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Wyszukujesz frazę "neutron activation" wg kryterium: Temat


Wyświetlanie 1-14 z 14
Tytuł:
Preliminary determination of angular distribution of neutrons emitted from PF-1000 facility by indium activation
Autorzy:
Jednoróg, S.
Szydłowski, A.
Scholz, M.
Paduch, M.
Bienkowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/146918.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
neutron activation technique
plasma diagnostics
Opis:
This paper presents a new method applied to measure the angular neutron emission from Plasma Focus (PF) - type deuterium discharges performed within the PF-1000 facility. Neutrons were recorded by activation of especially optimized (mass and shape) indium samples with subsequent gamma spectrometry to measure the induced activity of the samples. The neutron fluence rate on every indium sample used was determined using neutron transport calculation and measured activity of the samples.
Źródło:
Nukleonika; 2012, 57, 4; 563-568
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing
Autorzy:
Asztemborska, M.
Jakubiak, M.
Książyk, M.
Stęborowski, R.
Polkowska-Motrenko, H.
Bystrzejewska-Piotrowska, G.
Powiązania:
https://bibliotekanauki.pl/articles/146436.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
silver
nanoparticles
neutron activation
Chironomid larvae
Danio rerio
Opis:
Water environments are noted as being some of the most exposed to the infl uence of toxic nanoparticles (NPs). Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs) by freshwater larvae of Chironomus and fi sh Danio rerio. The infl uence of exposition time, concentration and the source of nanoparticles on the effi ciency of AgNP accumulation were studied. It was found that AgNPs are effi ciently accumulated by Chironomid larvae for the fi rst 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fi sh and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more effi ciently accumulated if fi sh are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organisms.
Źródło:
Nukleonika; 2014, 59, 4; 169-173
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of neutron activation for investigation of Fe3O4 nanoparticles accumulation by plants
Autorzy:
Bystrzejewska-Piotrowska, G.
Asztemborska, M
Stęborowski, R.
Polkowska-Motrenko, H.
Danko, B.
Ryniewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/146840.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iron (II,III) oxide
nanoparticles
neutron activation
plants
Opis:
As a result of the rapid development of nanotechnology and increasing application of nanoproducts in many areas of everyday life, there is a growing risk of production of nanowastes potentially dangerous for the environment. This makes it necessary to investigate the accumulation and toxicity of nanoparticles (NPs) at different trophic levels. In the studies neutron activation was applied for the investigation of iron (II,III) oxide nanoparticle (Fe3O4-NPs) accumulation by Lepidium sativum and Pisum sativum L. Plants were cultivated on growth medium contaminated with different concentrations (0.01-10 mmolźL-1) of Fe3O4-NPs. For the identification of the presence of Fe3O4-NPs in plant tissues gamma spectrometry following iron oxide (II,III) nanoparticles irradiation was applied. Both plant species were found to accumulate iron (II,III) oxide nanoparticles. The highest content of NPs was found in plant roots, reaching 40 g/kg for Pisum sativum L. More than 90% of accumulated NPs were found in roots. Accumulation of Fe3O4-NPs was found to depend on the concentration of nanostructures in the growth medium. The transfer factor for Lepidium sativum roots and shoots and Pisum sativum L. shoots decreased with increasing NP concentration in the medium; for Pisum sativum L. roots the tendency was reversed. Neutron activation of nanoparticles was shown to be a powerful tool for tracing the environmental fate of NPs and their uptake and accumulation in organisms.
Źródło:
Nukleonika; 2012, 57, 3; 427-430
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large Sample Neutron Activation Analysis: correction for neutron and gamma attenuation
Autorzy:
Tzika, F.
Stamatelatos, I.
Kalef-Ezra, J.
Bode, P.
Powiązania:
https://bibliotekanauki.pl/articles/147265.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutron activation analysis
neutron self-shielding
gamma-ray attenuation
MCNP code
Opis:
A Large Sample Neutron Activation Analysis (LSNAA) facility is under development at the GRR-1 research reactor, NCSR "Demokritos". The LSNAA facility design incorporates sample irradiation in the reactor graphite thermal neutron column and subsequent measurement of the activity induced in a gamma spectroscopy system with gamma ray transmission measurement options included. The Monte Carlo neutron and photon transport code MCNP-4C was used to model the facility. Appropriate correction factors accounting for neutron field perturbation during sample irradiation and high-purity germanium detector efficiency for the volume source were derived. The results of the computations were experimentally verified by measurements for a set of known materials. The LSNAA facility will be used to perform multi-element, non-destructive, contamination-free analysis of large volume samples with high sensitivity and excellent sampling. End-users of the facility will be archaeological, environmental, bio-medical research laboratories and industry.
Źródło:
Nukleonika; 2004, 49, 3; 115-121
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of organohalogens in foodstuffs and environmental samples by neutron activation analysis and related techniques
Autorzy:
Xu, D.
Chai, Z.
Zhang, H.
Mao, X.
Ouyang, H.
Sun, H.
Powiązania:
https://bibliotekanauki.pl/articles/147259.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
instrumental neutron activation analysis (INAA)
pine needle
foodstuff
extractable organohalogen
Opis:
Pine needles and foodstuffs collected from Beijing, China, were analyzed by instrumental neutron activation analysis (INAA) combined with organic solvent extraction for total halogens, extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX). The INAA detection limits are 50 ng, 8 ng and 3.5 ng for Cl, Br and I, respectively. The contents and distribution patterns of organohalogens in these samples are reported. EOCl accounted for 0.013 0.016% and 1.6 2.7% of the total chlorine in yogurt and apples, respectively, which suggested that chlorine in foodstuffs mainly existed as inorganic species and non-extractable organochlorines. EOCl contents in pine needles and foodstuffs were noticeably higher than those of EOBr and EOI. For pine needles, yogurt and apples, 1.6 34%, 23 58% and 29 35% of EOCl remained as extractable persistent organochlorine (EPOCl), respectively. Pine needle containing higher EOCl contents in chemical industrial and traffic hub areas indicated that chemical industries and exhaust emission from vehicle were the main sources of organochlorines in the Beijing's air. The relative proportions of the known organochlorines (such as HCHs, DDTs, chlordanes, heptachlor, HCB and PCBs) to the total EOCl and EPOCl were 0.04 1.6% and 0.7 21.5%, respectively, which implied that the identity of species of a major portion of the EOCl and EPOCl measured in pine needles was unknown.
Źródło:
Nukleonika; 2004, 49, 3; 101-106
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A contribution of INAA to the determination of the provenance of the fourteenth century sculpture
Autorzy:
Ligęza, M.
Pańczyk, E.
Rowińska, L.
Waliś, L.
Nalepa, B.
Powiązania:
https://bibliotekanauki.pl/articles/147539.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
alabaster sculpture
instrumental neutron activation analysis
provenance study
trace elements
Opis:
The object of the investigation is the so called Madonna Jackowa, or St. Hyacinthus's Madonna, a gothic alabaster figurine dated from the XIVth century. The purpose of the investigation is to provide an answer to the question whether Madonna Jackowa was made of native alabaster. Samples of alabaster from five various quarries located along the line Cracow-Lvov as well as in Lower Silesia were analyzed and the content of trace elements was compared with that of the sculpture. The determination of trace elements was carried out by means of the instrumental neutron activation analysis.
Źródło:
Nukleonika; 2001, 46, 2; 71-74
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of a neuro-fuzzy model for neutron activation analysis (NAA)Sb
Autorzy:
Khalafi, H.
Terman, M. S.
Rahmani, F.
Powiązania:
https://bibliotekanauki.pl/articles/147055.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neural network
fuzzy logic
neutron activation analysis (NAA)
gamma-line energy
Opis:
Neutron activation analysis (NAA) is a precise chemical multielemental method of analysis which is satisfactorily used for qualitative and quantitative analyses. Repeated irradiation is needed because of mal-determination of some elements due to peak overlap in qualitative analysis. In this study, NAA procedure has been modified using a neuro-fuzzy model to avoid repeated irradiation based on multilayer perceptrons network trained by the Levenberg-Marquardt algorithm. This method increases the precision of spectrum analysis in the case of strong background and peak overlap.
Źródło:
Nukleonika; 2011, 56, 1; 17-21
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical comparison of INAA and ICP-MS applied in the characterization of purity of TRISO fuel and substrates to its production
Autorzy:
Chajduk, Ewelina
Kalbarczyk, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2055667.pdf
Data publikacji:
2021
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
chemical purity
inductively coupled plasma mass spectrometry
instrumental neutron activation analysis
TRISO coated fue
Opis:
The application of inductively coupled plasma mass spectrometry (ICP-MS), both in solution and laser ablation (LA) mode, and instrumental neutron activation analysis (INAA) in the nuclear material analysis are presented in this paper. The possibility of each technique for the chemical characterization of substances used during TRISO fuel production and its advantages and limitations are discussed based on the obtained results of the analysis of real materials used in TRISO fuel production in the Institute of Nuclear Chemistry and Technology. The paper also reports the application of INAA and LA-ICP-MS to the verifi cation of the purity of the protective layers of pyrolytic carbon (PyC) and silicon carbide.
Źródło:
Nukleonika; 2021, 66, 4; 121--126
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trace analysis of Indonesian volcanic ash using thermal and epithermal neutron activation analysis
Autorzy:
Canion, B.
Jacques, C.
Landsberger, S.
Taftazani, A.
Powiązania:
https://bibliotekanauki.pl/articles/146890.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutron activation analysis (NAA)
trace elements
volcanic ash
rare earth elements (REE)
Mount Merapi
Opis:
There is continued great interest in determining the trace element and heavy metal content of volcanic ash for a variety of reasons. The motivation stems from the desire to understand the geochemistry of volcanic ash in imbedded geological formations, the impact on seawater, and the possible release of toxic elements into the environment that may impact livestock grazing and water systems. Ash from volcanic plumes can go as high 8-18 km thus affecting climate and air traffic. We have employed Compton suppression neutron activation analysis (NAA) with thermal and epithermal neutrons to determine trace elements in volcanic ash from Indonesian eruption of Mount Merapi in October 2010. We found a wide range of elements, including several rare earth elements.
Źródło:
Nukleonika; 2012, 57, 4; 585-589
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Instrumental neutron activation analysis (INAA) for steel analysis and certification
Autorzy:
Polkowska-Motrenko, H.
Chajduk, E.
Danko, B.
Powiązania:
https://bibliotekanauki.pl/articles/147648.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
steel analysis
neutron activation analysis (NAA)
proficiency testing/interlaboratory comparison (PT/ILC)
certification of steel reference materials
Opis:
Instrumental neutron activation analysis (INAA) procedure of elemental steel analysis has been elaborated. The reliability of results obtained by the described procedure has been proved in the frame of different proficiency testing/interlaboratory comparison (PT/ILC) programmes, in which the Institute of Nuclear Chemistry and Technology (INCT, Warsaw) took part since 2005. This work summarizes participation of INCT in these exercises and demonstrates the usefulness of INAA to the certification of steel reference materials.
Źródło:
Nukleonika; 2011, 56, 4; 311-315
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast Neutron Activation Analysis of gold by inelastic scattering, 197Au(n,ngamma)197Aum, by means of Plasma Focus device
Autorzy:
Verri, G.
Mezzetti, F.
Da Re, A.
Rapezzi, L.
Gribkov, V.
Powiązania:
https://bibliotekanauki.pl/articles/146754.pdf
Data publikacji:
2000
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
activation
gold
neutron
plasma focus
Opis:
The application of a Fast Neutron Activation Analysis (FNAA) technique on samples of pure gold, irradiated by a plasma focus of 7 kJ, has been investigated. The reaction was the inelastic scattering of neutrons, 197Au(n,n'gamma)197Aum. To avoid problems connected with peculiar features of the neutron emission from this kind of source, a preliminary standardisation of the method has been carried out. The results obtained have a practical interest in view of possible applications to the technology of extraction of minerals.
Źródło:
Nukleonika; 2000, 45, 3; 189-191
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the emission rate for the 14 MeV neutron generator with the use of radio-yttrium
Autorzy:
Laszynska, E.
Jednorog, S.
Ziolkowski, A.
Gierlik, M.
Rzadkiewicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/146115.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
14 MeV neutron generator
activation method
yttrium activation
Opis:
The neutron emission rate is a crucial parameter for most of the radiation sources that emit neutrons. In the case of large fusion devices the determination of this parameter is necessary for a proper assessment of the power release and the prediction for the neutron budget. The 14 MeV neutron generator will be used for calibration of neutron diagnostics at JET and ITER facilities. The stability of the neutron generator working parameters like emission and angular homogeneity affects the accuracy of calibration other neutron diagnostics. The aim of our experiment was to confi rm the usefulness of yttrium activation method for monitoring of the neutron generator SODERN Model: GENIE 16. The reaction rate induced by neutrons inside the yttrium sample was indirectly measured by activation of the yttrium sample, and then by means of the γ-spectrometry method. The pre-calibrated HPGe detector was used to determine the yttrium radioactivity. The emissivity of neutron generator calculated on the basis of the measured radioactivity was compared with the value resulting from its electrical settings, and both of these values were found to be consistent. This allowed for a positive verifi cation of the reaction cross section that was used to determine the reaction rate (6.45 × 10–21 reactions per second) and the neutron emission rate (1.04 × 108 n·s–1). Our study confi rms usefulness of the yttrium activation method for monitoring of the neutron generator.
Źródło:
Nukleonika; 2015, 60, 2; 319-322
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new concept of fusion neutron monitoring for PF-1000 device
Autorzy:
Jednorog, S.
Laszynska, E.
Bienkowska, B.
Ziolkowski, A.
Paduch, M.
Szewczak, K.
Mikszuta, K.
Malinowski, K.
Bajdel, M.
Potrykus, P.
Powiązania:
https://bibliotekanauki.pl/articles/148394.pdf
Data publikacji:
2017
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dense plasma focus (DPF)
PF-1000
neutron diagnostic
activation technique
Opis:
The power output of plasma experiments and fusion reactors is a crucial parameter. It is determined by neutron yields that are proportional and directly related to the fusion yield. The number of emitted neutrons should be known for safety reasons and for neutron budget management. The PF-1000 is the large plasma facility based on the plasma focus phenomenon. PF-1000 is operating in the Institute of Plasma Physics and Laser Microfusion in Warsaw. Neutron yield changes during subsequent pulses, which is immanent part of this type device and so it must be monitored in terms of neutron emission. The reference diagnostic intended for this purpose is the silver activation counter (SAC) used for many years. Our previous studies demonstrated the applicability of radio-yttrium for neutron yield measurements during the deuterium campaign on the PF-1000 facility. The obtained results were compared with data from silver activation counter and shown linear dependence but with some protuberances in local scale. Correlation between results for both neutron monitors was maintained. But the yttrium monitor registered the fast energy neutron that reached measurement apparatus directly from the plasma pinch. Based on the preliminary experiences, the yttrium monitor was designed to automatically register neutron-induced yttrium activity. The MCNP geometrical model of PF-1000 and yttrium monitor were both used for calculation of the activation coefficient for yttrium. The yttrium monitor has been established as the permanent diagnostic for monitoring fusion reactions in the PF-1000 device.
Źródło:
Nukleonika; 2017, 62, 1; 17-22
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spektrometria aktywacyjna dla potrzeb drugiej kampanii deuterowo-trytowej na Tokamaku JET
The activation spectrometry for the purpose of the Second Deuterum-Tritium Experimental Campaign on JET tokamak
Autorzy:
Łaszyńska, E.
Jednoróg, S.
Powiązania:
https://bibliotekanauki.pl/articles/214258.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
tokamak JET
metoda aktywacyjna
kalibracja diagnostyk neutronowych tokamaka JET
generator neutronów 14 MeV
wydajność neutronowa
JET tokamak
activation technique
alibration of neutron diagnostics for JET tokamak
14 MeV neutron
generator
neutron yield
Opis:
Metoda aktywacyjna stosowana do charakteryzacji różnych źródeł neutronów, należy do jednej z najstarszych metod stosowanych w neutronice. Pomimo tego jest wciąż ważna, gdyż prowadzi do otrzymywania wartości bezwzględnych wydajności neutronów, a czasami pozwala na dekonwolucje ich rozkładu energetycznego. Druga Deuterowo- Trytowa Kampania Eksperymentalna na Wspólnym Europejskim Tokamaku JET jest wielkim wyzwaniem. Po jej zakończeniu nastąpi zamknięcie i odstawienie JETa, a tym samym zakończenie jakże ważnego rozdziału w historii fizyki plazmy. Przed kampanią deuterowo-trytową nastąpi kalibracja diagnostyk neutronowych tokamaka i to z niepewnością niższą niż 5%. Technika aktywacyjna posłuży do charakteryzacji generatora neutronów, który będzie zastosowany, jako ustandaryzowane źródło neutronów 14 MeV, a następnie będzie zastosowana w czasie ostatniej kampanii eksperymentalnej do monitorowania wydajności neutronów.
The activation technique used for characterization of many different neutron sources belongs to the oldest one applied in neutronics area. It is still important because it leads to obtainment of obsolete value of neutron yield and from time to time allows neutron spectrum deconvolution. The Second Deuterium-Tritium Experimental Campaign that is held on Joint European Torus is a great challenge. After completing the above campaign the shut down and decommissioning of the JET is expected. Thus, the important chapter in history of plasma physics will be definitely closed. But before the deuterium-tritium campaign starts, the calibration of neutron diagnostic should be completed with uncertainty better than 5%. The activation technique is used for neutron diagnostics characterization that is chosen as the source of 14 MeV neutrons. Afterwards, the activation technique will be applied as neutron yield monitor during last experimental campaign on JET tokamak.
Źródło:
Postępy Techniki Jądrowej; 2016, 4; 21-29
0551-6846
Pojawia się w:
Postępy Techniki Jądrowej
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-14 z 14

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