Radiolumineszenz Photonen emittiert. Die Anzahl der Photonen ist dabei proportional zur applizierten Dosis. In Protonenfeldern zeigte sich bei vorigen Messungen mit zunehmendem Massenbremsvermögen eine Dosisunterschätzung. Dieser Effekt ist bekannt und konnte bei konventionellen Bestrahlungsmethoden erfolgreich korrigiert werden. In dieser Arbeit wurden Experimente in Protonenfeldern erhöhter Dosisleistung durchgeführt, um die Verwendung von Berylliumoxid-Sonden bei FLASH-Bestrahlung zu untersuchen. Es stellte sich heraus, dass zusätzlich zum Massenbremsvermögen die Anzahl emittierter Photonen auch durch die Dosisleistung beeinflusst wird. Das erfordert eine zusammenhängende Korrekturfunktion. Außerdem zeigte sich ein weiterer Einflussfaktor, für welchen bisher keine Korrekturfunktion gefunden werden konnte. Bei Experimenten mit Kohlenstoff-Ionen fand sich ein unerwarteter Zusammenhang zwischen der Anzahl emittierter Photonen und der applizierten Dosis, sodass bisher eine Dosisbestimmung für Kohlenstoff-Ionen nicht möglich ist.

Die Vorhersage von extremen Wetterereignissen wie Hitzewellen ist aufgrund ihrer Auswirkungen auf die Gesellschaft von großer Bedeutung. Subsaisonale Wettervorhersage (von 2 Wochen bis 2 Monaten) kann Frühwarnungen liefern, die für Pläne zur Risikoeinschränkung unerlässlich sind. Das fachübergreifende Ziel dieser Arbeit ist daher die Verbesserung der Wettervorhersage von Hitzewellen über Europoa auf subsaisonalen Zeitskala. Um dieses Ziel zu erreichen, werden zunächst die Quellen der Vorhersagbarkeit auf der subsaisonalen Skala herausarbeitet und analysiert und anschließend die Vorteile quantifiziert, die diese einzelne Prädiktoren bieten können. Im ersten Teil werden die Haupttypen von Hitzewellen über Europa anhand ihrer atmosphärischen Zirkulation definiert. Die europäischen Hitzewellen werden dazu in fünf Hitzewellentypen mit spezifischen Grosswetterlagen eingeteilt. Diese ermöglichen es wiederum, die vorhersagbare Komponente der Hitzewellenereignisse zu bestimmen: allen gemein sind starke, anhaltende antizyklonale Anomalien über der Region der Höchsttemperaturen. Anhand dieser Klassifizierung lässt sich zudem die relative Bedeutung anderer subsaisonaler Faktoren wie Bodenfeuchtigkeit und verstärkte tropische Konvektion bestimmen. Dabei hat es sich erwiesen, dass eine geringere Bodenfeuchtigkeit vor Hitzewellen nur für Hitzewellen über Südeuropa und für sehr extreme Hitzewellen von Bedeutung ist, da sie die Temperaturanomalien weiter verstärkt. Die Boreale Sommer Intrasaisonale Oszillation (BSISO) ist durch verschiedene Phasen schwacher und starker tropischer Konvektion gekennzeichnet. Die Beobachtung der Entwicklung der BSISO zeigt einen klaren Zusammenhang zwischen bestimmten aktiven Phasen der BSISO und dem Beginn russischer Hitzewellen, dass deren Überwachung zur einer besseren Vorhersagbarkeit beitragen könnte. Im zweiten Teil dieser Arbeit wird der durch die Verwendung der identifizierten Prädiktoren entstehende Vorteil quantifiziert. Dazu wird eine muster, The prediction of extreme events such as heatwaves is of high importance due to their impact on society. Subseasonal prediction (from 2 weeks to 2 months) can provide early warnings which are essential for setting up mitigation plans. Therefore, the overarching goal of this work is to improve the forecast of heatwaves at the subseasonal time scale over Europe. The approach used to tackle this goal, is to first identify and analyse the sources of predictability at the subseasonal scale, and to then quantify the benefits of each of these predictors. In the first phase, the main heatwave types over Europe are defined based on their atmospheric circulation. European heatwaves are therefore classified into five heatwave types with specific circulation patterns, allowing to determine the predictable component of heatwave events. They all have strong persistent anti-cyclonic anomalies over the region of maximum temperatures. The classification further allows to determine the relative importance of other subseasonal drivers such as soil moisture and tropical enhanced convection. Reduced soil moisture content prior to heatwaves is shown to be relevant only to heatwaves over southern Europe and for very extreme heatwaves, by further amplifying the temperature anomalies. The Boreal Summer Intraseasonal Oscillation (BSISO) is characterised by different phases of weak and strong tropical convection. Monitoring the evolution of the BSISO shows a clear link between certain active phases of the BSISO and the onset of Russian heatwaves in particular, suggesting that they could provide enhanced predictability for the onset of Russian heatwaves. In the second phase, the advantage of using the identified predictors is quantified. A pattern-based method is constructed, using the circulation patterns as predictors to infer the probability of extreme warm temperatures. Using reforecast data from the European Centre for Medium-Range Weather Forecasts (ECMWF), this method is compared to the

The photocatalytic degradation of the wastewater dye pollutant methylene blue (MB) at ZnO nanostructured porous thin films, deposited by direct current reactive magnetron sputtering on Si substrates, was studied. It was observed that over 4 photocatalytic cycles (0.3 mg · l−1 MB solution, 540 minUV irradiation), the rate constant k of MB degradation decreased by ∼50%, varying in the range (1.54 ÷ 0.78) · 10–9 (mol·l−1·min−1). For a deeper analysis of the photodegradation mechanism, detailed information on the nanostructured ZnO surface morphology and local surface and subsurface chemistry (nonstoichiometry) were obtained by using scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) as complementary analytical methods. The SEM studies revealed that at the surface of the nanostructured ZnO thin films a coral reef structure containing polycrystalline coral dendrites is present, and that, after the photocatalytic experiments, the sizes of individual crystallites increased, varying in the range 43 ÷ 76 nm for the longer axis, and in the range 28 ÷ 58 nm for the shorter axis. In turn, the XPS studies showed a slight non-stoichiometry, mainly defined by the relative [O]/[Zn] concentration of ca. 1.4, whereas [C]/[Zn] was ca. 1.2, both before and after the photocatalytic experiments. This phenomenon was directly related to the presence of superficial ZnO lattice oxygen atoms that can participate in the oxidation of the adsorbed MB molecules, as well as to the presence of surface hydroxyl groups acting as hole-acceptors to produce OH· radicals, which can be responsible for the generation of superoxide ions. In addition, after experiments, the XPS measurements revealed the presence of carboxyl and carbonyl functional groups, ascribable to the oxidation by-products formed during the photodegradation of MB.

In this thesis, the CW and pulse EPR techniques are employed to understand several information, such as the local and electronic structure and magnetic interactions of metal ions in metalorganic frameworks as well as the guest-host framework interaction upon gas adsorption. Other characterization techniques, such as PXRD, SQUID, and quantum chemical calculation, are also outlined, which are complementary to the information provided by EPR. In situ EPR studies give valuable details on structural transition, which can’t be attained by other techniques always. EPR spectroscopy confirms that post-synthetic modification is possible in paddle wheel-based MOFs through the magnetic coupling of metal centers and also gives information about magnetic mixed paddle wheel units, which is often complicated to understand. The quite challenging divalent nickel-based MOF is studied along with NO adsorption, and the result highlights the capabilities of sophisticated EPR techniques in combination with quantum chemical calculations to provide fundamental insights into the non-obvious electronic structure of open-shell species docked in metal-organic frameworks. Finally, the inter- and intra-trimer interactions of high-spin chromium-based trimers are discussed in detail in combination with SQUID magnetometry.

In Part I of this thesis we examine solitons – local, non-dissipative excitations – in the dynamics of spin systems. We open, in Ch. 1, with a short account of the history of solitons, from their first observation, to the theories of shallow water and the Korteweg-De Vries model; their appearance in field theories like the sine-Gordon model; to the general description of integrable systems, such as the Toda lattice. We pay particular attention, of course, to solitons in spin models – especially those obtained by Ishimori in an integrable classical spin chain which bears his name. In Ch. 2 we present our work which establishes the existence of solitons in non-integrable spin chains. We begin by constructing exact static solitons in the Heisenberg chain, which we connect to the static Ishimori solitons via an adiabatic interpolation. We then use this adiabatic transform to construct moving Heisenberg solitons, which show no sign of having a finite lifetime. We further show that the interactions of these solitons are remarkably similar to the integrable case, and we establish their presence in low temperature thermal states – which will have important consequences in Part II. Ch. 3 considers a different set-up, where we study the dynamics of domain walls in anisotropic spin chains. Our work shows a striking co-existence of linear and non-linear phenomena – to wit, we show that the free propagation and subdiffusive spreading of domain walls can be captured by non-interacting, linear spin wave theory; but that these domain walls are unstable to decay via the emission of topological solitons. In Part II we will show how the solitons we have discovered play a hydrodynamic role, and find that superdiffusion, far from being limited to the special cases where the model is integrable, may be observed in non-integrable spin chains for (arbitrarily) long times, at low – but non-zero – temperatures. We will, however, preface this with a review of the literature on superdiffusion

The DNA origami method was established by Paul Rothemund in 2009. It allows to produce self-assembling 2D nanostructures with precise geometry and tunable mechanical properties that can be equipped with a broad range of functionalizations. It was extended to 3D by the group of William Shih in 2009 which also presented caDNAno, a software that made the design of nanostructures easier and more accessible. Since then, DNA origami nanostructures were utilized in a broad range of applications, which enabled unprecedented insight into mechanisms and processes of biological systems at the nanoscale. In this thesis multiple nanostructures were designed and manufactured to perform studies at the single-molecule level, which yielded a number of scientifically relevant contributions in the fields of biophysics and nanotechnology. Development of DNA origami nanostructures to mimic the properties and function of membrane proteins As a first application, DNA origami nanostructures with defined geometric and mechanical properties were designed, that mimic the behaviour and function of membrane proteins. To this end, rod-shaped nanostructures were equipped with precisely placed, lipid-integrating cholesterol modifications as well as fluorescent dyes. Subsequently their interaction with lipid membranes was studied. It was found that the prepared nanostructures specifically bound to lipid membranes and could diffuse on their surface, for which the rotational and translational diffusion coefficients were determined. The presence of magnesium thereby promoted the nanostructures to migrate into specific lipid domains in a reversible, switchable manner. Furthermore, their high aspect ratio allowed to investigate crowding effects, which are considered important mechanisms for the self-organisation of membrane proteins. In addition, block-shaped DNA origami nanostructures that organized into micrometre-sized super-structures were designed and produced. They were capable of deforming lipid, Die DNA Origami Methode wurde im Jahr 2006 durch Paul Rothemund begründet. Sie erlaubt es selbst-assemblierende 2D Nanostrukturen mit präzisen Geometrien und kalibrierbaren mechanischen Eigenschaften zu erstellen, die zudem mit einer Vielzahl an Funktionalisierungen ausgestattet werden können. Die Methode wurde 2009 in der Gruppe von William Shih auf 3D Nanostrukturen erweitert, wobei zudem caDNAno präsentiert wurde, eine Software die die Erstellung solcher Nanostrukturen wesentlich einfacher und zugänglicher machte. Seitdem wurden DNA Origami Nanostrukturen in vielfältigen Anwendungen genutzt, die nie dagewesene Einblicke in Mechanismen und Prozesse von biologischen Systemen auf der Nanoskala erlaubten. In dieser Arbeit wird anhand mehrerer Beispiele gezeigt, wie solche Nanostrukturen genutzt werden können, um Studien auf der Einzelmolekül-Ebene durchzuführen. Entwicklung von DNA Origami Nanostrukturen, welche die Eigenschaften und Funktionen von Membranproteinen imitieren In einer ersten Anwendung wurden DNA Origami Nanostrukturen mit definierten geometrischen und mechanischen Eigenschaften entworfen, welche das Verhalten und die Funktion von Membranproteinen nachahmten. Dazu wurden stabförmige Nanostrukturen mit präzise platzierten, lipidintegrierenden Cholesterinmodifikationen und fluoreszierenden Farbstoffen ausgestattet. Anschließend wurde ihre Interaktion mit Lipidmembranen untersucht. Es zeigte sich, dass die Nanostrukturen spezifisch an Lipidmembranen binden und auf deren Oberfläche diffundieren konnten. Hierbei wurden die Diffusionskoeffizienten der Rotations- und Translationsbewegungen bestimmt. Zudem bewirkte die An- oder Abwesenheit freier Magnesiumionen die steuerbare und reversible Anreicherung in verschiedenen Lipiddomänen. Die längliche Form der Nanostrukturen erlaubte es zudem, Verdrängungseffekte zu untersuchen, die als wichtiger Mechanismus für die Selbstorganisation von Membranproteinen gelten. Des weiteren wurden blockartige, multimerisierende

This thesis compiles the publications I coauthored during my doctoral studies at University of Leipzig on the subject of optimizing thermodynamic systems, focusing on three optimization perspectives: maximum efficiency, maximum power, and maximum efficiency at given power. We considered two currently intensely studied models in finite-time thermodynamics, i.e., low-dissipation models and Brownian systems. The low-dissipation model is used to derive general bounds on the performance of real-world machines, while Brownian systems allow us to better understand the practical limits and features of small systems. First, we derived maximum efficiency at given power for various low-dissipation setups, with a particular focus on the behavior close to maximum power, which helps us to determine whether it is more beneficial to operate the system at maximum power, near maximum power or in a different regime. Then, we move to the design of maximum-efficiency and maximum-power protocols for Brownian systems under different boundary conditions. Particularly, when the constraints on control parameters are experimentally motivated, we presented a geometric method yielding maximum-efficiency and maximum-power protocols valid for systems with periodically scaled energy spectrum and otherwise arbitrary dynamics. Each chapter contains a short informal introduction to the matter as well as an outlook, pointing out the direction for our research in the future.

Wetland sites provide important knowledge about settlement history and historical infrastructure in the form of buried archaeological features. However, the subsurface is difficult to access, e.g. due to high groundwater levels or unstable sediments, making archaeological excavation difficult and the conservation of recovered artefacts, e.g. timbers, is expensive. In addition, one of the aims of heritage conservation is to disturb structures in such contexts as little as possible as part of preserving. Therefore, alternative non- and minimal-invasive methods, e.g. geophysical prospection and vibra-coring, are used for exploration. However, geophysical surveys face the issue of inaccurate depth values and rely on sufficient contrasts in the measured physical parameters. Vibra-coring allows direct access to the sediments, but again gives inaccurate depth values due to high compaction rates. For this reason, the implementation of alternative methods and the development of new methodical approaches to wetland site exploration are of extraordinary importance. One such wetland site is the Fossa Carolina, an early medieval canal that today is partially buried. Located in Southern Germany next to Treuchtlingen, south of Nuremberg, the canal was intended at the time to provide a navigable link between the Rhine-Main and Danube basins by bridging the European watershed. In the research for this thesis, direct push sensing was used as an alternative exploration technique to explore the site. In this method, various probes are pushed into the unconsolidated subsoil and the parameters are measured in situ with high depth accuracy. (i) Therefore, the colour logging tool (CLT) and the electrical conductivity (EC) probe were applied. (ii) In order to record archaeological structures and features, the soundings were distributed closely along a transect using an adaptive exploration strategy, thus recording a high-resolution cross-section of the structure. (iii) These prospections we, Feuchtgebiete bergen durch begrabene archäologische Strukturen wichtige Erkenntnisse zur Siedlungsgeschichte und historischen Infrastruktur. Schwierige Untergrundverhältnisse, z. B. durch hohen Grundwasserspiegel oder instabile Sedimente, erschweren jedoch archäologische Ausgrabungen und die Konservierung der geborgenen Artefakte, z. B. Hölzer, verursacht hohe Kosten. Darüber hinaus ist ein Ziel der Bodendenkmalpflege, archäologische Strukturen so wenig wie möglich zu beeinträchtigen und sie in situ zu erhalten. Daher werden alternative nicht- und minimal-invasive Methoden, z. B. geophysikalische Prospektionen und Rammkernsondierungen, zur Exploration eingesetzt. Bei geophysikalischen Untersuchungen ergeben sich jedoch Schwierigkeiten durch ungenaue Tiefenwerte und die Methoden sind auf ausreichende Kontraste der gemessenen physikalischen Parameter angewiesen. Rammkernsondierungen ermöglichen einen direkten Zugriff auf die Sedimente, erzeugen jedoch wiederum ungenaue Tiefenwerte durch hohe Kompaktionsraten. Aus diesem Grund sind die Implementierung alternativer Methoden und die Entwicklung neuer methodischer Ansätze für die Erforschung von Feuchtgebietsstandorten von herausragender Bedeutung. Die Fossa Carolina, ein frühmittelalterlicher, heute teilweise verschütteter Kanal, ist ein solcher Standort. Das Bauwerk befindet sich in Süddeutschland in der Nähe von Treuchtlingen, südlich von Nürnberg und sollte eine schiffbare Verbindung zwischen dem Rhein-Main- und dem Donaueinzugsgebiet herstellen, indem es die europäische Hauptwasserscheide überbrückte. Zur Erkundung des Bauwerks wurde als Alternative die in situ Direct-Push-Methode eingesetzt. Bei dieser Methode werden verschiedene Sonden in den unkonsolidierten Untergrund gedrückt und die Parameter in situ tiefengenau gemessen. (i) Dabei kamen die Farbsonde, engl. colour logging tool (CLT), und die Sonde zur Messung der elektrischen Leitfähigkeit, engl. electrical conductivity (EC) probe, zum Einsatz. (ii) Zur Erfass

Dust aerosol emission is a critical topic in agriculture, occurring either by aeolian process from bare or sparsely vegetated cropland or as fugitive emission during tilling, harvest and many other farming activities. Aerosols, which are in the case of agriculture either mineral dust, organic particles or a mixture, are known for impacting human health, cloud formation and ultimately, the earth’s climate and ecosystem. Coupled atmosphere and aerosol transport models are commonly used to study aerosol dispersion in the atmosphere, but so far, agricultural sources are under-represented. Hence, estimations of these emissions’ actual impact are still somewhat uncertain regarding their seasonality, spatial distribution and the fraction of the global aerosol load. To fill this gap, this study aims at identifying suitable approaches for modelling aeolian emissions from sparsely vegetated cropland and fugitive emissions from tilling. Fugitive emissions are challenging since they mainly depend on human activity that is not predictable, but observed events can be used as case studies. For this, a Lagrangian particle dispersion model was chosen, which can trace the trajectory of individual particles in the emitted dust plume. So the particle model “Itpas” was developed to tackle fugitive emissions and to be capable of simulating the complex turbulent mixing of dust particles inside the atmospheric boundary layer. This model was used to simulate a case study based on measured tilling emissions, showing the particle dispersion for a stable and unstable stratified boundary layer. It was shown that within a stably stratified boundary layer, the dust plume is restricted to the near-source region. In contrast, emissions in unstable boundary layers go into long-range transport. This illustrates the spatial range a single tillage operation can have an impact. Aeolian dust emissions are controlled by the wind. For cropland, the emission variability is caused mainly by the frequently ch

Spider silk is one of the most fascinating materials found in nature. Besides its properties like biodegradability, low immunoreactivity, and biocompatibility, especially the mechanical properties outperforming today’s artificial high-tech materials like Kevlar® are of great interest in biomedicine or material science. Spider silk comprises highly repetitive amino acid sequence motives, whose structure is accepted to be responsible for the extraordinary properties of spider silk. Typically, hydrophilic sequence motives alternate with hydrophobic ones making spider silk proteins resemble block copolymers. Additionally, the simple amino acid sequence and the possibility to form fibrillar structures are common characteristics of spider silk proteins as well as intrinsically disordered proteins (IDP) or protein regions (IDR). Both are suspected of being involved in the development of certain neurodegenerative diseases like Alzheimer´s disease. These aspects open promising possibilities of the use of spider silk proteins in nanotechnology, but also as model systems for the fibrillization processes of IDPs and IDRs, which are still unresolved today. Currently, most of the research and application is focused on 1-dimensional spider silk protein fibrils and fibers or 0-dimensional spider silk particles. However, 2-dimensional spider silk protein films or porous 3-dimensional objects are highly relevant platforms with the potential for cell-supporting scaffolds, biodegradable electrolyte materials in transistors, or e.g., planar drug-eluting implant coatings. Generally, the effects of sequence-based and external influences on the self-assembly and folding of spider silk proteins have not yet been fully elucidated in all of these various dimensional spider silk materials, even concerning IDP and IDR models. Thus, basic research regarding assembly and folding processes is still needed, especially in films. Particularly, 2-dimensional films allow a broad spectrum of (surface) a

The study of topological phases in condensed matter physics has seen remarkable advancements, primarily focusing on systems with a well-defined bulk and boundary. However, the emergence of topological phenomena on self-similar systems, characterized by the absence of a clear distinction between bulk and boundary, presents a fascinating challenge. This thesis focuses on the topological phases on self-similar systems, shedding light on their unique properties through the lens of adiabatic charge pumping. We observe that the spectral flow in these systems exhibits striking qualitative distinctions from that of translationally invariant non-interacting systems subjected to a perpendicular magnetic field. We show that the instantaneous eigenspectra can be used to understand the quantization of the charge pumped over a cycle, and hence to understand the topological character of the system. Furthermore, we establish a correspondence between the local contributions to the Hall conductivity and the spectral flow of edge-like states. We also find that the edge-like states can be approximated as eigenstates of the discrete angular-momentum operator, with their chiral characteristics stemming from this unique perspective. We also investigate the effect of local structure on the topological phases on self-similar structures embedded in two dimensions. We study a geometry dependent model on two self-similar structures having different coordination numbers, constructed from the Sierpinski gasket. For different non-spatial symmetries present in the system, we numerically study and compare the phases on both structures. We characterize these phases by the localization properties of the single-particle states, their robustness to disorder, and by using a real-space topological index. We find that both structures host topologically nontrivial phases and the phase diagrams are different on the two structures, emphasizing the interplay between non-spatial symmetries and the local struct

Die fortlaufenden Veränderungen von Landnutzung und Landschaftsstruktur in Europa und weltweit beeinflussen zunehmend die Fähigkeit der Landschaft, Ökosystemleistungen (Versorgungs-, Regulierungs- und kulturelle Leistungen) bereitzustellen, und führen zum Verlust historisch gewachsener Kulturlandschaften. Dabei haben Geschwindigkeit und Intensität dieser Veränderungsprozesse seit den 1960er Jahren deutlich zugenommen und die Verfügbarkeit und Qualität von Ökosystemleistungen signifikant verändert. In den in dieser Arbeit untersuchten Agrarräumen hat sich zum Beispiel das Erosionsrisiko (im Sinne eines Verlustes an natürlichem Erosionsschutz als Indikator für Regulierungsleistung) durch die Ausräumung der Landschaft und Bildung großflächiger Agrarflächen wesentlich erhöht und das natürliche Ertragspotential (Indikator für Versorgungsleistung) wurde durch zunehmende Bodendegradation gemindert. Das Risiko von Biodiversitätsabnahme (Indikator für kulturelle Leistung) ist durch Habitatverlust und zunehmender Homogenisierung der Standorte sowie durch veränderte Bewirtschaftungspraktiken (Technisierung und Chemisierung) stark angestiegen. Dabei kommt der Biodiversität eine Schlüsselrolle bei der Nahrungsmittelproduktion, bei Nährstoff- und Wasserkreisläufen oder dem Erosionsschutz sowie der Gesundheitsfürsorge (z. B. Erholung) zu. Andererseits konnten durch Meliorationsmaßnahmen und unter Einsatz neuer Bewirtschaftungspraktiken die Getreideerträge (Indikator für Versorgungsleistung) seit Beginn des 20. Jahrhunderts verdoppelt werden. Zielsetzung der vorliegenden Arbeit ist es, anhand von zwei ausgewählten Untersuchungsgebieten räumlich explizit und quantitativ Veränderungen in der Landnutzung und der Landschaftsstruktur und die Auswirkungen dieser Veränderungen auf ausgewählte bodenbezogene Ökosystemleistungen für den Zeitraum von 1750 bis 2018 zu analysieren. Damit soll ein Beitrag geleistet werden, historische und heutige Landnutzungsänderungen im Kontext gesellschaftspo, Ongoing changes in land use and landscape structure in Europe and worldwide are increasingly affecting the ability of the landscape to provide ecosystem services (provisioning, regulation and cultural services). Furthermore, they lead to the loss of historically cultural landscapes. In the process, the speed and intensity of these change processes have increased markedly since the 1960s and significantly affecting the availability and quality of ecosystem services. In the agricultural areas studied in this paper, for example, the risk of erosion (indicator of regulating service) has increased substantially due to the clearing of the countryside and formation of large-scale agricultural areas, and the natural yield potential (indicators of provisioning service) has been reduced by increasing soil degradation. The risk of biodiversity (indicator of cultural service) decline has greatly increased due to habitat loss and increasing homogenisation of sites, and changes in farming practices (mechanisation and chemicalisation). In this context, biodiversity plays a key role in food production, nutrient and water cycles or erosion control, as well as health care (e.g. recreation). On the other hand, improvement measures and the use of new farming practices have doubled cereal yields (indicators of provisioning service) since the beginning of the 20th century. The objective of this paper is to spatially and quantitatively analyse changes in land use and landscape structure and the effects of these changes on selected soil-related ecosystem services for the period from 1750 to 2018, using two selected study areas. The aim is to contribute to understanding historical and present-day land use changes in the context of socio-political and economic framework conditions and to evaluate them with regard to their effects on sustainable land use, on the conservation of biodiversity, and on the prevention of landscape and soil degradation, and to be able to derive respective recommend

Although Joule’s experiment on the mechanical equivalent of heat is well known and discussed in many introductory physics courses and textbooks, we are not aware of any version of this experiment that can be set up by lecturers or teachers using standard laboratory equipment. To fill this gap, we present a setup quite similar to Joule’s original experiment and show what kind of quantitative results can be obtained with it. It will be shown that temperature control is a major challenge, making Joule’s work even more impressive., Peer Reviewed

In this lab activity, carbon copy paper is used to record the horizontal distance a marble flies off a table after rolling down an incline. The minimal scatter of the dots visually shows the high precision—i.e. the small uncertainty—of the measurements to students. The theoretical prediction of this distance will be too big if students forget to include rotational energy in the energy balance when they calculate the marble’s speed at the bottom of the incline. This results in a discrepancy between the predicted horizontal distance and the measurement result. The precision of the experiment and the absence of overlap with the theoretical prediction is evidence that the prediction has to be wrong. Including rotational energy and taking a 10% energy loss due to friction into account, makes the measurement result overlap with the theoretical prediction, bringing them into agreement. Thus, measurement uncertainties guide the process of comparing the measurement result with the prediction: overlap between the theory-based prediction and the measurement result indicates agreement, whereas no overlap implies discrepancy. The lab activity presented here is an activity where measurement uncertainties are used in a meaningful, indispensable manner. The experimental result is evidence that forces students to rethink their assumptions, in this case about the conservation of energy. This leads to the revision of their calculation, emphasizing the necessity to include rotational energy and friction. Without it, the highly precise measurement result is in disagreement with the theoretical prediction. A procedure such as this—comparing empirical data with theory—is an authentic and common practice in science and should thus find its way into the physics classroom; but it cannot be done without an analysis of measurement uncertainties., Peer Reviewed

A recent stochastic pursuit model describes a pack of chasers (hounds) that actively move toward a target (hare) that undergoes pure Brownian diffusion (Bernardi and Lindner 2022 Phys. Rev. Lett. 128 040601). Here, this model is extended by introducing a deterministic ‘escape term’, which depends on the hounds’ positions. In other words, the hare can ‘see’ the approaching hounds and run away from them, in addition to the ‘blind’ random diffusion. In the case of a single chaser, the mean capture time (CT) can still be computed analytically. At weak noise, the qualitative behavior of the system depends on whether the hare’s maximum running drift speed is above or below a critical value (the pursuers’ speed), but not on the target’s viewing range, whereas the capture statistics at strong noise is similar to those of the original model without escape term. When multiple hounds are present, the behavior of the system is surprisingly similar to the original model with purely diffusing target, because the escape terms tend to compensate each other if the prey is encircled. At weak noise levels and ‘supracritical’ maximum escape speed, the hare can slip through the chaser pack and lead to a very strong increase of the mean CT with respect to the blind case. This large difference is due to rare events, which are enhanced when the symmetry in the initial conditions is disrupted by some randomness. Comparing the median of the CT probability density (which reflects the typical CT) with the mean CT makes clear the contribution of rare events with exceptionally long CTs., Peer Reviewed

Die Pfadintegral-Quantisierung der semi-klassischen Gravitation ist einer der vielversprechendsten Ansätze zur Vereinheitlichung von Quantenmechanik und allgemeiner Relativitätstheorie. In dieser Arbeit untersuchen wir die Konsequenzen der Anwendung dieses Pfadintegralansatzes auf die Kosmologie des sehr frühen Universums. Im ersten Teil konzentrieren wir uns auf den no-boundary proposal, der einen nicht-singulären Anfang des Universums konstruiert, indem er sich auf das gravitative Pfadintegral der allgemeinen Relativitätstheorie stützt. Wir beweisen, dass die no-boundary Lösung das Hinzufügen von Korrekturen höherer Ordnung zur Gravitationswirkung überlebt. Unsere Analyse deutet also darauf hin, dass semi-klassische Ergebnisse auch in der perturbative Störungstheorie der vollständigen Quantengravitation gültig sind. Anschließend beziehen wir ein Skalarfeld in den neuen no-boundary proposal ein, der im Lorentz-Formalismus als Summe über Geometrien mit festem Anfangsimpuls definiert ist. Unsere Ergebnisse sind der Schlüssel zur Bestätigung der Gültigkeit des neuen no-boundary proposals, denn Skalarfelder sind das einfachste Beispiel für Materiefelder, die in einer realistischen Theorie des frühen Universums enthalten sein müssen. Der zweite Teil der Arbeit befasst sich mit der Pfadintegralansatz für allgemeineren Modellen des frühen Universums. Zunächst testen wir die Gültigkeit des semi-klassischen Limits dieser Modelle mit dem Kriterium der endlichen Amplitude, das z.B. Theorien höherer Ordnung der Gravitation stark einschränkt und den no-boundary proposal sowie emergente Universen begünstigt. Schließlich wenden wir das Kriterium der komplexen Metrik von Kontsevich und Segal auf kosmologische Hintergründe an. Im Kontext der Quantenkosmologie angewandt, führt es zu einem neuen Verständnis des gravitativen Pfadintegrals im no-boundary proposal und schließt generische quantum bounces aus., The path integral quantization of gravity is one of the most promising approaches to unify quantum mechanics and general relativity. This thesis pursues the consequences of the path integral approach applied to the cosmology of the very early universe, for which this unification is crucial. The first part focuses on the no-boundary proposal, which constructs a non-singular beginning of the universe by relying on the gravitational path integral of general relativity. We prove that the no-boundary solution survives the addition of higher-order corrections to the gravity action, usually found in high-energy completions of general relativity such as string theory. This indicates that semi-classical results may still hold at the perturbative level of full quantum gravity. We then include a scalar field in the new no-boundary proposal, defined in the Lorentzian formalism as a sum over geometries with fixed initial momentum flow. Our results are key to confirming the viability of the proposal, but also highlight the non-locality puzzle of the no-boundary proposal in the presence of matter fields, for which we offer new perspectives. The second part of the thesis deals with the path integral treatment of more general early universe models. First we test the validity of the semi-classical limit of these models with a finite amplitude criterion, which severely constrains e.g. higher-order theories of gravity and globally favors the no-boundary proposal and emergent-like universes. At last, we apply Kontsevich and Segal’s complex metric criterion to cosmological backgrounds. This criterion tests the path integral convergence of any quantum field theory on a given metric background. Applied in the context of quantum cosmology, it leads to a new understanding of the path integral in the no-boundary proposal, rules out generic quantum bounces, and stresses the limitation of minisuperspace for classical transitions in de Sitter spacetime.

Narrow conduction channels are fabricated from an In0.75Ga0.25As-InP heterostructure using electron-beam lithography and dry etching. The etched surface is realized to be smooth by employing a reactive ion etching. The etching-induced surface conduction is eliminated by removing the damaged surface layer using a diluted HCl solution. The negligible surface depletion for the In-rich quantum well enables to create conducting channels in arbitrary geometries such as in a circular shape. We evidence the presence of a ballistic contribution in the electron transport by demonstrating a rectification of rf excitations that is achieved by the magnetic-field-tuned transmission asymmetry in the circularly-shaped channels. The absence of the surface depletion is shown to cause, on the other hand, a surface scattering for the electrons confined in the channels. An increase of the resistance, including its anomalous enhancement at low temperatures, is induced by the gas molecules attached to the sidewalls of the channels. We also report a large persistent photoconduction, which occurs as a parallel conduction in the undoped InP barrier layer., Peer Reviewed