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Wyszukujesz frazę "Michalec, B" wg kryterium: Autor


Wyświetlanie 1-4 z 4
Tytuł:
Seasonal variability of the soil CO2 flux and its isotopic composition in southern Poland
Autorzy:
Gorczyca, Z.
Rozanski, K.
Kuc, T.
Michalec, B.
Powiązania:
https://bibliotekanauki.pl/articles/148390.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
carbon-14
carbon-13
isotopic composition
soil CO2
oxygen-18
Opis:
The flux and isotopic composition of soil CO2 has been monitored at three sites located in the southern Poland, during the time period: January 1998 - December 2000. The sites represent typical ecosystems appearing in central Europe: mixed forest, cultivated agricultural field and grassland. To monitor the flux and isotopic composition of soil CO2, the method based on the inverted cup principle was used. The flux of soil CO2 reveals distinct seasonal fluctuations, with maximum values up to ca. 20 mmolźm-2 h-1 during summer and around ten times lower values during winter. Also significant differences among the monitored sites were detected, the CO2 flux being the highest for the mixed forest site and ca. two times lower for the grassland site. The 13C content of the soil CO2 flux is nearly constant throughout the year, with d13C values essentially reflecting the isotopic composition of the soil organic matter and the vegetation type. The 18O content of the soil CO2 flux shows a remarkable seasonality, with distinctly less negative d18O values recorded during summer. This seasonality is highly reduced in the CO2 sampled from different depths of the soil. The radiocarbon content of the CO2 flux turned out to be non-distinguishable, within the uncertainty of the measurements, from current 14C levels in atmospheric carbon dioxide. However, significant reduction of the radiocarbon content was measured in the soil CO2 sampled at 80 cm, when compared to the uppermost layer, reflecting increasing age of soil organic matter with depth.
Źródło:
Nukleonika; 2003, 48, 4; 187-196
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Alanine dosimetry of 60 MeV proton beam - preliminary results
Autorzy:
Michalec, B.
Mierzwińska, G.
Sowa, U.
Ptaszkiewicz, M.
Nowak, T.
Swakoń, J.
Powiązania:
https://bibliotekanauki.pl/articles/146730.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
alanine
dosimetry
electron paramagnetic resonance (EPR)
proton beam
Opis:
Electron paramagnetic resonance (EPR) spectrometry (X-band) was used to determine the dose absorbed in alanine detectors, of different shapes and different alanine content, irradiated with Co-60 gamma rays and in a 60 MeV proton beam. The goal of our study was to confirm applicability of alanine as a passive detector in therapeutic proton beam. In the paper dose response characteristic and relative efficiency of alanine are shown. The study confirmed that alanine detectors with a high alanine content (ca. 95%) may be a useful and convenient tool for dose measurements in proton beams, used for eye cancer treatment.
Źródło:
Nukleonika; 2012, 57, 4; 503-506
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dosimetric characteristics of active solid state detectors in a 60 MeV proton radiotherapy beam
Autorzy:
Sowa, U.
Nowak, T.
Michalec, B.
Mierzwińska, G.
Swakoń, J.
Olko, P.
Powiązania:
https://bibliotekanauki.pl/articles/146780.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
diamond dosimeter
diode Si
dosimetry
proton beam
Opis:
Several solid state detectors, such as dosimetric diodes, MOSFET detectors or diamond detectors are used for quality control of radiotherapy beams. The goal of this work was to determine dosimetric properties of the PTW diamond detector (DD) and the PTW silicon diode in the 60 MeV therapeutic beam (practical range in water Rp = 29.17 mm) located at the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN, Kraków). A PTW Markus ionization chamber was used as a reference device. The empirical correction factor for diamond detector, kDD(Rresidual), introduced in the Technical Report Series of IAEA, TRS-398 [9] as a function of beam quality, Rresidual, was found to decrease from 1.12 for Rresidual = 1.5 mm to 1.04 for Rresidual = 26 mm. The reproducibility of response of DD and PTW diodes in the proton filed did not exceed 0.11%. Our results show that diamond detectors and dosimetric diodes are useful tools for quality assurance (QA) of therapeutic proton beam, but each type of detectors has specific properties which should be taken into account when choosing particular application.
Źródło:
Nukleonika; 2012, 57, 4; 491-495
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of alanine dosimetry in dose assessment for ocular melanoma patients undergoing proton radiotherapy : preliminary results
Autorzy:
Mierzwińska, G.
Kłodowska, M.
Michalec, B.
Pędracka, A.
Rydygier, M.
Swakoń, J.
Waligórski, M. P. R.
Powiązania:
https://bibliotekanauki.pl/articles/146382.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
alanine
EPR dosimetry
proton beam
proton radiotherapy
Quality Assurance (QA)
Opis:
Basing on alanine solid state/electron paramagnetic resonance (EPR) dosimetry, a supplementary method of cumulatively recording the therapeutic dose received by ocular cancer patients undergoing fractionated proton radiotherapy is proposed. By applying alanine dosimetry during the delivery of consecutive fractions, the dose received within each fraction can be read out by EPR spectrometry and a fi nal permanent cumulative record of the total dose delivered obtained. The dose response of the alanine detector was found to be practically independent on its position within the extended proton Bragg peak region. Dose measurements based on entrance dose recorded in proton beams individually formed for each patient are presented. The described method will be applied as a complementary Quality Assurance procedure for patients undergoing proton radiotherapy at the Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland (IFJ PAN).
Źródło:
Nukleonika; 2015, 60, No. 3, part 2; 609-613
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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