372 research outputs found
Locally univalent approximations of analytic functions
In the present paper, we introduce a measure of the non-univalency of an analytic function, and we use it in order to find the best approximation of analytic function by a locally univalent normalized analytic function.</p
0+ states and collective bands in 228Th studied by the (p,t) reaction
The excitation spectra in the deformed nucleus 228Th have been studied by
means of the (p,t)-reaction, using the Q3D spectrograph facility at the Munich
Tandem accelerator. The angular distributions of tritons were measured for
about 110 excitations seen in the triton spectra up to 2.5 MeV. Firm 0+
assignments are made for 17 excited states by comparison of experimental
angular distributions with the calculated ones using the CHUCK3 code.
Assignments up to spin 6+ are made for other states. Sequences of states are
selected which can be treated as rotational bands and as multiplets of
excitations. Moments of inertia have been derived from these sequences, whose
values may be considered as evidence of the two-phonon nature of most 0+
excitations. Experimental data are compared with interacting boson model and
quasiparticle-phonon model calculations and with experimental data for 229Pa.Comment: 21 pages, 14 figure
How general are risk preferences? Choices under uncertainty in different domains.
We examine the extent to which an individual's actual insurance and investment choices display a stable ranking in willingness to bear risk, relative to his peers, across different contexts. We do so by examining the same individuals' decisions regarding their 401(k) asset allocations and their choices in five different employer-provided insurance domains, including health and disability insurance. We reject the null that there is no domain-general component of preferences. Among the five insurance domains, the magnitude of the domain-general component of preferences appears substantial; we find for example that one's choices in other insurance domains are substantially more predictive of one's choice in a given insurance domain than either one's detailed demographic characteristics or one's claims experience in that domain. However, we find considerably less predictive power between one's insurance choices and the riskiness of one's 401(k) asset allocations, suggesting that the common element of an individual's preferences may be stronger among domains that are "closer" in context. We also find that the relationship between insurance and investment choices appears considerably larger for employees who may be associated with better "financial sophistication." Overall, we view our findings as largely consistent with an important domain-general component of risk preferences.
Possible experimental signature of octupole correlations in the 0 states of the actinides
= 0 states have been investigated in the actinide nucleus
Pu up to an excitation energy of 3 MeV with a high-resolution (p,t)
experiment at = 24 MeV. To test the recently proposed = 0
double-octupole structure, the phenomenological approach of the
spdf-interacting boson model has been chosen. In addition, the total 0
strength distribution and the strength fragmentation have been compared
to the model predictions as well as to the previously studied (p,t) reactions
in the actinides. The results suggest that the structure of the 0 states
in the actinides might be more complex than the usually discussed pairing
isomers. Instead, the octupole degree of freedom might contribute
significantly. The signature of two close-lying 0 states below the
2-quasiparticle energy is presented as a possible manifestation of strong
octupole correlations in the structure of the 0 states in the actinides.Comment: 6 pages, 5 figures, published in Phys. Rev. C 88, 041303(R) (2013
A state of the art of flat-slab frame tests for gravity and lateral loading
The research was carried out in preparation of the SlabSTRESS experimental campaign, that is a part of the Transnational Access activities of the SERA (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe) project.This paper presents a critical review of the state of the art of experimental research concerning the seismic response of reinforced concrete flat slab frames. After a summary of tests on connections, the paper examines tests carried out on frames with gravity and cyclic lateral loading, and shake table tests; scaled specimens and one real scale study are included. A discussion of the results reached so far is provided focusing on the global response, the different load types and effects; the ultimate rotations at failure in relation to the gravity shear and a classification of different failure modes for different types of connections. Based on this analysis, the research needs are highlighted. An experimental program launched to address these open questions is described. Further open topics are highlighted.authorsversionpublishe
Positional Disorder, Spin-Orbit Coupling and Frustration in GaMnAs
We study the magnetic properties of metallic GaMnAs. We calculate the
effective RKKY interaction between Mn spins using several realistic models for
the valence band structure of GaAs. We also study the effect of positional
disorder of the Mn on the magnetic properties. We find that the interaction
between two Mn spins is anisotropic due to spin-orbit coupling within both the
so-called spherical approximation and in the more realistic six band model. The
spherical approximation strongly overestimates this anistropy, especially for
short distances between Mn ions. Using the obtained effective Hamiltonian we
carry out Monte Carlo simulations of finite and zero temperature magnetization
and find that, due to orientational frustration of the spins, non-collinear
states appear in both valence band approximations for disordered, uncorrelated
Mn impurities in the small concentration regime. Introducing correlations among
the substitutional Mn positions or increasing the Mn concentration leads to an
increase in the remnant magnetization at zero temperature and an almost fully
polarized ferromagnetic state.Comment: 17 Pages, 13 Figure
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