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Bukov PVP underground research laboratory - geotechnical conditions of construction
Souček, Kamil; Vavro, Martin; Staš, Lubomír; Koníček, Petr; Ptáček, Jiří; Waclawik, Petr; Vavro, Leona; Lednická, Markéta; Kaláb, Zdeněk; Šňupárek, Richard; Vondrovic, L.
2016 - English
Bukov PVP Underground Research Laboratory (Bukov URL) is designed to be a test site for the evaluation of properties and behavior of the rock mass which is of similar type as selected candidate sites in the Czech Republic. It is situated at a depth corresponding to the proposed storage depth of the final locality for the national deep repository of high-level radioactive waste. The Bukov URL, the construction of which has begun in 2013, is situated in the southern part of the Rožná uranium deposit, at the northeastern periphery of the Strážek Moldanubicum close to its contact with the Svratka Unit. The rock mass is composed of relatively monotonous rock sequences primarily of a volcanosedimentary origin. They are currently represented, due to the subsequent tectonometa-morphic development, by migmatized biotite paragneisses up to stromatitic and/or oftalmitic migmatites, amphibole-biotite to biotite-amphibole gneisses, and amphibolites. The workings of the Bukov URL are situated on the level 12 of the Bukov-1 shaft, at the depth of about 600 m below the earth’s surface. The Bukov URL is still under construction and the research works by the consortium of several organizations – ÚJV Řež, a.s., Czech Geological Survey, Institute of Geonics of the CAS, v.v.i., and Arcadis CZ, a.s. - are carried out simultaneously. The research activities focus on a complex geological and geotechnical characterization of the rock mass of interest, which is vital for the realization of further research in situ. This paper briefly describes the technical solution of the Bukov URL and the process of its construction.
Keywords:
Bukov URL; rock mass; radioactive waste
Available in digital repository of the ASCR
Bukov PVP underground research laboratory - geotechnical conditions of construction
Bukov PVP Underground Research Laboratory (Bukov URL) is designed to be a test site for the evaluation of properties and behavior of the rock mass which is of similar type as selected candidate sites ...
Secondary geodiversity and its potential for geoeducation and geotourism: a case study from Brno city
Kubalíková, Lucie; Bajer, A.; Kirchner, Karel
2016 - English
Geodiversity is considered to be the most important resource for geoeducational and geotourist activities. Usually the geoeducation and geotourism are developed within natural areas and they are based on the primary geodiversity (natural landforms). Nevertheless, so called secondary geodiversity or man-made/anthropogenic geodiversity (represented by the anthropogenic geosites as old quarries, pits or underground landforms) can be also viewed as a remarkable resource for these activities. Brno city is rich in these landforms; some of them already serve as excursion localities for the university students or they are used for recreation and leisure, some of them are unique (from the geoscience point of view) and they have also certain added values (historical, archaeological or ecological), however, their potential is not fully developed. The article presents examples of these geosites and outlines possibilities of the rational use for the geoeducation and geotourism purposes.
Keywords:
anthropogenic landforms; geosites; geoeducational and geotourist activities
Available in digital repository of the ASCR
Secondary geodiversity and its potential for geoeducation and geotourism: a case study from Brno city
Geodiversity is considered to be the most important resource for geoeducational and geotourist activities. Usually the geoeducation and geotourism are developed within natural areas and they are based ...
Preliminary study using pulsating water jet for bone cement demolition
Hloch, Sergej; Kloc, J.; Foldyna, Josef; Pude, F.; Smolko, I.; Zeleňák, Michal; Sitek, Libor; Hvizdoš, P.; Monka, P.; Monková, K.; Kozak, D.; Stoić, A.; Sedmak, A.; Milosevic, M.; Lehocká, D.; Mihalčinová, E.
2015 - English
The paper deals with the study of using the selective property of ultrasonic pulsating water jet for the disintegration of bone cement which creates the interface between femoral stem and trabecular bone tissue. For investigation, commercial bone cements were used. Bone cements were tested by nanoindentation in order to review their mechanical properties. A representative sample Palacos R+G was selected for disintegration of bone cement. Bone cements samples fixed between two plexiglasses were disintegrated using ultrasonic water jet and water jet generated by self-resonating nozzle at the pressure level of 20 MPa. Visualisation of bone cement demolition was provided with high speed 1 kHz cameras with two led pulsed sources. Potential were observed for using of pulsating water jet for bone cement demoliton during femoral stem extraction.
Keywords:
bone cement; ultrasonic pulsating water jet; revision arthroplasty
Available in digital repository of the ASCR
Preliminary study using pulsating water jet for bone cement demolition
The paper deals with the study of using the selective property of ultrasonic pulsating water jet for the disintegration of bone cement which creates the interface between femoral stem and trabecular ...
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 ...
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 ...
Effect of pulsating water jet peening on stainless steel
Hlaváček, Petr; Kruml, T.; Foldyna, Josef; Tobiáš, J.; Man, J.
2015 - English
Effects of action of pulsating water jet on polished surface of the stainless steel AISI 316L are presented. Surface slip bands appeared after this treatment. In the most severe conditions, microcracks were formed. Hardness measurement showed that the affected layer was thinner than 60 μm. Application of the pulsating water jet has beneficial effect on the fatigue life of the material.
Keywords:
pulsating water jet; surface treatment; fatigue life
Available in digital repository of the ASCR
Effect of pulsating water jet peening on stainless steel
Effects of action of pulsating water jet on polished surface of the stainless steel AISI 316L are presented. Surface slip bands appeared after this treatment. In the most severe conditions, ...
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