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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.
11

Modelování tepelných poměrů objektu. / Modeling of heat conditions of the object.

Weinfurtner, Jaroslav January 2016 (has links)
This thesis is dedicated to the usage of Finite element method for the purpose of modeling heat transfer within an object. The introduction describes the origin, application and principle of FEM. Then follows the description of ElmerFEM as the main tool for the calculation of heat transfer in a model. The work also includes a characterization of the tool for making and preparation of models Gmsh and another application for displaying results ParaView. Thesis then focuses on the analysis of the model preparation and the effect of these preparations on accuracy and calculation period. Lastly, results are displayed as well as the identification of problematic parts of the solution and finally some possibilities of scripting are showed.
12

Induction of ABCA1 Expression Is Correlated With Increased CREB Phosphorylation and Altered Cytokine Secretion

Zaid, Maryam January 2011 (has links)
ABCA1 is believed to affect macrophage inflammatory responses, but the mechanism by which ABCA1 may impact cytokine secretion in macrophages has yet to be fully defined. We observed that the induction of ABCA1 expression in three different cell lines, namely BHK, RAW 264.7 macrophages, and primary bone marrow derived macrophages (BMDMs), results in a significant increase in phosphorylated CREB, a known protein kinase A (PKA) substrate. In RAW macrophages, induction of ABCA1 expression by the LXR-agonist T0901317 is correlated with a decrease in LPS-stimulated secretion of proinflammatory cytokines IL-6 and TNF-α. Additionally, the secretion of anti-inflammatory cytokine IL-10 was increased upon ABCA1 induction. A similar trend was observed in BMDMS: ABCA1-expressing BMDMs released less TNF-α and more IL-10 compared to ABCA1-knockout BMDMs. We speculated that the inflammation modulating effects of ABCA1 in macrophages could be a result of PKA activation. Indeed, we found that the LXR-induced ABCA1 phenotype can be mimicked by cAMP in macrophages. 8-bromo-cAMP, a PKA activator, dose-dependently suppressed inflammatory cytokine secretion while promoting IL-10 release in the absence of ABCA1 expression. Finally, we found that the T0901317-induced ABCA1 expression is correlated with higher expression levels of MKP-1, a downstream target of PKA known to suppress inflammatory responses. Together, our results suggest that ABCA1 expression may activate PKA and CREB and that such activation may contribute to the inflammatory modulating effects of ABCA1.
13

Konstrukční návrh nesymetrické parabolické pružiny / Design of Asymmetrical Parabolic Spring

Žák, Ondřej January 2018 (has links)
This thesis is focused on design of parabolic spring for a truck. Characteristics of the spring are designed with respect to loads during heavy braking. Thesis contains a brief summary of current truck suspension, the spring design and suggestion for testing methodology for longitudinal load.
14

Studie využitelnosti PDE toolboxu MATLABu v mechanice / Study of MATLAB PDE toolbox usability in mechanics

Kováč, Patrik January 2021 (has links)
This thesis deals with the practical usability of the PDE Toolbox in the MATLAB. It brieflydescribes the mathematical fundamentals of solution. The thesis presents the possibilitiesof PDE Toolbox in the creation of the model, geometry, boundary conditions, mesh and displayof results. The PDE Toolbox results from selected tasks from static, modal and transientmechanics and thermomechanics are compared with the analytical solution or with the FEMsimulation from the ANSYS. The main part deals with the evaluation and generalizationof results.
15

Tvorba metodiky pro výpočet zbytkových napětí svařence v programovém prostředí Salome Meca / Development of a methodology for calculating the residual stresses of a weldment in the Salome Meca software environment

Babišta, Jan January 2021 (has links)
The usage of welding in the process of manufacturing has become very widespread, mainly due to its low cost, versatility and the possibility of its automation. With its expansion comes higher demand for the possibilities of weld evaluation during the phase of design. Nowadays its possible to use tools based on finite element method for such evaluation. But the most commonly used tools are often very expensive. Therefore, the possibility of using Open-Source tool such as Salome-Meca to simulate the welding process as an alternative to commercial software was investigated. The first part of the work deals with the welding process and a description of the formation of residual stresses and deformations. It also deals with the description of the Salome-Meca software environment and the Code-Aster solver. In the next part the capabilities of the software in relation to problem of welding simulation are discussed. Furthermore, the goemetry of solved weldment, welding conditions, material properties and boundary conditions of the calculation are described. And finally, the individual solutions, their results and disadvantages of used approaches.
16

Rám přívěsu pro přepravu odvalovacích kontejnerů / Trailer frame for transport of container with driving drum

Vlasák, Ondřej January 2009 (has links)
This diploma thesis deals with the strength analysis of three-axle frame for containers with driving drum. Total weighth of the trailer is 27 000 kg. Finite elemenths method was used for this calculation in programme I-DEAS. Dangerous parts of the construction were examined and their optimization was proposed. The final part consists of the drawing documentation of the recomended design changes.
17

Návrh řešení potrubní sítě v energetice / Design of energetic unit pipeline

Adamec, Martin January 2010 (has links)
This diploma work is aimed at a proposal and an overall controll of the pipeline net. There is a preliminary calculation performed (by the analytical method) in this diploma work. There is also a comparison with the numerical computing to find out whether the pipe branch does or does not comply.
18

Píst zážehového motoru na CNG o výkonu 140 kW / Piston for SI CNG 140 kW Engine

Hrouzek, Jan January 2013 (has links)
This master’s thesis deals with the piston for modified engine 1.4 TSI from Volkswagen concern. It includes calculation of kinematics and forces reactions of the crank mechanism of the engine for speed 6071 rpm elaborated in the program Mathcad Prime. Further the work includes calculation for reducing the magnitude of lateral force and design of several variants of the piston. For the proposed design variants of the piston are performed FEM analysis of mechanical state of stress and comparisons of contact pressures in the program ANSYS Workbench.
19

Pevnostní kontrola nákladního přívěsu HTV 18 / The FEM analysis truck trailer HTV 18

Chalupa, Pavel January 2014 (has links)
The subject of this master's thesis is the strength analysis of the cargo trailer HIPOCAR HTV 18 and proposed modifications. For the strength analysis was selected finite element method. The frame model was modified by the results of the strength analysis. After that has been carried out the strength analysis of the modified frame.
20

Návrh a výroba experimentálního dílu nápravy / Design and production of experimental axle part

Volfík, Jiří January 2015 (has links)
The content of this diploma thesis is a design of construction and selection of suitable material for upper-carrier part used for racing vehicle, produced by FDM 3D printing with the alternative option to replace an existing part, which was produced by conventional technique of CNC machining. Various versions of the experimental part are analyzed by FEM and compared in terms of safety coefficient with target to select the most appropriate construction design. The chosen version of the model is at the end compared with already existing part, which was also analyzed by FEM.

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