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Wave Soldering Fluxes Comparison
Stoklásek, Lukáš ; Martinec, Petr (referee) ; Starý, Jiří (advisor)
Semestral thesis introduces the problematics of wave soldering fluxes, flux residues and problems of electromigration. Practical part describes measuring of ionic contamination by using conductometric method, measuring the wettability by the wetting balance method and amount of failures on wave soldered printed circuit boards with these fluxes. The main object is to compare quality of the fluxes.
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Preparation of Tobermorite
Dlabajová, Lucie ; Palou, Martin (referee) ; Martinec, Petr (referee) ; Ptáček, Petr (advisor)
This doctoral thesis is focused on the study of reactions in the CaO–SiO2–H2O complex system, primarily to the synthesis of crystalline tobermorite. Hydrothermal conditions are necessary for the formation of crystalline tobermorite, whereas the course of the reaction is influenced by several factors. The main studied factor was the choice of the silica sources differing in means of solubility, crystallinity, particle size distribution, specific surface area, and purity. The water-to-solid ratio turned to be also an important factor as the length of the hydrothermal reaction. The influence of the mechanochemical pretreatment of starting materials to the final phase composition of samples was studied as well. The obtained results show that the crystallinity of the silica source is the main factor influencing the reaction rate and the purity of the synthesized tobermorite. While using the crystalline silica source the shorter silicate chains are formed and the formation of tobermorite structure is easier. Using the amorphous silica sources and the mechanochemical pretreatement of starting materials prolong the hydrothermal reaction. The prepared samples are always the mixture of crystalline or semicrystalline calcium hydrosilicates instead of the phase pure tobermorite.
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The Use of Artificial Intelligence for Optimization of Production
Svoboda, Radovan ; Martinec, Petr (referee) ; Dostál, Petr (advisor)
This paper deals with the problem of optimization of a production plan by using genetic algorithms. It contains a brief overview of the principles behind genetic algorithms in scope of evolutionary algorithms and artificial intelligence in general. It also takes a closer look on the challenge of production planning and control and all activities connected to it. This is followed by description of the modification of genetic algorithms that needed to be done in order to implement it into a computer program, which is used to create and optimize the production plan, and is a result to the issue that this paper deals with. Incorporated is detailed escription of principles and functions of the program, that it offers to its users.
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Methodology for determining the provenance of raw materials for the production of historical lime mortars
Martinec, Petr ; Ščučka, Jiří
The methodology was developed in the years 2018-2021 as part of the solution of the project Historical landscape on the border of Silesia and Moravia financed by the Ministry of Culture of the Czech Republic (project No. DG18P02OVV017, NAKI II programme). The methodology is based on the long-term experience of prof. Petr Martinec, Ph.D. and Jiří Ščučka, Ph.D. in the field of geomaterial and building material analyses, which are carried out at the Institute of Geonics of the Academy of Sciences of the Czech Republic in cooperation with experts from the fields of archaeology and monument care. The methodology includes a comprehensive procedure for identifying potential original sources of raw materials used for the production of the main material components of historical lime mortars – aggregate and binder. The methodology also includes: principles of sampling mortars and comparative rocks or soils in situ, procedures for laboratory material analysis of aggregates, binders and rocks to determine relevant comparative parameters, and the main information sources that can be used when searching for sources of raw materials.\n
Plný tet:  PDF
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Preparation of Tobermorite
Dlabajová, Lucie ; Palou, Martin (referee) ; Martinec, Petr (referee) ; Ptáček, Petr (advisor)
This doctoral thesis is focused on the study of reactions in the CaO–SiO2–H2O complex system, primarily to the synthesis of crystalline tobermorite. Hydrothermal conditions are necessary for the formation of crystalline tobermorite, whereas the course of the reaction is influenced by several factors. The main studied factor was the choice of the silica sources differing in means of solubility, crystallinity, particle size distribution, specific surface area, and purity. The water-to-solid ratio turned to be also an important factor as the length of the hydrothermal reaction. The influence of the mechanochemical pretreatment of starting materials to the final phase composition of samples was studied as well. The obtained results show that the crystallinity of the silica source is the main factor influencing the reaction rate and the purity of the synthesized tobermorite. While using the crystalline silica source the shorter silicate chains are formed and the formation of tobermorite structure is easier. Using the amorphous silica sources and the mechanochemical pretreatement of starting materials prolong the hydrothermal reaction. The prepared samples are always the mixture of crystalline or semicrystalline calcium hydrosilicates instead of the phase pure tobermorite.
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Comprehensive geological characterization of URF Bukov – part II Geotechnical characterization.
Souček, Kamil ; Vavro, Martin ; Staš, Lubomír ; Kaláb, Zdeněk ; Koníček, Petr ; Georgiovská, Lucie ; Kaláb, Tomáš ; Konečný, Pavel ; Kolcun, Alexej ; Králová, Lucie ; Kubina, Lukáš ; Lednická, Markéta ; Malík, Josef ; Martinec, Petr ; Ptáček, Jiří ; Vavro, Leona ; Waclawik, Petr ; Zajícová, Vendula
This final report was processed as a part of Radioactive Waste Repository Authority project Research support for safety evaluation of the deep repository, which is a part of the preparation for the deep repository of nuclear waste (further DR). The aims of the project were collection and interpretation of geological data, the creation of models and obtaining information necessary for evaluation of potential sites for DR emplacement regarding long-term safety. On the basis of public submitting act, a 4-year contract was signed with ÚJV Řež, a.s. and its subcontractors: Czech Geological Survey, Czech Technical University in Prague, Technical University in Liberec, Institute of Geonics of Czech Academy of Sciences, and companies Arcadis CZ, Progeo, Chemcomex Praha and Centre for Research Řež about providing research support for evaluation of long-term safety.
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Composition and microstructure of plasters in convent of the Želiv Monastery (Czech Republic)
Rezek, P. ; Martinec, Petr ; Ščučka, Jiří ; Majstríková, T.
The paper deals with analyses of composition and structure of historic plasters from the convent building of the Želiv Monastery (Czech Republic). Composition and microstructure of plaster samples taken from the historic object have been assessed using both traditional and advanced analytical methods. The following techniques have been used for the assessment of binders and fine aggregates in plasters: optical microscopy of thin sections, mineralogical and petrographic analysis of separated components, infrared spectroscopy, and thermal analysis. Presented results show significant differences in character of the studied materials of varying age and demonstrate the effectiveness of the taken analytical approach.
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Final research report to the project PB-2014-ZL-U2301-004-BUKOV
Souček, Kamil ; Vavro, Martin ; Staš, Lubomír ; Kaláb, Zdeněk ; Koníček, Petr ; Georgiovská, Lucie ; Kaláb, Tomáš ; Konečný, Pavel ; Kolcun, Alexej ; Králová, Lucie ; Kubina, Lukáš ; Lednická, Markéta ; Malík, Josef ; Martinec, Petr ; Ptáček, Jiří ; Vavro, Leona ; Waclawik, Petr ; Zajícová, Vendula
Bukov Underground Research Facility (Bukov URF) has been built as a test site to assess the properties and behaviour of the rock mass analogous to selected candidate sites. It is situated at a depth corresponding to the proposed storage depth of the final locality for the Czech Republic´s deep repository of high-level radioactive waste. Bukov URF is located in the Vysočina Region, the cadastral district of Bukov, approx. 3 km south-eastwards from the municipality of Dolní Rožínka. The underground research facility is placed approx. 300 m from the Bukov-1 shaft, namely on the level 12 of the shaft, at the depth of about 550 – 600 meters below the Earth’s surface. As for the regional geology, Bukov URF is found at the southern part of the Rožná uranium deposit, at the north-eastern edge of the Strážek Moldanubicum close to its contact with the Svratka Unit. The rock mass is composed of a relatively monotonous sequence of differently migmatized biotite gneisses to stromatic migmatites, continuing with amphibole-biotite to biotite-amphibole gneisses and amphiboles, with occasional fine intercalations of aplites, pegmatites or calc-silicate rocks (erlanes). Between 2013 and 2017 and within the complex geotechnical characterization of the Bukov URF, the Institute of Geonics of the Czech Academy of Sciences (Ústav geoniky AV ČR, v.v.i.) in Ostrava carried out a series of laboratory and field works in order to provide a detailed description of the geotechnical and geomechanical properties and quality of the rock mass. The works included the determination and assessment of the physical-mechanical properties of the rocks sampled from the walls, boreholes and ground surface in the locality, the determination of stress state and deformation properties of the rock mass using the methods of hydrofracturing of borehole walls, Goodman Jack and CCBO, or CCBM, determination of the rock mass quality based on selected index geomechanical properties, periodic, long-term strain-gauge measurements and convergence measurements, and the assessment of the effect of technical and mine-induced seismicity on the rock mass of interest. The implemented set of research works was supposed to render a sufficient and integral whole of geotechnical and geomechanical knowledge vital for the subsequent implementation of extensive research experiments focused on long-term safety and technical feasibility of the future national deep repository of radioactive waste.
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