Number of found documents: 320
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Characterization of fine-grained montmorillonite fractions suitable for composite preparation
Valovičová, Věra; Vaculíková, Lenka; Plevová, Eva; Dolinská, S.; Znamenáčková, I.; Danková, Z.
2019 - English
The aim of this experimental study was to characterize a fine-grained fraction of montmorillonites (SAz-2, STx-1, SWy-2 and Kunipia-F). It was investigated in order to provide more precise information of used montmorillonites than could be obtained by analysis of the unfractioned montmorillonites. At first, the fine fraction of montmorillonites were prepared by sedimentation and activation by means of Na2CO3. The prepared clay materials were characterized by the X-ray diffraction analysis and FTIR spectroscopy. The thermal behaviour of the studied samples was determinated according to the characteristic temperatures obtained from TG/DTA curves. The temperatures of dehydratation and dehydroxylation were evaluated and kinetic parameters were also calculated. The porosity and surface properties of the studied samples were gained by the nitrogen adsorption measurements. The obtained results confirmed that the fine fraction of montmorillonites could be a suitable material for subsequent preparation of composites with enhanced sorption properties, especially montmorillonite/MnO2 composite. Keywords: montmorillonite; activation; characterization; composites Available in digital repository of the ASCR
Characterization of fine-grained montmorillonite fractions suitable for composite preparation

The aim of this experimental study was to characterize a fine-grained fraction of montmorillonites (SAz-2, STx-1, SWy-2 and Kunipia-F). It was investigated in order to provide more precise information ...

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

Mathematical modelling and computational methods in applied sciences and engineering - Modelling 2019
Blaheta, Radim; Starý, Jiří; Sysala, Stanislav
2019 - English
Modelling 2019 is an international conference on Mathematical Modelling and Computational Methods in Applied Sciences and Engineering held in\nOlomouc, Czech Republic, in September 16 - 20, 2019. It aims to be a forum for an exchange of ideas, insights and experiences in different areas\nof mathematical modelling. It includes the fundamental formulation and analysis of mathematical models, the development of numerical methods and exploitation of capabilities of the contemporary high-performance computers or applications of mathematical modelling.\nThis conference belongs to a series of conferences previously held in Roznov in 2014 and 2009, in Pilsen in 2005 and 2001, and in Prague in 1998 and 1994. During the period of 25 years, the focus of the conference has been substantially enlarged. Besides the topics aiming at the development\nof numerical methods and analysis of mathematical models described by the partial differential equations, the conference relates to the inverse\nproblems, quantification of uncertainties in the input data, machine learning and exploitation of high-performance computing systems of petaflops and pre-exaflops performance. Increased attention is devoted to challenging industrial problems and collaboration with industry. Keywords: modelling; inverse problems; numerical methods; partial differential equations Available at various institutes of the ASCR
Mathematical modelling and computational methods in applied sciences and engineering - Modelling 2019

Modelling 2019 is an international conference on Mathematical Modelling and Computational Methods in Applied Sciences and Engineering held in\nOlomouc, Czech Republic, in September 16 - 20, 2019. It ...

Blaheta, Radim; Starý, Jiří; Sysala, Stanislav
Ústav geoniky, 2019

37th Czech - Polish - Slovak Symposium on Mining and Environmental Geophysics and 28th Conference OVA´19 - New Knowledge and Measurements in Seismology, Engineering Geophysics and Geotechnical Engineering.
Kaláb, Zdeněk; Lednická, Markéta
2019 - English
Main topics of event were: Environmental and mining geophysics, Natural, induced and technical seismicity, Deep geological repository,\nOther geophysical, geotechnical and related research. Participants represent both scientific institution and also commercial companies with \ngeophysical and geotechnical scopes. Keywords: engineering geophysics; geotechnical engineering; seismology Available at various institutes of the ASCR
37th Czech - Polish - Slovak Symposium on Mining and Environmental Geophysics and 28th Conference OVA´19 - New Knowledge and Measurements in Seismology, Engineering Geophysics and Geotechnical Engineering.

Main topics of event were: Environmental and mining geophysics, Natural, induced and technical seismicity, Deep geological repository,\nOther geophysical, geotechnical and related research. ...

Kaláb, Zdeněk; Lednická, Markéta
Ústav geoniky, 2019

Possibilities of using 3D laser scanning in geotechnical practise
Kukutsch, Radovan; Kajzar, Vlastimil; Šňupárek, Richard; Waclawik, Petr
2019 - English
We are experiencing the penetration of modern and smart technologies in all sectors of human activity, including mining and geotechnics. One of these technologies is 3D laser scanning, which has seen significant technological advancements over the last decade and has become an integral part of underground construction monitoring as a tool to enable comprehensive, accurate and unbiased capture of the spatial situation in digital form. This development was behind the fact that since 2013, 3D laser scanner has been used by the Institute of Geonics of the Czech Academy of Sciences as a necessary part of the geotechnical monitoring of mine works, when it is possible to precisely detect and quantify the time-space changes caused by man's intervention in the rock mass compared to the traditional established measuring methods. A leading project of recent years was the monitoring of the strain stress state of the rock massif during the 30th seam extraction during the trial operation of the Room and Pillar extraction method in the CSM Mine shaft safety pillar where, besides many other measuring instruments, 3D laser scanning was used for the convergence measuring of roadways, especially for capturing any deformation changes on the permanent pillars. A complementary function was the comparative evaluation with the results of other tools, e.g. with data measured by horizontal extensometers. The subject of the article will be a general description of the possibilities of using 3D laser scanning in geotechnical practice on spatial data acquired during the monitoring lasting almost 3.5 years, when important phenomena were detected in the movement of the pillar walls and the floor heave in the CSM Mine in the tens of cm, sometimes up to 100 cm. Keywords: 3D laser scanning; room and pillar; roadways deformation Available at various institutes of the ASCR
Possibilities of using 3D laser scanning in geotechnical practise

We are experiencing the penetration of modern and smart technologies in all sectors of human activity, including mining and geotechnics. One of these technologies is 3D laser scanning, which has seen ...

Kukutsch, Radovan; Kajzar, Vlastimil; Šňupárek, Richard; Waclawik, Petr
Ústav geoniky, 2019

Adsorption of pharmaceuticals from aqueous solutions onto clay minerals
Vallová, S.; Sokolová, B.; Valovičová, Věra; Plevová, Eva
2019 - English
The objective of this work was to investigate to possibility of clay minerals for the removal of drugs from aqueous solutions. Natural minerals such as montmorillonite, vermiculite, kaolinite and modified montmorillonites KSF and K10 (intercalated by Fe3+) were used as potential sorbents for three analgetics: paracetamol, ibuprofen and diclofenac from aqueous solutions. This research demonstrated that adsorption of all three pharmaceuticals onto natural untreated clay minerals, except paracetamol sorption on Na-MMT, is negligible. On the other hand, the chemically modified montmorillonites demonstrated significant sorption ability in the order diclofenac>ibuprofen>paracetamol. Keywords: adsorption; clay minerals; montmorillonite; paracetamol; ibuprofen; diclofenac Available at various institutes of the ASCR
Adsorption of pharmaceuticals from aqueous solutions onto clay minerals

The objective of this work was to investigate to possibility of clay minerals for the removal of drugs from aqueous solutions. Natural minerals such as montmorillonite, vermiculite, kaolinite and ...

Vallová, S.; Sokolová, B.; Valovičová, Věra; Plevová, Eva
Ústav geoniky, 2019

SNA´19 - Seminar on numerical analysis.
Blaheta, Radim; Starý, Jiří; Sysalová, Dagmar
2019 - English
Seminar on Numerical Analysis 2017 (SNA'17) is a continuation in a series of SNA events held\nin different places in the Czech Republic and organized alternatively by Ostrava and Prague\ninstitutions. The SNA'17 is organized by the Institute of Geonics of the CAS in collaboration with\nVŠB - Technical University of Ostrava and IT4Innovations National Supercomputing Centre.\nConference location is one of the lecture rooms in New Aula of the VŠB-TU Ostrava.\nLet us note that SNA 2016 was reshaped to EMS School in Applied Mathematics (ESSAM)\ndevoted to mathematical modelling, numerical analysis and scientiffc computing. The SNA'17\nis turning back to more traditional winter event.\nIt provides opportunity for meeting and mutual information of the community working in computational\nmathematics and computer science, but an important part of SNA is devoted to the\nWinter School with tutorial lectures focused on selected important topics within the scope of\nnumerical methods and modelling.\nThis year, a part of the Winter School will be the course Parallel Linear Algebra (PLA) organized\nby the European research infrastructure PRACE, particularly by the French PRACE Advanced\nTraining Centre - Maison de la Simulation. Winter school lectures will cover the ongoing topics\nrelated to domain decomposition methods, interval computations and numerical veriffcation. The\nPLA course will provide lectures from the area of direct and iterative parallel solvers, as well as\npractical training with selected programs. Keywords: numerical analysis; mathematical modelling; computer mathematics Fulltext is available at external website.
SNA´19 - Seminar on numerical analysis.

Seminar on Numerical Analysis 2017 (SNA'17) is a continuation in a series of SNA events held\nin different places in the Czech Republic and organized alternatively by Ostrava and Prague\ninstitutions. ...

Blaheta, Radim; Starý, Jiří; Sysalová, Dagmar
Ústav geoniky, 2019

Cultural functions and services of geodiversity within urban areas (with a special regard on tourism and recreation)
Kubalíková, Lucie; Bajer, A.; Drápela, E.; Zapletalová, D.; Kirchner, Karel; Balková, M.; Zágoršek, K.; Kuda, František; Roštínský, Pavel
2019 - English
Geodiversity (or abiotic nature) within urban areas has numerous functions and offers various benefits and services. In addition, it has strong links to cultural heritage and historical aspects and it influences and is influenced by urban development and planning. The geodiversity functions and services can be sorted according to the ecosystem services approach: regulating, supporting, provisioning and cultural services. The last mentioned includes a wide spectrum of aspects (spiritual, religious, historical, archaeological, social, artistic, sense of place etc.) and besides this, it encompasses also the tourist and recreational functions which are (in some cases) unexplored and underestimated in urban areas. The paper presents examples from two different Czech cities – Brno and Liberec. Selected geocultural sites are described and assessed and specific proposals for tourist, recreational and educational use are outlined. The results of evaluation show that they can represent an interesting alternative to the traditional tourist destinations within urban areas. Keywords: geotourism; geocultural site; assessment; Brno; Liberec Available in digital repository of the ASCR
Cultural functions and services of geodiversity within urban areas (with a special regard on tourism and recreation)

Geodiversity (or abiotic nature) within urban areas has numerous functions and offers various benefits and services. In addition, it has strong links to cultural heritage and historical aspects and it ...

Kubalíková, Lucie; Bajer, A.; Drápela, E.; Zapletalová, D.; Kirchner, Karel; Balková, M.; Zágoršek, K.; Kuda, František; Roštínský, Pavel
Ústav geoniky, 2019

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

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

EFFECTS OF ABRASIVES DURING ACCELERATED\nSIMULATION 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 on request at various institutes of the ASCR
EFFECTS OF ABRASIVES DURING ACCELERATED\nSIMULATION 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

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