National Repository of Grey Literature 67 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Quaternary climate and origin of eolian deposits
Obersteinová, Tereza ; Kadlec, Jaroslav (advisor) ; Martínek, Karel (referee)
The Quaternary climatic conditions have controlled the origin of eolian deposits. The loess/paleosol sequences represent a valuable natural archives used for understanding of Quaternary climate and stratigraphy. Loess deposits cover about 10% of the continent areas. We can compare a proxy-record from these sediments, often from distant areas, to get knowledge of global significance. The applied mineral magnetic analyses enable understand the paleoenvironmental signal preserved in the loess/paleosol sequences and compare it with a proxy-record obtained from deep ocean sediments
Magnetic fabric of loess and paleosols on selected localities in South Moravia
Obersteinová, Tereza ; Kadlec, Jaroslav (advisor) ; Chadima, Martin (referee)
Pleistocene loess-palaeosol sequences provide a unique proxy-record enabling detailed reconstruction of Quaternary palaeoenvironments. Environmental magnetic methods are often used to read the natural archives. The loess-palaeosol sequences exposed in two sections located in southern Moravia and a sequence from central Bohemia were studied in a frame of this Diploma Thesis. Variations of bulk magnetic susceptibility, measured in the sediments, show similar pattern as in the Chinese loess-palaeosol bodies - i.e. palaeosols reveal higher magnetic susceptibility in comparison with loess due to magnetic enhancement. The magnetic enhancement is driven by weathering during pedogenic processes related to the formation of ultra-fine magnetite particles. The magnetite content is controlling the sediment magnetic behavior. The magnetic enhancement rate indicates more intense pedogenic processes in the Moravia in comparison with Bohemia. Magnetic fabric in studied loess, represented by space orientation of anisotropy of magnetic susceptibility ellipsoid, indicates dominating glacial wind palaeocurrents across the southern Moravia blowing from W or SW, respectively. The magnetic fabric in the central Bohemian sequence has revealed a dominant control of running water and re-deposition of the loess material...
DC motor controller module
Duz, Aleksei ; Kadlec, Jaroslav (referee) ; Kuchta, Radek (advisor)
This thesis focuses on the design and creation of control unit for DC motors drives. A principle on which the DC motor is based, a method of its control and a possibility to obtain current information about the position are briefly described in this work. After that, the different types of buses for communication with a superior system and justification of the chosen one, are presented. In the next section, there is a special emphasis on creation of the suitable driver model and a design of the elecrical schematic and PCB. The end of the thesis contains a description of commission a PCB and testing the main functions.
Simulation of Collision Handling Based on Physical Model
Maštera, Petr ; Kadlec, Jaroslav (referee) ; Pečiva, Jan (advisor)
This MSc Thesis focuses on the collision detection between scene objects and consequent resolution of such collisions on the basis of physical model. The implementation of all the applications and algorithms is achieved in Win32 environment in Visual Studio using the programming language C++; it also employs the graphical library Open Inventor based on OpenGL. The work also includes additional application for the calculation of physical values. The demo applications involve algorithms for detection and resolution of explosive collision by the use of a simple and physical reflection on the basis of physical formulas and relationships. The main demo application called "tunnel transit" incorporates a simple game engine. The thesis also includes a discussion over the aroused problems with collision solving and some suggestions how to overcome them.
Magnetic fabric of detrital sediments as a record of depositional processes and tectonic deformation
Hladíková, Karolína ; Martínek, Karel (advisor) ; Kadlec, Jaroslav (referee)
Fabric of sedimentary rocks can be studied by the analysis of magnetic properties, especially by magnetic anisotropy. Anisotropy of magnetic susceptibility (AMS) is a relatively easy and quick method capable to recognize the rock fabric (primary or secondary). The results of AMS are strongly dependent on magnetic properties of rock- forming minerals and their preferred orientation. The preferred orientation of grains develops by sedimentation, post-depositional diagenetic processes and eventually by tectonic deformation, which can totally overprint the primary structure in some cases. I applied AMS to study the magnetic fabric of fine-grained lacustrine sedimentary rocks from 9 different beds of Vrchlabí section, situated in the northern part of the Krkonoše Piedmont Basin. Paramagnetic minerals dominate the magnetic susceptibility, with possible small amount of ferromagnetic phases of some iron oxides. Most of the samples are laminated mudstones and they have depositional magnetic fabric carried by flat grains of clay minerals deposited horizontally from suspension. Carbonate bed shows signs of inverse magnetic fabric, which is in accordance to magnetocrystalline anisotropy of calcite. Magnetic fabric of early tectonic overprint, probably present in some black shale and siltstone beds, may be...
Structural Properties of Ultralight Concrete and its Optimal Application in Structures
Kadlec, Jaroslav ; Bílek,, Vlastimil (referee) ; Adámek, Jiří (referee) ; Terzijski, Ivailo (advisor)
This doctoral thesis deals with design of three variants of ultra lightweight concrete (ULC) and their mechanical properties. The ULC usually has the dry density of 900-1200 kg/m3 and it is possible to use it for load bearing structures. Low density of ULC is achieved by replacing heavy aggregate for lightweight aggregate. The lightweight aggregate is known under the trade name Liapor in the Czech Republic. To achieve density below 1000 kg/m3, an aeration of the paste has to be done. An exchange of heavy aggregate for lightweight aggregate results in a very fragile behavior of ULC. A great attention is paid to bond strength between concrete and reinforcing steel in the thesis. In addition to the standard test of bond strength testing by pull-out, a modified pull-out test is designed, which includes the effect of minimum reinforcement cover. The mentioned test more precisely simulates a real behaviour of the structure exposed to bending moment. The doctoral thesis tries to point out on different parameters between measured data and the applicable standard for the design of load-bearing structures.

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