82,600 research outputs found
Managing Psychopathic Employees
[Excerpt] What if a small but definable subset of the employee population were responsible for a major share of corporate crime and ethical breaches? If so, then developing policies that target them would improve the firm’s performance, not to mention its ethical climate. In this article I claim that psychopathic employees constitute such a subset, and I suggest human resource policies that can help firms cope with them
Self-regulated black hole accretion, the M-sigma relation, and the growth of bulges in galaxies
We argue that the velocity dispersions and masses of galactic bulges and
spheroids are byproducts of the feedback that regulates rapid black hole growth
in protogalaxies. We suggest that the feedback energy liberated by accretion
must pass through the accreting material, in an energy-conserving flux close-in
and a momentum-conserving flux further out. If the inflowing gas dominates the
gravitational potential outside the Bondi radius, feedback from
Eddington-limited accretion drives the density profile of the gas to that of a
singular isothermal sphere. We find that the velocity dispersion associated
with the isothermal potential, sigma, increases with time as the black hole
mass M grows, in such a way that M is proportional to sigma^4. The coefficient
of this proportionality depends on the radius at which the flow switches from
energy conserving to momentum conserving, and gives the observed M-sigma
relation if the transition occurs at ~100 Schwarzschild radii. We associate
this transition with radiative cooling and show that bremsstrahlung, strongly
boosted by inverse Compton scattering in a two-temperature (T_p >> T_e) plasma,
leads to a transition at the desired radius.
According to this picture, bulge masses M_b are insensitive to the virial
masses of their dark matter haloes, but correlate linearly with black hole
mass. Our analytic model also explains the M_b-sigma (Faber-Jackson) relation
as a relic of black hole accretion. The model naturally explains why the
M-sigma relation has less scatter than either the M-M_b (Magorrian) or the
Faber-Jackson relation. It suggests that the M-sigma relation could extend down
to very low velocity dispersions, and predicts that the relation should not
evolve with redshift.Comment: 6 pages, no figures, submitted to Monthly Notices of the Royal
Astronomical Societ
Shifting Norms in Wage Determination
macroeconomics, wages, wage determination, norm shift, manufacturing, trucking, union labor
Airflow control system for supersonic inlets
In addition to fixed and variable bleed devices provided for controlling the position of a terminal shock wave in a supersonic inlet, a plurality of free piston valves are disposed around the periphery of a cowling of a supersonic engine inlet. The free piston valves are disposed in dump passageways, each of which begin at a bleed port in the cowling that is located in the throat region of the inlet, where the diameter of the centerbody is near maximum, and terminates at an opening in the cowling adjacent a free piston valve. Each valve is controlled by reference pressure
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