Browsing Ústav fyziky by Author "Ficker, Tomáš"

Now showing items 1-14 of 14

  • Computer Evaluation of Asperity Topology of Rock Joints 

    Ficker, Tomáš; Martišek, Dalibor (Elsevier, 2015-09-07)
    Grounds beneath large civil engineering structures (bridges, dams, tunnels) that are established in the terrain of rock discontinuities represent a risk of mechanical failure. The surface topology of joint surfaces strongly ...

  • Convective heat transfer inside planar solar collectors 

    Ficker, Tomáš (IOP Publishing, 2020-12-09)
    There is a permanent interest in improving the construction and thermal properties of the planar solar collectors. Minimizing the heat losses of the collectors and improving their energy gains are some of the relevant ...

  • Database 3D Surfaces for Evaluation of Joint Rock Coefficients 

    Ficker, Tomáš; Martišek, Dalibor (Elsevier, 2016-06-13)
    Surfaces of rock joints were classified by means of the computerized procedure utilizing three-dimensional reliefs. These standard reliefs were formed as fractal objects using scaling properties of rock joints. Applicability ...

  • Effect of Metallic Inclusions on the Compressive Strength of Cement-Based Materials 

    Ficker, Tomáš (Hindawi, 2018-12-26)
    In the concrete foundations, materials come into contact with bedrocks. The surfaces of bedrocks are often covered by sharp protrusions called asperities. Although geotechnical engineers have developed a reliable theory ...

  • Evaluation of Rock Joint Coefficients 

    Audy, Ondřej; Ficker, Tomáš (IOP Science, UK, 2017-11-28)
    A computer method for evaluation of rock joint coefficients is described and several applications are presented. The method is based on two absolute numerical indicators that are formed by means of the Fourier replicas of ...

  • Fitting Function for Flexural Strength of Cement Paste 

    Ficker, Tomáš (IOPPublishing, 2017-11-28)
    There are many analytical expressions for compressive strength as functions of porosity of cement-based materials but only a few such expressions exist for flexural strength of these materials. In the present paper a new ...

  • Fractal Analysis of Rock Joint Profiles 

    Audy, Ondřej; Ficker, Tomáš (IOP Publishing, 2017-11-28)
    Surface reliefs of rock joints are analyzed in geotechnics when shear strength of rocky slopes is estimated. The rock joint profiles actually are self-affine fractal curves and computations of their fractal dimensions ...

  • Heat losses of window compact shutters 

    Ficker, Tomáš (IOP Publishing, 2020-12-09)
    Window shutters are usually made of wood. They protect glazed windows at their external sides from mechanical damages and inconvenient weather conditions. A typical window compact shutter is described and its thermal ...

  • Large Rock Reliefs and Their 3D Reconstructions 

    Audy, Ondřej; Ficker, Tomáš (IOP Publishing, 2017-11-28)
    Rock reliefs are used for assessing joint rock coefficients that serve in geotechnical engineering for computing shear strength of rock joints. The three-dimensional reliefs of small rock joints amounting to several ...

  • Macrodefects and Microdefects within Porous Cement Pastes 

    Ficker, Tomáš (IOP Publishing, 2017-11-28)
    It is shown that the mechanical strength of cement matrix (hydrated cement paste) is a result of competitive interplay between macrodefects and microdefects. The dominance of one of these two kinds of defects depends not ...

  • Rock Joint Asperities and Mechanical Strength of Concrete 

    Ficker, Tomáš; Komárková, Tereza (IOP Publishing, 2017-11-28)
    Mechanical interactions between concrete foundations of large civil engineering structures (tunnels, bridges or dams) and the asperity surfaces of rock masses represent a useful topic for investigation. It is obvious that ...

  • Rock joint coefficients and their computerized classification 

    Ficker, Tomáš (Elsevier, 2019-09-15)
    A computerized method for determining rock joint coefficients is presented. Two relative similarity indicators are introduced to classify surface morphology of rock joints. The classification enables to compare investigated ...

  • Rock Joint Coefficients Derived from the Three-Dimensional Fourier Reliefs 

    Audy, Ondřej; Ficker, Tomáš (IOP Publishing, 2017-11-28)
    Coefficients of rock joints serve in geotechnical practice for determining shear strength of rock masses. Evaluation of the stability of rocky terrains containing joints is important from the viewpoint of safety. Larger ...

  • Rupture Strength and Irregularity of Fracture Surfaces 

    Ficker, Tomáš (IOP Publishing, 2017-11-28)
    Textural irregularities of fracture surfaces of cement-based materials seem to be an interesting source of information on some mechanical properties. Besides compressive strength, the flexural strength is strongly correlated ...