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Institution

Brno University of Technology

EducationBrno, Czechia
About: Brno University of Technology is a education organization based out in Brno, Czechia. It is known for research contribution in the topics: Fracture mechanics & Filter (video). The organization has 6339 authors who have published 15226 publications receiving 194088 citations. The organization is also known as: Vysoké učení technické v Brně & BUT.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a robotic approach for producing predetermined, complex 3D ceramic architectures by robotic deposition where UV radiation is used for solidification is presented, where homogeneous, highly loaded, solvent free colloidal inks with controlled viscoelastic properties are achieved by proper selection of monomers and surfactants.
Abstract: A novel approach for producing predetermined, complex 3d ceramic architectures by robotic deposition where UV radiation is used for solidification is presented. Homogeneous, highly loaded, solvent free colloidal inks with controlled viscoelastic properties are achieved by proper selection of monomers and surfactants. Room temperature deposition of complex 3d fiber networks having filaments in the 100 μm range is demonstrated for Al 2 O 3 and hydroxyapatite model particles for structural and biomedical applications. Solidification of the structures by UV radiation allows additional shaping of the structures by post-printing processes such as cutting, folding and bonding. 2d and 3d architectures with high aspect ratios retain their shape and transform to macroscopic ceramics after thermal debinding and sintering procedures. Sintered alumina fiber networks functionalized with a 3–5 μm layer of TiO 2 nanoparticles exhibit photocatalytic activity for the decomposition of formaldehyde as a similar weight of loose powder, indicating possible applications in catalytic reactors prototypes.

61 citations

Journal ArticleDOI
TL;DR: These issues are addressed in terms of sound-speed image reconstruction, using edge-preserving regularized algebraic reconstruction in combination with synthetic aperture focusing, and the critical points of the implementation are discussed, because they are crucial to enable a complete 3-D image reconstruction.
Abstract: The paper is focused on sound-speed image reconstruction in 3-D ultrasound transmission tomography. Along with ultrasound reflectivity and the attenuation coefficient, sound speed is an important parameter which is related to the type and pathological state of the imaged tissue. This is important in the intended application, breast cancer diagnosis. In contrast to 2-D ultrasound transmission tomography systems, a 3-D system can provide an isotropic spatial resolution in the x-, y-, and z-directions in reconstructed 3-D images of ultrasound parameters. Several challenges must, however, be addressed for 3-D systems-namely, a sparse transducer distribution, low signal-to-noise ratio, and higher computational complexity. These issues are addressed in terms of sound-speed image reconstruction, using edge-preserving regularized algebraic reconstruction in combination with synthetic aperture focusing. The critical points of the implementation are also discussed, because they are crucial to enable a complete 3-D image reconstruction. The methods were tested on a synthetic data set and on data sets measured with the Karlsruhe 3-D ultrasound computer tomography (USCT) I prototype using phantoms. The sound-speed estimates in the reconstructed volumes agreed with the reference values. The breast-phantom outlines and the lesion-mimicking objects were also detectable in the resulting sound-speed volumes.

61 citations

Journal ArticleDOI
TL;DR: In this article, a lightweight composite material with alkali-activated aluminosilicate binder is investigated and the intended use of this material is the high-temperature applications, such as the fire-protecting layers for Portland-cement based structures.
Abstract: A lightweight composite material with alkali-activated aluminosilicate binder is investigated. The intended use of this material is the high-temperature applications, such as the fire-protecting layers for Portland-cement based structures. Therefore, a heat-resistant mixture of expanded vermiculite and electrical porcelain is used as aggregates. Basic physical characteristics, mechanical properties and water- and water vapor transport properties are studied as functions of previous heat treatment up to 1200 °C. Experimental results show that the studied material has very good high-temperature properties which are quite superior to Portland-cement concrete. The open porosity increases only up to 7% between room temperature and 1000 °C. The material keeps 35% of its original compressive strength and 66% of its flexural strength even in the worst case of 800 °C pre-heating. After pre-heating to 1200 °C the compressive strength is found 30% higher and flexural strength three-and-half times higher than in the reference state. Liquid moisture diffusivity is after the heat treatment up to three orders of magnitude higher than in reference room-temperature conditions. The water vapor transport parameters allow fast removal of water vapor and other gaseous compounds over the whole studied heat-treatment range.

61 citations

Journal ArticleDOI
TL;DR: In this article, the surface topography of aluminum nitride (AlN) epilayers prepared by magnetron sputtering using the surface statistical parameters, according to ISO 25178-2:2012, was characterized.
Abstract: Abstract The aim of this study is to characterize the surface topography of aluminum nitride (AlN) epilayers prepared by magnetron sputtering using the surface statistical parameters, according to ISO 25178-2:2012. To understand the effect of temperature on the epilayer structure, the surface topography was investigated through atomic force microscopy (AFM). AFM data and analysis of surface statistical parameters indicated the dependence of morphology of the epilayers on their growth conditions. The surface statistical parameters provide important information about surface texture and are useful for manufacturers in developing AlN thin films with improved surface characteristics. These results are also important for understanding the nanoscale phenomena at the contacts between rough surfaces, such as the area of contact, the interfacial separation, and the adhesive and frictional properties.

61 citations

Journal ArticleDOI
TL;DR: In this article, the authors demonstrate coherent injection locking of the repetition frequency to a stabilized RF oscillator, resulting in the generation of a frequency comb, which is not only a versatile tool for allelectrical frequency stabilization, but also mitigates the fatal effect of optical feedback on the frequency comb.
Abstract: Quantum cascade laser (QCL) frequency combs are a promising candidate for chemical sensing and biomedical diagnostics, requiring only milliseconds of acquisition time to record absorption spectra without any moving parts. They are electrically pumped and have a small footprint, making them an ideal platform for on-chip integration. Until now, optical feedback is fatal for frequency comb generation in QCLs and destroys intermodal coherence. This property imposes strict limits on the possible degree of integration. Here, we demonstrate coherent injection locking of the repetition frequency to a stabilized RF oscillator. For the first time, we prove that the spectrum of the injection locked QCL can be phase-locked, resulting in the generation of a frequency comb. We show that injection locking is not only a versatile tool for all-electrical frequency stabilization, but also mitigates the fatal effect of optical feedback on the frequency comb. A prototype self-detected dual-comb setup consisting only of an injection locked dual-comb chip, a lens and a mirror demonstrates the enormous potential for on-chip dual-comb spectroscopy. These results pave the way to miniaturized and all-solid-state mid-infrared spectrometers.

61 citations


Authors

Showing all 6383 results

NameH-indexPapersCitations
Georg Kresse111430244729
Patrik Schmuki10976352669
Michael Schmid8871530874
Robert M. Malina8869138277
Jiří Jaromír Klemeš6456514892
Alessandro Piccolo6228414332
René Kizek6167216554
George Danezis5920911516
Stevo Stević583749832
Edvin Lundgren5728610158
Franz Halberg5575015400
Vojtech Adam5561114442
Lukas Burget5325221375
Jan Cermak532389563
Hynek Hermansky5131714372
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202328
2022106
20211,053
20201,010
20191,214
20181,131