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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.
1

Formulation et propriétés d’une mousse utilisée dans l’amortissement de chute et de chocs dans le domaine de l’industrie du nucléaire / Formulation and properties investigation of foams used as shock absorber in the nuclear field

Mougel, Christophe 20 July 2018 (has links)
Les travaux présentés dans ce manuscrit ont été consacrés à la compréhension du procédé de fabrication des mousses phénoliques et de la chimie associée, dans le but de proposer des modifications de la formulation permettant l’amélioration de ses propriétés mécaniques (friabilité et comportement en compression). Dans un second temps, les propriétés mécaniques en compression, en flexion et la friabilité ont été caractérisées en fonction de la densité relative de la mousse. Les caractéristiques de compression ont été modélisées et comparées aux modèles de Gibson et Ashby. Les résultats montrent que le module d’Young et la contrainte au plateau de compression sont des fonctions quadratiques de la densité relative. Le comportement thermique de la mousse phénolique a été également étudié. L’évolution de la structure chimique des résidus obtenus après différents traitement thermique a été suivie par IRTF. Les observations spectrales ont été interprétées en fonction des réactions de dégradat ion proposées dans la littérature. Les paramètres cinétiques de dégradation de la mousse phénolique ont été déterminés grâce à différentes méthodes dites « model-free kinetic» développées par Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose et Friedman. Finalement, dans une première approche, nous avons essayé de déterminer les paramètres cinétiques, en condition isotherme, du phénomène d’oxydation qui apparait à faible température / The following work has been devoted to the understanding of the phenolic foam manufacturing process and the associated chemistry, to propose modifications of the formulation itself that allows an enhancement in mechanical properties (friability and compression behavior). In addition, these mechanical properties in compression, bending and brittleness were characterized as a function of the foam relative density. Compression properties were modeled and compared to the Gibson and Ashby models. Results show that Young's modulus and collapse plateau stress are quadratic functions of the relative density. Moreover, the thermal behavior of the phenolic foam was also studied. The evolution of the chemical structure of the obtained residues after different thermal treatment was followed by FTIR. Spectral observations were interpreted according to the degradation reactions proposed in the literature. The kinetic parameters of phenolic foams degradation have been determined using different "mo del-free kinetic" approaches, developed by Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose and Friedman. Finally, in a first approach, we tried to determine the kinetic parameters, in isothermal condition, of the oxidation phenomenon that appears at low temperature
2

Vliv provedení zateplení administrativní budovy v Blansku na výdaje spojené s jejím provozem / The impact of executing new thermal insulation on an administrative building in Blansko on the expenses associated with its operation

Kopřivová, Petra January 2016 (has links)
The topic of the diploma thesis „ The impact of executing new thermal insulation on an administrative building in Blansko on the expenses associated with its operation“ is a draft and appraisal of four variants of thermal insulation of the building (EPS, EPS G, Mineral wool, Phenolic foam). It deals with an actual building situated in Blansko. All the variants are projected according to the same technical specifications (thermal transmittance) and their thermal parameters, technical parameters and the rate of return have been assessed. The assessed building (The A building) is at rectangular shape. It has six above - ground floors and a basement, it contains mainly administration sites. The construction system is concrete frame, which has curtain wall made of perforated blocks with thickness 250 mm. The building has got reinforced concrete floors, the roofing is made of double-skin roof construction. The supply for heating is a separate gas boiler room.
3

Vliv provedení zateplení bytového domu na výdaje spojené s provozem této nemovitosti / The impact of executing new thermal insulation on a apartment building on the expenses associated with its operation

Machová, Petra Unknown Date (has links)
The topic of the diploma thesis „The impact of executing new thermal insulation on a apartment building on the expenses associated with its operation “ is a draft and appraisal of four variants of thermal insulation of the building. The thesis deals with the assessment of the current proposal for apartment building envelopes along with proposing alternative plans with emphasis on reducing heating costs. The first section describes the types of buildings according to heating demand and a list of different variants of thermal insulation materials. The second part is devoted to a specific apartment building in the Ústí nad Labem for which there are designed in four variants of insulation. The work includes thermal assessment in original condition and the assessment of new condition modified by adding thermal insulation. Through research will bedetermined price of implementation of proposed insulation options together with the costs of operation of the apartment building. In conclusion, the diploma thesis evaluates the payback period of insulation.

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