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Effects of abrasives during accelerated simulation of mechanical corrosion of cement composites using abrasive water flow
Hlaváček, Petr; Sitek, Libor; Klichová, Dagmar; Bodnárová, L.
2019 - anglický
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.
Klíčová slova:
cement-based composite; erosion; abrasion; cavitation; high-speed water flow; abrasive material
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Effects of abrasives during accelerated simulation of mechanical corrosion of cement composites using abrasive water flow
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 ...
Cultural heritage and geodiversity of landforms in the landscape of the Archdiocese of Olomouc
Kirchner, Karel; Kuda, František; Kubalíková, Lucie; Havlíček, M.; Machar, I.; Pechanec, V.
2018 - anglický
Within the framework of the NAKI II project – Cultural heritage of landscape of the Archdiocese of Olomouc - research, presentation and management (DGB 16P02B014), we focus on the results that will contribute to the sustainable development of regional cultural identity through applied cultural heritage research in the cultural landscape of the area of interest. As part of the material cultural heritage, we include the landforms that originated from the conscious activity of man - the anthropogenic relief forms. These landforms complement the geodiversity of the landscape and are referred to as secondary geodiversity. Therefore, their identification and interpretation will make it possible to complement and enhance the diversity of cultural heritage and to specify the development of the cultural landscape. The first results from the area of Central Moravia will be presented with the using of the historical maps, the digital model of the relief DMR5G and the field research.
Klíčová slova:
cultural heritage; secondary geodiversity; Archdiocese of Olomouc
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Cultural heritage and geodiversity of landforms in the landscape of the Archdiocese of Olomouc
Within the framework of the NAKI II project – Cultural heritage of landscape of the Archdiocese of Olomouc - research, presentation and management (DGB 16P02B014), we focus on the results that will ...
The pre-industrial landscape as a cultural heritage: Malá Haná
Kolejka, Jaromír
2018 - anglický
The parts of the territory with a preserved secondary (economic) landscape structure, originated around the middle of the 19th century, may be considered as existing segments of the pre-industrial landscape. Such territory has retained a similar character of plot distribution and land use of that time. These segments have been pre-identified in the contemporary cultural landscape according to the recent colour orthophotomap. The existence of that cultural heritage has been confirmed or excluded by comparison with the maps of the 2nd military survey and indicating sketches of the cadastral survey from the 1st half of the 19th century. The records were systematically carried out according to the cadastral units of the so-called working regions of Moravia. The segments of the pre-industrial landscape identified in laboratory research then underwent a field research, followed by the determination of their properties and the assessment of the state and the threats.
Klíčová slova:
survey; inventory; Czech Republic
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
The pre-industrial landscape as a cultural heritage: Malá Haná
The parts of the territory with a preserved secondary (economic) landscape structure, originated around the middle of the 19th century, may be considered as existing segments of the pre-industrial ...
Influence of hydrodynamic nozzle wear on erosion effect of self-excited pulsating water jet
Klich, Jiří; Říha, Zdeněk; Foldyna, Vladimír
2017 - anglický
The article deals with the study of the wear of the hydrodynamic nozzle and its\ninfluence on the generation of a self-excited pulsating water jet (SPWJ). The nozzle\nwas monitored for the ability of the waterjet to erode the surface of the aluminum\nalloy EN AW 6060 at regular intervals.
Klíčová slova:
hydrodynamic nozzle; waterjet; erosion
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Influence of hydrodynamic nozzle wear on erosion effect of self-excited pulsating water jet
The article deals with the study of the wear of the hydrodynamic nozzle and its\ninfluence on the generation of a self-excited pulsating water jet (SPWJ). The nozzle\nwas monitored for the ability of ...
Properties and characteristics of recycled garnet abrasives for AWJ
Martinec, Petr; Hlaváček, Petr; Ruppenthalová, Lucie; Sitek, Libor
2017 - anglický
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).
Klíčová slova:
garnet; abrasive water jet; recycled abrasives; index of cutting efficiency of abrasive; microhardnes
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Properties and characteristics of recycled garnet abrasives for AWJ
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 ...
Effects of Water Jets on CNTs/concrete composite
Foldyna, Vladimír; Foldyna, Josef
2017 - anglický
Results of the resistance of carbon nanotubes concrete composite (CNTs/concrete\ncomposite) to the action of pulsating and continuous water jets are presented in\nthis paper. This work brings advanced results of fully hydrated CNTs/concrete\ncomposite (after 28 days) and it follows up the research of this composite\nhydrated 7 days. The experiments were focused at the determination of erosion\neffects of both types of water jets impinging the surface of reference (concrete) and\nCNTs/concrete composite samples. Erosion effects of water jets were evaluated in\nterms of material removal rate. Tests were performed at various operating\nparameters of continuous and pulsating water jets.
Klíčová slova:
CNTs/concrete composite; continuous and pulsating water jet; material removal
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Effects of Water Jets on CNTs/concrete composite
Results of the resistance of carbon nanotubes concrete composite (CNTs/concrete\ncomposite) to the action of pulsating and continuous water jets are presented in\nthis paper. This work brings advanced ...
Prospective of using pulsating water jet peening as a surface treatment process
Srivastava, M.; Hloch, Sergej; Tripathi, R.; Chattopadhyaya, S.; Dixit, A. R.; Foldyna, Josef; Hvizdoš, P.; Fides, M.; Adamčík, P.
2017 - anglický
This study focusses on exploring the effect of using Pulsating water jet technology\nas a surface treatment process. The AISI 304 plate samples were subjected to\nthe treatment process using circular nozzle at different levels of pressure and\nstand-off distance combination with variation of traverse speed. For evaluating\nthe effect of peening the surface residual stress was measured using the x-ray\ndiffraction technique. The results showed that the initial tensile residual stresses\non the surface were relieved and converted to compressive residual stress.\nThe present study shows that the new technology can be used as a potential\nsurface treatment method.
Klíčová slova:
residual stress; water jet; peening
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Prospective of using pulsating water jet peening as a surface treatment process
This study focusses on exploring the effect of using Pulsating water jet technology\nas a surface treatment process. The AISI 304 plate samples were subjected to\nthe treatment process using circular ...
Abrasive water jet drilling of cooling holes in aeroengines: preliminary experimental study
Hlaváček, Petr; Zlámal, T.; Sitek, Libor; Georgiovská, Lucie
2017 - anglický
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.
Klíčová slova:
abrasive water jet; drilling; thermal barrier coating
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Abrasive water jet drilling of cooling holes in aeroengines: preliminary experimental study
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 ...
Evaluation of quality of cut surfaces created by abrasive water jet according to swiss standard SN 214001
Klichová, Dagmar; Gurková, Lucie
2017 - anglický
The article focuses on the evaluation of the quality of cut surfaces created by\nan abrasive water jet (AWJ) according to the Swiss standard SN 214001 (2010).\nThe standard presents a quantified description of the texture of the cut. It defines\nnew parameters and methods of parameter measurements used in order to\ncategorize the cut surface in various quality levels Q. They are so far the most\ncommonly applied form of the qualitative description of the quality of the cut\nsurfaces created by the AWJ technology.
Klíčová slova:
surface quality; abrasive water jet; standard parameters
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Evaluation of quality of cut surfaces created by abrasive water jet according to swiss standard SN 214001
The article focuses on the evaluation of the quality of cut surfaces created by\nan abrasive water jet (AWJ) according to the Swiss standard SN 214001 (2010).\nThe standard presents a quantified ...
Erosion capability of ultra-high-speed continuous waterjet and pulsating waterjet: the comparison
Sitek, Libor; Hlaváček, Petr; Klichová, Dagmar; Trieb, F.; Pude, F.
2017 - anglický
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.
Klíčová slova:
hyperpressure; hydraulic power; ultra-high-speed waterjet; pulsating waterjet
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Erosion capability of ultra-high-speed continuous waterjet and pulsating waterjet: the comparison
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 ...
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