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Tytuł:
Impurity studies for the ITER half-field ICRF heating scenarios in hydrogen plasmas on JET
Autorzy:
Czarnecka, A.
Lerche, E.
Ongena, J.
Van Eester, D.
Figueiredo, A. C. A.
Coffey, I. H.
Zastrow, K. -D.
Powiązania:
https://bibliotekanauki.pl/articles/147692.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
tokamak
impurities
ICRF heating
ITER scenario
VUV plasma spectroscopy
Opis:
Two ion cyclotron range of frequencies (ICRF) heating scenarios, proposed for the non-activated half-B0 phase of ITER in hydrogen plasmas, were investigated on the JET tokamak. This paper we present a detailed study of the impurity content in plasma when the fundamental H and the 2nd harmonic 3He ICRF heating scenarios are realized. The ICRF conditions for those heating scenarios on ITER - i.e. the frequency of 42 MHz for the fundamental H and 53 MHz for the 2nd harmonic 3He heating, and the magnetic field B0 = 2.65 T – were closely reproduced in dedicated experiments on JET. The impurity content of the plasma was determined by means of the spectroscopy in the VUV range. The release of C and Ni impurities during the ICRF heating is presented as a function of the total ICRF heating power supplied in those heating scenarios. The contribution of the Ni impurity to the effective charge of the plasma, Zeff, and the plasma dilution are estimated. We find that for the 3He ICRF heating scenario the impurity content and the plasma energy loss through radiation was higher than for the fundamental hydrogen heating scenario.
Źródło:
Nukleonika; 2012, 57, 1; 25-30
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of cerium extraction by TBP and TODGA using a rotating diffusion cell
Autorzy:
Bromley, M. A.
Boxall, C.
Powiązania:
https://bibliotekanauki.pl/articles/148471.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
SACSESS
TBP
TODGA
rotating diffusion cell (RDC)
separation
extraction
Opis:
For the study of the coupled interfacial-mass transfer kinetics of, inter alia, TBP, TODGA, CyMe4-BTBP and CyMe4-BTPhen based solvent extraction processes, a new rotating diffusion cell (RDC) apparatus has been established at Lancaster University. RDC studies of Ce(IV)/TBP and Ce(III)/TODGA extraction systems have been undertaken in order to improve the understanding of the chemical and kinetic processes involved. In each case, an interesting dependency on local hydrodynamics at the solution phase boundary with results suggesting that the organic extractant molecules migrate into the aqueous phase in order to capture Ce.
Źródło:
Nukleonika; 2015, 60, No. 4, part 2; 859-864
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study about the measurement method of the homogeneity of radioactivity along an iridium-192 wire used in brachytherapy
Autorzy:
Costa, O. L.
Calvo, W. A. P.
Zeituni, C. A.
Rostelato, M. E. C. M.
Moura, J. A.
Feher, A.
Souza, C. D.
Somessari, S. L.
Powiązania:
https://bibliotekanauki.pl/articles/148238.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iridium-192
iridium wire
low dose rate brachytherapy
quality control
cancer treatment
radioactive sources production
Opis:
The Nuclear and Energy Research Institute has produced, since 1998, iridium-192 wires used in low dose rate brachytherapy. In the paper the authors studied the influence of wire profile on the homogeneity distribution of radioactivity of iridium-192 along the wire. The authors propose the improvements in the quality control procedure that will provide more accurate measurement data and suggest changes in control devices.
Źródło:
Nukleonika; 2014, 59, 1; 37-39
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:
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:
Radiation processing of detergents and possible environmental benefits
Autorzy:
Borrely, S. I.
Romanelli, M. F.
Pereira, M. C. C.
da Silva, G. P.
Mesquita, L. C. A.
de Moraes, M. C. F.
Powiązania:
https://bibliotekanauki.pl/articles/148020.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
EB irradiadion
anionic surfactants
effluent
Vibrio fischeri
Daphnia similis
Opis:
Detergents at waters inducing negative changes for biological degradability and water general quality. Some authors have evidenced a considerable amount of anionic surfactant and toxic effects into natural water and effluents related to detergents. The objective of the study was to apply electron irradiation for reducing toxicity, and for degradation of surfactants. To quantify surfactant LAS determination as MBAS (metylene blue active substances) was applied. The capacity of radiation to reduce surfactants was evidenced for real effluent and for water solution containing sodium dodecyl sulfate, linear alkylbenzene sulfonate (LAS), separately. An electron beam accelerator (EBA) 1.5 MeV was the radiation source. Anionic surfactant solutions as well as real effluents resulted in less toxic samples after irradiation. Toxicity was evaluated for Vibrio fischeri and Daphnia similis. An important decline of total anionic surfactant was observed after irradiation to doses: 6.0 kGy and 20 kGy (surfactant in water solutions and effluents, respectively). To conclude, EBA irradiations accounted for 88% to 96% less toxic surfactants solutions and effluents and 68% to 96% for MBAS compounds decomposition.
Źródło:
Nukleonika; 2009, 54, 2; 61-64
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:
Ultrafast X-ray introspective imaging of metallic objects using a Plasma Focus
Autorzy:
Moreno, C. H.
Clausse, A.
Martínez, J. F.
Llovera, R.
Tartaglione, A.
Powiązania:
https://bibliotekanauki.pl/articles/146595.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dense plasmas
electrical discharges
plasma focus
X-ray imaging
X-rays
Opis:
A compact-chamber 4.7 kJ, 30 kV, Plasma Focus operated in deuterium was used as a ultrafast high intensity radiation source for introspective radiographic imaging of metallic objects. The samples to be imaged were located outside the Plasma Focus chamber, about 1 m away from the chamber wall. A high-sensitivity, fast-response commercial radiographic film was used as a X-ray detector. Experimentally obtained images are presented showing a very high penetration power of the X-ray beam, demonstrating that the presented compact-chamber Plasma Focus is suited for introspective visualisation of pieces manufactured on metal.
Źródło:
Nukleonika; 2001, 46, suppl. 1; 33-34
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation curing of silica for silica-rubber composites
Autorzy:
Dondi, D.
Palamini, C.
Pepori, F.
Buttafava, A.
Galinetto, P.
Faucitano, A.
Powiązania:
https://bibliotekanauki.pl/articles/148026.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radiation
silica-rubber composites
modified silica
Opis:
The functional modification of silica samples based on the reaction of “grafting” of polybutadiene olygomers carried out by gamma-irradiation in the presence of air at room temperature has been investigated. The yield of grafted PB reaches a maximum at doses of about 30 kGy, then decreases as a consequence of the oxidative degradation. The reaction is accompanied by the build up of carbonyls and peroxides up to 0.1 moles/kg and it leads to a rapid consumption of the double bonds concentration as determined by both FTIR and Raman spectroscopy. The results of the EPR analysis are diagnostic of a mechanism of immobilization of the olygomer based on cross-linking of polybutadiene which is initiated by the SiO2 radiolytic species. Depending on the nature of the SiO2 species, the mechanism of initiation leads to immobilized PB either really grafted to the silica surface or simply physically absorbed.
Źródło:
Nukleonika; 2009, 54, 2; 71-75
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural, magnetic, and Mössbauer effect studies of bornite
Autorzy:
Przewoźnik, J.
Żukrowski, J.
Gondek, Ł.
Lemański, A.
Kapusta, C.
Piestrzyński, A.
Powiązania:
https://bibliotekanauki.pl/articles/147362.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
bornite
hyperfine interactions
magnetic properties
Mössbauer spectroscopy
Opis:
The results of a combined study of bornite with Mossbauer spectroscopy, X-ray diffraction and DC magnetometry are reported. The orthorhombic crystallographic structure of the mineral is observed at 15 K and 300 K. It exhibits an increase of the orthorhombic distortion with decreasing temperature. Magnetic susceptibility shows a Curie-Weiss like behaviour between 230 K and 380 K corresponding to the effective magnetic moment of 7.2(3) mi B per formula unit. The material undergoes a transition to an antiferromagnetic-like state at 75 K. Mossbauer spectra at the paramagnetic range are doublets with a small quadrupole splitting and the isomer shift corresponding to a high spin Fe3+ state. Upon magnetic ordering, a coexistence of the paramagnetic doublet with a broadened magnetic sextet is observed indicating an inhomogeneous character of the magnetic transition. The hyperfine field of 350 kOe at 4.2 K is much lower than that observed for a high spin Fe3+ in oxides (510 kOe) which is attributed to covalence effects and a possible copper contribution to the effective magnetic moment of the compound.
Źródło:
Nukleonika; 2013, 58, 1; 43-46
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the new Monte Carlo code AlfaMC to the calibration of alpha-particle sources
Autorzy:
Jurado Vargas, M.
Fernández Timón, A.
García Orellana, C.
Powiązania:
https://bibliotekanauki.pl/articles/148497.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
alpha-particle spectrometry
code AlfaMC
Monte Carlo simulation
scattering and self-absorption
Opis:
Measurements of α-particle sources require corrections to the counting rate due to scattering and self- -absorption in the source and the backing material. In this study, we describe a simple procedure to estimate these corrections using the new Monte Carlo code AlfaMC to consider the effects of scattering and self-absorption conjointly, and so to determine the activity of α emitters. The procedure proposed was applied to 235UO2 sources deposited on highly polished platinum backings. In general, the dependence of the efficiency with source thickness was in good agreement with a simple model considering a linear and a hyperbolic behavior for thin and thick sources, respectively, although significant deviations from this model were found for very thin sources. For these very thin sources, the Monte Carlo simulation revealed to be as a required method in the primary calibration of α-particle sources. The efficiency results obtained by simulation with AlfaMC were in agreement with available efficiency data.
Źródło:
Nukleonika; 2015, 60, No. 3, part 2; 651-655
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of lithium titanate by sol-gel method
Autorzy:
Deptuła, A.
Łada, W.
Olczak, T.
Sartowska, B.
Chmielewski, A.
Alvani, C.
Casadio, S.
Powiązania:
https://bibliotekanauki.pl/articles/147573.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Opis:
Medium sized spherical particles of Li2TiO3 (with diameters below 100 mi m) can be prepared from peroxy lithium titanate solution (stabilized with citric acid) by a modified INCT variant of the sol-gel process. The process consists of the following main steps: (I) formation of aqueous phase emulsion in 2-ethylhexanol-1 containing the surfactants 1v/o SPAN-80 and 1v/o Ethomen S-15 (EH); (II) gelation of emulsion drops by extraction of water with partially dehydrated EH; (III) filtration and washing with carbon tetrachloride or acetone; (IV) non-destructive thermal treatment. The tritium release from sol-gel process preparation of Li2TiO3 micro-spheres was found very close to that observed for other traditional material however, the new process is more efficient than other processes because of the morphology of the sintered specimens.
Źródło:
Nukleonika; 2001, 46, 3; 95-100
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:
Biokinetics and radiation dosimetry for [4-14C] cholesterol in humans
Autorzy:
Marcato, L. A.
Hamada, M. M.
de Mesquita, C. H.
Powiązania:
https://bibliotekanauki.pl/articles/146882.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
[4-14C]-cholesterol
internal dosimetry
dosimetric model
medical internal radiation dose (MIRD)
Opis:
This study proposes a biokinetic model for using in the assessment of the internal dose received by human subjects administered intravenously or orally with [4-14C]-cholesterol. The proposed model includes three systemic pools representing the short-term (T1/2 = 1 d), intermediate-term (T1/2 = 16 d) and long-term (T1/2 = 78 d) physiological exchanges and two excretion pathways: urine and feces. To validate the model, the predicted excretion and absorption of cholesterol was compared with that described in the literature. The radiometric doses were calculated in function of the phantom body mass (M) applying MIRD (medical internal radiation dose) protocol with ANACOMP software. The effective dose coefficients for oral administration were: 2.93×10–10 Sv.Bq–1 (73.3 kg); 3.84×10–10 Sv.Bq–1 (56.8 kg); 6.74 × 10–10 Sv.Bq–1 (33.2 kg) and 7.72 × 10–10 Sv.Bq–1 (19.8 kg). To determinate the dose for intermediate body mass M the polynomial interpolation can be used: Sv.Bq–1 (kg) = 6 × 10–15M3 – 8 × 10–13M2 + 2 × 10–11M + 6 × 10–10 (R2 ≅ 1). In the same way, for intravenous administration were: 3.72 × 10–10 Sv.Bq–1 (73.3 kg); 4.87 × 10–10 Sv.Bq–1 (56.8 kg); 8.49 × 10–10 Sv.Bq–1 (33.2 kg); 1.26 × 10–9 Sv.Bq–1 (19.8 kg). Similarly, for any M body mass: Sv.Bq–1 (kg) = –4 × 10–15M3 + 9 × 10–13M2 – 7 × 10–11M + 2 × 10–9 can be used.
Źródło:
Nukleonika; 2012, 57, 4; 607-613
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response surface methodology for cobalt removal from aqueous solutions using Isparta pumice and zeolite 4A adsorbents
Autorzy:
Çiçek, E.
Cojocaru, C.
Zakrzewska-Trznadel, G.
Jaworska, A.
Harasimowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/146766.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
zeolite
Isparta pumice
adsorption
radioactive waste
cobalt ions
response surface methodology
Opis:
In this study, the adsorption of non-radioactive cobalt ions from aqueous solutions onto Isparta pumice and zeolite 4A sorbents was investigated. Both adsorbent materials have been activated at 873 K for 2 h prior to adsorption experiments in batch mode. The maximum removal efficiencies of 90% and 99% have been obtained experimentally using Isparta pumice and zeolite 4A, respectively. In addition, the experiments with radioactive 60Co were performed to test zeolite ability to remove radioactive compounds. Likewise, the response surface methodology (RSM) has been applied to develop the predictive regression models to describe the adsorption of cobalt and radiocobalt ions onto zeolite 4A and Isparta pumice. The results indicated that zeolite 4A as well as Isparta pumice could be used as the efficient sorption materials for cobalt and radiocobalt ions removal.
Źródło:
Nukleonika; 2008, 53, suppl. 2; 121-128
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł

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