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Design and realization of the pull strength measuring device for SMD
Valíček, Jan ; Klíma, Martin (referee) ; Otáhal, Alexandr (advisor)
This thesis deals with the design and implementation of a device for measuring pull strength by surface mounted devices (SMD). It analyzes the theory of pull strength testing of solder joints with emphasis on standard IEC 62137-1-3 and describes the selection of components utilized to create mechanical construction and electrical parts. These electronic parts made or innovated in this work were control system based on microcontroler Atmega164P, power circuit for stepper motor and communication of measure equipment TEST 321 with PC. The whole design is complemented by simulation of mechanical stress to the critical components using ANSYS. The conclusion summarizes the most important parameters of this equipment.
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Realization of hybrid integrated circuits leads for high-temperature applications
Valíček, Jan ; Jankovský, Jaroslav (referee) ; Řezníček, Michal (advisor)
Bachelor thesis deals with realization possibilities of hybrid integrated circuit terminals for high temperature applications. It describes the realization method of direct mounting of terminals, this method of fixation using the conductive paste for the thick film technology. It also describes the selection of suitable materials and the temperature profile in the reflow and muffle furnace and follow removal of terminal oxides. Furthermore, a method for testing of terminals thermal resistance was realized. In conclusion, the method shows increased mechanical strength with the using of dielectric paste.
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Static and dynamic assessment of an outlook tower construction
Valíček, Jan ; Kala, Jiří (referee) ; Salajka, Vlastislav (advisor)
This thesis deals with static and dynamic analysis of an lookout tower construction. For dynamic analysis a computational model in ANSYS software is created. Static analysis is performed by Scia Engineer software. Both of this software use finite element method. It is also focused on wind load determination by Eurocode 1, structural factor calculation, modal analysis and vortex shedding. Verification of selected parts according to Eurocodes is included.
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Application of Spectral Analysis in 3D Evaluation of Surfaces
Brillová, Kateřina ; Valíček, Jan (referee) ; Hloch,, Sergej (referee) ; Ohlídal, Miloslav (advisor)
Thesis deals with the spectral analysis of 3D surface topography. The surface is described by a random function. Theoretical starting points necessary for right introduction and understanding of basic notions used within the framework of the surface topography spectral analysis are exactly formulated. They lie in the theory of random functions, the theory of the Fourier transform and the theory of signal processing. The notions mentioned are: the areal power spectral density (APSD) of a surface, the radial power spectral density (RPSD) of a surface and the angular power spectrum density (AnPSD) of a surface. These notions are introduced in their discrete form and generalized for the two-dimensional case. The thorough discussion of possible mistakes and inaccuracies which can be done during the application of spectral analysis techniques in a surface topography evaluation is performed. The procedure of APSD estimation by means of the periodogram method combined with the Welch´s method is discussed. The principle and capabilities of the optical profilometer MicroProf?FRT used for the surface topography measurement are described. Our original computer program computing APSD, RPSD and AnPSD is described too. The 3D spectral analyses is applied to surfaces generated by AWJ cutting, plane grinding and casting. We have focused our attention to AWJ cut surfaces, 3D spectral analyses of which brings new still unpublished opportunities of the surfaces topography evaluation. The influence of technological parameters on these AWJ cut surfaces topography is studied. The conclusion of the study is that results of the spectral analyses of these surfaces topography strongly depend on the technological conditions of the surfaces generation. An original procedure of the ASPD shape evaluation within individual regions of its frequency domain is mentioned. This procedure brings new substantial knowledge concerning the topography of surfaces. Results obtained from surfaces generated by plane grinding and casting are presented like examples of results from non-isotropic and isotropic surfaces.
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The cooperative as a business entity
Valíček, Jan ; Zahradníčková, Marie (advisor) ; Oehm, Jaroslav (referee)
1 Abstract The cooperative as a business entity The goal of this thesis is to look at the cooperatives from a different point of view as a business entity. The difference is explained on a fact that normally the cooperative is connected with ensuring of economic, social and other needs of its members. Chapter One deals with the basic features of a cooperative. With regard to the limited range of this thesis it considers only chosen features influencing the functioning of the cooperative as a business entity. Firstly a cooperative, entrepreneurship as a core of the market economy and the correlation between them is described. Then the thesis compares a cooperative with companies based on selected features. Chapter Two concentrates on types of cooperatives, on their constitution and utilization for business. This chapter focuses on housing cooperatives, consumer cooperatives, production cooperatives and credit unions. Last but not least the thesis comments the importance of alliances increasing competitiveness and advantages for the cooperative members. Chapter Three provides an outline of the European Cooperative Society. It is a necessary part with regard to the membership of Czech Republic in the European Union. The most important and most interesting parts related to the business utilization of the...
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The cooperative as a business entity
Valíček, Jan ; Zahradníčková, Marie (advisor) ; Oehm, Jaroslav (referee)
1 Abstract The cooperative as a business entity The goal of this thesis is to look at the cooperatives from a different point of view as a business entity. The difference is explained on a fact that normally the cooperative is connected with ensuring of economic, social and other needs of its members. Chapter One deals with the basic features of a cooperative. With regard to the limited range of this thesis it considers only chosen features influencing the functioning of the cooperative as a business entity. Firstly a cooperative, entrepreneurship as a core of the market economy and the correlation between them is described. Then the thesis compares a cooperative with companies based on selected features. Chapter Two concentrates on types of cooperatives, on their constitution and utilization for business. This chapter focuses on housing cooperatives, consumer cooperatives, production cooperatives and credit unions. Last but not least the thesis comments the importance of alliances increasing competitiveness and advantages for the cooperative members. Chapter Three provides an outline of the European Cooperative Society. It is a necessary part with regard to the membership of Czech Republic in the European Union. The most important and most interesting parts related to the business utilization of the...
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Realization of hybrid integrated circuits leads for high-temperature applications
Valíček, Jan ; Jankovský, Jaroslav (referee) ; Řezníček, Michal (advisor)
Bachelor thesis deals with realization possibilities of hybrid integrated circuit terminals for high temperature applications. It describes the realization method of direct mounting of terminals, this method of fixation using the conductive paste for the thick film technology. It also describes the selection of suitable materials and the temperature profile in the reflow and muffle furnace and follow removal of terminal oxides. Furthermore, a method for testing of terminals thermal resistance was realized. In conclusion, the method shows increased mechanical strength with the using of dielectric paste.
|
|
|
Application of Spectral Analysis in 3D Evaluation of Surfaces
Brillová, Kateřina ; Valíček, Jan (referee) ; Hloch,, Sergej (referee) ; Ohlídal, Miloslav (advisor)
Thesis deals with the spectral analysis of 3D surface topography. The surface is described by a random function. Theoretical starting points necessary for right introduction and understanding of basic notions used within the framework of the surface topography spectral analysis are exactly formulated. They lie in the theory of random functions, the theory of the Fourier transform and the theory of signal processing. The notions mentioned are: the areal power spectral density (APSD) of a surface, the radial power spectral density (RPSD) of a surface and the angular power spectrum density (AnPSD) of a surface. These notions are introduced in their discrete form and generalized for the two-dimensional case. The thorough discussion of possible mistakes and inaccuracies which can be done during the application of spectral analysis techniques in a surface topography evaluation is performed. The procedure of APSD estimation by means of the periodogram method combined with the Welch´s method is discussed. The principle and capabilities of the optical profilometer MicroProf?FRT used for the surface topography measurement are described. Our original computer program computing APSD, RPSD and AnPSD is described too. The 3D spectral analyses is applied to surfaces generated by AWJ cutting, plane grinding and casting. We have focused our attention to AWJ cut surfaces, 3D spectral analyses of which brings new still unpublished opportunities of the surfaces topography evaluation. The influence of technological parameters on these AWJ cut surfaces topography is studied. The conclusion of the study is that results of the spectral analyses of these surfaces topography strongly depend on the technological conditions of the surfaces generation. An original procedure of the ASPD shape evaluation within individual regions of its frequency domain is mentioned. This procedure brings new substantial knowledge concerning the topography of surfaces. Results obtained from surfaces generated by plane grinding and casting are presented like examples of results from non-isotropic and isotropic surfaces.
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Static and dynamic assessment of an outlook tower construction
Valíček, Jan ; Kala, Jiří (referee) ; Salajka, Vlastislav (advisor)
This thesis deals with static and dynamic analysis of an lookout tower construction. For dynamic analysis a computational model in ANSYS software is created. Static analysis is performed by Scia Engineer software. Both of this software use finite element method. It is also focused on wind load determination by Eurocode 1, structural factor calculation, modal analysis and vortex shedding. Verification of selected parts according to Eurocodes is included.
|
|
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Design and realization of the pull strength measuring device for SMD
Valíček, Jan ; Klíma, Martin (referee) ; Otáhal, Alexandr (advisor)
This thesis deals with the design and implementation of a device for measuring pull strength by surface mounted devices (SMD). It analyzes the theory of pull strength testing of solder joints with emphasis on standard IEC 62137-1-3 and describes the selection of components utilized to create mechanical construction and electrical parts. These electronic parts made or innovated in this work were control system based on microcontroler Atmega164P, power circuit for stepper motor and communication of measure equipment TEST 321 with PC. The whole design is complemented by simulation of mechanical stress to the critical components using ANSYS. The conclusion summarizes the most important parameters of this equipment.
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