SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Dewald A) "

Sökning: WFRF:(Dewald A)

  • Resultat 1-46 av 46
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Klintefjord, M., et al. (författare)
  • Measurement of lifetimes in Fe-62,Fe-64, Co-61,Co-63, and Mn-59
  • 2017
  • Ingår i: PHYSICAL REVIEW C. - 2469-9985. ; 95:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Lifetimes of the 4(1)(+) states in Fe-62,Fe-64 and the 11/2(1)(-) states in Co-61,Co-63 and Mn-59 were measured at the Grand Accelerateur National d'Ions Lourds (GANIL) facility by using the Advanced Gamma Tracking Array (AGATA) and the large-acceptance variable mode spectrometer (VAMOS++). The states were populated through multinucleon transfer reactions with a U-238 beam impinging on a Ni-64 target, and lifetimes in the picosecond range were measured by using the recoil distance Doppler shift method. The data show an increase of collectivity in the iron isotopes approaching N = 40. The reduction of the subshell gap between the nu 2p(1/2) and nu 1g(9/2) orbitals leads to an increased population of the quasi-SU(3) pair (nu 1g(9/2), nu 2d(5/2)), which causes an increase in quadrupole collectivity. This is not observed for the cobalt isotopes withN < 40 for which the neutron subshell gap is larger due to the repulsive monopole component of the tensor nucleon-nucleon interaction. The extracted experimental B(E2) values are compared with large-scale shell-model calculations and with beyond-mean-field calculations with the Gogny D1S interaction. A good agreement between calculations and experimental values is found, and the results demonstrate in particular the spectroscopic quality of the Lenzi, Nowacki, Poves, and Sieja (LNPS) shell-model interaction.
  •  
2.
  • Perez-Vidal, R. M., et al. (författare)
  • Evidence of Partial Seniority Conservation in the pi g9/2 Shell for the N=50 Isotones
  • 2022
  • Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 129:11
  • Tidskriftsartikel (refereegranskat)abstract
    • The reduced transition probabilities for the 4+1 -2+1 and 2+1 -0+1 transitions in 92Mo and 94Ru and for the 4+1 -2+1 and 6+1 -4+1 transitions in 90Zr have been determined in this experiment making use of a multinucleon transfer reaction. These results have been interpreted on the basis of realistic shell-model calculations in the f5=2, p3=2, p1=2, and g9=2 proton valence space. Only the combination of extensive lifetime information and large scale shell-model calculations allowed the extent of the seniority conservation in the N = 50 g9=2 orbital to be understood. The conclusion is that seniority is largely conserved in the first 71g9=2 orbital.
  •  
3.
  • Litzinger, J., et al. (författare)
  • Transition probabilities in neutron-rich Se-80,Se-82 and the role of the nu g(9/2) orbital
  • 2018
  • Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 97:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Transition probabilities of intermediate-spin yrast and non-yrast excitations in Se-80,Se-82 were investigated in a recoil distance Doppler-shift (RDDS) experiment performed at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. The Cologne Plunger device for deep inelastic scattering was used for the RDDS technique and was combined with the AGATA Demonstrator array for the gamma-ray detection and coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In Se-80, the level lifetimes of the yrast (6(1)(+)) and (8(1)(+)) states and of a non-yrast band feeding the yrast 4(1)(+) state are determined. A spin and parity assignment of the head of this sideband is discussed based on the experimental results and supported by large-scale shell-model calculations. In Se-82, the level lifetimes of the yrast 6(1)(+) state and the yrare 4(2)(+) state and lifetime limits of the yrast (10(1)(+)) state and of the 5(1)(-) state are determined. Although the experimental results contain large uncertainties, they are interpreted with care in terms of large-scale shell-model calculations using the effective interactions JUN45 and jj44b. The excited states' wave functions are investigated and discussed with respect to the role of the neutron g(9/2) orbital.
  •  
4.
  • Litzinger, J., et al. (författare)
  • Transition probabilities in neutron-rich Se-84,Se-86
  • 2015
  • Ingår i: Physical Review C. Nuclear Physics. - : American Physical Society. - 0556-2813 .- 1089-490X. ; 92:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Reduced quadrupole transition probabilities for low-lying transitions in neutron-rich Se-84,Se-86 are investigated with a recoil distance Doppler shift (RDDS) experiment. The experiment was performed at the Istituto Nazionale di Fisica Nucleare (INFN) Laboratori Nazionali di Legnaro using the Cologne Plunger device for the RDDS technique and the AGATA Demonstrator array for the gamma-ray detection coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In Se-86 the level lifetime of the yrast 2(1)(+) state and an upper limit for the lifetime of the 4(1)(+) state are determined for the first time. The results of Se-86 are in agreement with previously reported predictions of large-scale shell-model calculations using Ni78-I and Ni78-II effective interactions. In addition, intrinsic shape parameters of lowest yrast states in Se-86 are calculated. In semimagic Se-84 level lifetimes of the yrast 4(1)(+) and 6(1)(+) states are determined for the first time. Large-scale shell-model calculations using effective interactions Ni78-II, JUN45, jj4b, and jj4pna are performed. The calculations describe B(E2; 2(1)(+) -> 0(1)(+)) and B(E2; 6(1)(+) -> 4(1)(+)) fairly well and point out problems in reproducing the experimental B(E2; 4(1)(+) -> 2(1)(+)).
  •  
5.
  • Modamio, V., et al. (författare)
  • Lifetime measurements in neutron-rich Co-63,Co-65 isotopes using the AGATA demonstrator
  • 2013
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 88:4, s. 044326-
  • Tidskriftsartikel (refereegranskat)abstract
    • Lifetimes of the low-lying (11/2(-)) states in Co-63,Co-65 have been measured employing the recoil distance doppler shift method (RDDS) with the AGATA gamma-ray array and the PRISMA mass spectrometer. These nuclei were populated via a multinucleon transfer reaction by bombarding a U-238 target with a beam of Ni-64. The experimental B(E2) reduced transition probabilities for Co-63,Co-65 are well reproduced by large-scale shell-model calculations that predict a constant trend of the B(E2) values up to the N = 40 Co-67 isotope.
  •  
6.
  • Goldkuhle, A., et al. (författare)
  • Lifetime measurements in Ti-52,Ti-54 to study shell evolution toward N=32
  • 2019
  • Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 100:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Lifetimes of the excited states in the neutron-rich Ti-52,Ti-54 nuclei, produced in a multinucleon-transfer reaction, were measured by employing the Cologne plunger device and the recoil-distance Doppler-shift method. The experiment was performed at the Grand Accelerateur National d'Ions Lourds facility by using the Advanced Gamma Tracking Array for the gamma-ray detection, coupled to the large-acceptance variable mode spectrometer for an event-by-event particle identification. A comparison between the transition probabilities obtained from the measured lifetimes of the 2(1)(+) to 8(1)(+) yrast states in Ti-52,Ti-54 and that from the shell-model calculations based on the well-established GXPF1A, GXPF1B, and KB3G fp shell interactions support the N = 32 subshell closure. The B(E2) values for Ti-52 determined in this work are in disagreement with the known data, but are consistent with the predictions of the shell-model calculations and reduce the previously observed pronounced staggering across the even-even titanium isotopes.
  •  
7.
  • Sahin, E., et al. (författare)
  • Shell evolution beyond N=40 : Cu-69,Cu-71,Cu-73
  • 2015
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 91:3
  • Tidskriftsartikel (refereegranskat)abstract
    • The level structure of the neutron-rich Cu-69, Cu-71, and Cu-73 isotopes has been investigated by means of multinucleon transfer reactions. The experiment was performed at Laboratori Nazionali di Legnaro using the AGATA Demonstrator array coupled to the PRISMA magnetic spectrometer. Lifetimes of excited states in Cu nuclei were measured with the recoil-distance Doppler-shift method. The resulting electromagnetic matrix elements for transitions from excited states in Cu-69,Cu-71,Cu-73 nuclei are used to assess the collective or single-particle character of these states. The results are compared with predictions of large-scale shell-model calculations, giving further insight into the evolution of the proton pf shell as neutrons fill the 1g(9/2) orbital.
  •  
8.
  • Aktas, Özge, 1987-, et al. (författare)
  • First observation of γ-ray transitions in 111Mo
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X.
  • Tidskriftsartikel (refereegranskat)abstract
    • Excited states in the extremely neutron-rich nuclei 109Mo and 111Mo have been studied following nucleon knock-out reactions. Seven $\gamma$-ray transitions, some of them in prompt mutual coincidence, have been identified for the first time in 11Mo using the DALI2 and MINOS detector systems at the BigRIPS and ZeroDegree electromagnetic fragments separator at the RIBF, RIKEN, Japan. Total Routhian surface (TRS) and Particle- Plus Rotor calculations have been performed to investigate the predicted shape coexistence and its effect on the structure of nuclei in this region of the nuclear chart. Following the results of the calculations, theoretical level schemes are proposed for positive and negative parity states and compared with the experimental findings.
  •  
9.
  • Louchart, C., et al. (författare)
  • Collective nature of low-lying excitations in Zn-70,Zn-72,Zn-74 from lifetime measurements using the AGATA spectrometer demonstrator
  • 2013
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 87:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Neutron-rich nuclei with protons in the fp shell show an onset of collectivity around N=40. Spectroscopic information is required to understand the underlying mechanism and to determine the relevant terms of the nucleon-nucleon interaction that are responsible for the evolution of the shell structure in this mass region. Methods: We report on the lifetime measurement of the first 2(+) and 4(+) states in Zn-70,Zn-72 ,Zn-74 and the first 6(+) state in Zn-72 using the recoil distance Doppler shift method. The experiment was carried out at the INFN Laboratory of Legnaro with the AGATA demonstrator, first phase of the Advanced Gamma Tracking Array of highly segmented, high-purity germanium detectors coupled to the PRISMA magnetic spectrometer. The excited states of the nuclei of interest were populated in the deep inelastic scattering of a Ge-76 beam impinging on a U-238 target. Results: The maximum of collectivity along the chain of Zn isotopes is observed for Zn-72 at N=42. An unexpectedly long lifetime of 20(-5.2)(+1.8) ps was measured for the 4(+) state in Zn-74. Conclusions: Our results lead to small values of the B(E2;4(1)(+) -> 21(+))/B(E2;2(1)(+->)0(1)(+)) ratio for Zn-72,Zn-74, suggesting a significant noncollective contribution to these excitations. These experimental results are not reproduced by state-of-the-art microscopic models and call for lifetime measurements beyond the first 2(+) state in heavy zinc and nickel isotopes.
  •  
10.
  • Aktas, Özge, et al. (författare)
  • Single-particle structures in 85,87Ge
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X.
  • Tidskriftsartikel (refereegranskat)abstract
    • Gamma-ray transitions have been identified for the first time in the extremely neutron-rich (N =Z + 25) nucleus 87 Ge following nucleon knockout reactions studied at the RIBF, RIKEN, Japan.New γ-ray transitions from excited states in 85 Ge were also observed and placed in a tentative levelscheme. The exclusive parallel momentum distribution was measured for the 1/2 + state for theneutron knockout reaction leading to 85 Ge which is compared with calculated distorted wave impulseapproximation (DWIA) distributions. The 85,87 Ge results are compared with large-scale shell-modelcalculations and potential energy surface calculations based on the total Routhian surface formalism.
  •  
11.
  • Valiente-Dobon, J. J., et al. (författare)
  • Lifetime Measurements of the Neutron-Rich N=30 Isotones Ca-50 and Sc-51: Orbital Dependence of Effective Charges in the fp Shell
  • 2009
  • Ingår i: Physical Review Letters. - 1079-7114. ; 102:24
  • Tidskriftsartikel (refereegranskat)abstract
    • The lifetimes of the first excited states of the N=30 isotones Ca-50 and Sc-51 have been determined using the Recoil Distance Doppler Shift method in combination with the CLARA-PRISMA spectrometers. This is the first time such a method is applied to measure lifetimes of neutron-rich nuclei populated via a multinucleon transfer reaction. This extends the lifetime knowledge beyond the f(7/2) shell closure and allows us to derive the effective proton and neutron charges in the fp shell near the doubly magic nucleus Ca-48, using large-scale, shell-model calculations. These results indicate an orbital dependence of the core polarization along the fp shell.
  •  
12.
  • Doncel, Maria, et al. (författare)
  • Lifetime Measurements in Neutron-rich Cu Isotopes
  • 2013
  • Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 44:3, s. 505-510
  • Tidskriftsartikel (refereegranskat)abstract
    • The nuclear structure of neutron-rich nuclei close to the double-magic nucleus Ni-78 has been investigated by measuring the lifetime of excited states. In this contribution, it will be presented the lifetime of the J(pi) = 7/2(-) excited state at 981 keV of the Cu-71 isotope, measured using the AGATA Demonstrator coupled to the PRISMA spectrometer and the Koln plunger setup. This is the first time this combined setup has been used for a lifetime measurement.
  •  
13.
  • Petts, A., et al. (författare)
  • Lifetime measurements and coulomb excitation of light Hg nuclei
  • 2009
  • Ingår i: Capture Gamma-Ray Spectroscopy and Related Topics. - : American Institute of Physics (AIP). - 9780735406230 ; , s. 414-418
  • Konferensbidrag (refereegranskat)abstract
    • Two complementary experimental programs have taken place to investigate the origin and evolution of shape coexistence in the light mercury region. Recoil Distance Doppler-shift measurements were performed at the University of Jyväskylä utilizing the Köln plunger device in conjunction with the JUROGAM + RITU + GREAT setup. In addition, Coulomb excitation measurements of 184,186,188Hg were performed at REX-ISOLDE using the MINIBALL Ge-detector array. The results of the lifetime measurements of the yrast states up to Iπ = 10+ in 182Hg are reported. Preliminary analysis of the Coulomb excitation data is also discussed.
  •  
14.
  • Petri, M., et al. (författare)
  • Structure of C-16: Testing shell model and ab initio approaches
  • 2012
  • Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:4, s. Art. no. 044329-
  • Tidskriftsartikel (refereegranskat)abstract
    • Excited states in C-16 were populated via the Be-9(N-17,C-16+gamma)X one-proton knockout reaction. The lifetime of the 2(1)(+) state in C-16 was measured using the recoil distance method. The extracted lifetime of tau(+)(21) = 11.4(-0.9)(+0.8)(stat) +/- 0.7(syst(B rho))(-1.5)(+0.0)(syst(feeding)) ps yields a deduced B(E2;2(1)(+) -> 0(1)(+)) = 4.21(-0.26)(+0.34)(stat)(-0.24)(+0.28)(syst(B rho))(-0.00)(+0.64)(syst(feeding)) e(2)fm(4) value in good agreement with a previous measurement. The one-proton knockout cross section is used to extract the proton amplitude of the C-16 2(1)(+) state, which confirms the neutron dominant character of this state. Gamma-ray branching ratios between the 2(2)(+) state and the 2(1)(+) and ground states were also determined. The results are compared with p-sd shell model and no-core shell model (with NN and NN + NNN) calculations. The inclusion of three-body forces are essential in order for the no-core shell model calculations to reproduce the experimental findings on the gamma-ray branching ratios.
  •  
15.
  • Ashley, S. F., et al. (författare)
  • Lifetime determination of excited states in Cd-106
  • 2007
  • Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 38:4, s. 1385-1388
  • Tidskriftsartikel (refereegranskat)abstract
    • Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps.
  •  
16.
  • Caballero, L., et al. (författare)
  • Two-phonon octupole excitation in 146Gd
  • 2006
  • Ingår i: AIP Conf. Proc.. - : AIP. - 0735403236 - 9780735403239 ; , s. 213-216
  • Konferensbidrag (refereegranskat)abstract
    • The excited states in 146Gd have been re-investigated with the 144Sm(α,2n) reaction using a modern Ge γ-ray array including a polarimeter. Amongst the non-yrast states populated in this reaction we have identified the aligned 6 + member of the two-phonon octupole quartet from the observation of the E3 branching to the one phonon 3 - state. Our results represent the first observation of a 6 +→ 3 -→0 + E3 cascade in an even-even nucleus.
  •  
17.
  •  
18.
  • Lieder, E O, et al. (författare)
  • Investigation of lifetimes in quadrupole bands of Gd-142
  • 2008
  • Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 35:2, s. 135-158
  • Tidskriftsartikel (refereegranskat)abstract
    • For a level scheme investigation of Gd-142 an experiment with the gamma -spectrometer EUROBALLIII has been carried out and lifetimes have been measured with EUROBALL IV using the Doppler-shift attenuation method. The high-spin states have been populated in these experiments by means of the(99)Ru(Ti-48, 2p3n) reaction at a beam energy of 240MeV and the Sn-114(S-32, 2p2n) reaction at 160MeV, respectively. Reduced E2 transition probabilities B(E2) were determined for 15 members of four quadrupole bands. For the interpretation of the positive-parity even-spin quadrupole bands, calculations in the cranked Nilsson-Strutinsky as well as interacting boson models have been performed. From the former calculations it was concluded that the high-spin states of the (+ , 0)(1) band in Gd-142 represent a triaxial nucleus rotating around the longest principal axis.
  •  
19.
  • Milanović, T., et al. (författare)
  • Lifetime measurements of low-lying states in 73Ga and 70,72,74Zn isotopes
  • 2020
  • Ingår i: Acta Physica Polonica B. - 0587-4254. ; 51:3, s. 837-842
  • Tidskriftsartikel (refereegranskat)abstract
    • Lifetimes of low-lying states in 73Ga and 70,72,74Zn were measured using the Recoil Distance Doppler Shift (RDDS) method. These nuclei were produced in deep-inelastic reactions in inverse kinematics with a 208Pb beam impinging on a 76Ge target. Prompt γ rays were detected using the AGATA tracking array coupled to the VAMOS++ spectrometer. Lifetime of the 5/2- state in 73Ga, measured for the first time, provides additional evidence for the existence of a 1/2-, 3/2- ground-state doublet. The lifetimes of the 4+ states in 70,72,74Zn were remeasured in an attempt to understand the discrepancies observed between earlier measurements. Our results are in agreement with those of previous plunger experiments.
  •  
20.
  • Ralet, D., et al. (författare)
  • Lifetime measurement of neutron-rich even-even molybdenum isotopes
  • 2017
  • Ingår i: Physical Review C: covering nuclear physics. - : AMER PHYSICAL SOC. - 2469-9985 .- 2469-9993. ; 95:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: In the neutron-rich A≈100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A=100 up to mass A=108, and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the γ ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a γ-ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A=100 to A=108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: τ=29.7-9.1+11.3 ps for the 4+ state of Mo108 and τ=3.2-0.7+0.7 ps for the 6+ state of Mo102. Conclusions: The reduced transition strengths B(E2), calculated from lifetimes measured in this experiment, compared to beyond-mean-field calculations, indicate a gradual shape transition in the chain of molybdenum isotopes when going from A=100 to A=108 with a maximum reached at N=64. The transition probabilities decrease for Mo108 which may be related to its well-pronounced triaxial shape indicated by the calculations.
  •  
21.
  • Recchia, F, et al. (författare)
  • Position resolution of the prototype AGATA triple-cluster detector from an in-beam experiment
  • 2009
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 604:3, s. 555-562
  • Tidskriftsartikel (refereegranskat)abstract
    • AGATA belongs to a new generation of gamma-ray detector arrays for nuclear spectroscopy at present in its final stage of development. The detectors of these new arrays will be based on 36-fold electronically segmented coaxial germanium diodes operated in position sensitive mode. An in-beam test of the AGATA prototype triple cluster detector was carried out with the purpose of demonstrating the feasibility of such detectors and in order to measure the most sensitive parameters for their overall performance. An inverse kinematics reaction was performed, using a Ti-48 beam at an energy of 100MeV, impinging on a deuterated titanium tat-get. The results from the analysis of the experimental data, compared with the predictions of Monte Carlo Simulations, give an estimation of the position sensitivity of these detectors of about 5 mm FWHM, consistent with the specifications required. (C) 2009 Elsevier B.V. All rights reserved.
  •  
22.
  • Voss, P., et al. (författare)
  • Excited-state transition-rate measurements in C-18
  • 2012
  • Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Excited states in C-18 were populated by the one-proton knockout reaction of an intermediate energy radioactive N-19 beam. The lifetime of the first 2(+) state was measured with the Koln/NSCL plunger via the recoil distance method to be tau (2(1)(+)) = 22.4 +/- 0.9(stat)(-2.2)(+3.3)(syst) ps, which corresponds to a reduced quadrupole transition strength of B(E2; 2(1)(+) -> 0(1)(+)) = 3.64(-0.14)(+ 0.15)(stat)(-0.47)(+0.40)(syst) e(2)fm(4). In addition, an upper limit on the lifetime of a higher-lying state feeding the 2(1)(+) state was measured to be tau
  •  
23.
  • Carlsson, P. T. M., et al. (författare)
  • Comparison of isoprene chemical mechanisms under atmospheric night-time conditions in chamber experiments: evidence of hydroperoxy aldehydes and epoxy products from NO3 oxidation
  • 2023
  • Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 23:5, s. 3147-3180
  • Tidskriftsartikel (refereegranskat)abstract
    • The gas-phase reaction of isoprene with the nitrate radical (NO3) was investigated in experiments in the outdoor SAPHIR chamber under atmospherically relevant conditions specifically with respect to the chemical lifetime and fate of nitrato-organic peroxy radicals (RO2). Observations of organic products were compared to concentrations expected from different chemical mechanisms: (1) the Master Chemical Mechanism, which simplifies the NO3 isoprene chemistry by only considering one RO2 isomer; (2) the chemical mechanism derived from experiments in the Caltech chamber, which considers different RO2 isomers; and (3) the FZJ-NO3 isoprene mechanism derived from quantum chemical calculations, which in addition to the Caltech mechanism includes equilibrium reactions of RO(2 )isomers, unimolecular reactions of nitrate RO(2 )radicals and epoxidation reactions of nitrate alkoxy radicals. Measurements using mass spectrometer instruments give evidence that the new reactions pathways predicted by quantum chemical calculations play a role in the NO3 oxidation of isoprene. Hydroperoxy aldehyde (HPALD) species, which are specific to unimolecular reactions of nitrate RO2, were detected even in the presence of an OH scavenger, excluding the possibility that concurrent oxidation by hydroxyl radicals (OH) is responsible for their formation. In addition, ion signals at masses that can be attributed to epoxy compounds, which are specific to the epoxidation reaction of nitrate alkoxy radicals, were detected. Measurements of methyl vinyl ketone (MVK) and methacrolein (MACR) concentrations confirm that the decomposition of nitrate alkoxy radicals implemented in the Caltech mechanism cannot compete with the ring-closure reactions predicted by quantum chemical calculations. The validity of the FZJ-NO3 isoprene mechanism is further supported by a good agreement between measured and simulated hydroxyl radical (OH) reactivity. Nevertheless, the FZJ-NO3 isoprene mechanism needs further investigations with respect to the absolute importance of unimolecular reactions of nitrate RO2 and epoxidation reactions of nitrate alkoxy radicals. Absolute concentrations of specific organic nitrates such as nitrate hydroperoxides would be required to experimentally determine product yields and branching ratios of reactions but could not be measured in the chamber experiments due to the lack of calibration standards for these compounds. The temporal evolution of mass traces attributed to product species such as nitrate hydroperoxides, nitrate carbonyl and nitrate alcohols as well as hydroperoxy aldehydes observed by the mass spectrometer instruments demonstrates that further oxidation by the nitrate radical and ozone at atmospheric concentrations is small on the timescale of one night (12 h) for typical oxidant concentrations. However, oxidation by hydroxyl radicals present at night and potentially also produced from the decomposition of nitrate alkoxy radicals can contribute to their nocturnal chemical loss.
  •  
24.
  • de Angelis, G., et al. (författare)
  • Coherent proton-neutron contribution to octupole correlations in the neutron-deficient Xe-114 nucleus
  • 2002
  • Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 535:04-jan, s. 93-102
  • Tidskriftsartikel (refereegranskat)abstract
    • Gamma ray linear polarization and picosecond lifetimes have been measured for levels in the neutron deficient nucleus Xe-114 using the EUROBALL IV spectrometer and the Cologne plunger device. The EUCLIDES Si-ball was used to improve the reaction channel selectivity. The linear polarization results have, for the first time, unambiguously determined the electromagnetic character of the dipole transitions de-exciting the negative parity level sequence, providing clear evidence for enhanced octupole collectivity. The discovery of two E3 transitions and the measurement of the lifetimes of the states depopulated by these transitions have allowed a quantitative determination of the octupole collectivity in the A approximate to 112 mass region. The large measured B(E3) values, close to approximate to 70 W.u., are among the strongest observed hitherto and indicate a coherent proton-neutron contribution to the octupole moment.
  •  
25.
  • Grahn, T., et al. (författare)
  • Collectivity and configuration mixing in Pb186,188 and Po194
  • 2006
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Lifetimes of prolate intruder states in Pb186 and oblate intruder states in Po194 have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in Pb188 up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |β2|=0.29(5) and |β2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.
  •  
26.
  • Lieder, R. M., et al. (författare)
  • Investigations of the level scheme of Gd-144 and lifetimes in the quadrupole bands
  • 2004
  • Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 21:1, s. 37-55
  • Tidskriftsartikel (refereegranskat)abstract
    • For a level scheme investigation of Gd-144 an experiment with the gamma-spectrometer EUROBALL III has been carried out and lifetimes have been measured with the gamma-spectrometer GASP using the Doppler-shift attenuation method. The high-spin states have been populated in these experiments by means of the Mo-100(Ti-48,4n) reaction at 215 MeV and the Cd-114(S-36,6n) reaction at E = 182 MeV, respectively. The known quadrupole band has been modified and a new one has been established. Reduced E2 transition probabilities B(E2) were determined for seven members of these quadrupole bands. They show values between approximate to60 and 130 W.u. and this considerable enhancement gives evidence for a significant nuclear deformation. A (pih(11/2))(2) circle times (vh(11/2))(-2) configuration may be assigned to one of the quadrupole bands according to total Routhian surface calculations. The spin dependence of the B(E2) values has been explained by IBM calculations involving high-spin quasiparticle excitations.
  •  
27.
  • Park, Joochun, et al. (författare)
  • Toward the limit of nuclear binding on the N = Z line : Spectroscopy of Cd-96
  • 2019
  • Ingår i: Physical Review C. - : AMER PHYSICAL SOC. - 2469-9985 .- 2469-9993. ; 99:2
  • Tidskriftsartikel (refereegranskat)abstract
    • A gamma -decaying isomeric state (tau(1/2) = 197(-17)(+19) ns) has been identified in Cd-96, which is one alpha particle away from the last known bound N = Z nucleus, Sn-100. Comparison of the results with shell-model calculations has allowed a tentative experimental level scheme to be deduced and the isomer to be interpreted as a medium-spin negative-parity spin trap based on the coupling of isoscalar (T = 0) and isovector (T = 1) neutron-proton pairs. The data also suggest evidence for the population of a 9(+) T = 1 state, which is predicted by shell-model calculations to be yrast. Such a low-lying T = 1 state, which is unknown in lighter mass even-even self-conjugate nuclei, can also be interpreted in terms of the coupling of T = 0 and T = 1 neutron-proton pairs.
  •  
28.
  • Saygi, B., et al. (författare)
  • Reduced transition probabilities along the yrast line in W-166
  • 2017
  • Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 96:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Lifetimes of excited states in the yrast band of the neutron-deficient nuclide W-166 have been measured utilizing the DPUNS plunger device at the target position of the JUROGAM II gamma-ray spectrometer in conjunction with the RITU gas-filled separator and the GREAT focal-plane spectrometer. Excited states in W-166 were populated in the Mo-92(Kr-78, 4p) reaction at a bombarding energy of 380 MeV. The measurements reveal a low value for the ratio of reduced transitions probabilities for the lowest-lying transitions B(E2; 4(+)-> 2(+)) / B(E2; 2(+)-> 0(+)) = 0.33(5), compared with the expected ratio for an axially deformed rotor (B-4/2 = 1.43).
  •  
29.
  • Bhatt, A. S., et al. (författare)
  • Achieving a Maximally Tolerated beta-Blocker Dose in Heart Failure Patients Is There Room for Improvement?
  • 2017
  • Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097. ; 69:20, s. 2542-2550
  • Tidskriftsartikel (refereegranskat)abstract
    • Heart failure (HF) is associated with significant morbidity and mortality. Although initially thought to be harmful in HF, beta-adrenergic blockers (beta-blockers) have consistently been shown to reduce mortality and HF hospitalization in chronic HF with reduced ejection fraction. Proposed mechanisms include neurohormonal blockade and heart rate reduction. A new therapeutic agent now exists to target further heart rate lowering in patients who have been stable on a "maximally tolerated b-blocker dose," but this definition and how to achieve it are incompletely understood. In this review, the authors summarize published reports on the mechanisms by which beta-blockers improve clinical outcomes. The authors describe differences in doses achieved in landmark clinical trials and those observed in routine clinical practice. They further discuss reasons for intolerance and the evidence behind using b-blocker dose and heart rate as therapeutic targets. Finally, the authors offer recommendations for clinicians actively initiating and up-titrating b-blockers that may aid in achieving maximally tolerated doses. (C) 2017 by the American College of Cardiology Foundation.
  •  
30.
  • Bäck, Torbjörn, et al. (författare)
  • Lifetime measurement of the first excited 2(+) state in (108)Te
  • 2011
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 84:4, s. 041306-
  • Tidskriftsartikel (refereegranskat)abstract
    • The lifetime of the first excited 2(+) state in the neutron deficient nuclide (108)Te has been measured for the first time, using a combined recoil decay tagging and recoil distance Doppler shift technique. The deduced reduced transition probability is B(E2;0(g.s.)(+) -> 2(+)) = 0.39(-0.04)(+0.05)e(2)b(2). Compared to previous experimental data on neutron deficient tellurium isotopes, the new data point constitutes a large step (six neutrons) toward the N = 50 shell closure. In contrast to what has earlier been reported for the light tin isotopes, our result for tellurium does not show any enhanced transition probability with respect to the theoretical predictions and the tellurium systematics including the new data is successfully reproduced by state-of-the-art shell model calculations.
  •  
31.
  • Davies, P. J., et al. (författare)
  • The role of core excitations in the structure and decay of the 16(+) spin-gap isomer in Cd-96
  • 2017
  • Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 767, s. 474-479
  • Tidskriftsartikel (refereegranskat)abstract
    • The first evidence for beta-delayed proton emission from the 16(+) spin gap isomer in Cd-96 is presented. The data were obtained from the Rare Isotope Beam Factory, at the RIKEN Nishina Center, using the BigRIPS spectrometer and the EURICA decay station. beta p branching ratios for the ground state and 16(+) isomer have been extracted along with more precise lifetimes for these states and the lifetime for the ground state decay of Cd-95. Large scale shell model (LSSM) calculations have been performed and WKB estimates made for l = 0, 2, 4 proton emission from three resonance-like states in Ag-96, that are populated by the beta decay of the isomer, and the results compared to the new data. The calculations suggest that l = 2 proton emission from the resonance states, which reside similar to 5 MeV above the proton separation energy, dominates the proton decay. The results highlight the importance of core-excited wavefunction components for the 16(+) state.
  •  
32.
  • Haefner, G., et al. (författare)
  • Properties of γ-decaying Isomers in the 100Sn Region Revisited
  • 2019
  • Ingår i: Acta Physica Polonica B. - : JAGIELLONIAN UNIV PRESS. - 0587-4254 .- 1509-5770. ; 50:3, s. 431-437
  • Tidskriftsartikel (refereegranskat)abstract
    • The study of nuclei in the region around the N = Z doubly-magic nucleus 100Sn has been of long standing interest for the nuclear structure and nuclear astrophysics. Recently, Park et al.  have reported on properties of γ-decaying isomers and isomeric ratios in the vicinity of 100Sn. That experiment was performed at the Radioactive Ion Beam Factory (RIBF) of the RIKEN Nishina Center in Japan as a part of the EURICA campaign. Neutron-deficient nuclei were produced in a fragmentation reaction of a 124Xe primary beam on a 9Be target at an energy of 345 MeV/A. Secondary ions were separated and identified in the BigRIPS fragment separator and implanted in the silicon detector array WAS3ABi. The data presented here were obtained in another experiment performed at the RIBF using the same reaction but slightly different separator settings. New results of ratios of isomeric population and half-lives of γ-decaying isomers populated in the experiment are presented.
  •  
33.
  • Hagen, T. W., et al. (författare)
  • Evolution of nuclear shapes in odd-mass yttrium and niobium isotopes from lifetime measurements following fission reactions
  • 2017
  • Ingår i: Physical Review C: covering nuclear physics. - 2469-9985. ; 95:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Lifetimes of excited states in Y99,Y101,Nb101,Nb103, and Nb105 were measured in an experiment using the recoil distance Doppler shift method at GANIL (Grand Accélérateur National d'Ions Lourds). The neutron-rich nuclei were produced in fission reactions between a U238 beam and a Be9 target. Prompt γ rays were measured with the EXOGAM array and correlated with fission fragments that were identified in mass and atomic number with the VAMOS++ spectrometer. The measured lifetimes, together with branching ratios, provide B(M1) and B(E2) values for the strongly coupled rotational bands built on the [422]5/2+ ground state in the Y and Nb nuclei with neutron number N≥60. The comparison of the experimental results with triaxial particle-rotor calculations provides information about the evolution of the nuclear shape in this mass region.
  •  
34.
  • Häfner, G., et al. (författare)
  • Properties of γ-decaying isomers in the Sn 100 region populated in fragmentation of a Xe 124 beam
  • 2019
  • Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 100:2
  • Tidskriftsartikel (refereegranskat)abstract
    • A systematic study was performed of microsecond γ-decaying isomers around Sn100 produced in a fragmentation reaction of a Xe124 beam at 345 MeV/u at the Radioactive Ion Beam Factory of the RIKEN Nishina Center in Saitama, Japan. Half-lives of isomeric states in that region were remeasured allowing us to improve the currently available experimental information. Reduced transition probabilities were deduced and compared to shell-model calculations in various model spaces. The recently reported low-energy transitions in Rh92 and Ag96 were remeasured with improved precision. Additionally, experimental information on isomeric ratios, including five new ones, were extracted and compared to a previous experimental study and the sharp cutoff model of fragmentation reaction.
  •  
35.
  • Lenzi, SM, et al. (författare)
  • Coulomb energy differences in T=1 mirror rotational bands in Fe-50 and Cr-50 - art. no. 122501
  • 2001
  • Ingår i: PHYSICAL REVIEW LETTERS. - : AMERICAN PHYSICAL SOC. - 0031-9007. ; 8712:12, s. 2501-
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Gamma rays from the N = Z - 2 nucleus Fe-50 have been observed, establishing the rotational ground state band up to the state J(pi) = 11(+) at 6.994 MeV excitation energy. The experimental Coulomb energy differences, obtained by comparison with the isobar
  •  
36.
  • Moschner, K., et al. (författare)
  • Study of ground and excited state decays in N approximate to Z Ag nuclei
  • 2015
  • Ingår i: CGS15 - CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS. - : EDP Sciences. - 9782759817948
  • Konferensbidrag (refereegranskat)abstract
    • A decay spectroscopy experiment was performed within the EURICA campaign at RIKEN in 2012. It aimed at the isomer and particle spectroscopy of excited states and ground states in the mass region below the doubly magic Sn-100. The N = Z nuclei In-98, Cd-96 and Ag-94 were of particular interest for the present study. Preliminary results on the neutron deficient nuclei Ag-93 and Ag-94 are presented. In Ag-94 a more precise value for the half-life of the ground state's superallowed Fermi transition was deduced. In addition the energy spectra of the mentioned decay could be reproduced through precise Geant4 simulations of the used active stopper SIMBA. This will enable us to extract Q(beta) values from the measured data. The decay of Ag-93 is discussed based on the observed implantation-decay correlation events.
  •  
37.
  • Doncel, Maria, et al. (författare)
  • Determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method in combination with magnetic spectrometers
  • 2017
  • Ingår i: European Physical Journal A. - : SPRINGER. - 1434-6001 .- 1434-601X. ; 53:10
  • Tidskriftsartikel (refereegranskat)abstract
    • The current work presents the determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method, in combination with spectrometers for ion identification, normalizing the intensity of the peaks by the ions detected in the spectrometer as a valid technique that produces results comparable to the ones obtained by the conventional shifted-to-unsifted peak ratio method. The technique has been validated using data measured with the gamma-ray array AGATA, the PRISMA spectrometer and the Cologne plunger setup. In this paper a test performed with the AGATA-PRISMA setup at LNL and the advantages of this new approach with respect to the conventional Recoil Distance Doppler Shift Method are discussed.
  •  
38.
  • du Rietz, Rickard, et al. (författare)
  • Effective Charges in the fp Shell
  • 2004
  • Ingår i: Physical Review Letters. - 1079-7114. ; 93:22
  • Tidskriftsartikel (refereegranskat)abstract
    • Following the heavy-ion fusion-evaporation reaction S-32+Mg-24 at 95 MeV beam energy the lifetimes of analogue states in the T-z=+/-1/2 A=51 mirror nuclei Fe-51 and Mn-51 have been measured using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The deduced B(E2;27/2(-)-->23/2(-)) values afford a unique opportunity to probe isoscalar and isovector polarization charges and to derive effective proton and neutron charges, epsilon(p) and epsilon(n), in the fp shell. A comparison between the experimental results and several different large-scale shell-model calculations yields epsilon(p)similar to1.15e and epsilon(n)similar to0.80e.
  •  
39.
  • du Rietz, Rickard, et al. (författare)
  • Investigation of High-spin States in 53Fe
  • 2005
  • Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The fusion-evaporation reactions Si-28(S-32,1 alpha 2p1n)Fe-53 at 125 MeV and Mg-24(S-32,2p1n)Fe-53 at a 95-MeV beam energy were used to investigate excited states in Fe-53. The combination of the Gammasphere Ge detector array and ancillary devices led to the construction of an extensive level scheme comprising some 90 transitions connecting 40 states. The lifetime of the yrast 25/2(-) state and upper limits for the lifetimes of a number of additional states were determined using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The experimental results are compared to large-scale shell-model calculations using different sets of two-body matrix elements. In particular, predictions on electromagnetic decay properties such as lifetimes, branching ratios, and mixing ratios are studied in detail.
  •  
40.
  • Grahn, T., et al. (författare)
  • Excited states and reduced transition probabilities in Os-168
  • 2016
  • Ingår i: PHYSICAL REVIEW C. - : American Physical Society. - 2469-9985. ; 94:4
  • Tidskriftsartikel (refereegranskat)abstract
    • The level scheme of the neutron-deficient nuclide Os-168 has been extended and mean lifetimes of excited states have been measured by the recoil distance Doppler-shift method using the JUROGAM gamma-ray spectrometer in conjunction with the IKP Koln plunger device. The 168Os. rays were measured in delayed coincidence with recoiling fusion-evaporation residues detected at the focal plane of the RITU gas-filled separator. The ratio of reduced transition probabilities B(E2; 4(1)(+)-> 2(1)(+))/B(E2; 2(1)(+)-> 0(1)(+)) is measured to be 0.34(18), which is very unusual for collective band structures and cannot be reproduced by interacting boson model (IBM-2) calculations based on the SkM* energy-density functional.
  •  
41.
  • Granger, B. B., et al. (författare)
  • Results of the Chronic Heart Failure Intervention to Improve MEdication Adherence study: A randomized intervention in high-risk patients
  • 2015
  • Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703. ; 169:4, s. 539-548
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Poor adherence to evidence-based medications in heart failure (HF) is a major cause of avoidable hospitalizations, disability, and death. To test the feasibility of improving medication adherence, we performed a randomized proof-of-concept study of a self-management intervention in high-risk patients with HF. Methods Patients with HF who screened positively for poor adherence (<6 Morisky Medication Adherence Scale 8-item) were randomized to either the intervention or attention control group. In the intervention group (n = 44), a nurse conducted self-management training before discharge that focused on identification of medication goals, facilitation of medication-symptom associations, and use of a symptom response plan. The attention control group (n = 42) received usual care; both groups received follow-up calls at 1 week. However, the content of follow-up calls for the attention control group was unrelated to HF medications or symptoms. General linear mixed models were used to evaluate the magnitude of change in adherence and symptom-related events at 3-, 6-, and 12-month follow-up clinic visits. Efficacy was measured as improved medication adherence using nurse-assessed pill counts at each time point. Results Pooled over all time points, patients in the intervention group were more likely to be adherent to medications compared with patients in the attention control group (odds ratio 3.92, t = 3.51, P = .0007). Conclusions A nurse-delivered, self-care intervention improved medication adherence in patients with advanced HF. Further work is needed to examine whether this intervention can be sustained to improve clinical outcomes.
  •  
42.
  • Procter, M. G., et al. (författare)
  • Isomer-tagged differential-plunger measurements in Xe-113(54)
  • 2013
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 87:1, s. 014308-
  • Tidskriftsartikel (refereegranskat)abstract
    • The 278-keV M2 gamma decay from the vh(11/2) isomeric state in Xe-113 has been observed for the first time using the recoil-isomer tagging technique. The half-life of the isomer has been measured to be 6.9(3) mu s. The derived B(M2) value is in agreement with the trend of systematic measurements of M2 transition strengths in neutron-deficient tellurium and tin isotopes. The lifetime of the first excited state in the vh(11/2) band has been measured using the recoil distance Doppler-shift method. The extracted B(E2) value has been compared to theoretical CD-Bonn calculations and recent lifetime measurements in Te-109. This comparison of B(E2) values has been used to shed light on the possible influence of collective degrees of freedom on M2 transition strengths in the most neutron-deficient xenon nuclei. The vh(11/2) band is deduced to have a degree of deformation comparable with the ground-state bands of the even-mass xenon isotopes. However, the value deduced in this work indicates a loss of collective behavior when compared with the lower-mass Te-109. This result suggests that, while changes in deformation may be partly responsible for the observed trend in B(M2) values for increasing Z, other effects may also be present.
  •  
43.
  • Taylor, M. J., et al. (författare)
  • Competing single-particle and collective states in the low-energy structure of I-113
  • 2013
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 88:5, s. 054307-
  • Tidskriftsartikel (refereegranskat)abstract
    • To understand the low-energy structure of the neutron deficient iodine isotopes, lifetimes for the low-lying 9/2(+) and 11/2(+) positive-parity states in I-113 have been measured as tau = 28(4) ps and tau = 3.7(7) ps, respectively. The lifetime for the 11/2(-) state, which feeds the 9/2(+) and 11/2(+) states, was remeasured with improved accuracy as tau = 216(7) ps. The reduced transition probability, B(E2) = 32(5) W.u., for the 9/2(+) -> 5/2(+) transition agrees with that calculated within the shell model using a Hamiltonian based on the charge-dependent Bonn nucleon-nucleon interaction. In contrast, the much larger transition probability, B(E2) = 209(39) W.u., measured for the 11/2(+) -> 7/2(+) transition has been interpreted, with the aid of configuration-constrained total Routhian surface calculations, as resulting from a slightly gamma-soft rotor with an associated quadrupole deformation of beta(2) approximate to 0.18. Remarkably similar reduced E1 transition probabilities of 5.5(5) x 10(-4) and 4.9(5) x 10(-4) W.u. were deduced for the 11/2(-) -> 9/2(+) and 11/2(-) -> 11/2(+) transitions, respectively, which feed apparently dissimilar but competing structures.
  •  
44.
  • Hughes, Jonathan D., et al. (författare)
  • More anterior placement of femoral tunnel position in ACL-R is associated with postoperative meniscus tears
  • 2023
  • Ingår i: Journal of Experimental Orthopaedics. - 2197-1153. ; 10:1
  • Tidskriftsartikel (refereegranskat)abstract
    • PurposeThe purpose of this study was to investigate the relationship between tunnel position in ACL reconstruction (ACL-R) and postoperative meniscus tears.MethodsThis was a single institution, case-control study of 170 patients status-post ACL-R (2010-2019) separated into two matched groups (sex, age, BMI, graft type). Group 1-symptomatic, operative meniscus tears (both de novo and recurrent) after ACL-R. Group 2-no postoperative meniscus tears. Femoral and tibial tunnel positions were measured by 2 authors via lateral knee radiographs that were used to measure two ratios (a/t and b/h). Ratio a/t was defined as distance from the tunnel center to dorsal most subchondral contour of the lateral femoral condyle (a) divided by total sagittal diameter of the lateral condyle along Blumensaat's line (t). The ratio b/h was defined as distance between the tunnel and Blumensaat's line (b) divided by maximum intercondylar notch height (h). Wilcoxon sign-ranks paired test was used to compare measurements between groups (alpha set at p < 0.05).ResultsGroup 1 had average follow up of 45 months and Group 2 had average follow up of 22 months. There were no significant demographic differences between Groups 1 and 2. Group 1-a/t was 32.0% (& PLUSMN; 10.2), which was significantly more anterior than group 2, 29.3% (& PLUSMN; 7.3; p < 0.05). There was no difference in average femoral tunnel ratio b/h or tibial tunnel placement between groups.ConclusionsA relationship exists between more anterior/less anatomic femoral tunnel position and the presence of recurrent or de novo, operative meniscus tears after ACL-R. Surgeons performing ACL-R should strive for recreation of native anatomy via proper tunnel placement to maximize postoperative outcomes.
  •  
45.
  • Procter, M. G., et al. (författare)
  • Anomalous transition strength in the proton-unbound nucleus (109)(53)I56
  • 2011
  • Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 704:3, s. 118-122
  • Tidskriftsartikel (refereegranskat)abstract
    • A lifetime measurement has been made for the first excited 11/2(+) state in the proton-unbound nucleus (109)(53)I56 using the recoil-distance Doppler-shift method in conjunction with recoil-proton tagging. The experimental reduced transition probability is considerably smaller than the prediction of theoretical shell-model calculations using the CD-Bonn nucleon-nucleon potential. The discrepancy between the theoretical and experimental reduced transition strengths in this work most likely arises from the inability of the current shell-model calculations to accurately account for the behavior of the unbound nuclear states.
  •  
46.
  • Procter, M. G., et al. (författare)
  • Lifetime measurement in the proton-unbound nucleus 109I
  • 2011
  • Ingår i: AIP Conf. Proc.. - : AIP. - 9780735409835 ; , s. 105-110
  • Konferensbidrag (refereegranskat)abstract
    • The Recoil-Distance Doppler-shift method has been combined with Recoil-Decay Tagging for the first time to measure a lifetime in the proton-unbound nucleus 109I. The lifetime value was determined using the Differential Decay-Curve method in singles mode. The result has been compared to theoretical shell-model calculations in order to better understand the nature of unbound valence nucleons at the proton drip line.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-46 av 46

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy