11,906 research outputs found
Transmission of Staphylococcus aureus from humans to green monkeys in the Gambia as revealed by whole-genome sequencing
En el marco de la actual crisis económica internacional y las consecuentes políticas de ajuste estructural adoptadas por el gobierno de España desde 2008, la investigación desarrollada centró su atención en los impactos diferenciados sobre un grupo de mujeres migrantes de origen colombiano residentes en el Sur de España, teniendo en cuenta que, ni el origen, ni las políticas de ajuste estructural implementadas, ni los efectos que está generando la denominada crisis económica, tienen un carácter neutral en cuanto al género, la clase social, la edad y la condición de extranjería. En este sentido, la investigación indagó a través de un grupo de mujeres cómo desde diversas trayectorias familiares, socioeconómicas y condición de extranjería, sus hogares están vivenciando la actual crisis económica en relación con lo laboral y lo familiar, así como también la incidencia en sus más estrechos vínculos transnacionales, todo ello dentro del actual proceso de reacomodamiento de la economía global
Evaluation of a theory for pressure-strain rate
A theoretical expression for the slow part (the nonlinear fluctuation part) of the pressure-strain rate is compared with simulations of anisotropic homogeneous flows. The objective is to determine the quantitative accuracy of the theory and to test its prediction that the generalized Rotta coefficient, a non-dimensionalized ratio of slow term to the Reynolds stress anisotropy, varies with direction and can be negative. Comparisons are made between theoretical and simulation values of the slow term itself and of the generalized Rotta coefficients. The implications of the comparison for two-point closure theories and for Reynolds stress modeling are pointed out
Mechanistic studies of some reactions of 1- and 3-phenylallyl chlorides
Imperial Users onl
Optimization of design parameters for spacecraft nickel-cadmium cells containing recombination and control electrodes Quarterly report
Cycle capability of electrochemical cells built with oxygen recombination and oxygen sensing control electrode
An evaluation of thematic mapper simulator data for the geobotanical discrimination of rock types in Southwest Oregon
Rock type identification may be assisted by the use of remote sensing of associated vegetation, particularly in areas of dense vegetative cover where surface materials are not imaged directly by the sensor. The geobotanical discrimination of ultramafic parent materials was investigated and analytical techniques for lithologic mapping and mineral exploration were developed. The utility of remotely sensed data to discriminate vegetation types associated with ultramafic parent materials in a study area in southwest Oregon were evaluated. A number of specific objectives were identified, which include: (1) establishment of the association between vegetation and rock types; (2) examination of the spectral separability of vegetation types associated with rock types; (3) determination of the contribution of each TMS band for discriminating vegetation associated with rock types and (4) comparison of analytical techniques for spectrally classifying vegetation
Kinetic approach to electroweak baryogenesis
After a short review of baryogenesis mechanisms, we focus on the charge
transport mechanism at the electroweak scale, effective at strong electroweak
phase transitions. Starting from the one-loop Schwinger-Dyson equations for
fermions coupled to bosons, we present a derivation of the relevant kinetic
equations in the on-shell and gradient approximations, relevant for the thick
wall baryogenesis regime. We then discuss the CP-violating source from the
semiclassical force in the flow term, and compare it with the source arising in
the collision term of the kinetic equation. Finally, we summarize the results
concerning the chargino mediated baryogenesis in the Minimal Supersymmetric
Standard Model.Comment: 13 pages, 6 figures. Invited talk at the International Workshop
"Strong and Electroweak Matter 2002", October 2-5, 2002 Heidelberg, German
Quantum Boltzmann equations for electroweak baryogenesis including gauge fields
We review and extend to include the gauge fields our derivation of the
semiclassical limit of the collisionless quantum transport equations for the
fermions in presence of a CP-violating bubble wall at a first order electroweak
phase transition. We show how the (gradient correction modified) Lorenz-force
appears both in the Schwinger-Keldysh approach and in the semiclassical
WKB-treatment. In the latter approach the inclusion of gauge fields removes the
apparent phase reparametrization dependence of the intermediate calculations.
We also discuss setting up the fluid equations for practical calculations in
electroweak baryogenesis including the self-consistent (hyper)electric field
and the anomaly.Comment: 15 pages, talk presented by Kimmo Kainulainen at COSMO-01, Rovaniemi,
Finland, 09/200
Some aspects of collisional sources for electroweak baryogenesis
We consider the dynamics of fermions with a spatially varying mass which
couple to bosons through a Yukawa interaction term and perform a consistent
weak coupling truncation of the relevant kinetic equations. We then use a
gradient expansion and derive the CP-violating source in the collision term for
fermions which appears at first order in gradients. The collisional sources
together with the semiclassical force constitute the CP-violating sources
relevant for baryogenesis at the electroweak scale. We discuss also the absence
of sources at first order in gradients in the scalar equation, and the
limitations of the relaxation time approximation.Comment: 12 pages, 4 figures, talk presented by Tomislav Prokopec at COSMO-01,
Rovaniemi, Finland, 09/2001 references added, minor changes in sections 5.3
and
Inelastic diffractive scattering in nonperturbative QCD
We examine diffractive proton-proton scattering p p -> p X and photo- and
electroproduction of \rho^0 mesons \gamma^(*) p -> \rho^0 X, where X denotes a
proton or a final state, into which the proton can go by diffractive
dissociation. Using a functional integral approach we derive the scattering
amplitudes, which are governed by the expectation values of light-like
Wegner-Wilson loops, which are then evaluated using the model of the stochastic
vacuum. For the proton, we assume a quark-diquark structure. From the
scattering amplitudes we calculate total and differential cross sections for
high centre of mass energy and small momentum transfer and compare with
experiments. Furthermore we calculate isovector form factors for the proton and
the pion within the same model.Comment: 32 pages, 11 figures, v3: revised chapter 5, added appendix B, to be
published in Eur.Phys.J.
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