16,319 research outputs found
Thin film atomic hydrogen detectors
Thin film and bead thermistor atomic surface recombination hydrogen detectors were investigated both experimentally and theoretically. Devices were constructed on a thin Mylar film substrate. Using suitable Wheatstone bridge techniques sensitivities of 80 microvolts/2x10 to the 13th power atoms/sec are attainable with response time constants on the order of 5 seconds
SU(m|n) supersymmetric Calogero-Sutherland model confined in harmonic potential
In this work, we study a continuous quantum system of a mixture of bosons and
fermions with the supersymmetry SU(m|n). The particles are confined in a
harmonic well and interact with each other through the 1/r2 interaction. The
ground state wavefunction is constructed explicitly for the most general
SU(m|n) case, with the ground state energy given explicitly. The full energy
spectrum of excitations in the SU(m|n) model is also equal spaced. In the
limiting case where there are no bosons in the system, our results reduce to
those obtained previously.Comment: 9 pages, preprint of ETH-Lausanne (August 1996
Optically induced free carrier light modulator
Signal carrier laser beam is optically modulated by a second laser beam of different frequency acting on a free carrier source to which the signal carrier laser is directed. The second laser beam affects the transmission characteristics of the free carrier source to light from the signal carrier laser, thus modulating it
Health Insurance, Labor Supply, and Job Mobility: A Critical Review of the Literature
This paper provides a critical review of the empirical literature on the relationship between health insurance, labor supply, and job mobility. We review over 50 papers on this topic, almost exclusively written in the last 10 years. We reach five conclusions. First, there is clear and unambiguous evidence that health insurance is a central determinant of retirement decisions. Second, there is fairly clear evidence that health insurance is not a major determinant of the labor supply and welfare exit decisions of low income mothers. Third, there is fairly compelling evidence that health insurance is an important factor in the labor supply decisions of secondary earners. Fourth, while there is some division in the literature, the most convincing evidence suggests that health insurance plays an important role in job mobility decisions. Finally, there is virtually no evidence in the literature on the welfare implications of these results. We present some rudimentary calculations which suggest that the welfare costs of job lock are likely to be modest. Our general conclusion is that health insurance has important effects on both labor force participation and job choice, but that it is not clear whether or not these effects results in large losses of either welfare or efficiency.
One Thing After Another: Why the Passage of Time Is Not an Illusion
Does time seem to pass, even though it doesn’t, really? Many philosophers think the answer is ‘Yes’—at least when ‘time’s passing’ is understood in a particular way. They take time’s passing to be a process by which each time in turn acquires a special status, such as the status of being the only time that exists, or being the only time that is present. This chapter suggests that, on the contrary, all we perceive is temporal succession, one thing after another, a notion to which modern physics is not inhospitable. The contents of perception are best described in terms of ‘before’ and ‘after’, rather than ‘past’, ‘present, and ‘future’
On the Second Law of thermodynamics and the piston problem
The piston problem is investigated in the case where the length of the
cylinder is infinite (on both sides) and the ratio is a very small
parameter, where is the mass of one particle of the gaz and is the mass
of the piston. Introducing initial conditions such that the stochastic motion
of the piston remains in the average at the origin (no drift), it is shown that
the time evolution of the fluids, analytically derived from Liouville equation,
agrees with the Second Law of thermodynamics.
We thus have a non equilibrium microscopical model whose evolution can be
explicitly shown to obey the two laws of thermodynamics.Comment: 29 pages, 9 figures submitted to Journal of Statistical Physics
(2003
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