9,658 research outputs found
Ariel - Volume 4 Number 1
Editors
David A. Jacoby
Eugenia Miller
Tom Williams
Associate Editors
Paul Bialas
Terry Burt
Michael Leo
Gail Tenikat
Editor Emeritus and Business Manager
Richard J. Bonnano
Movie Editor
Robert Breckenridg
The effects on developing countries of the Kyoto Protocol and carbon dioxide emissions trading
The trading of rights to emit carbon dioxide has not officially been sanctioned by the United Nations Framework Convention on Climate Change, but it is of interest to investigate the consequences, both for industrial (Annex B) and developing countries, of allowing such trades. The authors examine the trading of caps assigned to Annex B countries under the Kyoto Protocol and compare the outcome with a world in which Annex B countries meet with their Kyoto targets without trading. Under the trading scenario the former Soviet Union is the main seller of carbon dioxide permits and Japan, the European Union, and the United States are the main buyers. Permit trading is estimated to reduce the aggregate cost of meeting the Kyoto targets by about 50 percent, compared with no trading. Developing countries, though they do not trade, are nonetheless affected by trading. For example, the price of oil and the demand for other developing country exports are higher with trading than without. The authors also consider what might happen if developing countries were to voluntarily accept caps equal to Business as Usual Emissions and were allowed to sell emission reductions below these caps to Annex B countries. The gains from emissions trading could be big enough to give buyers and sellers incentive to support the system. Indeed, a global market for rights to emit carbon dioxide could reduce the cost of meeting the Kyoto targets by almost 90 percent, if the market were to operate competitively. The division of trading gains, however, may make a competitive outcome unlikely: Under perfect competition, the vast majority of trading gains go to buyers of permits rather than to sellers. Even markets in which the supply of permits is restricted can, however, substantially reduce the cost to Annex B countries of meeting their Kyoto targets, while yielding profits to developing countries that elect to sell permits.Economic Theory&Research,Environmental Economics&Policies,Markets and Market Access,Montreal Protocol,Climate Change,Environmental Economics&Policies,Carbon Policy and Trading,Energy and Environment,Economic Theory&Research,Montreal Protocol
Magnetic shielding and vacuum test for passive hydrogen masers
Vibration tests on high permeability magnetic shields used in the SAO-NRL Advanced Development Model (ADM) hydrogen maser were made. Magnetic shielding factors were measured before and after vibration. Preliminary results indicate considerable (25%) degradation. Test results on the NRL designed vacuum pumping station for the ADM hydrogen maser are also discussed. This system employs sintered zirconium carbon getter pumps to pump hydrogen plus small ion pumps to pump the inert gases. In situ activation tests and pumping characteristics indicate that the system can meet design specifications
Chemical Abundances of Planetary Nebulae in M33
Using spectroscopic data presented in Magrini et al. (2003), we have analyzed
with the photoionization code CLOUDY 94.00 (Ferland et al. 1998) 11 Planetary
Nebulae belonging to the spiral galaxy M 33. Central star temperatures and
nebular parameters have been determined. In particular the chemical abundances
of He/H, O/H, N/H, Ar/H, and S/H have been measured and compared with values
obtained via the Ionization Correction Factors (ICFs) method, when available.
Chemical abundance relationships have been investigated; in particular, a
correlation between N/H and N/O similar to the Galactic one (Henry 1989), and a
feeble anti-correlation between O/H and N/O have been found.
A gradient in O/H across the disc of M~33 is indicatively consistent with the
one found from HII regions in this galaxy (Vilchez et al 1988). Further studies
in the more external parts of M~33 are however needed to ascertain this point.
The present result shows that oxygen and helium abundances (with lower accuracy
also nitrogen, argon and sulphur) can be actually estimated from the brightest
PNe of a galaxy, even if the electron temperature cannot be measured. We also
found that the oxygen abundance is quite independent of the absolute magnitude
of the PN and consequently the brightest PNe are representative of the whole PN
population. This represents an important tool to measure the metallicity of
galaxies at the time of the formation of PNe progenitors.Comment: 17 pages, 6 figures, A&A accepte
The Local Group Census: planetary nebulae in Sextans B
Five planetary nebulae (PNe) have been discovered in the nearby dwarf
irregular galaxy. Emission line images were obtained using the Wide Field
Camera of the 2.5m Isaac Newton Telescope (INT) at La Palma (Spain). The
candidate PNe were identified by their point-like appearance and relatively
strong [OIII] emission-line fluxes. They are located within a galactocentric
distance of 2.8 arcmin, corresponding to 1.1 kpc at the distance of Sextans B.
Luminosities are in the range 1800--5600Lsolar. Sextans B is one of the
smallest dwarf irregular galaxies with a PN population. The number of PNe
detected suggest an enhanced star formation rate between 1 and 5 Gyr ago.Comment: 7 pages, 2 figure
Evaluation and Management of Sleep Disorders in the Hand Surgery Patient.
Despite posing a significant public health threat, sleep disorders remain poorly understood and often underdiagnosed and mismanaged. Although sleep disorders are seemingly unrelated, hand surgeons should be mindful of these because numerous conditions of the upper extremity have known associations with sleep disturbances that can adversely affect patient function and satisfaction. In addition, patients with sleep disorders are at significantly higher risk for severe, even life-threatening medical comorbidities, further amplifying the role of hand surgeons in the recognition of this condition
The Rapidly Fading Afterglow from the Gamma-Ray Burst of 1999 May 6
We report on the discovery of the radio afterglow from the gamma-ray burst
(GRB) of 1999 May 6 (GRB 990506) using the Very Large Array (VLA). The radio
afterglow was detected at early times (1.5 days), but began to fade rapidly
sometime between 1 and 5 days after the burst. If we attribute the radio
emission to the forward shock from an expanding fireball, then this rapid onset
of the decay in the radio predicts that the corresponding optical transient
began to decay between 1 and 5 minutes after the burst. This could explain why
no optical transient for GRB 990506 was detected in spite of numerous searches.
The cause of the unusually rapid onset of the decay for the afterglow is
probably the result of an isotropically energetic fireball expanding into a low
density circumburst environment. At the location of the radio afterglow we find
a faint (R ~ 24 mag) host galaxy with a double morphology.Comment: in press at ApJ Letters, 13 page LaTeX document includes 2 postscript
figure
Investigation of the parameters of a dense, inductively generated stripping plasma for the FAIR-Project
- …
