910 research outputs found
Triaxial deformation in 10Be
The triaxial deformation in Be is investigated using a microscopic
model. The states of two valence neutrons are classified
based on the molecular-orbit (MO) model, and the -orbit is introduced
about the axis connecting the two -clusters for the description of the
rotational bands. There appear two rotational bands comprised mainly of and , respectively, at low excitation energy, where the two
valence neutrons occupy or orbits. The
triaxiality and the -mixing are discussed in connection to the molecular
structure, particularly, to the spin-orbit splitting. The extent of the
triaxial deformation is evaluated in terms of the electro-magnetic transition
matrix elements (Davydov-Filippov model, Q-invariant model), and density
distribution in the intrinsic frame. The obtained values turned out to be
.Comment: 15 pages, latex, 3 figure
Systematic analyses of the t t clustering effect in He isotopes
A systematic study on the ground state structure of He isotopes including 10He is presented through a new method developed on the basis of antisymmetrized molecular dynamics AMD , the generator coordinate method GCM , and the stochastic variational method SVM . In this approach, variational calculations are carried out by means of the GCM with the AMD wave functions produced by means of the SVM. A role of the t t cluster component is examined with the present method, allowing the wider configuration space containing simultaneously the t t valence neutrons structure and 4He valence neutrons strucutur
Emergency TeleOrthoPaedics m-health system for wireless communication links
For the first time, a complete wireless and mobile emergency TeleOrthoPaedics system with field trials and expert opinion is presented. The system enables doctors in a remote area to obtain a second opinion from doctors in the hospital using secured wireless telecommunication networks. Doctors can exchange securely medical images and video as well as other important data, and thus perform remote consultations, fast and accurately using a user friendly interface, via a reliable and secure telemedicine system of low cost. The quality of the transmitted compressed (JPEG2000) images was measured using different metrics and doctors opinions. The results have shown that all metrics were within acceptable limits. The performance of the system was evaluated successfully under different wireless communication links based on real data
Important role of the spin-orbit interaction in forming the 1/2^+ orbital structure in Be isotopes
The structure of the second 0^+ state of ^{10}Be is investigated using a
microscopic model based on the molecular-orbit (MO) model.
The second 0^+ state, which has dominantly the (1/2^+)^2 configuration, is
shown to have a particularly enlarged structure. The kinetic
energy of the two valence neutrons occupying along the axis is
reduced remarkably due to the strong clustering and, simultaneously,
the spin-orbit interaction unexpectedly plays important role to make the energy
of this state much lower. The mixing of states with different spin structure is
shown to be important in negative-parity states. The experimentally observed
small-level spacing between 1^- and 2^- (~ 300 keV) is found to be an evidence
of this spin-mixing effect. ^{12}{Be} is also investigated using
model, in which four valence neutrons are considered to
occupy the (3/2^-)^2(1/2^+)^2 configuration. The energy surface of ^{12}Be is
shown to exhibit similar characteristics, that the remarkable
clustering and the contribution of the spin-orbit interaction make the binding
of the state with (3/2^-)^2(1/2^+)^2 configuration properly stronger in
comparison with the closed p-shell (3/2^-)^2(1/2^-)^2 configuration.Comment: 14 pages, 4 figure
Static and Dynamic Chain Structures in the Mean-Field Theory
We give a brief overview of recent work examining the presence of
-clusters in light nuclei within the Skyrme-force Hartree-Fock model.
Of special significance are investigations into -chain structures in
carbon isotopes and O. Their stability and possible role in fusion
reactions are examined in static and time-dependent Hartree-Fock calculations.
We find a new type of shape transition in collisions and a centrifugal
stabilization of the chain state in a limited range of angular
momenta. No stabilization is found for the chain.Comment: Fusionn 11 Conference, St. Malo, France, 201
A massive star origin for an unusual helium-rich supernova in an elliptical galaxy
The unusual helium-rich (type Ib) supernova SN 2005E is distinguished from
any supernova hitherto observed by its faint and rapidly fading light curve,
prominent calcium lines in late-phase spectra and lack of any mark of recent
star formation near the supernova location. These properties are claimed to be
explained by a helium detonation in a thin surface layer of an accreting white
dwarf (Perets et al. 2010). Here we report on observations of SN 2005cz
appeared in an elliptical galaxy, whose observed properties resemble those of
SN 2005E in that it is helium-rich and unusually faint, fades rapidly, shows
much weaker oxygen emission lines than those of calcium in the well-evolved
spectrum. We argue that these properties are best explained by a core-collapse
supernova at the low-mass end () of the range of massive stars
that explode (Smartt 2009). Such a low mass progenitor had lost its
hydrogen-rich envelope through binary interaction, having very thin oxygen-rich
and silicon-rich layers above the collapsing core, thus ejecting a very small
amount of radioactive Ni and oxygen. Although the host galaxy NGC 4589
is an elliptical, some studies have revealed evidence of recent star-formation
activity (Zhang et al. 2008), consistent with the core-collapse scenario.Comment: Accepted by Nature (24 March 2010), 32 pages including Supplementary
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Molecular-orbital structure in neutron-rich C isotopes
The molecule-like structure of the C isotopes (A=12, 14, 16) is investigated using a microscopic model. The valence neutrons are classified based on the molecular-orbit (MO) model, and both -orbit and -orbit are introduced around three -clusters. The valence neutrons which occupy the -orbit increase the binding energy and stabilize the linear-chain of 3 against the breathing-like break-up. However, C with the -orbit does not show clear energy minimum against the bending-like path. The combination of the valence neutrons in the - and the -orbit is promising to stabilize the linear-chain state against the breathing- and bending- modes, and it is found that the excited states of C with the configuration for the four valence neutrons is one of the most promising candidates for such structure
Simplified method to include the tensor contribution in cluster model
We propose a simplified model to directly take into account the contribution of the tensor interaction SMT for light nuclei by extending the cluster model. In 8Be, the energy curve with respect to the relative distance between the two 4He clusters suggests that the cluster structure persists even though the tensor interaction contributes strongly. In addition to SMT, a simplified method to take into account the strong spin orbit contributions is introduced and the coupling effects of these two models is shown to be important in 12C, in contrast to 8B
Evaluation of inter-granular coupling in stacked perpendicular recording media
AbstractThe trial for quantitative evaluation of inter-granular coupling in stacked perpendicular recording media is reported. The evaluation is realized by analyzing magnetic domain in relation with microstructure of the cap layer initial growth layer. When the thickness of cap layer is increased, the change of magnetic domain from single magnetic domain to maze magnetic domain can be observed. The critical thickness of the cap layer where the change happened was around 5.1nm. According to this analysis, when granular layer and cap layer of stacked media are assumed to be single layer, inter-granular coupling with amount of around 2.9erg/cm2 was obtained which agrees with the simulation result qualitatively
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