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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 ...
Předindustriální a postindustriální krajina na Moravě: koncepce a realita
Kolejka, Jaromír; Batelková, Kateřina
2017 - český
Přípěvek pojednává odborný obsah pojmů postindustriální a předindustriální krajina a přehled datových zdrojů potřebných k jejich zjišťování na území České republiky. V přehledu je uveden současný stav poznání a výzkumu obou typů historických krajin. Ve stručnosti je uvedena metodika jejich zjišťování, mapování a klasifikace podle klíčových vlastností. Na příkladech z historického území Moravy jsou prezentovány ukázky postindustriální krajiny Rosicko-Oslavansko a předindustriální krajiny Bělečsko. Zdůrazněn je jejich význam pro poznávací, vzdělávací a ochranářskou praxi. The paper deals with the scientific concept of the terms the post-industrial and the pre-industrial landscape and presents available data sources needed for their identification in the Czech Republic. The overview shows the current state of knowledge and the research progress in the study of such historical landscapes. In brief, the methodology of their identification, mapping and classification is given. The post-industrial landscape Rosice-Oslavany and the pre-industrial landscape Bělečsko are presented as examples from the historical territory of Moravia. Their significance for cognitive, educational and conservation practices is emphasized.
Klíčová slova:
survey; assessment; classification; data sources; old maps; ortophoto
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Předindustriální a postindustriální krajina na Moravě: koncepce a realita
Přípěvek pojednává odborný obsah pojmů postindustriální a předindustriální krajina a přehled datových zdrojů potřebných k jejich zjišťování na území České republiky. V přehledu je uveden současný stav ...
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 ...
Velocity measurements on continuous micro water jet using fluorescent PMMA seeding particles
Zeleňák, Michal; Ščučka, Jiří; Souček, Kamil
2017 - anglický
The paper deals with application of optical diagnostic techniques for velocity\nmeasurements of continuous micro water jet. The combination of Particle image\nvelocimetry, Particle tracking velocimetry, Laser induced fluorescence and\nShadowgraphy methods have been applied together with the use of fluorescent\nPMMA seeding particles. An experimental closed water circuit was designed with\na low-pressure water pump, and a series of experiments was conducted to\nmeasure the velocity of seeding particles in the water jet flow below the diamond\nmicro-nozzle outlet. The basic principles of the methods used in experiments are\nalso described.
Klíčová slova:
micro water jet; fluorescent PMMA particles; velocity; LIF; PTV; PIV
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Velocity measurements on continuous micro water jet using fluorescent PMMA seeding particles
The paper deals with application of optical diagnostic techniques for velocity\nmeasurements of continuous micro water jet. The combination of Particle image\nvelocimetry, Particle tracking ...
Community area risk assessment for flash flood
Kolejka, Jaromír; Rapant, P.; Krejčí, Tomáš
2017 - anglický
The flash floods forecasting is struggling mainly with extraordinary irregularities in origin of causal precipitations. They only in conjunction with the territory water saturation caused by antecedent precipitations start effect of other local factors that can consequences of short-term extreme precipitation either worsen or mitigate vice versa. Other community area features represent a permanent potential for an adequate territory response after heavy rains. According to current knowledge, it is possible to assess the flash floods hazard of a particular territory in case of extreme precipitation in advance. If such precipitations are already on the ground, or if they are just coming up in the atmosphere, the local flood control headquarters has at least time enough to call alarm and issue a flood warning. In the ideal case, it is possible to incorporate such area assessment into the concept of decision-making of the disaster staff and to insert it into the master plan documentation. The aim of this text is to present above mentioned original method, which can be used in authomatic GIS environment by public administration as well as other users. Suggested procedure is based on automatic hydrologic modelling in ArcGIS platform in combination with advanced digital terrain model. Delimitation of partial catchment basins is also part of our proces, which enables to decide about the risk value of the area in more detail using weighted arithmetic mean. These methods result to detailed imagination about probably threatened localities - and it is essential tool for local authorities and their decision making process in case of early warning.
Klíčová slova:
flash flood; local development; risk assessment; planning documentation
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Community area risk assessment for flash flood
The flash floods forecasting is struggling mainly with extraordinary irregularities in origin of causal precipitations. They only in conjunction with the territory water saturation caused by ...
Perception of wind power plants construction on the local level: Case studies in East Bohemia
Janová, M.; Kunc, J.; Frantál, Bohumil
2017 - anglický
The paper aims to evaluate selected findings of a research regarding the attitudes of the inhabitants of East Bohemian municipalities (Anenska Studanka and Vitezna) towards the construction of wind power plants and the perception thereof. A survey was carried out among the inhabitants of the two municipalities, as well as nearby municipalities and guided interviews were conducted with their mayors. The two selected sites differ in population numbers, time of power plant construction, number and size of the turbines and form of financial settlement. In the case of Vitezna, the power plant in question was community-funded, meaning that a portion of the shares was offered to the inhabitants (a unique case in the Czech Republic). The results indicated that, over time, the attitudes and opinions of the respondents from all the municipalities concerned have shifted towards a more positive perception of wind power plants. They have, however, also become more polarized. Citizens' movements against further construction have been created, even though it is currently not possible in the Czech Republic, especially given that the government has cancelled funding for the support of clean power. Respondents who were found to have the fewest issues with the wind power plants were younger than 30 years, graduates of secondary education and resided at a greater distance from the stations without having direct visual contact with them from their home.
Klíčová slova:
wind power plants; perception; local level; Eastern Bohemia
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Perception of wind power plants construction on the local level: Case studies in East Bohemia
The paper aims to evaluate selected findings of a research regarding the attitudes of the inhabitants of East Bohemian municipalities (Anenska Studanka and Vitezna) towards the construction of wind ...
Application of high speed water jet technology for concrete repair
Bodnárová, L.; Sitek, Libor; Foldyna, Josef; Jarolím, T.
2017 - anglický
This article brings selected knowledge from the long-term cooperation between\nthe Brno University of Technology, the Faculty of Civil Engineering, the Institute of\nTechnology of Building Materials and Components, and the Academy of Sciences of\nthe Czech Republic, v.v.i., Institute of Geonics, Ostrava – Poruba in the field of\nthe interaction of high-speed water jets and concrete, especially with regard to\nthe use of high-speed water jet technology for the removal of surface layers of\nconcrete during repair of concrete.
Klíčová slova:
high speed water jet (HSWJ); concrete; concrete repair; X-ray CT; carbon nanotubes (CNTs)
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Application of high speed water jet technology for concrete repair
This article brings selected knowledge from the long-term cooperation between\nthe Brno University of Technology, the Faculty of Civil Engineering, the Institute of\nTechnology of Building Materials ...
Evaluation of selected surface characteristics of CW004A copper disintegrated by PWJ
Lehocká, D.; Klich, Jiří
2017 - anglický
Paper deals with copper CW004A surface characteristics evaluation after\ndisintegration by enhanced pulsating water jet. The main aim was identify and\ndescribe areas of pulsating water jet disintegration effects on material with using\ncircular nozzle diameter. 25 samples were disintegrated at change traverse speed\nv = 0.1 – 20 mm·s-1, for assessment of individual areas formation. Surface\ncharacteristics were evaluated based on surface roughness parameters Ra [μm],\nRz [μm], Rp [μm], Rv [μm], mass material removal Δm [mg.mm-1] and volume\nmaterial removal Vm [mm3]. Based on experimental investigation, three areas of\npulsating water jet effects on material were determined.
Klíčová slova:
pulsating water jet; copper; roughness; topography
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Evaluation of selected surface characteristics of CW004A copper disintegrated by PWJ
Paper deals with copper CW004A surface characteristics evaluation after\ndisintegration by enhanced pulsating water jet. The main aim was identify and\ndescribe areas of pulsating water jet ...
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