Number of found documents: 343
Published from to

Reliable computation and local mesh adaptivity in limit analysis
Sysala, Stanislav; Haslinger, Jaroslav; Repin, S.
2019 - English
The contribution is devoted to computations of the limit load for a perfectly plastic model with the von Mises yield criterion. The limit factor of a prescribed load is defined by a specific variational problem, the so-called limit analysis problem. This problem is solved in terms of deformation fields by a penalization, the finite element and the semismooth Newton methods. From the numerical solution, we derive a guaranteed upper bound of the limit factor. To achieve more accurate results, a local mesh adaptivity is used. Keywords: limit analysis; von Mises yield criterion; penalization; finite element method; Newton-like method; local mesh adaptivity Fulltext is available at external website.
Reliable computation and local mesh adaptivity in limit analysis

The contribution is devoted to computations of the limit load for a perfectly plastic model with the von Mises yield criterion. The limit factor of a prescribed load is defined by a specific ...

Sysala, Stanislav; Haslinger, Jaroslav; Repin, S.
Ústav geoniky, 2019

Application of bentonite-manganese oxide composites in removal of heavy metals
Dolinská, S.; Znamenáčková, I.; Tomčová, J.; Valovičová, Věra; Vaculíková, Lenka; Plevová, Eva
2019 - English
The paper is aimed on the using of non-homogeneous bentonites coated by manganese oxides for the removal of heavy metal cations from the water solutions. In the first stage Slovak natural bentonite was converted to sodium form using by Na2CO3 as the activating agent. After that the manganese oxides were precipitated on the surface of natural and sodium activated bentonite, respectively. The structural changes before and after the modifications of bentonites were characterized by X-ray diffraction analyses and X-ray photoelectron spectroscopy. To compare the sorption properties of the natural bentonite and modified bentonites, sorption experiments of Cd2+ from aqueous solutions were done. Keywords: bentonite; composites; adsorption Available in digital repository of the ASCR
Application of bentonite-manganese oxide composites in removal of heavy metals

The paper is aimed on the using of non-homogeneous bentonites coated by manganese oxides for the removal of heavy metal cations from the water solutions. In the first stage Slovak natural bentonite ...

Dolinská, S.; Znamenáčková, I.; Tomčová, J.; Valovičová, Věra; Vaculíková, Lenka; Plevová, Eva
Ústav geoniky, 2019

Thermal behaviour of organically modified smectites
Plevová, Eva; Vaculíková, Lenka; Valovičová, Věra; Simha Martynková, G.
2019 - English
The smectites were modified with different types of alkylammonium cations. The X-ray powder diffraction was used to calculate the values of the basal space of the modified smectites to confirm the intercalation of cations into the structure. The montmorillonites were also characterized by means of FTIR spectroscopy, which proved sorption or intercalation of the alkylammonium cations too. Thermal behaviour of the smectites was investigated by simultaneous thermogravimetry and differential thermal analysis. The temperatures of dehydratation and dehydroxylation and the temperatures related to total melting and recrystallization generally changed. Study of temperatures changes together with determination of kinetic parameters helped to obtained a comprehensive assessment of smectite thermal stability. Keywords: smectites; intercalation; thermal analysis Available in digital repository of the ASCR
Thermal behaviour of organically modified smectites

The smectites were modified with different types of alkylammonium cations. The X-ray powder diffraction was used to calculate the values of the basal space of the modified smectites to confirm the ...

Plevová, Eva; Vaculíková, Lenka; Valovičová, Věra; Simha Martynková, G.
Ústav geoniky, 2019

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 - English
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. Keywords: cement-based composite; erosion; abrasion; cavitation; high-speed water flow; abrasive material Available at various institutes of the ASCR
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 ...

Hlaváček, Petr; Sitek, Libor; Klichová, Dagmar; Bodnárová, L.
Ústav geoniky, 2019

Evaluation of fracture response of Silesian granite specimens via Effective Crack Model approach and finite element analysis
Malíková, L.; Vavro, Leona; Vavro, Martin; Keršner, Z.
2019 - English
The paper is focused on the advanced evaluation of fracture tests of selected rock specimens. Assessment of fracture response of chevron notch cylindrical specimens of Silesian granite subjected to three-point bending test was performed. The effective crack model is used and academic software chevroncylinder (author Petr Frantík) based on the finite element method is applied for the analyses. Based on the described procedures, estimation of maximum values of the effective fracture toughness are established and discussed. Keywords: granite; fracture test; chevron notch; load–displacement diagram; effective crack model Available in digital repository of the ASCR
Evaluation of fracture response of Silesian granite specimens via Effective Crack Model approach and finite element analysis

The paper is focused on the advanced evaluation of fracture tests of selected rock specimens. Assessment of fracture response of chevron notch cylindrical specimens of Silesian granite subjected to ...

Malíková, L.; Vavro, Leona; Vavro, Martin; Keršner, Z.
Ústav geoniky, 2019

Structural mapping of exploration boreholes walls within first phase - Safety boreholes for Boxcut
Waclawik, Petr; Souček, Kamil; Vavro, Martin; Kukutsch, Radovan; Ram, S.
2018 - English
Structural-geological analysis, i.e. core fracturing assessment within the boxcut safety\nborehole was carried out on the basis of optical televiewer record evaluation. In general,\noptical televiewer (OPTV) probe provides a continuous, unwrapped, high-resolution digital\n360° image of the borehole-walls oriented towards the cardinal points. This technique\nprovides information about the strike, dip direction, dip angle and depth of foliation, bedding\nplanes and fractures, as well as the frequency, aperture and infillings of fractures. Information\nabout spatial characteristics of structural elements is one of its indisputable advantages and\nallows for subsequent statistical evaluations.\nThe structural mapping of boreholes of Boxcut safety boreholes were carried out within the\ncontract of IG CAS (Contract No. D/18/156/00) GEOMET, s.r.o. (as a customer, contract No.\n01/2018). The aim of the contractual research was the realisation and interpretation of the\nfractures by digital logging of boreholes walls. Keywords: boreholes; structural mapping; rock quality Available at various institutes of the ASCR
Structural mapping of exploration boreholes walls within first phase - Safety boreholes for Boxcut

Structural-geological analysis, i.e. core fracturing assessment within the boxcut safety\nborehole was carried out on the basis of optical televiewer record evaluation. In general,\noptical televiewer ...

Waclawik, Petr; Souček, Kamil; Vavro, Martin; Kukutsch, Radovan; Ram, S.
Ústav geoniky, 2018

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 - English
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. Keywords: cultural heritage; secondary geodiversity; Archdiocese of Olomouc Available at various institutes of the ASCR
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 ...

Kirchner, Karel; Kuda, František; Kubalíková, Lucie; Havlíček, M.; Machar, I.; Pechanec, V.
Ústav geoniky, 2018

Tourist interest in illicit zone of ice caves
Nováková, Eva; Kuda, František; Kubalíková, Lucie
2018 - English
Ledové sluje (Ice Caves) in the Podyjí National Park represents one of the most spectacular sites within the area. It consists of the large boulder field and several pseudokarst caverns on the north-western slope of the ridge that are very important from the ecological and geomorphological point of view. The access to the site is restricted for the visitors of National Park as there exists a risk of damage and disturbance of these unique phenomena, tourist can use the marked paths leading around the site, they can reach the top part of the ridge. Currently, there are only several persons who have legal access to the site (employees of the National Park Administration and other researches with the permission issued by NP Administration). However, the installed sensor that counts the passages proved that the site is visited more frequently than it should be. The number of people who visit this site (situated within the first zone of National Park where there is no marked path and so the access is forbidden by decree) is quite alarming. Based on these findings, some proposals for the solution of this unfavourable situation are proposed and other possibilities how to avoid this undesirable phenomenon are discussed.\n Keywords: Podyji National Park; restricted area; passages monitoring Available in a digital repository NRGL
Tourist interest in illicit zone of ice caves

Ledové sluje (Ice Caves) in the Podyjí National Park represents one of the most spectacular sites within the area. It consists of the large boulder field and several pseudokarst caverns on the ...

Nováková, Eva; Kuda, František; Kubalíková, Lucie
Ústav geoniky, 2018

European Countryside and its Perception. Book of Abstracts
Zapletalová, Jana; Vaishar, A.; Šťastná, M.
2018 - English
Rural area was traditionally connected with agriculture. To compare with urban, rural areas were considered to be backwarded, retarded, not worthy of an intensive research. But the situation has changed during the last years. Although cities are still centres of development within the globalization process, people in Europe abandon them as a result of the trends of suburbanization, counter-urbanization, naturbanization. We intend to pay our attention on transformation trends of the European countryside where focusing on more processes occurring there as: transformation from productive to non-productive function,from central planned to the market oriented countryside, from the mono-functional to the multifunctional one, from the national to European and globalized scale. Such a transformation generates many impacts on natural, economic and social processes occurring \nin present European countryside. Their combination creates a set of different countryside types. Keywords: countryside; geography; Europe Fulltext is available at external website.
European Countryside and its Perception. Book of Abstracts

Rural area was traditionally connected with agriculture. To compare with urban, rural areas were considered to be backwarded, retarded, not worthy of an intensive research. But the ...

Zapletalová, Jana; Vaishar, A.; Šťastná, M.
Ústav geoniky, 2018

Geotourism within urban areas: New ways of promotion of natural and cultural heritage (Case study from Brno City).
Kubalíková, Lucie; Bajer, A.
2018 - English
Geotourism is based especially on geodiversity, but it also uses the cultural-historical aspects of an area, it is linked to the education and counts with active engagement of local people. Currently, geotourism is developed mainly within rural areas, but there are activities that point on the geodiversity and its importance within urban areas. Rational and sustainable use of geodiversity within urban areas can represent an alternative to the traditional tourist destinations and contributes to the understanding of the importance and necessity of protection of geodiversity itself. Geodiversity, respectively geoheritage within urban areas does not include only issues of primary (natural) geodiversity (substrate, Iandforms, soils), but also anthropogenic landforms and processes (secondary geodiversity), hydrological features (wells, millraces) and geodiversity ex-situ (museum collections, building material). The paper presents this new form of tourism and gives examples of selected geodiversity/geoheritage features within the Brno city. Keywords: geodiversity; geoheritage; urban geotourism; Brno Fulltext is available at external website.
Geotourism within urban areas: New ways of promotion of natural and cultural heritage (Case study from Brno City).

Geotourism is based especially on geodiversity, but it also uses the cultural-historical aspects of an area, it is linked to the education and counts with active engagement of local people. Currently, ...

Kubalíková, Lucie; Bajer, A.
Ústav geoniky, 2018

About project

NRGL provides central access to information on grey literature produced in the Czech Republic in the fields of science, research and education. You can find more information about grey literature and NRGL at service web

Send your suggestions and comments to nusl@techlib.cz

Provider

http://www.techlib.cz

Facebook

Other bases