Papers by Teresa Rzaca-urban
Zeitschrift für Physik A Hadrons and Nuclei, 1996
High-spin states in IS6Os have been populated by the 186W(aHe,4n)-reaction at 55MeV. The emitted ... more High-spin states in IS6Os have been populated by the 186W(aHe,4n)-reaction at 55MeV. The emitted 7radiation was detected with the OSIRIS spectrometer. The yrast band, for which the nucleus has a prolate shape, was found to terminate at U=18 +. The "),-ray intensity is then distributed between several irregular sequences. Different to other cases of band termination, the minimum in the total routhian surface corresponding to a collective shape is calculated to disappear in this spin region, although the available spin of the valence nucleons is far from being exhausted. A different structure, which is dominated by non-collective states becomes yrast.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998
A few accelerated ion beam requirements for in-beam e-γ spectroscopy are briefly reviewed as well... more A few accelerated ion beam requirements for in-beam e-γ spectroscopy are briefly reviewed as well as several features of the MP Tandem accelerator of IPN-Orsay and the accelerated ion-beam transport devices leading to the experimental area of in-beam e-γ spectroscopy. In particular, the main capabilities of the ion-sources, the ion pulsing system, the ion stripping and stabilizing devices as well
Magnetic dipole bands have been identified in 142,143,144Gd and 141Eu nuclei. The observed bands ... more Magnetic dipole bands have been identified in 142,143,144Gd and 141Eu nuclei. The observed bands are based on configurations with small oblate deformation involving high-Omega, h11/2 proton particles and low-Omega, h11/2 neutron holes. Information about the strength of the effective interaction between the constituent nucleons has been deduced using a semiclassical scheme of the coupling of two angular momentum vectors. The experimental results are compared with predictions of tilted axis cranking calculations. The transition from irregular dipole band in 144Gd to more regular ones in lighter Gd nuclei is observed.
Zeitschrift für Physik A Hadrons and Nuclei, 1997
Prompt γ radiation following spontaneous fission has been measured using the EUROGAM 2 array. Usi... more Prompt γ radiation following spontaneous fission has been measured using the EUROGAM 2 array. Using these data and newly developed analysis techniques a number of subjects were studied, which are briefly discussed. One of these subjects, shape transition in A≈100 Sr and Zr nuclei is discussed in more detail. Quadrupole moments were determined for rotational bands in the N=58,59,60,62 and 64 Sr and Zr isotopes. Deformation parameters, which increase from β 2 ≈ 0.1 at N=56 to β 2 ≈ 0.4 at N=64, suggest that in strontium and zirconium isotopes shape change happens gradually between N=56 and N=62 and is probably due to an occupancy of three or more deformation-driving orbitals of h 11/2 parentage.
Acta Physica Polonica Series B
Magnetic dipole bands have been identified in 142,143,144Gd and 141Eu nuclei. The observed bands ... more Magnetic dipole bands have been identified in 142,143,144Gd and 141Eu nuclei. The observed bands are based on configurations with small oblate deformation involving high-Omega, h11/2 proton particles and low-Omega, h11/2 neutron holes. Information about the strength of the effective interaction between the constituent nucleons has been deduced using a semiclassical scheme of the coupling of two angular momentum vectors. The experimental results are compared with predictions of tilted axis cranking calculations. The transition from irregular dipole band in 144Gd to more regular ones in lighter Gd nuclei is observed.
Progress in Particle and Nuclear Physics, 1997
... 1 , T. Rzaca-Urban 2 , HJ Jensen 1 , W. Gast 1 , A. Georgiev 1 , H. J??ger 1 , S. Utzelmann 1... more ... 1 , T. Rzaca-Urban 2 , HJ Jensen 1 , W. Gast 1 , A. Georgiev 1 , H. J??ger 1 , S. Utzelmann 1 , CA Ur 3 , GP Bolzonella 3 , D. Bazzacco 3 , S. Lunardi 3 , NH Medina 3 , R. Menegazzo 3 , CM Petrache 3 , MA Rizzuto 3 , C. Rossi-Alvarez 3 , G. De ... [10] W. NdZaiCWICG, R. "'yas aild A ...
Physical Review C, 2002
This work reports on the first observation of excited levels in the 139 I nucleus. Levels in 139 ... more This work reports on the first observation of excited levels in the 139 I nucleus. Levels in 139 I, populated in spontaneous fission of 248 Cm, were studied by means of prompt ␥-ray spectroscopy, using the EUROGAM2 array. The level scheme of 139 I obtained in this work shows patterns characteristic of a spherical vibrator, which result from a weak interaction of the 138 Te core with the odd proton. No signs of octupole correlations were observed in 139 I. The new data allow, for the first time systematic predictions to be made of energies and spins of states in the 137 Sb nucleus, helping the future studies of the r-process nuclei at the Zϭ50 line.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1999
ABSTRACT A brief introductory survey of γ-ray detector arrays and in-beam electron spectrometers ... more ABSTRACT A brief introductory survey of γ-ray detector arrays and in-beam electron spectrometers developed during the last three lustra is followed by a broad discussion of the general requirements for single and multiple in-beam e-γ spectrometers. A detailed analysis is made of a few important tools for reducing the low-energy electron background (i.e. simultaneous E-Bρ selection, true and random coincidence rates, EM static fields around the target region). This survey and discussion are illustrated by the results of several in-beam e-γ measurements dealing with nuclear spectroscopic investigations of a few medium and heavy nuclei.
The European Physical Journal A, 2000
Excited states in the neutron-rich, N=84 nuclei 134 Sn, 136 Te and 138 Xe, populated in the spont... more Excited states in the neutron-rich, N=84 nuclei 134 Sn, 136 Te and 138 Xe, populated in the spontaneous fission of 248 Cm, were studied to medium spins using the EUROGAM2 array. OXBASH code calculations support the experimental identification of maximum aligned configurations in these isotopes. Empirical shell model calculations agree with the proposed excitation energy of the neutron h 9/2 excitation in the 132 Sn region. A discrepancy between the observed and calculated excitation energy of the I π =12 + level in 136 Te indicates possible admixtures of collective excitations in this nucleus. Clear signs of collective excitations are observed in 138 Xe.
The European Physical Journal A, 2002
Excited states in the 134 Sb nucleus, populated in the β −-decay of 134 Sn, have been studied at ... more Excited states in the 134 Sb nucleus, populated in the β −-decay of 134 Sn, have been studied at the mass separator OSIRIS. The 134 Sn activity was produced via fast neutron-induced fission of 238 U target. A main result was the discovery of a very low-lying first-excited state of 134 Sb, at 13 keV, which has led to a strong revision of the level scheme. The new results are compared with different theoretical calculations and with the known data for the analogous neutron and proton two-particle nucleus in the 208 Pb region. On the basis of this comparison, the energy of the (πg 7/2 νf 7/2) 7 − isomer is estimated to be about 250 keV, some 100 keV lower than previously reported.
The European Physical Journal A, 2001
The 137 I nucleus, populated in the spontaneous fission of 248 Cm has been studied by means of pr... more The 137 I nucleus, populated in the spontaneous fission of 248 Cm has been studied by means of prompt γ-ray spectroscopy using the EUROGAM2 array. Medium-spin yrast excitations in 137 I were observed for the first time. The experimental level scheme is compared to the shell model calculation with modified Kuo-Herling interaction. The theoretical predictions differ significantly from the experimental results, indicating that the excitation pattern in 137 I deviates significantly from the shell model scheme.
Physical Review C, 1995
ABSTRACT
Acta Physica Polonica B, 2003
The previously known level scheme of 141Eu nucleus was revised and substantially extended. Three ... more The previously known level scheme of 141Eu nucleus was revised and substantially extended. Three dipole cascades, characterized by large B(M1)/B(E2) ratios, have been found. Spin and parity assignments were based on the angular distribution ratios and linear polarizations of gamma -rays. The experimental results have been compared with the calculations of Tilted Axis Cranking (TAC) model.
Physical Review C, 2000
... N. Schulz, M. Bentaleb * , and E. Lubkiewicz Institut de Recherches Subatomiques UMR7500, C... more ... N. Schulz, M. Bentaleb * , and E. Lubkiewicz Institut de Recherches Subatomiques UMR7500, CNRS-IN2P3 et Université Louis Pasteur, 67037 Strasbourg, France. ... A 300, 133 1981 . SJ Zhu et al., J. Phys. G 23, L77 1997 . M. Bentaleb et al., Z. Phys. A 354, 143 1996 . ...
Applied Surface Science, 2014
ABSTRACT
Journal of Industrial and Engineering Chemistry, 2014
ABSTRACT The adsorption and electrokinetic properties as well as the stability of the AST71 suspe... more ABSTRACT The adsorption and electrokinetic properties as well as the stability of the AST71 suspension in the absence and presence of polyvinyl alcohol (PVA) were examined. AST71 is a mixed oxide of alumina, silica and titania. All measurements were carried out as a function of solution pH and the polymer molecular weight. The pooled result analysis showed that the PVA adsorption amount strongly depends on the solution pH. The higher solution pH value is, the more polymer macromolecules are adsorbed on the solid surface. This dependence is mainly associated with the PVA chain conformation. The adsorption of polyvinyl alcohol changes the stability of the AST71 suspension, but only in the solution of pH 9. Under these conditions the system without PVA is unstable, which is connected with the isoelectric point of the solid particles. In the presence of the polymer the electrosteric stabilization occurs.
Journal of hazardous materials, Jan 11, 2015
The main goal of experiments was determination of solution pH and contents of anionic groups in p... more The main goal of experiments was determination of solution pH and contents of anionic groups in polyacrylamide (PAM) macromolecules on the stability mechanism of chromium (III) oxide suspension. The spectrophotometry, potentiometric titration, microelectrophoresis, viscosimetry and turbidimetry were applied. They enabled determination of polymer adsorbed amount, surface and diffusion charges of solid particles with and without PAM, thickness of polymer adsorption layer, macromolecule dimensions in the solution and stability of the Cr2O3 - polymer systems, respectively. It was found that adsorption of anionic PAM decreases and thickness of polymeric adsorption layer increases with the increasing pH. Slightly higher adsorption was obtained for the PAM samples containing a greater number of carboxyl groups. At pH 3 and 9 insignificant deterioration of stability conditions of Cr2O3 particle covered with polyacrylamide was observed (neutralization of solid positive charge by the adsorbed...
Immunopharmacology, 1986
The effects of an inorganic selenium salt on phagocytic functions of human neutrophilic granulocy... more The effects of an inorganic selenium salt on phagocytic functions of human neutrophilic granulocytes from donors with a low activity of glutathione peroxidase have been investigated. Granulocytes were exposed for 60 min in vitro to sodium selenite in two physiological concentrations (100 and 200 ng Se/ml) and one unphysiologically high concentration (2000 ng/ml). The spontaneous and chemotactic migration, the nitroblue tetrazolium reduction, the phagocytosis of fluorescein-labeled yeast particles and the intracellular killing of staphylococci were then studied in such granulocytes and compared to control cells, which had not been exposed to selenium. The migration and nitroblue tetrazolium reduction abilities of granulocytes were not affected by selenium exposure. The phagocytic and bactericidal activities were significantly increased in granulocytes exposed to selenium in physiological concentrations. However, at 2000 ng Se/ml these activities were found to be equal to or lower tha...
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Papers by Teresa Rzaca-urban