Die Nachahmung natürlichen Kollagens stellt aufgrund dessen einzigartiger Struktur erhöhte Anforderungen an die chemische und biochemische Synthese artifizieller kollagenartiger Peptide. In dieser Arbeit wurden Cystein-Knoten und Organo-Template als Konzepte zur Vororganisation vorgestellt, um Peptideinzelstränge in die Anordnung kollagenartiger Dreifachhelices (CTH) zu dirigieren. Zusätzlich wurden diese mit einem schaltbaren DEPSI Struktursegment zur Steuerung der Helixstruktur kombiniert. Die templatbasierte Strategie beruht auf einem dreiarmigen Gerüstmolekül, an welches drei Peptideinzelstränge mittels nativer chemischer Ligation geknüpft werden. Für das Cystein-Knoten-Konzept wurden kollagen-mimetische Peptide entwickelt. Diese bestehen aus einer Cystein-reichen Domäne (wc2-Domäne) und einem Abschnitt, der eine kollagenartige Sequenz von [Gly-Pro-Pro]x aufweist. Die Vororganisation, als auch der Schalterdefekt zeigten maßgebliche Auswirkungen bezüglich der Adaption der Peptide in kollagenartige Dreifachhelices. Abhängig von der Position modulieren die Schalterdefekte die wc2-Organisation, die Nukleierung und den CTH-Faltungsprozess. Die Cystein-Organisationsdomäne wies den Vorteil auf, dass derartige Sequenzen ohne chemische Modifikation direkt im biotechnologischen Prozess in Unimere eingebracht werden konnten. Eine E. coli-basierte Produktionsstrategie ermöglichte den Zugang zu [GPP]50-Konstrukten, die ebenfalls die wc2-Domäne trugen. Weitere Untersuchungen wiesen zudem eine redox-reaktive Schaltbarkeit der Peptide nach. Um die Verwendbarkeit der synthetischen Kollagene als Biomaterial zu testen, wurde die Kompatibilität in zweidimensionalen Adhäsions- und Zytotoxizitätstests überprüft. / Due to its unique structure, the imitation of natural collagen increased the demands on the chemical and biochemical synthesis of artificial collagen mimetic peptides (CMPs). In this thesis, concepts of cysteine knots and organo-templates were presented for the reorganization of peptide single strands into the arrangement of collagenous triple helices (CTHs). These techniques were additionally combined with a switchable DEPSI structure segment to further control the helix structure. The template-based strategy relies on a three-armed scaffold to which three peptide strands are attached by native chemical ligation. For the cysteine-knot concept, collagen mimetic peptides consisting of a cysteine-rich domain (wc2-domain) and a domain with a collagen-like sequence of [Gly-Pro-Pro]x were developed. The preorganization, as well as the switch defect, showed significant effects on the adaptation of the peptides in collagenous triple helices. Depending on the position, the switch defects modulate wc2-organization, nucleation and the CTH folding process. This cysteine organization domain had the advantage that such sequences could be introduced into unimers directly in the biotechnological process without chemical modification. An E. coli-based production strategy allowed access to [GPP]50 constructs, which also carried the wc2-domain. Further investigations also showed a redox-reactive switchability of the peptides. To examine the utility of the synthetic collagen as a biomaterial, compatibility was tested in two-dimensional adhesion and cytotoxicity tests.

This thesis discusses the mesoscopic physics of two examples for soft condensed matter: (i) aeolian sand transport and the ensuing structure formation and (ii) solutions of stiff biopolymers. It emphasizes the impact of a heterogeneous mesoscale structure on the macroscopic phenomenology. For the aeolian sand transport, we start with a coarse-grained description of the collisions between mobile grains and the sand bed. Combining the collision geometry with basic physical principles, like momentum and energy conservation, we derive the full splash statistics as a function of impact velocity and impactor--bed grain-size ratio. This serves as a starting point for attacking the complicated transport statistics of wind-blown sand. Two approaches are proposed: first, a two-species approximation that distinguishes between high-energy rebounding grains and low-energy bed ejecta, second, a statistical description that resolves the full distribution of grain trajectories. While the former provides an ideal framework to accurately predict macroscopic averages, the latter resolves the heterogeneous mesoscale structure of the transport layer. Both approaches are shown to be in excellent agreement with various laboratory and field data. We moreover establish a new perspective on the transport's saturation transients that illustrates the crucial influence of the intermittent turbulent wind fluctuations in the field, thereby resolving a long-standing debate. Eventually, we address the formation of megaripples, an aeolian bedform that is made from strongly polydisperse sand. Combining our proposed theory with long-term field measurements, we clarify the importance of wind-driven sand sorting and, again, intermittent turbulent fluctuations. Our approach suggests to describe the megaripples as down-scaled dunes, as indeed support by various field data for their morphology and migration. In the second part of the thesis, we consider the mesoscale structure and its influence on the viscoelastic response of entangled biopolymer solutions. Their mechanics is determined by the topological entanglements of the filamentous polymers that cannot pass through each other. The tube model for semiflexible polymers represents this effect on a mean-field level, where test filament is confined to a tube-like cage formed by surrounding polymers. We employ it to investigate the solution's mesoscale packing structure and its change under finite shear deformations. Comparing our predictions with systematic computer simulations and experiments, we find the tube deformations to relax quickly after the deformation, while tube alignment and hairpin conformations are found to be long lived. In a second step, we propose a new perspective on the entangled solution's dynamics. Accounting for the nonaffine response at the level of the test filament, and assuming sticky or frictional polymer contacts, we argue that soft bending deformations of the filaments can couple to stiff axial stretching modes. This allows us to explain various experimentally observed similarities of the entangled solutions to crosslinked networks, like the increasing elastic modulus with increasing length and bending rigidity of the filaments or the softening--stiffening transition as a function of polymer concentration, polymer length, deformation rate, and various solvent properties.:I Aeolian sand transport and megaripple formation 1 Introduction 2 The splash process 3 Aeolian sand transport 4 Structure formation 5 Outlook Bibliography II Solutions of stiff biopolymers 6 Introduction 7 Entangled solutions 8 Viscoelastic response Appendix Bibliography Acknowledgments

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The self-gravitating systems are formed by particles interacting through gravity. They describe structure formation in the universe. As a consequence of the long range interaction of gravity, they are inhomogeneous even at thermal equilibrium. We study the self-gravitating systems with several kinds of particles and the self-gravitating systems in the presence of the cosmological constant $ Lambda$. We formulate the statistical mechanics and the mean field approach describing the gaseous phase. We explicitely compute the density of particles and thermodynamic quantities. The presence of $ Lambda$ extends the domain of stability of the gaseous phase. Monte Carlo simulations show that the mean field describes the gaseous phase with an excellent accuracy. Scalling law of the self-gravitating systems with several kinds of particles is found. At the critical point the fractal dimension is independant of their composition and is $1.6...$~.

Die vorliegende Arbeit konzentriert sich auf die Entwicklung und Validierung eines reaktiven Kraftfelds (ReaxFF) für die Strukturbildungsprozesse der Zwillingspolymerisation (ZP). Die ZP ist eine neue Synthesemethode zur Herstellung nanostrukturierter Hybridmaterialien, wie beispielsweise nanostrukturierter Kohlenstoffe als Gasspeichermedium. Die ZP beruht dabei auf der Verwendung geeigneter Zwillingsmonomere, die kovalent gebundene organische und anorganische Strukturkomponenten aufweisen. Innerhalb der Polymerisation werden die Komponenten neu verknüpft, sodass mehrere ineinander verwobene Teilpolymere - zum Beispiel Phenolharz und Siliziumdioxid - als organisch-anorganische Mischung entstehen. Die Nanostrukturierung innerhalb des Prozesses liegt dabei an dem gekoppelten Wachstum durch die anfängliche kovalente Bindung im Zwillingsmonomer. Ein Überblick über die chemischen Details wird im zweiten Kapitel gegeben. Weiterhin werden für die Modellbildung genutzte reduzierte Testsysteme vorgestellt. Basierend auf dieser komplexen Strukturbildung wird im dritten Kapitel die gewählte Modellierungsmethode der reaktiven Molekulardynamik mit dem Kraftfeld ReaxFF vorgestellt. Für die Modellierung mit ReaxFF werden Referenzdaten benötigt um einen Parametersatz für das Kraftfeld zu entwickeln, welcher das chemische Modell darstellen kann. Dazu wird im vierten Kapitel eine Übersicht über die benutzten Methoden zur Referenzdatenerzeugung gegeben. Im fünften Kapitel fokussiert sich die Arbeit auf die anfänglich als Referenz zur Verfügung gestellte Theorie und ihre Erweiterung zur Unterstützung der Kraftfeldmodellierung. Ausgehend von den erhaltenen Referenzdaten werden die Kraftfeldresultate für die erste Parametrisierung (TP-a) vorgestellt. Diese zeigte eine ungünstige Mittelung aus aromatischen Ringeigenschaften und nichtaromatischen Brückeneigenschaften, welche dann mit einer erweiterte Kraftfelddefinition (TP-b) aufgehoben werden konnte. In den Simulationen konnten damit alle definierte Schritte der ZP nachgewiesen werden, allerdings mit verbleibenden Problemen aufgrund der Charakteristik des geladenen Gesamtsystems. Für das sechste Kapitel wird daher die Implementierung eines Kraftfeldes für die vollständige Darstellung einer Säure durchgeführt. Ein weiterer wichtiger Aspekt für diese Erweiterung ist die damit verbundene Aufklärung der Rolle des Anions in der Strukturbildung. Das siebte Kapitel fasst die Arbeit zusammen und erlaubt den Ausblick auf zukünftige Verbesserung der Modellierung. Weiterhin werden Aussagen zur Transferierbarkeit der Ergebnisse innerhalb der Zwillingspolymerisierung getroffen.

La distribution de masse dans l'Univers telle que tracée par les amas de galaxies constitue une sonde cosmologique puissante. La caractérisation des processus associés à l'origine et à la croissance des grandes structures permet de contraindre des paramètres cosmologiques via l'étude de la distribution des amas en fonction de leur masse et de leur redshift. Cependant, il existe un désaccord statistiquement significatif observé entre les contraintes cosmologiques établies par l'étude des anisotropies primaires du fond diffus cosmologique et celles issues de l'analyse de la distribution des amas de galaxies. Cela pourrait signifier que le modèle standard de la cosmologie est incomplet. L'une des méthodes d'observation des amas de galaxie exploite l'effet Sunyaev-Zel'dovich (SZ) qui permet de contraindre la pression du gaz contenu dans ces derniers. Cette observable peut être directement liée à la masse des amas via une relation d'échelle et un profil de pression. Il est donc essentiel de caractériser précisément ces derniers afin de limiter les potentiels biais et effets systématiques affectant les analyses cosmologiques. Cette thèse présente l'ensemble des travaux réalisés dans cet objectif. Elle porte sur des thématiques allant des observations SZ effectuées avec la caméra NIKA2 installée au télescope de 30 mètres de l’IRAM jusqu'à l'estimation des paramètres cosmologiques en passant par l'analyse des données brutes de NIKA2 et des cartes SZ réalisées.Une part du travail de thèse présenté dans ce document est consacrée à l'étude et l’amélioration des différentes étapes effectuées, depuis les observations d'amas de galaxies au télescope avec la caméra NIKA2 jusqu'à la production de cartes de l'effet SZ. Les procédures développées pour estimer les performances instrumentales de NIKA2 sont détaillées et la chaîne d'analyse utilisée pour réduire les données brutes est présentée.Les travaux réalisés dans cette thèse ont également consisté à caractériser les propriétés thermodynamiques d'amas de galaxies via des analyses jointes combinant les cartes SZ NIKA2 avec des données X mesurées par le satellite XMM-Newton. Nous détaillons les méthodes employées dans le logiciel de traitement des données SZ créé pour le grand programme SZ de NIKA2, la procédure de déprojection non-paramétrique développée pour caractériser le profil de pression des amas de galaxies et les résultats de la première observation SZ avec NIKA2.Les dernières activités présentées sont dédiées aux analyses réalisées afin de quantifier l'impact du grand programme SZ de NIKA2 sur la cosmologie. Nous analysons l'effet des perturbations dynamiques du milieu intra-amas sur la caractérisation du profil de pression avec NIKA2 via l'utilisation d'amas de la simulation numérique MUSIC. Finalement, nous détaillons l'étude permettant d'estimer l'impact d'une variation du profil de pression universel sur l'estimation des paramètres cosmologiques déduite du spectre de puissance de l'effet SZ mesuré par Planck. / The mass distribution in the Universe, as traced by galaxy clusters is a powerful cosmological probe. The characterization of the processes associated with the origin and the growth of the large scale structures enables constraining cosmological parameters by studying the distribution of clusters according to their mass and redshift. However, a tension is observed between the cosmological constraints established by the study of the primary anisotropies of the cosmological background and those resulting from the analysis of the distribution of galaxy clusters. This may imply that our cosmological model is incomplete. The observation of clusters from the Sunyaev-Zel'dovich (SZ) effect allows us to constrain their gas pressure. This observable can be directly linked to the mass of galaxy clusters via a scaling relation and a pressure profile. It is thus essential to characterize the latter precisely in order to limit the potential bias and systematic effects affecting cosmological analyses. This thesis presents the work carried out to this end. It covers topics ranging from SZ observations made with the NIKA2 camera installed at the IRAM 30-metre telescope to the estimation of cosmological parameters, and including the analysis of NIKA2 raw data and the SZ maps produced.Part of the thesis work presented in this document is dedicated to the study and the improvement of the different tasks carried out, from the observations of galaxy clusters with the NIKA2 camera to the production of maps of the SZ effect. The procedures developed to estimate the NIKA2 instrumental performance are detailed and the analysis pipeline used to analyze the raw data is presented.The work carried out in this thesis also consisted in characterizing the thermodynamic properties of galaxy clusters using joint analyzes that combine the NIKA2 SZ maps with X-ray data measured by the XMM-Newton satellite. We detail the methods used in the SZ data processing software created for the NIKA2 SZ large program, the non-parametric deprojection procedure developed to characterize the pressure profile of galaxy clusters and the results of the first SZ observation with NIKA2.The last activities presented are dedicated to the analyses carried out to quantify the impact of the NIKA2 SZ large program on cosmology. We analyze the effect of dynamic disturbances of the intracluster medium on the characterization of the pressure profile with NIKA2 via the use of clusters from the MUSIC N-body simulation. Finally, we detail the study realized in order to estimate the impact of a modification of the universal pressure profile on the estimation of cosmological parameters derived from the power spectrum of the SZ effect measured by Planck.

Theoretical aspects of multicomponent superconductivity and systemswith competing interactions are studied using Monte Carlo techniques.Motivated by recent experimental and theoretical results of complex struc-ture formation of vortices in multicomponent systems, possible vortex struc-ture formations due to vortex interactions that are not purely attractive orrepulsive are considered. Vortex structures such as clusters, superclusters,hierarchical structure formation, stripes, gossamer patters, glassy phases, aswell as checkerboard lattices and loops are demonstrated to be possible.The order of the superconducting phase transition is considered for multi-component lattice London superconductors. The phase transition is demon-strated to be either rst-order or continuous depending on the strength of asymmetry-breaking Josephson intercomponent interaction. It is argued thatthe rst-order phase transition is caused by a vortex phase separation due toa uctuation-induced attractive interaction between vortex lines. / <p>QC 20151117</p>

A time-delayed response of individual living organisms to information exchanged within flocks or swarms leads to the emergence of complex collective behaviors. A recent experimental setup by (Khadka et al 2018 Nat. Commun. 9 3864), employing synthetic microswimmers, allows to emulate and study such behavior in a controlled way, in the lab. Motivated by these experiments, we study a system of N Brownian particles interacting via a retarded harmonic interaction. For N 3 , we characterize its collective behavior analytically, by solving the pertinent stochastic delay-differential equations, and for N>3 by Brownian dynamics simulations. The particles form molecule-like non-equilibrium structures which become unstable with increasing number of particles, delay time, and interaction strength. We evaluate the entropy and information fluxes maintaining these structures and, to quantitatively characterize their stability, develop an approximate time-dependent transition-state theory to characterize transitions between different isomers of the molecules. For completeness, we include a comprehensive discussion of the analytical solution procedure for systems of linear stochastic delay differential equations in finite dimension, and new results for covariance and time-correlation matrices

Despite the many successes of the current standard model of cosmology on the largest physical scales, it relies on two phenomenologically motivated constituents, cold dark matter and dark energy, which account for approximately 95% of the energy-matter content of the universe. From a more fundamental point of view, however, the introduction of a dark energy (DE) component is theoretically challenging and extremely fine-tuned, despite the many proposals for its dynamics. On the other hand, the concept of cold dark matter (CDM) also suffers from several issues such as the lack of direct experimental detection, the question of its cosmological abundance and problems related to the formation of structure on small scales. A perhaps more natural solution might be that the gravitational interaction genuinely differs from that of general relativity, which expresses itself as either one or even both of the above dark components. Here we consider different possibilities on how to constrain hypothetical modifications to the gravitational sector, focusing on the subset of tensor-vector-scalar (TeVeS) theory as an alternative to CDM on galactic scales and a particular class of chameleon models which aim at explaining the coincidences of DE. Developing an analytic model for nonspherical lenses, we begin our analysis with testing TeVeS against observations of multiple-image systems. We then approach the role of low-density objects such as cosmic filaments in this framework and discuss potentially observable signatures. Along these lines, we also consider the possibility of massive neutrinos in TeVeS theory and outline a general approach for constraining this hypothesis with the help of cluster lenses. This approach is then demonstrated using the cluster lens A2390 with its remarkable straight arc. Presenting a general framework to explore the nonlinear clustering of density perturbations in coupled scalar field models, we then consider a particular chameleon model and highlight the possibility of measurable effects on intermediate scales, i.e. those relevant for galaxy clusters. Finally, we discuss the prospects of applying similar methods in the context of TeVeS and present an ansatz which allows to cast the linear perturbation equations into a more convenient form.

Tinkamas kapitalo struktūros parinkimas lemia sėkmingą įmonės veiklą ir perspektyvas. Keičiantis rinkoms, finansinei ir ekonominei situacijai, keičiasi finansinių šaltinių pasirinkimo alternatyvos. Siekiant rasti optimalią įmonės kapitalo struktūrą reikia efektyviai subalansuoti skolintas ir nuosavas lėšas bei nustatyti kokie veiksniai sąlygoja kapitalo struktūros formavimą. Tai gali būti tiek vidiniai, tokie kaip įmonių galimybės skolintis, pelningumas, įmonės dydis ir kt., tiek išoriniai veiksniai: bendrasis vidaus produktas, infliacija, palūkanų norma ir kt. Šio darbo objektas – įmonių kapitalo struktūros formavimas. Darbo tikslas – ištirti Lietuvos įmonių kapitalo struktūrą sąlygojančius veiksnius bei sudaryti kapitalo struktūros ir tiriamų veiksnių ryšio modelį. Siekiant iškelto tikslo, yra nagrinėjami tokie uždaviniai: • remiantis moksline literatūra išanalizuoti įmonės kapitalo struktūros sudėtį bei pagrindines kapitalo struktūros formavimo teorijas ir principus; • atlikti empirinių tyrimų analizę, kuriuose užsienio ir Lietuvos autoriai tiria veiksnius, sąlygojančius kapitalo struktūros formavimą. Ištirti ir palyginti keleto autorių sukurtus kapitalo struktūros formavimo modelius; • sudaryti makroekonominių rodiklių ir finansinio sverto sąveikos modelį bei nustatyti makroekonominių veiksnių poveikį Lietuvos įmonių kapitalo struktūros formavimui. Išanalizavus įmonių kapitalo struktūros formavimo teorijas galima teigti, kad šios teorijos ir požiūriai neatsako į klausimą... [toliau žr. visą tekstą] / Selection of appropriate capital structure determines the success and prospects of business. With changes in markets, financial and economic situation, there are changes also to the alternatives of funding sources. In order to find the optimal capital structure one has to balance the own and borrowed funds efficiency and to identify what factors determine the structure of capital formation. This can be both internal factors, such as business lending opportunities, profitability, company size, etc., as well as external factors: gross domestic product, inflation, interest rate and others. Objective of this work is corporate capital structure formation. The aim of this work is to explore the factors influencing the capital structure formation of Lithuanian companies and develop the communication model between the analysed factors. In order to achieve the objective, the following tasks are considered: • based on scientific literature, to analyze a company's capital structure composition and the basic theories and principles of the capital structure formation; • to carry out an analysis of empirical research where foreign and Lithuanian authors investigate the factors influencing the capital structure formation. To analyse and compare models for the formation of capital structure developed by several authors; • to develop a model for the interaction of macro-economic indicators and financial leverage and determine the influence of macroeconomic factors on the capital structure... [to full text]