3,753 research outputs found
On the Fekete-Szeg\"o problem for concave univalent functions
We consider the Fekete-Szeg\"o problem with real parameter for the
class of concave univalent functions.Comment: 9 page
Small Quadrupole Deformation for the Dipole Bands in 112In
High spin states in In were investigated using Mo(O,
p3n) reaction at 80 MeV. The excited level have been observed up to 5.6 MeV
excitation energy and spin 20 with the level scheme showing three
dipole bands. The polarization and lifetime measurements were carried out for
the dipole bands. Tilted axis cranking model calculations were performed for
different quasi-particle configurations of this doubly odd nucleus. Comparison
of the calculations of the model with the B(M1) transition strengths of the
positive and negative parity bands firmly established their configurations.Comment: 10 pages, 11 figures, 2 table
Shell model study of the pairing correlations
A systematic study of the pairing correlations as a function of temperature
and angular momentum has been performed in the sd-shell region using the
spherical shell model approach. The pairing correlations have been derived for
even-even, even-odd and odd-odd systems near N=Z and also for the asymmetric
case of N=Z+4. The results indicate that the pairing content and the behavior
of pair correlations is similar in even-even and odd-mass nuclei. For odd-odd
N=Z system, angular momentum I=0 state is an isospin, t=1 neutron-proton paired
configuration. Further, these t=1 correlations are shown to be dramatically
reduced for the asymmetric case of N=Z+4. The shell model results obtained are
qualitatively explained within a simplified degenerate model
Numerical Investigation of the Thermo-Hydraulic Performance of Water-Based Nanofluids in a Dimpled Channel Flow using Al₂O₃, CuO, and Hybrid Al₂O₃-CuO as Nanoparticles
In this study, the authors study the impact of spherical dimple surfaces and nanofluid coolants on heat transfer and pressure drop. The main objective of this paper is to evaluate the thermal performance of nanofluids with respect to different Reynolds numbers (Re) and nanoparticle compositions in dimpled channel flow. Water-based nanofluids with Al2O3, CuO, and Al2O3-CuO nanoparticles are considered for this investigation with 1%, 2%, and 4% volume fraction for each nanofluid. The simulations are conducted at low Reynolds numbers varying from 500 to 1250, assuming constant and uniform heat flux. The effective properties of nanofluids are estimated using models proposed in the literature and are combined with the computational fluid dynamics solver ANSYS Fluent for the analysis. The results are discussed in terms of heat transfer coefficient, temperature distributions, pressure drop, Nusselt number, friction factors, and performance criterion for all the cases. For all cases of different nanoparticle compositions, the heat transfer coefficient was seen as 35%-46% higher for the dimpled channel in comparison with the smooth channel. Besides, it was observed that with increasing volume fraction, the values of heat transfer and pressure drop were increased. With a maximum of 25.18% increase in the thermal performance, the 1% Al2O3/water was found to be the best performing nanofluid at Re = 500 in the dimpled channel flow
Finite to infinite steady state solutions, bifurcations of an integro-differential equation
We consider a bistable integral equation which governs the stationary
solutions of a convolution model of solid--solid phase transitions on a circle.
We study the bifurcations of the set of the stationary solutions as the
diffusion coefficient is varied to examine the transition from an infinite
number of steady states to three for the continuum limit of the
semi--discretised system. We show how the symmetry of the problem is
responsible for the generation and stabilisation of equilibria and comment on
the puzzling connection between continuity and stability that exists in this
problem
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