2,304 research outputs found
Impact assessment of irrigation management transfer in the Alto Rio Lerma Irrigation District, Mexico
Irrigation managementPrivatizationAssessmentEconomic aspectsLegal aspectsData collectionWater rightsWater allocationWater distributionGroundwaterFinancingMaintenanceOperationsAgricultural productionWater users' associationsFarmer participation
Performance of two transferred modules in the Lagunera Region: Water relations
Water policy / Performance / Privatization / Irrigation systems / Operations / Maintenance / Irrigation efficiency / Water users' associations / Water rights / Water allocation / Water supply / Water distribution
On the connection of Gamma-rays, Dark Matter and Higgs searches at LHC
Motivated by the upcoming Higgs analyzes we investigate the importance of the
complementarity of the Higgs boson chase on the low mass WIMP search in direct
detection experiments and the gamma-ray emission from the Galactic Center
measured by the Fermi-LAT telescope in the context of the . We obtain the relic abundance, thermal cross section,
the WIMP-nucleon cross section in the low mass regime and network them with the
branching ratios of the Higgs boson in the model. We conclude that the Higgs
boson search has a profound connection to the dark matter problem in our model,
in particular for the case that ( GeV) the BR(
WIMPs) . This scenario could explain this plateau of any mild
excess regarding the Higgs search as well as explain the gamma-ray emission
from the galactic center through the channel with a WIMP in the mass
range of 25-45 GeV, while still being consistent with the current limits from
XENON100 and CDMSII. However, if the recent modest excesses measured at LHC and
TEVATRON are confirmed and consistent with a standard model Higgs boson this
would imply that GeV, consequently ruling out any attempt to
explain the Fermi-LAT observations.Comment: 8 pages, 9 figure
MetodologÃa para Detección de CaracterÃsticas Faciales con Fines de Reconocimiento de Emociones
Se cree que la detección de emociones podrá llevar a determinar el estado de _animo de una persona e incluso un posible fraude. La detección de rasgos faciales claves para la detección de una emoción son de fácil reconocimiento para los humanos, pero la dificultad crece cuando se realiza por medio de software. Por este motivo, la presente investigación aborda el problema de detección mediante varias técnicas, identificando una en especial basada en las proporciones _áureas la cual robustece la detección de rasgos faciales y por consiguiente la detección de la emoción; guardando siempre unas medidas de incertidumbre racionales.It is believed that the detection of emotions could lead to determine the mood of a person or even a possible fraud. The detection of key facial features to detect emotions are of easy recognition for humans, but the
diffculty increases when is done by software. For this reason, this investigation addresses the problem of detection of emotions through several techniques, identifying one in particular based on the golden proportions, which strengthens the detection of facial features and therefore the detection of emotion, keeping rational measures of uncertainty
Decoherence induced by an ordered environment
This Letter deals with the time evolution of a qubit weakly coupled to a
reservoir which has a symmetry broken state with long range order at finite
temperatures. In particular, we model the ordered reservoir by a standard BCS
superconductor with s-wave pairing. We study the reduced density matrix of a
qubit using both the time-convolutionless and Nakajima-Zwanzig approximations.
We study different kinds of couplings between the qubit and the superconducting
bath. We find that ordering in the superconducting bath generically leads to an
unfavorable non- Markovian faster-than-exponential decay of the qubit
coherence. On the other hand, a coupling of the qubit to the non-ordered sector
of the bath can result in a Markovian decoherence of the qubit with a drastic
reduction of the decoherence rate. Since these behaviors are endemic to the
ordered phase, qubits can serve as useful probes of continuous phase
transitions in their environment. We also briefly discuss the validity of our
main result, faster than exponential decay of the qubit coherences, for a qubit
coupled to a generic ordered bath with a spontaneously broken continuous
symmetry at finite temperatures.Comment: 6 pages, 3 figure
Low-Energy Charge-Density Excitations in MgB: Striking Interplay between Single-Particle and Collective Behavior for Large Momenta
A sharp feature in the charge-density excitation spectra of single-crystal
MgB, displaying a remarkable cosine-like, periodic energy dispersion with
momentum transfer () along the -axis, has been observed for the first
time by high-resolution non-resonant inelastic x-ray scattering (NIXS).
Time-dependent density-functional theory calculations show that the physics
underlying the NIXS data is strong coupling between single-particle and
collective degrees of freedom, mediated by large crystal local-field effects.
As a result, the small- collective mode residing in the single-particle
excitation gap of the B bands reappears periodically in higher Brillouin
zones. The NIXS data thus embody a novel signature of the layered electronic
structure of MgB.Comment: 5 pages, 4 figures, submitted to PR
Ring Vibrations to Sense Anionic Ibuprofen in Aqueous Solution as Revealed by Resonance Raman
We unravel the potentialities of resonance Raman spectroscopy to detect ibuprofen in diluted aqueous solutions. In particular, we exploit a fully polarizable quantum mechanics/molecular mechanics (QM/MM) methodology based on fluctuating charges coupled to molecular dynamics (MD) in order to take into account the dynamical aspects of the solvation phenomenon. Our findings, which are discussed in light of a natural bond orbital (NBO) analysis, reveal that a selective enhancement of the Raman signal due to the normal mode associated with the C–C stretching in the ring, νC=C, can be achieved by properly tuning the incident wavelength, thus facilitating the recognition of ibuprofen in water samples
Effect of a gap on the decoherence of a qubit
We revisit the problem of the decoherence and relaxation of a central spin
coupled to a bath of conduction electrons. We consider both metallic and
semiconducting baths to study the effect of a gap in the bath density of states
(DOS) on the time evolution of the density matrix of the central spin. We use
two weak coupling approximation schemes to study the decoherence. At low
temperatures, though the temperature dependence of the decoherence rate in the
case of a metallic bath is the same irrespective of the details of the bath,
the same is not true for the semiconducting bath. We also calculate the
relaxation and decoherence rates as a function of external magnetic fields
applied both on the central spin and the bath. We find that in the presence of
the gap, there exists a certain regime of fields, for which surprisingly, the
metallic bath has lower rates of relaxation and decoherence than the
semiconducting bath.Comment: 9 pages, 9 figure
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