3,233 research outputs found
Cost-Benefit Analysis of the Greenland Offshore Shrimp Fishery
This paper examines the social economic value of the Greenland off-shore shrimp fishery. The contribution of the fishery to the economy is examined us-ing a cost-benefit analysis where the objective of the report is to examine the current state of the fishery rather than possible changes, which are a political decision. The analysis is undertaken by examining the state and development of the off-shore shrimp fishery in Greenland, as well as the changes in profits, sales and production in the years 2006 and 2007. Financial accounts and costs data pro-vided by the companies fishing in Greenland have contributed to estimating the net value of the industry. The management cost is included as well in the analysis. The paper concludes that there is a positive economic benefit from the shrimp fishery in Greenland, which is believed to be caused by the efficient manage-ment system of the fishery (based on Individual Transferable Quotas). It is fur-ther shown that the companies and the crew gains nearly the whole net-benefit from the fishery, while the public finance are not gaining much. Acknowledgements. We want to thank the contact persons from the companies and Greenland Statistics: Søren Brandt (Qajaq Trawl), Carl Christensen (Niisa Trawl), Jens Bisgaard (Royal Greenland and Ice Trawl), Henrik Krogh and Kjeld Holmstrup (Polar Seafood) and Gert Schmidt, Per Lyster Pedersen and Lars Geraa from Greenland Statistics. We also want to thank Henrik Leth and Jens K. Lyberth from the Confederation of Greenland Employers for good discussions and help during the project as well as financial support. The study was made possible thanks to financial support from the Confederation of Greenland Employers.Greenland, shrimp, fishery, Cost-Benefit Analysis, economic rent
Creation of long-term coherent optical memory via controlled nonlinear interactions in Bose-Einstein condensates
A Bose-Einstein condensate confined in an optical dipole trap is used to
generate long-term coherent memory for light, and storage times of more than
one second are observed. Phase coherence of the condensate as well as
controlled manipulations of elastic and inelastic atomic scattering processes
are utilized to increase the storage fidelity by several orders of magnitude
over previous schemes. The results have important applications for creation of
long-distance quantum networks and for generation of entangled states of light
and matter.Comment: published version of the pape
High Redshift Standard Candles: Predicted Cosmological Constraints
We investigate whether future measurements of high redshift standard candles
(HzSCs) will be a powerful probe of dark energy, when compared to other types
of planned dark energy measurements. Active galactic nuclei and gamma ray
bursts have both been proposed as potential HzSC candidates. Due to their high
luminosity, they can be used to probe unexplored regions in the expansion
history of the universe. Information from these regions can help constrain the
properties of dark energy, and in particular, whether it varies over time.
We consider both linear and piecewise parameterizations of the dark energy
equation of state, , and assess the optimal redshift distribution a
high-redshift standard-candle survey could take to constrain these models.
The more general the form of the dark energy equation of state being
tested, the more useful high-redshift standard candles become. For a linear
parameterization of , HzSCs give only small improvements over planned
supernova and baryon acoustic oscillation measurements; a wide redshift range
with many low redshift points is optimal to constrain this linear model.
However to constrain a general, and thus potentially more informative, form of
, having many HzSCs can significantly improve limits on the nature of
dark energy.Comment: Accepted MNRAS, 27 Pages, 15 figures, matches published versio
Downsizing of supermassive black holes from the SDSS quasar survey (II). Extension to z~4
Starting from the quasar sample of the Sloan Digital Sky Survey (SDSS) for
which the CIV line is observed, we use an analysis scheme to derive the
z-dependence of the maximum mass of active black holes, which overcomes the
problems related to the Malmquist bias. The same procedure is applied to the
low redshift sample of SDSS quasars for which Hbeta measurements are available.
Combining with the results from the previously studied MgII sample, we find
that the maximum mass of the quasar population increases as (1+z)^(1.64+/-0.04)
in the redshift range 0.1<z<4, which includes the epoch of maximum quasar
activity.Comment: 9 pages, 8 figures. To appear in MNRA
X-ray Emission from the Radio Jet in 3C 120
We report the discovery of X-ray emission from a radio knot at a projected
distance of 25" from the nucleus of the Seyfert galaxy, 3C 120. The data were
obtained with the ROSAT High Resolution Imager (HRI). Optical upper limits for
the knot preclude a simple power law extension of the radio spectrum and we
calculate some of the physical parameters for thermal bremsstrahlung and
synchrotron self-Compton models. We conclude that no simple model is consistent
with the data but if the knot contains small regions with flat spectra, these
could produce the observed X-rays (via synchrotron emission) without being
detected at other wavebands.Comment: 6 pages latex plus 3 ps/eps figures. Uses 10pt.sty and
emulateapj.sty. Accepted for publication in the ApJ (6 Jan 99
- âŚ