National Repository of Grey Literature 7,627 records found  1 - 10nextend  jump to record: Search took 0.36 seconds. 

Conductivity of carbon materials for alternative energy sources
Tichý, J. ; Novák, V. ; Barath, Peter
Object of this work was prepared electrodes with carbon materials and investigate their electrical properties.

Potential of IoT in Smart City
Pavlíček, Tomáš ; Gála, Libor (advisor) ; Basl, Josef (referee)
The aim of this masters thesis is to identify, in which phase of adoption of Internet of Things (IoT) application areas of concept Smart City are nowadays Czech regional cities, what is their outlook to 2025 and also identify in which dimensions of concept Smart city, supported by IoT technologies, perceive Czech regional cities the greatest potential. Based on information obtained from the studied materials, the concept of Internet of Things (IoT) is described, along with a detailed description of one of its application area, namely Smart City. This area is further divided into specific dimensions, that cover specific application areas which can, through internet technology, support things in a special way. With these insights, the questionnaire (built on identified IoT application areas of smart city) was developed. Thesis should be beneficial for all towns in the Czech Republic, because it provides a comprehensive view of individual IoT application areas of concept Smart City including information on which of these IoT application areas are currently focusing regional cities, and on which they want to focus to the future. On the other hand, the survey results could also be beneficial for commercial entities, which focus on IoT implementation in cities. These entities will be able to recognise which IoT products are currently best for cities.

Expected development of Business Intelligence applications in the coming years
Aschmann, Jakub ; Pour, Jan (advisor) ; Fortinová, Jana (referee)
This thesis focuses on the development of Business Intelligence applications. The main area is the potential development in the coming years, history of business intelligence and individual components. To acquire the necessary knowledge, I studied educational materials and electronic publications. In Chapter 3 I focus on the definition of BI, in the following chapter I analyse individual components and the last chapter is dedicated to the development in the future. This thesis will provide comprehensive knowledge and trends in business intelligence to readers who are interested in this area and are looking for complex information.

ELECTRON BEAM REMELTING OF PLASMA SPRAYED ALUMINA COATINGS
Matějíček, Jiří ; Veverka, J. ; Čížek, J. ; Kouřil, J.
Plasma sprayed alumina coatings find numerous applications in various fields, where they enhance the properties of the base material. Examples include thermal barriers, wear resistance, electrical insulation, and diffusion and corrosion barriers. A typical structure of plasma sprayed coatings, containing a multitude of voids and imperfectly bonded interfaces, gives them unique properties - particularly low thermal conductivity, high strain tolerance, etc. However, for certain applications such as permeation barriers or wear resistance, these voids may be detrimental.\nThis paper reports on the first experiments with remelting of plasma sprayed alumina coatings by electron beam technology, with the purpose of densifying the coatings and thereby eliminating the voids. Throughout the study, several parameters of the e-beam device were varied - beam current, traverse velocity and number of passes. The treated coatings were observed by light and electron microscopy and the thickness, structure and surface morphology of the remelted layer were determined and correlated with the process parameters. Based on the first series of experiments, the e-beam settings leading to dense and smooth remelted layer of sufficient thickness were obtained. In this layer, a change of phase composition and a marked increase in hardness were observed.\n

NUMERICAL SUPPORT FOR SPECIMEN LOADED BY BENDING AND WEDGE SPLITTING FORCES FOR MEASUREMENT OF CONCRETE PROPERTIES
Seitl, Stanislav ; Liedo, R. ; Holušová, T.
Fracture mechanical properties of silicate based materials are performed from various fracture mechanicals tests. For evaluation of parameters, the knowledge about calibration and compliance function is so important. Therefore, in contribution the compliance and calibration curves for a novel test based on combination wedge splitting test (WST) and three-point bend test (3PBT) are introduced. These selected variants exhibit significantly various stress state conditions at the crack tip, or, more generally, in the whole specimen ligament.

Design of Experiment for Non-Stationary Processes of Production
Jadrná, Monika ; Macák, Tomáš (advisor)
The doctoral thesis is concerned with the services sector and the area of mass production. Particularly, the optimization of the product portfolio of the travel agency and the optimization of production rounds of ammunition. The theoretical part deals with the current overview of discussed topic. Further, the terminology and methods of the decision-making process are defined to support decision making. The theoretical basis of research focused on the choice of appropriate input variables in the area of services, and on the choice of a particular material option in the production area and appropriate equipment for the production. The theoretical part forms the basis for the practical part of the thesis. For the doctoral thesis was chosen an enterprise operating in the defined sector. Product portfolio for the services sector is optimised using Fuzzy logic and Fuzzy sets so that the enterprise can maintain its competitiveness in todays highly ambitious market. Product portfolio for manufacture is optimised for achieving desired properties of the product. The main aim of the thesis is to propose a new methodological approach for the management of selected business processes in their nonstationary time course. The aim of the practical implementation is to verify the functionality of the proposed methodological approach, both in the area of services and in the field of mass production.

Properties of Aerosol, Produced by Laser Ablation of Standard Materials for ICP-MS Analysis.
Holá, M. ; Nováková, H. ; Ondráček, Jakub ; Vojtíšek, M. ; Kanický, V.
Laser ablation (LA), together with inductively coupled plasma mass spectrometry (ICP-MS) as a detection system, has become a routine method for the direct analysis of various solid samples. The product of laser ablation contains a mixture of vapour, droplets and solid particles. All components are finally transported to a plasma by a carrier gas as a dry aerosol including mainly agglomerates of primary nanoparticles. In general, characterisation of aerosols by their particle size distribution (PSD) represents indispensable tool for fundamental studies of the interaction of laser radiation with various materials. The particle size distribution of dry aerosol originating from laser ablation of standard material was monitored by two aerosol spectrometers – Fast Mobility Particle Sizer (EEPS) and Scanning Mobility Particle Sizer (SMPS) simultaneously with laser ablation - ICP-MS analysis.\n
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FRACTURE MECHANICS ASSESSMENT OF CRACKED WELDED POLYOLEFIN PIPES
Mikula, Jakub ; Ševčík, Martin ; Hutař, Pavel ; Náhlík, Luboš
The aim of this paper is to present methodology for estimation of fracture mechanics parameters in polyolefin pipes with an axially oriented crack using three dimensional numerical analyses. Linear elastic fracture mechanics is used for description of fracture behavior. In the paper, three different variants of pipe weld with an internal axial semi-elliptical crack are studied. Numerical models correspond to a cracked pipe containing material nonhomogeneity in the welding area caused by welding process. A critical locations of the crack initiated along the pipe wall is found and the stress intensity factor for such cracks with real crack shape are numerically estimated in these critical locations. The methodology presented here can be used for estimation of residual lifetime of welded polymer pipes containing crack.

The impact of executing new thermal insulation on a apartment building on the expenses associated with its operation
Machová, Petra ; Kosová, Jaroslava (referee) ; Čech, Josef (advisor)
The topic of the diploma thesis „The impact of executing new thermal insulation on a apartment building on the expenses associated with its operation “ is a draft and appraisal of four variants of thermal insulation of the building. The thesis deals with the assessment of the current proposal for apartment building envelopes along with proposing alternative plans with emphasis on reducing heating costs. The first section describes the types of buildings according to heating demand and a list of different variants of thermal insulation materials. The second part is devoted to a specific apartment building in the Ústí nad Labem for which there are designed in four variants of insulation. The work includes thermal assessment in original condition and the assessment of new condition modified by adding thermal insulation. Through research will bedetermined price of implementation of proposed insulation options together with the costs of operation of the apartment building. In conclusion, the diploma thesis evaluates the payback period of insulation.

Noise, Transport and Structural Properties of High Energy Radiation Detectors Based on CdTe
Šik, Ondřej ; Lazar, Josef (referee) ; Navrátil, Vladislav (referee) ; Grmela, Lubomír (advisor)
Poptávka ze strany vesmírného výzkumu, zdravotnictví a bezpečnostního průmyslu způsobila v posledních letech zvýšený zájem o vývoj materiálů pro detekci a zobrazování vysokoenergetického záření. CdTe a jeho slitina CdZnTe. jsou polovodiče umožnují detekci záření o energiích v rozsahu 10 keV až 500 keV. Šířka zakázaného pásma u CdTe / CdZnTe je 1.46 -1.6 eV, což umožňuje produkci krystalů o vysoké rezistivitě (10^10-10^11 cm), která je dostačující pro použití CdTe / CdZnTe při pokojové teplotě. V mé práci byly zkoumány detektory CdTe/CdZnTe v různých stádiích jejich poruchovosti. Byly použity velmi kvalitní spektroskopické detektory, materiál s nižší rezistivitou a výraznou polarizací, detektory s asymetrií elektrických parametrů kontaktů a teplotně degenerované vzorky. Z výsledků analýzy nízkofrekvenčního šumu je patrný obecný závěr, že zvýšená koncentrace defektů způsobí změnu povahy původně monotónního spektra typu 1/f na spektrum s výrazným vlivem generačně-rekombinačních procesů. Další výrazná vlastnost degenerovaných detektorů a detektorů nižší kvality je nárůst spektrální hustoty šumu typu 1/f se vzrůstajícím napájecím napětí se směrnicí výrazně vyšší než 2. Strukturální a chemické analýzy poukázaly, že teplotní generace detektorů způsobuje difuzi kovu použitého při kontaktování a stopových prvků hlouběji do objemu krystalu. Část mé práce je věnována modifikaci povrchu svazkem argonových iontů a jejímu vlivu na chemické složení a morfologii povrchu.