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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Objekt výzkumného centra v Brně - příprava realizace stavby / The Building of the Research Center in Brno - Preparation of Building Process

Dvorník, Pavel January 2012 (has links)
The purpose of the bachelor thesis is to develop selected parts of technologically-building project of the Masaryk university´s campus in Brno, Hall A29. The building will be used as a research establishment. It has eleven building sites and the main one is tackled in detail. The bachelor thesis includes a technical report about the technologically-building project, the time schedule, suggestion of the realization of the main stages of its construction, including recommendation of the major building machines. The bachelor thesis also includes the project of site equipment, technological regulations for carrying out the pilotage, the check and test plan, the plan of safety and health protection during work, the budget of fabric and specialization in the field of building construction.
142

Qualification of a Physical Model of Cladding Creep During Dry Storage of Spent Nuclear Fuel / Kvalificering av en Fysikalisk Modell av Krypning i Kapsling Under Torrt Slutförvar av Använt Kärnbränsle

Andersson, Robin January 2022 (has links)
In dry interim storage of spent nuclear fuel, thermal creep is one of the major threats to the fuel cladding integrity due to the constant decay heat generation from the fission products and minor actinides in the fuel, and the increase in fuel rod internal pressure which is present after burnup. Plenty of research has been done on either empty cladding tubes irradiated in a research reactor, or on spent fuel that is defueled prior to the examination. This type of research excludes the effects of the pellet-cladding bonding that may be present after burnup, where the bonding might have significant effects on the thermal creep behavior. Therefore, this work aims to construct and validate an experimental model that is designed to perform thermal creep tests on as-received spent nuclear fuel, where the pellet-cladding bonding is still intact, in order to gain knowledge in the causal relation that the pellet-cladding bonding has on the thermal creep phenomenon during dry storage. The experimental model is validated by a number of qualification tests, as well as a series of creep tests on unirradiated Zircaloy-4 tubes. The results are compared to the literature which shows the reproducibility of the model, which further supports its validity. / I torrt mellanförvar av använt kärnbränsle så är termisk krypning en av de främsta farhågorna för kapslingens fysiska integritet genom sönderfallsvärmen från klyvningsprodukter och andra aktinider, samt det förhöjda interna trycket i kapslingen som är närvarande efter utbränning. Åtskillig forskning har gjorts på antingen tomma kapslingsrör som är bestrålade i en forskningsreaktor, eller på använt bränsle där bränslekutsen är urborrad innan undersökning. Denna typ av forskning utelämnar effekten av kuts-kapsling bindningen som uppstår under uppbränning, där bindningen kan ha en betydande effekt på kapslingens beteende under termisk krypning. Därför så dedikeras detta arbete till att konstruera och validera en experimentell modell som är designad till att utföra tester av termisk krypning på opåverkat använt bränsle, där kuts-kapsling bindningslagret fortfarande är intakt, för att lära om bindningslagrets effekt på fenomenet termisk krypning under torrt mellanförvar. Den experimentella modellen är validerad genom ett antal kvalificeringstester, samt en serie av kruypningstester på obestrålade Zircaloy-4 rör. Resultaten är jämförda mot litteraturen, vilket visar reproducerbarheten hos modellen, som i sin tur understöder modellens validitet.
143

A material based approach to creating wear resistant surfaces for hot forging

Babu, Sailesh 22 December 2004 (has links)
No description available.
144

Autosalon / Autosalon

Bajer, Radim January 2015 (has links)
This master thesis is focused on elaboration of project documentation for constructing autosalon in Žďár nad Sázavou. Project and appendix are processed by current applicable laws, regulations and standarts. Designed object is situated on plat #6167/2. Both plat sis parts of cadastral area of Žďár nad Sázavou. There are all needed engineering netwoeks nearby. Object is divided on two functional parts, which are operationally and constructionally connected. First part is exhibition and representatice hall, which are capacity of 7 exhibited vehicles. Other partis formed by administrative facilities for staff including sanitary facilities for both staff and visitors. Second part is service for personal and light commercial vehicles with four working stations. Construction is designed reinforced concrete columnar structural system. Plan dimension autosalon is 31,06x22,6m. Plan dimension autoservise is 30,74x18,84m. The cladding autosalon is designed of ceramic tile 250mm. The cladding autoservis is designed of sandwich panel. Roof of building accross the surface is flat roof. Establishment of the object is a combination of footings and foundation belts. Cladding of exhibition hal lis more than 50% glazed. Parts of autosalon and autoservise are designed as sigle storey objects, while administrative part is designed as a two.
145

Ein Beitrag zum Schrägschneiden von Leichtbauprofilen

Kötter, Hanno 21 December 2010 (has links) (PDF)
Gegenstand der Dissertationsschrift ist eine Darstellung des gegebenen Wissensstandes zum Scherschneiden anhand der Literatur, mit einer Einordnung des Schrägschneidens. Auf dieser Grundlage erfolgt eine Verfahrens- und Prozeßbeschreibung des Schrägschneidens, als Variante des Scherschneidens, insbesondere eine Untersuchung des auftretenden Verschleisses. Es wird die Anwendung des Laser-Pulver-Auftragschweißen an Schneidwerkzeugen zur Verschleißminimierung erprobt und bewertet.
146

Raffinement de maillage multi-grille local en vue de la simulation 3D du combustible nucléaire des Réacteurs à Eau sous Pression / Local multigrid mesh refinement in view of nuclear fuel 3D modelling in Pressurised Water Reactors

Barbié, Laureline 03 October 2013 (has links)
Le but de cette étude est d'améliorer les performances, en termes d'espace mémoire et de temps de calcul, des simulations actuelles de l'Interaction mécanique Pastille-Gaine (IPG), phénomène complexe pouvant avoir lieu lors de fortes montées en puissance dans les réacteurs à eau sous pression. Parmi les méthodes de raffinement de maillage, méthodes permettant de simuler efficacement des singularités locales, une approche multi-grille locale a été choisie car elle présente l'intérêt de pouvoir utiliser le solveur en boîte noire tout en ayant un faible nombre de degrés de liberté à traiter par niveau. La méthode Local Defect Correction (LDC), adaptée à une discrétisation de type éléments finis, a tout d'abord été analysée et vérifiée en élasticité linéaire, sur des configurations issues de l'IPG, car son utilisation en mécanique des solides est peu répandue. Différentes stratégies concernant la mise en oeuvre pratique de l'algorithme multi-niveaux ont également été comparées. La combinaison de la méthode LDC et de l'estimateur d'erreur a posteriori de Zienkiewicz-Zhu, permettant d'automatiser la détection des zones à raffiner, a ensuite été testée. Les performances obtenues sur des cas bidimensionnels et tridimensionnels sont très satisfaisantes, l'algorithme proposé se montrant plus performant que des méthodes de raffinement h-adaptatives. Enfin, l'algorithme a été étendu à des problèmes mécaniques non linéaires. Les questions d'un raffinement espace/temps mais aussi de la transmission des conditions initiales lors du remaillage ont entre autres été abordées. Les premiers résultats obtenus sont encourageants et démontrent l'intérêt de la méthode LDC pour des calculs d'IPG. / The aim of this study is to improve the performances, in terms of memory space and computational time, of the current modelling of the Pellet-Cladding mechanical Interaction (PCI),complex phenomenon which may occurs during high power rises in pressurised water reactors. Among the mesh refinement methods - methods dedicated to efficiently treat local singularities - a local multi-grid approach was selected because it enables the use of a black-box solver while dealing few degrees of freedom at each level. The Local Defect Correction (LDC) method, well suited to a finite element discretisation, was first analysed and checked in linear elasticity, on configurations resulting from the PCI, since its use in solid mechanics is little widespread. Various strategies concerning the implementation of the multilevel algorithm were also compared. Coupling the LDC method with the Zienkiewicz-Zhu a posteriori error estimator in orderto automatically detect the zones to be refined, was then tested. Performances obtained on two-dimensional and three-dimensional cases are very satisfactory, since the algorithm proposed is more efficient than h-adaptive refinement methods. Lastly, the LDC algorithm was extended to nonlinear mechanics. Space/time refinement as well as transmission of the initial conditions during the remeshing step were looked at. The first results obtained are encouraging and show the interest of using the LDC method for PCI modelling.
147

Phenomena in material addition to laser generated melt pools

Prasad, Himani Siva January 2019 (has links)
No description available.
148

Natursten : Roll och förutsättningar som fasadmaterial inom byggproduktion / Natural Stones : Capacity and conditions as a façade material within building construction

Benchenaa, Amal January 2007 (has links)
I rapporten har vi skrivit om naturstenens roll och förutsättningar som fasadmaterial inom byggproduktion. Målet med undersökningen var att belysa nya tekniker som finns på marknaden. Metoder som har använts för att undersöka infästningstekniker är genom intervjuer och studiebesök.   Den stora frågan var att ta reda på hur dem nya teknikerna kan påverka vår arbetsmiljö, miljö samt estetik. En annan fråga var hur den nya tekniken kan uppfylla de nya kraven?   Natursten är ett naturligt material som är inhomogen och därför förekommer det färgskiftningar och variationer i stenskivorna. En beställare ska därför vara väldigt specifik när stenen utses.   Det finns en stor risk med att förankra stenskivor utan mekanisk förankring. Utan förankringen kan stenen lossna från fasaden. Idag bygger vi vanligen med tekniken ventilerad luftspalt, mellanrum mellan stenskivor och stomme. På det sättet kan alla stenskivor röra sig utan spänningar samtidigt som luftspalten ventilerar och dränerar ut fukten bakom stenskivorna. Genom att välja lämpliga stendimensioner och ankare i standardutförande kan kostnaderna minskas. Denna rapport tar upp ny teknik. FZP, Fischer Zykon Panel, är ett undercut ankare. Detta är en valmöjlighet om en beställare vill erhålla skivor som är 20 mm i tjocklek.   Björn Shouenborg har designat ett program som gör det möjligt att dimensionera sten på fasader. Programmmet visar om dimensioneringen är ok med hänsyn till säkerhetskraven.   Med tanke på de stora miljökraven som ställs är det både lönande att undersöka möjligheter och ny teknik. Stommen byggs med mer isolering vilket kräver en längre expanderbult eller ankare mellan stenen och stommen.   I denna rapport framkommer det att en arkitekt och stenentreprenör är positiva till ACT-systemet.  Den här rapporten har belyst att den nya tekniken har en positiv påverkan på arbetsmiljön, miljön, estetik och tid. / The report talks about the capacity and conditions as a façade material within building construction. The goal with the research was to shed light on the new technique available today.  The methods used to examine the mechanical anchoring techniques were through interview and fieldstudies. The main question was to find out how those new technologies can affect our health and safety, environment and aesthetics. Another question is how the new technology can meet the new requirements?   Natural stone is a natural material that is inhomogeneous and therefore there are color variations and variations in stone tiles. A client should therefore be very specific when the stone is appointed. There is a great risk to anchor stone tiles without mechanical anchoring, without it the stone can detach from the façade. The technology most commonly used in anchoring stone is using a ventilated air gap, a space between the stone tiles and facade. In this way, all stone tiles move without tension and furthermore the air gap ventilates and drains the moisture behind the stone tiles. It is possible to cut costs by choosing the appropriate stone dimensions and tiles in the standard execution. New technology opens up new possibilities. An alternative is FZP, Fischer Zykon Panel which is an undercut anchor. This could be used as an option if a client wishes to have 20 mm thick tiles. Bjorn Shouenborg, researcher, has designed a program that makes it possible to dimension stone facades.The software that shows if the design is ok with regard to safety requirements.   Given the large environmental requirements imposed today, it is conceivable both be worthwhile to explore the possibilities and new technologies. The façade is built with more insulation which requires a longer expansion of anchors.   In this report, it appears that an architect and stone contractor is positive for the ACT system. This report has highlighted that the new technology has a positive impact on the work environment, the environment, aesthetics and time.
149

Modifications microstructurales sous sollicitations thermomécaniques sévères : application au soudage par résistance des gaines de combustibles en aciers ODS / Microstructural changes under severe thermomechanical conditions : application to resistance upset welding of fuel cladding in ODS steels

Le Gloannec, Brendan 12 December 2016 (has links)
Les aciers renforcés par dispersion d’oxydes (ODS) sont des matériaux candidats pourconstituer les gaines de combustibles des réacteurs nucléaires de IVème génération refroidis au sodium(RNR-Na). Le soudage par résistance en bout de ces gaines est étudié dans ce travail, avec pourobjectif la détermination et la compréhension des effets du procédé sur l’évolution de la microstructuredes aciers ODS à 9 % et 14 % de chrome à l’échelle des grains et des oxydes nanométriques. Uneapproche couplant caractérisations microstructurales sur soudures, simulation numérique et simulationphysique du procédé, à l’aide d’un simulateur thermomécanique Gleeble 3500, est adoptée. Le soudagepar résistance en bout impose localement des conditions de sollicitations sévères en termes dedéformation, vitesse de déformation et température. Ces sollicitations induisent un affinement de lamicrostructure dont l’origine peut être attribuée à un mécanisme de recristallisation dynamique (acier à14 % de chrome) ou à l’association de la recristallisation dynamique et des transformations de phase(acier à 9 % de chrome). Les conditions d’occurrence de la recristallisation dynamique sont étudiéessur ces matériaux. On montre notamment la possibilité d’une transition entre recristallisation dynamiquecontinue et discontinue sur l’acier à 14 % de chrome en fonction des conditions de sollicitation. Il estégalement observé que ces sollicitations thermomécaniques sévères induisent une augmentation de lataille des oxydes nanométriques associée à une diminution de leur fraction volumique. / Oxide dispersion strengthened (ODS) steels are considered as candidate materials for thedevelopment of fuel cladding for sodium-cooled fast reactors (SFR). Resistance upset welding of thecladding is studied in this work. The aim is to determine and to understand the process effects on themicrostructure of ODS steels with 9% and 14% of chromium at the scales of the grains and thenanometric oxides. An approach coupling microstructural characterization of welds, numericalsimulation and physical simulation of the process, using a thermomechanical simulator Gleeble 3500,is proposed. Resistance welding locally imposes severe thermomechanical conditions in terms of strain,strain rate and temperature. Refinement of the microstructure is noted and correspond to a dynamicrecrystallization mechanism (14 % Cr steel) or the combination of dynamic recrystallization and phasetransformations (9 % Cr steel). The conditions of occurrence of dynamic recrystallization are studied.The possibility of a transition between continuous and discontinuous dynamic recrystallization is shownfor the 14 % Cr steel according to the loading conditions. Such severe thermomechanical conditionsinduce an increase in the size of nanoscale oxides associated with a decrease of their volume fraction.
150

Développement de nouvelles matrices vitreuses pour la fonctionnalisation de fibres optiques par l’exploitation de la technologie Poudre / Development of new glassy matrices for the functionalization of the optical fibers by utilization of Powder technology

Kudinova, Maryna 10 December 2015 (has links)
La majeure partie des fibres optiques utilisées dans les domaines des sources optiques et des capteurs sont dites 'fonctionnalisées', c'est à dire qu'elles possèdent des propriétés nouvelles, de par leur nature et/ou leur structure, par rapport aux fibres standards. Pour ce faire, nous allons exploiter la technologie 'Poudre' pour la réalisation de fibres optiques utilisant les propriétés de matrices vitreuses originales développées lors de cette thèse. Trois familles de fibres seront étudier afin de démontrer le fort potentiel de cette association, matériaux – technologie. La première exploitera la structuration de la gaine optique à l'aide de deux barreaux de verre vitreux (type Panda), dopés ou non à l'aide d'oxyde de cuivre. L'étude de cette fibre sera faite depuis la synthèse du matériau jusqu'au test de cette fibre en tant que capteur. La seconde fibre nous amènera à concevoir un verre optique inédit à ce jour, à définir la composition optimale et la décliner sous forme d'une fibre optique incluant ce verre pour le cœur. Enfin le procédé de fabrication de fibres optiques sera utilisé pour réaliser de premières fibres optiques à cœur vitrocéramique, c'est à dire partant d'une matrice vitreuse spécialement développée pour cette application arriver à faire croitre les nanostructures dans le cœur de la fibre et obtenir ainsi une famille de fibre inédite. / The main part of optical fibers used in the fields of optical sources and sensors are called 'functionalised', i.e. they have new properties, due to their nature and/or structure, compared to standard fibers. To do this, we will use 'Powder' technology for the realization of optical fiber using properties of original vitreous glasses developed during this thesis. Three families of optical fibers will be studied in order to demonstrate the great potential of this association, materials - technology. The first exploit the structuring of the cladding with two vitreous glass rods (Panda type) doped or not with copper oxide. The study of this fiber is done from the synthesis of the material up to the test of this fiber as a sensor. The second fiber leads us to design a novel optical glass matrix, to define the optimal composition and decline form of an optical fiber including the glass for the core. Finally, the optical fiber manufacturing process is used to produce optical fiber with glass-ceramic core, i.e. starting from a vitreous matrix specially developed for this application happen to grow the nano-structures in the core of the fiber and obtain a novel fiber family.

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