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Tytuł:
Study of some physicochemical and rheological properties of irradiated honey
Autorzy:
Bera, A
Almeida-Muradian, L. G.
Sabato, S. F.
Powiązania:
https://bibliotekanauki.pl/articles/147025.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma radiation
honey
rheology
physicochemical properties
Opis:
Honey is a sweet substance produced by bees, well appreciated in many places and its consumption has been increased either as raw material or as a food ingredient. Its use as food by the consumer, or even for exportation, implies safety inherent in its quality and processing control. Gamma radiation can be applied in food or ingredients for many objectives like pathogens microorganisms’ reduction, disinfestations, and sterilization. The aim of this work was to verify some physicochemical modifications, as well as rheological evaluation of honey submitted to irradiation at 10 kGy. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The rheological behavior was measured at different temperatures. The results indicated that few changes occurred; the rheological behavior was not impaired and did not present any significant physicochemical alteration.
Źródło:
Nukleonika; 2008, 53, suppl. 2; 85-87
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an irradiation system for a small size continuous run multipurpose gamma irradiator
Autorzy:
Calvo, W. A. P.
Rela, P. R.
Napolitano, C. M.
Kodama, Y.
Omi, N. M.
da Costa, F.
de Andrade e Silva, L. G.
Powiązania:
https://bibliotekanauki.pl/articles/148041.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
multipurpose irradiator
gamma irradiator
compact irradiator
cobalt-60 irradiator
gamma facility
Opis:
The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m2 of floor area, the irradiator design is a product overlap sources and the maximum capacity of cobalt-60 wet sources is 37 PBq. The performed qualification program of this multipurpose irradiator was based on AAMI/ISO 11137 standard, which recommends the inclusion of the following elements: installation and process qualification. The initial load of the multipurpose irradiator was 3.4 PBq with 13 cobalt-60 sources model C-188, supplied by MDS Nordion – Canada. For irradiator dose optimization, the source distribution was done using the software Cadgamma developed by IPEN-CNEN/SP. The polymethylmetacrylate (PMMA) dosimeter system, certified by the International Dose Assurance Service (IDAS) of the International Atomic Energy Agency (IAEA) was used for irradiator dose mapping. The economic analysis, performance concerning with dose uniformity and cobalt-60 utilization efficiency were calculated and compared with other commercial gamma irradiators available on the market.
Źródło:
Nukleonika; 2009, 54, 2; 93-97
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Status report of the LNS Superconducting Cyclotron
Autorzy:
Rifuggiato, D.
Calabretta, L.
Cuttone, G.
Powiązania:
https://bibliotekanauki.pl/articles/146187.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cyclotron
axial injection
electrostatic deflectors
proton therapy
Opis:
The LNS Superconducting Cyclotron has been working in stand alone mode since the beginning of 2000, after 5 years of operation as a booster of the 15 MV Tandem. The new mode has proven to be by far more advantageous than the previous one from the point of view of operation. Working with axial injection, a quite high number of new beam types has been developed. The new mode allows for acceleration of H2 + molecules, which break into two protons when crossing a stripper in the beam line out of the cyclotron. 62 MeV protons have been used for radiotherapy since February 2002. The new mode allows to inject a more intense beam as compared to the previous mode. Therefore, an upgrading program of the cyclotron has started, aiming at having an intense extracted beam to be used as a primary beam in a facility for production of radioactive beams. Beam tests have been accomplished to evaluate transmission figures, while the upgrading of the present electrostatic deflectors has started: new deflector systems, able to dissipate high beam power and allowing for easier maintenance, have been designed and will soon be tested in the machine.
Źródło:
Nukleonika; 2003, 48,suppl.2; 131-134
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multibarrier system preventing migration of radionuclides from radioactive waste repository
Autorzy:
Olszewska, W.
Miśkiewicz, A.
Zakrzewska-Kołtuniewicz, G.
Lankof, L.
Pająk, L.
Powiązania:
https://bibliotekanauki.pl/articles/148431.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
engineered barrier
migration
radionuclides
repository
radioactive waste
Opis:
Safety of radioactive waste repositories operation is associated with a multibarrier system designed and constructed to isolate and contain the waste from the biosphere. Each of radioactive waste repositories is equipped with system of barriers, which reduces the possibility of release of radionuclides from the storage site. Safety systems may differ from each other depending on the type of repository. They consist of the natural geological barrier provided by host rocks of the repository and its surroundings, and an engineered barrier system (EBS). The EBS may itself comprise a variety of sub-systems or components, such as waste forms, canisters, buffers, backfi lls, seals and plugs. The EBS plays a major role in providing the required disposal system performance. It is assumed that the metal canisters and system of barriers adequately isolate waste from the biosphere. The evaluation of the multibarrier system is carried out after detailed tests to determine its parameters, and after analysis including mathematical modeling of migration of contaminants. To provide an assurance of safety of radioactive waste repository multibarrier system, detailed long term safety assessments are developed. Usually they comprise modeling of EBS stability, corrosion rate and radionuclide migration in near fi eld in geosphere and biosphere. The principal goal of radionuclide migration modeling is assessment of the radionuclides release paths and rate from the repository, radionuclides concentration in geosphere in time and human exposure to ionizing radiation.
Źródło:
Nukleonika; 2015, 60, No. 3, part 2; 557-563
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical optimisation of the fission-converter and the filter/moderator arrangement for the Boron Neutron Capture Therapy
Autorzy:
Tracz, G.
Dąbkowski, L.
Dworak, D.
Pytel, K.
Woźnicka, U.
Powiązania:
https://bibliotekanauki.pl/articles/148388.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
BNCT
fission converter
Fluka
MCNP
Monte Carlo
neutrons
Opis:
The paper presents results of the numerical modelling of the fission-converter-based epithermal neutron source designed for a BNCT (Boron Neutron Capture Therapy) facility to be located at the Polish research nuclear reactor MARIA at Świerk. The unique design of the fission converter has been proposed due to a specific geometrical surrounding of the reactor. The filter/moderator arrangement has been optimised in order to moderate fission neutrons to epithermal energies and to get rid of both fast neutrons and photons from the therapeutic beam. The selected filter/moderator set-up ensures both the high epithermal neutron flux and the suitably low level of beam contamination. The elimination of photons originated in the reactor core is an exceptional advantage of the proposed design. It brings one order of magnitude lower gamma radiation dose than the permissible dose in such a type of therapeutic facility is required. The MCNP and FLUKA codes have been used for the computations.
Źródło:
Nukleonika; 2003, 48, 4; 177-185
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of the soft X-ray tungsten spectra expected to be registered by GEM detection system for WEST
Autorzy:
Syrocki, Ł.
Szymańska, E.
Słabkowska, K.
Polasik, M.
Pestka, G.
Powiązania:
https://bibliotekanauki.pl/articles/971490.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
X-ray spectra
tokamak
tungsten L, M, N, X-ray lines
GEM detection system
Opis:
In the future International Thermonuclear Experimental Reactor (ITER), the interaction between the plasma and the tungsten chosen as the plasma-facing wall material imposes that the hot central plasma loses energy by X-ray emission from tungsten ions. On the other hand, the registered X-ray spectra provide alternative diagnostics of the plasma itself. Highly ionized tungsten emits extremely complex X-ray spectra that can be understood only after exhaustive theoretical studies. The detailed analyses will be useful for proper interpretation of soft X-ray plasma radiation expected to be registered on ITER-like machines, that is, Tungsten (W) Environment in Steady-state Tokamak (WEST). The simulations of the soft X-ray spectra structures for tungsten ions have been performed using the flexible atomic code (FAC) package within the framework of collisional-radiative (CR) model approach for electron temperatures and densities relevant to WEST tokamak.
Źródło:
Nukleonika; 2016, 61, 4; 433-436
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:
Numerical simulation of space charge effects in the sector cyclotron
Autorzy:
Onischenko, L.
Samsonov, E.
Aleksandrov, V.
Shevtsov, V.
Shirkov, G.
Tuzikov, A.
Powiązania:
https://bibliotekanauki.pl/articles/148737.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
sector cyclotron
particle dynamics
Opis:
To study the effects of space charge in cyclotrons and synchrocyclotrons the code PHASCOL is developed. A method of large (macro)particles is realized in this code. The complete equations of motion of the charged particle in electromagnetic field of accelerator are integrated taking into account the three-dimensional self-electric field of beam. Two methods were used for the calculation of the beam field: the particle-to-particle method and the particle-in-cell one. The results of calculations which illustrate space-charge effects on the parameters of beam in the process of acceleration are given. Both methods have shown a similar influence of space charge on the beam.
Źródło:
Nukleonika; 2003, 48,suppl.2; 45-48
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence and positron annihilation lifetime studies on pellets of ZnO nanocrystals
Autorzy:
Karbowski, A.
Fedus, K.
Patyk, J.
Bujak, Ł.
Służewski, K.
Karwasz, G.
Powiązania:
https://bibliotekanauki.pl/articles/148001.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
photoluminescence (PL)
positron annihilation lifetime spectroscopy (PALS)
X-ray diffraction (XRD)
ZnO nanocrystals
Opis:
We explore the interrelationships between the X-ray diffraction patterns, the photoluminescence spectra and the positron lifetimes obtained from circular pellets composed of commercial ZnO nanoparticles. The experimental results are studied as a function of thermal treatment at different temperatures. X-ray diffractograms reveal the temperature- independent wurtzite phase structure of nanocrystals and show huge enlargement of ZnO grains after annealing at temperatures higher than 700 centigrade. Photoluminescence measurements exhibit two emission bands : a near band edge emission in UV (small tilde 378 nm) and a defect-related broad visible peak with a maximum in the green region ( small tilde 502 nm). The significant enhancement of the green emission at the expense of UV luminescence is observed after sample sintering at 800 and 1000 centigrade. The positron annihilation lifetime spectroscopy (PALS) is applied in order to study the thermally induced evolution of defects. The lifetime components show a step-like dependence on the thermal treatment, but do not follow exactly the variation in crystallographic phases and only vaguely follow differences in photoluminescence. The positron data indicate therefore some additional structural and/or defect changes. The possible origin of green luminescence from ZnO pellets is discussed.
Źródło:
Nukleonika; 2013, 58, 1; 189-194
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reprocessability of molybdenum and magnesia based inert matrix fuels
Autorzy:
Ebert, E. L.
Bukaemskiy, A.
Sadowski, F.
Lange, S
Wilden, A.
Modolo, G.
Powiązania:
https://bibliotekanauki.pl/articles/148138.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
CERCER
CERMET
dissolution
inert matrix fuels (IMF)
liquid-liquid extraction
minor actinides
reprocessing
Opis:
This work focuses on the reprocessability of metallic 92Mo and ceramic MgO, which is under investigation for (Pu,MA)-oxide (MA = minor actinide) fuel within a metallic 92Mo matrix (CERMET) and a ceramic MgO matrix (CERCER). Magnesium oxide and molybdenum reference samples have been fabricated by powder metallurgy. The dissolution of the matrices was studied as a function of HNO3 concentration (1–7 mol/L) and temperature (25–90°C). The rate of dissolution of magnesium oxide and metallic molybdenum increased with temperature. While the MgO rate was independent of the acid concentration (1–7 mol/L), the rate of dissolution of Mo increased with acid concentration. However, the dissolution of Mo at high temperatures and nitric acid concentrations was accompanied by precipitation of MoO3. The extraction of uranium, americium, and europium in the presence of macro amounts of Mo and Mg was studied by three different extraction agents: tri-n-butylphosphate (TBP), N,N'-dimethyl-N,N'-dioctylhexylethoxymalonamide (DMDOHEMA), and N,N,N’,N’- -tetraoctyldiglycolamide (TODGA). With TBP no extraction of Mo and Mg occurred. Both matrix materials are partly extracted by DMDOHEMA. Magnesium is not extracted by TODGA (D < 0.1), but a weak extraction of Mo is observed at low Mo concentration.
Źródło:
Nukleonika; 2015, 60, No. 4, part 2; 871-878
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Freeze-out and anisotropic flow in microscopic models
Autorzy:
Bravina, L.
Tywoniuk, K.
Zabrodin, E.
Burau, G.
Bleibel, J.
Fuchs, Ch.
Faessler, A.
Powiązania:
https://bibliotekanauki.pl/articles/148598.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
ultrarelativistic heavy-ion collisions
elliptic flow
freeze-out of particles
Monte-Carlo quark-gluon string model
Opis:
It appears that in microscopic calculations hadrons are continuously emitted from the whole reaction volume. Different species decouple at different times. At RHIC energies significant fractions of both mesons and baryons are emitted from the surface region within the first two fm/c. The hadrons contribute differently to the formation and evolution of the anisotropic flow, which can be decomposed into three components: (i) flow created by hadrons emitted from the surface at the onset of the collision; (ii) flow produced by jets; (iii) hydrodynamic flow. Due to these features, e.g., the elliptic flows of mesons and baryons have different transverse momentum dependences. Comparison with experimental data reveals that centrality, rapidity, and transverse momentum dependences of the anisotropic flow are reproduced, at least qualitatively, by the microscopic models.
Źródło:
Nukleonika; 2006, 51,suppl.3; 3-6
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uranium and neodymium partitioning in alkali chloride melts using low-melting gallium-based alloys
Autorzy:
Melchakov, S. Y.
Maltsev, D. S.
Volkovich, V. A.
Yamshchikov, L. F.
Lisienko, D. G.
Osipenko, A. G.
Rusakov, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/146407.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neodymium
uranium
gallium
separation factor
reductive extraction
pyrochemical reprocessing
Opis:
Partitioning of uranium and neodymium was studied in a ‘molten chloride salt – liquid Ga-X (X = In or Sn) alloy’ system. Chloride melts were based on the low-melting ternary LiCl-KCl-CsCl eutectic. Nd/U separation factors were calculated from the thermodynamic data as well as determined experimentally. Separation of uranium and neodymium was studied using reductive extraction with neodymium acting as a reducing agent. Efficient partitioning of lanthanides (Nd) and actinides (U), simulating fission products and fissile materials in irradiated nuclear fuels, was achieved in a single stage process. The experimentally observed Nd/U separation factor valued up to 106, depending on the conditions.
Źródło:
Nukleonika; 2015, 60, No. 4, part 2; 915-920
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An internal standard for Fast Neutron Activation Analysis spectra obtained by means of Plasma Focus devices
Autorzy:
Verri, G.
Tartari, A.
Rapezzi, L.
Mezzetti, F.
Gribkov, V. A.
Da Re, A.
Powiązania:
https://bibliotekanauki.pl/articles/147122.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gold
inelastic scattering
lead
mineral resources
NAA
plasma focus
Opis:
The behaviour of Pb activation peaks, which appear in an X-ray spectrum of Fast Neutron Activation Analysis (FNAA) performed by means of a Plasma Focus (PF) neutron source and an NaI scintillator counter, has been studied. The PF device generates neutron bursts of different intensities. To know the exact neutron flux illuminating a sample during PF discharges an external neutron counter is usually used. The nature and behaviour of the indicated peaks suggest that one could use one of them as an internal standard for neutron production measurement instead of an external counter. This technique allows more reliable and accurate determinations of the presence of various elements.
Źródło:
Nukleonika; 2001, 46, suppl. 1; 103-105
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary study on X-ray source from Plasma Focus device for fast radiography
Autorzy:
Da Re, A.
Mezzetti, F.
Tartari, A.
Verri, G.
Rapezzi, L.
Gribkov, V. A.
Powiązania:
https://bibliotekanauki.pl/articles/147243.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
X-ray sources
Opis:
Plasma derived flash X-ray sources may find potential applications in medicine and industry. Notwithstanding, as is the case of Plasma Focus (PF) devices, their characterisation in term of photon energy, temporal and spatial beam stability is far to be considered satisfactory. In this work, a radiographic approach, which avoids the effects caused by the intrinsic instability of the pinch output of a PF machine, is proposed and an attenuation curve can be attained even in presence of Xray emission instability. Using two radiographic films for each shot exposition symmetrically positioned and collimated to the pinch region the mean energy of the photons in the X-ray beam are evaluated. The X-ray emission symmetry from the pinch region was then utilised to control the validity of the proposed methodology.
Źródło:
Nukleonika; 2001, 46, suppl. 1; 123-125
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
TS-BTPhen as a promising hydrophilic complexing agent for selective Am(III) separation by solvent extraction
Autorzy:
Kaufholz, P.
Sadowski, F.
Wilden, A.
Modolo, G.
Lewis, F. W.
Smith, A. W.
Harwood, L. M.
Powiązania:
https://bibliotekanauki.pl/articles/147226.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Am-Cm separation
TODGA
TS-BTPhen
liquid-liquid extraction
Opis:
The novel hydrophilic back-extraction agent TS-BTPhen (3,3',3'',3'''-[3-(1,10-phenanthroline-2,9- -diyl)-1,2,4-triazine-5,5,6,6-tetrayl]tetrabenzenesulfonic acid) was tested for its selectivity towards Am(III) over Cm(III) and Eu(III) with a TODGA (N,N,N',N'-tetraoctyldiglycolamide) based solvent. Batch experiments were carried out using TS-BTPhen dissolved in aqueous nitric acid solution with tracers of 152Eu, 241Am and 244Cm. A signifi cant increase of the separation factor for Cm over Am from SFCm/Am = 1.6 up to SFCm/Am = 3.3 was observed compared to the use of a TODGA-nitric acid system alone. Furthermore, stripping was possible at high nitric acid concentrations (0.6–0.7 mol/L) resulting in a low sensitivity to acidity changes. The infl uence of the TS-BTPhen concentration was analyzed. A slope of –2 was expected taking into account literature stoichiometries of the lipophilic analogue CyMe4BTPhen. However, a slope of –1 was found. Batch stripping kinetics showed fast kinetics for the trivalent actinides. As an alternative organic ligand the methylated TODGA derivate Me-TODGA (2-methyl-N,N,N',N'-tetraoctyldiglycolamide) was tested in combination with the hydrophilic TS-BTPhen. The Am(III) separation was achieved at even higher nitric acid concentrations compared to TODGA.
Źródło:
Nukleonika; 2015, 60, No. 4, part 2; 815-820
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł

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