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Economic inequality and burden-sharing in the provision of local environmental quality
Theoretical insight on the LK-99 material
Two recent preprints in physics archive (arXiv) have called the attention as
they claim experimental evidence that a Cu-substituted apatite material (called
LK-99) exhibits superconductivity at room temperature and pressure. If this
proves to be true, LK-99 will be the holy grail of superconductors. In this
work, we used Density-Functional Theory calculations to elucidate some key
features of the electronic structure of LK-99. Although some aspects of our
calculations are preliminary, we found that: i) in the ground state of the
material the ferromagnetic and antiferromagnetic configurations are practically
degenerated, ii) the material is metallic, iii) the Cu atoms seem to be hosts
in the lattice with not covalent bonds to other atoms and supporting almost
flat bands around the Fermi level, and iv) the electron-phonon coupling of
these flat bands seems to be dramatically large
Lactic acid production a bibliometric study
Bibliometrics is a documentary analysis tool that is positioning itself as a support to know and understand the study status of a specific topic. In this case, the VOSviewer software was used to determine the evolution of lactic acid production, carried out through a programmed search with the VOSviewer application, which allowed a clear and reliable bibliographic review for the topic development under study, which made possible to obtain enough material to know who, where and in what year have published about the latest advances in the production of lactic acid. The database used was Scopus, with the search equation âlactic acidâ and production and ânatural sourcesâ
Quinstant Dark Energy Predictions for Structure Formation
We explore the predictions of a class of dark energy models, quinstant dark
energy, concerning the structure formation in the Universe, both in the linear
and non-linear regimes. Quinstant dark energy is considered to be formed by
quintessence and a negative cosmological constant. We conclude that these
models give good predictions for structure formation in the linear regime, but
fail to do so in the non-linear one, for redshifts larger than one.Comment: 9 pages, 14 figures, "Accepted for publication in Astrophysics &
Space Science
Preliminary optical design of PANIC, a wide-field infrared camera for CAHA
In this paper, we present the preliminary optical design of PANIC (PAnoramic
Near Infrared camera for Calar Alto), a wide-field infrared imager for the
Calar Alto 2.2 m telescope. The camera optical design is a folded single
optical train that images the sky onto the focal plane with a plate scale of
0.45 arcsec per 18 micron pixel. A mosaic of four Hawaii 2RG of 2k x 2k made by
Teledyne is used as detector and will give a field of view of 31.9 arcmin x
31.9 arcmin. This cryogenic instrument has been optimized for the Y, J, H and K
bands. Special care has been taken in the selection of the standard IR
materials used for the optics in order to maximize the instrument throughput
and to include the z band. The main challenges of this design are: to produce a
well defined internal pupil which allows reducing the thermal background by a
cryogenic pupil stop; the correction of off-axis aberrations due to the large
field available; the correction of chromatic aberration because of the wide
spectral coverage; and the capability of introduction of narrow band filters
(~1%) in the system minimizing the degradation in the filter passband without a
collimated stage in the camera. We show the optomechanical error budget and
compensation strategy that allows our as built design to met the performances
from an optical point of view. Finally, we demonstrate the flexibility of the
design showing the performances of PANIC at the CAHA 3.5m telescope.Comment: This paper has been presented in the SPIE of Astronomical Telescopes
and Instrumentation 2008 in Marseille (France
PANIC: the new panoramic NIR camera for Calar Alto
PANIC is a wide-field NIR camera, which is currently under development for
the Calar Alto observatory (CAHA) in Spain. It uses a mosaic of four Hawaii-2RG
detectors and covers the spectral range from 0.8-2.5 micron(z to K-band). The
field-of-view is 30x30 arcmin. This instrument can be used at the 2.2m
telescope (0.45arcsec/pixel, 0.5x0.5 degree FOV) and at the 3.5m telescope
(0.23arcsec/pixel, 0.25x0.25 degree FOV). The operating temperature is about
77K, achieved by liquid Nitrogen cooling. The cryogenic optics has three flat
folding mirrors with diameters up to 282 mm and nine lenses with diameters
between 130 mm and 255 mm. A compact filter unit can carry up to 19 filters
distributed over four filter wheels. Narrow band (1%) filters can be used. The
instrument has a diameter of 1.1 m and it is about 1 m long. The weight limit
of 400 kg at the 2.2m telescope requires a light-weight cryostat design. The
aluminium vacuum vessel and radiation shield have wall thicknesses of only 6 mm
and 3 mm respectively.Comment: This paper has been presented in the SPIE of Astronomical Telescopes
and Instrumentation 2008 in Marseille (France
Protease-Activated Receptor 1 Contributes to Angiotensin II-Induced Cardiovascular Remodeling and Inflammation
Angiotensin II (Ang II) plays an important role in cardiovascular disease. It also leads to the activation of coagulation. The coagulation protease thrombin induces cellular responses by activating protease activated receptor 1 (PAR-1). We investigated if PAR-1 contributes to Ang II-induced cardiovascular remodeling and inflammation
The challenge of modelling nitrogen management at the field scale : simulation and sensitivity analysis of N2O fluxes across nine experimental sites using DailyDayCent
Peer reviewedPublisher PD
Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico
In central Mexico during the spring of 2007 we measured the initial emissions of 12 gases and the aerosol speciation for elemental and organic carbon (EC, OC), anhydrosugars, Clâ, NO[subscript 3]â, and 20 metals from 10 cooking fires, four garbage fires, three brick making kilns, three charcoal making kilns, and two crop residue fires. Global biofuel use has been estimated at over 2600 Tg/y. With several simple case studies we show that cooking fires can be a major, or the major, source of several gases and fine particles in developing countries. Insulated cook stoves with chimneys were earlier shown to reduce indoor air pollution and the fuel use per cooking task. We confirm that they also reduce the emissions of VOC pollutants per mass of fuel burned by about half. We did not detect HCN emissions from cooking fires in Mexico or Africa. Thus, if regional source attribution is based on HCN emissions typical for other types of biomass burning (BB), then biofuel use and total BB will be underestimated in much of the developing world. This is also significant because cooking fires are not detected from space. We estimate that ~2000 Tg/y of garbage are generated globally and about half may be burned, making this a commonly overlooked major global source of emissions. We estimate a fine particle emission factor (EFPM2.5) for garbage burning of ~10.5±8.8 g/kg, which is in reasonable agreement with very limited previous work. We observe large HCl emission factors in the range 2â10 g/kg. Consideration of the Cl content of the global waste stream suggests that garbage burning may generate as much as 6â9 Tg/yr of HCl, which would make it a major source of this compound. HCl generated by garbage burning in dry environments may have a relatively greater atmospheric impact than HCl generated in humid areas. Garbage burning PM[subscript 2.5] was found to contain levoglucosan and K in concentrations similar to those for biomass burning, so it could be a source of interference in some areas when using these tracers to estimate BB. Galactosan was the anhydrosugar most closely correlated with BB in this study. Fine particle antimony (Sb) shows initial promise as a garbage burning tracer and suggests that this source could contribute a significant amount of the PM2.5 in the Mexico City metropolitan area. The fuel consumption and emissions due to industrial biofuel use are difficult to characterize regionally. This is partly because of the diverse range of fuels used and the very small profit margins of typical micro-enterprises. Brick making kilns produced low total EFPM[subscript 2.5] (~1.6 g/kg), but very high EC/OC ratios (6.72). Previous literature on brick kilns is scarce but does document some severe local impacts. Coupling data from Mexico, Brazil, and Zambia, we find that charcoal making kilns can exhibit an 8-fold increase in VOC/CO over their approximately one-week lifetime. Acetic acid emission factors for charcoal kilns were much higher in Mexico than elsewhere. Our dirt charcoal kiln EFPM2.5 emission factor was ~1.1 g/kg, which is lower than previous recommendations intended for all types of kilns. We speculate that some PM[subscript 2.5] is scavenged in the walls of dirt kilns.National Science Foundation (U.S.) (Grant ATM-0513055)United States. Dept. of Defense (Strategic Environmental Research and Development Program (SERDP))United States. Dept. of Agriculture (Agreement 07-JV-11221649-060)United States. Dept. of Agriculture (Agreement 08-JV-11272166-039)United States. Forest ServiceRocky Mountain Research Station (Fort Collins, Colo.)Pacific Southwest Research Statio
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