Petr Čermák: Service time assessment of the welded frame for the hydraulics of RONDOPRESS press machine The goal of this thesis is to assess durability of the welded frame for the hydraulics of RONDOPRESS press machine, which is used at the bakery sector in the food industry. The press machine chamber is made of stainless steel, because of food (dough) processing. But the strengthened part of the press machine consists of a carbon steel frame with a hydraulic cylinder. For the life of the RONDOPRESS machine is determining the rigidity and durability of the frame. Therefore it is necessary to carry out a study of carbon steel weldability, choose a suitable welding method and then make an evaluation of welded frame construction used in terms of weld joints in analyzed areas. Practical part consists of the frame computer model design, stress calculations and the service time calculation for required 1,825,000 cycles, choosing the appropriate welding method and avoiding undesired deformations. The final output is an operational frame of the RONDOPRESS press machine that meets the required service time specified by the number of production process cycles.

This Ph.D. thesis deals with methodology for determination of residual fatigue lifetime of railway axles based on damage tolerance approach. This approach accepts an existence of potential defect, which could lead to fatigue failure of whole axle. The behavior of crack in railway axle is described by approaches of linear elastic fracture mechanics. There are plenty of factors, which more or less influence determined residual fatigue lifetime. The aim of this thesis is to quantify effects of these factors. The first part of Ph.D. thesis represents overview of studied problems relating to fatigue damage of railway axles. This part is focused on parameters, which influence fatigue crack growth in railway axle materials. The second part of thesis shows procedure for determination of residual fatigue lifetime, which was developed at the Institute of Physics of Materials of the Academy of Sciences of the Czech Republic. The main aim of this thesis was to improve current procedure for more precise estimation of residual fatigue lifetime. Significant part of this work is determination of significance of studied factors, which influencing calculated residual fatigue lifetime of railway axles (e.g. effect of threshold value, load spectrum, retardation effects, residual stress, axle geometry, material of axle etc.). The procedures described and results obtained can be also used for determination of residual fatigue lifetime of general mechanical component (not only railway axles). Therefore, results obtained in this Ph.D. thesis can be used e.g. for assessment of regular inspection intervals of cyclically loaded general mechanical parts.

La structure nucléaire en couches sphériques évolue en allant vers des régions de plus en plus exotiques de la carte des noyaux. Par conséquent, les nombres magiques conventionnels (2, 8, 20, 28, 50, 82, 126) peuvent disparaître loin de la stabilité, tandis que de nouveaux apparaissent.L’évolution des gaps entre états de particule individuelle loin de la stabilité a essentiellement deux origines : les dérives monopolaires et l’augmentation de la collectivité. Les dérives monopolaires sont essentiellement dues à l’interaction proton-neutron (composante spin-isospin de l’interaction nucléaire). On se concentre dans cette thèse sur les isotopes impairs N=51 et en particulier sur 83Ge, le plus proche de 79Ni que l’on peut étudier actuellement par spectroscopie γ de précision. Pour cela, deux expériences complémentaires ont été réalisées. Une première expérience, au GANIL avec AGATA, VAMOS et le plunger OUPS a permis de mesurer les durées de vie des états excités Yrast des produits de la réaction 238U(9Be,f). Une seconde expérience pour l’étude par spectroscopie γ β-retardée de 83Ge afin de peupler les états non-Yrast a été réalisée afin d’avoir une vue d’ensemble de la spectroscopie de 83Ge.La complémentarité de ces deux expériences a permis de mettre en évidence un état intru pour la première fois au delà du gap N=50 dans 83Ge et ainsi avoir plus d’information sur l’évolution du gap νg9/2νd5/2 associé au nombre magique de spin-orbite N=50. Une analyse détaillée de ses deux expériences est présentée dans ce manuscript. De plus, une comparaison avec un modèle semi-microscopique coeur-particule est aussi réalisée. / Nuclear spherical shell structure evolves towards more and more exotic regions of the nuclear chart. Therefore, conventional magic numbers (2, 8, 20, 28, 50, 82, 126) can disappear while new ones appear. 
The evolution of gaps between single-particle states far from stability has essentially two origins : monopole drift and the collectivity enhancement. The monopole drifts are mostly coming from neutron-proton interaction (spin-isospin term of the nuclear interaction). In this thesis, we focused on the study of N=51 isotones and in particular 83Ge, the closest to 79Ni that can be studied nowadays by detailled γ-spectroscopy. For this purpose, two complementary experiments were performed. A first experiment, at GANIL with AGATA, VAMOS and the OUPS plunger device allowed us to measure lifetime of Yrast excited states in the 238U(9Be,f) reaction products. A second experiment for the study of β-delayed γ-spectroscopy of 83Ge was performed in order to populate non-Yrast states so that has an overview of the spectroscopy of 83Ge.The complementarity of these two experiments allowed highlighting for the first time an intruder state above the N=50 gap in 83Ge and thus, it adds information about the evolution of the νg9/2νd5/2 gap corresponding to the N=50 shell closure.A detailed analysis of both experiments is presented in this manuscript. In addition, a comparison to a semi-microscopic core-particle model is performed.

Maintaining and operating manual main distribution frames is labour-intensive. As a result, Automated Main Distribution Frames (AMDFs) have been developed to alleviate the task of maintaining subscriber loops. Commercial AMDFs are currently employed in telephone exchanges in some parts of the world. However, the most significant factors limiting their widespread adoption are costeffective scalability and reliability. Therefore, an impelling incentive is provided to create a simulation framework in order to explore typical implementations and scenarios. Such a framework will allow the evaluation and optimisation of a design in terms of both internal and external redundancies. One of the approaches to improve system performance, such as system reliability, is to allocate the optimal redundancy to all or some components in a system. Redundancy at the system or component levels can be implemented in one of two schemes: parallel redundancy or standby redundancy. It is also possible to mix these schemes for various components. Moreover, the redundant elements may or may not be of the same type. If all the redundant elements are of different types, the redundancy optimisation model is implemented with component mixing. Conversely, if all the redundant components are identical, the model is implemented without component mixing. The developed framework can be used both to develop new AMDF architectures and to evaluate existing AMDF architectures in terms of expected lifetimes, reliability and service availability. Two simulation models are presented. The first simulation model is concerned with optimising central office equipment within a telephone exchange and entails an environment of clients utilising services. Currently, such a model does not exist. The second model is a mathematical model incorporating stochastic simulation and a hybrid intelligent evolutionary algorithm to solve redundancy allocation problems. For the first model, the optimal partitioning of the model is determined to speed up the simulation run efficiently. For the second model, the hybrid intelligent algorithm is used to solve the redundancy allocation problem under various constraints. Finally, a candidate concept design of an AMDF is presented and evaluated with both simulation models. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Electrical, Electronic and Computer Engineering / unrestricted

Cette thèse s’intéresse à la relation de long-terme entre la longévité et le développement économique. Dans le premier chapitre, j’analyse l’impact des dépenses de santé sur la croissance et le bien-être. Pour cela, j’étudie l’influence du taux d’imposition dans une économie avec temps de vie endogène (Chakraborty (2004)). Je détermine le taux d’imposition qui maximise le taux de croissance. Puis je m’intéresse aux variations du niveau de production dans l’état stationnaire par rapport au taux d’imposition. Enfin, j’étudie le taux d’imposition qui maximise le bien-être dans l’état stationnaire. Dans le second chapitre, j'analyse l’impact sur la croissance de dépenses de santé choisies par les agents. En effet, je développe un modèle de croissance endogène dans lequel les individus peuvent dépenser des ressources pour vivre plus longtemps dans leur période de retraite. Je donne une caractérisation complète de l’équilibre général dynamique puis je détermine l’impact sur la croissance des dépenses de santé. Enfin, le troisième chapitre étudie l’impact théorique du vieillissement sur l’allocation sectorielle des travailleurs. Je développe un modèle multi-sectoriel dans lequel j’examine les conséquences sur le revenu par travailleur et l’allocation sectorielle des travailleurs d’un choc de longévité et de fertilité. Je montre que contrairement aux modèles uni-sectoriels, le revenu n’est pas forcément monotone par rapport aux variables démographiques. Des chocs démographiques réalistes produisent des mouvements non-négligeables de travailleurs. / This dissertation is interested in the long-run relationship between longevity and economic development. In the first chapter, I analyse the impact of health expenditures on economic growth and welfare. For this, I study the influence of the tax rate in an economy à la Chakraborty (2004). I first determine the growth-maximizing tax rate, which is shown to be 0 in low-income countries. Second, I show that the steady-state income level is an inverted U-shaped function or a decreasing function of the tax rate. Third, I study the tax rate that maximizes the steady-state welfare level. In the second chapter, I propose a theoretical model to study the growth impacts of health expenditures chosen by the agents. Indeed, I develop a Diamond model with endogenous growth in which young individuals can spend resources to increase their longevity in retirement period. I give a full characterization of the dynamic general equilibrium and determine the growth impacts of health expenditures. They can speed up or slow down economic growth. They can be a barrier or a necessity for growth to take place. A calibration to OECD countries suggests that the latter case is the most likely one. Finally, the third chapter studies the theoretical impact of the aging process on the sectorial labor allocation. To this aim, I develop a multi-sector two-period overlapping generations model in which I examine the consequences of both a longevity shift and a fertility shift on the labor allocation of the economy and on the income per worker level. I show that contrary to one-sector models, the income per worker level is not necessarily monotonic with respect to demographic variables. Realistic demographic shocks are also shown to create significant labor reallocation across sectors.

Les anticorps thérapeutiques sont couramment utilisés pour le traitement contre le cancer. Ils sont sélectionnées par leur affinité avec leur antigène mesuré normalement dans un environnent à trois dimensions (3D). Cependant, de fois les interactions anticorps-antigène ont lieu à l’interface entre deux cellules (i.e. 2D). Nous faisons l’hypothèse que les contraintes physiques à cette l’interface telles que la force et le mouvement relatif des molécules confinées aux surfaces modulent les propriétés de la liaison anticorps-antigène. Notre but est d’explorer les liens entre la mécanique de la liaison et la réponse cellulaire. Pour quantifier la cinétique 2D et la mécanique de ces interactions, nous avons effectué des mesures en utilisant la chambre à flux laminaire des deux anticorps à domaine unique (sdAbs) ciblant le récepteur CD16 exprimé dans la cellule Natural Killer (NK) et cinq sdAbs ciblant le marqueur tumoral HER-2 exprimé dans certains cancers. Nos résultats montrent des liaisons glissantes, idéales et pour la première fois, une liaison accrocheuse dans des interactions anticorps-antigène. Des expériences d’adhésion cellulaire montrent une corrélation entre la résistance à la force de la liaison accrocheuse et une meilleure adhésion des NK. Des sdAbs ont été sélectionnés pour constituer des anticorps bi-specifiques (bsAbs) capables de recruter des NK contre des cellules cancéreuses HER-2+. Ces bsAbs induisent une cytotoxicité supérieur a celle de l’anticorps de référence. Leur efficacité est modulée par la mécanique du coté antiCD16 du bsAbs en fonction de la nature de la cellule cancéreuse, suggérant un rôle de la force pour les faibles densités de HER-2. / Therapeutic antibodies have become a major treatment in cancer due in part to their ability to recruit immune cells onto tumours. They are selected on the basis of their affinity for their antigen in a three dimensions (3D) environment. However, in some major modes of action, antibodies do bind the antigen at the interface between immune cells and target cells. We hypothesize that the physical constraints of cell-cell interface (i.e. 2D), including force and relative motion of molecules confined at surfaces, modulate the antigen-antibody binding. Specifically, we aim at exploring the links between bond mechanics and cellular response. To quantify 2D kinetics and mechanics, we perform measurements using the laminar flow chamber of two Single Domains Antibodies (sdAbs) against the surface receptor CD16 expressed in Natural Killer (NK) cells and five sdAbs against the tumoral marker HER-2 expressed in some breast cancers. Our results show three different bond dissociation behaviour under force; slip, ideal and for the first time, a catch bond. Cell adhesion experiments over sdAb antiCD16 coated surfaces reveal a correlation between antibody resistance to force and a larger spreading of NK cells. Based on their force behaviour, some sdAbs were selected to be fused forming bi-specific antibodies (bsAbs) able to recruit NK cells toward HER-2+ cancer cells. All new bsAbs display a better efficacy in cytotoxicity than the reference therapeutic antibody. We show that their efficacy is modulated by the mechanical behaviour of the antiCD16 side, depending on the nature of the target cell line, which may hint to an effect of force dependence in the limit of low antigen coverage.

CHARLES UNIVERSITY and HASSELT UNIVERSITY / tUL Doctoral dissertation Collagen structures from cell culture to intact tendon ABSTRACT Author: Daniel Hadraba Promoters: Assoc. Prof. Karel Jelen | Charles University Prof. Marcel Ameloot | Hasselt University Co-promoters: Dr. Frantisek Lopot | Charles University Prof. Virginie Bito | Hasselt University Annotation Author: Ing. Mgr. Daniel Hadraba Doctoral thesis title: Collagen structures from cell culture to intact tendon Year: 2010 - 2017 Doctoral program: Doctor of Biomechanics at Charles University Doctor of Biomedical Science at Hasselt University / transnational University Limburg Departments: Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Dept. Biophysics | Hasselt University Promoters: Assoc. Prof. Karel Jelen | Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Prof. Marcel Ameloot | Hasselt University / transnational University Limburg Co-promoters: Dr. Frantisek Lopot | Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Prof. Virginie Bito | Hasselt University / transnational University Limburg Bibliography details: Pages 102 Figures 30 Tables 2 Equations 17 Keywords: tendon, collagen, crimps, orientation, aging,...

Title: Advanced spectroscopic characterization of quantum dot ensembles Author: Michael Greben Department: Department of Chemical Physics and Optics Supervisor of the doctoral thesis: Prof. Jan Valenta, Ph.D. Abstract: Semiconductor quantum dots (QDs) are small crystallites whose sizes (of the order of nm) cause spatial confinement of carriers in all 3 dimensions. As result, QDs often reveal very different physical properties in comparison with their bulk counterparts. From the optical point of view, the broadening of bandgap with QD-size shrinking is particularly interesting. It is a purely quantum mechanical effect that results from quantum confinement (QC), i.e. dimensional limitations of excitons. A strong spatial confinement leads to a relaxation of momentum (Heisenberg uncertainty principle), consequently, larger overlap of the wave-functions of carriers results in significant increase of probability of radiative recombination. Therefore ensembles of QDs are promising candidates for new generations of photonic and photovoltaic devices. This PhD thesis is primary focused on detailed spectroscopic characterization of ensembles of direct (PbS) and indirect (Si) semiconductor QDs in both colloidal (toluene) and matrix-embedded (oxide or oxinitrides multilayers) forms. The oleic- acid capped PbS QDs were...

Power electronics, which fully covers the generation, conversion, transmission and usage of electrical energy, is a key technology for human welfare. With the development of technologies, the requirements on the reliability of power electronic systems are keep increasing. Long term operation under harsh environments is often accompanied by higher switching frequency and higher power density. To allow a reliable and sustainable performance of the power electronic systems, precise lifetime estimation of the power semiconductor devices is of significant importance. This work covers some aspects in the lifetime prediction of power semiconductor devices, especially IGBT and diode, in power module and transfer-molded discrete package. Difference in device temperature determination was illustrated using analytical calculation, simulation and measurement. In addition, temperature calculation in the frequency domain was demonstrated which gives benefits in the application with several hundred devices. Furthermore, different control strategies in the power cycling test were compared. The linear cumulative damage theory was validated by using the power cycling test. For the high power IGBT module used in the MMC HVDC application, power cycling lifetime with 50 Hz heating processes was investigated. For the transfer-molded discrete package, the first lifetime model with comparable scope like the lifetime model of power modules was proposed. / Leistungselektronik, welche direkt relevant für die Erzeugung, Umwandlung, Übertragung und Nutzung elektrischer Energie ist, ist eine Schlüsseltechnologie für das Wohl der Menschen. Mit der Entwicklung von Technologien steigen die Anforderungen an die Zuverlässigkeit leistungselektronischer Systeme. Der Langzeitbetrieb unter rauen Umgebungsbedingungen geht häufig mit einer höheren Schaltfrequenz und einer höheren Leistungsdichte einher. Um eine zuverlässige und nachhaltige Operation der leistungselektronischen Systeme zu ermöglichen, ist die genaue Lebensdauerabschätzung der Halbleiter-Leistungsbauelemente von großer Bedeutung. Diese Arbeit befasst sich mit einigen Aspekten der Lebensdauerabschätzung von den Halbleiter-Leistungsbauelementen. Unterschied in der Temperaturabstimmung der Halbleiter-Leistungsbauelemente wird anhand von Berechnung, Simulation und Messung veranschaulicht. Darüber hinaus bietet die Temperaturberechnung im Frequenzbereich Vorteile bei der Anwendung mit mehreren hundert Bauelementen. Darüber hinaus wurden verschiedene Regelstrategien im Lastwechseltest verglichen. Die lineare kumulative Alterungstheorie wurde unter Verwendung des Lastwechseltests validiert. Für das in der MMC-HGÜ-Anwendung verwendete Hochleistungs-IGBT-Modul wurden Alterungsprozesse bei 50 Hz Erwärmung untersucht. Für das Diskrete-Gehäuse wird das erste Lebensdauermodell vorgestellt, welches ein vergleichbares Anwendungsbereich wie das Lebensdauermodell von Leistungsmodulen hat.

Die hochempfindliche Methode der „Microwave Detected Photoconductivity“ (MDP) wird eingesetzt, um technologisch relevante Halbleiterparameter wie die Ladungsträgerlebensdauer, Photoleitfähigkeit und Defektkonzentrationen über viele Größenordnungen der optischen Anregung hinweg zu untersuchen. Durch die Entwicklung und die Anwendung eines neuartigen Modellierungssystems für die Ladungsträgerdynamik in Halbleitern können wichtige Defektparameter quantitativ aus MDP Messungen in Abhängigkeit der Anregungsintensität bestimmt werden. Ein Verfahren zur Charakterisierung von Haftstellen (Konzentration, Energielage, Einfangsquerschnitt) bei konstanter Temperatur wird vorgestellt. Das technologisch relevante Verfahren des quantitativen Eisennachweises in p-dotiertem Silizium wird für die MDP Methode angepasst und entsprechende Messergebnisse mit DLTS Resultaten verglichen. Ein detaillierter Vergleich der gängigsten kontaktlosen Messverfahren QSSPC und MW-PCD mit der MDP zeigt, dass entgegen gängiger Annahmen die unterschiedlichen Anregungsbedingungen zu drastischen Unterschieden in den gemessenen Werten der Ladungsträgerlebensdauer führen. Dies wird sowohl durch theoretische Berechnungen als auch durch praktische Messergebnisse belegt.