| 1. |
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| 2. |
- Niemi, MEK, et al.
(author)
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- 2021
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swepub:Mat__t
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| 3. |
- Kanai, M, et al.
(author)
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- 2023
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swepub:Mat__t
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| 4. |
- Bentley, MA, et al.
(author)
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High-spin spectroscopy of natural and unnatural parity states in the mirror-pair V-45/Ti-45
- 2006
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 73:2: 024304
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Journal article (peer-reviewed)abstract
- High-spin states in the proton-rich nucleus V-45 have been identified for the first time. A comprehensive gamma-ray decay scheme has been established following an experiment performed at the Vivitron accelerator at IReS Strasbourg by using the Euroball gamma-ray detector array coupled to the Neutron Wall and Euclides detector arrays. The natural (negative-) parity scheme is identified up to the f(7/2) band termination in addition to a positive-parity collective structure based on a d(3/2) particle-hole excitation. Comparison of this scheme with that of the mirror partner, Ti-45, has yielded detailed information on the variation of Coulomb energy as a function of excitation energy and angular momentum. This is the first time that such an analysis has been performed for a collective structure built on a cross-shell excitation. Comparison of the observed Coulomb energies with those predicted by large-scale shell-model calculations is presented. In this case, unusually, the calculations do not fare as well as for heavier nuclei in the shell. In addition, stark differences between the two nuclei are observed for the decay intensities of the parity-changing E1 decays that de-excite the positive-parity deformed bands.
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| 5. |
- Caamano, M, et al.
(author)
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Isomers in neutron-rich A approximate to 190 nuclides from Pb-208 fragmentation
- 2005
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 23:2, s. 201-215
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Journal article (peer-reviewed)abstract
- Relativistic projectile fragmentation of Pb-208 has been used to produce isomers in neutron-rich, A approximate to 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of gamma-rays emitted by stopped ions has led to the assignment of isomers in Ta-188, W-190, Re-192, Re-193, Os-195, Ir-197, Ir-198, Pt-200, Pt-201, Pt-202 and Au-203, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for Er-174, Er-175, Hf-185, Re-191, Re-194 and Ir-199. In most cases, time-correlated, singles gamma-ray events provided the first spectroscopic data on excited states for each nuclide. In Pt-200 and Pt-201. the assignments are supported by gamma-gamma coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics.
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| 6. |
- Cederwall, Bo, et al.
(author)
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HIGH-SPIN STATES OF IR-175 - QUASIPROTON-INDUCED SHAPES AND EXTREME INTERACTION STRENGTH
- 1991
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 43:5, s. R2031-R2034
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Journal article (peer-reviewed)abstract
- For the first time, excited states of 175Ir have been observed. Remarkably different developments with rotation are found in bands built on the [541]1/2-, [505]11/2-, and [660]1/2+ orbitals. The data are analyzed within the deformed shell model. The pattern of the [505]11/2- band is interpreted as a combined stretching and alignment effect. For the [606]1/2+ band, an extremely strong interaction with the S band results in an almost entirely smeared out alignment process not explained by standard calculations. This feature might indicate a strong residual pn interaction.
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| 7. |
- FANT, B, et al.
(author)
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SHELL STRUCTURE AND SHAPE COEXISTENCE IN PB-195
- 1995
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In: Physica scripta. T. - 0281-1847. ; T56, s. 245-248
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Journal article (peer-reviewed)abstract
- Pb-195 was investigated utilizing the reactions Dy-164(S-36, 5n)Pb-195 and Dy-164(S-34, 3n)Pb-195 at beam energies of 170 and 160MeV respectively. Two new dipole bands which feed into the yrast 25/2(+) state, were found in Pb-195. The connection between the bands and the spherical states was established and thus spins and energies of the involved collective states were determined. The deformation is understood as mainly due to excitations of protons across the Z = 82 shell gap. The observed backbends are interpreted as alignment of i(13/2) neutrons.
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| 8. |
- Hammond, G, et al.
(author)
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Spectroscopy of T=3/2 Mirror Nuclei via Two-step Fragmentation using RISING
- 2005
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In: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 36:4, s. 1253-1257
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Journal article (peer-reviewed)abstract
- Two two-step fragmentation reactions were performed using RISING to populate excited states in A approximate to 50 mirror nuclei near to the proton-drip line, in order to test isospin symmetry. The experiments were designed to observe gamma decays of excited states in the mirror nuclei Ni-53(28)25/Mn-53(25)28, which have a large value of total isospin (T = 3/2). In the continuing off-line analysis, gamma transitions have been observed in Ni-54 indicating that two-step fragmentation is a successful technique for spectroscopic investigations of proton-rich nuclear systems in this mass region.
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| 9. |
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| 10. |
- Podolyak, Z, et al.
(author)
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Isomer spectroscopy of neutron rich W-190(116)
- 2000
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In: PHYSICS LETTERS B. - : ELSEVIER SCIENCE BV. - 0370-2693. ; 491:3-4, s. 225-231
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Journal article (other academic/artistic)abstract
- Gamma-rays de-exciting a millisecond isomer in the neutron-rich nucleus W-190(74)116 have been observed following relativistic projectile fragmentation of a I GeV per nucleon Pb-208 beam. Th, isomeric decay populates the ground-state rotational band, with
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| 11. |
- Romagnoni, A, et al.
(author)
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Comparative performances of machine learning methods for classifying Crohn Disease patients using genome-wide genotyping data
- 2019
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In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1, s. 10351-
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Journal article (peer-reviewed)abstract
- Crohn Disease (CD) is a complex genetic disorder for which more than 140 genes have been identified using genome wide association studies (GWAS). However, the genetic architecture of the trait remains largely unknown. The recent development of machine learning (ML) approaches incited us to apply them to classify healthy and diseased people according to their genomic information. The Immunochip dataset containing 18,227 CD patients and 34,050 healthy controls enrolled and genotyped by the international Inflammatory Bowel Disease genetic consortium (IIBDGC) has been re-analyzed using a set of ML methods: penalized logistic regression (LR), gradient boosted trees (GBT) and artificial neural networks (NN). The main score used to compare the methods was the Area Under the ROC Curve (AUC) statistics. The impact of quality control (QC), imputing and coding methods on LR results showed that QC methods and imputation of missing genotypes may artificially increase the scores. At the opposite, neither the patient/control ratio nor marker preselection or coding strategies significantly affected the results. LR methods, including Lasso, Ridge and ElasticNet provided similar results with a maximum AUC of 0.80. GBT methods like XGBoost, LightGBM and CatBoost, together with dense NN with one or more hidden layers, provided similar AUC values, suggesting limited epistatic effects in the genetic architecture of the trait. ML methods detected near all the genetic variants previously identified by GWAS among the best predictors plus additional predictors with lower effects. The robustness and complementarity of the different methods are also studied. Compared to LR, non-linear models such as GBT or NN may provide robust complementary approaches to identify and classify genetic markers.
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| 12. |
- Schlegel, C, et al.
(author)
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K-isomers in very neutron-rich nuclei around mass 180
- 2000
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In: PHYSICA SCRIPTA. - : ROYAL SWEDISH ACAD SCIENCES. - 0281-1847. ; T88, s. 72-76
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Journal article (other academic/artistic)abstract
- gamma-spectroscopy methods have been used to search for microsecond isomers among the fragmentation products of a 1 GeV/nucleon Pb-208 beam. In particular the population of the known K-pi = 35/2(-) isomer in W-179 has been investigated and several new iso
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| 13. |
- Taylor, MJ, et al.
(author)
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Spectroscopy of Nuclei Approaching the Proton Drip-line Using a Secondary-fragmentation Technique with the RISING Detector Array
- 2005
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. 1527-1530
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Journal article (peer-reviewed)abstract
- An experiment utilizing a double fragmentation reaction was performed to study isobaric analogue states in A similar to 50 nuclei approaching the proton drip-line. gamma-ray spectroscopy will be used to identify excited states in the neutron-deficient nuclei produced in the second fragmentation reaction. Excited state level schemes will be obtained, through comparison with states in their well-known mirror partners, along with information on Coulomb effects through measurements of the Coulomb energy differences between isobaric analogue excited states. The validity of isospin symmetry for nuclei approaching the proton drip-line can also be investigated and the information gained will aid in testing and improving fp shell model calculations. The analysis of the collected data is at a preliminary stage and current status of this work is reported.
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