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Wyszukujesz frazę "stable isotope" wg kryterium: Wszystkie pola


Wyświetlanie 1-6 z 6
Tytuł:
Stable isotope deuterium as a natural tracer of mixing processes in rivers
Autorzy:
Palige, J.
Ptaszek, S.
Zimnicki, R.
Chmielewski, A. G.
Wierzchnicki, R.
Powiązania:
https://bibliotekanauki.pl/articles/146756.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
stable isotopes
tracer
deuterium
oxygen-18
river
water flow
Opis:
The possibility of application of naturally existing differences in isotope contents 18O/16O, 2H/1H in waters for investigation of transport and mixing of various waters in the tributary-river system is presented. Experiments carried out on the Bug-Narew rivers-Zegrze Lake and the BugoNarew-Vistula rivers systems have indicated that the hydrogen isotope ratio 2H/1H can be used as an intrinsic tracer of natural mixing processes occurring in rivers. The IRMS methodology was used for isotope ratio measurement of water samples. The degrees of water mixing as a function of distance from the confluence point of rivers were determined. The obtained results indicate that in water systems where the natural differences in ?2H are higher than 5‰ this technique can replace the time-consuming and expensive dye (or radiotracer) dispersion tests for evaluation of pollutant transport in rivers.
Źródło:
Nukleonika; 2008, 53, 2; 63-67
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of stable isotope composition of chosen foodstuffs from the Polish market
Autorzy:
Malec-Czechowska, K.
Wierzchnicki, R.
Powiązania:
https://bibliotekanauki.pl/articles/148152.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
stable isotope
honey
meat
hen eggs
food authenticity
Opis:
In the present work the carbon and nitrogen isotopic composition of food products bought in the retail trade in Warsaw is demonstrated. The research was carried out using meat (pork, chicken), hen eggs and honey. These products originated from the conventional and ecological farms. The values of the isotopic ratios are expressed as δ notation and correspond to the international standards (V-PDB for δ13C, and air for δ15N) according to the following general formula: δ(‰) = [(R sample / R standard) – 1] × 1000, where R represents the ratio between the less abundant and more abundant isotopes, in particular 13C/12C and 15N/14N. The results received in our laboratory, were compared with results presented in the literature for similar products. The results of the study show that the N and C stable isotope ratios in the tested products can be applied to verify their authenticity.
Źródło:
Nukleonika; 2013, 58, 2; 323-327
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stable isotope composition of carbon dioxide emitted from anthropogenic sources in the Kraków region, Southern Poland
Autorzy:
Zimnoch, M.
Powiązania:
https://bibliotekanauki.pl/articles/148175.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
stable isotopes
carbon dioxide
anthropogenic sources
Kraków
Opis:
The summary of the measurements of CO2 stable isotopic composition emitted from different anthropogenic sources in the Krakow region is presented. The sources are divided into three main groups . high emission (electric and heat power plants), low emission (coal and methane burning in the households) and car traffic (gasoline, diesel and LPG supplied engines equipped and not equipped with catalyst). Presented results include two measurement campaigns made in the years 1995 and 2000. The measurements revealed three well-defined groups with respect to carbon isotope composition (delta13CVPDB): .30.60 plus-minus sign 0.37 per mille (thousand) sign (car traffic) .23.82 plus-minus sign 0.10 per mille (thousand) sign (coal burning) and .51.8 plus-minus sign 1.1per mille (thousand) sign (methane burning). The oxygen isotope composition (delta18OVPDB-CO2) of CO2 varied in a broad range, from ca. .11per mille (thousand) sign to ca. .22 per mille (thousand) sign, the most negative values being observed for coal and methane burning and the most positive for cars equipped with a catalyst. No significant isotopic shift has been observed between two measurement campaigns.
Źródło:
Nukleonika; 2009, 54, 4; 291-295
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of the stable oxygen isotope (18 O) to trace the distribution and uptake of water in riparian woodlands
Autorzy:
Lambs, L.
Loudes, J.
Berthelot, M.
Powiązania:
https://bibliotekanauki.pl/articles/147005.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
oxygen isotope
riparian forest
water origin
xylem sap
Opis:
Streamside vegetation forming narrow "corridors" in temperate regions, is typically dominated by deciduous tree species reflecting strong influences by human activities. Riparian woodlands depend on hydrological resources and have to adapt to rapid changes in water levels and soil moisture conditions. Three main water sources are typically present in the riparian zone: river water originating in the mountains, ground water and rainfall. Stable isotopes, such as oxygen-18, are useful tools which allow for water movement to be traced within the riparian zone and which help to identify water sources utilised by the trees growing in these areas.
Źródło:
Nukleonika; 2002, 47,suppl.1; 71-74
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isotopic study of CO2 from industrial off-gases emission
Autorzy:
Wierzchnicki, R.
Plewka, K.
Powiązania:
https://bibliotekanauki.pl/articles/148644.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
greenhouse gases
stable isotopes
CO2 anthropogenic emitters
isotope ratio mass spectrometry
Opis:
The monitoring of greenhouse gases originating from different sources will be a crucial problem during this century. Experiments have been performed in order to obtain stable isotope composition of CO2 emitted by large industrial off-gas emitters. A special set for sample collection in field conditions was designed and tested. Two different methods of CO2 extraction were elaborated: vacuum extraction and extraction with carrier gas. Preliminary results of CO2 stable isotope composition emitted from an electric power plant during one working season are presented.
Źródło:
Nukleonika; 2010, 55, 2; 247-250
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isotope effects in chemistry
Autorzy:
Van Hook, W. A.
Powiązania:
https://bibliotekanauki.pl/articles/146686.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
isotope effects
stable isotopes
kinetic isotope effects
Opis:
Isotope effects on chemical equilibria, reaction rates and molecular properties are reviewed together with the theoretical formalism for understanding such effects.
Źródło:
Nukleonika; 2011, 56, 3; 217-240
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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