Global ETD Search

31	The impact of the estrous cycle on the vaginal microbiota and its association to pregnancy rates in dairy cows Giroux, Adèle 03 1900 (has links) Plusieurs recherches ont été conduites pour déterminer les phases du cycle œstrus chez les vaches. Toutefois, peu est connue de leur microbiote vaginal. Cette étude a pour but de déterminer la composition du microbiote vaginal de vaches laitières durant les quatre phases du cycle œstrus, pour détecter son impact sur la fertilité de ces vaches. Cette information nous permettra d’un jour manipuler le microbiote vaginal d’autres vaches afin d’améliorer leur taux de fécondité. Vint-et- une vaches Holstein multipares de la même ferme ont subi l’insémination artificielle (IA) suite à la détection du début des chaleurs. Quatre frottis vaginaux ont été faits aux jours 1,3,15 et 19 du cycle. Au jour 31, une échographie a confirmé que neuf vaches étaient enceintes. Les données ont ensuite été analysées avec avec le séquençage rRNA 16S de la région hypervariable V4. Les résultats ont montré une prédominance nette de certains embranchements bactériens. Les firmicutes, bacteroidetes et protéobacteéries composait plus de 80% de la population microbiotique vaginale avec certaines fluctuations importantes. Une analyse statistique a déterminé qu’il y a eu des changements significatifs entre l’œstrus et le proestrus chez les vaches qui ne sont pas devenues enceintes de (P=0.028), et entre l’œstrus et le dioestrus chez les vaches enceintes de (P=0.043). Cette recherche est un premier pas important dans l’identification du microbiote vaginal et son impact possible sur la santé vaginale et la fertilité de vaches laitières. Cette recherche pourrait contribuer aux études futures tentant d’améliorer la fécondité bovine avec la manipulation du microbiote vaginal. / A great deal of research has been done on the four phases of the estrous cycle in cows, yet very few studies exist regarding their vaginal microbiota. This study explored the various differences in the vaginal microbiota in pregnant and non-pregnant multiparous Holstein dairy cows. This information will allow us to see what a healthy vaginal microbiota looks like in pregnant cows and to someday try to achieve similar microbiomes in other cows to aid in fertility issues on farms. The objective of this study is to investigate variations in microbiota populations during the estrous cycle and their possible association with pregnancy rates using next generation sequencing of the V4 hypervariable region of the 16S rRNA gene. Twenty-one multiparous Holstein cows on the same farm underwent artificial insemination (AI) after estrous detection. Vaginal swabs were collected four times, on days: 1 (before AI), 3, 15, and 19. Ultrasonography performed at day 31 confirmed that 9 cows became pregnant. A clear predominance of certain phyla was found, with Firmicutes, Bacteroidetes and Proteobacteria making up over 80% of the vaginal microbiota composition throughout, with notable variations between individuals. Differences in beta-diversity (community composition) that were proven statistically significant were between the estrus- proestrus phases in non-pregnant cows (P=0.028) and between the estrus and diestrus phase in pregnant cows at (P=0.043). These findings are a clear first step in identifying possible beneficial vaginal microbiota in pregnant cows that may help to determine how to proceed in manipulating other cows’ vaginal microbiota that have suffered from reproductive failure in the past. Holstein Vaches laitières 16S rRNA séquençage V4 microbiote vaginale oestrus dairy cows AI estrous microbiota vaginal
32	Investigation on how additive manufacturing with post-processing can be used to realize micronozzles Bugurcu, Alan January 2022 (has links) This is predominantly a qualitative study on the manufacturing of micronozzles with an additive manufacturing (AM) technique, namely the laser-powered powder bed fusion (PBF-LB). Manufacturing of micronozzles with standard microelectromechanical system technology often results in 2.5-D or close to 3-D structures and does not yield a fully rotationally symmetric nozzle. For this reason, AM can be a better solution. However, the structures obtained with PBF-LB exhibit very rough surfaces which will impair the performance of the micronozzle. To improve the surface finish electropolishing was performed on the interior walls. Given the shape and the scale of the components, uniformity of the polishing is a challenge, calling for an inventive electrode configuration and electrolyte feed solution. The approach was to integrate an electrode on the inside of the converging part of the nozzle, to serve as a cathode for the electropolishing, already in the process, and to make the nozzle itself the vital part of the fluidic system. With this, titanium micronozzles were manufactured with throat diameters varying between 300 and 800 μm. With the resolution of the used AM technique, it was possible to integrate the internal electrode in the micronozzles with a designed throat diameter down to 600 μm. Below this, the anode, and cathode, sometimes made contact short-circuiting the cell. Profilometry showed a decrease of the average surface roughness (𝑅𝑅𝑎𝑎) with 15-60 % for the electropolished micronozzles. The Schlieren imaging showed an exhaust that followed the throat’s axial direction and also demonstrated pressure disks and, hence, a supersonic jet exhaust. This study has shown that AM is a viable choice for manufacturing of rotationally symmetric micronozzles, and that electropolishing could be used to decrease the surface roughness on their inside uniformly with the integration of a cathode. additive manufacturing micronozzle micro rocket nozzle laser-powered powder bed fusion electropolishing supersonic micronozzle supersonic micro rocket nozzle titanium alloy titanium-64 Ti-Al6-V4 Materials Chemistry Materialkemi
33	Problematika obrábění titanových slitin / Problems in machining of titanium alloys Drábek, Tomáš January 2013 (has links) The theoretical part of the thesis contains a brief overview of some experimental methods that are used in machining technologies. The experimental part at first elaborates on the analysis of two titanium alloys. The actual experiment, which consists of milling of the two aforementioned materials with the use of several tools and holders, is then described. It was conducted in collaboration with the company Frentech Aerospace s.r.o. When milling, forces were measured with piezoelectric dynamometer. Further, the analysis of acquired data that is followed with discussion about its main findings, is provided. The conclusion of the thesis deals with the found facts corresponding with the information obtained by analysis of materials. The main results arise out of the comparison of used combinations of tools and holders for milling of material Ti-Al6-V4, observation of impact of particular factors on measured force, or out of different values of measured forces when milling two given materials.
34	Aktuální diverzifikační scénáře Ruské federace na jedné straně a zemí V4 na straně druhé v oblasti dodávek zemního plynu na pozadí teorie vzájemné asymetrické závislosti / Current diversification scenarios of the Russian Federation on one side and the V4 countries on the other with respect to the interdependence theory Záhradníková, Lea January 2017 (has links) The thesis focuses on current diversification scenarios in the field of gas supply the Visegrad Group (V4) and the Russian Federation relying on the model of asymmetrical interdependence. Russian Federation, the main supplier of natural gas to this region, has lost its status of a reliable partner due to the gas wars with Ukraine in 2006 and 2009, which have negatively affected the supply of natural gas to the EU countries. The research focuses on the current diversification options of V4 countries related to their suppliers and supply routes with respect to their relationship with the Russian Federation; the diversification options for the purchasing markets of the Russian Federation are also analyzed. The author validates the hypothesis that energy relations among the Visegrad countries and the Russian Federation in the field of gas supply are largely controlled by the asymmetric interdependence that is currently exacerbating tensions among the set actors. Current diversification scenarios are presented and evaluated, with the aim of assessing the importance of the projects with regard to actors' energy security. Keywords: interdependence, energy security, diversification, gas supply, gas interconnector, V4, Energy Union, Russian Federation, Nord Stream II, LNG
35	Projekty spolupráce soukromého a veřejného sektoru (PPP) v zemích Visegrádské čtyřky / PPP (Public Private Partnership) Projects in the countries of Visegrad Four Slánská, Marie January 2008 (has links) The diploma thesis is concerned with the problems of PPP projects (Public Private Partnership) in the countries of Visegrad Four. The term PPP can be understood as a cooperation of public and private sector. The principal aim of cooperation is to ensure public infrastructure and services. First part of thesis characterizes coutries of Visegrad Four, explains principles and benefits of PPP and informs about main countries and sectors in which PPP projects are realized. The core of the thesis is the fourth chapter which analyzes and evaluates V4 coutries on the basis of several criteria (legislation, institutional support, methodics and realized projects) and attempts to find out if those criteria influence the implementation and number of PPP projects in V4. Final part points out that PPP projects can be helpful for states in times of financial crisis to finance services or infrastructure if they do not have enough money.
36	Polohování objektu ve 3D prostoru pomocí paralelního lanového robota / Object positioning in 3D space using parallel cable-driven robot Rajnoha, Andrej January 2016 (has links) At the beginning of this master’s thesis the definition of types of robots using parallel kinematics are presented, its possibilities of usage and current prototypes are described. The second chapter focuses on the proposal of robot construction and sizing electric and non-electric components of robot hardware. Derivation of direct and inverse transform mechanisms with creating flowcharts of their algorithms are stated in the two following chapters. The state machine controlled from user interface is then programmed based on these flowcharts. At the end of the work, cable-driven robot positioning accuracy is evaluated and platform workspace, together with motion and electric parameters, are measured.
37	Determinanty rozvoje ekonomik zemí V4 a Rakouska / Determinants of Economic Development in V4 Countries and Austria Muzikář, Jakub January 2020 (has links) Determinants, economic growth, models of economic growth, foreign direct investment, openness, international trade, GDP
38	A plm implementation for aerospace systems engineering-conceptual rotorcraft design Hart, Peter Bartholomew 08 April 2009 (has links) The thesis will discuss the Systems Engineering phase of an original Conceptual Design Engineering Methodology for Aerospace Engineering-Vehicle Synthesis. This iterative phase is shown to benefit from digitization of Integrated Product&Process Design (IPPD) activities, through the application of Product Lifecycle Management (PLM) technologies. Requirements analysis through the use of Quality Function Deployment (QFD) and 7 MaP tools is explored as an illustration. A "Requirements Data Manager" (RDM) is used to show the ability to reduce the time and cost to design for both new and legacy/derivative designs. Here the COTS tool Teamcenter Systems Engineering (TCSE) is used as the RDM. The utility of the new methodology is explored through consideration of a legacy RFP based vehicle design proposal and associated aerospace engineering. The 2001 American Helicopter Society (AHS) 18th Student Design Competition RFP is considered as a starting point for the Systems Engineering phase. A Conceptual Design Engineering activity was conducted in 2000/2001 by Graduate students (including the author) in Rotorcraft Engineering at the Daniel Guggenheim School of Aerospace Engineering at the Georgia Institute of Technology, Atlanta GA. This resulted in the "Kingfisher" vehicle design, an advanced search and rescue rotorcraft capable of performing the "Perfect Storm" mission, from the movie of the same name. The associated requirements, architectures, and work breakdown structure data sets for the Kingfisher are used to relate the capabilities of the proposed Integrated Digital Environment (IDE). The IDE is discussed as a repository for legacy knowledge capture, management, and design template creation. A primary thesis theme is to promote the automation of the up-front conceptual definition of complex systems, specifically aerospace vehicles, while anticipating downstream preliminary and full spectrum lifecycle design activities. The thesis forms a basis for additional discussions of PLM tool integration across the engineering, manufacturing, MRO and EOL lifecycle phases to support business management processes. Teamcenter systems engineering Teamcenter community Teamcenter unified Teamcenter engineering Teamcenter manufacturing CATIA V5 Rotorcraft design Boeing AHS Joint heavy lift VPLM MBOM EBOM Product change control Product definition Configuration management Product structure architecture Design engineering Aerospace engineering System engineering PLM CIE IDE SE Affordability Cost savings Executive helicopter Joint chiefs of staff Marine CAE CAD CAM CAA MDO RSM DOE Consulting Engineering management Perfect storm Engineering software Requirements data management CATIA V4 NX Engineering communications RFP Digitization Air Force Navy Army BAMS FIPER ACSYNT Sikorsky Bell Georgia Tech Engineering methodology Requirements engineering System engineering Search Rescue IDE Integrated digital environment Kingfisher Search and rescue Helicopter Helicopter engineering QFD Legacy design IPPD Quality engineering Defense systems acquisition Coast Guard Decision support systems Rotors (Helicopters) Design Concurrent engineering

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