Karel Hruska

Karel Hruska

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 September 2010 in Nanotechnology
Verified
Journal Article
Closed access
JČJ Červenka
J Červenka
MLMartin Ledinsky
Martin Ledinsky
JSJ Stuchlík
J Stuchlík
HSH Stuchlíková
H Stuchlíková
Snejana BakardjievaSnejana Bakardjieva
Snejana Bakardjieva
JKJ Kočka
J Kočka
Silicon nanowires and nanoneedles show promise for many device applications in nanoelectronics and nanophotonics, but the remaining challenge is to grow them at low temperatures on low-cost materials. Here we present plasma-enhanced chemical vapor deposition of crystalline/amorphous Si nanoneedles on glass at temperatures as low as 250 °C. High resolution electron microscopy and micro-Raman spectroscopy have been used to study the crystal structure and the growth mechanism of individual Si nanoneedles. The H(2) dilution of the SiH(4) plasma working gas has caused the formation of extremely sharp nanoneedle tips that in some cases do not contain a catalytic particle at the end.

1 July 2010 in Applied Surface Science
Verified
Journal Article
Closed access
MDMarina Davydova
Marina Davydova
AKAlexander Kromka
Alexander Kromka
BRBohuslav Rezek
Bohuslav Rezek
OBOleg Babčenko
Oleg Babčenko
MSMartin Stuchlik
Martin Stuchlik
KHKarel Hruska
Karel Hruska

1 September 2010
Verified
Conference Paper
Closed access
KHKarel Hruska
Karel Hruska
VKVladimir Kindl
Vladimir Kindl
RPRoman Pechanek
Roman Pechanek
The paper deals with a study of new synchronous machine for use in hybrid vehicle. The synchronous machine is projected as permanent magnet synchronous motor with outer rotor embedded into rear rim of a bus. The main target of the study is design of an air self-cooled hub-wheel PMSM from electromagnetic point of view and using finite element analysis of electromagnetic field and thermal distribution. The analysis of losses in permanent magnets is also mentioned.

4 November 2021 in Energies
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Journal Article
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JLJan Laksar
Jan Laksar
RCRadek Cermak
Radek Cermak
KHKarel Hruska
Karel Hruska
The usage of multiphase electrical drives expands the operation possibilities of electrical machines and opens new directions of research on inverter-fed electrical machines. With an increasing number of phases, the standard approach of the electromagnetic design of machines has to be generalized to m-phase systems, which is not usually respected in the literature focused on electric machine design, and it is rarely published. This paper summarizes the specific problems linked with the design of machines with different numbers of phases, focusing on the winding design and the calculation of equivalent circuit parameters. In addition to the direct effect of different numbers of phases, the impact of injecting higher order time harmonic components on the electromagnetic design of electric machines is analyzed. The obtained analytical results are verified by the measurement of a nine-phase experimental induction motor.

24 July 2017 in Electrical Engineering
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Journal Article
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KHKarel Hruska
Karel Hruska
VKVladimir Kindl
Vladimir Kindl
RPRoman Pechanek
Roman Pechanek

24 June 2013 in Applied Physics Letters
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Journal Article
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LOLukáš Ondič
Lukáš Ondič
MVMarián Varga
Marián Varga
KHKarel Hruska
Karel Hruska
AKAlexander Kromka
Alexander Kromka
KHKateřina Herynková
Kateřina Herynková
IPIvan Pelant
Ivan Pelant
A two-dimensional photonic crystal (PhC) slab was fabricated from a luminescent planar waveguide, formed by a (800 nm thick) layer of silicon nanocrystals (SiNCs) embedded in a polished silica plate. Dimensions of the PhC were designed so that light emitted by SiNCs under excitation with an external UV source can, during its propagation in the layer, interact with the periodicity and be Bragg-diffracted into air. This approach leads to up to 8-fold vertical extraction enhancement of SiNCs luminescence from the PhC slab compared to the bare planar layer. Results of the experiment are supported by the computer simulation.