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Fiscal rules in selected EU countries between 2004-2015: sensible method for consolidation of public finances or fad of politicians?
Veselý, Lukáš ; Strejček, Ivo (advisor) ; Chmelová, Pavla (referee)
The subject of fiscal rules is very topical issue. The rise of public debt in certain developed countries resulted in what is sometimes called "debt crisis". Debt of those countries which is higher than their annual gross domestic product is viewed as unpayable by some economists. The main objective of this thesis has been to prove or disprove hypothesis that the fiscal rules studied in this paper are an effective solution for public finance consolidation. This verification was based on the analysis of fiscal rules functioning in selected countries between 2004 and 2015. As per results of analysis the paper aims to give recommendations for the Czech financial constitution proposal. The actual results of inquiry proved the hypothesis. Well-chosen fiscal rules are the right way towards fiscal consolidation, provided they are observed. Fiscal rules making thus requires an emphasis to be placed on the well-formulated exit clauses altogether with prospective sanctions. The current Czech financial constitution proposal is built on the correctly picked fiscal rule type, although the reference value lacks economic sense and it would not lead, with a high degree of probability, towards fiscal consolidation.
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Pulsed liquid jet generated by pulse multiplication technique
Dvorský, R. ; Sitek, Libor ; Sochor, T.
First theoretical papers summarizing the high mechanical energy cumulation when high-speed drops impacting the solid surface as a result of the water hammer effect have been known since 1960’s. Heymann has demonstrated that pressure maximum in the impact of a spherical drop of a liquid is several times higher than the presupposed maximum for the classical water hammer effect. The latter maximum pressure itself exceeds the mere stagnation pressure of the continuous jet many times hereat. When developing devices for pulse jet generation a new generalization of the classical water hammer theory for high pressures has been implemented. Based on this the new patented principle of “pulse multiplication” has been formulated. The pulse multiplier is the source of high-pressure pulses with 100% depth of modulation of liquid jet discharge velocity that allows increasing the jet disintegration effect significantly without the abrasive material application.
Fulltext: content.csg -  DOC
Plný tet: UGN_0398574 - DOC
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Coarse-grained particles conveying along a pipe bed
Vlasák, Pavel ; Chára, Zdeněk ; Konfršt, Jiří ; Kysela, Bohuš
The paper describes the results of a flow visualisation of model coarse-grained fully stratified particle-water mixtures. Investigation was focussed on study of the particle behaviour and carrier liquid and conveyed particles local velocities. Glass balls and washed graded pebble gravel of mean diameter of 6 mm were conveyed by water in a horizontal smooth pipe loop with a transparent pipe viewing section of inner diameter 40 mm. Particle movement along the pipe invert and particulate stationary bed, created by two layers of spherical particles of the same size as the conveyed particles, was studied. The effect of stationary bed on local velocity values of the carrier liquid and conveyed particles were determined. It was conducted that the maximum liquid velocity is significantly shifted from pipe centre to a higher position in the flow pattern with stationary bed.
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Impact of low oil and natural gas prices on the economy of Qatar since 2014
Šamánek, Ondřej ; Stuchlíková, Zuzana (advisor) ; Hasík, Gabriel (referee)
The bachelor thesis examines the impact of the oil and gas prices slump, which befell the world in 2014, on the economy of Qatar. The main objective of the thesis is to evaluate if and to what extend the price collapse influenced the relevant economic indicators and behaviour of the state and companies active in the affected field. The selected objective is examined using the method of data comparison, namely before and after the price slump, and with the help of the case study, in which the qatari company operating in the oil and gas is examined. From the conducted analysis it is possible to conclude that Qatar was directly influenced by the oil and gas prices collapse: its GDP slumped, fiscal deficit increased. The analysed company also experienced troubles caused by low prices: one year after the price slump, total amount of assigned tenders to company decreased substantially and historically high number of tenders was cancelled. Conclusions deriving from the thesis might be applied to other oil and gas export economies in the Persian Gulf, for fundamental traits of such economies are shared with the economy of Qatar.
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Comparison of Diffusion Coefficients in Initial Stages of Mutual Diffusion in Layered Structures Carbon/Ferrite and Carbon/Austenite for Chosen Alloys
Čermák, Jiří ; Král, Lubomír
Coefficients of mutual carbon diffusion were measured at initial stages of diffusion for surface thin layer of carbon/ferrite and carbon surface layer/austenite. The aim of the study was to compare the diffusion characteristics obtained at the present strongly non-equilibrium case with those known for carbon mutual diffusion in cases where the carbon concentration does not exceed the solubility limit in the respective substrate. The second goal was to judge, whether the carbon diffusivity is determined by the structure of the substrate matrix (BCC or FCC). As examples of ferrite substrate, pure Fe and chromium steel P91 were chosen, as an example of austenite substrate, AISI316 was taken. It was obtained that – similar to nearequilibrium case – the carbon diffusion measured close to interface C/austenite is significantly lower compared to carbon diffusion near the C/ferrite. Values of carbon diffusion coefficients in cases C/Fe and C/P91 are close one to another. All carbon diffusion coefficients are much lower than those, reported for near-equilibrium conditions; they approach values measured in carbides.
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Changes in structure and phase composition in the surface of tram rail
Švábenská, Eva ; Roupcová, Pavla ; Schneeweiss, Oldřich
We have investigated structure and phase composition of surface layer of tram rails after long time running and the results were compared with those obtained on the original part of material. Changes due to effects of severe plastic deformation together with thermal shocks by friction process were expected. The information about structure and phase composition was obtained by optical and scanning electron microscopy, X-Ray Powder Diffraction, Mössbauer Spectroscopy and Glow Discharge Emission Spectroscopy (GDOES) and this was completed by microhardness measurements. The results show that the surface layer in comparison with the original material exhibits important changes in grain structure, an increase in microhardness and high content of iron oxide and hydrooxides. According to the depth profile of the chemical composition measured by GDOES there is an increase in carbon content in the surface layer which can be effect of up-hill diffusion.
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STRAIN ENGINEERING OF THE ELECTRONIC STRUCTURE OF 2D MATERIALS
del Corro, Elena ; Peňa-Alvarez, M. ; Morales-García, A. ; Bouša, Milan ; Řáhová, Jaroslava ; Kavan, Ladislav ; Kalbáč, Martin ; Frank, Otakar
The research on graphene has attracted much attention since its first successful preparation in 2004. It possesses many unique properties, such as an extreme stiffness and strength, high electron mobility, ballistic transport even at room temperature, superior thermal conductivity and many others. The affection for graphene was followed swiftly by a keen interest in other two dimensional materials like transition metal dichalcogenides. As has been predicted and in part proven experimentally, the electronic properties of these materials can be modified by various means. The most common ones include covalent or non-covalent chemistry, electrochemical, gate or atomic doping, or quantum confinement. None of these methods has proven universal enough in terms of the devices' characteristics or scalability. However, another approach is known mechanical strain/stress, but experiments in that direction are scarce, in spite of their high promises.\nThe primary challenge consists in the understanding of the mechanical properties of 2D materials and in the ability to quantify the lattice deformation. Several techniques can be then used to apply strain to the specimens and thus to induce changes in their electronic structure. We will review their basic concepts and some of the examples so far documented experimentally and/or theoretically.
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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
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