1,860 research outputs found
When do we feel sorry for others?: an externality of lake use as an example
The purpose of the study was to verify, through the use of an experimental method, the assumption that the âeconomic humanâ pays more attention to the externality he/she causes as the strength of externality increases. We used a social-experiment design within an undergraduate classroom to test assumptions, using statistical method. A lakeside plant was used as an example. Our results confirmed the following: (1) 66% of subjects behaved altruistically, while the remainder (34%) behaved selfishly, suggesting that the assumption of mainstream economics may not be appropriate; (2) when we compared situations in which the plots with the natural resource (e.g. the plant) to which the economic human had property rights were large or small in number, those who possessed larger plots tended to be more conservative in resource use; and (3) when we compared situations where the economic humanâs extent of influence on natural resources was large or small, those with greater influence tended to be more conservative in resource use. Although mainstream economics assumes a rational economic humanâwho is supposedly selfishâour results suggest that altruistic behaviour dominates selfish behaviour, and that altruistic behavior should be taken into greater consideration when making policy
Peculiar Behavior of Si Cluster Ions in Solid Al
A peculiar ion behavior is found in a Si cluster, moving with a speed of
~0.22c (c: speed of light) in a solid Al plasma: the Si ion, moving behind the
forward moving Si ion closely in a several angstrom distance in the cluster,
feels the wake field generated by the forward Si. The interaction potential on
the rear Si may balance the deceleration backward force by itself with the
acceleration forward force by the forward Si in the longitudinal moving
direction. The forward Si would be decelerated normally. However, the
deceleration of the rear Si, moving behind closely, would be reduced
significantly, and the rear Si may catch up and overtake the forward moving Si
in the cluster during the Si cluster interaction with the high-density Al
plasma
SPMHD simulations of Structure Formation
The intracluster medium of galaxy clusters is permeated by {\mu}G magnetic
fields. Observations with current and future facilities have the potential to
illuminate the role of these magnetic fields play in the astrophysical
processes of galaxy clusters. To obtain a greater understanding of how the
initial seed fields evolve to the magnetic fields in the intracluster medium
requires magnetohydrodynamic simulations. We critically assess the current
Smoothed Particle Magneto-Hydrodynamics (SPMHD) schemes, especially
highlighting the impact of a hyperbolic divergence cleaning scheme and
artificial resistivity switch on the magnetic field evolution in cosmological
simulations of the formation of a galaxy cluster using the N-body/SPMHD code
gcmhd++. The impact and performance of the cleaning scheme and two different
schemes for the artificial resistivity switch is demonstrated via idealized
test cases and cosmological simulations. We demonstrate that the hyperbolic
divergence cleaning scheme is effective at suppressing the growth of the
numerical divergence error of the magnetic field and should be applied to any
SPMHD simulation. Although the artificial resistivity is important in the
strong field regime, it can suppress the growth of the magnetic field in the
weak field regime, such as galaxy clusters. With sufficient resolution,
simulations with divergence cleaning can reproduce observed magnetic fields. We
conclude that the cleaning scheme alone is sufficient for galaxy cluster
simulations, but our results indicate that the SPMHD scheme must be carefully
chosen depending on the regime of the magnetic field.Comment: 15 pages, 11 figures, published (MNRAS 476 2890
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