National Repository of Grey Literature 29 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Hlaváček, Petr ; Sitek, Libor ; Klichová, Dagmar ; Bodnárová, L.
The paper deals with the use of the abrasive water flow technology in an accelerated simulation of the process of mechanical degradation of surface layers of cement-based composites by flowing liquids. Effects of the abrasive particle size and the mass flow rate of abrasives in an abrasive water flow impacting on the surface of concrete samples have been studied. In addition, suitability of the application of the abrasive water flow for the simulation of real situation of the surface wear by flowing liquids has been evaluated.
Erosion capability of ultra-high-speed continuous waterjet and pulsating waterjet: the comparison
Sitek, Libor ; Hlaváček, Petr ; Klichová, Dagmar ; Trieb, F. ; Pude, F.
Advantages and possibilities of continuous ultra-high-speed waterjets (with\npressures of 600 MPa and more) when cutting metals are well known to\nthe professional public both from scientific studies and from practice. In addition\nto efficiency increased as water pressure increases and reduced water\nconsumption, abrasive consumption can also be reduced in the case of abrasive\nwaterjet. Ultra-high-speed waterjet technology allows not only to cut metal sheets\nwith pure water, but also allows cutting of harder materials such as ceramics.\nDespite the initial suspicion and technical problems associated with the reliability\nand sealing of some hyperpressure elements, high-pressure devices generating\nwater pressures around 600 MPa are now commercially available. However, no\ncomparison has been made so far concerning the efficiency of these jets with\nacoustically modulated high-speed pulsating waterjets using relatively low\npressures and higher water flow rates when eroding metallic materials.\nThe article compares cuts made by pure ultra-high-speed waterjet generated at\nhyperpressures (from 500 to 800 MPa) with erosive capabilities of pulsating\nwaterjets generated on the contrary at water pressures in the order of tens of MPa\non three metallic materials (stainless steel, mild steel and copper) using the same\njet hydraulic power.
Properties and characteristics of recycled garnet abrasives for AWJ
Martinec, Petr ; Hlaváček, Petr ; Ruppenthalová, Lucie ; Sitek, Libor
The use of recycled garnet abrasive from sludge after cutting materials is a current\nproblem. The behavior of individual garnet abrasives in the AWJ process depends\non the geological origin of the garnets, which also affects all the material\ncharacteristics of the garnet recyclate. The parameters of the BARTON HPX80 and\nGMA 80 abrasive inputs and their recycled products were compared: mineralogical\ntype, apparent density, granularity, grain shape and mineralogical purity,\nmicrohardness data and the degree of damage to the garnet grains. All individual\nparameters of abrasives and their recyclates are reflected in the index of cutting\nefficiency of abrasive. The effect of abrasive material properties on cuttability of\nabrasives is synergistic. The new parameters in the evaluation of abrasives are\nmicro-hardness (brittleness criterion), specific surface and pore size distribution\n(internal grain damage criterion).
Abrasive water jet drilling of cooling holes in aeroengines: preliminary experimental study
Hlaváček, Petr ; Zlámal, T. ; Sitek, Libor ; Georgiovská, Lucie
This paper addresses an experimental investigation on the feasibility of using\nabrasive water jet (AWJ) for the drilling of small-diameter holes in aeroengines\ncomponents. These components are sprayed with ceramic thermal barrier coating\n(TBC). The required holes are typically 0.5 to 1 mm in diameter with a drilling\nangle of 30 to 90 deg. The parameters of the AWJ were varied to study their effects\non both quantitative and qualitative hole drilling parameters.
Aspects of housing in high-rise buildings in China
Toman, Radek ; Kováč, Bohumil (referee) ; Topolčanská, Maria (referee) ; Hlaváček, Petr (referee) ; Havliš, Karel (advisor)
Modern cities are under the pressure of big social and building development. The thesis is based on aspects of housing and living of society in 21th century cities. Now China has been an extreme example of rapid urbanization. It gives us an opportunity to gain knowledge about urban development. Based on the analysis of selected examples of urban housing the thesis shows the options for the future alternatives of living. The work was process during my academic internship at Southeast University in Nanjing, China.
The Impact of FDI on Host Economy - A Case Study of TRCZ
Vazač, Adam ; Blažek, Jiří (advisor) ; Hlaváček, Petr (referee)
This study deals with foreign direct investments and their impacts on regional labour market and on domestic firms through spillover effects. The main goal was to find out if the foreign presence has positive influences on the host regional economy. This study has two important parts - quantitative and qualitative researches. The result of quantitative research based on multiple regression comes with no relevant empirical evidence of spillover effects. The qualitative research as a case study of TRCZ allows a trying to solve possible FDI-impacts on regional economy of Lovosice region. Keywords: foreign direct investment, multinational enterprises, impact of FDI, host economy, spillover effects
Actors and Mechanisms of Regional Development on Example of the Ústí Region
Hlaváček, Petr ; Blažek, Jiří (advisor) ; Novotný, Josef (referee) ; Maryáš, Jaroslav (referee)
1 Charles University in Prague Faculty of Science Department of Social Geography and Regional Development ACTORS AND MECHANISMS OF REGIONAL DEVELOPMENT ON EXAMPLE OF THE ÚSTÍ REGION Dissertation thesis summary Petr Hlaváček Supervisor: Doc. RNDr. Jiří Blažek, PhD. Ústí nad Labem 2010 2 CONTENT Introduction and theoretical framework Hypotheses and structure of the dissertation Conclusion Selected literature 3 Introduction and theoretical framework Current research of regional development sees themes focused on the institutional context of regional development in the foreground [Rutten, Boekema 2007], regional mechanisms are evaluated, key categories and groups of actos for the long-term improvement of the competitiveness of the region are sought [Breschi, Malerba 2007]. The theory is that regional development operates with various actors concepts. Traditional neo-classic approaches stemming from the individualized concept of a actor in the market environment are often completed with institutional approaches that highlight the understanding of the actor as an entity interwoven by many specific market mechanisms and social structures - production chains, subcontractor relationships and further formal and informal boundaries that define market potential. From the institutional economy point of view, the actor...
The Foundation of the Jesuit Mission in China and the Contribution of Mattei Ricci (1552-1610)
Bartošová, Hedvika ; Obuchová, Ľubica (advisor) ; Hlaváček, Petr (referee)
Missions are an important part of church history. With the spreading of the Christian faith goes the question: how far can one go to accommodate the gospel to the native countries and their cultures? Can this faith, with its Graeco-Roman origins, be accepted by people in different, non-European countries, without any changes? The first missionaries who sailed overseas to the Far East also had to handle this question.
Sports center
Hlaváček, Petr ; Píštěk, Rostislav (referee) ; Daněk, Lukáš (advisor)
The new building sport center without cellar. The object is based on strip foundation. The footing bottom is in frost resistant depth. Construction system is in both ways. Vertical walls are made by cut bricks POROTHERM. The external cladding is replenished by thermal insulation plaster POROTHERM TO. Horizontal constructions are made by filigree ceiling panels. Stairway is made by reinforced concrete. Heating system is ensured by gas boiler.
Family house with an establishment
Hlaváček, Petr ; Píštěk, Rostislav (referee) ; Daněk, Lukáš (advisor)
The new family house without cellar, with garage and an establishment – hairdressing salon. The object is based on strip foundation. The footing bottom is in frost resistant depth. Construction system is in both ways. Vertical walls are made by cut bricks POROTHERM. The external cladding is replenished by thermal insulation plaster POROTHERM TO. Horizontal constructions are made by ceramic girders and insert POROTHERM. Stairway is made by reinforced concrete. Heating system is ensured by gas boiler.

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4 Hlaváček, Pavel
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