10 research outputs found
Low-lying levels in F-15 and the shell model potential for drip-line nuclei
Journals published by the American Physical Society can be found at http://publish.aps.org/The ground and first excited states in F-15 were studied in resonant elastic scattering using the thick (CH4) gas target method in inverse kinematics with a separated O-14 beam. An analysis of the excitation functions of the elastic scattering was carried out with the potential model. The quantum numbers 1/2(+) (ground state) and 5/2(+) (first excited state) were assigned to the lowest two states in F-15. Also, the widths and the proton decay energies of the unbound levels were obtained. The analysis of the data indicates that a large diffuseness is needed in the Woods-Saxon potential in order to describe single-particle features in drip-line nuclei
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Clustering in N ≠Z nuclei
The structure of the 18O nucleus at excitation energies above the α decay threshold was studied using 14C+α resonance elastic scattering and (7Li,t) a-transfer reactions. A number of states with large α reduced widths have been observed, indicating that the a-cluster degree of freedom plays an important role in this NZ nucleus. A 0+ state with an α reduced width exceeding the single particle limit was identified at an excitation energy of 9.90.3 MeV. We discuss evidence that states of this kind are common in light nuclei and give possible explanations of this feature. Also, the astrophysical implications of the cluster structure of 18O is discussed. © 2010 IOP Publishing Ltd
Investigation of the alpha-cluster structure of Ne-22 and Mg-22
An excitation function for resonance elastic scattering of alpha particles on O-18 and Ne-18 was measured using the method of inverse geometry with a very thick target. Spectroscopic information was obtained for 23 levels in the excitation energy region from 11.9 to 13.7 MeV in Ne-22. Twelve of them are new. General features of a-cluster bands in Ne-22 are analyzed in the framework of the potential model with a deep potential well. Predictions for the 11(-) level in Ne-22, as well as for the isotopic shift of the cluster levels in Mg-22, are given. Evidence is presented that new perspectives on the study of nuclear structure and nuclear spectroscopy can be obtained in complimentary measurements of alpha-cluster states in mirror Nnot equalZ nuclei.status: publishe
New perspectives in the studies of resonance scattering
We consider various possibilities for studies of nuclear structure in resonance reactions induced by radioactive beam. We discuss investigations on both sides of nuclear stability as well as studies of the a-cluster structure of light nuclei applying the reverse geometry thick target method.status: publishe