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Tytuł:
A calculation model for liquid-liquid extraction of protactinium by 2,6-dimethyl-4-heptanol
Autorzy:
Knight, A. W.
Eitrheim, E. S.
Nelson, A. W.
Schultz, M. K.
Powiązania:
https://bibliotekanauki.pl/articles/146380.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
design of experiments
protactinium
solvent extraction
Opis:
Reprocessing of spent nuclear fuel usually employs the solvent extraction technique to recover fissile material, isolate other valuable radionuclides, recover precious metals, and remove contaminants. Effi cient recovery of these species from highly radioactive solutions requires a detailed understanding of reaction conditions and metal speciation that leads to their isolation in pure forms. Due to the complex nature of these systems, identification of ideal reaction conditions for the efficient extraction of specific metals can be challenging. Thus, the development of experimental approaches that have the potential to reduce the number of experiments required to identify ideal conditions are desirable. In this study, a full-factorial experimental design was used to identify the main effects and variable interactions of three chemical parameters on the extraction of protactinium (Pa). Specifi cally we investigated the main effects of the anion concentration (NO3 –, Cl–) extractant concentration, and solution acidity on the overall extraction of protactinium by 2,6-dimethyl-4-heptanol (diisobutylcarbinol; DIBC) from both HCl and HNO3 solutions. Our results indicate that in HCl, the extraction of protactinium was dominated by the solution acidity, while in nitric acid the extraction was strongly effected by the [DIBC]. Based on our results, a mathematical model was derived, that describes the relationship between concentrations of anions, extractant, and solution acidity and the expected values of Pa distribution coefficients in both HCl and HNO3. This study demonstrates the potential to predict the distribution coefficient values, based upon a mathematical model generated by a full-factorial experimental design.
Źródło:
Nukleonika; 2015, 60, No. 4, part 2; 837-845
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tubing decontamination during the leak test of iodine-125 seeds
Autorzy:
Moura, J. A.
Moura, E. S.
Sprenger, F. E.
Nagatomi, H. R.
Zeituni, C. A.
Feher, A.
Manzoli, J. E.
Souza, C. D.
Rostelato, M. E.
Powiązania:
https://bibliotekanauki.pl/articles/148765.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
brachytherapy
iodine seeds
leak test
sealed radioactive sources
Opis:
Leak tests were made to detect any leakage of radioactive material from inside the iodine-125 seeds applied in brachytherapy. These seeds are used in prostate cancer treatment. In the quality control routine, during seed production, leak tests are performed according to the International Standard Organization – radiation protection – sealed radioactive sources – ISO-9978 standard, and require liquid transfer between recipients. Any leakage causes contamination of the liquid and tubes. The aim of this study is the establishment of decontamination routines for tubes, allowing their repeated use, in the automated assay process.
Źródło:
Nukleonika; 2010, 55, 3; 409-413
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and production of radioactive sources used for cancer treatment in Brazil
Autorzy:
Rostelato, M. E. C. M.
Rela, P. R.
Zeituni, C. A.
Feher, A.
Manzoli, J. E.
Moura, J. A.
Moura, E. S.
Silva, C. P. G.
Powiązania:
https://bibliotekanauki.pl/articles/148305.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radioactive sources production
iodine-125 seeds
iridium-192 wires
brachytherapy
cancer treatment
Opis:
The number of cancer patients in Brazil is increasing and part of the patients are submitted to brachytherapy treatment using iridium-192 wire and iodine-125 radioactive seeds. The Nuclear Energy Research Institute established a programme to produce iridium-192 wire and iodine-125 radioactive seeds. With the purpose of settling a laboratory for iridium-192 sources production, a wire activation method was developed and a hot cell for the wire manipulation, quality assurance and packaging was built. The iodine-125 seeds consist of a welded titanium capsule containing iodine-125 adsorbed onto a silver rod. Concerning the setup of the local production, the following activities were carried out: superficial treatment of the silver rod, development of a process to absorb the iodine in the silver rod, welding methodology to seal the seeds, leakage and contamination test and source activity measurement.
Źródło:
Nukleonika; 2008, 53, suppl. 2; 99-103
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leakage test evaluation used for qualification of iodine-125 seeds sealing
Autorzy:
Feher, A.
Rostelato, M. E. C. M.
Zeituni, C. A.
Calvo, W. A. P.
Somessari, S. L.
Moura, J. A.
Moura, E. S.
Souza, C. D.
Rela, P. R.
Powiązania:
https://bibliotekanauki.pl/articles/147662.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
leakage test
iodine-125 seeds
prostate cancer
brachytherapy
titanium tube
standard ISO-9978
Opis:
Brachytherapy is one of the possible treatments with ionizing radiation available for prostate cancer, in which small seeds containing iodine-125 radioisotope are implanted directly into the prostate. The seed consists of a sealed titanium tube containing a central silver wire with adsorbed iodine-125. The tube sealing is made with titanium at the ends, using plasma arc-welding (PAW) or laser process. This sealing must be leakage-resistant and free of cracks, therefore avoiding iodine-125 to deposit in the silver wire to escape and spread into the human body. To ensure that this problem is not occurring, rigorous leakage tests in accordance with the standard ISO-9978 should be applied. The aim of this study is to determine, implement and evaluate the leakage test to be used in the iodine-125 seeds production, in order to qualify the sealing procedure. The standard ISO-9978 presents a list of tests to be carried out according to the type of source. The preferential methods for brachytherapy sources are soaking and helium. To assess the seeds leakage, the method of immersion test at room temperature was applied. The seeds are considered leakage-free if the detected activity does not exceed 185 Bq (5 nCi). An iodine standard was prepared and its value determined in a sodium iodide detector. A liquid scintillation counter was calibrated with the standard for seed leakage tests. Forty-eight seeds were plasma arc-welded for these tests.
Źródło:
Nukleonika; 2011, 56, 4; 375-379
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New method of pure 111In production by proton-induced nuclear reactions with enriched 112 Sn
Autorzy:
Betak, E.
Rurarz, E.
Mikołajewski, S.
Wojtkowska, J.
Powiązania:
https://bibliotekanauki.pl/articles/148256.pdf
Data publikacji:
2007
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cross sections
Sn isotopes
proton-induced reactions
111In production
diagnostic radioisotope
Opis:
We aimed at finding out a simple and reliable way of 111In production with the highest radionuclide purity from its grand parent 111Sb and parent 111Sn nuclei, produced by the 112Sn(p,2n)111Sb and 112Sn(p,pn)111Sn reactions, respectively. The target was a metallic 112Sn sample enriched to 84%. We have measured activation cross sections for seven reactions on an enriched 112Sn sample induced by 23.6 š 0.8 MeV energy protons. Gamma-ray spectroscopy with high-purity germanium detectors has been used. We also identified the activities of 55Co (T1/2 = 17.5 h) and 60Cu (T1/2 = 23.7 min) in proton beam monitoring Ni foils, induced in the natNi(p,X)55Co and natNi(p,X)60Cu reactions at 22.8 MeV proton energy. The cross sections determined for these reactions are: s[natNi(p,X)55Co] = 36.6 š 4 mb and s[natNi(p,X)60Cu] = 64.4 š 7 mb. The measured cross sections of reactions on tin isotopes are: sigma[112Sn(p,n)112Sb] = 4 š 0.8 mb; sigma[112Sn(p,2n)111Sb] = 182 š 26 mb; sigma[112Sn(p,pn)111Sn] = 307 š 35 mb; sigma[114Sn(p,2n)113Sb] = 442 š 52 mb; s[117Sn(p,n)117Sb] = 15 š 3 mb; sigma[117Sn(p,p’gamma)117mSn] = 0.37 š 0.06 mb; s[115Sn(p,2p)114m2In] = 0.01 š 0.002 mb. Our measurements indicated the expected yield of the 111In production to be 46 MBq/mAh (1.2 mCi/mi Ah). The contamination of 111In by the undesired nuclide 114m2In was determined and belongs to the smallest ones found in the literature. The measured cross sections were compared with theoretical calculations by two top-level nuclear reaction codes EMPIRE and TALYS.
Źródło:
Nukleonika; 2007, 52, 1; 17-27
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Erratum to "Production of 18F by proton irradiation of C6H6NF and C6H5NF2". (Nukleonika 2011;56(4):269-276)
Autorzy:
Běták, E.
Mikołajczak, R.
Staniszewska, J.
Mikołajewski, S.
Rurarz, E.
Wojtkowska, J.
Powiązania:
https://bibliotekanauki.pl/articles/146862.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Źródło:
Nukleonika; 2012, 57, 4; 642-642
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Production of 18F by proton irradiation of C6H6NF and C6H5NF2
Autorzy:
Běták, E.
Mikołajczak, R.
Staniszewska, J.
Mikołajewski, S.
Rurarz, E.
Wojtkowska, J.
Powiązania:
https://bibliotekanauki.pl/articles/147609.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radiopharmaceuticals
positron emitters
radiochemistry
18F
cyclotron
production cross section
Opis:
Fluorin--18 can be produced directly by the (p,pn) reaction and also indirectly by the (p,2n) reaction on the 19F target. The overall cross section for both routes is 108 plus or minus 20 mb at 22.5 plus or minus 2.5 MeV. In this work, we obtained 18F, using 25 MeV protons on 2\--fluoroaniline and 2,4-difluoroaniline targets. The chemical separation yield was 46 š 7% and 47 plus or minus 12% for 2-fluoroaniline and 2,4-difluoroaniline, respectively. Low-current 1 h irradiations led to 90 mi Ci of 18F produced from 2-fluoroaniline bombarded with a 70 nA beam (in good agreement with the theoretical value, 96 mi Ci) and to 76 mi Ci of 18F in case of 2,4-difluoroaniline and a 33 nA beam (prediction 85 mi Ci). Both values are close to the thick target result reported by Dmitriev and Molin [4] for 22 MeV protons.
Źródło:
Nukleonika; 2011, 56, 4; 269-276
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent developments of plasma - based technologies for medicine and industry
Autorzy:
Taran, V. S.
Garkusha, I. E.
Krasnyj, V. V.
Powiązania:
https://bibliotekanauki.pl/articles/146418.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
discharge
plasma
ozone sterilizer
coating
surface modification
Opis:
The paper presents an overview of experimental results of various plasma applications based on atmospheric and vacuum discharges. A multifunctional low-temperature ozone sterilizer with a ultrasonic cavitation and dielectric barrier discharge generated at atmospheric pressure as well as ozonators with a diaphragm for water treatment and disinfection of medical tools have been developed. Particular attention is paid to the investigation of arc, high-frequency and non-self maintained discharges generated in vacuum for coatings application. Some aspects of pulsed plasma treatment, surface modification and hardening due to nitriding, oxidation and carburization are discussed.
Źródło:
Nukleonika; 2012, 57, 2; 277-282
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accumulation properties of Norway spruce (Picea abies) for different radionuclides
Autorzy:
Tomankiewicz, E.
Mietelski, J.
Gaca, P.
Błażej, S.
Powiązania:
https://bibliotekanauki.pl/articles/148612.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
137Cs
50Sr
thorium
spruce tree
Tatra Mts.
aggregation coefficients
Opis:
The paper presents results for the 137Cs, 90Sr, 40K activity concentrations and 228Th/232Th, 230Th/232Th activity ratios in several samples needles from two Norway spruce (Picea abies) trees and two soil samples collected in the Tatra Mountains (Poland) area. Activities for artificial 137Cs and 90Sr show moderate values. Statistically different values were found between the mean concentration of 90Sr and 137Cs in current (C) and two years old (C+2) needles of the first tree, whereas for potassium no significant difference was observed. For the second, fallen tree, no significant difference between the mean activity concentration in needles for C+1 and C+2 was found for each radionuclide, but much lower levels of 137Cs contamination were observed. Observed values of the aggregation coefficients for 137Cs and 90Sr are presented.
Źródło:
Nukleonika; 2006, 51,suppl.2; 59-67
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rapid production of 18F fluoride from 2-fluoroaniline via the 19F(n,2n)18F reaction using 14 MeV neutrons
Autorzy:
Mikołajczak, R.
Staniszewska, J.
Mikołajewski, S.
Rurarz, E.
Powiązania:
https://bibliotekanauki.pl/articles/147126.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
chemical and production yields
fluorine-18
radiochemical separation
(n,2n) reaction cross section
Opis:
No carrier-added 18F fluoride was produced via the 19F(n,2n)18F reaction by 14 MeV neutron irradiation of 2-fluoroaniline and subsequent extraction of the produced 18F fluoride ion with water. The fluoride was then purified by liquid chromatography on a Chromabond-NO2 column. The time required for all chemical procedures was about 1 h. The average chemical separation yield was about 70%. The 18F activity obtained after 3 hours of irradiation at a flux rate of 108 n cm-2s-1 after a necessary 20-min delay was equal to several kBq per gram of fluorine in a 2-fluoroaniline sample, in accordance with the theoretically expected value. Improvement of the 18F production yield can be achieved by increasing neutron fluxes. Neutron generators with 14 MeV neutron fluxes of the order of 1010 n cm-2s-1 can produce tens MBq of 18F, sufficient for whole-day work in biomedical applications. Our results show that 14 MeV neutron irradiation of 2-fluoroaniline is a low cost alternative for the production of this nuclide in the countries which do not posses either cyclotrons or electron linear accelerator facilities.
Źródło:
Nukleonika; 2002, 47, 1; 13-18
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of definitive methods based on radiochemical neutron activation analysis for the determination of selenium and arsenic in materials used in proficiency testing
Autorzy:
Chajduk, E.
Polkowska-Motrenko, H.
Dybczyński, R. S.
Powiązania:
https://bibliotekanauki.pl/articles/147273.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
selenium
arsenic
RNAA definitive methods
proficiency testing
Opis:
This article describes the use of two definitive methods for the determination of Se and As traces in biological materials intended for proficiency testing. Radiochemical neutron activation analysis (RNAA) definitive methods are based on reactor neutron activation with a very selective and quantitative post-irradiation separation of the indicator radionuclide by column chromatography, followed by γ-ray spectrometric measurement. Each of these methods has detection limit of the order of ng·g–1 or better, and yields accurate results. The expanded standard uncertainty for both methods is ca. 4%. Definitive RNAA methods were used for establishing assigned values for Se and As in materials employed in proficiency testing of “Plants” series.
Źródło:
Nukleonika; 2008, 53, suppl. 2; 49-54
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The kinetics of 1,1-dichloroethene (CCl2=CH2) and trichloroethene (HClC=CCl2) decomposition in dry and humid air under the influence of electron beam
Autorzy:
Nichipor, H.
Dashouk, E.
Yacko, S.
Chmielewski, A.
Zimek, Z.
Sun, Y.
Vitale, S.
Powiązania:
https://bibliotekanauki.pl/articles/148600.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
1,1-dichloroethene
trichloroethene
electron beam decomposition
theoretical model
kinetics calculation
Opis:
New experimental data related to the removal of C2H2Cl2 and C2HCl3 in dry and humid (300 ppm of H2O) air at atmospheric pressure and a temperature of 25°C under the influence of electron beam in the dose range 1 < D < 100 kGy are published. Taking into account these experimental data, theoretical models of the decomposition of both compounds and computer simulations were performed by the present authors to find the kinetics of such processes. The influence of active atoms Cl, O and OH radicals on the VOC degradation process has been established. The theoretical model of C2H2Cl2 degradation under the influence of electron beam in dry and humid air describes the C2H2Cl2 decay and formation of the main products like Cl2, COCl2, CO, CO2, HCl, HCOCl and C2H2Cl2O. The results of calculation of the kinetics of C2H2Cl2 decomposition were compared with data obtained experimentally for the C2H2Cl2 concentration range 321-2213 ppm. It was established that the relation between the rate constants of intermediate product decomposition: C2H2Cl3O Ţ C2H2Cl2O + Cl; (k1) C2H2Cl3O Ţ COCl2 + CH2C2; (k2) should be k1/k2 = 40. The theoretical model of C2HCl3 degradation under the influence of electron beam in dry and humid air describes the C2HCl3 decay and formation of the main products like Cl2, COCl2, CO, CO2, HCl, HCOCl and C2HCl3O. A detailed comparison of experimental and theoretical data for the C2HCl3 concentration 108-3206 ppm shows that the relation between the rate constants of intermediate product decomposition: C2HCl4O Ţ C2HCl3O + Cl; (k3) C2HCl4O Ţ COCl2 + CHCl2; (k4) should be k3/k4 =10. It was also found that O2+ ions have been formed in a gas mixture as a result of charge transfer process from N2+ ions, partly in excited form, which may lead to charge transfer to C2HCl3 and degradation of those particles. According to performed calculation, it can be stated that in humid air (300 ppm of H2O) VOC degradation is occurring mainly due to a chain reaction stimulated by Cl atoms, but also OH radicals are playing an important role. In the described gas mixture, the OH radicals are formed in the following reactions: O2+) + H2O + M Ţ (O2+)H2O + M O2+ (H2O) + H2O Ţ O2 + (H3O+)OH (H3O+)OH + H2O Ţ H3O+ + OH + H2O VOC degradation process under the influence of electron beam is more effective in humid air than in dry air for the same initial VOC concentration level. This conclusion is also supported by experimental data. --------------------------------------------------------------------------------
Źródło:
Nukleonika; 2003, 48, 1; 45-50
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of the magnetic field formation in cyclotron DC-72
Autorzy:
Gulbekian, G.
Ivanenko, I.
Filatov, O.
Franko, J.
Kukhtin, V.
Lamzin, E.
Samsonov, E.
Semchenkov, A.
Semchenkova, O.
Sytchevsky, S. E.
Dmitrev, S. N.
Powiązania:
https://bibliotekanauki.pl/articles/148354.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cyclotron
magnetic field measurements
magnetic field simulations
Opis:
A method of the magnetic field formation in the cyclotron DC-72 model (scale 1:5) is described. The cyclotron is planned to be built in Slovakia. The stages in the shimming of the cyclotron sectors and an automatic system designed for magnetic measurements are described. The data on the magnetic field measurements in the median plane of the cyclotron are presented. A brief description of a computer simulation model and an algorithm of fitting the required sector profiles is presented, as well as the data on the computer simulation of magnetic field distributions. The data on the magnetic field measurements and those on the computer simulations are compared and analyzed. Possible reasons of differences between the measured and simulated data are discussed. The results of the above mentioned computer simulations will be used for building a large facility - the cyclotron DC-72.
Źródło:
Nukleonika; 2003, 48, 4; 207-210
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Freeze-out process with in-medium nucleon mass
Autorzy:
Zschocke, S.
Csernai, L.
Molnar, E.
Manninen, J.
Nyiri, A.
Powiązania:
https://bibliotekanauki.pl/articles/148362.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
freeze-out
nucleon mass shift
chiral condensate
heavy-ion collision
Opis:
We investigate the kinetic freeze-out scenario of a nucleon gas through a finite layer. The in-medium mass modification of nucleons and its impact on the freeze-out process is studied. A considerable modification of the thermodynamical parameters temperature, flow-velocity, energy density and particle density has been found in comparison with evaluations which use a constant vacuum nucleon mass.
Źródło:
Nukleonika; 2006, 51,suppl.3; 43-46
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quasi-spherical superfast Z-pinch implosion for pellet irradiation
Autorzy:
Smirnov, V. P.
Grabovskii, E. V.
Zakharov, S. V.
Powiązania:
https://bibliotekanauki.pl/articles/146366.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Z-pinch
Z-pinch implosion
Opis:
New simulation results of the quasi-spherical implosion induced by a 40 MA current pulse are discussed. Results on a quasi-spherical wire array production and some experimental observations of an implosion are presented.
Źródło:
Nukleonika; 2012, 57, 2; 215-219
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł

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