Jiří Frydrych

2011

• J. Pechousek, R. Prochazka, V. Prochazka, and J. Frydrych, “Virtual instrumentation technique used in the nuclear digital signal
  processing system design: Energy and time measurement tests,” NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION
  A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, vol. 637, iss. 1, pp. 200-205, 2011.
  [Bibtex]

  @article ISI:000289608000026,
  Author = Pechousek, J. and Prochazka, R. and Prochazka, V. and Frydrych, J.,
  Title = Virtual instrumentation technique used in the nuclear digital signal
     processing system design: Energy and time measurement tests,
  Journal = NUCLEAR INSTRUMENTS \& METHODS IN PHYSICS RESEARCH SECTION
     A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT,
  Year = 2011,
  Volume = 637,
  Number = 1,
  Pages = 200-205,
  Month = MAY 1,
  Abstract = In this report, computer-based digital signal processing system with a
     200 MS s(-1) sampling digitizer is presented. Virtual instrumentation
     technique is used to easily develop a system which provides spectroscopy
     measurements such as amplitude and time signal analysis, with the
     time-of-flight facility. Several test measurements were performed to
     determine the characteristics of a system. The presented system may find
     its application in the coincidence measurement since the system is
     usable for different types of detectors and sensitive to decay lifetimes
     from tens of nanoseconds to seconds. (C) 2011 Elsevier B.V. All rights
     reserved.,
  DOI = 10.1016/j.nima.2011.02.024,
  ISSN = 0168-9002,
  Unique-ID = ISI:000289608000026,
  

2010

• J. Frydrych, L. Machala, M. Hermanek, I. Medrik, M. Mashlan, J. Tucek, J. Pechousek, and V. K. Sharma, “A nanocrystalline hematite film prepared from iron(III) chloride
  precursor,” THIN SOLID FILMS, vol. 518, iss. 21, pp. 5916-5919, 2010.
  [Bibtex]

  @article ISI:000280989100008,
  Author = Frydrych, Jiri and Machala, Libor and Hermanek, Martin and Medrik, Ivo
     and Mashlan, Miroslav and Tucek, Jiri and Pechousek, Jiri and Sharma,
     Virender K.,
  Title = A nanocrystalline hematite film prepared from iron(III) chloride
     precursor,
  Journal = THIN SOLID FILMS,
  Year = 2010,
  Volume = 518,
  Number = 21,
  Pages = 5916-5919,
  Month = AUG 31,
  Abstract = This paper deals with a simple and low-cost method developed to deposit
     hematite (alpha-Fe(2)O(3)) layers on a fluorine-doped tin oxide (FTO/F
     center dot SnO(2)) substrate by thermal decomposition of solid iron(III)
     chloride hexahydrate (FeCl(3) 6H(2)O) Deposition procedure takes place
     through chemical intermediate iron(III) oxide chloride (FeOCl) film. A
     crucial influence of atmosphere dynamics involved in the calcination
     process of FeOCl has been observed As-deposited films were characterized
     by means of Conversion Electron Mossbauer Spectroscopy (CEMS), Grazing
     Angle X-Ray Diffractometry (GAXRD), Atomic Force Microscopy (AFM),
     Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX)
     analysis Final nanocrystalline hematite film with a cactus-field-like
     design consists of 20 nm thick porous crystal plates. A process of
     hematite doping by tin atoms from substrate coating is also discussed
     (C) 2010 Elsevier B V. All rights reserved.,
  DOI = 10.1016/j.tsf.2010.05.081,
  ISSN = 0040-6090,
  Unique-ID = ISI:000280989100008,
  

• K. Sivula, R. Zboril, F. Le Formal, R. Robert, A. Weidenkaff, J. Tucek, J. Frydrych, and M. Graetzel, “Photoelectrochemical Water Splitting with Mesoporous Hematite Prepared
  by a Solution-Based Colloidal Approach,” JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, vol. 132, iss. 21, pp. 7436-7444, 2010.
  [Bibtex]

  @article ISI:000278190600045,
  Author = Sivula, Kevin and Zboril, Radek and Le Formal, Florian and Robert, Rosa
     and Weidenkaff, Anke and Tucek, Jiri and Frydrych, Jiri and Graetzel,
     Michael,
  Title = Photoelectrochemical Water Splitting with Mesoporous Hematite Prepared
     by a Solution-Based Colloidal Approach,
  Journal = JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,
  Year = 2010,
  Volume = 132,
  Number = 21,
  Pages = 7436-7444,
  Month = JUN 2,
  Abstract = Sustainable hydrogen production through photoelectrochemical water
     splitting using hematite (alpha-Fe(2)O(3)) is a promising approach for
     the chemical storage of solar energy, but is complicated by the
     material's nonoptimal optoelectronic properties. Nanostructuring
     approaches have been shown to increase the performance of hematite, but
     the ideal nanostructure giving high efficiencies for all absorbed light
     wavelengths remains elusive. Here, we report for the first time
     mesoporous hematite photoelectodes prepared by a solution-based
     colloidal method which yield water-splitting photocurrents of 0.56 mA
     cm(-2) under standard conditions (AM 1.5G 100 mW cm(-2), 1.23 V vs
     reversible hydrogen electrode, RHE) and over 1.0 mA cm(-2) before the
     dark current onset (1.55 V vs RHE). The sintering temperature is found
     to increase the average particle size, and have a drastic effect on the
     photoactivity. X-ray photoelectron spectroscopy and magnetic
     measurements using a SQUID magnetometer link this effect to the
     diffusion and incorporation of dopant atoms from the transparent
     conducting substrate. In addition, examining the optical properties of
     the films reveals a considerable change in the absorption coefficient
     and onset properties, critical aspects for hematite as a solar energy
     converter, as a function of the sintering temperature. A detailed
     investigation into hematite's crystal structure using powder X-ray
     diffraction with Rietveld refinement to account for these effects
     correlates an increase in a C(3v)-type crystal lattice distortion to the
     improved optical properties.,
  DOI = 10.1021/ja101564f,
  ISSN = 0002-7863,
  Unique-ID = ISI:000278190600045,
  

• J. Pechousek, R. Prochazka, D. Jancik, J. Frydrych, and M. Mashlan, “Universal LabVIEW-powered Mossbauer spectrometer based on USB, PCI or
  PXI devices,” in INTERNATIONAL CONFERENCE ON THE APPLICATIONS OF THE MOSSBAUER EFFECT
  (ICAME 2009), 2010.
  [Bibtex]

  @inproceedings ISI:000287181700006,
  Author = Pechousek, J. and Prochazka, R. and Jancik, D. and Frydrych, J. and
     Mashlan, M.,
  Editor = Muller, H and Reissner, M and Steiner, W and Wiesinger, G,
  Title = Universal LabVIEW-powered Mossbauer spectrometer based on USB, PCI or
     PXI devices,
  Booktitle = INTERNATIONAL CONFERENCE ON THE APPLICATIONS OF THE MOSSBAUER EFFECT
     (ICAME 2009),
  Series = Journal of Physics Conference Series,
  Year = 2010,
  Volume = 217,
  Note = International Conference on the Applications of the Mossbauer Effect,
     Vienna Univ Technol, Vienna, AUSTRIA, JUL 19-24, 2009,
  Abstract = A new design of the universal Mossbauer spectrometer is presented.
     Hardware solution is based on commercial-available data acquisition
     devices working on the USB, PCI or PXI platform controlled by the main
     application running on the personal computer. Final application allows,
     in addition to Mossbauer spectra accumulation, the detailed analysis of
     the acquired detector signal in energy and time domains, and also to
     tune the velocity driving system separately. The experimental results
     show a high flexibility in various detectors and velocity transducers
     usage. It is easy to change the way of operation according to the
     different experimental requirements. This concept can be used with all
     common spectrometric benches with different velocity transducers,
     radioactive sources and gamma-ray detectors. This is a new approach in
     the Mossbauer spectrometer construction.,
  DOI = 10.1088/1742-6596/217/1/012006,
  Article-Number = 012006,
  ISSN = 1742-6588,
  Unique-ID = ISI:000287181700006,
  

• J. Pechousek, R. Prochazka, J. Cuda, J. Frydrych, and D. Jancik, “Investigation of the Mossbauer Spectrum Quality as a Dependence on the
  Frequency of the Velocity Signal,” in MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE – 2010, 2010, pp. 134-142.
  [Bibtex]

  @inproceedings ISI:000281606200019,
  Author = Pechousek, J. and Prochazka, R. and Cuda, J. and Frydrych, J. and
     Jancik, D.,
  Editor = Tucek, J and Miglierini, M,
  Title = Investigation of the Mossbauer Spectrum Quality as a Dependence on the
     Frequency of the Velocity Signal,
  Booktitle = MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE - 2010,
  Series = AIP Conference Proceedings,
  Year = 2010,
  Volume = 1258,
  Pages = 134-142,
  Note = International Conference on Mossbauer Spectroscopy in Materials Science,
     Liptovsky Jan, SLOVAKIA, JAN 31-FEB 05, 2010,
  Abstract = This paper is focused on a quality characterizing the Mossbauer spectra
     measured for various frequencies of the velocity signal. Standard
     electromechanical double-loudspeaker drive and digital PID velocity
     controller were used for calibration spectra measurement in the
     frequency interval from 4 up to 100 Hz. Several parameters were
     evaluated for recommendation of the suitable velocity signal frequency.,
  DOI = 10.1063/1.3473890,
  ISSN = 0094-243X,
  ISBN = 978-0-7354-0806-7,
  Unique-ID = ISI:000281606200019,
  

• R. Prochazka, J. Pechousek, and J. Frydrych, “Development of the Fast Scintillation Detector with Programmable High
  Voltage Adjustment Suitable for Mossbauer Spectroscopy,” in MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE – 2010, 2010, pp. 143-149.
  [Bibtex]

  @inproceedings ISI:000281606200020,
  Author = Prochazka, R. and Pechousek, J. and Frydrych, J.,
  Editor = Tucek, J and Miglierini, M,
  Title = Development of the Fast Scintillation Detector with Programmable High
     Voltage Adjustment Suitable for Mossbauer Spectroscopy,
  Booktitle = MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE - 2010,
  Series = AIP Conference Proceedings,
  Year = 2010,
  Volume = 1258,
  Pages = 143-149,
  Note = International Conference on Mossbauer Spectroscopy in Materials Science,
     Liptovsky Jan, SLOVAKIA, JAN 31-FEB 05, 2010,
  Abstract = This work is focused on a development of a compact fast scintillation
     detector suitable for Mossbauer spectroscopy (low energy X-ray/y-ray
     detection) where high counting rates are inevitable. Optimization of
     this part was necessary for a reliable function, better time resolution
     and to avoid a detector pulses pile-up effect. The pile-up effect
     decreases the measurement performance, significantly depends on the
     source activity and also on the pulse duration. Our new detection unit
     includes a fast scintillation crystal YAP:Ce, an R6095 photomultiplier
     tube, a high voltage power supply socket C9028-01 assembly, an AD5252
     digital potentiometer with an 12C interface and an AD8000 ultra fast
     operation preamplifier. The main advantages of this solution lie in a
     short pulse duration (less than 200 ns), stable operation for high
     activities, programmable gain of the high voltage supply and compact
     design in the aluminum housing.,
  DOI = 10.1063/1.3473891,
  ISSN = 0094-243X,
  ISBN = 978-0-7354-0806-7,
  Unique-ID = ISI:000281606200020,
  

2009

• C. Park, J. Walker, R. Tannenbaum, A. E. Stiegman, J. Frydrych, and L. Machala, “Sol-Gel-Derived Iron Oxide Thin Films on Silicon: Surface Properties and
  Interfacial Chemistry,” ACS APPLIED MATERIALS & INTERFACES, vol. 1, iss. 9, pp. 1843-1846, 2009.
  [Bibtex]

  @article ISI:000270363600001,
  Author = Park, Chi-dong and Walker, Jeremy and Tannenbaum, Rina and Stiegman, A.
     E. and Frydrych, J. and Machala, L.,
  Title = Sol-Gel-Derived Iron Oxide Thin Films on Silicon: Surface Properties and
     Interfacial Chemistry,
  Journal = ACS APPLIED MATERIALS \& INTERFACES,
  Year = 2009,
  Volume = 1,
  Number = 9,
  Pages = 1843-1846,
  Month = SEP,
  Abstract = Uniform high-quality iron oxide thin films can be formed from the spin
     coating of iron oxide/hydroxide sol-gels on a silicon substrate. Thermal
     processing of the films at temperatures of similar to 300 degrees C
     results in the transformation of films into a ternary layered structure
     with Iron oxide, Fe(2)O(3), at the surface, characterized by Mossbauer
     spectroscopy. and reduced Metallic iron characterized by depth profiling
     of the surface by X-ray photoelectron spectroscopy as a function of
     Ar(+) etching. Imaging of the etched surface by scanning electron
     microscopy reveals two distinct regions at the interface, nanoparticles
     that are very iron-rich separated by an unstructured region that is
     somewhat less iron-rich. The results demonstrate a synthetic protocol
     for the spontaneous formaton of a ternary layered structure from a
     simple one-step preparation.,
  DOI = 10.1021/am900362x,
  ISSN = 1944-8244,
  Unique-ID = ISI:000270363600001,
  

• J. Pechousek, R. Prochazka, M. Mashlan, D. Jancik, and J. Frydrych, “Digital proportional-integral-derivative velocity controller of a
  Mossbauer spectrometer,” MEASUREMENT SCIENCE & TECHNOLOGY, vol. 20, iss. 1, 2009.
  [Bibtex]

  @article ISI:000261627800038,
  Author = Pechousek, J. and Prochazka, R. and Mashlan, M. and Jancik, D. and
     Frydrych, J.,
  Title = Digital proportional-integral-derivative velocity controller of a
     Mossbauer spectrometer,
  Journal = MEASUREMENT SCIENCE \& TECHNOLOGY,
  Year = 2009,
  Volume = 20,
  Number = 1,
  Month = JAN,
  Abstract = The digital proportional-integral-derivative (PID) velocity controller
     used in the Mossbauer spectrometer implemented in field programmable
     gate array (FPGA) is based on the National Instruments CompactRIO
     embedded system and LabVIEW graphical programming tools. The system
     works as a remote system accessible via the Ethernet. The digital
     controller operates in real-time conditions, and the maximum sampling
     frequency is approximately 227 kS s(-1). The system was tested with
     standard sample measurements of alpha-Fe and alpha-(57)Fe(2)O(3) on two
     different electromechanical velocity transducers. The nonlinearities of
     the velocity scales in the relative form are better than 0.2\%. The
     replacement of the standard analog PID controller by the new system
     brings the possibility of optimizing the control process more precisely.,
  DOI = 10.1088/0957-0233/20/1/017001,
  Article-Number = 017001,
  ISSN = 0957-0233,
  Unique-ID = ISI:000261627800038,
  

2008

• J. Frydrych, M. Mashlan, J. Pechousek, and D. Jancik, “Conversion Electron Detectors for (57)Fe Mossbauer Measurements,” in MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE 2008, 2008, pp. 170-184.
  [Bibtex]

  @inproceedings ISI:000262290200021,
  Author = Frydrych, J. and Mashlan, M. and Pechousek, J. and Jancik, D.,
  Editor = Mashlan, M and Zboril, R,
  Title = Conversion Electron Detectors for (57)Fe Mossbauer Measurements,
  Booktitle = MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE 2008,
  Series = AIP Conference Proceedings,
  Year = 2008,
  Volume = 1070,
  Pages = 170-184,
  Note = International Conference on Mossbauer Spectroscopy in Materials Science,
     Hlohovec u Breclavi, CZECH REPUBLIC, JUN 16-20, 2008,
  Abstract = This review article is intended to help all those, who now begin to work
     in the field of conversion electron Mossbauer spectroscopy (CEMS) and
     who have to select a right type of a detector. There exist a large
     number of specific engineering designs in each of the detector kind,
     which is impossible to cover in one paper. That is why we only try to
     outline basic classification and general survey of properties of
     individual CEMS detector kinds supplemented by references to its more
     detailed analysis. (57)Fe is the most frequently used isotope in CEMS
     and thereby the paper is devoted to this case.,
  ISSN = 0094-243X,
  ISBN = 978-0-7354-0601-8,
  Unique-ID = ISI:000262290200021,
  

2007

• J. Pechousek, M. Mashlan, J. Frydrych, D. Jancik, and R. Prochazka, “Improving detector signal processing with pulse height analysis in
  Mossbauer spectrometers,” HYPERFINE INTERACTIONS, vol. 175, iss. 1-3, pp. 1-8, 2007.
  [Bibtex]

  @article ISI:000256911000001,
  Author = Pechousek, Jiri and Mashlan, Miroslav and Frydrych, Jiri and Jancik,
     Dalibor and Prochazka, Roman,
  Title = Improving detector signal processing with pulse height analysis in
     Mossbauer spectrometers,
  Journal = HYPERFINE INTERACTIONS,
  Year = 2007,
  Volume = 175,
  Number = 1-3,
  Pages = 1-8,
  Month = FEB,
  Abstract = A plenty of different programming techniques and instrument solutions
     are used in the development of Mossbauer spectrometers. Each of them
     should provide a faster spectrum accumulation process, increased
     productivity of measurements, decreased nonlinearity of the velocity
     scale, etc. The well known virtual instrumentation programming method
     has been used to design a computer-based Mossbauer spectrometer.
     Hardware solution was based on two commercially-available PCI modules
     produced by National Instruments Co. Virtual Mossbauer spectrometer is
     implemented by the graphical programming language LabVIEW 7 Express.
     This design environment allows to emulate the multichannel analyzer on
     the digital oscilloscope platform. This is a novel method based on
     Waveform Peak Detection function which allows detailed analysis of the
     acquired signal. The optimal treatment of the detector signal from
     various detector types is achieved by mathematical processing only. As a
     result, the possibility of an increase of signal/noise ratio is
     presented.,
  DOI = 10.1007/s10751-008-9580-5,
  ISSN = 0304-3843,
  Unique-ID = ISI:000256911000001,