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Design of cutting unit
Jelínek, Pavel ; Košťál, David (referee) ; Brandejs, Jan (advisor)
This thesis deals with a structural design of a cutting roller including a proposal for its drive and exhaust system of the flexography machine Premia produced by Soma spol. s r.o. company. The first part discusses the technology of flexography and about the issue of cropping and extraction of material in general. Another part discusses the optimization of these systems, including the final engineering design. The main outcome of this thesis are drawings of assemblies listed in the annexes.
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NC control system on Beckhoff platform
Jelínek, Pavel ; Bradáč, František (referee) ; Vetiška, Jan (advisor)
This thesis deals with a creation of a control system of 3-axis milling machine. The beginning of the thesis is dedicated to the general description of the problematic of the numerically controlled machines and the technologies used in this branch. The next chapter describes mechanical and electronical adjustments of the machine. Following chapters are dedicated to the creation of PLC program and HMI using the TwinCAT software. In conclusion, this thesis deals with commissioning of the machine, measuring its geometrical accuracy and testing.
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Theoretical study of charge states in molecular nanostructures on surfaces
Gallardo Caparrós, Aurelio Jesús ; Jelínek, Pavel (advisor) ; Brune, Harald (referee) ; Pignedoli, Carlo (referee)
Theoretical study of charge states in molecular nanostructures on surfaces. Aurelio Gallardo Abstract Scanning probe microscopy (SPM) techniques are well known to provide images of molecular structures deposited on surfaces. Equipped with functionalized tips, these techniques have broadly demonstrated to achieve atomic resolution. However, the origin of certain aspects of the obtained images is still under debate. This thesis investigates the origin of the sharp intermolecular features that frequently appear in the high-resolution SPM images. It is confirmed that the saddle points of the potential energy surface are the origin of the lateral bendings of the probe which are detected as narrow edges in the images. This situation can occur between non- covalently bonded atoms, due to their mere presence. Therefore, they cannot be interpreted as a direct representation of weak intermolecular bonds. This text also describes the work done to obtain direct images of anisotropic charge distributions, such as σ-holes, using a Kelvin probe force microscope with a properly functionalized tip. The simulations performed using a model developed expressly for this project demonstrate that the images obtained experimentally can reflect both the electrostatics of the tip and the sample. Additionally, the isomerization of...
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Theoretical simulations of charge transport in nanostructures
Hapala, Prokop ; Jelínek, Pavel (advisor) ; Arnau, Andrés (referee) ; Štich, Ivan (referee)
Ab initio simulations play an important role for deeper understanding of physical and chemical properties of nanostructures and allow to obtain basic information about their atomic and electronic structure. The goal of the doctoral thesis is an examination of electronic structure of nanosystems and its impact on physical and chemical properties of the systems under study, as well as charge transfer. The work should include further development of ab initio method (www.fireball-dft.org/), which enables effective ab initio simulations of complex nanostructures comprising 100-1000 atoms. Powered by TCPDF (www.tcpdf.org)
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Theoretical Investigation of Low-dimensional Magnetic Materials
Li, Shuo ; Grajciar, Lukáš (advisor) ; Frauenheim, Thomas (referee) ; Jelínek, Pavel (referee)
Low-dimensional (D) materials, such as graphene, transition metal dichalcogenides and chalcogenide nanowires, are attractive for spintronics and valleytronics due to their unique physical and chemical properties resulting from low dimensionality. Emerging concepts of spintronics devices will greatly benefit from using 1D and 2D materials, which opens up new ways to manipulate spin. A majority of 1D and 2D materials is non-magnetic, thus their applications in spintronics are limited. The exploration, design and synthesis of new 1D and 2D materials with intrinsic magnetism and high spin-polarization remains a challenge. In addition, the valley polarization and spin-valley coupling properties of 2D materials have attracted great attention for valleytronics, which not only manipulates the extra degree of freedom of electrons in the momentum space of crystals but also proposes a new way to store the information. The computational investigation of magnetic and electronic properties of low-dimensional materials is the subject of this thesis. We have systematically investigated geometric, electronic, magnetic and valleytronic properties of several 2D and 1D materials by using the density functional theory. These investigations not only theoretically show rich and adjustable magnetic properties of...
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Christian view of ethical issues in agriculture
Jelínek, Pavel ; Štica, Petr (advisor) ; Bouma, David (referee)
Pavel Jelínek Title of the thesis: A Christian view of ethical issues in agriculture Abstract: The work deals with the ethical issues of Czech agriculture. With the help of some indicators from the field of politics and sociology, the situation of Czech farmers is characterized, which can influence their ethical decisions. There are several facts that appear to be ethically problematic and require a certain position. Based on the analysis of some biblical texts and reflections on the relevant ecclesiastical documents, appropriate Christian attitudes are sought, with which it is possible to approach agriculture. The aim of the thesis is to indicate the contribution of the Christian attitude to ethical issues in agriculture, to design such an ethical orientation that will best correspond to Christian teaching in the context of current ethical dilemmas and to think about how to apply this orientation in practice. Keywords: Ethics in agriculture, social teaching of the church, soil protection, food production, environment, Czech agriculture
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