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Advanced Layered Composites for Dental Applications
Šedivý, Zbyněk ; Kučera, Jaroslav (referee) ; Štěpánek, Petr (referee) ; Jančář, Josef (advisor)
Disertační práce se zabývá mechanickou odezvou vrstevnatých kompozitů pro stomatologické aplikace. Různé skladby vrstev a různé částicové a vláknové kompozity jsou studovány v tříbodovém ohybu za pokojové teploty. Tyto výsledky jsou korelovány s výstupy dynamické termomechanické analýzy (DMTA) a optické analýzy (vysokorychlostní video záznam, SEM). Exeprimentální data byla použita pro srovnání s výsledky analytických a numerických modelů s cílem určit nejvhodnější model pro predikci základních mechanických vlastností vrstevnatých kompozitů. Na základě těchto analýz jsou navržena základní pravidla pro klinické použití vrstevnatých kompozitů ve stomatologických aplikacích jako jsou minimálně invazivní můstky nebo stabilizační dlahy.
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Modification of Polypropylene by Reactive Compounding
Svítil, Jan ; Kučera, Jaroslav (referee) ; Petrůj, Jaroslav (advisor)
Knowledge of radical initiated grafting was summarized in theoretical part. It also contains a part about adamantane, its derivatives and a study of their use in polymer chemistry. In experimental part radical grafted polypropylene was prepared in batch mixer Brabender at 185 and 195 °C, 40 RPM and reaction time 5 min. Initiator 2,5-dimethyl-2,5-bis(tert-buthylperoxy)hexane (Trigonox 101) in concentrations between 0,2 – 4 wt % was used. 1-vinyladamantane was chosen as a monomer and its concetration ranged from 0,75 to 2,24 wt %. Mechanical properties of prepared samples were tested. Sample with content of initiator 0,2 wt % and monomer 1,4 wt % showed increase in notch toughness by 56,3 %, strength by 8,7 %, ductility by 11,5 % and decrease in MFR (230 °C; 2,16 kg) by 29,7 %. Values of torque indicated grafting reactions which couldn’t be proven by use of FTIR method so more suitable methods have been proposed.
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The Effect of Temperature Annealing on Structure-Property Relationship of Oriented Polypropylene
Sadílek, Jiří ; Jančář, Josef (referee) ; Kohout,, Jan (referee) ; Hell,, Jaroslav (referee) ; Kučera, Jaroslav (advisor)
The aim of this work is to study the effect of thermal history to structure and properties not only of oriented polypropylene monofilaments with different orientation but of course of isotropic non-oriented polypropylene. Term thermal history includes thermal regimes from alpha relaxation temperature (T?) to melting temperature (Tm). This work consists of three parts. The changes of dynamic mechanical properties, strength, deformation and tensile modulus of polypropylene samples according to annealing temperature (Ta) are described in the first part of this work. In the second part, the changes of crystal phase are observed. Preferentially, calorimetric behaviour (DSC), changes of crystal dimensions and orientation function of crystal phase (X-ray) are observed. Measured values from the first and the second part of this work were used for calculation of total orientation function of PP samples. Rheological measurements are shown in the third part of this thesis. Rheological measurements consist of short isothermal creep, shrinkage of free tapes and static deformation at higher temperatures. Measured rheological values were performed using rheological models. Using these models characteristics of entropic spring, instantaneous elasticity and viscosity and tendency to get to state of ease were calculated.
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Fracture Behaviour of Pipe Grade Polyolefins
Fiedler, Lubomír ; Hutař, Pavel (referee) ; Kučera, Jaroslav (referee) ; Vlach, Bohumil (advisor)
The thesis deals with the study of the fracture behaviour of the pipe grades of high density polyethylene (HDPE). Detailed study of current state of knowledge was performed in the first part. The focus was put on those types of polymers used for pipeline applications, the limit states of the plastic pipes, and the key parameters affecting the fracture behaviour of plastic pipes’ materials. The methods used for testing the plastic pipes and native pipeline materials were summarized. In the second part of this work, the relationship between the processing conditions, internal structure and fracture behaviour of the native types of HDPE pipe grades was evaluated. Than, the correlation between short-term alternative tests and the standardized accelerated full notch creep test (FNCT) was studied. An experimental basis for numerical model for evaluation of the fracture behaviour of multilayer pipes was established. Two types of non-homogeneous specimens for evaluating the resistance of multilayer pipes against slow crack growth (SCG) were suggested. This evaluation was based on the parameters of linear elastic fracture mechanics (LEFM) and elasto-plastic fracture mechanics (EPFM).
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The impact of the arrival of displaced Germans for the economic development of the Federal Republic of Germany.
Hudecová, Dominika ; Kučera, Jaroslav (advisor) ; Konrád, Ota (referee)
The objective of this work is to analyze the influence of the arrival of expelled Germans on postwar reconstruction of West Germany in connection with their labor market integration. The precondition how to become an active participant on the economy recovery is a stable job. The conclusion of this work is, that expelled Germans were from the beginning an active part of postwar economic reconstruction of Germany, despite of the fact, that there were some structural problems in the economy like a black market, lack of accommodation facilities in the cities or unequable dislocation of these people in the occupied zones. These problems were removed by the currency and economy reforms. After the reforms came in sight, that expelled Germans represented a positive part of the economic reconstruction in form of free, qualified and cheap labour force, which could be purposefully use. This evaluation is based on critical interpretation of the facts received from the literature, scholarly articles and Internet sources.
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The development of the culture of remembrance of the Sudeten Germans and their expulsion in Ústí nad Labem after 1989
Masopustová, Sára ; Kučera, Jaroslav (advisor) ; Nigrin, Tomáš (referee)
The aim of the thesis is to explore how the culture of remembrance regarding the Sudeten Germans and their expulsion developed in Ústí nad Labem after 1989. The author tries to find out what were the forms of remembrance and commemoration and which actors participated in it and moved it forward. The thesis mentions how the elected political representation of the city contributed to the commemoration or what was the role of the state for instance in establishing institutions or museums focusing on remembering Germans and expulsion. The role of the public and citizens association is mentioned as well. Since the culture of remembrance includes all forms of remembering, the thesis not only focuses on the important moments of the city when the commemorative plaques were first unveiled, but the author also emphasizes another form of public remembrance as culture or cultural heritage. Ústí nad Labem was historically shaped by the German population and at the end of the Second World War one of the massacres of the German population took place here, it is necessary to mention the historical context in the first part. The thesis briefly discusses the communist period, when the expulsion of Germans and the Czech-German past was erased from the collective memory of society and when anything that in any way...
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The Problems of the Soul in the Context of Christianity
KUČERA, Jaroslav
The thesis deals with the emergence of the concept of soul and its anchoring in Christianity. In this context, the theisis indicates the importance of the posthumous surviving element, that is crucial in eschatological expectations. It answers the question of whether the "soul" is a church mechanism to ensure the obedience of believers, as profane society often believes. By describing the eschatological concepts of two Christian wholes, one of which treats the soul differently, the thesis reveals consequences that culminate in a very peculiar interpretation of Scripture. Finally, the thesis shows the "soul" as a theologically necessary category to ensure a cohesive Christian system in the light of biblical statements.
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The Sudeten German question in the Federal Assembly elections of 1990 and 1992
Kloučková, Klára ; Kunštát, Miroslav (advisor) ; Kučera, Jaroslav (referee)
The Sudeten German matter is a topic that repeatedly appears in Czech election campaigns. After the Velvet Revolution, the Sudeten German matter came to the forefront of social debates and became part of the election campaign. This paper examines how the various political parties worked with this issue in the run-up to the Federal Assembly elections in 1990 and 1992. For this purpose, a media analysis of selected periodicals was carried out for a month before the elections. The theoretical part of the thesis describes the different aspects of the Sudeten German question and the interested parties in the period under study. These aspects include mainly the historical dimension of Czech-German relations. The interested parties took different positions on these issues, which resulted in the conflict potential of the Sudeten German matter. The media analysis for 1990 did not show any significant use of the Sudeten German issue, with the exception of two left parties. For 1992, the results were already more convincing, also due to the larger number of available periodicals. The analysis shows that mainly left-wing parties and periodicals criticized government actions in the context of the approval of the Czechoslovak-German Treaty of Good Neighbourliness and Friendly Cooperation. They used emotional and...
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Reflection of the Sudeten German question in the Czech press in the crisis year 1938: Právo lidu and Venkov
Holmanová, Kateřina ; Kučera, Jaroslav (advisor) ; Konrád, Ota (referee)
anglicky The purpose of this thesis is to explore how the papers Právo lidu and Venkov, viewed the Sudeten German question in 1938 and how they expressed their opposition to the situation. The first key affair of 1938, which greatly strained coexistence between Czechs and Germans in Czechoslovakia, was the Anschluss of Austria, which many Sudeten Germans enthusiastically supported. This soon became the inspiration for a more severe solution to the Sudeten German question. The Anschluss supplied many Sudeten Germans with the conviction that the disputed Czechoslovak border areas would be annexed by the German Reich. This contributed towards increased hostilities between SdP supporters and Czechoslovak authorities. In negotiations with the government, Henlein pretended to be interested in improving the position of the German minority in Czechoslovakia, but in reality, the SdP sought to make the Sudeten-German issue a subject of international policy negotiations. The increased conflict, hand in hand with the gradual sharpening of SdP policy, radicalized the German population, primarily affecting the activist parties, who gradually lost all remnants of their support. Considering the tight scope of this bachelor thesis it would be impossible to record and recount the entire media spectrum of the period,...
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