Welcome to the BUT Digital Library - an institutional repository operated by the Central Library on the DSpace system.
Do you want to deposit your article or preceedings into Digital Library? It is very simple. You can find all the information in the manual published online on BUT Portal of libraries.
Central Library supports open access to scientific publishing - Open Access.
You can also request for grant for open publishing from Open Access Fund You can find more information OA fund web page.
Into the Digital Library is integrated citation manager Citace PRO. It will allow you to easily create a bibliographic citation or save a record in the manager.
Communities in DSpace
Select a community to browse its collections.
Recent Submissions
Item type:Item, Access status: Open Access , Assessment of the Effect of Toothpaste Abrasiveness on Friction and Wear of Dental Fillings(Springer Nature, 2026-03-21) Formankova, Pavla; Pavliňáková, Veronika; Čípek, Pavel; Svoboda, Petr; Dancova, Alena; Vojtová, Lucy; Vrbka, MartinThere is a notable deficiency in detailed investigations regarding the impact of abrasive elements on the friction and wear of dental restorations. Therefore, the primary objective of this study was to analyse how abrasive particles in toothpastes affect the friction and wear of dental fillings. The coefficient of friction (CoF) was evaluated as a time course from a brushing simulation conducted on a UMT TriboLab tribometer, which measured frictional and normal forces over a duration of 260 min. The tribological system consisted of three components: a Curaprox Ultra Soft 5460 toothbrush, a sample of dental filling material, and a mixture of artificial saliva (AS) combined with selected toothpaste. Six different toothpastes were evaluated (four for adults and two for children), varying in relative dentin abrasivity (RDA) values. Measurements with AS served as reference data. Wear was quantified by topographical analysis using a Bruker Contour GT-X optical profilometer to assess the samples before and after brushing, followed by volume loss calculations. Particle morphology was studied using a Tescan MIRA3 microscope, and the element analysis of evaluated toothpastes was performed using energy-dispersive X-ray spectroscopy (EDX). Results indicated that friction was highly variable, influenced by the random presence of particles in contact. While wear and particle size generally increased with RDA value, this relationship was not entirely consistent. Finally, it was revealed that the aggregate size of pastes and their density also affected the friction and wear of the fillings.Item type:Item, Access status: Open Access , Characterization of Nitinol Produced by Laser Powder Bed Fusion for Mechanical Metamaterial Applications(Wiley, 2026-04-27) Červinek, Ondřej; Hurník, Jakub; Šmíd, Miroslav; Zobac, Ondrej; Todt, Melanie; Koutný, DanielThis study investigates the relationship between the process parameters of the laser powder bed fusion technology and the functional properties of nitinol metamaterial for morphing actuator applications. Using an extraordinary wide range of laser powers (40-400 W) and scanning speeds (175-3000 mm s-1) provides the most comprehensive assessment of resulting morphologies, allowing identification of defect-free configurations, especially for low energy densities. The assessment is done with respect to porosity, thin-wall dimensional accuracy, crystallography, austenite-martensite phase transformation, and recoverability under cyclic loading. The results show that low volumetric energy density of 41-55 J mm-3 can lead to an internal porosity of less than 0.1%, although brittle cracking may occur. The cyclic compression tests show a variable quasilinear pseudoelasticity with low hysteresis. The highest total strain after 50 cycles is 5.43% with an associated cumulative residual strain of 2.79%, stabilizing after approximately 30 cycles. The recoverable strain decreases with increasing load, most significantly from 53.4% at 800 MPa to 35.1% at 1200 MPa. The computational estimation of metamaterial morphing capability provides reliable results if the linear assumption after the fifth cycle is adopted by the material model and geometrical thickness deviations are reflected.Item type:Item, Access status: Open Access , Film Thickness and Friction of Textured Surfaces in Hydrodynamic Inclined and Parallel Gaps-An Experimental Study(MDPI, 2026-01-06) Šperka, Petr; Knotek, Jan; Omasta, Milan; Křupka, Ivan; Polach, Pavel; Hartl, MartinThis paper presents an experimental study on the influence of surface texturing on friction and film thickness in the hydrodynamic lubrication regime. Using a pin-on-disk tribometer equipped with light-induced fluorescence microscopy, simultaneous measurements were conducted on smooth and textured samples under parallel and inclined surface conditions. The circular faces of the pins were partially or fully covered by circular laser-machined textures consisting of dimples with depths of 5 or 10 mu m, diameters of 50 or 100 mu m, and coverage density of 20%. The results demonstrate that while texturing significantly reduces friction and increases film thickness in parallel gaps, with partial inlet coverage being the most effective, its impact is minimal in inclined wedge gaps. The study further reveals that the global geometric wedge dominates over texture effects in inclined contacts and that in-texture cavitation, prevalent in parallel conditions, is suppressed by surface inclination. Three distinct contributions of the textures were discussed: a global hydrodynamic effect, a local hydrodynamic effect, and the influence of surface non-flatness (waviness). The findings suggest that texturing is primarily beneficial for acting as a pseudo-wedge or as surface roughness in contacts where a physical wedge is absent.Item type:Item, Access status: Metadata only , Experimental Study of the Effect of Surface Texture in Sliding Contacts Using Infrared Thermography(MDPI, 2026-01-31) Omasta, Milan; Knoth, Tomas; Šperka, Petr; Hajzman, Michal; Křupka, Ivan; Polach, Pavel; Hartl, MartinThis study investigates the influence of surface texturing on temperature distribution in lubricated sliding contacts using infrared thermography. The work addresses the broader challenge of understanding thermal effects in conformal hydrodynamic contacts, where localized heating and viscosity variations can significantly affect tribological performance. A pin-on-disc configuration was employed, featuring steel pins with laser-etched micro-dimples that slid against a sapphire disc, allowing for thermal imaging of the contact zone. A dual-bandpass filter infrared thermography technique was developed and rigorously calibrated to distinguish between the temperatures of the steel surface and the lubricant film. Friction measurements and laser-induced fluorescence were used in parallel to assess contact conditions and the behavior of the lubricant film. The results show that surface textures can alter local frictional heating and contribute to non-uniform temperature distributions, particularly in parallel contact geometries. Lubricant temperature was consistently higher than the surface temperature, highlighting the role of shear heating within the fluid film. However, within the tested parameter range, no unambiguous viscosity-wedge signature was identified beyond the dominant temperature-driven viscosity reduction captured by the in situ correction. The method provides a novel means of experimentally resolving temperature fields in sliding textured contacts, offering a valuable foundation for validating thermo-hydrodynamic models in lubricated tribological systems.Item type:Item, Access status: Open Access , UWB Indoor Localization Based on XGBoost NLOS Identification and DS-TWR Ranging(Radioengineering Society, 2026-06) Xu, X. Yao Z.; Liu, G.Indoor environments present significant challenges for ultra-wideband (UWB) localization due to ranging errors and non-line-of-sight (NLOS) propagation. This paper proposes a robust UWB indoor localization framework that integrates double-sided two-way ranging (DS-TWR), XGBoost-based NLOS identification, residual-weighted localization, and Kalman filter (KF). The main contribution of this work is the unified use of NLOS identification in both ranging correction and localization fusion, significantly improving localization accuracy in complex environments. Experimental results demonstrate improvements in ranging accuracy of up to 53.7% and 47.22% under human-body and wooden-board occlusions. In dynamic experiments, the proposed method outperforms conventional UWB localization, KF, and weighted least squares methods with positioning accuracy improvements of 38.64%, 28.95%, and 12.9%, respectively. These results confirm the framework’s effectiveness in mitigating NLOS impact and enhancing UWB localization robustness.