5,093 research outputs found
Nuclear Reactions: A Challenge for Few- and Many-Body Theory
A current interest in nuclear reactions, specifically with rare isotopes
concentrates on their reaction with neutrons, in particular neutron capture. In
order to facilitate reactions with neutrons one must use indirect methods using
deuterons as beam or target of choice. For adding neutrons, the most common
reaction is the (d,p) reaction, in which the deuteron breaks up and the neutron
is captured by the nucleus. Those (d,p) reactions may be viewed as a three-body
problem in a many-body context. This contribution reports on a feasibility
study for describing phenomenological nucleon-nucleus optical potentials in
momentum space in a separable form, so that they may be used for Faddeev
calculations of (d,p) reactions.Comment: to appear in the Proceedings of HITES 2012: Conference on `Horizons
of Innovative Theories, Experiments, and Supercomputing in Nuclear Physics',
June 4-7, 2012, New Orleans, Louisian
Estimation of Precautionary Demand by Financial Anxieties
Pioneering work of modelling financial anxieties was given by Kimura et al (1999) as psychological change of people due to financial shocks. Since they regressed financial position (easy or tight) by nonstationary interest rate, their results exhibit high peaks not only in financial crisis period of 1997 and 1998, but also in the bubble economy period of 1987 to 1989, which seems to be a spurious regression. Furthermore, defining financial anxieties as the conditional variance in TARCH model, one of estimated coefficients did not satisfy sign condition. We got rid of these difficulties by introducing a growth rate model, where a change of financial position (toward ''tight'') under a change of interest rate (toward ''fall'') is regarded as financial anxieties. Such anxieties are quantified by conditional variance of EGARCH model and shown to be stationary. Precautionary demand caused by financial anxieties is estimated in VEC model and it is shown that money adjusted by precautionary demand satisfies a long-run equilibrium relationship in the system (adjusted money, real GDP, interest rate) even in the interval 1980q1 to 2003q2.financial anxieties, precautionary demand, cointegration, EGARCH
FE analysis on tube hydroforming of small diametr ZM21 magnesium alloy tube
Tube hydroforming (THF) is one of the plasticity processing methods. Tubular parts, for instance automotive components are expanded by forces such as internal pressure and axial compression in order to deform an objective shape. THF has less restriction on shape and size of workpieces owing to adopting the liquid tool. The demand of a small diameter magnesium alloy tubular parts have been increased for applying small medical and electronic devices. In this study, it was investigated that influence of process conditions such as processing temperature, internal pressure and axial feeding amount on formability of small diameter ZM21 magnesium alloy tube with outer diameter of 2.0mm and thickness of 0.20mm. Furthermore, the processing conditions for improving the formability of material in THF were examined. For prior evaluation of deformation characteristics in the warm THF of small diameter ZM21 magnesium alloy tube, a finite element (FE) simulation was conducted. The FE method (FEM) code was used LS-DYNA 3D for analysis of the FE model of the tube and the dies. The material characteristics were obtained by tensile test and fracture test. From FE analysis results, it was elucidated that effect of the processing temperature, the variable internal pressure and the axial feeding amount on deformation behavior. The formability of ZM21 magnesium alloy tube was improved by processing at 250 C. The difference of deformation characteristic between FE results and experimental results was compared. As the results, the processing condition which could improve the formability of ZM21 tube was clarified using this FE model. The effect of adding the straightening stage in the loading path after the preform on formability was investigated. The thinning of the wall thickness of the tube was inhibited by calibration after the axial feeding
Transport criticality of the first-order Mott transition in a quasi-two-dimensional organic conductor, -(BEDT-TTF)Cu[N(CN)]Cl
An organic Mott insulator, -(BEDT-TTF)Cu[N(CN)]Cl, was
investigated by resistance measurements under continuously controllable He gas
pressure. The first-order Mott transition was demonstrated by observation of
clear jump in the resistance variation against pressure. Its critical endpoint
at 38 K is featured by vanishing of the resistive jump and critical divergence
in pressure derivative of resistance, , which are consistent with the prediction of the dynamical mean field
theory and have phenomenological correspondence with the liquid-gas transition.
The present results provide the experimental basis for physics of the Mott
transition criticality.Comment: 4 pages, 5 figure
NMR Evidence for Antiferromagnetic Transition in the Single-Component Molecular Conductor, [Au(tmdt)_{2}] at 110 K
We present the results of a ^{1}H NMR study of the single-component molecular
conductor, [Au(tmdt)_{2}].
A steep increase in the NMR line width and a peak formation of the nuclear
spin-lattice relaxation rate, 1/T_{1}, were observed at around 110 K.
This behavior provides clear and microscopic evidences for a magnetic phase
transition at considerably high temperature among organic conductors.
The observed variation in 1/T_{1} with respect to temperature indicates the
highly correlated nature of the metallic phase.Comment: 5pages, 6figures to be published in J. Phys. Soc. Jp
Resonant inelastic x-ray scattering probes the electron-phonon coupling in the spin-liquid kappa-(BEDT-TTF)2Cu2(CN)3
Resonant inelastic x-ray scattering at the N K edge reveals clearly resolved
harmonics of the anion plane vibrations in the kappa-(BEDT-TTF)2Cu2(CN)3
spin-liquid insulator. Tuning the incoming light energy at the K edge of two
distinct N sites permits to excite different sets of phonon modes. Cyanide CN
stretching mode is selected at the edge of the ordered N sites which are more
strongly connected to the BEDT-TTF molecules, while positionally disordered N
sites show multi-mode excitation. Combining measurements with calculations on
an anion plane cluster permits to estimate the sitedependent electron-phonon
coupling of the modes related to nitrogen excitation
Initial exploratory investigations of some simple candidate management procedures for southern Bluefin tuna.
Simple constant
proportion and target based empirical candidate management procedures are applied to the
basic grid operating model and a low recruitment robustness test for SBT . The first two approaches , DMM1 and
DMM2 , respectively use CPUE index data only, while DMM3 ad ds gene tagging data to the DMM2 approach.
The key results are that the DMM2 target based approach substantially outperforms the constant proportion
DMM1 one in terms of smoothness of the TAC trajectories, and that (at least as far as investigations have b een
possible to date) the addition of gene tagging data offers little improvement to depletion statistics in instances
where low recruitment has occurred . Performance under DMM2 is unusually good, but this approach still needs
to be subjected to the other robustness tests, and further attempts need to be made to seek more improvement
in performance when gene tagging data are used
Inclusive and exclusive photoproduction on the deuteron: - and -threshold phenomena
Inclusive and exclusive photoproduction on the deuteron are
investigated theoretically. Modern hyperon-nucleon forces and a recently
updated kaon photoproduction operator for the process are
used. Sizable effects of the hyperon-nucleon final state interaction are found
near the and thresholds in the inclusive reaction.
Angular distributions for the exclusive process show clear final state
interaction effects in certain kinematic regions. Precise data especially for
the inclusive process around the threshold would help to clarify
the strength and property of the interaction.Comment: 14 pages, 10 figure
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