164 research outputs found
Anatomie du nerf alvéolaire inférieur
International audienceLe nerf alvĂ©olaire infĂ©rieur prĂ©sente un trajet global commun, mais aussi une variabilitĂ© anatomique (type trifurquĂ©, bifurquĂ©, ou plexiforme, foramen men-tonnier unique ou double, rond ou ovale) qui doit tout de mĂȘme inciter Ă la plus grande prudence, par une imagerie systĂ©matique de type scanner mandibulaire, avant tout geste Ă proximitĂ© du nerf pour dĂ©tecter les Ă©ventuelles variation
Alpha decay and proton-neutron correlations
We study the influence of proton-neutron (p-n) correlations on alpha-decay
width. It is shown from the analysis of alpha Q values that the p-n
correlations increase the penetration of the alpha particle through the Coulomb
barrier in the treatment following Gamow's formalism, and enlarges the total
alpha-decay width significantly.
In particular, the isoscalar p-n interactions play an essential role in
enlarging the alpha-decay width.
The so-called "alpha-condensate" in Z > 84 isotopes are related to the strong
p-n correlations.Comment: 5 pages, 6 figures, accepted for publication in Phys. Rev. C (R.C.
Ternary cluster decay within the liquid drop model
Longitudinal ternary and binary fission barriers of Ar, Ni and
Cf nuclei have been determined within a rotational liquid drop model
taking into account the nuclear proximity energy. For the light nuclei the
heights of the ternary fission barriers become competitive with the binary ones
at high angular momenta since the maximum lies at an outer position and has a
much higher moment of inertia.Comment: Talk presented at the 9th International Conference on Clustering
Aspects of Nuclear Structure and Dynamics (CLUSTERS'07
Microsurgical anatomy of the fourth ventricle
Anatomical description of the fourth ventricle is essential for an accurate understanding of its related tumoral pathologies and surgical approach respecting cerebellar and brainstem structures. Numerous cadaver pictures illustrate this chapter which contains V4 floor and roof description and its vascularization
A novel manifestation of -clustering: new ' + Pb' states in Po revealed by their enhanced E1 decays
Excited states in Po were populated by transfer using the
Pb(O, C) reaction and their deexcitation -rays
were studied with the Euroball array. Several levels were found to decay by a
unique E1 transition (E 1 MeV) populating the yrast state with the
same spin value. Their lifetimes were measured by the DSAM method. The values,
found in the range [0.1-1.4] ps, lead to very enhanced transitions, B(E1) =
2 - 1 W.u.. These results are discussed in terms
of an -cluster structure which gives rise to states with non-natural
parity values, provided that the composite system cannot rotate collectively,
as expected in the ' + Pb' case. Such states due to the
oscillatory motion of the -core distance are observed for the first
time.Comment: 4 pages, 3 figures, accepted for publication in Phys. Rev. Let
Alpha-decay Rates of Yb and Gd in Solar Neutrino Detectors
The -decay rates for the nuclides Yb
and Gd have been estimated from transmission probabilities
in a systematic -nucleus potential and from an improved fit to
-decay rates in the rare-earth mass region. Whereas -decay of
Gd in natural gadolinium is a severe obstacle for the use of gadolinium
as a low-energy solar-neutrino detector, we show that
-decay does not contribute significantly to the background in a
ytterbium detector. An extremely long -decay lifetime of Yb
is obtained from calculation, which may be close to the sensitivity limit in a
low-background solar neutrino detector.Comment: 12 pages, 1 figure; An author name was correcte
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