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Application of high speed water jet technology for concrete repair
Bodnárová, L.; Sitek, Libor; Foldyna, Josef; Jarolím, T.
2017 - English
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.
Keywords:
high speed water jet (HSWJ); concrete; concrete repair; X-ray CT; carbon nanotubes (CNTs)
Available on request at various institutes of the ASCR
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 - English
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.
Keywords:
pulsating water jet; copper; roughness; topography
Available on request at various institutes of the ASCR
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 ...
Flow Field Analysis in Abrasive Head as Tool for High-Speed Abrasive Jet Cutting
Říha, Zdeněk; Zeleňák, Michal
2017 - English
The article presents an analysis of the calculated flow field of water, vapor and\nabrasive particles in the inner geometry of a tool called the abrasive head using\na multiphase numerical flow model. The results of the above-mentioned analysis\nare compared with measured values of abrasive particle velocities at the outlet of\nthe abrasive head. For measuring of abrasive particle velocities, the PIV method\nwas used.
Keywords:
abrasive head; high-speed water jet; abrasive particle velocity
Available on request at various institutes of the ASCR
Flow Field Analysis in Abrasive Head as Tool for High-Speed Abrasive Jet Cutting
The article presents an analysis of the calculated flow field of water, vapor and\nabrasive particles in the inner geometry of a tool called the abrasive head using\na multiphase numerical flow model. ...
Professor Ivo Marek (1933-2017)
Blaheta, Radim; Tůma, Miroslav
2017 - English
Ivo Marek, Professor at Charles University and the Czech Tec\nhnical University in Prague, was for many decades one of the best-known Czech ma\nthematicians, who contributed significantly to the development of computa\ntional methods and numerical analysis. At the same time, he was a teacher and a le\nading personality that integrated and influenced the Czech mathematical commu\nnity.
Fulltext is available at external website.
Professor Ivo Marek (1933-2017)
Ivo Marek, Professor at Charles University and the Czech Tec\nhnical University in Prague, was for many decades one of the best-known Czech ma\nthematicians, who contributed significantly to the ...
The GIS support to measures on the ground in case of leakage of liquid pollutant on the road
Kolejka, Jaromír; Rapant, P.; Zapletalová, Jana
2016 - English
Accidents on roads associated with the leakage of hazardous substances are one of the major challenges encountered by disaster management. Because of the impossibility of predicting the place and time of the event, then it is necessary in the event of such an accident to proceed in quick succession of steps. They are designed primarily to protect human life and health, and then to minimize to property and environment damage. The paper describes the response to this event using GIS tools and generally available geodata. The simulated accident on the D1 highway near Ostrava is applied as a demonstration example.
Keywords:
GIS decision support; geographic data and knowledge; geography
Available in digital repository of the ASCR
The GIS support to measures on the ground in case of leakage of liquid pollutant on the road
Accidents on roads associated with the leakage of hazardous substances are one of the major challenges encountered by disaster management. Because of the impossibility of predicting the place and time ...
Geodiversity values as a basis for geosite and geomorphosite assessment: a case study from Žďárské vrchy Highland
Bajer, A.; Kirchner, Karel; Kubalíková, L.
2016 - English
Paper presents geodiversity values, geodiversity is understood as a set of geological, geomorphological and pedological components, including systems consisting of this components and geological, geomorphological and pedological processes. Geodiversity values are analyzed in relation to ecosystem values (e.g. cultural, functional value). Geodiversity values were used as basis for a methodical approach to geosite and geomorphosite assessment. Methodological approach is presented at selected sites in the top part of the Žďárské vrchy Highland. The acquired results can serve as a basis for geoconservation of PLA Žďárské vrchy, development of geotourism as well as an offer for extension geoeducational activities.\n
Keywords:
geodiversity; geoeducation; geosite; geomorphosite assessment
Available in digital repository of the ASCR
Geodiversity values as a basis for geosite and geomorphosite assessment: a case study from Žďárské vrchy Highland
Paper presents geodiversity values, geodiversity is understood as a set of geological, geomorphological and pedological components, including systems consisting of this components and geological, ...
Assessment of the Aggregate in Historical Plasters
Rezek, P.; Martinec, Petr
2016 - English
This article deals with the analysis of the aggregates of historical plasters. In the paper there is described the assessment methodology of the aggregates of historical plasters. The assessment of the aggregates is carried out with the example of a set of original and modern-day aggregates taken in the prelature and convent of the Želiv Monastery. Composition of fine aggregates of historical plasters was compared to the composition of the aggregates from resources of nearby watercourses. As well as it was assessed the geological character of nearby vicinity of the Monastery. For the analysis of character of the plaster fine aggregates it is applied the optical microscopy of the plaster thin sections, grain size analysis, mineralogical and petrographic analysis of the aggregates. The presented results document the differences in the origin of the aggregate used in plasters.
Keywords:
aggregate; composition; geological situation; historical plaster; petrography
Available at various institutes of the ASCR
Assessment of the Aggregate in Historical Plasters
This article deals with the analysis of the aggregates of historical plasters. In the paper there is described the assessment methodology of the aggregates of historical plasters. The assessment of ...
A Comparison of Preconditioning Methods for Saddle Point Problems with an Application to Porous Media Flow Problems
Axelsson, Owe; Blaheta, Radim; Hasal, Martin
2016 - English
The paper overviews and compares some block preconditioners for the solution of saddle point systems, especially systems arising from the Brinkman model of porous media flow. The considered preconditioners involve different Schur complements as inverse free Schur complement in HSS (Hermitian - Skew Hermitian Splitting preconditioner), Schur complement to the velocity matrix and finally Schur complement to a regularization block in the augmented matrix preconditioner. The inverses appearing in most of the considered Schur complements are approximated by simple sparse approximation techniques as element-by-element and Frobenius norm minimization approaches. A special interest is devoted to problems involving various Darcy, Stokes and Brinkman flow regions, the efficiency of preconditioners in this case is demonstrated by some numerical experiments.
Keywords:
schur complements; linear-systems; high performance computing
Available at various institutes of the ASCR
A Comparison of Preconditioning Methods for Saddle Point Problems with an Application to Porous Media Flow Problems
The paper overviews and compares some block preconditioners for the solution of saddle point systems, especially systems arising from the Brinkman model of porous media flow. The considered ...
Composition and microstructure of plasters in convent of the Želiv Monastery (Czech Republic)
Rezek, P.; Martinec, Petr; Ščučka, Jiří; Majstríková, T.
2016 - English
The paper deals with analyses of composition and structure of historic plasters from the convent building of the Želiv Monastery (Czech Republic). Composition and microstructure of plaster samples taken from the historic object have been assessed using both traditional and advanced analytical methods. The following techniques have been used for the assessment of binders and fine aggregates in plasters: optical microscopy of thin sections, mineralogical and petrographic analysis of separated components, infrared spectroscopy, and thermal analysis. Presented results show significant differences in character of the studied materials of varying age and demonstrate the effectiveness of the taken analytical approach.
Keywords:
aggregate; thermal analysis; historic plaster; infrared spectroscopy; optical microscopy
Available at various institutes of the ASCR
Composition and microstructure of plasters in convent of the Želiv Monastery (Czech Republic)
The paper deals with analyses of composition and structure of historic plasters from the convent building of the Želiv Monastery (Czech Republic). Composition and microstructure of plaster samples ...
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 ...
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