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Study of surface topography of material eroded by pulsating water jet
Klich, Jiří; Klichová, Dagmar
2015 - English
The paper focuses on the study of the effect of technological parameters on the topography of a surface eroded by a pulsating water jet. Parameters of the water pressure and the traversing velocity of the nozzle over the surface were observed. Effects of technological parameters were compared to the surface roughness parameters Ra, Rz, Rv, Rp, Rsk and Rku. The material tested was the aluminium alloy EN AW6060 T66. The surface was measured using an optical profilometer and further assessed using the confocal microscope based on a metallographic section.
Keywords:
pulsating water jet (PWJ); surface roughness; erosion
Available in digital repository of the ASCR
Study of surface topography of material eroded by pulsating water jet
The paper focuses on the study of the effect of technological parameters on the topography of a surface eroded by a pulsating water jet. Parameters of the water pressure and the traversing velocity ...
Abrasives and possibilities of increase in efficiency of abrasive waterjets
Martinec, Petr; Sitek, Libor
2015 - English
The contribution focuses on the research into abrasive materials and possibilities of adjustment of their properties in order to increase the efficiency of the processes of machining and cutting with abrasive waterjets. Cutting ability of commonly available garnet concentrates and nontraditional products which are starting to access to the Czech market were tested and compared. In addition, entirely new garnet products which are not commercially available yet, recycled abrasives, abrasives with various sizes of grains and heat-affected abrasives or abrasives coated with a thin plastic layer were studied.
Keywords:
abrasive waterjets; abrasives; garnet; zirconia
Available in digital repository of the ASCR
Abrasives and possibilities of increase in efficiency of abrasive waterjets
The contribution focuses on the research into abrasive materials and possibilities of adjustment of their properties in order to increase the efficiency of the processes of machining and cutting ...
Use of micro X-ray computed tomography for development and research into waterjets
Souček, Kamil; Sitek, Libor; Gurková, Lucie; Georgiovská, Lucie
2015 - English
Non-destructive methods for analysis of various types of materials have been increasingly applied recently. One of these methods is the industrial micro X-ray computed tomography (CT). This paper presents an overview of experience in using the industrial micro X-ray computed tomography during research activities at the Institute of Geonics of the CAS. It discusses possibilities of the nondestructive visualization of the inner structures of a wide range of materials and objects, including examples of its use in research and development activities related to high speed waterjets.
Keywords:
micro X-ray computed tomography; inner structure of materials; porosity; defectoscopy; waterjet
Available in digital repository of the ASCR
Use of micro X-ray computed tomography for development and research into waterjets
Non-destructive methods for analysis of various types of materials have been increasingly applied recently. One of these methods is the industrial micro X-ray computed tomography (CT). This paper ...
Visualisation and quantitative analysis of flat continuous water jet structure
Ščučka, Jiří; Zeleňák, Michal; Foldyna, Josef; Lehocká, D.; Votavová, H.
2015 - English
The results of an experiment focused on the visualisation and structural analysis of flat continuous high-speed water jet used in descaling process are presented in this paper. The aim of the work was to test the applicability of the shadowgraph technique, combined with image processing and analysis methods, to visualise the water jet structure and analyse its main quantitative parameters. Volume percentage of water and air in the water jet structure, size of droplets and water bunches and other parameters were measured on digital images taken at various distances from the nozzle outlet. Knowledge of the water jet structure below the nozzle can facilitate an optimal setting of technological conditions of the water jetting with respect to the maximum disintegration effect on treated material. The described methods can also provide important information for development of new nozzles or entire water jetting tools for disintegration of materials.
Keywords:
descaling; flat continuous water jet; visualisation; shadowgraph technique; image analysis
Available in digital repository of the ASCR
Visualisation and quantitative analysis of flat continuous water jet structure
The results of an experiment focused on the visualisation and structural analysis of flat continuous high-speed water jet used in descaling process are presented in this paper. The aim of the work ...
Reinterpretace stratigrafie karbonu v hlubokém strukturním vrtu Stonava SV 2, česká část hornoslezské pánve
Horak, J.; Martinec, Petr; Waclawik, Petr; Málek, O.
2015 - Czech
Vrty ne Stonavě SV 2 byly realizovány v letech 1968 - 70 pro ověření stratigrafie karbonu vrstev v oblasti Karvinska. Tyto vrty byly pro regionální studie velmi důležité. Původní interpretace stratigrafie na Ostravsku a Karvinsku FMS byla nepřesná, to jest bez revize. Vrt SV 2 se nachází mezi Stonavou a Albrechticemi, je zatížen tektonickou poruchou, v bloku v příkopu Karviná. V této tektonické stavbě jsou silné tektonické poruchy. Vzhledem k tomu, že hranice jednotlivých členů ostravské Fm jsou uvedeny do stropů mořského horizontu, je chybou přehlížet nové poznatky ze studie jejich sdružení živočichů v mořských horizontů a geologickou stavbou v novém důlních vrtů, realizované později v sousedních vrtu SV 2. v případě dobré primární geologické dokumentace vrtu Stonava SV 2, je však možné kdykoliv přistoupit k přehodnocení. Borehole no Stonava SV 2 was realized in 1968 - 70 yrs. for the verification of the stratigraphy of Carboniferous strata in Karviná area. This borehole was very important for regional study. The original interpretation of the stratigraphy of the Ostrava and Karviná Fms in this borehole was inaccurate, that is, without the revision, used the current publications. The borehole SV 2 was situated between the Stonava and Albrechtice tectonic fault, in block in a Karviná graben. Strong tectonic disturbances in this tectonic structure lead without revision of correlation horizons incorrect determination of litostratigraphy and the thickness of individual members of Ostrava and Karviná Fms in Carboniferous strata. Because the boundaries of individual members of the Ostrava Fm are given into the ceilings of the marine horizon, it is a mistake to disregard the new findings from the study of their association of fauna in marine horizons and geological structure in a new mine boreholes, realized later in the neighbouring of the borehole SV 2. In the case of good primary geological documentation of borehole Stonava SV 2, however, it is possible at any time proceed to reinterpretation.
Keywords:
Upper Silesian basin; Upper Carboniferous; Serpuchovian; Bashkirian borehole Stonava SV2; lithostratigraphy
Available in digital repository of the ASCR
Reinterpretace stratigrafie karbonu v hlubokém strukturním vrtu Stonava SV 2, česká část hornoslezské pánve
Vrty ne Stonavě SV 2 byly realizovány v letech 1968 - 70 pro ověření stratigrafie karbonu vrstev v oblasti Karvinska. Tyto vrty byly pro regionální studie velmi důležité. Původní interpretace ...
Svahové pohyby jako přírodní hazard, jejich impakty a ohrožení krajiny
Batelková, Kateřina; Kirchner, Karel
2015 - Czech
Příspěvek se zabývá svahovými pohyby a jejich vlivy na krajinu. Podrobně jsou diskutovány sesuvné události spojené s výraznými srážkovými periodami na Moravě a ve Slezsku. Výzkumy svahových deformací umožnily zpřesnění i revizi geneze některých mezoforem flyšového reliéfu ve vrchovinách a hornatinách východní Moravy (zbytky zarovnaných povrchů, mrazové sruby). The contribution deals with the landslides and their impact on the landscape. Landslide events associated with extreme rainfall periods in Moravia and Silesia are discussed in detail. Research of slope deformations allow to specification and revision of the genesis of some meso-forms of the flysch relief in the highlands and mountains of eastern Moravia (remnants of planation surfaces, frost-riven cliffs).
Keywords:
slope movements; natural hazards; impact on landscape
Available in digital repository of the ASCR
Svahové pohyby jako přírodní hazard, jejich impakty a ohrožení krajiny
Příspěvek se zabývá svahovými pohyby a jejich vlivy na krajinu. Podrobně jsou diskutovány sesuvné události spojené s výraznými srážkovými periodami na Moravě a ve Slezsku. Výzkumy svahových deformací ...
Regional and flash flood as a limiting factor for development
Kolejka, Jaromír; Krejčí, Tomáš; Rapant, P.; Inspektor, T.
2015 - English
Locating and developing factors are generally well known, studied and taken into account in the accepting of the solution. In contrast, the limiting factors of development usually stands in the background. Current data sources, knowledge and modelling technologies allow greatly anticipate the extent of the flood situation. Evaluation of the risk of regional or flash floods is not discouraging information for investors, but rather to guide their activities to a safe area. Knowledge of risk locations in the Czech Republic in terms of these types of floods also help for the safety of visitors and the local population. Appropriately incorporated findings into the development plans of all dimensions support the initiatives of local and external investors. The paper illustrates the unconventional use of public available geodata in the form of an offer vital information into regional development plans.
Keywords:
flood; regional development; limiting factors; natural hazard
Available at various institutes of the ASCR
Regional and flash flood as a limiting factor for development
Locating and developing factors are generally well known, studied and taken into account in the accepting of the solution. In contrast, the limiting factors of development usually stands in the ...
Adaptace domácností na dopady extrémních projevů počasí. Případová studie povodí řeky Bečvy
Duží, Barbora; Stojanov, R.; Němec, D.
2015 - Czech
Hlavním cílem příspěvku je analýza způsobů adaptace domácností na dopady opakovaných extrémních projevů počasí, především povodní. Případová studie se zaměřuje na venkovskou oblast v severovýchodní části České republiky v povodí řeky Bečvy. U domácností je zkoumán stupeň adaptace a faktory, které ji ovlivňují. The main aim of the contribution is to analyze household adaptation to climate extreme impacts, especially floods. We selected Bečva river basin located in the norht-east part of the Czech Republic as the case study region. We analyze ways of adaptations and key drivers of adaptation.
Keywords:
adaptation; household; climate extreme
Available in digital repository of the ASCR
Adaptace domácností na dopady extrémních projevů počasí. Případová studie povodí řeky Bečvy
Hlavním cílem příspěvku je analýza způsobů adaptace domácností na dopady opakovaných extrémních projevů počasí, především povodní. Případová studie se zaměřuje na venkovskou oblast v severovýchodní ...
Concrete damaged by high temperature – possibilities of treatment with high speed water jet
Bodnárová, L.; Válek, J.; Sitek, Libor; Foldyna, Josef; Klich, Jiří
2015 - English
The paper describes analysis of behavior of cement based composite materials (concrete) exposed to high temperature. Recommendations for minimization of damage of thermally loaded structures are proposed and possibilities of renovation of fire damaged concrete using the technology of high speed water jet to remove damaged layers are given.
Keywords:
concrete; fire; high temperature; water jet
Available in digital repository of the ASCR
Concrete damaged by high temperature – possibilities of treatment with high speed water jet
The paper describes analysis of behavior of cement based composite materials (concrete) exposed to high temperature. Recommendations for minimization of damage of thermally loaded structures are ...
Hydro-abrasive machining of rotating workpieces from graphite and aluminium alloy
Cárach, J.; Hloch, Sergej; Klich, Jiří; Hlaváček, Petr; Klichová, Dagmar
2015 - English
The paper compares the quality of machined surface of graphite and aluminium alloy by abrasive water jet using the focusing tube with a diameter of df1 = 0.5 mm and df2 = 0.78 mm. The machining was carried out using the technology of rotating workpiece disintegration by abrasive water jet. Abrasive tangential water jet was used to carry out the experiment (water pressure p = 400 MPa). Workpieces were clamped in the rotating chucking appliance with rotation frequency n = 300 min-1. The change in focusing tube diameter caused the change in values of roughness parameters, and also caused the change of resulting shape of workpieces. Values of roughness parameters were measured using the MicroProf FRT optic profilometer.
Keywords:
abrasive water jet; machining; roughness parameters
Available in digital repository of the ASCR
Hydro-abrasive machining of rotating workpieces from graphite and aluminium alloy
The paper compares the quality of machined surface of graphite and aluminium alloy by abrasive water jet using the focusing tube with a diameter of df1 = 0.5 mm and df2 = 0.78 mm. The machining was ...
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