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Tytuł:
Low energy electrons in non-polar liquids
Autorzy:
Schmidt, W.
Illenberger, E.
Powiązania:
https://bibliotekanauki.pl/articles/148513.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electrons
energetics
kinetics
non-polar liquids
lifetime
Opis:
The properties of excess electrons in non-polar liquids have been studied for more than 30 years. Here, pertinent results are reviewed and discussed with respect to the possibility of studying electron-molecule interactions with low energy electrons in the liquid phase. Some new results on the estimate of the electron lifetime in the delocalized state in liquid hydrogen are presented.
Źródło:
Nukleonika; 2003, 48, 2; 75-82
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mössbauer study of the El Hammami olivine-bronzite meteorite
Autorzy:
Zarek, W.
Popiel, E.
Tuszyński, M.
Teper, E.
Powiązania:
https://bibliotekanauki.pl/articles/147220.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
meteorite
XRD
scanning electron microscopy
Mössbauer spectroscopy
kamacite
Opis:
The phase composition of the El Hammami meteorite was investigated by X-ray, magnetostatic, Mössbauer effect and environmental scanning electron microscopy methods. Performed investigations indicated that this meteorite consists of aluminosilicates, olivine (Mg,Fe)2SiO4, pyroxene (Ca,Mg,Fe)SiO3, kamacite (bcc Fe-Ni alloy) and troilite (FeS). Some inclusions of Ti and Cr were observed by scanning electron microscopy. The concentration of Ni in kamacite was determined by comparison of the Mössabauer spectra of Fe-Ni phase in the meteorite with those for synthetic bcc Fe-Ni alloys (5, 10, 25% Ni).
Źródło:
Nukleonika; 2004, 49,suppl.3; 59-62
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mössbauer study of the Heusler-type Fe2MAl compounds for M = V, Cr, Fe, Co, Ni
Autorzy:
Popiel, E.
Zarek, W.
Tuszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/147224.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Heusler alloys
Mössbauer spectroscopy
site preference
magnetostatic measurements
Opis:
The crystal structure and magnetic properties of Fe2MAl compounds for M = V, Cr, Fe, Co and Ni were investigated by X-ray, magnetostatic and Mössbauer effect methods. It was found that the investigated compounds possess not perfectly ordered fcc structure of the L21-type. With increasing number of 3d electrons of M component the transition from the paramagnetic to ferromagnetic behaviour follows. Mössbauer spectra were analysed by a hyperfine field distribution method. They are characterictic of the ferromagnetic phase for M = Fe, Co and Ni and indicated the early observed preference of these atoms for the Fe sites.
Źródło:
Nukleonika; 2004, 49,suppl.3; 49-52
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transient induced molecular negative ions formed in cold electron collisions with polarized molecules
Autorzy:
Toader, E. I.
Graham, W. G.
Powiązania:
https://bibliotekanauki.pl/articles/147748.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
interaction processes in plasmas
new negative molecular ions
Opis:
Using a relatively simple semiclassical model, it is shown that transient, induced molecular negative ions (TIMNI), are produced through a potential barrier interaction between cold electron collisions and polarizable molecules in plasma. Such new negative ions lead to radio-frequency absorption in such discharges. The calculated radio-frequency absorption frequencies are consistent with earlier experimental measurements.
Źródło:
Nukleonika; 2008, 53, 3; 123-126
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A sequential procedure for determining 238Pu, 239+240Pu, 241Am, 90Sr, U and Th activities in soils and peats from Spitsbergen
Autorzy:
Łokas, E.
Mietelski, J. W.
Kleszcz, K.
Tomankiewicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/148392.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
activity concentration
activity ratio 238Pu/239+240Pu
radioactive contamination
sequential radiochemical procedure
Opis:
This paper presents results of application of a sequential radiochemical procedure for multi-elemental analyses for samples collected in the Arctic environment. The levels of activity of 238Pu, 239+240Pu, 241Am, 90Sr and the content of natural radioisotopes (238U, 234U and 232Th, 230Th) were investigated in soils and peats in the proglacial zone of the Werenskiold glacier and on the strandflat in the vicinity of the glacier. Results on activity concentration shows general low level of radioactive contamination. Procedure was checked using reference materials. Reasonable recoveries were obtained for almost all analyzed radionuclides except for uranium. Further work is needed to improve this stage.
Źródło:
Nukleonika; 2010, 55, 2; 195-199
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isotope effects of gallium and indium in cation exchange chromatography
Autorzy:
Dembiński, W.
Herdzik, I.
Skwara, W.
Bulska, E.
Wysocka, A.
Powiązania:
https://bibliotekanauki.pl/articles/146163.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
isotope separation
chemical isotope effect
ion-exchange chromatography
Opis:
The isotope effects of gallium (69/71Ga) and indium (113/115In) have been determined in the system: strong cation exchanger (Dowex 50-X8)/HCl. The sings of gallium and indium effects were opposite, i.e., the heavier isotope of gallium was fractionated into the resin phase, while the heavy isotope of indium was fractionated into the liquid phase. The values of unit separation gains were found to be +3.0 ´ 10-5 for gallium and –2.0 ´ 10-4 for indium. A possible explanation of the effects is proposed.
Źródło:
Nukleonika; 2006, 51, 4; 217-220
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal order and magnetic properties of Fe2.4V0.6Al alloy studied by magnetostatic and Mössbauer methods
Autorzy:
Popiel, E.
Zarek, W.
Kapuśniak, Z.
Tuszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/148801.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
magnetic clusters
Mössbauer spectroscopy
relaxation time
Opis:
Performed investigations showed that the magnetic properties of the Fe2.4V0.6Al alloy markedly depend on the degree of atomic order of its cubic structure. The atomically disordered alloy with A2 (bcc) type structure exhibits ferromagnetic properties. Its Mössbauer spectra can be described by the hyperfine field distribution connected with various local environments of Fe atoms. Alloys with B2 (sc) and DO3 (fcc) type structure do not exhibit magnetic transition above 4.2 K. High values of the magnetization and its strongly non-linear variation with magnetic field intensity in a wide temperature range suggest the presence of magnetic iron clusters in these alloys. Superparamagnetic relaxation times of the order of 10-9 s and 5 × 10-8 s correspond to the largest magnetic clusters with a magnetic moment of 4 × 103 žB in B2 and 104 žB in DO3-type structure, respectively. Mössbauer spectra of these alloys confirm lack of the magnetic order and also suggest the presence of the Fe magnetic clusters with those relaxation times. It was shown that the increase of atomic order of the crystal structure causes formation of the Fe magnetic clusters and disappearing of the magnetic order.
Źródło:
Nukleonika; 2003, 48,suppl.1; 65-70
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Electron paramagnetic resonance (EPR) study of the short - living radicals generated thermally in phosphorylated maize starch with different amounts of amylose
Autorzy:
Bidzińska, E.
Dyrek, K.
Kruczała, K.
Szczygieł, J.
Wenda, E.
Błaszczak, W.
Fornal, J.
Powiązania:
https://bibliotekanauki.pl/articles/147482.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
carbon centred radicals
electron paramagnetic resonance (EPR) spectroscopy
PBN spin trap
starch phosphates
thermal treatment
Opis:
Quantitative electron paramagnetic resonance (EPR) spectroscopy was used for the determination of a number and properties of short-living radicals generated thermally in maize starch with various amounts of amylose. The EPR spectra of radical adducts with N-tert-butyl-α-phenylnitrone (PBN) spin trap reveal the presence of three types of radicals of mobility related with their localization in the zones of various degree of crystallinity. Hylon VII, which represents a matrix with a high content of amylose, offers better conditions for free rotation of radical species, whereas waxy maize, containing almost exclusively amylopectin, exhibits more restricted dynamics.
Źródło:
Nukleonika; 2013, 58, 3; 429-433
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A radiographic facility at the Soltan Institute for Nuclear Studies (SINS) at Świerk, Poland
Autorzy:
Bigolas, J.
Drabik, W.
Pławski, E.
Wysocka-Rabin, A.
Powiązania:
https://bibliotekanauki.pl/articles/147478.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
linear accelerator
electron RF accelerator
photon beam
radiography
Opis:
This paper describes the 6 MeV linac electron accelerator facility now operating at SINS, Świerk, Poland. The accelerator can work in both the electron or X-ray photon mode. The photon beam may be used for non-destructive radiographic investigations on a laboratory scale and, with some modifications, for industrial purposes, as well. As the accelerator's removable tungsten e/X converter is placed outside, the beam vacuum window, an external electron beam is also accessible. The design stages of the accelerator's construction are described, and examples of measurements and radiographic pictures are also presented.
Źródło:
Nukleonika; 2006, 51, 2; 131-135
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The behavior of amorphous alloys under swift heavy ion irradiation at room temperature
Autorzy:
Didyk, A.
Hofman, A.
Savin, V.
Semina, V.
Hajewska, E.
Szteke, W.
Starosta, W.
Powiązania:
https://bibliotekanauki.pl/articles/148691.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
amorphous alloy
heavy ion irradiation
sputtering
surface structure
swelling
Opis:
Experimental results of irradiation effects by heavy ions with high inelastic energy losses at the surfaces of some amorphous alloys are presented. It was shown that all studied alloys strongly swelled: up to 15% for Ni58Nb42 under irradiation with the 305 MeV 86Kr ion at a fluence of 1015 ion/cm2. Besides, the sputtering (evaporation) process takes place, too. Calculations of the temperatures on the ion trajectory axis were presented. It was shown that the calculated temperatures are higher than the melting temperature and the evaporation temperature, too. From these findings we can conclude that the sputtering (evaporation) of atoms in amorphous alloys is present.
Źródło:
Nukleonika; 2005, 50, 4; 149-152
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Activity ratios of thorium isotopes in living species compared with other environmental samples
Autorzy:
Kierepko, R.
Mietelski, J. W.
Gaca, P.
Tomankiewicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/146760.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
activity ratio 228Th/232Th
activity ratio 230Th/232Th
Opis:
The paper presents the results of alpha spectrometric measurements of 228Th/232Th and 230Th/232Th activity ratios for many samples of some living species analyzed within last years in our laboratory within different projects. The results were compared with typical values for soil or other non-biological samples. All results were obtained by means of alpha spectrometry.
Źródło:
Nukleonika; 2008, 53, 1; 27-30
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of the use of GEANT4 and MCNPX Monte Carlo codes for calculations of the depth-dose distributions in water for the proton therapy of eye tumours
Autorzy:
Grządziel, M.
Konefał, A.
Zipper, W.
Pietrzak, R.
Bzymek, E.
Powiązania:
https://bibliotekanauki.pl/articles/147530.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
depth-doses
GEANT4
MCNPX
therapeutic protons
Opis:
Verification of calculations of the depth-dose distributions in water, using GEANT4 (version of 4.9.3) and MCNPX (version of 2.7.0) Monte Carlo codes, was performed for the scatterer-phantom system used in the dosimetry measurements in the proton therapy of eye tumours. The simulated primary proton beam had the energy spectra distributed according to the Gauss distribution with the cut at energy greater than that related to the maximum of the spectrum. The energy spectra of the primary protons were chosen to get the possibly best agreement between the measured relative depth-dose distributions along the central-axis of the proton beam in a water phantom and that derived from the Monte Carlo calculations separately for the both tested codes. The local depth-dose differences between results from the calculations and the measurements were mostly less than 5% (the mean value of 2.1% and 3.6% for the MCNPX and GEANT4 calculations). In the case of the MCNPX calculations, the best fit to the experimental data was obtained for the spectrum with maximum at 60.8 MeV (more probable energy), FWHM of the spectrum of 0.4 MeV and the energy cut at 60.85 MeV whereas in the GEANT4 calculations more probable energy was 60.5 MeV, FWHM of 0.5 MeV, the energy cut at 60.7 MeV. Thus, one can say that the results obtained by means of the both considered Monte Carlo codes are similar but they are not the same. Therefore the agreement between the calculations and the measurements has to be verified before each application of the MCNPX and GEANT4 codes for the determination of the depth-dose curves for the therapeutic protons.
Źródło:
Nukleonika; 2014, 59, 2; 61-66
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an automation system for iodine-125 brachytherapy seed encapsulated by Nd:YAG laser welding
Autorzy:
Somessari, S. L.
Feher, A.
Sprenger, F. E.
Rostelato, M. E. C. M.
da Costa, F. E.
Calvo, W. A. P.
Powiązania:
https://bibliotekanauki.pl/articles/147664.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iodine-125 seeds
prostate cancer
brachytherapy
Nd:YAG laser welding
Opis:
The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at Institute for Nuclear and Energy Research, Săo Paulo, Brazil (IPEN-CNEN/SP) imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a programmable logic controller (PLC), a stepper motor, an Nd:YAG laser welding machine and a supervisory. The statistical repeatability of correctly encapsulated sealed sources with this automation system is greater than 95 per cent.
Źródło:
Nukleonika; 2011, 56, 4; 369-374
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent measurements of soft X-ray emission from the DPF-1000U facility
Autorzy:
Surała, W.
Sadowski, M. J.
Paduch, M.
Zielinska, E.
Tomaszewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/148171.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
X-ray emission
X-ray images
gas puffing
filaments
hot spots
Opis:
Soft X-ray imaging is a very useful diagnostic technique in plasma-focus (PF) experiments. This paper reports results of four experimental sessions which were carried out at the DPF-1000U plasma-focus facility in 2013 and 2014. Over 200 discharges were performed at various experimental conditions. Measurements were taken using two X-ray pinhole cameras with a line of sight perpendicular to the z-axis, at different azimuthal angles (about 20° and 200°), and looking towards the centre of the PF-pinch column. They were equipped with diaphragms 1000 μm or 200–300 μm in diameter and coated with filters of 500 μm Al foil and 10 μm Be foil, respectively. Data on the neutron emission were collected with silver activation counters. For time-resolved measurements the use was made of four PIN diodes equipped with various fi lters and oriented towards the centre of the PF-column, in the direction perpendicular to the electrode axis. The recorded X-ray images revealed that when the additional gas-puff system is activated during the discharge, the stability of the discharge is improved. The data collected in these experiments confi rmed the appearance of a filamentary fi ne structure in the PF discharges. In the past years the formation of such fi laments was observed in many Z-pinch type experiments. Some of the recorded X-ray images have also revealed the appearance of the so-called hot- -spots, i.e. small plasma regions of a very intense X-ray emission. Such a phenomenon was observed before in many PF experiments, e.g. in the MAJA-PF device, but it has not been investigated so far in a large facility such as the DPF-1000U. The time-resolved measurements provided the evidence of a time lapse between the X-ray emission from plasma regions located at different distance from the anode surface. The formation of distinct ‘hot-spots’ in different instants of the DPF-1000U discharge was also observed.
Źródło:
Nukleonika; 2015, 60, 2; 303-308
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł

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