This work deals with the thermal load during cut-off grinding of high-strength bearing rings. Linear cut-off operations lead to a high rise in temperature over the cutting process. These leads, together with the limited material volume, in a heat build-up and the resulting grinding burn. The aim of this work was to prevent this head build-up by using two-axis cut-off operations. Therefore, known methods were theoretically considered and from this, alternative two-axis strategies were determined. For testing, experiments were carried out on a test set-up developed in this work. The tests showed that the two-axis strategies lead to significantly reduced temperatures, as well as non-grinding burn and partially burr-free cutting surfaces. However, the two-axis methods lead to increased process times, which is why approaches for their optimization have been discussed.

Les technologies de captage, transport et stockage du CO2 ont pour finalité de capter le CO2 issu des industries afin de le stocker géologiquement et ainsi, réduire l impact de ces activités sur le réchauffement climatique. L Axe-Seine (Paris Le Havre) est un territoire très industrialisé et fortement émetteur de CO2. Dans ce territoire, les décideurs locaux envisagent l utilisation des technologies de CTSC afin de réduire les émissions de gaz à effet de serre. L objectif de notre recherche est de comprendre les futurs possibles de ces technologies dans l Axe-Seine. Dans cette perspective, cette thèse analyse tout d'abord le fonctionnement des technologies de CTSC dans une approche de sociologie des sciences et des techniques et les promesses technoscientifiques initiales associées à ce dispositif technique. Ensuite, cette recherche examine les dynamiques socio-spatiales de la vallée de la Seine concernant l'environnement. Enfin, cette thèse par une exploration des récits relatifs aux technologies de CTSC par les promoteurs de ce dispositif technique et des parties prenantes locales, identifie les hybridations potentielles entre ce dispositif technique et les dynamiques socio-spatiales de l'Axe-Seine. Ainsi est-il possible de décrire les futurs possibles des technologies dans l'Axe-Seine. Par ailleurs, dans cette recherche nous questionnons également la place des sciences sociales au côté des sciences de la vie et de la matière dans la dynamique de l'innovation technologique. / Carbon Capture and Storage enables industrial facilities to capture their CO2 emissions in order to geologically store it and then reduce their impact on global warming. The Seine Waterway Axis (from Paris to Le Havre) counts a lot of industrial facilities emitting huge quantities of CO2. From 2006 local stakeholders of this territory are willing to develop CCS to a commercial scale in order to reduce CO2 emissions.In our research we aim to understand potential futures of CCS technology in the Seine Waterway Axis. In this Phd thesis we first analyse initial technoscientific promises related to Carbon Capture and Storage in using Science and Technology Studies theoretical framework. Then we focus on the Seine Waterway Axis territorial dynamics regarding sustainable development. Finnaly, we focus on narratives related to Carbon Capture and Storage in the Seine Waterway Axis in order to identify hybridations between CCS implementations and territorial dynamics. These cross analysis will enable us to describe potential future of CCS establishment in the Seine Waterway Axis.

Puberty is a critical period of development characterized by rapid physiological changes and significant brain reorganizing and remodeling. These rapid changes render the developing brain particularly vulnerable to stress and immune challenge. In mice, exposure to an immune challenge (lipopolysaccharide; LPS) during puberty causes enduring effects on stress reactivity, cognitive functioning, and depression- and anxiety-like behaviors later in life. However, the mechanisms underlying these effects are unknown. The gut microbiome can profoundly influence the immune system. There is also close bidirectional communication between the gut microbiome and the central nervous system (CNS) through neural, endocrine and immune signaling pathways, which can alter brain chemistry and emotional behaviour. Thus, we hypothesized that altering microbial composition during puberty could mitigate acute immune responses and prevent enduring outcomes later in life. The current thesis examined the effect of gut manipulation with probiotics during puberty on LPS-induced immune responses and enduring anxiety- and depression-like behaviours, and stress-reactivity in adulthood, in male and female CD1 mice (Article 1). Next, we examined age and sex differences in gut microbial composition before and after exposure to an immune challenge. We also examined the effects of consuming a single strain probiotic bacterium (Lactobacillus Reuteri) during puberty on the immune response and the long-term changes in memory, anxiety-like behavior, and stress reactivity in adulthood (Article 2). Lastly, we examined how microbial colonization between pubertal and adult mice can alter acute peripheral and central inflammatory responses to LPS (Article 3). The current dissertation has addressed sex-specific vulnerabilities to an immune challenge during pubertal development and the moderating influence of the gut microbiome. These studies have demonstrated that manipulating the gut microbiome during puberty can mitigate acute immune responses and prevent enduring neurobehavioural outcomes later in life.

Die Arbeit untersucht planare optische Mikrokavitäten, welche aus einer beidseitig von Multischichtspiegeln umgebenen Kavitätsschicht bestehen. Im Rahmen einer Transfermatrixbeschreibung für ebene Wellen wird ein genereller Ansatz zur Berechnung von optischen Kavitätsmoden von planaren Mikrokavitäten entwickelt, welche aus optisch beliebig anisotropen Medien bestehen. Die zugrunde liegende Modenbedingung kommt ohne vorherige Einschränkungen bezüglich der betrachteten Lichtpolarisation aus. Basierend auf diesem Ansatz werden numerische Modenberechnungen von Mikrokavitäten mit optisch uniaxialen Kavitätsschichten vorgenommen. Generell sind die Moden in einem solchen System elliptisch polarisiert, und zudem i.A. nicht orthogonal. Ein besonderes Phänomen stellen sogenannte exzeptionelle Punkte dar. Dies sind Richtungen, für welche Energie und Verbreiterung der zwei Kavitätsphotonmoden zugleich entarten. Die Moden werden an solchen Punkten zirkular ko-polarisiert, die Orientierung der linearen Modenpolarisation windet sich im Impulsraum um diese Punkte herum. Die Eigenschaften der anisotropen Mikrokavitäten und exzeptionellen Punkte sind charakteristisch für singuläre, biaxiale Optik. So entsprechen die exzeptionellen Punkte Richtungen sogenannter singulärer optischer Achsen der effektiv biaxialen Strukturen, und können als Entartung nicht-Hermitescher Operatoren beschrieben werden. Die experimentelle Realisierung wird am Beispiel ZnO-basierter Mikrokavitäten gezeigt und bestätigt die theoretischen Vorhersagen im Wesentlichen, wenngleich im Experiment keine komplett zirkular polarisierten Zustände an den Entartungspunkten beobachtet wurden.:0 Introduction 1 Theory I: Linear optics principles 1.1 Maxwell theory 1.1.1 Plane-wave ansatz 1.1.2 Light polarization 1.1.3 Crystal optics 1.1.4 The polariton concept 1.2 Matrix formalisms for planar structures 1.2.1 Transfer-matrix approach 1.2.2 Scattering, Jones and Müller matrices 2 Theory II: Planar optical microcavities 2.1 Fabry-Pérot resonators and photonic modes 2.2 Practical mode computation 2.3 Quasi-particle approach 3 Computation: Exceptional points in anisotropic microcavities 3.1 Numerical methods 3.2 Model and findings for anisotropic, dielectric microcavities 3.3 Classification and discussion 3.3.1 General characteristics of exceptional points in anisotropic microcavities 3.3.2 Polarization vortices and singular optics 3.3.3 Net topology of the system 3.3.4 Effective-medium approaches 3.3.5 Quasi-particle approaches 3.3.6 Other familiar systems and phenomena 3.4 Anisotropic exciton-polaritons 4 Experiment: ZnO-based planar microcavities 4.1 Microcavity samples 4.2 Experimental methods 4.3 Experimental results vs. theoretical computations 4.4 Summary and discussion 5 Conclusion A Appendix A.1 Determining optic axes A.2 Exceptional points A.3 Expressions in Gaußian CGS units A.4 Polarization patterns of isotropic microcavities Bibliography Symbols and Abbreviations Authored and co-authored publications directly related to this thesis Acknowledgments Curriculum Vitae / In this thesis, planar optical cavities are investigated. They consist of a cavity layer which is surrounded by multi-layer mirrors. Using a transfer matrix technique for planar structures, a general mode condition is developed, which allows computation of cavity-photon modes for planar microcavities, which consist of optically arbitrarily anisotropic media. With this approach, no prior restriction of the considered light polarization is required. Based on this formalism, numerical computations of planar microcavities with optically uniaxial cavity layers are performed. Generally, the cavity-photon modes in such systems obtain elliptic polarization. Furthermore, they are in general not orthogonal to each other. A particular phenomenon is the occurrence of so called exceptional points. Here, the two cavity-photon modes degenerate in energy and broadening simultaneously, and the modes become circularly co-polarized. In addition, the exceptional points are vortex centers in momentum space for the orientation of the linear polarization of the modes. With this, anisotropic planar microcavities show typical characteristics of singular as well as biaxial optics. The exceptional points can be regarded as singular optic axes of the effectively biaxial structures. They can be described by the degeneracy of non-Hermitian operators. Experimental implementation is demonstrated by ZnO-based microcavities. In general, experimental findings prove the theoretical predictions, albeit the degree of circular polarization does not approach 100% at the exceptional points.:0 Introduction 1 Theory I: Linear optics principles 1.1 Maxwell theory 1.1.1 Plane-wave ansatz 1.1.2 Light polarization 1.1.3 Crystal optics 1.1.4 The polariton concept 1.2 Matrix formalisms for planar structures 1.2.1 Transfer-matrix approach 1.2.2 Scattering, Jones and Müller matrices 2 Theory II: Planar optical microcavities 2.1 Fabry-Pérot resonators and photonic modes 2.2 Practical mode computation 2.3 Quasi-particle approach 3 Computation: Exceptional points in anisotropic microcavities 3.1 Numerical methods 3.2 Model and findings for anisotropic, dielectric microcavities 3.3 Classification and discussion 3.3.1 General characteristics of exceptional points in anisotropic microcavities 3.3.2 Polarization vortices and singular optics 3.3.3 Net topology of the system 3.3.4 Effective-medium approaches 3.3.5 Quasi-particle approaches 3.3.6 Other familiar systems and phenomena 3.4 Anisotropic exciton-polaritons 4 Experiment: ZnO-based planar microcavities 4.1 Microcavity samples 4.2 Experimental methods 4.3 Experimental results vs. theoretical computations 4.4 Summary and discussion 5 Conclusion A Appendix A.1 Determining optic axes A.2 Exceptional points A.3 Expressions in Gaußian CGS units A.4 Polarization patterns of isotropic microcavities Bibliography Symbols and Abbreviations Authored and co-authored publications directly related to this thesis Acknowledgments Curriculum Vitae

The hepatic acute phase response (APR), stimulated by injury or inflammation, is characterized by significant changes in circulating acute phase protein (APP) concentrations. While individual functions of liver-derived APPs are known, the net consequence of APP changes is unclear. Pneumonia and sepsis elicit systemic inflammation and induce a robust APR. Although APR activation is regarded as a hallmark of infection, direct contributions of liver activation to pulmonary defense during pneumonia and sepsis-induced pneumonia remain unclear. Pneumonia causes a pulmonary inflammatory response coordinated largely by alveolar macrophages, and is typified by cytokine production, leukocyte recruitment and plasma extravasation, the latter of can enable delivery of hepatocyte-derived APPs to the infection site. To determine the functional significance of the hepatic APR during pneumonia, we challenged APR-null mice lacking hepatocyte signal transducer and activator of transcription-3 (STAT3) and RelA with 106 colony-forming units (CFU) Escherichia coli intratracheally. HepSTAT3/RelA-/- mice displayed ablated APP induction, significantly increased mortality, tumor necrosis factor-dependent hepatotoxicity, and pulmonary bacterial burdens. Following a lower (4x105 CFU) E. coli inoculum, hepSTAT3/RelA-/- mice had decreased APP concentrations with reduced pulmonary inflammation and diminished airspace macrophage activation. Similar results were obtained in the context of endotoxemia and pneumonia. We employed an endotoxemia/pneumonia model, whereby 18 hours of intraperitoneal E. coli lipopolysaccharide (5 mg/kg) was followed by intratracheal E. coli (106 CFU) in mice lacking hepatocyte STAT3 (hepSTAT3-/-) or control hepSTAT3+/+ mice. Following endotoxemia and pneumonia, hepSTAT3-/- mice, with significantly reduced levels of circulating and airspace APPs, exhibited significantly elevated lung and blood bacterial burdens and mortality. While neither recruited airspace neutrophils nor lung injury were altered in endotoxemic hepSTAT3-/- mice, in vivo production of reactive oxygen species in alveolar macrophage was significantly decreased. Additionally, bronchoalveolar lavage fluid from this group of hepSTAT3-/- mice allowed greater bacterial growth ex vivo. These results identify a lung-liver axis, whereby the liver response enhances macrophage activation and pulmonary host defense during pneumonia and sepsis-induced pneumonia. Taken together, induction of liver acute phase gene expression programs contributes to countering the deleterious consequences of pneumonia, whether it is alone or in the context of sepsis-induced infection.

Animal personality is a fairly new branch of biology and has been defined as a difference in behaviour between individuals that is relatively consistent across time and/or context. What researchers now are interested in is to find out what it is that creates and maintains this relatively consistent difference between individuals. One possibility is the stress hormone, corticosterone. I have in this report summed up some of the available studies regarding animal personality and its possible correlation to corticosterone. The personality traits that have been reviewed in this report are boldness, exploration, activity, aggressiveness and sociability. The result of these studies show that boldness have both a negative and a positive correlation; exploration showed different correlations between studies; aggressiveness showed different correlation between different animal types and sociability showed both a negative and none correlations. The only one that I could not determent the correlation for was activity. The research regarding animal personality and corticosterone can be of use when looking at animal welfare and how stress affects different individuals. This can give us a direction in our work to reduce stress for animals in research facilities and food production.

No description available.

Solar energy is a clean energy source which has a minimal impact on the environment than other forms of energy. Solar energy is now widely used in a variety of applications. Although solar energy is widely used, the efficiency of converting solar energy into electricity is insufficient since most solar panels are installed at a fixed angle and the fixed solar panels do not aim directly towards the sun due to the earth’s constant motion. Solar panels are very expensive for families or businesses that consume more energy than usual, as they require several solar panels to generate enough power. The main objective of this project is to build a working model so that to increase the efficiency of power output taken from solar panel by continuously tracking the sun’s rays through out the day and aligns the solar panel orthogonal to the sun. To develop a model that benefits people by producing more solar energy with fewer solar panels. In order to overcome this problem we come up with a solution through Arduino Uno system which consists of four LDR sensors which are responsible for the detection of the light intensity of the sun’s rays. Two micro servo motors are used for movement of the solar panel in azimuth and elevation direction since it is a dual axis tracking system. A solar panel is the core part we use in this model for the conversion of solar energy into electrical energy. The LCD displays shows the power output of the solar panel. The proposed system is a dual axis tracking system that actively tracks solar radiation and adjusts the panel so that the sun’s rays are perpendicular to it, maximizing the solar panel’s power output. The LCD display shows the power output of the solar panel. By this project, we can say that dual axis tracking system we built can track the sun’s rays and increases the power output of solar panel. The manual effort for changing the solar panel according to the sun position can be avoided.

Exercise is widely recognized for its role in the health management and prevention of several chronic diseases. Exercise is considered as a stimulus in the form of physical stress to which a group of anatomical structures in the human body responds by generating a stress response that enables certain physiological modifications essential for restoring systemic homeostasis. A major component of the response is produced through the complex hypothalamic-pituitary-adrenal (HPA) axis mechanism that results in the release of cortisol which then intercedes with the effects of the stimulus. To investigate how cortisol helps the body adapt to this physical stress it is necessary to gain deep insight into the cortisol response mechanism. However, this is a complex mechanism, so to better understand the mechanics and to be able to analyze complex data, mathematical models are used. Various mathematical models have already been developed that describe different metabolic responses to exercise but to date, to my knowledge, none of these existing models has illustrated the HPA axis response mechanism, particularly cortisol response to physical exercise. Therefore, I have developed a mathematical model that describes cortisol variations on a normal day in the absence of any form of stress and on the day of exercise. The developed cortisol response model could fit simulation to experimental data and also passed the χ2- statistical test. Additionally, the model has been validated on different cortisol experimental data with satisfying results. At last, considering the positive outcome of this mathematical model, it could be used as a groundwork for developing a comprehensive model which can describe other metabolic processes response to exercise such as glucose metabolism together with the cortisol response mechanism in the future.

No description available.